Re: [PATCH v2 1/6] grep.c: take regmatch_t as argument in match_line()

> In a subsequent patch, we teach show_line() to optionally include the
> column number of the first match on each matched line.
>
> The regmatch_t involved in match_line() and match_one_pattern() both
> contain this information (via regmatch_t->rm_so), but their current
> implementation throws this stack variable away at the end of the call.
>
> Instead, let's teach match_line() to take in a 'regmatch_t *' so that
> callers can inspect the result of their calls. This will prove useful in
> a subsequent commit when a caller will forward on information from the
> regmatch_t into show_line (as described above).
>
> The return condition remains unchanged, therefore the only change
> required of callers is the addition of a single argument.

> Signed-off-by: Taylor Blau <me@ttaylorr.com>
> ---
> diff --git a/grep.c b/grep.c
> @@ -1299,17 +1299,17 @@ static int match_expr(struct grep_opt *opt, char *bol, char *eol,
>  static int match_line(struct grep_opt *opt, char *bol, char *eol,
> -                     enum grep_context ctx, int collect_hits)
> +                     regmatch_t *match, enum grep_context ctx,
> +                     int collect_hits)
>  {
>         struct grep_pat *p;
> -       regmatch_t match;
>
>         if (opt->extended)
>                 return match_expr(opt, bol, eol, ctx, collect_hits);

>         /* we do not call with collect_hits without being extended */
>         for (p = opt->pattern_list; p; p = p->next) {
> -               if (match_one_pattern(p, bol, eol, ctx, &match, 0))
> +               if (match_one_pattern(p, bol, eol, ctx, match, 0))
>                         return 1;
>         }
>         return 0;