Using in Windows

[thewh1teagle]

It's unclear how can I use this codegen in Windows.
I would like to use it both locally and on Github actions for faster build with Rust on Windows.
Does it improve speed for release builds?

rustup default nightly

What should I do after installing nightly rust and set it as deafult?

[bjorn3]

Does it improve speed for release builds?

Cranelift doesn't support enough optimizations to make it useful in release mode.

It's unclear how can I use this codegen in Windows.

It isn't distibuted with rustup on Windows yet. You can download the latest version from https://github.com/rust-lang/rustc_codegen_cranelift/releases/tag/dev instead, extract it somewhere and then run the contained cargo-clif.exe in the place of cargo.exe.

[mikkelens]

I think it would be beneficial if there was a bigger notice in README.md that the usage instructions above the section mentioning precompiled binaries (for Windows) don't all easily transfer. I at least can't get rustc to accept the rustc_codegen_cranelift.dll in the "codegen-backends" in "sysroot" (mentioned in error when trying to use codegen-backend = "cranelift" without using rustup). I tried doing a few things to get it working per profile, including mirroring the layout that appears when using the rustup method on Linux. Only by passing -Zcodegen-backend=<absolute-path-to-dll> wholesale in a crate-wide rust flag can I get it working on Windows.

[thewh1teagle]

and then run the contained cargo-clif.exe in the place of cargo.exe.

I added cargo-clif to PATH and changed the default toolchain to nightly but it give me error:

C:\Users\User\Documents\code\rustduck\src-tauri>rustup default
nightly-x86_64-pc-windows-msvc (default)

C:\Users\User\Documents\code\rustduck\src-tauri>cargo-clif build
warning: `C:\Users\User\.cargo\config` is deprecated in favor of `config.toml`
note: if you need to support cargo 1.38 or earlier, you can symlink `config` to `config.toml`
warning: `C:\Users\User\.cargo\config` is deprecated in favor of `config.toml`
note: if you need to support cargo 1.38 or earlier, you can symlink `config` to `config.toml`
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `rustc - --crate-name ___ --print=file-names -Cpanic=abort -Zpanic-abort-tests -Zcodegen-backend=C:\apps\bin\cargo-clif\bin\rustc_codegen_cranelift.dll --sysroot C:\apps\bin\cargo-clif --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=split-debuginfo --print=crate-name --print=cfg` (exit code: 1)
  --- stderr
  error: the option `Z` is only accepted on the nightly compiler

  help: consider switching to a nightly toolchain: `rustup default nightly`

  note: selecting a toolchain with `+toolchain` arguments require a rustup proxy; see <https://rust-lang.github.io/rustup/concepts/index.html>

  note: for more information about Rust's stability policy, see <https://doc.rust-lang.org/book/appendix-07-nightly-rust.html#unstable-features>

  error: 1 nightly option were parsed

[thewh1teagle]

That was an issue with rustc. I reinstalled it and it got fixed.

---

I compared build time with cargo vs cargo-clif:

1. With cargo-clif
$start = Get-Date; cargo-clif build ; $elapsed = (Get-Date) - $start; Write-Output "Elapsed time: $elapsed"
   Elapsed time: 00:01:35.74

2. With cargo
$start = Get-Date; cargo build ; $elapsed = (Get-Date) - $start; Write-Output "Elapsed time: $elapsed"
   Elapsed time: 00:02:01.69

[bjorn3]

Sorry for the late reply @mikkelens. With the precompiled binaries from the releases page you probably want to use cargo-clif.exe instead of using the cargo configs.