[5.7] SILGen: Complete initialization of FinalContext in ConversionInitialization::tryPeephole #59123
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…zation::tryPeephole The callers to ConversionInitialization::tryPeephole assume that, if the conversion peephole succeeded, that the peepholed result was fully emitted into the initialization. However, if the ConversionInitialization sat on top of an in-memory initialization, then tryPeephole would only set the value of the ConversionInitialization, without forwarding the value into the underlying initialization, causing code generation to proceed leaving the underlying memory uninitialized. This problem becomes exposed now when literal closures are emitted with a return value that is indirectly returned and also reabstracted, and the return expression undergoes a ping-pong reabstraction pair: we see through the conversions and peephole away the reabstractions, but fail to emplace the result in the indirect return slot. Fixes rdar://92654098
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@swift-ci Please test |
tbkka
approved these changes
May 27, 2022
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Note: cherry-pick from #59122 |
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The callers to ConversionInitialization::tryPeephole assume that, if the conversion peephole
succeeded, that the peepholed result was fully emitted into the initialization. However, if
the ConversionInitialization sat on top of an in-memory initialization, then tryPeephole would
only set the value of the ConversionInitialization, without forwarding the value into the underlying
initialization, causing code generation to proceed leaving the underlying memory uninitialized.
This problem becomes exposed now when literal closures are emitted with a return value that is
indirectly returned and also reabstracted, and the return expression undergoes a ping-pong reabstraction
pair: we see through the conversions and peephole away the reabstractions, but fail to emplace the
result in the indirect return slot.
Fixes rdar://92654098