README.md

   1 # The Rust Programming Language
   2
   3 [![Rust Community](https://img.shields.io/badge/Rust_Community%20-Join_us-brightgreen?style=plastic&logo=rust)](https://www.rust-lang.org/community)
   4
   5 This is the main source code repository for [Rust]. It contains the compiler,
   6 standard library, and documentation.
   7
   8 [Rust]: https://www.rust-lang.org/
   9
  10 **Note: this README is for _users_ rather than _contributors_.**
  11 If you wish to _contribute_ to the compiler, you should read
  12 [CONTRIBUTING.md](CONTRIBUTING.md) instead.
  13
  14 ## Quick Start
  15
  16 Read ["Installation"] from [The Book].
  17
  18 ["Installation"]: https://doc.rust-lang.org/book/ch01-01-installation.html
  19 [The Book]: https://doc.rust-lang.org/book/index.html
  20
  21 ## Installing from Source
  22
  23 The Rust build system uses a Python script called `x.py` to build the compiler,
  24 which manages the bootstrapping process. It lives at the root of the project.
  25
  26 The `x.py` command can be run directly on most Unix systems in the following
  27 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 Some alternative ways are:
  35
  36 ```sh
  37 # On a Unix shell if you don't have the necessary `python3` command
  38 ./x <subcommand> [flags]
  39
  40 # On the Windows Command Prompt (if .py files are configured to run Python)
  41 x.py <subcommand> [flags]
  42
  43 # You can also run Python yourself, e.g.:
  44 python x.py <subcommand> [flags]
  45 ```
  46
  47 More information about `x.py` can be found by running it with the `--help` flag
  48 or reading the [rustc dev guide][rustcguidebuild].
  49
  50 [gettingstarted]: https://rustc-dev-guide.rust-lang.org/getting-started.html
  51 [rustcguidebuild]: https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html
  52
  53 ### Dependencies
  54
  55 Make sure you have installed the dependencies:
  56
  57 * `python` 3 or 2.7
  58 * `git`
  59 * A C compiler (when building for the host, `cc` is enough; cross-compiling may
  60   need additional compilers)
  61 * `curl` (not needed on Windows)
  62 * `pkg-config` if you are compiling on Linux and targeting Linux
  63 * `libiconv` (already included with glibc on Debian-based distros)
  64
  65 To build Cargo, you'll also need OpenSSL (`libssl-dev` or `openssl-devel` on
  66 most Unix distros).
  67
  68 If building LLVM from source, you'll need additional tools:
  69
  70 * `g++`, `clang++`, or MSVC with versions listed on
  71   [LLVM's documentation](https://llvm.org/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library)
  72 * `ninja`, or GNU `make` 3.81 or later (Ninja is recommended, especially on
  73   Windows)
  74 * `cmake` 3.13.4 or later
  75 * `libstdc++-static` may be required on some Linux distributions such as Fedora
  76   and Ubuntu
  77
  78 On tier 1 or tier 2 with host tools platforms, you can also choose to download
  79 LLVM by setting `llvm.download-ci-llvm = true`.
  80 Otherwise, you'll need LLVM installed and `llvm-config` in your path.
  81 See [the rustc-dev-guide for more info][sysllvm].
  82
  83 [sysllvm]: https://rustc-dev-guide.rust-lang.org/building/new-target.html#using-pre-built-llvm
  84
  85
  86 ### Building on a Unix-like system
  87
  88 1. Clone the [source] with `git`:
  89
  90    ```sh
  91    git clone https://github.com/rust-lang/rust.git
  92    cd rust
  93    ```
  94
  95 [source]: https://github.com/rust-lang/rust
  96
  97 2. Configure the build settings:
  98
  99    The Rust build system uses a file named `config.toml` in the root of the
 100    source tree to determine various configuration settings for the build.
 101    Set up the defaults intended for distros to get started. You can see a full
 102    list of options in `config.example.toml`.
 103
 104    ```sh
 105    printf 'profile = "user" \nchangelog-seen = 2 \n' > config.toml
 106    ```
 107
 108    If you plan to use `x.py install` to create an installation, it is
 109    recommended that you set the `prefix` value in the `[install]` section to a
 110    directory.
 111
 112 3. Build and install:
 113
 114    ```sh
 115    ./x.py build && ./x.py install
 116    ```
 117
 118    When complete, `./x.py install` will place several programs into
 119    `$PREFIX/bin`: `rustc`, the Rust compiler, and `rustdoc`, the
 120    API-documentation tool. If you've set `profile = "user"` or
 121    `build.extended = true`, it will also include [Cargo], Rust's package
 122    manager.
 123
 124 [Cargo]: https://github.com/rust-lang/cargo
 125
 126 ### Building on Windows
 127
 128 On Windows, we suggest using [winget] to install dependencies by running the
 129 following in a terminal:
 130
 131 ```powershell
 132 winget install -e Python.Python.3
 133 winget install -e Kitware.CMake
 134 winget install -e Git.Git
 135 ```
 136
 137 Then edit your system's `PATH` variable and add: `C:\Program Files\CMake\bin`.
 138 See
 139 [this guide on editing the system `PATH`](https://www.java.com/en/download/help/path.html)
 140 from the Java documentation.
 141
 142 [winget]: https://github.com/microsoft/winget-cli
 143
 144 There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by
 145 Visual Studio and the GNU ABI used by the GCC toolchain. Which version of Rust
 146 you need depends largely on what C/C++ libraries you want to interoperate with.
 147 Use the MSVC build of Rust to interop with software produced by Visual Studio
 148 and the GNU build to interop with GNU software built using the MinGW/MSYS2
 149 toolchain.
 150
 151 #### MinGW
 152
 153 [MSYS2][msys2] can be used to easily build Rust on Windows:
 154
 155 [msys2]: https://www.msys2.org/
 156
 157 1. Download the latest [MSYS2 installer][msys2] and go through the installer.
 158
 159 2. Run `mingw32_shell.bat` or `mingw64_shell.bat` from the MSYS2 installation
 160    directory (e.g. `C:\msys64`), depending on whether you want 32-bit or 64-bit
 161    Rust. (As of the latest version of MSYS2 you have to run `msys2_shell.cmd
 162    -mingw32` or `msys2_shell.cmd -mingw64` from the command line instead.)
 163
 164 3. From this terminal, install the required tools:
 165
 166    ```sh
 167    # Update package mirrors (may be needed if you have a fresh install of MSYS2)
 168    pacman -Sy pacman-mirrors
 169
 170    # Install build tools needed for Rust. If you're building a 32-bit compiler,
 171    # then replace "x86_64" below with "i686". If you've already got Git, Python,
 172    # or CMake installed and in PATH you can remove them from this list.
 173    # Note that it is important that you do **not** use the 'python2', 'cmake',
 174    # and 'ninja' packages from the 'msys2' subsystem.
 175    # The build has historically been known to fail with these packages.
 176    pacman -S git \
 177                make \
 178                diffutils \
 179                tar \
 180                mingw-w64-x86_64-python \
 181                mingw-w64-x86_64-cmake \
 182                mingw-w64-x86_64-gcc \
 183                mingw-w64-x86_64-ninja
 184    ```
 185
 186 4. Navigate to Rust's source code (or clone it), then build it:
 187
 188    ```sh
 189    ./x.py build && ./x.py install
 190    ```
 191
 192 #### MSVC
 193
 194 MSVC builds of Rust additionally require an installation of Visual Studio 2017
 195 (or later) so `rustc` can use its linker.  The simplest way is to get
 196 [Visual Studio], check the "C++ build tools" and "Windows 10 SDK" workload.
 197
 198 [Visual Studio]: https://visualstudio.microsoft.com/downloads/
 199
 200 (If you're installing CMake yourself, be careful that "C++ CMake tools for
 201 Windows" doesn't get included under "Individual components".)
 202
 203 With these dependencies installed, you can build the compiler in a `cmd.exe`
 204 shell with:
 205
 206 ```sh
 207 python x.py build
 208 ```
 209
 210 Right now, building Rust only works with some known versions of Visual Studio.
 211 If you have a more recent version installed and the build system doesn't
 212 understand, you may need to force rustbuild to use an older version.
 213 This can be done by manually calling the appropriate vcvars file before running
 214 the bootstrap.
 215
 216 ```batch
 217 CALL "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
 218 python x.py build
 219 ```
 220
 221 #### Specifying an ABI
 222
 223 Each specific ABI can also be used from either environment (for example, using
 224 the GNU ABI in PowerShell) by using an explicit build triple. The available
 225 Windows build triples are:
 226 - GNU ABI (using GCC)
 227     - `i686-pc-windows-gnu`
 228     - `x86_64-pc-windows-gnu`
 229 - The MSVC ABI
 230     - `i686-pc-windows-msvc`
 231     - `x86_64-pc-windows-msvc`
 232
 233 The build triple can be specified by either specifying `--build=<triple>` when
 234 invoking `x.py` commands, or by creating a `config.toml` file (as described in
 235 [Installing from Source](#installing-from-source)), and modifying the `build`
 236 option under the `[build]` section.
 237
 238 ### Configure and Make
 239
 240 While it's not the recommended build system, this project also provides a
 241 configure script and makefile (the latter of which just invokes `x.py`).
 242
 243 ```sh
 244 ./configure
 245 make && sudo make install
 246 ```
 247
 248 `configure` generates a `config.toml` which can also be used with normal `x.py`
 249 invocations.
 250
 251 ## Building Documentation
 252
 253 If you'd like to build the documentation, it's almost the same:
 254
 255 ```sh
 256 ./x.py doc
 257 ```
 258
 259 The generated documentation will appear under `doc` in the `build` directory for
 260 the ABI used. That is, if the ABI was `x86_64-pc-windows-msvc`, the directory
 261 will be `build\x86_64-pc-windows-msvc\doc`.
 262
 263 ## Notes
 264
 265 Since the Rust compiler is written in Rust, it must be built by a precompiled
 266 "snapshot" version of itself (made in an earlier stage of development).
 267 As such, source builds require an Internet connection to fetch snapshots, and an
 268 OS that can execute the available snapshot binaries.
 269
 270 See https://doc.rust-lang.org/nightly/rustc/platform-support.html for a list of
 271 supported platforms.
 272 Only "host tools" platforms have a pre-compiled snapshot binary available; to
 273 compile for a platform without host tools you must cross-compile.
 274
 275 You may find that other platforms work, but these are our officially supported
 276 build environments that are most likely to work.
 277
 278 ## Getting Help
 279
 280 See https://www.rust-lang.org/community for a list of chat platforms and forums.
 281
 282 ## Contributing
 283
 284 See [CONTRIBUTING.md](CONTRIBUTING.md).
 285
 286 ## License
 287
 288 Rust is primarily distributed under the terms of both the MIT license and the
 289 Apache License (Version 2.0), with portions covered by various BSD-like
 290 licenses.
 291
 292 See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and
 293 [COPYRIGHT](COPYRIGHT) for details.
 294
 295 ## Trademark
 296
 297 [The Rust Foundation][rust-foundation] owns and protects the Rust and Cargo
 298 trademarks and logos (the "Rust Trademarks").
 299
 300 If you want to use these names or brands, please read the
 301 [media guide][media-guide].
 302
 303 Third-party logos may be subject to third-party copyrights and trademarks. See
 304 [Licenses][policies-licenses] for details.
 305
 306 [rust-foundation]: https://foundation.rust-lang.org/
 307 [media-guide]: https://foundation.rust-lang.org/policies/logo-policy-and-media-guide/
 308 [policies-licenses]: https://www.rust-lang.org/policies/licenses