perf evlist: Add fprintf method

For debugging, etc.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-fjimge1ovgh976qlt8dtmlp0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evlist.c

@@ -889,3 +889,16 @@ int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *even
 	struct perf_evsel *evsel = perf_evlist__first(evlist);
 	return perf_evsel__parse_sample(evsel, event, sample, swapped);
 }
+
+size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
+{
+	struct perf_evsel *evsel;
+	size_t printed = 0;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
+				   perf_evsel__name(evsel));
+	}
+
+	return printed + fprintf(fp, "\n");;
+}

tools/perf/util/evlist.h

@@ -143,4 +143,6 @@ static inline struct perf_evsel *perf_evlist__last(struct perf_evlist *evlist)
 {
 	return list_entry(evlist->entries.prev, struct perf_evsel, node);
 }
+
+size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp);
 #endif /* __PERF_EVLIST_H */