-int errors(char *, char *);
-int fatal(char *);
-int warn(char *);
-int warns(char *, char *);
-int warni(char *, unsigned);
+int errors(const char *, char *);
+int fatal(const char *);
+int warn(const char *);
+int warns(const char *, char *);
+int warni(const char *, unsigned);