Add WASI abort, trace and seed implementations

[dcodeIO]

Terrible implementations of abort and trace specifically for WASI that are as minimal and robust as it gets (allocation would be especially evil in abort if the abort originates in MM/GC).

Output format is:

abort: MESSAGE in FILE(LINE:COLUMN)

trace: MESSAGE[ $0[ $1[ $2[ $3[ $4]]]]]

Also implements seed, which is a new API for seeding Math.random. Now happens automatically in WASI environments, and requires an import env.seed in other environments.

Presence of the WASI bindings is automatically detected. Usage is:

import "wasi"; // anywhere in your own or one of your dependency's code

with each of the APIs being overridable with --use just as before (with or without WASI being present).

[dcodeIO]

Alright, it now also supports UTF8 and can auto-detect the presence of the WASI bindings. New usage is:

import "wasi"; // anywhere in your code

As soon as the WASI bindings are used, the non-standard fallback abort handler is automatically replaced with WASI's.

[MaxGraey]

It could be great do same auto-detection for seedRandom: #1080 as well. wdyt?

[dcodeIO]

This now not only implements abort but also, trace and seed. The latter is new and a potential breaking change superseding #1080. Instead of adding configuration options, the seed function is provided by the WASI bindings respectively imported as env.seed, returning an f64. It's still possible to call NativeMath.seedRandom with this, but the import must always be present if random is used. Similar to abort, this one can also be overridden via --use seed=assembly/index/mySeed.

[dcodeIO]

Also verified that the tests "just work" in a few actual headless Wasm VMs, but I guess we'll want something to do that as part of the test suite eventually. Tried Wasmtime and Wasmer, which both seem very similar.

[torch2424]

Thank you sooooooo much for this! 🙏 😄

I think this is going to make WASI like 1000x easier to get started with in my opinion 😄 Especially once we update as-wasi on top of this 😄 👍

[torch2424]

Wooooaaaahhh this is soooo cool! 💥 🎉

Thank you so much for this, it's like 1000x cooler than what I was suggesting haha! 😄

[torch2424]

With the import "wasi" syntax. Does this automatically provide all of the bindings, without having to import them individually?

And I assume current projects can just keep importing them individually right? 😄 This is such a great solution 😄

[dcodeIO]

Yes, one can either enable all this stuff including stdlib-provided implementations abort/trace/seed by import "wasi" or use the bindings with custom implementations and command line options (similar to before, import "bindings/wasi"), with the former implying (and re-exporting) the latter.

[dcodeIO]

In case this didn't exactly answer the question: import * as wasi from "wasi" is what one would do to also have all the bindings at their fingertips :)

[torch2424]

Oh that's perfect! Thank you! 😄 👍

[jedisct1]

That's a very nice improvement!