void deprecated_directive (location const *loc,
char const *obsolete, char const *updated);
+/** Report a repeated directive for a rule. */
+void duplicate_directive (char const *directive,
+ location first, location second);
+
/** Warnings treated as errors shouldn't stop the execution as regular errors
should (because due to their nature, it is safe to go on). Thus, there are
three possible execution statuses. */