3 Thank you for your interest in contributing to Rust! There are many ways to
4 contribute, and we appreciate all of them. This document is a bit long, so here's
5 links to the major sections:
7 * [Feature Requests](#feature-requests)
8 * [Bug Reports](#bug-reports)
9 * [The Build System](#the-build-system)
10 * [Pull Requests](#pull-requests)
11 * [Writing Documentation](#writing-documentation)
12 * [Issue Triage](#issue-triage)
13 * [Out-of-tree Contributions](#out-of-tree-contributions)
14 * [Helpful Links and Information](#helpful-links-and-information)
16 If you have questions, please make a post on [internals.rust-lang.org][internals] or
17 hop on [#rust-internals][pound-rust-internals].
19 As a reminder, all contributors are expected to follow our [Code of Conduct][coc].
21 [pound-rust-internals]: http://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust-internals
22 [internals]: https://internals.rust-lang.org
23 [coc]: https://www.rust-lang.org/conduct.html
27 To request a change to the way that the Rust language works, please open an
28 issue in the [RFCs repository](https://github.com/rust-lang/rfcs/issues/new)
29 rather than this one. New features and other significant language changes
30 must go through the RFC process.
34 While bugs are unfortunate, they're a reality in software. We can't fix what we
35 don't know about, so please report liberally. If you're not sure if something
36 is a bug or not, feel free to file a bug anyway.
38 **If you believe reporting your bug publicly represents a security risk to Rust users,
39 please follow our [instructions for reporting security vulnerabilities](https://www.rust-lang.org/security.html)**.
41 If you have the chance, before reporting a bug, please [search existing
42 issues](https://github.com/rust-lang/rust/search?q=&type=Issues&utf8=%E2%9C%93),
43 as it's possible that someone else has already reported your error. This doesn't
44 always work, and sometimes it's hard to know what to search for, so consider this
45 extra credit. We won't mind if you accidentally file a duplicate report.
47 Opening an issue is as easy as following [this
48 link](https://github.com/rust-lang/rust/issues/new) and filling out the fields.
49 Here's a template that you can use to file a bug, though it's not necessary to
52 <short summary of the bug>
56 <code sample that causes the bug>
58 I expected to see this happen: <explanation>
60 Instead, this happened: <explanation>
64 `rustc --version --verbose`:
68 All three components are important: what you did, what you expected, what
69 happened instead. Please include the output of `rustc --version --verbose`,
70 which includes important information about what platform you're on, what
71 version of Rust you're using, etc.
73 Sometimes, a backtrace is helpful, and so including that is nice. To get
74 a backtrace, set the `RUST_BACKTRACE` environment variable. The easiest way
75 to do this is to invoke `rustc` like this:
78 $ RUST_BACKTRACE=1 rustc ...
83 Rust's build system allows you to bootstrap the compiler, run tests &
84 benchmarks, generate documentation, install a fresh build of Rust, and more.
85 It's your best friend when working on Rust, allowing you to compile & test
86 your contributions before submission.
88 All the configuration for the build system lives in [the `mk` directory][mkdir]
89 in the project root. It can be hard to follow in places, as it uses some
90 advanced Make features which make for some challenging reading. If you have
91 questions on the build system internals, try asking in
92 [`#rust-internals`][pound-rust-internals].
94 [mkdir]: https://github.com/rust-lang/rust/tree/master/mk/
98 Before you can start building the compiler you need to configure the build for
99 your system. In most cases, that will just mean using the defaults provided
100 for Rust. Configuring involves invoking the `configure` script in the project
107 There are large number of options accepted by this script to alter the
108 configuration used later in the build process. Some options to note:
110 - `--enable-debug` - Build a debug version of the compiler (disables optimizations)
111 - `--enable-optimize` - Enable optimizations (can be used with `--enable-debug`
112 to make a debug build with optimizations)
113 - `--disable-valgrind-rpass` - Don't run tests with valgrind
114 - `--enable-clang` - Prefer clang to gcc for building dependencies (e.g., LLVM)
115 - `--enable-ccache` - Invoke clang/gcc with ccache to re-use object files between builds
116 - `--enable-compiler-docs` - Build compiler documentation
118 To see a full list of options, run `./configure --help`.
122 Some common make targets are:
124 - `make rustc-stage1` - build up to (and including) the first stage. For most
125 cases we don't need to build the stage2 compiler, so we can save time by not
126 building it. The stage1 compiler is a fully functioning compiler and
127 (probably) will be enough to determine if your change works as expected.
128 - `make check` - build the full compiler & run all tests (takes a while). This
129 is what gets run by the continuous integration system against your pull
130 request. You should run this before submitting to make sure your tests pass
131 & everything builds in the correct manner.
132 - `make check-stage1-std NO_REBUILD=1` - test the standard library without
133 rebuilding the entire compiler
134 - `make check TESTNAME=<name-of-test-to-run>` - Run a single test file
135 - `TESTNAME` should be the fully qualified name of the test function, e.g.
136 `TESTNAME=collections::hash::map::test_map::test_capacity_not_less_than_len`
137 - `make check-stage1-rpass TESTNAME=<name-of-test-to-run>` - Run a single
138 rpass test with the stage1 compiler (this will be quicker than running the
139 command above as we only build the stage1 compiler, not the entire thing).
140 You can also leave off the `-rpass` to run all stage1 test types.
141 - `make check-stage1-coretest` - Run stage1 tests in `libcore`.
145 Pull requests are the primary mechanism we use to change Rust. GitHub itself
146 has some [great documentation][pull-requests] on using the Pull Request
147 feature. We use the 'fork and pull' model described there.
149 [pull-requests]: https://help.github.com/articles/using-pull-requests/
151 Please make pull requests against the `master` branch.
153 Compiling all of `make check` can take a while. When testing your pull request,
154 consider using one of the more specialized `make` targets to cut down on the
155 amount of time you have to wait. You need to have built the compiler at least
156 once before running these will work, but that’s only one full build rather than
159 $ make -j8 rustc-stage1 && make check-stage1
161 is one such example, which builds just `rustc`, and then runs the tests. If
162 you’re adding something to the standard library, try
164 $ make -j8 check-stage1-std NO_REBUILD=1
166 This will not rebuild the compiler, but will run the tests.
168 All pull requests are reviewed by another person. We have a bot,
169 @rust-highfive, that will automatically assign a random person to review your
172 If you want to request that a specific person reviews your pull request,
173 you can add an `r?` to the message. For example, Steve usually reviews
174 documentation changes. So if you were to make a documentation change, add
178 to the end of the message, and @rust-highfive will assign @steveklabnik instead
179 of a random person. This is entirely optional.
181 After someone has reviewed your pull request, they will leave an annotation
182 on the pull request with an `r+`. It will look something like this:
186 This tells @bors, our lovable integration bot, that your pull request has
187 been approved. The PR then enters the [merge queue][merge-queue], where @bors
188 will run all the tests on every platform we support. If it all works out,
189 @bors will merge your code into `master` and close the pull request.
191 [merge-queue]: http://buildbot.rust-lang.org/homu/queue/rust
193 Speaking of tests, Rust has a comprehensive test suite. More information about
195 [here](https://github.com/rust-lang/rust-wiki-backup/blob/master/Note-testsuite.md).
197 ## Writing Documentation
199 Documentation improvements are very welcome. The source of `doc.rust-lang.org`
200 is located in `src/doc` in the tree, and standard API documentation is generated
201 from the source code itself.
203 Documentation pull requests function in the same way as other pull requests,
204 though you may see a slightly different form of `r+`:
206 @bors: r+ 38fe8d2 rollup
208 That additional `rollup` tells @bors that this change is eligible for a 'rollup'.
209 To save @bors some work, and to get small changes through more quickly, when
210 @bors attempts to merge a commit that's rollup-eligible, it will also merge
211 the other rollup-eligible patches too, and they'll get tested and merged at
214 To find documentation-related issues, sort by the [A-docs label][adocs].
216 [adocs]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AA-docs
218 In many cases, you don't need a full `make doc`. You can use `rustdoc` directly
219 to check small fixes. For example, `rustdoc src/doc/reference.md` will render
220 reference to `doc/reference.html`. The CSS might be messed up, but you can
221 verify that HTML is right.
225 Sometimes, an issue will stay open, even though the bug has been fixed. And
226 sometimes, the original bug may go stale because something has changed in the
229 It can be helpful to go through older bug reports and make sure that they are
230 still valid. Load up an older issue, double check that it's still true, and
231 leave a comment letting us know if it is or is not. The [least recently
232 updated sort][lru] is good for finding issues like this.
234 Contributors with sufficient permissions on the Rust repo can help by adding
235 labels to triage issues:
237 * Yellow, **A**-prefixed labels state which **area** of the project an issue
240 * Magenta, **B**-prefixed labels identify bugs which are **blockers**.
242 * Green, **E**-prefixed labels explain the level of **experience** necessary
245 * Red, **I**-prefixed labels indicate the **importance** of the issue. The
246 [I-nominated][inom] label indicates that an issue has been nominated for
247 prioritizing at the next triage meeting.
249 * Orange, **P**-prefixed labels indicate a bug's **priority**. These labels
250 are only assigned during triage meetings, and replace the [I-nominated][inom]
253 * Blue, **T**-prefixed bugs denote which **team** the issue belongs to.
255 * Dark blue, **beta-** labels track changes which need to be backported into
258 * The purple **metabug** label marks lists of bugs collected by other
261 If you're looking for somewhere to start, check out the [E-easy][eeasy] tag.
263 [inom]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AI-nominated
264 [eeasy]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy
265 [lru]: https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-asc
267 ## Out-of-tree Contributions
269 There are a number of other ways to contribute to Rust that don't deal with
272 Answer questions in [#rust][pound-rust], or on [users.rust-lang.org][users],
273 or on [StackOverflow][so].
275 Participate in the [RFC process](https://github.com/rust-lang/rfcs).
277 Find a [requested community library][community-library], build it, and publish
278 it to [Crates.io](http://crates.io). Easier said than done, but very, very
281 [pound-rust]: http://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust
282 [users]: https://users.rust-lang.org/
283 [so]: http://stackoverflow.com/questions/tagged/rust
284 [community-library]: https://github.com/rust-lang/rfcs/labels/A-community-library
286 ## Helpful Links and Information
288 For people new to Rust, and just starting to contribute, or even for
289 more seasoned developers, some useful places to look for information
292 * The [Rust Internals forum][rif], a place to ask questions and
293 discuss Rust's internals
294 * The [generated documentation for rust's compiler][gdfrustc]
295 * The [rust reference][rr], even though it doesn't specifically talk about Rust's internals, it's a great resource nonetheless
296 * Although out of date, [Tom Lee's great blog article][tlgba] is very helpful
297 * [rustaceans.org][ro] is helpful, but mostly dedicated to IRC
298 * The [Rust Compiler Testing Docs][rctd]
299 * For @bors, [this cheat sheet][cheatsheet] is helpful (Remember to replace `@homu` with `@bors` in the commands that you use.)
300 * **Google!** ([search only in Rust Documentation][gsearchdocs] to find types, traits, etc. quickly)
301 * Don't be afraid to ask! The Rust community is friendly and helpful.
303 [gdfrustc]: http://manishearth.github.io/rust-internals-docs/rustc/
304 [gsearchdocs]: https://www.google.com/search?q=site:doc.rust-lang.org+your+query+here
305 [rif]: http://internals.rust-lang.org
306 [rr]: https://doc.rust-lang.org/book/README.html
307 [tlgba]: http://tomlee.co/2014/04/03/a-more-detailed-tour-of-the-rust-compiler/
308 [ro]: http://www.rustaceans.org/
309 [rctd]: ./COMPILER_TESTS.md
310 [cheatsheet]: http://buildbot.rust-lang.org/homu/