# About `//build` contains: * Core GN templates and configuration * Core Python build scripts Since this directory is DEPS'ed in by some other repositories (webrtc, pdfium, v8, etc), it should be kept as self-contained as possible by not referring to files outside of it. Some exceptions exist (`//testing`, select `//third_party` subdirectories), but new dependencies tend to break these other projects, and so should be avoided. Changes to `//build` should be landed in the Chromium repo. They will then be replicated to the stand-alone [build repo](https://chromium.googlesource.com/chromium/src/build) by the [gsubtreed tool.](https://chromium.googlesource.com/infra/infra/+/main/infra/services/gsubtreed) Note: You can find all directories already available through gsubtreed in the [list of all chromium repos](https://chromium.googlesource.com/). ## Contents * `//build/config` - Common templates via `.gni` files. * `//build/toolchain` - GN toolchain definitions. * `Other .py files` - Some are used by GN/Ninja. Some by gclient hooks, some are just random utilities. Files referenced by `//.gn`: * `//build/BUILDCONFIG.gn` - Included by all `BUILD.gn` files. * `//build/secondary` - An overlay for `BUILD.gn` files. Enables adding `BUILD.gn` to directories that live in sub-repositories. * `//build_overrides` - Refer to [//build_overrides/README.md](../build_overrides/README.md). ## Docs * [Writing GN Templates](docs/writing_gn_templates.md) * [Debugging Slow Builds](docs/debugging_slow_builds.md) * [Mac Hermetic Toolchains](docs/mac_hermetic_toolchain.md) * [Android Build Documentation](android/docs/README.md)