Unable to switch off diagnostics for "Invalid bitwise operation between different enumeration types"

[DominikDeak]

I have come across an issue where certain third party header files generates the following error, when included in C++26 projects:

/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX26.0.sdk/System/Library/Frameworks/CoreGraphics.framework/Headers/CGImage.h:96:18 Invalid bitwise operation between different enumeration types ('CGImageAlphaInfo' and 'CGImageComponentInfo')

Trying to disable diagnostics using the following pragmas does not work:

#pragma clang diagnostic push 
#pragma clang diagnostic ignored "-Wenum-conversion"
#include <Cocoa/Cocoa.h>
#pragma clang diagnostic pop

Sample test project for Xcode 26: Test.zip

I realise Apple uses their own custmised clang, but i'm speculating they pull most of core features/bugfixes from upstream llvm-project. I've also raised an issue with Apple, but I have not gotten a response. There is also a related issue #92340, but not sure what the outcome was for this.

If there is a work-around to disable the aforementioned enum diagnostics for third-party or system headers included in C++26 projects, that would be appreciated.

[AaronBallman]

In Clang you can pass -Wno-enum-enum-conversion to disable the diagnostic entirely, or -Wno-error=enum-enum-conversion to retain the diagnostic but downgrade it to a warning, in addition to the pragma to disable the diagnostic contextually: https://godbolt.org/z/abE83566d

Closing the issue as this is behaving by design in Clang. If Apple Clang does not support these mechanisms to disable or downgrade the diagnostic, that will have to be handled with Apple directly.