+void complain_at (location loc, char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 2, 3)));
+
+/* Generate a message aligned by an indent.
+ When *indent == 0, assign message's indent to *indent,
+ When *indent > 0, align the message by *indent value. */
+void complain_at_indent (location loc, unsigned *indent,
+ char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 3, 4)));
+
+/** An incompatibility with POSIX Yacc: mapped either to warn* or
+ complain* depending on yacc_flag. */
+
+void yacc_at (location loc, char const *format, ...)