X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=README.md;h=f811123f72a128cdc250ecdf7a34fe844f1e7b22;hb=faac1019840fd2b413a78c96d3bbd806d5d5ef91;hp=69f4d800dfc841a77d3cf8e95e70ff0fdb3280e1;hpb=7293a8b1223406f6cd607f1760fdfa9a0430fbd9;p=rust.git diff --git a/README.md b/README.md index 69f4d800dfc..f811123f72a 100644 --- a/README.md +++ b/README.md @@ -3,30 +3,17 @@ 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 If you use -stable or beta Rust toolchains, you must use the Syntex version (which is likely -to be a bit out of date).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 can use `rustfmt` on Rust 1.24 and above. +You can run `rustfmt` with Rust 1.24 and above. To install: @@ -40,6 +27,44 @@ to run on a cargo project in the current working directory: cargo fmt ``` +For the latest and greatest `rustfmt` (nightly required): +``` +rustup component add rustfmt-preview --toolchain nightly +``` +To run: +``` +cargo +nightly fmt +``` + +## Limitations + +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. + +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): + +* 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 ``` @@ -48,9 +73,10 @@ 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 @@ -66,51 +92,14 @@ 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`. - -* `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. - -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. +You can run `rustfmt --help` for information about argument. -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, +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). -``` -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 syntactically 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 @@ -120,28 +109,32 @@ You can run `rustfmt --help` for more information. * [Sublime Text 3](https://packagecontrol.io/packages/RustFmt) * [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. +* [IntelliJ or CLion](intellij.md) + ## 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`). -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 before_script: -- rustup toolchain install nightly -- rustup component add --toolchain nightly rustfmt-preview -- which rustfmt || cargo install --force rustfmt-nightly +- rustup component add rustfmt-preview script: -- cargo +nightly fmt --all -- --write-mode=diff +- cargo fmt --all -- --check - cargo build - cargo test ``` +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 `cargo build` to build. @@ -157,7 +150,7 @@ 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 @@ -174,40 +167,34 @@ See [Configurations.md](Configurations.md) for details. * 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 - `rustfmt --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 install), make sure you have the most recent version of Rust installed. -* If you get an error like `error while loading shared libraries` while starting - up rustfmt you should try the following: +* You can change the way rustfmt emits the changes with the --emit flag: - On Linux: + Example: ``` - export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH + cargo fmt -- --emit files ``` - On MacOS: - - ``` - export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$DYLD_LIBRARY_PATH - ``` - - On Windows (Git Bash/Mingw): - - ``` - export PATH=$(rustc --print sysroot)/lib/rustlib/x86_64-pc-windows-gnu/lib/:$PATH - ``` + 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