r314235 - Allow IUnknown/IInterface types to come from extern C++

[Erich Keane via cfe-commits]

Author: erichkeane
Date: Tue Sep 26 11:55:16 2017
New Revision: 314235

URL: http://llvm.org/viewvc/llvm-project?rev=314235&view=rev
Log:
Allow IUnknown/IInterface types to come from extern C++ 

It was brought up in response to my last implementation for
this struct-as-interface features that at least 1 header in
the MS SDK uses "extern C++" around an IUnknown declaration.

The previous implementation demanded that this type exist
in the TranslationUnit DeclContext.  This small change simply
also allows in the situation where we're extern "C++".

Modified:
    cfe/trunk/lib/AST/DeclCXX.cpp
    cfe/trunk/test/SemaCXX/ms-iunknown.cpp

Modified: cfe/trunk/lib/AST/DeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclCXX.cpp?rev=314235&r1=314234&r2=314235&view=diff
==============================================================================
--- cfe/trunk/lib/AST/DeclCXX.cpp (original)
+++ cfe/trunk/lib/AST/DeclCXX.cpp Tue Sep 26 11:55:16 2017
@@ -1491,7 +1491,8 @@ bool CXXRecordDecl::isInterfaceLike() co
 
   // Check "Special" types.
   const auto *Uuid = getAttr<UuidAttr>();
-  if (Uuid && isStruct() && getDeclContext()->isTranslationUnit() &&
+  if (Uuid && isStruct() && (getDeclContext()->isTranslationUnit() ||
+                             getDeclContext()->isExternCXXContext()) &&
       ((getName() == "IUnknown" &&
         Uuid->getGuid() == "00000000-0000-0000-C000-000000000046") ||
        (getName() == "IDispatch" &&

Modified: cfe/trunk/test/SemaCXX/ms-iunknown.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ms-iunknown.cpp?rev=314235&r1=314234&r2=314235&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/ms-iunknown.cpp (original)
+++ cfe/trunk/test/SemaCXX/ms-iunknown.cpp Tue Sep 26 11:55:16 2017
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s 
 
-struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
+extern "C++" struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
   void foo();
 };
 struct IPropertyPageBase : public IUnknown {};