|
|
|
Contributing to Bitcoin Core
|
|
|
|
============================
|
|
|
|
|
|
|
|
The Bitcoin Core project operates an open contributor model where anyone is
|
|
|
|
welcome to contribute towards development in the form of peer review, testing
|
|
|
|
and patches. This document explains the practical process and guidelines for
|
|
|
|
contributing.
|
|
|
|
|
|
|
|
Firstly in terms of structure, there is no particular concept of "Core
|
|
|
|
developers" in the sense of privileged people. Open source often naturally
|
|
|
|
revolves around meritocracy where longer term contributors gain more trust from
|
|
|
|
the developer community. However, some hierarchy is necessary for practical
|
|
|
|
purposes. As such there are repository "maintainers" who are responsible for
|
|
|
|
merging pull requests as well as a "lead maintainer" who is responsible for the
|
|
|
|
release cycle, overall merging, moderation and appointment of maintainers.
|
|
|
|
|
|
|
|
|
|
|
|
Contributor Workflow
|
|
|
|
--------------------
|
|
|
|
|
|
|
|
The codebase is maintained using the "contributor workflow" where everyone
|
|
|
|
without exception contributes patch proposals using "pull requests". This
|
|
|
|
facilitates social contribution, easy testing and peer review.
|
|
|
|
|
|
|
|
To contribute a patch, the workflow is as follows:
|
|
|
|
|
|
|
|
- Fork repository
|
|
|
|
- Create topic branch
|
|
|
|
- Commit patches
|
|
|
|
|
|
|
|
The project coding conventions in the [developer notes](doc/developer-notes.md)
|
|
|
|
must be adhered to.
|
|
|
|
|
|
|
|
In general [commits should be atomic](https://en.wikipedia.org/wiki/Atomic_commit#Atomic_commit_convention)
|
|
|
|
and diffs should be easy to read. For this reason do not mix any formatting
|
|
|
|
fixes or code moves with actual code changes.
|
|
|
|
|
|
|
|
Commit messages should be verbose by default consisting of a short subject line
|
|
|
|
(50 chars max), a blank line and detailed explanatory text as separate
|
|
|
|
paragraph(s); unless the title alone is self-explanatory (like "Corrected typo
|
|
|
|
in init.cpp") then a single title line is sufficient. Commit messages should be
|
|
|
|
helpful to people reading your code in the future, so explain the reasoning for
|
|
|
|
your decisions. Further explanation [here](http://chris.beams.io/posts/git-commit/).
|
|
|
|
|
|
|
|
If a particular commit references another issue, please add the reference, for
|
|
|
|
example `refs #1234`, or `fixes #4321`. Using the `fixes` or `closes` keywords
|
|
|
|
will cause the corresponding issue to be closed when the pull request is merged.
|
|
|
|
|
|
|
|
Please refer to the [Git manual](https://git-scm.com/doc) for more information
|
|
|
|
about Git.
|
|
|
|
|
|
|
|
- Push changes to your fork
|
|
|
|
- Create pull request
|
|
|
|
|
|
|
|
The title of the pull request should be prefixed by the component or area that
|
|
|
|
the pull request affects. Valid areas as:
|
|
|
|
|
|
|
|
- *Consensus* for changes to consensus critical code
|
|
|
|
- *Docs* for changes to the documentation
|
|
|
|
- *Qt* for changes to bitcoin-qt
|
|
|
|
- *Mining* for changes to the mining code
|
|
|
|
- *Net* or *P2P* for changes to the peer-to-peer network code
|
|
|
|
- *RPC/REST/ZMQ* for changes to the RPC, REST or ZMQ APIs
|
|
|
|
- *Scripts and tools* for changes to the scripts and tools
|
|
|
|
- *Tests* for changes to the bitcoin unit tests or QA tests
|
|
|
|
- *Trivial* should **only** be used for PRs that do not change generated
|
|
|
|
executable code. Notably, refactors (change of function arguments and code
|
|
|
|
reorganization) and changes in behavior should **not** be marked as trivial.
|
|
|
|
Examples of trivial PRs are changes to:
|
|
|
|
- comments
|
|
|
|
- whitespace
|
|
|
|
- variable names
|
|
|
|
- logging and messages
|
|
|
|
- *Utils and libraries* for changes to the utils and libraries
|
|
|
|
- *Wallet* for changes to the wallet code
|
|
|
|
|
|
|
|
Examples:
|
|
|
|
|
|
|
|
Consensus: Add new opcode for BIP-XXXX OP_CHECKAWESOMESIG
|
|
|
|
Net: Automatically create hidden service, listen on Tor
|
|
|
|
Qt: Add feed bump button
|
|
|
|
Trivial: Fix typo in init.cpp
|
|
|
|
|
|
|
|
If a pull request is specifically not to be considered for merging (yet) please
|
|
|
|
prefix the title with [WIP] or use [Tasks Lists](https://help.github.com/articles/basic-writing-and-formatting-syntax/#task-lists)
|
|
|
|
in the body of the pull request to indicate tasks are pending.
|
|
|
|
|
|
|
|
The body of the pull request should contain enough description about what the
|
|
|
|
patch does together with any justification/reasoning. You should include
|
|
|
|
references to any discussions (for example other tickets or mailing list
|
|
|
|
discussions).
|
|
|
|
|
|
|
|
At this stage one should expect comments and review from other contributors. You
|
|
|
|
can add more commits to your pull request by committing them locally and pushing
|
|
|
|
to your fork until you have satisfied all feedback.
|
|
|
|
|
|
|
|
Squashing Commits
|
|
|
|
---------------------------
|
|
|
|
If your pull request is accepted for merging, you may be asked by a maintainer
|
|
|
|
to squash and or [rebase](https://git-scm.com/docs/git-rebase) your commits
|
|
|
|
before it will be merged. The basic squashing workflow is shown below.
|
|
|
|
|
|
|
|
git checkout your_branch_name
|
|
|
|
git rebase -i HEAD~n
|
|
|
|
# n is normally the number of commits in the pull
|
|
|
|
# set commits from 'pick' to 'squash', save and quit
|
|
|
|
# on the next screen, edit/refine commit messages
|
|
|
|
# save and quit
|
|
|
|
git push -f # (force push to GitHub)
|
|
|
|
|
|
|
|
If you have problems with squashing (or other workflows with `git`), you can
|
|
|
|
alternatively enable "Allow edits from maintainers" in the right GitHub
|
|
|
|
sidebar and ask for help in the pull request.
|
|
|
|
|
|
|
|
Please refrain from creating several pull requests for the same change.
|
|
|
|
Use the pull request that is already open (or was created earlier) to amend
|
|
|
|
changes. This preserves the discussion and review that happened earlier for
|
|
|
|
the respective change set.
|
|
|
|
|
|
|
|
The length of time required for peer review is unpredictable and will vary from
|
|
|
|
pull request to pull request.
|
|
|
|
|
|
|
|
|
|
|
|
Pull Request Philosophy
|
|
|
|
-----------------------
|
|
|
|
|
|
|
|
Patchsets should always be focused. For example, a pull request could add a
|
|
|
|
feature, fix a bug, or refactor code; but not a mixture. Please also avoid super
|
|
|
|
pull requests which attempt to do too much, are overly large, or overly complex
|
|
|
|
as this makes review difficult.
|
|
|
|
|
|
|
|
|
|
|
|
###Features
|
|
|
|
|
|
|
|
When adding a new feature, thought must be given to the long term technical debt
|
|
|
|
and maintenance that feature may require after inclusion. Before proposing a new
|
|
|
|
feature that will require maintenance, please consider if you are willing to
|
|
|
|
maintain it (including bug fixing). If features get orphaned with no maintainer
|
|
|
|
in the future, they may be removed by the Repository Maintainer.
|
|
|
|
|
|
|
|
|
|
|
|
###Refactoring
|
|
|
|
|
|
|
|
Refactoring is a necessary part of any software project's evolution. The
|
|
|
|
following guidelines cover refactoring pull requests for the project.
|
|
|
|
|
|
|
|
There are three categories of refactoring, code only moves, code style fixes,
|
|
|
|
code refactoring. In general refactoring pull requests should not mix these
|
|
|
|
three kinds of activity in order to make refactoring pull requests easy to
|
|
|
|
review and uncontroversial. In all cases, refactoring PRs must not change the
|
|
|
|
behaviour of code within the pull request (bugs must be preserved as is).
|
|
|
|
|
|
|
|
Project maintainers aim for a quick turnaround on refactoring pull requests, so
|
|
|
|
where possible keep them short, uncomplex and easy to verify.
|
|
|
|
|
|
|
|
|
|
|
|
"Decision Making" Process
|
|
|
|
-------------------------
|
|
|
|
|
|
|
|
The following applies to code changes to the Bitcoin Core project (and related
|
|
|
|
projects such as libsecp256k1), and is not to be confused with overall Bitcoin
|
|
|
|
Network Protocol consensus changes.
|
|
|
|
|
|
|
|
Whether a pull request is merged into Bitcoin Core rests with the project merge
|
|
|
|
maintainers and ultimately the project lead.
|
|
|
|
|
|
|
|
Maintainers will take into consideration if a patch is in line with the general
|
|
|
|
principles of the project; meets the minimum standards for inclusion; and will
|
|
|
|
judge the general consensus of contributors.
|
|
|
|
|
|
|
|
In general, all pull requests must:
|
|
|
|
|
|
|
|
- have a clear use case, fix a demonstrable bug or serve the greater good of
|
|
|
|
the project (for example refactoring for modularisation);
|
|
|
|
- be well peer reviewed;
|
|
|
|
- have unit tests and functional tests where appropriate;
|
|
|
|
- follow code style guidelines;
|
|
|
|
- not break the existing test suite;
|
|
|
|
- where bugs are fixed, where possible, there should be unit tests
|
|
|
|
demonstrating the bug and also proving the fix. This helps prevent regression.
|
|
|
|
|
|
|
|
Patches that change Bitcoin consensus rules are considerably more involved than
|
|
|
|
normal because they affect the entire ecosystem and so must be preceded by
|
|
|
|
extensive mailing list discussions and have a numbered BIP. While each case will
|
|
|
|
be different, one should be prepared to expend more time and effort than for
|
|
|
|
other kinds of patches because of increased peer review and consensus building
|
|
|
|
requirements.
|
|
|
|
|
|
|
|
|
|
|
|
###Peer Review
|
|
|
|
|
|
|
|
Anyone may participate in peer review which is expressed by comments in the pull
|
|
|
|
request. Typically reviewers will review the code for obvious errors, as well as
|
|
|
|
test out the patch set and opine on the technical merits of the patch. Project
|
|
|
|
maintainers take into account the peer review when determining if there is
|
|
|
|
consensus to merge a pull request (remember that discussions may have been
|
|
|
|
spread out over github, mailing list and IRC discussions). The following
|
|
|
|
language is used within pull-request comments:
|
|
|
|
|
|
|
|
- ACK means "I have tested the code and I agree it should be merged";
|
|
|
|
- NACK means "I disagree this should be merged", and must be accompanied by
|
|
|
|
sound technical justification (or in certain cases of copyright/patent/licensing
|
|
|
|
issues, legal justification). NACKs without accompanying reasoning may be
|
|
|
|
disregarded;
|
|
|
|
- utACK means "I have not tested the code, but I have reviewed it and it looks
|
|
|
|
OK, I agree it can be merged";
|
|
|
|
- Concept ACK means "I agree in the general principle of this pull request";
|
|
|
|
- Nit refers to trivial, often non-blocking issues.
|
|
|
|
|
|
|
|
Reviewers should include the commit hash which they reviewed in their comments.
|
|
|
|
|
|
|
|
Project maintainers reserve the right to weigh the opinions of peer reviewers
|
|
|
|
using common sense judgement and also may weight based on meritocracy: Those
|
|
|
|
that have demonstrated a deeper commitment and understanding towards the project
|
|
|
|
(over time) or have clear domain expertise may naturally have more weight, as
|
|
|
|
one would expect in all walks of life.
|
|
|
|
|
|
|
|
Where a patch set affects consensus critical code, the bar will be set much
|
|
|
|
higher in terms of discussion and peer review requirements, keeping in mind that
|
|
|
|
mistakes could be very costly to the wider community. This includes refactoring
|
|
|
|
of consensus critical code.
|
|
|
|
|
|
|
|
Where a patch set proposes to change the Bitcoin consensus, it must have been
|
|
|
|
discussed extensively on the mailing list and IRC, be accompanied by a widely
|
|
|
|
discussed BIP and have a generally widely perceived technical consensus of being
|
|
|
|
a worthwhile change based on the judgement of the maintainers.
|
|
|
|
|
|
|
|
|
|
|
|
Release Policy
|
|
|
|
--------------
|
|
|
|
|
|
|
|
The project leader is the release manager for each Bitcoin Core release.
|
|
|
|
|
|
|
|
Copyright
|
|
|
|
---------
|
|
|
|
|
|
|
|
By contributing to this repository, you agree to license your work under the
|
|
|
|
MIT license unless specified otherwise in `contrib/debian/copyright` or at
|
|
|
|
the top of the file itself. Any work contributed where you are not the original
|
|
|
|
author must contain its license header with the original author(s) and source.
|