-void rpc_set_error(struct rpc_context *rpc, char *error_string, ...);
-void nfs_set_error(struct nfs_context *nfs, char *error_string, ...);
+void rpc_set_error(struct rpc_context *rpc, char *error_string, ...)
+#ifdef __GNUC__
+ __attribute__((format(printf, 2, 3)))
+#endif
+;
+
+void nfs_set_error(struct nfs_context *nfs, char *error_string, ...)
+#ifdef __GNUC__
+ __attribute__((format(printf, 2, 3)))
+#endif
+;