objects.c

/* GNU Objective C Runtime class related functions
 Copyright (C) 1993-2025 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() */

#ifOBJC_WITH_GC
# include<gc/gc.h>
# include<gc/gc_typed.h>
#endif

/* FIXME: The semantics of extraBytes are not really clear. */
inline
id
class_createInstance (Classclass, size_textraBytes)
{
idnew=nil;

#ifOBJC_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. */

returnnew;
}

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

id
object_dispose (idobject)
{
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);
 }
returnnil;
}

constchar*
object_getClassName (idobject)
{
if (object!=nil)
returnobject->class_pointer->name;
else
return"Nil";
}

Class
object_setClass (idobject, Classclass_)
{
if (object==nil)
returnNil;
else
 {
Classold_class=object->class_pointer;

object->class_pointer=class_;
returnold_class;
 }
}