Emit unreachable tuple.make properly #2701
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We previously though unreachable `tuple.make` instructions did not require special unreachable handling, but consider the following wast: ``` (module (func $foo (tuple.make (unreachable) (i32.const 42) ) ) ) ``` This validates because the only expression in the body is unreachable, but when it is emitted as a binary it becomes ``` unreachable i32.const 42 ``` This does not validate because it ends with an i32, but the function expected an empty stack at the end. The fix is to emit an extra `unreachable` after unreachable `tuple.make` instructions. Unfortunately it is impossible to write a test for this right now because the binary parser silently drops the `i32.const 42`, making the function valid again.
aheejin
approved these changes
Mar 18, 2020
kripken
approved these changes
Mar 18, 2020
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We previously though unreachable
tuple.makeinstructions did notrequire special unreachable handling, but consider the following wast:
This validates because the only expression in the body is unreachable,
but when it is emitted as a binary it becomes
This does not validate because it ends with an i32, but the function
expected an empty stack at the end. The fix is to emit an extra
unreachableafter unreachabletuple.makeinstructions. Unfortunately it is impossible to write a test for this
right now because the binary parser silently drops the
i32.const 42,making the function valid again.