When creating `destroy_value`s, create them with the `dead_end` flag if
all subsequent destroys (those from which it is notionally being
hoisted) have the flag.
When creating `destroy_value`s, create them with the `dead_end` flag if
all subsequent destroys (those from which it is notionally being
hoisted) have the flag.
Now that `isWithinBoundary` and `areUsesWithinBoundary` are "the same"
(up to the fact that one takes an instruction and the other an array of
operands), there's no reason to use the latter when looking at a single
instruction.
When checking whether an instruction is contained in a liveness
boundary, a pointer to a DeadEndBlocks instance must always be passed.
When the pointer is null, it is only checked that the instruction occurs
within the direct live region. When the pointer is non-null, it is
checked whether the instruction occurs within the region obtained by
extending the live region up to the availability boundary within
dead-end regions that are adjacent to the non-lifetime-ending portion of
the liveness boundary.
Use the more precise areUsesWithinBoundary API (which takes dead-end
blocks into account). This requires first updating liveness with the
newly created destroys.
Just clear all structures in a single method which is called wherever
clearing is done. Fixes a failure to clear discoveredBlocks under
certain circumstances.
Copies of a lexical lifetime are not lexical. Their destroys can be
hoisted over deinit barriers. So when extending lifetimes to deinit
barriers, only deal with the direct lifetime, not the copy-extended
lifetime.
Closures generally only inherit actor instance isolation if they directly
capture state from the actor instance. In this case, for some reason that is not
true, so we hit an assert that assumes that we will only see a global actor
isolated isolation.
Region Isolation should be able to handle code even if the closure isolation
invariant is violated by the frontend. So to do this, I am introducing a new
singleton actor instance to represent the isolation of a defer or closure
created in an actor instance isolated method. The reason why I am using a
singleton is that closures and defer are not methods so we do not actually know
which parameter is 'self' since it isn't in the abi. But we still need some
value to represent the captured values as belonging to. To square this circle, I
just did what we have done in a similar situation where we did not have a value:
(ActorAccessorInit). In that case, we just use a sentinel to represent the
instance (NOTE: This is represented just via a kind so ActorInstances that are
operator== equal will not &value equal since we are just using a kind).
Conflicts:
- `test/Interop/Cxx/class/method/methods-this-and-indirect-return-irgen-itanium.swift`
previously fixed on rebranch, now fixed on main (slightly differently).
Otherwise, in cases like the following, we look through the load to x.boolean
and think that the closure is actually capturing x instead of y:
```swift
func testBooleanCapture(_ x: inout NonSendableKlass) {
let y = x.boolean
Task.detached { @MainActor [z = y] in
print(z)
}
}
```
rdar://131369987
We are already using this routine in other parts of TransferNonSendable to
ensure that we look through common insts that SILGen inserts that do not change
the actual underlying actor instance that we are using. In this case, I added
support for casts, optional formation, optional extraction, existential ref
initialization.
As an example of where this came up is the following test case where we fail to
look through an init_existential_ref.
```swift
public actor MyActor {
private var intDict: [Int: Int] = [:]
public func test() async {
await withTaskGroup(of: Void.self) { taskGroup in
for (_, _) in intDict {}
await taskGroup.waitForAll() // Isolation merge failure happens here
}
}
}
```
I also added the ability to at the SIL level actual test out this merge
condition using the analysis test runner. I used this to validate that this
functionality works as expected in a precise way.
rdar://130113744
Before we wouldn't print them in all situations and even more so a few of the
printing routines did not have it at all. This just adds a centralized
SILIsolationInfo::dumpOptions() method and then goes through all of the printing
helpers and changes them to use them as appropriate.
Given a function or a partial_apply with an isolated parameter, we do not know
immediately what the actual isolation is of the function or partial_apply since
we do not know which instance will be applied to the function or partial_apply.
In this commit, I introduce a new bit into SILIsolationInfo that tracks this
information upon construction and allows for it to merge with ownership that has
the appropriate type and a specific instance. Since the values that created the
two isolations, will be in the same region this should ensure that the value is
only ever in a flow sensitive manner in a region with only one actor instance
(since regions with isolations with differing actor instances are illegal).
Before this change in the following code, we would say that message is isolated to the actor instead of the global actor isolation of the actor's method:
```swift
class Message { ... }
actor MessageHolder {
@MainActor func hold(_ message: Message) { ... }
}
@MainActor
func sendMessage() async {
let messageHolder = MessageHolder()
let message = Message()
// We identified messageHolder.hold as being MessageHolder isolated
// instead of main actor isolated.
messageHolder.hold(message)
Task { @MainActor in print(message) }
}
```
I also used this as an opportunity to simplify the logic in this part of the
code. Specifically, I had made it so that multiple interesting cases were
handled in the same conditional statement in a manner that it made it hard to
know which cases were actually being handled and why it was correct. Now I split
that into two separate if statements with comments that make it clear what we
are actually trying to pattern match against.
rdar://130980933
