Also avoid emitting the diagnostic for an out of
place binding pattern if there's an existing fix
on a parent call expression, as that's the real
source of the failure.
rdar://113025351
- Don't walk into the count type of a PackExpansionType, because
when matching two PackExpansionTypes, the solver only introduces
a shape constraint between the count types, which does not fix it
to a concrete type.
- Similarly, don't walk into type alias substitutions, because
only the desugared type is considered by the constraint solver.
This is mildly source breaking, in that before we let you declare
generic functions that could not be called.
The compiler derived implementations of `Codable` conformances for enums did
not take enum element unavailability into account. This could result in
unavailable values being instantiated at runtime, leading to a general
violation of the invariant that unavailable code is unreachable at runtime.
This problem is possible because synthesized code is not type checked; had the
conformances been hand-written, they would have been rejected for referencing
unavailable declarations inside of available declarations.
This change specifically alters derivation for the following declarations:
- `Decodable.init(from:)`
- `Encodable.encode(to:)`
- `CodingKey.init(stringValue:)`
Resolves rdar://110098469
The reason why we are doing this is that this combination of read/set forces the
compiler to emit a copy if we want to emit a modify operation.
The reason why we are forced to emit such a copy is that:
1. _read provides a guaranteed value in memory
2. performing a modify requires an owned value in memory.
This together implies that the only way we can do this is to copy from the _read
into temporary memory. But we have a noncopyable type so we can't do this.
rdar://112915525
Move the contextual type locator onto
ContextualTypeInfo, and consolidate the separate
fields in SyntacticElementTarget into storing a
ContextualTypeInfo. This then lets us plumb down
the locator for the branch contextual type of an
if/switch expression from the initial constraint
generation, rather than introducing it later. This
should be NFC.
This could also use `%kind` for the declaration kind, but that ends up
being "extension of struct" instead of just "extension", which seems
slightly worse.
This attribute can be attached to a noncopyable struct to specify that its
storage is raw, meaning the type definition is (with some limitations)
able to do as it pleases with the storage. This provides a basis for
implementing types for things like atomics, locks, and data structures
that use inline storage to store conditionally-initialized values.
The example in `test/Prototypes/UnfairLock.swift` demonstrates the use
of a raw layout type to wrap Darwin's `os_unfair_lock` APIs, allowing
a lock value to be stored inside of classes or other types without
needing a separate allocation, and using the borrow model to enforce
safe access to lock-guarded storage.
If either source or destination type is a hole conversion should
just be ignored because there is no r-value or other mismatch that
could be diagnosed in this case.
Placeholder types just like type variables are set up to return
a conformance ref which, in this case, would mean that we'd produce
an invalid diagnostic.
Such tuples should be treated specially because once pack expansion
is sufficiently resolved they'd get exploded and the resulting type
is what member lookup should use as a base.
Resolves: rdar://110721928
If a closure doesn't have a contextual type inferred yet it should
be delayed in favor of already resolved closure conjunction because
"resolving" such a closure early could miss result builder attribute
attached to a parameter the closure is passed to.
Partially resolves https://github.com/apple/swift/issues/67363
`same-shape` mismatch detection logic shouldn't expect that types are
always packs because they could be either invalid (i.e. Void) or pack
archetypes too.
Resolves: rdar://112090069
If one of the choices is variadic generic, let's use `matchCallArguments`
to find argument/parameter mappings and form pack expansions for arguments
when necessary.
Resolves: rdar://112029630
