Fix #10116: Fix adaptConstant to that it survives Ycheck #10280
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sjrd
requested changes
Nov 11, 2020
| @@ -3425,7 +3425,7 @@ class Typer extends Namer | |||
| // try converting a constant to the target type | |||
| val folded = ConstFold(tree, pt) | |||
| if (folded ne tree) | |||
| return adaptConstant(folded, folded.tpe.asInstanceOf[ConstantType]) | |||
| return adaptConstant(tree, folded.tpe.asInstanceOf[ConstantType]) | |||
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Hum. Looking at this fix and at ConstFold.apply(tree, pt), I think the latter basically produces an invalid tree, that is never safe to reuse.
I also see that ConstFold.Apply(tree, pt) is used only here. With the fix, we are therefore patching the invalid result of ConstFold.apply at its only call site; but if someone starts calling that overload somewhere else, they will likely reintroduce a similar bug.
Consider inlining the contents of that overload of ConstFold(tree, tp) here instead. Once you do that, you won't have to create that transient invalid tree, since you'll be able to directly use x.convertTo(tp) instead of folded.tpe.
This would prevent further invalid uses of that overload.
sjrd
approved these changes
Nov 11, 2020
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