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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,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion,
ICC_Conversion
};
return Category[(int)Kind];
}
/// GetConversionRank - Retrieve the implicit conversion rank
/// corresponding to the given implicit conversion kind.
ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) {
static const ImplicitConversionRank
Rank[(int)ICK_Num_Conversion_Kinds] = {
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Exact_Match,
ICR_Promotion,
ICR_Promotion,
ICR_Promotion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Conversion,
ICR_Complex_Real_Conversion
};
return Rank[(int)Kind];
}
/// GetImplicitConversionName - Return the name of this kind of
/// implicit conversion.
const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
"No conversion",
"Lvalue-to-rvalue",
"Array-to-pointer",
"Function-to-pointer",
"Noreturn adjustment",
"Qualification",
"Integral promotion",
"Floating point promotion",
"Complex promotion",
"Integral conversion",
"Floating conversion",
"Complex conversion",
"Floating-integral conversion",
"Pointer conversion",
"Pointer-to-member conversion",
"Boolean conversion",
"Compatible-types conversion",
"Derived-to-base conversion",
"Vector conversion",
"Vector splat",
"Complex-real conversion"
};
return Name[Kind];
}
/// StandardConversionSequence - Set the standard conversion
/// sequence to the identity conversion.
void StandardConversionSequence::setAsIdentityConversion() {
First = ICK_Identity;
Second = ICK_Identity;
Third = ICK_Identity;
DeprecatedStringLiteralToCharPtr = false;
ReferenceBinding = false;
DirectBinding = false;
RRefBinding = false;
CopyConstructor = 0;
}
/// getRank - Retrieve the rank of this standard conversion sequence
/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
/// implicit conversions.
ImplicitConversionRank StandardConversionSequence::getRank() const {
ImplicitConversionRank Rank = ICR_Exact_Match;
if (GetConversionRank(First) > Rank)
Rank = GetConversionRank(First);
if (GetConversionRank(Second) > Rank)
Rank = GetConversionRank(Second);
if (GetConversionRank(Third) > Rank)
Rank = GetConversionRank(Third);
return Rank;
}
/// isPointerConversionToBool - Determines whether this conversion is
/// a conversion of a pointer or pointer-to-member to bool. This is
/// used as part of the ranking of standard conversion sequences
/// (C++ 13.3.3.2p4).
bool StandardConversionSequence::isPointerConversionToBool() const {
// Note that FromType has not necessarily been transformed by the
// array-to-pointer or function-to-pointer implicit conversions, so
// check for their presence as well as checking whether FromType is
// a pointer.
if (getToType(1)->isBooleanType() &&
(getFromType()->isPointerType() ||
getFromType()->isObjCObjectPointerType() ||
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.
//
// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced
// into a class by a using declaration. The rules for whether to hide
// shadow declarations ignore some properties which otherwise figure
// into a function template's signature.
Sema::OverloadKind
Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
NamedDecl *&Match, bool NewIsUsingDecl) {
for (LookupResult::iterator I = Old.begin(), E = Old.end();
I != E; ++I) {
NamedDecl *OldD = *I;
bool OldIsUsingDecl = false;
if (isa<UsingShadowDecl>(OldD)) {
OldIsUsingDecl = true;
// We can always introduce two using declarations into the same
// context, even if they have identical signatures.
if (NewIsUsingDecl) continue;
OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
}
// If either declaration was introduced by a using declaration,
// we'll need to use slightly different rules for matching.
// Essentially, these rules are the normal rules, except that
// function templates hide function templates with different
// return types or template parameter lists.
bool UseMemberUsingDeclRules =
(OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord();
if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) {
if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) {
if (UseMemberUsingDeclRules && OldIsUsingDecl) {
HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
continue;
}
Match = *I;
return Ovl_Match;
}
} else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) {
if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
if (UseMemberUsingDeclRules && OldIsUsingDecl) {
HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
continue;
}
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,
bool UseUsingDeclRules) {
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.
//
// However, we don't consider either of these when deciding whether
// a member introduced by a shadow declaration is hidden.
if (!UseUsingDeclRules && NewTemplate &&
(!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
OldTemplate->getTemplateParameters(),
false, TPL_TemplateMatch) ||
OldType->getResultType() != NewType->getResultType()))
return true;
// If the function is a class member, its signature includes the
// cv-qualifiers (if any) on the function itself.
//
// As part of this, also check whether one of the member functions
// is static, in which case they are not overloads (C++
// 13.1p2). While not part of the definition of the signature,
// this check is important to determine whether these functions
// can be overloaded.
CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
if (OldMethod && NewMethod &&
!OldMethod->isStatic() && !NewMethod->isStatic() &&
OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers())
return true;
// The signatures match; this is not an overload.
return false;
}
/// TryImplicitConversion - Attempt to perform an implicit conversion
/// from the given expression (Expr) to the given type (ToType). This
/// function returns an implicit conversion sequence that can be used
/// to perform the initialization. Given
///
/// void f(float f);
/// void g(int i) { f(i); }
///
/// this routine would produce an implicit conversion sequence to
/// describe the initialization of f from i, which will be a standard
/// conversion sequence containing an lvalue-to-rvalue conversion (C++
/// 4.1) followed by a floating-integral conversion (C++ 4.9).
//
/// Note that this routine only determines how the conversion can be
/// performed; it does not actually perform the conversion. As such,
/// it will not produce any diagnostics if no conversion is available,
/// but will instead return an implicit conversion sequence of kind
/// "BadConversion".
///
/// If @p SuppressUserConversions, then user-defined conversions are
/// not permitted.
/// If @p AllowExplicit, then explicit user-defined conversions are
/// permitted.
ImplicitConversionSequence
Sema::TryImplicitConversion(Expr* From, QualType ToType,
bool SuppressUserConversions,
bool AllowExplicit,
bool InOverloadResolution) {
ImplicitConversionSequence ICS;
if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) {
ICS.setStandard();
return ICS;
}
if (!getLangOptions().CPlusPlus) {
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
return ICS;
}
if (SuppressUserConversions) {
// C++ [over.ics.user]p4:
// A conversion of an expression of class type to the same class
// type is given Exact Match rank, and a conversion of an
// expression of class type to a base class of that type is
// given Conversion rank, in spite of the fact that a copy/move
// constructor (i.e., a user-defined conversion function) is
// called for those cases.
QualType FromType = From->getType();
if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() ||
!(Context.hasSameUnqualifiedType(FromType, ToType) ||
IsDerivedFrom(FromType, ToType))) {
// We're not in the case above, so there is no conversion that
// we can perform.
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
return ICS;
}
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.setFromType(FromType);
ICS.Standard.setAllToTypes(ToType);
// We don't actually check at this point whether there is a valid
// copy/move constructor, since overloading just assumes that it
// exists. When we actually perform initialization, we'll find the
// appropriate constructor to copy the returned object, if needed.
ICS.Standard.CopyConstructor = 0;
// Determine whether this is considered a derived-to-base conversion.
if (!Context.hasSameUnqualifiedType(FromType, ToType))
ICS.Standard.Second = ICK_Derived_To_Base;
return ICS;
}
// Attempt user-defined conversion.
OverloadCandidateSet Conversions(From->getExprLoc());
OverloadingResult UserDefResult
= IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions,
AllowExplicit);
if (UserDefResult == OR_Success) {
ICS.setUserDefined();
// C++ [over.ics.user]p4:
// A conversion of an expression of class type to the same class
// type is given Exact Match rank, and a conversion of an
// expression of class type to a base class of that type is
// given Conversion rank, in spite of the fact that a copy
// constructor (i.e., a user-defined conversion function) is
// called for those cases.
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
QualType FromCanon
= Context.getCanonicalType(From->getType().getUnqualifiedType());
QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
if (Constructor->isCopyConstructor() &&
(FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) {
// Turn this into a "standard" conversion sequence, so that it
// gets ranked with standard conversion sequences.
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.setFromType(From->getType());
ICS.Standard.setAllToTypes(ToType);
ICS.Standard.CopyConstructor = Constructor;
if (ToCanon != FromCanon)
ICS.Standard.Second = ICK_Derived_To_Base;
}
}
// C++ [over.best.ics]p4:
// However, when considering the argument of a user-defined
// conversion function that is a candidate by 13.3.1.3 when
// invoked for the copying of the temporary in the second step
// of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or
// 13.3.1.6 in all cases, only standard conversion sequences and
// ellipsis conversion sequences are allowed.
if (SuppressUserConversions && ICS.isUserDefined()) {
ICS.setBad(BadConversionSequence::suppressed_user, From, ToType);
}
} else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) {
ICS.setAmbiguous();
ICS.Ambiguous.setFromType(From->getType());
ICS.Ambiguous.setToType(ToType);
for (OverloadCandidateSet::iterator Cand = Conversions.begin();
Cand != Conversions.end(); ++Cand)
if (Cand->Viable)
ICS.Ambiguous.addConversion(Cand->Function);
} else {
ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
}
return ICS;
}
/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType. Returns true if there was an
/// error, false otherwise. The expression From is replaced with the
/// converted expression. Flavor is the kind of conversion we're
/// performing, used in the error message. If @p AllowExplicit,
/// explicit user-defined conversions are permitted.
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
AssignmentAction Action, bool AllowExplicit) {
ImplicitConversionSequence ICS;
return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
}
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
AssignmentAction Action, bool AllowExplicit,
ImplicitConversionSequence& ICS) {
ICS = TryImplicitConversion(From, ToType,
/*SuppressUserConversions=*/false,
AllowExplicit,
/*InOverloadResolution=*/false);
return PerformImplicitConversion(From, ToType, ICS, Action);
}
/// \brief Determine whether the conversion from FromType to ToType is a valid
/// conversion that strips "noreturn" off the nested function type.
static bool IsNoReturnConversion(ASTContext &Context, QualType FromType,
QualType ToType, QualType &ResultTy) {
if (Context.hasSameUnqualifiedType(FromType, ToType))
return false;
// Strip the noreturn off the type we're converting from; noreturn can
// safely be removed.
FromType = Context.getNoReturnType(FromType, false);
if (!Context.hasSameUnqualifiedType(FromType, ToType))
return false;
ResultTy = FromType;
return true;
}
/// \brief Determine whether the conversion from FromType to ToType is a valid
/// vector conversion.
///
/// \param ICK Will be set to the vector conversion kind, if this is a vector
/// conversion.
static bool IsVectorConversion(ASTContext &Context, QualType FromType,
QualType ToType, ImplicitConversionKind &ICK) {
// We need at least one of these types to be a vector type to have a vector
// conversion.
if (!ToType->isVectorType() && !FromType->isVectorType())
return false;
// Identical types require no conversions.
if (Context.hasSameUnqualifiedType(FromType, ToType))
return false;
// There are no conversions between extended vector types, only identity.
if (ToType->isExtVectorType()) {
// There are no conversions between extended vector types other than the
// identity conversion.
if (FromType->isExtVectorType())
return false;
// Vector splat from any arithmetic type to a vector.
if (!FromType->isVectorType() && FromType->isArithmeticType()) {
ICK = ICK_Vector_Splat;
return true;
}
}
// If lax vector conversions are permitted and the vector types are of the
// same size, we can perform the conversion.
if (Context.getLangOptions().LaxVectorConversions &&
FromType->isVectorType() && ToType->isVectorType() &&
Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) {
ICK = ICK_Vector_Conversion;
return true;
}
return false;
}
/// IsStandardConversion - Determines whether there is a standard
/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
/// expression From to the type ToType. Standard conversion sequences
/// only consider non-class types; for conversions that involve class
/// types, use TryImplicitConversion. If a conversion exists, SCS will
/// contain the standard conversion sequence required to perform this
/// conversion and this routine will return true. Otherwise, this
/// routine will return false and the value of SCS is unspecified.
bool
Sema::IsStandardConversion(Expr* From, QualType ToType,
bool InOverloadResolution,
StandardConversionSequence &SCS) {
QualType FromType = From->getType();
// Standard conversions (C++ [conv])
SCS.setAsIdentityConversion();
SCS.DeprecatedStringLiteralToCharPtr = false;
SCS.IncompatibleObjC = false;
SCS.setFromType(FromType);
SCS.CopyConstructor = 0;
// There are no standard conversions for class types in C++, so
// abort early. When overloading in C, however, we do permit
if (FromType->isRecordType() || ToType->isRecordType()) {
if (getLangOptions().CPlusPlus)
return false;
// When we're overloading in C, we allow, as standard conversions,
}
// The first conversion can be an lvalue-to-rvalue conversion,
// array-to-pointer conversion, or function-to-pointer conversion
// (C++ 4p1).
if (FromType == Context.OverloadTy) {
DeclAccessPair AccessPair;
if (FunctionDecl *Fn
= ResolveAddressOfOverloadedFunction(From, ToType, false,
AccessPair)) {
// We were able to resolve the address of the overloaded function,
// so we can convert to the type of that function.
FromType = Fn->getType();
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
if (!Method->isStatic()) {
Type *ClassType
= Context.getTypeDeclType(Method->getParent()).getTypePtr();
FromType = Context.getMemberPointerType(FromType, ClassType);
}
}
// If the "from" expression takes the address of the overloaded
// function, update the type of the resulting expression accordingly.
if (FromType->getAs<FunctionType>())
if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens()))
if (UnOp->getOpcode() == UnaryOperator::AddrOf)
FromType = Context.getPointerType(FromType);
// Check that we've computed the proper type after overload resolution.
assert(Context.hasSameType(FromType,
FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()));
} else {
return false;
}
}
// Lvalue-to-rvalue conversion (C++ 4.1):
// An lvalue (3.10) of a non-function, non-array type T can be
// converted to an rvalue.
Expr::isLvalueResult argIsLvalue = From->isLvalue(Context);
if (argIsLvalue == Expr::LV_Valid &&
!FromType->isFunctionType() && !FromType->isArrayType() &&
Context.getCanonicalType(FromType) != Context.OverloadTy) {
SCS.First = ICK_Lvalue_To_Rvalue;
// If T is a non-class type, the type of the rvalue is the
// cv-unqualified version of T. Otherwise, the type of the rvalue
// is T (C++ 4.1p1). C++ can't get here with class types; in C, we
// just strip the qualifiers because they don't matter.
FromType = FromType.getUnqualifiedType();
} else if (FromType->isArrayType()) {
// Array-to-pointer conversion (C++ 4.2)
SCS.First = ICK_Array_To_Pointer;
// An lvalue or rvalue of type "array of N T" or "array of unknown
// bound of T" can be converted to an rvalue of type "pointer to
// T" (C++ 4.2p1).
FromType = Context.getArrayDecayedType(FromType);
if (IsStringLiteralToNonConstPointerConversion(From, ToType)) {
// This conversion is deprecated. (C++ D.4).
SCS.DeprecatedStringLiteralToCharPtr = true;
// For the purpose of ranking in overload resolution
// (13.3.3.1.1), this conversion is considered an
// array-to-pointer conversion followed by a qualification
// conversion (4.4). (C++ 4.2p2)
SCS.Second = ICK_Identity;
SCS.Third = ICK_Qualification;
SCS.setAllToTypes(FromType);
return true;
}
} else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) {
// Function-to-pointer conversion (C++ 4.3).
SCS.First = ICK_Function_To_Pointer;
// An lvalue of function type T can be converted to an rvalue of
// type "pointer to T." The result is a pointer to the
// function. (C++ 4.3p1).
FromType = Context.getPointerType(FromType);
} else {
// We don't require any conversions for the first step.
SCS.First = ICK_Identity;
}
SCS.setToType(0, FromType);
// The second conversion can be an integral promotion, floating
// point promotion, integral conversion, floating point conversion,
// floating-integral conversion, pointer conversion,
// pointer-to-member conversion, or boolean conversion (C++ 4p1).
// For overloading in C, this can also be a "compatible-type"
// conversion.
bool IncompatibleObjC = false;
ImplicitConversionKind SecondICK = ICK_Identity;
if (Context.hasSameUnqualifiedType(FromType, ToType)) {
// The unqualified versions of the types are the same: there's no
// conversion to do.
SCS.Second = ICK_Identity;
} else if (IsIntegralPromotion(From, FromType, ToType)) {
// Integral promotion (C++ 4.5).
SCS.Second = ICK_Integral_Promotion;
FromType = ToType.getUnqualifiedType();
} else if (IsFloatingPointPromotion(FromType, ToType)) {
// Floating point promotion (C++ 4.6).
SCS.Second = ICK_Floating_Promotion;
FromType = ToType.getUnqualifiedType();
} else if (IsComplexPromotion(FromType, ToType)) {
// Complex promotion (Clang extension)
SCS.Second = ICK_Complex_Promotion;
FromType = ToType.getUnqualifiedType();
} else if (FromType->isIntegralOrEnumerationType() &&
ToType->isIntegralType(Context)) {
// Integral conversions (C++ 4.7).
SCS.Second = ICK_Integral_Conversion;
FromType = ToType.getUnqualifiedType();
} else if (FromType->isComplexType() && ToType->isComplexType()) {
// Complex conversions (C99 6.3.1.6)
SCS.Second = ICK_Complex_Conversion;
FromType = ToType.getUnqualifiedType();
} else if ((FromType->isComplexType() && ToType->isArithmeticType()) ||
(ToType->isComplexType() && FromType->isArithmeticType())) {
// Complex-real conversions (C99 6.3.1.7)
SCS.Second = ICK_Complex_Real;
FromType = ToType.getUnqualifiedType();
} else if (FromType->isFloatingType() && ToType->isFloatingType()) {
// Floating point conversions (C++ 4.8).
SCS.Second = ICK_Floating_Conversion;
FromType = ToType.getUnqualifiedType();
} else if ((FromType->isFloatingType() &&
ToType->isIntegralType(Context) && !ToType->isBooleanType()) ||
(FromType->isIntegralOrEnumerationType() &&
ToType->isFloatingType())) {
// Floating-integral conversions (C++ 4.9).
SCS.Second = ICK_Floating_Integral;
FromType = ToType.getUnqualifiedType();
} else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution,
FromType, IncompatibleObjC)) {
// Pointer conversions (C++ 4.10).
SCS.Second = ICK_Pointer_Conversion;
SCS.IncompatibleObjC = IncompatibleObjC;
} else if (IsMemberPointerConversion(From, FromType, ToType,
InOverloadResolution, FromType)) {
// Pointer to member conversions (4.11).
SCS.Second = ICK_Pointer_Member;
} else if (ToType->isBooleanType() &&
(FromType->isArithmeticType() ||
FromType->isEnumeralType() ||
FromType->isAnyPointerType() ||
FromType->isBlockPointerType() ||
FromType->isMemberPointerType() ||
FromType->isNullPtrType())) {
// Boolean conversions (C++ 4.12).
SCS.Second = ICK_Boolean_Conversion;
FromType = Context.BoolTy;
} else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) {
SCS.Second = SecondICK;
FromType = ToType.getUnqualifiedType();
} else if (!getLangOptions().CPlusPlus &&
Context.typesAreCompatible(ToType, FromType)) {
// Compatible conversions (Clang extension for C function overloading)
SCS.Second = ICK_Compatible_Conversion;
FromType = ToType.getUnqualifiedType();
} else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) {
// Treat a conversion that strips "noreturn" as an identity conversion.
SCS.Second = ICK_NoReturn_Adjustment;
} else {
// No second conversion required.
SCS.Second = ICK_Identity;
}
SCS.setToType(1, FromType);
QualType CanonFrom;
QualType CanonTo;
// The third conversion can be a qualification conversion (C++ 4p1).
if (IsQualificationConversion(FromType, ToType)) {
SCS.Third = ICK_Qualification;
FromType = ToType;
CanonFrom = Context.getCanonicalType(FromType);
CanonTo = Context.getCanonicalType(ToType);
} else {
// No conversion required
SCS.Third = ICK_Identity;
// C++ [over.best.ics]p6:
// [...] Any difference in top-level cv-qualification is
// subsumed by the initialization itself and does not constitute
// a conversion. [...]
CanonFrom = Context.getCanonicalType(FromType);
CanonTo = Context.getCanonicalType(ToType);
if (CanonFrom.getLocalUnqualifiedType()
== CanonTo.getLocalUnqualifiedType() &&
(CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()
|| CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) {
FromType = ToType;
CanonFrom = CanonTo;
}
}
SCS.setToType(2, FromType);
// If we have not converted the argument type to the parameter type,
// this is a bad conversion sequence.
if (CanonFrom != CanonTo)
return false;
return true;
}
/// IsIntegralPromotion - Determines whether the conversion from the
/// expression From (whose potentially-adjusted type is FromType) to
/// ToType is an integral promotion (C++ 4.5). If so, returns true and
/// sets PromotedType to the promoted type.
bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
const BuiltinType *To = ToType->getAs<BuiltinType>();
// All integers are built-in.
if (!To) {
return false;
}
// An rvalue of type char, signed char, unsigned char, short int, or
// unsigned short int can be converted to an rvalue of type int if
// int can represent all the values of the source type; otherwise,
// the source rvalue can be converted to an rvalue of type unsigned
// int (C++ 4.5p1).
if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
!FromType->isEnumeralType()) {
if (// We can promote any signed, promotable integer type to an int
(FromType->isSignedIntegerType() ||
// We can promote any unsigned integer type whose size is
// less than int to an int.
(!FromType->isSignedIntegerType() &&
Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) {
return To->getKind() == BuiltinType::Int;
}
return To->getKind() == BuiltinType::UInt;
}
// An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2)
// can be converted to an rvalue of the first of the following types
// that can represent all the values of its underlying type: int,
// unsigned int, long, or unsigned long (C++ 4.5p2).
// We pre-calculate the promotion type for enum types.
if (const EnumType *FromEnumType = FromType->getAs<EnumType>())
if (ToType->isIntegerType())
return Context.hasSameUnqualifiedType(ToType,
FromEnumType->getDecl()->getPromotionType());
if (FromType->isWideCharType() && ToType->isIntegerType()) {
// Determine whether the type we're converting from is signed or
// unsigned.
bool FromIsSigned;
uint64_t FromSize = Context.getTypeSize(FromType);
// FIXME: Is wchar_t signed or unsigned? We assume it's signed for now.
FromIsSigned = true;
// The types we'll try to promote to, in the appropriate
// order. Try each of these types.
QualType PromoteTypes[6] = {
Context.IntTy, Context.UnsignedIntTy,
Context.LongTy, Context.UnsignedLongTy ,
Context.LongLongTy, Context.UnsignedLongLongTy
};
for (int Idx = 0; Idx < 6; ++Idx) {
uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
if (FromSize < ToSize ||
(FromSize == ToSize &&
FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
// We found the type that we can promote to. If this is the
// type we wanted, we have a promotion. Otherwise, no
// promotion.
return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
}
}
}
// An rvalue for an integral bit-field (9.6) can be converted to an
// rvalue of type int if int can represent all the values of the
// bit-field; otherwise, it can be converted to unsigned int if
// unsigned int can represent all the values of the bit-field. If
// the bit-field is larger yet, no integral promotion applies to
// it. If the bit-field has an enumerated type, it is treated as any
// other value of that type for promotion purposes (C++ 4.5p3).
// FIXME: We should delay checking of bit-fields until we actually perform the
// conversion.
using llvm::APSInt;
if (From)
if (FieldDecl *MemberDecl = From->getBitField()) {
APSInt BitWidth;
if (FromType->isIntegralType(Context) &&
MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
ToSize = Context.getTypeSize(ToType);
// Are we promoting to an int from a bitfield that fits in an int?
if (BitWidth < ToSize ||
(FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
return To->getKind() == BuiltinType::Int;
}
// Are we promoting to an unsigned int from an unsigned bitfield
// that fits into an unsigned int?
if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
return To->getKind() == BuiltinType::UInt;
}
return false;
}
}
// An rvalue of type bool can be converted to an rvalue of type int,
// with false becoming zero and true becoming one (C++ 4.5p4).
if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
return true;
}
return false;
}
/// IsFloatingPointPromotion - Determines whether the conversion from
/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
/// returns true and sets PromotedType to the promoted type.
bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
/// An rvalue of type float can be converted to an rvalue of type
/// double. (C++ 4.6p1).
if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
if (FromBuiltin->getKind() == BuiltinType::Float &&
ToBuiltin->getKind() == BuiltinType::Double)
return true;
// C99 6.3.1.5p1:
// When a float is promoted to double or long double, or a
// double is promoted to long double [...].
if (!getLangOptions().CPlusPlus &&
(FromBuiltin->getKind() == BuiltinType::Float ||
FromBuiltin->getKind() == BuiltinType::Double) &&
(ToBuiltin->getKind() == BuiltinType::LongDouble))
return true;
}
return false;
}
/// \brief Determine if a conversion is a complex promotion.
///
/// A complex promotion is defined as a complex -> complex conversion
/// where the conversion between the underlying real types is a
/// floating-point or integral promotion.
bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
const ComplexType *FromComplex = FromType->getAs<ComplexType>();
if (!FromComplex)
return false;
const ComplexType *ToComplex = ToType->getAs<ComplexType>();
if (!ToComplex)
return false;
return IsFloatingPointPromotion(FromComplex->getElementType(),
ToComplex->getElementType()) ||
IsIntegralPromotion(0, FromComplex->getElementType(),
ToComplex->getElementType());
}
/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
/// the pointer type FromPtr to a pointer to type ToPointee, with the
/// same type qualifiers as FromPtr has on its pointee type. ToType,
/// if non-empty, will be a pointer to ToType that may or may not have
/// the right set of qualifiers on its pointee.
static QualType
BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr,
QualType ToPointee, QualType ToType,
ASTContext &Context) {
QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType());
QualType CanonToPointee = Context.getCanonicalType(ToPointee);
Qualifiers Quals = CanonFromPointee.getQualifiers();
// Exact qualifier match -> return the pointer type we're converting to.
if (CanonToPointee.getLocalQualifiers() == Quals) {
// ToType is exactly what we need. Return it.
if (!ToType.isNull())
return ToType.getUnqualifiedType();
// Build a pointer to ToPointee. It has the right qualifiers
// already.
return Context.getPointerType(ToPointee);
}
// Just build a canonical type that has the right qualifiers.
return Context.getPointerType(
Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(),
Quals));
}
/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from
/// the FromType, which is an objective-c pointer, to ToType, which may or may
/// not have the right set of qualifiers.
static QualType
BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType,
QualType ToType,
ASTContext &Context) {
QualType CanonFromType = Context.getCanonicalType(FromType);
QualType CanonToType = Context.getCanonicalType(ToType);
Qualifiers Quals = CanonFromType.getQualifiers();
// Exact qualifier match -> return the pointer type we're converting to.
if (CanonToType.getLocalQualifiers() == Quals)
return ToType;
// Just build a canonical type that has the right qualifiers.
return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals);
}
static bool isNullPointerConstantForConversion(Expr *Expr,
bool InOverloadResolution,
ASTContext &Context) {
// Handle value-dependent integral null pointer constants correctly.
// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
return !InOverloadResolution;
return Expr->isNullPointerConstant(Context,
InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
: Expr::NPC_ValueDependentIsNull);
}
/// IsPointerConversion - Determines whether the conversion of the
/// expression From, which has the (possibly adjusted) type FromType,
/// can be converted to the type ToType via a pointer conversion (C++
/// 4.10). If so, returns true and places the converted type (that
/// might differ from ToType in its cv-qualifiers at some level) into
/// ConvertedType.
///
/// This routine also supports conversions to and from block pointers
/// and conversions with Objective-C's 'id', 'id<protocols...>', and
/// pointers to interfaces. FIXME: Once we've determined the
/// appropriate overloading rules for Objective-C, we may want to
/// split the Objective-C checks into a different routine; however,
/// GCC seems to consider all of these conversions to be pointer
/// conversions, so for now they live here. IncompatibleObjC will be
/// set if the conversion is an allowed Objective-C conversion that
/// should result in a warning.
bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
bool InOverloadResolution,
QualType& ConvertedType,
bool &IncompatibleObjC) {
IncompatibleObjC = false;
if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC))
return true;
// Conversion from a null pointer constant to any Objective-C pointer type.
if (ToType->isObjCObjectPointerType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// Blocks: Block pointers can be converted to void*.
if (FromType->isBlockPointerType() && ToType->isPointerType() &&
ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
ConvertedType = ToType;
return true;
}
// Blocks: A null pointer constant can be converted to a block
// pointer type.
if (ToType->isBlockPointerType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// If the left-hand-side is nullptr_t, the right side can be a null
// pointer constant.
if (ToType->isNullPtrType() &&
isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
const PointerType* ToTypePtr = ToType->getAs<PointerType>();
if (!ToTypePtr)
return false;
// A null pointer constant can be converted to a pointer type (C++ 4.10p1).
if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
ConvertedType = ToType;
return true;
}
// Beyond this point, both types need to be pointers
// , including objective-c pointers.
QualType ToPointeeType = ToTypePtr->getPointeeType();
if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) {
ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType,
ToType, Context);
return true;
}
const PointerType *FromTypePtr = FromType->getAs<PointerType>();
if (!FromTypePtr)
return false;
QualType FromPointeeType = FromTypePtr->getPointeeType();
// An rvalue of type "pointer to cv T," where T is an object type,
// can be converted to an rvalue of type "pointer to cv void" (C++
// 4.10p2).
if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
ToPointeeType,
ToType, Context);
return true;
}
// When we're overloading in C, we allow a special kind of pointer
// conversion for compatible-but-not-identical pointee types.
if (!getLangOptions().CPlusPlus &&
Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
ToPointeeType,
ToType, Context);
return true;
}
// C++ [conv.ptr]p3:
//
// An rvalue of type "pointer to cv D," where D is a class type,
// can be converted to an rvalue of type "pointer to cv B," where
// B is a base class (clause 10) of D. If B is an inaccessible
// (clause 11) or ambiguous (10.2) base class of D, a program that
// necessitates this conversion is ill-formed. The result of the
// conversion is a pointer to the base class sub-object of the
// derived class object. The null pointer value is converted to
// the null pointer value of the destination type.
//
// Note that we do not check for ambiguity or inaccessibility
// here. That is handled by CheckPointerConversion.
if (getLangOptions().CPlusPlus &&
FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
!Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
!RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) &&
IsDerivedFrom(FromPointeeType, ToPointeeType)) {
ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
ToPointeeType,
ToType, Context);
return true;
}
return false;
}
/// isObjCPointerConversion - Determines whether this is an
/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
/// with the same arguments and return values.
bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
QualType& ConvertedType,
bool &IncompatibleObjC) {
if (!getLangOptions().ObjC1)
return false;
// First, we handle all conversions on ObjC object pointer types.
const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>();
const ObjCObjectPointerType *FromObjCPtr =
FromType->getAs<ObjCObjectPointerType>();
if (ToObjCPtr && FromObjCPtr) {
// Objective C++: We're able to convert between "id" or "Class" and a
// pointer to any interface (in both directions).
if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) {
ConvertedType = ToType;
return true;
}
// Conversions with Objective-C's id<...>.
if ((FromObjCPtr->isObjCQualifiedIdType() ||
ToObjCPtr->isObjCQualifiedIdType()) &&
Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType,
/*compare=*/false)) {
ConvertedType = ToType;
return true;
}
// Objective C++: We're able to convert from a pointer to an
// interface to a pointer to a different interface.
if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
if (getLangOptions().CPlusPlus && LHS && RHS &&
!ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
FromObjCPtr->getPointeeType()))
return false;
ConvertedType = ToType;
return true;
}
if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
// Okay: this is some kind of implicit downcast of Objective-C
// interfaces, which is permitted. However, we're going to
// complain about it.
IncompatibleObjC = true;
ConvertedType = FromType;
return true;
}
}
// Beyond this point, both types need to be C pointers or block pointers.
QualType ToPointeeType;
if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
ToPointeeType = ToCPtr->getPointeeType();
else if (const BlockPointerType *ToBlockPtr =
ToType->getAs<BlockPointerType>()) {
// Objective C++: We're able to convert from a pointer to any object
// to a block pointer type.
if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
ConvertedType = ToType;
return true;
}
ToPointeeType = ToBlockPtr->getPointeeType();
}
else if (FromType->getAs<BlockPointerType>() &&
ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
// Objective C++: We're able to convert from a block pointer type to a
// pointer to any object.
ConvertedType = ToType;
return true;
}
else
return false;
QualType FromPointeeType;
if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
FromPointeeType = FromCPtr->getPointeeType();
else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>())
FromPointeeType = FromBlockPtr->getPointeeType();
else
return false;
// If we have pointers to pointers, recursively check whether this
// is an Objective-C conversion.
if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
IncompatibleObjC)) {
// We always complain about this conversion.
IncompatibleObjC = true;
ConvertedType = ToType;
return true;
}
// Allow conversion of pointee being objective-c pointer to another one;
// as in I* to id.
if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
ToPointeeType->getAs<ObjCObjectPointerType>() &&
isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
IncompatibleObjC)) {
ConvertedType = ToType;
return true;
}
// If we have pointers to functions or blocks, check whether the only
// differences in the argument and result types are in Objective-C
// pointer conversions. If so, we permit the conversion (but
// complain about it).
const FunctionProtoType *FromFunctionType
= FromPointeeType->getAs<FunctionProtoType>();
const FunctionProtoType *ToFunctionType
= ToPointeeType->getAs<FunctionProtoType>();
if (FromFunctionType && ToFunctionType) {
// If the function types are exactly the same, this isn't an
// Objective-C pointer conversion.
if (Context.getCanonicalType(FromPointeeType)
== Context.getCanonicalType(ToPointeeType))
return false;
// Perform the quick checks that will tell us whether these
// function types are obviously different.
if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() ||
FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
return false;
bool HasObjCConversion = false;
if (Context.getCanonicalType(FromFunctionType->getResultType())
== Context.getCanonicalType(ToFunctionType->getResultType())) {
// Okay, the types match exactly. Nothing to do.
} else if (isObjCPointerConversion(FromFunctionType->getResultType(),
ToFunctionType->getResultType(),
ConvertedType, IncompatibleObjC)) {
// Okay, we have an Objective-C pointer conversion.
HasObjCConversion = true;
} else {
// Function types are too different. Abort.
return false;
}
// Check argument types.
for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs();
ArgIdx != NumArgs; ++ArgIdx) {
QualType FromArgType = FromFunctionType->getArgType(ArgIdx);
QualType ToArgType = ToFunctionType->getArgType(ArgIdx);
if (Context.getCanonicalType(FromArgType)
== Context.getCanonicalType(ToArgType)) {
// Okay, the types match exactly. Nothing to do.
} else if (isObjCPointerConversion(FromArgType, ToArgType,
ConvertedType, IncompatibleObjC)) {
// Okay, we have an Objective-C pointer conversion.
HasObjCConversion = true;
} else {
// Argument types are too different. Abort.
return false;
}
}
if (HasObjCConversion) {
// We had an Objective-C conversion. Allow this pointer
// conversion, but complain about it.
ConvertedType = ToType;
IncompatibleObjC = true;
return true;
}
}
return false;
}
/// FunctionArgTypesAreEqual - This routine checks two function proto types
/// for equlity of their argument types. Caller has already checked that
/// they have same number of arguments. This routine assumes that Objective-C
/// pointer types which only differ in their protocol qualifiers are equal.
bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType,
FunctionProtoType* NewType){
if (!getLangOptions().ObjC1)
return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(),
NewType->arg_type_begin());
for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(),
N = NewType->arg_type_begin(),
E = OldType->arg_type_end(); O && (O != E); ++O, ++N) {
QualType ToType = (*O);
QualType FromType = (*N);
if (ToType != FromType) {
if (const PointerType *PTTo = ToType->getAs<PointerType>()) {
if (const PointerType *PTFr = FromType->getAs<PointerType>())
if ((PTTo->getPointeeType()->isObjCQualifiedIdType() &&
PTFr->getPointeeType()->isObjCQualifiedIdType()) ||
(PTTo->getPointeeType()->isObjCQualifiedClassType() &&
PTFr->getPointeeType()->isObjCQualifiedClassType()))
continue;
}
else if (const ObjCObjectPointerType *PTTo =
ToType->getAs<ObjCObjectPointerType>()) {
if (const ObjCObjectPointerType *PTFr =
FromType->getAs<ObjCObjectPointerType>())
if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl())
continue;
}
return false;
}
}
return true;
}
/// CheckPointerConversion - Check the pointer conversion from the
/// expression From to the type ToType. This routine checks for
/// ambiguous or inaccessible derived-to-base pointer
/// conversions for which IsPointerConversion has already returned
/// true. It returns true and produces a diagnostic if there was an
/// error, or returns false otherwise.
bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
CastExpr::CastKind &Kind,
CXXBaseSpecifierArray& BasePath,
bool IgnoreBaseAccess) {
QualType FromType = From->getType();
if (CXXBoolLiteralExpr* LitBool
= dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens()))
if (LitBool->getValue() == false)
Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false)
<< ToType;
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 (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
// Within each iteration of the loop, we check the qualifiers to
// determine if this still looks like a qualification
// conversion. Then, if all is well, we unwrap one more level of
// pointers or pointers-to-members and do it all again
// until there are no more pointers or pointers-to-members left to
// unwrap.
UnwrappedAnyPointer = true;
// -- for every j > 0, if const is in cv 1,j then const is in cv
// 2,j, and similarly for volatile.
if (!ToType.isAtLeastAsQualifiedAs(FromType))
return false;
// -- if the cv 1,j and cv 2,j are different, then const is in
// every cv for 0 < k < j.
if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers()
&& !PreviousToQualsIncludeConst)
return false;
// Keep track of whether all prior cv-qualifiers in the "to" type
// include const.
PreviousToQualsIncludeConst
= PreviousToQualsIncludeConst && ToType.isConstQualified();
}
// We are left with FromType and ToType being the pointee types
// after unwrapping the original FromType and ToType the same number
// of types. If we unwrapped any pointers, and if FromType and
// ToType have the same unqualified type (since we checked
// qualifiers above), then this is a qualification conversion.
return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
}
/// Determines whether there is a user-defined conversion sequence
/// (C++ [over.ics.user]) that converts expression From to the type
/// ToType. If such a conversion exists, User will contain the
/// user-defined conversion sequence that performs such a conversion
/// and this routine will return true. Otherwise, this routine returns
/// false and User is unspecified.
///
/// \param AllowExplicit true if the conversion should consider C++0x
/// "explicit" conversion functions as well as non-explicit conversion
/// functions (C++0x [class.conv.fct]p2).
OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType,
UserDefinedConversionSequence& User,
OverloadCandidateSet& CandidateSet,
bool AllowExplicit) {
// Whether we will only visit constructors.
bool ConstructorsOnly = false;
// If the type we are conversion to is a class type, enumerate its
// constructors.
if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
// C++ [over.match.ctor]p1:
// When objects of class type are direct-initialized (8.5), or
// copy-initialized from an expression of the same or a
// derived class type (8.5), overload resolution selects the
// constructor. [...] For copy-initialization, the candidate
// functions are all the converting constructors (12.3.1) of
// that class. The argument list is the expression-list within
// the parentheses of the initializer.
if (Context.hasSameUnqualifiedType(ToType, From->getType()) ||
(From->getType()->getAs<RecordType>() &&
IsDerivedFrom(From->getType(), ToType)))
ConstructorsOnly = true;
if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) {
// We're not going to find any constructors.
} else if (CXXRecordDecl *ToRecordDecl
= dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
DeclarationName ConstructorName
= Context.DeclarationNames.getCXXConstructorName(
Context.getCanonicalType(ToType).getUnqualifiedType());
DeclContext::lookup_iterator Con, ConEnd;
for (llvm::tie(Con, ConEnd)
= ToRecordDecl->lookup(ConstructorName);
Con != ConEnd; ++Con) {
NamedDecl *D = *Con;
DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess());
// Find the constructor (which may be a template).
CXXConstructorDecl *Constructor = 0;
FunctionTemplateDecl *ConstructorTmpl
= dyn_cast<FunctionTemplateDecl>(D);
if (ConstructorTmpl)
Constructor
= cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
else
Constructor = cast<CXXConstructorDecl>(D);
if (!Constructor->isInvalidDecl() &&
Constructor->isConvertingConstructor(AllowExplicit)) {
if (ConstructorTmpl)
AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl,
/*ExplicitArgs*/ 0,
&From, 1, CandidateSet,
/*SuppressUserConversions=*/!ConstructorsOnly);
else
// Allow one user-defined conversion when user specifies a
// From->ToType conversion via an static cast (c-style, etc).
AddOverloadCandidate(Constructor, FoundDecl,
&From, 1, CandidateSet,
/*SuppressUserConversions=*/!ConstructorsOnly);
}
}
}
}
// Enumerate conversion functions, if we're allowed to.
if (ConstructorsOnly) {
} else if (RequireCompleteType(From->getLocStart(), From->getType(),
PDiag(0) << From->getSourceRange())) {
// No conversion functions from incomplete types.
} else if (const RecordType *FromRecordType
= From->getType()->getAs<RecordType>()) {
if (CXXRecordDecl *FromRecordDecl
= dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
// Add all of the conversion functions as candidates.
const UnresolvedSetImpl *Conversions
= FromRecordDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
DeclAccessPair FoundDecl = I.getPair();
NamedDecl *D = FoundDecl.getDecl();
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
CXXConversionDecl *Conv;
FunctionTemplateDecl *ConvTemplate;
if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
if (AllowExplicit || !Conv->isExplicit()) {
if (ConvTemplate)
AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
ActingContext, From, ToType,
CandidateSet);
else
AddConversionCandidate(Conv, FoundDecl, ActingContext,
From, ToType, CandidateSet);
}
}
}
}
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) {
case OR_Success:
// Record the standard conversion we used and the conversion function.
if (CXXConstructorDecl *Constructor
= dyn_cast<CXXConstructorDecl>(Best->Function)) {
// C++ [over.ics.user]p1:
// If the user-defined conversion is specified by a
// constructor (12.3.1), the initial standard conversion
// sequence converts the source type to the type required by
// the argument of the constructor.
//
QualType ThisType = Constructor->getThisType(Context);
if (Best->Conversions[0].isEllipsis())
User.EllipsisConversion = true;
else {
User.Before = Best->Conversions[0].Standard;
User.EllipsisConversion = false;
}
User.ConversionFunction = Constructor;
User.After.setAsIdentityConversion();
User.After.setFromType(
ThisType->getAs<PointerType>()->getPointeeType());
User.After.setAllToTypes(ToType);
return OR_Success;
} else if (CXXConversionDecl *Conversion
= dyn_cast<CXXConversionDecl>(Best->Function)) {
// C++ [over.ics.user]p1:
//
// [...] If the user-defined conversion is specified by a
// conversion function (12.3.2), the initial standard
// conversion sequence converts the source type to the
// implicit object parameter of the conversion function.
User.Before = Best->Conversions[0].Standard;
User.ConversionFunction = Conversion;
User.EllipsisConversion = false;
// C++ [over.ics.user]p2:
// The second standard conversion sequence converts the
// result of the user-defined conversion to the target type
// for the sequence. Since an implicit conversion sequence
// is an initialization, the special rules for
// initialization by user-defined conversion apply when
// selecting the best user-defined conversion for a
// user-defined conversion sequence (see 13.3.3 and
// 13.3.3.1).
User.After = Best->FinalConversion;
return OR_Success;
} else {
assert(false && "Not a constructor or conversion function?");
return OR_No_Viable_Function;
}
case OR_No_Viable_Function:
return OR_No_Viable_Function;
case OR_Deleted:
// No conversion here! We're done.
return OR_Deleted;
case OR_Ambiguous:
return OR_Ambiguous;
}
return OR_No_Viable_Function;
}
bool
Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
ImplicitConversionSequence ICS;
OverloadCandidateSet CandidateSet(From->getExprLoc());
OverloadingResult OvResult =
IsUserDefinedConversion(From, ToType, ICS.UserDefined,
CandidateSet, false);
if (OvResult == OR_Ambiguous)
Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_ambiguous_condition)
<< From->getType() << ToType << From->getSourceRange();
else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty())
Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_nonviable_condition)
<< From->getType() << ToType << From->getSourceRange();
else
return false;
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1);
return true;
}
/// CompareImplicitConversionSequences - Compare two implicit
/// conversion sequences to determine whether one is better than the
/// other or if they are indistinguishable (C++ 13.3.3.2).
ImplicitConversionSequence::CompareKind
Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1,
const ImplicitConversionSequence& ICS2)
{
// (C++ 13.3.3.2p2): When comparing the basic forms of implicit
// conversion sequences (as defined in 13.3.3.1)
// -- a standard conversion sequence (13.3.3.1.1) is a better
// conversion sequence than a user-defined conversion sequence or
// an ellipsis conversion sequence, and
// -- a user-defined conversion sequence (13.3.3.1.2) is a better
// conversion sequence than an ellipsis conversion sequence
// (13.3.3.1.3).
//
// C++0x [over.best.ics]p10:
// For the purpose of ranking implicit conversion sequences as
// described in 13.3.3.2, the ambiguous conversion sequence is
// treated as a user-defined sequence that is indistinguishable
// from any other user-defined conversion sequence.
if (ICS1.getKindRank() < ICS2.getKindRank())
return ImplicitConversionSequence::Better;
else if (ICS2.getKindRank() < ICS1.getKindRank())
return ImplicitConversionSequence::Worse;
// The following checks require both conversion sequences to be of
// the same kind.
if (ICS1.getKind() != ICS2.getKind())
return ImplicitConversionSequence::Indistinguishable;
// Two implicit conversion sequences of the same form are
// indistinguishable conversion sequences unless one of the
// following rules apply: (C++ 13.3.3.2p3):
if (ICS1.isStandard())
return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard);
else if (ICS1.isUserDefined()) {
// User-defined conversion sequence U1 is a better conversion
// sequence than another user-defined conversion sequence U2 if
// they contain the same user-defined conversion function or
// constructor and if the second standard conversion sequence of
// U1 is better than the second standard conversion sequence of
// U2 (C++ 13.3.3.2p3).
if (ICS1.UserDefined.ConversionFunction ==
ICS2.UserDefined.ConversionFunction)
return CompareStandardConversionSequences(ICS1.UserDefined.After,
ICS2.UserDefined.After);
}
return ImplicitConversionSequence::Indistinguishable;
}
static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
Qualifiers Quals;
T1 = Context.getUnqualifiedArrayType(T1, Quals);
T2 = Context.getUnqualifiedArrayType(T2, Quals);
}
return Context.hasSameUnqualifiedType(T1, T2);
}
// Per 13.3.3.2p3, compare the given standard conversion sequences to
// determine if one is a proper subset of the other.
static ImplicitConversionSequence::CompareKind
compareStandardConversionSubsets(ASTContext &Context,
const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2) {
ImplicitConversionSequence::CompareKind Result
= ImplicitConversionSequence::Indistinguishable;
// the identity conversion sequence is considered to be a subsequence of
// any non-identity conversion sequence
if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) {
if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
return ImplicitConversionSequence::Better;
else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
return ImplicitConversionSequence::Worse;
}
if (SCS1.Second != SCS2.Second) {
if (SCS1.Second == ICK_Identity)
Result = ImplicitConversionSequence::Better;
else if (SCS2.Second == ICK_Identity)
Result = ImplicitConversionSequence::Worse;
else
return ImplicitConversionSequence::Indistinguishable;
} else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
return ImplicitConversionSequence::Indistinguishable;
if (SCS1.Third == SCS2.Third) {
return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
: ImplicitConversionSequence::Indistinguishable;
}
if (SCS1.Third == ICK_Identity)
return Result == ImplicitConversionSequence::Worse
? ImplicitConversionSequence::Indistinguishable
: ImplicitConversionSequence::Better;
if (SCS2.Third == ICK_Identity)
return Result == ImplicitConversionSequence::Better
? ImplicitConversionSequence::Indistinguishable
: ImplicitConversionSequence::Worse;
return ImplicitConversionSequence::Indistinguishable;
}
/// 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 (Context.UnwrapSimilarPointerTypes(T1, T2)) {
// Within each iteration of the loop, we check the qualifiers to
// determine if this still looks like a qualification
// conversion. Then, if all is well, we unwrap one more level of
// pointers or pointers-to-members and do it all again
// until there are no more pointers or pointers-to-members left
// to unwrap. This essentially mimics what
// IsQualificationConversion does, but here we're checking for a
// strict subset of qualifiers.
if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
// The qualifiers are the same, so this doesn't tell us anything
// about how the sequences rank.
;
else if (T2.isMoreQualifiedThan(T1)) {
// T1 has fewer qualifiers, so it could be the better sequence.
if (Result == ImplicitConversionSequence::Worse)
// Neither has qualifiers that are a subset of the other's
// qualifiers.
return ImplicitConversionSequence::Indistinguishable;
Result = ImplicitConversionSequence::Better;
} else if (T1.isMoreQualifiedThan(T2)) {
// T2 has fewer qualifiers, so it could be the better sequence.
if (Result == ImplicitConversionSequence::Better)
// Neither has qualifiers that are a subset of the other's
// qualifiers.
return ImplicitConversionSequence::Indistinguishable;
Result = ImplicitConversionSequence::Worse;
} else {
// Qualifiers are disjoint.
return ImplicitConversionSequence::Indistinguishable;
}
// If the types after this point are equivalent, we're done.
if (Context.hasSameUnqualifiedType(T1, T2))
break;
}
// Check that the winning standard conversion sequence isn't using
// the deprecated string literal array to pointer conversion.
switch (Result) {
case ImplicitConversionSequence::Better:
if (SCS1.DeprecatedStringLiteralToCharPtr)
Result = ImplicitConversionSequence::Indistinguishable;
break;
case ImplicitConversionSequence::Indistinguishable:
break;
case ImplicitConversionSequence::Worse:
if (SCS2.DeprecatedStringLiteralToCharPtr)
Result = ImplicitConversionSequence::Indistinguishable;
break;
}
return Result;
}
/// CompareDerivedToBaseConversions - Compares two standard conversion
/// sequences to determine whether they can be ranked based on their
/// various kinds of derived-to-base conversions (C++
/// [over.ics.rank]p4b3). As part of these checks, we also look at
/// conversions between Objective-C interface types.
ImplicitConversionSequence::CompareKind
Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1,
const StandardConversionSequence& SCS2) {
QualType FromType1 = SCS1.getFromType();
QualType ToType1 = SCS1.getToType(1);
QualType FromType2 = SCS2.getFromType();
QualType ToType2 = SCS2.getToType(1);
// Adjust the types we're converting from via the array-to-pointer
// conversion, if we need to.
if (SCS1.First == ICK_Array_To_Pointer)
FromType1 = Context.getArrayDecayedType(FromType1);
if (SCS2.First == ICK_Array_To_Pointer)
FromType2 = Context.getArrayDecayedType(FromType2);
// Canonicalize all of the types.
FromType1 = Context.getCanonicalType(FromType1);
ToType1 = Context.getCanonicalType(ToType1);
FromType2 = Context.getCanonicalType(FromType2);
ToType2 = Context.getCanonicalType(ToType2);
// C++ [over.ics.rank]p4b3:
//
// If class B is derived directly or indirectly from class A and
// class C is derived directly or indirectly from B,
//
// For Objective-C, we let A, B, and C also be Objective-C
// interfaces.
// Compare based on pointer conversions.
if (SCS1.Second == ICK_Pointer_Conversion &&
SCS2.Second == ICK_Pointer_Conversion &&
/*FIXME: Remove if Objective-C id conversions get their own rank*/
FromType1->isPointerType() && FromType2->isPointerType() &&
ToType1->isPointerType() && ToType2->isPointerType()) {
QualType FromPointee1
= FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType ToPointee1
= ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType FromPointee2
= FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
QualType ToPointee2
= ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>();
const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>();
const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>();
const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>();
// -- conversion of C* to B* is better than conversion of C* to A*,
if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
if (IsDerivedFrom(ToPointee1, ToPointee2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(ToPointee2, ToPointee1))
return ImplicitConversionSequence::Worse;
if (ToIface1 && ToIface2) {
if (Context.canAssignObjCInterfaces(ToIface2, ToIface1))
return ImplicitConversionSequence::Better;
else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2))
return ImplicitConversionSequence::Worse;
}
}
// -- conversion of B* to A* is better than conversion of C* to A*,
if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
if (IsDerivedFrom(FromPointee2, FromPointee1))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromPointee1, FromPointee2))
return ImplicitConversionSequence::Worse;
if (FromIface1 && FromIface2) {
if (Context.canAssignObjCInterfaces(FromIface1, FromIface2))
return ImplicitConversionSequence::Better;
else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1))
return ImplicitConversionSequence::Worse;
}
}
}
// Ranking of member-pointer types.
if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
const MemberPointerType * FromMemPointer1 =
FromType1->getAs<MemberPointerType>();
const MemberPointerType * ToMemPointer1 =
ToType1->getAs<MemberPointerType>();
const MemberPointerType * FromMemPointer2 =
FromType2->getAs<MemberPointerType>();
const MemberPointerType * ToMemPointer2 =
ToType2->getAs<MemberPointerType>();
const Type *FromPointeeType1 = FromMemPointer1->getClass();
const Type *ToPointeeType1 = ToMemPointer1->getClass();
const Type *FromPointeeType2 = FromMemPointer2->getClass();
const Type *ToPointeeType2 = ToMemPointer2->getClass();
QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
// conversion of A::* to B::* is better than conversion of A::* to C::*,
if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
if (IsDerivedFrom(ToPointee1, ToPointee2))
return ImplicitConversionSequence::Worse;
else if (IsDerivedFrom(ToPointee2, ToPointee1))
return ImplicitConversionSequence::Better;
}
// conversion of B::* to C::* is better than conversion of A::* to C::*
if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
if (IsDerivedFrom(FromPointee1, FromPointee2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromPointee2, FromPointee1))
return ImplicitConversionSequence::Worse;
}
}
if (SCS1.Second == ICK_Derived_To_Base) {
// -- conversion of C to B is better than conversion of C to A,
// -- binding of an expression of type C to a reference of type
// B& is better than binding an expression of type C to a
// reference of type A&,
if (Context.hasSameUnqualifiedType(FromType1, FromType2) &&
!Context.hasSameUnqualifiedType(ToType1, ToType2)) {
if (IsDerivedFrom(ToType1, ToType2))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(ToType2, ToType1))
return ImplicitConversionSequence::Worse;
}
// -- conversion of B to A is better than conversion of C to A.
// -- binding of an expression of type B to a reference of type
// A& is better than binding an expression of type C to a
// reference of type A&,
if (!Context.hasSameUnqualifiedType(FromType1, FromType2) &&
Context.hasSameUnqualifiedType(ToType1, ToType2)) {
if (IsDerivedFrom(FromType2, FromType1))
return ImplicitConversionSequence::Better;
else if (IsDerivedFrom(FromType1, FromType2))
return ImplicitConversionSequence::Worse;
}
}
return ImplicitConversionSequence::Indistinguishable;
}
/// CompareReferenceRelationship - Compare the two types T1 and T2 to
/// determine whether they are reference-related,
/// reference-compatible, reference-compatible with added
/// qualification, or incompatible, for use in C++ initialization by
/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
/// type, and the first type (T1) is the pointee type of the reference
/// type being initialized.
Sema::ReferenceCompareResult
Sema::CompareReferenceRelationship(SourceLocation Loc,
QualType OrigT1, QualType OrigT2,
bool& DerivedToBase) {
assert(!OrigT1->isReferenceType() &&
"T1 must be the pointee type of the reference type");
assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
QualType T1 = Context.getCanonicalType(OrigT1);
QualType T2 = Context.getCanonicalType(OrigT2);
Qualifiers T1Quals, T2Quals;
QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
// C++ [dcl.init.ref]p4:
// Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
// reference-related to "cv2 T2" if T1 is the same type as T2, or
// T1 is a base class of T2.
if (UnqualT1 == UnqualT2)
DerivedToBase = false;
else if (!RequireCompleteType(Loc, OrigT2, PDiag()) &&
IsDerivedFrom(UnqualT2, UnqualT1))
DerivedToBase = true;
else
return Ref_Incompatible;
// At this point, we know that T1 and T2 are reference-related (at
// least).
// If the type is an array type, promote the element qualifiers to the type
// for comparison.
if (isa<ArrayType>(T1) && T1Quals)
T1 = Context.getQualifiedType(UnqualT1, T1Quals);
if (isa<ArrayType>(T2) && T2Quals)
T2 = Context.getQualifiedType(UnqualT2, T2Quals);
// C++ [dcl.init.ref]p4:
// "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
// reference-related to T2 and cv1 is the same cv-qualification
// as, or greater cv-qualification than, cv2. For purposes of
// overload resolution, cases for which cv1 is greater
// cv-qualification than cv2 are identified as
// reference-compatible with added qualification (see 13.3.3.2).
if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers())
return Ref_Compatible;
else if (T1.isMoreQualifiedThan(T2))
return Ref_Compatible_With_Added_Qualification;
else
return Ref_Related;
}
/// \brief Compute an implicit conversion sequence for reference
/// initialization.
static ImplicitConversionSequence
TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType,
SourceLocation DeclLoc,
bool SuppressUserConversions,
bool AllowExplicit) {
assert(DeclType->isReferenceType() && "Reference init needs a reference");
// Most paths end in a failed conversion.
ImplicitConversionSequence ICS;
ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
QualType T2 = Init->getType();
// If the initializer is the address of an overloaded function, try
// to resolve the overloaded function. If all goes well, T2 is the
// type of the resulting function.
if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
DeclAccessPair Found;
if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
false, Found))
T2 = Fn->getType();
}
// Compute some basic properties of the types and the initializer.
bool isRValRef = DeclType->isRValueReferenceType();
bool DerivedToBase = false;
Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context);
Sema::ReferenceCompareResult RefRelationship
= S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase);
// C++ [over.ics.ref]p3:
// Except for an implicit object parameter, for which see 13.3.1,
// a standard conversion sequence cannot be formed if it requires
// binding an lvalue reference to non-const to an rvalue or
// binding an rvalue reference to an lvalue.
//
// FIXME: DPG doesn't trust this code. It seems far too early to
// abort because of a binding of an rvalue reference to an lvalue.
if (isRValRef && InitLvalue == Expr::LV_Valid)
return ICS;
// C++0x [dcl.init.ref]p16:
// A reference to type "cv1 T1" is initialized by an expression
// of type "cv2 T2" as follows:
// -- If the initializer expression
// -- is an lvalue (but is not a bit-field), and "cv1 T1" is
// reference-compatible with "cv2 T2," or
//
// Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
if (InitLvalue == Expr::LV_Valid &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
// C++ [over.ics.ref]p1:
// When a parameter of reference type binds directly (8.5.3)
// to an argument expression, the implicit conversion sequence
// is the identity conversion, unless the argument expression
// has a type that is a derived class of the parameter type,
// in which case the implicit conversion sequence is a
// derived-to-base Conversion (13.3.3.1).
ICS.setStandard();
ICS.Standard.First = ICK_Identity;
ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
ICS.Standard.Third = ICK_Identity;
ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
ICS.Standard.setToType(0, T2);
ICS.Standard.setToType(1, T1);
ICS.Standard.setToType(2, T1);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = true;
ICS.Standard.RRefBinding = false;
ICS.Standard.CopyConstructor = 0;
// Nothing more to do: the inaccessibility/ambiguity check for
// derived-to-base conversions is suppressed when we're
// computing the implicit conversion sequence (C++
// [over.best.ics]p2).
return ICS;
}
// -- has a class type (i.e., T2 is a class type), where T1 is
// not reference-related to T2, and can be implicitly
// converted to an lvalue of type "cv3 T3," where "cv1 T1"
// is reference-compatible with "cv3 T3" 92) (this
// conversion is selected by enumerating the applicable
// conversion functions (13.3.1.6) and choosing the best
// one through overload resolution (13.3)),
if (!isRValRef && !SuppressUserConversions && T2->isRecordType() &&
!S.RequireCompleteType(DeclLoc, T2, 0) &&
RefRelationship == Sema::Ref_Incompatible) {
CXXRecordDecl *T2RecordDecl
= dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
OverloadCandidateSet CandidateSet(DeclLoc);
const UnresolvedSetImpl *Conversions
= T2RecordDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
FunctionTemplateDecl *ConvTemplate
= dyn_cast<FunctionTemplateDecl>(D);
CXXConversionDecl *Conv;
if (ConvTemplate)
Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
else
Conv = cast<CXXConversionDecl>(D);
// If the conversion function doesn't return a reference type,
// it can't be considered for this conversion.
if (Conv->getConversionType()->isLValueReferenceType() &&
(AllowExplicit || !Conv->isExplicit())) {
if (ConvTemplate)
S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
Init, DeclType, CandidateSet);
else
S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
DeclType, CandidateSet);
}
}
OverloadCandidateSet::iterator Best;
switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) {
case OR_Success:
// C++ [over.ics.ref]p1:
//
// [...] If the parameter binds directly to the result of
// applying a conversion function to the argument
// expression, the implicit conversion sequence is a
// user-defined conversion sequence (13.3.3.1.2), with the
// second standard conversion sequence either an identity
// conversion or, if the conversion function returns an
// entity of a type that is a derived class of the parameter
// type, a derived-to-base Conversion.
if (!Best->FinalConversion.DirectBinding)
break;
ICS.setUserDefined();
ICS.UserDefined.Before = Best->Conversions[0].Standard;
ICS.UserDefined.After = Best->FinalConversion;
ICS.UserDefined.ConversionFunction = Best->Function;
ICS.UserDefined.EllipsisConversion = false;
assert(ICS.UserDefined.After.ReferenceBinding &&
ICS.UserDefined.After.DirectBinding &&
"Expected a direct reference binding!");
return ICS;
case OR_Ambiguous:
ICS.setAmbiguous();
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand)
if (Cand->Viable)
ICS.Ambiguous.addConversion(Cand->Function);
return ICS;
case OR_No_Viable_Function:
case OR_Deleted:
// There was no suitable conversion, or we found a deleted
// conversion; continue with other checks.
break;
}
}
// -- Otherwise, the reference shall be to a non-volatile const
// type (i.e., cv1 shall be const), or the reference shall be an
// rvalue reference and the initializer expression shall be an rvalue.
//
// We actually handle one oddity of C++ [over.ics.ref] at this
// point, which is that, due to p2 (which short-circuits reference
// binding by only attempting a simple conversion for non-direct
// bindings) and p3's strange wording, we allow a const volatile
// reference to bind to an rvalue. Hence the check for the presence
// of "const" rather than checking for "const" being the only
// qualifier.
if (!isRValRef && !T1.isConstQualified())
return ICS;
// -- if T2 is a class type and
// -- the initializer expression is an rvalue and "cv1 T1"
// is reference-compatible with "cv2 T2," or
//
// -- T1 is not reference-related to T2 and the initializer
// expression can be implicitly converted to an rvalue
// of type "cv3 T3" (this conversion is selected by
// enumerating the applicable conversion functions
// (13.3.1.6) and choosing the best one through overload
// resolution (13.3)),
//
// then the reference is bound to the initializer
// expression rvalue in the first case and to the object
// that is the result of the conversion in the second case
// (or, in either case, to the appropriate base class
// subobject of the object).
//
// We're only checking the first case here, which is a direct
// binding in C++0x but not in C++03.
if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
ICS.setStandard();
ICS.Standard.First = ICK_Identity;
ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
ICS.Standard.Third = ICK_Identity;
ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
ICS.Standard.setToType(0, T2);
ICS.Standard.setToType(1, T1);
ICS.Standard.setToType(2, T1);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x;
ICS.Standard.RRefBinding = isRValRef;
ICS.Standard.CopyConstructor = 0;
return ICS;
}
// -- Otherwise, a temporary of type "cv1 T1" is created and
// initialized from the initializer expression using the
// rules for a non-reference copy initialization (8.5). The
// reference is then bound to the temporary. If T1 is
// reference-related to T2, cv1 must be the same
// cv-qualification as, or greater cv-qualification than,
// cv2; otherwise, the program is ill-formed.
if (RefRelationship == Sema::Ref_Related) {
// If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
// we would be reference-compatible or reference-compatible with
// added qualification. But that wasn't the case, so the reference
// initialization fails.
return ICS;
}
// If at least one of the types is a class type, the types are not
// related, and we aren't allowed any user conversions, the
// reference binding fails. This case is important for breaking
// recursion, since TryImplicitConversion below will attempt to
// create a temporary through the use of a copy constructor.
if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
(T1->isRecordType() || T2->isRecordType()))
return ICS;
// C++ [over.ics.ref]p2:
// When a parameter of reference type is not bound directly to
// an argument expression, the conversion sequence is the one
// required to convert the argument expression to the
// underlying type of the reference according to
// 13.3.3.1. Conceptually, this conversion sequence corresponds
// to copy-initializing a temporary of the underlying type with
// the argument expression. Any difference in top-level
// cv-qualification is subsumed by the initialization itself
// and does not constitute a conversion.
ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions,
/*AllowExplicit=*/false,
/*InOverloadResolution=*/false);
// Of course, that's still a reference binding.
if (ICS.isStandard()) {
ICS.Standard.ReferenceBinding = true;
ICS.Standard.RRefBinding = isRValRef;
} else if (ICS.isUserDefined()) {
ICS.UserDefined.After.ReferenceBinding = true;
ICS.UserDefined.After.RRefBinding = isRValRef;
}
return ICS;
}
/// TryCopyInitialization - Try to copy-initialize a value of type
/// ToType from the expression From. Return the implicit conversion
/// sequence required to pass this argument, which may be a bad
/// conversion sequence (meaning that the argument cannot be passed to
/// a parameter of this type). If @p SuppressUserConversions, then we
/// do not permit any user-defined conversion sequences.
static ImplicitConversionSequence
TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
bool SuppressUserConversions,
bool InOverloadResolution) {
if (ToType->isReferenceType())
return TryReferenceInit(S, From, ToType,
/*FIXME:*/From->getLocStart(),
SuppressUserConversions,
/*AllowExplicit=*/false);
return S.TryImplicitConversion(From, ToType,
SuppressUserConversions,
/*AllowExplicit=*/false,
InOverloadResolution);
}
/// TryObjectArgumentInitialization - Try to initialize the object
/// parameter of the given member function (@c Method) from the
/// expression @p From.
ImplicitConversionSequence
Sema::TryObjectArgumentInitialization(QualType OrigFromType,
CXXMethodDecl *Method,
CXXRecordDecl *ActingContext) {
QualType ClassType = Context.getTypeDeclType(ActingContext);
// [class.dtor]p2: A destructor can be invoked for a const, volatile or
// const volatile object.
unsigned Quals = isa<CXXDestructorDecl>(Method) ?
Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals);
// Set up the conversion sequence as a "bad" conversion, to allow us
// to exit early.
ImplicitConversionSequence ICS;
// We need to have an object of class type.
QualType FromType = OrigFromType;
if (const PointerType *PT = FromType->getAs<PointerType>())
FromType = PT->getPointeeType();
assert(FromType->isRecordType());
// The implicit object parameter is has the type "reference to cv X",
// where X is the class of which the function is a member
// (C++ [over.match.funcs]p4). However, when finding an implicit
// conversion sequence for the argument, we are not allowed to
// create temporaries or perform user-defined conversions
// (C++ [over.match.funcs]p5). We perform a simplified version of
// reference binding here, that allows class rvalues to bind to
// non-constant references.
// First check the qualifiers. We don't care about lvalue-vs-rvalue
// with the implicit object parameter (C++ [over.match.funcs]p5).
QualType FromTypeCanon = Context.getCanonicalType(FromType);
if (ImplicitParamType.getCVRQualifiers()
!= FromTypeCanon.getLocalCVRQualifiers() &&
!ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
ICS.setBad(BadConversionSequence::bad_qualifiers,
OrigFromType, ImplicitParamType);
return ICS;
}
// Check that we have either the same type or a derived type. It
// affects the conversion rank.
QualType ClassTypeCanon = Context.getCanonicalType(ClassType);
ImplicitConversionKind SecondKind;
if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
SecondKind = ICK_Identity;
} else if (IsDerivedFrom(FromType, ClassType))
SecondKind = ICK_Derived_To_Base;
else {
ICS.setBad(BadConversionSequence::unrelated_class,
FromType, ImplicitParamType);
return ICS;
}
// Success. Mark this as a reference binding.
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.Second = SecondKind;
ICS.Standard.setFromType(FromType);
ICS.Standard.setAllToTypes(ImplicitParamType);
ICS.Standard.ReferenceBinding = true;
ICS.Standard.DirectBinding = true;
ICS.Standard.RRefBinding = false;
return ICS;
}
/// PerformObjectArgumentInitialization - Perform initialization of
/// the implicit object parameter for the given Method with the given
/// expression.
bool
Sema::PerformObjectArgumentInitialization(Expr *&From,
NestedNameSpecifier *Qualifier,
NamedDecl *FoundDecl,
CXXMethodDecl *Method) {
QualType FromRecordType, DestType;
QualType ImplicitParamRecordType =
Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
FromRecordType = PT->getPointeeType();
DestType = Method->getThisType(Context);
} else {
FromRecordType = From->getType();
DestType = ImplicitParamRecordType;
}
// Note that we always use the true parent context when performing
// the actual argument initialization.
ImplicitConversionSequence ICS
= TryObjectArgumentInitialization(From->getType(), Method,
Method->getParent());
if (ICS.isBad())
return Diag(From->getSourceRange().getBegin(),
diag::err_implicit_object_parameter_init)
<< ImplicitParamRecordType << FromRecordType << From->getSourceRange();
if (ICS.Standard.Second == ICK_Derived_To_Base)
return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
if (!Context.hasSameType(From->getType(), DestType))
ImpCastExprToType(From, DestType, CastExpr::CK_NoOp,
/*isLvalue=*/!From->getType()->isPointerType());
return false;
}
/// TryContextuallyConvertToBool - Attempt to contextually convert the
/// expression From to bool (C++0x [conv]p3).
ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) {
// FIXME: This is pretty broken.
return TryImplicitConversion(From, Context.BoolTy,
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
/*InOverloadResolution=*/false);
}
/// PerformContextuallyConvertToBool - Perform a contextual conversion
/// of the expression From to bool (C++0x [conv]p3).
bool Sema::PerformContextuallyConvertToBool(Expr *&From) {
ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From);
if (!ICS.isBad())
return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
return Diag(From->getSourceRange().getBegin(),
diag::err_typecheck_bool_condition)
<< From->getType() << From->getSourceRange();
return true;
}
/// TryContextuallyConvertToObjCId - Attempt to contextually convert the
/// expression From to 'id'.
ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) {
QualType Ty = Context.getObjCIdType();
return TryImplicitConversion(From, Ty,
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
/*InOverloadResolution=*/false);
}
/// PerformContextuallyConvertToObjCId - Perform a contextual conversion
/// of the expression From to 'id'.
bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) {
QualType Ty = Context.getObjCIdType();
ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From);
if (!ICS.isBad())
return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
return true;
}
/// AddOverloadCandidate - Adds the given function to the set of
/// candidate functions, using the given function call arguments. If
/// @p SuppressUserConversions, then don't allow user-defined
/// conversions via constructors or conversion operators.
///
/// \para PartialOverloading true if we are performing "partial" overloading
/// based on an incomplete set of function arguments. This feature is used by
/// code completion.
void
Sema::AddOverloadCandidate(FunctionDecl *Function,
DeclAccessPair FoundDecl,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions,
bool PartialOverloading) {
const FunctionProtoType* Proto
= dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
assert(Proto && "Functions without a prototype cannot be overloaded");
assert(!Function->getDescribedFunctionTemplate() &&
"Use AddTemplateOverloadCandidate for function templates");
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
if (!isa<CXXConstructorDecl>(Method)) {
// If we get here, it's because we're calling a member function
// that is named without a member access expression (e.g.,
// "this->f") that was either written explicitly or created
// implicitly. This can happen with a qualified call to a member
// function, e.g., X::f(). We use an empty type for the implied
// object argument (C++ [over.call.func]p3), and the acting context
// is irrelevant.
AddMethodCandidate(Method, FoundDecl, Method->getParent(),
QualType(), Args, NumArgs, CandidateSet,
SuppressUserConversions);
return;
}
// We treat a constructor like a non-member function, since its object
// argument doesn't participate in overload resolution.
}
if (!CandidateSet.isNewCandidate(Function))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){
// C++ [class.copy]p3:
// A member function template is never instantiated to perform the copy
// of a class object to an object of its class type.
QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
if (NumArgs == 1 &&
Constructor->isCopyConstructorLikeSpecialization() &&
(Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
IsDerivedFrom(Args[0]->getType(), ClassType)))
return;
}
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Function;
Candidate.Viable = true;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto &&
!Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// (C++ 13.3.2p2): A candidate function having more than m parameters
// is viable only if the (m+1)st parameter has a default argument
// (8.3.6). For the purposes of overload resolution, the
// parameter list is truncated on the right, so that there are
// exactly m parameters.
unsigned MinRequiredArgs = Function->getMinRequiredArguments();
if (NumArgs < MinRequiredArgs && !PartialOverloading) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
// Determine the implicit conversion sequences for each of the
// arguments.
Candidate.Conversions.resize(NumArgs);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
SuppressUserConversions,
/*InOverloadResolution=*/true);
if (Candidate.Conversions[ArgIdx].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx].setEllipsis();
}
}
}
/// \brief Add all of the function declarations in the given function set to
/// the overload canddiate set.
void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
NamedDecl *D = F.getDecl()->getUnderlyingDecl();
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
cast<CXXMethodDecl>(FD)->getParent(),
Args[0]->getType(), Args + 1, NumArgs - 1,
CandidateSet, SuppressUserConversions);
else
AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet,
SuppressUserConversions);
} else {
FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
!cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic())
AddMethodTemplateCandidate(FunTmpl, F.getPair(),
cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
/*FIXME: explicit args */ 0,
Args[0]->getType(), Args + 1, NumArgs - 1,
CandidateSet,
SuppressUserConversions);
else
AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
/*FIXME: explicit args */ 0,
Args, NumArgs, CandidateSet,
SuppressUserConversions);
}
}
}
/// AddMethodCandidate - Adds a named decl (which is some kind of
/// method) as a method candidate to the given overload set.
void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
NamedDecl *Decl = FoundDecl.getDecl();
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
if (isa<UsingShadowDecl>(Decl))
Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
"Expected a member function template");
AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
/*ExplicitArgs*/ 0,
ObjectType, Args, NumArgs,
CandidateSet,
SuppressUserConversions);
} else {
AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
ObjectType, Args, NumArgs,
CandidateSet, SuppressUserConversions);
}
}
/// AddMethodCandidate - Adds the given C++ member function to the set
/// of candidate functions, using the given function call arguments
/// and the object argument (@c Object). For example, in a call
/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
/// allow user-defined conversions via constructors or conversion
/// operators.
void
Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext, QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
const FunctionProtoType* Proto
= dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
assert(Proto && "Methods without a prototype cannot be overloaded");
assert(!isa<CXXConstructorDecl>(Method) &&
"Use AddOverloadCandidate for constructors");
if (!CandidateSet.isNewCandidate(Method))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Method;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if (NumArgs > NumArgsInProto && !Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// (C++ 13.3.2p2): A candidate function having more than m parameters
// is viable only if the (m+1)st parameter has a default argument
// (8.3.6). For the purposes of overload resolution, the
// parameter list is truncated on the right, so that there are
// exactly m parameters.
unsigned MinRequiredArgs = Method->getMinRequiredArguments();
if (NumArgs < MinRequiredArgs) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
Candidate.Viable = true;
Candidate.Conversions.resize(NumArgs + 1);
if (Method->isStatic() || ObjectType.isNull())
// The implicit object argument is ignored.
Candidate.IgnoreObjectArgument = true;
else {
// Determine the implicit conversion sequence for the object
// parameter.
Candidate.Conversions[0]
= TryObjectArgumentInitialization(ObjectType, Method, ActingContext);
if (Candidate.Conversions[0].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
return;
}
}
// Determine the implicit conversion sequences for each of the
// arguments.
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx + 1]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
SuppressUserConversions,
/*InOverloadResolution=*/true);
if (Candidate.Conversions[ArgIdx + 1].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx + 1].setEllipsis();
}
}
}
/// \brief Add a C++ member function template as a candidate to the candidate
/// set, using template argument deduction to produce an appropriate member
/// function template specialization.
void
Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
if (!CandidateSet.isNewCandidate(MethodTmpl))
return;
// C++ [over.match.funcs]p7:
// In each case where a candidate is a function template, candidate
// function template specializations are generated using template argument
// deduction (14.8.3, 14.8.2). Those candidates are then handled as
// candidate functions in the usual way.113) A given name can refer to one
// or more function templates and also to a set of overloaded non-template
// functions. In such a case, the candidate functions generated from each
// function template are combined with the set of non-template candidate
// functions.
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
FunctionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs,
Args, NumArgs, Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = MethodTmpl->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the function template specialization produced by template argument
// deduction as a candidate.
assert(Specialization && "Missing member function template specialization?");
assert(isa<CXXMethodDecl>(Specialization) &&
"Specialization is not a member function?");
AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
ActingContext, ObjectType, Args, NumArgs,
CandidateSet, SuppressUserConversions);
}
/// \brief Add a C++ function template specialization as a candidate
/// in the candidate set, using template argument deduction to produce
/// an appropriate function template specialization.
void
Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
DeclAccessPair FoundDecl,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool SuppressUserConversions) {
if (!CandidateSet.isNewCandidate(FunctionTemplate))
return;
// C++ [over.match.funcs]p7:
// In each case where a candidate is a function template, candidate
// function template specializations are generated using template argument
// deduction (14.8.3, 14.8.2). Those candidates are then handled as
// candidate functions in the usual way.113) A given name can refer to one
// or more function templates and also to a set of overloaded non-template
// functions. In such a case, the candidate functions generated from each
// function template are combined with the set of non-template candidate
// functions.
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
FunctionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs,
Args, NumArgs, Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = FunctionTemplate->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the function template specialization produced by template argument
// deduction as a candidate.
assert(Specialization && "Missing function template specialization?");
AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet,
SuppressUserConversions);
}
/// AddConversionCandidate - Add a C++ conversion function as a
/// candidate in the candidate set (C++ [over.match.conv],
/// C++ [over.match.copy]). From is the expression we're converting from,
/// and ToType is the type that we're eventually trying to convert to
/// (which may or may not be the same type as the type that the
/// conversion function produces).
void
Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
Expr *From, QualType ToType,
OverloadCandidateSet& CandidateSet) {
assert(!Conversion->getDescribedFunctionTemplate() &&
"Conversion function templates use AddTemplateConversionCandidate");
QualType ConvType = Conversion->getConversionType().getNonReferenceType();
if (!CandidateSet.isNewCandidate(Conversion))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = Conversion;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.FinalConversion.setAsIdentityConversion();
Candidate.FinalConversion.setFromType(ConvType);
Candidate.FinalConversion.setAllToTypes(ToType);
// Determine the implicit conversion sequence for the implicit
// object parameter.
Candidate.Viable = true;
Candidate.Conversions.resize(1);
Candidate.Conversions[0]
= TryObjectArgumentInitialization(From->getType(), Conversion,
ActingContext);
// Conversion functions to a different type in the base class is visible in
// the derived class. So, a derived to base conversion should not participate
// in overload resolution.
if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base)
Candidate.Conversions[0].Standard.Second = ICK_Identity;
if (Candidate.Conversions[0].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
return;
}
// We won't go through a user-define type conversion function to convert a
// derived to base as such conversions are given Conversion Rank. They only
// go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
QualType FromCanon
= Context.getCanonicalType(From->getType().getUnqualifiedType());
QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_trivial_conversion;
return;
}
// To determine what the conversion from the result of calling the
// conversion function to the type we're eventually trying to
// convert to (ToType), we need to synthesize a call to the
// conversion function and attempt copy initialization from it. This
// makes sure that we get the right semantics with respect to
// lvalues/rvalues and the type. Fortunately, we can allocate this
// call on the stack and we don't need its arguments to be
// well-formed.
DeclRefExpr ConversionRef(Conversion, Conversion->getType(),
From->getLocStart());
ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()),
CastExpr::CK_FunctionToPointerDecay,
&ConversionRef, CXXBaseSpecifierArray(), false);
// Note that it is safe to allocate CallExpr on the stack here because
// there are 0 arguments (i.e., nothing is allocated using ASTContext's
// allocator).
CallExpr Call(Context, &ConversionFn, 0, 0,
Conversion->getConversionType().getNonReferenceType(),
From->getLocStart());
ImplicitConversionSequence ICS =
TryCopyInitialization(*this, &Call, ToType,
/*SuppressUserConversions=*/true,
/*InOverloadResolution=*/false);
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion:
Candidate.FinalConversion = ICS.Standard;
// C++ [over.ics.user]p3:
// If the user-defined conversion is specified by a specialization of a
// conversion function template, the second standard conversion sequence
// shall have exact match rank.
if (Conversion->getPrimaryTemplate() &&
GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
}
break;
case ImplicitConversionSequence::BadConversion:
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_final_conversion;
break;
default:
assert(false &&
"Can only end up with a standard conversion sequence or failure");
}
}
/// \brief Adds a conversion function template specialization
/// candidate to the overload set, using template argument deduction
/// to deduce the template arguments of the conversion function
/// template from the type that we are converting to (C++
/// [temp.deduct.conv]).
void
Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingDC,
Expr *From, QualType ToType,
OverloadCandidateSet &CandidateSet) {
assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&
"Only conversion function templates permitted here");
if (!CandidateSet.isNewCandidate(FunctionTemplate))
return;
TemplateDeductionInfo Info(Context, CandidateSet.getLocation());
CXXConversionDecl *Specialization = 0;
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ToType,
Specialization, Info)) {
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate &Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = FunctionTemplate->getTemplatedDecl();
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_deduction;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
Info);
return;
}
// Add the conversion function template specialization produced by
// template argument deduction as a candidate.
assert(Specialization && "Missing function template specialization?");
AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
CandidateSet);
}
/// AddSurrogateCandidate - Adds a "surrogate" candidate function that
/// converts the given @c Object to a function pointer via the
/// conversion function @c Conversion, and then attempts to call it
/// with the given arguments (C++ [over.call.object]p2-4). Proto is
/// the type of function that we'll eventually be calling.
void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
DeclAccessPair FoundDecl,
CXXRecordDecl *ActingContext,
const FunctionProtoType *Proto,
QualType ObjectType,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet) {
if (!CandidateSet.isNewCandidate(Conversion))
return;
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = FoundDecl;
Candidate.Function = 0;
Candidate.Surrogate = Conversion;
Candidate.Viable = true;
Candidate.IsSurrogate = true;
Candidate.IgnoreObjectArgument = false;
Candidate.Conversions.resize(NumArgs + 1);
// Determine the implicit conversion sequence for the implicit
// object parameter.
ImplicitConversionSequence ObjectInit
= TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext);
if (ObjectInit.isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
Candidate.Conversions[0] = ObjectInit;
return;
}
// The first conversion is actually a user-defined conversion whose
// first conversion is ObjectInit's standard conversion (which is
// effectively a reference binding). Record it as such.
Candidate.Conversions[0].setUserDefined();
Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
Candidate.Conversions[0].UserDefined.After
= Candidate.Conversions[0].UserDefined.Before;
Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
// Find the
unsigned NumArgsInProto = Proto->getNumArgs();
// (C++ 13.3.2p2): A candidate function having fewer than m
// parameters is viable only if it has an ellipsis in its parameter
// list (8.3.5).
if (NumArgs > NumArgsInProto && !Proto->isVariadic()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_many_arguments;
return;
}
// Function types don't have any default arguments, so just check if
// we have enough arguments.
if (NumArgs < NumArgsInProto) {
// Not enough arguments.
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_too_few_arguments;
return;
}
// Determine the implicit conversion sequences for each of the
// arguments.
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
if (ArgIdx < NumArgsInProto) {
// (C++ 13.3.2p3): for F to be a viable function, there shall
// exist for each argument an implicit conversion sequence
// (13.3.3.1) that converts that argument to the corresponding
// parameter of F.
QualType ParamType = Proto->getArgType(ArgIdx);
Candidate.Conversions[ArgIdx + 1]
= TryCopyInitialization(*this, Args[ArgIdx], ParamType,
/*SuppressUserConversions=*/false,
/*InOverloadResolution=*/false);
if (Candidate.Conversions[ArgIdx + 1].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
} else {
// (C++ 13.3.2p2): For the purposes of overload resolution, any
// argument for which there is no corresponding parameter is
// considered to ""match the ellipsis" (C+ 13.3.3.1.3).
Candidate.Conversions[ArgIdx + 1].setEllipsis();
}
}
}
/// \brief Add overload candidates for overloaded operators that are
/// member functions.
///
/// Add the overloaded operator candidates that are member functions
/// for the operator Op that was used in an operator expression such
/// as "x Op y". , Args/NumArgs provides the operator arguments, and
/// CandidateSet will store the added overload candidates. (C++
/// [over.match.oper]).
void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
SourceLocation OpLoc,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
SourceRange OpRange) {
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
// C++ [over.match.oper]p3:
// For a unary operator @ with an operand of a type whose
// cv-unqualified version is T1, and for a binary operator @ with
// a left operand of a type whose cv-unqualified version is T1 and
// a right operand of a type whose cv-unqualified version is T2,
// three sets of candidate functions, designated member
// candidates, non-member candidates and built-in candidates, are
// constructed as follows:
QualType T1 = Args[0]->getType();
QualType T2;
if (NumArgs > 1)
T2 = Args[1]->getType();
// -- If T1 is a class type, the set of member candidates is the
// result of the qualified lookup of T1::operator@
// (13.3.1.1.1); otherwise, the set of member candidates is
// empty.
if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
// Complete the type if it can be completed. Otherwise, we're done.
if (RequireCompleteType(OpLoc, T1, PDiag()))
return;
LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
LookupQualifiedName(Operators, T1Rec->getDecl());
Operators.suppressDiagnostics();
for (LookupResult::iterator Oper = Operators.begin(),
OperEnd = Operators.end();
Oper != OperEnd;
++Oper)
AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
Args + 1, NumArgs - 1, CandidateSet,
/* SuppressUserConversions = */ false);
}
}
/// AddBuiltinCandidate - Add a candidate for a built-in
/// operator. ResultTy and ParamTys are the result and parameter types
/// of the built-in candidate, respectively. Args and NumArgs are the
/// arguments being passed to the candidate. IsAssignmentOperator
/// should be true when this built-in candidate is an assignment
/// operator. NumContextualBoolArguments is the number of arguments
/// (at the beginning of the argument list) that will be contextually
/// converted to bool.
void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet,
bool IsAssignmentOperator,
unsigned NumContextualBoolArguments) {
// Overload resolution is always an unevaluated context.
EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated);
// Add this candidate
CandidateSet.push_back(OverloadCandidate());
OverloadCandidate& Candidate = CandidateSet.back();
Candidate.FoundDecl = DeclAccessPair::make(0, AS_none);
Candidate.Function = 0;
Candidate.IsSurrogate = false;
Candidate.IgnoreObjectArgument = false;
Candidate.BuiltinTypes.ResultTy = ResultTy;
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
// Determine the implicit conversion sequences for each of the
// arguments.
Candidate.Viable = true;
Candidate.Conversions.resize(NumArgs);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
// C++ [over.match.oper]p4:
// For the built-in assignment operators, conversions of the
// left operand are restricted as follows:
// -- no temporaries are introduced to hold the left operand, and
// -- no user-defined conversions are applied to the left
// operand to achieve a type match with the left-most
// parameter of a built-in candidate.
//
// We block these conversions by turning off user-defined
// conversions, since that is the only way that initialization of
// a reference to a non-class type can occur from something that
// is not of the same type.
if (ArgIdx < NumContextualBoolArguments) {
assert(ParamTys[ArgIdx] == Context.BoolTy &&
"Contextual conversion to bool requires bool type");
Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]);
} else {
Candidate.Conversions[ArgIdx]
= TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
ArgIdx == 0 && IsAssignmentOperator,
/*InOverloadResolution=*/false);
}
if (Candidate.Conversions[ArgIdx].isBad()) {
Candidate.Viable = false;
Candidate.FailureKind = ovl_fail_bad_conversion;
break;
}
}
}
/// BuiltinCandidateTypeSet - A set of types that will be used for the
/// candidate operator functions for built-in operators (C++
/// [over.built]). The types are separated into pointer types and
/// enumeration types.
class BuiltinCandidateTypeSet {
/// TypeSet - A set of types.
typedef llvm::SmallPtrSet<QualType, 8> TypeSet;
/// PointerTypes - The set of pointer types that will be used in the
/// built-in candidates.
TypeSet PointerTypes;
/// MemberPointerTypes - The set of member pointer types that will be
/// used in the built-in candidates.
TypeSet MemberPointerTypes;
/// EnumerationTypes - The set of enumeration types that will be
/// used in the built-in candidates.
TypeSet EnumerationTypes;
/// \brief The set of vector types that will be used in the built-in
/// candidates.
TypeSet VectorTypes;
/// Sema - The semantic analysis instance where we are building the
/// candidate type set.
Sema &SemaRef;
/// Context - The AST context in which we will build the type sets.
ASTContext &Context;
bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
const Qualifiers &VisibleQuals);
bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
public:
/// iterator - Iterates through the types that are part of the set.
typedef TypeSet::iterator iterator;
BuiltinCandidateTypeSet(Sema &SemaRef)
: SemaRef(SemaRef), Context(SemaRef.Context) { }
void AddTypesConvertedFrom(QualType Ty,
SourceLocation Loc,
bool AllowUserConversions,
bool AllowExplicitConversions,
const Qualifiers &VisibleTypeConversionsQuals);
/// pointer_begin - First pointer type found;
iterator pointer_begin() { return PointerTypes.begin(); }
/// pointer_end - Past the last pointer type found;
iterator pointer_end() { return PointerTypes.end(); }
/// member_pointer_begin - First member pointer type found;
iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
/// member_pointer_end - Past the last member pointer type found;
iterator member_pointer_end() { return MemberPointerTypes.end(); }
/// enumeration_begin - First enumeration type found;
iterator enumeration_begin() { return EnumerationTypes.begin(); }
/// enumeration_end - Past the last enumeration type found;
iterator enumeration_end() { return EnumerationTypes.end(); }
iterator vector_begin() { return VectorTypes.begin(); }
iterator vector_end() { return VectorTypes.end(); }
};
/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
/// the set of pointer types along with any more-qualified variants of
/// that type. For example, if @p Ty is "int const *", this routine
/// will add "int const *", "int const volatile *", "int const
/// restrict *", and "int const volatile restrict *" to the set of
/// pointer types. Returns true if the add of @p Ty itself succeeded,
/// false otherwise.
///
/// FIXME: what to do about extended qualifiers?
bool
BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
const Qualifiers &VisibleQuals) {
// Insert this type.
if (!PointerTypes.insert(Ty))
return false;
const PointerType *PointerTy = Ty->getAs<PointerType>();
assert(PointerTy && "type was not a pointer type!");
QualType PointeeTy = PointerTy->getPointeeType();
// Don't add qualified variants of arrays. For one, they're not allowed
// (the qualifier would sink to the element type), and for another, the
// only overload situation where it matters is subscript or pointer +- int,
// and those shouldn't have qualifier variants anyway.
if (PointeeTy->isArrayType())
return true;
unsigned BaseCVR = PointeeTy.getCVRQualifiers();
if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy))
BaseCVR = Array->getElementType().getCVRQualifiers();
bool hasVolatile = VisibleQuals.hasVolatile();
bool hasRestrict = VisibleQuals.hasRestrict();
// Iterate through all strict supersets of BaseCVR.
for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
if ((CVR | BaseCVR) != CVR) continue;
// Skip over Volatile/Restrict if no Volatile/Restrict found anywhere
// in the types.
if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue;
QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
PointerTypes.insert(Context.getPointerType(QPointeeTy));
}
return true;
}
/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
/// to the set of pointer types along with any more-qualified variants of
/// that type. For example, if @p Ty is "int const *", this routine
/// will add "int const *", "int const volatile *", "int const
/// restrict *", and "int const volatile restrict *" to the set of
/// pointer types. Returns true if the add of @p Ty itself succeeded,
/// false otherwise.
///
/// FIXME: what to do about extended qualifiers?
bool
BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
QualType Ty) {
// Insert this type.
if (!MemberPointerTypes.insert(Ty))
return false;
const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
assert(PointerTy && "type was not a member pointer type!");
QualType PointeeTy = PointerTy->getPointeeType();
// Don't add qualified variants of arrays. For one, they're not allowed
// (the qualifier would sink to the element type), and for another, the
// only overload situation where it matters is subscript or pointer +- int,
// and those shouldn't have qualifier variants anyway.
if (PointeeTy->isArrayType())
return true;
const Type *ClassTy = PointerTy->getClass();
// Iterate through all strict supersets of the pointee type's CVR
// qualifiers.
unsigned BaseCVR = PointeeTy.getCVRQualifiers();
for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
if ((CVR | BaseCVR) != CVR) continue;
QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy));
}
return true;
}
/// AddTypesConvertedFrom - Add each of the types to which the type @p
/// Ty can be implicit converted to the given set of @p Types. We're
/// primarily interested in pointer types and enumeration types. We also
/// take member pointer types, for the conditional operator.
/// AllowUserConversions is true if we should look at the conversion
/// functions of a class type, and AllowExplicitConversions if we
/// should also include the explicit conversion functions of a class
/// type.
void
BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
SourceLocation Loc,
bool AllowUserConversions,
bool AllowExplicitConversions,
const Qualifiers &VisibleQuals) {
// Only deal with canonical types.
Ty = Context.getCanonicalType(Ty);
// Look through reference types; they aren't part of the type of an
// expression for the purposes of conversions.
if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
Ty = RefTy->getPointeeType();
// We don't care about qualifiers on the type.
Ty = Ty.getLocalUnqualifiedType();
// If we're dealing with an array type, decay to the pointer.
if (Ty->isArrayType())
Ty = SemaRef.Context.getArrayDecayedType(Ty);
if (const PointerType *PointerTy = Ty->getAs<PointerType>()) {
QualType PointeeTy = PointerTy->getPointeeType();
// Insert our type, and its more-qualified variants, into the set
// of types.
if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
return;
} else if (Ty->isMemberPointerType()) {
// Member pointers are far easier, since the pointee can't be converted.
if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
return;
} else if (Ty->isEnumeralType()) {
EnumerationTypes.insert(Ty);
} else if (Ty->isVectorType()) {
VectorTypes.insert(Ty);
} else if (AllowUserConversions) {
if (const RecordType *TyRec = Ty->getAs<RecordType>()) {
if (SemaRef.RequireCompleteType(Loc, Ty, 0)) {
// No conversion functions in incomplete types.
return;
}
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
const UnresolvedSetImpl *Conversions
= ClassDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = I.getDecl();
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
// Skip conversion function templates; they don't tell us anything
// about which builtin types we can convert to.
if (isa<FunctionTemplateDecl>(D))
continue;
CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
if (AllowExplicitConversions || !Conv->isExplicit()) {
AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
VisibleQuals);
}
}
}
}
}
/// \brief Helper function for AddBuiltinOperatorCandidates() that adds
/// the volatile- and non-volatile-qualified assignment operators for the
/// given type to the candidate set.
static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
QualType T,
Expr **Args,
unsigned NumArgs,
OverloadCandidateSet &CandidateSet) {
QualType ParamTypes[2];
// T& operator=(T&, T)
ParamTypes[0] = S.Context.getLValueReferenceType(T);
ParamTypes[1] = T;
S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/true);
if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
// volatile T& operator=(volatile T&, T)
ParamTypes[0]
= S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
ParamTypes[1] = T;
S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/true);
}
}
/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
/// if any, found in visible type conversion functions found in ArgExpr's type.
static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
Qualifiers VRQuals;
const RecordType *TyRec;
if (const MemberPointerType *RHSMPType =
ArgExpr->getType()->getAs<MemberPointerType>())
TyRec = RHSMPType->getClass()->getAs<RecordType>();
else
TyRec = ArgExpr->getType()->getAs<RecordType>();
if (!TyRec) {
// Just to be safe, assume the worst case.
VRQuals.addVolatile();
VRQuals.addRestrict();
return VRQuals;
}
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
if (!ClassDecl->hasDefinition())
return VRQuals;
const UnresolvedSetImpl *Conversions =
ClassDecl->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = I.getDecl();
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
CanTy = ResTypeRef->getPointeeType();
// Need to go down the pointer/mempointer chain and add qualifiers
// as see them.
bool done = false;
while (!done) {
if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
CanTy = ResTypePtr->getPointeeType();
else if (const MemberPointerType *ResTypeMPtr =
CanTy->getAs<MemberPointerType>())
CanTy = ResTypeMPtr->getPointeeType();
else
done = true;
if (CanTy.isVolatileQualified())
VRQuals.addVolatile();
if (CanTy.isRestrictQualified())
VRQuals.addRestrict();
if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
return VRQuals;
}
}
}
return VRQuals;
}
/// AddBuiltinOperatorCandidates - Add the appropriate built-in
/// operator overloads to the candidate set (C++ [over.built]), based
/// on the operator @p Op and the arguments given. For example, if the
/// operator is a binary '+', this routine might add "int
/// operator+(int, int)" to cover integer addition.
void
Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
SourceLocation OpLoc,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet& CandidateSet) {
// The set of "promoted arithmetic types", which are the arithmetic
// types are that preserved by promotion (C++ [over.built]p2). Note
// that the first few of these types are the promoted integral
// types; these types need to be first.
// FIXME: What about complex?
const unsigned FirstIntegralType = 0;
const unsigned LastIntegralType = 13;
const unsigned FirstPromotedIntegralType = 7,
LastPromotedIntegralType = 13;
const unsigned FirstPromotedArithmeticType = 7,
LastPromotedArithmeticType = 16;
const unsigned NumArithmeticTypes = 16;
QualType ArithmeticTypes[NumArithmeticTypes] = {
Context.BoolTy, Context.CharTy, Context.WCharTy,
// FIXME: Context.Char16Ty, Context.Char32Ty,
Context.SignedCharTy, Context.ShortTy,
Context.UnsignedCharTy, Context.UnsignedShortTy,
Context.IntTy, Context.LongTy, Context.LongLongTy,
Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy,
Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy
};
assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy &&
"Invalid first promoted integral type");
assert(ArithmeticTypes[LastPromotedIntegralType - 1]
== Context.UnsignedLongLongTy &&
"Invalid last promoted integral type");
assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy &&
"Invalid first promoted arithmetic type");
assert(ArithmeticTypes[LastPromotedArithmeticType - 1]
== Context.LongDoubleTy &&
"Invalid last promoted arithmetic type");
// Find all of the types that the arguments can convert to, but only
// if the operator we're looking at has built-in operator candidates
// that make use of these types.
Qualifiers VisibleTypeConversionsQuals;
VisibleTypeConversionsQuals.addConst();
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]);
BuiltinCandidateTypeSet CandidateTypes(*this);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(),
OpLoc,
true,
(Op == OO_Exclaim ||
Op == OO_AmpAmp ||
Op == OO_PipePipe),
VisibleTypeConversionsQuals);
bool isComparison = false;
switch (Op) {
case OO_None:
case NUM_OVERLOADED_OPERATORS:
assert(false && "Expected an overloaded operator");
break;
case OO_Star: // '*' is either unary or binary
if (NumArgs == 1)
goto UnaryStar;
else
goto BinaryStar;
break;
case OO_Plus: // '+' is either unary or binary
if (NumArgs == 1)
goto UnaryPlus;
else
goto BinaryPlus;
break;
case OO_Minus: // '-' is either unary or binary
if (NumArgs == 1)
goto UnaryMinus;
else
goto BinaryMinus;
break;
case OO_Amp: // '&' is either unary or binary
if (NumArgs == 1)
goto UnaryAmp;
else
goto BinaryAmp;
case OO_PlusPlus:
case OO_MinusMinus:
// C++ [over.built]p3:
//
// For every pair (T, VQ), where T is an arithmetic type, and VQ
// is either volatile or empty, there exist candidate operator
// functions of the form
//
// VQ T& operator++(VQ T&);
// T operator++(VQ T&, int);
//
// C++ [over.built]p4:
//
// For every pair (T, VQ), where T is an arithmetic type other
// than bool, and VQ is either volatile or empty, there exist
// candidate operator functions of the form
//
// VQ T& operator--(VQ T&);
// T operator--(VQ T&, int);
for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1);
Arith < NumArithmeticTypes; ++Arith) {
QualType ArithTy = ArithmeticTypes[Arith];
QualType ParamTypes[2]
= { Context.getLValueReferenceType(ArithTy), Context.IntTy };
// Non-volatile version.
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet);
// heuristic to reduce number of builtin candidates in the set.
// Add volatile version only if there are conversions to a volatile type.
if (VisibleTypeConversionsQuals.hasVolatile()) {
// Volatile version
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(ArithTy));
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet);
}
}
// C++ [over.built]p5:
//
// For every pair (T, VQ), where T is a cv-qualified or
// cv-unqualified object type, and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// T*VQ& operator++(T*VQ&);
// T*VQ& operator--(T*VQ&);
// T* operator++(T*VQ&, int);
// T* operator--(T*VQ&, int);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
// Skip pointer types that aren't pointers to object types.
if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType())
continue;
QualType ParamTypes[2] = {
Context.getLValueReferenceType(*Ptr), Context.IntTy
};
// Without volatile
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
if (!Context.getCanonicalType(*Ptr).isVolatileQualified() &&
VisibleTypeConversionsQuals.hasVolatile()) {
// With volatile
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(*Ptr));
if (NumArgs == 1)
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet);
else
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
}
break;
UnaryStar:
// C++ [over.built]p6:
// For every cv-qualified or cv-unqualified object type T, there
// exist candidate operator functions of the form
//
// T& operator*(T*);
//
// C++ [over.built]p7:
// For every function type T, there exist candidate operator
// functions of the form
// T& operator*(T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTy = *Ptr;
QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType();
AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy),
&ParamTy, Args, 1, CandidateSet);
}
break;
UnaryPlus:
// C++ [over.built]p8:
// For every type T, there exist candidate operator functions of
// the form
//
// T* operator+(T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTy = *Ptr;
AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet);
}
// Fall through
UnaryMinus:
// C++ [over.built]p9:
// For every promoted arithmetic type T, there exist candidate
// operator functions of the form
//
// T operator+(T);
// T operator-(T);
for (unsigned Arith = FirstPromotedArithmeticType;
Arith < LastPromotedArithmeticType; ++Arith) {
QualType ArithTy = ArithmeticTypes[Arith];
AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet);
}
// Extension: We also add these operators for vector types.
for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(),
VecEnd = CandidateTypes.vector_end();
Vec != VecEnd; ++Vec) {
QualType VecTy = *Vec;
AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet);
}
break;
case OO_Tilde:
// C++ [over.built]p10:
// For every promoted integral type T, there exist candidate
// operator functions of the form
//
// T operator~(T);
for (unsigned Int = FirstPromotedIntegralType;
Int < LastPromotedIntegralType; ++Int) {
QualType IntTy = ArithmeticTypes[Int];
AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet);
}
// Extension: We also add this operator for vector types.
for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(),
VecEnd = CandidateTypes.vector_end();
Vec != VecEnd; ++Vec) {
QualType VecTy = *Vec;
AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet);
}
break;
case OO_New:
case OO_Delete:
case OO_Array_New:
case OO_Array_Delete:
case OO_Call:
assert(false && "Special operators don't use AddBuiltinOperatorCandidates");
break;
case OO_Comma:
UnaryAmp:
case OO_Arrow:
// C++ [over.match.oper]p3:
// -- For the operator ',', the unary operator '&', or the
// operator '->', the built-in candidates set is empty.
break;
case OO_EqualEqual:
case OO_ExclaimEqual:
// C++ [over.match.oper]p16:
// For every pointer to member type T, there exist candidate operator
// functions of the form
//
// bool operator==(T,T);
// bool operator!=(T,T);
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd;
++MemPtr) {
QualType ParamTypes[2] = { *MemPtr, *MemPtr };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
// Fall through
case OO_Less:
case OO_Greater:
case OO_LessEqual:
case OO_GreaterEqual:
// C++ [over.built]p15:
//
// For every pointer or enumeration type T, there exist
// candidate operator functions of the form
//
// bool operator<(T, T);
// bool operator>(T, T);
// bool operator<=(T, T);
// bool operator>=(T, T);
// bool operator==(T, T);
// bool operator!=(T, T);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
for (BuiltinCandidateTypeSet::iterator Enum
= CandidateTypes.enumeration_begin();
Enum != CandidateTypes.enumeration_end(); ++Enum) {
QualType ParamTypes[2] = { *Enum, *Enum };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet);
}
// Fall through.
isComparison = true;
BinaryPlus:
BinaryMinus:
if (!isComparison) {
// We didn't fall through, so we must have OO_Plus or OO_Minus.
// C++ [over.built]p13:
//
// For every cv-qualified or cv-unqualified object type T
// there exist candidate operator functions of the form
//
// T* operator+(T*, ptrdiff_t);
// T& operator[](T*, ptrdiff_t); [BELOW]
// T* operator-(T*, ptrdiff_t);
// T* operator+(ptrdiff_t, T*);
// T& operator[](ptrdiff_t, T*); [BELOW]
//
// C++ [over.built]p14:
//
// For every T, where T is a pointer to object type, there
// exist candidate operator functions of the form
//
// ptrdiff_t operator-(T, T);
for (BuiltinCandidateTypeSet::iterator Ptr
= CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() };
// operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t)
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
if (Op == OO_Plus) {
// T* operator+(ptrdiff_t, T*);
ParamTypes[0] = ParamTypes[1];
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
} else {
// ptrdiff_t operator-(T, T);
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes,
Args, 2, CandidateSet);
}
}
}
// Fall through
case OO_Slash:
BinaryStar:
Conditional:
// C++ [over.built]p12:
//
// For every pair of promoted arithmetic types L and R, there
// exist candidate operator functions of the form
//
// LR operator*(L, R);
// LR operator/(L, R);
// LR operator+(L, R);
// LR operator-(L, R);
// bool operator<(L, R);
// bool operator>(L, R);
// bool operator<=(L, R);
// bool operator>=(L, R);
// bool operator==(L, R);
// bool operator!=(L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
//
// C++ [over.built]p24:
//
// For every pair of promoted arithmetic types L and R, there exist
// candidate operator functions of the form
//
// LR operator?(bool, L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
// Our candidates ignore the first parameter.
for (unsigned Left = FirstPromotedArithmeticType;
Left < LastPromotedArithmeticType; ++Left) {
for (unsigned Right = FirstPromotedArithmeticType;
Right < LastPromotedArithmeticType; ++Right) {
QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] };
QualType Result
= isComparison
? Context.BoolTy
: Context.UsualArithmeticConversionsType(LandR[0], LandR[1]);
AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet);
}
}
// Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the
// conditional operator for vector types.
for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(),
Vec1End = CandidateTypes.vector_end();
Vec1 != Vec1End; ++Vec1)
for (BuiltinCandidateTypeSet::iterator
Vec2 = CandidateTypes.vector_begin(),
Vec2End = CandidateTypes.vector_end();
Vec2 != Vec2End; ++Vec2) {
QualType LandR[2] = { *Vec1, *Vec2 };
QualType Result;
if (isComparison)
Result = Context.BoolTy;
else {
if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType())
Result = *Vec1;
else
Result = *Vec2;
}
AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet);
}
break;
case OO_Percent:
BinaryAmp:
case OO_Caret:
case OO_Pipe:
case OO_LessLess:
case OO_GreaterGreater:
// C++ [over.built]p17:
//
// For every pair of promoted integral types L and R, there
// exist candidate operator functions of the form
//
// LR operator%(L, R);
// LR operator&(L, R);
// LR operator^(L, R);
// LR operator|(L, R);
// L operator<<(L, R);
// L operator>>(L, R);
//
// where LR is the result of the usual arithmetic conversions
// between types L and R.
for (unsigned Left = FirstPromotedIntegralType;
Left < LastPromotedIntegralType; ++Left) {
for (unsigned Right = FirstPromotedIntegralType;
Right < LastPromotedIntegralType; ++Right) {
QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] };
QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater)
? LandR[0]
: Context.UsualArithmeticConversionsType(LandR[0], LandR[1]);
AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet);
}
}
break;
case OO_Equal:
// C++ [over.built]p20:
//
// For every pair (T, VQ), where T is an enumeration or
// pointer to member type and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// VQ T& operator=(VQ T&, T);
for (BuiltinCandidateTypeSet::iterator
Enum = CandidateTypes.enumeration_begin(),
EnumEnd = CandidateTypes.enumeration_end();
Enum != EnumEnd; ++Enum)
AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2,
CandidateSet);
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd; ++MemPtr)
AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2,
CandidateSet);
// Fall through.
case OO_PlusEqual:
case OO_MinusEqual:
// C++ [over.built]p19:
//
// For every pair (T, VQ), where T is any type and VQ is either
// volatile or empty, there exist candidate operator functions
// of the form
//
// T*VQ& operator=(T*VQ&, T*);
//
// C++ [over.built]p21:
//
// For every pair (T, VQ), where T is a cv-qualified or
// cv-unqualified object type and VQ is either volatile or
// empty, there exist candidate operator functions of the form
//
// T*VQ& operator+=(T*VQ&, ptrdiff_t);
// T*VQ& operator-=(T*VQ&, ptrdiff_t);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2];
ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType();
// non-volatile version
ParamTypes[0] = Context.getLValueReferenceType(*Ptr);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
if (!Context.getCanonicalType(*Ptr).isVolatileQualified() &&
VisibleTypeConversionsQuals.hasVolatile()) {
// volatile version
ParamTypes[0]
= Context.getLValueReferenceType(Context.getVolatileType(*Ptr));
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
}
}
// Fall through.
case OO_StarEqual:
case OO_SlashEqual:
// C++ [over.built]p18:
//
// For every triple (L, VQ, R), where L is an arithmetic type,
// VQ is either volatile or empty, and R is a promoted
// arithmetic type, there exist candidate operator functions of
// the form
//
// VQ L& operator=(VQ L&, R);
// VQ L& operator*=(VQ L&, R);
// VQ L& operator/=(VQ L&, R);
// VQ L& operator+=(VQ L&, R);
// VQ L& operator-=(VQ L&, R);
for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) {
for (unsigned Right = FirstPromotedArithmeticType;
Right < LastPromotedArithmeticType; ++Right) {
QualType ParamTypes[2];
ParamTypes[1] = ArithmeticTypes[Right];
// Add this built-in operator as a candidate (VQ is empty).
ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
// Add this built-in operator as a candidate (VQ is 'volatile').
if (VisibleTypeConversionsQuals.hasVolatile()) {
ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]);
ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
}
}
}
// Extension: Add the binary operators =, +=, -=, *=, /= for vector types.
for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(),
Vec1End = CandidateTypes.vector_end();
Vec1 != Vec1End; ++Vec1)
for (BuiltinCandidateTypeSet::iterator
Vec2 = CandidateTypes.vector_begin(),
Vec2End = CandidateTypes.vector_end();
Vec2 != Vec2End; ++Vec2) {
QualType ParamTypes[2];
ParamTypes[1] = *Vec2;
// Add this built-in operator as a candidate (VQ is empty).
ParamTypes[0] = Context.getLValueReferenceType(*Vec1);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
// Add this built-in operator as a candidate (VQ is 'volatile').
if (VisibleTypeConversionsQuals.hasVolatile()) {
ParamTypes[0] = Context.getVolatileType(*Vec1);
ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet,
/*IsAssigmentOperator=*/Op == OO_Equal);
}
}
break;
case OO_PercentEqual:
case OO_LessLessEqual:
case OO_GreaterGreaterEqual:
case OO_AmpEqual:
case OO_CaretEqual:
case OO_PipeEqual:
// C++ [over.built]p22:
//
// For every triple (L, VQ, R), where L is an integral type, VQ
// is either volatile or empty, and R is a promoted integral
// type, there exist candidate operator functions of the form
//
// VQ L& operator%=(VQ L&, R);
// VQ L& operator<<=(VQ L&, R);
// VQ L& operator>>=(VQ L&, R);
// VQ L& operator&=(VQ L&, R);
// VQ L& operator^=(VQ L&, R);
// VQ L& operator|=(VQ L&, R);
for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) {
for (unsigned Right = FirstPromotedIntegralType;
Right < LastPromotedIntegralType; ++Right) {
QualType ParamTypes[2];
ParamTypes[1] = ArithmeticTypes[Right];
// Add this built-in operator as a candidate (VQ is empty).
ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet);
if (VisibleTypeConversionsQuals.hasVolatile()) {
// Add this built-in operator as a candidate (VQ is 'volatile').
ParamTypes[0] = ArithmeticTypes[Left];
ParamTypes[0] = Context.getVolatileType(ParamTypes[0]);
ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]);
AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet);
}
}
}
break;
case OO_Exclaim: {
// C++ [over.operator]p23:
//
// There also exist candidate operator functions of the form
//
// bool operator!(bool);
// bool operator&&(bool, bool); [BELOW]
// bool operator||(bool, bool); [BELOW]
QualType ParamTy = Context.BoolTy;
AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet,
/*IsAssignmentOperator=*/false,
/*NumContextualBoolArguments=*/1);
break;
}
case OO_AmpAmp:
case OO_PipePipe: {
// C++ [over.operator]p23:
//
// There also exist candidate operator functions of the form
//
// bool operator!(bool); [ABOVE]
// bool operator&&(bool, bool);
// bool operator||(bool, bool);
QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy };
AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet,
/*IsAssignmentOperator=*/false,
/*NumContextualBoolArguments=*/2);
break;
}
case OO_Subscript:
// C++ [over.built]p13:
//
// For every cv-qualified or cv-unqualified object type T there
// exist candidate operator functions of the form
//
// T* operator+(T*, ptrdiff_t); [ABOVE]
// T& operator[](T*, ptrdiff_t);
// T* operator-(T*, ptrdiff_t); [ABOVE]
// T* operator+(ptrdiff_t, T*); [ABOVE]
// T& operator[](ptrdiff_t, T*);
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() };
QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType();
QualType ResultTy = Context.getLValueReferenceType(PointeeType);
// T& operator[](T*, ptrdiff_t)
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
// T& operator[](ptrdiff_t, T*);
ParamTypes[0] = ParamTypes[1];
ParamTypes[1] = *Ptr;
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
}
break;
case OO_ArrowStar:
// C++ [over.built]p11:
// For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type,
// C1 is the same type as C2 or is a derived class of C2, T is an object
// type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
// there exist candidate operator functions of the form
// CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
// where CV12 is the union of CV1 and CV2.
{
for (BuiltinCandidateTypeSet::iterator Ptr =
CandidateTypes.pointer_begin();
Ptr != CandidateTypes.pointer_end(); ++Ptr) {
QualType C1Ty = (*Ptr);
QualType C1;
QualifierCollector Q1;
if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) {
C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0);
if (!isa<RecordType>(C1))
continue;
// heuristic to reduce number of builtin candidates in the set.
// Add volatile/restrict version only if there are conversions to a
// volatile/restrict type.
if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile())
continue;
if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict())
continue;
}
for (BuiltinCandidateTypeSet::iterator
MemPtr = CandidateTypes.member_pointer_begin(),
MemPtrEnd = CandidateTypes.member_pointer_end();
MemPtr != MemPtrEnd; ++MemPtr) {
const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr);
QualType C2 = QualType(mptr->getClass(), 0);
C2 = C2.getUnqualifiedType();
if (C1 != C2 && !IsDerivedFrom(C1, C2))
break;
QualType ParamTypes[2] = { *Ptr, *MemPtr };
// build CV12 T&
QualType T = mptr->getPointeeType();
if (!VisibleTypeConversionsQuals.hasVolatile() &&
T.isVolatileQualified())
continue;
if (!VisibleTypeConversionsQuals.hasRestrict() &&
T.isRestrictQualified())
continue;
T = Q1.apply(T);
QualType ResultTy = Context.getLValueReferenceType(T);
AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet);
}
}
}
break;
case OO_Conditional:
// Note that we don't consider the first argument, since it has been
// contextually converted to bool long ago. The candidates below are
// therefore added as binary.
//
// C++ [over.built]p24:
// For every type T, where T is a pointer or pointer-to-member type,
// there exist candidate operator functions of the form
//
// T operator?(bool, T, T);
//
for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(),
E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
for (BuiltinCandidateTypeSet::iterator Ptr =
CandidateTypes.member_pointer_begin(),
E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) {
QualType ParamTypes[2] = { *Ptr, *Ptr };
AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet);
}
goto Conditional;
}
}
/// \brief Add function candidates found via argument-dependent lookup
/// to the set of overloading candidates.
///
/// This routine performs argument-dependent name lookup based on the
/// given function name (which may also be an operator name) and adds
/// all of the overload candidates found by ADL to the overload
/// candidate set (C++ [basic.lookup.argdep]).
void
Sema::AddArgumentDependentLookupCandidates(DeclarationName Name,
bool Operator,
Expr **Args, unsigned NumArgs,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
OverloadCandidateSet& CandidateSet,
bool PartialOverloading) {
ADLResult Fns;
// FIXME: This approach for uniquing ADL results (and removing
// redundant candidates from the set) relies on pointer-equality,
// which means we need to key off the canonical decl. However,
// always going back to the canonical decl might not get us the
// right set of default arguments. What default arguments are
// we supposed to consider on ADL candidates, anyway?
// FIXME: Pass in the explicit template arguments?
ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns);
// Erase all of the candidates we already knew about.
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
CandEnd = CandidateSet.end();
Cand != CandEnd; ++Cand)
if (Cand->Function) {
Fns.erase(Cand->Function);
if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate())
Fns.erase(FunTmpl);
}
// For each of the ADL candidates we found, add it to the overload
// set.
for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none);
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
if (ExplicitTemplateArgs)
continue;
AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet,
false, PartialOverloading);
} else
AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I),
FoundDecl, ExplicitTemplateArgs,
Args, NumArgs, CandidateSet);
}
}
/// isBetterOverloadCandidate - Determines whether the first overload
/// candidate is a better candidate than the second (C++ 13.3.3p1).
bool
Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1,
const OverloadCandidate& Cand2,
SourceLocation Loc) {
// Define viable functions to be better candidates than non-viable
// functions.
if (!Cand2.Viable)
return Cand1.Viable;
else if (!Cand1.Viable)
return false;
// C++ [over.match.best]p1:
//
// -- if F is a static member function, ICS1(F) is defined such
// that ICS1(F) is neither better nor worse than ICS1(G) for
// any function G, and, symmetrically, ICS1(G) is neither
// better nor worse than ICS1(F).
unsigned StartArg = 0;
if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument)
StartArg = 1;
// C++ [over.match.best]p1:
// A viable function F1 is defined to be a better function than another
// viable function F2 if for all arguments i, ICSi(F1) is not a worse
// conversion sequence than ICSi(F2), and then...
unsigned NumArgs = Cand1.Conversions.size();
assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
bool HasBetterConversion = false;
for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) {
switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx],
Cand2.Conversions[ArgIdx])) {
case ImplicitConversionSequence::Better:
// Cand1 has a better conversion sequence.
HasBetterConversion = true;
break;
case ImplicitConversionSequence::Worse:
// Cand1 can't be better than Cand2.
return false;
case ImplicitConversionSequence::Indistinguishable:
// Do nothing.
break;
}
}
// -- for some argument j, ICSj(F1) is a better conversion sequence than
// ICSj(F2), or, if not that,
if (HasBetterConversion)
return true;
// - F1 is a non-template function and F2 is a function template
// specialization, or, if not that,
if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) &&
Cand2.Function && Cand2.Function->getPrimaryTemplate())
return true;
// -- F1 and F2 are function template specializations, and the function
// template for F1 is more specialized than the template for F2
// according to the partial ordering rules described in 14.5.5.2, or,
// if not that,
if (Cand1.Function && Cand1.Function->getPrimaryTemplate() &&
Cand2.Function && Cand2.Function->getPrimaryTemplate())
if (FunctionTemplateDecl *BetterTemplate
= getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(),
Cand2.Function->getPrimaryTemplate(),
Loc,
isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion
: TPOC_Call))
return BetterTemplate == Cand1.Function->getPrimaryTemplate();
// -- the context is an initialization by user-defined conversion
// (see 8.5, 13.3.1.5) and the standard conversion sequence
// from the return type of F1 to the destination type (i.e.,
// the type of the entity being initialized) is a better
// conversion sequence than the standard conversion sequence
// from the return type of F2 to the destination type.
if (Cand1.Function && Cand2.Function &&
isa<CXXConversionDecl>(Cand1.Function) &&
isa<CXXConversionDecl>(Cand2.Function)) {
switch (CompareStandardConversionSequences(Cand1.FinalConversion,
Cand2.FinalConversion)) {
case ImplicitConversionSequence::Better:
// Cand1 has a better conversion sequence.
return true;
case ImplicitConversionSequence::Worse:
// Cand1 can't be better than Cand2.
return false;
case ImplicitConversionSequence::Indistinguishable:
// Do nothing
break;
}
}
return false;
}
/// \brief Computes the best viable function (C++ 13.3.3)
/// within an overload candidate set.
///
/// \param CandidateSet the set of candidate functions.
///
/// \param Loc the location of the function name (or operator symbol) for
/// which overload resolution occurs.
///
/// \param Best f overload resolution was successful or found a deleted
/// function, Best points to the candidate function found.
///
/// \returns The result of overload resolution.
OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet,
SourceLocation Loc,
OverloadCandidateSet::iterator& Best) {
// Find the best viable function.
Best = CandidateSet.end();
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand) {
if (Cand->Viable) {
if (Best == CandidateSet.end() ||
isBetterOverloadCandidate(*Cand, *Best, Loc))
Best = Cand;
}
}
// If we didn't find any viable functions, abort.
if (Best == CandidateSet.end())
return OR_No_Viable_Function;
// Make sure that this function is better than every other viable
// function. If not, we have an ambiguity.
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
Cand != CandidateSet.end(); ++Cand) {
if (Cand->Viable &&
Cand != Best &&
!isBetterOverloadCandidate(*Best, *Cand, Loc)) {
Best = CandidateSet.end();
return OR_Ambiguous;
}
}
// Best is the best viable function.
if (Best->Function &&
(Best->Function->isDeleted() ||
Best->Function->getAttr<UnavailableAttr>()))
return OR_Deleted;
// C++ [basic.def.odr]p2:
// An overloaded function is used if it is selected by overload resolution
// when referred to from a potentially-evaluated expression. [Note: this
// covers calls to named functions (5.2.2), operator overloading
// (clause 13), user-defined conversions (12.3.2), allocation function for
// placement new (5.3.4), as well as non-default initialization (8.5).
if (Best->Function)
MarkDeclarationReferenced(Loc, Best->Function);
return OR_Success;
}
namespace {
enum OverloadCandidateKind {
oc_function,
oc_method,
oc_constructor,
oc_function_template,
oc_method_template,
oc_constructor_template,
oc_implicit_default_constructor,
oc_implicit_copy_constructor,
oc_implicit_copy_assignment
};
OverloadCandidateKind ClassifyOverloadCandidate(Sema &S,
FunctionDecl *Fn,
std::string &Description) {
bool isTemplate = false;
if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) {
isTemplate = true;
Description = S.getTemplateArgumentBindingsText(
FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs());
}
if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) {
if (!Ctor->isImplicit())
return isTemplate ? oc_constructor_template : oc_constructor;
return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor
: oc_implicit_default_constructor;
}
if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) {
// This actually gets spelled 'candidate function' for now, but
// it doesn't hurt to split it out.
if (!Meth->isImplicit())
return isTemplate ? oc_method_template : oc_method;
assert(Meth->isCopyAssignment()
&& "implicit method is not copy assignment operator?");
return oc_implicit_copy_assignment;
}
return isTemplate ? oc_function_template : oc_function;
}
} // end anonymous namespace
// Notes the location of an overload candidate.
void Sema::NoteOverloadCandidate(FunctionDecl *Fn) {
std::string FnDesc;
OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc);
Diag(Fn->getLocation(), diag::note_ovl_candidate)
<< (unsigned) K << FnDesc;
}
/// Diagnoses an ambiguous conversion. The partial diagnostic is the
/// "lead" diagnostic; it will be given two arguments, the source and
/// target types of the conversion.
void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS,
SourceLocation CaretLoc,
const PartialDiagnostic &PDiag) {
Diag(CaretLoc, PDiag)
<< ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType();
for (AmbiguousConversionSequence::const_iterator
I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) {
NoteOverloadCandidate(*I);
}
}
namespace {
void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) {
const ImplicitConversionSequence &Conv = Cand->Conversions[I];
assert(Conv.isBad());
assert(Cand->Function && "for now, candidate must be a function");
FunctionDecl *Fn = Cand->Function;
// There's a conversion slot for the object argument if this is a
// non-constructor method. Note that 'I' corresponds the
// conversion-slot index.
bool isObjectArgument = false;
if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) {
if (I == 0)
isObjectArgument = true;
else
I--;
}
std::string FnDesc;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
Expr *FromExpr = Conv.Bad.FromExpr;
QualType FromTy = Conv.Bad.getFromType();
QualType ToTy = Conv.Bad.getToType();
if (FromTy == S.Context.OverloadTy) {
assert(FromExpr && "overload set argument came from implicit argument?");
Expr *E = FromExpr->IgnoreParens();
if (isa<UnaryOperator>(E))
E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
DeclarationName Name = cast<OverloadExpr>(E)->getName();
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< ToTy << Name << I+1;
return;
}
// Do some hand-waving analysis to see if the non-viability is due
// to a qualifier mismatch.
CanQualType CFromTy = S.Context.getCanonicalType(FromTy);
CanQualType CToTy = S.Context.getCanonicalType(ToTy);
if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>())
CToTy = RT->getPointeeType();
else {
// TODO: detect and diagnose the full richness of const mismatches.
if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>())
if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>())
CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType();
}
if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() &&
!CToTy.isAtLeastAsQualifiedAs(CFromTy)) {
// It is dumb that we have to do this here.
while (isa<ArrayType>(CFromTy))
CFromTy = CFromTy->getAs<ArrayType>()->getElementType();
while (isa<ArrayType>(CToTy))
CToTy = CFromTy->getAs<ArrayType>()->getElementType();
Qualifiers FromQs = CFromTy.getQualifiers();
Qualifiers ToQs = CToTy.getQualifiers();
if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy
<< FromQs.getAddressSpace() << ToQs.getAddressSpace()
<< (unsigned) isObjectArgument << I+1;
return;
}
unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
assert(CVR && "unexpected qualifiers mismatch");
if (isObjectArgument) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << (CVR - 1);
} else {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << (CVR - 1) << I+1;
}
return;
}
// Diagnose references or pointers to incomplete types differently,
// since it's far from impossible that the incompleteness triggered
// the failure.
QualType TempFromTy = FromTy.getNonReferenceType();
if (const PointerType *PTy = TempFromTy->getAs<PointerType>())
TempFromTy = PTy->getPointeeType();
if (TempFromTy->isIncompleteType()) {
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << ToTy << (unsigned) isObjectArgument << I+1;
return;
}
// TODO: specialize more based on the kind of mismatch
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv)
<< (unsigned) FnKind << FnDesc
<< (FromExpr ? FromExpr->getSourceRange() : SourceRange())
<< FromTy << ToTy << (unsigned) isObjectArgument << I+1;
}
void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand,
unsigned NumFormalArgs) {
// TODO: treat calls to a missing default constructor as a special case
FunctionDecl *Fn = Cand->Function;
const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>();
unsigned MinParams = Fn->getMinRequiredArguments();
// at least / at most / exactly
// FIXME: variadic templates "at most" should account for parameter packs
unsigned mode, modeCount;
if (NumFormalArgs < MinParams) {
assert((Cand->FailureKind == ovl_fail_too_few_arguments) ||
(Cand->FailureKind == ovl_fail_bad_deduction &&
Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments));
if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic())
mode = 0; // "at least"
else
mode = 2; // "exactly"
modeCount = MinParams;
} else {
assert((Cand->FailureKind == ovl_fail_too_many_arguments) ||
(Cand->FailureKind == ovl_fail_bad_deduction &&
Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments));
if (MinParams != FnTy->getNumArgs())
mode = 1; // "at most"
else
mode = 2; // "exactly"
modeCount = FnTy->getNumArgs();
}
std::string Description;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity)
<< (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode
<< modeCount << NumFormalArgs;
}
/// Diagnose a failed template-argument deduction.
void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
FunctionDecl *Fn = Cand->Function; // pattern
TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter();
NamedDecl *ParamD;
(ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) ||
(ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) ||
(ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>());
switch (Cand->DeductionFailure.Result) {
case Sema::TDK_Success:
llvm_unreachable("TDK_success while diagnosing bad deduction");
case Sema::TDK_Incomplete: {
assert(ParamD && "no parameter found for incomplete deduction result");
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction)
<< ParamD->getDeclName();
return;
}
case Sema::TDK_Inconsistent:
case Sema::TDK_InconsistentQuals: {
assert(ParamD && "no parameter found for inconsistent deduction result");
int which = 0;
if (isa<TemplateTypeParmDecl>(ParamD))
which = 0;
else if (isa<NonTypeTemplateParmDecl>(ParamD))
which = 1;
else {
which = 2;
}
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction)
<< which << ParamD->getDeclName()
<< *Cand->DeductionFailure.getFirstArg()
<< *Cand->DeductionFailure.getSecondArg();
return;
}
case Sema::TDK_InvalidExplicitArguments:
assert(ParamD && "no parameter found for invalid explicit arguments");
if (ParamD->getDeclName())
S.Diag(Fn->getLocation(),
diag::note_ovl_candidate_explicit_arg_mismatch_named)
<< ParamD->getDeclName();
else {
int index = 0;
if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD))
index = TTP->getIndex();
else if (NonTypeTemplateParmDecl *NTTP
= dyn_cast<NonTypeTemplateParmDecl>(ParamD))
index = NTTP->getIndex();
else
index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex();
S.Diag(Fn->getLocation(),
diag::note_ovl_candidate_explicit_arg_mismatch_unnamed)
<< (index + 1);
}
return;
case Sema::TDK_TooManyArguments:
case Sema::TDK_TooFewArguments:
DiagnoseArityMismatch(S, Cand, NumArgs);
return;
case Sema::TDK_InstantiationDepth:
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth);
return;
case Sema::TDK_SubstitutionFailure: {
std::string ArgString;
if (TemplateArgumentList *Args
= Cand->DeductionFailure.getTemplateArgumentList())
ArgString = S.getTemplateArgumentBindingsText(
Fn->getDescribedFunctionTemplate()->getTemplateParameters(),
*Args);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure)
<< ArgString;
return;
}
// TODO: diagnose these individually, then kill off
// note_ovl_candidate_bad_deduction, which is uselessly vague.
case Sema::TDK_NonDeducedMismatch:
case Sema::TDK_FailedOverloadResolution:
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction);
return;
}
}
/// Generates a 'note' diagnostic for an overload candidate. We've
/// already generated a primary error at the call site.
///
/// It really does need to be a single diagnostic with its caret
/// pointed at the candidate declaration. Yes, this creates some
/// major challenges of technical writing. Yes, this makes pointing
/// out problems with specific arguments quite awkward. It's still
/// better than generating twenty screens of text for every failed
/// overload.
///
/// It would be great to be able to express per-candidate problems
/// more richly for those diagnostic clients that cared, but we'd
/// still have to be just as careful with the default diagnostics.
void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
FunctionDecl *Fn = Cand->Function;
// Note deleted candidates, but only if they're viable.
if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) {
std::string FnDesc;
OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc);
S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted)
<< FnKind << FnDesc << Fn->isDeleted();
return;
}
// We don't really have anything else to say about viable candidates.
if (Cand->Viable) {
S.NoteOverloadCandidate(Fn);
return;
}
switch (Cand->FailureKind) {
case ovl_fail_too_many_arguments:
case ovl_fail_too_few_arguments:
return DiagnoseArityMismatch(S, Cand, NumArgs);
case ovl_fail_bad_deduction:
return DiagnoseBadDeduction(S, Cand, Args, NumArgs);
case ovl_fail_trivial_conversion:
case ovl_fail_bad_final_conversion:
case ovl_fail_final_conversion_not_exact:
return S.NoteOverloadCandidate(Fn);
case ovl_fail_bad_conversion: {
unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0);
for (unsigned N = Cand->Conversions.size(); I != N; ++I)
if (Cand->Conversions[I].isBad())
return DiagnoseBadConversion(S, Cand, I);
// FIXME: this currently happens when we're called from SemaInit
// when user-conversion overload fails. Figure out how to handle
// those conditions and diagnose them well.
return S.NoteOverloadCandidate(Fn);
}
}
}
void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) {
// Desugar the type of the surrogate down to a function type,
// retaining as many typedefs as possible while still showing
// the function type (and, therefore, its parameter types).
QualType FnType = Cand->Surrogate->getConversionType();
bool isLValueReference = false;
bool isRValueReference = false;
bool isPointer = false;
if (const LValueReferenceType *FnTypeRef =
FnType->getAs<LValueReferenceType>()) {
FnType = FnTypeRef->getPointeeType();
isLValueReference = true;
} else if (const RValueReferenceType *FnTypeRef =
FnType->getAs<RValueReferenceType>()) {
FnType = FnTypeRef->getPointeeType();
isRValueReference = true;
}
if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) {
FnType = FnTypePtr->getPointeeType();
isPointer = true;
}
// Desugar down to a function type.
FnType = QualType(FnType->getAs<FunctionType>(), 0);
// Reconstruct the pointer/reference as appropriate.
if (isPointer) FnType = S.Context.getPointerType(FnType);
if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType);
if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType);
S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand)
<< FnType;
}
void NoteBuiltinOperatorCandidate(Sema &S,
const char *Opc,
SourceLocation OpLoc,
OverloadCandidate *Cand) {
assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary");
std::string TypeStr("operator");
TypeStr += Opc;
TypeStr += "(";
TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString();
if (Cand->Conversions.size() == 1) {
TypeStr += ")";
S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr;
} else {
TypeStr += ", ";
TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString();
TypeStr += ")";
S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr;
}
}
void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc,
OverloadCandidate *Cand) {
unsigned NoOperands = Cand->Conversions.size();
for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) {
const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx];
if (ICS.isBad()) break; // all meaningless after first invalid
if (!ICS.isAmbiguous()) continue;
S.DiagnoseAmbiguousConversion(ICS, OpLoc,
S.PDiag(diag::note_ambiguous_type_conversion));
}
}
SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) {
if (Cand->Function)
return Cand->Function->getLocation();
if (Cand->IsSurrogate)
return Cand->Surrogate->getLocation();
return SourceLocation();
}
struct CompareOverloadCandidatesForDisplay {
Sema &S;
CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {}
bool operator()(const OverloadCandidate *L,
const OverloadCandidate *R) {
// Fast-path this check.
if (L == R) return false;
// Order first by viability.
if (L->Viable) {
if (!R->Viable) return true;
// TODO: introduce a tri-valued comparison for overload
// candidates. Would be more worthwhile if we had a sort
// that could exploit it.
if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true;
if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false;
} else if (R->Viable)
return false;
assert(L->Viable == R->Viable);
// Criteria by which we can sort non-viable candidates:
if (!L->Viable) {
// 1. Arity mismatches come after other candidates.
if (L->FailureKind == ovl_fail_too_many_arguments ||
L->FailureKind == ovl_fail_too_few_arguments)
return false;
if (R->FailureKind == ovl_fail_too_many_arguments ||
R->FailureKind == ovl_fail_too_few_arguments)
return true;
// 2. Bad conversions come first and are ordered by the number
// of bad conversions and quality of good conversions.
if (L->FailureKind == ovl_fail_bad_conversion) {
if (R->FailureKind != ovl_fail_bad_conversion)
return true;
// If there's any ordering between the defined conversions...
// FIXME: this might not be transitive.
assert(L->Conversions.size() == R->Conversions.size());
int leftBetter = 0;
unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument);
for (unsigned E = L->Conversions.size(); I != E; ++I) {
switch (S.CompareImplicitConversionSequences(L->Conversions[I],
R->Conversions[I])) {
case ImplicitConversionSequence::Better:
leftBetter++;
break;
case ImplicitConversionSequence::Worse:
leftBetter--;
break;
case ImplicitConversionSequence::Indistinguishable:
break;
}
}
if (leftBetter > 0) return true;
if (leftBetter < 0) return false;
} else if (R->FailureKind == ovl_fail_bad_conversion)
return false;
// TODO: others?
}
// Sort everything else by location.
SourceLocation LLoc = GetLocationForCandidate(L);
SourceLocation RLoc = GetLocationForCandidate(R);
// Put candidates without locations (e.g. builtins) at the end.
if (LLoc.isInvalid()) return false;
if (RLoc.isInvalid()) return true;
return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc);
}
};
/// CompleteNonViableCandidate - Normally, overload resolution only
/// computes up to the first
void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand,
Expr **Args, unsigned NumArgs) {
assert(!Cand->Viable);
// Don't do anything on failures other than bad conversion.
if (Cand->FailureKind != ovl_fail_bad_conversion) return;
// Skip forward to the first bad conversion.
unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0);
unsigned ConvCount = Cand->Conversions.size();
while (true) {
assert(ConvIdx != ConvCount && "no bad conversion in candidate");
ConvIdx++;
if (Cand->Conversions[ConvIdx - 1].isBad())
break;
}
if (ConvIdx == ConvCount)
return;
assert(!Cand->Conversions[ConvIdx].isInitialized() &&
"remaining conversion is initialized?");
// FIXME: this should probably be preserved from the overload
// operation somehow.
bool SuppressUserConversions = false;
const FunctionProtoType* Proto;
unsigned ArgIdx = ConvIdx;
if (Cand->IsSurrogate) {
QualType ConvType
= Cand->Surrogate->getConversionType().getNonReferenceType();
if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
ConvType = ConvPtrType->getPointeeType();
Proto = ConvType->getAs<FunctionProtoType>();
ArgIdx--;
} else if (Cand->Function) {
Proto = Cand->Function->getType()->getAs<FunctionProtoType>();
if (isa<CXXMethodDecl>(Cand->Function) &&
!isa<CXXConstructorDecl>(Cand->Function))
ArgIdx--;
} else {
// Builtin binary operator with a bad first conversion.
assert(ConvCount <= 3);
for (; ConvIdx != ConvCount; ++ConvIdx)
Cand->Conversions[ConvIdx]
= TryCopyInitialization(S, Args[ConvIdx],
Cand->BuiltinTypes.ParamTypes[ConvIdx],
SuppressUserConversions,
/*InOverloadResolution*/ true);
return;
}
// Fill in the rest of the conversions.
unsigned NumArgsInProto = Proto->getNumArgs();
for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) {
if (ArgIdx < NumArgsInProto)
Cand->Conversions[ConvIdx]
= TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx),
SuppressUserConversions,
/*InOverloadResolution=*/true);
else
Cand->Conversions[ConvIdx].setEllipsis();
}
}
} // end anonymous namespace
/// PrintOverloadCandidates - When overload resolution fails, prints
/// diagnostic messages containing the candidates in the candidate
/// set.
void
Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet,
OverloadCandidateDisplayKind OCD,
Expr **Args, unsigned NumArgs,
const char *Opc,
SourceLocation OpLoc) {
// Sort the candidates by viability and position. Sorting directly would
// be prohibitive, so we make a set of pointers and sort those.
llvm::SmallVector<OverloadCandidate*, 32> Cands;
if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size());
for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
LastCand = CandidateSet.end();
Cand != LastCand; ++Cand) {
if (Cand->Viable)
Cands.push_back(Cand);
else if (OCD == OCD_AllCandidates) {
CompleteNonViableCandidate(*this, Cand, Args, NumArgs);
if (Cand->Function || Cand->IsSurrogate)
Cands.push_back(Cand);
// Otherwise, this a non-viable builtin candidate. We do not, in general,
// want to list every possible builtin candidate.
}
}
std::sort(Cands.begin(), Cands.end(),
CompareOverloadCandidatesForDisplay(*this));
bool ReportedAmbiguousConversions = false;
llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E;
const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads();
unsigned CandsShown = 0;
for (I = Cands.begin(), E = Cands.end(); I != E; ++I) {
OverloadCandidate *Cand = *I;
// Set an arbitrary limit on the number of candidate functions we'll spam
// the user with. FIXME: This limit should depend on details of the
// candidate list.
if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) {
break;
}
++CandsShown;
if (Cand->Function)
NoteFunctionCandidate(*this, Cand, Args, NumArgs);
else if (Cand->IsSurrogate)
NoteSurrogateCandidate(*this, Cand);
else {
assert(Cand->Viable &&
"Non-viable built-in candidates are not added to Cands.");
// Generally we only see ambiguities including viable builtin
// operators if overload resolution got screwed up by an
// ambiguous user-defined conversion.
//
// FIXME: It's quite possible for different conversions to see
// different ambiguities, though.
if (!ReportedAmbiguousConversions) {
NoteAmbiguousUserConversions(*this, OpLoc, Cand);
ReportedAmbiguousConversions = true;
}
// If this is a viable builtin, print it.
NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand);
}
}
if (I != E)
Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I);
}
static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) {
if (isa<UnresolvedLookupExpr>(E))
return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D);
return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D);
}
/// ResolveAddressOfOverloadedFunction - Try to resolve the address of
/// an overloaded function (C++ [over.over]), where @p From is an
/// expression with overloaded function type and @p ToType is the type
/// we're trying to resolve to. For example:
///
/// @code
/// int f(double);
/// int f(int);
///
/// int (*pfd)(double) = f; // selects f(double)
/// @endcode
///
/// This routine returns the resulting FunctionDecl if it could be
/// resolved, and NULL otherwise. When @p Complain is true, this
/// routine will emit diagnostics if there is an error.
FunctionDecl *
Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType,
bool Complain,
DeclAccessPair &FoundResult) {
QualType FunctionType = ToType;
bool IsMember = false;
if (const PointerType *ToTypePtr = ToType->getAs<PointerType>())
FunctionType = ToTypePtr->getPointeeType();
else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>())
FunctionType = ToTypeRef->getPointeeType();
else if (const MemberPointerType *MemTypePtr =
ToType->getAs<MemberPointerType>()) {
FunctionType = MemTypePtr->getPointeeType();
IsMember = true;
}
// C++ [over.over]p1:
// [...] [Note: any redundant set of parentheses surrounding the
// overloaded function name is ignored (5.1). ]
// C++ [over.over]p1:
// [...] The overloaded function name can be preceded by the &
// operator.
OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer();
TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0;
if (OvlExpr->hasExplicitTemplateArgs()) {
OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer);
ExplicitTemplateArgs = &ETABuffer;
}
// We expect a pointer or reference to function, or a function pointer.
FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType();
if (!FunctionType->isFunctionType()) {
if (Complain)
Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref)
<< OvlExpr->getName() << ToType;
return 0;
}
assert(From->getType() == Context.OverloadTy);
// Look through all of the overloaded functions, searching for one
// whose type matches exactly.
llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches;
llvm::SmallVector<FunctionDecl *, 4> NonMatches;
bool FoundNonTemplateFunction = false;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end(); I != E; ++I) {
// Look through any using declarations to find the underlying function.
NamedDecl *Fn = (*I)->getUnderlyingDecl();
// C++ [over.over]p3:
// Non-member functions and static member functions match
// targets of type "pointer-to-function" or "reference-to-function."
// Nonstatic member functions match targets of
// type "pointer-to-member-function."
// Note that according to DR 247, the containing class does not matter.
if (FunctionTemplateDecl *FunctionTemplate
= dyn_cast<FunctionTemplateDecl>(Fn)) {
if (CXXMethodDecl *Method
= dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) {
// Skip non-static function templates when converting to pointer, and
// static when converting to member pointer.
if (Method->isStatic() == IsMember)
continue;
} else if (IsMember)
continue;
// C++ [over.over]p2:
// If the name is a function template, template argument deduction is
// done (14.8.2.2), and if the argument deduction succeeds, the
// resulting template argument list is used to generate a single
// function template specialization, which is added to the set of
// overloaded functions considered.
// FIXME: We don't really want to build the specialization here, do we?
FunctionDecl *Specialization = 0;
TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc());
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs,
FunctionType, Specialization, Info)) {
// FIXME: make a note of the failed deduction for diagnostics.
(void)Result;
} else {
// FIXME: If the match isn't exact, shouldn't we just drop this as
// a candidate? Find a testcase before changing the code.
assert(FunctionType
== Context.getCanonicalType(Specialization->getType()));
Matches.push_back(std::make_pair(I.getPair(),
cast<FunctionDecl>(Specialization->getCanonicalDecl())));
}
continue;
}
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
// Skip non-static functions when converting to pointer, and static
// when converting to member pointer.
if (Method->isStatic() == IsMember)
continue;
// If we have explicit template arguments, skip non-templates.
if (OvlExpr->hasExplicitTemplateArgs())
continue;
} else if (IsMember)
continue;
if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) {
QualType ResultTy;
if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) ||
IsNoReturnConversion(Context, FunDecl->getType(), FunctionType,
ResultTy)) {
Matches.push_back(std::make_pair(I.getPair(),
cast<FunctionDecl>(FunDecl->getCanonicalDecl())));
FoundNonTemplateFunction = true;
}
}
}
// If there were 0 or 1 matches, we're done.
if (Matches.empty()) {
if (Complain) {
Diag(From->getLocStart(), diag::err_addr_ovl_no_viable)
<< OvlExpr->getName() << FunctionType;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end();
I != E; ++I)
if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()))
NoteOverloadCandidate(F);
}
return 0;
} else if (Matches.size() == 1) {
FunctionDecl *Result = Matches[0].second;
FoundResult = Matches[0].first;
MarkDeclarationReferenced(From->getLocStart(), Result);
if (Complain)
CheckAddressOfMemberAccess(OvlExpr, Matches[0].first);
return Result;
}
// C++ [over.over]p4:
// If more than one function is selected, [...]
if (!FoundNonTemplateFunction) {
// [...] and any given function template specialization F1 is
// eliminated if the set contains a second function template
// specialization whose function template is more specialized
// than the function template of F1 according to the partial
// ordering rules of 14.5.5.2.
// The algorithm specified above is quadratic. We instead use a
// two-pass algorithm (similar to the one used to identify the
// best viable function in an overload set) that identifies the
// best function template (if it exists).
UnresolvedSet<4> MatchesCopy; // TODO: avoid!
for (unsigned I = 0, E = Matches.size(); I != E; ++I)
MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess());
UnresolvedSetIterator Result =
getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(),
TPOC_Other, From->getLocStart(),
PDiag(),
PDiag(diag::err_addr_ovl_ambiguous)
<< Matches[0].second->getDeclName(),
PDiag(diag::note_ovl_candidate)
<< (unsigned) oc_function_template);
assert(Result != MatchesCopy.end() && "no most-specialized template");
MarkDeclarationReferenced(From->getLocStart(), *Result);
FoundResult = Matches[Result - MatchesCopy.begin()].first;
if (Complain) {
CheckUnresolvedAccess(*this, OvlExpr, FoundResult);
DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc());
}
return cast<FunctionDecl>(*Result);
}
// [...] any function template specializations in the set are
// eliminated if the set also contains a non-template function, [...]
for (unsigned I = 0, N = Matches.size(); I != N; ) {
if (Matches[I].second->getPrimaryTemplate() == 0)
++I;
else {
Matches[I] = Matches[--N];
Matches.set_size(N);
}
}
// [...] After such eliminations, if any, there shall remain exactly one
// selected function.
if (Matches.size() == 1) {
MarkDeclarationReferenced(From->getLocStart(), Matches[0].second);
FoundResult = Matches[0].first;
if (Complain) {
CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first);
DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc());
}
return cast<FunctionDecl>(Matches[0].second);
}
// FIXME: We should probably return the same thing that BestViableFunction
// returns (even if we issue the diagnostics here).
Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous)
<< Matches[0].second->getDeclName();
for (unsigned I = 0, E = Matches.size(); I != E; ++I)
NoteOverloadCandidate(Matches[I].second);
return 0;
}
/// \brief Given an expression that refers to an overloaded function, try to
/// resolve that overloaded function expression down to a single function.
///
/// This routine can only resolve template-ids that refer to a single function
/// template, where that template-id refers to a single template whose template
/// arguments are either provided by the template-id or have defaults,
/// as described in C++0x [temp.arg.explicit]p3.
FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) {
// C++ [over.over]p1:
// [...] [Note: any redundant set of parentheses surrounding the
// overloaded function name is ignored (5.1). ]
// C++ [over.over]p1:
// [...] The overloaded function name can be preceded by the &
// operator.
if (From->getType() != Context.OverloadTy)
return 0;
OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer();
// If we didn't actually find any template-ids, we're done.
if (!OvlExpr->hasExplicitTemplateArgs())
return 0;
TemplateArgumentListInfo ExplicitTemplateArgs;
OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs);
// Look through all of the overloaded functions, searching for one
// whose type matches exactly.
FunctionDecl *Matched = 0;
for (UnresolvedSetIterator I = OvlExpr->decls_begin(),
E = OvlExpr->decls_end(); I != E; ++I) {
// C++0x [temp.arg.explicit]p3:
// [...] In contexts where deduction is done and fails, or in contexts
// where deduction is not done, if a template argument list is
// specified and it, along with any default template arguments,
// identifies a single function template specialization, then the
// template-id is an lvalue for the function template specialization.
FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I);
// C++ [over.over]p2:
// If the name is a function template, template argument deduction is
// done (14.8.2.2), and if the argument deduction succeeds, the
// resulting template argument list is used to generate a single
// function template specialization, which is added to the set of
// overloaded functions considered.
FunctionDecl *Specialization = 0;
TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc());
if (TemplateDeductionResult Result
= DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs,
Specialization, Info)) {
// FIXME: make a note of the failed deduction for diagnostics.
(void)Result;
continue;
}
// Multiple matches; we can't resolve to a single declaration.
if (Matched)
return 0;
Matched = Specialization;
}
return Matched;
}
/// \brief Add a single candidate to the overload set.
static void AddOverloadedCallCandidate(Sema &S,
DeclAccessPair FoundDecl,
const TemplateArgumentListInfo *ExplicitTemplateArgs,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet &CandidateSet,
bool PartialOverloading) {
NamedDecl *Callee = FoundDecl.getDecl();
if (isa<UsingShadowDecl>(Callee))
Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl();
if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) {
assert(!ExplicitTemplateArgs && "Explicit template arguments?");
S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet,
false, PartialOverloading);
return;
}
if (FunctionTemplateDecl *FuncTemplate
= dyn_cast<FunctionTemplateDecl>(Callee)) {
S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl,
ExplicitTemplateArgs,
Args, NumArgs, CandidateSet);
return;
}
assert(false && "unhandled case in overloaded call candidate");
// do nothing?
}
/// \brief Add the overload candidates named by callee and/or found by argument
/// dependent lookup to the given overload set.
void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
Expr **Args, unsigned NumArgs,
OverloadCandidateSet &CandidateSet,
bool PartialOverloading) {
#ifndef NDEBUG
// Verify that ArgumentDependentLookup is consistent with the rules
// in C++0x [basic.lookup.argdep]p3:
//
// Let X be the lookup set produced by unqualified lookup (3.4.1)
// and let Y be the lookup set produced by argument dependent
// lookup (defined as follows). If X contains
//
// -- a declaration of a class member, or
//
// -- a block-scope function declaration that is not a
// using-declaration, or
//
// -- a declaration that is neither a function or a function
// template
//
// then Y is empty.
if (ULE->requiresADL()) {
for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
E = ULE->decls_end(); I != E; ++I) {
assert(!(*I)->getDeclContext()->isRecord());
assert(isa<UsingShadowDecl>(*I) ||
!(*I)->getDeclContext()->isFunctionOrMethod());
assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate());
}
}
#endif
// It would be nice to avoid this copy.
TemplateArgumentListInfo TABuffer;
const TemplateArgumentListInfo *ExplicitTemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TABuffer);
ExplicitTemplateArgs = &TABuffer;
}
for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(),
E = ULE->decls_end(); I != E; ++I)
AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs,
Args, NumArgs, CandidateSet,
PartialOverloading);
if (ULE->requiresADL())
AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false,
Args, NumArgs,
ExplicitTemplateArgs,
CandidateSet,
PartialOverloading);
}
static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn,
Expr **Args, unsigned NumArgs) {
Fn->Destroy(SemaRef.Context);
for (unsigned Arg = 0; Arg < NumArgs; ++Arg)
Args[Arg]->Destroy(SemaRef.Context);
return SemaRef.ExprError();
}
/// Attempts to recover from a call where no functions were found.
///
/// Returns true if new candidates were found.
static Sema::OwningExprResult
BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
UnresolvedLookupExpr *ULE,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
CXXScopeSpec SS;
if (ULE->getQualifier()) {
SS.setScopeRep(ULE->getQualifier());
SS.setRange(ULE->getQualifierRange());
}
TemplateArgumentListInfo TABuffer;
const TemplateArgumentListInfo *ExplicitTemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TABuffer);
ExplicitTemplateArgs = &TABuffer;
}
LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(),
Sema::LookupOrdinaryName);
if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression))
return Destroy(SemaRef, Fn, Args, NumArgs);
assert(!R.empty() && "lookup results empty despite recovery");
// Build an implicit member call if appropriate. Just drop the
// casts and such from the call, we don't really care.
Sema::OwningExprResult NewFn = SemaRef.ExprError();
if ((*R.begin())->isCXXClassMember())
NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs);
else if (ExplicitTemplateArgs)
NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs);
else
NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false);
if (NewFn.isInvalid())
return Destroy(SemaRef, Fn, Args, NumArgs);
Fn->Destroy(SemaRef.Context);
// This shouldn't cause an infinite loop because we're giving it
// an expression with non-empty lookup results, which should never
// end up here.
return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc,
Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs),
CommaLocs, RParenLoc);
}
/// ResolveOverloadedCallFn - Given the call expression that calls Fn
/// (which eventually refers to the declaration Func) and the call
/// arguments Args/NumArgs, attempt to resolve the function call down
/// to a specific function. If overload resolution succeeds, returns
/// the function declaration produced by overload
/// resolution. Otherwise, emits diagnostics, deletes all of the
/// arguments and Fn, and returns NULL.
Sema::OwningExprResult
Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
#ifndef NDEBUG
if (ULE->requiresADL()) {
// To do ADL, we must have found an unqualified name.
assert(!ULE->getQualifier() && "qualified name with ADL");
// We don't perform ADL for implicit declarations of builtins.
// Verify that this was correctly set up.
FunctionDecl *F;
if (ULE->decls_begin() + 1 == ULE->decls_end() &&
(F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) &&
F->getBuiltinID() && F->isImplicit())
assert(0 && "performing ADL for builtin");
// We don't perform ADL in C.
assert(getLangOptions().CPlusPlus && "ADL enabled in C");
}
#endif
OverloadCandidateSet CandidateSet(Fn->getExprLoc());
// Add the functions denoted by the callee to the set of candidate
// functions, including those from argument-dependent lookup.
AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet);
// If we found nothing, try to recover.
// AddRecoveryCallCandidates diagnoses the error itself, so we just
// bailout out if it fails.
if (CandidateSet.empty())
return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs,
CommaLocs, RParenLoc);
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) {
case OR_Success: {
FunctionDecl *FDecl = Best->Function;
CheckUnresolvedLookupAccess(ULE, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc());
Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl);
return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc);
}
case OR_No_Viable_Function:
Diag(Fn->getSourceRange().getBegin(),
diag::err_ovl_no_viable_function_in_call)
<< ULE->getName() << Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
case OR_Ambiguous:
Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call)
<< ULE->getName() << Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs);
break;
case OR_Deleted:
Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call)
<< Best->Function->isDeleted()
<< ULE->getName()
<< Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
}
// Overload resolution failed. Destroy all of the subexpressions and
// return NULL.
Fn->Destroy(Context);
for (unsigned Arg = 0; Arg < NumArgs; ++Arg)
Args[Arg]->Destroy(Context);
return ExprError();
}
static bool IsOverloaded(const UnresolvedSetImpl &Functions) {
return Functions.size() > 1 ||
(Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
}
/// \brief Create a unary operation that may resolve to an overloaded
/// operator.
///
/// \param OpLoc The location of the operator itself (e.g., '*').
///
/// \param OpcIn The UnaryOperator::Opcode that describes this
/// operator.
///
/// \param Functions The set of non-member functions that will be
/// considered by overload resolution. The caller needs to build this
/// set based on the context using, e.g.,
/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
/// set should not contain any member functions; those will be added
/// by CreateOverloadedUnaryOp().
///
/// \param input The input argument.
Sema::OwningExprResult
Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn,
const UnresolvedSetImpl &Fns,
ExprArg input) {
UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn);
Expr *Input = (Expr *)input.get();
OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
Expr *Args[2] = { Input, 0 };
unsigned NumArgs = 1;
// For post-increment and post-decrement, add the implicit '0' as
// the second argument, so that we know this is a post-increment or
// post-decrement.
if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) {
llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy,
SourceLocation());
NumArgs = 2;
}
if (Input->isTypeDependent()) {
if (Fns.empty())
return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(),
Opc,
Context.DependentTy,
OpLoc));
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, OpLoc,
/*ADL*/ true, IsOverloaded(Fns),
Fns.begin(), Fns.end());
input.release();
return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
&Args[0], NumArgs,
Context.DependentTy,
OpLoc));
}
// Build an empty overload set.
OverloadCandidateSet CandidateSet(OpLoc);
// Add the candidates from the given function set.
AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false);
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet);
// Add candidates from ADL.
AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
Args, NumArgs,
/*ExplicitTemplateArgs*/ 0,
CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
// Convert the arguments.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl);
if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
} else {
// Convert the arguments.
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
move(input));
if (InputInit.isInvalid())
return ExprError();
input = move(InputInit);
Input = (Expr *)input.get();
}
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Determine the result type
QualType ResultTy = FnDecl->getResultType().getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
SourceLocation());
UsualUnaryConversions(FnExpr);
input.release();
Args[0] = Input;
ExprOwningPtr<CallExpr> TheCall(this,
new (Context) CXXOperatorCallExpr(Context, Op, FnExpr,
Args, NumArgs, ResultTy, OpLoc));
if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function:
// No viable function; fall through to handling this as a
// built-in operator, which will produce an error message for us.
break;
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< UnaryOperator::getOpcodeStr(Opc)
<< Input->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs,
UnaryOperator::getOpcodeStr(Opc), OpLoc);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< UnaryOperator::getOpcodeStr(Opc)
<< Input->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
return ExprError();
}
// Either we found no viable overloaded operator or we matched a
// built-in operator. In either case, fall through to trying to
// build a built-in operation.
input.release();
return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input));
}
/// \brief Create a binary operation that may resolve to an overloaded
/// operator.
///
/// \param OpLoc The location of the operator itself (e.g., '+').
///
/// \param OpcIn The BinaryOperator::Opcode that describes this
/// operator.
///
/// \param Functions The set of non-member functions that will be
/// considered by overload resolution. The caller needs to build this
/// set based on the context using, e.g.,
/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
/// set should not contain any member functions; those will be added
/// by CreateOverloadedBinOp().
///
/// \param LHS Left-hand argument.
/// \param RHS Right-hand argument.
Sema::OwningExprResult
Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
unsigned OpcIn,
const UnresolvedSetImpl &Fns,
Expr *LHS, Expr *RHS) {
Expr *Args[2] = { LHS, RHS };
LHS=RHS=0; //Please use only Args instead of LHS/RHS couple
BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn);
OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc);
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
// If either side is type-dependent, create an appropriate dependent
// expression.
if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
if (Fns.empty()) {
// If there are no functions to store, just build a dependent
// BinaryOperator or CompoundAssignment.
if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign)
return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc,
Context.DependentTy, OpLoc));
return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc,
Context.DependentTy,
Context.DependentTy,
Context.DependentTy,
OpLoc));
}
// FIXME: save results of ADL from here?
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, OpLoc,
/*ADL*/ true, IsOverloaded(Fns),
Fns.begin(), Fns.end());
return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
Args, 2,
Context.DependentTy,
OpLoc));
}
// If this is the .* operator, which is not overloadable, just
// create a built-in binary operator.
if (Opc == BinaryOperator::PtrMemD)
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
// If this is the assignment operator, we only perform overload resolution
// if the left-hand side is a class or enumeration type. This is actually
// a hack. The standard requires that we do overload resolution between the
// various built-in candidates, but as DR507 points out, this can lead to
// problems. So we do it this way, which pretty much follows what GCC does.
// Note that we go the traditional code path for compound assignment forms.
if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType())
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
// Build an empty overload set.
OverloadCandidateSet CandidateSet(OpLoc);
// Add the candidates from the given function set.
AddFunctionCandidates(Fns, Args, 2, CandidateSet, false);
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet);
// Add candidates from ADL.
AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true,
Args, 2,
/*ExplicitTemplateArgs*/ 0,
CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
// Convert the arguments.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
// Best->Access is only meaningful for class members.
CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl);
OwningExprResult Arg1
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[1]));
if (Arg1.isInvalid())
return ExprError();
if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
Args[1] = RHS = Arg1.takeAs<Expr>();
} else {
// Convert the arguments.
OwningExprResult Arg0
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[0]));
if (Arg0.isInvalid())
return ExprError();
OwningExprResult Arg1
= PerformCopyInitialization(
InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(1)),
SourceLocation(),
Owned(Args[1]));
if (Arg1.isInvalid())
return ExprError();
Args[0] = LHS = Arg0.takeAs<Expr>();
Args[1] = RHS = Arg1.takeAs<Expr>();
}
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Determine the result type
QualType ResultTy
= FnDecl->getType()->getAs<FunctionType>()->getResultType();
ResultTy = ResultTy.getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
OpLoc);
UsualUnaryConversions(FnExpr);
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr,
Args, 2, ResultTy,
OpLoc));
if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing) ||
PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
Best->Conversions[1], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function: {
// C++ [over.match.oper]p9:
// If the operator is the operator , [...] and there are no
// viable functions, then the operator is assumed to be the
// built-in operator and interpreted according to clause 5.
if (Opc == BinaryOperator::Comma)
break;
// For class as left operand for assignment or compound assigment operator
// do not fall through to handling in built-in, but report that no overloaded
// assignment operator found
OwningExprResult Result = ExprError();
if (Args[0]->getType()->isRecordType() &&
Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) {
Diag(OpLoc, diag::err_ovl_no_viable_oper)
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
} else {
// No viable function; try to create a built-in operation, which will
// produce an error. Then, show the non-viable candidates.
Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
assert(Result.isInvalid() &&
"C++ binary operator overloading is missing candidates!");
if (Result.isInvalid())
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
BinaryOperator::getOpcodeStr(Opc), OpLoc);
return move(Result);
}
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2,
BinaryOperator::getOpcodeStr(Opc), OpLoc);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2);
return ExprError();
}
// We matched a built-in operator; build it.
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
Action::OwningExprResult
Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
SourceLocation RLoc,
ExprArg Base, ExprArg Idx) {
Expr *Args[2] = { static_cast<Expr*>(Base.get()),
static_cast<Expr*>(Idx.get()) };
DeclarationName OpName =
Context.DeclarationNames.getCXXOperatorName(OO_Subscript);
// If either side is type-dependent, create an appropriate dependent
// expression.
if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) {
CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators
UnresolvedLookupExpr *Fn
= UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass,
0, SourceRange(), OpName, LLoc,
/*ADL*/ true, /*Overloaded*/ false,
UnresolvedSetIterator(),
UnresolvedSetIterator());
// Can't add any actual overloads yet
Base.release();
Idx.release();
return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn,
Args, 2,
Context.DependentTy,
RLoc));
}
// Build an empty overload set.
OverloadCandidateSet CandidateSet(LLoc);
// Subscript can only be overloaded as a member function.
// Add operator candidates that are member functions.
AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet);
// Add builtin operator candidates.
AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet);
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, LLoc, Best)) {
case OR_Success: {
// We found a built-in operator or an overloaded operator.
FunctionDecl *FnDecl = Best->Function;
if (FnDecl) {
// We matched an overloaded operator. Build a call to that
// operator.
CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LLoc);
// Convert the arguments.
CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
// Convert the arguments.
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
FnDecl->getParamDecl(0)),
SourceLocation(),
Owned(Args[1]));
if (InputInit.isInvalid())
return ExprError();
Args[1] = InputInit.takeAs<Expr>();
// Determine the result type
QualType ResultTy
= FnDecl->getType()->getAs<FunctionType>()->getResultType();
ResultTy = ResultTy.getNonReferenceType();
// Build the actual expression node.
Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
LLoc);
UsualUnaryConversions(FnExpr);
Base.release();
Idx.release();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript,
FnExpr, Args, 2,
ResultTy, RLoc));
if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(),
FnDecl))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
} else {
// We matched a built-in operator. Convert the arguments, then
// break out so that we will build the appropriate built-in
// operator node.
if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], AA_Passing) ||
PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1],
Best->Conversions[1], AA_Passing))
return ExprError();
break;
}
}
case OR_No_Viable_Function: {
if (CandidateSet.empty())
Diag(LLoc, diag::err_ovl_no_oper)
<< Args[0]->getType() << /*subscript*/ 0
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
else
Diag(LLoc, diag::err_ovl_no_viable_subscript)
<< Args[0]->getType()
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
"[]", LLoc);
return ExprError();
}
case OR_Ambiguous:
Diag(LLoc, diag::err_ovl_ambiguous_oper)
<< "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2,
"[]", LLoc);
return ExprError();
case OR_Deleted:
Diag(LLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted() << "[]"
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2,
"[]", LLoc);
return ExprError();
}
// We matched a built-in operator; build it.
Base.release();
Idx.release();
return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc,
Owned(Args[1]), RLoc);
}
/// BuildCallToMemberFunction - Build a call to a member
/// function. MemExpr is the expression that refers to the member
/// function (and includes the object parameter), Args/NumArgs are the
/// arguments to the function call (not including the object
/// parameter). The caller needs to validate that the member
/// expression refers to a member function or an overloaded member
/// function.
Sema::OwningExprResult
Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE,
SourceLocation LParenLoc, Expr **Args,
unsigned NumArgs, SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
// Dig out the member expression. This holds both the object
// argument and the member function we're referring to.
Expr *NakedMemExpr = MemExprE->IgnoreParens();
MemberExpr *MemExpr;
CXXMethodDecl *Method = 0;
DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public);
NestedNameSpecifier *Qualifier = 0;
if (isa<MemberExpr>(NakedMemExpr)) {
MemExpr = cast<MemberExpr>(NakedMemExpr);
Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
FoundDecl = MemExpr->getFoundDecl();
Qualifier = MemExpr->getQualifier();
} else {
UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
Qualifier = UnresExpr->getQualifier();
QualType ObjectType = UnresExpr->getBaseType();
// Add overload candidates
OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc());
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (UnresExpr->hasExplicitTemplateArgs()) {
UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(),
E = UnresExpr->decls_end(); I != E; ++I) {
NamedDecl *Func = *I;
CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext());
if (isa<UsingShadowDecl>(Func))
Func = cast<UsingShadowDecl>(Func)->getTargetDecl();
if ((Method = dyn_cast<CXXMethodDecl>(Func))) {
// If explicit template arguments were provided, we can't call a
// non-template member function.
if (TemplateArgs)
continue;
AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType,
Args, NumArgs,
CandidateSet, /*SuppressUserConversions=*/false);
} else {
AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func),
I.getPair(), ActingDC, TemplateArgs,
ObjectType, Args, NumArgs,
CandidateSet,
/*SuppressUsedConversions=*/false);
}
}
DeclarationName DeclName = UnresExpr->getMemberName();
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) {
case OR_Success:
Method = cast<CXXMethodDecl>(Best->Function);
FoundDecl = Best->FoundDecl;
CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc());
break;
case OR_No_Viable_Function:
Diag(UnresExpr->getMemberLoc(),
diag::err_ovl_no_viable_member_function_in_call)
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
case OR_Ambiguous:
Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call)
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
case OR_Deleted:
Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call)
<< Best->Function->isDeleted()
<< DeclName << MemExprE->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
// FIXME: Leaking incoming expressions!
return ExprError();
}
MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method);
// If overload resolution picked a static member, build a
// non-member call based on that function.
if (Method->isStatic()) {
return BuildResolvedCallExpr(MemExprE, Method, LParenLoc,
Args, NumArgs, RParenLoc);
}
MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens());
}
assert(Method && "Member call to something that isn't a method?");
ExprOwningPtr<CXXMemberCallExpr>
TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args,
NumArgs,
Method->getResultType().getNonReferenceType(),
RParenLoc));
// Check for a valid return type.
if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(),
TheCall.get(), Method))
return ExprError();
// Convert the object argument (for a non-static member function call).
// We only need to do this if there was actually an overload; otherwise
// it was done at lookup.
Expr *ObjectArg = MemExpr->getBase();
if (!Method->isStatic() &&
PerformObjectArgumentInitialization(ObjectArg, Qualifier,
FoundDecl, Method))
return ExprError();
MemExpr->setBase(ObjectArg);
// Convert the rest of the arguments
const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>();
if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs,
RParenLoc))
return ExprError();
if (CheckFunctionCall(Method, TheCall.get()))
return ExprError();
return MaybeBindToTemporary(TheCall.release());
}
/// BuildCallToObjectOfClassType - Build a call to an object of class
/// type (C++ [over.call.object]), which can end up invoking an
/// overloaded function call operator (@c operator()) or performing a
/// user-defined conversion on the object argument.
Sema::ExprResult
Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc) {
assert(Object->getType()->isRecordType() && "Requires object type argument");
const RecordType *Record = Object->getType()->getAs<RecordType>();
// C++ [over.call.object]p1:
// If the primary-expression E in the function call syntax
// evaluates to a class object of type "cv T", then the set of
// candidate functions includes at least the function call
// operators of T. The function call operators of T are obtained by
// ordinary lookup of the name operator() in the context of
// (E).operator().
OverloadCandidateSet CandidateSet(LParenLoc);
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call);
if (RequireCompleteType(LParenLoc, Object->getType(),
PDiag(diag::err_incomplete_object_call)
<< Object->getSourceRange()))
return true;
LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName);
LookupQualifiedName(R, Record->getDecl());
R.suppressDiagnostics();
for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
Oper != OperEnd; ++Oper) {
AddMethodCandidate(Oper.getPair(), Object->getType(),
Args, NumArgs, CandidateSet,
/*SuppressUserConversions=*/ false);
}
// C++ [over.call.object]p2:
// In addition, for each conversion function declared in T of the
// form
//
// operator conversion-type-id () cv-qualifier;
//
// where cv-qualifier is the same cv-qualification as, or a
// greater cv-qualification than, cv, and where conversion-type-id
// denotes the type "pointer to function of (P1,...,Pn) returning
// R", or the type "reference to pointer to function of
// (P1,...,Pn) returning R", or the type "reference to function
// of (P1,...,Pn) returning R", a surrogate call function [...]
// is also considered as a candidate function. Similarly,
// surrogate call functions are added to the set of candidate
// functions for each conversion function declared in an
// accessible base class provided the function is not hidden
// within T by another intervening declaration.
const UnresolvedSetImpl *Conversions
= cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions();
for (UnresolvedSetImpl::iterator I = Conversions->begin(),
E = Conversions->end(); I != E; ++I) {
NamedDecl *D = *I;
CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
if (isa<UsingShadowDecl>(D))
D = cast<UsingShadowDecl>(D)->getTargetDecl();
// Skip over templated conversion functions; they aren't
// surrogates.
if (isa<FunctionTemplateDecl>(D))
continue;
CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
// Strip the reference type (if any) and then the pointer type (if
// any) to get down to what might be a function type.
QualType ConvType = Conv->getConversionType().getNonReferenceType();
if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
ConvType = ConvPtrType->getPointeeType();
if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>())
AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto,
Object->getType(), Args, NumArgs,
CandidateSet);
}
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) {
case OR_Success:
// Overload resolution succeeded; we'll build the appropriate call
// below.
break;
case OR_No_Viable_Function:
if (CandidateSet.empty())
Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper)
<< Object->getType() << /*call*/ 1
<< Object->getSourceRange();
else
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_no_viable_object_call)
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
case OR_Ambiguous:
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_ambiguous_object_call)
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs);
break;
case OR_Deleted:
Diag(Object->getSourceRange().getBegin(),
diag::err_ovl_deleted_object_call)
<< Best->Function->isDeleted()
<< Object->getType() << Object->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs);
break;
}
if (Best == CandidateSet.end()) {
// We had an error; delete all of the subexpressions and return
// the error.
Object->Destroy(Context);
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
Args[ArgIdx]->Destroy(Context);
return true;
}
if (Best->Function == 0) {
// Since there is no function declaration, this is one of the
// surrogate candidates. Dig out the conversion function.
CXXConversionDecl *Conv
= cast<CXXConversionDecl>(
Best->Conversions[0].UserDefined.ConversionFunction);
CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc);
// We selected one of the surrogate functions that converts the
// object parameter to a function pointer. Perform the conversion
// on the object argument, then let ActOnCallExpr finish the job.
// Create an implicit member expr to refer to the conversion operator.
// and then call it.
CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl,
Conv);
return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc,
MultiExprArg(*this, (ExprTy**)Args, NumArgs),
CommaLocs, RParenLoc).result();
}
CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc);
// We found an overloaded operator(). Build a CXXOperatorCallExpr
// that calls this method, using Object for the implicit object
// parameter and passing along the remaining arguments.
CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>();
unsigned NumArgsInProto = Proto->getNumArgs();
unsigned NumArgsToCheck = NumArgs;
// Build the full argument list for the method call (the
// implicit object parameter is placed at the beginning of the
// list).
Expr **MethodArgs;
if (NumArgs < NumArgsInProto) {
NumArgsToCheck = NumArgsInProto;
MethodArgs = new Expr*[NumArgsInProto + 1];
} else {
MethodArgs = new Expr*[NumArgs + 1];
}
MethodArgs[0] = Object;
for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx)
MethodArgs[ArgIdx + 1] = Args[ArgIdx];
Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(),
SourceLocation());
UsualUnaryConversions(NewFn);
// Once we've built TheCall, all of the expressions are properly
// owned.
QualType ResultTy = Method->getResultType().getNonReferenceType();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn,
MethodArgs, NumArgs + 1,
ResultTy, RParenLoc));
delete [] MethodArgs;
if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(),
Method))
return true;
// We may have default arguments. If so, we need to allocate more
// slots in the call for them.
if (NumArgs < NumArgsInProto)
TheCall->setNumArgs(Context, NumArgsInProto + 1);
else if (NumArgs > NumArgsInProto)
NumArgsToCheck = NumArgsInProto;
bool IsError = false;
// Initialize the implicit object parameter.
IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0,
Best->FoundDecl, Method);
TheCall->setArg(0, Object);
// Check the argument types.
for (unsigned i = 0; i != NumArgsToCheck; i++) {
Expr *Arg;
if (i < NumArgs) {
Arg = Args[i];
// Pass the argument.
OwningExprResult InputInit
= PerformCopyInitialization(InitializedEntity::InitializeParameter(
Method->getParamDecl(i)),
SourceLocation(), Owned(Arg));
IsError |= InputInit.isInvalid();
Arg = InputInit.takeAs<Expr>();
} else {
OwningExprResult DefArg
= BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i));
if (DefArg.isInvalid()) {
IsError = true;
break;
}
Arg = DefArg.takeAs<Expr>();
}
TheCall->setArg(i + 1, Arg);
}
// If this is a variadic call, handle args passed through "...".
if (Proto->isVariadic()) {
// Promote the arguments (C99 6.5.2.2p7).
for (unsigned i = NumArgsInProto; i != NumArgs; i++) {
Expr *Arg = Args[i];
IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0);
TheCall->setArg(i + 1, Arg);
}
}
if (IsError) return true;
if (CheckFunctionCall(Method, TheCall.get()))
return true;
return MaybeBindToTemporary(TheCall.release()).result();
}
/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator->
/// (if one exists), where @c Base is an expression of class type and
/// @c Member is the name of the member we're trying to find.
Sema::OwningExprResult
Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) {
Expr *Base = static_cast<Expr *>(BaseIn.get());
assert(Base->getType()->isRecordType() && "left-hand side must have class type");
SourceLocation Loc = Base->getExprLoc();
// C++ [over.ref]p1:
//
// [...] An expression x->m is interpreted as (x.operator->())->m
// for a class object x of type T if T::operator->() exists and if
// the operator is selected as the best match function by the
// overload resolution mechanism (13.3).
DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow);
OverloadCandidateSet CandidateSet(Loc);
const RecordType *BaseRecord = Base->getType()->getAs<RecordType>();
if (RequireCompleteType(Loc, Base->getType(),
PDiag(diag::err_typecheck_incomplete_tag)
<< Base->getSourceRange()))
return ExprError();
LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName);
LookupQualifiedName(R, BaseRecord->getDecl());
R.suppressDiagnostics();
for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end();
Oper != OperEnd; ++Oper) {
AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet,
/*SuppressUserConversions=*/false);
}
// Perform overload resolution.
OverloadCandidateSet::iterator Best;
switch (BestViableFunction(CandidateSet, OpLoc, Best)) {
case OR_Success:
// Overload resolution succeeded; we'll build the call below.
break;
case OR_No_Viable_Function:
if (CandidateSet.empty())
Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
<< Base->getType() << Base->getSourceRange();
else
Diag(OpLoc, diag::err_ovl_no_viable_oper)
<< "operator->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1);
return ExprError();
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< "->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1);
return ExprError();
case OR_Deleted:
Diag(OpLoc, diag::err_ovl_deleted_oper)
<< Best->Function->isDeleted()
<< "->" << Base->getSourceRange();
PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1);
return ExprError();
}
CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl);
DiagnoseUseOfDecl(Best->FoundDecl, OpLoc);
// Convert the object parameter.
CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0,
Best->FoundDecl, Method))
return ExprError();
// No concerns about early exits now.
BaseIn.release();
// Build the operator call.
Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(),
SourceLocation());
UsualUnaryConversions(FnExpr);
QualType ResultTy = Method->getResultType().getNonReferenceType();
ExprOwningPtr<CXXOperatorCallExpr>
TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr,
&Base, 1, ResultTy, OpLoc));
if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(),
Method))
return ExprError();
return move(TheCall);
}
/// FixOverloadedFunctionReference - E is an expression that refers to
/// a C++ overloaded function (possibly with some parentheses and
/// perhaps a '&' around it). We have resolved the overloaded function
/// to the function declaration Fn, so patch up the expression E to
/// refer (possibly indirectly) to Fn. Returns the new expr.
Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found,
FunctionDecl *Fn) {
if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(),
Found, Fn);
if (SubExpr == PE->getSubExpr())
return PE->Retain();
return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr);
}
if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(),
Found, Fn);
assert(Context.hasSameType(ICE->getSubExpr()->getType(),
SubExpr->getType()) &&
"Implicit cast type cannot be determined from overload");
if (SubExpr == ICE->getSubExpr())
return ICE->Retain();
return new (Context) ImplicitCastExpr(ICE->getType(),
ICE->getCastKind(),
SubExpr, CXXBaseSpecifierArray(),
ICE->isLvalueCast());
}
if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) {
assert(UnOp->getOpcode() == UnaryOperator::AddrOf &&
"Can only take the address of an overloaded function");
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) {
if (Method->isStatic()) {
// Do nothing: static member functions aren't any different
// from non-member functions.
} else {
// Fix the sub expression, which really has to be an
// UnresolvedLookupExpr holding an overloaded member function
// or template.
Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
Found, Fn);
if (SubExpr == UnOp->getSubExpr())
return UnOp->Retain();
assert(isa<DeclRefExpr>(SubExpr)
&& "fixed to something other than a decl ref");
assert(cast<DeclRefExpr>(SubExpr)->getQualifier()
&& "fixed to a member ref with no nested name qualifier");
// We have taken the address of a pointer to member
// function. Perform the computation here so that we get the
// appropriate pointer to member type.
QualType ClassType
= Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext()));
QualType MemPtrType
= Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr());
return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf,
MemPtrType, UnOp->getOperatorLoc());
}
}
Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(),
Found, Fn);
if (SubExpr == UnOp->getSubExpr())
return UnOp->Retain();
return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf,
Context.getPointerType(SubExpr->getType()),
UnOp->getOperatorLoc());
}
if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) {
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (ULE->hasExplicitTemplateArgs()) {
ULE->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
return DeclRefExpr::Create(Context,
ULE->getQualifier(),
ULE->getQualifierRange(),
Fn,
ULE->getNameLoc(),
Fn->getType(),
TemplateArgs);
}
if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) {
// FIXME: avoid copy.
TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0;
if (MemExpr->hasExplicitTemplateArgs()) {
MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer);
TemplateArgs = &TemplateArgsBuffer;
}
Expr *Base;
// If we're filling in
if (MemExpr->isImplicitAccess()) {
if (cast<CXXMethodDecl>(Fn)->isStatic()) {
return DeclRefExpr::Create(Context,
MemExpr->getQualifier(),
MemExpr->getQualifierRange(),
Fn,
MemExpr->getMemberLoc(),
Fn->getType(),
TemplateArgs);
} else {
SourceLocation Loc = MemExpr->getMemberLoc();
if (MemExpr->getQualifier())
Loc = MemExpr->getQualifierRange().getBegin();
Base = new (Context) CXXThisExpr(Loc,
MemExpr->getBaseType(),
/*isImplicit=*/true);
}
} else
Base = MemExpr->getBase()->Retain();
return MemberExpr::Create(Context, Base,
MemExpr->isArrow(),
MemExpr->getQualifier(),
MemExpr->getQualifierRange(),
Fn,
Found,
MemExpr->getMemberLoc(),
TemplateArgs,
Fn->getType());
}
assert(false && "Invalid reference to overloaded function");
return E->Retain();
}
Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E,
DeclAccessPair Found,
FunctionDecl *Fn) {
return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn));
}
} // end namespace clang
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