FunctionRefKind was originally designed to represent
the handling needed for argument labels on function
references, in which the unapplied and compound cases
are effectively the same. However it has since been
adopted in a bunch of other places where the
spelling of the function reference is entirely
orthogonal to the application level.
Split out the application level from the
"is compound" bit. Should be NFC. I've left some
FIXMEs for non-NFC changes that I'll address in a
follow-up.
Currently we set `FunctionRefKind::Compound` for
enum element patterns with tuple sub-patterns to
ensure the member has argument labels stripped. As
such, we need to account for the correct application
level in `getNumApplications`. We ought to be
setting the correct FunctionRefKind and properly
handling the label matching in the solver though.
We also ought to consider changing FunctionRefKind
such that "is compound" is a separate bit from the
application level.
rdar://139234188
If the base type of the specialization is invalid,
the AST node is going to be replaced with `ErrorExpr`.
We need to handle that gracefully when attempting
to apply specialization in such situations.
Resolves: https://github.com/swiftlang/swift/issues/77644
Situations like:
```
let _: Double = <<CGFloat>>
<var/property of type Double> = <<CGFloat>>
```
Used to be supported due to an incorrect fix added in
diagnostic mode. Lower impact here means that right-hand
side of the assignment is allowed to maintain CGFloat
until the very end which minimizes the number of conversions
used and keeps literals as Double when possible.
Resolves: rdar://139675914
Allow witnesses to introduce `any Sendable` types into their interface
before requirements (predicated on presence of `@preconcurrency` and
Swift 5 language mode) as a pathway for concurrency adoption.
Resolves: rdar://134503878
Today ParenType is used:
1. As the type of ParenExpr
2. As the payload type of an unlabeled single
associated value enum case (and the type of
ParenPattern).
3. As the type for an `(X)` TypeRepr
For 1, this leads to some odd behavior, e.g the
type of `(5.0 * 5).squareRoot()` is `(Double)`. For
2, we should be checking the arity of the enum case
constructor parameters and the presence of
ParenPattern respectively. Eventually we ought to
consider replacing Paren/TuplePattern with a
PatternList node, similar to ArgumentList.
3 is one case where it could be argued that there's
some utility in preserving the sugar of the type
that the user wrote. However it's really not clear
to me that this is particularly desirable since a
bunch of diagnostic logic is already stripping
ParenTypes. In cases where we care about how the
type was written in source, we really ought to be
consulting the TypeRepr.
C++ foreign reference types have custom reference counting mechanisms, so they cannot conform to `AnyObject`.
Currently Swift's type system treats C++ FRTs as `AnyObject`s on non-Darwin platforms, which is incorrect. This change makes sure the behavior is consistent with Darwin platform, i.e. a cast of C++ FRT to `AnyObject` is rejected by the typechecker.
rdar://136664617
`resolveOverload` introduces a conversion if there were any adjustments
to a member type on existential base. This conversion exists only to
check adjustments in the member type, so the fact that adjustments also
cause a function conversion is unrelated.
Resolves: rdar://135974645
If left-hand side of any conversion constraint is `inout` type
and right is a pointer (or optional thereof), delay simplification
until `inout` is at least partially structurally resolved (cannot
be a type variable or dependent member) because eager simplification
won't record all of the possible conversions.
Check whether there are any opened generic parameters associated
with a declaration and if not, produce a fix which would be later
diagnosed as either a warning (in Swift 5 mode) or an error (if it
was a concrete type or the compiler is in Swift 6 language mode).
Resolves: rdar://135610320
