repo: declare the repo command

Currently, `git rev-parse` covers a wide range of functionality not
directly related to parsing revisions, as its name suggests. Over time,
many features like parsing datestrings, options, paths, and others
were added to it because there wasn't a more appropriate command
to place them.

Create a new Git command called `repo`. `git repo` will be the main
command for obtaining the information about a repository (such as
metadata and metrics).

Also declare a subcommand for `repo` called `info`. `git repo info`
will bring the functionality of retrieving repository-related
information currently returned by `rev-parse`.

Add the required documentation and build changes to enable usage of
this subcommand.

Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Justin Tobler <jltobler@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

.gitignore

@@ -139,6 +139,7 @@
 /git-repack
 /git-replace
 /git-replay
+/git-repo
 /git-request-pull
 /git-rerere
 /git-reset

Documentation/git-repo.adoc

@@ -0,0 +1,32 @@
+git-repo(1)
+===========
+
+NAME
+----
+git-repo - Retrieve information about the repository
+
+SYNOPSIS
+--------
+[synopsis]
+git repo info [<key>...]
+
+DESCRIPTION
+-----------
+Retrieve information about the repository.
+
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
+COMMANDS
+--------
+`info [<key>...]`::
+	Retrieve metadata-related information about the current repository. Only
+	the requested data will be returned based on their keys (see "INFO KEYS"
+	section below).
+
+SEE ALSO
+--------
+linkgit:git-rev-parse[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite

Documentation/meson.build

@@ -116,6 +116,7 @@ manpages = {
   'git-repack.adoc' : 1,
   'git-replace.adoc' : 1,
   'git-replay.adoc' : 1,
+  'git-repo.adoc' : 1,
   'git-request-pull.adoc' : 1,
   'git-rerere.adoc' : 1,
   'git-reset.adoc' : 1,

Makefile

@@ -1308,6 +1308,7 @@ BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/repack.o
 BUILTIN_OBJS += builtin/replace.o
 BUILTIN_OBJS += builtin/replay.o
+BUILTIN_OBJS += builtin/repo.o
 BUILTIN_OBJS += builtin/rerere.o
 BUILTIN_OBJS += builtin/reset.o
 BUILTIN_OBJS += builtin/rev-list.o

builtin.h

@@ -216,6 +216,7 @@ int cmd_remote_ext(int argc, const char **argv, const char *prefix, struct repos
 int cmd_remote_fd(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_repack(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_replay(int argc, const char **argv, const char *prefix, struct repository *repo);
+int cmd_repo(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_rerere(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_reset(int argc, const char **argv, const char *prefix, struct repository *repo);
 int cmd_restore(int argc, const char **argv, const char *prefix, struct repository *repo);

builtin/repo.c

@@ -0,0 +1,27 @@
+#include "builtin.h"
+#include "parse-options.h"
+
+static const char *const repo_usage[] = {
+	"git repo info [<key>...]",
+	NULL
+};
+
+static int repo_info(int argc UNUSED, const char **argv UNUSED,
+		     const char *prefix UNUSED, struct repository *repo UNUSED)
+{
+	return 0;
+}
+
+int cmd_repo(int argc, const char **argv, const char *prefix,
+	     struct repository *repo)
+{
+	parse_opt_subcommand_fn *fn = NULL;
+	struct option options[] = {
+		OPT_SUBCOMMAND("info", &fn, repo_info),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, options, repo_usage, 0);
+
+	return fn(argc, argv, prefix, repo);
+}

command-list.txt

@@ -164,6 +164,7 @@ git-remote                              ancillarymanipulators           complete
 git-repack                              ancillarymanipulators           complete
 git-replace                             ancillarymanipulators           complete
 git-replay                              plumbingmanipulators
+git-repo                                plumbinginterrogators
 git-request-pull                        foreignscminterface             complete
 git-rerere                              ancillaryinterrogators
 git-reset                               mainporcelain           history

git.c

@@ -611,6 +611,7 @@ static struct cmd_struct commands[] = {
 	{ "repack", cmd_repack, RUN_SETUP },
 	{ "replace", cmd_replace, RUN_SETUP },
 	{ "replay", cmd_replay, RUN_SETUP },
+	{ "repo", cmd_repo, RUN_SETUP },
 	{ "rerere", cmd_rerere, RUN_SETUP },
 	{ "reset", cmd_reset, RUN_SETUP },
 	{ "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },

meson.build

@@ -645,6 +645,7 @@ builtin_sources = [
   'builtin/repack.c',
   'builtin/replace.c',
   'builtin/replay.c',
+  'builtin/repo.c',
   'builtin/rerere.c',
   'builtin/reset.c',
   'builtin/rev-list.c',