Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34): Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34):fitzgen opened PR #14962 from fitzgen:transfer-borrow-to-owner to bytecodealliance:main:
When passing a resource borrow to the instance that defined the resource type, we do not put the borrow into the instance's table, but instead return the resource's rep directly. We actually statically know whether we are in this case or not, so this commit makes us emit a separate libcall that skips the dynamic check of whether we can save work or not and just does the right thing automatically.
This is not really a win by itself in practice, but is meant instead to start paving the way for an eventual inline fast path for this scenario.
<!--
Please make sure you include the following information:
If this work has been discussed elsewhere, please include a link to that
conversation. If it was discussed in an issue, just mention "issue #...".Explain why this change is needed. If the details are in an issue already,
this can be brief.Our development process is documented in the Wasmtime book:
https://docs.wasmtime.dev/contributing-development-process.htmlPlease review the Bytecode Alliance's AI tool usage policy at
https://github.com/bytecodealliance/governance/blob/main/AI_TOOL_POLICY.mdPlease ensure all communication follows the code of conduct:
https://github.com/bytecodealliance/wasmtime/blob/main/CODE_OF_CONDUCT.md
-->
Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34):fitzgen requested wasmtime-compiler-reviewers for a review on PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34):fitzgen requested cfallin for a review on PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34):fitzgen removed the review request for wasmtime-compiler-reviewers from PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 14:34):fitzgen requested wasmtime-core-reviewers for a review on PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 15:36)::thumbs_up: alexcrichton submitted PR review.
Wasmtime GitHub notifications bot (Oct 23 2026 at 15:36)::speech_balloon: alexcrichton created PR review comment:
This looks like it's not actually running anything, is that intentional?
Wasmtime GitHub notifications bot (Oct 23 2026 at 16:11)::memo: fitzgen submitted PR review.
Wasmtime GitHub notifications bot (Oct 23 2026 at 16:11)::speech_balloon: fitzgen created PR review comment:
Yeah, it exists to just make sure that we also compile the non-owner code path, but we can't really actually run it in the wast tests without host cooperation. Maybe it makes more sense as a disas test? Or do you think it is worth promoting to a
#[test]and actually running the code?
Wasmtime GitHub notifications bot (Oct 23 2026 at 18:50):github-actions[bot] added the label wasmtime:api on PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 19:37)::memo: alexcrichton submitted PR review.
Wasmtime GitHub notifications bot (Oct 23 2026 at 19:37)::speech_balloon: alexcrichton created PR review comment:
Ah ok, not worth a
#[test]IMO, but this might be runnable by having another component which calls this component with a borrow perhaps? I think thehostinterface has some sort of resource-creation functionality.
Wasmtime GitHub notifications bot (Oct 23 2026 at 21:38):fitzgen updated PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 21:38):fitzgen has enabled auto merge for PR #14962.
Wasmtime GitHub notifications bot (Oct 23 2026 at 21:48):fitzgen added PR #14962 Add a dedicated libcall for passing resource borrows to their owners to the merge queue.
Wasmtime GitHub notifications bot (Oct 24 2026 at 09:48)::check: fitzgen merged PR #14962.
Wasmtime GitHub notifications bot (Oct 24 2026 at 09:48):fitzgen removed PR #14962 Add a dedicated libcall for passing resource borrows to their owners from the merge queue.
Last updated: Oct 31 2026 at 23:03 UTC