A protocol conformance can be ill-formed due to isolation mismatches
between witnesses and requirements, or with associated conformances.
Previously, such failures would be emitted as a number of separate
errors (downgraded to warnings in Swift 5), one for each witness and
potentially an extra for associated conformances. The rest was a
potential flood of diagnostics that was hard to sort through.
Collect all of the isolation-related problems for a given conformance
together and produce a single error (downgraded to a warning when
appropriate) that describes the overall issue. That error will have up
to three notes suggesting specific courses of action:
* Isolating the conformance (when the experimental feature is enabled)
* Marking the witnesses as 'nonisolated' where needed
*
The diagnostic also has notes to point out the witnesses/associated
conformances that have isolation problems. There is a new educational
note that also describes these options.
We give the same treatment to missing 'distributed' on witnesses to a
distributed protocol.
When diagnosing an isolation mismatch between a requirement and witness,
we would produce notes on the requirement itself suggesting the addition of
`async`. This is almost never what you want to do, and is often so far
away from the actual conforming type as to be useless. Remove this note,
and the non-function fallback that just points at the requirement, because
they are unhelpful.
This is staging for a rework of the way we deal with conformance-level
actor isolation problems.
Use the `%target-swift-5.X-abi-triple` substitutions to compile the tests for
deployment to the minimum OS versions required for the APIs used in the tests,
instead of disabling availability checking.
When diagnosing a case where an actor-isolated witness cannot satisfy
a non-isolated requirement, also suggest that the conformance could be
annotated with `@preconcurrency`.
[Distributed] generic and inner test; without one edge case
[Distributed] fix distributed_thunk test; unsure about those extra hops, could remove later
[Distributed] Remove type pretending in getSILFunctionType; it is not needed
It seems our constant replacement in the earlier phases is enough, and
we don't need this trick at all.
[Distributed] Use thunk when calling cross-actor on DA protocols
The three options are now:
* `explicit`: Enforce Sendable constraints where it has been explicitly adopted and perform actor-isolation checking wherever code has adopted concurrency. (This is the default)
* `targeted`: Enforce Sendable constraints and perform actor-isolation checking wherever code has adopted concurrency, including code that has explicitly adopted Sendable.
* `complete`: Enforce Sendable constraints and actor-isolation checking throughout the entire module.
Reimplement the final client of ActorIsolationRestriction, conformance
isolation checking, to base it on the new "actor reference" logic.
Centralize the diagnostics emission so we have a single place where we
emit the primary diagnostic (which is heavily customized based on
actor isolation/distributed/etc.) and any relevant notes to make
adjustments to the witness and/or requirement, e.g., adding
'distributed', 'async', 'throws', etc. Improve the diagnostics
slightly by providing Fix-Its when suggesting that we add "async"
and/or "throws".
With the last client of ActorIsolationRestriction gone, remove it
entirely.
- reuse more code about getting the type and requirements
- handle protocols properly, including extensions with where clauses
- improve error messages
* [Distributed] towards DistributedActorSystem; synthesize the id earlier, since Identifiable.id
* Fix execute signature to what Pavel is working with
* funcs are ok in sil
* fixed lifetime of id in inits
* fix distributed_actor_deinit
* distributed_actor_local
* update more tests
fixing tests
fix TBD test
fix Serialization/distributed
fix irgen test
Fix null pointer crashes
* prevent issues with null func ptrs and fix Distributed prorotocol test
* fix deinit sil test
* [Distributed] Handle more cases of isolation, protocols, better errors/notes
* [Concurrency] Actor sync funcs can conform to async protocol reqs
* [Distributed] Offer fixit to add DistributedActor to type when dist func is encountered
* [Distributed] Witness protocol reqs in dist actor protocol extensions
* try to address availability issues
The _Distributed module is being introduced in Swift 5.6, so its definitions need to come with matching availability. (We don't have version numbers for the associated OS releases, so we need to use placeholder 9999 availability for these.)
The concurrency runtime now deploys back to macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, which corresponds to the 5.1 release of the stdlib.
Adjust macro usages accordingly.
Remove a few places where we are introducing extra distributed-related
actor isolation checking that either isn't necesssary or is incorrect.
Specifically:
* Hopping to a global actor *from* a distributed-actor isolated context
does not go through a distributed thunk (global actors can't have one).
* "Unrestricted" declarations are always unrestricted, so we don't
need an extra distributed check here (it won't ever occur).
* Actor isolation computation doesn't need a special case for
distributed; it marks too much, overriding (e.g.) global actor
isolation.
The primary semantic change visible here is that distributed actors
can now have truly 'nonisolated' members. They aren't required to be
'distributed' because they can't touch state anyway.
