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[PATCH v4 23/31] grep: factor test for \0 in grep patterns into a function

From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date
May 25, 2017, 19:45 UTC
Message-ID
<20170525194535.9324-24-avarab@gmail.com>
In-Reply-To
<20170525194535.9324-1-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 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>
---
 grep.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/grep.c b/grep.c
index bf6c2494fd..18306bc605 100644
--- a/grep.c
+++ b/grep.c
@@ -321,6 +321,18 @@ static NORETURN void compile_regexp_failed(const struct grep_pat *p,
 	die("%s'%s': %s", where, p->pattern, error);
 }
 
+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;
+}
+
 #ifdef USE_LIBPCRE
 static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 {
@@ -394,12 +406,6 @@ 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;
@@ -451,7 +457,9 @@ 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;

-- 
2.13.0.303.g4ebf302169
Previous: Ævar Arnfjörð BjarmasonNext: Ævar Arnfjörð Bjarmason
Message 23 of 32 in “Easy to review grep & pre-PCRE changes”
  1. 00/31 Easy to review grep & pre-PCRE changesÆvar Arnfjörð Bjarmason, May 25, 2017
  2. 01/31 Makefile & configure: reword inaccurate comment about PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  3. 02/31 grep & rev-list doc: stop promising libpcre for --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  4. 04/31 log: add exhaustive tests for pattern style options & configÆvar Arnfjörð Bjarmason, May 25, 2017
  5. 03/31 test-lib: rename the LIBPCRE prerequisite to PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  6. 05/31 log: make --regexp-ignore-case work with --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  7. 07/31 grep: add a test for backreferences in PCRE patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  8. 08/31 grep: change non-ASCII -i test to stop using --debugÆvar Arnfjörð Bjarmason, May 25, 2017
  9. 06/31 grep: add a test asserting that --perl-regexp dies when !PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  10. 09/31 grep: add tests for --threads=N and grep.threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  11. 10/31 grep: amend submodule recursion test for regex engine testingÆvar Arnfjörð Bjarmason, May 25, 2017
  12. 11/31 grep: add tests for grep pattern types being passed to submodulesÆvar Arnfjörð Bjarmason, May 25, 2017
  13. 12/31 grep: add a test helper function for less verbose -f \0 testsÆvar Arnfjörð Bjarmason, May 25, 2017
  14. 13/31 grep: prepare for testing binary regexes containing rx metacharactersÆvar Arnfjörð Bjarmason, May 25, 2017
  15. 14/31 grep: add tests to fix blind spots with \0 patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  16. 16/31 perf: emit progress output when unpacking & buildingÆvar Arnfjörð Bjarmason, May 25, 2017
  17. 18/31 perf: add a comparison test of grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  18. 17/31 perf: add a comparison test of grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  19. 15/31 perf: add a GIT_PERF_MAKE_COMMAND for when *_MAKE_OPTS won't doÆvar Arnfjörð Bjarmason, May 25, 2017
  20. 19/31 perf: add a comparison test of log --grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  21. 20/31 perf: add a comparison test of log --grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  22. 24/31 grep: change the internal PCRE macro names to be PCRE1Ævar Arnfjörð Bjarmason, May 25, 2017
  23. 23/31 grep: factor test for \0 in grep patterns into a functionÆvar Arnfjörð Bjarmason, May 25, 2017
  24. 21/31 grep: catch a missing enum in switch statementÆvar Arnfjörð Bjarmason, May 25, 2017
  25. 22/31 grep: remove redundant regflags assignmentsÆvar Arnfjörð Bjarmason, May 25, 2017
  26. 28/31 pack-objects & index-pack: add test for --threads warningÆvar Arnfjörð Bjarmason, May 25, 2017
  27. 30/31 grep: given --threads with NO_PTHREADS=YesPlease, warnÆvar Arnfjörð Bjarmason, May 25, 2017
  28. 25/31 grep: change internal *pcre* variable & function names to be *pcre1*Ævar Arnfjörð Bjarmason, May 25, 2017
  29. 31/31 grep: assert that threading is enabled when calling grep_{lock,unlock}Ævar Arnfjörð Bjarmason, May 25, 2017
  30. 29/31 pack-objects: fix buggy warning about threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  31. 27/31 test-lib: add a PTHREADS prerequisiteÆvar Arnfjörð Bjarmason, May 25, 2017
  32. 26/31 grep: move is_fixed() earlier to avoid forward declarationÆvar Arnfjörð Bjarmason, May 25, 2017

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