1246d4067f
Many of the core rust libraries have places that rely on integer wrapping behaviour. These places have been altered to use the wrapping_* methods: * core:#️⃣:sip - A number of macros * core::str - The `maximal_suffix` method in `TwoWaySearcher` * rustc::util::nodemap - Implementation of FnvHash * rustc_back::sha2 - A number of macros and other places * rand::isaac - Isaac64Rng, changed to use the Wrapping helper type Some places had "benign" underflow. This is when underflow or overflow occurs, but the unspecified value is not used due to other conditions. * collections::bit::Bitv - underflow when `self.nbits` is zero. * collections:#️⃣:{map,table} - Underflow when searching an empty table. Did cause undefined behaviour in this case due to an out-of-bounds ptr::offset based on the underflowed index. However the resulting pointers would never be read from. * syntax::ext::deriving::encodable - Underflow when calculating the index of the last field in a variant with no fields. These cases were altered to avoid the underflow, often by moving the underflowing operation to a place where underflow could not happen. There was one case that relied on the fact that unsigned arithmetic and two's complement arithmetic are identical with wrapping semantics. This was changed to use the wrapping_* methods. Finally, the calculation of variant discriminants could overflow if the preceeding discriminant was `U64_MAX`. The logic in `rustc::middle::ty` for this was altered to avoid the overflow completely, while the remaining places were changed to use wrapping methods. This is because `rustc::middle::ty::enum_variants` now throws an error when the calculated discriminant value overflows a `u64`. This behaviour can be triggered by the following code: ``` enum Foo { A = U64_MAX, B } ``` This commit also implements the remaining integer operators for Wrapped<T>.
The Rust Programming Language
This is a compiler for Rust, including standard libraries, tools and documentation. Rust is a systems programming language that is fast, memory safe and multithreaded, but does not employ a garbage collector or otherwise impose significant runtime overhead.
Quick Start
Read "Installing Rust" from The Book.
Building from Source
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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
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Clone the source with
git:$ git clone https://github.com/rust-lang/rust.git $ cd rust
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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:
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Grab the latest MSYS2 installer and go through the installer.
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From the MSYS2 terminal, install the
mingw64toolchain and other required tools.# Choose one based on platform: $ pacman -S mingw-w64-i686-toolchain $ pacman -S mingw-w64-x86_64-toolchain $ pacman -S base-devel -
Run
mingw32_shell.batormingw64_shell.batfrom wherever you installed MYSY2 (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
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:
- Windows (7, 8, Server 2008 R2), x86 and x86-64 (64-bit support added in Rust 0.12.0)
- Linux (2.6.18 or later, various distributions), x86 and x86-64
- OSX 10.7 (Lion) or greater, x86 and x86-64
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.md.
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.