661a5ad38e
Add dropflag hints (stack-local booleans) for unfragmented paths in trans. Part of #5016. Added code to maintain these hints at runtime, and to conditionalize drop-filling and calls to destructors. In this early stage of my incremental implementation strategy, we are using hints, so we are always free to leave out a flag for a path -- then we just pass `None` as the dropflag hint in the corresponding schedule cleanup call. But, once a path has a hint, we must at least maintain it: i.e. if the hint exists, we must ensure it is never set to "moved" if the data in question might actually have been initialized. It remains sound to conservatively set the hint to "initialized" as long as the true drop-flag embedded in the value itself is up-to-date. I hope the commit series has been broken up to be readable; most of the commits in the series should build (though I did not always check this). ---- Oh, I think this technically qualifies as a: [breaking-change] because it removes drop-filling in some cases where one could previously observe it. That should only affect `unsafe` code; no safe code should be able to inspect whether the drop-fill was present or not. For an example of code that needed to change to account for this, see commit a81c24ae0216ab47df59acd724f8a33124fb6d97 (a unit test of the `move_val_init` intrinsic). I have not encountered actual code that needed to be updated to account for the change, since this should only be skipping the drop-filling on *moved* values, not on dropped one, and so even types that use `unsafe_no_drop_flag` should be unchanged by this particular PR. (Their time will come later.)
The Rust Programming Language
Rust is a fast systems programming language that guarantees memory safety and offers painless concurrency (no data races). It does not employ a garbage collector and has minimal runtime overhead.
This repo contains the code for the compiler (rustc), as well
as standard libraries, tools and documentation for Rust.
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.# 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 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
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.