This CL adds the ability to create a list of "forwarding nodes" for a
source class. A forwarding node is a data structure that will later
be resolved to either an explicitly declared member in the class or a
superclass, or to a forwarding stub. The idea is that we will create
the forwarding nodes at the time of outline building, and later,
during type inference, we will resolve each forwarding node as it is
encountered.
The reason we need to defer resolution of the forwarding nodes until
inference is because we may need to use the results of type inference
to determine which member a given forwarding node resolves to. For
example:
num f() => 1;
class A {
final x = 1; // Inferred type: int
}
class B {
final x = f(); // Inferred type: num
}
abstract class C implements A, B {}
We cannot determine at the time of building the outline for C whether
it inherits its x from A or B, because we need the results of type
inference to determine which of the two x's has a more specific type.
Note that some refactoring of ClassHierarchy was necessary in order to
allow the front end to maintain member lists in the same order used
internally by ClassHierarchy. This will let us avoid unnecessary
redundant sorting of methods.
Change-Id: Iee754957e0ad3b16c4b60608e17a4a7b0006dfb4
Reviewed-on: https://dart-review.googlesource.com/7851
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Paul Berry
d9ca760992