[PATCH 27/30] tools lib traceevent: Carve out events format parsing routine

From: Arnaldo Carvalho de Melo
Date: Mon Sep 24 2012 - 12:04:01 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

The pevent_parse_event() routine will parse a events/sys/tp/format file
and add an event_format instance to the pevent struct.

This patch introduces a pevent_parse_format() routine with just the bits
needed to parse the event/sys/tp/format file and just return the
event_format instance, useful for when all we want is to parse the
format file, without requiring the pevent struct.

Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-lge0afl47arh86om0m6a5bqr@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/lib/traceevent/event-parse.c | 96 +++++++++++++++++++++++++++---------
tools/lib/traceevent/event-parse.h | 3 +
2 files changed, 75 insertions(+), 24 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index b3bc130..1fa71ca 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4794,8 +4794,7 @@ static int find_event_handle(struct pevent *pevent, struct event_format *event)
}

/**
- * pevent_parse_event - parse the event format
- * @pevent: the handle to the pevent
+ * __pevent_parse_format - parse the event format
* @buf: the buffer storing the event format string
* @size: the size of @buf
* @sys: the system the event belongs to
@@ -4807,15 +4806,16 @@ static int find_event_handle(struct pevent *pevent, struct event_format *event)
*
* /sys/kernel/debug/tracing/events/.../.../format
*/
-enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
- unsigned long size, const char *sys)
+enum pevent_errno __pevent_parse_format(struct event_format **eventp,
+ struct pevent *pevent, const char *buf,
+ unsigned long size, const char *sys)
{
struct event_format *event;
int ret;

init_input_buf(buf, size);

- event = alloc_event();
+ *eventp = event = alloc_event();
if (!event)
return PEVENT_ERRNO__MEM_ALLOC_FAILED;

@@ -4849,9 +4849,6 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
goto event_alloc_failed;
}

- /* Add pevent to event so that it can be referenced */
- event->pevent = pevent;
-
ret = event_read_format(event);
if (ret < 0) {
ret = PEVENT_ERRNO__READ_FORMAT_FAILED;
@@ -4862,19 +4859,16 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
* If the event has an override, don't print warnings if the event
* print format fails to parse.
*/
- if (find_event_handle(pevent, event))
+ if (pevent && find_event_handle(pevent, event))
show_warning = 0;

ret = event_read_print(event);
+ show_warning = 1;
+
if (ret < 0) {
- show_warning = 1;
ret = PEVENT_ERRNO__READ_PRINT_FAILED;
goto event_parse_failed;
}
- show_warning = 1;
-
- if (add_event(pevent, event))
- goto event_alloc_failed;

if (!ret && (event->flags & EVENT_FL_ISFTRACE)) {
struct format_field *field;
@@ -4898,24 +4892,78 @@ enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
return 0;
}

-#define PRINT_ARGS 0
- if (PRINT_ARGS && event->print_fmt.args)
- print_args(event->print_fmt.args);
-
return 0;

event_parse_failed:
event->flags |= EVENT_FL_FAILED;
- /* still add it even if it failed */
- if (add_event(pevent, event))
- goto event_alloc_failed;
-
return ret;

event_alloc_failed:
free(event->system);
free(event->name);
free(event);
+ *eventp = NULL;
+ return ret;
+}
+
+/**
+ * pevent_parse_format - parse the event format
+ * @buf: the buffer storing the event format string
+ * @size: the size of @buf
+ * @sys: the system the event belongs to
+ *
+ * This parses the event format and creates an event structure
+ * to quickly parse raw data for a given event.
+ *
+ * These files currently come from:
+ *
+ * /sys/kernel/debug/tracing/events/.../.../format
+ */
+enum pevent_errno pevent_parse_format(struct event_format **eventp, const char *buf,
+ unsigned long size, const char *sys)
+{
+ return __pevent_parse_format(eventp, NULL, buf, size, sys);
+}
+
+/**
+ * pevent_parse_event - parse the event format
+ * @pevent: the handle to the pevent
+ * @buf: the buffer storing the event format string
+ * @size: the size of @buf
+ * @sys: the system the event belongs to
+ *
+ * This parses the event format and creates an event structure
+ * to quickly parse raw data for a given event.
+ *
+ * These files currently come from:
+ *
+ * /sys/kernel/debug/tracing/events/.../.../format
+ */
+enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
+ unsigned long size, const char *sys)
+{
+ struct event_format *event = NULL;
+ int ret = __pevent_parse_format(&event, pevent, buf, size, sys);
+
+ if (event == NULL)
+ return ret;
+
+ /* Add pevent to event so that it can be referenced */
+ event->pevent = pevent;
+
+ if (add_event(pevent, event))
+ goto event_add_failed;
+
+#define PRINT_ARGS 0
+ if (PRINT_ARGS && event->print_fmt.args)
+ print_args(event->print_fmt.args);
+
+ return 0;
+
+event_add_failed:
+ free(event->system);
+ free(event->name);
+ free(event);
return ret;
}

@@ -5365,7 +5413,7 @@ static void free_formats(struct format *format)
free_format_fields(format->fields);
}

-static void free_event(struct event_format *event)
+void pevent_free_format(struct event_format *event)
{
free(event->name);
free(event->system);
@@ -5451,7 +5499,7 @@ void pevent_free(struct pevent *pevent)
}

for (i = 0; i < pevent->nr_events; i++)
- free_event(pevent->events[i]);
+ pevent_free_format(pevent->events[i]);

while (pevent->handlers) {
handle = pevent->handlers;
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index a4bbe24..24a4bba 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -540,6 +540,9 @@ int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long siz

enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
unsigned long size, const char *sys);
+enum pevent_errno pevent_parse_format(struct event_format **eventp, const char *buf,
+ unsigned long size, const char *sys);
+void pevent_free_format(struct event_format *event);

void *pevent_get_field_raw(struct trace_seq *s, struct event_format *event,
const char *name, struct pevent_record *record,
--
1.7.1

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