[PATCH 3/3] perf script: Align event name properly

[Jiri Olsa <jolsa@kernel.org>]

Adding code to align event names, so we get aligned output
in case of multiple events with different names.

Before:
  $ perf script
  :13757 13757 163918.230829: cpu/mem-snp-none/P: ffff88085f20d010
  :13757 13757 163918.230832: cpu/mem-loads,ldlat=30/P:     7f5a5f719f00
  :13757 13757 163918.230835: cpu/mem-loads,ldlat=30/P:     7f5a5f719f00
  :13758 13758 163918.230838: cpu/mem-snp-none/P: ffff88085f4ad810
  :13758 13758 163918.154093: cpu/mem-stores/P: ffff88085bb53f28
  :13757 13757 163918.155264: cpu/mem-snp-hitm/P:           601080
  ...

After:
  $ perf script
  :13757 13757 163918.228831:       cpu/mem-snp-none/P: ffffffff81a841c0
  :13757 13757 163918.228834: cpu/mem-loads,ldlat=30/P:     7f5a5f719f08
  :13757 13757 163918.228837: cpu/mem-loads,ldlat=30/P:     7f5a5f719f08
  :13758 13758 163918.228837:       cpu/mem-snp-none/P: ffff88085f4ad800
  :13758 13758 163918.154093:         cpu/mem-stores/P: ffff88085bb53f28
  :13757 13757 163918.155264:       cpu/mem-snp-hitm/P:           601080
  ...

Link: http://lkml.kernel.org/n/tip-hsrwmiogt9menjsg7uaxqvq2@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-script.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 3c3f8d0e3064..10a96da0ea56 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -594,9 +594,24 @@ struct perf_script {
 	bool			show_task_events;
 	bool			show_mmap_events;
 	bool			show_switch_events;
+	int			name_width;
 };
 
-static void process_event(struct perf_script *script __maybe_unused, union perf_event *event,
+static int perf_evlist__max_name_len(struct perf_evlist *evlist)
+{
+	struct perf_evsel *evsel;
+	int max = 0;
+
+	evlist__for_each(evlist, evsel) {
+		int len = strlen(perf_evsel__name(evsel));
+
+		max = MAX(len, max);
+	}
+
+	return max;
+}
+
+static void process_event(struct perf_script *script, union perf_event *event,
 			  struct perf_sample *sample, struct perf_evsel *evsel,
 			  struct addr_location *al)
 {
@@ -613,7 +628,12 @@ static void process_event(struct perf_script *script __maybe_unused, union perf_
 
 	if (PRINT_FIELD(EVNAME)) {
 		const char *evname = perf_evsel__name(evsel);
-		printf("%s: ", evname ? evname : "[unknown]");
+
+		if (!script->name_width)
+			script->name_width = perf_evlist__max_name_len(script->session->evlist);
+
+		printf("%*s: ", script->name_width,
+		       evname ? evname : "[unknown]");
 	}
 
 	if (print_flags)
-- 
2.4.3