add implements support#1756
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LGTM 🚀
This is basically ready, nothing but nits here -- thanks for knocking this out @ricochet. Shame we can't fully be sure it will work given the lack of support of try_table/exnref across engines (TIL), but certainly happy to land support for this sooner rather than later.
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Updates the wasmtime family (wasmtime, wasmtime-environ) from 46 to 47.0.2 (enabling wasmtime-environ's `anyhow` feature for error conversions), the wasm-tools family (wasm-encoder, wasm-metadata, wasmparser, wasmprinter, wat, wast, wit-component, wit-parser) from 0.253 to 0.254, and wit-bindgen(-core) from 0.59 to 0.60. Migration notes: - the per-instance flags global now holds a single boolean `may_leave` flag rather than a MAY_ENTER|MAY_LEAVE bitmask, so the generated JS global is initialized to `1` - wasmtime-environ 47's FACT-generated adapters wrap calls in exception barriers (`try_table` + `catch_all`) when the exceptions feature is enabled. The multi-memory augmenter learns to re-encode `try_table`, and a new `supports_wasm_exnref` transpile option (default off) controls whether the exceptions feature is enabled during validation, since the resulting core modules only run behind a flag (e.g. --experimental-wasm-exnref) in today's JS engines.
Adds support for the component model `implements` proposal (WebAssembly/component-model#613 and bytecodealliance#672): - `import label: ns:pkg/iface` / `export label: iface` in WIT: named (labeled) imports and exports of interfaces, including importing the same interface under multiple labels. Transpiled bindings import each label under its own specifier, and `--map` entries for the implemented interface id apply to labeled imports (label-specific mappings win) - resource-bearing interfaces imported under multiple labels resolve each label's resource class through that import instance's own resource table rather than the wit type, which is shared by all labels - `jco types` aliases each label to the shared interface module - `@external-id("...")` attributes round-trip through embed/new/print/wit - `(implements "...")` name validation is enabled during transpile via `WasmFeatures::CM_IMPLEMENTS` Adds an `implements-labels` rust test component exercising labeled imports and exports end to end at runtime. Note: binaries carrying `(external-id ...)` names can be produced and printed but not yet transpiled -- wasmtime-environ 47 embeds wasmparser 0.252, which predates external-id name-option parsing (0.253); support lands with the next wasmtime-environ release.
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Adds support for the component model
implementsproposal (WebAssembly/component-model#613 and WebAssembly/component-model#672):import label: ns:pkg/iface/export label: ifacein WIT: named (labeled) imports and exports of interfaces, including importing the same interface under multiple labels. Transpiled bindings import each label under its own specifier, and--mapentries for the implemented interface id apply to labeled imports (label-specific mappings win)jco typesaliases each label to the shared interface module@external-id("...")attributes round-trip through embed/new/print/wit(implements "...")name validation is enabled during transpile viaWasmFeatures::CM_IMPLEMENTSNote: binaries carrying
(external-id ...)names can be produced and printed but not yet transpiled. wasmtime-environ 47 embeds wasmparser 0.252, which predates external-id name-option parsing (0.253).This also updates wasmtime-environ from 46.0.1 to 47.0.2, enabling its
anyhowfeature for error conversions. Migration notes:may_leaveflag rather than a MAY_ENTER|MAY_LEAVE bitmask, so the generated JS global is initialized to1try_table+catch_all) when the exceptions feature is enabled. The multi-memory augmenter learns to re-encodetry_table, but the exceptions feature is masked off the transpile validator for now since the resulting core modules would only run behind --experimental-wasm-exnref in today's JS engines.I went ahead and bumped js-component-bindgen to 2.1.0 as this is a new feature. Is that the preferred flow here?