objc/objc_object.c

   1 /* Copyright (c) 2006-2009 Christopher J. W. Lloyd
   2
   3 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
   4
   5 The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
   6
   7 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
   8 #import <objc/runtime.h>
   9 #import "objc_class.h"
  10
  11 Class object_getClass(id object) {
  12     if(object == nil) {
  13         return Nil;
  14     }
  15     return object->isa;
  16 }
  17
  18 const char *object_getClassName(id object) {
  19     return class_getName(object_getClass(object));
  20 }
  21
  22 Ivar object_getInstanceVariable(id object, const char *name, void **ptrToValuep) {
  23     Ivar result = class_getInstanceVariable(object_getClass(object), name);
  24
  25     *ptrToValuep = (char *)object + result->ivar_offset;
  26
  27     return result;
  28 }
  29
  30 id object_getIvar(id object, Ivar ivar) {
  31     if(object == nil)
  32         return nil;
  33
  34     return *(id *)((char *)object + ivar->ivar_offset);
  35 }
  36
  37 void *object_getIndexedIvars(id object) {
  38     return (char *)object + object_getClass(object)->instance_size;
  39 }
  40
  41 Class object_setClass(id object, Class cls) {
  42     if(object == nil)
  43         return Nil;
  44
  45     Class result = object->isa;
  46
  47     object->isa = cls;
  48
  49     return result;
  50 }
  51
  52 static void ivarCopy(void *vdst, unsigned offset, void *vsrc, size_t length) {
  53     uint8_t *dst = vdst;
  54     uint8_t *src = vsrc;
  55     size_t i;
  56
  57     for(i = 0; i < length; i++)
  58         dst[offset + i] = src[i];
  59 }
  60
  61 // FIXME: This only works for 'id' ivars
  62 Ivar object_setInstanceVariable(id object, const char *name, void *value) {
  63     Ivar ivar = class_getInstanceVariable(object_getClass(object), name);
  64
  65     if(ivar != NULL)
  66         ivarCopy(object, ivar->ivar_offset, value, sizeof(id));
  67
  68     return ivar;
  69 }
  70
  71 void object_setIvar(id object, Ivar ivar, id value) {
  72     ivarCopy(object, ivar->ivar_offset, &value, sizeof(id));
  73 }
  74
  75 id object_copy(id object, size_t size) {
  76     // UNIMPLEMENTED
  77     return nil;
  78 }
  79
  80 id object_dispose(id object) {
  81     free(object);
  82     return nil;
  83 }
  84
  85 static inline BOOL OBJCCallCXXSelector(id self, Class class, SEL selector) {
  86     struct objc_method *result = NULL;
  87     if(!class->super_class)
  88         return YES;
  89
  90     if(!OBJCCallCXXSelector(self, class->super_class, selector))
  91         return NO;
  92
  93     if((result = OBJCLookupUniqueIdInOnlyThisClass(class, selector)) != NULL) {
  94         if(result->method_imp(self, selector)) {
  95             return YES;
  96         } else {
  97             object_cxxDestruct(self, class->super_class);
  98             return NO;
  99         }
 100     }
 101     return YES;
 102 }
 103
 104 BOOL object_cxxConstruct(id self, Class class) {
 105     static SEL cxx_constructor = 0;
 106     if(!cxx_constructor)
 107         cxx_constructor = sel_registerName(".cxx_construct");
 108
 109     if(!self)
 110         return YES;
 111     if(class->info & CLASS_HAS_CXX_STRUCTORS)
 112         return OBJCCallCXXSelector(self, class, cxx_constructor);
 113     return YES;
 114 }
 115
 116 BOOL object_cxxDestruct(id self, Class class) {
 117     static SEL cxx_destructor = 0;
 118     if(!cxx_destructor)
 119         cxx_destructor = sel_registerName(".cxx_destruct");
 120
 121     if(!self)
 122         return YES;
 123     if(class->info & CLASS_HAS_CXX_STRUCTORS)
 124         return OBJCCallCXXSelector(self, class, cxx_destructor);
 125     return YES;
 126 }