The compiler would previously accept use of `@_inheritActorContext`
on a parameter with a synchronous function type which wasn't marked
as `@isolated(any)`. That is incorrect because in such cases the
attribute has no effect and furthermore would prevent Sendable
and isolation checking.
Uses like that are currently diagnosed by the type-checker but we
need to go one step further and remove the effect in such case to
prevent invalid uses.
Resolves: rdar://143581268
(cherry picked from commit dbe19b6d5f)
This matches send non sendable but importantly also makes it clear that we are
talking about something that doesn't conform to the Sendable protocol which is
capitalized.
rdar://151802975
(cherry picked from commit 3ed4059a60)
Replaces generic `expression is 'async' but is not marked with 'await`
diagnostic with a tailed one for cases where there is an access to an
actor-isolated value outside of its actor without `await` keyword.
This makes the diagnostics for async and sync contexts consistent
and actually identifies a problem instead of simply pointing out
the solution.
Resolves: rdar://151720646
(cherry picked from commit 7a6ba8e8c58c58b3438f31fec06102d02bae81a5)
- Extend `@_inheritActorContext` attribute to support optional `always` modifier.
The new modifier will make closure context isolated even if the parameter is not
captured by the closure.
- Implementation `@_inheritActorContext` attribute validation - it could only be
used on parameter that have `@Sendable` or `sending` and `@isolated(any)` or
`async` function type (downgraded to a warning until future major Swift mode
to avoid source compatibility issues).
- Add a new language feature that guards use of `@_inheritActorContext(always)` in swift interface files
- Update `getLoweredLocalCaptures` to add an entry for isolation parameter implicitly captured by `@_inheritActorContext(always)`
- Update serialization code to store `always` modifier
(cherry picked from commit 04d46760bb)
(cherry picked from commit c050e8f75a)
(cherry picked from commit c0aca5384b)
(cherry picked from commit a4f6d710cf)
(cherry picked from commit 6c911f5d42)
(cherry picked from commit 17b8f7ef12)
A dot-reference of a method defined on `Self` (as well as through `self`)
should be permitted to be made in a different actor isolation than
the referenced function's actor isolation if a call is not yet made, as
the DeclRefExpr can store the isolation of the referenced decl. That said,
we currently can only express that known isolation with global actor
annotations until the language adopts closure isolation control.
This is fixed on main so just recomming for the tests
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.
`x declared here` is not helpful and clear enough, especially when there
are other notes attached. Swap it for a new note that says
`requirement x declared here`.
Otherwise, we'll in turn complain if the nonisolated lazy property was
@objc. This is also invalid, but the goal here is to avoid the source
break until -swift-version 6.
Fixes rdar://141967932.
Find all the usages of `--enable-experimental-feature` or
`--enable-upcoming-feature` in the tests and replace some of the
`REQUIRES: asserts` to use `REQUIRES: swift-feature-Foo` instead, which
should correctly apply to depending on the asserts/noasserts mode of the
toolchain for each feature.
Remove some comments that talked about enabling asserts since they don't
apply anymore (but I might had miss some).
All this was done with an automated script, so some formatting weirdness
might happen, but I hope I fixed most of those.
There might be some tests that were `REQUIRES: asserts` that might run
in `noasserts` toolchains now. This will normally be because their
feature went from experimental to upcoming/base and the tests were not
updated.
Instead, use the `%target-swift-5.1-abi-triple` substitution to compile the tests
for deployment to the minimum OS versions required for use of _Concurrency APIs.
wording.
Splitting up the diagnostic into separate diagnostics based on the reference
kind is easier for me to read. The wording of the error message now puts
the problem -- crossing an isolation boundary -- at the center of the message,
and attempts to clarify how the value crosses an isolation boundary. E.g. for
the witness diagnostics, the value crosses an isolation boundary when calling
the witness through the protocol requirement in generic code.
This change does not add any additional information to the diagnostics, but it'd
be valuable to show both the source and destination isolation.
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`.
When SE-0412 (strict concurrency for global variables) is enabled, each
global or static mutable variable will be diagnosed if it isn't
explicitly on a global actor or `nonisolated(unsafe)`.
Suppress diagnostics for references to such global variables when they
are in the same module as the declaration of the global variable
itself. While these diagnostics are technically correct, they are not
strictly necessary since we've already diagnosed the global variable
itself (with more actionable advice), and they tend to pile on the
developer in a manner that is not helpful.
When diagnosing a concurrency-unsafe global or static variable, provide
Fix-Its with specific guidance and advice. This is intended to aid the
workflow for folks enabling strict concurrency checking or Swift 6.
There are up to three Fix-Its attached to a diagnostic about
concurrency-unsafe global/static variables:
* convert 'global' to a 'let' constant to make the shared state
immutable, which replaces `var` with `let`
* restrict 'global' to the main actor if it will only be accessed from the
main thread, which adds `@MainActor`
* unsafely mark %0 as concurrency-safe if all accesses are protected
by an external synchronization mechanism, which adds `nonisolated(unsafe)`
I fretted over two things before deciding on this path:
1. For the second note, the reality is that any global actor will
suffice, but `@MainActor` is orders of magnitude more common than any
other global actor, so "common case convenience" wins over "precise
but less useful.
2. For the third note, `nonisolated(unsafe)` should only be used
sparingly, and surfacing it via Fix-It could cause overuse. However,
developers need to know about it, and this is how we do that. It comes
last in the list of notes (after the better options) and says "unsafe"
in not one but two places.
Instead of looking at captures, which wasn't sound with
recursive local functions; we would look at the captures of
the function currently being type checked, which are not
available yet.
