gcc/libobjc/objects.c

/* GNU Objective C Runtime class related functions
   Copyright (C) 1993, 1995, 1996, 2009, 2010, 2011
   Free Software Foundation, Inc.
   Contributed by Kresten Krab Thorup

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
details.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

#include "objc-private/common.h"
#include "objc/runtime.h"
#include "objc/thr.h"                   /* Required by objc-private/runtime.h.  */
#include "objc-private/module-abi-8.h"  /* For CLS_ISCLASS and similar.  */
#include "objc-private/runtime.h"	/* the kitchen sink */

#include <string.h>                     /* For memcpy()  */

#if OBJC_WITH_GC
# include <gc.h>
# include <gc_typed.h>
#endif

/* FIXME: The semantics of extraBytes are not really clear.  */
inline
id
class_createInstance (Class class, size_t extraBytes)
{
  id new = nil;

#if OBJC_WITH_GC
  if (CLS_ISCLASS (class))
    new = (id) GC_malloc_explicitly_typed (class->instance_size + extraBytes,
					   (GC_descr)class->gc_object_type);
#else
  if (CLS_ISCLASS (class))
    new = (id) objc_calloc (class->instance_size + extraBytes, 1);
#endif

  if (new != nil)
    {
      /* There is no need to zero the memory, since both
	 GC_malloc_explicitly_typed and objc_calloc return zeroed
	 memory.  */
      new->class_pointer = class;
    }

  /* TODO: Invoke C++ constructors on all appropriate C++ instance
     variables of the new object.  */

  return new;
}

/* Traditional GNU Objective-C Runtime API.  */
id
object_copy (id object, size_t extraBytes)
{
  if ((object != nil) && CLS_ISCLASS (object->class_pointer))
    {
      /* TODO: How should it work with C++ constructors ? */
      id copy = class_createInstance (object->class_pointer, extraBytes);
      memcpy (copy, object, object->class_pointer->instance_size + extraBytes);
      return copy;
    }
  else
    return nil;
}

id
object_dispose (id object)
{
  if ((object != nil) && CLS_ISCLASS (object->class_pointer))
    {
      /* TODO: Invoke C++ destructors on all appropriate C++ instance
	 variables.  But what happens with the garbage collector ?
	 Would object_dispose() be ever called in that case ?  */

      objc_free (object);
    }
  return nil;
}

const char *
object_getClassName (id object)
{
  if (object != nil)
    return object->class_pointer->name;
  else
    return "Nil";
}

Class
object_setClass (id object, Class class_)
{
  if (object == nil)
    return Nil;
  else
    {
      Class old_class = object->class_pointer;

      object->class_pointer = class_;
      return old_class;
    }
}