# 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 = [ # 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", ] [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: # "-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: # "-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 --"