#include <stdio.h>

#define DEBUG 1
#define MYDEF 1

#define TRACE(x) do { if (DEBUG) printf x; } while (0)

#ifdef MYDEF

#define IF_MY(x,y) x y

#else

#define IF_MY(x,y) x

#endif

int main(void) {
char *msg="aaa";

TRACE((IF_MY("Message: %s", "Additional stuff"), msg));

	return 0;
}