P3 taskReturn incorrectly assumes that parameters are passed in memory

[cpetig]

I know that support for P3 isn't completed, but perhaps a nicely self contained example can help debugging this remaining issue.

A function returning result<s32, string> will call [task-return][async]N with three flattened integer parameters (the result enum index, the number or an string address, zero or the string length). The current code assumes that the parameters are passed in memory and thus fails to correctly lift them.

jco_async_bug.zip

[vados-cosmonic]

Thanks for filing this @cpetig ! Yeah that number of params is definitely below the cut off for pushing to memory (MAX_FLAT_PARAMS is 4 IIRC) -- will take a look at the repro that you included and see if we can add a test to catch and fix this.

[cpetig]

@vados-cosmonic If providing the test in a different format (e.g. if you prefer wat or wast?) can help you please tell me.

[vados-cosmonic]

Nope a Rust component is perfect -- I may just end up adding the built component to the fixture suite since unfortunately JS components are much heavier that ones built in Rust for now.

[vados-cosmonic]

Hey @cpetig I've gotten this fixed now so your example works -- there are a bunch more spots that need touchups and more impl to check through, but as this is still experimental I'll get this version out quickly (with some other fixes) so that you can bump versions!

[jco-release-bot]

🎉 Code that fixes this issue is in the following release:
https://github.com/bytecodealliance/jco/releases/tag/js-component-bindgen-v1.13.0

[vados-cosmonic]

Also, the new js-component-bindgen version is out in jco 1.15.3, so please feel free to try that out!

[cpetig]

Thanks a lot!