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Alex Crichton 7046fea5be rustbuild: Compile rustc twice, not thrice
This commit switches the rustbuild build system to compiling the
compiler twice for a normal bootstrap rather than the historical three
times.

Rust is a bootstrapped language which means that a previous version of
the compiler is used to build the next version of the compiler. Over
time, however, we change many parts of compiler artifacts such as the
metadata format, symbol names, etc. These changes make artifacts from
one compiler incompatible from another compiler. Consequently if a
compiler wants to be able to use some artifacts then it itself must have
compiled the artifacts.

Historically the rustc build system has achieved this by compiling the
compiler three times:

* An older compiler (stage0) is downloaded to kick off the chain.
* This compiler now compiles a new compiler (stage1)
* The stage1 compiler then compiles another compiler (stage2)
* Finally, the stage2 compiler needs libraries to link against, so it
  compiles all the libraries again.

This entire process amounts in compiling the compiler three times.
Additionally, this process always guarantees that the Rust source tree
can compile itself because the stage2 compiler (created by a freshly
created compiler) would successfully compile itself again. This
property, ensuring Rust can compile itself, is quite important!

In general, though, this third compilation is not required for general
purpose development on the compiler. The third compiler (stage2) can
reuse the libraries that were created during the second compile. In
other words, the second compilation can produce both a compiler and the
libraries that compiler will use. These artifacts *must* be compatible
due to the way plugins work today anyway, and they were created by the
same source code so they *should* be compatible as well.

So given all that, this commit switches the default build process to
only compile the compiler three times, avoiding this third compilation
by copying artifacts from the previous one. Along the way a new entry in
the Travis matrix was also added to ensure that our full bootstrap can
succeed. This entry does not run tests, though, as it should not be
necessary.

To restore the old behavior of a full bootstrap (three compiles) you can
either pass:

    ./configure --enable-full-bootstrap

or if you're using config.toml:

    [build]
    full-bootstrap = true

Overall this will hopefully be an easy 33% win in build times of the
compiler. If we do 33% less work we should be 33% faster! This in turn
should affect cycle times and such on Travis and AppVeyor positively as
well as making it easier to work on the compiler itself.
2016-12-28 14:49:00 -08:00
man Update man pages 2016-08-31 15:54:34 +02:00
mk Auto merge of #38401 - redox-os:redox_cross, r=brson 2016-12-23 09:09:26 +00:00
src rustbuild: Compile rustc twice, not thrice 2016-12-28 14:49:00 -08:00
.gitattributes rustbuild: Tweak for vendored dependencies 2016-11-08 07:32:05 -08:00
.gitignore rustbuild: Tweak for vendored dependencies 2016-11-08 07:32:05 -08:00
.gitmodules Update .gitmodules 2016-02-20 20:37:30 +09:00
.mailmap Add another email address corresponding to Guillaume Gomez account 2016-02-18 11:38:59 +01:00
.travis.yml rustbuild: Compile rustc twice, not thrice 2016-12-28 14:49:00 -08:00
appveyor.yml rustbuild: Add sccache support 2016-12-14 15:40:18 -08:00
COMPILER_TESTS.md doc: fix typo 2016-03-29 19:48:46 +02:00
configure rustbuild: Compile rustc twice, not thrice 2016-12-28 14:49:00 -08:00
CONTRIBUTING.md Document --test-args for rustbuild 2016-12-14 01:31:48 +09:00
COPYRIGHT Mention initial copyright year 2016-01-28 09:44:04 +05:30
LICENSE-APACHE Update license, add license boilerplate to most files. Remainder will follow. 2012-12-03 17:12:14 -08:00
LICENSE-MIT Mention initial copyright year 2016-01-28 09:44:04 +05:30
Makefile.in Fixed the TAGS.rustc.emacs and TAGS.rustc.vi make targets. 2016-06-17 12:07:48 +02:00
README.md mk: Switch rustbuild to the default build system 2016-12-07 00:30:23 -08:00
RELEASES.md Edits. More platform support 2016-12-17 23:02:35 +00:00
x.py Handle Ctrl+C in the build script 2016-12-11 15:25:31 +00:00

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

  1. Make sure you have installed the dependencies:

    • g++ 4.7 or later or clang++ 3.x
    • python 2.7 (but not 3.x)
    • GNU make 3.81 or later
    • cmake 3.4.3 or later
    • curl
    • git
  2. Clone the source with git:

    $ git clone https://github.com/rust-lang/rust.git
    $ cd rust
    
  1. Build and install:

    $ ./configure
    $ make && sudo make install
    

    Note: Install locations can be adjusted by passing a --prefix argument to configure. Various other options are also supported pass --help for more information on them.

    When complete, sudo make install will place several programs into /usr/local/bin: rustc, the Rust compiler, and rustdoc, the API-documentation tool. This install does not include Cargo, Rust's package manager, which you may also want to build.

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:

  1. Grab the latest MSYS2 installer and go through the installer.

  2. Run mingw32_shell.bat or mingw64_shell.bat from wherever you installed MSYS2 (i.e. C:\msys64), depending on whether you want 32-bit or 64-bit Rust. (As of the latest version of MSYS2 you have to run msys2_shell.cmd -mingw32 or msys2_shell.cmd -mingw64 from the command line instead)

  3. From this terminal, install the required tools:

    # Update package mirrors (may be needed if you have a fresh install of MSYS2)
    $ pacman -Sy pacman-mirrors
    
    # Install build tools needed for Rust. If you're building a 32-bit compiler,
    # then replace "x86_64" below with "i686". If you've already got git, python,
    # or CMake installed and in PATH you can remove them from this list. Note
    # that it is important that the `python2` and `cmake` packages **not** used.
    # The build has historically been known to fail with these packages.
    $ pacman -S git \
                make \
                diffutils \
                tar \
                mingw-w64-x86_64-python2 \
                mingw-w64-x86_64-cmake \
                mingw-w64-x86_64-gcc
    
  4. Navigate to Rust's source code (or clone it), then 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” option.

With these dependencies installed, you can build the compiler in a cmd.exe shell with:

> python x.py build

If you're running inside of an msys shell, however, you can run:

$ ./configure --build=x86_64-pc-windows-msvc
$ make && make install

Currently building Rust only works with some known versions of Visual Studio. If you have a more recent version installed the build system doesn't understand then you may need to force rustbuild to use an older version. This can be done by manually calling the appropriate vcvars file before running the bootstrap.

CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\vcvars64.bat"
python x.py build

Building Documentation

If youd like to build the documentation, its almost the same:

$ ./configure
$ make docs

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.

Getting Help

The Rust community congregates in a few places:

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 would be #rust-beginners.

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.