depot_tools

Tools for working with Chromium development. It requires python 3.8.

Tools

The most important tools are:

• fetch: A gclient wrapper to checkout a project. Use fetch --help for more details.
• gclient: A meta-checkout tool. Think repo or git submodules, except that it support OS-specific rules, e.g. do not checkout Windows only dependencies when checking out for Android. Use gclient help for more details and README.gclient.md.
• git cl: A code review tool to interact with Rietveld or Gerrit. Use git cl help for more details and README.git-cl.md.
• roll-dep: A gclient dependency management tool to submit a dep roll, updating a dependency to a newer revision.

There are a lot of git utilities included.

Also, includes shell script/batch file for tools required to build chromium, e.g.

• gn: a meta-build system that generates build files for Ninja
• autoninja: a wrapper for siso and ninja.
• siso: a build tool that aims to significantly speed up Chromium's build.
• ninja: a small build system with a focus on speed. deprecated by Siso.

These shell script/batch file runs python script with python-bin/python3 that find binaries in chromium checkout, and run with proper setup/check. To use these wrappers, you need to initialize/bootstrap depot_tools (using gclient, update_depot_tools or ensure_bootstrap).

Installing

See set-up documentation.

depot_tools is also available in

• chromium's third_party/depot_tools: propagated by autoroller.

• on builder: infra_internal/recipe_bundles/chrome-internal.googlesource.com/chrome/tools/build bundles depot_tools. propagated by build_internal recipe roller

These depot_tools would not be initialized/bootstrapped (i.e. no python-bin/python3 binary available), so the build tool wrapper won't work, unless it is explicitly initialized by ensure_bootstrap. Or, directly call the python script instead of using the shell script/batch file.

Updating

depot_tools updates itself automatically when running gclient tool. To disable auto update, set the environment variable DEPOT_TOOLS_UPDATE=0 or run ./update_depot_tools_toggle.py --disable.

To update package manually, run update_depot_tools.bat on Windows, or ./update_depot_tools on Linux or Mac.

Running gclient will install python3 binary.

Contributing

To contribute change for review:

git new-branch <somename>
# Hack
git add .
git commit -a -m "Fixes goat teleporting"
# find reviewers
git cl owners
git log -- <yourfiles>

# Request a review.
git cl upload -r reviewer1@chromium.org,reviewer2@chromium.org --send-mail

# Edit change description if needed.
git cl desc

# If change is approved, flag it to be committed.
git cl set-commit

# If change needs more work.
git rebase-update
...
git cl upload -t "Fixes goat teleporter destination to be Australia"

See also open bugs, open reviews, forum or report problems.

cpplint.py

Until 2018, our cpplint.py was a copy of the upstream version at https://github.com/google/styleguide/tree/gh-pages/cpplint. Unfortunately, that repository is not maintained any more. If you want to update cpplint.py in depot_tools, just upload a patch to do so. We will figure out a long-term strategy via issue https://crbug.com/916550.