This document contains information about successfully releasing LLVM — - including subprojects: e.g., clang and dragonegg — to - the public. It is the Release Manager's responsibility to ensure that a high - quality build of LLVM is released.
- -LLVM is released on a time based schedule — roughly every 6 months. We - do not normally have dot releases because of the nature of LLVM's incremental - development philosophy. That said, the only thing preventing dot releases for - critical bug fixes from happening is a lack of resources — testers, - machines, time, etc. And, because of the high quality we desire for LLVM - releases, we cannot allow for a truncated form of release qualification.
- -The release process is roughly as follows:
- -Set code freeze and branch creation date for 6 months after last code - freeze date. Announce release schedule to the LLVM community and update - the website.
Create release branch and begin release process.
Send out release candidate sources for first round of testing. Testing - lasts 7-10 days. During the first round of testing, any regressions found - should be fixed. Patches are merged from mainline into the release - branch. Also, all features need to be completed during this time. Any - features not completed at the end of the first round of testing will be - removed or disabled for the release.
Generate and send out the second release candidate sources. Only - critial bugs found during this testing phase will be fixed. Any - bugs introduced by merged patches will be fixed. If so a third round of - testing is needed.
The release notes are updated.
Finally, release!
This section describes a few administrative tasks that need to be done for - the release process to begin. Specifically, it involves:
- -Branch the Subversion trunk using the following procedure:
- -Remind developers that the release branching is imminent and to refrain - from committing patches that might break the build. E.g., new features, - large patches for works in progress, an overhaul of the type system, an - exciting new TableGen feature, etc.
Verify that the current Subversion trunk is in decent shape by - examining nightly tester and buildbot results.
Create the release branch for llvm, clang, - the test-suite, and dragonegg from the last known good - revision. The branch's name is release_XY, - where X is the major and Y the minor release - numbers. The branches should be created using the following commands:
- --$ svn copy https://llvm.org/svn/llvm-project/llvm/trunk \ - https://llvm.org/svn/llvm-project/llvm/branches/release_XY - -$ svn copy https://llvm.org/svn/llvm-project/cfe/trunk \ - https://llvm.org/svn/llvm-project/cfe/branches/release_XY - -$ svn copy https://llvm.org/svn/llvm-project/dragonegg/trunk \ - https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY - -$ svn copy https://llvm.org/svn/llvm-project/test-suite/trunk \ - https://llvm.org/svn/llvm-project/test-suite/branches/release_XY --
Advise developers that they may now check their patches into the - Subversion tree again.
The Release Manager should switch to the release branch, because all - changes to the release will now be done in the branch. The easiest way to - do this is to grab a working copy using the following commands:
- --$ svn co https://llvm.org/svn/llvm-project/llvm/branches/release_XY llvm-X.Y - -$ svn co https://llvm.org/svn/llvm-project/cfe/branches/release_XY clang-X.Y - -$ svn co https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY dragonegg-X.Y - -$ svn co https://llvm.org/svn/llvm-project/test-suite/branches/release_XY test-suite-X.Y --
After creating the LLVM release branch, update the release branches' - autoconf and configure.ac versions from 'X.Ysvn' - to 'X.Y'. Update it on mainline as well to be the next version - ('X.Y+1svn'). Regenerate the configure scripts for both - llvm and the test-suite.
- -In addition, the version numbers of all the Bugzilla components must be - updated for the next release.
- -Create release candidates for llvm, clang, - dragonegg, and the LLVM test-suite by tagging the branch - with the respective release candidate number. For instance, to - create Release Candidate 1 you would issue the following commands:
- --$ svn mkdir https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XY -$ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XY \ - https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XY/rc1 - -$ svn mkdir https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XY -$ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_XY \ - https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XY/rc1 - -$ svn mkdir https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XY -$ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY \ - https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XY/rc1 - -$ svn mkdir https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XY -$ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XY \ - https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XY/rc1 --
Similarly, Release Candidate 2 would be named RC2 and so - on. This keeps a permanent copy of the release candidate around for people to - export and build as they wish. The final released sources will be tagged in - the RELEASE_XY directory as Final - (c.f. Tag the LLVM Final Release).
- -The Release Manager may supply pre-packaged source tarballs for users. This - can be done with the following commands:
- --$ svn export https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XY/rc1 llvm-X.Yrc1 -$ svn export https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XY/rc1 clang-X.Yrc1 -$ svn export https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XY/rc1 dragonegg-X.Yrc1 -$ svn export https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XY/rc1 llvm-test-X.Yrc1 - -$ tar -cvf - llvm-X.Yrc1 | gzip > llvm-X.Yrc1.src.tar.gz -$ tar -cvf - clang-X.Yrc1 | gzip > clang-X.Yrc1.src.tar.gz -$ tar -cvf - dragonegg-X.Yrc1 | gzip > dragonegg-X.Yrc1.src.tar.gz -$ tar -cvf - llvm-test-X.Yrc1 | gzip > llvm-test-X.Yrc1.src.tar.gz --
The builds of llvm, clang, and dragonegg - must be free of errors and warnings in Debug, Release+Asserts, and - Release builds. If all builds are clean, then the release passes Build - Qualification.
- -The make options for building the different modes:
- -| Mode | Options |
|---|---|
| Debug | ENABLE_OPTIMIZED=0 |
| Release+Asserts | ENABLE_OPTIMIZED=1 |
| Release | ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1 |
Build Debug, Release+Asserts, and Release versions - of llvm on all supported platforms. Directions to build - llvm are here.
- -Creating the clang binary distribution - (Debug/Release+Asserts/Release) requires performing the following steps for - each supported platform:
- -The table below specifies which compilers are used for each Arch/OS - combination when qualifying the build of llvm, clang, - and dragonegg.
- -| Architecture | OS | compiler |
|---|---|---|
| x86-32 | Mac OS 10.5 | gcc 4.0.1 |
| x86-32 | Linux | gcc 4.2.X, gcc 4.3.X |
| x86-32 | FreeBSD | gcc 4.2.X |
| x86-32 | mingw | gcc 3.4.5 |
| x86-64 | Mac OS 10.5 | gcc 4.0.1 |
| x86-64 | Linux | gcc 4.2.X, gcc 4.3.X |
| x86-64 | FreeBSD | gcc 4.2.X |
A release is qualified when it has no regressions from the previous release - (or baseline). Regressions are related to correctness first and performance - second. (We may tolerate some minor performance regressions if they are - deemed necessary for the general quality of the compiler.)
- -Regressions are new failures in the set of tests that are used to qualify - each product and only include things on the list. Every release will have - some bugs in it. It is the reality of developing a complex piece of - software. We need a very concrete and definitive release criteria that - ensures we have monotonically improving quality on some metric. The metric we - use is described below. This doesn't mean that we don't care about other - criteria, but these are the criteria which we found to be most important and - which must be satisfied before a release can go out
- - -LLVM is qualified when it has a clean test run without a front-end. And it - has no regressions when using either clang or dragonegg - with the test-suite from the previous release.
- -Clang is qualified when front-end specific tests in the - llvm dejagnu test suite all pass, clang's own test suite passes - cleanly, and there are no regressions in the test-suite.
- -| Architecture | OS | clang baseline | tests |
|---|---|---|---|
| x86-32 | Linux | last release | llvm dejagnu, clang tests, test-suite (including spec) |
| x86-32 | FreeBSD | last release | llvm dejagnu, clang tests, test-suite |
| x86-32 | mingw | none | QT |
| x86-64 | Mac OS 10.X | last release | llvm dejagnu, clang tests, test-suite (including spec) |
| x86-64 | Linux | last release | llvm dejagnu, clang tests, test-suite (including spec) |
| x86-64 | FreeBSD | last release | llvm dejagnu, clang tests, test-suite |
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. Ask that all LLVM developers test the release in 2 ways:
- -Ask LLVM developers to submit the test suite report and make check - results to the list. Verify that there are no regressions from the previous - release. The results are not used to qualify a release, but to spot other - potential problems. For unsupported targets, verify that make check - is at least clean.
- -During the first round of testing, all regressions must be fixed before the - second release candidate is tagged.
- -If this is the second round of testing, 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.
- -Below are the rules regarding patching the release branch:
- -Patches applied to the release branch may only be applied by the - release manager.
During the first round of testing, patches that fix regressions or that - are small and relatively risk free (verified by the appropriate code - owner) are applied to the branch. Code owners are asked to be very - conservative in approving patches for the branch. We reserve the right to - reject any patch that does not fix a regression as previously - defined.
During the remaining rounds of testing, only patches that fix critical - regressions may be applied.
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 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. Merge both changes from - mainline into the release branch.
- -Tag the final release sources using the following procedure:
- --$ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XY \ - https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XY/Final - -$ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_XY \ - https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_XY/Final - -$ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY \ - https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_XY/Final - -$ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XY \ - https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XY/Final --
The LLVM demo page must be updated to use the new release. This consists of - using the new clang binary and building LLVM.
- - -The website must be updated before the release announcement is sent out. Here - is what to do:
- -Have Chris send out the release announcement when everything is finished.
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