In @frozen structs, stored properties and property wrappers must
have inlinable initial value expressions, since they are re-emitted
into designated initializer bodies, which themselves might be
@inlinable.
However, 'lazy' properties don't follow this pattern; the
initial value expression is emitted inside the getter, which
is never @inlinable.
getFragileFunctionKind() would report that all initializers in
non-resilient public types were inlinable, including static
properties.
This was later patched by VarDecl::isInitExposedToClients(),
which was checked in diagnoseInlinableDeclRefAccess().
However, the latter function only looked at the innermost
DeclContexts, not all parent contexts, so it would incorrectly
diagnose code with a nested DeclContext inside of a static
property initializer.
Fix this by changing getFragileFunctionKind() to call
isInitExposedToClients() and simplifying
diagnoseInlinableDeclRefAccess().
This commit also introduces a new isLayoutExposedToClients()
method, which is similar to isInitExposedToClients(), except
it also returns 'true' if the property does not have an
initializer (and in fact the latter is implemented in terms
of the former).
This attribute allows to define a pre-specialized entry point of a
generic function in a library.
The following definition provides a pre-specialized entry point for
`genericFunc(_:)` for the parameter type `Int` that clients of the
library can call.
```
@_specialize(exported: true, where T == Int)
public func genericFunc<T>(_ t: T) { ... }
```
Pre-specializations of internal `@inlinable` functions are allowed.
```
@usableFromInline
internal struct GenericThing<T> {
@_specialize(exported: true, where T == Int)
@inlinable
internal func genericMethod(_ t: T) {
}
}
```
There is syntax to pre-specialize a method from a different module.
```
import ModuleDefiningGenericFunc
@_specialize(exported: true, target: genericFunc(_:), where T == Double)
func prespecialize_genericFunc(_ t: T) { fatalError("dont call") }
```
Specially marked extensions allow for pre-specialization of internal
methods accross module boundries (respecting `@inlinable` and
`@usableFromInline`).
```
import ModuleDefiningGenericThing
public struct Something {}
@_specializeExtension
extension GenericThing {
@_specialize(exported: true, target: genericMethod(_:), where T == Something)
func prespecialize_genericMethod(_ t: T) { fatalError("dont call") }
}
```
rdar://64993425
Extend the actor isolation checking rules to account for global
actors. For example, a function annotated with a given global actor
can invoke synchronous methods from the same global actor, but not
from a different global actor or a particular actor instance.
Similarly, a method of an (instance) actor that is annotated with a
global actor attribute is not part of the (instance) actor and,
therefore, cannot operate on its actor-isolated state.
Global actor types can be used as attributes on various kinds of
declarations to indicate that those declarations are part of the
isolated state of that global actor. Allow such annotation and perform
basic correctness checks.
The globalActor attribute indicates that a particular type describes a
global actor. Global actors allow the notion of actor state isolation
to be spread across various declarations throughout a program, rather
than being centered around a single actor class. There are useful
primarily for existing notions such as "main thread" or subsystems
accessed through global/singleton state.
Rather than relying on clients to cope with the potential for circular
inheritance of superclass declarations, teach SuperclassDeclRequest to
establish whether circular inheritance has occurred and produce "null"
in such cases. This allows other clients to avoid having to think about
To benefit from this, have SuperclassTypeRequest evaluate
SuperclassDeclRequest first and, if null, produce a Type(). This
ensures that we don't get into an inconsistent situation where there
is a superclass type but no superclass declaration.
Actor classes never have non-actor superclasses, so we can ensure that
all actor classes have a common vtable prefix for the
`enqueue(partialTask:)` operation. This allows us to treat all actor
classes uniformly, without having to go through the Actor witness
table every time.
checks to check for type context instead of local context.
This generalization will help us implement property wrappers on
global variables, which should use the same approach of not adding
synthesized accessors to the AST and instead lazily visit them in
SILGen.
Introduce a new Actor protocol, which is a class-bound protocol with only
one requirement:
func enqueue(partialTask: PartialAsyncTask)
All actor classes implicitly conform to this protocol, and will synthesize
a (currently empty) definition of `enqueue(partialTask:)` unless a suitable
one is provided explicitly.
This method had a messy contract:
- Setting the diags parameter to nullptr inhibited caching
- The initExpr out parameter could only used if no result
had yet been cached
Let's instead use the request evaluator here.
