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

#if !defined(MAC_OS_X_VERSION_10_12) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12
#define kAudioObjectPropertyElementMain kAudioObjectPropertyElementMaster
#endif

This is more a copy/paste where I didn’t update the version requirement.

[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

The majority of software there’s days expects to be build against the latest possible SDK and set the minimum target accordingly, however at least on Macports due to rev-upgrade that’s not exactly always possible.

[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.