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[PATCH] grep: add option to show whole function as context

From
René Scharfe <rene.scharfe@lsrfire.ath.cx>
Date
Jul 31, 2011, 15:59 UTC
Message-ID
<4E357BE2.8030409@lsrfire.ath.cx>
Add a new option, -S, to show the whole surrounding function of a match.

It uses the same regular expressions as -p and diff to find the beginning of sections.

Currently it will not display comments in front of a function, but those that are following one. Despite this shortcoming it is already useful, e.g. to simply see a more complete applicable context or to extract whole functions.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
---
Extending userdiff to allow comments to be recognized would be a bit more
involved, especially since we'd need to able to handle nested multi-line
comment blocks.
 Documentation/git-grep.txt |    6 ++++++
 builtin/grep.c             |    5 ++++-
 grep.c                     |   32 ++++++++++++++++++++++----------
 grep.h                     |    1 +
 t/t7810-grep.sh            |   14 ++++++++++++++
 5 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index 07b3c6a..78e6fc4 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -172,6 +172,12 @@ OPTIONS
 	patch hunk headers (see 'Defining a custom hunk-header' in
 	linkgit:gitattributes[5]).
 
+-S::
+	Show the surrounding text from the previous line containing a
+	function name up to the one before the next function name,
+	effectively showing the whole function in which the match was
+	found.
+
 -f <file>::
 	Read patterns from <file>, one per line.
 
diff --git a/builtin/grep.c b/builtin/grep.c
index cccf8da..fc50859 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -838,6 +838,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 			context_callback),
 		OPT_BOOLEAN('p', "show-function", &opt.funcname,
 			"show a line with the function name before matches"),
+		OPT_BOOLEAN('S', NULL, &opt.funcbody,
+			"show the surrounding function"),
 		OPT_GROUP(""),
 		OPT_CALLBACK('f', NULL, &opt, "file",
 			"read patterns from file", file_callback),
@@ -980,7 +982,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		use_threads = 0;
 
 	if (use_threads) {
-		if (opt.pre_context || opt.post_context || opt.file_break)
+		if (opt.pre_context || opt.post_context || opt.file_break ||
+		    opt.funcbody)
 			skip_first_line = 1;
 		start_threads(&opt);
 	}
diff --git a/grep.c b/grep.c
index 04e9ba4..26e8d8e 100644
--- a/grep.c
+++ b/grep.c
@@ -724,7 +724,7 @@ static void show_line(struct grep_opt *opt, char *bol, char *eol,
 	if (opt->file_break && opt->last_shown == 0) {
 		if (opt->show_hunk_mark)
 			opt->output(opt, "\n", 1);
-	} else if (opt->pre_context || opt->post_context) {
+	} else if (opt->pre_context || opt->post_context || opt->funcbody) {
 		if (opt->last_shown == 0) {
 			if (opt->show_hunk_mark) {
 				output_color(opt, "--", 2, opt->color_sep);
@@ -819,10 +819,13 @@ static void show_funcname_line(struct grep_opt *opt, const char *name,
 }
 
 static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
-			     char *bol, unsigned lno)
+			     char *bol, char *end, unsigned lno)
 {
 	unsigned cur = lno, from = 1, funcname_lno = 0;
-	int funcname_needed = opt->funcname;
+	int funcname_needed = !!opt->funcname;
+
+	if (opt->funcbody && !match_funcname(opt, bol, end))
+		funcname_needed = 2;
 
 	if (opt->pre_context < lno)
 		from = lno - opt->pre_context;
@@ -830,7 +833,8 @@ static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
 		from = opt->last_shown + 1;
 
 	/* Rewind. */
-	while (bol > buf && cur > from) {
+	while (bol > buf &&
+	       cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
 		char *eol = --bol;
 
 		while (bol > buf && bol[-1] != '\n')
@@ -942,13 +946,15 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
 	int binary_match_only = 0;
 	unsigned count = 0;
 	int try_lookahead = 0;
+	int show_function = 0;
 	enum grep_context ctx = GREP_CONTEXT_HEAD;
 	xdemitconf_t xecfg;
 
 	if (!opt->output)
 		opt->output = std_output;
 
-	if (opt->pre_context || opt->post_context || opt->file_break) {
+	if (opt->pre_context || opt->post_context || opt->file_break ||
+	    opt->funcbody) {
 		/* Show hunk marks, except for the first file. */
 		if (opt->last_shown)
 			opt->show_hunk_mark = 1;
@@ -1004,7 +1010,8 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
 		 */
 		if (try_lookahead
 		    && !(last_hit
-			 && lno <= last_hit + opt->post_context)
+			 && (show_function ||
+			     lno <= last_hit + opt->post_context))
 		    && look_ahead(opt, &left, &lno, &bol))
 			break;
 		eol = end_of_line(bol, &left);
@@ -1051,15 +1058,20 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
 			/* Hit at this line.  If we haven't shown the
 			 * pre-context lines, we would need to show them.
 			 */
-			if (opt->pre_context)
-				show_pre_context(opt, name, buf, bol, lno);
+			if (opt->pre_context || opt->funcbody)
+				show_pre_context(opt, name, buf, bol, eol, lno);
 			else if (opt->funcname)
 				show_funcname_line(opt, name, buf, bol, lno);
 			show_line(opt, bol, eol, name, lno, ':');
 			last_hit = lno;
+			if (opt->funcbody)
+				show_function = 1;
+			goto next_line;
 		}
-		else if (last_hit &&
-			 lno <= last_hit + opt->post_context) {
+		if (show_function && match_funcname(opt, bol, eol))
+			show_function = 0;
+		if (show_function ||
+		    (last_hit && lno <= last_hit + opt->post_context)) {
 			/* If the last hit is within the post context,
 			 * we need to show this line.
 			 */
diff --git a/grep.h b/grep.h
index c568297..ae50c45 100644
--- a/grep.h
+++ b/grep.h
@@ -98,6 +98,7 @@ struct grep_opt {
 	int color;
 	int max_depth;
 	int funcname;
+	int funcbody;
 	char color_context[COLOR_MAXLEN];
 	char color_filename[COLOR_MAXLEN];
 	char color_function[COLOR_MAXLEN];
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index a29ae45..3f127ac 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -509,6 +509,20 @@ test_expect_success 'grep -p -B5' '
 	test_cmp expected actual
 '
 
+cat >expected <<EOF
+hello.c=int main(int argc, const char **argv)
+hello.c-{
+hello.c-	printf("Hello world.\n");
+hello.c:	return 0;
+hello.c-	/* char ?? */
+hello.c-}
+EOF
+
+test_expect_success 'grep -S' '
+	git grep -S return >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'grep from a subdirectory to search wider area (1)' '
 	mkdir -p s &&
 	(

-- 
1.7.6
Next: Sverre Rabbelier
Message 1 of 11 in “grep: add option to show whole function as context”
  1. grep: add option to show whole function as contextRené Scharfe, Jul 31, 2011
  2. Sverre RabbelierJul 31, 2011
  3. René ScharfeAug 1, 2011
  4. Sverre RabbelierAug 1, 2011
  5. René ScharfeAug 1, 2011
  6. 1/2 grep: add option to show whole function as contextRené Scharfe, Aug 1, 2011
  7. Junio C HamanoAug 1, 2011
  8. René ScharfeAug 2, 2011
  9. 2/2 grep: long context optionsRené Scharfe, Aug 1, 2011
  10. TaitAug 2, 2011
  11. René ScharfeAug 2, 2011

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