Andrew Trick f7c3c6f437 Fix InteriorUseWalker: consider partial_apply [on_stack] an escape ...

Fixes a bug in MandatoryDestroyHoisting where a captured value is destroyed
before a copy of the closure.

On-stack closures can be copied, and all copied uses must be within the borrow
scope of the captured operand. This is just like any other non-Escapable value,
so treat it as such by checking `Value.mayEscape` rather than `Type.Escapable`.

Originally, I wanted to make it illegal to copy of partial_apply [on_stack], but
it looks like we still allow it.

I would rather not complicate any logic yet with special handling for this
case. To fix any performance concerns, we might be able to simplify the
representation instead by banning copy_value on on-stack closures.

Fixes rdar://165850554 swift-frontend crash: While running "CopyPropagation" -
Invalid SIL provided to OSSACompleteLifetime?!)

2025-12-09 14:38:04 -08:00

36 KiB

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