Re: [PATCH] cmake: ignore generated files

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 19, 2020, 00:50 UTC
Message-ID: <xmqq1riylhcu.fsf@gitster.c.googlers.com>
In-Reply-To: <20200919004030.GB1837@danh.dev>

Đoàn Trần Công Danh  <congdanhqx@gmail.com> writes:

Show 11 quoted lines

>> What can we do to make it easier for people to discover and follow
>> the best current practice?  Are there things in our build
>> instruction document (e.g. the comment at the top of CMakeLists.txt)
>> that needs updating?
>
> I think Sibi had done a lot of good work to write instruction at the
> top of CMakeLists.txt, I guess it's a bit too much instruction.
> The instruction for out of source build was written after the
> instruction to build in-tree.
>
> Should we change the order?  I don't really know.

Oh, absolutely.

It begins with

    cmake `relative-path-to-CMakeLists.txt` -DCMAKE_BUILD_TYPE=Release
    Eg.
    From the root of git source tree
            `cmake contrib/buildsystems/ `
    This will build the git binaries at the root

which tells exactly what Dscho did and got him writing the patch in question. You'd need to keep reading to be merely _aware_ that it is possible to do an out-of-tree build, without getting even told that it is the norm in CMake land.

We should just remove the above and start the comment seciton with something more like this:

    When using CMake, building in place is highly discouraged.
    Instead, create a new "git-build" directory and perform your
    build there, like this (from the top of the working tree):

            $ mkdir git-build
            $ cd git-build
            $ cmake ../contrib/buildsystems/ -DCMAKE_BUILD_TYPER=Release

    This will build the git binaries in git-build directory

Doing so would reduce the number of choices the user has to make, and reduce the confusion.

Thanks.