perf parse-events: Print all errors

Prior to this patch the first and the last error encountered during
parsing are printed. To see other errors verbose needs
enabling. Unfortunately this can drop useful errors, in particular on
terms. This patch changes the errors so that instead of the first and
last all errors are recorded and printed, the underlying data
structure is changed to a list.

Before:
```
$ perf stat -e 'slots/edge=2/' true
event syntax error: 'slots/edge=2/'
                                \___ Bad event or PMU

Unable to find PMU or event on a PMU of 'slots'

Initial error:
event syntax error: 'slots/edge=2/'
                     \___ Cannot find PMU `slots'. Missing kernel support?
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events
```

After:
```
$ perf stat -e 'slots/edge=2/' true
event syntax error: 'slots/edge=2/'
                     \___ Bad event or PMU

Unable to find PMU or event on a PMU of 'slots'

event syntax error: 'slots/edge=2/'
                                \___ value too big for format (edge), maximum is 1

event syntax error: 'slots/edge=2/'
                     \___ Cannot find PMU `slots'. Missing kernel support?
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events
```

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: tchen168@asu.edu
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240131134940.593788-3-irogers@google.com

2 files changed, 5 insertions, 7 deletions

diff --git a/tools/perf/tests/expand-cgroup.c b/tools/perf/tests/expand-cgroup.c
index 9c1a1f18db75..31966ff856f8 100644
--- a/tools/perf/tests/expand-cgroup.c
+++ b/tools/perf/tests/expand-cgroup.c
@@ -127,8 +127,7 @@ static int expand_group_events(void)
 	parse_events_error__init(&err);
 	ret = parse_events(evlist, event_str, &err);
 	if (ret < 0) {
-		pr_debug("failed to parse event '%s', err %d, str '%s'\n",
-			 event_str, ret, err.str);
+		pr_debug("failed to parse event '%s', err %d\n", event_str, ret);
 		parse_events_error__print(&err, event_str);
 		goto out;
 	}
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index fbdf710d5eea..feb5727584d1 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -2506,11 +2506,10 @@ static int test_event(const struct evlist_test *e)
 	parse_events_error__init(&err);
 	ret = parse_events(evlist, e->name, &err);
 	if (ret) {
-		pr_debug("failed to parse event '%s', err %d, str '%s'\n",
-			 e->name, ret, err.str);
+		pr_debug("failed to parse event '%s', err %d\n", e->name, ret);
 		parse_events_error__print(&err, e->name);
 		ret = TEST_FAIL;
-		if (err.str && strstr(err.str, "can't access trace events"))
+		if (parse_events_error__contains(&err, "can't access trace events"))
 			ret = TEST_SKIP;
 	} else {
 		ret = e->check(evlist);
@@ -2535,8 +2534,8 @@ static int test_event_fake_pmu(const char *str)
 	ret = __parse_events(evlist, str, /*pmu_filter=*/NULL, &err,
 			     &perf_pmu__fake, /*warn_if_reordered=*/true);
 	if (ret) {
-		pr_debug("failed to parse event '%s', err %d, str '%s'\n",
-			 str, ret, err.str);
+		pr_debug("failed to parse event '%s', err %d\n",
+			 str, ret);
 		parse_events_error__print(&err, str);
 	}