1  /* GNU Objective C Runtime class related functions
       2     Copyright (C) 1993-2023 Free Software Foundation, Inc.
       3     Contributed by Kresten Krab Thorup
       4  
       5  This file is part of GCC.
       6  
       7  GCC is free software; you can redistribute it and/or modify it under the
       8  terms of the GNU General Public License as published by the Free Software
       9  Foundation; either version 3, or (at your option) any later version.
      10  
      11  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      12  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      13  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
      14  details.
      15  
      16  Under Section 7 of GPL version 3, you are granted additional
      17  permissions described in the GCC Runtime Library Exception, version
      18  3.1, as published by the Free Software Foundation.
      19  
      20  You should have received a copy of the GNU General Public License and
      21  a copy of the GCC Runtime Library Exception along with this program;
      22  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23  <http://www.gnu.org/licenses/>.  */
      24  
      25  #include "objc-private/common.h"
      26  #include "objc/runtime.h"
      27  #include "objc/thr.h"                   /* Required by objc-private/runtime.h.  */
      28  #include "objc-private/module-abi-8.h"  /* For CLS_ISCLASS and similar.  */
      29  #include "objc-private/runtime.h"	/* the kitchen sink */
      30  
      31  #include <string.h>                     /* For memcpy()  */
      32  
      33  #if OBJC_WITH_GC
      34  # include <gc/gc.h>
      35  # include <gc/gc_typed.h>
      36  #endif
      37  
      38  /* FIXME: The semantics of extraBytes are not really clear.  */
      39  inline
      40  id
      41  class_createInstance (Class class, size_t extraBytes)
      42  {
      43    id new = nil;
      44  
      45  #if OBJC_WITH_GC
      46    if (CLS_ISCLASS (class))
      47      new = (id) GC_malloc_explicitly_typed (class->instance_size + extraBytes,
      48  					   (GC_descr)class->gc_object_type);
      49  #else
      50    if (CLS_ISCLASS (class))
      51      new = (id) objc_calloc (class->instance_size + extraBytes, 1);
      52  #endif
      53  
      54    if (new != nil)
      55      {
      56        /* There is no need to zero the memory, since both
      57  	 GC_malloc_explicitly_typed and objc_calloc return zeroed
      58  	 memory.  */
      59        new->class_pointer = class;
      60      }
      61  
      62    /* TODO: Invoke C++ constructors on all appropriate C++ instance
      63       variables of the new object.  */
      64  
      65    return new;
      66  }
      67  
      68  /* Traditional GNU Objective-C Runtime API.  */
      69  id
      70  object_copy (id object, size_t extraBytes)
      71  {
      72    if ((object != nil) && CLS_ISCLASS (object->class_pointer))
      73      {
      74        /* TODO: How should it work with C++ constructors ? */
      75        id copy = class_createInstance (object->class_pointer, extraBytes);
      76        memcpy (copy, object, object->class_pointer->instance_size + extraBytes);
      77        return copy;
      78      }
      79    else
      80      return nil;
      81  }
      82  
      83  id
      84  object_dispose (id object)
      85  {
      86    if ((object != nil) && CLS_ISCLASS (object->class_pointer))
      87      {
      88        /* TODO: Invoke C++ destructors on all appropriate C++ instance
      89  	 variables.  But what happens with the garbage collector ?
      90  	 Would object_dispose() be ever called in that case ?  */
      91  
      92        objc_free (object);
      93      }
      94    return nil;
      95  }
      96  
      97  const char *
      98  object_getClassName (id object)
      99  {
     100    if (object != nil)
     101      return object->class_pointer->name;
     102    else
     103      return "Nil";
     104  }
     105  
     106  Class
     107  object_setClass (id object, Class class_)
     108  {
     109    if (object == nil)
     110      return Nil;
     111    else
     112      {
     113        Class old_class = object->class_pointer;
     114  
     115        object->class_pointer = class_;
     116        return old_class;
     117      }
     118  }