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bitsetBitfieldComparison guards the shift with testShiftInRange's 0..63 check (64-bit word semantics) but shifts 1usize. On 32-bit targets (wasm32), usize is 32 bits and the shift amount wraps mod 32, so e.g. 1usize << 35 evaluates to 1 << 3 -- false set-membership, and ATN prediction takes the wrong alternative for any token whose offset lands in 32..63. Widening the literal to u64 matches the guard's assumption and is semantically identical on 64-bit targets. Fixes #47
Scans tests/gen for '1usize <<' -- enforceable on 64-bit CI (where the behavioral bug is invisible) because build.rs regenerates tests/gen from the grammars whenever the tool jar is present, so a template regression trips this on the next generating run. Also widens the one occurrence in the checked-in csvparser.rs, which was produced by the unfixed template. Full behavioral repro requires a 32-bit target (e.g. cargo test --target wasm32-wasip1); documented in the test.
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Fixes #47.
bitsetBitfieldComparisonguards the shift withtestShiftInRange's 0..63 check (64-bit word semantics) but shifts1usize. On 32-bit targets (wasm32),usizeis 32 bits and the shift amount wraps mod 32, so e.g.1usize << 35evaluates to1 << 3— false set-membership, and ATN prediction takes the wrong alternative for any token whose offset lands in 32..63 of a decision's mask. Same input parses correctly on 64-bit targets, which is what makes this easy to miss.Widening the literal to
u64matches the guard's assumption and is semantically identical on 64-bit (the mask literal infersu64from the lhs). Verified downstream on a large community grammar: applying exactly this widening to the generated output fixed all wasm32 misparses with no behavior change on 64-bit.