Inner value of CWPHYMode appears to change between integer and bitflags index between macOS versions

[keabarnes]

In the code below, the inner value of CWPHYMode which is returned by interface.activePHYMode() differs based on the macOS version.

unsafe {
  let client = CWWiFiClient::sharedWiFiClient();

  let interface = client.interface().unwrap();

  let phy_mode = interface.activePHYMode();
}

From observation I've noticed that

• on macOS 14.5 the inner value is represented by an integer that maps well to the const ... Self(n) constants on the enum
• on macOS 15.0 it seems like the value represents the naive conversion from a bitflag to an integer
  • 802.11n is returned as CWPHYMode(16) but should be CWPHYMode(4)
  • 802.11ax is returned as CWPHYMode(64) but should be CWPHYMode(6)

---

Cargo.toml for context

objc2 = { version = "0.5", features = ["apple"] }
objc2-foundation = { version = "0.2", features = ["apple"] }
objc2-core-wlan = { version = "0.2", features = [
  "CWInterface",
  "CWNetwork",
  "CWWiFiClient",
  "CWChannel",
  "CoreWLANTypes",
] }

[simlay]

Huh. This is interesting. I ran the example code. I'm on macOS 15 with an 802.11ac network. I get a CWPHYMode(32) when I presume it should be CWPHYMode(5). I get the same incorrect result mentioned above with an 802.11n network.

The mapping looks like:

• CWPHYMode(4) is returned as CWPHYMode(16)
• CWPHYMode(5) is returned as CWPHYMode(32)
• CWPHYMode(6) is returned as CWPHYMode(64).

Looks like the pattern is a bitmask rather than an integer?

[madsmtm]

I'm still on macOS 14.7, and can't test this in a virtual machine (since the virtual machines don't have WiFi), so could I get one of you to test the following:

1. RUSTFLAGS="-Clinker-flavor=ld" cargo run (in case this is dependent on the minos/sdk version in the binary)
2. The equivalent Swift code:

   import CoreWLAN
   
   let client = CWWiFiClient.shared()
   let interface = client.interface()!
   let phy_mode = interface.activePHYMode()
   print(phy_mode.rawValue)