A common pattern in in pipe-mode bugs is accessing an empty evlist. Return NULL to make it easier to catch this problems.
Signed-off-by: David Carrillo-Cisneros <davi...@google.com> --- tools/perf/util/evlist.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 39942995f537..ba4788462325 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -257,11 +257,15 @@ void perf_evlist__splice_list_tail(struct perf_evlist *evlist, static inline struct perf_evsel *perf_evlist__first(struct perf_evlist *evlist) { + if (list_empty(&evlist->entries)) + return NULL; return list_entry(evlist->entries.next, struct perf_evsel, node); } static inline struct perf_evsel *perf_evlist__last(struct perf_evlist *evlist) { + if (list_empty(&evlist->entries)) + return NULL; return list_entry(evlist->entries.prev, struct perf_evsel, node); } -- 2.12.2.715.g7642488e1d-goog