-void err(int, const char *, ...) __dead2;
-void verr(int, const char *, _BSD_VA_LIST_) __dead2;
-void errc(int, int, const char *, ...) __dead2;
-void verrc(int, int, const char *, _BSD_VA_LIST_) __dead2;
-void errx(int, const char *, ...) __dead2;
-void verrx(int, const char *, _BSD_VA_LIST_) __dead2;
-void warn(const char *, ...);
-void vwarn(const char *, _BSD_VA_LIST_);
-void warnc(int, const char *, ...);
-void vwarnc(int, const char *, _BSD_VA_LIST_);
-void warnx(const char *, ...);
-void vwarnx(const char *, _BSD_VA_LIST_);
+void err(int, const char *, ...) __dead2 __printflike(2, 3);
+void verr(int, const char *, __darwin_va_list) __dead2 __printflike(2, 0);
+void errc(int, int, const char *, ...) __dead2 __printflike(3, 4);
+void verrc(int, int, const char *, __darwin_va_list) __dead2 __printflike(3, 0);
+void errx(int, const char *, ...) __dead2 __printflike(2, 3);
+void verrx(int, const char *, __darwin_va_list) __dead2 __printflike(2, 0);
+void warn(const char *, ...) __printflike(1, 2);
+void vwarn(const char *, __darwin_va_list) __printflike(1, 0);
+void warnc(int, const char *, ...) __printflike(2, 3);
+void vwarnc(int, const char *, __darwin_va_list) __printflike(2, 0);
+void warnx(const char *, ...) __printflike(1, 2);
+void vwarnx(const char *, __darwin_va_list) __printflike(1, 0);