format: Fix formatting not taking into account suffixes

In subprinters (evaluated for penalty values), suffixes from higher up
the expression tree where not being included, resulting in incorrect
penalties. In some cases, this caused the formatter to believe that all
options were going to exceed 80 col, and so it failed badly by putting
[way] too much on a single line.

https://chromium-review.googlesource.com/c/chromium/src/+/2124534 is a
test run on all .gn/.gni files in Chromium. Only the first two files in
the CL are related to this change, and seem like improvements or
approximately as good.

Bug: gn:156
Change-Id: I017ef6bc2918c1c8fdbd971c1041f5069b4c26c7
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/7880
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>
4 files changed
tree: ab30afd04c30c51000c967f25d5f286aec2052b0
  1. build/
  2. docs/
  3. examples/
  4. infra/
  5. misc/
  6. src/
  7. .clang-format
  8. .editorconfig
  9. .gitignore
  10. .style.yapf
  11. AUTHORS
  12. LICENSE
  13. OWNERS
  14. README.md
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.

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

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

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 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’).

Community

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