Make regen with --dotfile and --root work.

Also add a test for GetSelfInvocationCommandLine().

Also fix a bug in MakeAbsoluteFilePathRelativeIfPossible() found
by the new test: It now works correctly if the two paths passed in
have different slash types right after the drive letter. If handed
"C:\foo" "C:/foo/f", the function used to return "..\foo\f", now it
returns just "f". This also makes the exe_path in the gn regen command
look nicer, and might fix a few other things.


Change-Id: I683d6f0ef5d742686181ff11545a62c052f06605
Commit-Queue: Brett Wilson <>
Reviewed-by: Brett Wilson <>
9 files changed
tree: 9f170a7eba39471d61d92fb48c48e6cbaa778691
  1. .clang-format
  2. .editorconfig
  3. .gitignore
  4. .style.yapf
  9. base/
  10. build/
  11. docs/
  12. infra/
  13. tools/
  14. util/


GN is a meta-build system that generates build files for Ninja. There is documentation in docs/.

Getting started

You can download the latest version of GN binary for Linux, macOS and Windows.

Alternatively, you can build GN from source:

git clone
cd gn
python build/
ninja -C out
# To run tests:

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.

Reporting bugs

If you find a bug, you can see if it is known or report it in the bug database.

Sending patches

GN uses Gerrit for code review. The short version of how to patch is:

Register at

... edit code ...
ninja -C out && out/gn_unittests

Then, to upload a change for review:

git commit
git cl upload --gerrit

When revising a change, use:

git commit --amend
git cl upload --gerrit

which will add the new changes to the existing code review, rather than creating a new one.

We ask that all contributors sign Google's Contributor License Agreement (either individual or corporate as appropriate, select ‘any other Google project’).


You may ask questions and follow along w/ GN‘s development on Chromium’s gn-dev@ Google Group.