libperf: Move 'leader' from tools/perf to perf_evsel::leader

Move evsel::leader to perf_evsel::leader, so we can move the group
interface to libperf.

Also add several evsel helpers to ease up the transition:

  struct evsel *evsel__leader(struct evsel *evsel);
  - get leader evsel

  bool evsel__has_leader(struct evsel *evsel, struct evsel *leader);
  - true if evsel has leader as leader

  bool evsel__is_leader(struct evsel *evsel);
  - true if evsel is itw own leader

  void evsel__set_leader(struct evsel *evsel, struct evsel *leader);
  - set leader for evsel

Committer notes:

Fix this when building with 'make BUILD_BPF_SKEL=1'

  tools/perf/util/bpf_counter.c

  -       if (evsel->leader->core.nr_members > 1) {
  +       if (evsel->core.leader->nr_members > 1) {

Signed-off-by: Jiri Olsa <[email protected]>
Requested-by: Shunsuke Nakamura <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h
index 86f674e36f62..1f3eacbad2e8 100644
--- a/tools/lib/perf/include/internal/evsel.h
+++ b/tools/lib/perf/include/internal/evsel.h
@@ -45,6 +45,7 @@ struct perf_evsel {
 	struct xyarray		*sample_id;
 	u64			*id;
 	u32			 ids;
+	struct perf_evsel	*leader;
 
 	/* parse modifier helper */
 	int			 nr_members;