grep: factor test for \0 in grep patterns into a function

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 change makes later changes that make use of either has_null() or is_fixed() (but not both) smaller. While I'm at it make the comment conform to the style guide, i.e. add an opening "/*\n". Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Ævar Arnfjörð Bjarmason committed May 25, 2017 at 19:45 UTC 219e65b65ca0f1352f5fbd4233520b6fc5be3726
1 file changed +15 -7
grep.c
+15 -7
@@ -321,6 +321,18 @@ static NORETURN void compile_regexp_failed(const struct grep_pat *p,
321 die("%s'%s': %s", where, p->pattern, error);
322 }
323
324 +static int has_null(const char *s, size_t len)
325 +{
326 + /*
327 + * regcomp cannot accept patterns with NULs so when using it
328 + * we consider any pattern containing a NUL fixed.
329 + */
330 + if (memchr(s, 0, len))
331 + return 1;
332 +
333 + return 0;
334 +}
335 +
336 #ifdef USE_LIBPCRE
337 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
338 {
@@ -394,12 +406,6 @@ static int is_fixed(const char *s, size_t len)
406 {
407 size_t i;
408
397 - /* regcomp cannot accept patterns with NULs so we
398 - * consider any pattern containing a NUL fixed.
399 - */
400 - if (memchr(s, 0, len))
401 - return 1;
402 -
409 for (i = 0; i < len; i++) {
410 if (is_regex_special(s[i]))
411 return 0;
@@ -451,7 +457,9 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
457 * simple string match using kws. p->fixed tells us if we
458 * want to use kws.
459 */
454 - if (opt->fixed || is_fixed(p->pattern, p->patternlen))
460 + if (opt->fixed ||
461 + has_null(p->pattern, p->patternlen) ||
462 + is_fixed(p->pattern, p->patternlen))
463 p->fixed = !icase || ascii_only;
464 else
465 p->fixed = 0;