blocks:

• SR-14195 Swift emits an invalid module interface when a public type has the same name as a module

Issue Description:

Given two modules with the same type, where one module has a type that has the same name as the module itself with generic parameters it will become impossible to explicitly refer to the type you want.

Example

Module A:

struct NoError: ErrorType {}

Module B:

struct B<T> {}
struct NoError: ErrorType {}

The app:

import A
import B

let ambiguousError: NoError // This correctly errors because it's ambiguous
let errorA: A.NoError // This correctly works since we make the module explicit
let errorB: B.NoError // This _incorrectly_ errors, complaining about required arguments

Expected behaviour

Only ambiguousError should give an error, the other two error constants should work since the module is specified to prevent ambiguous type errors.

What happend instead

The error we get with B.NoError is Reference to generic type 'B' requires arguments in <...>. The compiler incorrectly assumes we are referring to struct B instead of the module B. This makes it impossible to fix the ambiguity.

Workaround

It is possible to work around this by creating a typealias in a seperate file where we only import module B and there typealias BNoError = NoError then we can use the BNoError as the type of let errorB to work around the issue.