Stream: general

Topic: ✔ on move from 8.* -> 10.*,

view this post on Zulip Zeeshan Lakhani (Jul 04 2023 at 18:44):

After moving o the newest release(s), I get everything to work with my test suite, except a type using

(list (tuple string (union bool u16))), which returns an error of type not valid to be used as export (at offset 0x158 when using Component::new...

This export is all handled with a similar foundation to the make_echo_component code used in the wasmtime codebase. Which change from 8 -> 10 would change this behavior? It essentially does like the combo of list w/ union or tuple with union either.

cc @Pat Hickey.

view this post on Zulip Zeeshan Lakhani (Jul 04 2023 at 19:00):

For example, (list (tuple string string)) works no problem (we emulate this kinda type as a "map" variant)

view this post on Zulip Zeeshan Lakhani (Jul 04 2023 at 19:00):

So, probably related to for to validations and the test suite on this?

view this post on Zulip Zeeshan Lakhani (Jul 05 2023 at 04:00):

Though maybe my answer lies here: https://github.com/bytecodealliance/wasm-tools/blob/main/tests/local/component-model/type-export-restrictions.wast#L69, as they are incompatible, but wasn't being caught in 8.* versions?

wasm-tools/tests/local/component-model/type-export-restrictions.wast at main · bytecodealliance/wasm-tools
Low level tooling for WebAssembly in Rust. Contribute to bytecodealliance/wasm-tools development by creating an account on GitHub.

view this post on Zulip Lann Martin (Jul 05 2023 at 13:30):

Pretty sure it's this: https://github.com/bytecodealliance/wasm-tools/pull/966/commits/6fc54cd57487db05a3e85af969b6b040c9c4df0e

Initial implementation of resource types by alexcrichton · Pull Request #966 · bytecodealliance/wasm-tools
This commit is an initial implementation of resource types for the component model. The support added in this commit encompasses: wasmparser - parsing and validation of resource types wasmprinter ...

view this post on Zulip Alex Crichton (Jul 05 2023 at 14:06):

Yes wasms which were previously accepted are not longer accepted after the change the Lann mentioned, and IIRC the make_echo_component has had updates which you may wish to mirror if you based code on that.

view this post on Zulip Zeeshan Lakhani (Jul 06 2023 at 17:19):

Alex Crichton said:

Yes wasms which were previously accepted are not longer accepted after the change the Lann mentioned, and IIRC the make_echo_component has had updates which you may wish to mirror if you based code on that.

yep. Brought in these updates too. And, yes, thank you @Alex Crichton and @Lann Martin, this PR is what def makes sense toward the changes.

view this post on Zulip Notification Bot (Jul 06 2023 at 18:33):

Zeeshan Lakhani has marked this topic as resolved.

view this post on Zulip Zeeshan Lakhani (Aug 18 2023 at 04:20):

@Alex Crichton @Lann Martin (or anyone), is there a good link or definitive source or two to find the reasoning(s) on why certain type-export restrictions were made? I'm particularly interested in lists of variants for example, but open to learning more. Thanks!

view this post on Zulip Lann Martin (Aug 18 2023 at 10:57):

The component-model repo is as definitive as anything, though I don't know if it contains the answer to your question.

view this post on Zulip Alex Crichton (Aug 18 2023 at 14:28):

The main motivation for requiring names of exports was to facilitate bindings generation within guest/host languages where few languages have anonymous record or variant types, e.g. Rust requires named structs and named enum types. The requiring of names is also required for resources so this change was also made in anticipation of resources in the future.

Is this change causing issues for you though? It is theoretically the case that if you're using WIT with up-to-date tooling it's basically a non-issue, so the main pain in theory should be updating everything as opposed to hitting active issues when the tooling is all updated

view this post on Zulip Zeeshan Lakhani (Aug 19 2023 at 05:56):

@Alex Crichton Oh things are generally working and we're updated to the newest version and tooling :). But, we're building this interpreter between WIT and https://ipld.io/ (the underlying data model for IPFS and similar things), and semantically, while IPLD is a recursive data model/structure and can't be modeled directly as is of course, it'd be nice to model some types as lists of a variant type or union type for example or express maps as records and/or lists of tuples, where then you want to expose unions or variants as types for "values" of a tuple (k,v) pair. Nonetheless, thanks for responses to even bring it up :)

IPLD - The data model of the content-addressable web
The data model of the content-addressable web. It allows us to treat all hash-linked data structures as subsets of a unified information space, unifying all data models that link data with hashes as instances of IPLD.

view this post on Zulip Alex Crichton (Aug 21 2023 at 14:06):

Ah ok makes sense, and while tuple<...> does exist in WIT it sounds like you probably want a sort of map<K, V> which I think there's an issue for on the component model repo, but otherwise thanks for explaining :+1:

Last updated: Nov 22 2024 at 16:03 UTC