Re: [PATCH] build: get rid of the notion of a git library

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 11, 2013, 19:24 UTC
Message-ID: <7vobbca1sr.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CAMP44s3SL7qs-Pmfz=kV-4U5OnPedK2RDLZDOyU-eq8WebLt+Q@mail.gmail.com>

Felipe Contreras <felipe.contreras@gmail.com> writes:

Show 21 quoted lines

> On Tue, Jun 11, 2013 at 1:17 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Felipe Contreras <felipe.contreras@gmail.com> writes:
>>
>>> Moreover, if you are going to argue that we shouldn't be closing the
>>> door, then why not link ./builtin/*.o to libgit.a?
>>
>> Huh?  It does not make any sense.  builtin/*.o files have cmd_foo()
>> that are expected to be called from git.c::main(), but libgit.a
>> files are linked with no constraints whose main() they are linking
>> with.
> ...
>> That is exactly why I said that builtin/*.o should be refactored to
>> pick "does not have to be in builtin" bits, which will result in a
>> better division of labor.  Reusable bits should live in the library,
>> while a particular implementation of command remain in builtin/*
>> that utilize the reusable bits.
>>
>> You still haven't justified why we have to _forbid_ any outside
>> callers from calling copy_notes_for_rewrite().
>
> Because only builtins _should_ use it.

And there is no justification behind that "_should_" claim; you are not making any technical argument to explain it.

> I asked you for an example, and
> you said a hypothetical standalone 'git-filter-branch' might use it,

Of course it has to be hypothetical; I already said with the current code no standalone does use it---it is not arranged to be doable so there is no user. If you want to have examples of future possible callers, they have to be hypothetical---the future by definition hasn't happened. But that does not mean hypothetical is impractical nor useless.

There are out-of-tree programs like cgit that will not be built-in but already link with libgit.a. Moving things that can be used by outside people out of builtin/*.o to libgit.a would allow uses that you and I cannot imagine offhand. I do not see a reason for us to forbid a filter-branch replacement out of tree as a standalone.

I do not see a point in continuing to discuss this (or any design level issues) with you. You seem to go into a wrong direction to break the design of the overall system, not in a direction to improve anything. I do not know, and at this point I do not care, if you are doing so deliberately to sabotage Git. Just stop.