On 08-Jun-2021, at 18:02, Đoàn Trần Công Danh [off-list ref] wrote:

quoted

[...]
+static char *get_next_line(char *const begin, const char *const end)
+{
+	char *pos = begin;
+	while (pos != end && *pos++ != '\n');
+	return pos;
+}

On my first glance, this function looks like a reinvention of strchr(3).
Except that, this function also has a second parameter for "end".
Maybe it has a specical use-case?

quoted

+
+static void show_fetch_remotes(FILE *output, const char *sm_name, const char *git_dir_path)
+{
+	struct child_process cp_remote = CHILD_PROCESS_INIT;
+	struct strbuf sb_remote_out = STRBUF_INIT;
+
+	cp_remote.git_cmd = 1;
+	strvec_pushf(&cp_remote.env_array,
+		     "GIT_DIR=%s", git_dir_path);
+	strvec_push(&cp_remote.env_array, "GIT_WORK_TREE=.");
+	strvec_pushl(&cp_remote.args, "remote", "-v", NULL);
+	if (!capture_command(&cp_remote, &sb_remote_out, 0)) {
+		char *line;
+		char *begin = sb_remote_out.buf;
+		char *end = sb_remote_out.buf + sb_remote_out.len;
+		while (begin != end && (line = get_next_line(begin, end))) {

And this is the only use-case.  Because you also want to check if you
reached the last token or not.  I guess you really meant to write:

	while ((line = strchr(begin, '\n')) != NULL) {

Anyway, I would name the "line" variable as "nextline"

quoted

+			int namelen = 0, urllen = 0, taillen = 0;
+			char *name = parse_token(&begin, line, &namelen);
+			char *url = parse_token(&begin, line, &urllen);
+			char *tail = parse_token(&begin, line, &taillen);
+			if (!memcmp(tail, "(fetch)", 7))
+				fprintf(output, "  %.*s\t%.*s\n",
+					namelen, name, urllen, url);

I think this whole block is better replaced with strip_suffix_mem and
fprintf.

Overral I would replace the block inside capture_command with:

-----8<-----
	char *nextline;
	char *line = sb_remote_out.buf;
	while ((nextline = strchr(line, '\n')) != NULL) {
		size_t len = nextline - line;
		if (strip_suffix_mem(line, &len, "(fetch)"))
			fprintf(output, "  %.*s\n", (int)len, line);
		line = nextline + 1;
	}
---->8-----

And get rid of parse_token and get_next_line functions.

That looks much simpler. Thanks!

I realised that all the token parsing I do is not really necessary.
What I really want to do is "If this line ends with '(fetch)',
print it, but without the '(fetch)'", and I think your version
captures that succinctly.

quoted

+		}
+	}
+
+	strbuf_release(&sb_remote_out);
+}
+
+static int add_submodule(const struct add_data *add_data)
+{
+	char *submod_gitdir_path;
+	/* perhaps the path already exists and is already a git repo, else clone it */
+	if (is_directory(add_data->sm_path)) {
+		submod_gitdir_path = xstrfmt("%s/.git", add_data->sm_path);
+		if (is_directory(submod_gitdir_path) || file_exists(submod_gitdir_path))
+			printf(_("Adding existing path at '%s' to index\n"),
+			       add_data->sm_path);
+		else
+			die(_("'%s' already exists and is not a valid git repo"),
+			    add_data->sm_path);
+		free(submod_gitdir_path);
+	} else {
+		struct strvec clone_args = STRVEC_INIT;
+		struct child_process cp = CHILD_PROCESS_INIT;
+		submod_gitdir_path = xstrfmt(".git/modules/%s", add_data->sm_name);
+
+		if (is_directory(submod_gitdir_path)) {
+			if (!add_data->force) {
+				error(_("A git directory for '%s' is found "
+					"locally with remote(s):"), add_data->sm_name);

We don't capitalise first character of error message.
IOW, downcase "A git".

Got it.

Well, it's bug-for-bug with shell implementation, so it doesn't matter much, anyway.

While it is meant to be a faithful implementation, I think this
is a good opportunity to make minor style fixes.

quoted

+				show_fetch_remotes(stderr, add_data->sm_name,
+						   submod_gitdir_path);
+				fprintf(stderr,
+					_("If you want to reuse this local git "
+					  "directory instead of cloning again from\n"
+					  "  %s\n"
+					  "use the '--force' option. If the local git "
+					  "directory is not the correct repo\n"
+					  "or if you are unsure what this means, choose "
+					  "another name with the '--name' option.\n"),
+					add_data->realrepo);

Is there any reason we can't use "error" here?

The message in its entirety looks like this:

error: A git directory for 'test' is found locally with remote(s):
  origin	git@github.com:tfidfwastaken/abc.git
If you want to reuse this local git directory instead of cloning again from
  git@github.com:tfidfwastaken/test.git
use the '--force' option. If the local git directory is not the correct repo
or if you are unsure what this means, choose another name with the '--name' option.

Since the 'error:' is already there in the first line, having it
prepended before 'If you want to reuse...' felt redundant to me.

Besides, it's more of an informational message about what a user
can do next, rather than a message that signifies an error.

If there is a preferred convention or label for such messages,
I can use that. The shell version did not have any such thing though.

quoted

[...]
+	struct option options[] = {
+		OPT_STRING('b', "branch", &add_data.branch,
+			   N_("branch"),
+			   N_("branch of repository to checkout on cloning")),
+		OPT_STRING(0, "prefix", &add_data.prefix,
+			   N_("path"),
+			   N_("alternative anchor for relative paths")),
+		OPT_STRING(0, "path", &add_data.sm_path,
+			   N_("path"),
+			   N_("where the new submodule will be cloned to")),
+		OPT_STRING(0, "name", &add_data.sm_name,
+			   N_("string"),
+			   N_("name of the new submodule")),
+		OPT_STRING(0, "url", &add_data.realrepo,
+			   N_("string"),
+			   N_("url where to clone the submodule from")),
+		OPT_STRING(0, "reference", &add_data.reference_path,
+			   N_("repo"),
+			   N_("reference repository")),
+		OPT_BOOL(0, "dissociate", &dissociate,
+			 N_("use --reference only while cloning")),
+		OPT_INTEGER(0, "depth", &add_data.depth,
+			    N_("depth for shallow clones")),
+		OPT_BOOL(0, "progress", &progress,
+			 N_("force cloning progress")),
+		OPT_BOOL('f', "force", &force,
+			 N_("allow adding an otherwise ignored submodule path")),

We have OPT__FORCE, too.

Will switch over to that.

quoted

+		OPT__QUIET(&quiet, "Suppress output for cloning a submodule"),

And, please downcase "Suppress".

OK.

quoted

+		OPT_END()
+	};
+
+	const char *const usage[] = {
+		N_("git submodule--helper add-clone [--prefix=<path>] [--quiet] [--force] "
+		   "[--reference <repository>] [--depth <depth>] [-b|--branch <branch>]"
+		   "[--progress] [--dissociate] --url <url> --path <path> --name <name>"),

I think it's too crowded here, I guess it's better to write:

	N_("git submodule--helper add-clone [<options>...] --url <url> --path <path> --name <name>"),

OK. It shouldn't be an issue to shorten it, because this is not
user-facing, and is only ever used within 'cmd_add()'.

quoted

+		NULL
+	};
+
+	argc = parse_options(argc, argv, prefix, options, usage, 0);

From above usage, I think url, path, name is required, should we have a check for them, here?

We could. The reason why I was not too rigorous about this is
because I plan to eliminate the shell interface for this helper
eventually and call add-clone from within C, in the next few
patches.

But this is a small ask, and I can just add a quick check just
to be extra safe, so I'll do it.

quoted

+
+	add_data.progress = !!progress;
+	add_data.dissociate = !!dissociate;
+	add_data.force = !!force;
+	add_data.quiet = !!quiet;
+
+	if (add_submodule(&add_data))
+		return 1;
+
+	return 0;
+}
+
#define SUPPORT_SUPER_PREFIX (1<<0)

struct cmd_struct {

@@ -2757,6 +2955,7 @@ static struct cmd_struct commands[] = {

	{"list", module_list, 0},
	{"name", module_name, 0},
	{"clone", module_clone, 0},
+	{"add-clone", add_clone, 0},
	{"update-module-mode", module_update_module_mode, 0},
	{"update-clone", update_clone, 0},
	{"ensure-core-worktree", ensure_core_worktree, 0},

diff --git a/git-submodule.sh b/git-submodule.sh
index 4678378424..f71e1e5495 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh

@@ -241,43 +241,7 @@ cmd_add()

		die "$(eval_gettext "'$sm_name' is not a valid submodule name")"
	fi

-	# perhaps the path exists and is already a git repo, else clone it
-	if test -e "$sm_path"
-	then
-		if test -d "$sm_path"/.git || test -f "$sm_path"/.git
-		then
-			eval_gettextln "Adding existing repo at '\$sm_path' to the index"
-		else
-			die "$(eval_gettext "'\$sm_path' already exists and is not a valid git repo")"
-		fi
-
-	else
-		if test -d ".git/modules/$sm_name"
-		then
-			if test -z "$force"
-			then
-				eval_gettextln >&2 "A git directory for '\$sm_name' is found locally with remote(s):"
-				GIT_DIR=".git/modules/$sm_name" GIT_WORK_TREE=. git remote -v | grep '(fetch)' | sed -e s,^,"  ", -e s,' (fetch)',, >&2
-				die "$(eval_gettextln "\
-If you want to reuse this local git directory instead of cloning again from
-  \$realrepo
-use the '--force' option. If the local git directory is not the correct repo
-or you are unsure what this means choose another name with the '--name' option.")"
-			else
-				eval_gettextln "Reactivating local git directory for submodule '\$sm_name'."
-			fi
-		fi
-		git submodule--helper clone ${GIT_QUIET:+--quiet} ${progress:+"--progress"} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" ${reference:+"$reference"} ${dissociate:+"--dissociate"} ${depth:+"$depth"} || exit
-		(
-			sanitize_submodule_env
-			cd "$sm_path" &&
-			# ash fails to wordsplit ${branch:+-b "$branch"...}
-			case "$branch" in
-			'') git checkout -f -q ;;
-			?*) git checkout -f -q -B "$branch" "origin/$branch" ;;
-			esac
-		) || die "$(eval_gettext "Unable to checkout submodule '\$sm_path'")"
-	fi
+	git submodule--helper add-clone ${GIT_QUIET:+--quiet} ${force:+"--force"} ${progress:+"--progress"} ${branch:+--branch "$branch"} --prefix "$wt_prefix" --path "$sm_path" --name "$sm_name" --url "$realrepo" ${reference:+"$reference"} ${dissociate:+"--dissociate"} ${depth:+"$depth"} || exit
	git config submodule."$sm_name".url "$realrepo"

	git add --no-warn-embedded-repo $force "$sm_path" ||
-- 
2.31.1

-- 
Danh

Thanks for the comments!