Certain dynamic casts cannot work safely with isolated conformances,
regardless of what executor the code runs on. For such cases, reject
all attempts to conform to the type.
When performing a dynamic cast to an existential type that satisfies
(Metatype)Sendable, it is unsafe to allow isolated conformances of any
kind to satisfy protocol requirements for the existential. Identify
these cases and mark the corresponding cast instructions with a new flag,
`[prohibit_isolated_conformances]` that will be used to indicate to the
runtime that isolated conformances need to be rejected.
This commit compares the attributes on the decl inside the `@abi` attribute to those in the decl it’s attached to, diagnosing ABI-incompatible differences. It also rejects many attributes that don’t need to be specified in the `@abi` attribute, such as ObjC-ness, access control, or ABI-neutral traits like `@discardableResult`, so developers know to remove them.
This PR adds a set of DeclAttr.def flags for specifying how a given attribute interacts with `@abi`, and declares a behavior for each existing attribute. Future attributes will be *required* to declare an `@abi` behavior lest they fail a static assert.
Note that the behavior is not actually enforced in this commit—it is merely specified here.
Adds a new method to `DeclAttribute` which can compare two attributes and see if they would be “equivalent” in light of the given decl. “Equivalent” here means that they would have the same effect on the declaration; for instance, two attrs with different source locations can be equivalent, and two attributes with the same arguments in a different order are equivalent if the ordering of those argumetns is not semantically equivalent.
This capability is not yet used in this commit, but in a future commit `@abi` will check if certain attributes are equivalent or not.
This commit compares the decl inside the `@abi` attribute to the decl it’s attached to, diagnosing ABI-incompatible differences. It does not yet cover attributes, which are a large undertaking.
Correct an issue with `ImplementsAttr` that would come up if you ever tried to clone an attribute that had been deserialized.
No tests because there’s nothing in the compiler yet that might actually do so.
I am doing this in preparation for adding the ability to represent in the SIL
type system that a function is global actor isolated. Since we have isolated
parameters in SIL, we do not need to represent parameter, nonisolated, or
nonisolated caller in the type system. So this should be sufficient for our
purposes.
I am adding this since I need to ensure that we mangle into thunks that convert
execution(caller) functions to `global actor` functions what the global actor
is. Otherwise, we cannot tell the difference in between such a thunk and a thunk
that converts execution(caller) to execution(concurrent).
Currently, we only get warnings for using unsafe types in expressions
but not in the function signature. The tests did not use the std::string
object in the function body. As a result, we regressed and std::string
was considered unsafe.
The reason is that the annotation only mode for calculating escapability
of a type did not do what we intended. std::basic_string is
conditionally escapable if the template argument is escapable. We
considered 'char' to have unknown escapability in annotation only mode.
The annotation only mode was introduced to avoid suddenly importing
certain types as not escapable when they have pointer fields and break
backward compatibility.
The solution is to make annotation only mode to still consider char and
co as escapable types and only fall back to unknown when the inference
otherwise would have deduced non-escapable (for unannotated typed).
Fixes a false alarm in case of recursive calls with different type parameters.
For example:
```
protocol P {
associatedtype E: P
}
func noRecursionMismatchingTypeArgs1<T: P>(_ t: T.Type) {
if T.self == Int.self {
return
}
noRecursionMismatchingTypeArgs1(T.E.self)
}
```
This is a value operation that can work just fine on lowered types,
so there's no need to carry along a formal type. Make the value/address
duality clearer, and enforce it in the verifier.
The definition of `DefautlActorImpl` changed in https://github.com/swiftlang/swift/pull/73998. This change reflects those changes on to RemoteInspection's platform independent definition.
