Index: clang/test/Driver/autocomplete.c
===================================================================
--- clang/test/Driver/autocomplete.c
+++ clang/test/Driver/autocomplete.c
@@ -1,3 +1,8 @@
+// Test for --autocompletion flag, which is a API used for shell autocompletion.
+// If this test had broke due to adding/modifying flags or changing HelpText,
+// please modify this file according to the change you have made on flags
+// used in this file.
+
 // RUN: %clang --autocomplete=-fsyn | FileCheck %s -check-prefix=FSYN
 // FSYN: -fsyntax-only
 // RUN: %clang --autocomplete=-std= | FileCheck %s -check-prefix=STD