macOS: CONFIG+=serveronly needs two changes, not one

🤖 AI: #2551 left macOS out of CONFIG+=serveronly with an open invitation — "The MacOS build might be feasible but there were the bundle options already there and I've no way to check what's going on with the MacOS build. If someone else wants to have a go at that, add DEFINES += SERVER_ONLY and see if it works." Now it is run on a Mac, at c862872e, macOS 12.7.6, Qt 5.15.2, command-line qmake+make, x86_64.

That change does most of it, and is not sufficient. With DEFINES += SERVER_ONLY added to the macx branch and nothing else, the define reaches every compile line and all 15 client-side undefined symbols go away. Nine remain, and every one of them is CSoundBase:

$ qmake Jamulus.pro CONFIG+=serveronly CONFIG+=headless && make -j2
Project MESSAGE: Restricting build to server-only due to CONFIG+=serveronly.
Project MESSAGE: Using CoreAudio.
[...]
Undefined symbols for architecture x86_64:
  "CSoundBase::ReinitRequest(int)", referenced from:
      CSound::deviceNotification(unsigned int, unsigned int, AudioObjectPropertyAddress const*, void*) in sound.o
  "CSoundBase::staticMetaObject", referenced from:
      CSound::staticMetaObject in moc_sound.o
  "vtable for CSoundBase", referenced from:
      CSoundBase::~CSoundBase() in sound.o
[6 further CSoundBase symbols, 9 in total]
ld: symbol(s) not found for architecture x86_64

The nine come from the second difference between the branches: the macx branch adds coreaudio-mac/sound.cpp unconditionally, while soundbase.cpp is stripped platform-independently — so CSound is compiled without its base class. win32 does not hit this because its ASIO sources sit inside the else-branch of its own serveronly test. So macOS needs two changes, not one: the missing define, and a serveronly guard around the CoreAudio sources. With both, a plain CONFIG+=serveronly CONFIG+=headless build links and runs:

$ qmake Jamulus.pro CONFIG+=serveronly CONFIG+=headless && make -j2
Project MESSAGE: Restricting build to server-only due to CONFIG+=serveronly.
Project MESSAGE: Server-only build: skipping CoreAudio.
[...]
$ Jamulus.app/Contents/MacOS/Jamulus --version
- Starting in server mode by default (due to compile time option)
 *** Jamulus, Version 3.12.4dev-nogit

With neither change the option half-applies rather than being ignored: five platform-independent !contains(CONFIG, "serveronly") blocks strip client sources while SERVER_ONLY stays undefined, and the link fails with 24 undefined symbols.

No released artifact is affected: the macOS server app is built by mac/deploy_mac.sh with CONFIG+=server_bundle alone, which keeps both sound files — built at the same commit here, 0 errors, JamulusServer starts in server mode.

Documentation is affected either way: the compile-time arguments table marks server_bundle "macOS only" and jackonmac "on macOS", while serveronly carries no platform qualifier and its one worked example, qmake "CONFIG+=headless serveronly", sits under ## Linux.

🤖 This message was written by AI and reviewed by @mcfnord.

Jamulus.pro の macx ソースリストと既存の serveronly 条件分岐から始め、次に COMPILING.md のコンパイル時引数の表と Linux の例を確認します。macOS で CONFIG+=serveronly CONFIG+=headless を付けて qmake を実行し、server-only ビルドがリンクされ、Jamulus.app/Contents/MacOS/Jamulus --version がサーバーモードで起動することを確認します。macOS のサポートと関連するオプションを正確に説明するよう、ドキュメントを更新します。