This attribute controls whether cross-module access to the declaration
needs `@unknown default:` because it's allowed to gain new cases even
if the module is non-resilient.
We have a special hack to infer the 'Failure' type witness in
'AsyncIteratorProtocol' by considering the type of 'next()'
witness.
In eaf06eae0e I added a check to
fix some assertions that could happen if 'next()' was witnessed
by a declaration in a protocol extension or superclass, which
has a different generic signature.
However my check was too narrow, because it also prohibited
this form of inference when 'next()' was in a different
extension of the same nominal type.
Allow this again.
Fixes https://github.com/swiftlang/swift/issues/79367.
Fixes rdar://problem/145341658.
The changes in https://github.com/swiftlang/swift/pull/80040 caused the
compiler to start diagnosing extensions containing only members that are
either `@_spi`, `@_alwaysEmitIntoClient`, or unavailable when the
`-require-explicit-availability` flag is passed. Extensions should not be
diagnosed when they only contain members that would not be diagnosed
themselves.
Resolves rdar://148275432.
When a generic function has potentially Escapable outputs, those outputs
declare lifetime dependencies, which have no effect when substitution
leads to those types becoming `Escapable` in a concrete context.
This means that type substitution should canonically eliminate lifetime
dependencies targeting Escapable parameters or returns, and that
type checking should allow a function value with potentially-Escapable
lifetime dependencies to bind to a function type without those dependencies
when the target of the dependencies is Escapable.
Fixes rdar://147533059.
The following warning was being emitted by newer versions of clang:
```
comparisons like 'X<=Y<=Z' don't have their mathematical meaning [-Wparentheses]
```
This code needs to be reworked to ensure that the conditions that are meant to
be asserted are true.
Witness matching didn't handle the case where either the
requirement or the witness is a property with a throwing
getter, and the thrown error type contains a type parameter.
We must open the thrown error types first, replacing type
parameters with type variables, for the matching to work.
Associated type inference needs a similar fix. I'll land a
combined test case for both once I fix that.
Fixes https://github.com/swiftlang/swift/issues/80288.
Fixes rdar://problem/147874955.
Additional restrictions on when protocol inference could be considered
viable. If the chain is connected directly to a contextual type there
cannot be any other inference sources for the base type.
Resolves: rdar://148256978
Rather than representing a missing availability range on `PoundAvailableInfo`
with a default-constructed `AvailabilityRange` (empty), store the ranges as
optionals instead. This allows an empty range to represent an availability
condition which is known to be false at compile time, which will be necessary
when generating SIL for `if #available` queries that check custom availability
domains.
The `-require-explicit-availability` compiler flag is designed to help
developers find declarations that they've written with missing availability.
The flag is not printed in swiftinterface files, though, so if a module has
both `-library-level=api` and also has `-require-explicity-availability=ignore`
(as the Swift stdlib does) then the result is that superfluous diagnostics are
emitted when typechecking the emitted module interface that should have been
suppressed by the `ignore` flag. Suppress these diagnostics when typechecking
swiftinterface files since they are only designed to be seen by the owner of
the module when they are building the module from source and they don't have
much value in the context of interface verification.
Arguments that were already pack expansions were being wrapped in a
second layer--preventing some would-be unambiguous overloads from
resolving. This adds a check to avoid doing that.
Specifically:
1. I made it so that thunks from caller -> concurrent properly ignore the
isolated parameter of the thunk when calling the concurrent function.
rdar://148112362
2. I made it so that thunks from concurrent -> caller properly create a
Optional<any Actor>.none and pass that into the caller function.
rdar://148112384
3. I made it so that in cases where we are assigning an @Sendable caller to a
non-sendable caller variable, we allow for the conversion as long as the
parameters/results are sendable as well.
rdar://148112532
4. I made it so that when we generate a thunk from @execution(caller) ->
@GlobalActor, we mangle in @GlobalActor into the thunk.
rdar://148112569
5. I discovered that due to the way we handle function conversion expr/decl ref
expr, we were emitted two thunks when we assigned a global @caller function to a
local @caller variable. The result is that we would first cast from @caller ->
@concurrent and then back to @caller. The result of this would be that the
@caller function would always be called on the global queue.
rdar://148112646
I also added a bunch of basic tests as well that showed that this behavior was
broken.
