perf list: Display metric expressions for --details option

Display metric expression itself when --details is specified.

Current list with no details:

  # perf list metrics
  ...
  TopDownL1:
    IPC
         [Instructions Per Cycle (per logical thread)]
    SLOTS
         [Total issue-pipeline slots]
  ...

Detailed output with metric formula:

  # perf list --details metrics
  ...
  TopDownL1:
    IPC
         [Instructions Per Cycle (per logical thread)]
         [inst_retired.any / cpu_clk_unhalted.thread]
    SLOTS
         [Total issue-pipeline slots]
         [4*(( cpu_clk_unhalted.thread_any / 2 ) if #smt_on else cycles)]
  ...

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190213123246.4015-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/metricgroup.c

@@ -270,7 +270,7 @@ static void metricgroup__print_strlist(struct strlist *metrics, bool raw)
 }
 
 void metricgroup__print(bool metrics, bool metricgroups, char *filter,
-			bool raw)
+			bool raw, bool details)
 {
 	struct pmu_events_map *map = perf_pmu__find_map(NULL);
 	struct pmu_event *pe;
@@ -329,6 +329,12 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
 					if (asprintf(&s, "%s\n%*s%s]",
 						     pe->metric_name, 8, "[", pe->desc) < 0)
 						return;
+
+					if (details) {
+						if (asprintf(&s, "%s\n%*s%s]",
+							     s, 8, "[", pe->metric_expr) < 0)
+							return;
+					}
 				}
 
 				if (!s)

tools/perf/util/metricgroup.h

@@ -27,6 +27,7 @@ int metricgroup__parse_groups(const struct option *opt,
 			const char *str,
 			struct rblist *metric_events);
 
-void metricgroup__print(bool metrics, bool groups, char *filter, bool raw);
+void metricgroup__print(bool metrics, bool groups, char *filter,
+			bool raw, bool details);
 bool metricgroup__has_metric(const char *metric);
 #endif

tools/perf/util/parse-events.c

@@ -2540,7 +2540,7 @@ void print_events(const char *event_glob, bool name_only, bool quiet_flag,
 
 	print_sdt_events(NULL, NULL, name_only);
 
-	metricgroup__print(true, true, NULL, name_only);
+	metricgroup__print(true, true, NULL, name_only, details_flag);
 }
 
 int parse_events__is_hardcoded_term(struct parse_events_term *term)