Restore Darling specific changes

os/object.h

@@ -65,7 +65,7 @@
 #elif TARGET_OS_MAC && !TARGET_OS_IPHONE
 #  if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_8
 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
-#  elif defined(__i386__) && __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_12
+#  elif defined(__i386__) && __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_12 && !defined(DARLING)
 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 0
 #  else
 #  define OS_OBJECT_HAVE_OBJC_SUPPORT 1

os/object_private.h

@@ -73,7 +73,7 @@
         int volatile ref_cnt; \
         int volatile xref_cnt
 
-#if OS_OBJECT_HAVE_OBJC_SUPPORT
+#if OS_OBJECT_HAVE_OBJC_SUPPORT || defined(DARLING)
 #define OS_OBJECT_CLASS_SYMBOL(name) OS_##name##_class
 #if TARGET_OS_MAC && !TARGET_OS_SIMULATOR && defined(__i386__)
 #define OS_OBJECT_HAVE_OBJC1 1

src/inline_internal.h

@@ -1978,9 +1978,17 @@ DISPATCH_ALWAYS_INLINE DISPATCH_CONST
 static inline dispatch_queue_global_t
 _dispatch_get_root_queue(dispatch_qos_t qos, bool overcommit)
 {
+#ifdef DARLING
+	if (qos == 0) {
+		// !!! HACK !!!
+		// treat QoS `0` as the manager queue
+		return &_dispatch_mgr_root_queue;
+	}
+#else
 	if (unlikely(qos < DISPATCH_QOS_MIN || qos > DISPATCH_QOS_MAX)) {
 		DISPATCH_CLIENT_CRASH(qos, "Corrupted priority");
 	}
+#endif
 	return &_dispatch_root_queues[2 * (qos - 1) + overcommit];
 }
 

src/object.m

@@ -471,6 +471,8 @@ DISPATCH_UNAVAILABLE_INIT()
 @end
 
 
+// Darling-only conditional; the upstream sources don't have this conditional (but they should)
+#if defined(DARLING) && VOUCHER_USE_MACH_VOUCHER
 #pragma mark vouchers
 
 OS_OBJECT_NONLAZY_CLASS
@@ -502,6 +504,7 @@ DISPATCH_UNAVAILABLE_INIT()
 }
 
 @end
+#endif // defined(DARLING) && VOUCHER_USE_MACH_VOUCHER
 
 #if VOUCHER_ENABLE_RECIPE_OBJECTS
 OS_OBJECT_NONLAZY_CLASS

src/queue.c

@@ -7774,10 +7774,12 @@ _dispatch_root_queues_init_once(void *context DISPATCH_UNUSED)
 	int wq_supported = _pthread_workqueue_supported();
 	int r = ENOTSUP;
 
+#ifndef DARLING
 	if (!(wq_supported & WORKQ_FEATURE_MAINTENANCE)) {
 		DISPATCH_INTERNAL_CRASH(wq_supported,
 				"QoS Maintenance support required");
 	}
+#endif
 
 #if DISPATCH_USE_KEVENT_SETUP
 	struct pthread_workqueue_config cfg = {

src/queue_internal.h

@@ -457,6 +457,19 @@ typedef struct dispatch_queue_specific_head_s {
 	TAILQ_HEAD(, dispatch_queue_specific_s) dqsh_entries;
 } *dispatch_queue_specific_head_t;
 
+#ifdef DARLING
+// for Darling, we move this up here because otherwise it's an undefined type when it's used in `dispatch_workloop_attr_s`
+//
+// it really makes me wonder: does Apple even try compiling their own code? because i don't know any C compiler
+// that accepts a type being used before it's `typedef`ed
+typedef struct dispatch_pthread_root_queue_observer_hooks_s {
+	void (*queue_will_execute)(dispatch_queue_t queue);
+	void (*queue_did_execute)(dispatch_queue_t queue);
+} dispatch_pthread_root_queue_observer_hooks_s;
+typedef dispatch_pthread_root_queue_observer_hooks_s
+		*dispatch_pthread_root_queue_observer_hooks_t;
+#endif // DARLING
+
 #define DISPATCH_WORKLOOP_ATTR_HAS_SCHED      0x0001u
 #define DISPATCH_WORKLOOP_ATTR_HAS_POLICY     0x0002u
 #define DISPATCH_WORKLOOP_ATTR_HAS_CPUPERCENT 0x0004u
@@ -651,12 +664,14 @@ struct dispatch_queue_global_s {
 } DISPATCH_CACHELINE_ALIGN;
 
 
+#ifndef DARLING
 typedef struct dispatch_pthread_root_queue_observer_hooks_s {
 	void (*queue_will_execute)(dispatch_queue_t queue);
 	void (*queue_did_execute)(dispatch_queue_t queue);
 } dispatch_pthread_root_queue_observer_hooks_s;
 typedef dispatch_pthread_root_queue_observer_hooks_s
 		*dispatch_pthread_root_queue_observer_hooks_t;
+#endif // DARLING
 
 #ifdef __APPLE__
 #define DISPATCH_IOHID_SPI 1

src/source.c

@@ -936,11 +936,20 @@ _dispatch_source_invoke(dispatch_source_t ds, dispatch_invoke_context_t dic,
 #if DISPATCH_EVENT_BACKEND_KEVENT
 	if (flags & DISPATCH_INVOKE_WORKLOOP_DRAIN) {
 		dispatch_workloop_t dwl = (dispatch_workloop_t)_dispatch_get_wlh();
+#ifdef DARLING
+		// HACK: this is almost certainly wrong, but i don't see why WLH_ANON is being returned
+		if (dwl == DISPATCH_WLH_ANON) {
+			_dispatch_event_loop_drain_anon_timers();
+		} else {
+#endif
 		dispatch_timer_heap_t dth = dwl->dwl_timer_heap;
 		if (dth && dth[0].dth_dirty_bits) {
 			_dispatch_event_loop_drain_timers(dwl->dwl_timer_heap,
 					DISPATCH_TIMER_WLH_COUNT);
 		}
+#ifdef DARLING
+		}
+#endif
 	}
 #endif // DISPATCH_EVENT_BACKEND_KEVENT
 }