mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-13 14:46:53 +00:00
740e3db203
stand out better. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61475 91177308-0d34-0410-b5e6-96231b3b80d8
574 lines
28 KiB
HTML
574 lines
28 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
|
|
"http://www.w3.org/TR/html4/strict.dtd">
|
|
<html>
|
|
<head>
|
|
<title>LLVM Developer Policy</title>
|
|
<link rel="stylesheet" href="llvm.css" type="text/css">
|
|
</head>
|
|
<body>
|
|
|
|
<div class="doc_title">LLVM Developer Policy</div>
|
|
<ol>
|
|
<li><a href="#introduction">Introduction</a></li>
|
|
<li><a href="#policies">Developer Policies</a>
|
|
<ol>
|
|
<li><a href="#informed">Stay Informed</a></li>
|
|
<li><a href="#patches">Making a Patch</a></li>
|
|
<li><a href="#reviews">Code Reviews</a></li>
|
|
<li><a href="#owners">Code Owners</a></li>
|
|
<li><a href="#testcases">Test Cases</a></li>
|
|
<li><a href="#quality">Quality</a></li>
|
|
<li><a href="#commitaccess">Obtaining Commit Access</a></li>
|
|
<li><a href="#newwork">Making a Major Change</a></li>
|
|
<li><a href="#incremental">Incremental Development</a></li>
|
|
<li><a href="#attribution">Attribution of Changes</a></li>
|
|
</ol></li>
|
|
<li><a href="#clp">Copyright, License, and Patents</a>
|
|
<ol>
|
|
<li><a href="#copyright">Copyright</a></li>
|
|
<li><a href="#license">License</a></li>
|
|
<li><a href="#patents">Patents</a></li>
|
|
<li><a href="#devagree">Developer Agreements</a></li>
|
|
</ol></li>
|
|
</ol>
|
|
<div class="doc_author">Written by the LLVM Oversight Team</div>
|
|
|
|
<!--=========================================================================-->
|
|
<div class="doc_section"><a name="introduction">Introduction</a></div>
|
|
<!--=========================================================================-->
|
|
<div class="doc_text">
|
|
<p>This document contains the LLVM Developer Policy which defines the
|
|
project's policy towards developers and their contributions. The intent of
|
|
this policy is to eliminate mis-communication, rework, and confusion that
|
|
might arise from the distributed nature of LLVM's development. By stating
|
|
the policy in clear terms, we hope each developer can know ahead of time
|
|
what to expect when making LLVM contributions.</p>
|
|
<p>This policy is also designed to accomplish the following objectives:</p>
|
|
<ol>
|
|
<li>Attract both users and developers to the LLVM project.</li>
|
|
<li>Make life as simple and easy for contributors as possible.</li>
|
|
<li>Keep the top of Subversion trees as stable as possible.</li>
|
|
</ol>
|
|
|
|
<p>This policy is aimed at frequent contributors to LLVM. People interested in
|
|
contributing one-off patches can do so in an informal way by sending them to
|
|
the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits">
|
|
llvm-commits mailing list</a> and engaging another developer to see it through
|
|
the process.</p>
|
|
|
|
</div>
|
|
|
|
<!--=========================================================================-->
|
|
<div class="doc_section"><a name="policies">Developer Policies</a></div>
|
|
<!--=========================================================================-->
|
|
<div class="doc_text">
|
|
<p>This section contains policies that pertain to frequent LLVM
|
|
developers. We always welcome <a href="#patches">one-off patches</a> from
|
|
people who do not routinely contribute to LLVM, but we expect more from
|
|
frequent contributors to keep the system as efficient as possible for
|
|
everyone.
|
|
Frequent LLVM contributors are expected to meet the following requirements in
|
|
order for LLVM to maintain a high standard of quality.<p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="informed">Stay Informed</a> </div>
|
|
<div class="doc_text">
|
|
<p>Developers should stay informed by reading at least the
|
|
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">llvmdev</a>
|
|
email list. If you are doing anything more than just casual work on LLVM,
|
|
it is suggested that you also subscribe to the
|
|
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits">llvm-commits</a>
|
|
list and pay attention to changes being made by others.</p>
|
|
<p>We recommend that active developers register an email account with
|
|
<a href="http://llvm.org/bugs/">LLVM Bugzilla</a> and preferably subscribe to
|
|
the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs">llvm-bugs</a>
|
|
email list to keep track of bugs and enhancements occurring in LLVM.</p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="patches">Making a Patch</a></div>
|
|
|
|
<div class="doc_text">
|
|
|
|
<p>When making a patch for review, the goal is to make it as easy for the
|
|
reviewer to read it as possible. As such, we recommend that you:</p>
|
|
<ol>
|
|
<li>Make your patch against the Subversion trunk, not a branch, and not an
|
|
old version of LLVM. This makes it easy to apply the patch.</li>
|
|
|
|
<li>Similarly, patches should be submitted soon after they are generated.
|
|
Old patches may not apply correctly if the underlying code changes between
|
|
the time the patch was created and the time it is applied.</li>
|
|
|
|
<li>Patches should be made with this command:
|
|
<div class="doc_code"><pre>svn diff -x -u</pre></div>
|
|
or with the utility <tt>utils/mkpatch</tt>, which makes it easy to read the
|
|
diff.</li>
|
|
|
|
<li>Patches should not include differences in generated code such as the
|
|
code generated by <tt>flex</tt>, <tt>bison</tt> or <tt>tblgen</tt>. The
|
|
<tt>utils/mkpatch</tt> utility takes care of this for you.</li>
|
|
</ol>
|
|
|
|
<p>When sending a patch to a mailing list, it is a good idea to send it as an
|
|
<em>attachment</em> to the message, not embedded into the text of the
|
|
message. This ensures that your mailer will not mangle the patch when it
|
|
sends it (e.g. by making whitespace changes or by wrapping lines).</p>
|
|
|
|
<p><em>For Thunderbird users:</em> Before submitting a patch, please open
|
|
<em>Preferences → Advanced → General → Config Editor</em>,
|
|
find the key <tt>mail.content_disposition_type</tt>, and set its value to
|
|
<tt>1</tt>. Without this setting, Thunderbird sends your attachment using
|
|
<tt>Content-Disposition: inline</tt> rather than <tt>Content-Disposition:
|
|
attachment</tt>. Apple Mail gamely displays such a file inline, making it
|
|
difficult to work with for reviewers using that program.</p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="reviews">Code Reviews</a></div>
|
|
<div class="doc_text">
|
|
<p>LLVM has a code review policy. Code review is one way to increase the
|
|
quality of software. We generally follow these policies:</p>
|
|
<ol>
|
|
<li>All developers are required to have significant changes reviewed
|
|
before they are committed to the repository.</li>
|
|
<li>Code reviews are conducted by email, usually on the llvm-commits
|
|
list.</li>
|
|
<li>Code can be reviewed either before it is committed or after. We expect
|
|
major changes to be reviewed before being committed, but smaller
|
|
changes (or changes where the developer owns the component) can be
|
|
reviewed after commit.</li>
|
|
<li>The developer responsible for a code change is also responsible for
|
|
making all necessary review-related changes.</li>
|
|
<li>Code review can be an iterative process, which continues until the patch
|
|
is ready to be committed.</li>
|
|
</ol>
|
|
|
|
<p>Developers should participate in code reviews as both reviewers and
|
|
reviewees. If someone is kind enough to review your code, you should
|
|
return the favor for someone else. Note that anyone is welcome to review
|
|
and give feedback on a patch, but only people with Subversion write access
|
|
can approve it.</p>
|
|
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="owners">Code Owners</a></div>
|
|
<div class="doc_text">
|
|
|
|
<p>The LLVM Project relies on two features of its process to maintain rapid
|
|
development in addition to the high quality of its source base: the
|
|
combination of code review plus post-commit review for trusted maintainers.
|
|
Having both is a great way for the project to take advantage of the fact
|
|
that most people do the right thing most of the time, and only commit
|
|
patches without pre-commit review when they are confident they are
|
|
right.</p>
|
|
|
|
<p>The trick to this is that the project has to guarantee that all patches
|
|
that are committed are reviewed after they go in: you don't want everyone
|
|
to assume someone else will review it, allowing the patch to go unreviewed.
|
|
To solve this problem, we have a notion of an 'owner' for a piece of the
|
|
code. The sole responsibility of a code owner is to ensure that a commit
|
|
to their area of the code is appropriately reviewed, either by themself or
|
|
by someone else. The current code owners are:</p>
|
|
|
|
<ol>
|
|
<li><b>Anton Korobeynikov</b>: Exception handling, debug information, and
|
|
Windows codegen.</li>
|
|
<li><b>Duncan Sands</b>: llvm-gcc 4.2.</li>
|
|
<li><b>Evan Cheng</b>: Code generator and all targets.</li>
|
|
<li><b>Chris Lattner</b>: Everything else.</li>
|
|
</ol>
|
|
|
|
<p>Note that code ownership is completely different than reviewers: anyone can
|
|
review a piece of code, and we welcome code review from anyone who is
|
|
interested. Code owners are the "last line of defense" to guarantee that
|
|
all patches that are committed are actually reviewed.</p>
|
|
|
|
<p>Being a code owner is a somewhat unglamorous position, but it is incredibly
|
|
important for the ongoing success of the project. Because people get busy,
|
|
interests change, and unexpected things happen, code ownership is purely
|
|
opt-in, and anyone can choose to resign their "title" at any time. For now,
|
|
we do not have an official policy on how one gets elected to be a code
|
|
owner.
|
|
</p>
|
|
|
|
</div>
|
|
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="testcases">Test Cases</a></div>
|
|
<div class="doc_text">
|
|
<p>Developers are required to create test cases for any bugs fixed and any new
|
|
features added. Some tips for getting your testcase approved:</p>
|
|
<ol>
|
|
<li>All feature and regression test cases are added to the
|
|
<tt>llvm/test</tt> directory. The appropriate sub-directory should be
|
|
selected (see the <a href="TestingGuide.html">Testing Guide</a> for
|
|
details).</li>
|
|
<li>Test cases should be written in
|
|
<a href="LangRef.html">LLVM assembly language</a> unless the
|
|
feature or regression being tested requires another language (e.g. the
|
|
bug being fixed or feature being implemented is in the llvm-gcc C++
|
|
front-end, in which case it must be written in C++).</li>
|
|
<li>Test cases, especially for regressions, should be reduced as much as
|
|
possible, by <a href="Bugpoint.html">bugpoint</a> or
|
|
manually. It is unacceptable
|
|
to place an entire failing program into <tt>llvm/test</tt> as this creates
|
|
a <i>time-to-test</i> burden on all developers. Please keep them short.</li>
|
|
</ol>
|
|
|
|
<p>Note that llvm/test is designed for regression and small feature tests
|
|
only. More extensive test cases (e.g., entire applications, benchmarks,
|
|
etc) should be added to the <tt>llvm-test</tt> test suite. The llvm-test
|
|
suite is for coverage (correctness, performance, etc) testing, not feature
|
|
or regression testing.</p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="quality">Quality</a></div>
|
|
<div class="doc_text">
|
|
<p>The minimum quality standards that any change must satisfy before being
|
|
committed to the main development branch are:</p>
|
|
<ol>
|
|
<li>Code must adhere to the
|
|
<a href="CodingStandards.html">LLVM Coding Standards</a>.</li>
|
|
<li>Code must compile cleanly (no errors, no warnings) on at least one
|
|
platform.</li>
|
|
<li>Bug fixes and new features should <a href="#testcases">include a
|
|
testcase</a> so we know if the fix/feature ever regresses in the
|
|
future.</li>
|
|
<li>Code must pass the dejagnu (<tt>llvm/test</tt>) test suite.</li>
|
|
<li>The code must not cause regressions on a reasonable subset of llvm-test,
|
|
where "reasonable" depends on the contributor's judgement and the scope
|
|
of the change (more invasive changes require more testing). A reasonable
|
|
subset might be something like
|
|
"<tt>llvm-test/MultiSource/Benchmarks</tt>".</li>
|
|
</ol>
|
|
<p>Additionally, the committer is responsible for addressing any problems
|
|
found in the future that the change is responsible for. For example:</p>
|
|
<ul>
|
|
<li>The code should compile cleanly on all supported platforms.</li>
|
|
<li>The changes should not cause any correctness regressions in the
|
|
<tt>llvm-test</tt> suite and must not cause any major performance
|
|
regressions.</li>
|
|
<li>The change set should not cause performance or correctness regressions
|
|
for the LLVM tools.</li>
|
|
<li>The changes should not cause performance or correctness regressions in
|
|
code compiled by LLVM on all applicable targets.</li>
|
|
<li>You are expected to address any <a href="http://llvm.org/bugs/">bugzilla
|
|
bugs</a> that result from your change.</li>
|
|
</ul>
|
|
|
|
<p>We prefer for this to be handled before submission but understand that it
|
|
isn't possible to test all of this for every submission. Our nightly
|
|
testing
|
|
infrastructure normally finds these problems. A good rule of thumb is to
|
|
check the nightly testers for regressions the day after your change.</p>
|
|
|
|
<p>Commits that violate these quality standards (e.g. are very broken) may
|
|
be reverted. This is necessary when the change blocks other developers from
|
|
making progress. The developer is welcome to re-commit the change after
|
|
the problem has been fixed.</p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection">
|
|
<a name="commitaccess">Obtaining Commit Access</a></div>
|
|
<div class="doc_text">
|
|
|
|
<p>
|
|
We grant commit access to contributors with a track record of submitting high
|
|
quality patches. If you would like commit access, please send an email to
|
|
<a href="mailto:sabre@nondot.org">Chris</a> with the following information:</p>
|
|
|
|
<ol>
|
|
<li>The user name you want to commit with, e.g. "sabre".</li>
|
|
<li>The full name and email address you want message to llvm-commits to come
|
|
from, e.g. "Chris Lattner <sabre@nondot.org>".</li>
|
|
<li>A "password hash" of the password you want to use, e.g. "2ACR96qjUqsyM".
|
|
Note that you don't ever tell us what your password is, you just give it
|
|
to us in an encrypted form. To get this, run "htpasswd" (a utility that
|
|
comes with apache) in crypt mode (often enabled with "-d"), or find a web
|
|
page that will do it for you.</li>
|
|
</ol>
|
|
|
|
<p>Once you've been granted commit access, you should be able to check out an
|
|
LLVM tree with an SVN URL of "https://username@llvm.org/..." instead of the
|
|
normal anonymous URL of "http://llvm.org/...". The first time you commit
|
|
you'll have to type in your password. Note that you may get a warning from
|
|
SVN about an untrusted key, you can ignore this. To verify that your commit
|
|
access works, please do a test commit (e.g. change a comment or add a blank
|
|
line). Your first commit to a repository may require the autogenerated email
|
|
to be approved by a mailing list. This is normal, and will be done when
|
|
the mailing list owner has time.</p>
|
|
|
|
<p>If you have recently been granted commit access, these policies apply:</p>
|
|
|
|
<ol>
|
|
<li>You are granted <i>commit-after-approval</i> to all parts of LLVM.
|
|
To get approval, submit a <a href="#patches">patch</a> to
|
|
<a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits">
|
|
llvm-commits</a>. When approved you may commit it yourself.</li>
|
|
<li>You are allowed to commit patches without approval which you think are
|
|
obvious. This is clearly a subjective decision — we simply expect you
|
|
to use good judgement. Examples include: fixing build breakage, reverting
|
|
obviously broken patches, documentation/comment changes, any other minor
|
|
changes.</li>
|
|
<li>You are allowed to commit patches without approval to those portions
|
|
of LLVM that you have contributed or maintain (i.e., have been assigned
|
|
responsibility for), with the proviso that such commits must not break the
|
|
build. This is a "trust but verify" policy and commits of this nature are
|
|
reviewed after they are committed.</li>
|
|
<li>Multiple violations of these policies or a single egregious violation
|
|
may cause commit access to be revoked.</li>
|
|
</ol>
|
|
|
|
<p>In any case, your changes are still subject to <a href="#reviews">code
|
|
review</a> (either before or after they are committed, depending on the nature
|
|
of the change). You are encouraged to review other peoples' patches as well,
|
|
but you aren't required to.</p>
|
|
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="newwork">Making a Major Change</a></div>
|
|
<div class="doc_text">
|
|
<p>When a developer begins a major new project with the aim of contributing
|
|
it back to LLVM, s/he should inform the community with an email to
|
|
the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">llvmdev</a>
|
|
email list, to the extent possible. The reason for this is to:
|
|
<ol>
|
|
<li>keep the community informed about future changes to LLVM, </li>
|
|
<li>avoid duplication of effort by preventing multiple parties working on
|
|
the same thing and not knowing about it, and</li>
|
|
<li>ensure that any technical issues around the proposed work are
|
|
discussed and resolved before any significant work is done.</li>
|
|
</ol>
|
|
|
|
<p>The design of LLVM is carefully controlled to ensure that all the pieces
|
|
fit together well and are as consistent as possible. If you plan to make a
|
|
major change to the way LLVM works or want to add a major new extension, it
|
|
is a good idea to get consensus with the development
|
|
community before you start working on it.</p>
|
|
|
|
<p>Once the design of the new feature is finalized, the work itself should be
|
|
done as a series of <a href="#incremental">incremental changes</a>, not as
|
|
a long-term development branch.</p>
|
|
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"> <a name="incremental">Incremental Development</a>
|
|
</div>
|
|
<div class="doc_text">
|
|
<p>In the LLVM project, we do all significant changes as a series of
|
|
incremental patches. We have a strong dislike for huge changes or
|
|
long-term development branches. Long-term development branches have a
|
|
number of drawbacks:</p>
|
|
|
|
<ol>
|
|
<li>Branches must have mainline merged into them periodically. If the branch
|
|
development and mainline development occur in the same pieces of code,
|
|
resolving merge conflicts can take a lot of time.</li>
|
|
<li>Other people in the community tend to ignore work on branches.</li>
|
|
<li>Huge changes (produced when a branch is merged back onto mainline) are
|
|
extremely difficult to <a href="#reviews">code review</a>.</li>
|
|
<li>Branches are not routinely tested by our nightly tester
|
|
infrastructure.</li>
|
|
<li>Changes developed as monolithic large changes often don't work until the
|
|
entire set of changes is done. Breaking it down into a set of smaller
|
|
changes increases the odds that any of the work will be committed to the
|
|
main repository.</li>
|
|
</ol>
|
|
|
|
<p>
|
|
To address these problems, LLVM uses an incremental development style and we
|
|
require contributors to follow this practice when making a large/invasive
|
|
change. Some tips:</p>
|
|
|
|
<ul>
|
|
<li>Large/invasive changes usually have a number of secondary changes that
|
|
are required before the big change can be made (e.g. API cleanup, etc).
|
|
These sorts of changes can often be done before the major change is done,
|
|
independently of that work.</li>
|
|
<li>The remaining inter-related work should be decomposed into unrelated
|
|
sets of changes if possible. Once this is done, define the first increment
|
|
and get consensus on what the end goal of the change is.</li>
|
|
|
|
<li>Each change in the set can be stand alone (e.g. to fix a bug), or part
|
|
of a planned series of changes that works towards the development goal.</li>
|
|
|
|
<li>Each change should be kept as small as possible. This simplifies your
|
|
work (into a logical progression), simplifies code review and reduces the
|
|
chance that you will get negative feedback on the change. Small increments
|
|
also facilitate the maintenance of a high quality code base.</li>
|
|
|
|
<li>Often, an independent precursor to a big change is to add a new API and
|
|
slowly migrate clients to use the new API. Each change to use the new
|
|
API is often "obvious" and can be committed without review. Once the
|
|
new API is in place and used, it is much easier to replace the
|
|
underlying implementation of the API. This implementation change is
|
|
logically separate from the API change.</li>
|
|
</ul>
|
|
|
|
<p>If you are interested in making a large change, and this scares you, please
|
|
make sure to first <a href="#newwork">discuss the change/gather
|
|
consensus</a> then ask about the best way to go about making
|
|
the change.</p>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"><a name="attribution">Attribution of
|
|
Changes</a></div>
|
|
<div class="doc_text">
|
|
<p>We believe in correct attribution of contributions to
|
|
their contributors. However, we do not want the source code to be littered
|
|
with random attributions "this code written by J Random Guy" (this is noisy
|
|
and distracting). In practice, the revision control system keeps a perfect
|
|
history of who changed what, and the CREDITS.txt file describes higher-level
|
|
contributions. If you commit a patch for someone else, please say "patch
|
|
contributed by J Random Guy!" in the commit message.</p>
|
|
|
|
<p>Overall, please do not add contributor names to the source code.</p>
|
|
</div>
|
|
|
|
|
|
|
|
<!--=========================================================================-->
|
|
<div class="doc_section">
|
|
<a name="clp">Copyright, License, and Patents</a>
|
|
</div>
|
|
<!--=========================================================================-->
|
|
|
|
<div class="doc_text">
|
|
<p>This section addresses the issues of copyright, license and patents for
|
|
the LLVM project.
|
|
Currently, the University of Illinois is the LLVM copyright holder and the
|
|
terms of its license to LLVM users and developers is the
|
|
<a href="http://www.opensource.org/licenses/UoI-NCSA.php">University of
|
|
Illinois/NCSA Open Source License</a>.</p>
|
|
|
|
<div class="doc_notes">
|
|
<p style="text-align:center;font-weight:bold">NOTE: This section
|
|
deals with legal matters but does not provide legal advice. We are not
|
|
lawyers, please seek legal counsel from an attorney.</p>
|
|
</div>
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"><a name="copyright">Copyright</a></div>
|
|
<div class="doc_text">
|
|
<p>
|
|
<p>For consistency and ease of management, the project requires the
|
|
copyright for all LLVM software to be held by a single copyright holder:
|
|
the University of Illinois (UIUC).</p>
|
|
|
|
<p>
|
|
Although UIUC may eventually reassign the copyright of the software to another
|
|
entity (e.g. a dedicated non-profit "LLVM Organization")
|
|
the intent for the project is to always have a single entity hold the
|
|
copyrights to LLVM at any given time.</p>
|
|
|
|
<p>We believe that having a single copyright
|
|
holder is in the best interests of all developers and users as it greatly
|
|
reduces the managerial burden for any kind of administrative or technical
|
|
decisions about LLVM. The goal of the LLVM project is to always keep the code
|
|
open and <a href="#license">licensed under a very liberal license</a>.</p>
|
|
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"><a name="license">License</a></div>
|
|
<div class="doc_text">
|
|
<p>We intend to keep LLVM perpetually open source
|
|
and to use a liberal open source license. The current license is the
|
|
<a href="http://www.opensource.org/licenses/UoI-NCSA.php">
|
|
University of Illinois/NCSA Open Source License</a>, which boils
|
|
down to this:</p>
|
|
<ul>
|
|
<li>You can freely distribute LLVM.</li>
|
|
<li>You must retain the copyright notice if you redistribute LLVM.</li>
|
|
<li>Binaries derived from LLVM must reproduce the copyright notice (e.g.
|
|
in an included readme file).</li>
|
|
<li>You can't use our names to promote your LLVM derived products.</li>
|
|
<li>There's no warranty on LLVM at all.</li>
|
|
</ul>
|
|
|
|
<p>We believe this fosters the widest adoption of LLVM because it <b>allows
|
|
commercial products to be derived from LLVM</b> with few restrictions and
|
|
without a requirement for making any derived works also open source (i.e.
|
|
LLVM's license is not a "copyleft" license like the GPL). We suggest that you
|
|
read the <a href="http://www.opensource.org/licenses/UoI-NCSA.php">License</a>
|
|
if further clarification is needed.</p>
|
|
|
|
<p>Note that the LLVM Project does distribute llvm-gcc, <b>which is GPL.</b>
|
|
This means that anything "linked" into llvm-gcc must itself be compatible
|
|
with the GPL, and must be releasable under the terms of the GPL. This implies
|
|
that <b>any code linked into llvm-gcc and distributed to others may be subject
|
|
to the viral aspects of the GPL</b> (for example, a proprietary code generator
|
|
linked into llvm-gcc must be made available under the GPL). This is not a
|
|
problem for code already distributed under a more liberal license (like the
|
|
UIUC license), and does not affect code generated by llvm-gcc. It may be a
|
|
problem if you intend to base commercial development on llvm-gcc without
|
|
redistributing your source code.</p>
|
|
|
|
<p>We have no plans to change the license of LLVM. If you have questions
|
|
or comments about the license, please contact the <a
|
|
href="mailto:llvm-oversight@cs.uiuc.edu">LLVM Oversight Group</a>.</p>
|
|
|
|
</div>
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"><a name="patents">Patents</a></div>
|
|
<div class="doc_text">
|
|
|
|
<p>To the best of our knowledge, LLVM does not infringe on any patents (we have
|
|
actually removed code from LLVM in the past that was found to infringe).
|
|
Having code in LLVM that infringes on patents would violate an important
|
|
goal of the project by making it hard or impossible to reuse the code for
|
|
arbitrary purposes (including commercial use).</p>
|
|
|
|
<p>When contributing code, we expect contributors to notify us of any potential
|
|
for patent-related trouble with their changes. If you or your employer
|
|
own the rights to a
|
|
patent and would like to contribute code to LLVM that relies on it, we
|
|
require that
|
|
the copyright owner sign an agreement that allows any other user of LLVM to
|
|
freely use your patent. Please contact the <a
|
|
href="mailto:llvm-oversight@cs.uiuc.edu">oversight group</a> for more
|
|
details.</p>
|
|
</div>
|
|
|
|
|
|
<!-- _______________________________________________________________________ -->
|
|
<div class="doc_subsection"><a name="devagree">Developer Agreements</a></div>
|
|
<div class="doc_text">
|
|
<p>With regards to the LLVM copyright and licensing, developers agree to
|
|
assign their copyrights to UIUC for any contribution made so that
|
|
the entire software base can be managed by a single copyright holder. This
|
|
implies that any contributions can be licensed under the license that the
|
|
project uses.</p>
|
|
|
|
<p>When contributing code, you also affirm that you are legally entitled to
|
|
grant this copyright, personally or on behalf of your employer. If the code
|
|
belongs to some other entity, please raise this issue with the oversight
|
|
group before the code is committed.</p>
|
|
</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>
|
|
Written by the
|
|
<a href="mailto:llvm-oversight@cs.uiuc.edu">LLVM Oversight Group</a><br>
|
|
<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
|
|
Last modified: $Date$
|
|
</address>
|
|
</body>
|
|
</html>
|