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-rw-r--r--clang/lib/Sema/SemaOverload.cpp156
1 files changed, 95 insertions, 61 deletions
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f0b1fcb6d05..db563cf96db 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -685,24 +685,17 @@ Sema::TryImplicitConversion(Expr* From, QualType 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;
- }
-
+ // 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))) {
ICS.setStandard();
ICS.Standard.setAsIdentityConversion();
ICS.Standard.setFromType(FromType);
@@ -713,11 +706,18 @@ Sema::TryImplicitConversion(Expr* From, QualType ToType,
// 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;
+ }
+
+ if (SuppressUserConversions) {
+ // 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;
}
@@ -2630,16 +2630,21 @@ Sema::CompareReferenceRelationship(SourceLocation Loc,
return Ref_Related;
}
-/// \brief Look for a user-defined conversion to an lvalue reference-compatible
+/// \brief Look for a user-defined conversion to an value reference-compatible
/// with DeclType. Return true if something definite is found.
static bool
-FindConversionToLValue(Sema &S, ImplicitConversionSequence &ICS,
- QualType DeclType, SourceLocation DeclLoc,
- Expr *Init, QualType T2, bool AllowExplicit) {
+FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
+ QualType DeclType, SourceLocation DeclLoc,
+ Expr *Init, QualType T2, bool AllowRvalues,
+ bool AllowExplicit) {
assert(T2->isRecordType() && "Can only find conversions of record types.");
CXXRecordDecl *T2RecordDecl
= dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
+ QualType ToType
+ = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType()
+ : DeclType;
+
OverloadCandidateSet CandidateSet(DeclLoc);
const UnresolvedSetImpl *Conversions
= T2RecordDecl->getVisibleConversionFunctions();
@@ -2658,21 +2663,40 @@ FindConversionToLValue(Sema &S, ImplicitConversionSequence &ICS,
else
Conv = cast<CXXConversionDecl>(D);
- // If the conversion function doesn't return a reference type,
- // it can't be considered for this conversion. An rvalue reference
- // is only acceptable if its referencee is a function type.
- const ReferenceType *RefType =
- Conv->getConversionType()->getAs<ReferenceType>();
- if (RefType && (RefType->isLValueReferenceType() ||
- RefType->getPointeeType()->isFunctionType()) &&
- (AllowExplicit || !Conv->isExplicit())) {
- if (ConvTemplate)
- S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
- Init, DeclType, CandidateSet);
- else
- S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
- DeclType, CandidateSet);
+ // If this is an explicit conversion, and we're not allowed to consider
+ // explicit conversions, skip it.
+ if (!AllowExplicit && Conv->isExplicit())
+ continue;
+
+ if (AllowRvalues) {
+ bool DerivedToBase = false;
+ bool ObjCConversion = false;
+ if (!ConvTemplate &&
+ S.CompareReferenceRelationship(DeclLoc,
+ Conv->getConversionType().getNonReferenceType().getUnqualifiedType(),
+ DeclType.getNonReferenceType().getUnqualifiedType(),
+ DerivedToBase, ObjCConversion)
+ == Sema::Ref_Incompatible)
+ continue;
+ } else {
+ // If the conversion function doesn't return a reference type,
+ // it can't be considered for this conversion. An rvalue reference
+ // is only acceptable if its referencee is a function type.
+
+ const ReferenceType *RefType =
+ Conv->getConversionType()->getAs<ReferenceType>();
+ if (!RefType ||
+ (!RefType->isLValueReferenceType() &&
+ !RefType->getPointeeType()->isFunctionType()))
+ continue;
}
+
+ if (ConvTemplate)
+ S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
+ Init, ToType, CandidateSet);
+ else
+ S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
+ ToType, CandidateSet);
}
OverloadCandidateSet::iterator Best;
@@ -2808,8 +2832,9 @@ TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType,
if (!SuppressUserConversions && T2->isRecordType() &&
!S.RequireCompleteType(DeclLoc, T2, 0) &&
RefRelationship == Sema::Ref_Incompatible) {
- if (FindConversionToLValue(S, ICS, DeclType, DeclLoc,
- Init, T2, AllowExplicit))
+ if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
+ Init, T2, /*AllowRvalues=*/false,
+ AllowExplicit))
return ICS;
}
}
@@ -2861,28 +2886,37 @@ TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType,
// 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 (InitCategory.isRValue() && T2->isRecordType() &&
- RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
- ICS.setStandard();
- ICS.Standard.First = ICK_Identity;
- ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
- : ObjCConversion? ICK_Compatible_Conversion
- : 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;
+ if (T2->isRecordType()) {
+ // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a
+ // direct binding in C++0x but not in C++03.
+ if (InitCategory.isRValue() &&
+ RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
+ ICS.setStandard();
+ ICS.Standard.First = ICK_Identity;
+ ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
+ : ObjCConversion? ICK_Compatible_Conversion
+ : 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;
+ }
+
+ // Second case: not reference-related.
+ if (RefRelationship == Sema::Ref_Incompatible &&
+ !S.RequireCompleteType(DeclLoc, T2, 0) &&
+ FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
+ Init, T2, /*AllowRvalues=*/true,
+ AllowExplicit))
+ 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
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