In the context of Rust development on macOS, zld refers to a faster alternative linker for Apple's linker ld. It is designed to significantly speed up the linking phase of the build process, which can be a bottleneck in large projects.

Key Features of zld

• Speed Optimization: zld uses optimized data structures like Swiss Tables and parallelizes multiple processing steps to speed up the linking process.
• Compatibility: It works seamlessly with tools like Xcode, Bazel, and Rust.
• Ease of Integration: zld can be easily integrated into existing projects without requiring changes to the project configuration.

Usage in Rust Projects

To use zld in a Rust project on macOS, you can follow these steps:

1. Install zld using Homebrew:

brew install michaeleisel/zld/zld

2. Configure your Rust project to use zld by adding the following to your .cargo/config.toml file:

[target.x86_64-apple-darwin]
rustflags = ["-C", "link-arg=-fuse-ld=/usr/local/bin/zld"]

Performance Benefits

Using zld can lead to significant reductions in build times. For example, in some projects, it has been reported to reduce build times by 40% or more.

Note

While zld is a powerful tool for speeding up the build process on macOS, it is worth noting that the Rust community is also exploring other linkers like lld for broader platform support and performance improvements.