Re: [GSoC] [PATCH v4 0/4] rebase: rewrite rebase in C

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jul 8, 2018, 21:14 UTC
Message-ID: <nycvar.QRO.7.76.6.1807082311540.75@tvgsbejvaqbjf.bet>
In-Reply-To: <20180708180104.17921-1-predatoramigo@gmail.com>

Hi Pratik,

On Sun, 8 Jul 2018, Pratik Karki wrote:

Show 24 quoted lines

> As a GSoC project, I have been working on the builtin rebase.
> 
> The motivation behind the rewrite of rebase i.e. from shell script to C
> are for following reasons:
> 
> 1.  Writing shell scripts and getting it to production is much faster
>     than doing the equivalent in C but lacks in performance and extra
>     workarounds are needed for non-POSIX platforms.
> 
> 2.  Git for Windows is at loss as the installer size increases due to
>     addition of extra dependencies for the shell scripts which are usually
>     available in POSIX compliant platforms.
> 
> This series of patches serves to demonstrate a minimal builtin rebase
> which supports running `git rebase <upstream>` and also serves to ask for
> reviews.
> 
> Changes since v3:
> 
>   -  Fix commit message of `rebase: start implementing it as a builtin`.
> 
>   -  Acknowledge Junio's style reviews.
> 
>   -  Acknowledge Johannes Schindelin's review.

The range-diff looks like this (and makes sense to me; you might want to fix the typo s/retun/return/, but that's all for now):

-- snipsnap --
 1:  7baec70f219 !  1:  42778b20edf rebase: start implementing it as a builtin
    @@ -13,6 +13,12 @@
         be able to conveniently test new features by configuring
         `rebase.useBuiltin`.

    +    In the original difftool conversion, if sane_execvp() that attempts to
    +    run the legacy scripted version returned with non-negative status, the
    +    command silently exited without doing anything with success, but
    +    sane_execvp() should not retun with non-negative status in the first
    +    place, so we use die() to notice such an abnormal case.
    +
         We intentionally avoid reading the config directly to avoid
         messing up the GIT_* environment variables when we need to fall back to
         exec()ing the shell script. The test of builtin rebase can be done by
 2:  f385f42dc56 !  2:  a28be7308e6 rebase: refactor common shell functions into their own file
    @@ -45,6 +45,20 @@
     diff --git a/git-legacy-rebase.sh b/git-legacy-rebase.sh
     --- a/git-legacy-rebase.sh
     +++ b/git-legacy-rebase.sh
    +@@
    + LF='
    + '
    + ok_to_skip_pre_rebase=
    +-resolvemsg="
    +-$(gettext 'Resolve all conflicts manually, mark them as resolved with
    +-"git add/rm <conflicted_files>", then run "git rebase --continue".
    +-You can instead skip this commit: run "git rebase --skip".
    +-To abort and get back to the state before "git rebase", run "git rebase --abort".')
    +-"
    ++
    + squash_onto=
    + unset onto
    + unset restrict_revision
     @@
      true)     gpg_sign_opt=-S ;;
      *)        gpg_sign_opt= ;;
    @@ -128,6 +142,13 @@
     +++ b/git-rebase--common.sh
     @@
     +
    ++resolvemsg="
    ++$(gettext 'Resolve all conflicts manually, mark them as resolved with
    ++"git add/rm <conflicted_files>", then run "git rebase --continue".
    ++You can instead skip this commit: run "git rebase --skip".
    ++To abort and get back to the state before "git rebase", run "git rebase --abort".')
    ++"
    ++
     +write_basic_state () {
     +  echo "$head_name" > "$state_dir"/head-name &&
     +  echo "$onto" > "$state_dir"/onto &&
 3:  147699bd195 =  3:  7591098c4d1 sequencer: refactor the code to detach HEAD to checkout.c
 4:  bbaa4264caa !  4:  f8429e950a4 builtin/rebase: support running "git rebase <upstream>"
    @@ -232,13 +232,14 @@
     +  }
     +
     +  /*
    -+  * If the branch to rebase is given, that is the branch we will rebase
    -+  * branch_name -- branch/commit being rebased, or HEAD (already detached)
    -+  * orig_head -- commit object name of tip of the branch before rebasing
    -+  * head_name -- refs/heads/<that-branch> or "detached HEAD"
    -+  */
    ++   * If the branch to rebase is given, that is the branch we will rebase
    ++   * branch_name -- branch/commit being rebased, or
    ++   *                HEAD (already detached)
    ++   * orig_head -- commit object name of tip of the branch before rebasing
    ++   * head_name -- refs/heads/<that-branch> or "detached HEAD"
    ++   */
     +  if (argc > 1)
    -+           die ("TODO: handle switch_to");
    ++           die("TODO: handle switch_to");
     +  else {
     +          /* Do not need to switch branches, we are already on it.  */
     +          options.head_name =