We definitely welcome your patches and contributions to gRPC!
If you are new to github, please start by reading Pull Request howto
In order to protect both you and ourselves, you will need to sign the Contributor License Agreement.
Before starting any development work you will need a local copy of the gRPC repository. Please follow the instructions in Building gRPC C++: Clone the repository.
Different languages use different build systems. To hide the complexity of needing to build with many different build systems, a portable python script that unifies the experience of building and testing gRPC in different languages and on different platforms is provided.
To build gRPC in the language of choice (e.g. c++, csharp, php, python, ruby, ...)
src/YOUR-LANGUAGE directory.python tools/run_tests/run_tests.py -l YOUR_LANGUAGE --build_only
python tools/run_tests/run_tests.py -l YOUR_LANGUAGE
You can also run python tools/run_tests/run_tests.py --help to discover useful command line flags supported. For more details, see tools/run_tests where you will also find guidance on how to run various other test suites (e.g. interop tests, benchmarks).
To ease maintenance of language- and platform- specific build systems, many projects files are generated using templates and should not be edited by hand. Run tools/buildgen/generate_projects.sh to regenerate. See templates for details.
As a rule of thumb, if you see the "sanity tests" failing you've most likely edited generated files or you didn't regenerate the projects properly (or your code formatting doesn't match our code style).
How to get your contributions merged smoothly and quickly.
Create small PRs that are narrowly focused on addressing a single concern. We often times receive PRs that are trying to fix several things at a time, but only one fix is considered acceptable, nothing gets merged and both author's & review's time is wasted. Create more PRs to address different concerns and everyone will be happy.
For speculative changes, consider opening an issue and discussing it first. If you are suggesting a behavioral or API change, consider starting with a gRFC proposal.
Provide a good PR description as a record of what change is being made and why it was made. Link to a GitHub issue if it exists.
Don't fix code style and formatting unless you are already changing that line to address an issue. PRs with irrelevant changes won't be merged. If you do want to fix formatting or style, do that in a separate PR.
Unless your PR is trivial, you should expect there will be reviewer comments that you'll need to address before merging. We expect you to be reasonably responsive to those comments, otherwise the PR will be closed after 2-3 weeks of inactivity.
If you have non-trivial contributions, please consider adding an entry to the AUTHORS file listing the copyright holder for the contribution (yourself, if you are signing the individual CLA, or your company, for corporate CLAs) in the same PR as your contribution. This needs to be done only once, for each company, or individual.
Maintain clean commit history and use meaningful commit messages. PRs with messy commit history are difficult to review and won't be merged. Use rebase -i upstream/master to curate your commit history and/or to bring in latest changes from master (but avoid rebasing in the middle of a code review).
Keep your PR up to date with upstream/master (if there are merge conflicts, we can't really merge your change).
If you are regenerating the projects using tools/buildgen/generate_projects.sh, make changes to generated files a separate commit with commit message regenerate projects. Mixing changes to generated and hand-written files make your PR difficult to review. Note that running this script requires the installation of Python packages pyyaml and mako (typically installed using pip) as well as a recent version of go.
All tests need to be passing before your change can be merged. We recommend you run tests locally before creating your PR to catch breakages early on (see tools/run_tests. Ultimately, the green signal will be provided by our testing infrastructure. The reviewer will help you if there are test failures that seem not related to the change you are making.
Exceptions to the rules can be made if there's a compelling reason for doing so.