//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 by the gsubtreed tool. Note: You can find all directories already available through gsubtreed in the list of all chromium repos.

• //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.

• Writing GN Templates
• Debugging Slow Builds
• Mac Hermetic Toolchains
• Android Build Documentation