Disallow non-buildable sources in binary targets

When adding a file that's not a source, header, or object file to a source_set,
loadable_module, shared_library, executable, or static_library, gn will now
generate an error like the following:

ERROR at //third_party/protobuf/proto_library.gni:369:15: Only source, header,
and object files belong in the sources of a
source_set. //out/Test/pyproto/google_apis/gcm/protocol/mcs_pb2.py is not one of
the valid types.
    sources = get_target_outputs(":$action_name")
See //google_apis/gcm/BUILD.gn:78:1: whence it was called.
proto_library("proto") {
See //BUILD.gn:89:7: which caused the file to be included.


Change-Id: I4ed8da10c48e3e5d74f79e51d8222c998a7b883a
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/4980
Commit-Queue: Brett Wilson <brettw@google.com>
Reviewed-by: Brett Wilson <brettw@google.com>
6 files changed
tree: 3c325948931e7bb69b785d4a7353e946013911fd
  1. .clang-format
  2. .editorconfig
  3. .gitignore
  4. .style.yapf
  8. README.md
  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/ and a presentation on it.

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 https://gn.googlesource.com/gn
cd gn
python build/gen.py
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 https://gn-review.googlesource.com.

... 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.