Rust-for-Linux VS rustc_codegen_gcc

You're welcome.

> Any concerns of the same kind of thing?

Here's the canonical list: https://github.com/Rust-for-Linux/linux/issues/2

There's a lot, and I don't know the status of many of them, personally. But I don't see anything there that I know is not gonna work out, like for example, they aren't using specialization. Most of it feels like very nuts and bolts codegen options and similar things.

That said, back in August, the Rust Project announced their goals for the second half of this year: https://blog.rust-lang.org/2024/08/12/Project-goals.html

They say that they're committed to getting this stuff done, and in particular: https://rust-lang.github.io/rust-project-goals/2024h2/rfl_st...

> Closing these issues gets us within striking distance of being able to build the RFL codebase on stable Rust.

So, things sound good, in my mind.

The goal of rust for linux isn't to wholesale translate linux into rust, but simply to be able to write pieces of linux (largely new ones) in rust. I think it's very unlikely anyone (including google) will take on a wholesale translation anytime soon. That said

> It's unlikely that Google has much sway here

Google has helped fund the rust for linux project pretty much from the start [1], they're one of three organizations mentioned on the homepage due to their sponorship [2]. They're actively involved in it, and have already ported their android "binder" driver into it with the intent to ship it in android. This strikes me as a very weird take.

[1] https://www.memorysafety.org/blog/supporting-miguel-ojeda-ru...

[2] https://rust-for-linux.com/

Rust is backwards compatible when you stick to stable features, but the kernel uses unstable features that can and do incur breaking changes.

https://github.com/Rust-for-Linux/linux/issues/2

> How would this work?

Don't know exactly what you're asking.

> And why would it be a better idea?

Poorly written device drivers are a significant attack vector. It's one of the reasons Linux is now exploring using Rust for its own device drivers.[0] You may be asking -- why Rust and not some other language? Rust has many of the performance and interoperability advantages of C and C++, but as noted, makes certain classes of memory safety issues impossible. Rust also has significant mindshare among systems programming communities.

[0]: https://rust-for-linux.com

Rust-for-Linux issue tracker

It's true that if this project succeeds, that would be an outcome, but it's probably worth noting that you'd really only have to add support for the GCC backend to do that, and not reimplement the frontend as well (parsing, type checking, lifetime checking, etc.). There's an unrelated project working to do that: https://github.com/antoyo/rustc_codegen_gcc that would likely yield those same benefits for less effort.

platform support (may improve soon)

Here's the gcc backend for rustc here https://github.com/antoyo/rustc_codegen_gcc Since this just swaps the optimizer/codegen module and reuses all the other stuff from rustc it needs less work and can already compile many valid rust programs.

I'd like to use the rustc_codegen_gcc backend to compile some Rust programs, but I'm confused about how to install and use the patched libgccjit dependency. I've downloaded the fork provided but don't know where to go from there.

I was being a little sloppy and mixing together "actual embedded hardware" with "extensions for applications written in other languages" in my head. I think your point about LLVM is still accurate, though I hear peeps about different projects working on GCC support from time to time.

This doesn't have anything to do with using GCC to compile rust, but instead using rustc to compile Rust using the GCC backend. You can do that today by using the linked project, rustc_codegen_gcc, which is intended to be integrated into rustc at some point in the (hopefully near) future.

Rather than mrustc you should probably look at rustc_codegen_gcc which uses gcc as a backend to rustc (WIP) or GCC Rust which tries to implement a rust frontend for gcc (also WIP). I think rustc_codegen_gcc looks the most promising at the moment

Libgccjit AOT Codegen for Rustc\ (2 comments)