libobjc/objects.c

   1 /* GNU Objective C Runtime class related functions
   2    Copyright (C) 1993, 1995, 1996, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4    Contributed by Kresten Krab Thorup
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under the
   9 terms of the GNU General Public License as published by the Free Software
  10 Foundation; either version 3, or (at your option) any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14 FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  15 details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "objc-private/common.h"
  27 #include "objc/runtime.h"
  28 #include "objc/thr.h"                   /* Required by objc-private/runtime.h.  */
  29 #include "objc-private/module-abi-8.h"  /* For CLS_ISCLASS and similar.  */
  30 #include "objc-private/runtime.h"       /* the kitchen sink */
  31
  32 #include <string.h>                     /* For memcpy()  */
  33
  34 #if OBJC_WITH_GC
  35 # include <gc.h>
  36 # include <gc_typed.h>
  37 #endif
  38
  39 /* FIXME: The semantics of extraBytes are not really clear.  */
  40 inline
  41 id
  42 class_createInstance (Class class, size_t extraBytes)
  43 {
  44   id new = nil;
  45
  46 #if OBJC_WITH_GC
  47   if (CLS_ISCLASS (class))
  48     new = (id) GC_malloc_explicitly_typed (class->instance_size + extraBytes,
  49                                            (GC_descr)class->gc_object_type);
  50 #else
  51   if (CLS_ISCLASS (class))
  52     new = (id) objc_calloc (class->instance_size + extraBytes, 1);
  53 #endif
  54
  55   if (new != nil)
  56     {
  57       /* There is no need to zero the memory, since both
  58          GC_malloc_explicitly_typed and objc_calloc return zeroed
  59          memory.  */
  60       new->class_pointer = class;
  61     }
  62
  63   /* TODO: Invoke C++ constructors on all appropriate C++ instance
  64      variables of the new object.  */
  65
  66   return new;
  67 }
  68
  69 /* Traditional GNU Objective-C Runtime API.  */
  70 id
  71 object_copy (id object, size_t extraBytes)
  72 {
  73   if ((object != nil) && CLS_ISCLASS (object->class_pointer))
  74     {
  75       /* TODO: How should it work with C++ constructors ? */
  76       id copy = class_createInstance (object->class_pointer, extraBytes);
  77       memcpy (copy, object, object->class_pointer->instance_size + extraBytes);
  78       return copy;
  79     }
  80   else
  81     return nil;
  82 }
  83
  84 id
  85 object_dispose (id object)
  86 {
  87   if ((object != nil) && CLS_ISCLASS (object->class_pointer))
  88     {
  89       /* TODO: Invoke C++ destructors on all appropriate C++ instance
  90          variables.  But what happens with the garbage collector ?
  91          Would object_dispose() be ever called in that case ?  */
  92
  93       objc_free (object);
  94     }
  95   return nil;
  96 }
  97
  98 const char *
  99 object_getClassName (id object)
 100 {
 101   if (object != nil)
 102     return object->class_pointer->name;
 103   else
 104     return "Nil";
 105 }
 106
 107 Class
 108 object_setClass (id object, Class class_)
 109 {
 110   if (object == nil)
 111     return Nil;
 112   else
 113     {
 114       Class old_class = object->class_pointer;
 115
 116       object->class_pointer = class_;
 117       return old_class;
 118     }
 119 }