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 The build system for Rust is complex. It covers bootstrapping the compiler,
84 running tests, building documentation and more.
86 If Makefiles are your thing, all the configuration lives in
87 [the `mk` directory][mkdir] in the project root. Is can be hard to follow
88 in places, as it uses some advanced Make features which make for some
89 challenging reading. If you have questions on the build system internals, try
90 asking in [`#rust-internals`][pound-rust-internals].
92 [mkdir]: https://github.com/rust-lang/rust/tree/master/mk/
96 Before you can start building the compiler you need to configure the build for
97 your system. In most cases, that will just mean using the defaults provided
98 for Rust. Configuring involves invoking the `configure` script in the project
105 There are large number of options accepted by this script to alter the
106 configuration used later in the build process. Some options to note:
108 - `--enable-debug` - Build a debug version of the compiler (disables optimizations)
109 - `--enable-optimize` - Enable optimizations (can be used with `--enable-debug`
110 to make a debug build with optimizations)
111 - `--disable-valgrind-rpass` - Don't run tests with valgrind
112 - `--enable-clang` - Prefer clang to gcc for building dependencies (e.g., LLVM)
113 - `--enable-ccache` - Invoke clang/gcc with ccache to re-use object files between builds
114 - `--enable-compiler-docs` - Build compiler documentation
116 To see a full list of options, run `./configure --help`.
120 Some common make targets are:
122 - `make rustc-stage1` - build up to (and including) the first stage. For most
123 cases we don't need to build the stage2 compiler, so we can save time by not
124 building it. The stage1 compiler is a fully functioning compiler and
125 (probably) will be enough to determine if your change works as expected.
126 - `make check` - build the full compiler & run all tests (takes a while). This
127 is what gets run by the continuous integration system against your pull
128 request. You should run this before submitting to make sure your tests pass
129 & everything builds in the correct manner.
130 - `make check-stage1-std NO_REBUILD=1` - test the standard library without
131 rebuilding the entire compiler
132 - `make check TESTNAME=<path-to-test-file>.rs` - Run a single test file
133 - `make check-stage1-rpass TESTNAME=<path-to-test-file>.rs` - Run a single
134 rpass test with the stage1 compiler (this will be quicker than running the
135 command above as we only build the stage1 compiler, not the entire thing).
136 You can also leave off the `-rpass` to run all stage1 test types.
137 - `make check-stage1-coretest` - Run stage1 tests in `libcore`.
141 Pull requests are the primary mechanism we use to change Rust. GitHub itself
142 has some [great documentation][pull-requests] on using the Pull Request
143 feature. We use the 'fork and pull' model described there.
145 [pull-requests]: https://help.github.com/articles/using-pull-requests/
147 Please make pull requests against the `master` branch.
149 Compiling all of `make check` can take a while. When testing your pull request,
150 consider using one of the more specialized `make` targets to cut down on the
151 amount of time you have to wait. You need to have built the compiler at least
152 once before running these will work, but that’s only one full build rather than
155 $ make -j8 rustc-stage1 && make check-stage1
157 is one such example, which builds just `rustc`, and then runs the tests. If
158 you’re adding something to the standard library, try
160 $ make -j8 check-stage1-std NO_REBUILD=1
162 This will not rebuild the compiler, but will run the tests.
164 All pull requests are reviewed by another person. We have a bot,
165 @rust-highfive, that will automatically assign a random person to review your
168 If you want to request that a specific person reviews your pull request,
169 you can add an `r?` to the message. For example, Steve usually reviews
170 documentation changes. So if you were to make a documentation change, add
174 to the end of the message, and @rust-highfive will assign @steveklabnik instead
175 of a random person. This is entirely optional.
177 After someone has reviewed your pull request, they will leave an annotation
178 on the pull request with an `r+`. It will look something like this:
182 This tells @bors, our lovable integration bot, that your pull request has
183 been approved. The PR then enters the [merge queue][merge-queue], where @bors
184 will run all the tests on every platform we support. If it all works out,
185 @bors will merge your code into `master` and close the pull request.
187 [merge-queue]: http://buildbot.rust-lang.org/homu/queue/rust
189 Speaking of tests, Rust has a comprehensive test suite. More information about
191 [here](https://github.com/rust-lang/rust-wiki-backup/blob/master/Note-testsuite.md).
193 ## Writing Documentation
195 Documentation improvements are very welcome. The source of `doc.rust-lang.org`
196 is located in `src/doc` in the tree, and standard API documentation is generated
197 from the source code itself.
199 Documentation pull requests function in the same way as other pull requests,
200 though you may see a slightly different form of `r+`:
202 @bors: r+ 38fe8d2 rollup
204 That additional `rollup` tells @bors that this change is eligible for a 'rollup'.
205 To save @bors some work, and to get small changes through more quickly, when
206 @bors attempts to merge a commit that's rollup-eligible, it will also merge
207 the other rollup-eligible patches too, and they'll get tested and merged at
210 To find documentation-related issues, sort by the [A-docs label][adocs].
212 [adocs]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AA-docs
214 In many cases, you don't need a full `make doc`. You can use `rustdoc` directly
215 to check small fixes. For example, `rustdoc src/doc/reference.md` will render
216 reference to `doc/reference.html`. The CSS might be messed up, but you can
217 verify that HTML is right.
221 Sometimes, an issue will stay open, even though the bug has been fixed. And
222 sometimes, the original bug may go stale because something has changed in the
225 It can be helpful to go through older bug reports and make sure that they are
226 still valid. Load up an older issue, double check that it's still true, and
227 leave a comment letting us know if it is or is not. The [least recently
228 updated sort][lru] is good for finding issues like this.
230 Contributors with sufficient permissions on the Rust repo can help by adding
231 labels to triage issues:
233 * Yellow, **A**-prefixed labels state which **area** of the project an issue
236 * Magenta, **B**-prefixed labels identify bugs which are **blockers**.
238 * Green, **E**-prefixed labels explain the level of **experience** necessary
241 * Red, **I**-prefixed labels indicate the **importance** of the issue. The
242 [I-nominated][inom] label indicates that an issue has been nominated for
243 prioritizing at the next triage meeting.
245 * Orange, **P**-prefixed labels indicate a bug's **priority**. These labels
246 are only assigned during triage meetings, and replace the [I-nominated][inom]
249 * Blue, **T**-prefixed bugs denote which **team** the issue belongs to.
251 * Dark blue, **beta-** labels track changes which need to be backported into
254 * The purple **metabug** label marks lists of bugs collected by other
257 If you're looking for somewhere to start, check out the [E-easy][eeasy] tag.
259 [inom]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AI-nominated
260 [eeasy]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy
261 [lru]: https://github.com/rust-lang/rust/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-asc
263 ## Out-of-tree Contributions
265 There are a number of other ways to contribute to Rust that don't deal with
268 Answer questions in [#rust][pound-rust], or on [users.rust-lang.org][users],
269 or on [StackOverflow][so].
271 Participate in the [RFC process](https://github.com/rust-lang/rfcs).
273 Find a [requested community library][community-library], build it, and publish
274 it to [Crates.io](http://crates.io). Easier said than done, but very, very
277 [pound-rust]: http://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust
278 [users]: https://users.rust-lang.org/
279 [so]: http://stackoverflow.com/questions/tagged/rust
280 [community-library]: https://github.com/rust-lang/rfcs/labels/A-community-library
282 ## Helpful Links and Information
284 For people new to Rust, and just starting to contribute, or even for
285 more seasoned developers, some useful places to look for information
288 * The [Rust Internals forum][rif], a place to ask questions and
289 discuss Rust's internals
290 * The [generated documentation for rust's compiler][gdfrustc]
291 * The [rust reference][rr], even though it doesn't specifically talk about Rust's internals, it's a great resource nonetheless
292 * Although out of date, [Tom Lee's great blog article][tlgba] is very helpful
293 * [rustaceans.org][ro] is helpful, but mostly dedicated to IRC
294 * The [Rust Compiler Testing Docs][rctd]
295 * For @bors, [this cheat sheet][cheatsheet] is helpful (Remember to replace `@homu` with `@bors` in the commands that you use.)
296 * **Google!** ([search only in Rust Documentation][gsearchdocs] to find types, traits, etc. quickly)
297 * Don't be afraid to ask! The Rust community is friendly and helpful.
299 [gdfrustc]: http://manishearth.github.io/rust-internals-docs/rustc/
300 [gsearchdocs]: https://www.google.com/search?q=site:doc.rust-lang.org+your+query+here
301 [rif]: http://internals.rust-lang.org
302 [rr]: https://doc.rust-lang.org/book/README.html
303 [tlgba]: http://tomlee.co/2014/04/03/a-more-detailed-tour-of-the-rust-compiler/
304 [ro]: http://www.rustaceans.org/
305 [rctd]: ./COMPILER_TESTS.md
306 [cheatsheet]: http://buildbot.rust-lang.org/homu/