1=============================
2How To Validate a New Release
3=============================
4
5.. contents::
6   :local:
7   :depth: 1
8
9Introduction
10============
11
12This document contains information about testing the release candidates that
13will ultimately be the next LLVM release. For more information on how to
14manage the actual release, please refer to :doc:`HowToReleaseLLVM`.
15
16Overview of the Release Process
17-------------------------------
18
19Once the release process starts, the Release Manager will ask for volunteers,
20and it'll be the role of each volunteer to:
21
22* Test and benchmark the previous release
23
24* Test and benchmark each release candidate, comparing to the previous release
25  and candidates
26
27* Identify, reduce and report every regression found during tests and benchmarks
28
29* Make sure the critical bugs get fixed and merged to the next release candidate
30
31Not all bugs or regressions are show-stoppers and it's a bit of a grey area what
32should be fixed before the next candidate and what can wait until the next
33release.
34
35It'll depend on:
36
37* The severity of the bug, how many people it affects and if it's a regression
38  or a known bug. Known bugs are "unsupported features" and some bugs can be
39  disabled if they have been implemented recently.
40
41* The stage in the release. Less critical bugs should be considered to be
42  fixed between RC1 and RC2, but not so much at the end of it.
43
44* If it's a correctness or a performance regression. Performance regression
45  tends to be taken more lightly than correctness.
46
47.. _scripts:
48
49Scripts
50=======
51
52The scripts are in the ``utils/release`` directory.
53
54test-release.sh
55---------------
56
57This script will check-out, configure and compile LLVM+Clang (+ most add-ons,
58like ``compiler-rt``, ``libcxx``, ``libomp`` and ``clang-extra-tools``) in
59three stages, and will test the final stage.
60It'll have installed the final binaries on the Phase3/Releasei(+Asserts)
61directory, and that's the one you should use for the test-suite and other
62external tests.
63
64To run the script on a specific release candidate run::
65
66   ./test-release.sh \
67        -release 3.3 \
68        -rc 1 \
69        -no-64bit \
70        -test-asserts \
71        -no-compare-files
72
73Each system will require different options. For instance, x86_64 will
74obviously not need ``-no-64bit`` while 32-bit systems will, or the script will
75fail.
76
77The important flags to get right are:
78
79* On the pre-release, you should change ``-rc 1`` to ``-final``. On RC2,
80  change it to ``-rc 2`` and so on.
81
82* On non-release testing, you can use ``-final`` in conjunction with
83  ``-no-checkout``, but you'll have to create the ``final`` directory by hand
84  and link the correct source dir to ``final/llvm.src``.
85
86* For release candidates, you need ``-test-asserts``, or it won't create a
87  "Release+Asserts" directory, which is needed for release testing and
88  benchmarking. This will take twice as long.
89
90* On the final candidate you just need Release builds, and that's the binary
91  directory you'll have to pack.
92
93* On macOS, you must export ``MACOSX_DEPLOYMENT_TARGET=10.9`` before running
94  the script.
95
96This script builds three phases of Clang+LLVM twice each (Release and
97Release+Asserts), so use screen or nohup to avoid headaches, since it'll take
98a long time.
99
100Use the ``--help`` option to see all the options and chose it according to
101your needs.
102
103
104findRegressions-nightly.py
105--------------------------
106
107TODO
108
109.. _test-suite:
110
111Test Suite
112==========
113
114.. contents::
115   :local:
116
117Follow the `LNT Quick Start Guide
118<https://llvm.org/docs/lnt/quickstart.html>`__ link on how to set-up the
119test-suite
120
121The binary location you'll have to use for testing is inside the
122``rcN/Phase3/Release+Asserts/llvmCore-REL-RC.install``.
123Link that directory to an easier location and run the test-suite.
124
125An example on the run command line, assuming you created a link from the correct
126install directory to ``~/devel/llvm/install``::
127
128   ./sandbox/bin/python sandbox/bin/lnt runtest \
129       nt \
130       -j4 \
131       --sandbox sandbox \
132       --test-suite ~/devel/llvm/test/test-suite \
133       --cc ~/devel/llvm/install/bin/clang \
134       --cxx ~/devel/llvm/install/bin/clang++
135
136It should have no new regressions, compared to the previous release or release
137candidate. You don't need to fix all the bugs in the test-suite, since they're
138not necessarily meant to pass on all architectures all the time. This is
139due to the nature of the result checking, which relies on direct comparison,
140and most of the time, the failures are related to bad output checking, rather
141than bad code generation.
142
143If the errors are in LLVM itself, please report every single regression found
144as blocker, and all the other bugs as important, but not necessarily blocking
145the release to proceed. They can be set as "known failures" and to be
146fix on a future date.
147
148.. _pre-release-process:
149
150Pre-Release Process
151===================
152
153.. contents::
154   :local:
155
156When the release process is announced on the mailing list, you should prepare
157for the testing, by applying the same testing you'll do on the release
158candidates, on the previous release.
159
160You should:
161
162* Download the previous release sources from
163  https://llvm.org/releases/download.html.
164
165* Run the test-release.sh script on ``final`` mode (change ``-rc 1`` to
166  ``-final``).
167
168* Once all three stages are done, it'll test the final stage.
169
170* Using the ``Phase3/Release+Asserts/llvmCore-MAJ.MIN-final.install`` base,
171  run the test-suite.
172
173If the final phase's ``make check-all`` failed, it's a good idea to also test
174the intermediate stages by going on the obj directory and running
175``make check-all`` to find if there's at least one stage that passes (helps
176when reducing the error for bug report purposes).
177
178.. _release-process:
179
180Release Process
181===============
182
183.. contents::
184   :local:
185
186When the Release Manager sends you the release candidate, download all sources,
187unzip on the same directory (there will be sym-links from the appropriate places
188to them), and run the release test as above.
189
190You should:
191
192* Download the current candidate sources from where the release manager points
193  you (ex. https://llvm.org/pre-releases/3.3/rc1/).
194
195* Repeat the steps above with ``-rc 1``, ``-rc 2`` etc modes and run the
196  test-suite the same way.
197
198* Compare the results, report all errors on Bugzilla and publish the binary blob
199  where the release manager can grab it.
200
201Once the release manages announces that the latest candidate is the good one,
202you have to pack the ``Release`` (no Asserts) install directory on ``Phase3``
203and that will be the official binary.
204
205* Rename (or link) ``clang+llvm-REL-ARCH-ENV`` to the .install directory
206
207* Tar that into the same name with ``.tar.gz`` extension from outside the
208  directory
209
210* Make it available for the release manager to download
211
212.. _bug-reporting:
213
214Bug Reporting Process
215=====================
216
217.. contents::
218   :local:
219
220If you found regressions or failures when comparing a release candidate with the
221previous release, follow the rules below:
222
223* Critical bugs on compilation should be fixed as soon as possible, possibly
224  before releasing the binary blobs.
225
226* Check-all tests should be fixed before the next release candidate, but can
227  wait until the test-suite run is finished.
228
229* Bugs in the test suite or unimportant check-all tests can be fixed in between
230  release candidates.
231
232* New features or recent big changes, when close to the release, should have
233  done in a way that it's easy to disable. If they misbehave, prefer disabling
234  them than releasing an unstable (but untested) binary package.
235