Wasmtime GitHub notifications bot (Oct 30 2026 at 21:42): Wasmtime GitHub notifications bot (Oct 30 2026 at 21:42):alexcrichton opened PR #15099 from alexcrichton:remove-concrete-exn-in-api to bytecodealliance:main:
This commit removes the
ConcreteExnvariant from the public API of Wasmtime and itsHeapTypeenum. I brought this up earlier in #14011 which was closed, but I'd like to push on this again at least from the angle of the public API of Wasmtime. Specifically this fixes a possible unusual situation where:
- A host function is created with
HeapType::ConcreteExnas one of its arguments.- This function is called with a different kind of concrete exception.
- Due to a missing type check which in theory shouldn't actually be necessary, this actually passes at runtime.
There's no panic/etc here and this is just a weird situation, but this exposes a part of exposing
ConcreteExnin the public API which is that it affects not just what's read from WebAssembly but what's also passed back in from the host. For example creating a GCstructtype with concrete exception types doesn't really make sense, but it's possible with today's embedder API.This change is not as invasive as #14011 and only limits the public API surface area of Wasmtime. The goal is to have the public API faithfully reflect wasm's type system to avoid introducing our own abstractions and having to reconcile that.
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Wasmtime GitHub notifications bot (Oct 30 2026 at 21:42):alexcrichton requested cfallin for a review on PR #15099.
Wasmtime GitHub notifications bot (Oct 30 2026 at 21:42):alexcrichton removed the review request for wasmtime-core-reviewers from PR #15099.
Wasmtime GitHub notifications bot (Oct 30 2026 at 21:42):alexcrichton requested wasmtime-core-reviewers for a review on PR #15099.
Wasmtime GitHub notifications bot (Oct 30 2026 at 21:47):alexcrichton updated PR #15099.
Wasmtime GitHub notifications bot (Oct 31 2026 at 00:49):github-actions[bot] added the label wasmtime:api on PR #15099.
Wasmtime GitHub notifications bot (Oct 31 2026 at 00:49):github-actions[bot] added the label wasmtime:c-api on PR #15099.
Wasmtime GitHub notifications bot (Oct 31 2026 at 00:49):github-actions[bot] added the label wasmtime:ref-types on PR #15099.
Wasmtime GitHub notifications bot (Oct 31 2026 at 01:45):github-actions[bot] commented on PR #15099:
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Last updated: Oct 31 2026 at 23:03 UTC