Switch Semaphore to use dispatch_semaphore_t on Mac.

The dispatch_semaphore_t is a higher-level, more-efficient semaphore
primitive if the cross-process capabilities of semaphore_t are not
needed.

Bug: chromium:1012386
Change-Id: I9c1b50805ce7ec54f4848a2633b4a7b260e00578
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/6240
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>
2 files changed
tree: 19a0a12714c0e6f0e8406bd587bd0397468b27e0
  1. .clang-format
  2. .editorconfig
  3. .gitignore
  4. .style.yapf
  5. AUTHORS
  6. LICENSE
  7. OWNERS
  8. README.md
  9. base/
  10. build/
  11. docs/
  12. examples/
  13. infra/
  14. tools/
  15. util/
README.md

GN

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 https://gn.googlesource.com/gn
cd gn
python build/gen.py
ninja -C out
# To run tests:
out/gn_unittests

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.

Examples

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

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 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’).

Community

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