-#define DBG(fmt, args...) fprintf(stderr, fmt "\n", ## args)
-#define WARN(fmt, args...) fprintf(stderr, "usertrace: WARNING: " fmt "\n", ## args)
-#define ERR(fmt, args...) fprintf(stderr, "usertrace: ERROR: " fmt "\n", ## args)
-#define PERROR(call) perror("usertrace: ERROR: " call)
+#ifndef USTERR_H
+#define USTERR_H
+
+//#define DEBUG
+#ifdef DEBUG
+# define DBG(fmt, args...) do { fprintf(stderr, fmt "\n", ## args); fflush(stderr); } while(0)
+#else
+# define DBG(fmt, args...) do {} while(0)
+#endif
+#define WARN(fmt, args...) fprintf(stderr, "libust: WARNING: " fmt "\n", ## args); fflush(stderr)
+#define ERR(fmt, args...) fprintf(stderr, "libust: ERROR: " fmt "\n", ## args); fflush(stderr)
+#define BUG(fmt, args...) fprintf(stderr, "libust: BUG: " fmt "\n", ## args); fflush(stderr)
+#define PERROR(call) perror("ust: ERROR: " call)
#define BUG_ON(condition) do { if (unlikely(condition)) ERR("condition not respected (BUG)"); } while(0)
-#define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected"); } while(0)
+#define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected on line %s:%d", __FILE__, __LINE__); } while(0)
+#endif /* USTERR_H */