wild-linker / wild

Wild linker Wild is a linker with the goal of being very fast for iterative development. The plan is to eventually make it incremental, however that isn't yet implemented. It is however already pretty fast even without incremental linking. Installation From GitHub releases Download a tarball from the releases page. Unpack it and copy the binary somewhere on your path. Cargo binstall If you have cargo-binstall, you can install wild as follows: Build latest release from crates.io Build from git head To build and install the latest, unreleased code: Nix To use a stable Wild from Nixpkgs: to use the latest unstable git revision of wild, see the nix documentation Using as your default linker If you'd like to use Wild as your default linker for building Rust code, you can put the following in . On Linux: Alternatively, you can create symlink pointing to and use: The above steps also work for clang when building C/C++ code, just add the following to your LDFLAGS after adding the symlink: GCC doesn't have native support for in any released version yet. You can make it force use it with the -Bprefix option. Create a symlink pointing to and pass the directory containing it to gcc. For example you can do the following: And when compiling C/C++ code pass the directory containing to your CFLAGS,CXXFLAGS and LDFLAGS: Afterwards you can check if wild was used for linking with readelf On Illumos: Using wild in CI If you'd like to use Wild as your linker for Rust code in CI, see wild-action. Q&A Why another linker? Mold is already very fast, however it doesn't do incremental linking and the author has stated that they don't intend to. Wild doesn't do incremental linking yet, but that is the end-goal. By writing Wild in Rust, it's hoped that the complexity of incremental linking will be achievable. What's working? The following platforms / architectures are currently supported: • x86-64 on Linux • ARM64 on Linux • RISC-V (riscv64gc) on Linux • LoongArch64 on Linux (initial support) The following is working with the caveat that there may be bugs: • Output to statically linked, non-relocatable binaries • Output to statically linked, position-independent binaries (static-PIE) • Output to dynamically linked binaries • Output to shared objects (.so files) • Rust proc-macros, when linked with Wild work • Most of the top downloaded crates on crates.io have been tested with Wild and pass their tests • Debug info • GNU jobserver support • Very basic linker script support (section mapping, keeping sections, alignment, defining start / stop symbols). What isn't yet supported? Lots of stuff. Here are some of the larger things that aren't yet done, roughly sorted by current priority: • Incremental linking • Support for more architectures • Support for a wider range of linker flags • More complex linker scripts • Mac support • Windows support • Linker plugin LTO (initial experimental support is behind but it doesn't yet work very well). How can I verify that Wild was used to link a binary? Install (available from binutils package), then run: Look for a line like: You can probably also get away with (also available from binutils package): Where did the name come from? It's somewhat of a tradition for linkers to end with the letters "ld". e.g. "GNU ld, "gold", "lld", "mold". Since the end-goal is for the linker to be incremental, an "I" is added. Let's say the "W" stands for "Wild", since recursive acronyms are popular in open-source projects. Benchmarks The goal of Wild is to eventually be very fast via incremental linking. However, we also want to be as fast as we can be for non-incremental linking and for the initial link when incremental linking is enabled. All benchmarks are run with output to a tmpfs. See BENCHMARKING.md for details on running benchmarks. We run benchmarks on a few different systems: • Ryzen 9 9955HX (16 core, 32 thread) • 2020 era Intel-based laptop with 4 cores and 8 threads • Raspberry Pi 5 Here's a few highlights. Ryzen 9955HX (16 core, 32 thread) First, we link the Chrome web browser (or technically, Chromium). Memory consumption when linking Chromium: librustc-driver is the shared object where most of the code in the Rust compiler lives. This benchmark shows the time to link it. For something much smaller, this is the time to link Wild itself. This also shows a few different Wild versions, so you can see how the link time has been tracking over releases. Raspberry Pi 5 Here's linking rust-analyzer on a Raspberry Pi 5. Linking Rust code The following is a command-line that can be used to build and test a crate using Wild. This has been run successfully on a few popular crates (e.g. ripgrep, serde, tokio, rand, bitflags). It assumes that the "wild" binary is on your path. It also depends on the Clang compiler being installed, since GCC doesn't allow using an arbitrary linker. Alternatively, with symlink pointing at : Contributing For more information on contributing to see CONTRIBUTING.md. For a high-level overview of Wild's design, see DESIGN.md. Chat server We have a Zulip server for Wild-related chat. You can join here. Further reading Many of the posts on David's blog are about various aspects of the Wild linker. Sponsorship If you'd like to sponsor this work, that would be very much appreciated. The more sponsorship I get the longer I can continue to work on this project full time. Code of Conduct The Wild project adheres to the Rust code of conduct. If you have any moderation concerns or queries, please email wild-mod@googlegroups.com. License Licensed under either of Apache License, Version 2.0 or MIT license at your option. Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Wild by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.