First pass at abstracting out a class for the target C++ ABI.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173514 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 5 deletions

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index f6cad26989..4819363f27 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -1667,11 +1667,16 @@ QualType Sema::BuildMemberPointerType(QualType T, QualType Class,
     return QualType();
   }
 
-  // In the Microsoft ABI, the class is allowed to be an incomplete
-  // type. In such cases, the compiler makes a worst-case assumption.
-  // We make no such assumption right now, so emit an error if the
-  // class isn't a complete type.
-  if (Context.getTargetInfo().getCXXABI() == CXXABI_Microsoft &&
+  // C++ allows the class type in a member pointer to be an incomplete type.
+  // In the Microsoft ABI, the size of the member pointer can vary
+  // according to the class type, which means that we really need a
+  // complete type if possible, which means we need to instantiate templates.
+  //
+  // For now, just require a complete type, which will instantiate
+  // templates.  This will also error if the type is just forward-declared,
+  // which is a bug, but it's a bug that saves us from dealing with some
+  // complexities at the moment.
+  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
       RequireCompleteType(Loc, Class, diag::err_incomplete_type))
     return QualType();