[PATCH RFC 1/2] tools lib traceevent: add priv field to truct format_field.

[Wang Nan <wangnan0@huawei.com>]

In https://lkml.org/lkml/2015/1/21/383 , Jiri Olsa gives a suggestion
about changing lib traceevent to solve a bug of perf-convert-to-ctf,
which is related to duplicated field names. I think his suggestion
should be something like this patch.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/lib/traceevent/event-parse.c | 2 ++
 tools/lib/traceevent/event-parse.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index cf3a44b..5f76003 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -5909,6 +5909,8 @@ static void free_format_fields(struct format_field *field)
 		free(field->type);
 		free(field->name);
 		free(field);
+		if (field->destroy_priv)
+			field->destroy_priv(field);
 		field = next;
 	}
 }
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 7a3873f..928d801 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -190,6 +190,8 @@ struct format_field {
 	unsigned int		arraylen;
 	unsigned int		elementsize;
 	unsigned long		flags;
+	void			*priv;
+	void 			(*destroy_priv)(struct format_field *);
 };
 
 struct format {
-- 
1.8.4