Basic support for prototype-style object orientation (you can now add methods to an individual object).

ANNOUNCE

@@ -8,15 +8,17 @@ release include:
 
 - Support for small objects (ones hidden inside a pointer).  On 32-bit systems,
   the runtime permits one small object class, on 64-bit systems it permits 4.
+- Support for prototype-style object orientation.  You can now add methods, as
+  well as associated references, to individual objects.
 
 You may obtain the code for this release from subversion at the following
 subversion branch:
 
-svn://svn.gna.org/svn/gnustep/libs/libobjc2/1.5
+svn://svn.gna.org/svn/gnustep/libs/libobjc2/1.6
 
 Alternatively, a tarball is available from:
 
-http://download.gna.org/gnustep/libobjc2-1.5.tar.bz2
+http://download.gna.org/gnustep/libobjc2-1.6.tar.bz2
 
 The runtime library is responsible for implementing the core features of the
 object model, as well as exposing introspection features to the user.  The

Makefile

@@ -3,7 +3,7 @@
 .SUFFIXES: .cc .c .m .o
 
 MAJOR_VERSION = 1
-MINOR_VERSION = 5
+MINOR_VERSION = 6
 SUBMINOR_VERSION = 0
 VERSION = $(MAJOR_VERSION).$(MINOR_VERSION).$(SUBMINOR_VERSION)
 

associate.m

@@ -227,13 +227,14 @@ static inline Class initHiddenClassForObject(id obj)
 	}
 	else
 	{
-		const char *types =
+		static SEL cxx_destruct;
-			method_getTypeEncoding(class_getInstanceMethod(obj->isa,
+		if (NULL == cxx_destruct)
-						SELECTOR(dealloc)));
+		{
-		class_addMethod(hiddenClass, SELECTOR(dealloc), (IMP)deallocHiddenClass,
+			cxx_destruct = sel_registerName(".cxx_destruct");
-				types);
+		}
-		class_addMethod(hiddenClass, SELECTOR(finalize), (IMP)deallocHiddenClass,
+		const char *types = sizeof(void*) == 4 ? "v8@0:4" : "v16@0:8";
-				types);
+		class_addMethod(hiddenClass, cxx_destruct,
+			(IMP)deallocHiddenClass, types);
 		obj->isa = hiddenClass;
 	}
 	return hiddenClass;
@@ -242,20 +243,13 @@ static inline Class initHiddenClassForObject(id obj)
 static void deallocHiddenClass(id obj, SEL _cmd)
 {
 	Class hiddenClass = findHiddenClass(obj);
-	Class realClass = class_getSuperclass(hiddenClass);
-	// Call the real -dealloc method (this ordering is required in case the
-	// user does @synchronized(self) in -dealloc)
-	struct objc_super super = {obj, realClass};
-	objc_msg_lookup_super(&super, _cmd)(obj, _cmd);
 	// After calling [super dealloc], the object will no longer exist.
 	// Free the hidden
 	struct reference_list *list = object_getIndexedIvars(hiddenClass);
 	DESTROY_LOCK(&list->lock);
 	cleanupReferenceList(list);
 	freeReferenceList(list->next);
-
 	free_dtable(hiddenClass->dtable);
-
 	// Free the class
 	free(hiddenClass);
 }
@@ -357,3 +351,37 @@ int objc_sync_exit(id object)
 	}
 	return 1;
 }
+
+static Class hiddenClassForObject(id object)
+{
+	if (isSmallObject(object)) { return nil; }
+	if (class_isMetaClass(object->isa))
+	{
+		return object->isa;
+	}
+	Class hiddenClass = findHiddenClass(object);
+	if (NULL == hiddenClass)
+	{
+		volatile int *lock = lock_for_pointer(object);
+		lock_spinlock(lock);
+		hiddenClass = findHiddenClass(object);
+		if (NULL == hiddenClass)
+		{
+			hiddenClass = initHiddenClassForObject(object);
+			struct reference_list *list = object_getIndexedIvars(hiddenClass);
+			INIT_LOCK(list->lock);
+		}
+		unlock_spinlock(lock);
+	}
+	return hiddenClass;
+}
+
+BOOL object_addMethod_np(id object, SEL name, IMP imp, const char *types)
+{
+	return class_addMethod(hiddenClassForObject(object), name, imp, types);
+}
+
+IMP object_replaceMethod_np(id object, SEL name, IMP imp, const char *types)
+{
+	return class_replaceMethod(hiddenClassForObject(object), name, imp, types);
+}

objc/runtime.h

@@ -822,6 +822,17 @@ void objc_setAssociatedObject(id object, void *key, id value, objc_AssociationPo
  */
 void objc_removeAssociatedObjects(id object);
 
+/**
+ * Adds a method to a specific object,  This method will not be added to any
+ * other instances of the same class.
+ */
+BOOL object_addMethod_np(id object, SEL name, IMP imp, const char *types);
+
+/**
+ * Replaces a method on a specific object,  This method will not be added to
+ * any other instances of the same class.
+ */
+IMP object_replaceMethod_np(id object, SEL name, IMP imp, const char *types);
 
 /**
  * Toggles whether Objective-C objects caught in C++ exception handlers in

runtime.c

@@ -41,8 +41,8 @@ PRIVATE void call_cxx_destruct(id obj)
 		cls = Nil;
 		if (NULL != slot)
 		{
-			slot->method(obj, cxx_destruct);
 			cls = slot->owner->super_class;
+			slot->method(obj, cxx_destruct);
 		}
 	}
 }