Attempt to fix LV2 Vstgui on macOS

lv2/sfizz_ui.cpp

@@ -374,6 +374,9 @@ lv2ui_descriptor(uint32_t index)
 #if LINUX
    VSTGUI::initializeSoHandle();
 #endif
+#if MAC
+   VSTGUI::initializeBundleRef();
+#endif
 
     switch (index)
     {

lv2/vstgui_helpers.cpp

@@ -18,6 +18,9 @@
 #if WINDOWS
 #include <windows.h>
 #endif
+#if MAC
+#include "vstgui/plugin-bindings/getpluginbundle.h"
+#endif
 
 #if LINUX
 void Lv2IdleRunLoop::execIdle()
@@ -184,3 +187,38 @@ BOOL WINAPI DllMain(HINSTANCE dllInstance, DWORD reason, LPVOID)
     return TRUE;
 }
 #endif
+
+///
+#if MAC
+namespace VSTGUI
+{
+void* gBundleRef = nullptr;
+
+static volatile bool gBundleRefInitialized = false;
+static std::mutex gBundleRefMutex;
+
+struct CFBundle_deleter {
+    void operator()(CFBundleRef x) const noexcept
+    {
+        CFRelease(x);
+    }
+};
+static std::unique_ptr<__CFBundle, CFBundle_deleter> gBundleRefPointer;
+} // namespace VSTGUI
+
+void VSTGUI::initializeBundleRef()
+{
+   if (VSTGUI::gBundleRefInitialized)
+      return;
+
+   std::lock_guard<std::mutex> lock(VSTGUI::gBundleRefMutex);
+   if (VSTGUI::gBundleRefInitialized)
+      return;
+
+   CFBundleRef bundleRef = GetPluginBundle();
+   VSTGUI::gBundleRef = bundleRef;
+   VSTGUI::gBundleRefPointer.reset(bundleRef);
+
+   VSTGUI::gBundleRefInitialized = true;
+}
+#endif

lv2/vstgui_helpers.h

@@ -66,3 +66,10 @@ namespace VSTGUI
 void initializeSoHandle();
 }
 #endif
+
+#if MAC
+namespace VSTGUI
+{
+void initializeBundleRef();
+}
+#endif