Compiler-explorer: Rustc: Would it be possible to support WASM?

[adiba]

Compiling with rustc and --target wasm32-unknown-unknown fails because this target is not installed.
Support for WASM and WebAssembly Text Format in the output pane would be great.

[CryZe]

It may actually make sense to add other targets like arm, powerpc and co. as well, considering some other languages have those.

It should mostly be fairly trivial to add this as rustc can already cross compile, it just needs a precompiled std which you can get from rustup and co.

[CryZe]

It already works if you try hard enough (copying parts of rust's core library, so we don't need a precompiled one). Here's a little rust fibonacci implementation compiled to WebAssembly, AArch64 and PowerPC64 on Godbolt: Godbolt Craziness

Also fun: compiling to JavaScript

[adiba]

@CryZe interesting!
why does it fail with opt-level=0 though?

[CryZe]

If you mean the missing panic item error. That's because opt-level=0 has panic paths that would get optimized away otherwise and I didn't copy the panic handling code from libcore / libstd. But I think wasm-unknown-unknown generally has problems with opt-level=0 atm