A bug of generated X-Swift.h

Using Swift
1

I found a bug of generated X-Swift.h, but I don't know whether it is a bug of Swift or a bug of Xcode, so I post it here.

A.framework

open class C: NSObject {}

open class O1: NSObject {}

open class O2: NSObject {}

extension O1 {
    open class M: C {}
}

extension O2 {
    open class M: C {}
}

If I didn't add @objc to O1.M, it will not be seen in A-Swift.h, and it is fine.
But, if I write

extension O1.M {}

extension O2.M {}

It can compile, but it comes to a bug, I cannot use A.framework in other framework.
It is because O1.M and O2.M will be generated in A-Swift.h.

SWIFT_CLASS("_TtCC1A2O21M")
@interface M : C
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
@end




SWIFT_CLASS("_TtCC1A2O11M")
@interface M : C
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
@end

In B.framwork

import A

Duplicate interface definition for class 'M'
Could not build Objective-C module 'A'

Where should I report this bug.

2 
A.framework

open class C: NSObject {}

open class O1: NSObject {}

open class O2: NSObject {}

extension O1 {
    open class M: C {}
}

extension O2 {
    open class M: C {}
}

O1.M will not be generated to A-Swift.h

B.framework

open class T: O1.M {
    
}

T will be generated to B-Swift.h

SWIFT_CLASS("_TtC1B1T")
@interface T : M
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
@end

In C.framework

import B

Cannot find interface declaration for 'M', superclass of 'T'
Could not build Objective-C module 'B'