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

1 files changed, 11 insertions, 4 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 98db60854f..3540cd02e6 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -2273,10 +2273,17 @@ static OverloadingResult TryRefInitWithConversionFunction(Sema &S,
   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()),