README.md

   1 # The Rust Programming Language
   2
   3 This is the main source code repository for [Rust]. It contains the compiler,
   4 standard library, and documentation.
   5
   6 [Rust]: https://www.rust-lang.org
   7
   8 **Note: this README is for _users_ rather than _contributors_.
   9 If you wish to _contribute_ to the compiler, you should read the
  10 [Getting Started][gettingstarted] section of the rustc-dev-guide instead.
  11 You can ask for help in the [#new members Zulip stream][new-members].**
  12
  13 [new-members]: https://rust-lang.zulipchat.com/#narrow/stream/122652-new-members
  14
  15 ## Quick Start
  16
  17 Read ["Installation"] from [The Book].
  18
  19 ["Installation"]: https://doc.rust-lang.org/book/ch01-01-installation.html
  20 [The Book]: https://doc.rust-lang.org/book/index.html
  21
  22 ## Installing from Source
  23
  24 The Rust build system uses a Python script called `x.py` to build the compiler,
  25 which manages the bootstrapping process. It lives in the root of the project.
  26
  27 The `x.py` command can be run directly on most systems in the following format:
  28
  29 ```sh
  30 ./x.py <subcommand> [flags]
  31 ```
  32
  33 This is how the documentation and examples assume you are running `x.py`.
  34
  35 Systems such as Ubuntu 20.04 LTS do not create the necessary `python` command by default when Python is installed that allows `x.py` to be run directly. In that case you can either create a symlink for `python` (Ubuntu provides the `python-is-python3` package for this), or run `x.py` using Python itself:
  36
  37 ```sh
  38 # Python 3
  39 python3 x.py <subcommand> [flags]
  40
  41 # Python 2.7
  42 python2.7 x.py <subcommand> [flags]
  43 ```
  44
  45 More information about `x.py` can be found
  46 by running it with the `--help` flag or reading the [rustc dev guide][rustcguidebuild].
  47
  48 [gettingstarted]: https://rustc-dev-guide.rust-lang.org/getting-started.html
  49 [rustcguidebuild]: https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html
  50
  51 ### Building on a Unix-like system
  52 1. Make sure you have installed the dependencies:
  53
  54    * `g++` 5.1 or later or `clang++` 3.5 or later
  55    * `python` 3 or 2.7
  56    * GNU `make` 3.81 or later
  57    * `cmake` 3.13.4 or later
  58    * `ninja`
  59    * `curl`
  60    * `git`
  61    * `ssl` which comes in `libssl-dev` or `openssl-devel`
  62    * `pkg-config` if you are compiling on Linux and targeting Linux
  63
  64 2. Clone the [source] with `git`:
  65
  66    ```sh
  67    git clone https://github.com/rust-lang/rust.git
  68    cd rust
  69    ```
  70
  71 [source]: https://github.com/rust-lang/rust
  72
  73 3. Configure the build settings:
  74
  75     The Rust build system uses a file named `config.toml` in the root of the
  76     source tree to determine various configuration settings for the build.
  77     Copy the default `config.toml.example` to `config.toml` to get started.
  78
  79     ```sh
  80     cp config.toml.example config.toml
  81     ```
  82
  83     If you plan to use `x.py install` to create an installation, it is recommended
  84     that you set the `prefix` value in the `[install]` section to a directory.
  85
  86     Create install directory if you are not installing in default directory.
  87
  88 4. Build and install:
  89
  90     ```sh
  91     ./x.py build && ./x.py install
  92     ```
  93
  94     When complete, `./x.py install` will place several programs into
  95     `$PREFIX/bin`: `rustc`, the Rust compiler, and `rustdoc`, the
  96     API-documentation tool. This install does not include [Cargo],
  97     Rust's package manager. To build and install Cargo, you may
  98     run `./x.py install cargo` or set the `build.extended` key in
  99     `config.toml` to `true` to build and install all tools.
 100
 101 [Cargo]: https://github.com/rust-lang/cargo
 102
 103 ### Building on Windows
 104
 105 There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by
 106 Visual Studio, and the GNU ABI used by the GCC toolchain. Which version of Rust
 107 you need depends largely on what C/C++ libraries you want to interoperate with:
 108 for interop with software produced by Visual Studio use the MSVC build of Rust;
 109 for interop with GNU software built using the MinGW/MSYS2 toolchain use the GNU
 110 build.
 111
 112 #### MinGW
 113
 114 [MSYS2][msys2] can be used to easily build Rust on Windows:
 115
 116 [msys2]: https://www.msys2.org/
 117
 118 1. Grab the latest [MSYS2 installer][msys2] and go through the installer.
 119
 120 2. Run `mingw32_shell.bat` or `mingw64_shell.bat` from wherever you installed
 121    MSYS2 (i.e. `C:\msys64`), depending on whether you want 32-bit or 64-bit
 122    Rust. (As of the latest version of MSYS2 you have to run `msys2_shell.cmd
 123    -mingw32` or `msys2_shell.cmd -mingw64` from the command line instead)
 124
 125 3. From this terminal, install the required tools:
 126
 127    ```sh
 128    # Update package mirrors (may be needed if you have a fresh install of MSYS2)
 129    pacman -Sy pacman-mirrors
 130
 131    # Install build tools needed for Rust. If you're building a 32-bit compiler,
 132    # then replace "x86_64" below with "i686". If you've already got git, python,
 133    # or CMake installed and in PATH you can remove them from this list. Note
 134    # that it is important that you do **not** use the 'python2', 'cmake' and 'ninja'
 135    # packages from the 'msys2' subsystem. The build has historically been known
 136    # to fail with these packages.
 137    pacman -S git \
 138                make \
 139                diffutils \
 140                tar \
 141                mingw-w64-x86_64-python \
 142                mingw-w64-x86_64-cmake \
 143                mingw-w64-x86_64-gcc \
 144                mingw-w64-x86_64-ninja
 145    ```
 146
 147 4. Navigate to Rust's source code (or clone it), then build it:
 148
 149    ```sh
 150    ./x.py build && ./x.py install
 151    ```
 152
 153 #### MSVC
 154
 155 MSVC builds of Rust additionally require an installation of Visual Studio 2017
 156 (or later) so `rustc` can use its linker.  The simplest way is to get the
 157 [Visual Studio], check the “C++ build tools” and “Windows 10 SDK” workload.
 158
 159 [Visual Studio]: https://visualstudio.microsoft.com/downloads/
 160
 161 (If you're installing cmake yourself, be careful that “C++ CMake tools for
 162 Windows” doesn't get included under “Individual components”.)
 163
 164 With these dependencies installed, you can build the compiler in a `cmd.exe`
 165 shell with:
 166
 167 ```sh
 168 python x.py build
 169 ```
 170
 171 Currently, building Rust only works with some known versions of Visual Studio. If
 172 you have a more recent version installed and the build system doesn't understand,
 173 you may need to force rustbuild to use an older version. This can be done
 174 by manually calling the appropriate vcvars file before running the bootstrap.
 175
 176 ```batch
 177 CALL "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
 178 python x.py build
 179 ```
 180
 181 #### Specifying an ABI
 182
 183 Each specific ABI can also be used from either environment (for example, using
 184 the GNU ABI in PowerShell) by using an explicit build triple. The available
 185 Windows build triples are:
 186 - GNU ABI (using GCC)
 187     - `i686-pc-windows-gnu`
 188     - `x86_64-pc-windows-gnu`
 189 - The MSVC ABI
 190     - `i686-pc-windows-msvc`
 191     - `x86_64-pc-windows-msvc`
 192
 193 The build triple can be specified by either specifying `--build=<triple>` when
 194 invoking `x.py` commands, or by copying the `config.toml` file (as described
 195 in [Installing From Source](#installing-from-source)), and modifying the
 196 `build` option under the `[build]` section.
 197
 198 ### Configure and Make
 199
 200 While it's not the recommended build system, this project also provides a
 201 configure script and makefile (the latter of which just invokes `x.py`).
 202
 203 ```sh
 204 ./configure
 205 make && sudo make install
 206 ```
 207
 208 When using the configure script, the generated `config.mk` file may override the
 209 `config.toml` file. To go back to the `config.toml` file, delete the generated
 210 `config.mk` file.
 211
 212 ## Building Documentation
 213
 214 If you’d like to build the documentation, it’s almost the same:
 215
 216 ```sh
 217 ./x.py doc
 218 ```
 219
 220 The generated documentation will appear under `doc` in the `build` directory for
 221 the ABI used. I.e., if the ABI was `x86_64-pc-windows-msvc`, the directory will be
 222 `build\x86_64-pc-windows-msvc\doc`.
 223
 224 ## Notes
 225
 226 Since the Rust compiler is written in Rust, it must be built by a
 227 precompiled "snapshot" version of itself (made in an earlier stage of
 228 development). As such, source builds require a connection to the Internet, to
 229 fetch snapshots, and an OS that can execute the available snapshot binaries.
 230
 231 Snapshot binaries are currently built and tested on several platforms:
 232
 233 | Platform / Architecture                     | x86 | x86_64 |
 234 |---------------------------------------------|-----|--------|
 235 | Windows (7, 8, 10, ...)                     | ✓   | ✓      |
 236 | Linux (kernel 2.6.32, glibc 2.11 or later)  | ✓   | ✓      |
 237 | macOS (10.7 Lion or later)                  | (\*) | ✓      |
 238
 239 (\*): Apple dropped support for running 32-bit binaries starting from macOS 10.15 and iOS 11.
 240 Due to this decision from Apple, the targets are no longer useful to our users.
 241 Please read [our blog post][macx32] for more info.
 242
 243 [macx32]: https://blog.rust-lang.org/2020/01/03/reducing-support-for-32-bit-apple-targets.html
 244
 245 You may find that other platforms work, but these are our officially
 246 supported build environments that are most likely to work.
 247
 248 ## Getting Help
 249
 250 The Rust community congregates in a few places:
 251
 252 * [Stack Overflow] - Direct questions about using the language.
 253 * [users.rust-lang.org] - General discussion and broader questions.
 254 * [/r/rust] - News and general discussion.
 255
 256 [Stack Overflow]: https://stackoverflow.com/questions/tagged/rust
 257 [/r/rust]: https://reddit.com/r/rust
 258 [users.rust-lang.org]: https://users.rust-lang.org/
 259
 260 ## Contributing
 261
 262 If you are interested in contributing to the Rust project, please take a look
 263 at the [Getting Started][gettingstarted] guide in the [rustc-dev-guide].
 264
 265 [rustc-dev-guide]: https://rustc-dev-guide.rust-lang.org
 266
 267 ## License
 268
 269 Rust is primarily distributed under the terms of both the MIT license
 270 and the Apache License (Version 2.0), with portions covered by various
 271 BSD-like licenses.
 272
 273 See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and
 274 [COPYRIGHT](COPYRIGHT) for details.
 275
 276 ## Trademark
 277
 278 [The Rust Foundation][rust-foundation] owns and protects the Rust and Cargo
 279 trademarks and logos (the “Rust Trademarks”).
 280
 281 If you want to use these names or brands, please read the [media guide][media-guide].
 282
 283 Third-party logos may be subject to third-party copyrights and trademarks. See
 284 [Licenses][policies-licenses] for details.
 285
 286 [rust-foundation]: https://foundation.rust-lang.org/
 287 [media-guide]: https://www.rust-lang.org/policies/media-guide
 288 [policies-licenses]: https://www.rust-lang.org/policies/licenses