1 files changed, 12 insertions, 0 deletions
diff --git a/test/PCH/cxx-friends.h b/test/PCH/cxx-friends.h
index 2a33f15a5329..05dcc9606636 100644
--- a/test/PCH/cxx-friends.h
+++ b/test/PCH/cxx-friends.h
@@ -4,3 +4,15 @@ class A {
   int x;
   friend class F;
 };
+
+namespace PR12585 {
+  struct future_base {
+    template<typename> class setter;
+  };
+  template<typename> class promise {
+    // We used to inject this into future_base with no access specifier,
+    // then crash during AST writing.
+    template<typename> friend class future_base::setter;
+    int k;
+  };
+}