Fix malloc() / free() imbalance.

Author: theraven

gc_boehm.c

@@ -429,6 +429,7 @@ static id allocate_class(Class cls, size_t extra)
 	return obj;
 }
 
+static void free_object(id obj) {}
 id objc_allocate_object(Class cls, int extra)
 {
 	return class_createInstance(cls, extra);
@@ -714,6 +715,7 @@ static void debug_free(void *ptr)
 PRIVATE struct gc_ops gc_ops_boehm =
 {
 	.allocate_class = allocate_class,
+	.free_object    = free_object,
 	.malloc         = debug_malloc,
 	.free           = debug_free,
 };

gc_none.c

@@ -11,6 +11,11 @@ static id allocate_class(Class cls, size_t extraBytes)
 	return (id)(addr + 1);
 }
 
+static void free_object(id obj)
+{
+	free((void*)(((intptr_t)obj) - 1));
+}
+
 static void *alloc(size_t size)
 {
 	return calloc(size, 1);
@@ -19,6 +24,7 @@ static void *alloc(size_t size)
 PRIVATE struct gc_ops gc_ops_none = 
 {
 	.allocate_class = allocate_class,
+	.free_object    = free_object,
 	.malloc         = alloc,
 	.free           = free
 };

gc_ops.h

@@ -12,6 +12,10 @@ struct gc_ops
 	 * Allocates enough space for a class, followed by some extra bytes.
 	 */
 	id (*allocate_class)(Class, size_t);
+	/**
+	 * Frees an object.
+	 */
+	void (*free_object)(id);
 	/**
 	 * Allocates some memory that can be used to store pointers.  This must be
 	 * used instead of malloc() for internal data structures that will store

runtime.c

@@ -358,8 +358,11 @@ id object_copy(id obj, size_t size)
 
 id object_dispose(id obj)
 {
-	call_cxx_destruct(obj);
-	gc->free(obj);
+	if (isGCEnabled)
+	{
+		call_cxx_destruct(obj);
+		gc->free_object(obj);
+	}
 	return nil;
 }