Fix #8785: StackEntry wasm stack type invariants and unreachable parser regressions - #8978
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ANAMASGARD wants to merge 7 commits into
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Fix #8785: StackEntry wasm stack type invariants and unreachable parser regressions#8978ANAMASGARD wants to merge 7 commits into
ANAMASGARD wants to merge 7 commits into
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Track Wasm operand-stack effects separately from Binaryen IR types via StackEntry::wasmStackType. Key fixes: - Sync wasmStackType to none when dropping unreachable predecessors - Guard finishScope tuple repackaging when hoist is empty - Mask deeper stack values under unreachable in hoistLastValue Adds validation tests for unreachable void-block drop, multivalue tuple parsing, and related edge cases.
Extend pushControlFlow/finishScope handling so void unreachable fallthrough control flow and return_call inside try remain parseable in concrete-result functions, while preserving WebAssembly#8785 rejection of (block (unreachable)) (drop). Allow void unreachable fallthrough blocks to satisfy concrete operand pops (e.g. if/br_if conditions). Skip struct.get field typing when the ref is unreachable. Add focused validation regressions for try/return_call and concrete block ends. Lit ledger: /tmp/binaryen-lit-ledger/report.md
Track void stack entries skipped in unreachable scopes so operand popping can match concrete values below (gufa struct.new) while still synthesizing unreachable operands when types mismatch (br_table index).
Treat wasm unreachable instructions (wasmStackType none but expr type unreachable) as polymorphic stack values in hoistLastValue, checkNeedsUnreachableFallback, and pop. Drop non-final concrete stack entries when building typed multi-expression blocks. Fixes array-multibyte parser failure and wasm-split validator errors. Adds unreachable-array-store-value-valid.wast regression test.
When wasmStackType is none but a void block retains expr->type unreachable, treat it as a poppable stack entry. Fixes -S pipe roundtrip on array-multibyte and drop(block) reparse paths.
The parser now distinguishes unreachable barriers from ordinary void entries, which changes block/drop/unreachable nesting in -S output across many tests. Also fixes scratch-local-roundtrip RTRIP checks and updates two validation tests to match baseline parse behavior.
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Fixes parser/IRBuilder regressions from tracking Wasm operand-stack effects separately via
StackEntry::wasmStackType(#8785).wasmStackTypeon the IRBuilder expression stack and keep it in sync with Wasm stack semantics (unreachable barriers vs ordinary void instructions).-Spipe roundtrip, e.g.array-multibyte).-Sexpectations: output shape changes (extrablock/drop/unreachablenesting), not semantic IR changes.Test plan
build-clang/bin/binaryen-unittests— 379/379build-clang/bin/binaryen-lit test/lit -j 2— 982/986 (only 4 pre-existingd8/fuzz_shell*.wastfailures; needv8)test/lit/validation/unreachable-*.wastarray-multibyte,wat-kitchen-sink,remove-unused-brs_enable-multivalue,wasm-split/split-module-items