perf parse-events: Make common term list to strbuf helper

A term list is turned into a string for debug output and for the str
value in the alias.

Add a helper to do this based on existing code, but then fix for
situations like events being identified.

Use strbuf to manage the dynamic memory allocation and remove the 256
byte limit.

Use in various places the string of the term list is required.

Before:

  $ sudo perf stat -vv -e inst_retired.any true
  Using CPUID GenuineIntel-6-8D-1
  intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
  Attempting to add event pmu 'cpu' with 'inst_retired.any,' that may result in non-fatal errors
  After aliases, add event pmu 'cpu' with 'event,period,' that may result in non-fatal errors
  inst_retired.any -> cpu/inst_retired.any/
  ...

After:

$ sudo perf stat -vv -e inst_retired.any true

  Using CPUID GenuineIntel-6-8D-1
  intel_pt default config: tsc,mtc,mtc_period=3,psb_period=3,pt,branch
  Attempt to add: cpu/inst_retired.any/
  ..after resolving event: cpu/event=0xc0,period=0x1e8483/
  inst_retired.any -> cpu/event=0xc0,period=0x1e8483/
  ...

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20230830070753.1821629-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 6d75d853ce00..20bdc35d6112 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -18,6 +18,7 @@ struct parse_events_error;
 
 struct option;
 struct perf_pmu;
+struct strbuf;
 
 const char *event_type(int type);
 
@@ -152,6 +153,7 @@ int parse_events_term__clone(struct parse_events_term **new,
 void parse_events_term__delete(struct parse_events_term *term);
 void parse_events_terms__delete(struct list_head *terms);
 void parse_events_terms__purge(struct list_head *terms);
+int parse_events_term__to_strbuf(struct list_head *term_list, struct strbuf *sb);
 int parse_events__modifier_event(struct list_head *list, char *str, bool add);
 int parse_events__modifier_group(struct list_head *list, char *event_mod);
 int parse_events_name(struct list_head *list, const char *name);