Index: cfe/trunk/test/Driver/autocomplete.c
===================================================================
--- cfe/trunk/test/Driver/autocomplete.c
+++ cfe/trunk/test/Driver/autocomplete.c
@@ -1,3 +1,7 @@
+// Test for the --autocompletion flag, which is an API used for shell
+// autocompletion. You may have to update tests in this file when you
+// add/modify flags, change HelpTexts or the values of some flags.
+
 // RUN: %clang --autocomplete=-fsyn | FileCheck %s -check-prefix=FSYN
 // FSYN: -fsyntax-only
 // RUN: %clang --autocomplete=-std= | FileCheck %s -check-prefix=STD