darling-libcxx/utils/google-benchmark/CONTRIBUTING.md
Eric Fiselier d9b9ef75a8 [libcxx] Add support for benchmark tests using Google Benchmark.
Summary:
This patch does the following:

1. Checks in a copy of the Google Benchmark library into the libc++ repo under `utils/google-benchmark`.
2. Teaches libc++ how to build Google Benchmark against both (A) in-tree libc++ and (B) the platforms native STL.
3. Allows performance benchmarks to be built as part of the libc++ build.

Building the benchmarks (and Google Benchmark) is off by default. It must be enabled using the CMake option `-DLIBCXX_INCLUDE_BENCHMARKS=ON`. When this option is enabled the tests under `libcxx/benchmarks`  can be built using the `libcxx-benchmarks` target.

On Linux platforms where libstdc++ is the default STL the CMake option `-DLIBCXX_BUILD_BENCHMARKS_NATIVE_STDLIB=ON` can be used to build each benchmark test against libstdc++ as well. This is useful for comparing performance between standard libraries.

Support for benchmarks is currently very minimal. They must be manually run by the user and there is no mechanism for detecting performance regressions.

Known Issues:

* `-DLIBCXX_INCLUDE_BENCHMARKS=ON` is only supported for Clang, and not GCC, since the `-stdlib=libc++` option is needed to build Google Benchmark.








Reviewers: danalbert, dberlin, chandlerc, mclow.lists, jroelofs

Subscribers: chandlerc, dberlin, tberghammer, danalbert, srhines, hfinkel

Differential Revision: https://reviews.llvm.org/D22240

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276049 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-19 23:07:03 +00:00

2.4 KiB

How to contribute

We'd love to accept your patches and contributions to this project. There are a just a few small guidelines you need to follow.

Contributor License Agreement

Contributions to any Google project must be accompanied by a Contributor License Agreement. This is not a copyright assignment, it simply gives Google permission to use and redistribute your contributions as part of the project.

  • If you are an individual writing original source code and you're sure you own the intellectual property, then you'll need to sign an individual CLA.

  • If you work for a company that wants to allow you to contribute your work, then you'll need to sign a corporate CLA.

You generally only need to submit a CLA once, so if you've already submitted one (even if it was for a different project), you probably don't need to do it again.

Once your CLA is submitted (or if you already submitted one for another Google project), make a commit adding yourself to the AUTHORS and CONTRIBUTORS files. This commit can be part of your first pull request.

Submitting a patch

  1. It's generally best to start by opening a new issue describing the bug or feature you're intending to fix. Even if you think it's relatively minor, it's helpful to know what people are working on. Mention in the initial issue that you are planning to work on that bug or feature so that it can be assigned to you.

  2. Follow the normal process of forking the project, and setup a new branch to work in. It's important that each group of changes be done in separate branches in order to ensure that a pull request only includes the commits related to that bug or feature.

  3. Do your best to have well-formed commit messages for each change. This provides consistency throughout the project, and ensures that commit messages are able to be formatted properly by various git tools.

  4. Finally, push the commits to your fork and submit a pull request.