Re: [GSoC][PATCH 4/5 v4] submodule: port submodule subcommand 'status' from shell to C

[Stefan Beller]

On Thu, Jul 13, 2017 at 1:05 PM, 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 
> Mentored-by: Stefan Beller 
> Signed-off-by: Prathamesh Chavan 
> ---
> In this new version of patch:
>
> Instead of using cmd_diff_files(), the process is optimized
> by using ce_match_stat().

Apart from this I have reviewed the patch and found it a faithful
conversion.

I am not an expert in the diff area  and wonder how
the cmd_diff_files functionality is achieved with just a stat call
and then comparing it to  ce_match_stat. 'Using "dirty" ignores
all changes to the work tree of submodules, only changes to the
commits stored in the superproject are shown.' So I'd have
expected ce->oid to be compared (is there an index entry differing,
i.e. more than one stage?)


> Also, the child_process running the command 'rev-parse --verify HEAD'
> is removed for optimization reasons, and instead head_ref_submodule()
> is used with callback function handle_submodule_head_ref().

Cool.

[GSoC][PATCH 4/5 v4] 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 
Mentored-by: Stefan Beller 
Signed-off-by: Prathamesh Chavan 
---
In this new version of patch:

Instead of using cmd_diff_files(), the process is optimized
by using ce_match_stat().

Also, the child_process running the command 'rev-parse --verify HEAD'
is removed for optimization reasons, and instead head_ref_submodule()
is used with callback function handle_submodule_head_ref().

The series differs from the complete weekly-update series as these patches
have been reviewed with mentors as well as on mailing list more no. of
times then the rest patches from the complete series, and hence
IMO, are ready for getting included. If not so, I would like to have
suggestions for improvising it.

The patches pass the complete test suite.

 builtin/submodule--helper.c | 146 
 git-submodule.sh|  49 +--
 2 files changed, 147 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 80f744407..9c1630495 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -560,6 +560,151 @@ 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(_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(_item->oid));
+   char *displaypath;
+   struct stat st;
+
+   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;
+   }
+
+   if (!lstat(list_item->name, ) && !ce_match_stat(list_item, , 0)) {
+   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, ))
+   die(_("could not resolve HEAD ref inside the"
+ "submodule '%s'"), list_item->name);
+   print_status(info, '+', list_item->name, sb.buf,
+displaypath);
+   strbuf_release();
+   } else {
+   

[GSoC][PATCH 4/5 v4] 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 
Mentored-by: Stefan Beller 
Signed-off-by: Prathamesh Chavan 
---
A NEEDSWORK tag was added at the two places where optimization
for future.

 builtin/submodule--helper.c | 154 
 git-submodule.sh|  49 +-
 2 files changed, 155 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 5884a9725..d67a97062 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -560,6 +560,159 @@ 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(_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 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(_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_initialized(list_item->name)) {
+   print_status(info, '-', list_item->name, sub_sha1, displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   /* NEEDSWORK: future optimization possible */
+   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 child_process cp = CHILD_PROCESS_INIT;
+   struct strbuf sb = STRBUF_INIT;
+
+   prepare_submodule_repo_env(_array);
+   cp.git_cmd = 1;
+   cp.dir = list_item->name;
+
+   argv_array_pushl(, "rev-parse",
+"--verify", "HEAD", NULL);
+
+   /* NEEDSWORK: future optimization possible */
+   if (capture_command(, , 0))
+   die(_("could not run 'git rev-parse --verify"
+ "HEAD' in submodule %s"),
+ list_item->name);
+
+   strbuf_strip_suffix(, "\n");
+   print_status(info, '+', list_item->name, sb.buf,
+displaypath);
+   strbuf_release();
+   } else {
+   print_status(info, '+', list_item->name, sub_sha1,
+displaypath);
+   }
+   }
+
+   if (info->recursive) {
+   struct child_process cpr =