HowToReleaseLLVM.html [plain text]
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>How To Release LLVM To The Public</title>
<link rel="stylesheet" href="_static/llvm.css" type="text/css">
</head>
<body>
<h1>How To Release LLVM To The Public</h1>
<ol>
<li><a href="#introduction">Introduction</a></li>
<li><a href="#criteria">Qualification Criteria</a></li>
<li><a href="#introduction">Release Timeline</a></li>
<li><a href="#process">Release Process</a></li>
</ol>
<div class="doc_author">
<p>Written by <a href="mailto:tonic@nondot.org">Tanya Lattner</a>,
<a href="mailto:rspencer@x10sys.com">Reid Spencer</a>,
<a href="mailto:criswell@cs.uiuc.edu">John Criswell</a>, &
<a href="mailto:wendling@apple.com">Bill Wendling</a>
</p>
</div>
<!-- *********************************************************************** -->
<h2><a name="introduction">Introduction</a></h2>
<!-- *********************************************************************** -->
<div>
<p>This document contains information about successfully releasing LLVM —
including subprojects: e.g., <tt>clang</tt> and <tt>dragonegg</tt> — to
the public. It is the Release Manager's responsibility to ensure that a high
quality build of LLVM is released.</p>
</div>
<!-- *********************************************************************** -->
<h2><a name="process">Release Timeline</a></h2>
<!-- *********************************************************************** -->
<div>
<p>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.</p>
<p>The release process is roughly as follows:</p>
<ul>
<li><p>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.</p></li>
<li><p>Create release branch and begin release process.</p></li>
<li><p>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.</p></li>
<li><p>Generate and send out the second release candidate sources. Only
<em>critial</em> 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.</p></li>
<li><p>The release notes are updated.</p></li>
<li><p>Finally, release!</p></li>
</ul>
</div>
<!-- *********************************************************************** -->
<h2><a name="process">Release Process</a></h2>
<!-- *********************************************************************** -->
<div>
<ol>
<li><a href="#release-admin">Release Administrative Tasks</a>
<ol>
<li><a href="#branch">Create Release Branch</a></li>
<li><a href="#verchanges">Update Version Numbers</a></li>
</ol>
</li>
<li><a href="#release-build">Building the Release</a>
<ol>
<li><a href="#dist">Build the LLVM Source Distributions</a></li>
<li><a href="#build">Build LLVM</a></li>
<li><a href="#clangbin">Build the Clang Binary Distribution</a></li>
<li><a href="#target-build">Target Specific Build Details</a></li>
</ol>
</li>
<li><a href="#release-qualify">Release Qualification Criteria</a>
<ol>
<li><a href="#llvm-qualify">Qualify LLVM</a></li>
<li><a href="#clang-qualify">Qualify Clang</a></li>
<li><a href="#targets">Specific Target Qualification Details</a></li>
</ol>
</li>
<li><a href="#commTest">Community Testing</a></li>
<li><a href="#release-patch">Release Patch Rules</a></li>
<li><a href="#release-final">Release final tasks</a>
<ol>
<li><a href="#updocs">Update Documentation</a></li>
<li><a href="#tag">Tag the LLVM Final Release</a></li>
<li><a href="#updemo">Update the LLVM Demo Page</a></li>
<li><a href="#webupdates">Update the LLVM Website</a></li>
<li><a href="#announce">Announce the Release</a></li>
</ol>
</li>
</ol>
<!-- ======================================================================= -->
<h3><a name="release-admin">Release Administrative Tasks</a></h3>
<div>
<p>This section describes a few administrative tasks that need to be done for
the release process to begin. Specifically, it involves:</p>
<ul>
<li>Creating the release branch,</li>
<li>Setting version numbers, and</li>
<li>Tagging release candidates for the release team to begin testing</li>
</ul>
<!-- ======================================================================= -->
<h4><a name="branch">Create Release Branch</a></h4>
<div>
<p>Branch the Subversion trunk using the following procedure:</p>
<ol>
<li><p>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.</p></li>
<li><p>Verify that the current Subversion trunk is in decent shape by
examining nightly tester and buildbot results.</p></li>
<li><p>Create the release branch for <tt>llvm</tt>, <tt>clang</tt>,
the <tt>test-suite</tt>, and <tt>dragonegg</tt> from the last known good
revision. The branch's name is <tt>release_<i>XY</i></tt>,
where <tt>X</tt> is the major and <tt>Y</tt> the minor release
numbers. The branches should be created using the following commands:</p>
<div class="doc_code">
<pre>
$ svn copy https://llvm.org/svn/llvm-project/llvm/trunk \
https://llvm.org/svn/llvm-project/llvm/branches/release_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/cfe/trunk \
https://llvm.org/svn/llvm-project/cfe/branches/release_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/dragonegg/trunk \
https://llvm.org/svn/llvm-project/dragonegg/branches/release_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/test-suite/trunk \
https://llvm.org/svn/llvm-project/test-suite/branches/release_<i>XY</i>
</pre>
</div></li>
<li><p>Advise developers that they may now check their patches into the
Subversion tree again.</p></li>
<li><p>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:</p>
<div class="doc_code">
<pre>
$ svn co https://llvm.org/svn/llvm-project/llvm/branches/release_<i>XY</i> llvm-<i>X.Y</i>
$ svn co https://llvm.org/svn/llvm-project/cfe/branches/release_<i>XY</i> clang-<i>X.Y</i>
$ svn co https://llvm.org/svn/llvm-project/dragonegg/branches/release_<i>XY</i> dragonegg-<i>X.Y</i>
$ svn co https://llvm.org/svn/llvm-project/test-suite/branches/release_<i>XY</i> test-suite-<i>X.Y</i>
</pre>
</div></li>
</ol>
</div>
<!-- ======================================================================= -->
<h4><a name="verchanges">Update LLVM Version</a></h4>
<div>
<p>After creating the LLVM release branch, update the release branches'
<tt>autoconf</tt> and <tt>configure.ac</tt> versions from '<tt>X.Ysvn</tt>'
to '<tt>X.Y</tt>'. Update it on mainline as well to be the next version
('<tt>X.Y+1svn</tt>'). Regenerate the configure scripts for both
<tt>llvm</tt> and the <tt>test-suite</tt>.</p>
<p>In addition, the version numbers of all the Bugzilla components must be
updated for the next release.</p>
</div>
<!-- ======================================================================= -->
<h4><a name="dist">Build the LLVM Release Candidates</a></h4>
<div>
<p>Create release candidates for <tt>llvm</tt>, <tt>clang</tt>,
<tt>dragonegg</tt>, and the LLVM <tt>test-suite</tt> by tagging the branch
with the respective release candidate number. For instance, to
create <b>Release Candidate 1</b> you would issue the following commands:</p>
<div class="doc_code">
<pre>
$ svn mkdir https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_<i>XY</i> \
https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_<i>XY</i>/rc1
$ svn mkdir https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_<i>XY</i> \
https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_<i>XY</i>/rc1
$ svn mkdir https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_<i>XY</i> \
https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_<i>XY</i>/rc1
$ svn mkdir https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_<i>XY</i>
$ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_<i>XY</i> \
https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_<i>XY</i>/rc1
</pre>
</div>
<p>Similarly, <b>Release Candidate 2</b> would be named <tt>RC2</tt> 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 <tt>RELEASE_<i>XY</i></tt> directory as <tt>Final</tt>
(c.f. <a href="#tag">Tag the LLVM Final Release</a>).</p>
<p>The Release Manager may supply pre-packaged source tarballs for users. This
can be done with the following commands:</p>
<div class="doc_code">
<pre>
$ svn export https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_<i>XY</i>/rc1 llvm-<i>X.Y</i>rc1
$ svn export https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_<i>XY</i>/rc1 clang-<i>X.Y</i>rc1
$ svn export https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_<i>XY</i>/rc1 dragonegg-<i>X.Y</i>rc1
$ svn export https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_<i>XY</i>/rc1 llvm-test-<i>X.Y</i>rc1
$ tar -cvf - llvm-<i>X.Y</i>rc1 | gzip > llvm-<i>X.Y</i>rc1.src.tar.gz
$ tar -cvf - clang-<i>X.Y</i>rc1 | gzip > clang-<i>X.Y</i>rc1.src.tar.gz
$ tar -cvf - dragonegg-<i>X.Y</i>rc1 | gzip > dragonegg-<i>X.Y</i>rc1.src.tar.gz
$ tar -cvf - llvm-test-<i>X.Y</i>rc1 | gzip > llvm-test-<i>X.Y</i>rc1.src.tar.gz
</pre>
</div>
</div>
</div>
<!-- ======================================================================= -->
<h3><a name="release-build">Building the Release</a></h3>
<div>
<p>The builds of <tt>llvm</tt>, <tt>clang</tt>, and <tt>dragonegg</tt>
<em>must</em> be free of errors and warnings in Debug, Release+Asserts, and
Release builds. If all builds are clean, then the release passes Build
Qualification.</p>
<p>The <tt>make</tt> options for building the different modes:</p>
<table>
<tr><th>Mode</th><th>Options</th></tr>
<tr align="left"><td>Debug</td><td><tt>ENABLE_OPTIMIZED=0</tt></td></tr>
<tr align="left"><td>Release+Asserts</td><td><tt>ENABLE_OPTIMIZED=1</tt></td></tr>
<tr align="left"><td>Release</td><td><tt>ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt></td></tr>
</table>
<!-- ======================================================================= -->
<h4><a name="build">Build LLVM</a></h4>
<div>
<p>Build <tt>Debug</tt>, <tt>Release+Asserts</tt>, and <tt>Release</tt> versions
of <tt>llvm</tt> on all supported platforms. Directions to build
<tt>llvm</tt> are <a href="GettingStarted.html#quickstart">here</a>.</p>
</div>
<!-- ======================================================================= -->
<h4><a name="clangbin">Build Clang Binary Distribution</a></h4>
<div>
<p>Creating the <tt>clang</tt> binary distribution
(Debug/Release+Asserts/Release) requires performing the following steps for
each supported platform:</p>
<ol>
<li>Build clang according to the directions
<a href="http://clang.llvm.org/get_started.html">here</a>.</li>
<li>Build both a Debug and Release version of clang. The binary will be the
Release build.</lI>
<li>Package <tt>clang</tt> (details to follow).</li>
</ol>
</div>
<!-- ======================================================================= -->
<h4><a name="target-build">Target Specific Build Details</a></h4>
<div>
<p>The table below specifies which compilers are used for each Arch/OS
combination when qualifying the build of <tt>llvm</tt>, <tt>clang</tt>,
and <tt>dragonegg</tt>.</p>
<table>
<tr><th>Architecture</th> <th>OS</th> <th>compiler</th></tr>
<tr><td>x86-32</td> <td>Mac OS 10.5</td> <td>gcc 4.0.1</td></tr>
<tr><td>x86-32</td> <td>Linux</td> <td>gcc 4.2.X, gcc 4.3.X</td></tr>
<tr><td>x86-32</td> <td>FreeBSD</td> <td>gcc 4.2.X</td></tr>
<tr><td>x86-32</td> <td>mingw</td> <td>gcc 3.4.5</td></tr>
<tr><td>x86-64</td> <td>Mac OS 10.5</td> <td>gcc 4.0.1</td></tr>
<tr><td>x86-64</td> <td>Linux</td> <td>gcc 4.2.X, gcc 4.3.X</td></tr>
<tr><td>x86-64</td> <td>FreeBSD</td> <td>gcc 4.2.X</td></tr>
</table>
</div>
</div>
<!-- ======================================================================= -->
<h3><a name="release-qualify">Building the Release</a></h3>
<div>
<p>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.)</p>
<p><b>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</b></p>
<!-- ======================================================================= -->
<h4><a name="llvm-qualify">Qualify LLVM</a></h4>
<div>
<p>LLVM is qualified when it has a clean test run without a front-end. And it
has no regressions when using either <tt>clang</tt> or <tt>dragonegg</tt>
with the <tt>test-suite</tt> from the previous release.</p>
</div>
<!-- ======================================================================= -->
<h4><a name="clang-qualify">Qualify Clang</a></h4>
<div>
<p><tt>Clang</tt> is qualified when front-end specific tests in the
<tt>llvm</tt> dejagnu test suite all pass, clang's own test suite passes
cleanly, and there are no regressions in the <tt>test-suite</tt>.</p>
</div>
<!-- ======================================================================= -->
<h4><a name="targets">Specific Target Qualification Details</a></h4>
<div>
<table>
<tr><th>Architecture</th> <th>OS</th> <th>clang baseline</th> <th>tests</th></tr>
<tr><td>x86-32</td> <td>Linux</td> <td>last release</td> <td>llvm dejagnu, clang tests, test-suite (including spec)</td></tr>
<tr><td>x86-32</td> <td>FreeBSD</td> <td>last release</td> <td>llvm dejagnu, clang tests, test-suite</td></tr>
<tr><td>x86-32</td> <td>mingw</td> <td>none</td> <td>QT</td></tr>
<tr><td>x86-64</td> <td>Mac OS 10.X</td> <td>last release</td> <td>llvm dejagnu, clang tests, test-suite (including spec)</td></tr>
<tr><td>x86-64</td> <td>Linux</td> <td>last release</td> <td>llvm dejagnu, clang tests, test-suite (including spec)</td></tr>
<tr><td>x86-64</td> <td>FreeBSD</td> <td>last release</td> <td>llvm dejagnu, clang tests, test-suite</td></tr>
</table>
</div>
</div>
<!-- ======================================================================= -->
<h3><a name="commTest">Community Testing</a></h3>
<div>
<p>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:</p>
<ol>
<li>Download <tt>llvm-<i>X.Y</i></tt>, <tt>llvm-test-<i>X.Y</i></tt>, and the
appropriate <tt>clang</tt> binary. Build LLVM. Run <tt>make check</tt> and
the full LLVM test suite (<tt>make TEST=nightly report</tt>).</li>
<li>Download <tt>llvm-<i>X.Y</i></tt>, <tt>llvm-test-<i>X.Y</i></tt>, and the
<tt>clang</tt> sources. Compile everything. Run <tt>make check</tt> and
the full LLVM test suite (<tt>make TEST=nightly report</tt>).</li>
</ol>
<p>Ask LLVM developers to submit the test suite report and <tt>make check</tt>
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 <tt>make check</tt>
is at least clean.</p>
<p>During the first round of testing, all regressions must be fixed before the
second release candidate is tagged.</p>
<p>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. <i>This
is not the time to solve additional and unrelated bugs!</i> If no patches are
merged in, the release is determined to be ready and the release manager may
move onto the next stage.</p>
</div>
<!-- ======================================================================= -->
<h3><a name="release-patch">Release Patch Rules</a></h3>
<div>
<p>Below are the rules regarding patching the release branch:</p>
<ol>
<li><p>Patches applied to the release branch may only be applied by the
release manager.</p></li>
<li><p>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.</p></li>
<li><p>During the remaining rounds of testing, only patches that fix critical
regressions may be applied.</p></li>
</ol>
</div>
<!-- ======================================================================= -->
<h3><a name="release-final">Release Final Tasks</a></h3>
<div>
<p>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.</p>
<!-- ======================================================================= -->
<h4><a name="updocs">Update Documentation</a></h4>
<div>
<p>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.</p>
</div>
<!-- ======================================================================= -->
<h4><a name="tag">Tag the LLVM Final Release</a></h4>
<div>
<p>Tag the final release sources using the following procedure:</p>
<div class="doc_code">
<pre>
$ svn copy https://llvm.org/svn/llvm-project/llvm/branches/release_XY \
https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_<i>XY</i>/Final
$ svn copy https://llvm.org/svn/llvm-project/cfe/branches/release_XY \
https://llvm.org/svn/llvm-project/cfe/tags/RELEASE_<i>XY</i>/Final
$ svn copy https://llvm.org/svn/llvm-project/dragonegg/branches/release_XY \
https://llvm.org/svn/llvm-project/dragonegg/tags/RELEASE_<i>XY</i>/Final
$ svn copy https://llvm.org/svn/llvm-project/test-suite/branches/release_XY \
https://llvm.org/svn/llvm-project/test-suite/tags/RELEASE_<i>XY</i>/Final
</pre>
</div>
</div>
</div>
<!-- ======================================================================= -->
<h3><a name="updemo">Update the LLVM Demo Page</a></h3>
<div>
<p>The LLVM demo page must be updated to use the new release. This consists of
using the new <tt>clang</tt> binary and building LLVM.</p>
<!-- ======================================================================= -->
<h4><a name="webupdates">Update the LLVM Website</a></h4>
<div>
<p>The website must be updated before the release announcement is sent out. Here
is what to do:</p>
<ol>
<li>Check out the <tt>www</tt> module from Subversion.</li>
<li>Create a new subdirectory <tt>X.Y</tt> in the releases directory.</li>
<li>Commit the <tt>llvm</tt>, <tt>test-suite</tt>, <tt>clang</tt> source,
<tt>clang binaries</tt>, <tt>dragonegg</tt> source, and <tt>dragonegg</tt>
binaries in this new directory.</li>
<li>Copy and commit the <tt>llvm/docs</tt> and <tt>LICENSE.txt</tt> files
into this new directory. The docs should be built with
<tt>BUILD_FOR_WEBSITE=1</tt>.</li>
<li>Commit the <tt>index.html</tt> to the <tt>release/X.Y</tt> directory to
redirect (use from previous release.</li>
<li>Update the <tt>releases/download.html</tt> file with the new release.</li>
<li>Update the <tt>releases/index.html</tt> with the new release and link to
release documentation.</li>
<li>Finally, update the main page (<tt>index.html</tt> and sidebar) to point
to the new release and release announcement. Make sure this all gets
committed back into Subversion.</li>
</ol>
</div>
<!-- ======================================================================= -->
<h4><a name="announce">Announce the Release</a></h4>
<div>
<p>Have Chris send out the release announcement when everything is finished.</p>
</div>
</div>
</div>
<!-- *********************************************************************** -->
<hr>
<address>
<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
<a href="http://validator.w3.org/check/referer"><img
src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
<a href="http://llvm.org/">The LLVM Compiler Infrastructure</a>
<br>
Last modified: $Date$
</address>
</body>
</html>