The issue here was that we inferred the contextual type of the `Mixer` call to be the following, inferred from the result type of the partial call to the initializer of `Mixer`
```
(bound_generic_struct_type decl="swift_ide_test.(file).Mixer@/Users/alex/src/swift/test/IDE/complete_parameter_pack_as_call_argument.swift:3:8"
(pack_type num_elements=1
(pack_expansion_type
(pattern=unresolved_type)
(count=unresolved_type))))
```
Technically, the contextual type that we should have here should be `Any` (from `print`) but getting that information out of the constraint system turns out to be quite hard. https://github.com/apple/swift/pull/72568 makes some improvements in this area but in general the constraint system does not contain enough information to figure out the contextual type of an arbitrary expression.
The important thing right now is that the unresolved type in here trips the constraint system over when comparing types of code completion results with the contextual type. To prevent the crash for now, reset the expected call type if the computed type contains an unresolved type.
rdar://124166587
Co-authored-by: Pavel Yaskevich <pyaskevich@apple.com>
We were incorrectly unwrapping too many levels of metatype, and
our ErasureExpr would end up with conformances for the instance
type and not the metatype itself.
In the old universe, this was not a problem, but now Any has two
protocol conformance members, so suddently this violated invariants.
This was a regression, introduced in 6027bf46a6.
Fixes rdar://125460667.
Some notes:
1. If the result is non-Sendable and we didn't infer something that is
transferring, we still emit the current sema error that says that one cannot
assign a non-Sendable value to an async let.
2. When region isolation is enabled, but transferring args and results are
disabled, we leave the async let semantics alone. This means that the async let
closure is still @Sendable and one cannot pass in non-Sendable values to it.
In #39612 we added subtyping for keypaths-as-functions, but during application
the implementation naively coerced the keypath expression itself to the
inferred supertype, resulting in erroneous results. This patch updates the
solution application logic to build the keypath-function conversion expression
based entirely on the 'natural' keypath type, only converting to the inferred
supertype at the end via the usual coerceToType machinery for function
conversions.
This is going to be used to determine whether the substitutions are
computed for `DistributedActorSystem::remoteCall` and adjust the
generic signature with witness conformance requirements.
The IDE's use isn't correct under noncopyable generics and only the
constraint solver uses it. It's a misleading method now that nearly
every archetype has Copyable/Escapable requirements.
Unify with `CTP_ReturnStmt`, and have the
SyntacticElementTarget carry the ReturnStmt for
regular type-checking, which we can use to record
implied returns.
Track the implied result exprs in the constraint
system, and allow arbitrary propagation of
implied results down if/switch expression
branches. This is required for allowing implied
results in non-single-expression closures.
Passing an isolated function value into an API that doesn't have full
static concurrency checking is unsafe and requires runtime checks
to make sure that function is always called in the expected context.
Unify the implementation between single-expression
and multi-statement closures. Because we're now
storing a contextual type for single expression
closure returns, update a code completion test to
bring its behavior inline with the multi-statement
case.
`adjustSelfTypeForMember` shouldn't load base if member reference
is a potential init accessor use, the proper use of `self` would
be determined during lowering of the `assign_or_init` instruction
and defensive load for `nonmutating` sets is unnecessary in this
case.
This models the conversion from an uninhabited
value to any type, and allows us to get rid of
a couple of places where we'd attempt to drop
the return statement instead.
Remove this bit from function decls and closures.
Instead, for closures, infer it from the presence
of a single return or single expression AST node
in the body, which ought to be equivalent, and
automatically takes result builders into
consideration. We can also completely drop this
query from AbstractFunctionDecl, replacing it
instead with a bit on ReturnStmt.
This couples together several changes to move entirely from
`@rethrows` over to typed throws:
* Use the `Failure` type to determine whether an async for-each loop
will throw, rather than depending on rethrows checking
* Introduce a special carve-out for `rethrows` functions that have a
generic requirement on an `AsyncSequence` or `AsyncIteratorProtocol`,
which uses that requirement's `Failure` type as potentially being part
of the thrown error type. This allows existing generic functions like
the following to continue to work:
func f<S: AsyncSequence>(_: S) rethrows
* Switch SIL generation for the async for-each loop from the prior
`next()` over to the typed-throws version `_nextElement`.
* Remove `@rethrows` from `AsyncSequence` and `AsyncIteratorProtocol`
entirely. We are now fully dependent on typed throws.
Remove keypath subtype asserts; always use cached root type
Add tests for keypaths converted to funcs with inout param
Add unit test for overload selection
It's not clear that its worth keeping this as a
base class for SerializedAbstractClosure and
SerializedTopLevelCodeDecl, most clients are
interested in the concrete kinds, not only whether
the context is serialized.
Most clients only want to set one of the two
parameters, split it into `setPattern` and
`setInitContext` (the latter of which now
handles calling `setBinding`).
Switch from promising a DeclContext to a
PatternBindingInitializer.
This has a couple of benefits:
- It eliminates a few places where we were force
`cast`'ing to PatternBindingInitializer.
- It improves the clarity of what's being stored,
it's not whatever the parent context of the
initializer is, it's specifically the
PatternBindingInitializer context if it exists.
Introduce a new expression macro that produces an value of type
`(any AnyActor)?` that describes the current actor isolation. This
isolation will be `nil` in non-isolated code, and refer to either the
actor instance of shared global actor in other cases.
This is currently behind the experimental feature flag
OptionalIsolatedParameters.
Obsolete the `-enable-swift3-objc-inference` option and related options by
removing support for inferring `@objc` attributes using Swift 3 rules.
Automated migration from Swift 3 has not been supported by the compiler for
many years.
There are a bunch of static `collectExistentialConformances` copied
around Sema and SILGen that are almost the same, save for whether they
want to permit missing conformances and/or check conditional
conformances.
This commit requestifies and combines all but one of these functions
into a `ModuleDecl::collectExistentialConformances`. The motivation for
this clean-up is another place that will need this procedure.
