dmd VS rustc_codegen_cranelift

Here's the pipeline spitting out the same error as on my macbook did.

https://github.com/dlang/dmd/actions/runs/8023469412/job/219...

Not completely on topic (if you read TFA) but my favorite Git commit is by compiler badass and HN frequenter, where he checks in an entire C compiler to the D language repo:

https://github.com/dlang/dmd/pull/12507

https://news.ycombinator.com/item?id=27102584

A new generated code alone is 4000 lines long [1]. The actual code added is just 2000 lines, and some are used to pay debts, I mean, to make a proper code generator (which can be alternatively written in a simpler scripting langauge). In any case it is never comparable to the entier C parser proper.

[1] https://github.com/dlang/dmd/pull/15307/files#diff-3677bcc89...

D is completely opensource already (https://github.com/dlang/dmd). The "open" of OpenD is just ADR saying that OpenD will be more open to new language features than D has historically been.

The reference compiler, DMD, is open source: https://github.com/dlang/dmd

But they don't accept just any Pull Request or features the community submits, understandably. There's a process called DIP for language improvements: https://github.com/dlang/DIPs/blob/master/DIPs/README.md

However, by some accounts, it's really hard to get anything through.

Given D already has so many feature, I find that to be a good thing , to be honest, by not everyone agrees, of course.

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/...