-# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt)
+# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/project/nrc/rustfmt) [](https://crates.io/crates/rustfmt-nightly)
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+to be a bit out of date).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.
+
+
## Quick start
+You must be using the latest nightly compiler toolchain.
+
To install:
```
-cargo install rustfmt
+cargo install rustfmt-nightly
```
to run on a cargo project in the current working directory:
## Installation
-> **Note:** this method currently requires you to be running cargo 0.6.0 or
-> newer.
+```
+cargo install rustfmt-nightly
+```
+
+or if you're using [Rustup](https://www.rustup.rs/)
+
+```
+rustup update
+rustup run nightly cargo install rustfmt-nightly
+```
+
+If you don't have a nightly toolchain, you can add it using rustup:
```
-cargo install rustfmt
+rustup install nightly
```
-or if you're using [`multirust`](https://github.com/brson/multirust)
+You can make the nightly toolchain the default by running:
```
-multirust run nightly cargo install rustfmt
+rustup default nightly
```
+If you choose not to do that you'll have to run rustfmt using `rustup run ...`
+or by adding `+nightly` to the cargo invocation.
+
Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is
installed alongside rustfmt. To only install rustfmt run
```
-cargo install --no-default-features rustfmt
+cargo install --no-default-features rustfmt-nightly
```
## Installing from source
```
cargo install --path .
```
-This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/cargo/bin` directory to
+
+This will install `rustfmt` in your `~/.cargo/bin`. Make sure to add `~/.cargo/bin` directory to
your PATH variable.
+
## Running
You can run Rustfmt by just typing `rustfmt filename` if you used `cargo
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, and checkstyle.
+`diff`, `replace`, `overwrite`, `display`, `coverage`, `checkstyle`, and `plain`.
-* `replace` Is the default and overwrites the original files after creating backups of the files.
-* `overwrite` Overwrites the original files _without_ creating backups.
+* `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=replace` by default.
+`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,
+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`.
## Running Rustfmt from your editor
-* [Vim](http://johannh.me/blog/rustfmt-vim.html)
-* [Emacs](https://github.com/fbergroth/emacs-rustfmt)
-* [Sublime Text 3](https://packagecontrol.io/packages/BeautifyRust)
+* [Vim](https://github.com/rust-lang/rust.vim#formatting-with-rustfmt)
+* [Emacs](https://github.com/rust-lang/rust-mode)
+* [Sublime Text 3](https://packagecontrol.io/packages/RustFmt)
* [Atom](atom.md)
-* Visual Studio Code using [RustyCode](https://github.com/saviorisdead/RustyCode) or [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt)
+* 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
+rustfmt to exit with an error code if the input is not formatted correctly.
+It will also print any found differences.
+
+(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:
+
+```yaml
+language: rust
+cache: cargo
+before_script:
+- export PATH="$PATH:$HOME/.cargo/bin"
+- which rustfmt || cargo install rustfmt-nightly
+script:
+- cargo fmt -- --write-mode=diff
+- cargo build
+- cargo test
+```
+
+Note that using `cache: cargo` is optional but highly recommended to speed up the installation.
## How to build and test
## Configuring Rustfmt
Rustfmt is designed to be very configurable. You can create a TOML file called
-rustfmt.toml, place it in the project 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 source code, [src/config.rs](src/config.rs).
+`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
+visual style previews, [Configurations.md](Configurations.md).
-By default, Rustfmt uses a style which (mostly) conforms to the
-[Rust style guidelines](https://github.com/rust-lang/rust/tree/master/src/doc/style).
-There are many details which the style guidelines do not cover, and in these
-cases we try to adhere to a style similar to that used in the
-[Rust repo](https://github.com/rust-lang/rust). Once Rustfmt is more complete, and
-able to re-format large repositories like Rust, we intend to go through the Rust
-RFC process to nail down the default style in detail.
+By default, Rustfmt uses a style which conforms to the [Rust style guide][style
+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
#[rustfmt_skip] // requires nightly and #![feature(custom_attribute)] in crate root
#[cfg_attr(rustfmt, rustfmt_skip)] // works in stable
```
-* When you run rustfmt, place a file named rustfmt.toml in target file
- directory or its parents to override the default settings of rustfmt.
+* 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.
* 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:
+
+On Linux:
+
+```
+export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
+```
+
+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
+```
+
+(Substitute `x86_64` by `i686` and `gnu` by `msvc` depending on which version of rustc was used to install rustfmt).
## License
Apache License (Version 2.0).
See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.
+
+[rust]: https://github.com/rust-lang/rust
+[fmt rfcs]: https://github.com/rust-lang-nursery/fmt-rfcs
+[style guide]: https://github.com/rust-lang-nursery/fmt-rfcs/blob/master/guide/guide.md
projects / rust.git / blobdiff