Revert "Specify deps format for actions"

This reverts commit 7d9b8111a2e0c31c429a064f0480f16bb8b51e0f.

Reason for revert: Breaks backward compatibility with Ninja 1.8 which Chrome currently requires.

Original change's description:
> Specify deps format for actions
> Setting deps format is necessary for Ninja to store the depfile in its
> internal dependency database. This can significantly speed up loading
> for large dependency files, which can be the case for custom language
> support, e.g. Go or Dart in Fuchsia, where we emit large depfiles from
> actions. This also enables the use of `ninja -t deps` tool for custom
> actions.
> We hardcode the format to gcc since the documentation for depfile
> already explicitly specifies that "format is that of a Makefile".
> Change-Id: Iddaad90d6c1dcf0de40b0ed8fa005ac9c5b45bd6
> Reviewed-on:
> Reviewed-by: Brett Wilson <>
> Commit-Queue: Petr Hosek <>,,

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I4ce30794acfe0445e253719cd6c2232e296d5999
Reviewed-by: Brett Wilson <>
Commit-Queue: Brett Wilson <>
2 files changed
tree: 3aa4f6a513e529dc0b05e211cc8eeeaa91a8f37e
  1. build/
  2. docs/
  3. examples/
  4. infra/
  5. misc/
  6. src/
  7. tools/
  8. .clang-format
  9. .editorconfig
  10. .gitignore
  11. .style.yapf
  14. OWNERS


GN is a meta-build system that generates build files for Ninja.

Related resources:

Getting a binary

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.


There is a simple example in examples/simple_build directory that is a good place to get started with the minimal configuration.

To build and run the simple example with the default gcc compiler:

cd examples/simple_build
../../out/gn gen -C out
ninja -C out

For a maximal configuration see the Chromium setup:

and the Fuchsia setup:

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 push origin HEAD:refs/for/master

The first time you do this you'll get an error from the server about a missing change-ID. Follow the directions in the error message to install the change-ID hook and run git commit --amend to apply the hook to the current commit.

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.

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 with GN‘s development on Chromium’s gn-dev@ Google Group.