X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=README.md;h=04f9f2f928c8de6ed1fc9743b41e90303bdede6e;hb=693c7d69f94b6c1e41c4411bb27442290d7d6916;hp=4942c537437f70cc86d8210d719d4c69c962d609;hpb=9754bcb535fa84c000fe78cb91b30c3f661fc849;p=rust.git diff --git a/README.md b/README.md index 4942c537437..04f9f2f928c 100644 --- a/README.md +++ b/README.md @@ -1,32 +1,24 @@ -# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt) [![crates.io](https://img.shields.io/crates/v/rustfmt-nightly.svg)](https://crates.io/crates/rustfmt-nightly) +# rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt) [![Build Status](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt?svg=true)](https://ci.appveyor.com/project/nrc/rustfmt) [![crates.io](https://img.shields.io/crates/v/rustfmt-nightly.svg)](https://crates.io/crates/rustfmt-nightly) [![Travis Configuration Status](https://img.shields.io/travis/davidalber/rustfmt-travis.svg?label=travis%20example)](https://travis-ci.org/davidalber/rustfmt-travis) A tool for formatting Rust code according to style guidelines. If you'd like to help out (and you should, it's a fun project!), see -[Contributing.md](Contributing.md). - -We are changing the default style used by rustfmt. There is an ongoing [RFC -process][fmt rfcs]. The last version using the old style was 0.8.6. From 0.9 -onwards, the RFC style is the default. If you want the old style back, you can -use [legacy-rustfmt.toml](legacy-rustfmt.toml) as your rustfmt.toml. - -The current `master` branch uses libsyntax (part of the compiler). It is -published as `rustfmt-nightly`. The `syntex` branch uses Syntex instead of -libsyntax, it is published (for now) as `rustfmt`. Most development happens on -the `master` branch, however, this only supports nightly toolchains. If you use -stable or beta Rust toolchains, you must use the Syntex version (which is likely -to be a bit out of date). Version 0.1 of rustfmt-nightly is forked from version -0.9 of the syntex branch. +[Contributing.md](Contributing.md) and our [Code of +Conduct](CODE_OF_CONDUCT.md). +You can use rustfmt in Travis CI builds. We provide a minimal Travis CI +configuration (see [here](#checking-style-on-a-ci-server)) and verify its status +using another repository. The status of that repository's build is reported by +the "travis example" badge above. ## Quick start -You must be using the latest nightly compiler toolchain. +You can run `rustfmt` with Rust 1.24 and above. To install: ``` -cargo install rustfmt-nightly +rustup component add rustfmt-preview ``` to run on a cargo project in the current working directory: @@ -35,45 +27,62 @@ to run on a cargo project in the current working directory: cargo fmt ``` -## Installation - +For the latest and greatest `rustfmt` (nightly required): ``` -cargo install rustfmt-nightly +rustup component add rustfmt-preview --toolchain nightly ``` - -or if you're using [Rustup](https://www.rustup.rs/) - +To run: ``` -rustup update -rustup run nightly cargo install rustfmt-nightly +cargo +nightly fmt ``` -If you don't have a nightly toolchain, you can add it using rustup: +To format code that requires edition 2018, create a `rustfmt.toml` [configuration](#configuring-rustfmt) file containing: -``` -rustup install nightly +```toml +edition = "Edition2018" ``` -You can make the nightly toolchain the default by running: +## Limitations -``` -rustup default nightly -``` +Rustfmt tries to work on as much Rust code as possible, sometimes, the code +doesn't even need to compile! As we approach a 1.0 release we are also looking +to limit areas of instability; in particular, post-1.0, the formatting of most +code should not change as Rustfmt improves. However, there are some things that +Rustfmt can't do or can't do well (and thus where formatting might change +significantly, even post-1.0). We would like to reduce the list of limitations +over time. -If you choose not to do that you'll have to run rustfmt using `rustup run ...` -or by adding `+nightly` to the cargo invocation. +The following list enumerates areas where Rustfmt does not work or where the +stability guarantees do not apply (we don't make a distinction between the two +because in the future Rustfmt might work on code where it currently does not): -Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is -installed alongside rustfmt. To only install rustfmt run +* a program where any part of the program does not parse (parsing is an early + stage of compilation and in Rust includes macro expansion). +* Macro declarations and uses (current status: some macro declarations and uses + are formatted). +* Comments, including any AST node with a comment 'inside' (Rustfmt does not + currently attempt to format comments, it does format code with comments inside, but that formatting may change in the future). +* Rust code in code blocks in comments. +* Any fragment of a program (i.e., stability guarantees only apply to whole + programs, even where fragments of a program can be formatted today). +* Code containing non-ascii unicode characters (we believe Rustfmt mostly works + here, but do not have the test coverage or experience to be 100% sure). +* Bugs in Rustfmt (like any software, Rustfmt has bugs, we do not consider bug + fixes to break our stability guarantees). + + +## Installation ``` -cargo install --no-default-features rustfmt-nightly +rustup component add rustfmt-preview ``` + ## Installing from source -To install from source, first checkout to the tag or branch you want to install, then issue +To install from source (nightly required), first checkout to the tag or branch you want to install, then issue + ``` -cargo install --path . +cargo install --path . ``` This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to @@ -89,51 +98,14 @@ just need to run on the root file (usually mod.rs or lib.rs). Rustfmt can also read data from stdin. Alternatively, you can use `cargo fmt` to format all binary and library targets of your crate. -You'll probably want to specify the write mode. Currently, there are modes for -`diff`, `replace`, `overwrite`, `display`, `coverage`, `checkstyle`, and `plain`. +You can run `rustfmt --help` for information about argument. -* `overwrite` Is the default and overwrites the original files _without_ creating backups. -* `replace` Overwrites the original files after creating backups of the files. -* `display` Will print the formatted files to stdout. -* `plain` Also writes to stdout, but with no metadata. -* `diff` Will print a diff between the original files and formatted files to stdout. - Will also exit with an error code if there are any differences. -* `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file, - that can be used by tools like Jenkins. +When running with `--check`, Rustfmt will exit with `0` if Rustfmt would not +make any formatting changes to the input, and `1` if Rustfmt would make changes. +In other modes, Rustfmt will exit with `1` if there was some error during +formatting (for example a parsing or internal error) and `0` if formatting +completed without error (whether or not changes were made). -The write mode can be set by passing the `--write-mode` flag on -the command line. For example `rustfmt --write-mode=display src/filename.rs` - -`cargo fmt` uses `--write-mode=overwrite` by default. - -If you want to restrict reformatting to specific sets of lines, you can -use the `--file-lines` option. Its argument is a JSON array of objects -with `file` and `range` properties, where `file` is a file name, and -`range` is an array representing a range of lines like `[7,13]`. Ranges -are 1-based and inclusive of both end points. Specifying an empty array -will result in no files being formatted. For example, - -``` -rustfmt --file-lines '[ - {"file":"src/lib.rs","range":[7,13]}, - {"file":"src/lib.rs","range":[21,29]}, - {"file":"src/foo.rs","range":[10,11]}, - {"file":"src/foo.rs","range":[15,15]}]' -``` - -would format lines `7-13` and `21-29` of `src/lib.rs`, and lines `10-11`, -and `15` of `src/foo.rs`. No other files would be formatted, even if they -are included as out of line modules from `src/lib.rs`. - -If `rustfmt` successfully reformatted the code it will exit with `0` exit -status. Exit status `1` signals some unexpected error, like an unknown option or -a failure to read a file. Exit status `2` is returned if there are syntax errors -in the input files. `rustfmt` can't format syntatically invalid code. Finally, -exit status `3` is returned if there are some issues which can't be resolved -automatically. For example, if you have a very long comment line `rustfmt` -doesn't split it. Instead it prints a warning and exits with `3`. - -You can run `rustfmt --help` for more information. ## Running Rustfmt from your editor @@ -144,32 +116,31 @@ You can run `rustfmt --help` for more information. * [Atom](atom.md) * Visual Studio Code using [vscode-rust](https://github.com/editor-rs/vscode-rust), [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt) or [rls_vscode](https://github.com/jonathandturner/rls_vscode) through RLS. + ## Checking style on a CI server To keep your code base consistently formatted, it can be helpful to fail the CI build -when a pull request contains unformatted code. Using `--write-mode=diff` instructs +when a pull request contains unformatted code. Using `--check` instructs rustfmt to exit with an error code if the input is not formatted correctly. -It will also print any found differences. +It will also print any found differences. (Older versions of Rustfmt don't +support `--check`, use `--write-mode diff`). -(These instructions use the Syntex version of Rustfmt. If you want to use the -nightly version replace `install rustfmt` with `install rustfmt-nightly`, -however you must then only run this with the nightly toolchain). - -A minimal Travis setup could look like this: +A minimal Travis setup could look like this (requires Rust 1.24.0 or greater): ```yaml language: rust -cache: cargo +rust: +- nightly before_script: -- export PATH="$PATH:$HOME/.cargo/bin" -- which rustfmt || cargo install rustfmt +- rustup component add rustfmt-preview script: -- cargo fmt -- --write-mode=diff +- cargo fmt --all -- --check - cargo build - cargo test ``` -Note that using `cache: cargo` is optional but highly recommended to speed up the installation. +See [this blog post](https://medium.com/@ag_dubs/enforcing-style-in-ci-for-rust-projects-18f6b09ec69d) +for more info. ## How to build and test @@ -186,16 +157,16 @@ notes above on running rustfmt. Rustfmt is designed to be very configurable. You can create a TOML file called `rustfmt.toml` or `.rustfmt.toml`, place it in the project or any other parent directory and it will apply the options in that file. See `rustfmt ---config-help` for the options which are available, or if you prefer to see +--help=config` for the options which are available, or if you prefer to see visual style previews, [Configurations.md](Configurations.md). By default, Rustfmt uses a style which conforms to the [Rust style guide][style -guide]. For details that have not yet been formalized through the [style RFC -process][fmt rfcs], we try to adhere to a style similar to that used in the -[Rust repo][rust]. +guide] that has been formalized through the [style RFC +process][fmt rfcs]. -If there are styling choices you don't agree with, we are usually happy to add -options covering different styles. File an issue, or even better, submit a PR. +Configuration options are either stable or unstable. Stable options can always +be used, while unstable ones are only available on a nightly toolchain, and opt-in. +See [Configurations.md](Configurations.md) for details. ## Tips @@ -203,13 +174,13 @@ options covering different styles. File an issue, or even better, submit a PR. * For things you do not want rustfmt to mangle, use one of ```rust - #[rustfmt_skip] // requires nightly and #![feature(custom_attribute)] in crate root + #[rustfmt::skip] // requires nightly Rust and #![feature(tool_attributes)] in crate root #[cfg_attr(rustfmt, rustfmt_skip)] // works in stable ``` * When you run rustfmt, place a file named `rustfmt.toml` or `.rustfmt.toml` in target file directory or its parents to override the default settings of rustfmt. You can generate a file containing the default configuration with - `rustfm --dump-default-config rustfmt.toml` and customize as needed. + `rustfmt --print-config default rustfmt.toml` and customize as needed. * After successful compilation, a `rustfmt` executable can be found in the target directory. * If you're having issues compiling Rustfmt (or compile errors when trying to @@ -218,25 +189,42 @@ options covering different styles. File an issue, or even better, submit a PR. * If you get an error like `error while loading shared libraries` while starting up rustfmt you should try the following: -On Linux: + On Linux: -``` -export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH -``` + ``` + export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH + ``` -On MacOS: + On MacOS: -``` -export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$DYLD_LIBRARY_PATH -``` + ``` + export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$DYLD_LIBRARY_PATH + ``` -On Windows (Git Bash/Mingw): + On Windows (Git Bash/Mingw): -``` -export PATH=$(rustc --print sysroot)/lib/rustlib/x86_64-pc-windows-gnu/lib/:$PATH -``` + ``` + export PATH=$(rustc --print sysroot)/lib/rustlib/x86_64-pc-windows-gnu/lib/:$PATH + ``` + + (Substitute `x86_64` by `i686` and `gnu` by `msvc` depending on which version of rustc was used to install rustfmt). + +* You can change the way rustfmt emits the changes with the --emit flag: + + Example: + + ``` + cargo fmt --emit files + ``` + + Options: -(Substitute `x86_64` by `i686` and `gnu` by `msvc` depending on which version of rustc was used to install rustfmt). + | Flag |Description| Nightly Only | + |:---:|:---:|:---:| + | files | overwrites output to files | No | + | stdout | writes output to stdout | No | + | coverage | displays how much of the input file was processed | Yes | + | checkstyle | emits in a checkstyle format | Yes | ## License