On Thu, May 11, 2017 at 10:15 PM, Brandon Williams <[email protected]> wrote:
> 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 <[email protected]>
>> ---
>> 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?
Just losing the forest for the trees in rebasing this giant, willdo in
v2, i.e. just make this a function in the right place in this change.
>> + 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
