I missed upgrading this to an error for Swift 6 mode, let's upgrade it
to an error for a future language mode. It's important we reject these
cases since we're otherwise allowing subtyping to be a weaker constraint
than conversion.
This change adds detection for nested type references in KeyPath
components and applies the appropriate fix to generate meaningful error
messages, following the same pattern already established for method
references.
The fix ensures that invalid KeyPath references fail gracefully in
normal mode and provide helpful diagnostics in diagnostic mode,
improving the developer experience when working with KeyPaths.
Resolves: https://github.com/swiftlang/swift/issues/83197
For a method key path use the locator for the apply itself rather
than the member, ensuring we handle invalid cases where the apply is
the first component, and providing more accurate location info.
Set an upper bound on the number of chained lookups we attempt to
avoid spinning while trying to recursively apply the same dynamic
member lookup to itself.
rdar://157288911
To pave the way for the new experimental feature which will operate on '@const' attribute and expand the scope of what's currently handled by '_const' without breaking compatibility, for now.
Within the constraint system, introduce a new kind of conformance constraint,
a "nonisolated conforms-to" constraint, which can only be satisfied by
nonisolated conformances. Introduce this constraint instead of the normal
conforms-to constraint whenever the subject type is a type parameter that
has either a `Sendable` or `SendableMetatype` constraint, i.e., when the type
or its values can escape the current isolation domain.
Using an unwrap operator with 'as' or the wrong keyword (i.e. `is`)
when already checking a cast via ~= results in error:
'pattern variable binding cannot appear in an expression'.
Add a diagnostic that provides more guidance and a fix-it
for the removal of ?/! or replacement of 'is' with 'as'.
Some invalid specializations were previously allowed by the compiler
and we found some existing code that used that (albeit invalid) syntax,
so we need to stage that error as a warning until Swift 6 language mode
to avoid source compatibility break.
Resolves: rdar://134740240
Always add constraints, find fixes during simplify.
New separate fix for allow generic function specialization.
Improve parse heuristic for isGenericTypeDisambiguatingToken.
Degrade concrete type specialization fix to warning for macros.
Always add constraints, find fixes during simplify.
New separate fix for allow generic function specialization.
Improve parse heuristic for isGenericTypeDisambiguatingToken.
Control enforcement of member import visibility requirements via a new option,
instead of piggy-backing on the existing IgnoreAccessControl option. Adopt the
option when doing fallback lookups for unviable members so that the compiler
can diagnose the reason that a member is inaccessible more reliably.
Previously, with MemberImportVisibility enabled decls with the package access
level could be mis-diagnosed as inaccessible due to their access level when
really they were inaccessible due to a missing import.
Resolves rdar://131501862.
Make sure `CouldNotInferPlaceholderType` can
produce a diagnostic for a `PlaceholderType`
locator element, and avoid emitting an extra
diagnostic for a placeholder type in an invalid
position.
This will ensure that we do not break anyone who has adopted APIs like
CheckedContinuation.resume that now have sending parameters.
An example of where this can come up is shown by the ProcessType in SwiftToolsCore:
```swift
@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
@discardableResult
public func waitUntilExit() async throws -> ProcessResult {
try await withCheckedThrowingContinuation { continuation in
DispatchQueue.processConcurrent.async {
self.waitUntilExit(continuation.resume(with:))
}
}
}
```
This fails to compile since self.waitUntilExit doesn't expect a function that
takes a sending parameter. We want to give people time to fix such issues.
Removing the old, ad-hoc diagnostics code improves the diagnostics we
emit, since the existing diagnostics for missing conformances is already
pretty good.
rdar://127369509
Teach the constraint solver about the subtyping rule that permits
converting one function type to another when the effective thrown error
type of one is a subtype of the effective thrown error type of the
other, using `any Error` for untyped throws and `Never` for
non-throwing.
With minor other fixes, this allows us to use typed throws for generic
functions that carry a typed error from their arguments through to
themselves, which is in effect a typed `rethrows`:
```swift
func mapArray<T, U, E: Error>(_ array: [T], body: (T) throws(E) -> U)
throws(E) -> [U] {
var resultArray: [U] = .init()
for value in array {
resultArray.append(try body(value))
}
return resultArray
}
```
