What's the current status of WASM/WASI support?

[Sebastiaan Koppe]

On Monday, 16 October 2023 at 04:11:19 UTC, redthing1 wrote:
> On Tuesday, 14 March 2023 at 23:45:12 UTC, ChrisG wrote:
>> In 2019, there was a blog post that indicated a strong push 
>> for wasm support was afoot. I've had a hard time pulling 
>> together information since then. I was curious if anyone has a 
>> good general perspective on the state of D wasm support. I 
>> can't tell if it's a mostly dead subject. It looks like 
>> betterC support is generally there, but I'm not sure about 
>> runtime or library support. Specifically, I was interested in:
>>
>> - What's the runtime support story (can I use GC)?
>> - What's the phobos support story?
>> - Are there alternate general purpose libraries folks have 
>> settled on for wasm development? (spasm?)
>> - Anything about WASI or Emscripten?
>>
>> Thanks.
>
> I was wondering actually, has anyone experimented with WASI + 
> D? I am interested in looking into it.

The d runtime port I did years ago used wasi and the wasi-libc. I 
ported the whole of druntime (aside from things like catching 
exception, fibers, etc.) but got stuck on the GC.

The trouble is that the GC is unable to scan the wasm stack (let 
alone the registers) so you have to spill pointers to the shadow 
stack. I know its possible, but never managed to find time to do 
it.