perry VS rustc_codegen_cranelift

On other sites, like github and reddit. This exchange was funny though. He eventually gets called out by the other commenter to stop responding with an LLM: https://github.com/PerryTS/perry/issues/139#issuecomment-429...

Hey HN — I've been building Perry, a compiler that takes TypeScript and emits native binaries. No V8, no runtime, no Electron. It maps to platform-native UI widgets: AppKit on macOS, UIKit on iOS, Android Views on Android, GTK4 on Linux, Win32 on Windows.

Pry is the first real app built with it — a JSON viewer, deliberately small.

It's in the iOS/macOS App Store and Google Play right now. Linux build works, Windows is waiting on code signing.

The compiler itself is written in Rust. It handles TypeScript parsing, type checking, and lowers to native code. The UI bindings aren't a wrapper library — the compiler generates the actual platform API calls.

This is a building-in-public thing. Pry is the proof-of-concept. The bigger goal is a full IDE. Happy to answer questions about the compiler architecture, the app store submission process, or anything else.

Compiler repo: https://github.com/PerryTS/perry

> I wonder if how much value there is in skipping LLVM in favor of having a JIT optimized linked in instead. For release builds it would get you a reasonable proxy if it optimized decently while still retaining better debugability.

Rust is in the process of building out the cranelift backend. Cranelift was originally built to be a JIT compiler. The hope is that this can become the debug build compiler.

https://github.com/rust-lang/rustc_codegen_cranelift

There's no reason? Are you sure about this?

I think you mean there could theoretically be an interpreted Rust, but I don't think anyone has ever made a prototype of a Rust interpreter.

The closest is probably rust-analyzer (the official language server), that maintains internal state and reacts to changes you make, but it doesn't create an executable artifact.

The other is probably the Cranelift Backend (https://github.com/rust-lang/rustc_codegen_cranelift), which can produce debug builds quickly.

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.