Re: [PATCH v1 0/5] Incremental rewrite of git-submodules: git-foreach

[Prathamesh Chavan]

Since due to some reason, the previous patch-series list was
unavailable on the mailing list, I have re-posted the series.
It is available at:
https://public-inbox.org/git/20180202045745.5076-1-pc44...@gmail.com/

Thanks,
Prathamesh Chavan

[PATCH v1 5/5] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_listed_submodule(), which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule_cb(). This third function is a callback function that
calls runcommand_in_submodule() with the appropriate parameters and then
takes care of running the command in that submodule, and recursively
performing the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute(), generates the list of
submodules present in the current working tree.

The second function for_each_listed_submodule() traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule_cb()) is called for each entry.

The third function runcommand_in_submodule_cb() calls the function
runcommand_in_submodule() after passing appropraite parameters.

The fourth function runcommand_in_submodule(), generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the  of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The fourth function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input  of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmw...@google.com>
Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 151 
 git-submodule.sh|  39 +---
 2 files changed, 152 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a69..46dee6bf5 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -718,6 +718,156 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct cb_foreach {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int flags;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0 }
+
+static void runcommand_in_submodule(const char *path, const struct object_id 
*ce_oid,
+   int argc, const char **argv, const char 
*prefix,
+   unsigned int flags)
+{
+   const struct submodule *sub;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *displaypath;
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   sub = submodule_from_path(_oid, path);
+
+   if (!sub)
+   die(_("No url found for submodule path '%s' in .gitmodules"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(path, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+
+   /*
+* For the purpose of executing  in the submodule,
+* separate shell is used for the purpose of running the
+* child process.
+*/
+   cp.use_shell = 1;
+   cp.dir = path;
+
+   /*
+* NEEDSWORK: the command currently has access to the variables $name,
+* $sm_path, $displaypath, $sha1 and $toplevel only when the command
+* contains a single argument. This is done for maintianing a faithful
+* translation from shell script.
+*/
+   if (argc == 1) {
+   char *toplevel = xgetcwd();
+
+   argv_array_pushf(_array, "name=%s", sub->name);
+   argv_array_pushf(_array, "sm_path=%s", path);
+   argv_array_pushf(_array, "displaypath=%s", displaypath);
+   argv_array_pushf(_array, "sha1=%s",
+oid_to_hex(ce_oid));
+   argv_array_pushf(_array, "toplevel=%s", toplevel);
+
+   /*
+* Since the path variable was accessible from the script
+* before porting, it is also made available after porting.
+* The environment variable "PATH" has a very special purpose
+* on windows. And since environment variables are
+* case-insensitive in windows, it interferes w

[PATCH v1 2/5] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 10 ++
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $path, $sha1 and
+   The command has access to the variables $name, $sm_path, $sha1 and
$toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
-   $path is the name of the submodule directory relative to the
-   superproject, $sha1 is the commit as recorded in the superproject,
-   and $toplevel is the absolute path to the top-level of the superproject.
+   $sm_path is the path of the submodule as recorded in the superproject,
+   $sha1 is the commit as recorded in the superproject, and
+   $toplevel is the absolute path to the top-level of the superproject.
+   Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+   variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
ignored by this command. Unless given `--quiet`, foreach prints the name
of each submodule before evaluating the command.
-- 
2.15.1

[PATCH v1 4/5] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt |  6 --
 t/t7407-submodule-foreach.sh| 22 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $sm_path, $sha1 and
-   $toplevel:
+   The command has access to the variables $name, $sm_path, $displaypath,
+   $sha1 and $toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
+   $displaypath contains the relative path from the current working
+   directory to the submodules root directory,
$sha1 is the commit as recorded in the superproject, and
$toplevel is the absolute path to its superproject, such that
$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <../../actual
+   git submodule foreach "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd 
clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <../../actual
+   git submodule foreach --recursive "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
-- 
2.15.1

[PATCH v1 3/5] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] ::
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
$sha1 is the commit as recorded in the superproject, and
-   $toplevel is the absolute path to the top-level of the superproject.
+   $toplevel is the absolute path to its superproject, such that
+   $toplevel/$sm_path is the absolute path of the submodule.
Note that to avoid conflicts with '$PATH' on Windows, the '$path'
variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
-- 
2.15.1

[PATCH v1 0/5] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Following series of patches focuses on porting submodule subcommand
git-foreach from shell to C.
An initial attempt for porting was introduced about 9 months back,
and since then then patches have undergone many changes. Some of the 
notable discussion thread which I would like to point out is: [1] 
The previous version of this patch series which was floated is
available at: [2].

The following changes were made to that:
* As it was observed in other submodule subcommand's ported function
  that the number of params increased a lot, the variables quiet and 
  recursive, were replaced in the cb_foreach struct with a single
  unsigned integer variable called flags.

* To accomodate the possiblity of a direct call to the functions
  runcommand_in_submodule(), callback function
  runcommand_in_submodule_cb() was introduced.

[1]: https://public-inbox.org/git/20170419170513.16475-1-pc44...@gmail.com/T/#u
[2]: https://public-inbox.org/git/20170807211900.15001-14-pc44...@gmail.com/

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-3

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-3
Build #202

Prathamesh Chavan (5):
  submodule foreach: correct '$path' in nested submodules from a
subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |  15 ++--
 builtin/submodule--helper.c | 151 
 git-submodule.sh|  40 +--
 t/t7407-submodule-foreach.sh|  38 +-
 4 files changed, 197 insertions(+), 47 deletions(-)

-- 
2.15.1

[PATCH v1 1/5] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
superproject to the mount point of the submodule.
In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
case the path is equal to the relative path from $pwd to the
submodules working directory. When following this model,
the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 git-submodule.sh |  1 -
 t/t7407-submodule-foreach.sh | 36 ++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 156255a9e..7305ee25f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -345,7 +345,6 @@ cmd_foreach()
prefix="$prefix$sm_path/"
sanitize_submodule_env
cd "$sm_path" &&
-   sm_path=$(git submodule--helper relative-path 
"$sm_path" "$wt_prefix") &&
# we make $path available to scripts ...
path=$sm_path &&
if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <expect <../../actual
+   ) &&
+   test_i18ncmp expect actual
+'
 
 cat > expect <

[PATCH v1 0/5] Incremental rewrite of git-submodules: git-foreach

[Prathamesh Chavan]

Following series of patches focuses on porting submodule subcommand
git-foreach from shell to C.
An initial attempt for porting was introduced about 9 months back,
and since then then patches have undergone many changes. Some of the 
notable discussion thread which I would like to point out is: [1] 
The previous version of this patch series which was floated is
available at: [2].

The following changes were made to that:
* As it was observed in other submodule subcommand's ported function
  that the number of params increased a lot, the variables quiet and 
  recursive, were replaced in the cb_foreach struct with a single
  unsigned integer variable called flags.

* To accomodate the possiblity of a direct call to the functions
  runcommand_in_submodule(), callback function
  runcommand_in_submodule_cb() was introduced.

[1]: https://public-inbox.org/git/20170419170513.16475-1-pc44...@gmail.com/T/#u
[2]: https://public-inbox.org/git/20170807211900.15001-14-pc44...@gmail.com/

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-3

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-3
Build #202

Prathamesh Chavan (5):
  submodule foreach: correct '$path' in nested submodules from a
subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |  15 ++--
 builtin/submodule--helper.c | 151 
 git-submodule.sh|  40 +--
 t/t7407-submodule-foreach.sh|  38 +-
 4 files changed, 197 insertions(+), 47 deletions(-)

-- 
2.15.1

[PATCH v1 4/5] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt |  6 --
 t/t7407-submodule-foreach.sh| 22 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $sm_path, $sha1 and
-   $toplevel:
+   The command has access to the variables $name, $sm_path, $displaypath,
+   $sha1 and $toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
+   $displaypath contains the relative path from the current working
+   directory to the submodules root directory,
$sha1 is the commit as recorded in the superproject, and
$toplevel is the absolute path to its superproject, such that
$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <../../actual
+   git submodule foreach "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd 
clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <../../actual
+   git submodule foreach --recursive "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
-- 
2.15.1

[PATCH v1 5/5] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_listed_submodule(), which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule_cb(). This third function is a callback function that
calls runcommand_in_submodule() with the appropriate parameters and then
takes care of running the command in that submodule, and recursively
performing the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute(), generates the list of
submodules present in the current working tree.

The second function for_each_listed_submodule() traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule_cb()) is called for each entry.

The third function runcommand_in_submodule_cb() calls the function
runcommand_in_submodule() after passing appropraite parameters.

The fourth function runcommand_in_submodule(), generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the  of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The fourth function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input  of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmw...@google.com>
Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 151 
 git-submodule.sh|  39 +---
 2 files changed, 152 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a69..46dee6bf5 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -718,6 +718,156 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct cb_foreach {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int flags;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0 }
+
+static void runcommand_in_submodule(const char *path, const struct object_id 
*ce_oid,
+   int argc, const char **argv, const char 
*prefix,
+   unsigned int flags)
+{
+   const struct submodule *sub;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *displaypath;
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   sub = submodule_from_path(_oid, path);
+
+   if (!sub)
+   die(_("No url found for submodule path '%s' in .gitmodules"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(path, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+
+   /*
+* For the purpose of executing  in the submodule,
+* separate shell is used for the purpose of running the
+* child process.
+*/
+   cp.use_shell = 1;
+   cp.dir = path;
+
+   /*
+* NEEDSWORK: the command currently has access to the variables $name,
+* $sm_path, $displaypath, $sha1 and $toplevel only when the command
+* contains a single argument. This is done for maintianing a faithful
+* translation from shell script.
+*/
+   if (argc == 1) {
+   char *toplevel = xgetcwd();
+
+   argv_array_pushf(_array, "name=%s", sub->name);
+   argv_array_pushf(_array, "sm_path=%s", path);
+   argv_array_pushf(_array, "displaypath=%s", displaypath);
+   argv_array_pushf(_array, "sha1=%s",
+oid_to_hex(ce_oid));
+   argv_array_pushf(_array, "toplevel=%s", toplevel);
+
+   /*
+* Since the path variable was accessible from the script
+* before porting, it is also made available after porting.
+* The environment variable "PATH" has a very special purpose
+* on windows. And since environment variables are
+* case-insensitive in windows, it interferes w

[PATCH v1 3/5] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] ::
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
$sha1 is the commit as recorded in the superproject, and
-   $toplevel is the absolute path to the top-level of the superproject.
+   $toplevel is the absolute path to its superproject, such that
+   $toplevel/$sm_path is the absolute path of the submodule.
Note that to avoid conflicts with '$PATH' on Windows, the '$path'
variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
-- 
2.15.1

[PATCH v1 1/5] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
superproject to the mount point of the submodule.
In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
case the path is equal to the relative path from $pwd to the
submodules working directory. When following this model,
the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 git-submodule.sh |  1 -
 t/t7407-submodule-foreach.sh | 36 ++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index 156255a9e..7305ee25f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -345,7 +345,6 @@ cmd_foreach()
prefix="$prefix$sm_path/"
sanitize_submodule_env
cd "$sm_path" &&
-   sm_path=$(git submodule--helper relative-path 
"$sm_path" "$wt_prefix") &&
# we make $path available to scripts ...
path=$sm_path &&
if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <expect <../../actual
+   ) &&
+   test_i18ncmp expect actual
+'
 
 cat > expect <

[PATCH v1 2/5] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 10 ++
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $path, $sha1 and
+   The command has access to the variables $name, $sm_path, $sha1 and
$toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
-   $path is the name of the submodule directory relative to the
-   superproject, $sha1 is the commit as recorded in the superproject,
-   and $toplevel is the absolute path to the top-level of the superproject.
+   $sm_path is the path of the submodule as recorded in the superproject,
+   $sha1 is the commit as recorded in the superproject, and
+   $toplevel is the absolute path to the top-level of the superproject.
+   Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+   variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
ignored by this command. Unless given `--quiet`, foreach prints the name
of each submodule before evaluating the command.
-- 
2.15.1

[PATCH v3 1/2] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing four functions: module_sync(),
sync_submodule(), sync_submodule_cb() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 193 
 git-submodule.sh|  57 +
 2 files changed, 194 insertions(+), 56 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a69..745d070ea 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -50,6 +50,20 @@ static char *get_default_remote(void)
return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char 
*prefix)
+{
+   const char *remote;
+
+   if (argc != 1)
+   die(_("submodule--helper print-default-remote takes no 
arguments"));
+
+   remote = get_default_remote();
+   if (remote)
+   printf("%s\n", remote);
+
+   return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
return str[0] == '.' && is_dir_sep(str[1]);
@@ -358,6 +372,25 @@ static void module_list_active(struct module_list *list)
*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+   int i;
+   struct strbuf sb = STRBUF_INIT;
+
+   for (i = count_slashes(path); i; i--)
+   strbuf_addstr(, "../");
+
+   /*
+* Check if 'path' ends with slash or not
+* for having the same output for dir/sub_dir
+* and dir/sub_dir/
+*/
+   if (!is_dir_sep(path[strlen(path) - 1]))
+   strbuf_addstr(, "../");
+
+   return strbuf_detach(, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
int i;
@@ -718,6 +751,164 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct sync_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+
+#define SYNC_CB_INIT { NULL, 0 }
+
+static void sync_submodule(const char *path, const char *prefix,
+  unsigned int flags)
+{
+   const struct submodule *sub;
+   char *remote_key = NULL;
+   char *sub_origin_url, *super_config_url, *displaypath;
+   struct strbuf sb = STRBUF_INIT;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *sub_config_path = NULL;
+
+   if (!is_submodule_active(the_repository, path))
+   return;
+
+   sub = submodule_from_path(_oid, path);
+
+   if (sub && sub->url) {
+   if (starts_with_dot_dot_slash(sub->url) ||
+   starts_with_dot_slash(sub->url)) {
+   char *remote_url, *up_path;
+   char *remote = get_default_remote();
+   strbuf_addf(, "remote.%s.url", remote);
+
+   if (git_config_get_string(sb.buf, _url))
+   remote_url = xgetcwd();
+
+   up_path = get_up_path(path);
+   sub_origin_url = relative_url(remote_url, sub->url, 
up_path);
+   super_config_url = relative_url(remote_url, sub->url, 
NULL);
+
+   free(remote);
+   free(up_path);
+   free(remote_url);
+   } else {
+   sub_origin_url = xstrdup(sub->url);
+   super_config_url = xstrdup(sub->url);
+   }
+   } else {
+   sub_origin_url = xstrdup("");
+   super_config_url = xstrdup("");
+   }
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   if (!(flags & OPT_QUIET))
+   printf(_("Synchronizing submodule url for '%s'\n"),
+displaypath);
+
+   strbuf_reset();
+   strbuf_addf(, "submodule.%s.url", sub->name);
+   if (git_config_set_gently(sb.buf, super_config_url))
+   die(_("failed to register url for submodule path '%s'"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(path, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+   cp.git_cmd = 1;
+   cp.dir = path;
+   argv_array_pushl(, "submodule--helper",
+"print-default-remote", NULL);
+
+   strbuf_reset();
+   if (capture_command(, , 0))
+   

[PATCH v3 2/2] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into four
functions: module_deinit(), for_each_listed_submodule(),
deinit_submodule() and deinit_submodule_cb().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 147 
 git-submodule.sh|  55 +
 2 files changed, 148 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 745d070ea..b1daca995 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -20,6 +20,7 @@
 #define OPT_QUIET (1 << 0)
 #define OPT_CACHED (1 << 1)
 #define OPT_RECURSIVE (1 << 2)
+#define OPT_FORCE (1 << 3)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
  void *cb_data);
@@ -909,6 +910,151 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+#define DEINIT_CB_INIT { NULL, 0 }
+
+static void deinit_submodule(const char *path, const char *prefix,
+unsigned int flags)
+{
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", path);
+
+   sub = submodule_from_path(_oid, path);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(path)) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   /*
+* protect submodules containing a .git directory
+* NEEDSWORK: instead of dying, automatically call
+* absorbgitdirs and (possibly) warn.
+*/
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory (use 'rm -rf' if you really want "
+ "to remove it including all of its history)"),
+   displaypath);
+
+   if (!(flags & OPT_FORCE)) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+path, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   strbuf_addstr(_rm, path);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work tree 
'%s'\n");
+
+   if (!(flags & OPT_QUIET))
+   printf(format, displaypath);
+
+   strbuf_release(_rm);
+   }
+
+   if (mkdir(path, 0777))
+   printf(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later decides to init this submodule again
+*/
+   git_config_rename_section_in_file(NULL, sub_key, NULL);
+   if (!(flags & OPT_QUIET))
+   printf(_("Submodule '%s' (%s) unregistered for path 
'%s'\n"),
+sub->name, sub->url, displaypath);
+   free(sub_key);
+   }
+
+cleanup:
+   free(displaypath);
+   free(sub_git_dir);
+   strbuf_release(_config);
+}
+
+static void deinit_submodule_cb(const struct cache_entry *list_item,
+  

[PATCH v3 0/2] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v3:

* For the variables: super_config_url and sub_origin_url, xstrdup() was used
  while assigning "" to them, before freeing.

* In case of the function deinit_submodule, since the orignal code doesn't die
  upon failure of the function mkdir(), printf was used instead of die_errno.

As before you can find this series at:
https://github.com/pratham-pc/git/commits/patch-series-2

And its build report is available at:
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-2
Build #197

Prathamesh Chavan (2):
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C

 builtin/submodule--helper.c | 340 
 git-submodule.sh| 112 +--
 2 files changed, 342 insertions(+), 110 deletions(-)

-- 
2.15.1

[PATCH v2 2/2] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into four
functions: module_deinit(), for_each_listed_submodule(),
deinit_submodule() and deinit_submodule_cb().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 147 
 git-submodule.sh|  55 +
 2 files changed, 148 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index eb6f96981..b93e1d50b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -20,6 +20,7 @@
 #define OPT_QUIET (1 << 0)
 #define OPT_CACHED (1 << 1)
 #define OPT_RECURSIVE (1 << 2)
+#define OPT_FORCE (1 << 3)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
  void *cb_data);
@@ -911,6 +912,151 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+#define DEINIT_CB_INIT { NULL, 0 }
+
+static void deinit_submodule(const char *path, const char *prefix,
+unsigned int flags)
+{
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", path);
+
+   sub = submodule_from_path(_oid, path);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(path)) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   /*
+* protect submodules containing a .git directory
+* NEEDSWORK: instead of dying, automatically call
+* absorbgitdirs and (possibly) warn.
+*/
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory (use 'rm -rf' if you really want "
+ "to remove it including all of its history)"),
+   displaypath);
+
+   if (!(flags & OPT_FORCE)) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+path, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   strbuf_addstr(_rm, path);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work tree 
'%s'\n");
+
+   if (!(flags & OPT_QUIET))
+   printf(format, displaypath);
+
+   strbuf_release(_rm);
+   }
+
+   if (mkdir(path, 0777))
+   die_errno(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later decides to init this submodule again
+*/
+   git_config_rename_section_in_file(NULL, sub_key, NULL);
+   if (!(flags & OPT_QUIET))
+   printf(_("Submodule '%s' (%s) unregistered for path 
'%s'\n"),
+sub->name, sub->url, displaypath);
+   free(sub_key);
+   }
+
+cleanup:
+   free(displaypath);
+   free(sub_git_dir);
+   strbuf_release(_config);
+}
+
+static void deinit_submodule_cb(const struct cache_entry *list_item,
+  

[PATCH v2 1/2] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing four functions: module_sync(),
sync_submodule(), sync_submodule_cb() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 195 
 git-submodule.sh|  57 +
 2 files changed, 196 insertions(+), 56 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a69..eb6f96981 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -50,6 +50,20 @@ static char *get_default_remote(void)
return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char 
*prefix)
+{
+   const char *remote;
+
+   if (argc != 1)
+   die(_("submodule--helper print-default-remote takes no 
arguments"));
+
+   remote = get_default_remote();
+   if (remote)
+   printf("%s\n", remote);
+
+   return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
return str[0] == '.' && is_dir_sep(str[1]);
@@ -358,6 +372,25 @@ static void module_list_active(struct module_list *list)
*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+   int i;
+   struct strbuf sb = STRBUF_INIT;
+
+   for (i = count_slashes(path); i; i--)
+   strbuf_addstr(, "../");
+
+   /*
+* Check if 'path' ends with slash or not
+* for having the same output for dir/sub_dir
+* and dir/sub_dir/
+*/
+   if (!is_dir_sep(path[strlen(path) - 1]))
+   strbuf_addstr(, "../");
+
+   return strbuf_detach(, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
int i;
@@ -718,6 +751,166 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct sync_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+
+#define SYNC_CB_INIT { NULL, 0 }
+
+static void sync_submodule(const char *path, const char *prefix,
+  unsigned int flags)
+{
+   const struct submodule *sub;
+   char *remote_key = NULL;
+   char *sub_origin_url, *super_config_url, *displaypath;
+   struct strbuf sb = STRBUF_INIT;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *sub_config_path = NULL;
+
+   if (!is_submodule_active(the_repository, path))
+   return;
+
+   sub = submodule_from_path(_oid, path);
+
+   if (sub && sub->url) {
+   if (starts_with_dot_dot_slash(sub->url) ||
+   starts_with_dot_slash(sub->url)) {
+   char *remote_url, *up_path;
+   char *remote = get_default_remote();
+   strbuf_addf(, "remote.%s.url", remote);
+
+   if (git_config_get_string(sb.buf, _url))
+   remote_url = xgetcwd();
+
+   up_path = get_up_path(path);
+   sub_origin_url = relative_url(remote_url, sub->url, 
up_path);
+   super_config_url = relative_url(remote_url, sub->url, 
NULL);
+
+   free(remote);
+   free(up_path);
+   free(remote_url);
+   } else {
+   sub_origin_url = xstrdup(sub->url);
+   super_config_url = xstrdup(sub->url);
+   }
+   } else {
+   sub_origin_url = "";
+   super_config_url = "";
+   }
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   if (!(flags & OPT_QUIET))
+   printf(_("Synchronizing submodule url for '%s'\n"),
+displaypath);
+
+   strbuf_reset();
+   strbuf_addf(, "submodule.%s.url", sub->name);
+   if (git_config_set_gently(sb.buf, super_config_url))
+   die(_("failed to register url for submodule path '%s'"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(path, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+   cp.git_cmd = 1;
+   cp.dir = path;
+   argv_array_pushl(, "submodule--helper",
+"print-default-remote", NULL);
+
+   strbuf_reset();
+   if (capture_command(, , 0))
+   

[PATCH v2 0/2] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes made to the previous version of the patch series[1]:

* Since later on with certain patches, the number of bit-parameters to
  be passed to a few functions depend on many parameters, I prefered
  using a single flag bit.

* Memory-leak of the variable 'remote' in the function:
  print_default_remote() was avoided.

* Additional condition were introduced while freeing the variables:
  sub_origin_url and super_config_url.

* print messages and comments in the deinit_submodule function were
  corrected as suggested in previous review of this patch[2].

* Call to the function lstat() for identifying the directory mode was
  avoided and instead 0777 was used. An additional improvement is to be
  made over this patch, but since the improvement can not directly be
  part of the "rewirte in C", the patch would be floated saperately on
  the mailing list.

As before you can find this series at:
https://github.com/pratham-pc/git/commits/patch-series-2

And its build report is available at:
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-2
Build #196

[1]: https://public-inbox.org/git/20180109175703.4793-1-pc44...@gmail.com/ 
[2]: https://public-inbox.org/git/xmqq7esq4tf6@gitster.mtv.corp.google.com/

Prathamesh Chavan (2):
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C

 builtin/submodule--helper.c | 342 
 git-submodule.sh| 112 +--
 2 files changed, 344 insertions(+), 110 deletions(-)

-- 
2.15.1

Re: [PATCH v1 2/2] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

On Wed, Jan 10, 2018 at 2:54 AM, Junio C Hamano <gits...@pobox.com> wrote:
> Prathamesh Chavan <pc44...@gmail.com> writes:
>
>> The same mechanism is used even for porting this submodule
>> subcommand, as used in the ported subcommands till now.
>> The function cmd_deinit in split up after porting into four
>> functions: module_deinit(), for_each_listed_submodule(),
>> deinit_submodule() and deinit_submodule_cb().
>>
>> Mentored-by: Christian Couder <christian.cou...@gmail.com>
>> Mentored-by: Stefan Beller <sbel...@google.com>
>> Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
>> ---
>>  builtin/submodule--helper.c | 153 
>> 
>>  git-submodule.sh|  55 +---
>>  2 files changed, 154 insertions(+), 54 deletions(-)
>>
>> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
>> index dd7737acd..54b0e46fc 100644
>> --- a/builtin/submodule--helper.c
>> +++ b/builtin/submodule--helper.c
>> @@ -20,6 +20,7 @@
>>  #define OPT_QUIET (1 << 0)
>>  #define OPT_CACHED (1 << 1)
>>  #define OPT_RECURSIVE (1 << 2)
>> +#define OPT_FORCE (1 << 3)
>>
>>  typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
>> void *cb_data);
>> @@ -908,6 +909,157 @@ static int module_sync(int argc, const char **argv, 
>> const char *prefix)
>>   return 0;
>>  }
>>
>> +struct deinit_cb {
>> + const char *prefix;
>> + unsigned int flags;
>> +};
>> +#define DEINIT_CB_INIT { NULL, 0 }
>> +
>> +static void deinit_submodule(const char *path, const char *prefix,
>> +  unsigned int flags)
>> +{
>> + const struct submodule *sub;
>> + char *displaypath = NULL;
>> + struct child_process cp_config = CHILD_PROCESS_INIT;
>> + struct strbuf sb_config = STRBUF_INIT;
>> + char *sub_git_dir = xstrfmt("%s/.git", path);
>> + mode_t mode = 0777;
>> +
>> + sub = submodule_from_path(_oid, path);
>> +
>> + if (!sub || !sub->name)
>> + goto cleanup;
>> +
>> + displaypath = get_submodule_displaypath(path, prefix);
>> +
>> + /* remove the submodule work tree (unless the user already did it) */
>> + if (is_directory(path)) {
>> + struct stat st;
>> + /*
>> +  * protect submodules containing a .git directory
>> +  * NEEDSWORK: automatically call absorbgitdirs before
>> +  * warning/die.
>> +  */
>
> I guess that you mean "instead of dying, automatically call absorb
> and (possibly) warn"?  That sounds like a sensible improvement.
>
>> + if (is_directory(sub_git_dir))
>> + die(_("Submodule work tree '%s' contains a .git "
>> +   "directory use 'rm -rf' if you really want "
>> +   "to remove it including all of its history"),
>
> This changes the message text by removing () around "use ... history",
> which I do not think you intended to do.
>
>> +   displaypath);
>> +
>> + if (!(flags & OPT_FORCE)) {
>> + struct child_process cp_rm = CHILD_PROCESS_INIT;
>> + cp_rm.git_cmd = 1;
>> + argv_array_pushl(_rm.args, "rm", "-qn",
>> +  path, NULL);
>> +
>> + if (run_command(_rm))
>> + die(_("Submodule work tree '%s' contains local 
>> "
>> +   "modifications; use '-f' to discard 
>> them"),
>> +   displaypath);
>> + }
>> +
>> + if (!lstat(path, )) {
>
> What is this if statement doing here?  It does not make sense,
> especially without an 'else' clause on the other side, at least to
> me.
>
> At this point in the flow, the code has already determined that path
> is a directory above before starting to check if it has ".git/"
> immediately below it, or trying to run "git rm" in the dry run mode
> to see if it yields an error, so at this point lstat() should
> succeed (and would say it is a directory).  I would sort-of
> understand it if this "if()" has an "else" clause to act on 

[PATCH v1 2/2] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into four
functions: module_deinit(), for_each_listed_submodule(),
deinit_submodule() and deinit_submodule_cb().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 153 
 git-submodule.sh|  55 +---
 2 files changed, 154 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index dd7737acd..54b0e46fc 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -20,6 +20,7 @@
 #define OPT_QUIET (1 << 0)
 #define OPT_CACHED (1 << 1)
 #define OPT_RECURSIVE (1 << 2)
+#define OPT_FORCE (1 << 3)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
  void *cb_data);
@@ -908,6 +909,157 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+#define DEINIT_CB_INIT { NULL, 0 }
+
+static void deinit_submodule(const char *path, const char *prefix,
+unsigned int flags)
+{
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", path);
+   mode_t mode = 0777;
+
+   sub = submodule_from_path(_oid, path);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(path)) {
+   struct stat st;
+   /*
+* protect submodules containing a .git directory
+* NEEDSWORK: automatically call absorbgitdirs before
+* warning/die.
+*/
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory use 'rm -rf' if you really want "
+ "to remove it including all of its history"),
+ displaypath);
+
+   if (!(flags & OPT_FORCE)) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+path, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   if (!lstat(path, )) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   strbuf_addstr(_rm, path);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work 
tree '%s'\n");
+
+   if (!(flags & OPT_QUIET))
+   printf(format, displaypath);
+
+   mode = st.st_mode;
+
+   strbuf_release(_rm);
+   }
+   }
+
+   if (mkdir(path, mode))
+   die_errno(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later decides to init this submodule again
+*/
+   git_config_rename_section_in_file(NULL, sub_key, NULL);
+   if (!(flags & OPT_QUIET))
+   printf(_("Submodule '%s' (%s) unregistered for path 
'%s'\n"),
+sub->name, sub

[PATCH v1 1/2] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing four functions: module_sync(),
sync_submodule(), sync_submodule_cb() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 192 
 git-submodule.sh|  57 +
 2 files changed, 193 insertions(+), 56 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a5c4a8a69..dd7737acd 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -50,6 +50,20 @@ static char *get_default_remote(void)
return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char 
*prefix)
+{
+   const char *remote;
+
+   if (argc != 1)
+   die(_("submodule--helper print-default-remote takes no 
arguments"));
+
+   remote = get_default_remote();
+   if (remote)
+   printf("%s\n", remote);
+
+   return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
return str[0] == '.' && is_dir_sep(str[1]);
@@ -358,6 +372,25 @@ static void module_list_active(struct module_list *list)
*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+   int i;
+   struct strbuf sb = STRBUF_INIT;
+
+   for (i = count_slashes(path); i; i--)
+   strbuf_addstr(, "../");
+
+   /*
+* Check if 'path' ends with slash or not
+* for having the same output for dir/sub_dir
+* and dir/sub_dir/
+*/
+   if (!is_dir_sep(path[strlen(path) - 1]))
+   strbuf_addstr(, "../");
+
+   return strbuf_detach(, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
int i;
@@ -718,6 +751,163 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct sync_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+
+#define SYNC_CB_INIT { NULL, 0 }
+
+static void sync_submodule(const char *path, const char *prefix,
+  unsigned int flags)
+{
+   const struct submodule *sub;
+   char *remote_key = NULL;
+   char *sub_origin_url, *super_config_url, *displaypath;
+   struct strbuf sb = STRBUF_INIT;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *sub_config_path = NULL;
+
+   if (!is_submodule_active(the_repository, path))
+   return;
+
+   sub = submodule_from_path(_oid, path);
+
+   if (sub && sub->url) {
+   if (starts_with_dot_dot_slash(sub->url) || 
starts_with_dot_slash(sub->url)) {
+   char *remote_url, *up_path;
+   char *remote = get_default_remote();
+   strbuf_addf(, "remote.%s.url", remote);
+
+   if (git_config_get_string(sb.buf, _url))
+   remote_url = xgetcwd();
+
+   up_path = get_up_path(path);
+   sub_origin_url = relative_url(remote_url, sub->url, 
up_path);
+   super_config_url = relative_url(remote_url, sub->url, 
NULL);
+
+   free(remote);
+   free(up_path);
+   free(remote_url);
+   } else {
+   sub_origin_url = xstrdup(sub->url);
+   super_config_url = xstrdup(sub->url);
+   }
+   } else {
+   sub_origin_url = "";
+   super_config_url = "";
+   }
+
+   displaypath = get_submodule_displaypath(path, prefix);
+
+   if (!(flags & OPT_QUIET))
+   printf(_("Synchronizing submodule url for '%s'\n"),
+displaypath);
+
+   strbuf_reset();
+   strbuf_addf(, "submodule.%s.url", sub->name);
+   if (git_config_set_gently(sb.buf, super_config_url))
+   die(_("failed to register url for submodule path '%s'"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(path, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+   cp.git_cmd = 1;
+   cp.dir = path;
+   argv_array_pushl(, "submodule--helper",
+"print-default-remote", NULL);
+
+   strbuf_reset();
+   if (capture_command(, , 0))
+   die(_("failed to get

[PATCH v1 0/2] Incremental rewrite of git-submodules

[Prathamesh Chavan]

The patches [1] and [2] concerning the porting of submodule
subcommands: sync and deinit were updated in accoudance with
the changes made in one of such similar portings made earlier
for submodule subcommand status[3]. Following are the changes
made:

* It was observed that the number of params increased a lot due to flags
  like quiet, recursive, cached, etc, and keeping in mind the future
  subcommand's ported functions as well, a single unsigned int called
  flags was introduced to store all of these flags, instead of having
  parameter for each one.

* To accomodate the possiblity of a direct call to the functions
  deinit_submodule() and sync_submodule(), callback functions were
  introduced.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-2

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-2
Build #195

[1]: https://public-inbox.org/git/20170807211900.15001-6-pc44...@gmail.com/
[2]: https://public-inbox.org/git/20170807211900.15001-7-pc44...@gmail.com/
[3]: https://public-inbox.org/git/20171006132415.2876-4-pc44...@gmail.com/

Prathamesh Chavan (2):
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C

 builtin/submodule--helper.c | 345 
 git-submodule.sh| 112 +-
 2 files changed, 347 insertions(+), 110 deletions(-)

-- 
2.14.2

[PATCH v7 1/3] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 35 +++
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 06ed02f99..56c1c52e2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -219,6 +219,26 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+/* the result should be freed by the caller. */
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   return xstrfmt("%s%s", super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -334,15 +354,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -357,9 +369,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -367,7 +379,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -404,9 +415,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.14.2

[PATCH v7 0/3] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v7:

* Instead of using cb_flags in the callback data's struct, 'flags' is used.

* Similar changes were applied to the CB_OPT_QUIET and other bits.

* The function compute_rev_name() was formatted in accordance with the "make
  style", into a compact version.

* Call to precompose_argv() in the function status_submodule() was dropped
  as the call was unnecessary.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-1

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-1
Build #190

The above changes were based on master branch.

Another branch, similar to the above, was created, but was based
on the 'next' branch.
Complete build report of that is also available at:
https://travis-ci.org/pratham-pc/git/builds
Branch: patch-series-1-next
Build #189
The above changes are also push on github and are available at:
https://github.com/pratham-pc/git/commits/patch-series-1-next

Prathamesh Chavan (3):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_listed_submodule()
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 273 +---
 git-submodule.sh|  61 +-
 2 files changed, 257 insertions(+), 77 deletions(-)

-- 
2.14.2

[PATCH v7 2/3] submodule--helper: introduce for_each_listed_submodule()

[Prathamesh Chavan]

Introduce function for_each_listed_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 40 +++-
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 56c1c52e2..29e3fde16 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,11 @@
 #include "refs.h"
 #include "connect.h"
 
+#define OPT_QUIET (1 << 0)
+
+typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -348,7 +353,23 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_listed_submodule(const struct module_list *list,
+ each_submodule_fn fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const char *path, const char *prefix,
+  unsigned int flags)
 {
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
@@ -410,7 +431,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!(flags & OPT_QUIET))
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -437,12 +458,18 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
free(upd);
 }
 
+static void init_submodule_cb(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct init_cb *info = cb_data;
+   init_submodule(list_item->name, info->prefix, info->flags);
+}
+
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -467,8 +494,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   if (quiet)
+   info.flags |= OPT_QUIET;
+
+   for_each_listed_submodule(, init_submodule_cb, );
 
return 0;
 }
-- 
2.14.2

[PATCH v7 3/3] 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
four functions: module_status(), submodule_status_cb(),
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_listed_submodule() looping through the
list obtained.

Then for_each_listed_submodule() calls submodule_status_cb() for each of
the submodule in its list. The function submodule_status_cb() calls
submodule_status() after passing appropriate arguments to the funciton.
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.

Function set_name_rev() is also ported from git-submodule to the
submodule--helper builtin function compute_rev_name(), which now
generates the value of the revision name as required.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 198 
 git-submodule.sh|  61 +-
 2 files changed, 199 insertions(+), 60 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 29e3fde16..d366e8e7b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,8 +13,13 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 #define OPT_QUIET (1 << 0)
+#define OPT_CACHED (1 << 1)
+#define OPT_RECURSIVE (1 << 2)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
  void *cb_data);
@@ -244,6 +249,44 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = { NULL };
+
+   static const char *describe_tags[] = { "--tags", NULL };
+
+   static const char *describe_contains[] = { "--contains", NULL };
+
+   static const char *describe_all_always[] = { "--all", "--always", NULL 
};
+
+   static const char **describe_argv[] = { describe_bare, describe_tags,
+   describe_contains,
+   describe_all_always, NULL };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0)) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -503,6 +546,160 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct status_cb {
+   const char *prefix;
+   unsigned int flags;
+};
+
+#define STATUS_CB_INIT { NULL, 0 }
+
+static void print_status(unsigned int flags, char state, const char *path,
+const struct object_id *oid, const char *displaypath)
+{
+   if (flags & OPT_QUIET)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+')
+   printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
+
+   printf("\n");
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const char *path, const struct object_id *ce_oid,
+unsigned int ce_flags, const char *prefix,
+unsigned int flags)
+{
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+   struct rev_info rev

[PATCH v6 3/3] 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
four functions: module_status(), submodule_status_cb(),
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_listed_submodule() looping through the
list obtained.

Then for_each_listed_submodule() calls submodule_status_cb() for each of
the submodule in its list. The function submodule_status_cb() calls
submodule_status() after passing appropriate arguments to the funciton.
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.

Function set_name_rev() is also ported from git-submodule to the
submodule--helper builtin function compute_rev_name(), which now
generates the value of the revision name as required.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 207 
 git-submodule.sh|  61 +
 2 files changed, 208 insertions(+), 60 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 20a1ef868..50d38fc20 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,8 +13,13 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 #define CB_OPT_QUIET   (1<<0)
+#define CB_OPT_CACHED  (1<<1)
+#define CB_OPT_RECURSIVE   (1<<2)
 
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
  void *cb_data);
@@ -245,6 +250,53 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0)) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -503,6 +555,160 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct status_cb {
+   const char *prefix;
+   unsigned int cb_flags;
+};
+#define STATUS_CB_INIT { NULL, 0 }
+
+static void print_status(unsigned int flags, char state, const char *path,
+const struct object_id *oid, const char *displaypath)
+{
+   if (flags & CB_OPT_QUIET)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+')
+   printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
+
+   printf("\n");
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const char *path, const struct object_id *ce_oid,
+unsigned int ce_flags, const char *prefix,
+unsigned int cb_flags)
+{
+   char *displaypath;
+   struct argv_ar

[PATCH v6 2/3] submodule--helper: introduce for_each_listed_submodule()

[Prathamesh Chavan]

Introduce function for_each_listed_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 ++-
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index cdae54426..20a1ef868 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,11 @@
 #include "refs.h"
 #include "connect.h"
 
+#define CB_OPT_QUIET   (1<<0)
+
+typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -349,7 +354,22 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_listed_submodule(const struct module_list *list,
+ each_submodule_fn fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int cb_flags;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const char *path, const char *prefix,
+  unsigned int cb_flags)
 {
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
@@ -411,7 +431,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!(cb_flags & CB_OPT_QUIET))
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -438,12 +458,18 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
free(upd);
 }
 
+static void init_submodule_cb(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct init_cb *info = cb_data;
+   init_submodule(list_item->name, info->prefix, info->cb_flags);
+}
+
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -468,8 +494,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   if (quiet)
+   info.cb_flags |= CB_OPT_QUIET;
+
+   for_each_listed_submodule(, init_submodule_cb, );
 
return 0;
 }
-- 
2.13.0

[PATCH v6 1/3] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 35 +++
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 818fe74f0..cdae54426 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,26 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+/* the result should be freed by the caller. */
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   return xstrfmt("%s%s", super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -335,15 +355,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -358,9 +370,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -368,7 +380,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -405,9 +416,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0

[PATCH v6 0/3] Incremental rewrite of git-submodules

[Prathamesh Chavan]

changes in v6:

* The function get_submodule_displaypath() was modified for the case
  when get_super_prefix() returns a non-null value. The condition to check
  if the super-prefix ends with a '/' is removed. To accomodate this change
  appropriate value of super_prefix is passed instead in the recursive calls
  of init_submodule() and status_submodule().

* To accomodate the possiblity of a direct call to the function
  init_submodule(), a callback function init_submodule_cb() is introduced
  which takes cache_entry and init_cb structures as input params, and
  calls init_submodule() with parameters which are more appropriate
  for a direct call of this function.

* Similar changes were even done for status_submodule(). But as it was
  observed that the number of params increased a lot due to flags
  like quiet, recursive, cached, etc, and keeping in mind the future
  subcommand's ported functions as well, a single unsigned int called
  cb_flags was introduced to store all of these flags, instead of having
  parameter for each one.

* Patches [3/4] and [4/4] from the previous series were merged as a single
  step.

* Call to function cmd_diff_files was avoided in the function status_submodule()
  and instead used the function run_diff_files() for the same purpose.

Since there were many changes the patches required, I took more time on
making these changes. Thank you, Junio for the last reviews. They
helped a lot for improving the patch series.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-1

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-1
Build #184

Prathamesh Chavan (3):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_listed_submodule()
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 281 +---
 git-submodule.sh|  61 +-
 2 files changed, 265 insertions(+), 77 deletions(-)

-- 
2.13.0

[PATCH v5 2/4] submodule--helper: introduce for_each_listed_submodule()

[Prathamesh Chavan]

Introduce function for_each_listed_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 36 
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index d24ac9028..d12790b5c 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -352,15 +355,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_listed_submodule(const struct module_list *list,
+ each_submodule_fn fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
 {
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(_oid, path);
+   sub = submodule_from_path(_oid, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -372,7 +390,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
strbuf_reset();
@@ -414,7 +432,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -443,10 +461,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -471,8 +489,10 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   for_each_listed_submodule(, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[PATCH v5 1/4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 38 ++
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 818fe74f0..d24ac9028 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,29 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+/* the result should be freed by the caller. */
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = (len > 0 && is_dir_sep(super_prefix[len - 
1])) ? "%s%s" : "%s/%s";
+
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -335,15 +358,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -358,9 +373,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -368,7 +383,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -405,9 +419,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0

[PATCH v5 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function compute_rev_name() generates the
value of the revision name as required.
The function get_rev_name() calls compute_rev_name() and receives the
revision name, and later handles its formatting and printing.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index d12790b5c..7ca8e8153 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -246,6 +246,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int get_rev_name(int argc, const char **argv, const char *prefix)
+{
+   char *revname;
+   if (argc != 3)
+   die("get-rev-name only accepts two arguments:  ");
+
+   revname = compute_rev_name(argv[1], argv[2]);
+   if (revname && revname[0])
+   printf(" (%s)", revname);
+   printf("\n");
+
+   free(revname);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1293,6 +1355,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"get-rev-name", get_rev_name, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index 66d1ae8ef..5211361c5 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -758,18 +758,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1041,14 +1029,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[PATCH v5 0/4] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v5:
* in print_status() function, we now call compute_rev_name() directly
  instead of doing the argv setup and calling get_rev_name() function.
* Since we no longer use the helper function get_rev_name(), we have
  removed it from the code base after porting submodule subcommand
  'status'.
* function get_submodule_displaypath() has been modified, and now handles
  the case of super_prefix being non-null and of length zero.
* I have still kept the name of the function get_rev_name() unchanged,
  since in the function cmd_status(), it is used to get the value of
  the variable revname. And in the next commit since we do not require
  the function anymore, we reomve it from the code base.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-1

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-1
Build #179

Thanks, Han-Wen Nienhuys for reviewing the previous patch series.

Prathamesh Chavan (4):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_listed_submodule()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 265 
 git-submodule.sh|  61 +-
 2 files changed, 247 insertions(+), 79 deletions(-)

-- 
2.13.0

[PATCH v5 4/4] 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_listed_submodule() looping through the
list obtained.

Then for_each_listed_submodule() 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.

Helper function get_rev_name() removed after porting the above subcommand
as it is no longer used.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 162 +++-
 git-submodule.sh|  49 +-
 2 files changed, 147 insertions(+), 64 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7ca8e8153..8876a4a08 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -293,21 +293,6 @@ static char *compute_rev_name(const char *sub_path, const 
char* object_id)
return NULL;
 }
 
-static int get_rev_name(int argc, const char **argv, const char *prefix)
-{
-   char *revname;
-   if (argc != 3)
-   die("get-rev-name only accepts two arguments:  ");
-
-   revname = compute_rev_name(argv[1], argv[2]);
-   if (revname && revname[0])
-   printf(" (%s)", revname);
-   printf("\n");
-
-   free(revname);
-   return 0;
-}
-
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -559,6 +544,151 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+')
+   printf(" (%s)", compute_rev_name(path, oid_to_hex(oid)));
+
+   printf("\n");
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(_oid, 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 (ce_stage(list_item)) {
+   print_status(info, 'U', list_item->name,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   if 
(refs_head_ref(get_submodule_ref_store(list_item->name), 
handle_submodule_head_ref, ))
+   die(_("could not resolve HEAD ref inside the"
+ "submodule '%s'"), list_item->name);
+
+ 

[GSoC][PATCH v4 4/4] 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_listed_submodule() looping through the
list obtained.

Then for_each_listed_submodule() 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 155 
 git-submodule.sh|  49 +-
 2 files changed, 156 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 85df11129..abf5c126a 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -558,6 +558,160 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array get_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "get-rev-name",
+path, oid_to_hex(oid), NULL);
+   get_rev_name(get_rev_args.argc, get_rev_args.argv,
+info->prefix);
+
+   argv_array_clear(_rev_args);
+   } else {
+   printf("\n");
+   }
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(_oid, 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 (ce_stage(list_item)) {
+   print_status(info, 'U', list_item->name,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   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, ,
+displaypath);
+   } else {
+   print_status(info, '+', list_item->name,
+_item->oid, displaypath);
+   }
+   }
+
+   if (info->recursive) {
+   struct child_process cpr = CHILD_PROCESS_INIT;
+
+

[GSoC][PATCH v4 2/4] submodule--helper: introduce for_each_listed_submodule()

[Prathamesh Chavan]

Introduce function for_each_listed_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 36 
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e25854371..ea99d8e39 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -351,15 +354,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_listed_submodule(const struct module_list *list,
+ each_submodule_fn fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
 {
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(_oid, path);
+   sub = submodule_from_path(_oid, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -371,7 +389,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
strbuf_reset();
@@ -413,7 +431,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -442,10 +460,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -470,8 +488,10 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   for_each_listed_submodule(, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC][PATCH v4 1/4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 37 +
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 818fe74f0..e25854371 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,28 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -335,15 +357,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -358,9 +372,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -368,7 +382,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -405,9 +418,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0

[GSoC][PATCH v4 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function compute_rev_name() generates the
value of the revision name as required.
The function get_rev_name() calls compute_rev_name() and receives the
revision name, and later handles its formating and printing.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index ea99d8e39..85df11129 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -245,6 +245,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int get_rev_name(int argc, const char **argv, const char *prefix)
+{
+   char *revname;
+   if (argc != 3)
+   die("get-rev-name only accepts two arguments:  ");
+
+   revname = compute_rev_name(argv[1], argv[2]);
+   if (revname && revname[0])
+   printf(" (%s)", revname);
+   printf("\n");
+
+   free(revname);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1292,6 +1354,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"get-rev-name", get_rev_name, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index 66d1ae8ef..5211361c5 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -758,18 +758,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1041,14 +1029,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[GSoC][PATCH v4 0/4] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v4:
* The patches were adjusted to recent codebase.
  Also, the gitmodules_config() was call was removed
  from the functions module_init() and module_status()
  which was essential after the merge of the branch
  bw/submodule-config-cleanup.
  Since it was mentioned earlier, I even tried basing
  the patch series on the branch nd/prune-in-worktree.
  Conflicts occured while doing so, since the later
  branch is based on the master branch with the HEAD
  pointing to the commit:  The fourth batch post 2.14
  I think there won't be any conflicts, if that is changed.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/patch-series-1

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: patch-series-1
Build #167

The above changes were based on master branch.

Another branch, similar to the above, was created, but was based
on the 'next' branch.

Complete build report of that is also available at:
https://travis-ci.org/pratham-pc/git/builds
Branch: patch-series-1-next
Build #168

The above changes are also push on github and are available at:
https://github.com/pratham-pc/git/commits/patch-series-1-next

Prathamesh Chavan (4):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_listed_submodule()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 289 +---
 git-submodule.sh|  61 +-
 2 files changed, 271 insertions(+), 79 deletions(-)

-- 
2.13.0

Re: [GSoC][PATCH v3 0/4] Incremental rewrite of git-submodules

[Prathamesh Chavan]

On Sat, Aug 26, 2017 at 12:21 AM, Junio C Hamano <gits...@pobox.com> wrote:
> Thanks.  I'll try to queue these before I'll go offline.
>
> Mentors may want to help the student further in adjusting the patch
> series to the more recent codebase; unfortunately the area the GSoC
> project touches is a bit fluid these days.  I resolved the conflicts
> with nd/pune-in-worktree and bw/submodule-config-cleanup topics so
> that the result would compile, but I am not sure if the resolution
> is correct (e.g. there may be a new leak I introduced while doing
> so).
>

Thanks.
I'll see the dirty merges and will resend the whole series after reviewing
the dirty merge and sending a new one with/without changes as required.

Thanks,
Prathamesh Chavan

[GSoC][PATCH v3 4/4] 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_listed_submodule() looping through the
list obtained.

Then for_each_listed_submodule() 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 156 
 git-submodule.sh|  49 +-
 2 files changed, 157 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6ea6408c2..577494e31 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -561,6 +561,161 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array get_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "get-rev-name",
+path, oid_to_hex(oid), NULL);
+   get_rev_name(get_rev_args.argc, get_rev_args.argv,
+info->prefix);
+
+   argv_array_clear(_rev_args);
+   } else {
+   printf("\n");
+   }
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(_oid, 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 (ce_stage(list_item)) {
+   print_status(info, 'U', list_item->name,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   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, ,
+displaypath);
+   } else {
+   print_status(info, '+', list_item->name,
+_item->oid, displaypath);
+   }
+   }
+
+   if (info->recursive) {
+   struct child_process cpr = CHILD_PROCESS_INIT;
+
+

[GSoC][PATCH v3 2/4] submodule--helper: introduce for_each_listed_submodule()

[Prathamesh Chavan]

Introduce function for_each_listed_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 +--
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e666f84ba..8cd81b144 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -353,17 +356,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_listed_submodule(const struct module_list *list,
+ each_submodule_fn fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
 {
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   /* Only loads from .gitmodules, no overlay with .git/config */
-   gitmodules_config();
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(_oid, path);
+   sub = submodule_from_path(_oid, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -375,7 +391,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
strbuf_reset();
@@ -417,7 +433,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -446,10 +462,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -474,8 +490,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   gitmodules_config();
+   for_each_listed_submodule(, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC][PATCH v3 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function compute_rev_name() generates the
value of the revision name as required.
The function get_rev_name() calls compute_rev_name() and receives the
revision name, and later handles its formating and printing.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 8cd81b144..6ea6408c2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -245,6 +245,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int get_rev_name(int argc, const char **argv, const char *prefix)
+{
+   char *revname;
+   if (argc != 3)
+   die("get-rev-name only accepts two arguments:  ");
+
+   revname = compute_rev_name(argv[1], argv[2]);
+   if (revname && revname[0])
+   printf(" (%s)", revname);
+   printf("\n");
+
+   free(revname);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1243,6 +1305,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"get-rev-name", get_rev_name, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..91f043ec6 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[GSoC][PATCH v3 1/4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 38 +-
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 84562ec83..e666f84ba 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,28 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -339,16 +361,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
/* Only loads from .gitmodules, no overlay with .git/config */
gitmodules_config();
-
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -363,9 +376,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -373,7 +386,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -410,9 +422,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0

[GSoC][PATCH v3 0/4] Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v3:

* The name of the iterator function for_each_submodule() was changed
  to the for_each_listed_submodule(), as the function fits the naming
  pattern for_each_Y_X(), as here we iterate over group of listed
  submodules (X) which are listed (Y) by the function module_list_compute()
* The name of the call back function type for the above pattern
  for_each_Y_X() is each_X_fn. Hence, this pattern was followed and
  the name of the call back function type for for_each_listed_submodule()
  was changed from submodule_list_func_t to each_submodule_fn.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/week-14-1

And its build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: week-14-1
Build #164

Prathamesh Chavan (4):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_listed_submodule()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 294 
 git-submodule.sh|  61 +
 2 files changed, 273 insertions(+), 82 deletions(-)

-- 
2.13.0

[GSoC][PATCH v2 4/4] 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() looping through the
list obtained.

Then for_each_submodule() 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 156 
 git-submodule.sh|  49 +-
 2 files changed, 157 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6ae93ce38..933073251 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -561,6 +561,161 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array get_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "get-rev-name",
+path, oid_to_hex(oid), NULL);
+   get_rev_name(get_rev_args.argc, get_rev_args.argv,
+info->prefix);
+
+   argv_array_clear(_rev_args);
+   } else {
+   printf("\n");
+   }
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(_oid, 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 (ce_stage(list_item)) {
+   print_status(info, 'U', list_item->name,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   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, ,
+displaypath);
+   } else {
+   print_status(info, '+', list_item->name,
+_item->oid, displaypath);
+   }
+   }
+
+   if (info->recursive) {
+   struct child_process cpr = CHILD_PROCESS_INIT;
+
+

[GSoC][PATCH v2 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function compute_rev_name() generates the
value of the revision name as required.
The function get_rev_name() calls compute_rev_name() and receives the
revision name, and later handles its formating and printing.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 847fba854..6ae93ce38 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -245,6 +245,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *compute_rev_name(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int get_rev_name(int argc, const char **argv, const char *prefix)
+{
+   char *revname;
+   if (argc != 3)
+   die("get-rev-name only accepts two arguments:  ");
+
+   revname = compute_rev_name(argv[1], argv[2]);
+   if (revname && revname[0])
+   printf(" (%s)", revname);
+   printf("\n");
+
+   free(revname);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1243,6 +1305,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"get-rev-name", get_rev_name, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..91f043ec6 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper get-rev-name "$sm_path" 
"$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[GSoC][PATCH v2 2/4] submodule--helper: introduce for_each_submodule()

[Prathamesh Chavan]

Introduce function for_each_submodule() and replace a loop
in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 +--
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e666f84ba..847fba854 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -353,17 +356,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule(const struct module_list *list,
+  submodule_list_func_t fn, void *cb_data)
+{
+   int i;
+   for (i = 0; i < list->nr; i++)
+   fn(list->entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
 {
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   /* Only loads from .gitmodules, no overlay with .git/config */
-   gitmodules_config();
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(_oid, path);
+   sub = submodule_from_path(_oid, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -375,7 +391,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
strbuf_reset();
@@ -417,7 +433,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -446,10 +462,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -474,8 +490,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   gitmodules_config();
+   for_each_submodule(, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC][PATCH v2 1/4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 38 +-
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 84562ec83..e666f84ba 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,28 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -339,16 +361,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
/* Only loads from .gitmodules, no overlay with .git/config */
gitmodules_config();
-
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -363,9 +376,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
+   strbuf_reset();
}
 
/*
@@ -373,7 +386,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * To look up the url in .git/config, we must not fall back to
 * .gitmodules, so look it up directly.
 */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.url", sub->name);
if (git_config_get_string(sb.buf, )) {
if (!sub->url)
@@ -410,9 +422,9 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
}
+   strbuf_reset();
 
/* Copy "update" setting when it is not set yet */
-   strbuf_reset();
strbuf_addf(, "submodule.%s.update", sub->name);
if (git_config_get_string(sb.buf, ) &&
sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
-- 
2.13.0

[GSoC][PATCH v2 0/4] submodule: Incremental rewrite of git-submodules

[Prathamesh Chavan]

Changes in v2:

* In the function get_submodule_displaypath(), I tried avoiding the extra
  memory allocation, but it rather invoked test 5 from
  t7406-submodule-update. The details of the test failiure can be seen
  in the build report as well. (Build #162)
  This failure occured as even though the function relative_path(),
  returned the value correctly, NULL was stored in sb.buf
  Hence currently the function is still using the old way of
  allocating extra memory and releasing the strbuf first, and return
  the extra allocated memory.
* It was observed that strbuf_reset was being done just before the strbuf
  was being reused. It made more sense to reset them just after their use 
  instead. Hence, these function calls of strbuf_reset() were moved
  accordingly.
  (The above change was limited to the function init_submodule() only,
   since already there was a deletion of one such funciton call,
   and IMO, it won't be suitable to carryout the operation for the complete
   file in the same commit.)
* The function name for_each_submodule_list() was changed to
  for_each_submodule().
* Instead of passing the complete list to the function for_each_submodule(),
  only its pointer is passed to avoid the compiler from making copy of the
  list, and to make the code more efficient.
* The function names of print_name_rev() and get_name_rev() were changed
  to get_rev_name() and compute_rev_name(). Now the function get_rev_name()
  acts as the front end of the subcommand and calls the function
  compute_rev_name() for generating and receiving the value of revision name.
* The above change was also accompanied by the change in names of some
  variables used internally in the functions.

As before you can find this series at: 
https://github.com/pratham-pc/git/commits/week-14-1

And the build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: week-14-1
Build #163

Prathamesh Chavan (4):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 294 
 git-submodule.sh|  61 +
 2 files changed, 273 insertions(+), 82 deletions(-)

-- 
2.13.0

[GSoC] Update: Week 14

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller 
Christian Couder 

UPDATES:

Following are the updates about my ongoing project:

* add: Although much time was spent by me on trying to debug the
  patch, the attempts made were unsuccessful or were
  rather partially successful (since while fixing one issue,
  they invoked a different one). After getting   suggestions and
  help from mentors for the remaining tests, now there are only
  two tests which the patch is currently failing at.
  The current status of the patch can be viewed at [2].

* update: porting this subcommand is already underway, and
  porting of the functions is_tip_reachable() and
  fetch_in_submodule() as completed.

* patches: a smaller patch series is floated on the mailing list
  for the maintainer's review.

The small patch series which recently was floated is pushed on Github
and is available at [3].

PLAN FOR WEEK-15 (22 August 2017 to 28 August 2017):

* add: One of the main aims of the next week is to resolve the
  the two tests which the current patch fails at.

* patches: will be working on getting the smaller series merged, and
  once its done, will prepare and float the next patch for the
  same purpose. Till then, I aim to stay more active on the mailing
  list as well for responding to the reviews.

Since I am a bit busier the following week (due to college academics),
I will resume porting submodule subcommand 'update' in the following week.

[1]: 
https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: https://github.com/pratham-pc/git/commits/week-14-1

Re: [GSoC][PATCH 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

On Mon, Aug 21, 2017 at 10:17 PM, Heiko Voigt <hvo...@hvoigt.net> wrote:
> On Mon, Aug 21, 2017 at 09:45:14PM +0530, Prathamesh Chavan wrote:
>> Function set_name_rev() is ported from git-submodule to the
>> submodule--helper builtin. The function get_name_rev() generates the
>> value of the revision name as required, and the function
>> print_name_rev() handles the formating and printing of the obtained
>> revision name.
>>
>> Mentored-by: Christian Couder <christian.cou...@gmail.com>
>> Mentored-by: Stefan Beller <sbel...@google.com>
>> Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
>> ---
>>  builtin/submodule--helper.c | 63 
>> +
>>  git-submodule.sh| 16 ++--
>>  2 files changed, 65 insertions(+), 14 deletions(-)
>>
>> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
>> index 7803457ba..a4bff3f38 100644
>> --- a/builtin/submodule--helper.c
>> +++ b/builtin/submodule--helper.c
>
> [...]
>
>> @@ -1242,6 +1304,7 @@ static struct cmd_struct commands[] = {
>>   {"relative-path", resolve_relative_path, 0},
>>   {"resolve-relative-url", resolve_relative_url, 0},
>>   {"resolve-relative-url-test", resolve_relative_url_test, 0},
>> + {"print-name-rev", print_name_rev, 0},
>
> I see the function in git-submodule.sh was named kind of reverse. How
> about we do it more naturally here and call this 'rev-name' instead?
> That makes is more clear to me and is also similar to the used variable
> name 'revname'.

The functions 'print_name_rev()' and 'get_name_rev()' are the ported
C functions of the function 'set_name_rev()'
Their names were assigned so due to the existing function's name,
and hence to faithfully port the functions.

But, thanks for the above suggestion, and also for reviewing
the patch. I will update the names as print_rev_name() and
get_rev_name() respectively.
>
> I would also prefix it differently like 'get' or 'calculate' instead of
> 'print' since it tries to find a name and is not just a simple lookup.

The former function from the shell script, 'set_name_rev()' is split
into two functions, namely: 'print_name_rev()' and 'get_name_rev()'
The function print_name_rev() is just the front_end of the function,
and exists to printf the return value of the get_name_rev() function
is the required format.
Calculation of the value is actually done by the function
get_name_rev().
Hence, I named the functions the way they are.

Thanks,
Prathamesh Chavan

[GSoC][PATCH 4/4] 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
The patch below underwent some changes after its previous version.

In the shell script, the submodules, which had merge-conflicts are
identified by checking if the $stage variable has the value 'U'
Till the last patch series, this was done by checking if ce_flags have
a non-zero value. In this new patch series, this was changed and
instead ce_stage() was called on the list_item(cache_entry), and then
we check whether it has a non-zero value.

 builtin/submodule--helper.c | 156 
 git-submodule.sh|  49 +-
 2 files changed, 157 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a4bff3f38..831370d6e 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -560,6 +560,161 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "print-name-rev",
+path, oid_to_hex(oid), NULL);
+   print_name_rev(name_rev_args.argc, name_rev_args.argv,
+  info->prefix);
+
+   argv_array_clear(_rev_args);
+   } else {
+   printf("\n");
+   }
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(_oid, 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 (ce_stage(list_item)) {
+   print_status(info, 'U', list_item->name,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   if (head_ref_submodule(list_item->name,
+  handle_submodule_head_ref, ))
+   die(_("could not resolve HEAD ref inside the"
+ "submodule '%s'&qu

[GSoC][PATCH 1/4] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
As said in the previous update,
a short patch series is floated for the maintainer's review,
and is consisting of the following changes:
* introduce function get_submodule_displaypath()
* introduce function for_each_submodule_list()
* port function set_name_rev() from shell to C
* port submodule subcommand 'status' from shell to C

The complete build report for the above series of patches is available
at:
https://travis-ci.org/pratham-pc/git/builds
Branch: week-14-1
Build #158
The above changes are also push on github and are available at:
https://github.com/pratham-pc/git/commits/week-14-1

The above changes were based on master branch.
But along with the above changes, the same series was also applied
to a separate branch based on the 'next' branch. The changes were
applicable without any additional changes to the patches.
Complete build report of that is also available at:
https://travis-ci.org/pratham-pc/git/builds
Branch: week-14-1-next
Build #159
The above changes are also push on github and are available at:
https://github.com/pratham-pc/git/commits/week-14-1-next

 builtin/submodule--helper.c | 33 ++---
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 84562ec83..dcdbde963 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
/* Only loads from .gitmodules, no overlay with .git/config */
gitmodules_config();
-
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(_oid, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
-- 
2.13.0

[GSoC][PATCH 3/4] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function get_name_rev() generates the
value of the revision name as required, and the function
print_name_rev() handles the formating and printing of the obtained
revision name.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7803457ba..a4bff3f38 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -244,6 +244,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *get_name_rev(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int print_name_rev(int argc, const char **argv, const char *prefix)
+{
+   char *namerev;
+   if (argc != 3)
+   die("print-name-rev only accepts two arguments:  ");
+
+   namerev = get_name_rev(argv[1], argv[2]);
+   if (namerev && namerev[0])
+   printf(" (%s)", namerev);
+   printf("\n");
+
+   free(namerev);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1242,6 +1304,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"print-name-rev", print_name_rev, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..e988167e0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[GSoC][PATCH 2/4] submodule--helper: introduce for_each_submodule_list()

[Prathamesh Chavan]

Introduce function for_each_submodule_list() and
replace a loop in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 +--
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index dcdbde963..7803457ba 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -352,17 +355,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule_list(const struct module_list list,
+   submodule_list_func_t fn, void *cb_data)
 {
+   int i;
+   for (i = 0; i < list.nr; i++)
+   fn(list.entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   /* Only loads from .gitmodules, no overlay with .git/config */
-   gitmodules_config();
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(_oid, path);
+   sub = submodule_from_path(_oid, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -374,7 +390,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
@@ -416,7 +432,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -445,10 +461,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -473,8 +489,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   gitmodules_config();
+   for_each_submodule_list(list, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC] Update: Week-13

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller 
Christian Couder 

UPDATES:

Following are the updates about my ongoing project:

* add: most of the time of the week was spent in debugging the
  ported submodule subcommand functions. But, even after so,
  currently the ported functions fail in total 15 tests from
  the test suit. The WIP patches have been updated regularly,
  and currently the patch is under discussion with the mentors
  as well. The current status of the patch is pushed on github as
  well, and can be viewed at:[2]

Since the rest of the patches were almost the same as that in the
previous update(except for the 'summary' patch, which was last
updated after Christian's review), the haven't been uploaded
again to avoid unnecessary floating patches.
The previous updated series is available at: [3]
But given that, next week I plan to float a separate patch
series, containing the initial patches from the subcommand porting
series (till deinit), which IMO, are ready for maintainer's
review.

Also, this week's update was one-day late, since I was traveling
on the previous day. But a prior idea about this was given to the
mentors.

PLAN FOR WEEK-14 (15 August 2017 to 21 August 2017):

* patches: Float a separate series, till deinit, and ask the maintainer
  for its review.

* add: The main aim of the next week is to resolve the issues with
  the current patch, and get all the tests pass.

* update: it is the last remaining subcommand to be ported. I aim to
  atleast start with this in the following week.

The work till week-13 is pushed on Github and is available at: [4].

[1]: 
https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: https://public-inbox.org/git/20170807211900.15001-1-pc44...@gmail.com/
[4]: https://github.com/pratham-pc/git/commits/week-13

[GSoC][PATCH 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_submodule_list, which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule. This third function is a calling function that
takes care of running the command in that submodule, and recursively
perform the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute, generates the list of
submodules present in the current working tree.

The second function for_each_submodule_list traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule) is called for each entry.

The third function runcommand_in_submodule, generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the  of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The third function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input  of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmw...@google.com>
Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* A comment was added to clarify why the env variables were made
  available only for the case of argc == 1.

 builtin/submodule--helper.c | 142 
 git-submodule.sh|  39 +---
 2 files changed, 143 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 2080f4fb9..0717ecf80 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -770,6 +770,147 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct cb_foreach {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int recursive: 1;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
+
+static void runcommand_in_submodule(const struct cache_entry *list_item,
+   void *cb_data)
+{
+   struct cb_foreach *info = cb_data;
+   const struct submodule *sub;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *displaypath;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub)
+   die(_("No url found for submodule path '%s' in .gitmodules"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(list_item->name, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+
+   /*
+* For the purpose of executing  in the submodule,
+* separate shell is used for the purpose of running the
+* child process.
+*/
+   cp.use_shell = 1;
+   cp.dir = list_item->name;
+
+   /*
+* NEEDSWORK: the command currently has access to the variables $name,
+* $sm_path, $displaypath, $sha1 and $toplevel only when the command
+* contains a single argument. This is done for maintianing a faithful
+* translation from shell script.
+*/
+   if (info->argc == 1) {
+   char *toplevel = xgetcwd();
+
+   argv_array_pushf(_array, "name=%s", sub->name);
+   argv_array_pushf(_array, "sm_path=%s", list_item->name);
+   argv_array_pushf(_array, "displaypath=%s", displaypath);
+   argv_array_pushf(_array, "sha1=%s",
+oid_to_hex(_item->oid));
+   argv_array_pushf(_array, "toplevel=%s", toplevel);
+
+   /*
+* Since the path variable was accessible from the script
+* before porting, it is also made available after porting.
+* The environment variable "PATH" has a very special purpose
+* on windows. And since environment variables are
+* case-insensitive in windows, 

[GSoC][PATCH 12/13] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt |  6 --
 t/t7407-submodule-foreach.sh| 22 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $sm_path, $sha1 and
-   $toplevel:
+   The command has access to the variables $name, $sm_path, $displaypath,
+   $sha1 and $toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
+   $displaypath contains the relative path from the current working
+   directory to the submodules root directory,
$sha1 is the commit as recorded in the superproject, and
$toplevel is the absolute path to its superproject, such that
$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <../../actual
+   git submodule foreach "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd 
clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <../../actual
+   git submodule foreach --recursive "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
-- 
2.13.0

[GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

The submodule subcommand 'summary' is ported in the process of
making git-submodule a builtin. The function cmd_summary() from
git-submodule.sh is ported to functions module_summary(),
compute_summary_module_list(), prepare_submodule_summary() and
generate_submodule_summary(), print_summary().

The first function module_summary() parses the options of submodule
subcommand and also acts as the front-end of this subcommand.
After parsing them, it calls the compute_summary_module_list()

The functions compute_summary_module_list() runs the diff_cmd,
and generates the modules list, as required by the subcommand.
The generation of this module list is done by the using the
callback function submodule_summary_callback(), and stored in the
structure module_cb.

Once the module list is generated, prepare_submodule_summary()
further goes through the list and filters the list, for
eventually calling the generate_submodule_summary() function.

The function generate_submodule_summary() takes care of generating
the summary for each submodule and then calls the function
print_summary() for printing it.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
The major changes the patch underwent through is the splitting of the
function print_submodule_summary() into generate_submodule_summary()
and print_summary()

Apart from this, there are also minor changes which include
removal of variables sha1_abbr_dst and sha1_abbr_src,
the variable remote_key wasn't freed earlier, but now it is.

 builtin/submodule--helper.c | 428 
 git-submodule.sh| 183 +--
 2 files changed, 429 insertions(+), 182 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 02787e4a4..2080f4fb9 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,6 +13,9 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
  void *cb_data);
@@ -767,6 +770,430 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct module_cb {
+   unsigned int mod_src;
+   unsigned int mod_dst;
+   struct object_id oid_src;
+   struct object_id oid_dst;
+   char status;
+   const char *sm_path;
+};
+#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
+
+struct module_cb_list {
+   struct module_cb **entries;
+   int alloc, nr;
+};
+#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
+
+struct summary_cb {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int cached: 1;
+   unsigned int for_status: 1;
+   unsigned int quiet: 1;
+   unsigned int files: 1;
+   int summary_limits;
+};
+#define SUMMARY_CB_INIT { 0, NULL, NULL, 0, 0, 0, 0, 0 }
+
+static enum {
+   DIFF_INDEX,
+   DIFF_FILES
+} diff_cmd = DIFF_INDEX;
+
+static int verify_submodule_object_name(const char *sm_path, const char *sha1)
+{
+   struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+   cp_rev_parse.git_cmd = 1;
+   cp_rev_parse.no_stdout = 1;
+   cp_rev_parse.dir = sm_path;
+   prepare_submodule_repo_env(_rev_parse.env_array);
+   argv_array_pushl(_rev_parse.args, "rev-parse", "-q",
+"--verify", NULL);
+   argv_array_pushf(_rev_parse.args, "%s^0", sha1);
+
+   if (run_command(_rev_parse))
+   return 1;
+
+   return 0;
+}
+
+static void print_summary(struct summary_cb *info, int errmsg, int 
total_commits,
+ int missing_src, int missing_dst, const char 
*displaypath,
+ int is_sm_git_dir, struct module_cb *p)
+{
+   if (p->status == 'T') {
+   if (S_ISGITLINK(p->mod_dst))
+   printf(_("* %s %s(blob)->%s(submodule)"),
+displaypath, 
find_unique_abbrev(p->oid_src.hash, 7),
+find_unique_abbrev(p->oid_dst.hash, 7));
+   else
+   printf(_("* %s %s(submodule)->%s(blob)"),
+displaypath, 
find_unique_abbrev(p->oid_src.hash, 7),
+find_unique_abbrev(p->oid_dst.hash, 7));
+   } else {
+   printf("* %s %s...%s", displaypath, 
find_unique_abbrev(p->oid_src.hash, 7),
+find_unique_abbrev(p->oid_dst.hash, 7));
+   }
+
+   if (total_commits < 0)
+   printf(":\n");
+   else
+ 

[GSoC][PATCH 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 10 ++
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $path, $sha1 and
+   The command has access to the variables $name, $sm_path, $sha1 and
$toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
-   $path is the name of the submodule directory relative to the
-   superproject, $sha1 is the commit as recorded in the superproject,
-   and $toplevel is the absolute path to the top-level of the superproject.
+   $sm_path is the path of the submodule as recorded in the superproject,
+   $sha1 is the commit as recorded in the superproject, and
+   $toplevel is the absolute path to the top-level of the superproject.
+   Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+   variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
ignored by this command. Unless given `--quiet`, foreach prints the name
of each submodule before evaluating the command.
-- 
2.13.0

[GSoC][PATCH 11/13] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] ::
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
$sha1 is the commit as recorded in the superproject, and
-   $toplevel is the absolute path to the top-level of the superproject.
+   $toplevel is the absolute path to its superproject, such that
+   $toplevel/$sm_path is the absolute path of the submodule.
Note that to avoid conflicts with '$PATH' on Windows, the '$path'
variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
-- 
2.13.0

[GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
superproject to the mount point of the submodule.
In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
case the path is equal to the relative path from $pwd to the
submodules working directory. When following this model,
the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 git-submodule.sh |  1 -
 t/t7407-submodule-foreach.sh | 36 ++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index ec57d6528..4b7da2fc1 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
prefix="$prefix$sm_path/"
sanitize_submodule_env
cd "$sm_path" &&
-   sm_path=$(git submodule--helper relative-path 
"$sm_path" "$wt_prefix") &&
# we make $path available to scripts ...
path=$sm_path &&
if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <expect <../../actual
+   ) &&
+   test_i18ncmp expect actual
+'
 
 cat > expect <

[GSoC][PATCH 07/13] diff: change scope of the function count_lines()

[Prathamesh Chavan]

Change the scope of function count_lines for allowing the function
to be reused in other parts of the code as well.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 diff.c | 2 +-
 diff.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index 85e714f6c..03ed64f93 100644
--- a/diff.c
+++ b/diff.c
@@ -425,7 +425,7 @@ struct emit_callback {
struct strbuf *header;
 };
 
-static int count_lines(const char *data, int size)
+int count_lines(const char *data, int size)
 {
int count, ch, completely_empty = 1, nl_just_seen = 0;
count = 0;
diff --git a/diff.h b/diff.h
index 2d442e296..8522514e9 100644
--- a/diff.h
+++ b/diff.h
@@ -273,6 +273,7 @@ extern struct diff_filepair *diff_unmerge(struct 
diff_options *, const char *pat
 extern int parse_long_opt(const char *opt, const char **argv,
 const char **optarg);
 
+extern int count_lines(const char *data, int size);
 extern int git_diff_basic_config(const char *var, const char *value, void *cb);
 extern int git_diff_heuristic_config(const char *var, const char *value, void 
*cb);
 extern void init_diff_ui_defaults(void);
-- 
2.13.0

[GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 148 
 git-submodule.sh|  55 +---
 2 files changed, 149 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 82f1aed87..02787e4a4 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -915,6 +915,153 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int force: 1;
+   unsigned int all: 1;
+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+void *cb_data)
+{
+   struct deinit_cb *info = cb_data;
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+   mode_t mode = 0777;
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(list_item->name)) {
+   struct stat st;
+   /*
+* protect submodules containing a .git directory
+* NEEDSWORK: automatically call absorbgitdirs before
+* warning/die.
+*/
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory use 'rm -rf' if you really want "
+ "to remove it including all of its history"),
+ displaypath);
+
+   if (!info->force) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+list_item->name, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   if (!lstat(list_item->name, )) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   strbuf_addstr(_rm, list_item->name);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work 
tree '%s'\n");
+
+   if (!info->quiet)
+   printf(format, displaypath);
+
+   mode = st.st_mode;
+
+   strbuf_release(_rm);
+   }
+   }
+
+   if (mkdir(list_item->name, mode))
+   die_errno(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later decides to init this submodule again
+*/
+   git_config_rename_section_in_file(NULL, sub_key, NULL);
+   if (!info->quiet)
+   printf(_("Submodule '%s' (%s) unregistered for path 
'%s'\n"),
+sub->name, sub->url, displaypath);
+   free(sub_key);
+   }
+
+cleanup:
+   free(displaypath);
+   free(sub_gi

[GSoC][PATCH 04/13] 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 156 
 git-submodule.sh|  49 +-
 2 files changed, 157 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 421eee1e2..1bf7bb2a2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -560,6 +560,161 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "print-name-rev",
+path, oid_to_hex(oid), NULL);
+   print_name_rev(name_rev_args.argc, name_rev_args.argv,
+  info->prefix);
+
+   argv_array_clear(_rev_args);
+   } else {
+   printf("\n");
+   }
+}
+
+static int handle_submodule_head_ref(const char *refname,
+const struct object_id *oid, int flags,
+void *cb_data)
+{
+   struct object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   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,
+_oid, displaypath);
+   goto cleanup;
+   }
+
+   if (!is_submodule_active(the_repository, list_item->name)) {
+   print_status(info, '-', list_item->name, _item->oid,
+displaypath);
+   goto cleanup;
+   }
+
+   argv_array_pushl(_files_args, "diff-files",
+"--ignore-submodules=dirty", "--quiet", "--",
+list_item->name, NULL);
+
+   if (!cmd_diff_files(diff_files_args.argc, diff_files_args.argv,
+   info->prefix)) {
+   print_status(info, ' ', list_item->name, _item->oid,
+displaypath);
+   } else {
+   if (!info->cached) {
+   struct object_id oid;
+
+   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, ,
+displaypath);
+   } else {
+   print_status(info, '+', list_item->name,
+_item->oid, displaypath);
+   }
+   }
+
+   if (info->recursive) {
+   struct child_process cpr = CHILD_PROCESS_INIT;
+
+ 

[GSoC][PATCH 05/13] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing three functions: module_sync(),
sync_submodule() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 183 
 git-submodule.sh|  57 +-
 2 files changed, 184 insertions(+), 56 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 1bf7bb2a2..82f1aed87 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -44,6 +44,20 @@ static char *get_default_remote(void)
return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char 
*prefix)
+{
+   const char *remote;
+
+   if (argc != 1)
+   die(_("submodule--helper print-default-remote takes no 
arguments"));
+
+   remote = get_default_remote();
+   if (remote)
+   printf("%s\n", remote);
+
+   return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
return str[0] == '.' && is_dir_sep(str[1]);
@@ -379,6 +393,25 @@ static void module_list_active(struct module_list *list)
*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+   int i;
+   struct strbuf sb = STRBUF_INIT;
+
+   for (i = count_slashes(path); i; i--)
+   strbuf_addstr(, "../");
+
+   /*
+* Check if 'path' ends with slash or not
+* for having the same output for dir/sub_dir
+* and dir/sub_dir/
+*/
+   if (!is_dir_sep(path[strlen(path) - 1]))
+   strbuf_addstr(, "../");
+
+   return strbuf_detach(, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
int i;
@@ -734,6 +767,154 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct sync_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int recursive: 1;
+};
+#define SYNC_CB_INIT { NULL, 0, 0 }
+
+static void sync_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+   struct sync_cb *info = cb_data;
+   const struct submodule *sub;
+   char *remote_key = NULL;
+   char *sub_origin_url, *super_config_url, *displaypath;
+   struct strbuf sb = STRBUF_INIT;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *sub_config_path = NULL;
+
+   if (!is_submodule_active(the_repository, list_item->name))
+   return;
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (sub && sub->url) {
+   if (starts_with_dot_dot_slash(sub->url) || 
starts_with_dot_slash(sub->url)) {
+   char *remote_url, *up_path;
+   char *remote = get_default_remote();
+   strbuf_addf(, "remote.%s.url", remote);
+
+   if (git_config_get_string(sb.buf, _url))
+   remote_url = xgetcwd();
+
+   up_path = get_up_path(list_item->name);
+   sub_origin_url = relative_url(remote_url, sub->url, 
up_path);
+   super_config_url = relative_url(remote_url, sub->url, 
NULL);
+
+   free(remote);
+   free(up_path);
+   free(remote_url);
+   } else {
+   sub_origin_url = xstrdup(sub->url);
+   super_config_url = xstrdup(sub->url);
+   }
+   } else {
+   sub_origin_url = "";
+   super_config_url = "";
+   }
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   if (!info->quiet)
+   printf(_("Synchronizing submodule url for '%s'\n"),
+displaypath);
+
+   strbuf_reset();
+   strbuf_addf(, "submodule.%s.url", sub->name);
+   if (git_config_set_gently(sb.buf, super_config_url))
+   die(_("failed to register url for submodule path '%s'"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(list_item->name, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+   cp.git_cmd = 1;
+   cp.dir = list_item->name;
+   argv_array_pushl(, "submodule--helper",
+"print-defa

[GSoC][PATCH 01/13] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 33 ++---
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6abdad329..7af4de09b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
/* Only loads from .gitmodules, no overlay with .git/config */
gitmodules_config();
-
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(null_sha1, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
-- 
2.13.0

[GSoC][PATCH 00/13] Update: Week-12

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller <sbel...@google.com>
Christian Couder <christian.cou...@gmail.com>

UPDATES:

Following are the updates about my ongoing project:

* Following patches were updated after the previous reviews:
  submodule subcommands:
  - deinit
  - summary
  - foreach

* summary: the function print_submodule_summary() is split-up
  into two separate functions: generate_submodule_summary()
  and print_summary().

* porting of submodule subcommand 'add' is completed and I have
  started with debugging ported function. Currently, the
  entire function cmd_add() is ported to the function
  module_add() in C. Soon, its first patch will be floated
  here as well once debugging is completed. Its progress can be
  viewed at [2].

* displaypath: Last week, there was some confusion produced
  with the way, the value of displaypath is being generated,
  which led to some discussion, which is available at: [3].

PLAN FOR WEEK-13 (8 August 2017 to 14 August 2017):

* patches: IMO, the patches till deinit are reviewed many times,
  and hence will try to get at least these patches merged.

* add: As this subcommand is widely used in the test suite, there
  are many tests this ported function is failing at. Hence,
  debugging the subcommand would be another task for the next week.

* deinit: A bug was identified by Stefan in the last patch-series.
  its details are available at: [4]
  Currenlty, the bug was handled by adding a NEEDSWORK tagged
  comment as suggest. If possible, I will also start working
  on debugging the issue asap.

A complete build report of these series of patches is available at: [5].
Build #151
Branch: week-12

The work is pushed on Github and is available at: [6].

[1]: 
https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: 
https://public-inbox.org/git/CAME+mvXsh53kLJ4se4uKY=SJcvSbHtEZQ6K2CgAPs=1wxux...@mail.gmail.com/
[4]: 
https://public-inbox.org/git/CAGZ79kbyyR54me_+wQDZRrikqKTp_a98yozVfr8P85QHfyyy=q...@mail.gmail.com/
[5]: https://travis-ci.org/pratham-pc/git/builds/
[6]: https://github.com/pratham-pc/git/commits/week-12

Prathamesh Chavan (13):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c | 1190 ++-
 diff.c  |2 +-
 diff.h  |1 +
 git-submodule.sh|  396 +
 t/t7407-submodule-foreach.sh|   38 +-
 6 files changed, 1222 insertions(+), 420 deletions(-)

-- 
2.13.0

[GSoC][PATCH 02/13] submodule--helper: introduce for_each_submodule_list()

[Prathamesh Chavan]

Introduce function for_each_submodule_list() and
replace a loop in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 +--
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7af4de09b..e41572f7a 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -352,17 +355,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule_list(const struct module_list list,
+   submodule_list_func_t fn, void *cb_data)
 {
+   int i;
+   for (i = 0; i < list.nr; i++)
+   fn(list.entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   /* Only loads from .gitmodules, no overlay with .git/config */
-   gitmodules_config();
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(null_sha1, path);
+   sub = submodule_from_path(null_sha1, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -374,7 +390,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
@@ -416,7 +432,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -445,10 +461,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -473,8 +489,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   gitmodules_config();
+   for_each_submodule_list(list, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC][PATCH 03/13] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function get_name_rev() generates the
value of the revision name as required, and the function
print_name_rev() handles the formating and printing of the obtained
revision name.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 63 +
 git-submodule.sh| 16 ++--
 2 files changed, 65 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e41572f7a..421eee1e2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -244,6 +244,68 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *get_name_rev(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int print_name_rev(int argc, const char **argv, const char *prefix)
+{
+   char *namerev;
+   if (argc != 3)
+   die("print-name-rev only accepts two arguments:  ");
+
+   namerev = get_name_rev(argv[1], argv[2]);
+   if (namerev && namerev[0])
+   printf(" (%s)", namerev);
+   printf("\n");
+
+   free(namerev);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1242,6 +1304,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"print-name-rev", print_name_rev, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..e988167e0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

Re: [GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

On Sat, Aug 5, 2017 at 10:25 PM, Christian Couder
<christian.cou...@gmail.com> wrote:
> On Sat, Aug 5, 2017 at 12:28 PM, Prathamesh Chavan <pc44...@gmail.com> wrote:
>> On Tue, Aug 1, 2017 at 4:57 AM, Christian Couder
>> <christian.cou...@gmail.com> wrote:
>>> On Mon, Jul 31, 2017 at 10:56 PM, Prathamesh Chavan <pc44...@gmail.com> 
>>> wrote:
>>>
>> We can avoid it to behave same for "" and NULL, by checking if diff_cmd
>> is "cmd_diff_files", since its value is set NULL by this case.
>>
>> ret = compute_summary_module_list(strcmp(diff_cmd, "diff-files") ?
>> NULL: sb.buf, );
>> strbuf_release();
>
> It looks error prone, more fagile and less efficient to me.

I think by using enum { DIFF_INDEX, DIFF_FILES },
we can avoid using strcmp() here, and make it more efficient
not only here but also in other parts of the code, since
all such steps involving strcmp could be removed.

Thanks,
Prathamesh Chavan

Re: [GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

On Tue, Aug 1, 2017 at 4:57 AM, Christian Couder
<christian.cou...@gmail.com> wrote:
> On Mon, Jul 31, 2017 at 10:56 PM, Prathamesh Chavan <pc44...@gmail.com> wrote:
>
>> * variable head was no longer used in module_summary() and instead the strbuf
>>   was utilized.
>
> Good but there might be a few problems in the way it is used. See below.
>
>> +static int compute_summary_module_list(char *head, struct summary_cb *info)
>> +{
>> +   struct argv_array diff_args = ARGV_ARRAY_INIT;
>> +   struct rev_info rev;
>> +   struct module_cb_list list = MODULE_CB_LIST_INIT;
>> +
>> +   argv_array_push(_args, info->diff_cmd);
>> +   if (info->cached)
>> +   argv_array_push(_args, "--cached");
>> +   argv_array_pushl(_args, "--ignore-submodules=dirty", "--raw",
>> +NULL);
>> +   if (head)
>> +   argv_array_push(_args, head);
>> +   argv_array_push(_args, "--");
>> +   if (info->argc)
>> +   argv_array_pushv(_args, info->argv);
>> +
>> +   git_config(git_diff_basic_config, NULL);
>> +   init_revisions(, info->prefix);
>> +   gitmodules_config();
>> +   rev.abbrev = 0;
>> +   precompose_argv(diff_args.argc, diff_args.argv);
>> +
>> +   diff_args.argc = setup_revisions(diff_args.argc, diff_args.argv,
>> +, NULL);
>> +   rev.diffopt.output_format = DIFF_FORMAT_NO_OUTPUT | 
>> DIFF_FORMAT_CALLBACK;
>> +   rev.diffopt.format_callback = submodule_summary_callback;
>> +   rev.diffopt.format_callback_data = 
>> +
>> +   if (!info->cached) {
>> +   if (!strcmp(info->diff_cmd, "diff-index"))
>> +   setup_work_tree();
>> +   if (read_cache_preload() < 0) {
>> +   perror("read_cache_preload");
>> +   return -1;
>> +   }
>> +   } else if (read_cache() < 0) {
>> +   perror("read_cache");
>> +   return -1;
>> +   }
>> +
>> +   if (!strcmp(info->diff_cmd, "diff-index"))
>> +   run_diff_index(, info->cached);
>> +   else
>> +   run_diff_files(, 0);
>> +   prepare_submodule_summary(info, );
>> +
>> +   free(head);
>
> It is a bit strange to have this function free() an argument it is passed.
>
>> +   return 0;
>> +
>
> Spurious new line.
>
>> +}
>> +
>> +static int module_summary(int argc, const char **argv, const char *prefix)
>> +{
>> +   struct summary_cb info = SUMMARY_CB_INIT;
>> +   int cached = 0;
>> +   char *diff_cmd = "diff-index";
>> +   int for_status = 0;
>> +   int quiet = 0;
>> +   int files = 0;
>> +   int summary_limits = -1;
>> +   struct child_process cp_rev = CHILD_PROCESS_INIT;
>> +   struct strbuf sb = STRBUF_INIT;
>
> [...]
>
>> +   if (!capture_command(_rev, , 0)) {
>> +   strbuf_strip_suffix(, "\n");
>> +   if (argc) {
>> +   argv++;
>> +   argc--;
>> +   }
>> +   } else if (!argc || !strcmp(argv[0], "HEAD")) {
>> +   /* before the first commit: compare with an empty tree */
>> +   struct stat st;
>> +   struct object_id oid;
>> +   if (fstat(0, ) < 0 || index_fd(oid.hash, 0, , 2, 
>> prefix, 3))
>> +   die("Unable to add %s to database", oid.hash);
>> +   strbuf_addstr(, oid_to_hex());
>> +   if (argc) {
>> +   argv++;
>> +   argc--;
>> +   }
>> +   } else {
>> +   strbuf_addstr(, "HEAD");
>> +   }
>> +
>> +   if (files) {
>> +   if (cached)
>> +   die(_("The --cached option cannot be used with the 
>> --files option"));
>> +   diff_cmd = "diff-files";
>> +
>> +   strbuf_reset();
>
> strbuf_reset() does not free the memory allocated to sb.buf...
>
>> +   sb.buf = NULL;
>
> ...then this makes sure that the memory previously allocated to sb.buf
> will not be free()d.
>
> 

Re: [GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

On Tue, Aug 1, 2017 at 3:12 AM, Stefan Beller <sbel...@google.com> wrote:
> On Mon, Jul 31, 2017 at 1:56 PM, Prathamesh Chavan <pc44...@gmail.com> wrote:
>> The same mechanism is used even for porting this submodule
>> subcommand, as used in the ported subcommands till now.
>> The function cmd_deinit in split up after porting into three
>> functions: module_deinit(), for_each_submodule_list() and
>> deinit_submodule().
>>
>> Mentored-by: Christian Couder <christian.cou...@gmail.com>
>> Mentored-by: Stefan Beller <sbel...@google.com>
>> Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
>> ---
>> In this new version, the following changes have been made:
>> * In the function deinit_submodule, since the test is_git_directory()
>>   adds an additional condition, instead is_directory() is used to check
>>   if "sm_path/.git" is a directory.
>
> Thanks for writing these patches.
> I wonder if (some of) these notes are best put into the code
> as a comment such as
>
> /* NEEDSWORK: convert to is_submodule_active */
>
> such that people reading this code later realize that checking
> for a directory may not be the "correct" thing, but a thing which
> was easy to express using shell.
>
>> +struct deinit_cb {
>> +   const char *prefix;
>> +   unsigned int quiet: 1;
>> +   unsigned int force: 1;
>> +   unsigned int all: 1;
>
> The value 'all' seems to be unused, i.e. we assign it but never read it?
>
>> +};
>> +#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
>> +
>> +static void deinit_submodule(const struct cache_entry *list_item,
>> +void *cb_data)
>> +{
>> +   struct deinit_cb *info = cb_data;
>> +   const struct submodule *sub;
>> +   char *displaypath = NULL;
>> +   struct child_process cp_config = CHILD_PROCESS_INIT;
>> +   struct strbuf sb_config = STRBUF_INIT;
>> +   char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
>> +   mode_t mode = 0777;
>> +
>> +   sub = submodule_from_path(null_sha1, list_item->name);
>> +
>> +   if (!sub || !sub->name)
>> +   goto cleanup;
>> +
>> +   displaypath = get_submodule_displaypath(list_item->name, 
>> info->prefix);
>> +
>> +   /* remove the submodule work tree (unless the user already did it) */
>> +   if (is_directory(list_item->name)) {
>> +   struct stat st;
>> +   /* protect submodules containing a .git directory */
>
> Here may a good place to put:
>   /* NEEDSWORK: automatically call absorbgitdirs before warning/die. */
> (It was not in the shell version, so feel free to ignore)
>
>> +   if (!info->force) {
>> +   struct child_process cp_rm = CHILD_PROCESS_INIT;
>> +   cp_rm.git_cmd = 1;
>> +   argv_array_pushl(_rm.args, "rm", "-qn",
>> +list_item->name, NULL);
>
> A bug that exists in the shell version as well as here:
> What if the submodule has the name '--cached', which happens
> to be a valid argument for git-rm?
>
> The call to git-rm would die claiming that the  is missing,
> as the file name was miss-interpreted as another flag.
>
> To solve this problem we would insert a '--' after the options,
> before the file name to state that the last argument is a .
>
> Not sure if we want to fix the bug while we're here or if we rather
> want to add
>
> /* NEEDSWORK: add '--' to confirm  argument */
>
IMO, I would first port the subcommand, and add an additional comment
for pointing the bug out. And then later, we may have a bug-fix patch in this
series of patch itself for tackling this bug out.

Thanks,
Prathamesh Chavan

Re: [GSoC][PATCH 04/13] submodule: port submodule subcommand 'status' from shell to C

[Prathamesh Chavan]

On Tue, Aug 1, 2017 at 2:42 AM, Stefan Beller <sbel...@google.com> wrote:
> On Mon, Jul 31, 2017 at 1:56 PM, Prathamesh Chavan <pc44...@gmail.com> 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 <christian.cou...@gmail.com>
>> Mentored-by: Stefan Beller <sbel...@google.com>
>> Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
>> ---
>> In this new version, the following changes have been made:
>> * parameters passed to the function print_status() have been changed.
>>   Instead of passing char *sub_sha1, instead the object_id is being passed.
>>
>> * Also, since the passed parameter displaypath's value isn't changed
>>   by the function, it is passed to the funcition as const char *displaypath
>>   instead of char *displaypath.
>>
>> * the output type of the function handle_submodule_head_ref() is changed
>>   from strbuf to object_id, as we will use the object_id instead of the
>>   hex of sha1 being stored in a struct strbuf.
>>
>> * diff_files_args is cleared after using it by passing it as args in the
>>   function cmd_diff_files.
>>
>> * In the function status_submodule(), for checking if a submodule has merge
>>   conflicts, the patch currently checks if the value of any of the ce_flags
>>   is non-zero. Currently, I think the we aren't interested in a partiular 
>> flag,
>>   but I'm not sure on this.
>>
>> * Debugging leftovers and suprious new-lines are removed.
>>
>> * The confusion with displaypath being passed as te super-prefix in many
>>   of the ported subcommands may be a result of the fact that the
>>   function generating the displaypath: get_submodule_displaypath()
>>   uses the super-prefix as simply a path concatenated with the current
>>   submodule name to denote our current location.
>>   The function get_super_prefix() is declared in cache.h and defined in
>>   environment.c, but is majorly used in the builtin/submodule--helper.c
>>   and also in unpack-trees.c
>>   Also, for generating any submodule's displaypath, it would be important to
>>   have ".." passed to the submodule, and currently it is possible only via 
>> the
>>   super-prefix.
>>   This is also other instaces where the super-prefix contained ".." as well.
>>   One of such instance is Test 4 from t7406-submodule-update.sh
>>   Hence, maybe documenting the value of displaypath might a solution
>>   for the above problem.
>>   I'm just stating my views and would like to recieve your opinion on this
>>   matter.
>
> Yes, I agree that the display path is not quite easily understood as it can be
> ambiguous.  I am confused by this paragraph:
> * does test 4 from 7406 fail here, or was it just the starting point
>   of the discussion and it all works fine?

Sorry for misleading there. In the discussion earlier, Brandon mentioned that
displaypath's value may contain ".." as well.
To this, I replied pointing out one of the test which checks for the value of
displaypath.
In this test, ( Test 4 from t7406-submodule-update.sh), the value of displaypath
is being calculated via the submodule_init() function present in
submodule--helper.c
Here, I wanted to point out that, even in the case of this function,
the variable
displaypath is evaluated after receiving the value of "../super/" as
the value returned
by the function get_super_prefix().
Hence, to correct this confusion about the usage of super-prefix,
(which as pointed out by Brandon has been traditionally defined
as the path from the root of the superproject down to the root of
the submodule which further means that there should not ever be
any relative '..'s.), we may either have to get the value of super-prefix's
Documentation to accomodate this change, and to accept the way it is
used in submodule--helper and the current patch series, or else,
change the way it is being used in the various function, and used
another method for evaluation of displaypath.

Thanks,
Prathamesh Chavan

[GSoC][PATCH 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

The submodule subcommand 'summary' is ported in the process of
making git-submodule a builtin. The function cmd_summary() from
git-submodule.sh is ported to functions module_summary(),
compute_summary_module_list(), prepare_submodule_summary() and
print_submodule_summary().

The first function module_summary() parses the options of submodule
subcommand and also acts as the front-end of this subcommand.
After parsing them, it calls the compute_summary_module_list()

The functions compute_summary_module_list() runs the diff_cmd,
and generates the modules list, as required by the subcommand.
The generation of this module list is done by the using the
callback function submodule_summary_callback(), and stored in the
structure module_cb.

Once the module list is generated, prepare_submodule_summary()
further goes through the list and filters the list, for
eventually calling the print_submodule_summary() function.

Finally, the print_submodule_summary() takes care of generating
and printing the summary for each submodule.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:

* Firstly, about the function compute_summary_module_list().
  This function is created to generate the list of modules, for which
  we will generate the summary further. Since the list is actually
  generated using the git-diff-files or git-diff-index command, but for
  porting this, we required to create a function similar to the builtin
  functions of the above commands. But we can't directly call cmd_diff_files() 
  and cmd_diff_index() since we don't have to display the output and instead
  need to store it. Hence, this function is introduced.
 
* Also, the module_cb_list *list is not freed since it is a non-heap object.
  Hence, free() can't be using on the non-heap objects.

* In the function prepare_submodule_summary(), as suggested
  'git_config_get_string_const' was used instead of instead of '_value'

* Some variables which weren't modified throughout the function-call were
  passed as const.

* The '!!' trick, which wasn't used in the last patch, is now used in this
  new version .

* the variables sha1_dst and sha1_src are removed from the function
  print_submodule_summary(), and instead the p->oid_src and p->oid_dst are
  used.

* The variable sm_git_dir is freed at the end of the function.

* variable head was no longer used in module_summary() and instead the strbuf
  was utilized.

 builtin/submodule--helper.c | 425 
 git-submodule.sh| 182 +--
 2 files changed, 426 insertions(+), 181 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index f642f9889..94438d6ce 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,6 +13,9 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
  void *cb_data);
@@ -766,6 +769,427 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct module_cb {
+   unsigned int mod_src;
+   unsigned int mod_dst;
+   struct object_id oid_src;
+   struct object_id oid_dst;
+   char status;
+   const char *sm_path;
+};
+#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
+
+struct module_cb_list {
+   struct module_cb **entries;
+   int alloc, nr;
+};
+#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
+
+struct summary_cb {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   char *diff_cmd;
+   unsigned int cached: 1;
+   unsigned int for_status: 1;
+   unsigned int quiet: 1;
+   unsigned int files: 1;
+   int summary_limits;
+};
+#define SUMMARY_CB_INIT { 0, NULL, NULL, NULL, 0, 0, 0, 0, 0 }
+
+static int verify_submodule_object_name(const char *sm_path, const char *sha1)
+{
+   struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+   cp_rev_parse.git_cmd = 1;
+   cp_rev_parse.no_stdout = 1;
+   cp_rev_parse.dir = sm_path;
+   prepare_submodule_repo_env(_rev_parse.env_array);
+
+   argv_array_pushl(_rev_parse.args, "rev-parse", "-q",
+"--verify", NULL);
+   argv_array_pushf(_rev_parse.args, "%s^0", sha1);
+
+   if (run_command(_rev_parse))
+   return 1;
+
+   return 0;
+}
+
+static void print_submodule_summary(struct summary_cb *info,
+   struct module_cb *p)
+{
+   int missing_src = 0;
+   int missing_dst = 0;
+   char *displaypath;
+   const 

[GSoC][PATCH 11/13] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] ::
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
$sha1 is the commit as recorded in the superproject, and
-   $toplevel is the absolute path to the top-level of the superproject.
+   $toplevel is the absolute path to its superproject, such that
+   $toplevel/$sm_path is the absolute path of the submodule.
Note that to avoid conflicts with '$PATH' on Windows, the '$path'
variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
-- 
2.13.0

[GSoC][PATCH 05/13] submodule: port submodule subcommand 'sync' from shell to C

[Prathamesh Chavan]

Port the submodule subcommand 'sync' from shell to C using the same
mechanism as that used for porting submodule subcommand 'status'.
Hence, here the function cmd_sync() is ported from shell to C.
This is done by introducing three functions: module_sync(),
sync_submodule() and print_default_remote().

The function print_default_remote() is introduced for getting
the default remote as stdout.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* There was no good reason for using puts in the function print_default_remote()
  Hence, in this patch, we instead use printf to do the same, as it is what
  is generally used throughout the codebase.

* As suggested, this patch ensures a more efficient use of variables, and
  removes most of the variables by reusing 'strbuf sb' at places required.

 builtin/submodule--helper.c | 182 
 git-submodule.sh|  56 +-
 2 files changed, 183 insertions(+), 55 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a6e6a48cc..91945337f 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -44,6 +44,20 @@ static char *get_default_remote(void)
return ret;
 }
 
+static int print_default_remote(int argc, const char **argv, const char 
*prefix)
+{
+   const char *remote;
+
+   if (argc != 1)
+   die(_("submodule--helper print-default-remote takes no 
arguments"));
+
+   remote = get_default_remote();
+   if (remote)
+   printf("%s\n", remote);
+
+   return 0;
+}
+
 static int starts_with_dot_slash(const char *str)
 {
return str[0] == '.' && is_dir_sep(str[1]);
@@ -380,6 +394,25 @@ static void module_list_active(struct module_list *list)
*list = active_modules;
 }
 
+static char *get_up_path(const char *path)
+{
+   int i;
+   struct strbuf sb = STRBUF_INIT;
+
+   for (i = count_slashes(path); i; i--)
+   strbuf_addstr(, "../");
+
+   /*
+* Check if 'path' ends with slash or not
+* for having the same output for dir/sub_dir
+* and dir/sub_dir/
+*/
+   if (!is_dir_sep(path[strlen(path) - 1]))
+   strbuf_addstr(, "../");
+
+   return strbuf_detach(, NULL);
+}
+
 static int module_list(int argc, const char **argv, const char *prefix)
 {
int i;
@@ -733,6 +766,153 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct sync_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int recursive: 1;
+};
+#define SYNC_CB_INIT { NULL, 0, 0 }
+
+static void sync_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+   struct sync_cb *info = cb_data;
+   const struct submodule *sub;
+   char *remote_key;
+   char *sub_origin_url, *super_config_url, *displaypath;
+   struct strbuf sb = STRBUF_INIT;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *sub_config_path = NULL;
+
+   if (!is_submodule_active(the_repository, list_item->name))
+   return;
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (sub && sub->url) {
+   if (starts_with_dot_dot_slash(sub->url) || 
starts_with_dot_slash(sub->url)) {
+   char *remote_url, *up_path;
+   char *remote = get_default_remote();
+   strbuf_addf(, "remote.%s.url", remote);
+
+   if (git_config_get_string(sb.buf, _url))
+   remote_url = xgetcwd();
+
+   up_path = get_up_path(list_item->name);
+   sub_origin_url = relative_url(remote_url, sub->url, 
up_path);
+   super_config_url = relative_url(remote_url, sub->url, 
NULL);
+
+   free(remote);
+   free(up_path);
+   free(remote_url);
+   } else {
+   sub_origin_url = xstrdup(sub->url);
+   super_config_url = xstrdup(sub->url);
+   }
+   } else {
+   sub_origin_url = "";
+   super_config_url = "";
+   }
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   if (!info->quiet)
+   printf(_("Synchronizing submodule url for '%s'\n"),
+displaypath);
+
+   strbuf_reset();
+   strbuf_addf(, "submodule.%s.url", sub->name);
+   if (git_config_set_gently(sb.buf, super_config_url))
+   die(_("failed to re

[GSoC][PATCH 07/13] diff: change scope of the function count_lines()

[Prathamesh Chavan]

Change the scope of function count_lines for allowing the function
to be reused in other parts of the code as well.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 diff.c | 2 +-
 diff.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index 85e714f6c..03ed64f93 100644
--- a/diff.c
+++ b/diff.c
@@ -425,7 +425,7 @@ struct emit_callback {
struct strbuf *header;
 };
 
-static int count_lines(const char *data, int size)
+int count_lines(const char *data, int size)
 {
int count, ch, completely_empty = 1, nl_just_seen = 0;
count = 0;
diff --git a/diff.h b/diff.h
index 2d442e296..8522514e9 100644
--- a/diff.h
+++ b/diff.h
@@ -273,6 +273,7 @@ extern struct diff_filepair *diff_unmerge(struct 
diff_options *, const char *pat
 extern int parse_long_opt(const char *opt, const char **argv,
 const char **optarg);
 
+extern int count_lines(const char *data, int size);
 extern int git_diff_basic_config(const char *var, const char *value, void *cb);
 extern int git_diff_heuristic_config(const char *var, const char *value, void 
*cb);
 extern void init_diff_ui_defaults(void);
-- 
2.13.0

[GSoC][PATCH 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* In the function deinit_submodule, since the test is_git_directory()
  adds an additional condition, instead is_directory() is used to check
  if "sm_path/.git" is a directory.

* since it was possible in the previous path that the value st.st_mode passed
  to the function mkdir contained a garbage value, instead we intrduce a
  mode_t variable mode, initially containing a default mode value '0777'.
  This is what the default of mode is set in case, that the value is
  not set after the lstat call. 

 builtin/submodule--helper.c | 144 
 git-submodule.sh|  55 +
 2 files changed, 145 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 91945337f..f642f9889 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -913,6 +913,149 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int force: 1;
+   unsigned int all: 1;
+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+void *cb_data)
+{
+   struct deinit_cb *info = cb_data;
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+   mode_t mode = 0777;
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(list_item->name)) {
+   struct stat st;
+   /* protect submodules containing a .git directory */
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory use 'rm -rf' if you really want "
+ "to remove it including all of its history"),
+ displaypath);
+
+   if (!info->force) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+list_item->name, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   if (!lstat(list_item->name, )) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   strbuf_addstr(_rm, list_item->name);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work 
tree '%s'\n");
+
+   if (!info->quiet)
+   printf(format, displaypath);
+
+   mode = st.st_mode;
+
+   strbuf_release(_rm);
+   }
+   }
+
+   if (mkdir(list_item->name, mode))
+   die(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later d

[GSoC][PATCH 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
This patch is same as its previous version.
Although here I'll like to add a point that we aim to slowly drop the support
of the variable 'path'.

 Documentation/git-submodule.txt | 10 ++
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $path, $sha1 and
+   The command has access to the variables $name, $sm_path, $sha1 and
$toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
-   $path is the name of the submodule directory relative to the
-   superproject, $sha1 is the commit as recorded in the superproject,
-   and $toplevel is the absolute path to the top-level of the superproject.
+   $sm_path is the path of the submodule as recorded in the superproject,
+   $sha1 is the commit as recorded in the superproject, and
+   $toplevel is the absolute path to the top-level of the superproject.
+   Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+   variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
ignored by this command. Unless given `--quiet`, foreach prints the name
of each submodule before evaluating the command.
-- 
2.13.0

[GSoC][PATCH 12/13] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* Spelling mistake in the commit message was corrected.

 Documentation/git-submodule.txt |  6 --
 t/t7407-submodule-foreach.sh| 22 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $sm_path, $sha1 and
-   $toplevel:
+   The command has access to the variables $name, $sm_path, $displaypath,
+   $sha1 and $toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
+   $displaypath contains the relative path from the current working
+   directory to the submodules root directory,
$sha1 is the commit as recorded in the superproject, and
$toplevel is the absolute path to its superproject, such that
$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <../../actual
+   git submodule foreach "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd 
clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <../../actual
+   git submodule foreach --recursive "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
-- 
2.13.0

[GSoC][PATCH 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_submodule_list, which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule. This third function is a calling function that
takes care of running the command in that submodule, and recursively
perform the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute, generates the list of
submodules present in the current working tree.

The second function for_each_submodule_list traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule) is called for each entry.

The third function runcommand_in_submodule, generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the  of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The third function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input  of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmw...@google.com>
Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* Comment style is improved in the function runcommand_in_submodule()

* Comment in added about why the variable "path" was exposed via args
  argv_array instead of exposing it via the env_array.

* This patch exposes the various variables when argc == 1 only, just
  for maintaining a faithful porting. You can also find discussion about
  the same at [1].

[1]: 
https://public-inbox.org/git/came+mvusgafbn5j-_hv7qpas57hq4wgh+yz7xjmpuyqn1ga...@mail.gmail.com/

 builtin/submodule--helper.c | 136 
 git-submodule.sh|  39 +
 2 files changed, 137 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 94438d6ce..935f56510 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -769,6 +769,141 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct cb_foreach {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int recursive: 1;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
+
+static void runcommand_in_submodule(const struct cache_entry *list_item,
+   void *cb_data)
+{
+   struct cb_foreach *info = cb_data;
+   const struct submodule *sub;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *displaypath;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub)
+   die(_("No url found for submodule path '%s' in .gitmodules"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(list_item->name, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+
+   /*
+* For the purpose of executing  in the submodule,
+* separate shell is used for the purpose of running the
+* child process.
+*/
+   cp.use_shell = 1;
+   cp.dir = list_item->name;
+
+   if (info->argc == 1) {
+   char *toplevel = xgetcwd();
+
+   argv_array_pushf(_array, "name=%s", sub->name);
+   argv_array_pushf(_array, "sm_path=%s", list_item->name);
+   argv_array_pushf(_array, "displaypath=%s", displaypath);
+   argv_array_pushf(_array, "sha1=%s",
+oid_to_hex(_item->oid));
+   argv_array_pushf(_array, "toplevel=%s", toplevel);
+
+   /*
+* Since the path variable was accessible from the script
+* before porting, it is also made available after porting.
+* The environment variable "PATH" has a very special purpose
+* on windows. And since environment

[GSoC][PATCH 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
superproject to the mount point of the submodule.
In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
case the path is equal to the relative path from $pwd to the
submodules working directory. When following this model,
the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 git-submodule.sh |  1 -
 t/t7407-submodule-foreach.sh | 36 ++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a427ddafd..493a64372 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
prefix="$prefix$sm_path/"
sanitize_submodule_env
cd "$sm_path" &&
-   sm_path=$(git submodule--helper relative-path 
"$sm_path" "$wt_prefix") &&
# we make $path available to scripts ...
path=$sm_path &&
if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <expect <../../actual
+   ) &&
+   test_i18ncmp expect actual
+'
 
 cat > expect <

[GSoC][PATCH 04/13] 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* parameters passed to the function print_status() have been changed.
  Instead of passing char *sub_sha1, instead the object_id is being passed.
 
* Also, since the passed parameter displaypath's value isn't changed
  by the function, it is passed to the funcition as const char *displaypath
  instead of char *displaypath.

* the output type of the function handle_submodule_head_ref() is changed
  from strbuf to object_id, as we will use the object_id instead of the
  hex of sha1 being stored in a struct strbuf.

* diff_files_args is cleared after using it by passing it as args in the
  function cmd_diff_files.

* In the function status_submodule(), for checking if a submodule has merge
  conflicts, the patch currently checks if the value of any of the ce_flags
  is non-zero. Currently, I think the we aren't interested in a partiular flag,
  but I'm not sure on this.

* Debugging leftovers and suprious new-lines are removed.

* The confusion with displaypath being passed as te super-prefix in many
  of the ported subcommands may be a result of the fact that the
  function generating the displaypath: get_submodule_displaypath()
  uses the super-prefix as simply a path concatenated with the current
  submodule name to denote our current location.
  The function get_super_prefix() is declared in cache.h and defined in
  environment.c, but is majorly used in the builtin/submodule--helper.c
  and also in unpack-trees.c
  Also, for generating any submodule's displaypath, it would be important to
  have ".." passed to the submodule, and currently it is possible only via the
  super-prefix.
  This is also other instaces where the super-prefix contained ".." as well.
  One of such instance is Test 4 from t7406-submodule-update.sh
  Hence, maybe documenting the value of displaypath might a solution
  for the above problem.
  I'm just stating my views and would like to recieve your opinion on this
  matter.

 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 2cb72d68e..a6e6a48cc 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -561,6 +561,159 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+   if (state == ' ' || state == '+') {
+   struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "print-name-rev",
+path, oid_to_hex(oid), 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 object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   char *displaypath;
+   struct argv_array diff_files_args = ARGV_ARRAY_INIT;
+
+   if (!submodule_from_path(null_sha1, list_item->name))
+

[GSoC][PATCH 03/13] submodule: port set_name_rev() from shell to C

[Prathamesh Chavan]

Function set_name_rev() is ported from git-submodule to the
submodule--helper builtin. The function get_name_rev() generates the
value of the revision name as required, and the function
print_name_rev() handles the formating and printing of the obtained
revision name.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* The variable namerev from print_name_rev is now freed at the end of the 
  function.

 builtin/submodule--helper.c | 64 +
 git-submodule.sh| 16 ++--
 2 files changed, 66 insertions(+), 14 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index e41572f7a..2cb72d68e 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -244,6 +244,69 @@ static char *get_submodule_displaypath(const char *path, 
const char *prefix)
}
 }
 
+static char *get_name_rev(const char *sub_path, const char* object_id)
+{
+   struct strbuf sb = STRBUF_INIT;
+   const char ***d;
+
+   static const char *describe_bare[] = {
+   NULL
+   };
+
+   static const char *describe_tags[] = {
+   "--tags", NULL
+   };
+
+   static const char *describe_contains[] = {
+   "--contains", NULL
+   };
+
+   static const char *describe_all_always[] = {
+   "--all", "--always", NULL
+   };
+
+   static const char **describe_argv[] = {
+   describe_bare, describe_tags, describe_contains,
+   describe_all_always, NULL
+   };
+
+   for (d = describe_argv; *d; d++) {
+   struct child_process cp = CHILD_PROCESS_INIT;
+   prepare_submodule_repo_env(_array);
+   cp.dir = sub_path;
+   cp.git_cmd = 1;
+   cp.no_stderr = 1;
+
+   argv_array_push(, "describe");
+   argv_array_pushv(, *d);
+   argv_array_push(, object_id);
+
+   if (!capture_command(, , 0) && sb.len) {
+   strbuf_strip_suffix(, "\n");
+   return strbuf_detach(, NULL);
+   }
+
+   }
+
+   strbuf_release();
+   return NULL;
+}
+
+static int print_name_rev(int argc, const char **argv, const char *prefix)
+{
+   char *namerev;
+   if (argc != 3)
+   die("print-name-rev only accepts two arguments:  ");
+
+   namerev = get_name_rev(argv[1], argv[2]);
+   if (namerev && namerev[0])
+   printf(" (%s)", namerev);
+   printf("\n");
+
+   free(namerev);
+   return 0;
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -1242,6 +1305,7 @@ static struct cmd_struct commands[] = {
{"relative-path", resolve_relative_path, 0},
{"resolve-relative-url", resolve_relative_url, 0},
{"resolve-relative-url-test", resolve_relative_url_test, 0},
+   {"print-name-rev", print_name_rev, 0},
{"init", module_init, SUPPORT_SUPER_PREFIX},
{"remote-branch", resolve_remote_submodule_branch, 0},
{"push-check", push_check, 0},
diff --git a/git-submodule.sh b/git-submodule.sh
index e131760ee..e988167e0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -759,18 +759,6 @@ cmd_update()
}
 }
 
-set_name_rev () {
-   revname=$( (
-   sanitize_submodule_env
-   cd "$1" && {
-   git describe "$2" 2>/dev/null ||
-   git describe --tags "$2" 2>/dev/null ||
-   git describe --contains "$2" 2>/dev/null ||
-   git describe --all --always "$2"
-   }
-   ) )
-   test -z "$revname" || revname=" ($revname)"
-}
 #
 # Show commit summary for submodules in index or working tree
 #
@@ -1042,14 +1030,14 @@ cmd_status()
fi
if git diff-files --ignore-submodules=dirty --quiet -- 
"$sm_path"
then
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say " $sha1 $displaypath$revname"
else
if test -z "$cached"
then
sha1=$(sanitize_submodule_env; cd "$sm_path" && 
git rev-parse --verify HEAD)
fi
-   set_name_rev "$sm_path" "$sha1"
+   revname=$(git submodule--helper print-name-rev 
"$sm_path" "$sha1")
say "+$sha1 $displaypath$revname"
fi
 
-- 
2.13.0

[GSoC][PATCH 02/13] submodule--helper: introduce for_each_submodule_list()

[Prathamesh Chavan]

Introduce function for_each_submodule_list() and
replace a loop in module_init() with a call to it.

The new function will also be used in other parts of the
system in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 39 +--
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 7af4de09b..e41572f7a 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -14,6 +14,9 @@
 #include "refs.h"
 #include "connect.h"
 
+typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
+ void *cb_data);
+
 static char *get_default_remote(void)
 {
char *dest = NULL, *ret;
@@ -352,17 +355,30 @@ static int module_list(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
-static void init_submodule(const char *path, const char *prefix, int quiet)
+static void for_each_submodule_list(const struct module_list list,
+   submodule_list_func_t fn, void *cb_data)
 {
+   int i;
+   for (i = 0; i < list.nr; i++)
+   fn(list.entries[i], cb_data);
+}
+
+struct init_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+};
+#define INIT_CB_INIT { NULL, 0 }
+
+static void init_submodule(const struct cache_entry *list_item, void *cb_data)
+{
+   struct init_cb *info = cb_data;
const struct submodule *sub;
struct strbuf sb = STRBUF_INIT;
char *upd = NULL, *url = NULL, *displaypath;
 
-   /* Only loads from .gitmodules, no overlay with .git/config */
-   gitmodules_config();
-   displaypath = get_submodule_displaypath(path, prefix);
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
 
-   sub = submodule_from_path(null_sha1, path);
+   sub = submodule_from_path(null_sha1, list_item->name);
 
if (!sub)
die(_("No url found for submodule path '%s' in .gitmodules"),
@@ -374,7 +390,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 *
 * Set active flag for the submodule being initialized
 */
-   if (!is_submodule_active(the_repository, path)) {
+   if (!is_submodule_active(the_repository, list_item->name)) {
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
@@ -416,7 +432,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
if (git_config_set_gently(sb.buf, url))
die(_("Failed to register url for submodule path '%s'"),
displaypath);
-   if (!quiet)
+   if (!info->quiet)
fprintf(stderr,
_("Submodule '%s' (%s) registered for path 
'%s'\n"),
sub->name, url, displaypath);
@@ -445,10 +461,10 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
 static int module_init(int argc, const char **argv, const char *prefix)
 {
+   struct init_cb info = INIT_CB_INIT;
struct pathspec pathspec;
struct module_list list = MODULE_LIST_INIT;
int quiet = 0;
-   int i;
 
struct option module_init_options[] = {
OPT__QUIET(, N_("Suppress output for initializing a 
submodule")),
@@ -473,8 +489,11 @@ static int module_init(int argc, const char **argv, const 
char *prefix)
if (!argc && git_config_get_value_multi("submodule.active"))
module_list_active();
 
-   for (i = 0; i < list.nr; i++)
-   init_submodule(list.entries[i]->name, prefix, quiet);
+   info.prefix = prefix;
+   info.quiet = !!quiet;
+
+   gitmodules_config();
+   for_each_submodule_list(list, init_submodule, );
 
return 0;
 }
-- 
2.13.0

[GSoC][PATCH 01/13] submodule--helper: introduce get_submodule_displaypath()

[Prathamesh Chavan]

Introduce function get_submodule_displaypath() to replace the code
occurring in submodule_init() for generating displaypath of the
submodule with a call to it.

This new function will also be used in other parts of the system
in later patches.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 builtin/submodule--helper.c | 33 ++---
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6abdad329..7af4de09b 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -220,6 +220,27 @@ static int resolve_relative_url_test(int argc, const char 
**argv, const char *pr
return 0;
 }
 
+static char *get_submodule_displaypath(const char *path, const char *prefix)
+{
+   const char *super_prefix = get_super_prefix();
+
+   if (prefix && super_prefix) {
+   BUG("cannot have prefix '%s' and superprefix '%s'",
+   prefix, super_prefix);
+   } else if (prefix) {
+   struct strbuf sb = STRBUF_INIT;
+   char *displaypath = xstrdup(relative_path(path, prefix, ));
+   strbuf_release();
+   return displaypath;
+   } else if (super_prefix) {
+   int len = strlen(super_prefix);
+   const char *format = is_dir_sep(super_prefix[len - 1]) ? "%s%s" 
: "%s/%s";
+   return xstrfmt(format, super_prefix, path);
+   } else {
+   return xstrdup(path);
+   }
+}
+
 struct module_list {
const struct cache_entry **entries;
int alloc, nr;
@@ -339,16 +360,7 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 
/* Only loads from .gitmodules, no overlay with .git/config */
gitmodules_config();
-
-   if (prefix && get_super_prefix())
-   die("BUG: cannot have prefix and superprefix");
-   else if (prefix)
-   displaypath = xstrdup(relative_path(path, prefix, ));
-   else if (get_super_prefix()) {
-   strbuf_addf(, "%s%s", get_super_prefix(), path);
-   displaypath = strbuf_detach(, NULL);
-   } else
-   displaypath = xstrdup(path);
+   displaypath = get_submodule_displaypath(path, prefix);
 
sub = submodule_from_path(null_sha1, path);
 
@@ -363,7 +375,6 @@ static void init_submodule(const char *path, const char 
*prefix, int quiet)
 * Set active flag for the submodule being initialized
 */
if (!is_submodule_active(the_repository, path)) {
-   strbuf_reset();
strbuf_addf(, "submodule.%s.active", sub->name);
git_config_set_gently(sb.buf, "true");
}
-- 
2.13.0

[GSoC][PATCH 00/13] Update: Week-11

[Prathamesh Chavan]

SUMMARY OF MY PROJECT:

Git submodule subcommands are currently implemented by using shell script
'git-submodule.sh'. There are several reasons why we'll prefer not to
use the shell script. My project intends to convert the subcommands into
C code, thus making them builtins. This will increase Git's portability
and hence the efficiency of working with the git-submodule commands.
Link to the complete proposal: [1]

Mentors:
Stefan Beller 
Christian Couder 

UPDATES:

Following are the updates about my ongoing project:

* Following patches were updated after the previous reviews:
  - set_name_rev()
  submodule subcommands:
  - status
  - sync
  - deinit
  - summary
  - foreach

* Reviews from both Christian Couder  and
  Brandon Williams  helped in improvising these patches
  and their suggestions were implemented.

* Porting of submodule subcommand add is still underway. Its progess can be
  viewed at [2].

PLAN FOR WEEK-12 (1 August 2017 to 7 August 2017):

* summary: One of the problems pointed out by Brandon this week was that
  the function print_submodule_summary() was too big to keep track of
  all the things that are happening. Hence, I will be splitting the
  function into smaller functions.

* displaypath: There is some confusion produced with the way the
  value of displaypath is being generated, using super-prefix. [3]
  Via having discussion on this, I'll try to resolve the issues
  regarding it. In the patches following the update, I have addressed
  this issue as well.

* add: Porting of this subcommand is still underway and will be working
  on to completely port this subcommand.

A complete build report of these series of patches is available at: [4].
Build #145
Branch: week-11

The work is push on github and is available at: [5].

[1]: 
https://docs.google.com/document/d/1krxVLooWl--75Pot3dazhfygR3wCUUWZWzTXtK1
L-xU/
[2]: https://github.com/pratham-pc/git/commits/sub-add
[3]: https://public-inbox.org/git/20170724213028.gb92...@google.com/
[4]: https://travis-ci.org/pratham-pc/git/builds/
[5]: https://github.com/pratham-pc/git/commits/week-11

  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule_list()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C
  submodule: port submodule subcommand 'sync' from shell to C
  submodule: port submodule subcommand 'deinit' from shell to C
  diff: change scope of the function count_lines()
  submodule: port submodule subcommand 'summary' from shell to C
  submodule foreach: correct '$path' in nested submodules from a
subdirectory
  submodule foreach: document '$sm_path' instead of '$path'
  submodule foreach: clarify the '$toplevel' variable documentation
  submodule foreach: document variable '$displaypath'
  submodule: port submodule subcommand 'foreach' from shell to C

 Documentation/git-submodule.txt |   15 +-
 builtin/submodule--helper.c | 1175 ++-
 diff.c  |2 +-
 diff.h  |1 +
 git-submodule.sh|  394 +
 t/t7407-submodule-foreach.sh|   38 +-
 6 files changed, 1207 insertions(+), 418 deletions(-)

-- 
2.13.0

Re: [GSoC][PATCH v2 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

On Sun, Jul 30, 2017 at 10:58 AM, Christian Couder
<christian.cou...@gmail.com> wrote:
> On Sun, Jul 30, 2017 at 12:23 AM, Prathamesh Chavan <pc44...@gmail.com> wrote:
>
>> +static int module_summary(int argc, const char **argv, const char *prefix)
>> +{
>> +   struct summary_cb info = SUMMARY_CB_INIT;
>> +   int cached = 0;
>> +   char *diff_cmd = "diff-index";
>> +   int for_status = 0;
>> +   int quiet = 0;
>> +   int files = 0;
>> +   int summary_limits = -1;
>> +   struct child_process cp_rev = CHILD_PROCESS_INIT;
>> +   char *head;
>> +   struct strbuf sb = STRBUF_INIT;
>> +   int ret;
>> +
>> +   struct option module_summary_options[] = {
>> +   OPT__QUIET(, N_("Suppress output for initializing a 
>> submodule")),
>> +   OPT_BOOL(0, "cached", , N_("Use the commit stored in 
>> the index instead of the submodule HEAD")),
>> +   OPT_BOOL(0, "files", , N_("To compares the commit in 
>> the index with that in the submodule HEAD")),
>> +   OPT_BOOL(0, "for-status", _status, N_("Skip submodules 
>> with 'all' ignore_config value")),
>> +   OPT_INTEGER('n', "summary-limits", _limits, 
>> N_("Limit the summary size")),
>> +   OPT_END()
>> +   };
>> +
>> +   const char *const git_submodule_helper_usage[] = {
>> +   N_("git submodule--helper summary [] [--] 
>> []"),
>> +   NULL
>> +   };
>> +
>> +   argc = parse_options(argc, argv, prefix, module_summary_options,
>> +git_submodule_helper_usage, 0);
>> +
>> +   if (!summary_limits)
>> +   return 0;
>> +
>> +   cp_rev.git_cmd = 1;
>> +   argv_array_pushl(_rev.args, "rev-parse", "-q", "--verify",
>> +argc ? argv[0] : "HEAD", NULL);
>> +
>> +   if (!capture_command(_rev, , 0)) {
>> +   strbuf_strip_suffix(, "\n");
>> +   if (argc) {
>> +   argv++;
>> +   argc--;
>> +   }
>> +   } else if (!argc || !strcmp(argv[0], "HEAD")) {
>> +   /* before the first commit: compare with an empty tree */
>> +   struct stat st;
>> +   struct object_id oid;
>> +   if (fstat(0, ) < 0 || index_fd(oid.hash, 0, , 2, 
>> prefix, 3))
>> +   die("Unable to add %s to database", oid.hash);
>> +   strbuf_addstr(, oid_to_hex());
>> +   if (argc) {
>> +   argv++;
>> +   argc--;
>> +   }
>> +   } else {
>> +   strbuf_addstr(, "HEAD");
>> +   }
>> +
>> +   head = strbuf_detach(, NULL);
>
> I am not sure this "head" variable is really needed.
>
>> +   if (files) {
>> +   if (cached)
>> +   die(_("The --cached option cannot be used with the 
>> --files option"));
>> +   diff_cmd = "diff-files";
>> +
>> +   free(head);
>> +
>> +   head = NULL;
>
> If "head" isn't used, "strbuf_reset()" could be used instead.
> If "head" is still needed, "FREE_AND_NULL(head)" could be used.

Thank you for reviewing this patch.
As suggested, here we can remove the variable head, and instead use
the strbuf struct.
But in the above lines, along with strbuf_reset(), later we are
also required to set
sb.buf to NULL.

>
>> +   }
>> +
>> +   info.argc = argc;
>> +   info.argv = argv;
>> +   info.prefix = prefix;
>> +   info.cached = !!cached;
>> +   info.for_status = !!for_status;
>> +   info.quiet = quiet;
>> +   info.files = files;
>> +   info.summary_limits = summary_limits;
>> +   info.diff_cmd = diff_cmd;
>> +
>> +   ret = compute_summary_module_list(head, );

we may even remove the variable ret, but passing strbuf_detach(, NULL) here
to the function compute_summary_module_list(), and then later on free(head) at
the end of the function compute_summary_module_list().

Thanks,
Prathamesh Chavan

[GSoC][PATCH v2 12/13] submodule foreach: document variable '$displaypath'

[Prathamesh Chavan]

It was observed that the variable '$displaypath' was accessible but
undocumented. Hence, document it.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:

* Spelling mistake in the commit message was corrected.

 Documentation/git-submodule.txt |  6 --
 t/t7407-submodule-foreach.sh| 22 +++---
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 8e7930ebc..0cca702cb 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,10 +183,12 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $sm_path, $sha1 and
-   $toplevel:
+   The command has access to the variables $name, $sm_path, $displaypath,
+   $sha1 and $toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
+   $displaypath contains the relative path from the current working
+   directory to the submodules root directory,
$sha1 is the commit as recorded in the superproject, and
$toplevel is the absolute path to its superproject, such that
$toplevel/$sm_path is the absolute path of the submodule.
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 0663622a4..6ad57e061 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,16 +82,16 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <../../actual
+   git submodule foreach "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
@@ -206,25 +206,25 @@ submodulesha1=$(cd 
clone2/nested1/nested2/nested3/submodule && git rev-parse HEA
 
 cat >expect <../../actual
+   git submodule foreach --recursive "echo 
\$toplevel-\$name-\$sm_path-\$displaypath-\$sha1" >../../actual
) &&
test_i18ncmp expect actual
 '
-- 
2.13.0

[GSoC][PATCH v2 13/13] submodule: port submodule subcommand 'foreach' from shell to C

[Prathamesh Chavan]

This aims to make git-submodule foreach a builtin. This is the very
first step taken in this direction. Hence, 'foreach' is ported to
submodule--helper, and submodule--helper is called from git-submodule.sh.
The code is split up to have one function to obtain all the list of
submodules. This function acts as the front-end of git-submodule foreach
subcommand. It calls the function for_each_submodule_list, which basically
loops through the list and calls function fn, which in this case is
runcommand_in_submodule. This third function is a calling function that
takes care of running the command in that submodule, and recursively
perform the same when --recursive is flagged.

The first function module_foreach first parses the options present in
argv, and then with the help of module_list_compute, generates the list of
submodules present in the current working tree.

The second function for_each_submodule_list traverses through the
list, and calls function fn (which in case of submodule subcommand
foreach is runcommand_in_submodule) is called for each entry.

The third function runcommand_in_submodule, generates a submodule struct sub
for $name, value and then later prepends name=sub->name; and other
value assignment to the env argv_array structure of a child_process.
Also the  of submodule-foreach is push to args argv_array
structure and finally, using run_command the commands are executed
using a shell.

The third function also takes care of the recursive flag, by creating
a separate child_process structure and prepending "--super-prefix displaypath",
to the args argv_array structure. Other required arguments and the
input  of submodule-foreach is also appended to this argv_array.

Helped-by: Brandon Williams <bmw...@google.com>
Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:

* Comment style is improved in the function runcommand_in_submodule()

* Comment in added about why the variable "path" was exposed via args
  argv_array instead of exposing it via the env_array.

* This patch exposes the various variables when argc == 1 only, just
  for maintaining a faithful porting. You can also find discussion about
  the same at [1].

[1]: 
https://public-inbox.org/git/came+mvusgafbn5j-_hv7qpas57hq4wgh+yz7xjmpuyqn1ga...@mail.gmail.com/

 builtin/submodule--helper.c | 136 
 git-submodule.sh|  39 +
 2 files changed, 137 insertions(+), 38 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index d8bf16f1d..d5527aa93 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -772,6 +772,141 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct cb_foreach {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int recursive: 1;
+};
+#define CB_FOREACH_INIT { 0, NULL, NULL, 0, 0 }
+
+static void runcommand_in_submodule(const struct cache_entry *list_item,
+   void *cb_data)
+{
+   struct cb_foreach *info = cb_data;
+   const struct submodule *sub;
+   struct child_process cp = CHILD_PROCESS_INIT;
+   char *displaypath;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub)
+   die(_("No url found for submodule path '%s' in .gitmodules"),
+ displaypath);
+
+   if (!is_submodule_populated_gently(list_item->name, NULL))
+   goto cleanup;
+
+   prepare_submodule_repo_env(_array);
+
+   /*
+* For the purpose of executing  in the submodule,
+* separate shell is used for the purpose of running the
+* child process.
+*/
+   cp.use_shell = 1;
+   cp.dir = list_item->name;
+
+   if (info->argc == 1) {
+   char *toplevel = xgetcwd();
+
+   argv_array_pushf(_array, "name=%s", sub->name);
+   argv_array_pushf(_array, "sm_path=%s", list_item->name);
+   argv_array_pushf(_array, "displaypath=%s", displaypath);
+   argv_array_pushf(_array, "sha1=%s",
+oid_to_hex(_item->oid));
+   argv_array_pushf(_array, "toplevel=%s", toplevel);
+
+   /*
+* Since the path variable was accessible from the script
+* before porting, it is also made available after porting.
+* The environment variable "PATH" has a very special purpose
+* on windows. And since environment

[GSoC][PATCH v2 08/13] submodule: port submodule subcommand 'summary' from shell to C

[Prathamesh Chavan]

The submodule subcommand 'summary' is ported in the process of
making git-submodule a builtin. The function cmd_summary() from
git-submodule.sh is ported to functions module_summary(),
compute_summary_module_list(), prepare_submodule_summary() and
print_submodule_summary().

The first function module_summary() parses the options of submodule
subcommand and also acts as the front-end of this subcommand.
After parsing them, it calls the compute_summary_module_list()

The functions compute_summary_module_list() runs the diff_cmd,
and generates the modules list, as required by the subcommand.
The generation of this module list is done by the using the
callback function submodule_summary_callback(), and stored in the
structure module_cb.

Once the module list is generated, prepare_submodule_summary()
further goes through the list and filters the list, for
eventually calling the print_submodule_summary() function.

Finally, the print_submodule_summary() takes care of generating
and printing the summary for each submodule.

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:

* Firstly, about the function compute_summary_module_list().
  This function is created to generate the list of modules, for which
  we will generate the summary further. Since the list is actually
  generated using the git-diff-files or git-diff-index command, but for
  porting this, we required to create a function similar to the builtin
  functions of the above commands. But we can't directly call cmd_diff_files()
  and cmd_diff_index() since we don't have to display the output and instead
  need to store it. Hence, this function is introduced.

* Also, the module_cb_list *list is not freed since it is a non-heap object.
  Hence, free() can't be using on the non-heap objects.

* In the function prepare_submodule_summary(), as suggested
  'git_config_get_string_const' was used instead of instead of '_value'

* Some variables which weren't modified throughout the function-call were
  passed as const.

* The '!!' trick, which wasn't used in the last patch, is now used in this
  new version .

* the variables sha1_dst and sha1_src are removed from the function
  print_submodule_summary(), and instead the p->oid_src and p->oid_dst are
  used.

* The variable sm_git_dir is freed at the end of the function.

 builtin/submodule--helper.c | 433 
 git-submodule.sh| 182 +--
 2 files changed, 434 insertions(+), 181 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 038be7ee2..d8bf16f1d 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -13,6 +13,9 @@
 #include "remote.h"
 #include "refs.h"
 #include "connect.h"
+#include "revision.h"
+#include "diffcore.h"
+#include "diff.h"
 
 typedef void (*submodule_list_func_t)(const struct cache_entry *list_item,
  void *cb_data);
@@ -769,6 +772,435 @@ static int module_name(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct module_cb {
+   unsigned int mod_src;
+   unsigned int mod_dst;
+   struct object_id oid_src;
+   struct object_id oid_dst;
+   char status;
+   const char *sm_path;
+};
+#define MODULE_CB_INIT { 0, 0, NULL, NULL, '\0', NULL }
+
+struct module_cb_list {
+   struct module_cb **entries;
+   int alloc, nr;
+};
+#define MODULE_CB_LIST_INIT { NULL, 0, 0 }
+
+struct summary_cb {
+   int argc;
+   const char **argv;
+   const char *prefix;
+   char *diff_cmd;
+   unsigned int cached: 1;
+   unsigned int for_status: 1;
+   unsigned int quiet: 1;
+   unsigned int files: 1;
+   int summary_limits;
+};
+#define SUMMARY_CB_INIT { 0, NULL, NULL, NULL, 0, 0, 0, 0, 0 }
+
+static int verify_submodule_object_name(const char *sm_path, const char *sha1)
+{
+   struct child_process cp_rev_parse = CHILD_PROCESS_INIT;
+
+   cp_rev_parse.git_cmd = 1;
+   cp_rev_parse.no_stdout = 1;
+   cp_rev_parse.dir = sm_path;
+   prepare_submodule_repo_env(_rev_parse.env_array);
+
+   argv_array_pushl(_rev_parse.args, "rev-parse", "-q",
+"--verify", NULL);
+   argv_array_pushf(_rev_parse.args, "%s^0", sha1);
+
+   if (run_command(_rev_parse))
+   return 1;
+
+   return 0;
+}
+
+static void print_submodule_summary(struct summary_cb *info,
+   struct module_cb *p)
+{
+   int missing_src = 0;
+   int missing_dst = 0;
+   char *displaypath;
+   const char *sha1_abbr_src;
+   const char *sha1_abbr_dst;
+   int errmsg = 0;
+   int total_commits

[GSoC][PATCH v2 10/13] submodule foreach: document '$sm_path' instead of '$path'

[Prathamesh Chavan]

As using a variable '$path' may be harmful to users due to
capitalization issues, see 64394e3ae9 (git-submodule.sh: Don't
use $path variable in eval_gettext string, 2012-04-17). Adjust
the documentation to advocate for using $sm_path,  which contains
the same value. We still make the 'path' variable available and
document it as a deprecated synonym of 'sm_path'.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
This patch is same as its previous version.
Although here I'll like to add a point that we aim to slowly drop the support
of the variable 'path'.

 Documentation/git-submodule.txt | 10 ++
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index ff612001d..a23baef62 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -183,12 +183,14 @@ information too.
 
 foreach [--recursive] ::
Evaluates an arbitrary shell command in each checked out submodule.
-   The command has access to the variables $name, $path, $sha1 and
+   The command has access to the variables $name, $sm_path, $sha1 and
$toplevel:
$name is the name of the relevant submodule section in `.gitmodules`,
-   $path is the name of the submodule directory relative to the
-   superproject, $sha1 is the commit as recorded in the superproject,
-   and $toplevel is the absolute path to the top-level of the superproject.
+   $sm_path is the path of the submodule as recorded in the superproject,
+   $sha1 is the commit as recorded in the superproject, and
+   $toplevel is the absolute path to the top-level of the superproject.
+   Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+   variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
ignored by this command. Unless given `--quiet`, foreach prints the name
of each submodule before evaluating the command.
-- 
2.13.0

[GSoC][PATCH v2 11/13] submodule foreach: clarify the '$toplevel' variable documentation

[Prathamesh Chavan]

It does not contain the topmost superproject as the author assumed,
but the direct superproject, such that $toplevel/$sm_path is the
actual absolute path of the submodule.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
 Documentation/git-submodule.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index a23baef62..8e7930ebc 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -188,7 +188,8 @@ foreach [--recursive] ::
$name is the name of the relevant submodule section in `.gitmodules`,
$sm_path is the path of the submodule as recorded in the superproject,
$sha1 is the commit as recorded in the superproject, and
-   $toplevel is the absolute path to the top-level of the superproject.
+   $toplevel is the absolute path to its superproject, such that
+   $toplevel/$sm_path is the absolute path of the submodule.
Note that to avoid conflicts with '$PATH' on Windows, the '$path'
variable is now a deprecated synonym of '$sm_path' variable.
Any submodules defined in the superproject but not checked out are
-- 
2.13.0

[GSoC][PATCH v2 09/13] submodule foreach: correct '$path' in nested submodules from a subdirectory

[Prathamesh Chavan]

When running 'git submodule foreach' from a subdirectory of your
repository, nested submodules get a bogus value for $sm_path:
For a submodule 'sub' that contains a nested submodule 'nested',
running 'git -C dir submodule foreach echo $path' would report
path='../nested' for the nested submodule. The first part '../' is
derived from the logic computing the relative path from $pwd to the
root of the superproject. The second part is the submodule path inside
the submodule. This value is of little use and is hard to document.

There are two different possible solutions that have more value:
(a) The path value is documented as the path from the toplevel of the
superproject to the mount point of the submodule.
In this case we would want to have path='sub/nested'.

(b) As Ramsay noticed the documented value is wrong. For the non-nested
case the path is equal to the relative path from $pwd to the
submodules working directory. When following this model,
the expected value would be path='../sub/nested'.

The behavior for (b) was introduced in 091a6eb0fe (submodule: drop the
top-level requirement, 2013-06-16) the intent for $path seemed to be
relative to $cwd to the submodule worktree, but that did not work for
nested submodules, as the intermittent submodules were not included in
the path.

If we were to fix the meaning of the $path using (a) such that "path"
is "the path from the toplevel of the superproject to the mount point
of the submodule", we would break any existing submodule user that runs
foreach from non-root of the superproject as the non-nested submodule
'../sub' would change its path to 'sub'.

If we would fix the meaning of the $path using (b), such that "path"
is "the relative path from $pwd to the submodule", then we would break
any user that uses nested submodules (even from the root directory) as
the 'nested' would become 'sub/nested'.

Both groups can be found in the wild.  The author has no data if one group
outweighs the other by large margin, and offending each one seems equally
bad at first.  However in the authors imagination it is better to go with
(a) as running from a sub directory sounds like it is carried out
by a human rather than by some automation task.  With a human on
the keyboard the feedback loop is short and the changed behavior can be
adapted to quickly unlike some automation that can break silently.

Discussed-with: Ramsay Jones <ram...@ramsayjones.plus.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
Signed-off-by: Stefan Beller <sbel...@google.com>
---
 git-submodule.sh |  1 -
 t/t7407-submodule-foreach.sh | 36 ++--
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/git-submodule.sh b/git-submodule.sh
index a427ddafd..493a64372 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -320,7 +320,6 @@ cmd_foreach()
prefix="$prefix$sm_path/"
sanitize_submodule_env
cd "$sm_path" &&
-   sm_path=$(git submodule--helper relative-path 
"$sm_path" "$wt_prefix") &&
# we make $path available to scripts ...
path=$sm_path &&
if test $# -eq 1
diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 6ba5daf42..0663622a4 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -82,9 +82,9 @@ test_expect_success 'test basic "submodule foreach" usage' '
 
 cat >expect <expect <../../actual
+   ) &&
+   test_i18ncmp expect actual
+'
 
 cat > expect <

[GSoC][PATCH v2 06/13] submodule: port submodule subcommand 'deinit' from shell to C

[Prathamesh Chavan]

The same mechanism is used even for porting this submodule
subcommand, as used in the ported subcommands till now.
The function cmd_deinit in split up after porting into three
functions: module_deinit(), for_each_submodule_list() and
deinit_submodule().

Mentored-by: Christian Couder <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* In the function deinit_submodule, since the test is_git_directory()
  adds an additional condition, instead is_directory() is used to check
  if "sm_path/.git" is a directory.

* since it was possible in the previous path that the value st.st_mode passed
  to the function mkdir contained a garbage value, instead we intrduce a
  mode_t variable mode, initially containing a default mode value '0777'.
  This is what the default of mode is set in case, that the value is
  not set after the lstat call.

 builtin/submodule--helper.c | 144 
 git-submodule.sh|  55 +
 2 files changed, 145 insertions(+), 54 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 877215567..038be7ee2 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -916,6 +916,149 @@ static int module_sync(int argc, const char **argv, const 
char *prefix)
return 0;
 }
 
+struct deinit_cb {
+   const char *prefix;
+   unsigned int quiet: 1;
+   unsigned int force: 1;
+   unsigned int all: 1;
+};
+#define DEINIT_CB_INIT { NULL, 0, 0, 0 }
+
+static void deinit_submodule(const struct cache_entry *list_item,
+void *cb_data)
+{
+   struct deinit_cb *info = cb_data;
+   const struct submodule *sub;
+   char *displaypath = NULL;
+   struct child_process cp_config = CHILD_PROCESS_INIT;
+   struct strbuf sb_config = STRBUF_INIT;
+   char *sub_git_dir = xstrfmt("%s/.git", list_item->name);
+   mode_t mode = 0777;
+
+   sub = submodule_from_path(null_sha1, list_item->name);
+
+   if (!sub || !sub->name)
+   goto cleanup;
+
+   displaypath = get_submodule_displaypath(list_item->name, info->prefix);
+
+   /* remove the submodule work tree (unless the user already did it) */
+   if (is_directory(list_item->name)) {
+   struct stat st;
+   /* protect submodules containing a .git directory */
+   if (is_directory(sub_git_dir))
+   die(_("Submodule work tree '%s' contains a .git "
+ "directory use 'rm -rf' if you really want "
+ "to remove it including all of its history"),
+ displaypath);
+
+   if (!info->force) {
+   struct child_process cp_rm = CHILD_PROCESS_INIT;
+   cp_rm.git_cmd = 1;
+   argv_array_pushl(_rm.args, "rm", "-qn",
+list_item->name, NULL);
+
+   if (run_command(_rm))
+   die(_("Submodule work tree '%s' contains local "
+ "modifications; use '-f' to discard 
them"),
+ displaypath);
+   }
+
+   if (!lstat(list_item->name, )) {
+   struct strbuf sb_rm = STRBUF_INIT;
+   const char *format;
+
+   strbuf_addstr(_rm, list_item->name);
+
+   if (!remove_dir_recursively(_rm, 0))
+   format = _("Cleared directory '%s'\n");
+   else
+   format = _("Could not remove submodule work 
tree '%s'\n");
+
+   if (!info->quiet)
+   printf(format, displaypath);
+
+   mode = st.st_mode;
+
+   strbuf_release(_rm);
+   }
+   }
+
+   if (mkdir(list_item->name, mode))
+   die(_("could not create empty submodule directory %s"),
+ displaypath);
+
+   cp_config.git_cmd = 1;
+   argv_array_pushl(_config.args, "config", "--get-regexp", NULL);
+   argv_array_pushf(_config.args, "submodule.%s\\.", sub->name);
+
+   /* remove the .git/config entries (unless the user already did it) */
+   if (!capture_command(_config, _config, 0) && sb_config.len) {
+   char *sub_key = xstrfmt("submodule.%s", sub->name);
+   /*
+* remove the whole section so we have a clean state when
+* the user later d

[GSoC][PATCH v2 04/13] 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 <christian.cou...@gmail.com>
Mentored-by: Stefan Beller <sbel...@google.com>
Signed-off-by: Prathamesh Chavan <pc44...@gmail.com>
---
In this new version, the following changes have been made:
* parameters passed to the function print_status() have been changed.
  Instead of passing char *sub_sha1, instead the object_id is being passed.

* Also, since the passed parameter displaypath's value isn't changed
  by the function, it is passed to the funcition as const char *displaypath
  instead of char *displaypath.

* the output type of the function handle_submodule_head_ref() is changed
  from strbuf to object_id, as we will use the object_id instead of the
  hex of sha1 being stored in a struct strbuf.

* diff_files_Args is cleared after using it by passing it as args in the
  function cmd_diff_files.

* In the function status_submodule(), for checking if a submodule has merge
  conflicts, the patch currently checks if the value of any of the ce_flags
  is non-zero. Currently, I think the we aren't interested in a partiular flag,
  but I'm not sure on this.

* The confusion with displaypath being passed as te super-prefix in many
  of the ported subcommands may be a result of the fact that the
  function generating the displaypath: get_submodule_displaypath()
  uses the super-prefix as simply a path concatenated with the current
  submodule name to denote our current location.
  Also, for generating any submodule's displaypath, it would be important to
  have ".." passed to the submodule, and currently it is possible only via the
  super-prefix.

 builtin/submodule--helper.c | 157 
 git-submodule.sh|  49 +-
 2 files changed, 158 insertions(+), 48 deletions(-)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 2cb72d68e..0bd969b7c 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -561,6 +561,162 @@ 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,
+const struct object_id *oid, const char *displaypath)
+{
+   if (info->quiet)
+   return;
+
+   printf("%c%s %s", state, oid_to_hex(oid), displaypath);
+
+
+   if (state == ' ' || state == '+') {
+   struct argv_array name_rev_args = ARGV_ARRAY_INIT;
+
+   argv_array_pushl(_rev_args, "print-name-rev",
+path, oid_to_hex(oid), 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 object_id *output = cb_data;
+   if (oid)
+   oidcpy(output, oid);
+
+   return 0;
+}
+
+static void status_submodule(const struct cache_entry *list_item, void 
*cb_data)
+{
+   struct status_cb *info = cb_data;
+   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);
+
+   trace_printf("the value of flag is %d\n", list_item->ce_flags);
+   if (list_item->ce_flags) {
+   trace_printf("for U the value of flag is %d\n", 
list_item->ce_flags);
+   print_status(info, 'U', list_item->name,
+_oid, di