auto import from //depot/cupcake/@135843
diff --git a/src/complain.h b/src/complain.h
new file mode 100644
index 0000000..9ae334a
--- /dev/null
+++ b/src/complain.h
@@ -0,0 +1,62 @@
+/* Declaration for error-reporting function for Bison.
+ Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the
+ Free Software Foundation; either version 2, or (at your option) any
+ later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ USA. */
+
+#ifndef COMPLAIN_H_
+# define COMPLAIN_H_ 1
+
+# include "location.h"
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+/* Informative messages, but we proceed. */
+
+void warn (char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 1, 2)));
+
+void warn_at (location loc, char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 2, 3)));
+
+/* Something bad happened, but let's continue and die later. */
+
+void complain (char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 1, 2)));
+
+void complain_at (location loc, char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 2, 3)));
+
+/* Something bad happened, and let's die now. */
+
+void fatal (char const *format, ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 1, 2)));
+
+void fatal_at (location loc, char const *format, ...)
+ __attribute__ ((__noreturn__, __format__ (__printf__, 2, 3)));
+
+/* This variable is set each time `warn' is called. */
+extern bool warning_issued;
+
+/* This variable is set each time `complain' is called. */
+extern bool complaint_issued;
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif /* !COMPLAIN_H_ */