git/contrib
Sibi Siddharthan 061c2240b1 Introduce CMake support for configuring Git
At the moment, the recommended way to configure Git's builds is to
simply run `make`. If that does not work, the recommended strategy is to
look at the top of the `Makefile` to see whether any "Makefile knob" has
to be turned on/off, e.g. `make NO_OPENSSL=YesPlease`.

Alternatively, Git also has an `autoconf` setup which allows configuring
builds via `./configure [<option>...]`.

Both of these options are fine if the developer works on Unix or Linux.
But on Windows, we have to jump through hoops to configure a build
(read: we force the user to install a full Git for Windows SDK, which
occupies around two gigabytes (!) on disk and downloads about three
quarters of a gigabyte worth of Git objects).

The build infrastructure for Git is written around being able to run
make, which is not supported natively on Windows.
To help Windows developers a CMake build script is introduced here.

With a working support CMake, developers on Windows need only install
CMake, configure their build, load the generated Visual Studio solution
and immediately start modifying the code and build their own version of
Git. Likewise, developers on other platforms can use the convenient GUI
tools provided by CMake to configure their build.

So let's start building CMake support for Git.

This is only the first step, and to make it easier to review, it only
allows for configuring builds on the platform that is easiest to
configure for: Linux.

The CMake script checks whether the headers are present(eg. libgen.h),
whether the functions are present(eg. memmem), whether the funtions work
properly (eg. snprintf) and generate the required compile definitions
for the platform. The script also searches for the required libraries,
if it fails to find the required libraries the respective executables
won't be built.(eg. If libcurl is not found then git-remote-http won't
be built). This will help building Git easier.

With a CMake script an out of source build of git is possible resulting
in a clean source tree.

Note: this patch asks for the minimum version v3.14 of CMake (which is
not all that old as of time of writing) because that is the first
version to offer a platform-independent way to generate hardlinks as
part of the build. This is needed to generate all those hardlinks for
the built-in commands of Git.

Signed-off-by: Sibi Siddharthan <sibisiddharthan.github@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-12 13:19:32 -07:00
..
buildsystems Introduce CMake support for configuring Git 2020-06-12 13:19:32 -07:00
coccinelle Merge branch 'jk/remove-sha1-to-hex' 2019-12-01 09:04:36 -08:00
completion Merge branch 'vs/complete-stash-show-p-fix' 2020-06-08 18:06:29 -07:00
contacts git-contacts: also recognise "Reported-by:" 2017-07-27 09:42:55 -07:00
credential contrib/credential/netrc: work outside a repo 2019-12-20 12:40:52 -08:00
diff-highlight diff-highlight: fix a whitespace nit 2019-10-15 14:08:37 +09:00
emacs git{,-blame}.el: remove old bitrotting Emacs code 2018-04-16 17:25:49 +09:00
examples Merge branch 'bw/c-plus-plus' into ds/lazy-load-trees 2018-04-11 10:46:32 +09:00
fast-import import-tars: ignore the global PAX header 2020-03-24 14:39:47 -07:00
git-jump contrib/git-jump/git-jump: jump to exact location 2018-06-22 12:59:02 -07:00
git-shell-commands
hg-to-git hg-to-git: make it compatible with both python3 and python2 2019-09-18 12:03:05 -07:00
hooks multimail: fix a few simple spelling errors 2019-11-10 16:00:55 +09:00
long-running-filter docs: warn about possible '=' in clean/smudge filter process values 2016-12-06 11:29:52 -08:00
mw-to-git Fix spelling errors in no-longer-updated-from-upstream modules 2019-11-10 16:00:55 +09:00
persistent-https docs/config: mention protocol implications of url.insteadOf 2017-06-01 10:07:10 +09:00
remote-helpers contrib: git-remote-{bzr,hg} placeholders don't need Python 2017-03-03 11:09:34 -08:00
stats contrib: update stats/mailmap script 2012-12-12 11:09:11 -08:00
subtree subtree: fix build with AsciiDoctor 2 2020-04-08 12:10:36 -07:00
svn-fe Fix spelling errors in messages shown to users 2019-11-10 16:00:54 +09:00
thunderbird-patch-inline contrib/thunderbird-patch-inline/appp.sh: use the $( ... ) construct for command substitution 2015-12-27 15:33:13 -08:00
update-unicode unicode_width.h: rename to use dash in file name 2018-04-11 18:11:00 +09:00
vscode vscode: let cSpell work on commit messages, too 2018-07-30 13:14:39 -07:00
workdir git-new-workdir: mark script as LF-only 2017-05-10 13:32:50 +09:00
coverage-diff.sh contrib: add coverage-diff script 2018-10-10 10:11:35 +09:00
git-resurrect.sh Merge branch 'jc/bs-t-is-not-a-tab-for-sed' 2017-04-16 23:29:29 -07:00
README
remotes2config.sh
rerere-train.sh contrib/rerere-train: optionally overwrite existing resolutions 2017-07-26 13:38:48 -07:00

Contributed Software

Although these pieces are available as part of the official git
source tree, they are in somewhat different status.  The
intention is to keep interesting tools around git here, maybe
even experimental ones, to give users an easier access to them,
and to give tools wider exposure, so that they can be improved
faster.

I am not expecting to touch these myself that much.  As far as
my day-to-day operation is concerned, these subdirectories are
owned by their respective primary authors.  I am willing to help
if users of these components and the contrib/ subtree "owners"
have technical/design issues to resolve, but the initiative to
fix and/or enhance things _must_ be on the side of the subtree
owners.  IOW, I won't be actively looking for bugs and rooms for
enhancements in them as the git maintainer -- I may only do so
just as one of the users when I want to scratch my own itch.  If
you have patches to things in contrib/ area, the patch should be
first sent to the primary author, and then the primary author
should ack and forward it to me (git pull request is nicer).
This is the same way as how I have been treating gitk, and to a
lesser degree various foreign SCM interfaces, so you know the
drill.

I expect that things that start their life in the contrib/ area
to graduate out of contrib/ once they mature, either by becoming
projects on their own, or moving to the toplevel directory.  On
the other hand, I expect I'll be proposing removal of disused
and inactive ones from time to time.

If you have new things to add to this area, please first propose
it on the git mailing list, and after a list discussion proves
there are some general interests (it does not have to be a
list-wide consensus for a tool targeted to a relatively narrow
audience -- for example I do not work with projects whose
upstream is svn, so I have no use for git-svn myself, but it is
of general interest for people who need to interoperate with SVN
repositories in a way git-svn works better than git-svnimport),
submit a patch to create a subdirectory of contrib/ and put your
stuff there.

-jc