This document collects information about successfully releasing LLVM to the public. It is the release manager's guide to ensuring that a high quality build of LLVM is released.
The following is the basic criteria for releasing LLVM:
Branch the Subversion HEAD using the following procedure:
Verify that the current Subversion HEAD is in decent shape by examining nightly tester results.
Request all developers to refrain from committing. Offenders get commit rights taken away (temporarily).
Create the release branch for llvm, llvm-gcc4.2, and the test-suite. The branch name will be release_XX, where XX is the major and minor release numbers. These branches can be created without checking out anything from subversion.
svn copy https://llvm.org/svn/llvm-project/llvm/trunk \ https://llvm.org/svn/llvm-project/llvm/branches/release_XX svn copy https://llvm.org/svn/llvm-project/llvm-gcc-4.2/trunk \ https://llvm.org/svn/llvm-project/llvm-gcc-4.2/branches/release_XX svn copy https://llvm.org/svn/llvm-project/test-suite/trunk \ https://llvm.org/svn/llvm-project/test-suite/branches/release_XX
Advise developers they can work on Subversion HEAD again.
The Release Manager should switch to the release branch (as all changes to the release will now be done in the branch). The easiest way to do this is to grab another working copy using the following commands:
svn co https://llvm.org/svn/llvm-project/llvm/branches/release_XX svn co https://llvm.org/svn/llvm-project/llvm-gcc-4.2/branches/release_XX svn co https://llvm.org/svn/llvm-project/test-suite/branches/release_XX
After creating the LLVM release branch, update the release branches' autoconf/configure.ac version from X.Xsvn to just X.X. Update it on mainline as well to be the next version (X.X+1svn). Regenerated the configure script for both. This must be done for both llvm and the test-suite.
In addition, the version number of all the Bugzilla components must be updated for the next release.
Create source distributions for LLVM, LLVM GCC, and the LLVM Test Suite by exporting the source from Subversion and archiving it. This can be done with the following commands:
svn export https://llvm.org/svn/llvm-project/llvm/branches/release_XX llvm-X.X svn export https://llvm.org/svn/llvm-project/llvm-gcc-4.2/branches/release_XX llvm-gcc4.2-X.X.source svn export https://llvm.org/svn/llvm-project/test-suite/branches/release_XX llvm-test-X.X tar -cvf - llvm-X.X | gzip > llvm-X.X.tar.gz tar -cvf - llvm-test-X.X | gzip > llvm-test-X.X.tar.gz tar -cvf - llvm-gcc4.2-X.X.source | gzip > llvm-gcc-4.2-X.X.source.tar.gz
Build both debug and release (optimized) versions of LLVM on all platforms. Ensure the build is warning and error free on each platform. Note that when building the LLVM GCC Binary, use a release build of LLVM.
Creating the LLVM GCC binary distribution (release/optimized) requires performing the following steps for each supported platform:
Using the newly built llvm-gcc and llvm, reconfigure llvm to locate llvm-gcc. Run make check and ensure there are no unexpected failures. If there are, resolve the failures or file a bug. If there is a fix commited to mainline, merge back into the release branch, and restart testing by re-building LLVM and llvm-gcc. If no fix will be made, XFAIL the test and commit back to the release branch.
Ensure that 'make check' passes on all platforms for all targets. The test suite must complete with "0 unexpected failures" before sending out the pre-releases for testing.
Run the llvm-test suite and ensure there are no unacceptable failures. Unacceptable failures are regression from the previous release and (optionally) major performance regressions from the previous release. If a regression is found a bug is filled, but the pre-releases may still go out.
You can, optionally, create source and binary RPM packages for LLVM. These may make it easier to get LLVM into a distribution. This can be done with the following commands:
make dist # Build the distribution source tarball make dist-check # Check that the source tarball can build itself. cp llvm-M.m.tar.gz /usr/src/redhat/SOURCES # Required by rpmbuild make srpm # for source rpm make rpm # for binary rpm
First, use make dist to simply build the distribution. Any failures need to be corrected (on the branch). Once make dist can be successful, do make dist-check. This target will do the same thing as the 'dist' target but also test that distribution to make sure it can build itself and runs make check as well. This ensures that needed files are not missing and that the src tarball can be successfully unpacked, built, installed, and cleaned. Once you have a reliable tarball, you need to copy it to the /usr/src/redhat/SOURCES directory which is a requirement of the rpmbuild tool. The last two make invocations just run rpmbuild to build either a source (srpm) or binary (rpm) RPM package.
Once all testing has been completed and appropriate bugs filed, the pre-release tar balls may be 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 report and make check results to the list. Verify that there are no regressions from the previous release. For unsupported targets, verify that make check at least is clean.
The first round of pre-release testing will be the longest. During this time, all regressions must be fixed before the second pre-release is created (repeat steps 4-8).
If this is the second round of testing, this is only to ensure the 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 step.
Tag the release branch using the following procedure:
svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XX \ https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_XX svn copy https://llvm.org/svn/llvm-project/llvm-gcc-4.2/branches/release_XX \ https://llvm.org/svn/llvm-project/llvm-gcc-4.2/tags/RELEASE_XX svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XX \ https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_XX
Review the documentation and ensure that it is up to date. The Release Notes must be updated to reflect 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 avaiable from Subversion and changes in basic system requirements. Merge both changes from mainline into the release branch.
The LLVM demo page must be updated to use the new release. This consists of using the llvm-gcc binary and building LLVM. Update the website demo page configuration to use the new release.
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.
The first thing you need to understand is that there are multiple make targets to support this feature. Here's an overview, we'll delve into the details later.
Okay, that's the basic functionality. When making a release, we want to ensure that the tree you build the distribution from passes dist-check. Beyond fixing the usual bugs, there is generally one impediment to making the release in this fashion: missing files. The dist-check process guards against that possibility. It will either fail and that failure will indicate what's missing, or it will succeed meaning that it has proved that the tarballs can actually succeed in building LLVM correctly and that it passes make check.
This target builds the distribution directory which is the directory from which the tarballs are generated. The distribution directory has the same name as the release, e.g. LLVM-1.7). This target goes through the following process:
To control the process of making the distribution directory correctly, each Makefile can utilize two features:
You will see various messages if things go wrong:
This target does exactly what distdir target does, but also includes assembling the tarballs. There are actually four related targets here:
This target checks the distribution. The basic idea is that it unpacks the distribution tarball and ensures that it can build. It takes the following actions:
If it can pass all that, the distribution will be deemed distribution worth y and you will see:
===== LLVM-1.7.tar.gz Ready For Distribution =====
This means the tarball should then be tested on other platforms and have the nightly test run against it. If those all pass, THEN it is ready for distribution.
A note about disk space: using dist-check will easily triple the amount of disk space your build tree is using. You might want to check available space before you begin.
In addition to doing a normal clean, this target will clean up the files and directories created by the distribution targets. In particular the distribution directory (LLVM-X.X), check directory (_distcheckdir), and the various tarballs will be removed. You do this after the release has shipped and you no longer need this stuff in your build tree.