kc3-lang/libbsd

diff --git a/include/bsd/err.h b/include/bsd/err.h
index fcaaa85..b465c1b 100644
--- a/include/bsd/err.h
+++ b/include/bsd/err.h
@@ -39,10 +39,14 @@
 #include <stdarg.h>
 
 __BEGIN_DECLS
-extern void warnc (int code, const char *format, ...);
-extern void vwarnc (int code, const char *format, va_list ap);
-extern void errc (int status, int code, const char *format, ...);
-extern void verrc (int status, int code, const char *format, va_list ap);
+void warnc(int code, const char *format, ...)
+	__printflike(2, 3);
+void vwarnc(int code, const char *format, va_list ap)
+	__printflike(2, 0);
+void errc(int status, int code, const char *format, ...)
+	__printflike(3, 4);
+void verrc(int status, int code, const char *format, va_list ap)
+	__printflike(3, 0);
 __END_DECLS
 
 #endif
diff --git a/include/bsd/unistd.h b/include/bsd/unistd.h
index 5dfa605..78a4525 100644
--- a/include/bsd/unistd.h
+++ b/include/bsd/unistd.h
@@ -60,7 +60,8 @@ void closefrom(int lowfd);
 #define initsetproctitle(c, a, e) setproctitle_init((c), (a), (e))
 
 void setproctitle_init(int argc, char *argv[], char *envp[]);
-void setproctitle(const char *fmt, ...);
+void setproctitle(const char *fmt, ...)
+	__printflike(1, 2);
 
 int getpeereid(int s, uid_t *euid, gid_t *egid);
 __END_DECLS