Don't duplicate instruction encodings in wast - #2679
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alexcrichton merged 1 commit intoSep 28, 2026
Merged
alexcrichton merged 1 commit into
alexcrichton merged 1 commit into
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This commit resolves a longstanding issue where instruction encodings in the `wasm-encoder` crate are duplicated in the `wast` crate. This dates back to where `wast` came before `wasm-encoder`, but nowadays it's just duplication that's a bit onerous to maintain. This commit refactors the macro here to be a bit wordier/un-idiomatic but delegates to `wasm_encoder::InstructionSink` for encoding all instructions. Most instructions fit in a pattern that don't need custom code, but a number of instructions are annotated with `#[custom_encode]` now to manually specify how the `wast` structures are translated to `wasm-encoder` arguments.
dicej
approved these changes
Sep 28, 2026
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This commit resolves a longstanding issue where instruction encodings in the
wasm-encodercrate are duplicated in thewastcrate. This dates back to wherewastcame beforewasm-encoder, but nowadays it's just duplication that's a bit onerous to maintain. This commit refactors the macro here to be a bit wordier/un-idiomatic but delegates towasm_encoder::InstructionSinkfor encoding all instructions. Most instructions fit in a pattern that don't need custom code, but a number of instructions are annotated with#[custom_encode]now to manually specify how thewaststructures are translated towasm-encoderarguments.