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From:   Ian Rogers <irogers@google.com>
Date:   Fri, 26 Jun 2020 13:25:44 -0700
Message-ID: <CAP-5=fWDoFrUL5ieFGYZ=W-4aq3OJMN=vCNoDDTP1z9x4mic6g@mail.gmail.com>
Subject: Re: [PATCH 04/10] perf tools: Change expr__get_id to return struct expr_parse_data
To:     Jiri Olsa <jolsa@kernel.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Michael Petlan <mpetlan@redhat.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        John Garry <john.garry@huawei.com>,
        "Paul A. Clarke" <pc@us.ibm.com>,
        Stephane Eranian <eranian@google.com>
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On Fri, Jun 26, 2020 at 12:47 PM Jiri Olsa <jolsa@kernel.org> wrote:
>
> Changing expr__get_id to use and return struct expr_parse_data
> pointer as value for the ID. This way we can access data other
> than value for given ID in following changes.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  tools/perf/util/expr.c | 10 +++-------
>  tools/perf/util/expr.h |  3 ++-
>  tools/perf/util/expr.y | 14 +++++++++-----
>  3 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c
> index 0b6d3a6ce88e..29cdef18849c 100644
> --- a/tools/perf/util/expr.c
> +++ b/tools/perf/util/expr.c
> @@ -69,14 +69,10 @@ int expr__add_val(struct expr_parse_ctx *ctx, const char *name, double val)
>         return ret;
>  }
>
> -int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr)
> +int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
> +                struct expr_parse_data **data)
>  {
> -       struct expr_parse_data *data;
> -
> -       if (!hashmap__find(&ctx->ids, id, (void **)&data))
> -               return -1;
> -       *val_ptr = (data == NULL) ?  0.0 : data->val;
> -       return 0;
> +       return hashmap__find(&ctx->ids, id, (void **)data) ? 0 : -1;
>  }

Nit, the 0 vs -1 here is a bit sad given hashmap__find is using true
to mean present. I'm also guilty of not trying to clean this up.

Acked-by: Ian Rogers <irogers@google.com>

>  void expr__ctx_init(struct expr_parse_ctx *ctx)
> diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h
> index 5452e641acf4..0af5b887b6c7 100644
> --- a/tools/perf/util/expr.h
> +++ b/tools/perf/util/expr.h
> @@ -28,7 +28,8 @@ void expr__ctx_init(struct expr_parse_ctx *ctx);
>  void expr__ctx_clear(struct expr_parse_ctx *ctx);
>  int expr__add_id(struct expr_parse_ctx *ctx, const char *name);
>  int expr__add_val(struct expr_parse_ctx *ctx, const char *id, double val);
> -int expr__get_id(struct expr_parse_ctx *ctx, const char *id, double *val_ptr);
> +int expr__get_id(struct expr_parse_ctx *ctx, const char *id,
> +                struct expr_parse_data **data);
>  int expr__parse(double *final_val, struct expr_parse_ctx *ctx,
>                 const char *expr, int runtime);
>  int expr__find_other(const char *expr, const char *one,
> diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
> index ac4b119877e0..6252d9f6cfc8 100644
> --- a/tools/perf/util/expr.y
> +++ b/tools/perf/util/expr.y
> @@ -87,12 +87,16 @@ if_expr:
>         ;
>
>  expr:    NUMBER
> -       | ID                    { if (expr__get_id(ctx, $1, &$$)) {
> -                                       pr_debug("%s not found\n", $1);
> +       | ID                    {
> +                                       struct expr_parse_data *data;
> +
> +                                       if (expr__get_id(ctx, $1, &data) || !data) {
> +                                               pr_debug("%s not found\n", $1);
> +                                               free($1);
> +                                               YYABORT;
> +                                       }
> +                                       $$ = data->val;
>                                         free($1);
> -                                       YYABORT;
> -                                 }
> -                                 free($1);
>                                 }
>         | expr '|' expr         { $$ = (long)$1 | (long)$3; }
>         | expr '&' expr         { $$ = (long)$1 & (long)$3; }
> --
> 2.25.4
>