[PATCH 21/29] grep: factor test for \0 in grep patterns into a function
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- May 11, 2017, 09:18 UTC
- Message-ID
- <20170511091829.5634-22-avarab@gmail.com>
- In-Reply-To
- <20170511091829.5634-1-avarab@gmail.com>
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@gmail.com> --- 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. + */ + 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