MS ABI: Tweak pointer-to-member mangling/inheritance model selection

Properly determine the inheritance model when dealing with nullptr:
- If a nullptr template argument is being checked against
  pointer-to-member parameter, nail down an inheritance model.
  N.B. We will chose an inheritance model even if we won't ultimately
  choose the template to instantiate!  Cooky, right?
- Null pointer-to-datamembers have a virtual base table offset of -1,
  not zero. Previously, we chose an offset of 0.

llvm-svn: 200920

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp
index 499e8b18be8..5d49225ac4c 100644
--- a/clang/lib/Sema/SemaCast.cpp
+++ b/clang/lib/Sema/SemaCast.cpp
@@ -1433,6 +1433,10 @@ TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
       msg = 0;
       return TC_Failed;
     }
+  } else if (DestType->isMemberPointerType()) {
+    if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+      Self.RequireCompleteType(OpRange.getBegin(), DestType, 0);
+    }
   }
 
   InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);