blob: fa36d2ceb77dd2320505a873d2287b16ea7a8635 [file] [log] [blame]
.. _chapter-contributing:
We welcome contributions to Ceres, whether they are new features, bug
fixes or tests. The Ceres `mailing
<>`_ list is the best place
for all development related discussions. Please consider joining
it. If you have ideas on how you would like to contribute to Ceres, it
is a good idea to let us know on the mailing list before you start
development. We may have suggestions that will save effort when trying
to merge your work into the main branch. If you are looking for ideas,
please let us know about your interest and skills and we will be happy
to make a suggestion or three.
We follow Google's `C++ Style Guide
<>`_ and
use `git <>`_ for version control. We use the
`Gerrit <>`_ to collaborate and
review changes to Ceres. Gerrit enables pre-commit reviews so that
Ceres can maintain a linear history with clean, reviewed commits, and
no merges.
We now describe how to set up your development environment and submit
a change list for review via Gerrit.
Setting up your Environment
1. Download and configure ``git``.
* Mac ``brew install git``.
* Linux ``sudo apt-get install git``.
* Windows. Download `msysgit
<>`_, which includes a minimal
`Cygwin <>`_ install.
2. Sign up for `Gerrit
<>`_. You will also
need to sign the Contributor License Agreement (CLA) with Google,
which gives Google a royalty-free unlimited license to use your
contributions. You retain copyright.
3. Clone the Ceres Solver ``git`` repository from Gerrit.
.. code-block:: bash
git clone
4. Build Ceres, following the instructions in
On Mac and Linux, the ``CMake`` build will download and enable
the Gerrit pre-commit hook automatically. This pre-submit hook
creates `Change-Id: ...` lines in your commits.
If this does not work OR you are on Windows, execute the
following in the root directory of the local ``git`` repository:
.. code-block:: bash
curl -o .git/hooks/commit-msg
chmod +x .git/hooks/commit-msg
5. Configure your Gerrit password with a ``.netrc`` (Mac and Linux)
or ``_netrc`` (Windows) which allows pushing to Gerrit without
having to enter a very long random password every time:
* Sign into `
* Click ``Settings -> HTTP Password -> Obtain Password``.
* (maybe) Select an account for multi-login. This should be the
same as your Gerrit login.
* Click ``Allow access`` when the page requests access to your
``git`` repositories.
* Copy the contents of the ``netrc`` into the clipboard.
- On Mac and Linux, paste the contents into ``~/.netrc``.
- On Windows, by default users do not have a ``%HOME%``
Executing ``setx HOME %USERPROFILE%`` in a terminal will set up
the ``%HOME%`` environment variable persistently, and is used
by ``git`` to find ``%HOME%\_netrc``.
Then, create a new text file named ``_netrc`` and put it in
e.g. ``C:\Users\username`` where ``username`` is your user
Submitting a change
1. Make your changes against master or whatever branch you
like. Commit your changes as one patch. When you commit, the Gerrit
hook will add a `Change-Id:` line as the last line of the commit.
Make sure that your commit message is formatted in the `50/72 style
2. Push your changes to the Ceres Gerrit instance:
.. code-block:: bash
git push origin HEAD:refs/for/master
When the push succeeds, the console will display a URL showing the
address of the review. Go to the URL and add at least one of the
maintainers (Sameer Agarwal, Keir Mierle, or Alex Stewart) as reviewers.
3. Wait for a review.
4. Once review comments come in, address them. Please reply to each
comment in Gerrit, which makes the re-review process easier. After
modifying the code in your ``git`` instance, *don't make a new
commit*. Instead, update the last commit using a command like the
.. code-block:: bash
git commit --amend -a
This will update the last commit, so that it has both the original
patch and your updates as a single commit. You will have a chance
to edit the commit message as well. Push the new commit to Gerrit
as before.
Gerrit will use the ``Change-Id:`` to match the previous commit
with the new one. The review interface retains your original patch,
but also shows the new patch.
Publish your responses to the comments, and wait for a new round
of reviews.