Support for `aarch64-pc-windows-gnullvm`

[mcandre]

Problem you are trying to solve

Can we get target triples going to support Cygwin-style Rust applications for ARM Windows?

While we do technically have aarch64-pc-windows-msvc available, cross-compiling Windows Rust apps from non-Windows hosts is remarkably easier with the windows-gnu target triple variants. So a aarch-pc-windows-gnu target may be easier for many macOS/Linux/UNIX Rust devs to support than aarch64-pc-windows-msvc.

Solution you'd like

Introduce aarch-pc-windows-gnu to the set of available rustup targets, similar to the other windows-gnu targets.

Notes

No response

[ChrisDenton]

I think that this would be an issue for the main rust repository. Rustup just distributes whatever prebuilt targets exist.

And if you look on the platform support page you'll see there's no aarch64-pc-windows-gnu target.

There is a new aarch64-pc-windows-gnullvm target (gnu with llvm linker and other tools) but that's currently tier 3 so the rust repository doesn't distribute builds. It would need to be promoted to tier 2 before that can happen.

[rami3l]

Sorry, that was a misclick: https://doc.rust-lang.org/nightly/rustc/platform-support/pc-windows-gnullvm.html says it's now tier 2, but without host tools. We'll keep an eye on it.

[djc]

IMO since this is not actionable from our side, closing it makes more sense to me -- it can be reopened (or we can work in a new issue) once host tools are available for the target.

[rami3l]

IMO since this is not actionable from our side, closing it makes more sense to me -- it can be reopened (or we can work in a new issue) once host tools are available for the target.

Makes sense; will close it for now until rustc and friends say otherwise.

[benjyw]

FWIW aarch64-pc-windows-gnullvm is now tier 2 with host tools, per https://doc.rust-lang.org/nightly/rustc/platform-support.html

[ChrisDenton]

Is there anything for us to do here?

[rami3l]

@ChrisDenton I see at least two: adjust the CI to include that target; adjust the shell script to allow detection for it.