[PATCH 1/5] tools lib traceevent: Add WARN and WARN_ONCE macros

[Namhyung Kim <namhyung@kernel.org>]

They're copied from the perf code and will be used to print error
message during trace_seq_printf() and friends.

Suggested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/lib/traceevent/event-utils.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tools/lib/traceevent/event-utils.h b/tools/lib/traceevent/event-utils.h
index e76c9acb92cd..5dc0aec5ab50 100644
--- a/tools/lib/traceevent/event-utils.h
+++ b/tools/lib/traceevent/event-utils.h
@@ -38,6 +38,28 @@ void __vdie(const char *fmt, ...);
 void __vwarning(const char *fmt, ...);
 void __vpr_stat(const char *fmt, ...);
 
+#define likely(x)	__builtin_expect(!!(x), 1)
+#define unlikely(x)	__builtin_expect(!!(x), 0)
+
+#define __WARN_printf(arg...)	do { fprintf(stderr, arg); } while (0)
+
+#define WARN(condition, format...) ({		\
+	int __ret_warn_on = !!(condition);	\
+	if (unlikely(__ret_warn_on))		\
+		__WARN_printf(format);		\
+	unlikely(__ret_warn_on);		\
+})
+
+#define WARN_ONCE(condition, format...)	({	\
+	static int __warned;			\
+	int __ret_warn_once = !!(condition);	\
+						\
+	if (unlikely(__ret_warn_once))		\
+		if (WARN(!__warned, format)) 	\
+			__warned = 1;		\
+	unlikely(__ret_warn_once);		\
+})
+
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\
 	typeof(y) _min2 = (y);			\
-- 
1.7.11.7