On 05/11, Ævar Arnfjörð Bjarmason wrote:
> Factor the test for \0 in grep patterns into a function. Since commit
> 9eceddeec6 ("Use kwset in grep", 2011-08-21) any pattern containing a
> \0 is considered fixed as regcomp() can't handle it.
>
> This limitation was never documented, and other some regular
> expression engines are capable of compiling a pattern containing a
> \0. Factoring this out makes a subsequent change which does that
> smaller.
>
> See a previous commit in this series ("grep: add tests to fix blind
> spots with \0 patterns", 2017-04-21) for further details & rationale.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
> ---
> grep.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/grep.c b/grep.c
> index bf6c2494fd..27de615209 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -394,12 +394,6 @@ static int is_fixed(const char *s, size_t len)
> {
> size_t i;
>
> - /* regcomp cannot accept patterns with NULs so we
> - * consider any pattern containing a NUL fixed.
> - */
> - if (memchr(s, 0, len))
> - return 1;
> -
> for (i = 0; i < len; i++) {
> if (is_regex_special(s[i]))
> return 0;
> @@ -408,6 +402,17 @@ static int is_fixed(const char *s, size_t len)
> return 1;
> }
>
> +static int has_null(const char *s, size_t len)
> +{
> + /* regcomp cannot accept patterns with NULs so when using it
> + * we consider any pattern containing a NUL fixed.
> + */
I commented on a later patch but really the comment should be fixed
here. And why not simply move this to where you intend it to be at the
end of the series now?
> + if (memchr(s, 0, len))
> + return 1;
> +
> + return 0;
> +}
> +
> static void compile_fixed_regexp(struct grep_pat *p, struct grep_opt *opt)
> {
> struct strbuf sb = STRBUF_INIT;
> @@ -451,7 +456,7 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
> * simple string match using kws. p->fixed tells us if we
> * want to use kws.
> */
> - if (opt->fixed || is_fixed(p->pattern, p->patternlen))
> + if (opt->fixed || has_null(p->pattern, p->patternlen) || is_fixed(p->pattern, p->patternlen))
> p->fixed = !icase || ascii_only;
> else
> p->fixed = 0;
> --
> 2.11.0
>
--
Brandon Williams