This document contains information about successfully releasing LLVM — including sub-projects: e.g., clang and compiler-rt — to the public. It is the Release Manager’s responsibility to ensure that a high quality build of LLVM is released.
If you’re looking for the document on how to test the release candidates and create the binary packages, please refer to the How To Validate a New Release instead.
LLVM is released on a time based schedule — with major releases roughly every 6 months. In between major releases there may be dot releases. The release manager will determine if and when to make a dot release based on feedback from the community. Typically, dot releases should be made if there are large number of bug-fixes in the stable branch or a critical bug has been discovered that affects a large number of users.
Unless otherwise stated, dot releases will follow the same procedure as major releases.
The release process is roughly as follows:
This section describes a few administrative tasks that need to be done for the release process to begin. Specifically, it involves:
Branch the Git trunk using the following procedure:
$ git tag -a llvmorg-N-init
After creating the LLVM release branch, update the release branches’ CMakeLists.txt versions from ‘X.0.0git‘ to ‘X.0.0‘.
In addition, the version numbers of all the Bugzilla components must be updated for the next release.
Tag release candidates:
$ git tag -a llvmorg-X.Y.Z-rcN
The Release Manager must supply pre-packaged source tarballs for users. This can be done with the export.sh script in utils/release.
Tarballs, release binaries, or any other release artifacts must be uploaded to GitHub. This can be done using the github-upload-release.py script in utils/release.
$ github-upload-release.py upload --token <github-token> --release X.Y.Z-rcN --files <release_files>
$ ./export.sh -release X.Y.Z -rc $RC
This will generate source tarballs for each LLVM project being validated, which can be uploaded to github for further testing.
Creating the binary distribution requires following the instructions here.
That process will perform both Release+Asserts and Release builds but only pack the Release build for upload. You should use the Release+Asserts sysroot, normally under final/Phase3/Release+Asserts/llvmCore-3.8.1-RCn.install/, for test-suite and run-time benchmarks, to make sure nothing serious has passed through the net. For compile-time benchmarks, use the Release version.
The minimum required version of the tools you’ll need are here
There are no official release qualification criteria. It is up to the the release manager to determine when a release is ready. The release manager should pay attention to the results of community testing, the number of outstanding bugs, and then number of regressions when determining whether or not to make a release.
The community values time based releases, so releases should not be delayed for too long unless there are critical issues remaining. In most cases, the only kind of bugs that are critical enough to block a release would be a major regression from a previous release.
A few developers in the community have dedicated time to validate the release candidates and volunteered to be the official release testers for each architecture.
These will be the ones testing, generating and uploading the official binaries to the server, and will be the minimum tests necessary for the release to proceed.
This will obviously not cover all OSs and distributions, so additional community validation is important. However, if community input is not reached before the release is out, all bugs reported will have to go on the next stable release.
The official release managers are:
The official release testers are volunteered from the community and have consistently validated and released binaries for their targets/OSs. To contact them, you should email the release-testers@lists.llvm.org mailing list.
The official testers list is in the file RELEASE_TESTERS.TXT, in the LLVM repository.
Once all testing has been completed and appropriate bugs filed, the release candidate tarballs are put on the website and the LLVM community is notified.
We ask that all LLVM developers test the release in any the following ways:
We also ask that the OS distribution release managers test their packages with the first candidate of every release, and report any new errors in Bugzilla. If the bug can be reproduced with an unpatched upstream version of the release candidate (as opposed to the distribution’s own build), the priority should be release blocker.
During the first round of testing, all regressions must be fixed before the second release candidate is tagged.
In the subsequent stages, the testing is only to ensure that bug fixes previously merged in have not created new major problems. This is not the time to solve additional and unrelated bugs! If no patches are merged in, the release is determined to be ready and the release manager may move onto the next stage.
Every regression that is found during the tests (as per the criteria above), should be filled in a bug in Bugzilla with the priority release blocker and blocking a specific release.
To help manage all the bugs reported and which ones are blockers or not, a new “[meta]” bug should be created and all regressions blocking that Meta. Once all blockers are done, the Meta can be closed.
If a bug can’t be reproduced, or stops being a blocker, it should be removed from the Meta and its priority decreased to normal. Debugging can continue, but on trunk.
You can use any of the following methods to request that a revision from trunk be merged into a release branch:
Below are the rules regarding patching the release branch:
Use the git cherry-pick -x command to merge patches to the release branch:
The final stages of the release process involves tagging the “final” release branch, updating documentation that refers to the release, and updating the demo page.
Review the documentation in the release branch and ensure that it is up to date. The “Release Notes” must be updated to reflect new features, bug fixes, new known issues, and changes in the list of supported platforms. The “Getting Started Guide” should be updated to reflect the new release version number tag available from Subversion and changes in basic system requirements.
Tag the final release sources:
$ git tag -a llvmorg-X.Y.Z
$ git push https://github.com/llvm/llvm-project.git llvmorg-X.Y.Z
The website must be updated before the release announcement is sent out. Here is what to do:
Send an email to the list announcing the release, pointing people to all the relevant documentation, download pages and bugs fixed.