GN is a meta-build system that generates build files for Ninja.
git clone https://gn.googlesource.com/gn cd gn python build/gen.py ninja -C out
On Windows, it is expected that cl.exe, link.exe, and lib.exe can be found in PATH, so you'll want to run from a Visual Studio command prompt, or similar.
On Linux and Mac, the default compiler is clang++, a recent version is expected to be found in PATH. This can be overridden by setting CC, CXX, and AR.
GN uses Gerrit for code review. The short version of how to patch is:
... edit code ... ninja -C out && out/gn_unittests
Then, to upload a change for review:
git commit git push origin HEAD:refs/for/master # This uploads for review.
When revising a change, use:
git commit --amend git push origin HEAD:refs/for/master
which will add the new changes to the existing code review, rather than creating a new one.
TODO: AUTHORS, CLA, etc.