perf parse-events: Pass ownership of the group name

Pass ownership of the group name rather than copying and freeing the
original. This saves a memory allocation and copy.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20230312021543.3060328-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/parse-events.c

@@ -1761,6 +1761,7 @@ parse_events__set_leader_for_uncore_aliase(char *name, struct list_head *list,
 
 handled:
 	ret = 1;
+	free(name);
 out:
 	free(leaders);
 	return ret;
@@ -1786,7 +1787,7 @@ void parse_events__set_leader(char *name, struct list_head *list,
 
 	leader = arch_evlist__leader(list);
 	__perf_evlist__set_leader(list, &leader->core);
-	leader->group_name = name ? strdup(name) : NULL;
+	leader->group_name = name;
 	list_move(&leader->core.node, list);
 }
 

tools/perf/util/parse-events.y

@@ -202,8 +202,8 @@ PE_NAME '{' events '}'
 	struct list_head *list = $3;
 
 	inc_group_count(list, _parse_state);
+	/* Takes ownership of $1. */
 	parse_events__set_leader($1, list, _parse_state);
-	free($1);
 	$$ = list;
 }
 |