libobjc/ivars.c

   1 /* GNU Objective C Runtime ivar related functions.
   2    Copyright (C) 2010 Free Software Foundation, Inc.
   3    Contributed by Nicola Pero
   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/objc.h"
  27 #include "objc/objc-api.h"
  28 #include "objc-private/runtime.h"               /* the kitchen sink */
  29 #include <string.h> /* For strcmp */
  30
  31 struct objc_ivar *
  32 class_getInstanceVariable (Class class_, const char *name)
  33 {
  34   if (class_ != Nil  &&  name != NULL)
  35     {
  36       objc_mutex_lock (__objc_runtime_mutex);
  37       while (class_ != Nil)
  38         {
  39           struct objc_ivar_list *ivars = class_->ivars;
  40           if (ivars != NULL)
  41             {
  42               int i;
  43
  44               for (i = 0; i < ivars->ivar_count; i++)
  45                 {
  46                   struct objc_ivar *ivar = &(ivars->ivar_list[i]);
  47
  48                   if (!strcmp (ivar->ivar_name, name))
  49                     {
  50                       objc_mutex_unlock (__objc_runtime_mutex);
  51                       return ivar;
  52                     }
  53                 }
  54             }
  55           class_ = class_->super_class;
  56         }
  57       objc_mutex_unlock (__objc_runtime_mutex);
  58     }
  59   return NULL;
  60 }
  61
  62 void *
  63 object_getIndexedIvars (id object)
  64 {
  65   if (object == nil)
  66     return NULL;
  67   else
  68     {
  69       return (void *)(((char *)object)
  70                       + object->class_pointer->instance_size);
  71     }
  72 }
  73
  74 struct objc_ivar *
  75 object_getInstanceVariable (id object, const char *name, void **returnValue)
  76 {
  77   if (object == nil  ||  name == NULL)
  78     return NULL;
  79   else
  80     {
  81       struct objc_ivar * variable = class_getInstanceVariable (object->class_pointer, name);
  82
  83       if (variable != NULL  &&  returnValue != NULL)
  84         {
  85           char *location = (char *)object + variable->ivar_offset;
  86
  87           *returnValue = *((id *)location);
  88         }
  89
  90       return variable;
  91     }
  92 }
  93
  94 struct objc_ivar *
  95 object_setInstanceVariable (id object, const char *name, void *newValue)
  96 {
  97   if (object == nil  ||  name == NULL)
  98     return NULL;
  99   else
 100     {
 101       struct objc_ivar * variable = class_getInstanceVariable (object->class_pointer, name);
 102
 103       if (variable != NULL)
 104         {
 105           char *location = (char *)object + variable->ivar_offset;
 106
 107           *((id *)location) = (id)newValue;
 108         }
 109
 110       return variable;
 111     }
 112 }
 113
 114 id object_getIvar (id object, struct objc_ivar * variable)
 115 {
 116   if (object == nil  ||  variable == NULL)
 117     return nil;
 118   else
 119     {
 120       char *location = (char *)object + variable->ivar_offset;
 121
 122       return *((id *)location);
 123     }
 124 }
 125
 126 void object_setIvar (id object, struct objc_ivar * variable, id value)
 127 {
 128   if (object == nil  ||  variable == NULL)
 129     return;
 130   else
 131     {
 132       char *location = (char *)object + variable->ivar_offset;
 133
 134       *((id *)location) = value;
 135     }
 136 }
 137
 138 const char * ivar_getName (struct objc_ivar * variable)
 139 {
 140   return variable->ivar_name;
 141 }
 142
 143 ptrdiff_t ivar_getOffset (struct objc_ivar * variable)
 144 {
 145   return (ptrdiff_t)(variable->ivar_offset);
 146 }
 147
 148 const char * ivar_getTypeEncoding (struct objc_ivar * variable)
 149 {
 150   return variable->ivar_type;
 151 }