| commit | 4cb8097270b58b4e7b3e2f4b38db2cc9b1f037c4 | [log] [tgz] |
|---|---|---|
| author | Petr Hosek <phosek@google.com> | Sun Jun 14 01:35:43 2020 -0700 |
| committer | Commit Bot <commit-bot@chromium.org> | Wed Jun 17 16:15:40 2020 +0000 |
| tree | e3def0dcc944e0b54a4610c7d877f6840fda35c6 | |
| parent | db55efd4bccc863849e396df094b754b31cb7d4b [diff] |
Omit stamp when inputs are only used by a single build rule When a target depends on a multiple inputs, but itself has only a single build rule, omit the stamp and depend on inputs directly. While it's not very common to have a target with only single source file in hand written code, it's pretty common for generated code such as various bindings, where this optimization can save significant amount of stamping. For example, in Fuchsia x64.core build this saves 2351 stamps. Bug: gn:172 Change-Id: If58241f56bd1ee902b0d32909f0662003fc499ed Reviewed-on: https://gn-review.googlesource.com/c/gn/+/8960 Reviewed-by: Brett Wilson <brettw@chromium.org> Commit-Queue: Petr Hosek <phosek@google.com>
GN is a meta-build system that generates build files for Ninja.
Related resources:
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.
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:
If you find a bug, you can see if it is known or report it in the bug database.
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’).
You may ask questions and follow along with GN‘s development on Chromium’s gn-dev@ Google Group.