Michael Gottesman 14d39c0cf9 [silgenpattern] Fix ownership error which could result in a use-after-free. ...

Specifically, in order to generate runtime errors when we do not handle an enum
appropriately, we form a metatype from the input of the switch. The problem is
that by the time we get to the leaf of the emission tree where this metatype is
created, the input of the switch may have already been consumed. This means
creating the metatype could be a use after free.

This patch fixes the problem by emitting the value_metatype after we emit the
subject of the switch, but before we emit the switch itself.

rdar://49562761

2019-04-10 08:48:27 -07:00

2.0 KiB

Raw Blame History

View Raw