cargo-zigbuild VS c2rust

https://github.com/rust-cross/cargo-zigbuild

I’m curious what the blockers are for rustc to cross-compile like zig does natively.

Perhaps you can try cargo-zigbuild, it uses zig-cc for cross-compilation instead of creating a container, so it should be much more lightweight on MacOS, without all the cost of virtualization and file sharing.

I have tried, however I haven't been able to get it to work reliably (e.g. building on windows + linux on WSL works, Mac is a lot more involved; tried building for windows + linux on Mac and I couldn't get it to work at all); I've had some luck using zigbuild but that too doesn't seem to work for Mac.

Zig also takes this approach, and even exposes its C compiler (which if I recall correctly is basically Clang plus diverse sysroots and other customisation out of the box) as a separate `zig cc`.

I do a lot of work in Rust, and cross-compilation can be a pain when you have a lot of C dependencies. Fortunately https://github.com/messense/cargo-zigbuild exists. It sounds crazy, but using Zig's inbuilt C compiler to help build my Rust projects has been the smoothest option I've found.

I can't help but wonder if it would be worth it for Rust to follow D and Zig by shipping its own inbuilt C compiler, even if they still want to also support external C toolchains. It should be roughly the same effort as it was for Zig, given that they both use LLVM.

Wait until you start using cargo zig-build. Suddenly it becomes way better than Go's cross compiler because you can seamlessly cross-compile rust AND C (thanks to Zig compiler of course). https://github.com/messense/cargo-zigbuild

I've personally used cargo-zigbuild and cargo-xwin to distribute a GUI app built with iced.

A recent practical example of the former: the fish shell re-wrote incrementally from C++ to Rust, and is almost finished https://github.com/fish-shell/fish-shell/discussions/10123

An example of the latter: c2rust, which is a work in progress but is very impressive https://github.com/immunant/c2rust

It currently translates into unsafe Rust, but the strategy is to separate the "compile C to unsafe Rust" steps and the "compile unsafe Rust to safe Rust" steps. As I see it, as it makes the overall task simpler, allows for more user freedom, and makes the latter potentially useful even for non-transpiled code. https://immunant.com/blog/2023/03/lifting/

> The date at the bottom of the article is 2022-06-13. Has there been further progress?

The article links to their github repo:

https://github.com/immunant/c2rust

There's commits in the last hour, so at least some signal of life.

This is arguably already the state of things.

Rust might get compiled down through MIR, down through LLVM IR, down to assembly or wasm... which then might be JIT or AOT (re)compiled into other bytecodes... which might perhaps be decompiled back up to C... and C might be retranslated back to horrific unsafe-spamming Rust by the likes of https://c2rust.com/. We've come full circle!

The main issue is that retranslating high level languages into other high level languages isn't something that there's actually a lot of demand for, especially commercially, especially given the N x M translation matrix going on. So a lot of the projects "stabilize" (get abandoned). And automatically translating between the idioms of those languages gets even nastier in terms of matrix bloat.

Well, you've got stuff like MSIL and JVM bytecodes which are higher level, and preserve more type information, and can be compiled to / decompiled from while still preserving more structure, but they still form competing incompatible ecosystems.

That's the wrong direction. What's needed are intelligent converters which convert less-strict languages to more-strict ones.

Non-intelligent converters just make a mess. Here's c2rust.[1]

Classic C++ to modern C++, plus a compiler flag to lock out all the old unsafe stuff, would be an achievement.

[1] https://c2rust.com/

Well, technically, it's not hard to build such data structures. If you are willing to liberally use raw pointers, UnsafeCell, MaybeUninit and ManuallyDrop, then you can more-or-less write C-equivalent code in unsafe Rust. (there are even transpilers from C to Rust)

In the chart at [1], this step is represented by a magic wand.

(I wanted to give some examples, but https://c2rust.com/ seems to not be translating today.)

[1] https://c2rust.com/manual/

There are some tools specific to some transformations at least:

https://c2rust.com/

I expect that is because you're not particularly familiar with either LLVM or Rust, considering C can literally be transpiled to Rust.