mpd @0.23.8: builds failing for all macOS releases prior to monterey

[mascguy (Christopher Nielsen)]

The following failure is occurring.

../mpd-0.23.8/src/output/plugins/OSXOutputPlugin.cxx:163:3: error: use of undeclared identifier 'kAudioObjectPropertyElementMain'; did you mean 'kAudioObjectPropertyElementName'?
                kAudioObjectPropertyElementMain,
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                kAudioObjectPropertyElementName
/Library/Developer/CommandLineTools/SDKs/MacOSX11.sdk/System/Library/Frameworks/CoreAudio.framework/Headers/AudioHardwareBase.h:331:5: note: 'kAudioObjectPropertyElementName' declared here
    kAudioObjectPropertyElementName         = 'lchn',
    ^

Does the latest upstream release require Monterey and later? If so, we should fallback to an earlier release, for Big Sur and prior.

[l2dy (Zero King)]

Unfortunately, a dependency update made all earlier releases fail to build. You may need to backport a patch, see ​https://github.com/MusicPlayerDaemon/MPD/commit/138738075b95d3d8eae3468daa542c0270965299.

[mascguy (Christopher Nielsen)]

Replying to l2dy:

Unfortunately, a dependency update made all earlier releases fail to build. You may need to backport a patch, see ​https://github.com/MusicPlayerDaemon/MPD/commit/138738075b95d3d8eae3468daa542c0270965299.

Yes, I'm actively working on that, as it affects a number of ports. See issue:65619

[Christopher Nielsen <mascguy@…>]

In 8eea3b9366698a3c777e08282cee69818b109a83/macports-ports (master):

mpd: fallback: support 10.15 and big sur

• Still more work necessary, for 10.14 and prior

See: #65653

[mascguy (Christopher Nielsen)]

We can certainly add additional fallbacks for 10.14 and prior, if there's demand.

But at least we now support 10.15 and Big Sur once again, so that's an improvement!

[Gcenx]

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

So you’d want to map kAudioObjectPropertyElementMain to kAudioObjectPropertyElementMaster for prior versions of macOS.

[Gcenx]

You’d do something like the following within the relevant header

#ifndef kAudioObjectPropertyElementMain
#define kAudioObjectPropertyElementMain kAudioObjectPropertyElementMaster
#endif

[Gcenx]

I don’t have access to all the SDKs currently as I’m at work but I believe this change happened from the macOS12.sdk

[Gcenx]

mpd also needs

#ifndef kAudioHardwareServiceDeviceProperty_VirtualMainVolume
#define kAudioHardwareServiceDeviceProperty_VirtualMainVolume kAudioHardwareServiceDeviceProperty_VirtualMasterVolume
#endif

#ifndef kAudioHardwareServiceDeviceProperty_VirtualMainBalance
#define kAudioHardwareServiceDeviceProperty_VirtualMainBalance kAudioHardwareServiceDeviceProperty_VirtualMasterBalance
#endif

This along with the prior mapping gets mpd to compile on macOS Big Sur where before it wouldn't compile with the MacOSX11.sdk

[Gcenx]

Some additional info

Also tested on macOS Mojave with PR49 for legacy-support, Xcode11 fails to compile but after blacklisting anything below Xcode12 and Macports pulled in llvm/clang-14 mpd compiled without issue.