Check in LLVM r95781.
diff --git a/test/SemaCXX/format-attribute.cpp b/test/SemaCXX/format-attribute.cpp
new file mode 100644
index 0000000..92b7cf5
--- /dev/null
+++ b/test/SemaCXX/format-attribute.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+// PR5521
+struct A { void a(const char*,...) __attribute((format(printf,2,3))); };
+void b(A x) {
+ x.a("%d", 3);
+}
+struct X { void a(const char*,...) __attribute((format(printf,1,3))); }; // expected-error {{format argument not a string type}}