1 files changed, 25 insertions, 0 deletions

diff --git a/test/SemaCXX/libstdcxx_map_base_hack.cpp b/test/SemaCXX/libstdcxx_map_base_hack.cpp
new file mode 100644
index 000000000000..a556281fc0f8
--- /dev/null
+++ b/test/SemaCXX/libstdcxx_map_base_hack.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fsyntax-only %s
+
+// libstdc++ 4.2.x contains a bug where a friend struct template
+// declaration for std::tr1::__detail::_Map base has different
+// template arguments than the real declaration. Clang has an
+// egregious hack to work around this problem, since we can't modify
+// all of the world's libstdc++'s.
+
+namespace std { namespace tr1 { namespace __detail {
+  template<typename _Key, typename _Value, typename _Ex, bool __unique,
+	   typename _Hashtable>
+    struct _Map_base { };
+
+} } } 
+
+namespace std { namespace tr1 {
+  template<typename T>
+  struct X1 {
+    template<typename _Key2, typename _Pair, typename _Hashtable>
+    friend struct __detail::_Map_base;
+  };
+
+} }
+
+std::tr1::X1<int> x1i;