perf evsel: Allow const evsel for certain accesses

List sorting, added later to evlist, passes const elements requiring
helper functions to also be const. Make the argument to
evsel__find_pmu, evsel__is_aux_event and evsel__leader const.
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/evsel.c

@@ -3139,7 +3139,7 @@ bool evsel__is_hybrid(const struct evsel *evsel)
 	return evsel->pmu_name && perf_pmu__is_hybrid(evsel->pmu_name);
 }
 
-struct evsel *evsel__leader(struct evsel *evsel)
+struct evsel *evsel__leader(const struct evsel *evsel)
 {
 	return container_of(evsel->core.leader, struct evsel, core);
 }

tools/perf/util/evsel.h

@@ -212,8 +212,8 @@ int evsel__object_config(size_t object_size,
 			 int (*init)(struct evsel *evsel),
 			 void (*fini)(struct evsel *evsel));
 
-struct perf_pmu *evsel__find_pmu(struct evsel *evsel);
-bool evsel__is_aux_event(struct evsel *evsel);
+struct perf_pmu *evsel__find_pmu(const struct evsel *evsel);
+bool evsel__is_aux_event(const struct evsel *evsel);
 
 struct evsel *evsel__new_idx(struct perf_event_attr *attr, int idx);
 
@@ -505,7 +505,7 @@ int evsel__store_ids(struct evsel *evsel, struct evlist *evlist);
 
 void evsel__zero_per_pkg(struct evsel *evsel);
 bool evsel__is_hybrid(const struct evsel *evsel);
-struct evsel *evsel__leader(struct evsel *evsel);
+struct evsel *evsel__leader(const struct evsel *evsel);
 bool evsel__has_leader(struct evsel *evsel, struct evsel *leader);
 bool evsel__is_leader(struct evsel *evsel);
 void evsel__set_leader(struct evsel *evsel, struct evsel *leader);

tools/perf/util/pmu.c

@@ -988,7 +988,7 @@ struct perf_pmu *perf_pmu__scan(struct perf_pmu *pmu)
 	return NULL;
 }
 
-struct perf_pmu *evsel__find_pmu(struct evsel *evsel)
+struct perf_pmu *evsel__find_pmu(const struct evsel *evsel)
 {
 	struct perf_pmu *pmu = NULL;
 
@@ -1000,11 +1000,11 @@ struct perf_pmu *evsel__find_pmu(struct evsel *evsel)
 			break;
 	}
 
-	evsel->pmu = pmu;
+	((struct evsel *)evsel)->pmu = pmu;
 	return pmu;
 }
 
-bool evsel__is_aux_event(struct evsel *evsel)
+bool evsel__is_aux_event(const struct evsel *evsel)
 {
 	struct perf_pmu *pmu = evsel__find_pmu(evsel);
 

tools/perf/util/python.c

@@ -83,7 +83,7 @@ const char *perf_env__arch(struct perf_env *env __maybe_unused)
  * far, for the perf python binding known usecases, revisit if this become
  * necessary.
  */
-struct perf_pmu *evsel__find_pmu(struct evsel *evsel __maybe_unused)
+struct perf_pmu *evsel__find_pmu(const struct evsel *evsel __maybe_unused)
 {
 	return NULL;
 }