Currently if there is a conditional conformance to a type marked
as `@dynamicMemberLookup` with member that shadows one accessible
through dynamic lookup we'd report an error if that conformance
has not been satisfied.
Better behavior would be to consider dynamic member lookup and
if that fits let the expression type-check.
Resolves: rdar://problem/52779809
Currently only valid way to form keypath subscript is to use `keyPath:`
label in subscript invocation, so let's avoid adding keypath overload
choice to every subscript lookup and instead only add it when it could
potentially match.
This among other things greatly helps diagnostics because sometimes
`keypath application` becomes the only choice even although it's
not really viable, which impedes member reference diagnostics.
While trying to figure out whether there is a missing or extraneous
property wrapper reference, let's not try to fix any generic argument
mismatches associated with wrapper or wrapped types, otherwise the
fix is going to be incorrect.
Additionally, refactor some of the logic for the original add $ diagnostic
so that a lot of logic can be shared between the two. Also rename the
original fix and diagnostic to better reflect their purpose.
Extend use of "instance member on type" fix to cover potentially
invalid partial applications, references to instance members on
metatypes, and remove related and now obsolete code from `CSDiag`.
Resolves: [SR-9415](https://bugs.swift.org/browse/SR-9415)
We would previously fail to match something like (C<$T1> & P) against
(C<Int> & P) when the constraint kind was <= Subtype, because we would
fall back to a type equality test in that case.
However, this was only valid for protocol compositions without superclass
constraints since the superclass could contain a type variable on one
side of the constraint.
Fix this by adding support for protocol composition types to
matchDeepEqualityTypes().
It's only needed in one place in the constraint solver to allow
`() -> T` to `() -> ()` and `() -> Never` to `() -> T` for expressions
representing return of a single expression functions, so to simplify
contextual type handling in diagnostic and other places it would be
better to replace dedicated locator kind with a flag on existing `ContextualType`.
Resolves: rdar://problem/51641323
Use the opened type from the callee declaration to open up references to
generic function builders that contain type parameters. This allows general
use of generic function builders.
When calling a function whose parameter specifies a function builder
with a multi-statement closure argument, transform the closure into
a single expression via the function builder. Should the result
type checker, replace the closure body with the single expression.
- Add a precondition on `doesDeclRefApplyCurriedSelf` to expect
a member decl, and rename it to make the precondition explicit.
- Don't assume that not having a base type means this isn't a member
reference, as member references to static operators don't have base
types.
Resolves SR-10843.
This fixes an oversight related to `ReferenceWritableKeyPath` overloads
of the KeyPath dynamic member lookup. Original check filtered out only
`WritableKeyPath` if the storage is read-only, but it should check for
both `WritableKeyPath` and `ReferenceWritableKeyPath`, otherwise program
is going to crash at run time.
Resolves: rdar://problem/51456614
Add `llvm_unreachable` to mark covered switches which MSVC does not
analyze correctly and believes that there exists a path through the
function without a return value.
Use this function to replace various places where the logic is
duplicated.
In addition, isolate the logic where subscripts are treated as having
curried self parameters to CalleeCandidateInfo, as their interface types
don't have a curried self, but get curried with self by
CalleeCandidateInfo. Ideally we'd fix this by having a subscript's
interface type be curried with self, but given that most of this CSDiag
logic should be going away, this may not be necessary.
