textDocument/implementation on a protocol requirement returns locations at which conformance to that protocol is stated instead of their implementations

[ahoppen]

Consider doing an implementation request at 1️⃣ in the following.

protocol MyProto {
  func 1️⃣myFunc()
}

class ClassA: MyProto {
  func 2️⃣myFunc() {}
}
class ClassB: MyProto {
  func 3️⃣myFunc() {}
}
class 4️⃣ClassBSubA: ClassB {}
class 5️⃣ClassBSubB: ClassB {}

class RetroactiveConformanceClassWithMyFuncInClassDecl {
  func 6️⃣myFunc() { }
}
extension 7️⃣RetroactiveConformanceClassWithMyFuncInClassDecl: MyProto {}

class RetroactiveConformanceClassWithMyFuncInExtension {}
extension RetroactiveConformanceClassWithMyFuncInExtension: MyProto {
  func 8️⃣myFunc() { }
}

Currently, we report 2, 3, 4, 5, 7, 8

We should not be reporting locations 4, 5 and 7 because they don't actually contain myFunc. We should, however, be reporting location 6.

[ahoppen]

Synced to Apple’s issue tracker as rdar://132935019