cargo-udeps VS rustc_codegen_cranelift

I'm releasing cargo-udeps 0.1.33 today. The release marks a big change in the evolution of cargo-udeps, as the default backend is changed from using save-analysis to depinfo. This change was needed because the compiler is removing support for save-analysis. I will remove support for the save-analysis backend entirely in a couple of weeks, when the 1.64 release is made, and I'll update cargo-udeps to the new cargo release.

rust-analyzer only provides a handful of diagnostics by itself, everything else is forwarded from cargo check (if checkOnSave is enabled). Neither tool currently emits a warning for unused dependencies, since it's pretty hard to do, but cargo-udeps can do it (though I'm not sure how reliable it is).

Maybe an extension to cargo-udeps?

cargo-udeps does a great job at letting us know which dependencies in our `Cargo.toml` are left unused. I am pretty impressed with it.

You can also turn off debuginfo completely. Personally, someone who does printf debugging, I mainly need it to debug segfaults, which are really rare in Rust. Sometimes the call stack of a panic is useful as well, but if I need debuginfo I can just re-enable it.

https://github.com/est31/cargo-udeps/commit/e550d93c7a6d756e...

Windows is supported. See https://github.com/rust-lang/rustc_codegen_cranelift/issues/....

> When this happens, it seems like it'll be possible to get the LLVM bits out of the bootstrap process and lead to a fully self-hosted Rust.

What do you mean by "when this happens"? GP's point is that this has already happened: the Cranelift backend is feature-complete from the perspective of the language [0], except for inline assembly and unwinding on panic. It was merged into the upstream compiler in 2020 [1], and a compiler built with only the Cranelift backend is perfectly capable of building another compiler. LLVM hasn't been a necessary component of the Rust compiler for quite some time.

[0] https://github.com/bjorn3/rustc_codegen_cranelift

[1] https://github.com/rust-lang/rust/pull/77975

Note that the Cranelift codegen will eventually become standard for debug builds to speed them up.

Maybe one day we'll have rustc b3 backend like what they did with Cranelift

Additionally, there is gcc codegen for rustc (https://github.com/rust-lang/rustc_codegen_gcc), which is not a compiler per se, but an alternative code generator, with more architectures supported and other nice things. It's also coming along, but there's still a lot of work to do there too. There's also Cranelift codegen (https://github.com/bjorn3/rustc_codegen_cranelift), which is designed to make debug builds faster, but this is not as exciting/useful as the other 2.

For the instant reloading, that's in Sycamore, so you should speak to its devs, but as for the alternative compiler backend, it's not my project, but it uses Cranelift and works pretty well! See https://github.com/bjorn3/rustc_codegen_cranelift for details.

The more immediate goal of "distribute the cranelift backend as a rustup component" has been making good progress and seems like it might happen relatively soon https://github.com/bjorn3/rustc_codegen_cranelift/milestone/...