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Mofei Zhang
c434ef4b70
---
We were throwing `InvalidReact` errors on valid inputs.
```js
// Input
function Foo() {
log("block0");
for (const _ of foo) {
log("loop");
}
useBar();
}
// IR
bb0:
// log("block0");
ForOf init=bb2 loop=bb3 fallthrough=bb1
bb2:
// init
Branch: then:bb3 else:bb1
bb3:
// log("loop")
Goto(Continue) bb2
bb1:
// useBar();
Return
```
We correctly compute post dominators here.
```js
// In validateUnconditionalHooks
console.log(dominators.debug());
/* Output:
(read x => y as x is the post-dominator for y (all paths from x to the exit must
go through y))
"bb4" => "bb4",
"bb1" => "bb4",
"bb2" => "bb1",
"bb3" => "bb2",
"bb0" => "bb2",
*/
```
However, `findBlocksWithBackEdges` prevented us from adding `bb1` to the
`unconditionalBlocks` set as `bb2` (its post dominator) has a back edge. I'm not
sure what the `findBlocksWithBackEdges` was doing previously, so I replaced it
with an invariant asserting that the loop terminates.