Subject: Re: [PATCH] submodule: implement `module_name` as a builtin helper

From: Junio C Hamano <[email-masked]>
Date: Fri, 07 Aug 2015 13:03:21 -0700

Stefan Beller <[email-masked]> writes:

> This incorporates the changes from Jens fixup! commit
> (which addresses all issues he pointed out).
>
> I agree this looks much cleaner. :)

The only thing I found somewhat questionable is where to call
gitmodules_config() from.  I think it is OK to do this at the
beginning of module_name(), at least for now, simply because the
other function module_list() does not need to.

When you rewrite sufficiently large parts of the scripted Porcelain
into C so that different pieces translated from the shell functions
directly call into each other, that may have to change, though.  I
do not think gitmodules_config() is designed to be called more than
once, and I expect module_name() would be called many times inside a
loop.

Other than that, this is a trivial refactoring (i.e. a new helper
function added to submodule.c can be used from an existing
open-coded logic in the same file, and then the same helper function
gains a new callsite in submodule--helper.c) that makes things
easier to read.

Thanks.

>  builtin/submodule--helper.c | 22 ++++++++++++++++++++++
>  git-submodule.sh            | 32 +++++++-------------------------
>  submodule.c                 | 19 ++++++++++++++-----
>  submodule.h                 |  1 +
>  4 files changed, 44 insertions(+), 30 deletions(-)
>
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index cb18ddf..bc37b74 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -5,6 +5,8 @@
>  #include "pathspec.h"
>  #include "dir.h"
>  #include "utf8.h"
> +#include "submodule.h"
> +#include "string-list.h"
>  
>  static char *ps_matched;
>  static const struct cache_entry **ce_entries;
> @@ -98,6 +100,23 @@ static int module_list(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +static int module_name(int argc, const char **argv, const char *prefix)
> +{
> +	const char *name;
> +
> +	if (argc != 1)
> +		usage("git submodule--helper module_name <path>\n");
> +
> +	gitmodules_config();
> +	name = submodule_name_for_path(argv[0]);
> +
> +	if (!name)
> +		die("No submodule mapping found in .gitmodules for path '%s'", argv[0]);
> +
> +	printf("%s\n", name);
> +	return 0;
> +}
> +
>  int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
>  {
>  	if (argc < 2)
> @@ -106,6 +125,9 @@ int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
>  	if (!strcmp(argv[1], "module_list"))
>  		return module_list(argc - 1, argv + 1, prefix);
>  
> +	if (!strcmp(argv[1], "module_name"))
> +		return module_name(argc - 2, argv + 2, prefix);
> +
>  usage:
>  	usage("git submodule--helper module_list\n");
>  }
> diff --git a/git-submodule.sh b/git-submodule.sh
> index af9ecef..e6ff38d 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -178,24 +178,6 @@ get_submodule_config () {
>  	printf '%s' "${value:-$default}"
>  }
>  
> -
> -#
> -# Map submodule path to submodule name
> -#
> -# $1 = path
> -#
> -module_name()
> -{
> -	# Do we have "submodule.<something>.path = $1" defined in .gitmodules file?
> -	sm_path="$1"
> -	re=$(printf '%s\n' "$1" | sed -e 's/[].[^$\\*]/\\&/g')
> -	name=$( git config -f .gitmodules --get-regexp '^submodule\..*\.path$' |
> -		sed -n -e 's|^submodule\.\(.*\)\.path '"$re"'$|\1|p' )
> -	test -z "$name" &&
> -	die "$(eval_gettext "No submodule mapping found in .gitmodules for path '\$sm_path'")"
> -	printf '%s\n' "$name"
> -}
> -
>  #
>  # Clone a submodule
>  #
> @@ -498,7 +480,7 @@ cmd_foreach()
>  		then
>  			displaypath=$(relative_path "$sm_path")
>  			say "$(eval_gettext "Entering '\$prefix\$displaypath'")"
> -			name=$(module_name "$sm_path")
> +			name=$(git submodule--helper module_name "$sm_path")
>  			(
>  				prefix="$prefix$sm_path/"
>  				clear_local_git_env
> @@ -554,7 +536,7 @@ cmd_init()
>  	while read mode sha1 stage sm_path
>  	do
>  		die_if_unmatched "$mode"
> -		name=$(module_name "$sm_path") || exit
> +		name=$(git submodule--helper module_name "$sm_path") || exit
>  
>  		displaypath=$(relative_path "$sm_path")
>  
> @@ -636,7 +618,7 @@ cmd_deinit()
>  	while read mode sha1 stage sm_path
>  	do
>  		die_if_unmatched "$mode"
> -		name=$(module_name "$sm_path") || exit
> +		name=$(git submodule--helper module_name "$sm_path") || exit
>  
>  		displaypath=$(relative_path "$sm_path")
>  
> @@ -758,7 +740,7 @@ cmd_update()
>  			echo >&2 "Skipping unmerged submodule $prefix$sm_path"
>  			continue
>  		fi
> -		name=$(module_name "$sm_path") || exit
> +		name=$(git submodule--helper module_name "$sm_path") || exit
>  		url=$(git config submodule."$name".url)
>  		branch=$(get_submodule_config "$name" branch master)
>  		if ! test -z "$update"
> @@ -1022,7 +1004,7 @@ cmd_summary() {
>  			# Respect the ignore setting for --for-status.
>  			if test -n "$for_status"
>  			then
> -				name=$(module_name "$sm_path")
> +				name=$(git submodule--helper module_name "$sm_path")
>  				ignore_config=$(get_submodule_config "$name" ignore none)
>  				test $status != A && test $ignore_config = all && continue
>  			fi
> @@ -1184,7 +1166,7 @@ cmd_status()
>  	while read mode sha1 stage sm_path
>  	do
>  		die_if_unmatched "$mode"
> -		name=$(module_name "$sm_path") || exit
> +		name=$(git submodule--helper module_name "$sm_path") || exit
>  		url=$(git config submodule."$name".url)
>  		displaypath=$(relative_path "$prefix$sm_path")
>  		if test "$stage" = U
> @@ -1261,7 +1243,7 @@ cmd_sync()
>  	while read mode sha1 stage sm_path
>  	do
>  		die_if_unmatched "$mode"
> -		name=$(module_name "$sm_path")
> +		name=$(git submodule--helper module_name "$sm_path")
>  		url=$(git config -f .gitmodules --get submodule."$name".url)
>  
>  		# Possibly a url relative to parent
> diff --git a/submodule.c b/submodule.c
> index 15e90d1..78d7616 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -686,6 +686,16 @@ static void calculate_changed_submodule_paths(void)
>  	initialized_fetch_ref_tips = 0;
>  }
>  
> +const char *submodule_name_for_path(const char *path)
> +{
> +	struct string_list_item *item;
> +	item = unsorted_string_list_lookup(&config_name_for_path, path);
> +	if (!item)
> +		return NULL;
> +
> +	return item->util;
> +}
> +
>  int fetch_populated_submodules(const struct argv_array *options,
>  			       const char *prefix, int command_line_option,
>  			       int quiet)
> @@ -693,7 +703,6 @@ int fetch_populated_submodules(const struct argv_array *options,
>  	int i, result = 0;
>  	struct child_process cp = CHILD_PROCESS_INIT;
>  	struct argv_array argv = ARGV_ARRAY_INIT;
> -	struct string_list_item *name_for_path;
>  	const char *work_tree = get_git_work_tree();
>  	if (!work_tree)
>  		goto out;
> @@ -723,10 +732,10 @@ int fetch_populated_submodules(const struct argv_array *options,
>  		if (!S_ISGITLINK(ce->ce_mode))
>  			continue;
>  
> -		name = ce->name;
> -		name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
> -		if (name_for_path)
> -			name = name_for_path->util;
> +		name = submodule_name_for_path(ce->name);
> +		if (!name)
> +			/* Not in .gitmodules, try the default name == path */
> +			name = ce->name;
>  
>  		default_argv = "yes";
>  		if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
> diff --git a/submodule.h b/submodule.h
> index 7beec48..fc7f8a6 100644
> --- a/submodule.h
> +++ b/submodule.h
> @@ -41,5 +41,6 @@ int find_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_nam
>  		struct string_list *needs_pushing);
>  int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name);
>  void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir);
> +const char *submodule_name_for_path(const char *path);
>  
>  #endif