[GSoC][PATCH 00/13] Update: Week 10

[GSoC][PATCH 00/13] Update: Week 10

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller <sbeller@google.com>
Christian Couder <christian.couder@gmail.com>

UPDATES:

Following are the updates about my ongoing project:

* status: some of the optimization changes which were suggested
  earlier were reverted, as I wasn't sure it fulfilled the
  purpose.

* sync & summary: some changes to the code were suggested after the
  previous review. Those changes were implemented successfully.

* add: the porting of this subcommand is underway. In the function
  cmd_add(), the value of sm_path undergoes quite a few changes
  which are taken care by the sed command. I'm currently working
  on porting them.

* foreach: as said in the previous update, the former patch [2] was
  spilt up into 4 patches, to get a clear picture of different changes
  made to submodule foreach. All of these patches are attached with
  this update. Also, the subcommand foreach is ported in accordance
  with this new changes as well.

PLAN FOR WEEK-11 (25 July 2017 to 31 July 2017):

* As all the patches prepared so far are posted on the mailing list, I'll
  focus on getting these patches merged and do the needful improvisions.

* Apart from this, as stated before, the porting of submodule subcommand
  is underway and will try my best to finish its porting and discuss it
  with the mentors as well in this following week. 

Also, a complete build report of this work is available at [3].
Branch: week-10
Build #140

And the work has also been pushed on github. It is available at [4].

[1]: https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1L-xU/
[2]: https://public-inbox.org/git/20170603003710.5558-1-sbeller@google.com/
[3]: https://travis-ci.org/pratham-pc/git/builds/
[4]: https://github.com/pratham-pc/git/commits/week-10

Prathamesh Chavan (13):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
    subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c     | 1165 ++++++++++++++++++++++++++++++++++++++-
 diff.c                          |    2 +-
 diff.h                          |    1 +
 git-submodule.sh                |  394 +------------
 t/t7407-submodule-foreach.sh    |   38 +-
 6 files changed, 1197 insertions(+), 418 deletions(-)

-- 
2.13.0

[GSoC][PATCH 01/13] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6abdad329..7af4de09b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char **argv, const char *pr
 	return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+	const char *super_prefix = get_super_prefix();
+
+	if (prefix && super_prefix) {
+		BUG("cannot have prefix '%s' and superprefix '%s'",
+		    prefix, super_prefix);
+	} else if (prefix) {
+		struct strbuf sb = STRBUF_INIT;
+		char *displaypath = xstrdup(relative_path(path, prefix, &sb));
+		strbuf_release(&sb);
+		return displaypath;
+	} else if (super_prefix) {
+		int len = strlen(super_prefix);
+		const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" : "%s/%s";
+		return xstrfmt(format, super_prefix, path);
+	} else {
+		return xstrdup(path);
+	}
+}
+
 struct module_list {
 	const struct cache_entry **entries;
 	int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 
 	/* Only loads from .gitmodules, no overlay with .git/config */
 	gitmodules_config();
-
-	if (prefix && get_super_prefix())
-		die("BUG: cannot have prefix and superprefix");
-	else if (prefix)
-		displaypath = xstrdup(relative_path(path, prefix, &sb));
-	else if (get_super_prefix()) {
-		strbuf_addf(&sb, "%s%s", get_super_prefix(), path);
-		displaypath = strbuf_detach(&sb, NULL);
-	} else
-		displaypath = xstrdup(path);
+	displaypath = get_submodule_displaypath(path, prefix);
 
 	sub = submodule_from_path(null_sha1, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 	 * Set active flag for the submodule being initialized
 	 */
 	if (!is_submodule_active(the_repository, path)) {
-		strbuf_reset(&sb);
 		strbuf_addf(&sb, "submodule.%s.active", sub->name);
 		git_config_set_gently(sb.buf, "true");
 	}
-- 
2.13.0

[GSoC][PATCH 02/13] submodule--helper: introduce for_each_submodule_list()

[Prathamesh Chavan]

Introduce function for_each_submodule_list() and
replace a loop in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7af4de09b..e41572f7a 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+				      void *cb_data);
+
 static char *get_default_remote(void)
 {
 	char *dest = NULL, *ret;
@@ -352,17 +355,30 @@ static int module_list(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule_list(const struct module_list list,
+				    submodule_list_func_t fn, void *cb_data)
 {
+	int i;
+	for (i = 0; i < list.nr; i++)
+		fn(list.entries[i], cb_data);
+}
+
+struct init_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct init_cb *info = cb_data;
 	const struct submodule *sub;
 	struct strbuf sb = STRBUF_INIT;
 	char *upd = NULL, *url = NULL, *displaypath;
 
-	/* Only loads from .gitmodules, no overlay with .git/config */
-	gitmodules_config();
-	displaypath = get_submodule_displaypath(path, prefix);
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-	sub = submodule_from_path(null_sha1, path);
+	sub = submodule_from_path(null_sha1, list_item->name);
 
 	if (!sub)
 		die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -374,7 +390,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 	 *
 	 * Set active flag for the submodule being initialized
 	 */
-	if (!is_submodule_active(the_repository, path)) {
+	if (!is_submodule_active(the_repository, list_item->name)) {
 		strbuf_addf(&sb, "submodule.%s.active", sub->name);
 		git_config_set_gently(sb.buf, "true");
 	}
@@ -416,7 +432,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 		if (git_config_set_gently(sb.buf, url))
 			die(_("Failed to register url for submodule path '%s'"),
 			    displaypath);
-		if (!quiet)
+		if (!info->quiet)
 			fprintf(stderr,
 				_("Submodule '%s' (%s) registered for path '%s'\n"),
 				sub->name, url, displaypath);
@@ -445,10 +461,10 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+	struct init_cb info = INIT_CB_INIT;
 	struct pathspec pathspec;
 	struct module_list list = MODULE_LIST_INIT;
 	int quiet = 0;
-	int i;
 
 	struct option module_init_options[] = {
 		OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
@@ -473,8 +489,11 @@ static int module_init(int argc, const char **argv, const char *prefix)
 	if (!argc && git_config_get_value_multi("submodule.active"))
 		module_list_active(&list);
 
-	for (i = 0; i < list.nr; i++)
-		init_submodule(list.entries[i]->name, prefix, quiet);
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+
+	gitmodules_config();
+	for_each_submodule_list(list, init_submodule, &info);
 
 	return 0;
 }
-- 
2.13.0

[GSoC][PATCH 03/13] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function get_name_rev() generates the
value of the revision name as required, and the function
print_name_rev() handles the formating and printing of the obtained
revision name.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 63 +++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            | 16 ++----------
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e41572f7a..80f744407 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -244,6 +244,68 @@ static char *get_submodule_displaypath(const char *path, const char *prefix)
 	}
 }
 
+static char *get_name_rev(const char *sub_path, const char* object_id)
+{
+	struct strbuf sb = STRBUF_INIT;
+	const char ***d;
+
+	static const char *describe_bare[] = {
+		NULL
+	};
+
+	static const char *describe_tags[] = {
+		"--tags", NULL
+	};
+
+	static const char *describe_contains[] = {
+		"--contains", NULL
+	};
+
+	static const char *describe_all_always[] = {
+		"--all", "--always", NULL
+	};
+
+	static const char **describe_argv[] = {
+		describe_bare, describe_tags, describe_contains,
+		describe_all_always, NULL
+	};
+
+	for (d = describe_argv; *d; d++) {
+		struct child_process cp = CHILD_PROCESS_INIT;
+		prepare_submodule_repo_env(&cp.env_array);
+		cp.dir = sub_path;
+		cp.git_cmd = 1;
+		cp.no_stderr = 1;
+
+		argv_array_push(&cp.args, "describe");
+		argv_array_pushv(&cp.args, *d);
+		argv_array_push(&cp.args, object_id);
+
+		if (!capture_command(&cp, &sb, 0) && sb.len) {
+			strbuf_strip_suffix(&sb, "\n");
+			return strbuf_detach(&sb, NULL);
+		}
+
+	}
+
+	strbuf_release(&sb);
+	return NULL;
+}
+
+static int print_name_rev(int argc, const char **argv, const char *prefix)
+{
+	char *namerev;
+	if (argc != 3)
+		die("print-name-rev only accepts two arguments: <path> <sha1>");
+
+	namerev = get_name_rev(argv[1], argv[2]);
+	if (namerev && namerev[0])
+		printf(" (%s)", namerev);
+	printf("\n");
+
+	return 0;
+}
+
 struct module_list {
 	const struct cache_entry **entries;
 	int alloc, nr;
@@ -1242,6 +1304,7 @@ static struct cmd_struct commands[] = {
 	{"relative-path", resolve_relative_path, 0},
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
+	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..e988167e0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
 	}
 }
 
-set_name_rev () {
-	revname=$( (
-		sanitize_submodule_env
-		cd "$1" && {
-			git describe "$2" 2>/dev/null ||
-			git describe --tags "$2" 2>/dev/null ||
-			git describe --contains "$2" 2>/dev/null ||
-			git describe --all --always "$2"
-		}
-	) )
-	test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
 		fi
 		if git diff-files --ignore-submodules=dirty --quiet -- "$sm_path"
 		then
-			set_name_rev "$sm_path" "$sha1"
+			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
 			say " $sha1 $displaypath$revname"
 		else
 			if test -z "$cached"
 			then
 				sha1=$(sanitize_submodule_env; cd "$sm_path" && git rev-parse --verify HEAD)
 			fi
-			set_name_rev "$sm_path" "$sha1"
+			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
 			say "+$sha1 $displaypath$revname"
 		fi
 
-- 
2.13.0

Re: [GSoC][PATCH 03/13] submodule: port set_name_rev() from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> +static int print_name_rev(int argc, const char **argv, const char *prefix)
> +{
> +	char *namerev;
> +	if (argc != 3)
> +		die("print-name-rev only accepts two arguments: <path> <sha1>");
> +
> +	namerev = get_name_rev(argv[1], argv[2]);
> +	if (namerev && namerev[0])
> +		printf(" (%s)", namerev);
> +	printf("\n");
> +

'namerev' needs to be freed at the end of this function.

> +	return 0;
> +}
> +

-- 
Brandon Williams

[GSoC][PATCH 04/13] submodule: port submodule subcommand 'status' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule 'status' a built-in. Hence, the function
cmd_status() is ported from shell to C. This is done by introducing
three functions: module_status(), submodule_status() and print_status().

The function module_status() acts as the front-end of the subcommand.
It parses subcommand's options and then calls the function
module_list_compute() for computing the list of submodules. Then
this functions calls for_each_submodule_list() looping through the
list obtained.

Then for_each_submodule_list() calls submodule_status() for each of the
submodule in its list. The function submodule_status() is responsible
for generating the status each submodule it is called for, and
then calls print_status().

Finally, the function print_status() handles the printing of submodule's
status.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version of patch, following changes were made:
* instead of using the ce_match_stat(), cmd_diff_files is used.
* currently, no comment about future scope of optimization wrt the
  cmd_diff_files() usage was added as currently, I'm not fully sure of
  the way to optimize the function.

 builtin/submodule--helper.c | 151 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  49 +-------------
 2 files changed, 152 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 80f744407..b39828174 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -560,6 +560,156 @@ static int module_init(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct status_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+	unsigned int cached: 1;
+};
+#define STATUS_CB_INIT { NULL, 0, 0, 0 }
+
+static void print_status(struct status_cb *info, char state, const char *path,
+			 char *sub_sha1, char *displaypath)
+{
+	if (info->quiet)
+		return;
+
+	printf("%c%s %s", state, sub_sha1, displaypath);
+
+	if (state == ' ' || state == '+') {
+		struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+		argv_array_pushl(&name_rev_args, "print-name-rev",
+				 path, sub_sha1, NULL);
+		print_name_rev(name_rev_args.argc, name_rev_args.argv,
+			       info->prefix);
+	} else {
+		printf("\n");
+	}
+}
+
+static int handle_submodule_head_ref(const char *refname,
+				     const struct object_id *oid, int flags,
+				     void *cb_data)
+{
+	struct strbuf *output = cb_data;
+	if (oid)
+		strbuf_addstr(output, oid_to_hex(oid));
+	return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct status_cb *info = cb_data;
+	char *sub_sha1 = xstrdup(oid_to_hex(&list_item->oid));
+	char *displaypath;
+	struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+	if (!submodule_from_path(null_sha1, list_item->name))
+		die(_("no submodule mapping found in .gitmodules for path '%s'"),
+		      list_item->name);
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	if (list_item->ce_flags) {
+		print_status(info, 'U', list_item->name,
+			     sha1_to_hex(null_sha1), displaypath);
+		goto cleanup;
+	}
+
+	if (!is_submodule_active(the_repository, list_item->name)) {
+		print_status(info, '-', list_item->name, sub_sha1, displaypath);
+		goto cleanup;
+	}
+
+	argv_array_pushl(&diff_files_args, "diff-files",
+			 "--ignore-submodules=dirty", "--quiet", "--",
+			 list_item->name, NULL);
+
+	if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+			    info->prefix)) {
+		print_status(info, ' ', list_item->name, sub_sha1, displaypath);
+	} else {
+		if (!info->cached) {
+			struct strbuf sb = STRBUF_INIT;
+			if (head_ref_submodule(list_item->name,
+					       handle_submodule_head_ref, &sb))
+				die(_("could not resolve HEAD ref inside the"
+				      "submodule '%s'"), list_item->name);
+			print_status(info, '+', list_item->name, sb.buf,
+				     displaypath);
+			strbuf_release(&sb);
+		} else {
+			print_status(info, '+', list_item->name, sub_sha1,
+				     displaypath);
+		}
+	}
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "status", "--recursive",
+				 NULL);
+
+		if (info->cached)
+			argv_array_push(&cpr.args, "--cached");
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		if (run_command(&cpr))
+			die(_("failed to recurse into submodule '%s'"),
+			      list_item->name);
+	}
+
+cleanup:
+	free(displaypath);
+	free(sub_sha1);
+}
+
+static int module_status(int argc, const char **argv, const char *prefix)
+{
+	struct status_cb info = STATUS_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int cached = 0;
+	int recursive = 0;
+
+	struct option module_status_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
+		OPT_BOOL(0, "cached", &cached, N_("Use commit stored in the index instead of the one stored in the submodule HEAD")),
+		OPT_BOOL(0, "recursive", &recursive, N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule status [--quiet] [--cached] [--recursive] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_status_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+	info.cached = !!cached;
+
+	gitmodules_config();
+	for_each_submodule_list(list, status_submodule, &info);
+
+	return 0;
+}
+
 static int module_name(int argc, const char **argv, const char *prefix)
 {
 	const struct submodule *sub;
@@ -1306,6 +1456,7 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
+	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index e988167e0..51b057d82 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1005,54 +1005,7 @@ cmd_status()
 		shift
 	done
 
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		name=$(git submodule--helper name "$sm_path") || exit
-		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-		if test "$stage" = U
-		then
-			say "U$sha1 $displaypath"
-			continue
-		fi
-		if ! git submodule--helper is-active "$sm_path" ||
-		{
-			! test -d "$sm_path"/.git &&
-			! test -f "$sm_path"/.git
-		}
-		then
-			say "-$sha1 $displaypath"
-			continue;
-		fi
-		if git diff-files --ignore-submodules=dirty --quiet -- "$sm_path"
-		then
-			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
-			say " $sha1 $displaypath$revname"
-		else
-			if test -z "$cached"
-			then
-				sha1=$(sanitize_submodule_env; cd "$sm_path" && git rev-parse --verify HEAD)
-			fi
-			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
-			say "+$sha1 $displaypath$revname"
-		fi
-
-		if test -n "$recursive"
-		then
-			(
-				prefix="$displaypath/"
-				sanitize_submodule_env
-				wt_prefix=
-				cd "$sm_path" &&
-				eval cmd_status
-			) ||
-			die "$(eval_gettext "Failed to recurse into submodule path '\$sm_path'")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper status ${GIT_QUIET:+--quiet} ${cached:+--cached} ${recursive:+--recursive} "$@"
 }
 #
 # Sync remote urls for submodules
-- 
2.13.0

Re: [GSoC][PATCH 04/13] submodule: port submodule subcommand 'status' from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> This aims to make git-submodule 'status' a built-in. Hence, the function
> cmd_status() is ported from shell to C. This is done by introducing
> three functions: module_status(), submodule_status() and print_status().
> 
> The function module_status() acts as the front-end of the subcommand.
> It parses subcommand's options and then calls the function
> module_list_compute() for computing the list of submodules. Then
> this functions calls for_each_submodule_list() looping through the
> list obtained.
> 
> Then for_each_submodule_list() calls submodule_status() for each of the
> submodule in its list. The function submodule_status() is responsible
> for generating the status each submodule it is called for, and
> then calls print_status().
> 
> Finally, the function print_status() handles the printing of submodule's
> status.
> 
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
> In this new version of patch, following changes were made:
> * instead of using the ce_match_stat(), cmd_diff_files is used.
> * currently, no comment about future scope of optimization wrt the
>   cmd_diff_files() usage was added as currently, I'm not fully sure of
>   the way to optimize the function.
> 
>  builtin/submodule--helper.c | 151 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            |  49 +-------------
>  2 files changed, 152 insertions(+), 48 deletions(-)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 80f744407..b39828174 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -560,6 +560,156 @@ static int module_init(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +struct status_cb {
> +	const char *prefix;
> +	unsigned int quiet: 1;
> +	unsigned int recursive: 1;
> +	unsigned int cached: 1;
> +};
> +#define STATUS_CB_INIT { NULL, 0, 0, 0 }
> +
> +static void print_status(struct status_cb *info, char state, const char *path,
> +			 char *sub_sha1, char *displaypath)

Lets mark these strings as 'const char *' since you aren't modifying
them in the function, only using them.  Also it may make more sense to
pass the 'struct object_id' instead of a hex string of the object id.
Then you can call the necessary 'oid_to_hex' function when you are
adding the object id to the argv array.  That would also eliminate an
allocation in 'status_submodule'.

Also eliminates the need to use the word 'sha1' as we want to eliminate
its usage in the codebase.

> +{
> +	if (info->quiet)
> +		return;
> +
> +	printf("%c%s %s", state, sub_sha1, displaypath);
> +
> +	if (state == ' ' || state == '+') {
> +		struct argv_array name_rev_args = ARGV_ARRAY_INIT;
> +
> +		argv_array_pushl(&name_rev_args, "print-name-rev",
> +				 path, sub_sha1, NULL);
> +		print_name_rev(name_rev_args.argc, name_rev_args.argv,
> +			       info->prefix);
> +	} else {
> +		printf("\n");
> +	}
> +}
> +
> +static int handle_submodule_head_ref(const char *refname,
> +				     const struct object_id *oid, int flags,
> +				     void *cb_data)
> +{
> +	struct strbuf *output = cb_data;
> +	if (oid)
> +		strbuf_addstr(output, oid_to_hex(oid));

Since we're going to be working with 'struct object_id' instead of
strings this would need to change slightly.  Instead of copying into a
strbuf we could just pass a pointer to a 'struct object_id' and use
'oidcpy' to copy the contents of oid to output.

  struct object_id *output = cb_data;
  if (oid)
    oidcpy(output, oid);

> +	return 0;
> +}
> +
> +static void status_submodule(const struct cache_entry *list_item, void *cb_data)
> +{
> +	struct status_cb *info = cb_data;
> +	char *sub_sha1 = xstrdup(oid_to_hex(&list_item->oid));
> +	char *displaypath;
> +	struct argv_array diff_files_args = ARGV_ARRAY_INIT;

'diff_files_args' needs to be cleared at the end of the function when
doing cleanup to prevent a memory leak.

> +
> +	if (!submodule_from_path(null_sha1, list_item->name))
> +		die(_("no submodule mapping found in .gitmodules for path '%s'"),
> +		      list_item->name);
> +
> +	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
> +
> +	if (list_item->ce_flags) {

Is there a particular flag we are interested in here or only that a flag
is set?

> +		print_status(info, 'U', list_item->name,
> +			     sha1_to_hex(null_sha1), displaypath);

Since we are already using OID's in other parts of this code lets be
consistant and use null_oid instead like 'oid_to_hex(&null_oid)'.

> +		goto cleanup;
> +	}
> +
> +	if (!is_submodule_active(the_repository, list_item->name)) {
> +		print_status(info, '-', list_item->name, sub_sha1, displaypath);
> +		goto cleanup;
> +	}
> +
> +	argv_array_pushl(&diff_files_args, "diff-files",
> +			 "--ignore-submodules=dirty", "--quiet", "--",
> +			 list_item->name, NULL);
> +
> +	if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
> +			    info->prefix)) {
> +		print_status(info, ' ', list_item->name, sub_sha1, displaypath);
> +	} else {
> +		if (!info->cached) {
> +			struct strbuf sb = STRBUF_INIT;
> +			if (head_ref_submodule(list_item->name,
> +					       handle_submodule_head_ref, &sb))
> +				die(_("could not resolve HEAD ref inside the"
> +				      "submodule '%s'"), list_item->name);
> +			print_status(info, '+', list_item->name, sb.buf,
> +				     displaypath);
> +			strbuf_release(&sb);

Like i mentioned above this would change into using a 'struct object_id'
which can be allocated on the stack, eliminating the need for the
allocation and releasing of the strbuf too.

> +		} else {
> +			print_status(info, '+', list_item->name, sub_sha1,
> +				     displaypath);
> +		}
> +	}
> +
> +	if (info->recursive) {
> +		struct child_process cpr = CHILD_PROCESS_INIT;
> +
> +		cpr.git_cmd = 1;
> +		cpr.dir = list_item->name;
> +		prepare_submodule_repo_env(&cpr.env_array);
> +
> +		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,

This bit here doesn't seem right.  'displaypath' can include relative
'..'s if you are not at the root of the project but rather in a
subdirectory.  'super_prefix' has traditionally been defined as the path
from the root of the superproject down to the root of the submodule.
This means that there should not ever be any relative '..'s.

> +				 "submodule--helper", "status", "--recursive",
> +				 NULL);
> +
> +		if (info->cached)
> +			argv_array_push(&cpr.args, "--cached");
> +
> +		if (info->quiet)
> +			argv_array_push(&cpr.args, "--quiet");
> +
> +		if (run_command(&cpr))
> +			die(_("failed to recurse into submodule '%s'"),
> +			      list_item->name);
> +	}
> +
> +cleanup:
> +	free(displaypath);
> +	free(sub_sha1);
> +}
> +
> +static int module_status(int argc, const char **argv, const char *prefix)
> +{
> +	struct status_cb info = STATUS_CB_INIT;
> +	struct pathspec pathspec;
> +	struct module_list list = MODULE_LIST_INIT;
> +	int quiet = 0;
> +	int cached = 0;
> +	int recursive = 0;
> +
> +	struct option module_status_options[] = {
> +		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
> +		OPT_BOOL(0, "cached", &cached, N_("Use commit stored in the index instead of the one stored in the submodule HEAD")),
> +		OPT_BOOL(0, "recursive", &recursive, N_("Recurse into nested submodules")),
> +		OPT_END()
> +	};
> +
> +	const char *const git_submodule_helper_usage[] = {
> +		N_("git submodule status [--quiet] [--cached] [--recursive] [<path>]"),
> +		NULL
> +	};
> +
> +	argc = parse_options(argc, argv, prefix, module_status_options,
> +			     git_submodule_helper_usage, 0);
> +
> +	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
> +		return 1;
> +
> +	info.prefix = prefix;
> +	info.quiet = !!quiet;
> +	info.recursive = !!recursive;
> +	info.cached = !!cached;
> +
> +	gitmodules_config();
> +	for_each_submodule_list(list, status_submodule, &info);
> +
> +	return 0;
> +}
> +
>  static int module_name(int argc, const char **argv, const char *prefix)
>  {
>  	const struct submodule *sub;
> @@ -1306,6 +1456,7 @@ static struct cmd_struct commands[] = {
>  	{"resolve-relative-url-test", resolve_relative_url_test, 0},
>  	{"print-name-rev", print_name_rev, 0},
>  	{"init", module_init, SUPPORT_SUPER_PREFIX},
> +	{"status", module_status, SUPPORT_SUPER_PREFIX},
>  	{"remote-branch", resolve_remote_submodule_branch, 0},
>  	{"push-check", push_check, 0},
>  	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
> diff --git a/git-submodule.sh b/git-submodule.sh
> index e988167e0..51b057d82 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -1005,54 +1005,7 @@ cmd_status()
>  		shift
>  	done
>  
> -	{
> -		git submodule--helper list --prefix "$wt_prefix" "$@" ||
> -		echo "#unmatched" $?
> -	} |
> -	while read -r mode sha1 stage sm_path
> -	do
> -		die_if_unmatched "$mode" "$sha1"
> -		name=$(git submodule--helper name "$sm_path") || exit
> -		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
> -		if test "$stage" = U
> -		then
> -			say "U$sha1 $displaypath"
> -			continue
> -		fi
> -		if ! git submodule--helper is-active "$sm_path" ||
> -		{
> -			! test -d "$sm_path"/.git &&
> -			! test -f "$sm_path"/.git
> -		}
> -		then
> -			say "-$sha1 $displaypath"
> -			continue;
> -		fi
> -		if git diff-files --ignore-submodules=dirty --quiet -- "$sm_path"
> -		then
> -			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
> -			say " $sha1 $displaypath$revname"
> -		else
> -			if test -z "$cached"
> -			then
> -				sha1=$(sanitize_submodule_env; cd "$sm_path" && git rev-parse --verify HEAD)
> -			fi
> -			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
> -			say "+$sha1 $displaypath$revname"
> -		fi
> -
> -		if test -n "$recursive"
> -		then
> -			(
> -				prefix="$displaypath/"
> -				sanitize_submodule_env
> -				wt_prefix=
> -				cd "$sm_path" &&
> -				eval cmd_status
> -			) ||
> -			die "$(eval_gettext "Failed to recurse into submodule path '\$sm_path'")"
> -		fi
> -	done
> +	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper status ${GIT_QUIET:+--quiet} ${cached:+--cached} ${recursive:+--recursive} "$@"
>  }
>  #
>  # Sync remote urls for submodules
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 05/13] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing three functions: module_sync(),
sync_submodule() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version of patch, following changes were made:
* the code use to die when sub->url was found to be NULL. This was not a
  correct translation of code. It was corrected by using an empty string
  instead of sub->url.
* a process was used in the previous patch for registering the submodule
  url. This was avoided by the suggested changes on the previous patch.
* some nits were also corrected.
 
 builtin/submodule--helper.c | 183 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  56 +-------------
 2 files changed, 184 insertions(+), 55 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index b39828174..2d1d3984d 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -44,6 +44,20 @@ static char *get_default_remote(void)
 	return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char *prefix)
+{
+	const char *remote;
+
+	if (argc != 1)
+		die(_("submodule--helper print-default-remote takes no arguments"));
+
+	remote = get_default_remote();
+	if (remote)
+		puts(remote);
+
+	return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
 	return str[0] == '.' && is_dir_sep(str[1]);
@@ -379,6 +393,25 @@ static void module_list_active(struct module_list *list)
 	*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+	int i;
+	struct strbuf sb = STRBUF_INIT;
+
+	for (i = count_slashes(path); i; i--)
+		strbuf_addstr(&sb, "../");
+
+	/*
+	 * Check if 'path' ends with slash or not
+	 * for having the same output for dir/sub_dir
+	 * and dir/sub_dir/
+	 */
+	if (!is_dir_sep(path[strlen(path) - 1]))
+		strbuf_addstr(&sb, "../");
+
+	return strbuf_detach(&sb, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
 	int i;
@@ -729,6 +762,154 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct sync_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+};
+#define SYNC_CB_INIT { NULL, 0, 0 }
+
+static void sync_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct sync_cb *info = cb_data;
+	const struct submodule *sub;
+	char *sub_key, *remote_key;
+	char *sub_origin_url, *super_config_url, *displaypath;
+	struct strbuf sb = STRBUF_INIT;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	struct strbuf sub_repo_path = STRBUF_INIT;
+	char *sub_config_path = NULL;
+
+	if (!is_submodule_active(the_repository, list_item->name))
+		return;
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (sub && sub->url) {
+		if (starts_with_dot_dot_slash(sub->url) || starts_with_dot_slash(sub->url)) {
+			char *remote_url, *up_path;
+			char *remote = get_default_remote();
+			char *remote_key = xstrfmt("remote.%s.url", remote);
+
+			if (git_config_get_string(remote_key, &remote_url))
+				remote_url = xgetcwd();
+
+			up_path = get_up_path(list_item->name);
+			sub_origin_url = relative_url(remote_url, sub->url, up_path);
+			super_config_url = relative_url(remote_url, sub->url, NULL);
+
+			free(remote);
+			free(remote_key);
+			free(up_path);
+			free(remote_url);
+		} else {
+			sub_origin_url = xstrdup(sub->url);
+			super_config_url = xstrdup(sub->url);
+		}
+	} else {
+		sub_origin_url = "";
+		super_config_url = "";
+	}
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	if (!info->quiet)
+		printf(_("Synchronizing submodule url for '%s'\n"),
+			 displaypath);
+
+	sub_key = xstrfmt("submodule.%s.url", sub->name);
+	if (git_config_set_gently(sub_key, super_config_url))
+		die(_("failed to register url for submodule path '%s'"),
+		      displaypath);
+
+	if (!is_submodule_populated_gently(list_item->name, NULL))
+		goto cleanup;
+
+	prepare_submodule_repo_env(&cp.env_array);
+	cp.git_cmd = 1;
+	cp.dir = list_item->name;
+	argv_array_pushl(&cp.args, "submodule--helper",
+			 "print-default-remote", NULL);
+
+	if (capture_command(&cp, &sb, 0))
+		die(_("failed to get the default remote for submodule '%s'"),
+		      list_item->name);
+
+	strbuf_strip_suffix(&sb, "\n");
+	remote_key = xstrfmt("remote.%s.url", sb.buf);
+	strbuf_release(&sb);
+
+	submodule_to_gitdir(&sub_repo_path, list_item->name);
+	sub_config_path = xstrfmt("%s/config", sub_repo_path.buf);
+	strbuf_release(&sub_repo_path);
+
+	if (git_config_set_in_file_gently(sub_config_path, remote_key, sub_origin_url))
+		die(_("failed to update remote for submodule '%s'"),
+		      list_item->name);
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "sync", "--recursive",
+				 NULL);
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		if (run_command(&cpr))
+			die(_("failed to recurse into submodule '%s'"),
+			      list_item->name);
+	}
+
+cleanup:
+	free(sub_key);
+	free(super_config_url);
+	free(displaypath);
+	free(sub_config_path);
+	free(sub_origin_url);
+}
+
+static int module_sync(int argc, const char **argv, const char *prefix)
+{
+	struct sync_cb info = SYNC_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int recursive = 0;
+
+	struct option module_sync_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output of synchronizing submodule url")),
+		OPT_BOOL(0, "recursive", &recursive,
+			N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper sync [--quiet] [--recursive] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_sync_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+
+	gitmodules_config();
+	for_each_submodule_list(list, sync_submodule, &info);
+
+	return 0;
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference,
 			   int quiet, int progress)
@@ -1457,6 +1638,8 @@ static struct cmd_struct commands[] = {
 	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
+	{"print-default-remote", print_default_remote, 0},
+	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 51b057d82..6bfc5e17d 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1037,63 +1037,9 @@ cmd_sync()
 			;;
 		esac
 	done
-	cd_to_toplevel
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-
-		# skip inactive submodules
-		if ! git submodule--helper is-active "$sm_path"
-		then
-			continue
-		fi
-
-		name=$(git submodule--helper name "$sm_path")
-		url=$(git config -f .gitmodules --get submodule."$name".url)
-
-		# Possibly a url relative to parent
-		case "$url" in
-		./*|../*)
-			# rewrite foo/bar as ../.. to find path from
-			# submodule work tree to superproject work tree
-			up_path="$(printf '%s\n' "$sm_path" | sed "s/[^/][^/]*/../g")" &&
-			# guarantee a trailing /
-			up_path=${up_path%/}/ &&
-			# path from submodule work tree to submodule origin repo
-			sub_origin_url=$(git submodule--helper resolve-relative-url "$url" "$up_path") &&
-			# path from superproject work tree to submodule origin repo
-			super_config_url=$(git submodule--helper resolve-relative-url "$url") || exit
-			;;
-		*)
-			sub_origin_url="$url"
-			super_config_url="$url"
-			;;
-		esac
 
-		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-		say "$(eval_gettext "Synchronizing submodule url for '\$displaypath'")"
-		git config submodule."$name".url "$super_config_url"
-
-		if test -e "$sm_path"/.git
-		then
-		(
-			sanitize_submodule_env
-			cd "$sm_path"
-			remote=$(get_default_remote)
-			git config remote."$remote".url "$sub_origin_url"
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper sync ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
 
-			if test -n "$recursive"
-			then
-				prefix="$prefix$sm_path/"
-				eval cmd_sync
-			fi
-		)
-		fi
-	done
 }
 
 cmd_absorbgitdirs()
-- 
2.13.0

Re: [GSoC][PATCH 05/13] submodule: port submodule subcommand 'sync' from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> Port the submodule subcommand 'sync' from shell to C using the same
> mechanism as that used for porting submodule subcommand 'status'.
> Hence, here the function cmd_sync() is ported from shell to C.
> This is done by introducing three functions: module_sync(),
> sync_submodule() and print_default_remote().
> 
> The function print_default_remote() is introduced for getting
> the default remote as stdout.
> 
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
> In this new version of patch, following changes were made:
> * the code use to die when sub->url was found to be NULL. This was not a
>   correct translation of code. It was corrected by using an empty string
>   instead of sub->url.
> * a process was used in the previous patch for registering the submodule
>   url. This was avoided by the suggested changes on the previous patch.
> * some nits were also corrected.
>  
>  builtin/submodule--helper.c | 183 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            |  56 +-------------
>  2 files changed, 184 insertions(+), 55 deletions(-)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index b39828174..2d1d3984d 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -44,6 +44,20 @@ static char *get_default_remote(void)
>  	return ret;
>  }
>  
> +static int print_default_remote(int argc, const char **argv, const char *prefix)
> +{
> +	const char *remote;
> +
> +	if (argc != 1)
> +		die(_("submodule--helper print-default-remote takes no arguments"));
> +
> +	remote = get_default_remote();
> +	if (remote)
> +		puts(remote);

Any reason why puts is used instead of a printf function?

> +
> +	return 0;
> +}
> +
>  static int starts_with_dot_slash(const char *str)
>  {
>  	return str[0] == '.' && is_dir_sep(str[1]);
> @@ -379,6 +393,25 @@ static void module_list_active(struct module_list *list)
>  	*list = active_modules;
>  }
>  
> +static char *get_up_path(const char *path)
> +{
> +	int i;
> +	struct strbuf sb = STRBUF_INIT;
> +
> +	for (i = count_slashes(path); i; i--)
> +		strbuf_addstr(&sb, "../");
> +
> +	/*
> +	 * Check if 'path' ends with slash or not
> +	 * for having the same output for dir/sub_dir
> +	 * and dir/sub_dir/
> +	 */
> +	if (!is_dir_sep(path[strlen(path) - 1]))
> +		strbuf_addstr(&sb, "../");
> +
> +	return strbuf_detach(&sb, NULL);
> +}
> +
>  static int module_list(int argc, const char **argv, const char *prefix)
>  {
>  	int i;
> @@ -729,6 +762,154 @@ static int module_name(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +struct sync_cb {
> +	const char *prefix;
> +	unsigned int quiet: 1;
> +	unsigned int recursive: 1;
> +};
> +#define SYNC_CB_INIT { NULL, 0, 0 }
> +
> +static void sync_submodule(const struct cache_entry *list_item, void *cb_data)
> +{
> +	struct sync_cb *info = cb_data;
> +	const struct submodule *sub;
> +	char *sub_key, *remote_key;
> +	char *sub_origin_url, *super_config_url, *displaypath;
> +	struct strbuf sb = STRBUF_INIT;
> +	struct child_process cp = CHILD_PROCESS_INIT;
> +	struct strbuf sub_repo_path = STRBUF_INIT;

Not the most important but you could be a lot more efficient here with
your variables.  You could allocate a single strbuf and reuse it for
'sub_key'. 'remote_key', 'sb', and 'sub_repo_path' as it doesn't look
like you need any of those two at the same time.

> +	char *sub_config_path = NULL;
> +
> +	if (!is_submodule_active(the_repository, list_item->name))
> +		return;
> +
> +	sub = submodule_from_path(null_sha1, list_item->name);

Since is_submodule_active also calls into the submodule-config subsystem
to retrieve a submodule this call should never return a NULL ptr...so it
may be safer to return instead of proceeding if 'sub' ends up being null
here.

> +
> +	if (sub && sub->url) {
> +		if (starts_with_dot_dot_slash(sub->url) || starts_with_dot_slash(sub->url)) {
> +			char *remote_url, *up_path;
> +			char *remote = get_default_remote();
> +			char *remote_key = xstrfmt("remote.%s.url", remote);
> +
> +			if (git_config_get_string(remote_key, &remote_url))
> +				remote_url = xgetcwd();
> +
> +			up_path = get_up_path(list_item->name);
> +			sub_origin_url = relative_url(remote_url, sub->url, up_path);
> +			super_config_url = relative_url(remote_url, sub->url, NULL);
> +
> +			free(remote);
> +			free(remote_key);
> +			free(up_path);
> +			free(remote_url);
> +		} else {
> +			sub_origin_url = xstrdup(sub->url);
> +			super_config_url = xstrdup(sub->url);
> +		}
> +	} else {
> +		sub_origin_url = "";
> +		super_config_url = "";
> +	}
> +
> +	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
> +
> +	if (!info->quiet)
> +		printf(_("Synchronizing submodule url for '%s'\n"),
> +			 displaypath);
> +
> +	sub_key = xstrfmt("submodule.%s.url", sub->name);
> +	if (git_config_set_gently(sub_key, super_config_url))
> +		die(_("failed to register url for submodule path '%s'"),
> +		      displaypath);
> +
> +	if (!is_submodule_populated_gently(list_item->name, NULL))
> +		goto cleanup;
> +
> +	prepare_submodule_repo_env(&cp.env_array);
> +	cp.git_cmd = 1;
> +	cp.dir = list_item->name;
> +	argv_array_pushl(&cp.args, "submodule--helper",
> +			 "print-default-remote", NULL);
> +
> +	if (capture_command(&cp, &sb, 0))
> +		die(_("failed to get the default remote for submodule '%s'"),
> +		      list_item->name);
> +
> +	strbuf_strip_suffix(&sb, "\n");
> +	remote_key = xstrfmt("remote.%s.url", sb.buf);
> +	strbuf_release(&sb);
> +
> +	submodule_to_gitdir(&sub_repo_path, list_item->name);

This function (submodule_to_gitdir) has some poor characteristics in
that it will succeed even if there isn't a configured submodule but
there just happens to be a submodule at the provided path...but it looks
like none of them will affect this as the fist thing this function does
is check if the submodule is active before preceding.

> +	sub_config_path = xstrfmt("%s/config", sub_repo_path.buf);
> +	strbuf_release(&sub_repo_path);
> +
> +	if (git_config_set_in_file_gently(sub_config_path, remote_key, sub_origin_url))
> +		die(_("failed to update remote for submodule '%s'"),
> +		      list_item->name);
> +
> +	if (info->recursive) {
> +		struct child_process cpr = CHILD_PROCESS_INIT;
> +
> +		cpr.git_cmd = 1;
> +		cpr.dir = list_item->name;
> +		prepare_submodule_repo_env(&cpr.env_array);
> +
> +		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,

Same comment as the previous patch here.

> +				 "submodule--helper", "sync", "--recursive",
> +				 NULL);
> +
> +		if (info->quiet)
> +			argv_array_push(&cpr.args, "--quiet");
> +
> +		if (run_command(&cpr))
> +			die(_("failed to recurse into submodule '%s'"),
> +			      list_item->name);
> +	}
> +
> +cleanup:
> +	free(sub_key);
> +	free(super_config_url);
> +	free(displaypath);
> +	free(sub_config_path);
> +	free(sub_origin_url);
> +}
> +
> +static int module_sync(int argc, const char **argv, const char *prefix)
> +{
> +	struct sync_cb info = SYNC_CB_INIT;
> +	struct pathspec pathspec;
> +	struct module_list list = MODULE_LIST_INIT;
> +	int quiet = 0;
> +	int recursive = 0;
> +
> +	struct option module_sync_options[] = {
> +		OPT__QUIET(&quiet, N_("Suppress output of synchronizing submodule url")),
> +		OPT_BOOL(0, "recursive", &recursive,
> +			N_("Recurse into nested submodules")),
> +		OPT_END()
> +	};
> +
> +	const char *const git_submodule_helper_usage[] = {
> +		N_("git submodule--helper sync [--quiet] [--recursive] [<path>]"),
> +		NULL
> +	};
> +
> +	argc = parse_options(argc, argv, prefix, module_sync_options,
> +			     git_submodule_helper_usage, 0);
> +
> +	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
> +		return 1;
> +
> +	info.prefix = prefix;
> +	info.quiet = !!quiet;
> +	info.recursive = !!recursive;
> +
> +	gitmodules_config();
> +	for_each_submodule_list(list, sync_submodule, &info);
> +
> +	return 0;
> +}
> +
>  static int clone_submodule(const char *path, const char *gitdir, const char *url,
>  			   const char *depth, struct string_list *reference,
>  			   int quiet, int progress)
> @@ -1457,6 +1638,8 @@ static struct cmd_struct commands[] = {
>  	{"print-name-rev", print_name_rev, 0},
>  	{"init", module_init, SUPPORT_SUPER_PREFIX},
>  	{"status", module_status, SUPPORT_SUPER_PREFIX},
> +	{"print-default-remote", print_default_remote, 0},
> +	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
>  	{"remote-branch", resolve_remote_submodule_branch, 0},
>  	{"push-check", push_check, 0},
>  	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
> diff --git a/git-submodule.sh b/git-submodule.sh
> index 51b057d82..6bfc5e17d 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -1037,63 +1037,9 @@ cmd_sync()
>  			;;
>  		esac
>  	done
> -	cd_to_toplevel
> -	{
> -		git submodule--helper list --prefix "$wt_prefix" "$@" ||
> -		echo "#unmatched" $?
> -	} |
> -	while read -r mode sha1 stage sm_path
> -	do
> -		die_if_unmatched "$mode" "$sha1"
> -
> -		# skip inactive submodules
> -		if ! git submodule--helper is-active "$sm_path"
> -		then
> -			continue
> -		fi
> -
> -		name=$(git submodule--helper name "$sm_path")
> -		url=$(git config -f .gitmodules --get submodule."$name".url)
> -
> -		# Possibly a url relative to parent
> -		case "$url" in
> -		./*|../*)
> -			# rewrite foo/bar as ../.. to find path from
> -			# submodule work tree to superproject work tree
> -			up_path="$(printf '%s\n' "$sm_path" | sed "s/[^/][^/]*/../g")" &&
> -			# guarantee a trailing /
> -			up_path=${up_path%/}/ &&
> -			# path from submodule work tree to submodule origin repo
> -			sub_origin_url=$(git submodule--helper resolve-relative-url "$url" "$up_path") &&
> -			# path from superproject work tree to submodule origin repo
> -			super_config_url=$(git submodule--helper resolve-relative-url "$url") || exit
> -			;;
> -		*)
> -			sub_origin_url="$url"
> -			super_config_url="$url"
> -			;;
> -		esac
>  
> -		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
> -		say "$(eval_gettext "Synchronizing submodule url for '\$displaypath'")"
> -		git config submodule."$name".url "$super_config_url"
> -
> -		if test -e "$sm_path"/.git
> -		then
> -		(
> -			sanitize_submodule_env
> -			cd "$sm_path"
> -			remote=$(get_default_remote)
> -			git config remote."$remote".url "$sub_origin_url"
> +	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper sync ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
>  
> -			if test -n "$recursive"
> -			then
> -				prefix="$prefix$sm_path/"
> -				eval cmd_sync
> -			fi
> -		)
> -		fi
> -	done
>  }
>  
>  cmd_absorbgitdirs()
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 141 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  55 +----------------
 2 files changed, 142 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 2d1d3984d..5e84fc42d 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -910,6 +910,146 @@ static int module_sync(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct deinit_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int force: 1;
+	unsigned int all: 1;
+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+			     void *cb_data)
+{
+	struct deinit_cb *info = cb_data;
+	const struct submodule *sub;
+	char *displaypath = NULL;
+	struct child_process cp_config = CHILD_PROCESS_INIT;
+	struct strbuf sb_config = STRBUF_INIT;
+	char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+	struct stat st;
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (!sub || !sub->name)
+		goto cleanup;
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	/* remove the submodule work tree (unless the user already did it) */
+	if (is_directory(list_item->name)) {
+		/* protect submodules containing a .git directory */
+		if (is_git_directory(sub_git_dir))
+			die(_("Submodule work tree '%s' contains a .git "
+			      "directory use 'rm -rf' if you really want "
+			      "to remove it including all of its history"),
+			      displaypath);
+
+		if (!info->force) {
+			struct child_process cp_rm = CHILD_PROCESS_INIT;
+			cp_rm.git_cmd = 1;
+			argv_array_pushl(&cp_rm.args, "rm", "-qn",
+					 list_item->name, NULL);
+
+			if (run_command(&cp_rm))
+				die(_("Submodule work tree '%s' contains local "
+				      "modifications; use '-f' to discard them"),
+				      displaypath);
+		}
+
+		if (!lstat(list_item->name, &st)) {
+			struct strbuf sb_rm = STRBUF_INIT;
+			const char *format;
+
+			strbuf_addstr(&sb_rm, list_item->name);
+
+			if (!remove_dir_recursively(&sb_rm, 0))
+				format = _("Cleared directory '%s'\n");
+			else
+				format = _("Could not remove submodule work tree '%s'\n");
+
+			if (!info->quiet)
+				printf(format, displaypath);
+
+			strbuf_release(&sb_rm);
+		}
+	}
+
+	if (mkdir(list_item->name, st.st_mode))
+		die(_("could not create empty submodule directory %s"),
+		      displaypath);
+
+	cp_config.git_cmd = 1;
+	argv_array_pushl(&cp_config.args, "config", "--get-regexp", NULL);
+	argv_array_pushf(&cp_config.args, "submodule.%s\\.", sub->name);
+
+	/* remove the .git/config entries (unless the user already did it) */
+	if (!capture_command(&cp_config, &sb_config, 0) && sb_config.len) {
+		char *sub_key = xstrfmt("submodule.%s", sub->name);
+		/*
+		 * remove the whole section so we have a clean state when
+		 * the user later decides to init this submodule again
+		 */
+		git_config_rename_section_in_file(NULL, sub_key, NULL);
+		if (!info->quiet)
+			printf(_("Submodule '%s' (%s) unregistered for path '%s'\n"),
+				 sub->name, sub->url, displaypath);
+		free(sub_key);
+	}
+
+cleanup:
+	free(displaypath);
+	free(sub_git_dir);
+	strbuf_release(&sb_config);
+}
+
+static int module_deinit(int argc, const char **argv, const char *prefix)
+{
+	struct deinit_cb info = DEINIT_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int force = 0;
+	int all = 0;
+
+	struct option module_deinit_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
+		OPT__FORCE(&force, N_("Remove submodule working trees even if they contain local changes")),
+		OPT_BOOL(0, "all", &all, N_("Unregister all submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule deinit [--quiet] [-f | --force] [--all | [--] [<path>...]]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_deinit_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		BUG("module_list_compute should not choke on empty pathspec");
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.all = !!all;
+	info.force = !!force;
+
+	if (all && argc) {
+		error("pathspec and --all are incompatible");
+		usage_with_options(git_submodule_helper_usage,
+				   module_deinit_options);
+	}
+
+	if (!argc && !all)
+		die(_("Use '--all' if you really want to deinitialize all submodules"));
+
+	gitmodules_config();
+	for_each_submodule_list(list, deinit_submodule, &info);
+
+	return 0;
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference,
 			   int quiet, int progress)
@@ -1640,6 +1780,7 @@ static struct cmd_struct commands[] = {
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"print-default-remote", print_default_remote, 0},
 	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
+	{"deinit", module_deinit, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 6bfc5e17d..73e6f093f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -428,60 +428,7 @@ cmd_deinit()
 		shift
 	done
 
-	if test -n "$deinit_all" && test "$#" -ne 0
-	then
-		echo >&2 "$(eval_gettext "pathspec and --all are incompatible")"
-		usage
-	fi
-	if test $# = 0 && test -z "$deinit_all"
-	then
-		die "$(eval_gettext "Use '--all' if you really want to deinitialize all submodules")"
-	fi
-
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		name=$(git submodule--helper name "$sm_path") || exit
-
-		displaypath=$(git submodule--helper relative-path "$sm_path" "$wt_prefix")
-
-		# Remove the submodule work tree (unless the user already did it)
-		if test -d "$sm_path"
-		then
-			# Protect submodules containing a .git directory
-			if test -d "$sm_path/.git"
-			then
-				die "$(eval_gettext "\
-Submodule work tree '\$displaypath' contains a .git directory
-(use 'rm -rf' if you really want to remove it including all of its history)")"
-			fi
-
-			if test -z "$force"
-			then
-				git rm -qn "$sm_path" ||
-				die "$(eval_gettext "Submodule work tree '\$displaypath' contains local modifications; use '-f' to discard them")"
-			fi
-			rm -rf "$sm_path" &&
-			say "$(eval_gettext "Cleared directory '\$displaypath'")" ||
-			say "$(eval_gettext "Could not remove submodule work tree '\$displaypath'")"
-		fi
-
-		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$displaypath'")"
-
-		# Remove the .git/config entries (unless the user already did it)
-		if test -n "$(git config --get-regexp submodule."$name\.")"
-		then
-			# Remove the whole section so we have a clean state when
-			# the user later decides to init this submodule again
-			url=$(git config submodule."$name".url)
-			git config --remove-section submodule."$name" 2>/dev/null &&
-			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$displaypath'")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${force:+--force} ${deinit_all:+--all} "$@"
 }
 
 is_tip_reachable () (
-- 
2.13.0

Re: [GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> The same mechanism is used even for porting this submodule
> subcommand, as used in the ported subcommands till now.
> The function cmd_deinit in split up after porting into three
> functions: module_deinit(), for_each_submodule_list() and
> deinit_submodule().
> 
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
>  builtin/submodule--helper.c | 141 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            |  55 +----------------
>  2 files changed, 142 insertions(+), 54 deletions(-)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 2d1d3984d..5e84fc42d 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -910,6 +910,146 @@ static int module_sync(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +struct deinit_cb {
> +	const char *prefix;
> +	unsigned int quiet: 1;
> +	unsigned int force: 1;
> +	unsigned int all: 1;
> +};
> +#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
> +
> +static void deinit_submodule(const struct cache_entry *list_item,
> +			     void *cb_data)
> +{
> +	struct deinit_cb *info = cb_data;
> +	const struct submodule *sub;
> +	char *displaypath = NULL;
> +	struct child_process cp_config = CHILD_PROCESS_INIT;
> +	struct strbuf sb_config = STRBUF_INIT;
> +	char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
> +	struct stat st;
> +
> +	sub = submodule_from_path(null_sha1, list_item->name);
> +
> +	if (!sub || !sub->name)
> +		goto cleanup;
> +
> +	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
> +
> +	/* remove the submodule work tree (unless the user already did it) */
> +	if (is_directory(list_item->name)) {
> +		/* protect submodules containing a .git directory */
> +		if (is_git_directory(sub_git_dir))

This may be too strict of a test.  The original code simply checks if
'submodule/.git' is a directory and dies if it is.  This adds additional
checks ensuring it is a gitdir.  If we want to have a straight
conversion from the shell code we should have this only check if it is a
directory.

> +			die(_("Submodule work tree '%s' contains a .git "
> +			      "directory use 'rm -rf' if you really want "
> +			      "to remove it including all of its history"),
> +			      displaypath);
> +
> +		if (!info->force) {
> +			struct child_process cp_rm = CHILD_PROCESS_INIT;
> +			cp_rm.git_cmd = 1;
> +			argv_array_pushl(&cp_rm.args, "rm", "-qn",
> +					 list_item->name, NULL);
> +
> +			if (run_command(&cp_rm))
> +				die(_("Submodule work tree '%s' contains local "
> +				      "modifications; use '-f' to discard them"),
> +				      displaypath);
> +		}
> +
> +		if (!lstat(list_item->name, &st)) {

What's the purpose of the lstat call here?

> +			struct strbuf sb_rm = STRBUF_INIT;
> +			const char *format;
> +
> +			strbuf_addstr(&sb_rm, list_item->name);
> +
> +			if (!remove_dir_recursively(&sb_rm, 0))
> +				format = _("Cleared directory '%s'\n");
> +			else
> +				format = _("Could not remove submodule work tree '%s'\n");
> +
> +			if (!info->quiet)
> +				printf(format, displaypath);
> +
> +			strbuf_release(&sb_rm);
> +		}
> +	}
> +
> +	if (mkdir(list_item->name, st.st_mode))

What should the mode be when making the empty directory? Right now you
have the potential for it to be garbage as 'st' has the potential of not
being set by the lstat call above (since it happens inside the above if
statement).  Also we may not want it to depend on what the permissions
were set as on the filesystem assuming the user didn't already remove
the submodule themselves.

> +		die(_("could not create empty submodule directory %s"),
> +		      displaypath);
> +
> +	cp_config.git_cmd = 1;
> +	argv_array_pushl(&cp_config.args, "config", "--get-regexp", NULL);
> +	argv_array_pushf(&cp_config.args, "submodule.%s\\.", sub->name);
> +
> +	/* remove the .git/config entries (unless the user already did it) */
> +	if (!capture_command(&cp_config, &sb_config, 0) && sb_config.len) {
> +		char *sub_key = xstrfmt("submodule.%s", sub->name);
> +		/*
> +		 * remove the whole section so we have a clean state when
> +		 * the user later decides to init this submodule again
> +		 */
> +		git_config_rename_section_in_file(NULL, sub_key, NULL);
> +		if (!info->quiet)
> +			printf(_("Submodule '%s' (%s) unregistered for path '%s'\n"),
> +				 sub->name, sub->url, displaypath);
> +		free(sub_key);
> +	}
> +
> +cleanup:
> +	free(displaypath);
> +	free(sub_git_dir);
> +	strbuf_release(&sb_config);
> +}
> +
> +static int module_deinit(int argc, const char **argv, const char *prefix)
> +{
> +	struct deinit_cb info = DEINIT_CB_INIT;
> +	struct pathspec pathspec;
> +	struct module_list list = MODULE_LIST_INIT;
> +	int quiet = 0;
> +	int force = 0;
> +	int all = 0;
> +
> +	struct option module_deinit_options[] = {
> +		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
> +		OPT__FORCE(&force, N_("Remove submodule working trees even if they contain local changes")),
> +		OPT_BOOL(0, "all", &all, N_("Unregister all submodules")),
> +		OPT_END()
> +	};
> +
> +	const char *const git_submodule_helper_usage[] = {
> +		N_("git submodule deinit [--quiet] [-f | --force] [--all | [--] [<path>...]]"),
> +		NULL
> +	};
> +
> +	argc = parse_options(argc, argv, prefix, module_deinit_options,
> +			     git_submodule_helper_usage, 0);
> +
> +	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
> +		BUG("module_list_compute should not choke on empty pathspec");
> +
> +	info.prefix = prefix;
> +	info.quiet = !!quiet;
> +	info.all = !!all;
> +	info.force = !!force;
> +
> +	if (all && argc) {
> +		error("pathspec and --all are incompatible");
> +		usage_with_options(git_submodule_helper_usage,
> +				   module_deinit_options);
> +	}
> +
> +	if (!argc && !all)
> +		die(_("Use '--all' if you really want to deinitialize all submodules"));
> +
> +	gitmodules_config();
> +	for_each_submodule_list(list, deinit_submodule, &info);
> +
> +	return 0;
> +}
> +
>  static int clone_submodule(const char *path, const char *gitdir, const char *url,
>  			   const char *depth, struct string_list *reference,
>  			   int quiet, int progress)
> @@ -1640,6 +1780,7 @@ static struct cmd_struct commands[] = {
>  	{"status", module_status, SUPPORT_SUPER_PREFIX},
>  	{"print-default-remote", print_default_remote, 0},
>  	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
> +	{"deinit", module_deinit, SUPPORT_SUPER_PREFIX},
>  	{"remote-branch", resolve_remote_submodule_branch, 0},
>  	{"push-check", push_check, 0},
>  	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
> diff --git a/git-submodule.sh b/git-submodule.sh
> index 6bfc5e17d..73e6f093f 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -428,60 +428,7 @@ cmd_deinit()
>  		shift
>  	done
>  
> -	if test -n "$deinit_all" && test "$#" -ne 0
> -	then
> -		echo >&2 "$(eval_gettext "pathspec and --all are incompatible")"
> -		usage
> -	fi
> -	if test $# = 0 && test -z "$deinit_all"
> -	then
> -		die "$(eval_gettext "Use '--all' if you really want to deinitialize all submodules")"
> -	fi
> -
> -	{
> -		git submodule--helper list --prefix "$wt_prefix" "$@" ||
> -		echo "#unmatched" $?
> -	} |
> -	while read -r mode sha1 stage sm_path
> -	do
> -		die_if_unmatched "$mode" "$sha1"
> -		name=$(git submodule--helper name "$sm_path") || exit
> -
> -		displaypath=$(git submodule--helper relative-path "$sm_path" "$wt_prefix")
> -
> -		# Remove the submodule work tree (unless the user already did it)
> -		if test -d "$sm_path"
> -		then
> -			# Protect submodules containing a .git directory
> -			if test -d "$sm_path/.git"
> -			then
> -				die "$(eval_gettext "\
> -Submodule work tree '\$displaypath' contains a .git directory
> -(use 'rm -rf' if you really want to remove it including all of its history)")"
> -			fi
> -
> -			if test -z "$force"
> -			then
> -				git rm -qn "$sm_path" ||
> -				die "$(eval_gettext "Submodule work tree '\$displaypath' contains local modifications; use '-f' to discard them")"
> -			fi
> -			rm -rf "$sm_path" &&
> -			say "$(eval_gettext "Cleared directory '\$displaypath'")" ||
> -			say "$(eval_gettext "Could not remove submodule work tree '\$displaypath'")"
> -		fi
> -
> -		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$displaypath'")"
> -
> -		# Remove the .git/config entries (unless the user already did it)
> -		if test -n "$(git config --get-regexp submodule."$name\.")"
> -		then
> -			# Remove the whole section so we have a clean state when
> -			# the user later decides to init this submodule again
> -			url=$(git config submodule."$name".url)
> -			git config --remove-section submodule."$name" 2>/dev/null &&
> -			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$displaypath'")"
> -		fi
> -	done
> +	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${force:+--force} ${deinit_all:+--all} "$@"
>  }
>  
>  is_tip_reachable () (
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 07/13] diff: change scope of the function count_lines()

[Prathamesh Chavan]

Change the scope of function count_lines for allowing the function
to be reused in other parts of the code as well.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 diff.c | 2 +-
 diff.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index 85e714f6c..03ed64f93 100644
--- a/diff.c
+++ b/diff.c
@@ -425,7 +425,7 @@ struct emit_callback {
 	struct strbuf *header;
 };
 
-static int count_lines(const char *data, int size)
+int count_lines(const char *data, int size)
 {
 	int count, ch, completely_empty = 1, nl_just_seen = 0;
 	count = 0;
diff --git a/diff.h b/diff.h
index 2d442e296..8522514e9 100644
--- a/diff.h
+++ b/diff.h
@@ -273,6 +273,7 @@ extern struct diff_filepair *diff_unmerge(struct diff_options *, const char *pat
 extern int parse_long_opt(const char *opt, const char **argv,
 			 const char **optarg);
 
+extern int count_lines(const char *data, int size);
 extern int git_diff_basic_config(const char *var, const char *value, void *cb);
 extern int git_diff_heuristic_config(const char *var, const char *value, void *cb);
 extern void init_diff_ui_defaults(void);
-- 
2.13.0

[GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

The submodule subcommand 'summary' is ported in the process of
making git-submodule a builtin. The function cmd_summary() from
git-submodule.sh is ported to functions module_summary(),
compute_summary_module_list(), prepare_submodule_summary() and
print_submodule_summary().

The first function module_summary() parses the options of submodule
subcommand and also acts as the front-end of this subcommand.
After parsing them, it calls the compute_summary_module_list()

The functions compute_summary_module_list() runs the diff_cmd,
and generates the modules list, as required by the subcommand.
The generation of this module list is done by the using the
callback function submodule_summary_callback(), and stored in the
structure module_cb.

Once the module list is generated, prepare_submodule_summary()
further goes through the list and filters the list, for
eventually calling the print_submodule_summary() function.

Finally, the print_submodule_summary() takes care of generating
and printing the summary for each submodule.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version of patch, following changes were made:
* the way of generating sub_sha1_src and sub_sha1_dst (abbrev of sha1_src
  and sha1_dst resp.) were changed. Since there was no direct way of
  abbrevating a string(sha1_dst), in this patch sha1_dst was converted first
  to an object id (converting to sha1 was avoided) and then abbrevated using
  find_unique_abbrev().
* A few big if() statements were reduced.
* for reducing the two big if() statements, a new function
  verify_submodule_object_name() was introduced.
* this new version also corrects a few other nits.

 builtin/submodule--helper.c | 428 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            | 182 +------------------
 2 files changed, 429 insertions(+), 181 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 5e84fc42d..94d6254f0 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,6 +13,9 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
 				      void *cb_data);
@@ -762,6 +765,430 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct module_cb {
+	unsigned int mod_src;
+	unsigned int mod_dst;
+	struct object_id oid_src;
+	struct object_id oid_dst;
+	char status;
+	const char *sm_path;
+};
+#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
+
+struct module_cb_list {
+	struct module_cb **entries;
+	int alloc, nr;
+};
+#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
+
+struct summary_cb {
+	int argc;
+	const char **argv;
+	const char *prefix;
+	char *diff_cmd;
+	unsigned int cached: 1;
+	unsigned int for_status: 1;
+	unsigned int quiet: 1;
+	unsigned int files: 1;
+	int summary_limits;
+};
+#define SUMMARY_CB_INIT { 0, NULL, NULL, NULL, 0, 0, 0, 0, 0 }
+
+static int verify_submodule_object_name(const char *sm_path, const char *sha1)
+{
+	struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+	cp_rev_parse.git_cmd = 1;
+	cp_rev_parse.no_stdout = 1;
+	cp_rev_parse.dir = sm_path;
+	prepare_submodule_repo_env(&cp_rev_parse.env_array);
+
+	argv_array_pushl(&cp_rev_parse.args, "rev-parse", "-q",
+			 "--verify", NULL);
+	argv_array_pushf(&cp_rev_parse.args, "%s^0", sha1);
+
+	if (run_command(&cp_rev_parse))
+		return 1;
+
+	return 0;
+}
+
+static void print_submodule_summary(struct summary_cb *info,
+				    struct module_cb *p)
+{
+	int missing_src = 0;
+	int missing_dst = 0;
+	char *displaypath;
+	const char *sha1_abbr_src;
+	const char *sha1_abbr_dst;
+	struct object_id oid_dst;
+	int errmsg = 0;
+	int total_commits = -1;
+	const char *sha1_dst = oid_to_hex(&p->oid_dst);
+	const char *sha1_src = oid_to_hex(&p->oid_src);
+	char *sm_git_dir = xstrfmt("%s/.git", p->sm_path);
+	int is_sm_git_dir = 0;
+
+	if (!info->cached && !strcmp(sha1_dst, sha1_to_hex(null_sha1))) {
+		if (S_ISGITLINK(p->mod_dst)) {
+			struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+			struct strbuf sb_rev_parse = STRBUF_INIT;
+
+			cp_rev_parse.git_cmd = 1;
+			cp_rev_parse.no_stderr = 1;
+			cp_rev_parse.dir = p->sm_path;
+			prepare_submodule_repo_env(&cp_rev_parse.env_array);
+
+			argv_array_pushl(&cp_rev_parse.args,
+					 "rev-parse", "HEAD", NULL);
+			if (!capture_command(&cp_rev_parse, &sb_rev_parse, 0)) {
+				strbuf_strip_suffix(&sb_rev_parse, "\n");
+				sha1_dst = xstrdup(sb_rev_parse.buf);
+			}
+			strbuf_release(&sb_rev_parse);
+		} else if (S_ISLNK(p->mod_dst) || S_ISREG(p->mod_dst)) {
+			struct child_process cp_hash_object = CHILD_PROCESS_INIT;
+			struct strbuf sb_hash_object = STRBUF_INIT;
+
+			cp_hash_object.git_cmd = 1;
+			argv_array_pushl(&cp_hash_object.args,
+					 "hash-object", p->sm_path,
+					 NULL);
+			if (!capture_command(&cp_hash_object,
+					     &sb_hash_object, 0)) {
+				strbuf_strip_suffix(&sb_hash_object, "\n");
+				sha1_dst = xstrdup(sb_hash_object.buf);
+			}
+			strbuf_release(&sb_hash_object);
+		} else {
+			if (p->mod_dst)
+				die(_("unexpected mode %d\n"), p->mod_dst);
+		}
+	}
+
+	if (is_git_directory(sm_git_dir))
+		is_sm_git_dir = 1;
+
+	if (is_sm_git_dir && S_ISGITLINK(p->mod_src))
+		missing_src = verify_submodule_object_name(p->sm_path,
+							   sha1_src);
+
+	if (is_sm_git_dir && S_ISGITLINK(p->mod_dst))
+		missing_dst = verify_submodule_object_name(p->sm_path,
+							   sha1_dst);
+
+	displaypath = get_submodule_displaypath(p->sm_path, info->prefix);
+
+	if (!missing_dst && !missing_src) {
+		if (is_sm_git_dir) {
+			struct child_process cp_rev_list = CHILD_PROCESS_INIT;
+			struct strbuf sb_rev_list = STRBUF_INIT;
+			char *range;
+
+			if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst))
+				range = xstrfmt("%s...%s", sha1_src, sha1_dst);
+			else if (S_ISGITLINK(p->mod_src))
+				range = xstrdup(sha1_src);
+			else
+				range = xstrdup(sha1_dst);
+
+			cp_rev_list.git_cmd = 1;
+			cp_rev_list.dir = p->sm_path;
+			prepare_submodule_repo_env(&cp_rev_list.env_array);
+
+			argv_array_pushl(&cp_rev_list.args, "rev-list",
+					 "--first-parent", range, "--", NULL);
+			if (!capture_command(&cp_rev_list, &sb_rev_list, 0)) {
+				if (sb_rev_list.len)
+					total_commits = count_lines(sb_rev_list.buf,
+								    sb_rev_list.len);
+				else
+					total_commits = 0;
+			}
+
+			free(range);
+			strbuf_release(&sb_rev_list);
+		}
+	} else {
+		errmsg = 1;
+	}
+
+	get_oid_hex(sha1_dst, &oid_dst);
+
+	sha1_abbr_src = find_unique_abbrev(p->oid_src.hash, 7);
+	sha1_abbr_dst = find_unique_abbrev(oid_dst.hash, 7);
+
+	if (p->status == 'T') {
+		if (S_ISGITLINK(p->mod_dst))
+			printf(_("* %s %s(blob)->%s(submodule)"),
+				 displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+		else
+			printf(_("* %s %s(submodule)->%s(blob)"),
+				 displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+	} else {
+			printf("* %s %s...%s", displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+	}
+
+	if (total_commits < 0)
+		printf(":\n");
+	else
+		printf(" (%d):\n", total_commits);
+
+	if (errmsg) {
+		/*
+		 * Don't give error msg for modification whose dst is not
+		 * submodule, i.e. deleted or changed to blob
+		 */
+		if (S_ISGITLINK(p->mod_src)) {
+			if (missing_src && missing_dst) {
+				printf(_("  Warn: %s doesn't contain commits %s and %s\n"),
+				 displaypath, sha1_src, sha1_dst);
+			} else if (missing_src) {
+				printf(_("  Warn: %s doesn't contain commit %s\n"),
+				 displaypath, sha1_src);
+			} else {
+				printf(_("  Warn: %s doesn't contain commit %s\n"),
+				 displaypath, sha1_dst);
+			}
+		}
+	} else if (is_sm_git_dir) {
+		struct child_process cp_log = CHILD_PROCESS_INIT;
+
+		cp_log.git_cmd = 1;
+		cp_log.dir = p->sm_path;
+		prepare_submodule_repo_env(&cp_log.env_array);
+		argv_array_pushl(&cp_log.args, "log", NULL);
+
+		if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst)) {
+			if (info->summary_limits > 0)
+				argv_array_pushf(&cp_log.args, "-%d", info->summary_limits);
+
+			argv_array_pushl(&cp_log.args, "--pretty=  %m %s",
+					 "--first-parent", NULL);
+			argv_array_pushf(&cp_log.args, "%s...%s", sha1_src,
+					 sha1_dst);
+		} else if (S_ISGITLINK(p->mod_dst)) {
+			argv_array_pushl(&cp_log.args, "--pretty=  > %s",
+					 "-1", sha1_dst, NULL);
+		} else {
+			argv_array_pushl(&cp_log.args, "--pretty=  < %s",
+					 "-1", sha1_src, NULL);
+		}
+
+		run_command(&cp_log);
+	}
+	printf("\n");
+
+	free(displaypath);
+}
+
+static void prepare_submodule_summary(struct summary_cb *info,
+				      struct module_cb_list *list)
+{
+	int i;
+	for (i = 0; i < list->nr; i++) {
+		struct module_cb *p = list->entries[i];
+		struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+		if (p->status == 'D' || p->status == 'T') {
+			print_submodule_summary(info, p);
+			continue;
+		}
+
+		if (info->for_status) {
+			char *config_key;
+			const char *ignore_config = "none";
+			const char *value;
+			const struct submodule *sub = submodule_from_path(null_sha1, p->sm_path);
+
+			if (sub && p->status != 'A') {
+				config_key = xstrfmt("submodule.%s.ignore",
+						     sub->name);
+				if (!git_config_get_value(config_key, &value))
+					ignore_config = value;
+				else if (sub->ignore)
+					ignore_config = sub->ignore;
+
+				free(config_key);
+
+				if (!strcmp(ignore_config, "all"))
+					continue;
+			}
+		}
+
+		/* Also show added or modified modules which are checked out */
+		cp_rev_parse.dir = p->sm_path;
+		cp_rev_parse.git_cmd = 1;
+		cp_rev_parse.no_stderr = 1;
+		cp_rev_parse.no_stdout = 1;
+
+		argv_array_pushl(&cp_rev_parse.args, "rev-parse",
+				 "--git-dir", NULL);
+
+		if (!run_command(&cp_rev_parse))
+			print_submodule_summary(info, p);
+	}
+}
+
+static void submodule_summary_callback(struct diff_queue_struct *q,
+				       struct diff_options *options,
+				       void *data)
+{
+	int i;
+	struct module_cb_list *list = data;
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		struct module_cb *temp;
+
+		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
+			continue;
+		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
+		temp->mod_src = p->one->mode;
+		temp->mod_dst = p->two->mode;
+		temp->oid_src = p->one->oid;
+		temp->oid_dst = p->two->oid;
+		temp->status = p->status;
+		temp->sm_path = xstrdup(p->one->path);
+
+		ALLOC_GROW(list->entries, list->nr + 1, list->alloc);
+		list->entries[list->nr++] = temp;
+	}
+}
+
+static int compute_summary_module_list(char *head, struct summary_cb *info)
+{
+	struct argv_array diff_args = ARGV_ARRAY_INIT;
+	struct rev_info rev;
+	struct module_cb_list list = MODULE_CB_LIST_INIT;
+
+	argv_array_push(&diff_args, info->diff_cmd);
+	if (info->cached)
+		argv_array_push(&diff_args, "--cached");
+	argv_array_pushl(&diff_args, "--ignore-submodules=dirty", "--raw",
+			 NULL);
+	if (head)
+		argv_array_push(&diff_args, head);
+	argv_array_push(&diff_args, "--");
+	if (info->argc)
+		argv_array_pushv(&diff_args, info->argv);
+
+	git_config(git_diff_basic_config, NULL);
+	init_revisions(&rev, info->prefix);
+	gitmodules_config();
+	rev.abbrev = 0;
+	precompose_argv(diff_args.argc, diff_args.argv);
+
+	diff_args.argc = setup_revisions(diff_args.argc, diff_args.argv,
+					 &rev, NULL);
+	rev.diffopt.output_format = DIFF_FORMAT_NO_OUTPUT | DIFF_FORMAT_CALLBACK;
+	rev.diffopt.format_callback = submodule_summary_callback;
+	rev.diffopt.format_callback_data = &list;
+
+	if (!info->cached) {
+		if (!strcmp(info->diff_cmd, "diff-index"))
+			setup_work_tree();
+		if (read_cache_preload(&rev.diffopt.pathspec) < 0) {
+			perror("read_cache_preload");
+			return -1;
+		}
+	} else if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
+
+	if (!strcmp(info->diff_cmd, "diff-index"))
+		run_diff_index(&rev, info->cached);
+	else
+		run_diff_files(&rev, 0);
+	prepare_submodule_summary(info, &list);
+
+	return 0;
+
+}
+
+static int module_summary(int argc, const char **argv, const char *prefix)
+{
+	struct summary_cb info = SUMMARY_CB_INIT;
+	int cached = 0;
+	char *diff_cmd = "diff-index";
+	int for_status = 0;
+	int quiet = 0;
+	int files = 0;
+	int summary_limits = -1;
+	struct child_process cp_rev = CHILD_PROCESS_INIT;
+	char *head;
+	struct strbuf sb = STRBUF_INIT;
+
+	struct option module_summary_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
+		OPT_BOOL(0, "cached", &cached, N_("Use the commit stored in the index instead of the submodule HEAD")),
+		OPT_BOOL(0, "files", &files, N_("To compares the commit in the index with that in the submodule HEAD")),
+		OPT_BOOL(0, "for-status", &for_status, N_("Skip submodules with 'all' ignore_config value")),
+		OPT_INTEGER('n', "summary-limits", &summary_limits, N_("Limit the summary size")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper summary [<options>] [--] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_summary_options,
+			     git_submodule_helper_usage, 0);
+
+	if (!summary_limits)
+		return 0;
+
+	cp_rev.git_cmd = 1;
+	argv_array_pushl(&cp_rev.args, "rev-parse", "-q", "--verify",
+			 argc ? argv[0] : "HEAD", NULL);
+
+	if (!capture_command(&cp_rev, &sb, 0)) {
+		strbuf_strip_suffix(&sb, "\n");
+		if (argc) {
+			argv++;
+			argc--;
+		}
+	} else if (!argc || !strcmp(argv[0], "HEAD")) {
+		/* before the first commit: compare with an empty tree */
+		struct stat st;
+		unsigned char sha1[20];
+		if (fstat(0, &st) < 0 || index_fd(sha1, 0, &st, 2, prefix, 3))
+			die("Unable to add %s to database", sha1);
+		strbuf_addstr(&sb, sha1_to_hex(sha1));
+		if (argc) {
+			argv++;
+			argc--;
+		}
+	} else {
+		strbuf_addstr(&sb, "HEAD");
+	}
+
+	head = strbuf_detach(&sb, NULL);
+
+	if (files) {
+		if (cached)
+			die(_("The --cached option cannot be used with the --files option"));
+		diff_cmd = "diff-files";
+		head = NULL;
+	}
+
+	info.argc = argc;
+	info.argv = argv;
+	info.prefix = prefix;
+	info.cached = cached;
+	info.for_status = for_status;
+	info.quiet = quiet;
+	info.files = files;
+	info.summary_limits = summary_limits;
+	info.diff_cmd = diff_cmd;
+
+	return compute_summary_module_list(head, &info);
+}
+
 struct sync_cb {
 	const char *prefix;
 	unsigned int quiet: 1;
@@ -1781,6 +2208,7 @@ static struct cmd_struct commands[] = {
 	{"print-default-remote", print_default_remote, 0},
 	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
 	{"deinit", module_deinit, SUPPORT_SUPER_PREFIX},
+	{"summary", module_summary, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 73e6f093f..a427ddafd 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -51,31 +51,6 @@ die_if_unmatched ()
 	fi
 }
 
-#
-# Print a submodule configuration setting
-#
-# $1 = submodule name
-# $2 = option name
-# $3 = default value
-#
-# Checks in the usual git-config places first (for overrides),
-# otherwise it falls back on .gitmodules.  This allows you to
-# distribute project-wide defaults in .gitmodules, while still
-# customizing individual repositories if necessary.  If the option is
-# not in .gitmodules either, print a default value.
-#
-get_submodule_config () {
-	name="$1"
-	option="$2"
-	default="$3"
-	value=$(git config submodule."$name"."$option")
-	if test -z "$value"
-	then
-		value=$(git config -f .gitmodules submodule."$name"."$option")
-	fi
-	printf '%s' "${value:-$default}"
-}
-
 isnumber()
 {
 	n=$(($1 + 0)) 2>/dev/null && test "$n" = "$1"
@@ -755,163 +730,8 @@ cmd_summary() {
 		shift
 	done
 
-	test $summary_limit = 0 && return
-
-	if rev=$(git rev-parse -q --verify --default HEAD ${1+"$1"})
-	then
-		head=$rev
-		test $# = 0 || shift
-	elif test -z "$1" || test "$1" = "HEAD"
-	then
-		# before the first commit: compare with an empty tree
-		head=$(git hash-object -w -t tree --stdin </dev/null)
-		test -z "$1" || shift
-	else
-		head="HEAD"
-	fi
-
-	if [ -n "$files" ]
-	then
-		test -n "$cached" &&
-		die "$(gettext "The --cached option cannot be used with the --files option")"
-		diff_cmd=diff-files
-		head=
-	fi
-
-	cd_to_toplevel
-	eval "set $(git rev-parse --sq --prefix "$wt_prefix" -- "$@")"
-	# Get modified modules cared by user
-	modules=$(git $diff_cmd $cached --ignore-submodules=dirty --raw $head -- "$@" |
-		sane_egrep '^:([0-7]* )?160000' |
-		while read -r mod_src mod_dst sha1_src sha1_dst status sm_path
-		do
-			# Always show modules deleted or type-changed (blob<->module)
-			if test "$status" = D || test "$status" = T
-			then
-				printf '%s\n' "$sm_path"
-				continue
-			fi
-			# Respect the ignore setting for --for-status.
-			if test -n "$for_status"
-			then
-				name=$(git submodule--helper name "$sm_path")
-				ignore_config=$(get_submodule_config "$name" ignore none)
-				test $status != A && test $ignore_config = all && continue
-			fi
-			# Also show added or modified modules which are checked out
-			GIT_DIR="$sm_path/.git" git-rev-parse --git-dir >/dev/null 2>&1 &&
-			printf '%s\n' "$sm_path"
-		done
-	)
-
-	test -z "$modules" && return
-
-	git $diff_cmd $cached --ignore-submodules=dirty --raw $head -- $modules |
-	sane_egrep '^:([0-7]* )?160000' |
-	cut -c2- |
-	while read -r mod_src mod_dst sha1_src sha1_dst status name
-	do
-		if test -z "$cached" &&
-			test $sha1_dst = 0000000000000000000000000000000000000000
-		then
-			case "$mod_dst" in
-			160000)
-				sha1_dst=$(GIT_DIR="$name/.git" git rev-parse HEAD)
-				;;
-			100644 | 100755 | 120000)
-				sha1_dst=$(git hash-object $name)
-				;;
-			000000)
-				;; # removed
-			*)
-				# unexpected type
-				eval_gettextln "unexpected mode \$mod_dst" >&2
-				continue ;;
-			esac
-		fi
-		missing_src=
-		missing_dst=
-
-		test $mod_src = 160000 &&
-		! GIT_DIR="$name/.git" git-rev-parse -q --verify $sha1_src^0 >/dev/null &&
-		missing_src=t
-
-		test $mod_dst = 160000 &&
-		! GIT_DIR="$name/.git" git-rev-parse -q --verify $sha1_dst^0 >/dev/null &&
-		missing_dst=t
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper summary ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${for_status:+--for-status} ${files:+--files} ${cached:+--cached} ${summary_limit:+-n $summary_limit} "$@"
 
-		display_name=$(git submodule--helper relative-path "$name" "$wt_prefix")
-
-		total_commits=
-		case "$missing_src,$missing_dst" in
-		t,)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_src")"
-			;;
-		,t)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_dst")"
-			;;
-		t,t)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commits \$sha1_src and \$sha1_dst")"
-			;;
-		*)
-			errmsg=
-			total_commits=$(
-			if test $mod_src = 160000 && test $mod_dst = 160000
-			then
-				range="$sha1_src...$sha1_dst"
-			elif test $mod_src = 160000
-			then
-				range=$sha1_src
-			else
-				range=$sha1_dst
-			fi
-			GIT_DIR="$name/.git" \
-			git rev-list --first-parent $range -- | wc -l
-			)
-			total_commits=" ($(($total_commits + 0)))"
-			;;
-		esac
-
-		sha1_abbr_src=$(echo $sha1_src | cut -c1-7)
-		sha1_abbr_dst=$(echo $sha1_dst | cut -c1-7)
-		if test $status = T
-		then
-			blob="$(gettext "blob")"
-			submodule="$(gettext "submodule")"
-			if test $mod_dst = 160000
-			then
-				echo "* $display_name $sha1_abbr_src($blob)->$sha1_abbr_dst($submodule)$total_commits:"
-			else
-				echo "* $display_name $sha1_abbr_src($submodule)->$sha1_abbr_dst($blob)$total_commits:"
-			fi
-		else
-			echo "* $display_name $sha1_abbr_src...$sha1_abbr_dst$total_commits:"
-		fi
-		if test -n "$errmsg"
-		then
-			# Don't give error msg for modification whose dst is not submodule
-			# i.e. deleted or changed to blob
-			test $mod_dst = 160000 && echo "$errmsg"
-		else
-			if test $mod_src = 160000 && test $mod_dst = 160000
-			then
-				limit=
-				test $summary_limit -gt 0 && limit="-$summary_limit"
-				GIT_DIR="$name/.git" \
-				git log $limit --pretty='format:  %m %s' \
-				--first-parent $sha1_src...$sha1_dst
-			elif test $mod_dst = 160000
-			then
-				GIT_DIR="$name/.git" \
-				git log --pretty='format:  > %s' -1 $sha1_dst
-			else
-				GIT_DIR="$name/.git" \
-				git log --pretty='format:  < %s' -1 $sha1_src
-			fi
-			echo
-		fi
-		echo
-	done
 }
 #
 # List all submodules, prefixed with:
-- 
2.13.0

Re: [GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> The submodule subcommand 'summary' is ported in the process of
> making git-submodule a builtin. The function cmd_summary() from
> git-submodule.sh is ported to functions module_summary(),
> compute_summary_module_list(), prepare_submodule_summary() and
> print_submodule_summary().
> 
> The first function module_summary() parses the options of submodule
> subcommand and also acts as the front-end of this subcommand.
> After parsing them, it calls the compute_summary_module_list()
> 
> The functions compute_summary_module_list() runs the diff_cmd,
> and generates the modules list, as required by the subcommand.
> The generation of this module list is done by the using the
> callback function submodule_summary_callback(), and stored in the
> structure module_cb.
> 
> Once the module list is generated, prepare_submodule_summary()
> further goes through the list and filters the list, for
> eventually calling the print_submodule_summary() function.
> 
> Finally, the print_submodule_summary() takes care of generating
> and printing the summary for each submodule.
> 
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>

This is a big one, hopefully I can try to understand everything that is
happening.

> ---
> In this new version of patch, following changes were made:
> * the way of generating sub_sha1_src and sub_sha1_dst (abbrev of sha1_src
>   and sha1_dst resp.) were changed. Since there was no direct way of
>   abbrevating a string(sha1_dst), in this patch sha1_dst was converted first
>   to an object id (converting to sha1 was avoided) and then abbrevated using
>   find_unique_abbrev().
> * A few big if() statements were reduced.
> * for reducing the two big if() statements, a new function
>   verify_submodule_object_name() was introduced.
> * this new version also corrects a few other nits.
> 
>  builtin/submodule--helper.c | 428 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            | 182 +------------------
>  2 files changed, 429 insertions(+), 181 deletions(-)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 5e84fc42d..94d6254f0 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -13,6 +13,9 @@
>  #include "remote.h"
>  #include "refs.h"
>  #include "connect.h"
> +#include "revision.h"
> +#include "diffcore.h"
> +#include "diff.h"
>  
>  typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
>  				      void *cb_data);
> @@ -762,6 +765,430 @@ static int module_name(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +struct module_cb {
> +	unsigned int mod_src;
> +	unsigned int mod_dst;
> +	struct object_id oid_src;
> +	struct object_id oid_dst;
> +	char status;
> +	const char *sm_path;
> +};
> +#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
> +
> +struct module_cb_list {
> +	struct module_cb **entries;
> +	int alloc, nr;
> +};
> +#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
> +
> +struct summary_cb {
> +	int argc;
> +	const char **argv;
> +	const char *prefix;
> +	char *diff_cmd;
> +	unsigned int cached: 1;
> +	unsigned int for_status: 1;
> +	unsigned int quiet: 1;
> +	unsigned int files: 1;
> +	int summary_limits;
> +};
> +#define SUMMARY_CB_INIT { 0, NULL, NULL, NULL, 0, 0, 0, 0, 0 }
> +
> +static int verify_submodule_object_name(const char *sm_path, const char *sha1)
> +{
> +	struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
> +
> +	cp_rev_parse.git_cmd = 1;
> +	cp_rev_parse.no_stdout = 1;
> +	cp_rev_parse.dir = sm_path;
> +	prepare_submodule_repo_env(&cp_rev_parse.env_array);
> +
> +	argv_array_pushl(&cp_rev_parse.args, "rev-parse", "-q",
> +			 "--verify", NULL);
> +	argv_array_pushf(&cp_rev_parse.args, "%s^0", sha1);
> +
> +	if (run_command(&cp_rev_parse))
> +		return 1;
> +
> +	return 0;
> +}
> +
> +static void print_submodule_summary(struct summary_cb *info,
> +				    struct module_cb *p)
> +{

This is one large function so it may be difficult to keep track of
everything and I don't know how easy it would be to split.

> +	int missing_src = 0;
> +	int missing_dst = 0;
> +	char *displaypath;
> +	const char *sha1_abbr_src;
> +	const char *sha1_abbr_dst;
> +	struct object_id oid_dst;
> +	int errmsg = 0;
> +	int total_commits = -1;
> +	const char *sha1_dst = oid_to_hex(&p->oid_dst);
> +	const char *sha1_src = oid_to_hex(&p->oid_src);

You have these two variables which are defined as 'const char *' yet you
allocate memory for them at different points via 'xstrdup' and then
never free it.  Really what you should be trying to do is use 'struct
object_id' as much as you can instead of storing the hash in hex form.
that way you can use 'oidcmp' instead of 'strcmp' at some points in the
code.  At one point you then convert back to an oid from hex.  When you
get output from a capture_command call and then dup the hex string, what
you really should do is convert the hex  SHA1 directly to an OID and use
it in OID form as much as possible.  Then you can convert it back to a
hex string at the point of use.  It just seems clunky to pass around hex
strings instead of the OID itself.

> +	char *sm_git_dir = xstrfmt("%s/.git", p->sm_path);

This variable is never freed.

> +	int is_sm_git_dir = 0;
> +
> +	if (!info->cached && !strcmp(sha1_dst, sha1_to_hex(null_sha1))) {
> +		if (S_ISGITLINK(p->mod_dst)) {
> +			struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
> +			struct strbuf sb_rev_parse = STRBUF_INIT;
> +
> +			cp_rev_parse.git_cmd = 1;
> +			cp_rev_parse.no_stderr = 1;
> +			cp_rev_parse.dir = p->sm_path;
> +			prepare_submodule_repo_env(&cp_rev_parse.env_array);
> +
> +			argv_array_pushl(&cp_rev_parse.args,
> +					 "rev-parse", "HEAD", NULL);
> +			if (!capture_command(&cp_rev_parse, &sb_rev_parse, 0)) {
> +				strbuf_strip_suffix(&sb_rev_parse, "\n");
> +				sha1_dst = xstrdup(sb_rev_parse.buf);
> +			}
> +			strbuf_release(&sb_rev_parse);
> +		} else if (S_ISLNK(p->mod_dst) || S_ISREG(p->mod_dst)) {
> +			struct child_process cp_hash_object = CHILD_PROCESS_INIT;
> +			struct strbuf sb_hash_object = STRBUF_INIT;
> +
> +			cp_hash_object.git_cmd = 1;
> +			argv_array_pushl(&cp_hash_object.args,
> +					 "hash-object", p->sm_path,
> +					 NULL);
> +			if (!capture_command(&cp_hash_object,
> +					     &sb_hash_object, 0)) {
> +				strbuf_strip_suffix(&sb_hash_object, "\n");
> +				sha1_dst = xstrdup(sb_hash_object.buf);
> +			}
> +			strbuf_release(&sb_hash_object);
> +		} else {
> +			if (p->mod_dst)
> +				die(_("unexpected mode %d\n"), p->mod_dst);
> +		}
> +	}
> +
> +	if (is_git_directory(sm_git_dir))
> +		is_sm_git_dir = 1;
> +
> +	if (is_sm_git_dir && S_ISGITLINK(p->mod_src))
> +		missing_src = verify_submodule_object_name(p->sm_path,
> +							   sha1_src);
> +
> +	if (is_sm_git_dir && S_ISGITLINK(p->mod_dst))
> +		missing_dst = verify_submodule_object_name(p->sm_path,
> +							   sha1_dst);
> +
> +	displaypath = get_submodule_displaypath(p->sm_path, info->prefix);
> +
> +	if (!missing_dst && !missing_src) {
> +		if (is_sm_git_dir) {
> +			struct child_process cp_rev_list = CHILD_PROCESS_INIT;
> +			struct strbuf sb_rev_list = STRBUF_INIT;
> +			char *range;
> +
> +			if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst))
> +				range = xstrfmt("%s...%s", sha1_src, sha1_dst);
> +			else if (S_ISGITLINK(p->mod_src))
> +				range = xstrdup(sha1_src);
> +			else
> +				range = xstrdup(sha1_dst);
> +
> +			cp_rev_list.git_cmd = 1;
> +			cp_rev_list.dir = p->sm_path;
> +			prepare_submodule_repo_env(&cp_rev_list.env_array);
> +
> +			argv_array_pushl(&cp_rev_list.args, "rev-list",
> +					 "--first-parent", range, "--", NULL);
> +			if (!capture_command(&cp_rev_list, &sb_rev_list, 0)) {
> +				if (sb_rev_list.len)
> +					total_commits = count_lines(sb_rev_list.buf,
> +								    sb_rev_list.len);
> +				else
> +					total_commits = 0;
> +			}
> +
> +			free(range);
> +			strbuf_release(&sb_rev_list);
> +		}
> +	} else {
> +		errmsg = 1;
> +	}
> +
> +	get_oid_hex(sha1_dst, &oid_dst);
> +
> +	sha1_abbr_src = find_unique_abbrev(p->oid_src.hash, 7);
> +	sha1_abbr_dst = find_unique_abbrev(oid_dst.hash, 7);
> +
> +	if (p->status == 'T') {
> +		if (S_ISGITLINK(p->mod_dst))
> +			printf(_("* %s %s(blob)->%s(submodule)"),
> +				 displaypath, sha1_abbr_src,
> +				 sha1_abbr_dst);
> +		else
> +			printf(_("* %s %s(submodule)->%s(blob)"),
> +				 displaypath, sha1_abbr_src,
> +				 sha1_abbr_dst);
> +	} else {
> +			printf("* %s %s...%s", displaypath, sha1_abbr_src,
> +				 sha1_abbr_dst);
> +	}
> +
> +	if (total_commits < 0)
> +		printf(":\n");
> +	else
> +		printf(" (%d):\n", total_commits);
> +
> +	if (errmsg) {
> +		/*
> +		 * Don't give error msg for modification whose dst is not
> +		 * submodule, i.e. deleted or changed to blob
> +		 */
> +		if (S_ISGITLINK(p->mod_src)) {
> +			if (missing_src && missing_dst) {
> +				printf(_("  Warn: %s doesn't contain commits %s and %s\n"),
> +				 displaypath, sha1_src, sha1_dst);
> +			} else if (missing_src) {
> +				printf(_("  Warn: %s doesn't contain commit %s\n"),
> +				 displaypath, sha1_src);
> +			} else {
> +				printf(_("  Warn: %s doesn't contain commit %s\n"),
> +				 displaypath, sha1_dst);
> +			}
> +		}
> +	} else if (is_sm_git_dir) {
> +		struct child_process cp_log = CHILD_PROCESS_INIT;
> +
> +		cp_log.git_cmd = 1;
> +		cp_log.dir = p->sm_path;
> +		prepare_submodule_repo_env(&cp_log.env_array);
> +		argv_array_pushl(&cp_log.args, "log", NULL);
> +
> +		if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst)) {
> +			if (info->summary_limits > 0)
> +				argv_array_pushf(&cp_log.args, "-%d", info->summary_limits);
> +
> +			argv_array_pushl(&cp_log.args, "--pretty=  %m %s",
> +					 "--first-parent", NULL);
> +			argv_array_pushf(&cp_log.args, "%s...%s", sha1_src,
> +					 sha1_dst);
> +		} else if (S_ISGITLINK(p->mod_dst)) {
> +			argv_array_pushl(&cp_log.args, "--pretty=  > %s",
> +					 "-1", sha1_dst, NULL);
> +		} else {
> +			argv_array_pushl(&cp_log.args, "--pretty=  < %s",
> +					 "-1", sha1_src, NULL);
> +		}
> +
> +		run_command(&cp_log);
> +	}
> +	printf("\n");
> +
> +	free(displaypath);
> +}
> +
> +static void prepare_submodule_summary(struct summary_cb *info,
> +				      struct module_cb_list *list)
> +{
> +	int i;
> +	for (i = 0; i < list->nr; i++) {
> +		struct module_cb *p = list->entries[i];
> +		struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
> +
> +		if (p->status == 'D' || p->status == 'T') {
> +			print_submodule_summary(info, p);
> +			continue;
> +		}
> +
> +		if (info->for_status) {
> +			char *config_key;
> +			const char *ignore_config = "none";
> +			const char *value;
> +			const struct submodule *sub = submodule_from_path(null_sha1, p->sm_path);
> +
> +			if (sub && p->status != 'A') {
> +				config_key = xstrfmt("submodule.%s.ignore",
> +						     sub->name);
> +				if (!git_config_get_value(config_key, &value))
> +					ignore_config = value;
> +				else if (sub->ignore)
> +					ignore_config = sub->ignore;

Since this is a string it may make sense to use
'git_config_get_string_const' instead of '_value', unless you had a
reason for using value the over string variant.

> +
> +				free(config_key);
> +
> +				if (!strcmp(ignore_config, "all"))
> +					continue;
> +			}
> +		}
> +
> +		/* Also show added or modified modules which are checked out */
> +		cp_rev_parse.dir = p->sm_path;
> +		cp_rev_parse.git_cmd = 1;
> +		cp_rev_parse.no_stderr = 1;
> +		cp_rev_parse.no_stdout = 1;
> +
> +		argv_array_pushl(&cp_rev_parse.args, "rev-parse",
> +				 "--git-dir", NULL);
> +
> +		if (!run_command(&cp_rev_parse))
> +			print_submodule_summary(info, p);
> +	}
> +}
> +
> +static void submodule_summary_callback(struct diff_queue_struct *q,
> +				       struct diff_options *options,
> +				       void *data)
> +{
> +	int i;
> +	struct module_cb_list *list = data;
> +	for (i = 0; i < q->nr; i++) {
> +		struct diff_filepair *p = q->queue[i];
> +		struct module_cb *temp;
> +
> +		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
> +			continue;
> +		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
> +		temp->mod_src = p->one->mode;
> +		temp->mod_dst = p->two->mode;
> +		temp->oid_src = p->one->oid;
> +		temp->oid_dst = p->two->oid;
> +		temp->status = p->status;
> +		temp->sm_path = xstrdup(p->one->path);
> +
> +		ALLOC_GROW(list->entries, list->nr + 1, list->alloc);
> +		list->entries[list->nr++] = temp;
> +	}
> +}
> +
> +static int compute_summary_module_list(char *head, struct summary_cb *info)

Make 'head' a 'const char *' since you aren't modifying it in the
function.

> +{
> +	struct argv_array diff_args = ARGV_ARRAY_INIT;
> +	struct rev_info rev;
> +	struct module_cb_list list = MODULE_CB_LIST_INIT;
> +
> +	argv_array_push(&diff_args, info->diff_cmd);
> +	if (info->cached)
> +		argv_array_push(&diff_args, "--cached");
> +	argv_array_pushl(&diff_args, "--ignore-submodules=dirty", "--raw",
> +			 NULL);
> +	if (head)
> +		argv_array_push(&diff_args, head);
> +	argv_array_push(&diff_args, "--");
> +	if (info->argc)
> +		argv_array_pushv(&diff_args, info->argv);
> +
> +	git_config(git_diff_basic_config, NULL);
> +	init_revisions(&rev, info->prefix);
> +	gitmodules_config();
> +	rev.abbrev = 0;
> +	precompose_argv(diff_args.argc, diff_args.argv);

What's the purpose of the precompose call?

> +
> +	diff_args.argc = setup_revisions(diff_args.argc, diff_args.argv,
> +					 &rev, NULL);
> +	rev.diffopt.output_format = DIFF_FORMAT_NO_OUTPUT | DIFF_FORMAT_CALLBACK;
> +	rev.diffopt.format_callback = submodule_summary_callback;
> +	rev.diffopt.format_callback_data = &list;
> +
> +	if (!info->cached) {
> +		if (!strcmp(info->diff_cmd, "diff-index"))
> +			setup_work_tree();
> +		if (read_cache_preload(&rev.diffopt.pathspec) < 0) {
> +			perror("read_cache_preload");
> +			return -1;
> +		}
> +	} else if (read_cache() < 0) {
> +		perror("read_cache");
> +		return -1;
> +	}

I'm not understanding this hunk of code.  Why are you using
read_cache_preload in one part and read_cache in another?  also if you
could use read_index instead of read_cache that would be great.  We want
to reduce the number of cache macros that are used and replace them with
the 'index' flavor.

> +
> +	if (!strcmp(info->diff_cmd, "diff-index"))
> +		run_diff_index(&rev, info->cached);
> +	else
> +		run_diff_files(&rev, 0);
> +	prepare_submodule_summary(info, &list);

'list' has a bunch of allocated entries which need to be freed here.

> +
> +	return 0;
> +
> +}
> +
> +static int module_summary(int argc, const char **argv, const char *prefix)
> +{
> +	struct summary_cb info = SUMMARY_CB_INIT;
> +	int cached = 0;
> +	char *diff_cmd = "diff-index";
> +	int for_status = 0;
> +	int quiet = 0;
> +	int files = 0;
> +	int summary_limits = -1;
> +	struct child_process cp_rev = CHILD_PROCESS_INIT;
> +	char *head;
> +	struct strbuf sb = STRBUF_INIT;
> +
> +	struct option module_summary_options[] = {
> +		OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
> +		OPT_BOOL(0, "cached", &cached, N_("Use the commit stored in the index instead of the submodule HEAD")),
> +		OPT_BOOL(0, "files", &files, N_("To compares the commit in the index with that in the submodule HEAD")),
> +		OPT_BOOL(0, "for-status", &for_status, N_("Skip submodules with 'all' ignore_config value")),
> +		OPT_INTEGER('n', "summary-limits", &summary_limits, N_("Limit the summary size")),
> +		OPT_END()
> +	};
> +
> +	const char *const git_submodule_helper_usage[] = {
> +		N_("git submodule--helper summary [<options>] [--] [<path>]"),
> +		NULL
> +	};
> +
> +	argc = parse_options(argc, argv, prefix, module_summary_options,
> +			     git_submodule_helper_usage, 0);
> +
> +	if (!summary_limits)
> +		return 0;
> +
> +	cp_rev.git_cmd = 1;
> +	argv_array_pushl(&cp_rev.args, "rev-parse", "-q", "--verify",
> +			 argc ? argv[0] : "HEAD", NULL);
> +
> +	if (!capture_command(&cp_rev, &sb, 0)) {
> +		strbuf_strip_suffix(&sb, "\n");
> +		if (argc) {
> +			argv++;
> +			argc--;
> +		}
> +	} else if (!argc || !strcmp(argv[0], "HEAD")) {
> +		/* before the first commit: compare with an empty tree */
> +		struct stat st;
> +		unsigned char sha1[20];

Use a 'struct object_id' here.  There's no reason to use sha1's 20 char
arrays anymore.  If you need to use a call that takes an unsigned char
array you can always pass oid.hash.  This limits the amount of
conversion we'll have to do later.

> +		if (fstat(0, &st) < 0 || index_fd(sha1, 0, &st, 2, prefix, 3))

What's the reasoning behind the fstat and index_fd call?  Not saying
they aren't needed I just need more context to understand whats going
on.

> +			die("Unable to add %s to database", sha1);
> +		strbuf_addstr(&sb, sha1_to_hex(sha1));
> +		if (argc) {
> +			argv++;
> +			argc--;
> +		}
> +	} else {
> +		strbuf_addstr(&sb, "HEAD");
> +	}
> +
> +	head = strbuf_detach(&sb, NULL);

So head is a 'char *' and it is never freed.  You should free it at the
end of this function to prevent memleaks.

> +
> +	if (files) {
> +		if (cached)
> +			die(_("The --cached option cannot be used with the --files option"));
> +		diff_cmd = "diff-files";
> +		head = NULL;

If you are assigning NULL here make sure that you free head first as you
could have allocated memory which head is already pointing to.

> +	}
> +
> +	info.argc = argc;
> +	info.argv = argv;
> +	info.prefix = prefix;
> +	info.cached = cached;
> +	info.for_status = for_status;
> +	info.quiet = quiet;
> +	info.files = files;
> +	info.summary_limits = summary_limits;
> +	info.diff_cmd = diff_cmd;

You aren't doing the '!!' trick here like you did in the other patches.
Any reason for that?

> +
> +	return compute_summary_module_list(head, &info);
> +}
> +

-- 
Brandon Williams

[GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
    superproject to the mount point of the submodule.
    In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
    case the path is equal to the relative path from $pwd to the
    submodules working directory. When following this model,
    the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 git-submodule.sh             |  1 -
 t/t7407-submodule-foreach.sh | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a427ddafd..493a64372 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
 				prefix="$prefix$sm_path/"
 				sanitize_submodule_env
 				cd "$sm_path" &&
-				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
 				# we make $path available to scripts ...
 				path=$sm_path &&
 				if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-../sub1-$sub1sha1
+$pwd/clone-foo1-sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-../sub3-$sub3sha1
+$pwd/clone-foo3-sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
@@ -196,6 +196,38 @@ test_expect_success 'test messages from "foreach --recursive" from subdirectory'
 	) &&
 	test_i18ncmp expect actual
 '
+sub1sha1=$(cd clone2/sub1 && git rev-parse HEAD)
+sub2sha1=$(cd clone2/sub2 && git rev-parse HEAD)
+sub3sha1=$(cd clone2/sub3 && git rev-parse HEAD)
+nested1sha1=$(cd clone2/nested1 && git rev-parse HEAD)
+nested2sha1=$(cd clone2/nested1/nested2 && git rev-parse HEAD)
+nested3sha1=$(cd clone2/nested1/nested2/nested3 && git rev-parse HEAD)
+submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEAD)
+
+cat >expect <<EOF
+Entering '../nested1'
+$pwd/clone2-nested1-nested1-$nested1sha1
+Entering '../nested1/nested2'
+$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+Entering '../nested1/nested2/nested3'
+$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+Entering '../nested1/nested2/nested3/submodule'
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+Entering '../sub1'
+$pwd/clone2-foo1-sub1-$sub1sha1
+Entering '../sub2'
+$pwd/clone2-foo2-sub2-$sub2sha1
+Entering '../sub3'
+$pwd/clone2-foo3-sub3-$sub3sha1
+EOF
+
+test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
+	(
+		cd clone2/untracked &&
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+	) &&
+	test_i18ncmp expect actual
+'
 
 cat > expect <<EOF
 nested1-nested1
-- 
2.13.0

Re: [GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> When running 'git submodule foreach' from a subdirectory of your
> repository, nested submodules get a bogus value for $sm_path:
> For a submodule 'sub' that contains a nested submodule 'nested',
> running 'git -C dir submodule foreach echo $path' would report
> path='../nested' for the nested submodule. The first part '../' is
> derived from the logic computing the relative path from $pwd to the
> root of the superproject. The second part is the submodule path inside
> the submodule. This value is of little use and is hard to document.
> 
> There are two different possible solutions that have more value:
> (a) The path value is documented as the path from the toplevel of the
>     superproject to the mount point of the submodule.
>     In this case we would want to have path='sub/nested'.
> 
> (b) As Ramsay noticed the documented value is wrong. For the non-nested
>     case the path is equal to the relative path from $pwd to the
>     submodules working directory. When following this model,
>     the expected value would be path='../sub/nested'.
> 
> The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
> top-level requirement, 2013-06-16) the intent for $path seemed to be
> relative to $cwd to the submodule worktree, but that did not work for
> nested submodules, as the intermittent submodules were not included in
> the path.
> 
> If we were to fix the meaning of the $path using (a) such that "path"
> is "the path from the toplevel of the superproject to the mount point
> of the submodule", we would break any existing submodule user that runs
> foreach from non-root of the superproject as the non-nested submodule
> '../sub' would change its path to 'sub'.
> 
> If we would fix the meaning of the $path using (b), such that "path"
> is "the relative path from $pwd to the submodule", then we would break
> any user that uses nested submodules (even from the root directory) as
> the 'nested' would become 'sub/nested'.
> 
> Both groups can be found in the wild.  The author has no data if one group
> outweighs the other by large margin, and offending each one seems equally
> bad at first.  However in the authors imagination it is better to go with
> (a) as running from a sub directory sounds like it is carried out
> by a human rather than by some automation task.  With a human on
> the keyboard the feedback loop is short and the changed behavior can be
> adapted to quickly unlike some automation that can break silently.

Great explanation, and I agree with going with choice (a).

> 
> Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  git-submodule.sh             |  1 -
>  t/t7407-submodule-foreach.sh | 36 ++++++++++++++++++++++++++++++++++--
>  2 files changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/git-submodule.sh b/git-submodule.sh
> index a427ddafd..493a64372 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -320,7 +320,6 @@ cmd_foreach()
>  				prefix="$prefix$sm_path/"
>  				sanitize_submodule_env
>  				cd "$sm_path" &&
> -				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
>  				# we make $path available to scripts ...
>  				path=$sm_path &&
>  				if test $# -eq 1
> diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
> index 6ba5daf42..0663622a4 100755
> --- a/t/t7407-submodule-foreach.sh
> +++ b/t/t7407-submodule-foreach.sh
> @@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
>  
>  cat >expect <<EOF
>  Entering '../sub1'
> -$pwd/clone-foo1-../sub1-$sub1sha1
> +$pwd/clone-foo1-sub1-$sub1sha1
>  Entering '../sub3'
> -$pwd/clone-foo3-../sub3-$sub3sha1
> +$pwd/clone-foo3-sub3-$sub3sha1
>  EOF
>  
>  test_expect_success 'test "submodule foreach" from subdirectory' '
> @@ -196,6 +196,38 @@ test_expect_success 'test messages from "foreach --recursive" from subdirectory'
>  	) &&
>  	test_i18ncmp expect actual
>  '
> +sub1sha1=$(cd clone2/sub1 && git rev-parse HEAD)
> +sub2sha1=$(cd clone2/sub2 && git rev-parse HEAD)
> +sub3sha1=$(cd clone2/sub3 && git rev-parse HEAD)
> +nested1sha1=$(cd clone2/nested1 && git rev-parse HEAD)
> +nested2sha1=$(cd clone2/nested1/nested2 && git rev-parse HEAD)
> +nested3sha1=$(cd clone2/nested1/nested2/nested3 && git rev-parse HEAD)
> +submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEAD)
> +
> +cat >expect <<EOF
> +Entering '../nested1'
> +$pwd/clone2-nested1-nested1-$nested1sha1
> +Entering '../nested1/nested2'
> +$pwd/clone2/nested1-nested2-nested2-$nested2sha1
> +Entering '../nested1/nested2/nested3'
> +$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
> +Entering '../nested1/nested2/nested3/submodule'
> +$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
> +Entering '../sub1'
> +$pwd/clone2-foo1-sub1-$sub1sha1
> +Entering '../sub2'
> +$pwd/clone2-foo2-sub2-$sub2sha1
> +Entering '../sub3'
> +$pwd/clone2-foo3-sub3-$sub3sha1
> +EOF
> +
> +test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
> +	(
> +		cd clone2/untracked &&
> +		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
> +	) &&
> +	test_i18ncmp expect actual
> +'
>  
>  cat > expect <<EOF
>  nested1-nested1
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 Documentation/git-submodule.txt | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] <command>::
 	Evaluates an arbitrary shell command in each checked out submodule.
-	The command has access to the variables $name, $path, $sha1 and
+	The command has access to the variables $name, $sm_path, $sha1 and
 	$toplevel:
 	$name is the name of the relevant submodule section in `.gitmodules`,
-	$path is the name of the submodule directory relative to the
-	superproject, $sha1 is the commit as recorded in the superproject,
-	and $toplevel is the absolute path to the top-level of the superproject.
+	$sm_path is the path of the submodule as recorded in the superproject,
+	$sha1 is the commit as recorded in the superproject, and
+	$toplevel is the absolute path to the top-level of the superproject.
+	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+	variable is now a deprecated synonym of '$sm_path' variable.
 	Any submodules defined in the superproject but not checked out are
 	ignored by this command. Unless given `--quiet`, foreach prints the name
 	of each submodule before evaluating the command.
-- 
2.13.0

Re: [GSoC][PATCH 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> As using a variable '$path' may be harmful to users due to
> capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
> use $path variable in eval_gettext string, 2012-04-17). Adjust
> the documentation to advocate for using $sm_path,  which contains
> the same value. We still make the 'path' variable available and
> document it as a deprecated synonym of 'sm_path'.

I assume then at some point we would want to drop support for 'path' via
a normal deprecation cycle (whatever that might be, 6 months or a year
or more).

> 
> Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
>  Documentation/git-submodule.txt | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> index ff612001d..a23baef62 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -183,12 +183,14 @@ information too.
>  
>  foreach [--recursive] <command>::
>  	Evaluates an arbitrary shell command in each checked out submodule.
> -	The command has access to the variables $name, $path, $sha1 and
> +	The command has access to the variables $name, $sm_path, $sha1 and
>  	$toplevel:
>  	$name is the name of the relevant submodule section in `.gitmodules`,
> -	$path is the name of the submodule directory relative to the
> -	superproject, $sha1 is the commit as recorded in the superproject,
> -	and $toplevel is the absolute path to the top-level of the superproject.
> +	$sm_path is the path of the submodule as recorded in the superproject,
> +	$sha1 is the commit as recorded in the superproject, and
> +	$toplevel is the absolute path to the top-level of the superproject.
> +	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
> +	variable is now a deprecated synonym of '$sm_path' variable.
>  	Any submodules defined in the superproject but not checked out are
>  	ignored by this command. Unless given `--quiet`, foreach prints the name
>  	of each submodule before evaluating the command.
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 11/13] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] <command>::
 	$name is the name of the relevant submodule section in `.gitmodules`,
 	$sm_path is the path of the submodule as recorded in the superproject,
 	$sha1 is the commit as recorded in the superproject, and
-	$toplevel is the absolute path to the top-level of the superproject.
+	$toplevel is the absolute path to its superproject, such that
+	$toplevel/$sm_path is the absolute path of the submodule.
 	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
 	variable is now a deprecated synonym of '$sm_path' variable.
 	Any submodules defined in the superproject but not checked out are
-- 
2.13.0

[GSoC][PATCH 12/13] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observer that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 Documentation/git-submodule.txt |  6 ++++--
 t/t7407-submodule-foreach.sh    | 22 +++++++++++-----------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] <command>::
 	Evaluates an arbitrary shell command in each checked out submodule.
-	The command has access to the variables $name, $sm_path, $sha1 and
-	$toplevel:
+	The command has access to the variables $name, $sm_path, $displaypath,
+	$sha1 and $toplevel:
 	$name is the name of the relevant submodule section in `.gitmodules`,
 	$sm_path is the path of the submodule as recorded in the superproject,
+	$displaypath contains the relative path from the current working
+	directory to the submodules root directory,
 	$sha1 is the commit as recorded in the superproject, and
 	$toplevel is the absolute path to its superproject, such that
 	$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-sub1-$sub1sha1
+$pwd/clone-foo1-sub1-../sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-sub3-$sub3sha1
+$pwd/clone-foo3-sub3-../sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
 	mkdir clone/sub &&
 	(
 		cd clone/sub &&
-		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
 	) &&
 	test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <<EOF
 Entering '../nested1'
-$pwd/clone2-nested1-nested1-$nested1sha1
+$pwd/clone2-nested1-nested1-../nested1-$nested1sha1
 Entering '../nested1/nested2'
-$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+$pwd/clone2/nested1-nested2-nested2-../nested1/nested2-$nested2sha1
 Entering '../nested1/nested2/nested3'
-$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+$pwd/clone2/nested1/nested2-nested3-nested3-../nested1/nested2/nested3-$nested3sha1
 Entering '../nested1/nested2/nested3/submodule'
-$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-../nested1/nested2/nested3/submodule-$submodulesha1
 Entering '../sub1'
-$pwd/clone2-foo1-sub1-$sub1sha1
+$pwd/clone2-foo1-sub1-../sub1-$sub1sha1
 Entering '../sub2'
-$pwd/clone2-foo2-sub2-$sub2sha1
+$pwd/clone2-foo2-sub2-../sub2-$sub2sha1
 Entering '../sub3'
-$pwd/clone2-foo3-sub3-$sub3sha1
+$pwd/clone2-foo3-sub3-../sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
 	(
 		cd clone2/untracked &&
-		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
 	) &&
 	test_i18ncmp expect actual
 '
-- 
2.13.0

Re: [GSoC][PATCH 12/13] submodule foreach: document variable '$displaypath'

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> It was observer that the variable '$displaypath' was accessible but

s/observer/observed 

> undocumented. Hence, document it.
> 
> Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
>  Documentation/git-submodule.txt |  6 ++++--
>  t/t7407-submodule-foreach.sh    | 22 +++++++++++-----------
>  2 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> index 8e7930ebc..0cca702cb 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -183,10 +183,12 @@ information too.
>  
>  foreach [--recursive] <command>::
>  	Evaluates an arbitrary shell command in each checked out submodule.
> -	The command has access to the variables $name, $sm_path, $sha1 and
> -	$toplevel:
> +	The command has access to the variables $name, $sm_path, $displaypath,
> +	$sha1 and $toplevel:
>  	$name is the name of the relevant submodule section in `.gitmodules`,
>  	$sm_path is the path of the submodule as recorded in the superproject,
> +	$displaypath contains the relative path from the current working
> +	directory to the submodules root directory,
>  	$sha1 is the commit as recorded in the superproject, and
>  	$toplevel is the absolute path to its superproject, such that
>  	$toplevel/$sm_path is the absolute path of the submodule.
> diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
> index 0663622a4..6ad57e061 100755
> --- a/t/t7407-submodule-foreach.sh
> +++ b/t/t7407-submodule-foreach.sh
> @@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
>  
>  cat >expect <<EOF
>  Entering '../sub1'
> -$pwd/clone-foo1-sub1-$sub1sha1
> +$pwd/clone-foo1-sub1-../sub1-$sub1sha1
>  Entering '../sub3'
> -$pwd/clone-foo3-sub3-$sub3sha1
> +$pwd/clone-foo3-sub3-../sub3-$sub3sha1
>  EOF
>  
>  test_expect_success 'test "submodule foreach" from subdirectory' '
>  	mkdir clone/sub &&
>  	(
>  		cd clone/sub &&
> -		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
> +		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
>  	) &&
>  	test_i18ncmp expect actual
>  '
> @@ -206,25 +206,25 @@ submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
>  
>  cat >expect <<EOF
>  Entering '../nested1'
> -$pwd/clone2-nested1-nested1-$nested1sha1
> +$pwd/clone2-nested1-nested1-../nested1-$nested1sha1
>  Entering '../nested1/nested2'
> -$pwd/clone2/nested1-nested2-nested2-$nested2sha1
> +$pwd/clone2/nested1-nested2-nested2-../nested1/nested2-$nested2sha1
>  Entering '../nested1/nested2/nested3'
> -$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
> +$pwd/clone2/nested1/nested2-nested3-nested3-../nested1/nested2/nested3-$nested3sha1
>  Entering '../nested1/nested2/nested3/submodule'
> -$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
> +$pwd/clone2/nested1/nested2/nested3-submodule-submodule-../nested1/nested2/nested3/submodule-$submodulesha1
>  Entering '../sub1'
> -$pwd/clone2-foo1-sub1-$sub1sha1
> +$pwd/clone2-foo1-sub1-../sub1-$sub1sha1
>  Entering '../sub2'
> -$pwd/clone2-foo2-sub2-$sub2sha1
> +$pwd/clone2-foo2-sub2-../sub2-$sub2sha1
>  Entering '../sub3'
> -$pwd/clone2-foo3-sub3-$sub3sha1
> +$pwd/clone2-foo3-sub3-../sub3-$sub3sha1
>  EOF
>  
>  test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
>  	(
>  		cd clone2/untracked &&
> -		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
> +		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
>  	) &&
>  	test_i18ncmp expect actual
>  '
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_submodule_list, which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule. This third function is a calling function that
takes care of running the command in that submodule, and recursively
perform the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute, generates the list of
submodules present in the current working tree.

The second function for_each_submodule_list traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule) is called for each entry.

The third function runcommand_in_submodule, generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the <command> of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The third function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input <command> of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmwill@google.com>
Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 129 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  39 +-------------
 2 files changed, 130 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 94d6254f0..be278bf8d 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -765,6 +765,134 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct cb_foreach {
+	int argc;
+	const char **argv;
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
+
+static void runcommand_in_submodule(const struct cache_entry *list_item,
+				    void *cb_data)
+{
+	struct cb_foreach *info = cb_data;
+	const struct submodule *sub;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	char *displaypath;
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (!sub)
+		die(_("No url found for submodule path '%s' in .gitmodules"),
+		      displaypath);
+
+	if (!is_submodule_populated_gently(list_item->name, NULL))
+		goto cleanup;
+
+	prepare_submodule_repo_env(&cp.env_array);
+	/* For the purpose of executing <command> in the submodule,
+	 * separate shell is used for the purpose of running the
+	 * child process.
+	 */
+	cp.use_shell = 1;
+	cp.dir = list_item->name;
+
+	if (info->argc == 1) {
+		char *toplevel = xgetcwd();
+
+		argv_array_pushf(&cp.env_array, "name=%s", sub->name);
+		argv_array_pushf(&cp.env_array, "sm_path=%s", list_item->name);
+		argv_array_pushf(&cp.env_array, "displaypath=%s", displaypath);
+		argv_array_pushf(&cp.env_array, "sha1=%s",
+				 oid_to_hex(&list_item->oid));
+		argv_array_pushf(&cp.env_array, "toplevel=%s", toplevel);
+
+		/*
+		 * Since still the path variable was accessible from the
+		 * script before porting, it is also made available.
+		 */
+		argv_array_pushf(&cp.args, "path=%s; %s",
+				 list_item->name, info->argv[0]);
+		free(toplevel);
+	} else {
+		argv_array_pushv(&cp.args, info->argv);
+	}
+
+	if (!info->quiet)
+		printf(_("Entering '%s'\n"), displaypath);
+
+	if (info->argv[0] && run_command(&cp))
+		die(_("run_command returned non-zero status for %s\n."),
+		      displaypath);
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "foreach", "--recursive",
+				 NULL);
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		argv_array_pushv(&cpr.args, info->argv);
+
+		if (run_command(&cpr))
+			die(_("run_command returned non-zero status while"
+			      "recursing in the nested submodules of %s\n."),
+			      displaypath);
+	}
+
+cleanup:
+	free(displaypath);
+}
+
+static int module_foreach(int argc, const char **argv, const char *prefix)
+{
+	struct cb_foreach info;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int recursive = 0;
+
+	struct option module_foreach_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output of entering each submodule command")),
+		OPT_BOOL(0, "recursive", &recursive,
+			 N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper foreach [--quiet] [--recursive] <command>"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_foreach_options,
+			     git_submodule_helper_usage, PARSE_OPT_KEEP_UNKNOWN);
+
+	if (module_list_compute(0, NULL, prefix, &pathspec, &list) < 0)
+		BUG("module_list_compute should not choke on empty pathspec");
+
+	info.argc = argc;
+	info.argv = argv;
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+
+	gitmodules_config();
+	for_each_submodule_list(list, runcommand_in_submodule, &info);
+
+	return 0;
+}
+
 struct module_cb {
 	unsigned int mod_src;
 	unsigned int mod_dst;
@@ -2203,6 +2331,7 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"print-name-rev", print_name_rev, 0},
+	{"foreach", module_foreach, SUPPORT_SUPER_PREFIX},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"print-default-remote", print_default_remote, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index 493a64372..e25b2c613 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -298,44 +298,7 @@ cmd_foreach()
 		shift
 	done
 
-	toplevel=$(pwd)
-
-	# dup stdin so that it can be restored when running the external
-	# command in the subshell (and a recursive call to this function)
-	exec 3<&0
-
-	{
-		git submodule--helper list --prefix "$wt_prefix" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		if test -e "$sm_path"/.git
-		then
-			displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-			say "$(eval_gettext "Entering '\$displaypath'")"
-			name=$(git submodule--helper name "$sm_path")
-			(
-				prefix="$prefix$sm_path/"
-				sanitize_submodule_env
-				cd "$sm_path" &&
-				# we make $path available to scripts ...
-				path=$sm_path &&
-				if test $# -eq 1
-				then
-					eval "$1"
-				else
-					"$@"
-				fi &&
-				if test -n "$recursive"
-				then
-					cmd_foreach "--recursive" "$@"
-				fi
-			) <&3 3<&- ||
-			die "$(eval_gettext "Stopping at '\$displaypath'; script returned non-zero status.")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper foreach ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
 }
 
 #
-- 
2.13.0

Re: [GSoC][PATCH 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Brandon Williams]

On 07/25, Prathamesh Chavan wrote:
> This aims to make git-submodule foreach a builtin. This is the very
> first step taken in this direction. Hence, 'foreach' is ported to
> submodule--helper, and submodule--helper is called from git-submodule.sh.
> The code is split up to have one function to obtain all the list of
> submodules. This function acts as the front-end of git-submodule foreach
> subcommand. It calls the function for_each_submodule_list, which basically
> loops through the list and calls function fn, which in this case is
> runcommand_in_submodule. This third function is a calling function that
> takes care of running the command in that submodule, and recursively
> perform the same when --recursive is flagged.
> 
> The first function module_foreach first parses the options present in
> argv, and then with the help of module_list_compute, generates the list of
> submodules present in the current working tree.
> 
> The second function for_each_submodule_list traverses through the
> list, and calls function fn (which in case of submodule subcommand
> foreach is runcommand_in_submodule) is called for each entry.
> 
> The third function runcommand_in_submodule, generates a submodule struct sub
> for $name, value and then later prepends name=sub->name; and other
> value assignment to the env argv_array structure of a child_process.
> Also the <command> of submodule-foreach is push to args argv_array
> structure and finally, using run_command the commands are executed
> using a shell.
> 
> The third function also takes care of the recursive flag, by creating
> a separate child_process structure and prepending "--super-prefix displaypath",
> to the args argv_array structure. Other required arguments and the
> input <command> of submodule-foreach is also appended to this argv_array.
> 
> Helped-by: Brandon Williams <bmwill@google.com>
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
> ---
>  builtin/submodule--helper.c | 129 ++++++++++++++++++++++++++++++++++++++++++++
>  git-submodule.sh            |  39 +-------------
>  2 files changed, 130 insertions(+), 38 deletions(-)
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 94d6254f0..be278bf8d 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -765,6 +765,134 @@ static int module_name(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +struct cb_foreach {
> +	int argc;
> +	const char **argv;
> +	const char *prefix;
> +	unsigned int quiet: 1;
> +	unsigned int recursive: 1;
> +};
> +#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
> +
> +static void runcommand_in_submodule(const struct cache_entry *list_item,
> +				    void *cb_data)
> +{
> +	struct cb_foreach *info = cb_data;
> +	const struct submodule *sub;
> +	struct child_process cp = CHILD_PROCESS_INIT;
> +	char *displaypath;
> +
> +	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
> +
> +	sub = submodule_from_path(null_sha1, list_item->name);
> +
> +	if (!sub)
> +		die(_("No url found for submodule path '%s' in .gitmodules"),
> +		      displaypath);
> +
> +	if (!is_submodule_populated_gently(list_item->name, NULL))
> +		goto cleanup;
> +
> +	prepare_submodule_repo_env(&cp.env_array);
> +	/* For the purpose of executing <command> in the submodule,
> +	 * separate shell is used for the purpose of running the
> +	 * child process.
> +	 */

comment style

> +	cp.use_shell = 1;
> +	cp.dir = list_item->name;
> +
> +	if (info->argc == 1) {

Why are you only exposing these variables if argc == 1?

> +		char *toplevel = xgetcwd();
> +
> +		argv_array_pushf(&cp.env_array, "name=%s", sub->name);
> +		argv_array_pushf(&cp.env_array, "sm_path=%s", list_item->name);
> +		argv_array_pushf(&cp.env_array, "displaypath=%s", displaypath);
> +		argv_array_pushf(&cp.env_array, "sha1=%s",
> +				 oid_to_hex(&list_item->oid));
> +		argv_array_pushf(&cp.env_array, "toplevel=%s", toplevel);
> +
> +		/*
> +		 * Since still the path variable was accessible from the
> +		 * script before porting, it is also made available.
> +		 */
> +		argv_array_pushf(&cp.args, "path=%s; %s",
> +				 list_item->name, info->argv[0]);

This bit looks odd. Why are you appending argv[0] after a semicolon?
Oh...its to handle the funny path stuff.  I'd add a comment indicating
why you have to expose path  via the args argv_array and not the
env_array.

> +		free(toplevel);
> +	} else {
> +		argv_array_pushv(&cp.args, info->argv);
> +	}
> +
> +	if (!info->quiet)
> +		printf(_("Entering '%s'\n"), displaypath);
> +
> +	if (info->argv[0] && run_command(&cp))
> +		die(_("run_command returned non-zero status for %s\n."),
> +		      displaypath);
> +
> +	if (info->recursive) {
> +		struct child_process cpr = CHILD_PROCESS_INIT;
> +
> +		cpr.git_cmd = 1;
> +		cpr.dir = list_item->name;
> +		prepare_submodule_repo_env(&cpr.env_array);
> +
> +		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,

Same comment as a few of the other commands about super-prefix.

> +				 "submodule--helper", "foreach", "--recursive",
> +				 NULL);
> +
> +		if (info->quiet)
> +			argv_array_push(&cpr.args, "--quiet");
> +
> +		argv_array_pushv(&cpr.args, info->argv);
> +
> +		if (run_command(&cpr))
> +			die(_("run_command returned non-zero status while"
> +			      "recursing in the nested submodules of %s\n."),
> +			      displaypath);
> +	}
> +
> +cleanup:
> +	free(displaypath);
> +}
> +
> +static int module_foreach(int argc, const char **argv, const char *prefix)
> +{
> +	struct cb_foreach info;
> +	struct pathspec pathspec;
> +	struct module_list list = MODULE_LIST_INIT;
> +	int quiet = 0;
> +	int recursive = 0;
> +
> +	struct option module_foreach_options[] = {
> +		OPT__QUIET(&quiet, N_("Suppress output of entering each submodule command")),
> +		OPT_BOOL(0, "recursive", &recursive,
> +			 N_("Recurse into nested submodules")),
> +		OPT_END()
> +	};
> +
> +	const char *const git_submodule_helper_usage[] = {
> +		N_("git submodule--helper foreach [--quiet] [--recursive] <command>"),
> +		NULL
> +	};
> +
> +	argc = parse_options(argc, argv, prefix, module_foreach_options,
> +			     git_submodule_helper_usage, PARSE_OPT_KEEP_UNKNOWN);
> +
> +	if (module_list_compute(0, NULL, prefix, &pathspec, &list) < 0)
> +		BUG("module_list_compute should not choke on empty pathspec");
> +
> +	info.argc = argc;
> +	info.argv = argv;
> +	info.prefix = prefix;
> +	info.quiet = !!quiet;
> +	info.recursive = !!recursive;
> +
> +	gitmodules_config();
> +	for_each_submodule_list(list, runcommand_in_submodule, &info);
> +
> +	return 0;
> +}
> +
>  struct module_cb {
>  	unsigned int mod_src;
>  	unsigned int mod_dst;
> @@ -2203,6 +2331,7 @@ static struct cmd_struct commands[] = {
>  	{"resolve-relative-url", resolve_relative_url, 0},
>  	{"resolve-relative-url-test", resolve_relative_url_test, 0},
>  	{"print-name-rev", print_name_rev, 0},
> +	{"foreach", module_foreach, SUPPORT_SUPER_PREFIX},
>  	{"init", module_init, SUPPORT_SUPER_PREFIX},
>  	{"status", module_status, SUPPORT_SUPER_PREFIX},
>  	{"print-default-remote", print_default_remote, 0},
> diff --git a/git-submodule.sh b/git-submodule.sh
> index 493a64372..e25b2c613 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -298,44 +298,7 @@ cmd_foreach()
>  		shift
>  	done
>  
> -	toplevel=$(pwd)
> -
> -	# dup stdin so that it can be restored when running the external
> -	# command in the subshell (and a recursive call to this function)
> -	exec 3<&0
> -
> -	{
> -		git submodule--helper list --prefix "$wt_prefix" ||
> -		echo "#unmatched" $?
> -	} |
> -	while read -r mode sha1 stage sm_path
> -	do
> -		die_if_unmatched "$mode" "$sha1"
> -		if test -e "$sm_path"/.git
> -		then
> -			displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
> -			say "$(eval_gettext "Entering '\$displaypath'")"
> -			name=$(git submodule--helper name "$sm_path")
> -			(
> -				prefix="$prefix$sm_path/"
> -				sanitize_submodule_env
> -				cd "$sm_path" &&
> -				# we make $path available to scripts ...
> -				path=$sm_path &&
> -				if test $# -eq 1
> -				then
> -					eval "$1"
> -				else
> -					"$@"
> -				fi &&
> -				if test -n "$recursive"
> -				then
> -					cmd_foreach "--recursive" "$@"
> -				fi
> -			) <&3 3<&- ||
> -			die "$(eval_gettext "Stopping at '\$displaypath'; script returned non-zero status.")"
> -		fi
> -	done
> +	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper foreach ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
>  }
>  
>  #
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH v2 00/13] Update: Week 10

[Prathamesh Chavan]

Thank you Brandon Williams <bmwill@google.com> for reviewing the previous
patch series.
Also, I'm sorry for repling late to your reviews. The main reason was
to give sufficient time to prepare the next version of each patch as
suggested.
The changes made in each patch are enlisted in the patch itself.

Complete build report of this work is available at: [1]
Branch: week-10
Build #142

Also, I have push the work on github as well and can be checked out at: [2]

[1]: https://travis-ci.org/pratham-pc/git/builds
[2]: https://github.com/pratham-pc/git/commits/week-10

Prathamesh Chavan (13):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
    subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c     | 1186 ++++++++++++++++++++++++++++++++++++++-
 diff.c                          |    2 +-
 diff.h                          |    1 +
 git-submodule.sh                |  394 +------------
 t/t7407-submodule-foreach.sh    |   38 +-
 6 files changed, 1218 insertions(+), 418 deletions(-)

-- 
2.13.0

[GSoC][PATCH v2 01/13] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6abdad329..7af4de09b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char **argv, const char *pr
 	return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+	const char *super_prefix = get_super_prefix();
+
+	if (prefix && super_prefix) {
+		BUG("cannot have prefix '%s' and superprefix '%s'",
+		    prefix, super_prefix);
+	} else if (prefix) {
+		struct strbuf sb = STRBUF_INIT;
+		char *displaypath = xstrdup(relative_path(path, prefix, &sb));
+		strbuf_release(&sb);
+		return displaypath;
+	} else if (super_prefix) {
+		int len = strlen(super_prefix);
+		const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" : "%s/%s";
+		return xstrfmt(format, super_prefix, path);
+	} else {
+		return xstrdup(path);
+	}
+}
+
 struct module_list {
 	const struct cache_entry **entries;
 	int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 
 	/* Only loads from .gitmodules, no overlay with .git/config */
 	gitmodules_config();
-
-	if (prefix && get_super_prefix())
-		die("BUG: cannot have prefix and superprefix");
-	else if (prefix)
-		displaypath = xstrdup(relative_path(path, prefix, &sb));
-	else if (get_super_prefix()) {
-		strbuf_addf(&sb, "%s%s", get_super_prefix(), path);
-		displaypath = strbuf_detach(&sb, NULL);
-	} else
-		displaypath = xstrdup(path);
+	displaypath = get_submodule_displaypath(path, prefix);
 
 	sub = submodule_from_path(null_sha1, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 	 * Set active flag for the submodule being initialized
 	 */
 	if (!is_submodule_active(the_repository, path)) {
-		strbuf_reset(&sb);
 		strbuf_addf(&sb, "submodule.%s.active", sub->name);
 		git_config_set_gently(sb.buf, "true");
 	}
-- 
2.13.0

[GSoC][PATCH v2 02/13] submodule--helper: introduce for_each_submodule_list()

[Prathamesh Chavan]

Introduce function for_each_submodule_list() and
replace a loop in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 builtin/submodule--helper.c | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7af4de09b..e41572f7a 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+				      void *cb_data);
+
 static char *get_default_remote(void)
 {
 	char *dest = NULL, *ret;
@@ -352,17 +355,30 @@ static int module_list(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule_list(const struct module_list list,
+				    submodule_list_func_t fn, void *cb_data)
 {
+	int i;
+	for (i = 0; i < list.nr; i++)
+		fn(list.entries[i], cb_data);
+}
+
+struct init_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct init_cb *info = cb_data;
 	const struct submodule *sub;
 	struct strbuf sb = STRBUF_INIT;
 	char *upd = NULL, *url = NULL, *displaypath;
 
-	/* Only loads from .gitmodules, no overlay with .git/config */
-	gitmodules_config();
-	displaypath = get_submodule_displaypath(path, prefix);
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-	sub = submodule_from_path(null_sha1, path);
+	sub = submodule_from_path(null_sha1, list_item->name);
 
 	if (!sub)
 		die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -374,7 +390,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 	 *
 	 * Set active flag for the submodule being initialized
 	 */
-	if (!is_submodule_active(the_repository, path)) {
+	if (!is_submodule_active(the_repository, list_item->name)) {
 		strbuf_addf(&sb, "submodule.%s.active", sub->name);
 		git_config_set_gently(sb.buf, "true");
 	}
@@ -416,7 +432,7 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 		if (git_config_set_gently(sb.buf, url))
 			die(_("Failed to register url for submodule path '%s'"),
 			    displaypath);
-		if (!quiet)
+		if (!info->quiet)
 			fprintf(stderr,
 				_("Submodule '%s' (%s) registered for path '%s'\n"),
 				sub->name, url, displaypath);
@@ -445,10 +461,10 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+	struct init_cb info = INIT_CB_INIT;
 	struct pathspec pathspec;
 	struct module_list list = MODULE_LIST_INIT;
 	int quiet = 0;
-	int i;
 
 	struct option module_init_options[] = {
 		OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
@@ -473,8 +489,11 @@ static int module_init(int argc, const char **argv, const char *prefix)
 	if (!argc && git_config_get_value_multi("submodule.active"))
 		module_list_active(&list);
 
-	for (i = 0; i < list.nr; i++)
-		init_submodule(list.entries[i]->name, prefix, quiet);
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+
+	gitmodules_config();
+	for_each_submodule_list(list, init_submodule, &info);
 
 	return 0;
 }
-- 
2.13.0

[GSoC][PATCH v2 03/13] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function get_name_rev() generates the
value of the revision name as required, and the function
print_name_rev() handles the formating and printing of the obtained
revision name.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:
* The variable namerev from print_name_rev is now freed at the end of the
  function.

 builtin/submodule--helper.c | 64 +++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            | 16 ++----------
 2 files changed, 66 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e41572f7a..2cb72d68e 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -244,6 +244,69 @@ static char *get_submodule_displaypath(const char *path, const char *prefix)
 	}
 }
 
+static char *get_name_rev(const char *sub_path, const char* object_id)
+{
+	struct strbuf sb = STRBUF_INIT;
+	const char ***d;
+
+	static const char *describe_bare[] = {
+		NULL
+	};
+
+	static const char *describe_tags[] = {
+		"--tags", NULL
+	};
+
+	static const char *describe_contains[] = {
+		"--contains", NULL
+	};
+
+	static const char *describe_all_always[] = {
+		"--all", "--always", NULL
+	};
+
+	static const char **describe_argv[] = {
+		describe_bare, describe_tags, describe_contains,
+		describe_all_always, NULL
+	};
+
+	for (d = describe_argv; *d; d++) {
+		struct child_process cp = CHILD_PROCESS_INIT;
+		prepare_submodule_repo_env(&cp.env_array);
+		cp.dir = sub_path;
+		cp.git_cmd = 1;
+		cp.no_stderr = 1;
+
+		argv_array_push(&cp.args, "describe");
+		argv_array_pushv(&cp.args, *d);
+		argv_array_push(&cp.args, object_id);
+
+		if (!capture_command(&cp, &sb, 0) && sb.len) {
+			strbuf_strip_suffix(&sb, "\n");
+			return strbuf_detach(&sb, NULL);
+		}
+
+	}
+
+	strbuf_release(&sb);
+	return NULL;
+}
+
+static int print_name_rev(int argc, const char **argv, const char *prefix)
+{
+	char *namerev;
+	if (argc != 3)
+		die("print-name-rev only accepts two arguments: <path> <sha1>");
+
+	namerev = get_name_rev(argv[1], argv[2]);
+	if (namerev && namerev[0])
+		printf(" (%s)", namerev);
+	printf("\n");
+
+	free(namerev);
+	return 0;
+}
+
 struct module_list {
 	const struct cache_entry **entries;
 	int alloc, nr;
@@ -1242,6 +1305,7 @@ static struct cmd_struct commands[] = {
 	{"relative-path", resolve_relative_path, 0},
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
+	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..e988167e0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
 	}
 }
 
-set_name_rev () {
-	revname=$( (
-		sanitize_submodule_env
-		cd "$1" && {
-			git describe "$2" 2>/dev/null ||
-			git describe --tags "$2" 2>/dev/null ||
-			git describe --contains "$2" 2>/dev/null ||
-			git describe --all --always "$2"
-		}
-	) )
-	test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
 		fi
 		if git diff-files --ignore-submodules=dirty --quiet -- "$sm_path"
 		then
-			set_name_rev "$sm_path" "$sha1"
+			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
 			say " $sha1 $displaypath$revname"
 		else
 			if test -z "$cached"
 			then
 				sha1=$(sanitize_submodule_env; cd "$sm_path" && git rev-parse --verify HEAD)
 			fi
-			set_name_rev "$sm_path" "$sha1"
+			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
 			say "+$sha1 $displaypath$revname"
 		fi
 
-- 
2.13.0

[GSoC][PATCH v2 04/13] submodule: port submodule subcommand 'status' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule 'status' a built-in. Hence, the function
cmd_status() is ported from shell to C. This is done by introducing
three functions: module_status(), submodule_status() and print_status().

The function module_status() acts as the front-end of the subcommand.
It parses subcommand's options and then calls the function
module_list_compute() for computing the list of submodules. Then
this functions calls for_each_submodule_list() looping through the
list obtained.

Then for_each_submodule_list() calls submodule_status() for each of the
submodule in its list. The function submodule_status() is responsible
for generating the status each submodule it is called for, and
then calls print_status().

Finally, the function print_status() handles the printing of submodule's
status.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:
* parameters passed to the function print_status() have been changed.
  Instead of passing char *sub_sha1, instead the object_id is being passed.

* Also, since the passed parameter displaypath's value isn't changed
  by the function, it is passed to the funcition as const char *displaypath
  instead of char *displaypath.

* the output type of the function handle_submodule_head_ref() is changed
  from strbuf to object_id, as we will use the object_id instead of the
  hex of sha1 being stored in a struct strbuf.

* diff_files_Args is cleared after using it by passing it as args in the
  function cmd_diff_files.

* In the function status_submodule(), for checking if a submodule has merge
  conflicts, the patch currently checks if the value of any of the ce_flags
  is non-zero. Currently, I think the we aren't interested in a partiular flag,
  but I'm not sure on this.

* The confusion with displaypath being passed as te super-prefix in many
  of the ported subcommands may be a result of the fact that the
  function generating the displaypath: get_submodule_displaypath()
  uses the super-prefix as simply a path concatenated with the current
  submodule name to denote our current location.
  Also, for generating any submodule's displaypath, it would be important to
  have ".." passed to the submodule, and currently it is possible only via the
  super-prefix.

 builtin/submodule--helper.c | 157 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  49 +-------------
 2 files changed, 158 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 2cb72d68e..0bd969b7c 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -561,6 +561,162 @@ static int module_init(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct status_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+	unsigned int cached: 1;
+};
+#define STATUS_CB_INIT { NULL, 0, 0, 0 }
+
+static void print_status(struct status_cb *info, char state, const char *path,
+			 const struct object_id *oid, const char *displaypath)
+{
+	if (info->quiet)
+		return;
+
+	printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+
+	if (state == ' ' || state == '+') {
+		struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+		argv_array_pushl(&name_rev_args, "print-name-rev",
+				 path, oid_to_hex(oid), NULL);
+		print_name_rev(name_rev_args.argc, name_rev_args.argv,
+			       info->prefix);
+	} else {
+		printf("\n");
+	}
+}
+
+static int handle_submodule_head_ref(const char *refname,
+				     const struct object_id *oid, int flags,
+				     void *cb_data)
+{
+	struct object_id *output = cb_data;
+	if (oid)
+		oidcpy(output, oid);
+
+	return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct status_cb *info = cb_data;
+	char *displaypath;
+	struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+	if (!submodule_from_path(null_sha1, list_item->name))
+		die(_("no submodule mapping found in .gitmodules for path '%s'"),
+		      list_item->name);
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	trace_printf("the value of flag is %d\n", list_item->ce_flags);
+	if (list_item->ce_flags) {
+		trace_printf("for U the value of flag is %d\n", list_item->ce_flags);
+		print_status(info, 'U', list_item->name,
+			     &null_oid, displaypath);
+		goto cleanup;
+	}
+
+	if (!is_submodule_active(the_repository, list_item->name)) {
+		print_status(info, '-', list_item->name, &list_item->oid,
+			     displaypath);
+		goto cleanup;
+	}
+
+	argv_array_pushl(&diff_files_args, "diff-files",
+			 "--ignore-submodules=dirty", "--quiet", "--",
+			 list_item->name, NULL);
+
+	if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+			    info->prefix)) {
+		print_status(info, ' ', list_item->name, &list_item->oid,
+			     displaypath);
+	} else {
+		if (!info->cached) {
+			struct object_id oid;
+
+			if (head_ref_submodule(list_item->name,
+					       handle_submodule_head_ref, &oid))
+				die(_("could not resolve HEAD ref inside the"
+				      "submodule '%s'"), list_item->name);
+
+			print_status(info, '+', list_item->name, &oid,
+				     displaypath);
+		} else {
+			print_status(info, '+', list_item->name,
+				     &list_item->oid, displaypath);
+		}
+	}
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "status", "--recursive",
+				 NULL);
+
+		if (info->cached)
+			argv_array_push(&cpr.args, "--cached");
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		if (run_command(&cpr))
+			die(_("failed to recurse into submodule '%s'"),
+			      list_item->name);
+	}
+
+cleanup:
+	argv_array_clear(&diff_files_args);
+	free(displaypath);
+}
+
+static int module_status(int argc, const char **argv, const char *prefix)
+{
+	struct status_cb info = STATUS_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int cached = 0;
+	int recursive = 0;
+
+	struct option module_status_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
+		OPT_BOOL(0, "cached", &cached, N_("Use commit stored in the index instead of the one stored in the submodule HEAD")),
+		OPT_BOOL(0, "recursive", &recursive, N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule status [--quiet] [--cached] [--recursive] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_status_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+	info.cached = !!cached;
+
+	gitmodules_config();
+	for_each_submodule_list(list, status_submodule, &info);
+
+	return 0;
+}
+
 static int module_name(int argc, const char **argv, const char *prefix)
 {
 	const struct submodule *sub;
@@ -1307,6 +1463,7 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
+	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index e988167e0..51b057d82 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1005,54 +1005,7 @@ cmd_status()
 		shift
 	done
 
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		name=$(git submodule--helper name "$sm_path") || exit
-		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-		if test "$stage" = U
-		then
-			say "U$sha1 $displaypath"
-			continue
-		fi
-		if ! git submodule--helper is-active "$sm_path" ||
-		{
-			! test -d "$sm_path"/.git &&
-			! test -f "$sm_path"/.git
-		}
-		then
-			say "-$sha1 $displaypath"
-			continue;
-		fi
-		if git diff-files --ignore-submodules=dirty --quiet -- "$sm_path"
-		then
-			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
-			say " $sha1 $displaypath$revname"
-		else
-			if test -z "$cached"
-			then
-				sha1=$(sanitize_submodule_env; cd "$sm_path" && git rev-parse --verify HEAD)
-			fi
-			revname=$(git submodule--helper print-name-rev "$sm_path" "$sha1")
-			say "+$sha1 $displaypath$revname"
-		fi
-
-		if test -n "$recursive"
-		then
-			(
-				prefix="$displaypath/"
-				sanitize_submodule_env
-				wt_prefix=
-				cd "$sm_path" &&
-				eval cmd_status
-			) ||
-			die "$(eval_gettext "Failed to recurse into submodule path '\$sm_path'")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper status ${GIT_QUIET:+--quiet} ${cached:+--cached} ${recursive:+--recursive} "$@"
 }
 #
 # Sync remote urls for submodules
-- 
2.13.0

Re: [GSoC][PATCH v2 04/13] submodule: port submodule subcommand 'status' from shell to C

[Christian Couder]

On Sun, Jul 30, 2017 at 12:23 AM, Prathamesh Chavan <pc44800@gmail.com> wrote:

> +static void print_status(struct status_cb *info, char state, const char *path,
> +                        const struct object_id *oid, const char *displaypath)
> +{
> +       if (info->quiet)
> +               return;
> +
> +       printf("%c%s %s", state, oid_to_hex(oid), displaypath);
> +
> +

Spurious new line.

> +       if (state == ' ' || state == '+') {
> +               struct argv_array name_rev_args = ARGV_ARRAY_INIT;
> +
> +               argv_array_pushl(&name_rev_args, "print-name-rev",
> +                                path, oid_to_hex(oid), NULL);
> +               print_name_rev(name_rev_args.argc, name_rev_args.argv,
> +                              info->prefix);
> +       } else {
> +               printf("\n");
> +       }
> +}

> +static void status_submodule(const struct cache_entry *list_item, void *cb_data)
> +{
> +       struct status_cb *info = cb_data;
> +       char *displaypath;
> +       struct argv_array diff_files_args = ARGV_ARRAY_INIT;
> +
> +       if (!submodule_from_path(null_sha1, list_item->name))
> +               die(_("no submodule mapping found in .gitmodules for path '%s'"),
> +                     list_item->name);
> +
> +       displaypath = get_submodule_displaypath(list_item->name, info->prefix);
> +
> +       trace_printf("the value of flag is %d\n", list_item->ce_flags);

Debugging left over.

> +       if (list_item->ce_flags) {
> +               trace_printf("for U the value of flag is %d\n", list_item->ce_flags);
> +               print_status(info, 'U', list_item->name,
> +                            &null_oid, displaypath);
> +               goto cleanup;
> +       }

[GSoC][PATCH v2 05/13] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing three functions: module_sync(),
sync_submodule() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:
* There was no good reason for using puts in the function print_default_remote()
  Hence, in this patch, we instead use printf to do the same, as it is what
  is generally used throughout the codebase.

* As suggested, this patch ensures a more efficient use of variables, and
  removes most of the variables by reusing 'strbuf sb' at places required.

 builtin/submodule--helper.c | 182 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  56 +-------------
 2 files changed, 183 insertions(+), 55 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 0bd969b7c..877215567 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -44,6 +44,20 @@ static char *get_default_remote(void)
 	return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char *prefix)
+{
+	const char *remote;
+
+	if (argc != 1)
+		die(_("submodule--helper print-default-remote takes no arguments"));
+
+	remote = get_default_remote();
+	if (remote)
+		printf("%s\n", remote);
+
+	return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
 	return str[0] == '.' && is_dir_sep(str[1]);
@@ -380,6 +394,25 @@ static void module_list_active(struct module_list *list)
 	*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+	int i;
+	struct strbuf sb = STRBUF_INIT;
+
+	for (i = count_slashes(path); i; i--)
+		strbuf_addstr(&sb, "../");
+
+	/*
+	 * Check if 'path' ends with slash or not
+	 * for having the same output for dir/sub_dir
+	 * and dir/sub_dir/
+	 */
+	if (!is_dir_sep(path[strlen(path) - 1]))
+		strbuf_addstr(&sb, "../");
+
+	return strbuf_detach(&sb, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
 	int i;
@@ -736,6 +769,153 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct sync_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+};
+#define SYNC_CB_INIT { NULL, 0, 0 }
+
+static void sync_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+	struct sync_cb *info = cb_data;
+	const struct submodule *sub;
+	char *remote_key;
+	char *sub_origin_url, *super_config_url, *displaypath;
+	struct strbuf sb = STRBUF_INIT;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	char *sub_config_path = NULL;
+
+	if (!is_submodule_active(the_repository, list_item->name))
+		return;
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (sub && sub->url) {
+		if (starts_with_dot_dot_slash(sub->url) || starts_with_dot_slash(sub->url)) {
+			char *remote_url, *up_path;
+			char *remote = get_default_remote();
+			strbuf_addf(&sb, "remote.%s.url", remote);
+
+			if (git_config_get_string(sb.buf, &remote_url))
+				remote_url = xgetcwd();
+
+			up_path = get_up_path(list_item->name);
+			sub_origin_url = relative_url(remote_url, sub->url, up_path);
+			super_config_url = relative_url(remote_url, sub->url, NULL);
+
+			free(remote);
+			free(up_path);
+			free(remote_url);
+		} else {
+			sub_origin_url = xstrdup(sub->url);
+			super_config_url = xstrdup(sub->url);
+		}
+	} else {
+		sub_origin_url = "";
+		super_config_url = "";
+	}
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	if (!info->quiet)
+		printf(_("Synchronizing submodule url for '%s'\n"),
+			 displaypath);
+
+	strbuf_reset(&sb);
+	strbuf_addf(&sb, "submodule.%s.url", sub->name);
+	if (git_config_set_gently(sb.buf, super_config_url))
+		die(_("failed to register url for submodule path '%s'"),
+		      displaypath);
+
+	if (!is_submodule_populated_gently(list_item->name, NULL))
+		goto cleanup;
+
+	prepare_submodule_repo_env(&cp.env_array);
+	cp.git_cmd = 1;
+	cp.dir = list_item->name;
+	argv_array_pushl(&cp.args, "submodule--helper",
+			 "print-default-remote", NULL);
+
+	strbuf_reset(&sb);
+	if (capture_command(&cp, &sb, 0))
+		die(_("failed to get the default remote for submodule '%s'"),
+		      list_item->name);
+
+	strbuf_strip_suffix(&sb, "\n");
+	remote_key = xstrfmt("remote.%s.url", sb.buf);
+
+	strbuf_reset(&sb);
+	submodule_to_gitdir(&sb, list_item->name);
+	strbuf_addstr(&sb, "/config");
+
+	if (git_config_set_in_file_gently(sb.buf, remote_key, sub_origin_url))
+		die(_("failed to update remote for submodule '%s'"),
+		      list_item->name);
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "sync", "--recursive",
+				 NULL);
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		if (run_command(&cpr))
+			die(_("failed to recurse into submodule '%s'"),
+			      list_item->name);
+	}
+
+cleanup:
+	strbuf_release(&sb);
+	free(super_config_url);
+	free(displaypath);
+	free(sub_config_path);
+	free(sub_origin_url);
+}
+
+static int module_sync(int argc, const char **argv, const char *prefix)
+{
+	struct sync_cb info = SYNC_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int recursive = 0;
+
+	struct option module_sync_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output of synchronizing submodule url")),
+		OPT_BOOL(0, "recursive", &recursive,
+			N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper sync [--quiet] [--recursive] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_sync_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		return 1;
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+
+	gitmodules_config();
+	for_each_submodule_list(list, sync_submodule, &info);
+
+	return 0;
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference,
 			   int quiet, int progress)
@@ -1464,6 +1644,8 @@ static struct cmd_struct commands[] = {
 	{"print-name-rev", print_name_rev, 0},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
+	{"print-default-remote", print_default_remote, 0},
+	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 51b057d82..6bfc5e17d 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -1037,63 +1037,9 @@ cmd_sync()
 			;;
 		esac
 	done
-	cd_to_toplevel
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-
-		# skip inactive submodules
-		if ! git submodule--helper is-active "$sm_path"
-		then
-			continue
-		fi
-
-		name=$(git submodule--helper name "$sm_path")
-		url=$(git config -f .gitmodules --get submodule."$name".url)
-
-		# Possibly a url relative to parent
-		case "$url" in
-		./*|../*)
-			# rewrite foo/bar as ../.. to find path from
-			# submodule work tree to superproject work tree
-			up_path="$(printf '%s\n' "$sm_path" | sed "s/[^/][^/]*/../g")" &&
-			# guarantee a trailing /
-			up_path=${up_path%/}/ &&
-			# path from submodule work tree to submodule origin repo
-			sub_origin_url=$(git submodule--helper resolve-relative-url "$url" "$up_path") &&
-			# path from superproject work tree to submodule origin repo
-			super_config_url=$(git submodule--helper resolve-relative-url "$url") || exit
-			;;
-		*)
-			sub_origin_url="$url"
-			super_config_url="$url"
-			;;
-		esac
 
-		displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-		say "$(eval_gettext "Synchronizing submodule url for '\$displaypath'")"
-		git config submodule."$name".url "$super_config_url"
-
-		if test -e "$sm_path"/.git
-		then
-		(
-			sanitize_submodule_env
-			cd "$sm_path"
-			remote=$(get_default_remote)
-			git config remote."$remote".url "$sub_origin_url"
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper sync ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
 
-			if test -n "$recursive"
-			then
-				prefix="$prefix$sm_path/"
-				eval cmd_sync
-			fi
-		)
-		fi
-	done
 }
 
 cmd_absorbgitdirs()
-- 
2.13.0

[GSoC][PATCH v2 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:
* In the function deinit_submodule, since the test is_git_directory()
  adds an additional condition, instead is_directory() is used to check
  if "sm_path/.git" is a directory.

* since it was possible in the previous path that the value st.st_mode passed
  to the function mkdir contained a garbage value, instead we intrduce a
  mode_t variable mode, initially containing a default mode value '0777'.
  This is what the default of mode is set in case, that the value is
  not set after the lstat call.

 builtin/submodule--helper.c | 144 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  55 +----------------
 2 files changed, 145 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 877215567..038be7ee2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -916,6 +916,149 @@ static int module_sync(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct deinit_cb {
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int force: 1;
+	unsigned int all: 1;
+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+			     void *cb_data)
+{
+	struct deinit_cb *info = cb_data;
+	const struct submodule *sub;
+	char *displaypath = NULL;
+	struct child_process cp_config = CHILD_PROCESS_INIT;
+	struct strbuf sb_config = STRBUF_INIT;
+	char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+	mode_t mode = 0777;
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (!sub || !sub->name)
+		goto cleanup;
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	/* remove the submodule work tree (unless the user already did it) */
+	if (is_directory(list_item->name)) {
+		struct stat st;
+		/* protect submodules containing a .git directory */
+		if (is_directory(sub_git_dir))
+			die(_("Submodule work tree '%s' contains a .git "
+			      "directory use 'rm -rf' if you really want "
+			      "to remove it including all of its history"),
+			      displaypath);
+
+		if (!info->force) {
+			struct child_process cp_rm = CHILD_PROCESS_INIT;
+			cp_rm.git_cmd = 1;
+			argv_array_pushl(&cp_rm.args, "rm", "-qn",
+					 list_item->name, NULL);
+
+			if (run_command(&cp_rm))
+				die(_("Submodule work tree '%s' contains local "
+				      "modifications; use '-f' to discard them"),
+				      displaypath);
+		}
+
+		if (!lstat(list_item->name, &st)) {
+			struct strbuf sb_rm = STRBUF_INIT;
+			const char *format;
+
+			strbuf_addstr(&sb_rm, list_item->name);
+
+			if (!remove_dir_recursively(&sb_rm, 0))
+				format = _("Cleared directory '%s'\n");
+			else
+				format = _("Could not remove submodule work tree '%s'\n");
+
+			if (!info->quiet)
+				printf(format, displaypath);
+
+			mode = st.st_mode;
+
+			strbuf_release(&sb_rm);
+		}
+	}
+
+	if (mkdir(list_item->name, mode))
+		die(_("could not create empty submodule directory %s"),
+		      displaypath);
+
+	cp_config.git_cmd = 1;
+	argv_array_pushl(&cp_config.args, "config", "--get-regexp", NULL);
+	argv_array_pushf(&cp_config.args, "submodule.%s\\.", sub->name);
+
+	/* remove the .git/config entries (unless the user already did it) */
+	if (!capture_command(&cp_config, &sb_config, 0) && sb_config.len) {
+		char *sub_key = xstrfmt("submodule.%s", sub->name);
+		/*
+		 * remove the whole section so we have a clean state when
+		 * the user later decides to init this submodule again
+		 */
+		git_config_rename_section_in_file(NULL, sub_key, NULL);
+		if (!info->quiet)
+			printf(_("Submodule '%s' (%s) unregistered for path '%s'\n"),
+				 sub->name, sub->url, displaypath);
+		free(sub_key);
+	}
+
+cleanup:
+	free(displaypath);
+	free(sub_git_dir);
+	strbuf_release(&sb_config);
+}
+
+static int module_deinit(int argc, const char **argv, const char *prefix)
+{
+	struct deinit_cb info = DEINIT_CB_INIT;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int force = 0;
+	int all = 0;
+
+	struct option module_deinit_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress submodule status output")),
+		OPT__FORCE(&force, N_("Remove submodule working trees even if they contain local changes")),
+		OPT_BOOL(0, "all", &all, N_("Unregister all submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule deinit [--quiet] [-f | --force] [--all | [--] [<path>...]]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_deinit_options,
+			     git_submodule_helper_usage, 0);
+
+	if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
+		BUG("module_list_compute should not choke on empty pathspec");
+
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.all = !!all;
+	info.force = !!force;
+
+	if (all && argc) {
+		error("pathspec and --all are incompatible");
+		usage_with_options(git_submodule_helper_usage,
+				   module_deinit_options);
+	}
+
+	if (!argc && !all)
+		die(_("Use '--all' if you really want to deinitialize all submodules"));
+
+	gitmodules_config();
+	for_each_submodule_list(list, deinit_submodule, &info);
+
+	return 0;
+}
+
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 			   const char *depth, struct string_list *reference,
 			   int quiet, int progress)
@@ -1646,6 +1789,7 @@ static struct cmd_struct commands[] = {
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"print-default-remote", print_default_remote, 0},
 	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
+	{"deinit", module_deinit, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 6bfc5e17d..73e6f093f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -428,60 +428,7 @@ cmd_deinit()
 		shift
 	done
 
-	if test -n "$deinit_all" && test "$#" -ne 0
-	then
-		echo >&2 "$(eval_gettext "pathspec and --all are incompatible")"
-		usage
-	fi
-	if test $# = 0 && test -z "$deinit_all"
-	then
-		die "$(eval_gettext "Use '--all' if you really want to deinitialize all submodules")"
-	fi
-
-	{
-		git submodule--helper list --prefix "$wt_prefix" "$@" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		name=$(git submodule--helper name "$sm_path") || exit
-
-		displaypath=$(git submodule--helper relative-path "$sm_path" "$wt_prefix")
-
-		# Remove the submodule work tree (unless the user already did it)
-		if test -d "$sm_path"
-		then
-			# Protect submodules containing a .git directory
-			if test -d "$sm_path/.git"
-			then
-				die "$(eval_gettext "\
-Submodule work tree '\$displaypath' contains a .git directory
-(use 'rm -rf' if you really want to remove it including all of its history)")"
-			fi
-
-			if test -z "$force"
-			then
-				git rm -qn "$sm_path" ||
-				die "$(eval_gettext "Submodule work tree '\$displaypath' contains local modifications; use '-f' to discard them")"
-			fi
-			rm -rf "$sm_path" &&
-			say "$(eval_gettext "Cleared directory '\$displaypath'")" ||
-			say "$(eval_gettext "Could not remove submodule work tree '\$displaypath'")"
-		fi
-
-		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$displaypath'")"
-
-		# Remove the .git/config entries (unless the user already did it)
-		if test -n "$(git config --get-regexp submodule."$name\.")"
-		then
-			# Remove the whole section so we have a clean state when
-			# the user later decides to init this submodule again
-			url=$(git config submodule."$name".url)
-			git config --remove-section submodule."$name" 2>/dev/null &&
-			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$displaypath'")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper deinit ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${force:+--force} ${deinit_all:+--all} "$@"
 }
 
 is_tip_reachable () (
-- 
2.13.0

[GSoC][PATCH v2 07/13] diff: change scope of the function count_lines()

[Prathamesh Chavan]

Change the scope of function count_lines for allowing the function
to be reused in other parts of the code as well.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 diff.c | 2 +-
 diff.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index 85e714f6c..03ed64f93 100644
--- a/diff.c
+++ b/diff.c
@@ -425,7 +425,7 @@ struct emit_callback {
 	struct strbuf *header;
 };
 
-static int count_lines(const char *data, int size)
+int count_lines(const char *data, int size)
 {
 	int count, ch, completely_empty = 1, nl_just_seen = 0;
 	count = 0;
diff --git a/diff.h b/diff.h
index 2d442e296..8522514e9 100644
--- a/diff.h
+++ b/diff.h
@@ -273,6 +273,7 @@ extern struct diff_filepair *diff_unmerge(struct diff_options *, const char *pat
 extern int parse_long_opt(const char *opt, const char **argv,
 			 const char **optarg);
 
+extern int count_lines(const char *data, int size);
 extern int git_diff_basic_config(const char *var, const char *value, void *cb);
 extern int git_diff_heuristic_config(const char *var, const char *value, void *cb);
 extern void init_diff_ui_defaults(void);
-- 
2.13.0

[GSoC][PATCH v2 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

The submodule subcommand 'summary' is ported in the process of
making git-submodule a builtin. The function cmd_summary() from
git-submodule.sh is ported to functions module_summary(),
compute_summary_module_list(), prepare_submodule_summary() and
print_submodule_summary().

The first function module_summary() parses the options of submodule
subcommand and also acts as the front-end of this subcommand.
After parsing them, it calls the compute_summary_module_list()

The functions compute_summary_module_list() runs the diff_cmd,
and generates the modules list, as required by the subcommand.
The generation of this module list is done by the using the
callback function submodule_summary_callback(), and stored in the
structure module_cb.

Once the module list is generated, prepare_submodule_summary()
further goes through the list and filters the list, for
eventually calling the print_submodule_summary() function.

Finally, the print_submodule_summary() takes care of generating
and printing the summary for each submodule.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:

* Firstly, about the function compute_summary_module_list().
  This function is created to generate the list of modules, for which
  we will generate the summary further. Since the list is actually
  generated using the git-diff-files or git-diff-index command, but for
  porting this, we required to create a function similar to the builtin
  functions of the above commands. But we can't directly call cmd_diff_files()
  and cmd_diff_index() since we don't have to display the output and instead
  need to store it. Hence, this function is introduced.

* Also, the module_cb_list *list is not freed since it is a non-heap object.
  Hence, free() can't be using on the non-heap objects.

* In the function prepare_submodule_summary(), as suggested
  'git_config_get_string_const' was used instead of instead of '_value'

* Some variables which weren't modified throughout the function-call were
  passed as const.

* The '!!' trick, which wasn't used in the last patch, is now used in this
  new version .

* the variables sha1_dst and sha1_src are removed from the function
  print_submodule_summary(), and instead the p->oid_src and p->oid_dst are
  used.

* The variable sm_git_dir is freed at the end of the function.

 builtin/submodule--helper.c | 433 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            | 182 +------------------
 2 files changed, 434 insertions(+), 181 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 038be7ee2..d8bf16f1d 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,6 +13,9 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
 				      void *cb_data);
@@ -769,6 +772,435 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct module_cb {
+	unsigned int mod_src;
+	unsigned int mod_dst;
+	struct object_id oid_src;
+	struct object_id oid_dst;
+	char status;
+	const char *sm_path;
+};
+#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
+
+struct module_cb_list {
+	struct module_cb **entries;
+	int alloc, nr;
+};
+#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
+
+struct summary_cb {
+	int argc;
+	const char **argv;
+	const char *prefix;
+	char *diff_cmd;
+	unsigned int cached: 1;
+	unsigned int for_status: 1;
+	unsigned int quiet: 1;
+	unsigned int files: 1;
+	int summary_limits;
+};
+#define SUMMARY_CB_INIT { 0, NULL, NULL, NULL, 0, 0, 0, 0, 0 }
+
+static int verify_submodule_object_name(const char *sm_path, const char *sha1)
+{
+	struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+	cp_rev_parse.git_cmd = 1;
+	cp_rev_parse.no_stdout = 1;
+	cp_rev_parse.dir = sm_path;
+	prepare_submodule_repo_env(&cp_rev_parse.env_array);
+
+	argv_array_pushl(&cp_rev_parse.args, "rev-parse", "-q",
+			 "--verify", NULL);
+	argv_array_pushf(&cp_rev_parse.args, "%s^0", sha1);
+
+	if (run_command(&cp_rev_parse))
+		return 1;
+
+	return 0;
+}
+
+static void print_submodule_summary(struct summary_cb *info,
+				    struct module_cb *p)
+{
+	int missing_src = 0;
+	int missing_dst = 0;
+	char *displaypath;
+	const char *sha1_abbr_src;
+	const char *sha1_abbr_dst;
+	int errmsg = 0;
+	int total_commits = -1;
+	char *sm_git_dir = xstrfmt("%s/.git", p->sm_path);
+	int is_sm_git_dir = 0;
+
+	if (!info->cached && !oidcmp(&p->oid_dst, &null_oid)) {
+		if (S_ISGITLINK(p->mod_dst)) {
+			struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+			struct strbuf sb_rev_parse = STRBUF_INIT;
+
+			cp_rev_parse.git_cmd = 1;
+			cp_rev_parse.no_stderr = 1;
+			cp_rev_parse.dir = p->sm_path;
+			prepare_submodule_repo_env(&cp_rev_parse.env_array);
+
+			argv_array_pushl(&cp_rev_parse.args,
+					 "rev-parse", "HEAD", NULL);
+			if (!capture_command(&cp_rev_parse, &sb_rev_parse, 0)) {
+				strbuf_strip_suffix(&sb_rev_parse, "\n");
+
+				get_oid_hex(sb_rev_parse.buf, &p->oid_dst);
+			}
+			strbuf_release(&sb_rev_parse);
+		} else if (S_ISLNK(p->mod_dst) || S_ISREG(p->mod_dst)) {
+			struct child_process cp_hash_object = CHILD_PROCESS_INIT;
+			struct strbuf sb_hash_object = STRBUF_INIT;
+
+			cp_hash_object.git_cmd = 1;
+			argv_array_pushl(&cp_hash_object.args,
+					 "hash-object", p->sm_path,
+					 NULL);
+			if (!capture_command(&cp_hash_object,
+					     &sb_hash_object, 0)) {
+				strbuf_strip_suffix(&sb_hash_object, "\n");
+
+				get_oid_hex(sb_hash_object.buf, &p->oid_dst);
+			}
+			strbuf_release(&sb_hash_object);
+		} else {
+			if (p->mod_dst)
+				die(_("unexpected mode %d\n"), p->mod_dst);
+		}
+	}
+
+	if (is_git_directory(sm_git_dir))
+		is_sm_git_dir = 1;
+
+	if (is_sm_git_dir && S_ISGITLINK(p->mod_src))
+		missing_src = verify_submodule_object_name(p->sm_path,
+							   oid_to_hex(&p->oid_src));
+
+	if (is_sm_git_dir && S_ISGITLINK(p->mod_dst))
+		missing_dst = verify_submodule_object_name(p->sm_path,
+							   oid_to_hex(&p->oid_dst));
+
+	displaypath = get_submodule_displaypath(p->sm_path, info->prefix);
+
+	if (!missing_dst && !missing_src) {
+		if (is_sm_git_dir) {
+			struct child_process cp_rev_list = CHILD_PROCESS_INIT;
+			struct strbuf sb_rev_list = STRBUF_INIT;
+			char *range;
+
+			if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst))
+				range = xstrfmt("%s...%s", oid_to_hex(&p->oid_src), oid_to_hex(&p->oid_dst));
+			else if (S_ISGITLINK(p->mod_src))
+				range = xstrdup(oid_to_hex(&p->oid_src));
+			else
+				range = xstrdup(oid_to_hex(&p->oid_dst));
+
+			cp_rev_list.git_cmd = 1;
+			cp_rev_list.dir = p->sm_path;
+			prepare_submodule_repo_env(&cp_rev_list.env_array);
+
+			argv_array_pushl(&cp_rev_list.args, "rev-list",
+					 "--first-parent", range, "--", NULL);
+			if (!capture_command(&cp_rev_list, &sb_rev_list, 0)) {
+				if (sb_rev_list.len)
+					total_commits = count_lines(sb_rev_list.buf,
+								    sb_rev_list.len);
+				else
+					total_commits = 0;
+			}
+
+			free(range);
+			strbuf_release(&sb_rev_list);
+		}
+	} else {
+		errmsg = 1;
+	}
+
+	sha1_abbr_src = find_unique_abbrev(p->oid_src.hash, 7);
+	sha1_abbr_dst = find_unique_abbrev(p->oid_dst.hash, 7);
+
+	if (p->status == 'T') {
+		if (S_ISGITLINK(p->mod_dst))
+			printf(_("* %s %s(blob)->%s(submodule)"),
+				 displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+		else
+			printf(_("* %s %s(submodule)->%s(blob)"),
+				 displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+	} else {
+			printf("* %s %s...%s", displaypath, sha1_abbr_src,
+				 sha1_abbr_dst);
+	}
+
+	if (total_commits < 0)
+		printf(":\n");
+	else
+		printf(" (%d):\n", total_commits);
+
+	if (errmsg) {
+		/*
+		 * Don't give error msg for modification whose dst is not
+		 * submodule, i.e. deleted or changed to blob
+		 */
+		if (S_ISGITLINK(p->mod_src)) {
+			if (missing_src && missing_dst) {
+				printf(_("  Warn: %s doesn't contain commits %s and %s\n"),
+				 displaypath, oid_to_hex(&p->oid_src), oid_to_hex(&p->oid_dst));
+			} else if (missing_src) {
+				printf(_("  Warn: %s doesn't contain commit %s\n"),
+				 displaypath, oid_to_hex(&p->oid_src));
+			} else {
+				printf(_("  Warn: %s doesn't contain commit %s\n"),
+				 displaypath, oid_to_hex(&p->oid_dst));
+			}
+		}
+	} else if (is_sm_git_dir) {
+		struct child_process cp_log = CHILD_PROCESS_INIT;
+
+		cp_log.git_cmd = 1;
+		cp_log.dir = p->sm_path;
+		prepare_submodule_repo_env(&cp_log.env_array);
+		argv_array_pushl(&cp_log.args, "log", NULL);
+
+		if (S_ISGITLINK(p->mod_src) && S_ISGITLINK(p->mod_dst)) {
+			if (info->summary_limits > 0)
+				argv_array_pushf(&cp_log.args, "-%d", info->summary_limits);
+
+			argv_array_pushl(&cp_log.args, "--pretty=  %m %s",
+					 "--first-parent", NULL);
+			argv_array_pushf(&cp_log.args, "%s...%s", oid_to_hex(&p->oid_src), oid_to_hex(&p->oid_dst));
+		} else if (S_ISGITLINK(p->mod_dst)) {
+			argv_array_pushl(&cp_log.args, "--pretty=  > %s",
+					 "-1", oid_to_hex(&p->oid_dst), NULL);
+		} else {
+			argv_array_pushl(&cp_log.args, "--pretty=  < %s",
+					 "-1", oid_to_hex(&p->oid_src), NULL);
+		}
+
+		run_command(&cp_log);
+	}
+	printf("\n");
+
+	free(displaypath);
+	free(sm_git_dir);
+}
+
+static void prepare_submodule_summary(struct summary_cb *info,
+				      struct module_cb_list *list)
+{
+	int i;
+	for (i = 0; i < list->nr; i++) {
+		struct module_cb *p = list->entries[i];
+		struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+		if (p->status == 'D' || p->status == 'T') {
+			print_submodule_summary(info, p);
+			continue;
+		}
+
+		if (info->for_status) {
+			char *config_key;
+			const char *ignore_config = "none";
+			const char *value;
+			const struct submodule *sub = submodule_from_path(null_sha1, p->sm_path);
+
+			if (sub && p->status != 'A') {
+				config_key = xstrfmt("submodule.%s.ignore",
+						     sub->name);
+				if (!git_config_get_string_const(config_key, &value))
+					ignore_config = value;
+				else if (sub->ignore)
+					ignore_config = sub->ignore;
+
+				free(config_key);
+
+				if (!strcmp(ignore_config, "all"))
+					continue;
+			}
+		}
+
+		/* Also show added or modified modules which are checked out */
+		cp_rev_parse.dir = p->sm_path;
+		cp_rev_parse.git_cmd = 1;
+		cp_rev_parse.no_stderr = 1;
+		cp_rev_parse.no_stdout = 1;
+
+		argv_array_pushl(&cp_rev_parse.args, "rev-parse",
+				 "--git-dir", NULL);
+
+		if (!run_command(&cp_rev_parse))
+			print_submodule_summary(info, p);
+	}
+}
+
+static void submodule_summary_callback(struct diff_queue_struct *q,
+				       struct diff_options *options,
+				       void *data)
+{
+	int i;
+	struct module_cb_list *list = data;
+	for (i = 0; i < q->nr; i++) {
+		struct diff_filepair *p = q->queue[i];
+		struct module_cb *temp;
+
+		if (!S_ISGITLINK(p->one->mode) && !S_ISGITLINK(p->two->mode))
+			continue;
+		temp = (struct module_cb*)malloc(sizeof(struct module_cb));
+		temp->mod_src = p->one->mode;
+		temp->mod_dst = p->two->mode;
+		temp->oid_src = p->one->oid;
+		temp->oid_dst = p->two->oid;
+		temp->status = p->status;
+		temp->sm_path = xstrdup(p->one->path);
+
+		ALLOC_GROW(list->entries, list->nr + 1, list->alloc);
+		list->entries[list->nr++] = temp;
+	}
+}
+
+static int compute_summary_module_list(const char *head, struct summary_cb *info)
+{
+	struct argv_array diff_args = ARGV_ARRAY_INIT;
+	struct rev_info rev;
+	struct module_cb_list list = MODULE_CB_LIST_INIT;
+
+	argv_array_push(&diff_args, info->diff_cmd);
+	if (info->cached)
+		argv_array_push(&diff_args, "--cached");
+	argv_array_pushl(&diff_args, "--ignore-submodules=dirty", "--raw",
+			 NULL);
+	if (head)
+		argv_array_push(&diff_args, head);
+	argv_array_push(&diff_args, "--");
+	if (info->argc)
+		argv_array_pushv(&diff_args, info->argv);
+
+	git_config(git_diff_basic_config, NULL);
+	init_revisions(&rev, info->prefix);
+	gitmodules_config();
+	rev.abbrev = 0;
+	precompose_argv(diff_args.argc, diff_args.argv);
+
+	diff_args.argc = setup_revisions(diff_args.argc, diff_args.argv,
+					 &rev, NULL);
+	rev.diffopt.output_format = DIFF_FORMAT_NO_OUTPUT | DIFF_FORMAT_CALLBACK;
+	rev.diffopt.format_callback = submodule_summary_callback;
+	rev.diffopt.format_callback_data = &list;
+
+	if (!info->cached) {
+		if (!strcmp(info->diff_cmd, "diff-index"))
+			setup_work_tree();
+		if (read_cache_preload(&rev.diffopt.pathspec) < 0) {
+			perror("read_cache_preload");
+			return -1;
+		}
+	} else if (read_cache() < 0) {
+		perror("read_cache");
+		return -1;
+	}
+
+	if (!strcmp(info->diff_cmd, "diff-index"))
+		run_diff_index(&rev, info->cached);
+	else
+		run_diff_files(&rev, 0);
+	prepare_submodule_summary(info, &list);
+
+	return 0;
+
+}
+
+static int module_summary(int argc, const char **argv, const char *prefix)
+{
+	struct summary_cb info = SUMMARY_CB_INIT;
+	int cached = 0;
+	char *diff_cmd = "diff-index";
+	int for_status = 0;
+	int quiet = 0;
+	int files = 0;
+	int summary_limits = -1;
+	struct child_process cp_rev = CHILD_PROCESS_INIT;
+	char *head;
+	struct strbuf sb = STRBUF_INIT;
+	int ret;
+
+	struct option module_summary_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
+		OPT_BOOL(0, "cached", &cached, N_("Use the commit stored in the index instead of the submodule HEAD")),
+		OPT_BOOL(0, "files", &files, N_("To compares the commit in the index with that in the submodule HEAD")),
+		OPT_BOOL(0, "for-status", &for_status, N_("Skip submodules with 'all' ignore_config value")),
+		OPT_INTEGER('n', "summary-limits", &summary_limits, N_("Limit the summary size")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper summary [<options>] [--] [<path>]"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_summary_options,
+			     git_submodule_helper_usage, 0);
+
+	if (!summary_limits)
+		return 0;
+
+	cp_rev.git_cmd = 1;
+	argv_array_pushl(&cp_rev.args, "rev-parse", "-q", "--verify",
+			 argc ? argv[0] : "HEAD", NULL);
+
+	if (!capture_command(&cp_rev, &sb, 0)) {
+		strbuf_strip_suffix(&sb, "\n");
+		if (argc) {
+			argv++;
+			argc--;
+		}
+	} else if (!argc || !strcmp(argv[0], "HEAD")) {
+		/* before the first commit: compare with an empty tree */
+		struct stat st;
+		struct object_id oid;
+		if (fstat(0, &st) < 0 || index_fd(oid.hash, 0, &st, 2, prefix, 3))
+			die("Unable to add %s to database", oid.hash);
+		strbuf_addstr(&sb, oid_to_hex(&oid));
+		if (argc) {
+			argv++;
+			argc--;
+		}
+	} else {
+		strbuf_addstr(&sb, "HEAD");
+	}
+
+	head = strbuf_detach(&sb, NULL);
+
+	if (files) {
+		if (cached)
+			die(_("The --cached option cannot be used with the --files option"));
+		diff_cmd = "diff-files";
+
+		free(head);
+
+		head = NULL;
+	}
+
+	info.argc = argc;
+	info.argv = argv;
+	info.prefix = prefix;
+	info.cached = !!cached;
+	info.for_status = !!for_status;
+	info.quiet = quiet;
+	info.files = files;
+	info.summary_limits = summary_limits;
+	info.diff_cmd = diff_cmd;
+
+	ret = compute_summary_module_list(head, &info);
+	if (head)
+		free(head);
+	return ret;
+
+}
+
 struct sync_cb {
 	const char *prefix;
 	unsigned int quiet: 1;
@@ -1790,6 +2222,7 @@ static struct cmd_struct commands[] = {
 	{"print-default-remote", print_default_remote, 0},
 	{"sync", module_sync, SUPPORT_SUPER_PREFIX},
 	{"deinit", module_deinit, SUPPORT_SUPER_PREFIX},
+	{"summary", module_summary, SUPPORT_SUPER_PREFIX},
 	{"remote-branch", resolve_remote_submodule_branch, 0},
 	{"push-check", push_check, 0},
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
diff --git a/git-submodule.sh b/git-submodule.sh
index 73e6f093f..a427ddafd 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -51,31 +51,6 @@ die_if_unmatched ()
 	fi
 }
 
-#
-# Print a submodule configuration setting
-#
-# $1 = submodule name
-# $2 = option name
-# $3 = default value
-#
-# Checks in the usual git-config places first (for overrides),
-# otherwise it falls back on .gitmodules.  This allows you to
-# distribute project-wide defaults in .gitmodules, while still
-# customizing individual repositories if necessary.  If the option is
-# not in .gitmodules either, print a default value.
-#
-get_submodule_config () {
-	name="$1"
-	option="$2"
-	default="$3"
-	value=$(git config submodule."$name"."$option")
-	if test -z "$value"
-	then
-		value=$(git config -f .gitmodules submodule."$name"."$option")
-	fi
-	printf '%s' "${value:-$default}"
-}
-
 isnumber()
 {
 	n=$(($1 + 0)) 2>/dev/null && test "$n" = "$1"
@@ -755,163 +730,8 @@ cmd_summary() {
 		shift
 	done
 
-	test $summary_limit = 0 && return
-
-	if rev=$(git rev-parse -q --verify --default HEAD ${1+"$1"})
-	then
-		head=$rev
-		test $# = 0 || shift
-	elif test -z "$1" || test "$1" = "HEAD"
-	then
-		# before the first commit: compare with an empty tree
-		head=$(git hash-object -w -t tree --stdin </dev/null)
-		test -z "$1" || shift
-	else
-		head="HEAD"
-	fi
-
-	if [ -n "$files" ]
-	then
-		test -n "$cached" &&
-		die "$(gettext "The --cached option cannot be used with the --files option")"
-		diff_cmd=diff-files
-		head=
-	fi
-
-	cd_to_toplevel
-	eval "set $(git rev-parse --sq --prefix "$wt_prefix" -- "$@")"
-	# Get modified modules cared by user
-	modules=$(git $diff_cmd $cached --ignore-submodules=dirty --raw $head -- "$@" |
-		sane_egrep '^:([0-7]* )?160000' |
-		while read -r mod_src mod_dst sha1_src sha1_dst status sm_path
-		do
-			# Always show modules deleted or type-changed (blob<->module)
-			if test "$status" = D || test "$status" = T
-			then
-				printf '%s\n' "$sm_path"
-				continue
-			fi
-			# Respect the ignore setting for --for-status.
-			if test -n "$for_status"
-			then
-				name=$(git submodule--helper name "$sm_path")
-				ignore_config=$(get_submodule_config "$name" ignore none)
-				test $status != A && test $ignore_config = all && continue
-			fi
-			# Also show added or modified modules which are checked out
-			GIT_DIR="$sm_path/.git" git-rev-parse --git-dir >/dev/null 2>&1 &&
-			printf '%s\n' "$sm_path"
-		done
-	)
-
-	test -z "$modules" && return
-
-	git $diff_cmd $cached --ignore-submodules=dirty --raw $head -- $modules |
-	sane_egrep '^:([0-7]* )?160000' |
-	cut -c2- |
-	while read -r mod_src mod_dst sha1_src sha1_dst status name
-	do
-		if test -z "$cached" &&
-			test $sha1_dst = 0000000000000000000000000000000000000000
-		then
-			case "$mod_dst" in
-			160000)
-				sha1_dst=$(GIT_DIR="$name/.git" git rev-parse HEAD)
-				;;
-			100644 | 100755 | 120000)
-				sha1_dst=$(git hash-object $name)
-				;;
-			000000)
-				;; # removed
-			*)
-				# unexpected type
-				eval_gettextln "unexpected mode \$mod_dst" >&2
-				continue ;;
-			esac
-		fi
-		missing_src=
-		missing_dst=
-
-		test $mod_src = 160000 &&
-		! GIT_DIR="$name/.git" git-rev-parse -q --verify $sha1_src^0 >/dev/null &&
-		missing_src=t
-
-		test $mod_dst = 160000 &&
-		! GIT_DIR="$name/.git" git-rev-parse -q --verify $sha1_dst^0 >/dev/null &&
-		missing_dst=t
+	git ${wt_prefix:+-C "$wt_prefix"} submodule--helper summary ${GIT_QUIET:+--quiet} ${prefix:+--prefix "$prefix"} ${for_status:+--for-status} ${files:+--files} ${cached:+--cached} ${summary_limit:+-n $summary_limit} "$@"
 
-		display_name=$(git submodule--helper relative-path "$name" "$wt_prefix")
-
-		total_commits=
-		case "$missing_src,$missing_dst" in
-		t,)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_src")"
-			;;
-		,t)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_dst")"
-			;;
-		t,t)
-			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commits \$sha1_src and \$sha1_dst")"
-			;;
-		*)
-			errmsg=
-			total_commits=$(
-			if test $mod_src = 160000 && test $mod_dst = 160000
-			then
-				range="$sha1_src...$sha1_dst"
-			elif test $mod_src = 160000
-			then
-				range=$sha1_src
-			else
-				range=$sha1_dst
-			fi
-			GIT_DIR="$name/.git" \
-			git rev-list --first-parent $range -- | wc -l
-			)
-			total_commits=" ($(($total_commits + 0)))"
-			;;
-		esac
-
-		sha1_abbr_src=$(echo $sha1_src | cut -c1-7)
-		sha1_abbr_dst=$(echo $sha1_dst | cut -c1-7)
-		if test $status = T
-		then
-			blob="$(gettext "blob")"
-			submodule="$(gettext "submodule")"
-			if test $mod_dst = 160000
-			then
-				echo "* $display_name $sha1_abbr_src($blob)->$sha1_abbr_dst($submodule)$total_commits:"
-			else
-				echo "* $display_name $sha1_abbr_src($submodule)->$sha1_abbr_dst($blob)$total_commits:"
-			fi
-		else
-			echo "* $display_name $sha1_abbr_src...$sha1_abbr_dst$total_commits:"
-		fi
-		if test -n "$errmsg"
-		then
-			# Don't give error msg for modification whose dst is not submodule
-			# i.e. deleted or changed to blob
-			test $mod_dst = 160000 && echo "$errmsg"
-		else
-			if test $mod_src = 160000 && test $mod_dst = 160000
-			then
-				limit=
-				test $summary_limit -gt 0 && limit="-$summary_limit"
-				GIT_DIR="$name/.git" \
-				git log $limit --pretty='format:  %m %s' \
-				--first-parent $sha1_src...$sha1_dst
-			elif test $mod_dst = 160000
-			then
-				GIT_DIR="$name/.git" \
-				git log --pretty='format:  > %s' -1 $sha1_dst
-			else
-				GIT_DIR="$name/.git" \
-				git log --pretty='format:  < %s' -1 $sha1_src
-			fi
-			echo
-		fi
-		echo
-	done
 }
 #
 # List all submodules, prefixed with:
-- 
2.13.0

Re: [GSoC][PATCH v2 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Christian Couder]

On Sun, Jul 30, 2017 at 12:23 AM, Prathamesh Chavan <pc44800@gmail.com> wrote:

> +static int module_summary(int argc, const char **argv, const char *prefix)
> +{
> +       struct summary_cb info = SUMMARY_CB_INIT;
> +       int cached = 0;
> +       char *diff_cmd = "diff-index";
> +       int for_status = 0;
> +       int quiet = 0;
> +       int files = 0;
> +       int summary_limits = -1;
> +       struct child_process cp_rev = CHILD_PROCESS_INIT;
> +       char *head;
> +       struct strbuf sb = STRBUF_INIT;
> +       int ret;
> +
> +       struct option module_summary_options[] = {
> +               OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
> +               OPT_BOOL(0, "cached", &cached, N_("Use the commit stored in the index instead of the submodule HEAD")),
> +               OPT_BOOL(0, "files", &files, N_("To compares the commit in the index with that in the submodule HEAD")),
> +               OPT_BOOL(0, "for-status", &for_status, N_("Skip submodules with 'all' ignore_config value")),
> +               OPT_INTEGER('n', "summary-limits", &summary_limits, N_("Limit the summary size")),
> +               OPT_END()
> +       };
> +
> +       const char *const git_submodule_helper_usage[] = {
> +               N_("git submodule--helper summary [<options>] [--] [<path>]"),
> +               NULL
> +       };
> +
> +       argc = parse_options(argc, argv, prefix, module_summary_options,
> +                            git_submodule_helper_usage, 0);
> +
> +       if (!summary_limits)
> +               return 0;
> +
> +       cp_rev.git_cmd = 1;
> +       argv_array_pushl(&cp_rev.args, "rev-parse", "-q", "--verify",
> +                        argc ? argv[0] : "HEAD", NULL);
> +
> +       if (!capture_command(&cp_rev, &sb, 0)) {
> +               strbuf_strip_suffix(&sb, "\n");
> +               if (argc) {
> +                       argv++;
> +                       argc--;
> +               }
> +       } else if (!argc || !strcmp(argv[0], "HEAD")) {
> +               /* before the first commit: compare with an empty tree */
> +               struct stat st;
> +               struct object_id oid;
> +               if (fstat(0, &st) < 0 || index_fd(oid.hash, 0, &st, 2, prefix, 3))
> +                       die("Unable to add %s to database", oid.hash);
> +               strbuf_addstr(&sb, oid_to_hex(&oid));
> +               if (argc) {
> +                       argv++;
> +                       argc--;
> +               }
> +       } else {
> +               strbuf_addstr(&sb, "HEAD");
> +       }
> +
> +       head = strbuf_detach(&sb, NULL);

I am not sure this "head" variable is really needed.

> +       if (files) {
> +               if (cached)
> +                       die(_("The --cached option cannot be used with the --files option"));
> +               diff_cmd = "diff-files";
> +
> +               free(head);
> +
> +               head = NULL;

If "head" isn't used, "strbuf_reset(&sb)" could be used instead.
If "head" is still needed, "FREE_AND_NULL(head)" could be used.

> +       }
> +
> +       info.argc = argc;
> +       info.argv = argv;
> +       info.prefix = prefix;
> +       info.cached = !!cached;
> +       info.for_status = !!for_status;
> +       info.quiet = quiet;
> +       info.files = files;
> +       info.summary_limits = summary_limits;
> +       info.diff_cmd = diff_cmd;
> +
> +       ret = compute_summary_module_list(head, &info);
> +       if (head)
> +               free(head);

"sb.buf" could be passed to compute_summary_module_list() instead of
"head". In this case that function should check that head is not an
empty string before using it.

If "head" is not used then strbuf_release(&sb) can be used to free any
memory sb still holds.
If "head" is still used, "if (head)" can be removed before
"free(head)" as free() already checks if its argument is NULL.

> +       return ret;
> +

Spurious new line.

> +}

Re: [GSoC][PATCH v2 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

On Sun, Jul 30, 2017 at 10:58 AM, Christian Couder
<christian.couder@gmail.com> wrote:
> On Sun, Jul 30, 2017 at 12:23 AM, Prathamesh Chavan <pc44800@gmail.com> wrote:
>
>> +static int module_summary(int argc, const char **argv, const char *prefix)
>> +{
>> +       struct summary_cb info = SUMMARY_CB_INIT;
>> +       int cached = 0;
>> +       char *diff_cmd = "diff-index";
>> +       int for_status = 0;
>> +       int quiet = 0;
>> +       int files = 0;
>> +       int summary_limits = -1;
>> +       struct child_process cp_rev = CHILD_PROCESS_INIT;
>> +       char *head;
>> +       struct strbuf sb = STRBUF_INIT;
>> +       int ret;
>> +
>> +       struct option module_summary_options[] = {
>> +               OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
>> +               OPT_BOOL(0, "cached", &cached, N_("Use the commit stored in the index instead of the submodule HEAD")),
>> +               OPT_BOOL(0, "files", &files, N_("To compares the commit in the index with that in the submodule HEAD")),
>> +               OPT_BOOL(0, "for-status", &for_status, N_("Skip submodules with 'all' ignore_config value")),
>> +               OPT_INTEGER('n', "summary-limits", &summary_limits, N_("Limit the summary size")),
>> +               OPT_END()
>> +       };
>> +
>> +       const char *const git_submodule_helper_usage[] = {
>> +               N_("git submodule--helper summary [<options>] [--] [<path>]"),
>> +               NULL
>> +       };
>> +
>> +       argc = parse_options(argc, argv, prefix, module_summary_options,
>> +                            git_submodule_helper_usage, 0);
>> +
>> +       if (!summary_limits)
>> +               return 0;
>> +
>> +       cp_rev.git_cmd = 1;
>> +       argv_array_pushl(&cp_rev.args, "rev-parse", "-q", "--verify",
>> +                        argc ? argv[0] : "HEAD", NULL);
>> +
>> +       if (!capture_command(&cp_rev, &sb, 0)) {
>> +               strbuf_strip_suffix(&sb, "\n");
>> +               if (argc) {
>> +                       argv++;
>> +                       argc--;
>> +               }
>> +       } else if (!argc || !strcmp(argv[0], "HEAD")) {
>> +               /* before the first commit: compare with an empty tree */
>> +               struct stat st;
>> +               struct object_id oid;
>> +               if (fstat(0, &st) < 0 || index_fd(oid.hash, 0, &st, 2, prefix, 3))
>> +                       die("Unable to add %s to database", oid.hash);
>> +               strbuf_addstr(&sb, oid_to_hex(&oid));
>> +               if (argc) {
>> +                       argv++;
>> +                       argc--;
>> +               }
>> +       } else {
>> +               strbuf_addstr(&sb, "HEAD");
>> +       }
>> +
>> +       head = strbuf_detach(&sb, NULL);
>
> I am not sure this "head" variable is really needed.
>
>> +       if (files) {
>> +               if (cached)
>> +                       die(_("The --cached option cannot be used with the --files option"));
>> +               diff_cmd = "diff-files";
>> +
>> +               free(head);
>> +
>> +               head = NULL;
>
> If "head" isn't used, "strbuf_reset(&sb)" could be used instead.
> If "head" is still needed, "FREE_AND_NULL(head)" could be used.

Thank you for reviewing this patch.
As suggested, here we can remove the variable head, and instead use
the strbuf struct.
But in the above lines, along with strbuf_reset(&sb), later we are
also required to set
sb.buf to NULL.

>
>> +       }
>> +
>> +       info.argc = argc;
>> +       info.argv = argv;
>> +       info.prefix = prefix;
>> +       info.cached = !!cached;
>> +       info.for_status = !!for_status;
>> +       info.quiet = quiet;
>> +       info.files = files;
>> +       info.summary_limits = summary_limits;
>> +       info.diff_cmd = diff_cmd;
>> +
>> +       ret = compute_summary_module_list(head, &info);

we may even remove the variable ret, but passing strbuf_detach(&sb, NULL) here
to the function compute_summary_module_list(), and then later on free(head) at
the end of the function compute_summary_module_list().

Thanks,
Prathamesh Chavan

[GSoC][PATCH v2 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
    superproject to the mount point of the submodule.
    In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
    case the path is equal to the relative path from $pwd to the
    submodules working directory. When following this model,
    the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 git-submodule.sh             |  1 -
 t/t7407-submodule-foreach.sh | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a427ddafd..493a64372 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
 				prefix="$prefix$sm_path/"
 				sanitize_submodule_env
 				cd "$sm_path" &&
-				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
 				# we make $path available to scripts ...
 				path=$sm_path &&
 				if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-../sub1-$sub1sha1
+$pwd/clone-foo1-sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-../sub3-$sub3sha1
+$pwd/clone-foo3-sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
@@ -196,6 +196,38 @@ test_expect_success 'test messages from "foreach --recursive" from subdirectory'
 	) &&
 	test_i18ncmp expect actual
 '
+sub1sha1=$(cd clone2/sub1 && git rev-parse HEAD)
+sub2sha1=$(cd clone2/sub2 && git rev-parse HEAD)
+sub3sha1=$(cd clone2/sub3 && git rev-parse HEAD)
+nested1sha1=$(cd clone2/nested1 && git rev-parse HEAD)
+nested2sha1=$(cd clone2/nested1/nested2 && git rev-parse HEAD)
+nested3sha1=$(cd clone2/nested1/nested2/nested3 && git rev-parse HEAD)
+submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEAD)
+
+cat >expect <<EOF
+Entering '../nested1'
+$pwd/clone2-nested1-nested1-$nested1sha1
+Entering '../nested1/nested2'
+$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+Entering '../nested1/nested2/nested3'
+$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+Entering '../nested1/nested2/nested3/submodule'
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+Entering '../sub1'
+$pwd/clone2-foo1-sub1-$sub1sha1
+Entering '../sub2'
+$pwd/clone2-foo2-sub2-$sub2sha1
+Entering '../sub3'
+$pwd/clone2-foo3-sub3-$sub3sha1
+EOF
+
+test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
+	(
+		cd clone2/untracked &&
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+	) &&
+	test_i18ncmp expect actual
+'
 
 cat > expect <<EOF
 nested1-nested1
-- 
2.13.0

[GSoC][PATCH v2 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
This patch is same as its previous version.
Although here I'll like to add a point that we aim to slowly drop the support
of the variable 'path'.

 Documentation/git-submodule.txt | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] <command>::
 	Evaluates an arbitrary shell command in each checked out submodule.
-	The command has access to the variables $name, $path, $sha1 and
+	The command has access to the variables $name, $sm_path, $sha1 and
 	$toplevel:
 	$name is the name of the relevant submodule section in `.gitmodules`,
-	$path is the name of the submodule directory relative to the
-	superproject, $sha1 is the commit as recorded in the superproject,
-	and $toplevel is the absolute path to the top-level of the superproject.
+	$sm_path is the path of the submodule as recorded in the superproject,
+	$sha1 is the commit as recorded in the superproject, and
+	$toplevel is the absolute path to the top-level of the superproject.
+	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+	variable is now a deprecated synonym of '$sm_path' variable.
 	Any submodules defined in the superproject but not checked out are
 	ignored by this command. Unless given `--quiet`, foreach prints the name
 	of each submodule before evaluating the command.
-- 
2.13.0

[GSoC][PATCH v2 11/13] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] <command>::
 	$name is the name of the relevant submodule section in `.gitmodules`,
 	$sm_path is the path of the submodule as recorded in the superproject,
 	$sha1 is the commit as recorded in the superproject, and
-	$toplevel is the absolute path to the top-level of the superproject.
+	$toplevel is the absolute path to its superproject, such that
+	$toplevel/$sm_path is the absolute path of the submodule.
 	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
 	variable is now a deprecated synonym of '$sm_path' variable.
 	Any submodules defined in the superproject but not checked out are
-- 
2.13.0

[GSoC][PATCH v2 12/13] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:

* Spelling mistake in the commit message was corrected.

 Documentation/git-submodule.txt |  6 ++++--
 t/t7407-submodule-foreach.sh    | 22 +++++++++++-----------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] <command>::
 	Evaluates an arbitrary shell command in each checked out submodule.
-	The command has access to the variables $name, $sm_path, $sha1 and
-	$toplevel:
+	The command has access to the variables $name, $sm_path, $displaypath,
+	$sha1 and $toplevel:
 	$name is the name of the relevant submodule section in `.gitmodules`,
 	$sm_path is the path of the submodule as recorded in the superproject,
+	$displaypath contains the relative path from the current working
+	directory to the submodules root directory,
 	$sha1 is the commit as recorded in the superproject, and
 	$toplevel is the absolute path to its superproject, such that
 	$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-sub1-$sub1sha1
+$pwd/clone-foo1-sub1-../sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-sub3-$sub3sha1
+$pwd/clone-foo3-sub3-../sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
 	mkdir clone/sub &&
 	(
 		cd clone/sub &&
-		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+		git submodule foreach "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
 	) &&
 	test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <<EOF
 Entering '../nested1'
-$pwd/clone2-nested1-nested1-$nested1sha1
+$pwd/clone2-nested1-nested1-../nested1-$nested1sha1
 Entering '../nested1/nested2'
-$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+$pwd/clone2/nested1-nested2-nested2-../nested1/nested2-$nested2sha1
 Entering '../nested1/nested2/nested3'
-$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+$pwd/clone2/nested1/nested2-nested3-nested3-../nested1/nested2/nested3-$nested3sha1
 Entering '../nested1/nested2/nested3/submodule'
-$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-../nested1/nested2/nested3/submodule-$submodulesha1
 Entering '../sub1'
-$pwd/clone2-foo1-sub1-$sub1sha1
+$pwd/clone2-foo1-sub1-../sub1-$sub1sha1
 Entering '../sub2'
-$pwd/clone2-foo2-sub2-$sub2sha1
+$pwd/clone2-foo2-sub2-../sub2-$sub2sha1
 Entering '../sub3'
-$pwd/clone2-foo3-sub3-$sub3sha1
+$pwd/clone2-foo3-sub3-../sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
 	(
 		cd clone2/untracked &&
-		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
 	) &&
 	test_i18ncmp expect actual
 '
-- 
2.13.0

[GSoC][PATCH v2 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_submodule_list, which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule. This third function is a calling function that
takes care of running the command in that submodule, and recursively
perform the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute, generates the list of
submodules present in the current working tree.

The second function for_each_submodule_list traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule) is called for each entry.

The third function runcommand_in_submodule, generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the <command> of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The third function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input <command> of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmwill@google.com>
Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
---
In this new version, the following changes have been made:

* Comment style is improved in the function runcommand_in_submodule()

* Comment in added about why the variable "path" was exposed via args
  argv_array instead of exposing it via the env_array.

* This patch exposes the various variables when argc == 1 only, just
  for maintaining a faithful porting. You can also find discussion about
  the same at [1].

[1]: https://public-inbox.org/git/CAME+mvUSGAFbN5j-_hv7QpAS57hq4wgH+yZ7XJMPuyQN1gALaA@mail.gmail.com/

 builtin/submodule--helper.c | 136 ++++++++++++++++++++++++++++++++++++++++++++
 git-submodule.sh            |  39 +------------
 2 files changed, 137 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index d8bf16f1d..d5527aa93 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -772,6 +772,141 @@ static int module_name(int argc, const char **argv, const char *prefix)
 	return 0;
 }
 
+struct cb_foreach {
+	int argc;
+	const char **argv;
+	const char *prefix;
+	unsigned int quiet: 1;
+	unsigned int recursive: 1;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
+
+static void runcommand_in_submodule(const struct cache_entry *list_item,
+				    void *cb_data)
+{
+	struct cb_foreach *info = cb_data;
+	const struct submodule *sub;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	char *displaypath;
+
+	displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+	sub = submodule_from_path(null_sha1, list_item->name);
+
+	if (!sub)
+		die(_("No url found for submodule path '%s' in .gitmodules"),
+		      displaypath);
+
+	if (!is_submodule_populated_gently(list_item->name, NULL))
+		goto cleanup;
+
+	prepare_submodule_repo_env(&cp.env_array);
+
+	/*
+	 * For the purpose of executing <command> in the submodule,
+	 * separate shell is used for the purpose of running the
+	 * child process.
+	 */
+	cp.use_shell = 1;
+	cp.dir = list_item->name;
+
+	if (info->argc == 1) {
+		char *toplevel = xgetcwd();
+
+		argv_array_pushf(&cp.env_array, "name=%s", sub->name);
+		argv_array_pushf(&cp.env_array, "sm_path=%s", list_item->name);
+		argv_array_pushf(&cp.env_array, "displaypath=%s", displaypath);
+		argv_array_pushf(&cp.env_array, "sha1=%s",
+				 oid_to_hex(&list_item->oid));
+		argv_array_pushf(&cp.env_array, "toplevel=%s", toplevel);
+
+		/*
+		 * Since the path variable was accessible from the script
+		 * before porting, it is also made available after porting.
+		 * The environment variable "PATH" has a very special purpose
+		 * on windows. And since environment variables are
+		 * case-insensitive in windows, it interferes with the
+		 * existing PATH variable. Hence, to avoid that, we expose
+		 * path via the args argv_array and not via env_array.
+		 */
+		argv_array_pushf(&cp.args, "path=%s; %s",
+				 list_item->name, info->argv[0]);
+		free(toplevel);
+	} else {
+		argv_array_pushv(&cp.args, info->argv);
+	}
+
+	if (!info->quiet)
+		printf(_("Entering '%s'\n"), displaypath);
+
+	if (info->argv[0] && run_command(&cp))
+		die(_("run_command returned non-zero status for %s\n."),
+		      displaypath);
+
+	if (info->recursive) {
+		struct child_process cpr = CHILD_PROCESS_INIT;
+
+		cpr.git_cmd = 1;
+		cpr.dir = list_item->name;
+		prepare_submodule_repo_env(&cpr.env_array);
+
+		argv_array_pushl(&cpr.args, "--super-prefix", displaypath,
+				 "submodule--helper", "foreach", "--recursive",
+				 NULL);
+
+		if (info->quiet)
+			argv_array_push(&cpr.args, "--quiet");
+
+		argv_array_pushv(&cpr.args, info->argv);
+
+		if (run_command(&cpr))
+			die(_("run_command returned non-zero status while"
+			      "recursing in the nested submodules of %s\n."),
+			      displaypath);
+	}
+
+cleanup:
+	free(displaypath);
+}
+
+static int module_foreach(int argc, const char **argv, const char *prefix)
+{
+	struct cb_foreach info;
+	struct pathspec pathspec;
+	struct module_list list = MODULE_LIST_INIT;
+	int quiet = 0;
+	int recursive = 0;
+
+	struct option module_foreach_options[] = {
+		OPT__QUIET(&quiet, N_("Suppress output of entering each submodule command")),
+		OPT_BOOL(0, "recursive", &recursive,
+			 N_("Recurse into nested submodules")),
+		OPT_END()
+	};
+
+	const char *const git_submodule_helper_usage[] = {
+		N_("git submodule--helper foreach [--quiet] [--recursive] <command>"),
+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, module_foreach_options,
+			     git_submodule_helper_usage, PARSE_OPT_KEEP_UNKNOWN);
+
+	if (module_list_compute(0, NULL, prefix, &pathspec, &list) < 0)
+		BUG("module_list_compute should not choke on empty pathspec");
+
+	info.argc = argc;
+	info.argv = argv;
+	info.prefix = prefix;
+	info.quiet = !!quiet;
+	info.recursive = !!recursive;
+
+	gitmodules_config();
+	for_each_submodule_list(list, runcommand_in_submodule, &info);
+
+	return 0;
+}
+
 struct module_cb {
 	unsigned int mod_src;
 	unsigned int mod_dst;
@@ -2217,6 +2352,7 @@ static struct cmd_struct commands[] = {
 	{"resolve-relative-url", resolve_relative_url, 0},
 	{"resolve-relative-url-test", resolve_relative_url_test, 0},
 	{"print-name-rev", print_name_rev, 0},
+	{"foreach", module_foreach, SUPPORT_SUPER_PREFIX},
 	{"init", module_init, SUPPORT_SUPER_PREFIX},
 	{"status", module_status, SUPPORT_SUPER_PREFIX},
 	{"print-default-remote", print_default_remote, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index 493a64372..e25b2c613 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -298,44 +298,7 @@ cmd_foreach()
 		shift
 	done
 
-	toplevel=$(pwd)
-
-	# dup stdin so that it can be restored when running the external
-	# command in the subshell (and a recursive call to this function)
-	exec 3<&0
-
-	{
-		git submodule--helper list --prefix "$wt_prefix" ||
-		echo "#unmatched" $?
-	} |
-	while read -r mode sha1 stage sm_path
-	do
-		die_if_unmatched "$mode" "$sha1"
-		if test -e "$sm_path"/.git
-		then
-			displaypath=$(git submodule--helper relative-path "$prefix$sm_path" "$wt_prefix")
-			say "$(eval_gettext "Entering '\$displaypath'")"
-			name=$(git submodule--helper name "$sm_path")
-			(
-				prefix="$prefix$sm_path/"
-				sanitize_submodule_env
-				cd "$sm_path" &&
-				# we make $path available to scripts ...
-				path=$sm_path &&
-				if test $# -eq 1
-				then
-					eval "$1"
-				else
-					"$@"
-				fi &&
-				if test -n "$recursive"
-				then
-					cmd_foreach "--recursive" "$@"
-				fi
-			) <&3 3<&- ||
-			die "$(eval_gettext "Stopping at '\$displaypath'; script returned non-zero status.")"
-		fi
-	done
+	git ${wt_prefix:+-C "$wt_prefix"} ${prefix:+--super-prefix "$prefix"} submodule--helper foreach ${GIT_QUIET:+--quiet} ${recursive:+--recursive} "$@"
 }
 
 #
-- 
2.13.0

Re: [GSoC][PATCH v2 00/13] Update: Week 10

[Brandon Williams]

On 07/30, Prathamesh Chavan wrote:
> Thank you Brandon Williams <bmwill@google.com> for reviewing the previous
> patch series.
> Also, I'm sorry for repling late to your reviews. The main reason was
> to give sufficient time to prepare the next version of each patch as
> suggested.

No worries, things take time.  That and I was busy most of last week
anyway :)

> The changes made in each patch are enlisted in the patch itself.
> 
> Complete build report of this work is available at: [1]
> Branch: week-10
> Build #142
> 
> Also, I have push the work on github as well and can be checked out at: [2]
> 
> [1]: https://travis-ci.org/pratham-pc/git/builds
> [2]: https://github.com/pratham-pc/git/commits/week-10
> 
> Prathamesh Chavan (13):
>   submodule--helper: introduce get_submodule_displaypath()
>   submodule--helper: introduce for_each_submodule_list()
>   submodule: port set_name_rev() from shell to C
>   submodule: port submodule subcommand 'status' from shell to C
>   submodule: port submodule subcommand 'sync' from shell to C
>   submodule: port submodule subcommand 'deinit' from shell to C
>   diff: change scope of the function count_lines()
>   submodule: port submodule subcommand 'summary' from shell to C
>   submodule foreach: correct '$path' in nested submodules from a
>     subdirectory
>   submodule foreach: document '$sm_path' instead of '$path'
>   submodule foreach: clarify the '$toplevel' variable documentation
>   submodule foreach: document variable '$displaypath'
>   submodule: port submodule subcommand 'foreach' from shell to C
> 
>  Documentation/git-submodule.txt |   15 +-
>  builtin/submodule--helper.c     | 1186 ++++++++++++++++++++++++++++++++++++++-
>  diff.c                          |    2 +-
>  diff.h                          |    1 +
>  git-submodule.sh                |  394 +------------
>  t/t7407-submodule-foreach.sh    |   38 +-
>  6 files changed, 1218 insertions(+), 418 deletions(-)
> 
> -- 
> 2.13.0
> 

-- 
Brandon Williams

[GSoC][PATCH 00/13] Update: Week-11

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller <sbeller@google.com>
Christian Couder <christian.couder@gmail.com>

UPDATES:

Following are the updates about my ongoing project:

* Following patches were updated after the previous reviews:
  - set_name_rev()
  submodule subcommands:
  - status
  - sync
  - deinit
  - summary
  - foreach

* Reviews from both Christian Couder <christian.couder@gmail.com> and
  Brandon Williams <bmwill@google.com> helped in improvising these patches
  and their suggestions were implemented.

* Porting of submodule subcommand add is still underway. Its progess can be
  viewed at [2].

PLAN FOR WEEK-12 (1 August 2017 to 7 August 2017):

* summary: One of the problems pointed out by Brandon this week was that
  the function print_submodule_summary() was too big to keep track of
  all the things that are happening. Hence, I will be splitting the
  function into smaller functions.

* displaypath: There is some confusion produced with the way the
  value of displaypath is being generated, using super-prefix. [3]
  Via having discussion on this, I'll try to resolve the issues
  regarding it. In the patches following the update, I have addressed
  this issue as well.

* add: Porting of this subcommand is still underway and will be working
  on to completely port this subcommand.

A complete build report of these series of patches is available at: [4].
Build #145
Branch: week-11

The work is push on github and is available at: [5].

[1]: https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1    L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: https://public-inbox.org/git/20170724213028.GB92874@google.com/
[4]: https://travis-ci.org/pratham-pc/git/builds/
[5]: https://github.com/pratham-pc/git/commits/week-11

  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
    subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c     | 1175 ++++++++++++++++++++++++++++++++++++++-
 diff.c                          |    2 +-
 diff.h                          |    1 +
 git-submodule.sh                |  394 +------------
 t/t7407-submodule-foreach.sh    |   38 +-
 6 files changed, 1207 insertions(+), 418 deletions(-)

-- 
2.13.0

[GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
    superproject to the mount point of the submodule.
    In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
    case the path is equal to the relative path from $pwd to the
    submodules working directory. When following this model,
    the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 git-submodule.sh             |  1 -
 t/t7407-submodule-foreach.sh | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a427ddafd..493a64372 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
 				prefix="$prefix$sm_path/"
 				sanitize_submodule_env
 				cd "$sm_path" &&
-				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
 				# we make $path available to scripts ...
 				path=$sm_path &&
 				if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-../sub1-$sub1sha1
+$pwd/clone-foo1-sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-../sub3-$sub3sha1
+$pwd/clone-foo3-sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
@@ -196,6 +196,38 @@ test_expect_success 'test messages from "foreach --recursive" from subdirectory'
 	) &&
 	test_i18ncmp expect actual
 '
+sub1sha1=$(cd clone2/sub1 && git rev-parse HEAD)
+sub2sha1=$(cd clone2/sub2 && git rev-parse HEAD)
+sub3sha1=$(cd clone2/sub3 && git rev-parse HEAD)
+nested1sha1=$(cd clone2/nested1 && git rev-parse HEAD)
+nested2sha1=$(cd clone2/nested1/nested2 && git rev-parse HEAD)
+nested3sha1=$(cd clone2/nested1/nested2/nested3 && git rev-parse HEAD)
+submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEAD)
+
+cat >expect <<EOF
+Entering '../nested1'
+$pwd/clone2-nested1-nested1-$nested1sha1
+Entering '../nested1/nested2'
+$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+Entering '../nested1/nested2/nested3'
+$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+Entering '../nested1/nested2/nested3/submodule'
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+Entering '../sub1'
+$pwd/clone2-foo1-sub1-$sub1sha1
+Entering '../sub2'
+$pwd/clone2-foo2-sub2-$sub2sha1
+Entering '../sub3'
+$pwd/clone2-foo3-sub3-$sub3sha1
+EOF
+
+test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
+	(
+		cd clone2/untracked &&
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+	) &&
+	test_i18ncmp expect actual
+'
 
 cat > expect <<EOF
 nested1-nested1
-- 
2.13.0

[GSoC][PATCH 00/13] Update: Week-12

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller <sbeller@google.com>
Christian Couder <christian.couder@gmail.com>

UPDATES:

Following are the updates about my ongoing project:

* Following patches were updated after the previous reviews:
  submodule subcommands:
  - deinit
  - summary
  - foreach

* summary: the function print_submodule_summary() is split-up
  into two separate functions: generate_submodule_summary()
  and print_summary().

* porting of submodule subcommand 'add' is completed and I have
  started with debugging ported function. Currently, the
  entire function cmd_add() is ported to the function
  module_add() in C. Soon, its first patch will be floated
  here as well once debugging is completed. Its progress can be
  viewed at [2].

* displaypath: Last week, there was some confusion produced
  with the way, the value of displaypath is being generated,
  which led to some discussion, which is available at: [3].

PLAN FOR WEEK-13 (8 August 2017 to 14 August 2017):

* patches: IMO, the patches till deinit are reviewed many times,
  and hence will try to get at least these patches merged.

* add: As this subcommand is widely used in the test suite, there
  are many tests this ported function is failing at. Hence,
  debugging the subcommand would be another task for the next week.

* deinit: A bug was identified by Stefan in the last patch-series.
  its details are available at: [4]
  Currenlty, the bug was handled by adding a NEEDSWORK tagged
  comment as suggest. If possible, I will also start working
  on debugging the issue asap.

A complete build report of these series of patches is available at: [5].
Build #151
Branch: week-12

The work is pushed on Github and is available at: [6].

[1]: https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: https://public-inbox.org/git/CAME+mvXsh53kLJ4se4uKY=SJcvSbHtEZQ6K2CgAPs=1wxUxk1A@mail.gmail.com/
[4]: https://public-inbox.org/git/CAGZ79kbyyR54me_+wQDZRrikqKTp_a98yozVfr8P85QHfyyy=Q@mail.gmail.com/
[5]: https://travis-ci.org/pratham-pc/git/builds/
[6]: https://github.com/pratham-pc/git/commits/week-12

Prathamesh Chavan (13):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
    subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c     | 1190 ++++++++++++++++++++++++++++++++++++++-
 diff.c                          |    2 +-
 diff.h                          |    1 +
 git-submodule.sh                |  396 +------------
 t/t7407-submodule-foreach.sh    |   38 +-
 6 files changed, 1222 insertions(+), 420 deletions(-)

-- 
2.13.0

[GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
    superproject to the mount point of the submodule.
    In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
    case the path is equal to the relative path from $pwd to the
    submodules working directory. When following this model,
    the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44800@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 git-submodule.sh             |  1 -
 t/t7407-submodule-foreach.sh | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index ec57d6528..4b7da2fc1 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
 				prefix="$prefix$sm_path/"
 				sanitize_submodule_env
 				cd "$sm_path" &&
-				sm_path=$(git submodule--helper relative-path "$sm_path" "$wt_prefix") &&
 				# we make $path available to scripts ...
 				path=$sm_path &&
 				if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <<EOF
 Entering '../sub1'
-$pwd/clone-foo1-../sub1-$sub1sha1
+$pwd/clone-foo1-sub1-$sub1sha1
 Entering '../sub3'
-$pwd/clone-foo3-../sub3-$sub3sha1
+$pwd/clone-foo3-sub3-$sub3sha1
 EOF
 
 test_expect_success 'test "submodule foreach" from subdirectory' '
@@ -196,6 +196,38 @@ test_expect_success 'test messages from "foreach --recursive" from subdirectory'
 	) &&
 	test_i18ncmp expect actual
 '
+sub1sha1=$(cd clone2/sub1 && git rev-parse HEAD)
+sub2sha1=$(cd clone2/sub2 && git rev-parse HEAD)
+sub3sha1=$(cd clone2/sub3 && git rev-parse HEAD)
+nested1sha1=$(cd clone2/nested1 && git rev-parse HEAD)
+nested2sha1=$(cd clone2/nested1/nested2 && git rev-parse HEAD)
+nested3sha1=$(cd clone2/nested1/nested2/nested3 && git rev-parse HEAD)
+submodulesha1=$(cd clone2/nested1/nested2/nested3/submodule && git rev-parse HEAD)
+
+cat >expect <<EOF
+Entering '../nested1'
+$pwd/clone2-nested1-nested1-$nested1sha1
+Entering '../nested1/nested2'
+$pwd/clone2/nested1-nested2-nested2-$nested2sha1
+Entering '../nested1/nested2/nested3'
+$pwd/clone2/nested1/nested2-nested3-nested3-$nested3sha1
+Entering '../nested1/nested2/nested3/submodule'
+$pwd/clone2/nested1/nested2/nested3-submodule-submodule-$submodulesha1
+Entering '../sub1'
+$pwd/clone2-foo1-sub1-$sub1sha1
+Entering '../sub2'
+$pwd/clone2-foo2-sub2-$sub2sha1
+Entering '../sub3'
+$pwd/clone2-foo3-sub3-$sub3sha1
+EOF
+
+test_expect_success 'test "submodule foreach --recursive" from subdirectory' '
+	(
+		cd clone2/untracked &&
+		git submodule foreach --recursive "echo \$toplevel-\$name-\$sm_path-\$sha1" >../../actual
+	) &&
+	test_i18ncmp expect actual
+'
 
 cat > expect <<EOF
 nested1-nested1
-- 
2.13.0