[PATCH v2 2/7] perf metricgroup: Use early return in add_metric

Ian Rogers
2020-05-20T18:21:11Z

Use early return in metricgroup__add_metric and try to make the intent
of the returns more intention revealing.

Suggested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/metricgroup.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 7a43ee0a2e40..5c0603ef4c75 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -524,7 +524,8 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
{
struct pmu_events_map *map = perf_pmu__find_map(NULL);
struct pmu_event *pe;
- int i, ret = -EINVAL;
+ int i, ret;
+ bool has_match = false;

if (!map)
return 0;
@@ -532,17 +533,23 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
for (i = 0; ; i++) {
pe = &map->table[i];

- if (!pe->name && !pe->metric_group && !pe->metric_name)
+ if (!pe->name && !pe->metric_group && !pe->metric_name) {
+ /* End of pmu events. */
+ if (!has_match)
+ return -EINVAL;
break;
+ }
if (!pe->metric_expr)
continue;
if (match_metric(pe->metric_group, metric) ||
match_metric(pe->metric_name, metric)) {
-
+ has_match = true;
pr_debug("metric expr %s for %s\n", pe->metric_expr, pe->metric_name);

if (!strstr(pe->metric_expr, "?")) {
ret = __metricgroup__add_metric(events, group_list, pe, 1);
+ if (ret)
+ return ret;
} else {
int j, count;

@@ -553,14 +560,15 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
* those events to group_list.
*/

- for (j = 0; j < count; j++)
+ for (j = 0; j < count; j++) {
ret = __metricgroup__add_metric(events, group_list, pe, j);
+ if (ret)
+ return ret;
+ }
}
- if (ret == -ENOMEM)
- break;
}
}
- return ret;
+ return 0;
}

static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
--
2.26.2.761.g0e0b3e54be-goog