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 31The release process is roughly as follows: 32 33* Set code freeze and branch creation date for 6 months after last code freeze 34 date. Announce release schedule to the LLVM community and update the website. 35 36* Create release branch and begin release process. 37 38* Send out release candidate sources for first round of testing. Testing lasts 39 7-10 days. During the first round of testing, any regressions found should be 40 fixed. Patches are merged from mainline into the release branch. Also, all 41 features need to be completed during this time. Any features not completed at 42 the end of the first round of testing will be removed or disabled for the 43 release. 44 45* Generate and send out the second release candidate sources. Only *critical* 46 bugs found during this testing phase will be fixed. Any bugs introduced by 47 merged patches will be fixed. If so a third round of testing is needed. 48 49* The release notes are updated. 50 51* Finally, release! 52 53The release process will be accelerated for dot releases. If the first round 54of testing finds no critical bugs and no regressions since the last major release, 55then additional rounds of testing will not be required. 56 57Release Process 58=============== 59 60.. contents:: 61 :local: 62 63Release Administrative Tasks 64---------------------------- 65 66This section describes a few administrative tasks that need to be done for the 67release process to begin. Specifically, it involves: 68 69* Updating version numbers, 70 71* Creating the release branch, and 72 73* Tagging release candidates for the release team to begin testing. 74 75Create Release Branch 76^^^^^^^^^^^^^^^^^^^^^ 77 78Branch the Git trunk using the following procedure: 79 80#. Remind developers that the release branching is imminent and to refrain from 81 committing patches that might break the build. E.g., new features, large 82 patches for works in progress, an overhaul of the type system, an exciting 83 new TableGen feature, etc. 84 85#. Verify that the current git trunk is in decent shape by 86 examining nightly tester and buildbot results. 87 88#. Bump the version in trunk to N.0.0git and tag the commit with llvmorg-N-init. 89 If ``X`` is the version to be released, then ``N`` is ``X + 1``. 90 91:: 92 93 $ git tag -a llvmorg-N-init 94 95#. Clear the release notes in trunk. 96 97#. Create the release branch from the last known good revision from before the 98 version bump. The branch's name is release/X.x where ``X`` is the major version 99 number and ``x`` is just the letter ``x``. 100 101#. All tags and branches need to be created in both the llvm/llvm-project and 102 llvm/llvm-test-suite repos. 103 104Update LLVM Version 105^^^^^^^^^^^^^^^^^^^ 106 107After creating the LLVM release branch, update the release branches' 108``CMakeLists.txt`` versions from '``X.0.0git``' to '``X.0.0``'. 109 110In addition, the version numbers of all the Bugzilla components must be updated 111for the next release. 112 113Tagging the LLVM Release Candidates 114^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 115 116Tag release candidates: 117 118:: 119 120 $ git tag -a llvmorg-X.Y.Z-rcN 121 122The Release Manager may supply pre-packaged source tarballs for users. This can 123be done with the export.sh script in utils/release. 124 125Tarballs, release binaries, or any other release artifacts must be uploaded to 126GitHub. This can be done using the github-upload-release.py script in utils/release. 127 128:: 129 130 $ github-upload-release.py upload --token <github-token> --release X.Y.Z-rcN --files <release_files> 131 132:: 133 134 $ ./export.sh -release X.Y.Z -rc $RC 135 136This will generate source tarballs for each LLVM project being validated, which 137can be uploaded to github for further testing. 138 139Build The Binary Distribution 140^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 141 142Creating the binary distribution requires following the instructions 143:doc:`here <ReleaseProcess>`. 144 145That process will perform both Release+Asserts and Release builds but only 146pack the Release build for upload. You should use the Release+Asserts sysroot, 147normally under ``final/Phase3/Release+Asserts/llvmCore-3.8.1-RCn.install/``, 148for test-suite and run-time benchmarks, to make sure nothing serious has 149passed through the net. For compile-time benchmarks, use the Release version. 150 151The minimum required version of the tools you'll need are :doc:`here <GettingStarted>` 152 153Release Qualification Criteria 154------------------------------ 155 156A release is qualified when it has no regressions from the previous release (or 157baseline). Regressions are related to correctness first and performance second. 158(We may tolerate some minor performance regressions if they are deemed 159necessary for the general quality of the compiler.) 160 161More specifically, Clang/LLVM is qualified when it has a clean test with all 162supported sub-projects included (``make check-all``), per target, and it has no 163regressions with the ``test-suite`` in relation to the previous release. 164 165Regressions are new failures in the set of tests that are used to qualify 166each product and only include things on the list. Every release will have 167some bugs in it. It is the reality of developing a complex piece of 168software. We need a very concrete and definitive release criteria that 169ensures we have monotonically improving quality on some metric. The metric we 170use is described below. This doesn't mean that we don't care about other 171criteria, but these are the criteria which we found to be most important and 172which must be satisfied before a release can go out. 173 174Official Testing 175---------------- 176 177A few developers in the community have dedicated time to validate the release 178candidates and volunteered to be the official release testers for each 179architecture. 180 181These will be the ones testing, generating and uploading the official binaries 182to the server, and will be the minimum tests *necessary* for the release to 183proceed. 184 185This will obviously not cover all OSs and distributions, so additional community 186validation is important. However, if community input is not reached before the 187release is out, all bugs reported will have to go on the next stable release. 188 189The official release managers are: 190 191* Major releases (X.0): Hans Wennborg 192* Stable releases (X.n): Tom Stellard 193 194The official release testers are volunteered from the community and have 195consistently validated and released binaries for their targets/OSs. To contact 196them, you should email the ``[email protected]`` mailing list. 197 198The official testers list is in the file ``RELEASE_TESTERS.TXT``, in the ``LLVM`` 199repository. 200 201Community Testing 202----------------- 203 204Once all testing has been completed and appropriate bugs filed, the release 205candidate tarballs are put on the website and the LLVM community is notified. 206 207We ask that all LLVM developers test the release in any the following ways: 208 209#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang`` 210 binary. Build LLVM. Run ``make check`` and the full LLVM test suite (``make 211 TEST=nightly report``). 212 213#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the ``clang`` sources. Compile 214 everything. Run ``make check`` and the full LLVM test suite (``make 215 TEST=nightly report``). 216 217#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang`` 218 binary. Build whole programs with it (ex. Chromium, Firefox, Apache) for 219 your platform. 220 221#. Download ``llvm-X.Y``, ``llvm-test-X.Y``, and the appropriate ``clang`` 222 binary. Build *your* programs with it and check for conformance and 223 performance regressions. 224 225#. Run the :doc:`release process <ReleaseProcess>`, if your platform is 226 *different* than that which is officially supported, and report back errors 227 only if they were not reported by the official release tester for that 228 architecture. 229 230We also ask that the OS distribution release managers test their packages with 231the first candidate of every release, and report any *new* errors in Bugzilla. 232If the bug can be reproduced with an unpatched upstream version of the release 233candidate (as opposed to the distribution's own build), the priority should be 234release blocker. 235 236During the first round of testing, all regressions must be fixed before the 237second release candidate is tagged. 238 239In the subsequent stages, the testing is only to ensure that bug 240fixes previously merged in have not created new major problems. *This is not 241the time to solve additional and unrelated bugs!* If no patches are merged in, 242the release is determined to be ready and the release manager may move onto the 243next stage. 244 245Reporting Regressions 246--------------------- 247 248Every regression that is found during the tests (as per the criteria above), 249should be filled in a bug in Bugzilla with the priority *release blocker* and 250blocking a specific release. 251 252To help manage all the bugs reported and which ones are blockers or not, a new 253"[meta]" bug should be created and all regressions *blocking* that Meta. Once 254all blockers are done, the Meta can be closed. 255 256If a bug can't be reproduced, or stops being a blocker, it should be removed 257from the Meta and its priority decreased to *normal*. Debugging can continue, 258but on trunk. 259 260Merge Requests 261-------------- 262 263You can use any of the following methods to request that a revision from trunk 264be merged into a release branch: 265 266#. Use the ``utils/release/merge-request.sh`` script which will automatically 267 file a bug_ requesting that the patch be merged. e.g. To request revision 268 12345 be merged into the branch for the 5.0.1 release: 269 ``llvm.src/utils/release/merge-request.sh -stable-version 5.0 -r 12345 -user [email protected]`` 270 271#. Manually file a bug_ with the subject: "Merge r12345 into the X.Y branch", 272 enter the commit(s) that you want merged in the "Fixed by Commit(s)" and mark 273 it as a blocker of the current release bug. Release bugs are given aliases 274 in the form of release-x.y.z, so to mark a bug as a blocker for the 5.0.1 275 release, just enter release-5.0.1 in the "Blocks" field. 276 277#. Reply to the commit email on llvm-commits for the revision to merge and cc 278 the release manager. 279 280.. _bug: https://bugs.llvm.org/ 281 282Release Patch Rules 283------------------- 284 285Below are the rules regarding patching the release branch: 286 287#. Patches applied to the release branch may only be applied by the release 288 manager, the official release testers or the code owners with approval from 289 the release manager. 290 291#. During the first round of testing, patches that fix regressions or that are 292 small and relatively risk free (verified by the appropriate code owner) are 293 applied to the branch. Code owners are asked to be very conservative in 294 approving patches for the branch. We reserve the right to reject any patch 295 that does not fix a regression as previously defined. 296 297#. During the remaining rounds of testing, only patches that fix critical 298 regressions may be applied. 299 300#. For dot releases all patches must maintain both API and ABI compatibility with 301 the previous major release. Only bug-fixes will be accepted. 302 303Merging Patches 304^^^^^^^^^^^^^^^ 305 306Use the ``git cherry-pick -x`` command to merge patches to the release branch: 307 308#. ``git cherry-pick -x abcdef0`` 309 310#. Run regression tests. 311 312Release Final Tasks 313------------------- 314 315The final stages of the release process involves tagging the "final" release 316branch, updating documentation that refers to the release, and updating the 317demo page. 318 319Update Documentation 320^^^^^^^^^^^^^^^^^^^^ 321 322Review the documentation in the release branch and ensure that it is up 323to date. The "Release Notes" must be updated to reflect new features, bug 324fixes, new known issues, and changes in the list of supported platforms. 325The "Getting Started Guide" should be updated to reflect the new release 326version number tag available from Subversion and changes in basic system 327requirements. 328 329.. _tag: 330 331Tag the LLVM Final Release 332^^^^^^^^^^^^^^^^^^^^^^^^^^ 333 334Tag the final release sources: 335 336:: 337 338 $ git tag -a llvmorg-X.Y.Z 339 $ git push https://github.com/llvm/llvm-project.git llvmorg-X.Y.Z 340 341Update the LLVM Website 342^^^^^^^^^^^^^^^^^^^^^^^ 343 344The website must be updated before the release announcement is sent out. Here 345is what to do: 346 347#. Check out the ``www-releases`` module from GitHub. 348 349#. Create a new sub-directory ``X.Y.Z`` in the releases directory. 350 351#. Copy and commit the ``llvm/docs`` and ``LICENSE.txt`` files into this new 352 directory. 353 354#. Update the ``releases/download.html`` file with links to the release 355 binaries on GitHub. 356 357#. Update the ``releases/index.html`` with the new release and link to release 358 documentation. 359 360#. Finally checkout the llvm-www repo and update the main page 361 (``index.html`` and sidebar) to point to the new release and release 362 announcement. 363 364Announce the Release 365^^^^^^^^^^^^^^^^^^^^ 366 367Send an email to the list announcing the release, pointing people to all the 368relevant documentation, download pages and bugs fixed. 369 370