-# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/api/projects/status/github/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) [](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).
+[Contributing.md](Contributing.md) and our [Code of
+Conduct](CODE_OF_CONDUCT.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
to be a bit out of date). Version 0.1 of rustfmt-nightly is forked from version
0.9 of the syntex branch.
+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 use `rustfmt` on 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:
cargo fmt
```
-## Installation
-```
-cargo install rustfmt-nightly
-```
+## Limitations
-or if you're using [Rustup](https://www.rustup.rs/)
+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.
-```
-rustup update
-rustup run nightly cargo install rustfmt-nightly
-```
+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):
-If you don't have a nightly toolchain, you can add it using rustup:
+* 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).
-```
-rustup install nightly
-```
-You can make the nightly toolchain the default by running:
+## Installation
```
-rustup default nightly
+rustup component add rustfmt-preview
```
-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-nightly
-```
## Installing from source
To install from source, first checkout to the tag or branch you want to install, then issue
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`.
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:
+A minimal Travis setup could look like this (requires Rust 1.24.0 or greater):
```yaml
language: rust
-cache: cargo
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 -- --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
`cargo build` to build.
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
```
* 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.
+ 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
* 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):
+
+ ```
+ 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
projects / rust.git / blobdiff