From dac66e83b2b8c2fb88a9fc272a78857d8a048668 Mon Sep 17 00:00:00 2001 From: BD103 <59022059+BD103@users.noreply.github.com> Date: Tue, 30 Apr 2024 13:42:28 -0400 Subject: [PATCH] Improve `config_fast_builds.toml` (#13136) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit # Objective - `config_fast_builds.toml` could use some general improvements and additions. - [Mold](https://github.com/rui314/mold) is a modern linker with serious performance improvements that provides a good alternative to LLD. - This is exactly the same as #12949; I accidentally deleted the branch. 😅 ## Solution - Majorly improve `config_fast_builds.toml`. - Add further documentation. - Add a section for the alternative Mold linker, which is **much** faster. - Disable nightly options by default so that developers running stable can copy the file without having to edit it. (Nightly is still recommended, but this is following suite with `rustfmt.toml`.) --- ## Changelog - Majorly improved `config_fast_builds.toml` documentation and added Mold linker. --- .cargo/config_fast_builds.toml | 146 ++++++++++++++++++++++++++++----- 1 file changed, 126 insertions(+), 20 deletions(-) diff --git a/.cargo/config_fast_builds.toml b/.cargo/config_fast_builds.toml index 2d82ca39a89c0..ae5581b058337 100644 --- a/.cargo/config_fast_builds.toml +++ b/.cargo/config_fast_builds.toml @@ -1,40 +1,146 @@ -# Add the contents of this file to `config.toml` to enable "fast build" configuration. Please read the notes below. - -# NOTE: For maximum performance, build using a nightly compiler -# If you are using rust stable, remove the "-Zshare-generics=y" below. +# Copy this file to `config.toml` to speed up your builds. +# +# # Faster linker +# +# One of the slowest aspects of compiling large Rust programs is the linking time. This file configures an +# alternate linker that may improve build times. When choosing a new linker, you have two options: +# +# ## LLD +# +# LLD is a linker from the LLVM project that supports Linux, Windows, MacOS, and WASM. It has the greatest +# platform support and the easiest installation process. It is enabled by default in this file for Linux +# and Windows. On MacOS, the default linker yields higher performance than LLD and is used instead. +# +# To install, please scroll to the corresponding table for your target (eg. `[target.x86_64-pc-windows-msvc]` +# for Windows) and follow the steps under `LLD linker`. +# +# For more information, please see LLD's website at . +# +# ## Mold +# +# Mold is a newer linker written by one of the authors of LLD. It boasts even greater performance, specifically +# through its high parallelism, though it only supports Linux. +# +# Mold is disabled by default in this file. If you wish to enable it, follow the installation instructions for +# your corresponding target, disable LLD by commenting out its `-Clink-arg=...` line, and enable Mold by +# *uncommenting* its `-Clink-arg=...` line. +# +# There is a fork of Mold named Sold that supports MacOS, but it is unmaintained and is about the same speed as +# the default ld64 linker. For this reason, it is not included in this file. +# +# For more information, please see Mold's repository at . +# +# # Nightly configuration +# +# Be warned that the following features require nightly Rust, which is expiremental and may contain bugs. If you +# are having issues, skip this section and use stable Rust instead. +# +# There are a few unstable features that can improve performance. To use them, first install nightly Rust +# through Rustup: +# +# ``` +# rustup toolchain install nightly +# ``` +# +# Finally, uncomment the lines under the `Nightly` heading for your corresponding target table (eg. +# `[target.x86_64-unknown-linux-gnu]` for Linux) to enable the following features: +# +# ## `share-generics` +# +# Usually rustc builds each crate separately, then combines them all together at the end. `share-generics` forces +# crates to share monomorphized generic code, so they do not duplicate work. +# +# In other words, instead of crate 1 generating `Foo` and crate 2 generating `Foo` separately, +# only one crate generates `Foo` and the other adds on to the pre-exiting work. +# +# Note that you may have some issues with this flag on Windows. If compiling fails due to the 65k symbol limit, +# you may have to disable this setting. For more information and possible solutions to this error, see +# . +# +# ## `threads` +# +# This option enables rustc's parallel frontend, which improves performance when parsing, type checking, borrow +# checking, and more. We currently set `threads=0`, which defaults to the amount of cores in your CPU. +# +# For more information, see the blog post at . [target.x86_64-unknown-linux-gnu] linker = "clang" rustflags = [ - "-Clink-arg=-fuse-ld=lld", # Use LLD Linker - "-Zshare-generics=y", # (Nightly) Make the current crate share its generic instantiations - "-Zthreads=0", # (Nightly) Use improved multithreading with the recommended amount of threads. + # LLD linker + # + # You may need to install it: + # + # - Ubuntu: `sudo apt-get install lld clang` + # - Fedora: `sudo dnf install lld clang` + # - Arch: `sudo pacman -S lld clang` + "-Clink-arg=-fuse-ld=lld", + + # Mold linker + # + # You may need to install it: + # + # - Ubuntu: `sudo apt-get install mold clang` + # - Fedora: `sudo dnf install mold clang` + # - Arch: `sudo pacman -S mold clang` + # "-Clink-arg=-fuse-ld=/usr/bin/mold", + + # Nightly + # "-Zshare-generics=y", + # "-Zthreads=0", ] -# NOTE: you must install [Mach-O LLD Port](https://lld.llvm.org/MachO/index.html) on mac. you can easily do this by installing llvm which includes lld with the "brew" package manager: -# `brew install llvm` [target.x86_64-apple-darwin] rustflags = [ - "-Clink-arg=-fuse-ld=/usr/local/opt/llvm/bin/ld64.lld", # Use LLD Linker - "-Zshare-generics=y", # (Nightly) Make the current crate share its generic instantiations - "-Zthreads=0", # (Nightly) Use improved multithreading with the recommended amount of threads. + # LLD linker + # + # The default ld64 linker is faster, you should continue using it instead. + # + # You may need to install it: + # + # Brew: `brew install llvm` + # Manually: + # "-Clink-arg=-fuse-ld=/usr/local/opt/llvm/bin/ld64.lld", + + # Nightly + # "-Zshare-generics=y", + # "-Zthreads=0", ] [target.aarch64-apple-darwin] rustflags = [ - "-Clink-arg=-fuse-ld=/opt/homebrew/opt/llvm/bin/ld64.lld", # Use LLD Linker - "-Zshare-generics=y", # (Nightly) Make the current crate share its generic instantiations - "-Zthreads=0", # (Nightly) Use improved multithreading with the recommended amount of threads. + # LLD linker + # + # The default ld64 linker is faster, you should continue using it instead. + # + # You may need to install it: + # + # Brew: `brew install llvm` + # Manually: + # "-Clink-arg=-fuse-ld=/opt/homebrew/opt/llvm/bin/ld64.lld", + + # Nightly + # "-Zshare-generics=y", + # "-Zthreads=0", ] [target.x86_64-pc-windows-msvc] -linker = "rust-lld.exe" # Use LLD Linker +# LLD linker +# +# You may need to install it: +# +# ``` +# cargo install -f cargo-binutils +# rustup component add llvm-tools +# ``` +linker = "rust-lld.exe" rustflags = [ - "-Zshare-generics=n", # (Nightly) - "-Zthreads=0", # (Nightly) Use improved multithreading with the recommended amount of threads. + # Nightly + # "-Zshare-generics=y", + # "-Zthreads=0", ] # Optional: Uncommenting the following improves compile times, but reduces the amount of debug info to 'line number tables only' # In most cases the gains are negligible, but if you are on macos and have slow compile times you should see significant gains. -#[profile.dev] -#debug = 1 +# [profile.dev] +# debug = 1