Re: [PATCH v2 13/13] perf parse-events: Remove ABORT_ON

From: Namhyung Kim <namhyung@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@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>,
	Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
	Kan Liang <kan.liang@linux.intel.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	bpf@vger.kernel.org
Subject: Re: [PATCH v2 13/13] perf parse-events: Remove ABORT_ON
Date: Thu, 29 Jun 2023 14:49:29 -0700	[thread overview]
Message-ID: <CAM9d7cjxrNTOUGxmTAycko_Gn_uY5aX8cBWTa-jrhLoc-Bur1g@mail.gmail.com> (raw)
In-Reply-To: <20230627181030.95608-14-irogers@google.com>

On Tue, Jun 27, 2023 at 11:11 AM Ian Rogers <irogers@google.com> wrote:
>
> Prefer informative messages rather than none with ABORT_ON. Document
> one failure mode and add an error message for another.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/parse-events.y | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 844646752462..454577f7aff6 100644
> --- a/tools/perf/util/parse-events.y
> +++ b/tools/perf/util/parse-events.y
> @@ -22,12 +22,6 @@
>
>  void parse_events_error(YYLTYPE *loc, void *parse_state, void *scanner, char const *msg);
>
> -#define ABORT_ON(val) \
> -do { \
> -       if (val) \
> -               YYABORT; \
> -} while (0)
> -
>  #define PE_ABORT(val) \
>  do { \
>         if (val == -ENOMEM) \
> @@ -618,7 +612,9 @@ PE_RAW opt_event_config
>                 YYNOMEM;
>         errno = 0;
>         num = strtoull($1 + 1, NULL, 16);
> -       ABORT_ON(errno);
> +       /* Given the lexer will only give [a-fA-F0-9]+ a failure here should be impossible. */
> +       if (errno)
> +               YYABORT;
>         free($1);
>         err = parse_events_add_numeric(_parse_state, list, PERF_TYPE_RAW, num, $2,
>                                        /*wildcard=*/false);
> @@ -978,7 +974,17 @@ PE_VALUE PE_ARRAY_RANGE PE_VALUE
>  {
>         struct parse_events_array array;
>
> -       ABORT_ON($3 < $1);
> +       if ($3 < $1) {
> +               struct parse_events_state *parse_state = _parse_state;
> +               struct parse_events_error *error = parse_state->error;
> +               char *err_str;
> +
> +               if (asprintf(&err_str, "Expected '%ld' to be less-than '%ld'", $3, $1) < 0)

Isn't it to be "greater-than or equal" ?

Thanks,
Namhyung

> +                       err_str = NULL;
> +
> +               parse_events_error__handle(error, @1.first_column, err_str, NULL);
> +               YYABORT;
> +       }
>         array.nr_ranges = 1;
>         array.ranges = malloc(sizeof(array.ranges[0]));
>         if (!array.ranges)
> --
> 2.41.0.162.gfafddb0af9-goog
>