The reason why this failed is that concurrently to @xedin landing
79af04ccc4, I enabled
NonisolatedNonsendingByDefault on a bunch of other tests. That change broke the
test and so we needed to fix it.
This commit fixes a few issues that were exposed:
1. We do not propagate nonisolated(nonsending) into a closure if its inferred
context isolation is global actor isolated or if the closure captures an
isolated parameter. We previously just always inferred
nonisolated(nonsending). Unfortunately since we do not yet have capture
information in CSApply, this required us to put the isolation change into
TypeCheckConcurrency.cpp and basically have function conversions of the form:
```
(function_conversion_expr type="nonisolated(nonsending) () async -> Void"
(closure_expr type="() async -> ()" isolated_to_caller_isolation))
```
Notice how we have a function conversion to nonisolated(nonsending) from a
closure expr that has an isolation that is isolated_to_caller.
2. With this in hand, we found that this pattern caused us to first thunk a
nonisolated(nonsending) function to an @concurrent function and then thunk that
back to nonisolated(nonsending), causing the final function to always be
concurrent. I put into SILGen a peephole that recognizes this pattern and emits
the correct code.
3. With that in hand, we found that we were emitting nonisolated(nonsending)
parameters for inheritActorContext functions. This was then fixed by @xedin in
With all this in hand, closure literal isolation and all of the other RBI tests
with nonisolated(nonsending) enabled pass.
rdar://154969621
(cherry picked from commit 648bb8fe30)
Specifically, there is currently a bug in TypeCheckConcurrency.cpp where we do
not visit autoclosures. This causes us to never set the autoclosure's
ActorIsolation field like all other closures. For a long time we were able to
get away with this just by relying on the isolation of the decl context of the
autoclosure... but with the introduction of nonisolated(nonsending), we found
cases where the generated single curry autoclosure would necessarily be
different than its decl context (e.x.: a synchronous outer curry thunk that is
nonisolated that returns an inner curry thunk that is
nonisolated(nonsending)). This problem caused us to hit asserts later in the
compiler since the inner closure was actually nonisolated(nonsending), but we
were thinking that it should have been concurrent.
To work around this problem, I changed the type checker in
ced96aa5cd to explicitly set the isolation of
single curry thunk autoclosures when it generates them. The reason why we did
this is that it made it so that we did not have to have a potential large source
break in 6.2 by changing TypeCheckConcurrency.cpp to visit all autoclosures it
has not been visiting.
This caused a follow on issue where since we were now inferring the inner
autoclosure to have the correct isolation, in cases where we were creating a
double curry thunk for an access to a global actor isolated field of a
non-Sendable non-global actor isolated nominal type, we would have the outer
curry thunk have unspecified isolation instead of main actor isolation. An
example of this is the following:
```swift
class A {
var block: @MainActor () -> Void = {}
}
class B {
let a = A()
func d() {
a.block = c // Error! Passing task isolated 'self' to @MainActor closure.
}
@MainActor
func c() {}
}
```
This was unintentional. To work around this, this commit changes the type
checker to explicitly set the double curry thunk isolation to the correct value
when the type checker generates the double curry thunk in the same manner as it
does for single curry thunks and validates that if we do set the value to
something explicitly that it has the same value as the single curry thunk.
rdar://152522631
(cherry picked from commit c28490b527)
Check for unsafe constructs in all modes, so that we can emit the
"unsafe does not cover any unsafe constructs" warning consistently.
One does not need to write "unsafe" outside of strict memory safety
mode, but if you do... it needs to cover unsafe behavior.
(cherry picked from commit 1b94c3b3d6)
- 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)
When the attribute is specified explicitly passing a `@concurrent`
closure to a global actor-isolated parameter or contextual type
should result in a conversion and closure itself should be nonisolated.
Resolves: rdar://151797372
(cherry picked from commit efc6efc4ed)
While building an initializer call the declaration reference
should have the same implicitness as the call when it doesn't
require thunking, otherwise don't attempt to mark autoclosures
as non-implicit because it could break assumptions elsewhere.
(cherry picked from commit 37e2f374aa)
Some notes:
1. In most cases, I think we were getting lucky with this by just inferring the
closure's isolation from its decl context. In the specific case that we were
looking at here, this was not true since we are returning from an @concurrent
async function a nonisolated(nonsending) method that closes over self. This
occurs since even when NonisolatedNonsendingByDefault we want to start importing
objc async functions as nonisolated(nonsending).
2. I also discovered that in the ActorIsolationChecker we were not visiting the
inner autoclosure meaning that we never set the ActorIsolation field on the
closure. After some discussion with @xedin about potentially visiting the
function in the ActorIsolationChecker, we came to the conclusion that this was
likely to result in source stability changes. So we put in a targeted fix just
for autoclosures in this specific case by setting their actor isolation in the
type checker.
3. Beyond adding tests to objc_async_from_swift to make sure that when
NonisolatedNonsendingByDefault is disabled we do the right thing, I noticed that
we did not have any tests that actually tested the behavior around
objc_async_from_swift when NonisolatedNonsendingByDefault is enabled. So I added
the relevant test lines so we can be sure that we get correct behavior in such a
case.
rdar://150209093
(cherry picked from commit ced96aa5cd)
Always infer `nonisolated(nonsending)` from context directly on
a closure unless the closure is marked as `@concurrent`, otherwise
the closure is not going to get correct isolation and going to hop
to the wrong executor in its preamble.
Resolves: rdar://149107104
(cherry picked from commit 3de72c5452)
Downgrade to a warning until the next language mode. This is
necessary since we previously missed coercing macro arguments to
parameter types, resulting in cases where closure arguments weren't
being treated as `async` when they should have been.
rdar://149328745
The code that determines whether a reference to a static method (that
is not a call) assumed that metatypes were always Sendable. This is no
longer the case, so update this code to go through the normal Sendable
checking on the metatype.
(cherry picked from commit 3ed1d6c390)
Previously we would avoid rewriting the arguments in CSApply, but
that can result in incorrect behavior in MiscDiagnostics passes, e.g
incorrectly treating all closure arguments as escaping. Make sure
we rewrite the arguments as we would in regular type-checking.
rdar://148665502
- Track environments for `PackExpansionExpr` directly
instead of using a locator.
- Split up the querying and creation of the environment
such that the mismatch logic can be done directly in
CSSimplify instead of duplicating it.
- Just store the environment directly instead of
the shape and UUID.
It should be possible to pass values with `any Sendable` as arguments
to `inout` parameters that expect `Any`. This is pretty much the same
as an l-value conversion.
Resolves: https://github.com/swiftlang/swift/issues/79361
Resolves: rdar://144794132
When calling a distributed function for an actor that might not be local,
the call can throw due to the distributed actor system producing an
error. The function might, independently, also throw. When the
function uses typed throws, we incorrectly treated the call is if it
would always throw the error type specified by the function. This
leads to incorrectly accepting invalid code, and compiler crashes in
SILGen.
The change here is to always mark calls to distributed functions
outside the actor as "implicitly throwing", which makes sure that we
treat the call sites as throwing 'any Error'. The actual handling of
the typed throw (from the local function) and the untyped throw (from
the distributed actor system) occurs in thunk generation in SILGen,
and was already handled correctly.
Fixes rdar://144093249, and undoes the ban introduced by rdar://136467528
Introduce an `unsafe` expression akin to `try` and `await` that notes
that there are unsafe constructs in the expression to the right-hand
side. Extend the effects checker to also check for unsafety along with
throwing and async operations. This will result in diagnostics like
the following:
10 | func sum() -> Int {
11 | withUnsafeBufferPointer { buffer in
12 | let value = buffer[0]
| | `- note: reference to unsafe subscript 'subscript(_:)'
| |- warning: expression uses unsafe constructs but is not marked with 'unsafe'
| `- note: reference to parameter 'buffer' involves unsafe type 'UnsafeBufferPointer<Int>'
13 | tryWithP(X())
14 | return fastAdd(buffer.baseAddress, buffer.count)
These will come with a Fix-It that inserts `unsafe` into the proper
place. There's also a warning that appears when `unsafe` doesn't cover
any unsafe code, making it easier to clean up extraneous `unsafe`.
This approach requires that `@unsafe` be present on any declaration
that involves unsafe constructs within its signature. Outside of the
signature, the `unsafe` expression is used to identify unsafe code.
`any Sendable` -> `Any` in generic argument positions should be
supported for l-value and inout types as well otherwise it won't
be possible to call setters and mutating methods.
If type equality check fails we need to check whether the types
are the same with deep equality restriction since `any Sendable`
to `Any` conversion is now supported in generic argument positions
of @preconcurrency declarations. i.e. referencing a member on
`[any Sendable]` if member declared in an extension that expects
`Element` to be equal to `Any`.
Instead of using `one-way` constraints, just like in closure contexts
for-in statements should type-check their `where` clauses separately.
This also unifies and simplifies for-in preamble handling in the
solver.
