DBG
#define DBG(...) do { printf(__VA_ARGS__); } while (0)
#define DBG(...) do {} while (0)
#define DBG(x) x
#define DBG(x)
#define DBG(flag) (vrc4172gpio_debug & (flag))
#define DBG(flag) (0)
#define DBG(flag, msg) do { \
#define DBG(...)
#define DBG 0
#define DBG 0