Previously, we attempted to infer @objc-ness based on conformance, but
doing so is fraught with ordering dependencies, and just doesn't work
in the general case. Among other crimes, this allowed us to
retroactively mark a non-@objc method from an imported module as
@objc... even though nobody would ever then emit the @objc entry
points for it.
Fixes the rest of rdar://problem/18383574.
Swift SVN r24831
An optional @objc requirement within a protocol can be left
unsatisfied in a well-formed program. However, there may still be a
conflict within the Objective-C runtime if the conforming class
defines a method with the corresponding Objective-C selector(s) for
that requirement, which means that the Swift and Objective-C semantics
will differ. Diagnose such issues.
More steps along the road to fixing rdar://problem/18383574.
Diagnose conflicts between unsatisfied, optional @objc requirements and
Swift SVN r24830
When we match a witness to a requirement in a protocol, we do so based
on the Swift name (which is correct). When the requirement is @objc
(because it is in an @objc protocol), also check that the Objective-C
selectors of the witness match those of the requirement.
Fixes the majority of rdar://problem/18383574.
Swift SVN r24829
