Added helper function for C++ non-POD type atomic properties.

Fixed prototypes of specialised property functions.

ANNOUNCE

@@ -8,6 +8,9 @@ programs.  Highlights of this release include:
 
 - A new CMake-based build system
 
+- Added specialised property accessor functions and support for atomic
+  properties with C++ non-POD types.
+
 - A new exception implementation providing better integration with foreign
   exceptions (e.g. C++ exceptions) (TODO)
 

properties.m

@@ -84,7 +84,7 @@ void objc_setProperty(id obj, SEL _cmd, ptrdiff_t offset, id arg, BOOL isAtomic,
 	objc_release(old);
 }
 
-void objc_setProperty_atomic(id obj, SEL _cmd, ptrdiff_t offset, id arg)
+void objc_setProperty_atomic(id obj, SEL _cmd, id arg, ptrdiff_t offset)
 {
 	char *addr = (char*)obj;
 	addr += offset;
@@ -97,7 +97,7 @@ void objc_setProperty_atomic(id obj, SEL _cmd, ptrdiff_t offset, id arg)
 	objc_release(old);
 }
 
-void objc_setProperty_atomic_copy(id obj, SEL _cmd, ptrdiff_t offset, id arg)
+void objc_setProperty_atomic_copy(id obj, SEL _cmd, id arg, ptrdiff_t offset)
 {
 	char *addr = (char*)obj;
 	addr += offset;
@@ -111,7 +111,7 @@ void objc_setProperty_atomic_copy(id obj, SEL _cmd, ptrdiff_t offset, id arg)
 	objc_release(old);
 }
 
-void objc_setProperty_nonatomic(id obj, SEL _cmd, ptrdiff_t offset, id arg)
+void objc_setProperty_nonatomic(id obj, SEL _cmd, id arg, ptrdiff_t offset)
 {
 	char *addr = (char*)obj;
 	addr += offset;
@@ -121,7 +121,7 @@ void objc_setProperty_nonatomic(id obj, SEL _cmd, ptrdiff_t offset, id arg)
 	objc_release(old);
 }
 
-void objc_setProperty_nonatomic_copy(id obj, SEL _cmd, ptrdiff_t offset, id arg)
+void objc_setProperty_nonatomic_copy(id obj, SEL _cmd, id arg, ptrdiff_t offset)
 {
 	char *addr = (char*)obj;
 	addr += offset;
@@ -130,6 +130,36 @@ void objc_setProperty_nonatomic_copy(id obj, SEL _cmd, ptrdiff_t offset, id arg)
 	objc_release(old);
 }
 
+void objc_copyCppObjectAtomic(void *dest, const void *src,
+                              void (*copyHelper) (void *dest, const void *source))
+{
+	volatile int *lock = lock_for_pointer(src < dest ? src : dest);
+	volatile int *lock2 = lock_for_pointer(src < dest ? dest : src);
+	lock_spinlock(lock);
+	lock_spinlock(lock2);
+	copyHelper(dest, src);
+	unlock_spinlock(lock);
+	unlock_spinlock(lock2);
+}
+
+void objc_getCppObjectAtomic(void *dest, const void *src,
+                             void (*copyHelper) (void *dest, const void *source))
+{
+	volatile int *lock = lock_for_pointer(src);
+	lock_spinlock(lock);
+	copyHelper(dest, src);
+	unlock_spinlock(lock);
+}
+
+void objc_setCppObjectAtomic(void *dest, const void *src,
+                             void (*copyHelper) (void *dest, const void *source))
+{
+	volatile int *lock = lock_for_pointer(dest);
+	lock_spinlock(lock);
+	copyHelper(dest, src);
+	unlock_spinlock(lock);
+}
+
 /**
  * Structure copy function.  This is provided for compatibility with the Apple
  * APIs (it's an ABI function, so it's semi-public), but it's a bad design so
@@ -145,8 +175,8 @@ void objc_copyPropertyStruct(void *dest,
 {
 	if (atomic)
 	{
-		volatile int *lock = lock_for_pointer(src);
-		volatile int *lock2 = lock_for_pointer(src);
+		volatile int *lock = lock_for_pointer(src < dest ? src : dest);
+		volatile int *lock2 = lock_for_pointer(src < dest ? dest : src);
 		lock_spinlock(lock);
 		lock_spinlock(lock2);
 		memcpy(dest, src, size);

spinlock.h

@@ -26,7 +26,7 @@ extern int spinlocks[spinlock_count];
  * contention between the same property in different objects, so we can't just
  * use the ivar offset.
  */
-static inline volatile int *lock_for_pointer(void *ptr)
+static inline volatile int *lock_for_pointer(const void *ptr)
 {
 	intptr_t hash = (intptr_t)ptr;
 	// Most properties will be pointers, so disregard the lowest few bits