-# Contribution Guide
+# Contributing to Rust
-If you want to hack on Miri yourself, great! Here are some resources you might
-find useful.
+Thank you for your interest in contributing to Rust! There are many ways to contribute
+and we appreciate all of them.
-## Getting started
+The best way to get started is by asking for help in the [#new
+members](https://rust-lang.zulipchat.com/#narrow/stream/122652-new-members)
+Zulip stream. We have lots of docs below of how to get started on your own, but
+the Zulip stream is the best place to *ask* for help.
-Check out the issues on this GitHub repository for some ideas. In particular,
-look for the green `E-*` labels which mark issues that should be rather
-well-suited for onboarding. For more ideas or help with hacking on Miri, you can
-contact us (`oli-obk` and `RalfJ`) on the [Rust Zulip].
+Documentation for contributing to the compiler or tooling is located in the [Guide to Rustc
+Development][rustc-dev-guide], commonly known as the [rustc-dev-guide]. Documentation for the
+standard library in the [Standard library developers Guide][std-dev-guide], commonly known as the [std-dev-guide].
-[Rust Zulip]: https://rust-lang.zulipchat.com
+## About the [rustc-dev-guide]
-## Preparing the build environment
+The [rustc-dev-guide] is meant to help document how rustc –the Rust compiler– works,
+as well as to help new contributors get involved in rustc development. It is recommend
+to read and understand the [rustc-dev-guide] before making a contribution. This guide
+talks about the different bots in the Rust ecosystem, the Rust development tools,
+bootstrapping, the compiler architecture, source code representation, and more.
-Miri heavily relies on internal and unstable rustc interfaces to execute MIR,
-which means it is important that you install a version of rustc that Miri
-actually works with.
+## [Getting help](https://rustc-dev-guide.rust-lang.org/getting-started.html#asking-questions)
-The `rust-version` file contains the commit hash of rustc that Miri is currently
-tested against. Other versions will likely not work. After installing
-[`rustup-toolchain-install-master`], you can run the following command to
-install that exact version of rustc as a toolchain:
-```
-./rustup-toolchain
-```
-This will set up a rustup toolchain called `miri` and set it as an override for
-the current directory.
+There are many ways you can get help when you're stuck. Rust has many platforms for this:
+[internals], [rust-zulip], and [rust-discord]. It is recommended to ask for help on
+the [rust-zulip], but any of these platforms are a great way to seek help and even
+find a mentor! You can learn more about asking questions and getting help in the
+[Asking Questions](https://rustc-dev-guide.rust-lang.org/getting-started.html#asking-questions) chapter of the [rustc-dev-guide].
-You can also create a `.auto-everything` file (contents don't matter, can be empty), which
-will cause any `./miri` command to automatically call `rustup-toolchain`, `clippy` and `rustfmt`
-for you. If you don't want all of these to happen, you can add individual `.auto-toolchain`,
-`.auto-clippy` and `.auto-fmt` files respectively.
+## Bug reports
-[`rustup-toolchain-install-master`]: https://github.com/kennytm/rustup-toolchain-install-master
+Did a compiler error message tell you to come here? If you want to create an ICE report,
+refer to [this section][contributing-bug-reports] and [open an issue][issue template].
-## Building and testing Miri
-
-Invoking Miri requires getting a bunch of flags right and setting up a custom
-sysroot with xargo. The `miri` script takes care of that for you. With the
-build environment prepared, compiling Miri is just one command away:
-
-```
-./miri build
-```
-
-Run `./miri` without arguments to see the other commands our build tool
-supports.
-
-### Testing the Miri driver
-
-The Miri driver compiled from `src/bin/miri.rs` is the "heart" of Miri: it is
-basically a version of `rustc` that, instead of compiling your code, runs it.
-It accepts all the same flags as `rustc` (though the ones only affecting code
-generation and linking obviously will have no effect) [and more][miri-flags].
-
-[miri-flags]: README.md#miri--z-flags-and-environment-variables
-
-For example, you can (cross-)run the driver on a particular file by doing
-
-```sh
-./miri run tests/pass/format.rs
-./miri run tests/pass/hello.rs --target i686-unknown-linux-gnu
-```
-
-and you can (cross-)run the entire test suite using:
-
-```
-./miri test
-MIRI_TEST_TARGET=i686-unknown-linux-gnu ./miri test
-```
-
-If your target doesn't support libstd, you can run miri with
-
-```
-MIRI_NO_STD=1 MIRI_TEST_TARGET=thumbv7em-none-eabihf ./miri test tests/fail/alloc/no_global_allocator.rs
-MIRI_NO_STD=1 ./miri run tests/pass/no_std.rs --target thumbv7em-none-eabihf
-```
-
-to avoid attempting (and failing) to build libstd. Note that almost no tests will pass
-this way, but you can run individual tests.
-
-`./miri test FILTER` only runs those tests that contain `FILTER` in their
-filename (including the base directory, e.g. `./miri test fail` will run all
-compile-fail tests).
-
-You can get a trace of which MIR statements are being executed by setting the
-`MIRI_LOG` environment variable. For example:
-
-```sh
-MIRI_LOG=info ./miri run tests/pass/vec.rs
-```
-
-Setting `MIRI_LOG` like this will configure logging for Miri itself as well as
-the `rustc_middle::mir::interpret` and `rustc_mir::interpret` modules in rustc. You
-can also do more targeted configuration, e.g. the following helps debug the
-stacked borrows implementation:
-
-```sh
-MIRI_LOG=rustc_mir::interpret=info,miri::stacked_borrows ./miri run tests/pass/vec.rs
-```
-
-In addition, you can set `MIRI_BACKTRACE=1` to get a backtrace of where an
-evaluation error was originally raised.
-
-#### UI testing
-
-We use ui-testing in Miri, meaning we generate `.stderr` and `.stdout` files for the output
-produced by Miri. You can use `./miri bless` to automatically (re)generate these files when
-you add new tests or change how Miri presents certain output.
-
-Note that when you also use `MIRIFLAGS` to change optimizations and similar, the ui output
-will change in unexpected ways. In order to still be able
-to run the other checks while ignoring the ui output, use `MIRI_SKIP_UI_CHECKS=1 ./miri test`.
-
-For more info on how to configure ui tests see [the documentation on the ui test crate][ui_test]
-
-[ui_test]: ui_test/README.md
-
-### Testing `cargo miri`
-
-Working with the driver directly gives you full control, but you also lose all
-the convenience provided by cargo. Once your test case depends on a crate, it
-is probably easier to test it with the cargo wrapper. You can install your
-development version of Miri using
-
-```
-./miri install
-```
-
-and then you can use it as if it was installed by `rustup`. Make sure you use
-the same toolchain when calling `cargo miri` that you used when installing Miri!
-Usually this means you have to write `cargo +miri miri ...` to select the `miri`
-toolchain that was installed by `./rustup-toolchain`.
-
-There's a test for the cargo wrapper in the `test-cargo-miri` directory; run
-`./run-test.py` in there to execute it. Like `./miri test`, this respects the
-`MIRI_TEST_TARGET` environment variable to execute the test for another target.
-
-### Using a modified standard library
-
-Miri re-builds the standard library into a custom sysroot, so it is fairly easy
-to test Miri against a modified standard library -- you do not even have to
-build Miri yourself, the Miri shipped by `rustup` will work. All you have to do
-is set the `MIRI_LIB_SRC` environment variable to the `library` folder of a
-`rust-lang/rust` repository checkout. Note that changing files in that directory
-does not automatically trigger a re-build of the standard library; you have to
-clear the Miri build cache manually (on Linux, `rm -rf ~/.cache/miri`;
-and on Windows, `rmdir /S "%LOCALAPPDATA%\rust-lang\miri\cache"`).
-
-### Benchmarking
-
-Miri comes with a few benchmarks; you can run `./miri bench` to run them with the locally built
-Miri. Note: this will run `./miri install` as a side-effect. Also requires `hyperfine` to be
-installed (`cargo install hyperfine`).
-
-## Configuring `rust-analyzer`
-
-To configure `rust-analyzer` and VS Code for working on Miri, save the following
-to `.vscode/settings.json` in your local Miri clone:
-
-```json
-{
- "rust-analyzer.rustc.source": "discover",
- "rust-analyzer.linkedProjects": [
- "./Cargo.toml",
- "./cargo-miri/Cargo.toml"
- ],
- "rust-analyzer.checkOnSave.overrideCommand": [
- "env",
- "MIRI_AUTO_OPS=no",
- "./miri",
- "check",
- "--message-format=json"
- ],
- "rust-analyzer.buildScripts.overrideCommand": [
- "env",
- "MIRI_AUTO_OPS=no",
- "./miri",
- "check",
- "--message-format=json",
- ],
- "rust-analyzer.rustfmt.extraArgs": [
- "+nightly"
- ],
-}
-```
-
-> #### Note
->
-> If you are [building Miri with a locally built rustc][], set
-> `rust-analyzer.rustcSource` to the relative path from your Miri clone to the
-> root `Cargo.toml` of the locally built rustc. For example, the path might look
-> like `../rust/Cargo.toml`.
-
-See the rustc-dev-guide's docs on ["Configuring `rust-analyzer` for `rustc`"][rdg-r-a]
-for more information about configuring VS Code and `rust-analyzer`.
-
-[rdg-r-a]: https://rustc-dev-guide.rust-lang.org/building/suggested.html#configuring-rust-analyzer-for-rustc
-
-## Advanced topic: other build environments
-
-We described above the simplest way to get a working build environment for Miri,
-which is to use the version of rustc indicated by `rustc-version`. But
-sometimes, that is not enough.
-
-### Updating `rustc-version`
-
-The `rustc-version` file is regularly updated to keep Miri close to the latest
-version of rustc. Usually, new contributors do not have to worry about this. But
-sometimes a newer rustc is needed for a patch, and sometimes Miri needs fixing
-for changes in rustc. In both cases, `rustc-version` needs updating.
-
-To update the `rustc-version` file and install the latest rustc, you can run:
-```
-./rustup-toolchain HEAD
-```
-
-Now edit Miri until `./miri test` passes, and submit a PR. Generally, it is
-preferred to separate updating `rustc-version` and doing what it takes to get
-Miri working again, from implementing new features that rely on the updated
-rustc. This avoids blocking all Miri development on landing a big PR.
-
-### Building Miri with a locally built rustc
-
-[building Miri with a locally built rustc]: #building-miri-with-a-locally-built-rustc
-
-A big part of the Miri driver lives in rustc, so working on Miri will sometimes
-require using a locally built rustc. The bug you want to fix may actually be on
-the rustc side, or you just need to get more detailed trace of the execution
-than what is possible with release builds -- in both cases, you should develop
-Miri against a rustc you compiled yourself, with debug assertions (and hence
-tracing) enabled.
-
-The setup for a local rustc works as follows:
-```sh
-# Clone the rust-lang/rust repo.
-git clone https://github.com/rust-lang/rust rustc
-cd rustc
-# Create a config.toml with defaults for working on Miri.
-./x.py setup compiler
- # Now edit `config.toml` and under `[rust]` set `debug-assertions = true`.
-
-# Build a stage 2 rustc, and build the rustc libraries with that rustc.
-# This step can take 30 minutes or more.
-./x.py build --stage 2 compiler/rustc
-# If you change something, you can get a faster rebuild by doing
-./x.py build --keep-stage 0 --stage 2 compiler/rustc
-# You may have to change the architecture in the next command
-rustup toolchain link stage2 build/x86_64-unknown-linux-gnu/stage2
-# Now cd to your Miri directory, then configure rustup
-rustup override set stage2
-```
-
-Note: When you are working with a locally built rustc or any other toolchain that
-is not the same as the one in `rust-version`, you should not have `.auto-everything` or
-`.auto-toolchain` as that will keep resetting your toolchain.
-
-```
-rm -f .auto-everything .auto-toolchain
-```
-
-Important: You need to delete the Miri cache when you change the stdlib; otherwise the
-old, chached version will be used. On Linux, the cache is located at `~/.cache/miri`,
-and on Windows, it is located at `%LOCALAPPDATA%\rust-lang\miri\cache`; the exact
-location is printed after the library build: "A libstd for Miri is now available in ...".
-
-Note: `./x.py --stage 2 compiler/rustc` currently errors with `thread 'main'
-panicked at 'fs::read(stamp) failed with No such file or directory (os error 2)`,
-you can simply ignore that error; Miri will build anyway.
-
-For more information about building and configuring a local compiler,
-see <https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html>.
-
-With this, you should now have a working development setup! See
-[above](#building-and-testing-miri) for how to proceed working on Miri.
+[Contributing to Rust]: https://rustc-dev-guide.rust-lang.org/contributing.html#contributing-to-rust
+[rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org/
+[std-dev-guide]: https://std-dev-guide.rust-lang.org/
+[contributing-bug-reports]: https://rustc-dev-guide.rust-lang.org/contributing.html#bug-reports
+[issue template]: https://github.com/rust-lang/rust/issues/new/choose
+[internals]: https://internals.rust-lang.org
+[rust-discord]: http://discord.gg/rust-lang
+[rust-zulip]: https://rust-lang.zulipchat.com
projects / rust.git / blobdiff