Stream: git-wasmtime

Topic: wasmtime / PR #9145 Introduce `wasmtime::ArrayRef` and al...

Wasmtime GitHub notifications bot (Aug 19 2024 at 22:06):

fitzgen requested wasmtime-core-reviewers for a review on PR #9145.

Wasmtime GitHub notifications bot (Aug 19 2024 at 22:06):

fitzgen requested alexcrichton for a review on PR #9145.

Wasmtime GitHub notifications bot (Aug 19 2024 at 22:06):

fitzgen opened PR #9145 from fitzgen:host-allocate-gc-arrays to bytecodealliance:main:

This commit introduces the wasmtime::ArrayRef type and support for allocating Wasm GC arrays from the host. This commit does not add support for the array.new family of Wasm instructions; guests still cannot allocate Wasm GC objects yet, but initial support should be pretty straightforward after this commit lands.

The ArrayRef type has everything you expect from other value types in the wasmtime crate:

• A method to get its type or check whether it matches a given type

• An implementation of WasmTy so that it can be used with Func::wrap-style APIs

• The ability to upcast it into an AnyRef and to do checked downcasts in the opposite direction

There are, additionally, methods for getting, setting, and enumerating a ArrayRef's elements.

Similar to how allocating a Wasm GC struct requires a StructRefPre, allocating a Wasm GC array requires an ArrayRefPre, and this is motivated by the same reasons.

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Wasmtime GitHub notifications bot (Aug 19 2024 at 22:19):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 01:04):

github-actions[bot] commented on PR #9145:

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Wasmtime GitHub notifications bot (Aug 20 2024 at 15:09):

alexcrichton created PR review comment:

Should these propagate Result to avoid panicking on out-of-bounds things?

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:09):

alexcrichton created PR review comment:

(same for writing below)

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:09):

alexcrichton created PR review comment:

I realize this is preexisting but having read/write on arrays not actually return a result above felt a bit weird

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:09):

alexcrichton created PR review comment:

Could this be std::iter::repeat(..).take(N)?

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:09):

alexcrichton submitted PR review:

Just some minor comments :+1:

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:18):

fitzgen submitted PR review.

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:18):

fitzgen created PR review comment:

This isn't really a user-visible failure case; the only way it can fail is a bug in the runtime or the GC. Additionally, the non-vm layer is responsible for performing the various type checks and such — everything that is fallible and recoverable from the user — and this layer is just handing out bytes from the GC heap, but also makes sure that everything is in bounds to preserve our memory-safety-in-the-face-of-GC-bugs properties. Given all that, I'm inclined to leave things as they are, although I am happy to update docs if you think the docs at the top of this type aren't detailed enough.

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:20):

fitzgen submitted PR review.

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:20):

fitzgen created PR review comment:

Unfortunately not because std::iter::Take is only an ExactSizeIterator when its inner iterator is, and std::iter::Repeat is not an ExactSizeIterator.

Wasmtime GitHub notifications bot (Aug 20 2024 at 15:24):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 16:38):

fitzgen requested abrown for a review on PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 16:38):

fitzgen requested wasmtime-default-reviewers for a review on PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 16:38):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 16:39):

fitzgen has enabled auto merge for PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 17:35):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 18:24):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 19:25):

fitzgen updated PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 19:25):

fitzgen has enabled auto merge for PR #9145.

Wasmtime GitHub notifications bot (Aug 20 2024 at 19:54):

fitzgen merged PR #9145.

Last updated: Dec 13 2025 at 19:03 UTC