Reference binding via user-defined conversion can compute a binding
that is not reference-related (because it requires another implicit
conversion to which we can find). Fixes PR6483.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97922 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 0708d41..b959202 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -4526,20 +4526,23 @@
OverloadCandidateSet::iterator Best;
switch (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;
+
// This is a direct binding.
BindsDirectly = true;
if (ICS) {
- // 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.
ICS->setUserDefined();
ICS->UserDefined.Before = Best->Conversions[0].Standard;
ICS->UserDefined.After = Best->FinalConversion;
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 98db608..3540cd0 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -2273,10 +2273,17 @@
Sema::ReferenceCompareResult NewRefRelationship
= S.CompareReferenceRelationship(DeclLoc, T1, T2.getNonReferenceType(),
NewDerivedToBase);
- assert(NewRefRelationship != Sema::Ref_Incompatible &&
- "Overload resolution picked a bad conversion function");
- (void)NewRefRelationship;
- if (NewDerivedToBase)
+ if (NewRefRelationship == Sema::Ref_Incompatible) {
+ // If the type we've converted to is not reference-related to the
+ // type we're looking for, then there is another conversion step
+ // we need to perform to produce a temporary of the right type
+ // that we'll be binding to.
+ ImplicitConversionSequence ICS;
+ ICS.setStandard();
+ ICS.Standard = Best->FinalConversion;
+ T2 = ICS.Standard.getToType(2);
+ Sequence.AddConversionSequenceStep(ICS, T2);
+ } else if (NewDerivedToBase)
Sequence.AddDerivedToBaseCastStep(
S.Context.getQualifiedType(T1,
T2.getNonReferenceType().getQualifiers()),