Seems that during refactorings of child cancellations we somehow missed
also cancelling the group itself. It seems we did not have good test
coverage of the addTaskUnlessCancelled somehow and thus this slipped
through.
This adds a regression test for addTaskUnlessCancelled and fixes how we
handle the cancellation effect in TaskStatus.
resolves#80789
resolves rdar://149177600
The IsolatedConformances feature moves to a normal, supported feature.
Remove all of the experimental-feature flags on test cases and such.
The InferIsolatedConformances feature moves to an upcoming feature for
Swift 7. This should become an adoptable feature, adding "nonisolated"
where needed.
This is going to need a proper implementation in the requirement
machine. For the moment, provide a slightly-less-broken implementation
but leave a test case where we incorrectly accept racey code.
It has been decided to split the attribute into `@concurrent` and
`nonisolated(nonsending`. Adjusting diagnostics to accept the attribute
makes the transition easier.
This implements basic checks on the validity of the @cdecl attribute and
ensures the parameters and result types are representable in C. Many
more diagnostics will need to be updated to verify full representability
in C.
Because `TaskAllocator` is not a round multiple of the machine word
size on 64-bit platforms, I think we end up with padding before the
`TaskLocal::Storage` following it, which makes the `PrivateStorage`
structure larger than the calculation in `ABI/Task.h`.
rdar://149067144
We decided that using a magic typealias to set the executor factory was better
than using a compiler option. Remove the `-executor-factory` option, and replace
by looking up the `DefaultExecutorFactory` type, first in the main module, and
then if that fails in Concurrency.
rdar://149058236
Function types aren't always trivially copyable, e.g. with address-discriminated signed pointers on ARM64e. Introduce a function_cast helper and use that instead.
I am doing this so I can mark requires as being on a mutable non-Sendable base
from a Sendable value.
I also took this as an opportunity to compress the size of PartitionOp to be 24
bytes instead of 40 bytes.
Currently, the macro plugin options are included as cache key and the
absolute path of the plugin executable and library will affect cache
hit, even the plugin itself is identical.
Using the new option `-resolved-plugin-validation` flag, the macro
plugin paths are remapped just like the other paths during dependency
scanning. `swift-frontend` will unmap to its original path during the
compilation, make sure the content hasn't changed, and load the plugin.
It also hands few other corner cases for macro plugins:
* Make sure the plugin options in the swift module is prefix mapped.
* Make sure the remarks of the macro loading is not cached, as the
mesasge includes the absolute path of the plugin, and is not
cacheable.
rdar://148465899
Previously, when we saw any Sendable type and attempted to look up an underlying
tracked value, we just bailed. This caused an issue in situations like the
following where we need to emit an error:
```swift
func test() {
var x = 5
Task.detached { x += 1 }
print(x)
}
```
The problem with the above example is that despite value in x being Sendable,
'x' is actually in a non-Sendable box. We are passing that non-Sendable box into
the detached task by reference causing a race against the read from the
non-Sendable box later in the function. In SE-0414, this is explicitly banned in
the section called "Accessing Sendable fields of non-Sendable types after weak
transferring". In this example, the box is the non-Sendable type and the value
stored in the box is the Sendable field.
To properly represent this, we need to change how the underlying object part of
our layering returns underlying objects and vends TrackableValues to the actual
analysis for addresses. NOTE: We leave the current behavior alone for SIL
objects.
By doing this, in situations like the above, despite have a Sendable value (the
integer), we are able to ensure that we require that the non-Sendable box
containing the integer is not used after we have sent it into the other Task
despite us not actually using the box directly.
Below I describe the representation change in more detail and describe the
various cases here. In this commit, I only change the representation and do not
actually use the new base information. I do that in the next commit to make this
change easier for others to read and review. I made sure that change was NFC by
leaving RegionAnalysis.cpp:727 returning an optional.none if the value found was
a Sendable value.
----
The way we modify the representation is that we instead of just returning a
single TrackedValue return a pair of tracked values, one for the base and one
for the "value". We return this pair in what is labeled a
"TrackableValueLookupResult":
```c++
struct TrackableValueLookupResult {
TrackableValue value;
std::optional<TrackableValue> base;
TrackableValueLookupResult(TrackableValue value)
: value(value), base() {}
TrackableValueLookupResult(TrackableValue value, TrackableValue base)
: value(value), base(base) {}
};
```
In the case where we are accessing a projection path out of a non-Sendable type
that contains all non-Sendable fields, we do not do anything different than we
did previously. We just walk up from use->def until we find the access path base
which we use as the representative of the leaf of the chain and return
TrackableValueLookupResult(access path base).
In the case where we are accessing a Sendable leaf type projected from a
non-Sendable base, we store the leaf type as our value and return the actual
non-Sendable base in TrackableValueLookupResult. Importantly this ensures that
even though our Sendable value will be ignored by the rest of the analysis, the
rest of the analysis will ensure that our base is required if our base is a var
that had been escaped into a closure by reference.
In the case where we are accessing a non-Sendable leaf type projected from a
Sendable type (which we may have continued to be projected subsequently out of
additional Sendable types or a non-Sendable type), we make the last type on the
projection path before the Sendable type, the value of the leaf type. We return
the eventual access path base as our underlying value base. The logic here is
that since we are dealing with access paths, our access path can only consist of
projections into a recursive value type (e.x.: struct/tuple/enum... never a
class). The minute that we hit a pointer or a class, we will no longer be along
the access path since we will be traversing a non-contiguous piece of
memory (consider a class vs the class's storage) and the traversal from use->def
will stop. Thus, we know that there are only two ways we can get a field in that
value type to be Sendable and have a non-Sendable field:
1. The struct can be @unchecked Sendable. In such a case, we want to treat the
leaf field as part of its own disconnected region.
2. The struct can be global actor isolated. In such a case, we want to treat the
leaf field as part of the global actor's region rather than whatever actor.
The reason why we return the eventual access path base as our tracked value base
is that we want to ensure that if the var value had been escaped by reference,
we can require that the var not be sent since we are going to attempt to access
state from the var in order to get the global actor guarded struct that we are
going to attempt to extract our non-Sendable leaf value out of.
Simply omit the 'nocapture' attribute on the parameter.
Fixes rdar://148039510 ([nonescapable] IRGen: lower addressable
params to LLVM: captures(ret: address, provenance))
When generating a stub fix-it for a protocol conformance or implementation extension, Swift will now evaluate whether the context allows the declaration of stored properties and, if so, will suggest one. It will also use the `let` keyword instead of `var` if the property has no setter.
