[wasm2js] Enforce declared memory maximum in __wasm_memory_grow#8352
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sumleo wants to merge 2 commits intoWebAssembly:mainfrom
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[wasm2js] Enforce declared memory maximum in __wasm_memory_grow#8352sumleo wants to merge 2 commits intoWebAssembly:mainfrom
sumleo wants to merge 2 commits intoWebAssembly:mainfrom
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The generated __wasm_memory_grow JS function only checked against the absolute wasm32 page limit (65536) but did not enforce the module's declared memory maximum. For example, a module with (memory 1 2) would allow growing beyond 2 pages in the JS output. Add a check against wasm->memories[0]->max when the memory has a declared maximum, generating an additional (newPages <= max) condition in the grow function's guard.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
__wasm_memory_growJS function generated by wasm2js only checked against the absolute wasm32 page limit (65536) but did not enforce the module's declared memory maximum. For example, a module with(memory 1 2)(max 2 pages) would allow growing beyond 2 pages in the generated JS output.maxwhen the memory has one, generating an additional(newPages <= max)condition in the grow function's guard clause.grow-memory-max.wast) that exercises memory growth with a declared maximum.Test plan
binaryen-unittests)check.py wasm2js), including the newgrow-memory-max.wasttestemscripten-grow-yestests which declare(memory 256 1024)-- now correctly includes(newPages <= 1024)in the grow guardnewPages < 65536)