-void report (FILE *fp, const char *format, ...);
-void report_build (FILE *fp, const char *format, ...);
-void report_complete (FILE *fp, const char *format, ...);
-void report_at_line (FILE *fp, int, const char *, unsigned int, const char *, ...);
+void report (FILE *fp, const char *format, ...)
+ __attribute__ ((format (printf, 2, 3)))
+ ;
+void report_build (FILE *fp, const char *format, ...)
+ __attribute__ ((format (printf, 2, 3)))
+ ;
+void report_complete (FILE *fp, const char *format, ...)
+ __attribute__ ((format (printf, 2, 3)))
+ ;
+void report_at_line (FILE *fp, int, const char *, unsigned int, const char *, ...)
+ __attribute__ ((format (printf, 5, 6)))
+ ;