1=================================
2How To Release LLVM To The Public
3=================================
4
5Introduction
6============
7
8This document contains information about successfully releasing LLVM ---
9including sub-projects: e.g., ``clang`` and ``compiler-rt`` --- to the public.
10It is the Release Manager's responsibility to ensure that a high quality build
11of LLVM is released.
12
13If you're looking for the document on how to test the release candidates and
14create the binary packages, please refer to the :doc:`ReleaseProcess` instead.
15
16.. _timeline:
17
18Release Timeline
19================
20
21LLVM is released on a time based schedule --- with major releases roughly
22every 6 months.  In between major releases there may be dot releases.
23The release manager will determine if and when to make a dot release based
24on feedback from the community.  Typically, dot releases should be made if
25there are large number of bug-fixes in the stable branch or a critical bug
26has been discovered that affects a large number of users.
27
28Unless otherwise stated, dot releases will follow the same procedure as
29major releases.
30
31Annual Release Schedule
32-----------------------
33
34Here is the annual release schedule for LLVM.  This is meant to be a
35guide, and release managers are not required to follow this exactly.
36Releases should be tagged on Tuesdays.
37
38=============================== =========================
39Release                         Approx. Date
40=============================== =========================
41*release branch: even releases* *4th Tue in January*
42*release branch: odd releases*  *4th Tue in July*
43X.0.0-rc1                       3 days after branch.
44X.0.0-rc2                       2 weeks after branch.
45X.0.0-rc3                       4 weeks after branch
46**X.0.0-final**                 **6 weeks after branch**
47**X.0.1**                       **8 weeks after branch**
48**X.0.2**                       **10 weeks after branch**
49**X.0.3**                       **12 weeks after branch**
50**X.0.4**                       **14 weeks after branch**
51**X.0.5**                       **16 weeks after branch**
52**X.0.6 (if necessary)**        **18 weeks after branch**
53=============================== =========================
54
55Release Process Summary
56-----------------------
57
58* Announce release schedule to the LLVM community and update the website.  Do
59  this at least 3 weeks before the -rc1 release.
60
61* Create release branch and begin release process.
62
63* Send out release candidate sources for first round of testing.  Testing lasts
64  6 weeks.  During the first round of testing, any regressions found should be
65  fixed.  Patches are merged from mainline into the release branch.  Also, all
66  features need to be completed during this time.  Any features not completed at
67  the end of the first round of testing will be removed or disabled for the
68  release.
69
70* Generate and send out the second release candidate sources.  Only *critical*
71  bugs found during this testing phase will be fixed.  Any bugs introduced by
72  merged patches will be fixed.  If so a third round of testing is needed.
73
74* The release notes are updated.
75
76* Finally, release!
77
78* Announce bug fix release schedule to the LLVM community and update the website.
79
80* Do bug-fix releases every two weeks until X.0.5 or X.0.6 (if necessary).
81
82Release Process
83===============
84
85.. contents::
86   :local:
87
88Release Administrative Tasks
89----------------------------
90
91This section describes a few administrative tasks that need to be done for the
92release process to begin.  Specifically, it involves:
93
94* Updating version numbers,
95
96* Creating the release branch, and
97
98* Tagging release candidates for the release team to begin testing.
99
100Create Release Branch
101^^^^^^^^^^^^^^^^^^^^^
102
103Branch the Git trunk using the following procedure:
104
105#. Remind developers that the release branching is imminent and to refrain from
106   committing patches that might break the build.  E.g., new features, large
107   patches for works in progress, an overhaul of the type system, an exciting
108   new TableGen feature, etc.
109
110#. Verify that the current git trunk is in decent shape by
111   examining nightly tester and buildbot results.
112
113#. Bump the version in trunk to N.0.0git and tag the commit with llvmorg-N-init.
114   If ``X`` is the version to be released, then ``N`` is ``X + 1``.
115
116::
117
118  $ git tag -a llvmorg-N-init
119
120#. Clear the release notes in trunk.
121
122#. Create the release branch from the last known good revision from before the
123   version bump.  The branch's name is release/X.x where ``X`` is the major version
124   number and ``x`` is just the letter ``x``.
125
126#. All tags and branches need to be created in both the llvm/llvm-project and
127   llvm/llvm-test-suite repos.
128
129Update LLVM Version
130^^^^^^^^^^^^^^^^^^^
131
132After creating the LLVM release branch, update the release branches'
133``CMakeLists.txt`` versions from '``X.0.0git``' to '``X.0.0``'.
134
135In addition, the version numbers of all the Bugzilla components must be updated
136for the next release.
137
138Tagging the LLVM Release Candidates
139^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
140
141Tag release candidates:
142
143::
144
145  $ git tag -a llvmorg-X.Y.Z-rcN
146
147The Release Manager must supply pre-packaged source tarballs for users.  This can
148be done with the export.sh script in utils/release.
149
150Tarballs, release binaries,  or any other release artifacts must be uploaded to
151GitHub.  This can be done using the github-upload-release.py script in utils/release.
152
153::
154
155  $ github-upload-release.py upload --token <github-token> --release X.Y.Z-rcN --files <release_files>
156
157::
158
159  $ ./export.sh -release X.Y.Z -rc $RC
160
161This will generate source tarballs for each LLVM project being validated, which
162can be uploaded to github for further testing.
163
164Build The Binary Distribution
165^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
166
167Creating the binary distribution requires following the instructions
168:doc:`here <ReleaseProcess>`.
169
170That process will perform both Release+Asserts and Release builds but only
171pack the Release build for upload. You should use the Release+Asserts sysroot,
172normally under ``final/Phase3/Release+Asserts/llvmCore-3.8.1-RCn.install/``,
173for test-suite and run-time benchmarks, to make sure nothing serious has
174passed through the net. For compile-time benchmarks, use the Release version.
175
176The minimum required version of the tools you'll need are :doc:`here <GettingStarted>`
177
178Release Qualification Criteria
179------------------------------
180
181There are no official release qualification criteria.  It is up to the
182the release manager to determine when a release is ready.  The release manager
183should pay attention to the results of community testing, the number of outstanding
184bugs, and then number of regressions when determining whether or not to make a
185release.
186
187The community values time based releases, so releases should not be delayed for
188too long unless there are critical issues remaining.  In most cases, the only
189kind of bugs that are critical enough to block a release would be a major regression
190from a previous release.
191
192Official Testing
193----------------
194
195A few developers in the community have dedicated time to validate the release
196candidates and volunteered to be the official release testers for each
197architecture.
198
199These will be the ones testing, generating and uploading the official binaries
200to the server, and will be the minimum tests *necessary* for the release to
201proceed.
202
203This will obviously not cover all OSs and distributions, so additional community
204validation is important. However, if community input is not reached before the
205release is out, all bugs reported will have to go on the next stable release.
206
207The official release managers are:
208
209* Major releases (X.0): Hans Wennborg
210* Stable releases (X.n): Tom Stellard
211
212The official release testers are volunteered from the community and have
213consistently validated and released binaries for their targets/OSs. To contact
214them, you should post on the `Discourse forums (Project
215Infrastructure - Release Testers). <https://discourse.llvm.org/c/infrastructure/release-testers/66>`_
216
217The official testers list is in the file ``RELEASE_TESTERS.TXT``, in the ``LLVM``
218repository.
219
220Community Testing
221-----------------
222
223Once all testing has been completed and appropriate bugs filed, the release
224candidate tarballs are put on the website and the LLVM community is notified.
225
226We ask that all LLVM developers test the release in any the following ways:
227
228#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang``
229   binary.  Build LLVM.  Run ``make check`` and the full LLVM test suite (``make
230   TEST=nightly report``).
231
232#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the ``clang`` sources.  Compile
233   everything.  Run ``make check`` and the full LLVM test suite (``make
234   TEST=nightly report``).
235
236#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang``
237   binary. Build whole programs with it (ex. Chromium, Firefox, Apache) for
238   your platform.
239
240#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang``
241   binary. Build *your* programs with it and check for conformance and
242   performance regressions.
243
244#. Run the :doc:`release process <ReleaseProcess>`, if your platform is
245   *different* than that which is officially supported, and report back errors
246   only if they were not reported by the official release tester for that
247   architecture.
248
249We also ask that the OS distribution release managers test their packages with
250the first candidate of every release, and report any *new* errors in Bugzilla.
251If the bug can be reproduced with an unpatched upstream version of the release
252candidate (as opposed to the distribution's own build), the priority should be
253release blocker.
254
255During the first round of testing, all regressions must be fixed before the
256second release candidate is tagged.
257
258In the subsequent stages, the testing is only to ensure that bug
259fixes previously merged in have not created new major problems. *This is not
260the time to solve additional and unrelated bugs!* If no patches are merged in,
261the release is determined to be ready and the release manager may move onto the
262next stage.
263
264Reporting Regressions
265---------------------
266
267Every regression that is found during the tests (as per the criteria above),
268should be filled in a bug in Bugzilla with the priority *release blocker* and
269blocking a specific release.
270
271To help manage all the bugs reported and which ones are blockers or not, a new
272"[meta]" bug should be created and all regressions *blocking* that Meta. Once
273all blockers are done, the Meta can be closed.
274
275If a bug can't be reproduced, or stops being a blocker, it should be removed
276from the Meta and its priority decreased to *normal*. Debugging can continue,
277but on trunk.
278
279Backport Requests
280-----------------
281
282Instructions for requesting a backport to a stable branch can be found :doc:`here <GitHub>`.
283
284Triaging Bug Reports for Releases
285---------------------------------
286
287This section describes how to triage bug reports:
288
289#. Search for bugs with a Release Milestone that have not been added to the
290   "Release Status" github project:
291
292   https://github.com/llvm/llvm-project/issues?q=is%3Aissue+milestone%3A%22LLVM+14.0.5+Release%22+no%3Aproject+
293
294   Replace 14.0.5 in this query with the version from the Release Milestone being
295   targeted.
296
297   Add these bugs to the "Release Status" project.
298
299#. Navigate to the `Release Status project <https://github.com/orgs/llvm/projects/3>`_
300   to see the list of bugs that are being considered for the release.
301
302#. Review each bug and first check if it has been fixed in main.  If it has, update
303   its status to "Needs Pull Request", and create a pull request for the fix
304   using the /cherry-pick or /branch comments if this has not been done already.
305
306#. If a bug has been fixed and has a pull request created for backporting it,
307   then update its status to "Needs Review" and notify a knowledgeable reviewer.
308   Usually you will want to notify the person who approved the patch in Phabricator,
309   but you may use your best judgement on who a good reviewer would be.  Once
310   you have identified the reviewer(s), assign the issue to them and mention
311   them (i.e @username) in a comment and ask them if the patch is safe to backport.
312   You should also review the bug yourself to ensure that it meets the requirements
313   for committing to the release branch.
314
315#. Once a bug has been reviewed, add the release:reviewed label and update the
316   issue's status to "Needs Merge".  Check the pull request associated with the
317   issue.  If all the tests pass, then the pull request can be merged.  If not,
318   then add a comment on the issue asking someone to take a look at the failures.
319
320#. Once the pull request has been merged push it to the official release branch:
321
322   ::
323
324      git checkout release/XX.x
325      git pull --ff-only https://github.com/llvm/llvm-project-release-prs release/XX.x
326      git push https://github.com/llvm/llvm-project release/XX.x:release/XX.x
327
328   Then add a comment to the issue stating that the fix has been merged along with
329   the git hashes from the release branch.  Add the release:merged label to the issue
330   and close it.
331
332
333Release Patch Rules
334-------------------
335
336Below are the rules regarding patching the release branch:
337
338#. Patches applied to the release branch may only be applied by the release
339   manager, the official release testers or the code owners with approval from
340   the release manager.
341
342#. Release managers are encouraged, but not required, to get approval from code
343   owners before approving patches.  If there is no code owner or the code owner
344   is unreachable then release managers can ask approval from patch reviewers or
345   other developers active in that area.
346
347#. *Before RC1* Patches should be limited to bug fixes, important optimization
348   improvements, or completion of features that were started before the branch
349   was created.  As with all phases, release managers and code owners can reject
350   patches that are deemed too invasive.
351
352#. *Before RC2* Patches should be limited to bug fixes or backend specific
353   improvements that are determined to be very safe.
354
355#. *Before RC3/Final Major Release* Patches should be limited to critical
356   bugs or regressions.
357
358#. *Bug fix releases* Patches should be limited to bug fixes or very safe
359   and critical performance improvements.  Patches must maintain both API and
360   ABI compatibility with the previous major release.
361
362
363Merging Patches
364^^^^^^^^^^^^^^^
365
366Use the ``git cherry-pick -x`` command to merge patches to the release branch:
367
368#. ``git cherry-pick -x abcdef0``
369
370#. Run regression tests.
371
372Release Final Tasks
373-------------------
374
375The final stages of the release process involves tagging the "final" release
376branch, updating documentation that refers to the release, and updating the
377demo page.
378
379Update Documentation
380^^^^^^^^^^^^^^^^^^^^
381
382Review the documentation in the release branch and ensure that it is up
383to date.  The "Release Notes" must be updated to reflect new features, bug
384fixes, new known issues, and changes in the list of supported platforms.
385The "Getting Started Guide" should be updated to reflect the new release
386version number tag available from Subversion and changes in basic system
387requirements.
388
389.. _tag:
390
391Tag the LLVM Final Release
392^^^^^^^^^^^^^^^^^^^^^^^^^^
393
394Tag the final release sources:
395
396::
397
398  $ git tag -a llvmorg-X.Y.Z
399  $ git push https://github.com/llvm/llvm-project.git llvmorg-X.Y.Z
400
401Update the LLVM Website
402^^^^^^^^^^^^^^^^^^^^^^^
403
404The website must be updated before the release announcement is sent out.  Here
405is what to do:
406
407#. Check out the ``www-releases`` module from GitHub.
408
409#. Create a new sub-directory ``X.Y.Z`` in the releases directory.
410
411#. Copy and commit the ``llvm/docs`` and ``LICENSE.txt`` files into this new
412   directory.
413
414#. Update the ``releases/download.html`` file with links to the release
415   binaries on GitHub.
416
417#. Update the ``releases/index.html`` with the new release and link to release
418   documentation.
419
420#. After you push the changes to the www-releases repo, someone with admin
421   access must login to prereleases-origin.llvm.org and manually pull the new
422   changes into /data/www-releases/.  This is where the website is served from.
423
424#. Finally checkout the llvm-www repo and update the main page
425   (``index.html`` and sidebar) to point to the new release and release
426   announcement.
427
428Announce the Release
429^^^^^^^^^^^^^^^^^^^^
430
431Create a new post in the `Announce Category <https://discourse.llvm.org/c/announce>`_
432once all the release tasks are complete.  For X.0.0 releases, make sure to include a
433link to the release notes in the post.  For X.0.1+ releases, generate a changelog
434using this command and add it to the post.
435
436::
437
438  $ git log --format="[%h %s](https://github.com/llvm/llvm-project/commit/%H)" llvmorg-X.0.N-1..llvmorg-X.0.N
439
440Once the release has been announced add a link to the announcement on the llvm
441homepage (from the llvm-www repo) in the "Release Emails" section.
442