tracing/events: Move TRACE_SYSTEM outside of include guard

If TRACE_INCLDUE_FILE is defined, <trace/events/TRACE_INCLUDE_FILE.h>
will be included and compiled, otherwise it will be
<trace/events/TRACE_SYSTEM.h>

So TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.

Imaging this scenario:

 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == foo
 ...
 #include <trace/events/bar.h>
    -> TRACE_SYSTEM == bar
 ...
 #define CREATE_TRACE_POINTS
 #include <trace/events/foo.h>
    -> TRACE_SYSTEM == bar !!!

and then bar.h will be included and compiled.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 20 insertions, 17 deletions

diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 9977a756fb32..f24ae370e514 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -1,21 +1,4 @@
 /*
- * Notice that this file is not protected like a normal header.
- * We also must allow for rereading of this file. The
- *
- *  || defined(TRACE_HEADER_MULTI_READ)
- *
- * serves this purpose.
- */
-#if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _TRACE_EVENT_SAMPLE_H
-
-/*
- * All trace headers should include tracepoint.h, until we finally
- * make it into a standard header.
- */
-#include <linux/tracepoint.h>
-
-/*
  * If TRACE_SYSTEM is defined, that will be the directory created
  * in the ftrace directory under /debugfs/tracing/events/<system>
  *
@@ -34,11 +17,31 @@
  * #define TRACE_INCLUDE_FILE trace-events-sample
  *
  * As we do an the bottom of this file.
+ *
+ * Notice that TRACE_SYSTEM should be defined outside of #if
+ * protection, just like TRACE_INCLUDE_FILE.
  */
 #undef TRACE_SYSTEM
 #define TRACE_SYSTEM sample
 
 /*
+ * Notice that this file is not protected like a normal header.
+ * We also must allow for rereading of this file. The
+ *
+ *  || defined(TRACE_HEADER_MULTI_READ)
+ *
+ * serves this purpose.
+ */
+#if !defined(_TRACE_EVENT_SAMPLE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EVENT_SAMPLE_H
+
+/*
+ * All trace headers should include tracepoint.h, until we finally
+ * make it into a standard header.
+ */
+#include <linux/tracepoint.h>
+
+/*
  * The TRACE_EVENT macro is broken up into 5 parts.
  *
  * name: name of the trace point. This is also how to enable the tracepoint.