Contributing to Zircon

Important: Zircon is under active development. At this time Zircon is not seeking major changes or new features from new contributors. However, small bug fixes are encouraged.

Here are some general guidelines for patches to Zircon.


  • Follow the process for Fuchsia patches outlined in Contribute changes.

  • Patches are handled through Gerrit Code Review{:.external}.

  • Make sure Zircon is buildable for all major targets (x86-64, arm64) at every change. Use fx multi bringup-cq so that Zircon is buildable. For more information, see Building Zircon for all targets.

  • Avoid breaking the unit tests. Boot Zircon and run the tests to verify that they're all passing.

  • Avoid whitespace or style changes. Especially, do not mix style changes with patches that contain other changes, as style changes are often a distraction. Use fx format-code to format the code with the consistent style.

  • Avoid changes that touch multiple modules at once if possible. Most changes should be to a single library, driver, app, and so on.

Documentation for Zircon

Writing documentation is a great idea and is encouraged:

  • Documentation should be in Markdown files.
  • Zircon documentation is located in /docs/concepts/kernel.
  • Before submitting documentation, make sure that the Markdown renders correctly.

When editing or adding syscalls or cmdlines, update the following:


How to deprecate #define constants

You can create a deprecated typedef and have the constant definition cast to that type. The warning or error that is generated includes the name of the deprecated typedef.

typedef int ZX_RESUME_NOT_HANDLED_DEPRECATION __attribute__((deprecated));