|author||David Turner <email@example.com>||Mon Oct 19 18:46:52 2020 +0000|
|committer||Commit Bot <firstname.lastname@example.org>||Mon Oct 19 18:47:11 2020 +0000|
Revert "gn recipe: Link GN with rpmalloc to speed it up." This reverts commit 4323e7015d8a7f74208962dd11f2d1065ae8aa15. Reason for revert: https://bugs.chromium.org/p/gn/issues/detail?id=208 Original change's description: > gn recipe: Link GN with rpmalloc to speed it up. > > This CL changes the GN recipe to link the executable with the > rpmalloc allocator from https://github.com/mjansson/rpmalloc > > This speeds up the 'gn gen' operation of both Chromium and Fuchsia > operations by 28% and 12% respectively , and has slightly better > performance than using tcmalloc from gperftools in the Fuchsia case. > > Note that: > > - The sources are grabbed directly from github.com, but it might be > desirable to use a Chromium or Fuchsia supported mirror instead. > > - Only Linux has been tested so far, so only this platform enables > this build mode. > >  Median measurements from 10 runs of 'gn gen' using the default > Linux allocator (glibc), gperftools' tcmalloc, and rpmalloc: > > Fuchsia: > glibc (default): 9917 ms > gperftools: 7858 ms (26% faster) > rpmalloc: 7752 ms (28% faster) > > Chromium: > glibc (default): 4742 ms > gperftools: 4186 ms (13% faster) > rpmalloc: 4235 ms (12% faster) > > Change-Id: Ia52134ef602f546d6e8b33bef0146c620d214b58 > Reviewed-on: https://gn-review.googlesource.com/c/gn/+/9920 > Commit-Queue: David Turner <email@example.com> > Reviewed-by: Scott Graham <firstname.lastname@example.org> > Reviewed-by: Petr Hosek <email@example.com> TBRfirstname.lastname@example.org,email@example.com,firstname.lastname@example.org,email@example.com Change-Id: I654d4646dae1d75d0aa2c110dbd7128dc0dd0911 No-Presubmit: true No-Tree-Checks: true No-Try: true Reviewed-on: https://gn-review.googlesource.com/c/gn/+/10360 Reviewed-by: David Turner <firstname.lastname@example.org> Commit-Queue: David Turner <email@example.com>
GN is a meta-build system that generates build files for Ninja.
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
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
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.