- Extend `@_inheritActorContext` attribute to support optional `always` modifier.
The new modifier will make closure context isolated even if the parameter is not
captured by the closure.
- Implementation `@_inheritActorContext` attribute validation - it could only be
used on parameter that have `@Sendable` or `sending` and `@isolated(any)` or
`async` function type (downgraded to a warning until future major Swift mode
to avoid source compatibility issues).
- Add a new language feature that guards use of `@_inheritActorContext(always)` in swift interface files
- Update `getLoweredLocalCaptures` to add an entry for isolation parameter implicitly captured by `@_inheritActorContext(always)`
- Update serialization code to store `always` modifier
(cherry picked from commit 04d46760bb)
(cherry picked from commit c050e8f75a)
(cherry picked from commit c0aca5384b)
(cherry picked from commit a4f6d710cf)
(cherry picked from commit 6c911f5d42)
(cherry picked from commit 17b8f7ef12)
* Move `AvailabilitySpec` handling logic to AST, so they can be shared
between libParse and ASTGen
* Requestify '-define-availability' arguments parsing and parse them
with 'SwiftParser' according to the 'ParserASTGen' feature flag
* Implement 'AvailableAttr' generation in ASTGen
Since the introduction of custom attributes (as part of property
wrappers), we've modeled the context of expressions within these
attributes as PatternBindingInitializers. These
PatternBindingInitializers would get wired in to the variable
declarations they apply to, establishing the appropriate declaration
context hierarchy. This worked because property wrappers only every
applied to---you guessed it!---properties, so the
PatternBindingInitializer would always get filled in.
When custom attributes were extended to apply to anything for the
purposes of macros, the use of PatternBindingInitializer became less
appropriate. Specifically, the binding declaration would never get
filled in (it's always NULL), so any place in the compiler that
accesses the binding might have to deal with it being NULL, which is a
new requirement. Few did, crashes ensued.
Rather than continue to play whack-a-mole with the abused
PatternBindingInitializer, introduce a new CustomAttributeInitializer
to model the context of custom attribute arguments. When the
attributes are assigned to a declaration that has a
PatternBindingInitializer, we reparent this new initializer to the
PatternBindingInitializer. This helps separate out the logic for
custom attributes vs. actual initializers.
Fixes https://github.com/swiftlang/swift/issues/76409 / rdar://136997841