#define READLINE_MAX_CMDS 64
#define READLINE_MAX_COMPLETIONS 256
-typedef void ReadLinePrintfFunc(void *opaque, const char *fmt, ...);
+typedef void GCC_FMT_ATTR(2, 3) ReadLinePrintfFunc(void *opaque,
+ const char *fmt, ...);
typedef void ReadLineFlushFunc(void *opaque);
typedef void ReadLineFunc(void *opaque, const char *str,
void *readline_opaque);