config_fast_builds.toml

# 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 <https://lld.llvm.org>.
#
# ## 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 <https://github.com/rui314/mold>.
#
# # Nightly configuration
#
# Be warned that the following features require nightly Rust, which is experimental 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<String>` and crate 2 generating `Foo<String>` separately,
# only one crate generates `Foo<String>` and the other adds on to the pre-existing 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
# <https://github.com/bevyengine/bevy/issues/1110>.
#
# ## `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 <https://blog.rust-lang.org/2023/11/09/parallel-rustc.html>.

[target.x86_64-unknown-linux-gnu]
linker = "clang"
rustflags = [
  # 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=mold",

  # Nightly
  # "-Zshare-generics=y",
  # "-Zthreads=0",
]
# Some systems may experience linker performance issues when running doc tests.
# See https://github.com/bevyengine/bevy/issues/12207 for details.
rustdocflags = [
  # LLD linker
  "-Clink-arg=-fuse-ld=lld",

  # Mold linker
  # "-Clink-arg=-fuse-ld=mold",
]

[target.x86_64-apple-darwin]
rustflags = [
  # 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: <https://lld.llvm.org/MachO/index.html>
  # "-Clink-arg=-fuse-ld=/usr/local/opt/llvm/bin/ld64.lld",

  # Nightly
  # "-Zshare-generics=y",
  # "-Zthreads=0",
]

[target.aarch64-apple-darwin]
rustflags = [
  # 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: <https://lld.llvm.org/MachO/index.html>
  # "-Clink-arg=-fuse-ld=/opt/homebrew/opt/llvm/bin/ld64.lld",

  # Nightly
  # "-Zshare-generics=y",
  # "-Zthreads=0",
]

[target.x86_64-pc-windows-msvc]
# LLD linker
#
# You may need to install it:
#
# ```
# cargo install -f cargo-binutils
# rustup component add llvm-tools
# ```
linker = "rust-lld.exe"
rustdocflags = ["-Clinker=rust-lld.exe"]
rustflags = [
  # Nightly
  # "-Zshare-generics=n", # This needs to be off if you use dynamic linking on Windows.
  # "-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

# This enables you to run the CI tool using `cargo ci`.
# This is not enabled by default, you need to copy this file to `config.toml`.
[alias]
ci = "run --package ci --"