2 files changed, 37 insertions, 2 deletions
diff --git a/clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/p7.cpp b/clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/p7.cpp
index 98d12f99a59..f92362380a1 100644
--- a/clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/p7.cpp
+++ b/clang/test/CXX/dcl.dcl/basic.namespace/namespace.def/p7.cpp
@@ -3,11 +3,11 @@
 namespace NIL {} // expected-note {{previous definition}}
 inline namespace NIL {} // expected-error {{cannot be reopened as inline}}
 inline namespace IL {} // expected-note {{previous definition}}
-namespace IL {} // expected-warning{{inline namespace cannot be re-opened as a non-inline namespace}}
+namespace IL {} // expected-warning{{inline namespace cannot be reopened as a non-inline namespace}}
 
 namespace {} // expected-note {{previous definition}}
 inline namespace {} // expected-error {{cannot be reopened as inline}}
 namespace X {
   inline namespace {} // expected-note {{previous definition}}
-  namespace {} // expected-error {{cannot be reopened as non-inline}}
+  namespace {} // expected-warning {{cannot be reopened as a non-inline namespace}}
 }
diff --git a/clang/test/SemaCXX/libstdcxx_atomic_ns_hack.cpp b/clang/test/SemaCXX/libstdcxx_atomic_ns_hack.cpp
new file mode 100644
index 00000000000..4e4523f8532
--- /dev/null
+++ b/clang/test/SemaCXX/libstdcxx_atomic_ns_hack.cpp
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s
+
+// libstdc++ 4.6.x contains a bug where it defines std::__atomic[0,1,2] as a
+// non-inline namespace, then selects one of those namespaces and reopens it
+// as inline, as a strange way of providing something like a using-directive.
+// Clang has an egregious hack to work around the problem, by allowing a
+// namespace to be converted from non-inline to inline in this one specific
+// case.
+
+#ifdef BE_THE_HEADER
+
+#pragma clang system_header
+
+namespace std {
+  namespace __atomic0 {
+    typedef int foobar;
+  }
+  namespace __atomic1 {
+    typedef void foobar;
+  }
+
+  inline namespace __atomic0 {}
+}
+
+#else
+
+#define BE_THE_HEADER
+#include "libstdcxx_atomic_ns_hack.cpp"
+
+std::foobar fb;
+
+using T = void; // expected-note {{here}}
+using T = std::foobar; // expected-error {{different types ('std::foobar' (aka 'int') vs 'void')}}
+
+#endif