We record fixes while solving normal expressions for code completion and we should do the same when solving result builders if we are reporting the solutions to completion callbacks.
This flag biases the overload checker in favor of selecting an
asynchronous main function over a synchronous main. If no asynchronous
main function exists, a synchronous one will still be selected.
Likewise, if the flag is not passed and there are only asynchronous main
functions available, the most specific asynchronous main function will
still be selected.
`typeEraseExistentialSelfReferences` shouldn't account for
contextual signature because that signature could have
generic parameters of it's own unrelated to the reference
which would be located before generic parameters of the
member, e.g. when the code is located in a protocol extension,
which invalidates the assumption that `Self` is located at
depth = 0, index = 0.
Resolves: rdar://91110069
When we open an existential argument in a call to a generic function,
type-erase contravariant uses of that opened existential in subsequent
parameters. This primarily impacts closure parameters, where we want
the closure to be provided with an existential parameter type rather
than permit the parameter to have opened existential type. This
prevents the opened existential type from being directly exposed in
the type system.
Note that we do not need to perform this erasure when the argument is
a reference to a generic function, because there it is suitable to
infer that the generic arguments are the opened archetypes. This
subsumes the use case for `_openExistential`.
This hooks up call argument position completion to the typeCheckForCodeCompletion API to generate completions from all the solutions the constraint solver produces (even those requiring fixes), rather than relying on a single solution being applied to the AST (if any).
Co-authored-by: Nathan Hawes <nathan.john.hawes@gmail.com>
This ensures that opened archetypes always inherit any outer generic parameters from the context in which they reside. This matters because class bounds may bind generic parameters from these outer contexts, and without the outer context you can wind up with ill-formed generic environments like
<τ_0_0, where τ_0_0 : C<T>, τ_0_0 : P>
Where T is otherwise unbound because there is no entry for it among the generic parameters of the environment's associated generic signature.
Since `SolutionApplicationTarget` could represent whole statement
or pattern with multiple expressions, it makes sense to add a dedicated
method to pre-check everything together.
It's a convenient way to use existing logic for default argument inference
because suhc inference cannot open whole signature but only conformance
and layout constraints associated generic parameters used in a particular
parameter position.
When calling a generic function with an argument of existential type,
implicitly "open" the existential type into a concrete archetype, which
can then be bound to the generic type. This extends the implicit
opening that is performed when accessing a member of an existential
type from the "self" parameter to all parameters. For example:
func unsafeFirst<C: Collection>(_ c: C) -> C.Element { c.first! }
func g(c: any Collection) {
unsafeFirst(c) // currently an error
// with this change, succeeds and produces an 'Any'
}
This avoids many common sources of errors of the form
protocol 'P' as a type cannot conform to the protocol itself
which come from calling generic functions with an existential, and
allows another way "out" if one has an existention and needs to treat
it generically.
This feature is behind a frontend flag
`-enable-experimental-opened-existential-types`.
Instead of asking callers of `isExpired` to provide the threshold,
let's ask for that upfront. This change also allows us to check how
much time remains in the timer and build timers with different
thresholds without having to safe that information somewhere else.
Some implicit calls to `.callAsFunction` require that a new root
expression to be created for them in order to record argument list
and resolved overload choice.
Opaque opaque types and record them within the "opened types" of the
constraint system, then use that information to compute the set of
substitutions needed for the opaque type declaration using the normal
mechanism of the constraint solver. Record these substitutions within
the underlying-to-opaque conversion.
Use the recorded substitutions in the underlying-to-opaque conversion
to set the underlying substitutions for the opaque type declaration
itself, rather than reconstructing the substitutions in an ad hoc manner
that does not account for structural opaque result types.
When evaluating whether code is within a closure that uses concurrency
features, use the type of the closure as it's known during type checking,
so that contextual information (e.g., it's passed to a `@Sendable` or
`async` parameter of function type) can affect the result. This
corrects the definition for doing strict checking within a minimal
context for the end result of the type-check, rather than it's initial
state, catching more issues.
Fixes SR-15131 / rdar://problem/82535088.
Use this to enable better detection of async contexts when determining
whether to diagnose problems with concurrency.
Part of SR-15131 / rdar://problem/82535088.
We need to modify the pointer pointing to the cancellation flag when reusing an ASTContext for code completion. This is not possible by the previous design because `TypeCheckerOptions` was `const`. Moving the cancellation flag to `ASTContext` will also allow other stages of the compiler to honor a cancellation request.
