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From: Ian Rogers <irogers@google.com>
Date: Thu, 16 May 2024 13:15:23 -0700
Message-ID: <CAP-5=fUaUGJ-09N-u39YyZgJOnj_WE91-hUc8dv+tf7ozA3K2Q@mail.gmail.com>
Subject: Re: [PATCH v3] perf list: Fix the --no-desc option
To: Breno Leitao <leitao@debian.org>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
	Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, 
	Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Adrian Hunter <adrian.hunter@intel.com>, leit@meta.com, 
	"open list:PERFORMANCE EVENTS SUBSYSTEM" <linux-perf-users@vger.kernel.org>, 
	"open list:PERFORMANCE EVENTS SUBSYSTEM" <linux-kernel@vger.kernel.org>
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On Thu, May 16, 2024 at 6:18=E2=80=AFAM Breno Leitao <leitao@debian.org> wr=
ote:
>
> Currently, the --no-desc option in perf list isn't functioning as
> intended.
>
> This issue arises from the overwriting of struct option->desc with the
> opposite value of struct option->long_desc. Consequently, whatever
> parse_options() returns at struct option->desc gets overridden later,
> rendering the --desc or --no-desc arguments ineffective.
>
> To resolve this, set ->desc as true by default and allow parse_options()
> to adjust it accordingly. This adjustment will fix the --no-desc
> option while preserving the functionality of the other parameters.
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
> Changelog:
>
> v3:
>         * Applied the same logic to default_print_metric() and
>           json_print_event() functions, as identified by Ian Rogers.

I don't think we should change the json behavior. We're generating a
dictionary and the consumer of the dictionary isn't obligated to read
all of it. I tested the non-json output and it all looks good.

Thanks,
Ian

> v2:
>         * Do not print desc if long_desc is being printed, as identified
>           by Ian Rogers.
>
> ---
>  tools/perf/builtin-list.c | 34 +++++++++++++++-------------------
>  1 file changed, 15 insertions(+), 19 deletions(-)
>
> diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
> index 02bf608d585e..8a0e123587f3 100644
> --- a/tools/perf/builtin-list.c
> +++ b/tools/perf/builtin-list.c
> @@ -149,7 +149,11 @@ static void default_print_event(void *ps, const char=
 *pmu_name, const char *topi
>         } else
>                 fputc('\n', fp);
>
> -       if (desc && print_state->desc) {
> +       if (long_desc && print_state->long_desc) {
> +               fprintf(fp, "%*s", 8, "[");
> +               wordwrap(fp, long_desc, 8, pager_get_columns(), 0);
> +               fprintf(fp, "]\n");
> +       } else if (desc && print_state->desc) {
>                 char *desc_with_unit =3D NULL;
>                 int desc_len =3D -1;
>
> @@ -165,12 +169,6 @@ static void default_print_event(void *ps, const char=
 *pmu_name, const char *topi
>                 fprintf(fp, "]\n");
>                 free(desc_with_unit);
>         }
> -       long_desc =3D long_desc ?: desc;
> -       if (long_desc && print_state->long_desc) {
> -               fprintf(fp, "%*s", 8, "[");
> -               wordwrap(fp, long_desc, 8, pager_get_columns(), 0);
> -               fprintf(fp, "]\n");
> -       }
>
>         if (print_state->detailed && encoding_desc) {
>                 fprintf(fp, "%*s", 8, "");
> @@ -243,15 +241,14 @@ static void default_print_metric(void *ps,
>         }
>         fprintf(fp, "  %s\n", name);
>
> -       if (desc && print_state->desc) {
> -               fprintf(fp, "%*s", 8, "[");
> -               wordwrap(fp, desc, 8, pager_get_columns(), 0);
> -               fprintf(fp, "]\n");
> -       }
>         if (long_desc && print_state->long_desc) {
>                 fprintf(fp, "%*s", 8, "[");
>                 wordwrap(fp, long_desc, 8, pager_get_columns(), 0);
>                 fprintf(fp, "]\n");
> +       } else if (desc && print_state->desc) {
> +               fprintf(fp, "%*s", 8, "[");
> +               wordwrap(fp, desc, 8, pager_get_columns(), 0);
> +               fprintf(fp, "]\n");
>         }
>         if (expr && print_state->detailed) {
>                 fprintf(fp, "%*s", 8, "[");
> @@ -395,17 +392,16 @@ static void json_print_event(void *ps, const char *=
pmu_name, const char *topic,
>                                    deprecated ? "1" : "0");
>                 need_sep =3D true;
>         }
> -       if (desc) {
> -               fix_escape_fprintf(fp, &buf, "%s\t\"BriefDescription\": \=
"%S\"",
> -                                  need_sep ? ",\n" : "",
> -                                  desc);
> -               need_sep =3D true;
> -       }
>         if (long_desc) {
>                 fix_escape_fprintf(fp, &buf, "%s\t\"PublicDescription\": =
\"%S\"",
>                                    need_sep ? ",\n" : "",
>                                    long_desc);
>                 need_sep =3D true;
> +       } else if (desc) {
> +               fix_escape_fprintf(fp, &buf, "%s\t\"BriefDescription\": \=
"%S\"",
> +                                  need_sep ? ",\n" : "",
> +                                  desc);
> +               need_sep =3D true;
>         }
>         if (encoding_desc) {
>                 fix_escape_fprintf(fp, &buf, "%s\t\"Encoding\": \"%S\"",
> @@ -491,6 +487,7 @@ int cmd_list(int argc, const char **argv)
>         int i, ret =3D 0;
>         struct print_state default_ps =3D {
>                 .fp =3D stdout,
> +               .desc =3D true,
>         };
>         struct print_state json_ps =3D {
>                 .fp =3D stdout,
> @@ -563,7 +560,6 @@ int cmd_list(int argc, const char **argv)
>                 };
>                 ps =3D &json_ps;
>         } else {
> -               default_ps.desc =3D !default_ps.long_desc;
>                 default_ps.last_topic =3D strdup("");
>                 assert(default_ps.last_topic);
>                 default_ps.visited_metrics =3D strlist__new(NULL, NULL);
> --
> 2.43.0
>