Re: [PATCH v2 2/9] perf tools: splice events onto evlist even on error

Jiri Olsa
2019-10-23T08:40:54Z

On Tue, Oct 22, 2019 at 05:53:30PM -0700, Ian Rogers wrote:
> If event parsing fails the event list is leaked, instead splice the list
> onto the out result and let the caller cleanup.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/parse-events.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 4d42344698b8..a8f8801bd127 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1962,15 +1962,20 @@ int parse_events(struct evlist *evlist, const char *str,
>
> ret = parse_events__scanner(str, &parse_state, PE_START_EVENTS);
> perf_pmu__parse_cleanup();
> +

I dont understand.. is there something on the list in case we fail?

> + if (list_empty(&parse_state.list)) {
> + WARN_ONCE(true, "WARNING: event parser found nothing\n");
> + return -1;
> + }

this will display extra warning message for fail case:

[jolsa@krava perf]$ ./perf record -e krava ls
WARNING: event parser found nothing
event syntax error: 'krava'
\___ parser error

we don't want that

jirka

> +
> + /*
> + * Add list to the evlist even with errors to allow callers to clean up.
> + */
> + perf_evlist__splice_list_tail(evlist, &parse_state.list);
> +
> if (!ret) {
> struct evsel *last;
>
> - if (list_empty(&parse_state.list)) {
> - WARN_ONCE(true, "WARNING: event parser found nothing\n");
> - return -1;
> - }
> -
> - perf_evlist__splice_list_tail(evlist, &parse_state.list);
> evlist->nr_groups += parse_state.nr_groups;
> last = evlist__last(evlist);
> last->cmdline_group_boundary = true;
> --
> 2.23.0.866.gb869b98d4c-goog
>