Sema: Fix opaque type accessors with inactive availability conditions #77519
+136
−24
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It doesn't make sense to use `VersionRange::empty()` to represent "universally available" since something that is available in an empty version range is effectively never available.
Opaque type metadata accessor functions could be miscompiled for functions that
contain `if #available` checks for inactive platforms. For example, this
function will always return `A` when compiled for macOS, but the opaque type
accessor would instead return the type metadata for `B`:
```
func f() -> some P {
if #available(iOS 99, *) {
return A() // Returns an A on macOS
} else {
return B()
}
}
```
Resolves rdar://139487970.
tshortli
requested review from
xymus,
rjmccall,
hborla,
slavapestov and
xedin
as code owners
|
@swift-ci please test |
xedin
approved these changes
Nov 11, 2024
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Opaque type metadata accessor functions could be miscompiled for functions that contain
if #availablechecks for inactive platforms. For example, this function will always returnAwhen compiled for macOS, but the opaque type accessor would instead return the type metadata forB:Resolves rdar://139487970.