Re: [RFC PATCH v2 2/6] audio/coreaudio: Remove a deprecation warning on macOS 12

[Christian Schoenebeck]

On Montag, 10. Januar 2022 13:24:06 CET Philippe Mathieu-Daudé wrote:
> On 1/10/22 09:44, Philippe Mathieu-Daudé wrote:
> > On 1/10/22 09:17, Akihiko Odaki wrote:
> >> On 2022/01/10 2:06, Philippe Mathieu-Daudé wrote:
> >>> When building on macOS 12 we get:
> >>> 
> >>>    audio/coreaudio.c:50:5: error: 'kAudioObjectPropertyElementMaster'
> >>> is deprecated: first deprecated in macOS 12.0
> >>> [-Werror,-Wdeprecated-declarations]
> >>>        kAudioObjectPropertyElementMaster
> >>>        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>>        kAudioObjectPropertyElementMain
> >>>   
> >>> /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frame
> >>> works/CoreAudio.framework/Headers/AudioHardwareBase.h:208:5: note:
> >>> 'kAudioObjectPropertyElementMaster' has been explicitly marked
> >>> deprecated here
> >>>        kAudioObjectPropertyElementMaster
> >>> API_DEPRECATED_WITH_REPLACEMENT("kAudioObjectPropertyElementMain",
> >>> macos(10.0, 12.0), ios(2.0, 15.0), watchos(1.0, 8.0), tvos(9.0, 15.0))
> >>> = kAudioObjectPropertyElementMain
> >>>        ^
> >>> 
> >>> Use kAudioObjectPropertyElementMain (define it to
> >>> kAudioObjectPropertyElementMaster on macOS < 12).
> >>> 
> >>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >>> ---
> >>>   audio/coreaudio.c | 16 ++++++++++------
> >>>   1 file changed, 10 insertions(+), 6 deletions(-)
> >>> 
> >>> diff --git a/audio/coreaudio.c b/audio/coreaudio.c
> >>> index d8a21d3e507..c836bc9dd37 100644
> >>> --- a/audio/coreaudio.c
> >>> +++ b/audio/coreaudio.c
> >>> @@ -44,10 +44,14 @@ typedef struct coreaudioVoiceOut {
> >>>       bool enabled;
> >>>   } coreaudioVoiceOut;
> >>>   +#if !defined(MAC_OS_VERSION_12_0)
> >>> +#define kAudioObjectPropertyElementMain
> >>> kAudioObjectPropertyElementMaster
> >>> +#endif
> >>> +
> >> 
> >> Semantically MAC_OS_VERSION_12_0 defines the numeric value of version
> >> 12.0 and its existence does not mean that
> >> kAudioObjectPropertyElementMain is defined. I suggest the following:
> >> #if !__is_identifier(kAudioObjectPropertyElementMain)
> >> #define kAudioObjectPropertyElementMain kAudioObjectPropertyElementMaster
> >> #endif
> 
> Apparently __is_identifier() is Clang specific. It might be acceptable
> since this file is restricted to macOS. Similarly for the other
> block/file-posix.c patch, the section is conditional to  __APPLE__
> being defined.

Correct, __is_identifier() is a clang extension and does not work with GCC
(tested). I would not use it. People on Mac usually use clang, but there are
also cross compilers for macOS binaries.

I'd suggest to use:

#if !defined(MAC_OS_VERSION_12_0) ||
    (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_VERSION_12_0)
#define kAudioObjectPropertyElementMain kAudioObjectPropertyElementMaster
#endif

Best regards,
Christian Schoenebeck