77ed39cfe3
See https://github.com/rust-lang/rfcs/pull/16 and https://github.com/rust-lang/rust/issues/15701 - Added syntax support for attributes on expressions and all syntax nodes in statement position. - Extended `#[cfg]` folder to allow removal of statements, and of expressions in optional positions like expression lists and trailing block expressions. - Extended lint checker to recognize lint levels on expressions and locals. - As per RFC, attributes are not yet accepted on `if` expressions. Examples: ```rust let x = y; { ... } assert_eq!((1, #[cfg(unset)] 2, 3), (1, 3)); let FOO = 0; ``` Implementation wise, there are a few rough corners and open questions: - The parser work ended up a bit ugly. - The pretty printer change was based mostly on guessing. - Similar to the `if` case, there are some places in the grammar where a new `Expr` node starts, but where it seemed weird to accept attributes and hence the parser doesn't. This includes: - const expressions in patterns - in the middle of an postfix operator chain (that is, after `.`, before indexing, before calls) - on range expressions, since `#[attr] x .. y` parses as `(#[attr] x) .. y`, which is inconsistent with `#[attr] .. y` which would parse as `#[attr] (.. y)` - Attributes are added as additional `Option<Box<Vec<Attribute>>>` fields in expressions and locals. - Memory impact has not been measured yet. - A cfg-away trailing expression in a block does not currently promote the previous `StmtExpr` in a block to a new trailing expr. That is to say, this won't work: ```rust let x = { #[cfg(foo)] Foo { data: x } #[cfg(not(foo))] Foo { data: y } }; ``` - One-element tuples can have their inner expression removed to become Unit, but just Parenthesis can't. Eg, `(#[cfg(unset)] x,) == ()` but `(#[cfg(unset)] x) == error`. This seemed reasonable to me since tuples and unit are type constructors, but could probably be argued either way. - Attributes on macro nodes are currently unconditionally dropped during macro expansion, which seemed fine since macro disappear at that point? - Attributes on `ast::ExprParens` will be prepend-ed to the inner expression in the hir folder. - The work on pretty printer tests for this did trigger, but not fix errors regarding macros: - expression `foo![]` prints as `foo!()` - expression `foo!{}` prints as `foo!()` - statement `foo![];` prints as `foo!();` - statement `foo!{};` prints as `foo!();` - statement `foo!{}` triggers a `None` unwrap ICE.
The Rust Programming Language
This is the main source code repository for Rust. It contains the compiler, standard library, and documentation.
Quick Start
Read "Installing Rust" from The Book.
Building from Source
-
Make sure you have installed the dependencies:
g++4.7 orclang++3.xpython2.6 or later (but not 3.x)- GNU
make3.81 or later curlgit
-
Clone the source with
git:$ git clone https://github.com/rust-lang/rust.git $ cd rust
-
Build and install:
$ ./configure $ make && make installNote: You may need to use
sudo make installif you do not normally have permission to modify the destination directory. The install locations can be adjusted by passing a--prefixargument toconfigure. Various other options are also supported – pass--helpfor more information on them.When complete,
make installwill place several programs into/usr/local/bin:rustc, the Rust compiler, andrustdoc, the API-documentation tool. This install does not include Cargo, Rust's package manager, which you may also want to build.
Building on Windows
MSYS2 can be used to easily build Rust on Windows:
-
Grab the latest MSYS2 installer and go through the installer.
-
From the MSYS2 terminal, install the
mingw64toolchain and other required tools.# Update package mirrors (may be needed if you have a fresh install of MSYS2) $ pacman -Sy pacman-mirrors # Choose one based on platform: # *** see the note below *** $ pacman -S mingw-w64-i686-toolchain $ pacman -S mingw-w64-x86_64-toolchain # Make git available in MSYS2 (if not already available on path) $ pacman -S git $ pacman -S base-devel -
Run
mingw32_shell.batormingw64_shell.batfrom wherever you installed MSYS2 (i.e.C:\msys), depending on whether you want 32-bit or 64-bit Rust. -
Navigate to Rust's source code, configure and build it:
$ ./configure $ make && make install
Note: gcc versions >= 5 currently have issues building LLVM on Windows resulting in a segmentation fault when building Rust. In order to avoid this it may be necessary to obtain an earlier version of gcc such as 4.9.x.
Msys'spacmanwill install the latest version, so for the time being it is recommended to skip gcc toolchain installation step above and use Mingw-Builds project's installer instead. Be sure to add gccbindirectory to the path before runningconfigure.
For more information on this see issue #28260.
Building Documentation
If you’d like to build the documentation, it’s almost the same:
./configure
$ make docs
Building the documentation requires building the compiler, so the above details will apply. Once you have the compiler built, you can
$ make docs NO_REBUILD=1
To make sure you don’t re-build the compiler because you made a change to some documentation.
The generated documentation will appear in a top-level doc directory,
created by the make rule.
Notes
Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier state of development). As such, source builds require a connection to the Internet, to fetch snapshots, and an OS that can execute the available snapshot binaries.
Snapshot binaries are currently built and tested on several platforms:
| Platform \ Architecture | x86 | x86_64 |
|---|---|---|
| Windows (7, 8, Server 2008 R2) | ✓ | ✓ |
| Linux (2.6.18 or later) | ✓ | ✓ |
| OSX (10.7 Lion or later) | ✓ | ✓ |
You may find that other platforms work, but these are our officially supported build environments that are most likely to work.
Rust currently needs about 1.5 GiB of RAM to build without swapping; if it hits swap, it will take a very long time to build.
There is more advice about hacking on Rust in CONTRIBUTING.md.
Getting Help
The Rust community congregates in a few places:
- Stack Overflow - Direct questions about using the language.
- users.rust-lang.org - General discussion and broader questions.
- /r/rust - News and general discussion.
Contributing
To contribute to Rust, please see CONTRIBUTING.
Rust has an IRC culture and most real-time collaboration happens in a variety of channels on Mozilla's IRC network, irc.mozilla.org. The most popular channel is #rust, a venue for general discussion about Rust, and a good place to ask for help.
License
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-MIT, and COPYRIGHT for details.