Re: [RFC][GSoC] Project proposal: convert interactive rebase to C

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 21, 2018, 23:51 UTC
Message-ID: <nycvar.QRO.7.76.6.1803220043180.77@ZVAVAG-6OXH6DA.rhebcr.pbec.zvpebfbsg.pbz>
In-Reply-To: <46112353.MVnaADNoVi@andromeda>

Hi Alban,

On Wed, 21 Mar 2018, Alban Gruin wrote:

Show 11 quoted lines

> Le mardi 20 mars 2018 17:29:28 CET, vous avez écrit :
> 
> > Also, I have a hunch that there is actually almost nothing left to
> > rewrite after my sequencer improvements that made it into Git v2.13.0,
> > together with the upcoming changes (which are on top of the
> > --recreate-merges patch series, hence I did not send them to the
> > mailing list yet) in
> > https://github.com/dscho/git/commit/c261f17a4a3e
> 
> One year ago, you said[2] that converting this script "will fill up 3
> month, very easily". Is this not accurate anymore?

Let me read that mail ;-)

*goes and reads*

Well, I was talking about two different aspects to Ivan and to you. I should have been clearer. So let me try again:

To convert `git-rebase--interactive.sh`, I think the most important part is to factor out the preserve-merges code into its own script. After that, there is little I can think of (apart from support for --root, which a not-yet-contributed patch in my sequencer-shears branch on https://github.com/dscho/git addresses) that still needs to be converted. For somebody familiar with Git's source code, I would estimate one week (and therefore 3 weeks would be a realistic estimate :-)).

Come to think of it, a better approach might be to leave the preserve-merges stuff in, and teach `git-rebase.sh` to call the sequencer directly for --interactive without --preserve-merges, then rename the script to git-rebase--preserve.sh

The other aspect, the one I thought would take up to 3 months, easily, was to convert the entirety of rebase -i into C. That would entail also the option parsing, for which you would have to convert also git-rebase.sh (and if you do not convert git-rebase--am.sh and git-rebase--merge.sh first, you would then have to teach builtin/rebase.c to populate the environment variables expected by those shell scripts while spawning them).

I still think that the latter is too big a task for a single GSoC.

> I’ll send a new draft as soon as possible (hopefully this afternoon).

I look forward to reading it!

Ciao, Johannes