[cxx-interop] NSNotification.Name has no member

[tcollins590]

Description I have a swift package that I am trying to add c++ interop to. The package compiles until I add swiftSettings: [.interoperabilityMode(.Cxx)]. I'm then presented with a few errors in my existing swift code

The code

NotificationCenter.default.addObserver(self,
                                       selector: #selector(self.changeCamera),
                                       name: NSNotification.Name.AVCaptureDeviceWasConnected,
                                       object: nil)

NotificationCenter.default.addObserver(self,
                                          selector: #selector(self.changeCamera),
                                          name: NSNotification.Name.AVCaptureDeviceWasDisconnected,
                                          object: nil)

The error Type 'NSNotification.Name' has no member 'AVCaptureDeviceWasConnected Type 'NSNotification.Name' has no member 'AVCaptureDeviceWasDisconnected

Steps to reproduce Add an observer to the NotificationCenter to observe NSNotification.Name.AVCaptureDeviceWasDisconnected. Compile without swift interop and then attempt to compile with swift interop

Expected behavior I expect this to compile with swift interop just as it does without interop enabled

Environment

• Swift compiler version info swift-driver version: 1.87.1 Apple Swift version 5.9 (swiftlang-5.9.0.128.108 clang-1500.0.40.1) Target: arm64-apple-macosx14.0
• Xcode version info Xcode 15.0 Build version 15A240d
• Deployment target: iOS and iOS simulator

[AnthonyLatsis]

cc @egorzhdan

[egorzhdan]

Thanks, this is tracked internally as rdar://115424525, and we're working to fix this in https://github.com/apple/swift/pull/69776

[tcollins590]

@egorzhdan Thanks for the update. I've found several other pieces of swift code that break when enabling interop such as pieces of ARKit. Would you like those as separate issues?

[egorzhdan]

@tcollins590 yes, please! The issues with NSNotification.Name are all caused by the same underlying problem, so there's no need to report them, but other cases of source breakage caused by C++ interop are definitely worth reporting separately.

[knielsen-foreflight]

Is there a workaround for this issue?

[tcollins590]

@knielsen-foreflight sorry for the delay in response. As a temporary workaround I implemented a polling based solution for the specific use case. In my case I needed to see if an external camera was attached. To achieve this I poll the camera configuration to see if there is one attached. This is not an optimal fix but allowed me to solve the issue while I wait for a future fix in swift.

[code-per-day]

I have the same issue for our app, do we have an ETA for when this fix will be released?

[ElJabato]

@knielsen-foreflight sorry for the delay in response. As a temporary workaround I implemented a polling based solution for the specific use case. In my case I needed to see if an external camera was attached. To achieve this I poll the camera configuration to see if there is one attached. This is not an optimal fix but allowed me to solve the issue while I wait for a future fix in swift.

There is a workaround, based in "init raw value". Swift code:

NotificationCenter.default.addObserver(forName: Notification.Name.GCControllerDidConnect, object: nil, queue: nil, using: connectMFIController)

Is equivalent to

NotificationCenter.default.addObserver(forName: Notification.Name.init(rawValue: "GCControllerDidConnectNotification"), object: nil, queue: nil, using: connectMFIController)

Find the string name is possible with "print" (swift):

print(Notification.Name.GCControllerDidConnect)

Output this:

NSNotificationName(_rawValue: GCControllerDidConnectNotification)

(Of course you must set interop to "C / Objective C" firstly).

[schwa]

This just hit me and I spent way too long trying to understand what caused it. Is there an ETA? I see the fix is merged but it's unavailable to me as of Xcode 15.4 and the macOS 14 SDK

[AnthonyLatsis]

Is there an ETA?

Apparently this was not nominated for 5.10, so it will ship with 6.0, the next release.