01118928fc
typestrong const integers
~~It would be great if someone could run crater on this PR, as this has a high danger of breaking valid code~~ Crater ran. Good to go.
----
So this PR does a few things:
1. ~~const eval array values when const evaluating an array expression~~
2. ~~const eval repeat value when const evaluating a repeat expression~~
3. ~~const eval all struct and tuple fields when evaluating a struct/tuple expression~~
4. remove the `ConstVal::Int` and `ConstVal::Uint` variants and replace them with a single enum (`ConstInt`) which has variants for all integral types
* `usize`/`isize` are also enums with variants for 32 and 64 bit. At creation and various usage steps there are assertions in place checking if the target bitwidth matches with the chosen enum variant
5. enum discriminants (`ty::Disr`) are now `ConstInt`
6. trans has its own `Disr` type now (newtype around `u64`)
This obviously can't be done without breaking changes (the ones that are noticable in stable)
We could probably write lints that find those situations and error on it for a cycle or two. But then again, those situations are rare and really bugs imo anyway:
```rust
let v10 = 10 as i8;
let v4 = 4 as isize;
assert_eq!(v10 << v4 as usize, 160 as i8);
```
stops compiling because 160 is not a valid i8
```rust
struct S<T, S> {
a: T,
b: u8,
c: S
}
let s = S { a: 0xff_ff_ff_ffu32, b: 1, c: 0xaa_aa_aa_aa as i32 };
```
stops compiling because `0xaa_aa_aa_aa` is not a valid i32
----
cc @eddyb @pnkfelix
related: https://github.com/rust-lang/rfcs/issues/1071
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| configure | ||
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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.xpython2.7 (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
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Building on Windows
There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by Visual Studio, and the GNU ABI used by the GCC toolchain. Which version of Rust you need depends largely on what C/C++ libraries you want to interoperate with: for interop with software produced by Visual Studio use the MSVC build of Rust; for interop with GNU software built using the MinGW/MSYS2 toolchain use the GNU build.
MinGW
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
Download MinGW from
here, and choose the
threads=win32,exceptions=dwarf/seh flavor when installing. Also, make sure to install to a path without spaces in it. After installing,
add its bin directory to your PATH. This is due to #28260, in the future,
installing from pacman should be just fine.
# 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
MSVC
MSVC builds of Rust additionally require an installation of Visual Studio 2013
(or later) so rustc can use its linker. Make sure to check the “C++ tools”
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With these dependencies installed, the build takes two steps:
$ ./configure
$ make && make install
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
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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 between 600MiB and 1.5GiB to build, depending on platform. If it hits swap, it will take a very long time to build.
There is more advice about hacking on Rust in CONTRIBUTING.md.
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See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.