[gwbas1c]

It's been awhile since I skimmed the proposal. What I remember is that it was "just enough" to be compatible with Javascript; but didn't have the hooks that C# needs. (I don't remember any mentions about the JVM.)

I remember that the C# WASM team wanted callbacks for destructors and type metadata.

Personally, having spent > 20 years working in C#, destructors is a smell of a bigger problem; and really only useful for debugging resource leaks. I'd rather turn them off in the WASM apps that I'm working on.

Type metadata is another thing that I think could be handled within the C# runtime: Much like IntPtr is used to encapsulate native pointers, and it can be encapsulated in a struct for type safety when working with native code, there can be a struct type used for interacting with non-C# WASM managed objects that doesn't contain type metadata.

[neonsunset]

Here's the issue which gives an overview of the problems: https://github.com/WebAssembly/gc/issues/77

Further discussion can be found here: https://github.com/dotnet/runtime/issues/94420

Turning off destructors will not help even a little because the biggest pain points are support for byref pointers and insufficient degree of control over object memory layout.