[BUG]: Availability error for __typeof__(AHardwareBuffer_acquire) when targeting android24

[twaik]

Description

__typeof__(AHardwareBuffer_acquire) is a type-only query.

It does not call the function, does not require code generation, and does not involve linking. Availability checks should not trigger in this context.

Is this intended, or a bug in availability diagnostics?

I understand that __ANDROID_UNAVAILABLE_SYMBOLS_ARE_WEAK__ can be used, but it makes it easy to accidentally call AHardwareBuffer_acquire instead of, for example, pAHardwareBuffer_acquire, which can lead to a segmentation fault due to a null function pointer. If type-only usage were allowed, it would be possible to define simple wrappers or substitutes that could be called uniformly (e.g., pAHardwareBuffer_acquire) without the risk of accidentally invoking the original function.

Minimal repro:

#include <android/hardware_buffer.h>
__typeof__(AHardwareBuffer_acquire)* p = NULL;

Build with something like

~/Android/Sdk/ndk/29.0.14206865/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang ./test.c

Result:

./test.c:3:12: error: 'AHardwareBuffer_acquire' is unavailable: introduced in Android 26 android
    3 | __typeof__(AHardwareBuffer_acquire)* p = NULL;
      |            ^
/home/twaik/Android/Sdk/ndk/29.0.14206865/toolchains/llvm/prebuilt/linux-x86_64/bin/../sysroot/usr/include/android/hardware_buffer.h:432:6: note: 'AHardwareBuffer_acquire' has been explicitly marked unavailable here
  432 | void AHardwareBuffer_acquire(AHardwareBuffer* _Nonnull buffer) __INTRODUCED_IN(26);
      |      ^
1 error generated.

I am using a supported NDK

• I have checked and the NDK I'm using is currently supported

Affected versions

r29

[enh-google]

Is this intended, or a bug in availability diagnostics?

yeah, that seems like a compiler bug to me...