2012-08-23 15:12:19

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: [PATCH 09/12] tools lib traceevent: Introduce pevent_errno

From: Namhyung Kim <[email protected]>

Define and use error numbers for pevent_parse_event() and get rid of
die() and do_warning() calls. If the function returns non-zero value,
the caller can check the return code and do appropriate things.

I chose the error numbers to be negative not to clash with standard
errno, and as usual, 0 for success.

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/lib/traceevent/event-parse.c | 50 +++++++++++++++++++++--------------
tools/lib/traceevent/event-parse.h | 26 +++++++++++++++++-
2 files changed, 54 insertions(+), 22 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 33fcd94..a46cae7 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4686,9 +4686,8 @@ static int find_event_handle(struct pevent *pevent, struct event_format *event)
*
* /sys/kernel/debug/tracing/events/.../.../format
*/
-int pevent_parse_event(struct pevent *pevent,
- const char *buf, unsigned long size,
- const char *sys)
+enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
+ unsigned long size, const char *sys)
{
struct event_format *event;
int ret;
@@ -4697,17 +4696,16 @@ int pevent_parse_event(struct pevent *pevent,

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

event->name = event_read_name();
if (!event->name) {
/* Bad event? */
- free(event);
- return -1;
+ ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
+ goto event_alloc_failed;
}

if (strcmp(sys, "ftrace") == 0) {
-
event->flags |= EVENT_FL_ISFTRACE;

if (strcmp(event->name, "bprint") == 0)
@@ -4715,20 +4713,28 @@ int pevent_parse_event(struct pevent *pevent,
}

event->id = event_read_id();
- if (event->id < 0)
- die("failed to read event id");
+ if (event->id < 0) {
+ ret = PEVENT_ERRNO__READ_ID_FAILED;
+ /*
+ * This isn't an allocation error actually.
+ * But as the ID is critical, just bail out.
+ */
+ goto event_alloc_failed;
+ }

event->system = strdup(sys);
- if (!event->system)
- die("failed to allocate system");
+ if (!event->system) {
+ ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
+ 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) {
- do_warning("failed to read event format for %s", event->name);
- goto event_failed;
+ ret = PEVENT_ERRNO__READ_FORMAT_FAILED;
+ goto event_parse_failed;
}

/*
@@ -4740,10 +4746,9 @@ int pevent_parse_event(struct pevent *pevent,

ret = event_read_print(event);
if (ret < 0) {
- do_warning("failed to read event print fmt for %s",
- event->name);
show_warning = 1;
- goto event_failed;
+ ret = PEVENT_ERRNO__READ_PRINT_FAILED;
+ goto event_parse_failed;
}
show_warning = 1;

@@ -4760,10 +4765,9 @@ int pevent_parse_event(struct pevent *pevent,
arg->type = PRINT_FIELD;
arg->field.name = strdup(field->name);
if (!arg->field.name) {
- do_warning("failed to allocate field name");
event->flags |= EVENT_FL_FAILED;
free_arg(arg);
- return -1;
+ return PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED;
}
arg->field.field = field;
*list = arg;
@@ -4778,11 +4782,17 @@ int pevent_parse_event(struct pevent *pevent,

return 0;

- event_failed:
+ event_parse_failed:
event->flags |= EVENT_FL_FAILED;
/* still add it even if it failed */
add_event(pevent, event);
- return -1;
+ return ret;
+
+ event_alloc_failed:
+ free(event->system);
+ free(event->name);
+ free(event);
+ return ret;
}

int get_field_val(struct trace_seq *s, struct format_field *field,
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 5772ad8..3c48229 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -345,6 +345,28 @@ enum pevent_flag {
PEVENT_NSEC_OUTPUT = 1, /* output in NSECS */
};

+enum pevent_errno {
+ PEVENT_ERRNO__SUCCESS = 0,
+
+ /*
+ * Choose an arbitrary negative big number not to clash with standard
+ * errno since SUS requires the errno has distinct positive values.
+ * See 'Issue 6' in the link below.
+ *
+ * http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
+ */
+ __PEVENT_ERRNO__START = -100000,
+
+ PEVENT_ERRNO__MEM_ALLOC_FAILED = __PEVENT_ERRNO__START,
+ PEVENT_ERRNO__PARSE_EVENT_FAILED,
+ PEVENT_ERRNO__READ_ID_FAILED,
+ PEVENT_ERRNO__READ_FORMAT_FAILED,
+ PEVENT_ERRNO__READ_PRINT_FAILED,
+ PEVENT_ERRNO__OLD_FTRACE_ARG_FAILED,
+
+ __PEVENT_ERRNO__END,
+};
+
struct cmdline;
struct cmdline_list;
struct func_map;
@@ -509,8 +531,8 @@ void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long size,
int long_size);

-int pevent_parse_event(struct pevent *pevent, const char *buf,
- unsigned long size, const char *sys);
+enum pevent_errno pevent_parse_event(struct pevent *pevent, const char *buf,
+ unsigned long size, const char *sys);

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