[PATCH v2 3/3] perf parse-events: Allow names to start with digits

[Dominique Martinet <asmadeus@codewreck.org>]

Tracepoints can start with digits, although we don't have many of these:

$ rg -g '*.h' '\bTRACE_EVENT\([0-9]'
net/mac802154/trace.h
53:TRACE_EVENT(802154_drv_return_int,
...

net/ieee802154/trace.h
66:TRACE_EVENT(802154_rdev_add_virtual_intf,
...

include/trace/events/9p.h
124:TRACE_EVENT(9p_client_req,
...

Just allow names to start with digits too so e.g. perf probe -e '9p:*'
works

Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
---
Changelog:
 v1 at https://lkml.kernel.org/r/20220612061508.1449636-1-asmadeus@codewreck.org
 v1->v2: add extra test now it doesn't break for everyone else :)

Ian suggested simplifying the name regex to:  [a-zA-Z0-9_*?\[\]!]+
but that:
- breaks probe names with a dot; or if we add a dot allows them to start
  with one
- also allows probes to start with !

I don't think that'd break anything if we allow .! as leading character
but it doesn't really make much difference to me either so I kept the
patch minimal: please say if you have an opinion.


 tools/perf/tests/parse-events.c | 5 +++++
 tools/perf/util/parse-events.l  | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index a8b5a570aaf6..0dc1fbc80447 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -1941,6 +1941,11 @@ static const struct evlist_test test__events[] = {
 		.check = test__exclusive_group,
 		/* 7 */
 	},
+	{
+		.name  = "9p:9p_client_req",
+		.check = test__checkevent_tracepoint,
+		/* 8 */
+	},
 };
 
 static const struct evlist_test test__events_pmu[] = {
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 3a9ce96c8bce..360f3c5de4fd 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -211,7 +211,7 @@ bpf_source	[^,{}]+\.c[a-zA-Z0-9._]*
 num_dec		[0-9]+
 num_hex		0x[a-fA-F0-9]+
 num_raw_hex	[a-fA-F0-9]+
-name		[a-zA-Z_*?\[\]][a-zA-Z0-9_*?.\[\]!]*
+name		[a-zA-Z0-9_*?\[\]][a-zA-Z0-9_*?.\[\]!]*
 name_tag	[\'][a-zA-Z_*?\[\]][a-zA-Z0-9_*?\-,\.\[\]:=]*[\']
 name_minus	[a-zA-Z_*?][a-zA-Z0-9\-_*?.:]*
 drv_cfg_term	[a-zA-Z0-9_\.]+(=[a-zA-Z0-9_*?\.:]+)?
-- 
2.37.3