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

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 11, 2013, 19:59 UTC
Message-ID: <7vehc8a05n.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CA+55aFwYAFuz5p0=8QiAFDy4e66f1pF3v=D5nnL6+3um7Z3L2g@mail.gmail.com>

Linus Torvalds <torvalds@linux-foundation.org> writes:

> This whole thread has been one long argument about totally pointless
> things that wouldn't improve anything one way or the other. It's
> bikeshedding of the worst kind. Just let it go.

The proposal to move sequencer.c to builtins/sequencer.c and then adding a filter in Makefile to exclude so that "git-sequencer" is not built is "it wouldn't improve anything one way or the other". It is to throw in something into a set to which it does not belong, and then working around that mistake with another kludge.

The problem that triggered the wrong solution actually is real, however.

A function that sequencer.c (in libgit.a so that it could be used by standalone) may want to use in the future currently lives in builtin/notes.c. If you add a call to that function to sequencer.c without doing anything else, standalones like git-upload-pack will stop linking correctly. The git-upload-pack wants the revision traversal machinery in revision.o, which in turn wants to be able to see log-tree.o, which in turn wants to link with sequencer.o to see one global variable (there may be other dependencies). All of these objects are currently in libgit.a so that both builtins and standalones can use them.

Moving sequencer.c to builtin/ is not even a solution. Linking git-upload-pack will still pull in builtin/notes.o along with cmd_notes(), which is not called from main(); as you remember, cmd_foo() in all builtin/*.o are designed to be called from git.c::main().

There is only one right solution. If a useful function is buried in builtin/*.o as a historical accident (i.e. it started its life as a helper for that particular command, and nobody else used it from outside so far) and that makes it impossible to use the function from outside builtin/*.o, refactor the function and its callers and move it to libgit.a.

So I do not think this is not even a bikeshedding. Just one side being right, and the other side continuing to repeat nonsense without listening.