extern size_t log_info(const char *format, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
extern size_t __log_buf(struct buf_output *, const char *format, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
extern size_t log_valist(const char *str, va_list);
extern size_t log_info(const char *format, ...) __attribute__ ((__format__ (__printf__, 1, 2)));
extern size_t __log_buf(struct buf_output *, const char *format, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
extern size_t log_valist(const char *str, va_list);