As part of the criteria to determine whether a method override requires a new
vtable entry in addition to overriding the base class's vtable entry for the
method, we compare the visibility of the base class to that of the derived
class, since if further subclasses of the derived class cannot see the original
base class's method descriptor, they would not be able to directly override its
vtable entry.
However, there was a subtle inconsistency in our checks in two different
places: `NeedsNewVTableEntryRequest::evaluate` compared the visibility of the
derived method to its immediate override method, whereas
`SILGenModule::emitVTableMethod` compared visibility with the ultimate base
method that originated the vtable entry in question. Internal imports create
a situation where this leads to inconsistent answers, causing us to emit
a vtable thunk but without a corresponding new vtable entry, causing the thunk
to become self-recursive (rdar://147360093). If the base class is in a separate
module:
```
// Module1
open class Base {
public required init() {}
}
```
and an intermediate class inherits that base class, it must `public import`
the module in the file defining the class to do so:
```
// Module2
public import Module1
open class MidDerived: Base { }
```
However, another file in the same module can further inherit that class, but
with only an `internal import` of the base module:
```
// Also Module2
import Module1
open class MostDerived: MidDerived { }
```
The implicit `init()` is `public` in each class, but from the perspective of
`MostDerived.init`, `Base.init` is `internal` because of the import. However,
the fact that its immediate parent is `public` should be sufficient evidence
that its original definition had visibility to `Base`, so no thunk should
be necessary.
On a very recent tip-of-tree build of Clang, this was producing
the following error:
`variable 'eltMV' is uninitialized when used within its own initialization [-Werror,-Wuninitialized]`
The Protocol field isn't really necessary, because the conformance
stores the protocol. But we do need the substituted subject type
of the requirement, just temporarily, until an abstract conformance
stores its own subject type too.
Added an `-executor-factory` argument to the compiler to let you safely
specify the executors you wish to use (by naming a type that returns
them).
Also added some tests of the new functionality.
rdar://141348916
To ensure that dependent values have a persistent-enough memory representation
to point into, when an immutable binding is referenced as an addressable
argument to a call, have SILGen retroactively emit a stack allocation and
materialization that covers the binding's scope.
To ensure that dependent values have a persistent-enough memory representation
to point into, when an immutable binding is referenced as an addressable
argument to a call, have SILGen retroactively emit a stack allocation and
materialization that covers the binding's scope.
Without this, the borrow of the hop_to_executor lasts after the apply. Beyond
being unnecessary this results in an OSSA violation if we are passing an actor
as an isolated parameter to an initializer since we hop_to_executor the actor
and then pass it as a +1 parameter to the initializer causing the actor to be
consumed before its borrow ends.
rdar://144994837
Introduce a constructor that takes an `llvm::VersionTuple` directly, instead of
needing to spell out `VersionRange::allGTE(<tuple>)` which is unnecessarily
verbose.
In C++, we always expected to invoke the dtor for moved-from objects.
This is not the case for swift. Fortunately, @inCxx calling convention
is already expressing that the caller supposed to destroy the object.
This fixes the missing dtor calls when calling C++ functions taking
rvalue references. Fixes#77894.
rdar://140786022
At one point, OpenedArchetypeType did not exist as a separate subclass
of ArchetypeType, so this method did something. Now, it's just
equivalent to calling is<> or isa<>.
I also removed a couple of asserts that were obvious no-ops as a result.
