Stream: git-wasmtime

Topic: wasmtime / PR #14873 Rework the `named_imports` lookup in...

Wasmtime GitHub notifications bot (Oct 19 2026 at 22:25):

jrandolf opened PR #14873 from jrandolf:named-imports-lookup-api to bytecodealliance:main:

This builds on #14867, so only the last two commits are new here.

It reworks the named_imports lookup that bindgen! generates:

• The lookup gets the import's ComponentExtern next to its name, so it can use external-id, which the spec intends for telling the host how to supply an import. Before, it only got the name.
• The lookup returns Result<Option<Id>>. Ok(None) skips the import, leaving it to be defined some other way, e.g. with add_to_linker_instance or define_unknown_imports_as_traps. Before, the only way to not bind an import was to fail linking.
• Tracing records the label. The named add_to_linker_instance now also takes the import's name, which traced functions record as label in their spans. Before, a.get and b.get logged identical spans.
• Clear errors for label keys. A with, imports, named_imports or trappable_error_type key that names a labelled import (e.g. "a" or "a.get") used to give a misleading "not referenced" or "unused rules" error. It now explains that labelled imports share their interface's bindings and are configured through the interface's name. The docs now describe how keys work for labelled imports vs labelled exports.

wasmtime-wasi's and wasmtime-wasi-http's add_named_to_linker functions take the same lookup, with the Interface as an extra first argument. This is a breaking change, but these APIs only matter with implements, which is unstable and off by default.

Tracing for labelled imports without named_imports still looks the same for every label. Those all go through the one shared add_to_linker_instance, which doesn't know the name, and changing that would touch every generated interface.

#14872 changes the same generated add_to_linker loop, so whichever lands second will need a rebase.

Closes #14860

Last updated: Oct 31 2026 at 23:03 UTC