X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=include%2Fust%2Ftracepoint.h;h=626f8af545dfea3d9c5136503ad7a61c44fae6ef;hb=377d33ed8d03fbfd6c8655862de50d7fc213c0f4;hp=2f89c1566c419bb3f85b61e55189e715768347b4;hpb=bf5fe926fa64722edcc3efa14a4683e3bb9c2673;p=ust.git

diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index 2f89c15..626f8af 100644
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -49,6 +49,18 @@ struct tracepoint {
 #define TP_PROTO(args...)	args
 #define TP_ARGS(args...)	args
 
+/*
+ * Tracepoints should be added to the instrumented code using the
+ * "tracepoint()" macro.
+ */
+#define tracepoint(name, args...)	__trace_##name(args)
+
+#define register_tracepoint(name, probe, data)			\
+		__register_trace_##name(probe, data)
+
+#define unregister_tracepoint(name, probe, data)		\
+		__unregister_trace_##name(probe, data)
+
 #define CONFIG_TRACEPOINTS
 #ifdef CONFIG_TRACEPOINTS
 
@@ -99,7 +111,7 @@ struct tracepoint {
  */
 #define __DECLARE_TRACE(name, proto, args, data_proto, data_args)	\
 	extern struct tracepoint __tracepoint_##name;			\
-	static inline void trace_##name(proto)				\
+	static inline void __trace_##name(proto)			\
 	{								\
 		__CHECK_TRACE(name, 0, TP_PROTO(data_proto),		\
 			      TP_ARGS(data_args));			\
@@ -110,14 +122,14 @@ struct tracepoint {
 			      TP_ARGS(data_args));			\
 	}								\
 	static inline int						\
-	register_trace_##name(void (*probe)(data_proto), void *data)	\
+	__register_trace_##name(void (*probe)(data_proto), void *data)	\
 	{								\
 		return tracepoint_probe_register(#name, (void *)probe,	\
 						 data);			\
 									\
 	}								\
 	static inline int						\
-	unregister_trace_##name(void (*probe)(data_proto), void *data)	\
+	__unregister_trace_##name(void (*probe)(data_proto), void *data)\
 	{								\
 		return tracepoint_probe_unregister(#name, (void *)probe, \
 						   data);		\
@@ -145,11 +157,11 @@ extern void tracepoint_update_probe_range(struct tracepoint * const *begin,
 	{ }								\
 	static inline void _trace_##name(proto)				\
 	{ }								\
-	static inline int register_trace_##name(void (*probe)(proto), void *data)	\
+	static inline int __register_trace_##name(void (*probe)(proto), void *data)	\
 	{								\
 		return -ENOSYS;						\
 	}								\
-	static inline int unregister_trace_##name(void (*probe)(proto), void *data)	\
+	static inline int __unregister_trace_##name(void (*probe)(proto), void *data)	\
 	{								\
 		return -ENOSYS;						\
 	}
@@ -163,10 +175,27 @@ static inline void tracepoint_update_probe_range(struct tracepoint *begin,
 { }
 #endif /* CONFIG_TRACEPOINTS */
 
-#define DECLARE_TRACE(name, proto, args)			\
-	__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),	\
-			PARAMS(void *__data, proto),		\
-			PARAMS(__data, args))
+/*
+ * The need for the DECLARE_TRACE_NOARGS() is to handle the prototype
+ * (void). "void" is a special value in a function prototype and can
+ * not be combined with other arguments. Since the DECLARE_TRACE()
+ * macro adds a data element at the beginning of the prototype,
+ * we need a way to differentiate "(void *data, proto)" from
+ * "(void *data, void)". The second prototype is invalid.
+ *
+ * DECLARE_TRACE_NOARGS() passes "void" as the tracepoint prototype
+ * and "void *__data" as the callback prototype.
+ *
+ * DECLARE_TRACE() passes "proto" as the tracepoint protoype and
+ * "void *__data, proto" as the callback prototype.
+ */
+#define DECLARE_TRACE_NOARGS(name)					\
+		__DECLARE_TRACE(name, void, , void *__data, __data)
+
+#define DECLARE_TRACE(name, proto, args)				\
+		__DECLARE_TRACE(name, PARAMS(proto), PARAMS(args),	\
+				PARAMS(void *__data, proto),		\
+				PARAMS(__data, args))
 
 /*
  * Connect a probe to a tracepoint.
@@ -222,16 +251,18 @@ extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_star
 #define TRACEPOINT_LIB							\
 	extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
 	extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \
+	static struct tracepoint * const __tracepoint_ptr_dummy		\
+	__attribute__((used, section("__tracepoints_ptrs"))) = NULL;	\
 	static void __attribute__((constructor)) __tracepoints__init(void)	\
 	{									\
-		tracepoint_register_lib(__start___tracepoints,			\
-					__stop___tracepoints -			\
-					__start___tracepoints);			\
+		tracepoint_register_lib(__start___tracepoints_ptrs,			\
+					__stop___tracepoints_ptrs -			\
+					__start___tracepoints_ptrs);			\
 	}									\
 										\
 	static void __attribute__((destructor)) __tracepoints__destroy(void)	\
 	{									\
-		tracepoint_unregister_lib(__start___tracepoints);		\
+		tracepoint_unregister_lib(__start___tracepoints_ptrs);		\
 	}
 
 
@@ -377,6 +408,8 @@ extern int trace_event_unregister_lib(struct trace_event * const *start_trace_ev
 	__attribute__((weak, visibility("hidden")));			\
 	extern struct trace_event * const __stop___trace_events_ptrs[]	\
 	__attribute__((weak, visibility("hidden")));			\
+	static struct trace_event * const __event_ptrs_dummy		\
+	__attribute__((used, section("__trace_events_ptrs"))) =	NULL;	\
 	static void __attribute__((constructor))			\
 	__trace_events__init(void)					\
 	{								\