[PATCH 2/6] grep: move pattern-type bits support to top-level grep.[ch]

[Junio C Hamano <gitster@pobox.com>]

Switching between -E/-G/-P/-F correctly needs a lot more than just
flipping opt->regflags bit these days, and we have a nice helper
function buried in builtin/grep.c for the sole use of "git grep".

Extract it so that "log --grep" family can also use it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/grep.c | 38 +++-----------------------------------
 grep.c         | 32 ++++++++++++++++++++++++++++++++
 grep.h         |  1 +
 3 files changed, 36 insertions(+), 35 deletions(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index ce379d5..2b14fee 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -261,38 +261,6 @@ static int wait_all(void)
 }
 #endif
 
-static void grep_pattern_type_options(const int pattern_type, struct grep_opt *opt)
-{
-	switch (pattern_type) {
-	case GREP_PATTERN_TYPE_UNSPECIFIED:
-		/* fall through */
-
-	case GREP_PATTERN_TYPE_BRE:
-		opt->fixed = 0;
-		opt->pcre = 0;
-		opt->regflags &= ~REG_EXTENDED;
-		break;
-
-	case GREP_PATTERN_TYPE_ERE:
-		opt->fixed = 0;
-		opt->pcre = 0;
-		opt->regflags |= REG_EXTENDED;
-		break;
-
-	case GREP_PATTERN_TYPE_FIXED:
-		opt->fixed = 1;
-		opt->pcre = 0;
-		opt->regflags &= ~REG_EXTENDED;
-		break;
-
-	case GREP_PATTERN_TYPE_PCRE:
-		opt->fixed = 0;
-		opt->pcre = 1;
-		opt->regflags &= ~REG_EXTENDED;
-		break;
-	}
-}
-
 static void *lock_and_read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
 {
 	void *data;
@@ -810,11 +778,11 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			     PARSE_OPT_NO_INTERNAL_HELP);
 
 	if (pattern_type_arg != GREP_PATTERN_TYPE_UNSPECIFIED)
-		grep_pattern_type_options(pattern_type_arg, &opt);
+		grep_set_pattern_type_option(pattern_type_arg, &opt);
 	else if (opt.pattern_type_option != GREP_PATTERN_TYPE_UNSPECIFIED)
-		grep_pattern_type_options(opt.pattern_type_option, &opt);
+		grep_set_pattern_type_option(opt.pattern_type_option, &opt);
 	else if (opt.extended_regexp_option)
-		grep_pattern_type_options(GREP_PATTERN_TYPE_ERE, &opt);
+		grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &opt);
 
 	if (use_index && !startup_info->have_repository)
 		/* die the same way as if we did it at the beginning */
diff --git a/grep.c b/grep.c
index 551a2ed..0d8df65 100644
--- a/grep.c
+++ b/grep.c
@@ -1585,3 +1585,35 @@ int grep_config(const char *var, const char *value, void *cb)
 	}
 	return 0;
 }
+
+void grep_set_pattern_type_option(enum grep_pattern_type pattern_type, struct grep_opt *opt)
+{
+	switch (pattern_type) {
+	case GREP_PATTERN_TYPE_UNSPECIFIED:
+		/* fall through */
+
+	case GREP_PATTERN_TYPE_BRE:
+		opt->fixed = 0;
+		opt->pcre = 0;
+		opt->regflags &= ~REG_EXTENDED;
+		break;
+
+	case GREP_PATTERN_TYPE_ERE:
+		opt->fixed = 0;
+		opt->pcre = 0;
+		opt->regflags |= REG_EXTENDED;
+		break;
+
+	case GREP_PATTERN_TYPE_FIXED:
+		opt->fixed = 1;
+		opt->pcre = 0;
+		opt->regflags &= ~REG_EXTENDED;
+		break;
+
+	case GREP_PATTERN_TYPE_PCRE:
+		opt->fixed = 0;
+		opt->pcre = 1;
+		opt->regflags &= ~REG_EXTENDED;
+		break;
+	}
+}
diff --git a/grep.h b/grep.h
index 5381adc..2f6aaa5 100644
--- a/grep.h
+++ b/grep.h
@@ -145,6 +145,7 @@ extern void compile_grep_patterns(struct grep_opt *opt);
 extern void free_grep_patterns(struct grep_opt *opt);
 extern int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size);
 
+void grep_set_pattern_type_option(enum grep_pattern_type, struct grep_opt *opt);
 int grep_config(const char *var, const char *value, void *cb);
 
 struct grep_source {
-- 
1.8.0.rc0.57.g712528f