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Matthias Krüger dde77f7a33
Rollup merge of - Zalathar:file-table, r=cjgillot
coverage: Emit the filenames section before encoding per-function mappings

When embedding coverage information in LLVM IR (and ultimately in the resulting binary), there are two main things that each CGU needs to emit:

- A single `__llvm_covmap` record containing a coverage header, which mostly consists of a list of filenames used by the CGU's coverage mappings.
- Several `__llvm_covfun` records, one for each instrumented function, each of which contains the hash of the list of filenames in the header.

There is a kind of loose cyclic dependency between the two: we need the hash of the file table before we can emit the covfun records, but we need to traverse all of the instrumented functions in order to build the file table.

The existing code works by processing the individual functions first. It lazily adds filenames to the file table, and stores the mostly-complete function records in a temporary list. After this it hashes the file table, emits the header (containing the file table), and then uses the hash to emit all of the function records.

This PR reverses that order: first we traverse all of the functions (without trying to prepare their function records) to build a *complete* file table, and then emit it immediately. At this point we have the file table hash, so we can then proceed to build and emit all of the function records, without needing to store them in an intermediate list.

---

Along the way, this PR makes some necessary changes that are also worthwhile in their own right:
- We split `FunctionCoverage` into distinct collector/finished phases, which neatly avoids some borrow-checker hassles when extracting a function's final expression/mapping data.
- We avoid having to re-sort a function's mappings when preparing the list of filenames that it uses.
2023-10-23 08:12:39 +02:00
.github Auto merge of - cuviper:ci-llvm-17, r=Mark-Simulacrum 2023-10-22 06:15:18 +00:00
.reuse Add integration for new bors 2023-09-28 10:43:24 +02:00
compiler Rollup merge of - Zalathar:file-table, r=cjgillot 2023-10-23 08:12:39 +02:00
library Rollup merge of - ChrisDenton:skip-unsupported, r=Mark-Simulacrum 2023-10-22 09:15:42 +02:00
LICENSES Remove unused NCSA license 2023-07-26 10:20:15 -04:00
src Rollup merge of - notriddle:notriddle/stab-baseline, r=GuillaumeGomez 2023-10-23 08:12:39 +02:00
tests Rollup merge of - Zalathar:file-table, r=cjgillot 2023-10-23 08:12:39 +02:00
.editorconfig Only use max_line_length = 100 for *.rs 2023-07-10 15:18:36 -07:00
.git-blame-ignore-revs Ignore let-chains formatting 2023-10-15 18:30:34 +00:00
.gitattributes Rename config.toml.example to config.example.toml 2023-03-11 14:10:00 -08:00
.gitignore don't globally ignore rustc-ice files 2023-09-16 09:44:44 +02:00
.gitmodules Update to LLVM 17.0.0 2023-09-19 11:14:35 +02:00
.mailmap Rollup merge of - blyxyas:fix-mailmap, r=Nilstrieb 2023-10-19 04:34:47 +02:00
Cargo.lock Rollup merge of - Zalathar:file-table, r=cjgillot 2023-10-23 08:12:39 +02:00
Cargo.toml chore: prep v1.7.0 release 2023-10-22 20:18:45 -05:00
CODE_OF_CONDUCT.md Remove the code of conduct; instead link https://www.rust-lang.org/conduct.html 2019-10-05 22:55:19 +02:00
config.example.toml Auto merge of - onur-ozkan:config-change-tracking, r=Mark-Simulacrum 2023-10-02 07:41:52 +00:00
configure Enforce Python 3 as much as possible 2020-04-10 09:09:58 -04:00
CONTRIBUTING.md Update contributing links for rustc-dev-guide changes 2023-03-30 13:36:40 -04:00
COPYRIGHT Update COPYRIGHT file 2022-10-30 10:23:14 -04:00
LICENSE-APACHE Remove appendix from LICENCE-APACHE 2019-12-30 14:25:53 +00:00
LICENSE-MIT LICENSE-MIT: Remove inaccurate (misattributed) copyright notice 2017-07-26 16:51:58 -07:00
README.md Updated README with expandable table of content. 2023-10-19 22:32:11 +02:00
RELEASES.md Update docs for mips target tier demotion. 2023-10-06 18:26:34 -07:00
rust-bors.toml Add integration for new bors 2023-09-28 10:43:24 +02:00
rustfmt.toml rust-installer and rls no longer submodule, so fix rustfmt.toml 2023-07-04 18:39:48 +03:00
triagebot.toml trigger the triagebot for modifications to bootstrap/defaults 2023-10-19 08:39:55 +03:00
x Make x capable of resolving symlinks 2023-10-14 17:53:33 +03:00
x.ps1 Don't print "x.ps1" 2023-06-24 14:44:53 -05:00
x.py Fix recent python linting errors 2023-08-02 04:40:28 -04:00

The Rust Programming Language

Rust Community

This is the main source code repository for Rust. It contains the compiler, standard library, and documentation.

Note: this README is for users rather than contributors. If you wish to contribute to the compiler, you should read CONTRIBUTING.md instead.

Table of content

Quick Start

Read "Installation" from The Book.

Installing from Source

The Rust build system uses a Python script called x.py to build the compiler, which manages the bootstrapping process. It lives at the root of the project. It also uses a file named config.toml to determine various configuration settings for the build. You can see a full list of options in config.example.toml.

The x.py command can be run directly on most Unix systems in the following format:

./x.py <subcommand> [flags]

This is how the documentation and examples assume you are running x.py. See the rustc dev guide if this does not work on your platform.

More information about x.py can be found by running it with the --help flag or reading the rustc dev guide.

Dependencies

Make sure you have installed the dependencies:

  • python 3 or 2.7
  • git
  • A C compiler (when building for the host, cc is enough; cross-compiling may need additional compilers)
  • curl (not needed on Windows)
  • pkg-config if you are compiling on Linux and targeting Linux
  • libiconv (already included with glibc on Debian-based distros)

To build Cargo, you'll also need OpenSSL (libssl-dev or openssl-devel on most Unix distros).

If building LLVM from source, you'll need additional tools:

  • g++, clang++, or MSVC with versions listed on LLVM's documentation
  • ninja, or GNU make 3.81 or later (Ninja is recommended, especially on Windows)
  • cmake 3.13.4 or later
  • libstdc++-static may be required on some Linux distributions such as Fedora and Ubuntu

On tier 1 or tier 2 with host tools platforms, you can also choose to download LLVM by setting llvm.download-ci-llvm = true. Otherwise, you'll need LLVM installed and llvm-config in your path. See the rustc-dev-guide for more info.

Building on a Unix-like system

Build steps

  1. Clone the source with git:

    git clone https://github.com/rust-lang/rust.git
    cd rust
    
  1. Configure the build settings:

    ./configure
    

    If you plan to use x.py install to create an installation, it is recommended that you set the prefix value in the [install] section to a directory: ./configure --set install.prefix=<path>

  2. Build and install:

    ./x.py build && ./x.py install
    

    When complete, ./x.py install will place several programs into $PREFIX/bin: rustc, the Rust compiler, and rustdoc, the API-documentation tool. By default, it will also include Cargo, Rust's package manager. You can disable this behavior by passing --set build.extended=false to ./configure.

Configure and Make

This project provides a configure script and makefile (the latter of which just invokes x.py). ./configure is the recommended way to programmatically generate a config.toml. make is not recommended (we suggest using x.py directly), but it is supported and we try not to break it unnecessarily.

./configure
make && sudo make install

configure generates a config.toml which can also be used with normal x.py invocations.

Building on Windows

On Windows, we suggest using winget to install dependencies by running the following in a terminal:

winget install -e Python.Python.3
winget install -e Kitware.CMake
winget install -e Git.Git

Then edit your system's PATH variable and add: C:\Program Files\CMake\bin. See this guide on editing the system PATH from the Java documentation.

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. Use the MSVC build of Rust to interop with software produced by Visual Studio and the GNU build to interop with GNU software built using the MinGW/MSYS2 toolchain.

MinGW

MSYS2 can be used to easily build Rust on Windows:

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

  2. Run mingw32_shell.bat or mingw64_shell.bat from the MSYS2 installation directory (e.g. 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 you do **not** use the 'python2', 'cmake',
    # and 'ninja' packages from the 'msys2' subsystem.
    # The build has historically been known to fail with these packages.
    pacman -S git \
                make \
                diffutils \
                tar \
                mingw-w64-x86_64-python \
                mingw-w64-x86_64-cmake \
                mingw-w64-x86_64-gcc \
                mingw-w64-x86_64-ninja
    
  4. Navigate to Rust's source code (or clone it), then build it:

    python x.py setup user && python x.py build && python x.py install
    

MSVC

MSVC builds of Rust additionally require an installation of Visual Studio 2017 (or later) so rustc can use its linker. The simplest way is to get Visual Studio, check the "C++ build tools" and "Windows 10 SDK" workload.

(If you're installing CMake yourself, be careful that "C++ CMake tools for Windows" doesn't get included under "Individual components".)

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

python x.py setup user
python x.py build

Right now, building Rust only works with some known versions of Visual Studio. If you have a more recent version installed and the build system doesn't understand, 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\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
python x.py build

Specifying an ABI

Each specific ABI can also be used from either environment (for example, using the GNU ABI in PowerShell) by using an explicit build triple. The available Windows build triples are:

  • GNU ABI (using GCC)
    • i686-pc-windows-gnu
    • x86_64-pc-windows-gnu
  • The MSVC ABI
    • i686-pc-windows-msvc
    • x86_64-pc-windows-msvc

The build triple can be specified by either specifying --build=<triple> when invoking x.py commands, or by creating a config.toml file (as described in Building on a Unix-like system), and passing --set build.build=<triple> to ./configure.

Building Documentation

If you'd like to build the documentation, it's almost the same:

./x.py doc

The generated documentation will appear under doc in the build directory for the ABI used. That is, if the ABI was x86_64-pc-windows-msvc, the directory will be build\x86_64-pc-windows-msvc\doc.

Notes

Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier stage of development). As such, source builds require an Internet connection to fetch snapshots, and an OS that can execute the available snapshot binaries.

See https://doc.rust-lang.org/nightly/rustc/platform-support.html for a list of supported platforms. Only "host tools" platforms have a pre-compiled snapshot binary available; to compile for a platform without host tools you must cross-compile.

You may find that other platforms work, but these are our officially supported build environments that are most likely to work.

Getting Help

See https://www.rust-lang.org/community for a list of chat platforms and forums.

Contributing

See CONTRIBUTING.md.

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.

Trademark

The Rust Foundation owns and protects the Rust and Cargo trademarks and logos (the "Rust Trademarks").

If you want to use these names or brands, please read the media guide.

Third-party logos may be subject to third-party copyrights and trademarks. See Licenses for details.