+# 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)));
+
+/* 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 warn_at_indent (location loc, unsigned *indent,
+ char const *format, ...)
+ __attribute__ ((__format__ (__printf__, 3, 4)));