X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=README.md;h=27e7145c5a99e4afadff029b4685473f0423ac5f;hb=3fa692c8b22cfcd4d13e0568056b680235d0cef0;hp=f74de7de42b8b0d20d5c59b2d71cace4f776c7e6;hpb=7600535511a0b8c76bf28f40e1b5c4a45a57b28f;p=rust.git diff --git a/README.md b/README.md index f74de7de42b..27e7145c5a9 100644 --- a/README.md +++ b/README.md @@ -1,257 +1,287 @@ -# Clippy +# The Rust Programming Language -[![Clippy Test](https://github.com/rust-lang/rust-clippy/workflows/Clippy%20Test%20(bors)/badge.svg?branch=auto&event=push)](https://github.com/rust-lang/rust-clippy/actions?query=workflow%3A%22Clippy+Test+(bors)%22+event%3Apush+branch%3Aauto) -[![License: MIT OR Apache-2.0](https://img.shields.io/crates/l/clippy.svg)](#license) +This is the main source code repository for [Rust]. It contains the compiler, +standard library, and documentation. -A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code. +[Rust]: https://www.rust-lang.org -[There are over 550 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html) +**Note: this README is for _users_ rather than _contributors_. +If you wish to _contribute_ to the compiler, you should read the +[Getting Started][gettingstarted] section of the rustc-dev-guide instead. +You can ask for help in the [#new members Zulip stream][new-members].** -Lints are divided into categories, each with a default [lint level](https://doc.rust-lang.org/rustc/lints/levels.html). -You can choose how much Clippy is supposed to ~~annoy~~ help you by changing the lint level by category. +[new-members]: https://rust-lang.zulipchat.com/#narrow/stream/122652-new-members -| Category | Description | Default level | -| --------------------- | ----------------------------------------------------------------------------------- | ------------- | -| `clippy::all` | all lints that are on by default (correctness, suspicious, style, complexity, perf) | **warn/deny** | -| `clippy::correctness` | code that is outright wrong or useless | **deny** | -| `clippy::suspicious` | code that is most likely wrong or useless | **warn** | -| `clippy::style` | code that should be written in a more idiomatic way | **warn** | -| `clippy::complexity` | code that does something simple but in a complex way | **warn** | -| `clippy::perf` | code that can be written to run faster | **warn** | -| `clippy::pedantic` | lints which are rather strict or have occasional false positives | allow | -| `clippy::nursery` | new lints that are still under development | allow | -| `clippy::cargo` | lints for the cargo manifest | allow | +## Quick Start -More to come, please [file an issue](https://github.com/rust-lang/rust-clippy/issues) if you have ideas! +Read ["Installation"] from [The Book]. -The [lint list](https://rust-lang.github.io/rust-clippy/master/index.html) also contains "restriction lints", which are -for things which are usually not considered "bad", but may be useful to turn on in specific cases. These should be used -very selectively, if at all. +["Installation"]: https://doc.rust-lang.org/book/ch01-01-installation.html +[The Book]: https://doc.rust-lang.org/book/index.html -Table of contents: +## Installing from Source -* [Usage instructions](#usage) -* [Configuration](#configuration) -* [Contributing](#contributing) -* [License](#license) +The Rust build system uses a Python script called `x.py` to build the compiler, +which manages the bootstrapping process. It lives at the root of the project. -## Usage +The `x.py` command can be run directly on most systems in the following format: -Below are instructions on how to use Clippy as a cargo subcommand, -in projects that do not use cargo, or in Travis CI. +```sh +./x.py [flags] +``` -### As a cargo subcommand (`cargo clippy`) +This is how the documentation and examples assume you are running `x.py`. -One way to use Clippy is by installing Clippy through rustup as a cargo -subcommand. +Systems such as Ubuntu 20.04 LTS do not create the necessary `python` command by default when Python is installed that allows `x.py` to be run directly. In that case, you can either create a symlink for `python` (Ubuntu provides the `python-is-python3` package for this), or run `x.py` using Python itself: -#### Step 1: Install Rustup +```sh +# Python 3 +python3 x.py [flags] -You can install [Rustup](https://rustup.rs/) on supported platforms. This will help -us install Clippy and its dependencies. +# Python 2.7 +python2.7 x.py [flags] +``` -If you already have Rustup installed, update to ensure you have the latest -Rustup and compiler: +More information about `x.py` can be found +by running it with the `--help` flag or reading the [rustc dev guide][rustcguidebuild]. -```terminal -rustup update -``` +[gettingstarted]: https://rustc-dev-guide.rust-lang.org/getting-started.html +[rustcguidebuild]: https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html -#### Step 2: Install Clippy +### Building on a Unix-like system +1. Make sure you have installed the dependencies: -Once you have rustup and the latest stable release (at least Rust 1.29) installed, run the following command: + * `g++` 5.1 or later or `clang++` 3.5 or later + * `python` 3 or 2.7 + * GNU `make` 3.81 or later + * `cmake` 3.13.4 or later + * `ninja` + * `curl` + * `git` + * `ssl` which comes in `libssl-dev` or `openssl-devel` + * `pkg-config` if you are compiling on Linux and targeting Linux -```terminal -rustup component add clippy -``` -If it says that it can't find the `clippy` component, please run `rustup self update`. +2. Clone the [source] with `git`: -#### Step 3: Run Clippy + ```sh + git clone https://github.com/rust-lang/rust.git + cd rust + ``` -Now you can run Clippy by invoking the following command: +[source]: https://github.com/rust-lang/rust -```terminal -cargo clippy -``` +3. Configure the build settings: -#### Automatically applying Clippy suggestions + The Rust build system uses a file named `config.toml` in the root of the + source tree to determine various configuration settings for the build. + Copy the default `config.toml.example` to `config.toml` to get started. -Clippy can automatically apply some lint suggestions, just like the compiler. + ```sh + cp config.toml.example config.toml + ``` -```terminal -cargo clippy --fix -``` + If you plan to use `x.py install` to create an installation, it is recommended + that you set the `prefix` value in the `[install]` section to a directory. -#### Workspaces + Create an install directory if you are not installing in the default directory. -All the usual workspace options should work with Clippy. For example the following command -will run Clippy on the `example` crate: +4. Build and install: -```terminal -cargo clippy -p example -``` + ```sh + ./x.py build && ./x.py install + ``` -As with `cargo check`, this includes dependencies that are members of the workspace, like path dependencies. -If you want to run Clippy **only** on the given crate, use the `--no-deps` option like this: + When complete, `./x.py install` will place several programs into + `$PREFIX/bin`: `rustc`, the Rust compiler, and `rustdoc`, the + API-documentation tool. This install does not include [Cargo], + Rust's package manager. To build and install Cargo, you may + run `./x.py install cargo` or set the `build.extended` key in + `config.toml` to `true` to build and install all tools. -```terminal -cargo clippy -p example -- --no-deps -``` +[Cargo]: https://github.com/rust-lang/cargo -### Using `clippy-driver` +### Building on Windows -Clippy can also be used in projects that do not use cargo. To do so, run `clippy-driver` -with the same arguments you use for `rustc`. For example: +There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by +Visual Studio and the GNU ABI used by the GCC toolchain. Which version of Rust +you need depends largely on what C/C++ libraries you want to interoperate with. +Use the MSVC build of Rust to interop with software produced by Visual Studio and +the GNU build to interop with GNU software built using the MinGW/MSYS2 toolchain. -```terminal -clippy-driver --edition 2018 -Cpanic=abort foo.rs -``` +#### MinGW -Note that `clippy-driver` is designed for running Clippy only and should not be used as a general -replacement for `rustc`. `clippy-driver` may produce artifacts that are not optimized as expected, -for example. - -### Travis CI - -You can add Clippy to Travis CI in the same way you use it locally: - -```yml -language: rust -rust: - - stable - - beta -before_script: - - rustup component add clippy -script: - - cargo clippy - # if you want the build job to fail when encountering warnings, use - - cargo clippy -- -D warnings - # in order to also check tests and non-default crate features, use - - cargo clippy --all-targets --all-features -- -D warnings - - cargo test - # etc. -``` +[MSYS2][msys2] can be used to easily build Rust on Windows: -Note that adding `-D warnings` will cause your build to fail if **any** warnings are found in your code. -That includes warnings found by rustc (e.g. `dead_code`, etc.). If you want to avoid this and only cause -an error for Clippy warnings, use `#![deny(clippy::all)]` in your code or `-D clippy::all` on the command -line. (You can swap `clippy::all` with the specific lint category you are targeting.) +[msys2]: https://www.msys2.org/ -## Configuration +1. Download the latest [MSYS2 installer][msys2] and go through the installer. -### Allowing/denying lints +2. Run `mingw32_shell.bat` or `mingw64_shell.bat` from the MSYS2 installation + directory (e.g. `C:\msys64`), depending on whether you want 32-bit or 64-bit + Rust. (As of the latest version of MSYS2 you have to run `msys2_shell.cmd + -mingw32` or `msys2_shell.cmd -mingw64` from the command line instead) -You can add options to your code to `allow`/`warn`/`deny` Clippy lints: +3. From this terminal, install the required tools: -* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`). - Note that `rustc` has additional [lint groups](https://doc.rust-lang.org/rustc/lints/groups.html). + ```sh + # Update package mirrors (may be needed if you have a fresh install of MSYS2) + pacman -Sy pacman-mirrors -* all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`, - `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive - lints prone to false positives. + # Install build tools needed for Rust. If you're building a 32-bit compiler, + # then replace "x86_64" below with "i686". If you've already got git, python, + # or CMake installed and in PATH you can remove them from this list. Note + # that it is important that you do **not** use the 'python2', 'cmake' and 'ninja' + # packages from the 'msys2' subsystem. The build has historically been known + # to fail with these packages. + pacman -S git \ + make \ + diffutils \ + tar \ + mingw-w64-x86_64-python \ + mingw-w64-x86_64-cmake \ + mingw-w64-x86_64-gcc \ + mingw-w64-x86_64-ninja + ``` -* only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc.) +4. Navigate to Rust's source code (or clone it), then build it: -* `allow`/`warn`/`deny` can be limited to a single function or module using `#[allow(...)]`, etc. + ```sh + ./x.py build && ./x.py install + ``` -Note: `allow` means to suppress the lint for your code. With `warn` the lint -will only emit a warning, while with `deny` the lint will emit an error, when -triggering for your code. An error causes clippy to exit with an error code, so -is useful in scripts like CI/CD. +#### MSVC -If you do not want to include your lint levels in your code, you can globally -enable/disable lints by passing extra flags to Clippy during the run: +MSVC builds of Rust additionally require an installation of Visual Studio 2017 +(or later) so `rustc` can use its linker. The simplest way is to get +[Visual Studio], check the “C++ build tools” and “Windows 10 SDK” workload. -To allow `lint_name`, run +[Visual Studio]: https://visualstudio.microsoft.com/downloads/ -```terminal -cargo clippy -- -A clippy::lint_name -``` +(If you're installing cmake yourself, be careful that “C++ CMake tools for +Windows” doesn't get included under “Individual components”.) -And to warn on `lint_name`, run +With these dependencies installed, you can build the compiler in a `cmd.exe` +shell with: -```terminal -cargo clippy -- -W clippy::lint_name +```sh +python x.py build ``` -This also works with lint groups. For example, you -can run Clippy with warnings for all lints enabled: -```terminal -cargo clippy -- -W clippy::pedantic -``` +Right now, building Rust only works with some known versions of Visual Studio. If +you have a more recent version installed and the build system doesn't understand, +you may need to force rustbuild to use an older version. This can be done +by manually calling the appropriate vcvars file before running the bootstrap. -If you care only about a single lint, you can allow all others and then explicitly warn on -the lint(s) you are interested in: -```terminal -cargo clippy -- -A clippy::all -W clippy::useless_format -W clippy::... +```batch +CALL "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat" +python x.py build ``` -### Configure the behavior of some lints +#### Specifying an ABI -Some lints can be configured in a TOML file named `clippy.toml` or `.clippy.toml`. It contains a basic `variable = -value` mapping e.g. +Each specific ABI can also be used from either environment (for example, using +the GNU ABI in PowerShell) by using an explicit build triple. The available +Windows build triples are: +- GNU ABI (using GCC) + - `i686-pc-windows-gnu` + - `x86_64-pc-windows-gnu` +- The MSVC ABI + - `i686-pc-windows-msvc` + - `x86_64-pc-windows-msvc` -```toml -avoid-breaking-exported-api = false -disallowed-names = ["toto", "tata", "titi"] -cognitive-complexity-threshold = 30 -``` +The build triple can be specified by either specifying `--build=` when +invoking `x.py` commands, or by copying the `config.toml` file (as described +in [Installing From Source](#installing-from-source)), and modifying the +`build` option under the `[build]` section. -See the [list of lints](https://rust-lang.github.io/rust-clippy/master/index.html) for more information about which -lints can be configured and the meaning of the variables. +### Configure and Make -> **Note** -> -> `clippy.toml` or `.clippy.toml` cannot be used to allow/deny lints. +While it's not the recommended build system, this project also provides a +configure script and makefile (the latter of which just invokes `x.py`). -To deactivate the “for further information visit *lint-link*” message you can -define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable. +```sh +./configure +make && sudo make install +``` -### Specifying the minimum supported Rust version +When using the configure script, the generated `config.mk` file may override the +`config.toml` file. To go back to the `config.toml` file, delete the generated +`config.mk` file. -Projects that intend to support old versions of Rust can disable lints pertaining to newer features by -specifying the minimum supported Rust version (MSRV) in the clippy configuration file. +## Building Documentation -```toml -msrv = "1.30.0" +If you’d like to build the documentation, it’s almost the same: + +```sh +./x.py doc ``` -Alternatively, the [`rust-version` field](https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field) -in the `Cargo.toml` can be used. +The generated documentation will appear under `doc` in the `build` directory for +the ABI used. I.e., if the ABI was `x86_64-pc-windows-msvc`, the directory will be +`build\x86_64-pc-windows-msvc\doc`. -```toml -# Cargo.toml -rust-version = "1.30" -``` +## Notes -The MSRV can also be specified as an inner attribute, like below. +Since the Rust compiler is written in Rust, it must be built by a +precompiled "snapshot" version of itself (made in an earlier stage of +development). As such, source builds require an Internet connection to +fetch snapshots, and an OS that can execute the available snapshot binaries. -```rust -#![feature(custom_inner_attributes)] -#![clippy::msrv = "1.30.0"] +Snapshot binaries are currently built and tested on several platforms: -fn main() { - ... -} -``` +| Platform / Architecture | x86 | x86_64 | +|---------------------------------------------|-----|--------| +| Windows (7, 8, 10, ...) | ✓ | ✓ | +| Linux (kernel 3.2, glibc 2.17 or later) | ✓ | ✓ | +| macOS (10.7 Lion or later) | (\*) | ✓ | + +(\*): Apple dropped support for running 32-bit binaries starting from macOS 10.15 and iOS 11. +Due to this decision from Apple, the targets are no longer useful to our users. +Please read [our blog post][macx32] for more info. + +[macx32]: https://blog.rust-lang.org/2020/01/03/reducing-support-for-32-bit-apple-targets.html + +You may find that other platforms work, but these are our officially +supported build environments that are most likely to work. + +## Getting Help -You can also omit the patch version when specifying the MSRV, so `msrv = 1.30` -is equivalent to `msrv = 1.30.0`. +The Rust community congregates in a few places: -Note: `custom_inner_attributes` is an unstable feature, so it has to be enabled explicitly. +* [Stack Overflow] - Direct questions about using the language. +* [users.rust-lang.org] - General discussion and broader questions. +* [/r/rust] - News and general discussion. -Lints that recognize this configuration option can be found [here](https://rust-lang.github.io/rust-clippy/master/index.html#msrv) +[Stack Overflow]: https://stackoverflow.com/questions/tagged/rust +[/r/rust]: https://reddit.com/r/rust +[users.rust-lang.org]: https://users.rust-lang.org/ ## Contributing -If you want to contribute to Clippy, you can find more information in [CONTRIBUTING.md](https://github.com/rust-lang/rust-clippy/blob/master/CONTRIBUTING.md). +If you are interested in contributing to the Rust project, please take a look +at the [Getting Started][gettingstarted] guide in the [rustc-dev-guide]. + +[rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org ## License -Copyright 2014-2022 The Rust Project Developers +Rust is primarily distributed under the terms of both the MIT license +and the Apache License (Version 2.0), with portions covered by various +BSD-like licenses. + +See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and +[COPYRIGHT](COPYRIGHT) for details. + +## Trademark + +[The Rust Foundation][rust-foundation] owns and protects the Rust and Cargo +trademarks and logos (the “Rust Trademarks”). + +If you want to use these names or brands, please read the [media guide][media-guide]. + +Third-party logos may be subject to third-party copyrights and trademarks. See +[Licenses][policies-licenses] for details. -Licensed under the Apache License, Version 2.0 or the MIT license -, at your -option. Files in the project may not be -copied, modified, or distributed except according to those terms. +[rust-foundation]: https://foundation.rust-lang.org/ +[media-guide]: https://www.rust-lang.org/policies/media-guide +[policies-licenses]: https://www.rust-lang.org/policies/licenses