perf parse-events: Add new 'fake_tp' parameter for tests

The next commit will allow tracepoints starting with digits, but most
systems do not have any available by default so tests should skip the
actual "check if it exists in /sys/kernel/debug/tracing" step.

In order to do that, add a new boolean flag specifying if we should
actually "format" the probe or not.

Originally-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240510-perf_digit-v4-2-db1553f3233b@codewreck.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/parse-events.c

@@ -2493,7 +2493,8 @@ static int test_event(const struct evlist_test *e)
 		return TEST_FAIL;
 	}
 	parse_events_error__init(&err);
-	ret = parse_events(evlist, e->name, &err);
+	ret = __parse_events(evlist, e->name, /*pmu_filter=*/NULL, &err, /*fake_pmu=*/NULL,
+			     /*warn_if_reordered=*/true, /*fake_tp=*/true);
 	if (ret) {
 		pr_debug("failed to parse event '%s', err %d\n", e->name, ret);
 		parse_events_error__print(&err, e->name);
@@ -2521,7 +2522,8 @@ static int test_event_fake_pmu(const char *str)
 
 	parse_events_error__init(&err);
 	ret = __parse_events(evlist, str, /*pmu_filter=*/NULL, &err,
-			     &perf_pmu__fake, /*warn_if_reordered=*/true);
+			     &perf_pmu__fake, /*warn_if_reordered=*/true,
+			     /*fake_tp=*/true);
 	if (ret) {
 		pr_debug("failed to parse event '%s', err %d\n",
 			 str, ret);

tools/perf/tests/pmu-events.c

@@ -842,7 +842,7 @@ static int check_parse_id(const char *id, struct parse_events_error *error,
 		*cur = '/';
 
 	ret = __parse_events(evlist, dup, /*pmu_filter=*/NULL, error, fake_pmu,
-			     /*warn_if_reordered=*/true);
+			     /*warn_if_reordered=*/true, /*fake_tp=*/false);
 	free(dup);
 
 	evlist__delete(evlist);

tools/perf/util/evlist.c

@@ -298,7 +298,8 @@ struct evsel *evlist__add_aux_dummy(struct evlist *evlist, bool system_wide)
 #ifdef HAVE_LIBTRACEEVENT
 struct evsel *evlist__add_sched_switch(struct evlist *evlist, bool system_wide)
 {
-	struct evsel *evsel = evsel__newtp_idx("sched", "sched_switch", 0);
+	struct evsel *evsel = evsel__newtp_idx("sched", "sched_switch", 0,
+					       /*format=*/true);
 
 	if (IS_ERR(evsel))
 		return evsel;

tools/perf/util/evsel.c

@@ -452,7 +452,7 @@ struct evsel *evsel__clone(struct evsel *orig)
  * Returns pointer with encoded error via <linux/err.h> interface.
  */
 #ifdef HAVE_LIBTRACEEVENT
-struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx)
+struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx, bool format)
 {
 	struct evsel *evsel = zalloc(perf_evsel__object.size);
 	int err = -ENOMEM;
@@ -469,14 +469,20 @@ struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx)
 		if (asprintf(&evsel->name, "%s:%s", sys, name) < 0)
 			goto out_free;
 
-		evsel->tp_format = trace_event__tp_format(sys, name);
-		if (IS_ERR(evsel->tp_format)) {
-			err = PTR_ERR(evsel->tp_format);
-			goto out_free;
+		event_attr_init(&attr);
+
+		if (format) {
+			evsel->tp_format = trace_event__tp_format(sys, name);
+			if (IS_ERR(evsel->tp_format)) {
+				err = PTR_ERR(evsel->tp_format);
+				goto out_free;
+			}
+			attr.config = evsel->tp_format->id;
+		} else {
+			attr.config = (__u64) -1;
 		}
 
-		event_attr_init(&attr);
-		attr.config = evsel->tp_format->id;
+
 		attr.sample_period = 1;
 		evsel__init(evsel, &attr, idx);
 	}

tools/perf/util/evsel.h

@@ -234,14 +234,14 @@ void free_config_terms(struct list_head *config_terms);
 
 
 #ifdef HAVE_LIBTRACEEVENT
-struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx);
+struct evsel *evsel__newtp_idx(const char *sys, const char *name, int idx, bool format);
 
 /*
  * Returns pointer with encoded error via <linux/err.h> interface.
  */
 static inline struct evsel *evsel__newtp(const char *sys, const char *name)
 {
-	return evsel__newtp_idx(sys, name, 0);
+	return evsel__newtp_idx(sys, name, 0, true);
 }
 #endif
 

tools/perf/util/metricgroup.c

@@ -1502,7 +1502,8 @@ static int parse_ids(bool metric_no_merge, struct perf_pmu *fake_pmu,
 	pr_debug("Parsing metric events '%s'\n", events.buf);
 	parse_events_error__init(&parse_error);
 	ret = __parse_events(parsed_evlist, events.buf, /*pmu_filter=*/NULL,
-			     &parse_error, fake_pmu, /*warn_if_reordered=*/false);
+			     &parse_error, fake_pmu, /*warn_if_reordered=*/false,
+			     /*fake_tp=*/false);
 	if (ret) {
 		parse_events_error__print(&parse_error, events.buf);
 		goto err_out;

tools/perf/util/parse-events.c

@@ -550,7 +550,8 @@ static int add_tracepoint(struct parse_events_state *parse_state,
 			  struct parse_events_terms *head_config, void *loc_)
 {
 	YYLTYPE *loc = loc_;
-	struct evsel *evsel = evsel__newtp_idx(sys_name, evt_name, parse_state->idx++);
+	struct evsel *evsel = evsel__newtp_idx(sys_name, evt_name, parse_state->idx++,
+					       !parse_state->fake_tp);
 
 	if (IS_ERR(evsel)) {
 		tracepoint_error(err, PTR_ERR(evsel), sys_name, evt_name, loc->first_column);
@@ -2135,14 +2136,15 @@ static int parse_events__sort_events_and_fix_groups(struct list_head *list)
 
 int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filter,
 		   struct parse_events_error *err, struct perf_pmu *fake_pmu,
-		   bool warn_if_reordered)
+		   bool warn_if_reordered, bool fake_tp)
 {
 	struct parse_events_state parse_state = {
 		.list	  = LIST_HEAD_INIT(parse_state.list),
 		.idx	  = evlist->core.nr_entries,
 		.error	  = err,
 		.stoken	  = PE_START_EVENTS,
 		.fake_pmu = fake_pmu,
+		.fake_tp  = fake_tp,
 		.pmu_filter = pmu_filter,
 		.match_legacy_cache_terms = true,
 	};
@@ -2352,7 +2354,8 @@ int parse_events_option(const struct option *opt, const char *str,
 
 	parse_events_error__init(&err);
 	ret = __parse_events(*args->evlistp, str, args->pmu_filter, &err,
-			     /*fake_pmu=*/NULL, /*warn_if_reordered=*/true);
+			     /*fake_pmu=*/NULL, /*warn_if_reordered=*/true,
+			     /*fake_tp=*/false);
 
 	if (ret) {
 		parse_events_error__print(&err, str);

tools/perf/util/parse-events.h

@@ -32,14 +32,14 @@ int parse_events_option_new_evlist(const struct option *opt, const char *str, in
 __attribute__((nonnull(1, 2, 4)))
 int __parse_events(struct evlist *evlist, const char *str, const char *pmu_filter,
 		   struct parse_events_error *error, struct perf_pmu *fake_pmu,
-		   bool warn_if_reordered);
+		   bool warn_if_reordered, bool fake_tp);
 
 __attribute__((nonnull(1, 2, 3)))
 static inline int parse_events(struct evlist *evlist, const char *str,
 			       struct parse_events_error *err)
 {
 	return __parse_events(evlist, str, /*pmu_filter=*/NULL, err, /*fake_pmu=*/NULL,
-			      /*warn_if_reordered=*/true);
+			      /*warn_if_reordered=*/true, /*fake_tp=*/false);
 }
 
 int parse_event(struct evlist *evlist, const char *str);
@@ -152,6 +152,8 @@ struct parse_events_state {
 	int			   stoken;
 	/* Special fake PMU marker for testing. */
 	struct perf_pmu		  *fake_pmu;
+	/* Skip actual tracepoint processing for testing. */
+	bool			   fake_tp;
 	/* If non-null, when wildcard matching only match the given PMU. */
 	const char		  *pmu_filter;
 	/* Should PE_LEGACY_NAME tokens be generated for config terms? */