Restrict redeclaration of tags introduced by using decls to MSVCCompat

This limits the facility added in r199490 while we seek clarification on the
standard.

llvm-svn: 199531

1 files changed, 21 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/MicrosoftCompatibility.cpp b/clang/test/SemaCXX/MicrosoftCompatibility.cpp
index 1f27deb0ee1..0971646e73b 100644
--- a/clang/test/SemaCXX/MicrosoftCompatibility.cpp
+++ b/clang/test/SemaCXX/MicrosoftCompatibility.cpp
@@ -120,6 +120,27 @@ private:
 
 }
 
+namespace using_tag_redeclaration
+{
+  struct S;
+  namespace N {
+    using ::using_tag_redeclaration::S;
+    struct S {}; // expected-note {{previous definition is here}}
+  }
+  void f() {
+    N::S s1;
+    S s2;
+  }
+  void g() {
+    struct S; // expected-note {{forward declaration of 'S'}}
+    S s3; // expected-error {{variable has incomplete type 'S'}}
+  }
+  void h() {
+    using ::using_tag_redeclaration::S;
+    struct S {}; // expected-error {{redefinition of 'S'}}
+  }
+}
+
 
 namespace MissingTypename {