3 Contribute to |Gromacs|
4 =======================
6 |Gromacs| is a community-driven project, and we love getting
7 contributions from people. Contributions are welcome in many forms,
8 including improvements to documentation, patches to fix bugs, advice
9 on the forums, bug reports that let us reproduce the issue, and new
12 If you are planning to contribute new functionality to |Gromacs|, we
13 strongly encourage you to get in contact with us first at an early
14 stage. New things can lead to exciting science, and we love
15 that. However, the subsequent code maintenance is time-consuming and
16 requires both "up front" and long-term commitment from you, and others
17 who might not share your particular scientific enthusiasm. Please read
18 this page first, and at least post on the `developer mailing list`_.
19 Sometimes we'll be able to save you a lot of time even at the
22 Much of the documentation is found alongside the source code in the
23 git repository. If you have changes to suggest there, those
24 contributions can be done using the same mechanism as the source code
25 contributions, and will be reviewed in similar ways.
30 Before you send us your code for review and inclusion into |Gromacs|,
31 please make sure that you have checked all the points on this list:
33 * *Usefulness*: Your code should have wide applicability within the scientific
34 community. You are welcome to have smaller projects tracking our code,
35 but we are not prepared to include and maintain code that will only have
36 limited application. Evidence that people are already using your code or
37 method is one good way to show that your code is useful.
38 Scientific publications is another, but those publications should
39 ideally come from several different research groups to show
40 widespread adoption of the method.
42 * *Advance discussion*: Please communicate with the other developers,
43 e.g. on the `developer mailing list`_ mailing list, or
44 `issue tracker`_ to let them know of the general
45 nature of your plans. This will prevent duplicate or wasted
46 effort. It is also a good idea to search those resources as well as
47 the literature and WWW for other projects that may be relevant.
49 * *Verifiable*: If you propose a new method that passes the first check,
50 please make sure that we can easily verify that it will be correct
51 from a physics point of view. That must include documentation (both
52 in the source code and as later additions to the user guide and/or
53 reference manual) that a capable graduate student can read and
54 understand well enough to use your method appropriately. The source
55 code documentation will also help in maintenance and later
58 This will be facilitated by the inclusions of unit tests for your code,
59 as described in the section on how to write
60 :ref:`new tests <gmx-make-new-tests>`.
62 We also need some form of automated high-level test of your code,
63 because people who do not understand its details need to be able to
64 change the infrastructure that you depend on. |Gromacs| uses
65 automated continuous-integration testing in :doc:`GitLab <gitlab-ci>`,
66 and we need quick feedback about whether your
67 code would be affected by a proposed change. This means the users of
68 your feature can continue to do good science based upon trustworthy
69 results generated by new versions of |Gromacs| released after you've
70 contributed your feature.
72 * *Structured change process*: Reviewing code for correctness, quality
73 and performance is a very time consuming process, which we are
74 committed to because it is necessary in order to deliver software
75 that is of high enough quality for reliable scientific
76 results. However, human beings are busy and have short attention
77 spans, and a proposed change affecting 10,000 lines of code is
78 likely to generate little enthusiasm from other developers to review
79 it. Your local git commit history is likely full of changes that are
80 no longer present in the version you'd like to contribute, so we
81 can't reasonably review that, either. It might be reasonable to
82 break the process into manageable pieces, such as
84 * the functionality to read the :doc:`mdp settings <../user-guide/mdp-options>` you might require and
86 * the functionality for :ref:`mdrun <gmx mdrun>` to execute the simplest form of your
88 * further extensions and/or optimizations for your feature, and
89 * functionality for an analysis tool to do useful things with the
92 Do get in touch with us, e.g. on the `developer mailing list`_, to
95 * *Timeliness*: We make an annual release of |Gromacs|, with a feature
96 freeze (and git branch fork) on a fixed date, which is agreed more
97 than six months in advance. We still need a month or more to do
98 quality testing on that branch, after the fork and before the
99 release, so there's a period when we cannot accept certain kinds of
100 potentially risky changes. (The master branch will remain open for
101 all kinds of changes, but it is likely that the focus of many of the
102 core developers will be on the release process.) If you have a large
103 change to propose, you need to
105 * make a group of smaller changes,
106 * negotiate in advance who will do the code review, and
107 * have them available for review and improvement months(!) before
108 that date. Even smaller changes are unlikely to be prioritized
109 by others for review in the last month or so!
111 * *Coding style*: Please make sure that your code follows all the
112 :doc:`coding style <style>` and :ref:`code formatting <code-formatting>`
113 guidelines. This will make the code review go more smoothly on both sides. There are a number of
114 tools already included with |Gromacs| to facilitate this, please have
115 a look at :ref:`the respective part of the documentation <gmx-codeformatting>`.
117 * *Code documentation*: To ensure proper code documentation, please follow the
118 instructions provided for the use of :doc:`doxygen <doxygen>`. In addition to this,
119 the new functionality should be documented in the manual and possibly the user guide .
121 * In addition to coding style, please also follow the instructions given
122 concerning the :ref:`commit style <code-commitstyle>`. This will also
123 facilitate the code review process.
125 Preparing code for submission
126 -----------------------------
128 |Gromacs| uses ``git`` for :doc:`change-management`.
129 Instead of accepting "pull requests", |Gromacs| changes are submitted as individual
130 commits on the tip of the ``master`` branch hosted at `gitlab`_.
131 Preparing, submitting, and managing patches for a change requires a little bit
132 of set-up. Refer to :doc:`change-management` for information about
134 * accessing the |Gromacs| *git* repository
135 * structure of the repository
136 * source control without merge commits
137 * ``git`` usage that may be less common in other development work flows
142 |Gromacs| has a public mirror available on GitHub at
143 https://github.com/gromacs/gromacs. You may wish to fork the project
144 under your own GitHub account and make your feature available that
145 way. This should help you to generate a following of users that would
146 help make the case for contributing the feature to the core. This
147 process would then still need to follow the remaining criteria
148 outlined here. If you fork |Gromacs|, please set the CMake variable
149 ``GMX_VERSION_STRING_OF_FORK`` to an appropriate descriptive string
150 - see cmake/gmxVersionInfo.cmake for details.
152 There is a project underway to develop a stable API for |Gromacs|,
153 which promises to be a great tool for permitting innovation while
154 ensuring ongoing quality of the core functionality. You might prefer
155 to plan to port your functionality to that API when it becomes
156 available. Do keep in touch on the `developer mailing list`_, so
157 you'll be the first to know when such functionality is ready for people to
160 Do you have more questions?
161 ---------------------------
163 If you have questions regarding these points, or would like feedback on your ideas for contributing,
164 please feel free to contact us through the `developer mailing list`_.
165 If your code is of interest to the wider |Gromacs| community, we will be happy to assist you
166 in the process of including it in the main source tree.
168 .. _developer mailing list: https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-developers
170 Removing functionality
171 ----------------------
173 This is occasionally necessary, and there is :ref:`policy for such
174 occasions <deprecation-policy>`. For users, there are also lists of
175 :ref:`anticipated changes <anticipated-changes>` and :ref:`deprecated
176 functionality <deprecated-functionality>` as of |Gromacs| 2019.