Am 05.05.2018 um 04:42 schrieb Taylor Blau:
> When calling match_line(), callers presently cannot determine the
> relative offset of the match because match_line() discards the
> 'regmatch_t' that contains this information.
>
> Instead, teach match_line() to take in a 'regmatch_t *' so that callers
> can inspect the match's starting and ending offset from the beginning of
> the line. This additional argument has no effect when opt->extended is
> non-zero.
>
> We will later pass the starting offset from 'regmatch_t *' to
> show_line() in order to display the column number of the first match.
>
> Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
> ---
> grep.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/grep.c b/grep.c
> index 65b90c10a3..1c25782355 100644
> --- 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);
If ->extended is set then match won't be touched...
>
> /* 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;
> @@ -1699,6 +1699,7 @@ static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int colle
> int try_lookahead = 0;
> int show_function = 0;
> struct userdiff_driver *textconv = NULL;
> + regmatch_t match;
> enum grep_context ctx = GREP_CONTEXT_HEAD;
> xdemitconf_t xecfg;
>
> @@ -1788,7 +1789,7 @@ static int grep_source_1(struct grep_opt *opt, struct grep_source *gs, int colle
> if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
> ctx = GREP_CONTEXT_BODY;
>
> - hit = match_line(opt, bol, eol, ctx, collect_hits);
> + hit = match_line(opt, bol, eol, &match, ctx, collect_hits);
> *eol = ch;
>
> if (collect_hits)
>
... which leaves it uninitialized.
So at least the combination of extended matches and --column should error
out. Supporting it would be better, of course. That could get tricky for
negations, though (e.g. git grep --not -e foo).
René
