perf evsel: Add support for synthesized branch stack sample type

Allow for a synthesized branch stack to be added to samples. As with
synthesized call chains, the sample type cannot be changed because it is
needed to continue to parse events. So add and use helper function
evsel__has_br_stack() to indicate a branch stack, whether original or
synthesized.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-6-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.h

@@ -417,6 +417,16 @@ static inline bool evsel__has_callchain(const struct evsel *evsel)
 	       evsel->synth_sample_type & PERF_SAMPLE_CALLCHAIN;
 }
 
+static inline bool evsel__has_br_stack(const struct evsel *evsel)
+{
+	/*
+	 * For reporting purposes, an evsel sample can have a recorded branch
+	 * stack or a branch stack synthesized from AUX area data.
+	 */
+	return evsel->core.attr.sample_type & PERF_SAMPLE_BRANCH_STACK ||
+	       evsel->synth_sample_type & PERF_SAMPLE_BRANCH_STACK;
+}
+
 struct perf_env *perf_evsel__env(struct evsel *evsel);
 
 int perf_evsel__store_ids(struct evsel *evsel, struct evlist *evlist);

tools/perf/util/session.c

@@ -1243,7 +1243,7 @@ static void dump_sample(struct evsel *evsel, union perf_event *event,
 	if (evsel__has_callchain(evsel))
 		callchain__printf(evsel, sample);
 
-	if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+	if (evsel__has_br_stack(evsel))
 		branch_stack__printf(sample, perf_evsel__has_branch_callstack(evsel));
 
 	if (sample_type & PERF_SAMPLE_REGS_USER)