From: Glen Choo <chooglen@google.com>
Date: Wed, 15 Jun 2022 04:01:44 GMT
Subject: Re: [PATCH v2 08/12] submodule--helper: report "submodule" as our name in "-h" output
Message-ID: <kl6lczfa60d3.fsf@chooglen-macbookpro.roam.corp.google.com>
In-Reply-To: <patch-v2-08.12-99ac52d810f-20220613T220150Z-avarab@gmail.com>


Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 574d6e0a79b..c2f55779cb1 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -286,7 +286,7 @@ static int module_list(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper list [--prefix=<path>] [<path>...]"),
> +		N_("git submodule list [--prefix=<path>] [<path>...]"),
>  		NULL
>  	};
> @@ -444,7 +444,7 @@ static int module_foreach(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper foreach [--quiet] [--recursive] [--] <command>"),
> +		N_("git submodule foreach [--quiet] [--recursive] [--] <command>"),
>  		NULL
>  	};
>  
> @@ -582,7 +582,7 @@ static int module_init(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper init [<options>] [<path>]"),
> +		N_("git submodule init [<options>] [<path>]"),
>  		NULL
>  	};
>  
> @@ -786,7 +786,7 @@ static int module_name(int argc, const char **argv, const char *prefix)
>  	const struct submodule *sub;
>  
>  	if (argc != 2)
> -		usage(_("git submodule--helper name <path>"));
> +		usage(_("git submodule name <path>"));
>  
>  	sub = submodule_from_path(the_repository, null_oid(), argv[1]);
>  
> @@ -1185,7 +1185,7 @@ static int module_summary(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper summary [<options>] [<commit>] [--] [<path>]"),
> +		N_("git submodule summary [<options>] [<commit>] [--] [<path>]"),
>  		NULL
>  	};
>  
> @@ -1349,7 +1349,7 @@ static int module_sync(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper sync [--quiet] [--recursive] [<path>]"),
> +		N_("git submodule sync [--quiet] [--recursive] [<path>]"),
>  		NULL
>  	};
>  
> @@ -1789,7 +1789,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper clone [--prefix=<path>] [--quiet] "
> +		N_("git submodule clone [--prefix=<path>] [--quiet] "
>  		   "[--reference <repository>] [--name <name>] [--depth <depth>] "
>  		   "[--single-branch] [--filter <filter-spec>] "
>  		   "--url <url> --path <path>"),
> @@ -2787,7 +2787,7 @@ static int absorb_git_dirs(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper absorbgitdirs [<options>] [<path>...]"),
> +		N_("git submodule absorbgitdirs [<options>] [<path>...]"),
>  		NULL
>  	};
>  
> @@ -2851,9 +2851,9 @@ static int module_config(int argc, const char **argv, const char *prefix)
>  		OPT_END()
>  	};
>  	const char *const git_submodule_helper_usage[] = {
> -		N_("git submodule--helper config <name> [<value>]"),
> -		N_("git submodule--helper config --unset <name>"),
> -		"git submodule--helper config --check-writeable",
> +		N_("git submodule config <name> [<value>]"),
> +		N_("git submodule config --unset <name>"),
> +		"git submodule config --check-writeable",
>  		NULL
>  	};
>  
> @@ -2892,7 +2892,7 @@ static int module_set_url(int argc, const char **argv, const char *prefix)
>  		OPT_END()
>  	};
>  	const char *const usage[] = {
> -		N_("git submodule--helper set-url [--quiet] <path> <newurl>"),
> +		N_("git submodule set-url [--quiet] <path> <newurl>"),
>  		NULL
>  	};
>  
> @@ -2931,8 +2931,8 @@ static int module_set_branch(int argc, const char **argv, const char *prefix)
>  		OPT_END()
>  	};
>  	const char *const usage[] = {
> -		N_("git submodule--helper set-branch [-q|--quiet] (-d|--default) <path>"),
> -		N_("git submodule--helper set-branch [-q|--quiet] (-b|--branch) <branch> <path>"),
> +		N_("git submodule set-branch [-q|--quiet] (-d|--default) <path>"),
> +		N_("git submodule set-branch [-q|--quiet] (-b|--branch) <branch> <path>"),
>  		NULL
>  	};
>  
> @@ -2973,7 +2973,7 @@ static int module_create_branch(int argc, const char **argv, const char *prefix)
>  		OPT_END()
>  	};
>  	const char *const usage[] = {
> -		N_("git submodule--helper create-branch [-f|--force] [--create-reflog] [-q|--quiet] [-t|--track] [-n|--dry-run] <name> <start-oid> <start-name>"),
> +		N_("git submodule create-branch [-f|--force] [--create-reflog] [-q|--quiet] [-t|--track] [-n|--dry-run] <name> <start-oid> <start-name>"),
>  		NULL
>  	};
>  
> @@ -3276,7 +3276,7 @@ static int module_add(int argc, const char **argv, const char *prefix)
>  	};
>  
>  	const char *const usage[] = {
> -		N_("git submodule--helper add [<options>] [--] <repository> [<path>]"),
> +		N_("git submodule add [<options>] [--] <repository> [<path>]"),
>  		NULL
>  	};

I don't feel positive about pretending to be "git submodule" when the
subcommand is internal-only. Such commands are only invoked as "git
submodule--helper foo" and we will probably never turn them into
external-facing "git submodule foo" [1]. Even if it is internal-only,
there is a debugging benefit to emitting a usage string with the
correct, non-user facing command name.

I admit it might be a bit confusing to have a mix of usage strings with
"submodule--helper" vs "submodule", but as long as we clearly label
which commands are user-facing and which aren't, it shouldn't be too
hard to maintain, e.g. this might just be a matter of adding comments to
the array of commands like:

  static struct cmd_struct commands[] = {
    /* User facing commands - pretend to be "git submodule" */
    {"name", module_name},
    {"add", module_add},
    [...]
    /* Internal-only commands */
    {"clone", module_clone},
    {"resolve-relative-url-test", resolve_relative_url_test},
    [...]
  };

Notably, even with this patch we still _kind of_ have 'pseudo usage
strings' that reference "git submodule--helper". These are just
internal-only commands that don't use the parse_options() API, e.g.

	if (argc < 3)
		die("submodule--helper push-check requires at least 2 arguments");

I think it's ok to leave them as-is, provided we also leave the other
internal-only commands as-is.

[1] For convenience, here is a list of all of the subcommands changed in
this patch and whether they are user-facing/internal-only:

User-facing                 Internal-only

- foreach                   - list
- init                      - name
- summary                   - clone
- sync                      - config
- absorbgitdirs             - create-branch
- set-url
- set-branch
- add