runtime/Protocol.m

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26         Protocol.h
  27         Copyright 1991-1996 NeXT Software, Inc.
  28 */
  29
  30
  31 #include "objc-private.h"
  32 #import <objc/Protocol.h>
  33
  34 #include <objc/objc-runtime.h>
  35 #include <stdlib.h>
  36
  37 #include <mach-o/dyld.h>
  38 #include <mach-o/ldsyms.h>
  39
  40 /* some forward declarations */
  41
  42 static struct objc_method_description *
  43 lookup_method(struct objc_method_description_list *mlist, SEL aSel);
  44
  45 static struct objc_method_description *
  46 lookup_class_method(struct objc_protocol_list *plist, SEL aSel);
  47
  48 static struct objc_method_description *
  49 lookup_instance_method(struct objc_protocol_list *plist, SEL aSel);
  50
  51 @implementation Protocol
  52
  53
  54 + _fixup: (OBJC_PROTOCOL_PTR)protos numElements: (int) nentries
  55 {
  56   int i;
  57   for (i = 0; i < nentries; i++)
  58     {
  59       /* isa has been overloaded by the compiler to indicate version info */
  60       protos[i] OBJC_PROTOCOL_DEREF isa = self; // install the class descriptor.
  61     }
  62
  63   return self;
  64 }
  65
  66 + load
  67 {
  68   OBJC_PROTOCOL_PTR p;
  69   int size;
  70   headerType **hp;
  71   headerType **hdrs;
  72   hdrs = _getObjcHeaders();
  73
  74   for (hp = hdrs; *hp; hp++)
  75     {
  76       p = (OBJC_PROTOCOL_PTR)_getObjcProtocols((headerType*)*hp, &size);
  77       if (p && size) { [self _fixup:p numElements: size]; }
  78     }
  79   free (hdrs);
  80
  81   return self;
  82 }
  83
  84 - (BOOL) conformsTo: (Protocol *)aProtocolObj
  85 {
  86   if (!aProtocolObj)
  87     return NO;
  88
  89   if (strcmp(aProtocolObj->protocol_name, protocol_name) == 0)
  90     return YES;
  91   else if (protocol_list)
  92     {
  93     int i;
  94
  95     for (i = 0; i < protocol_list->count; i++)
  96       {
  97       Protocol *p = protocol_list->list[i];
  98
  99       if (strcmp(aProtocolObj->protocol_name, p->protocol_name) == 0)
 100         return YES;
 101
 102       if ([p conformsTo:aProtocolObj])
 103         return YES;
 104       }
 105     return NO;
 106     }
 107   else
 108     return NO;
 109 }
 110
 111 - (struct objc_method_description *) descriptionForInstanceMethod:(SEL)aSel
 112 {
 113    struct objc_method_description *m = lookup_method(instance_methods, aSel);
 114
 115    if (!m && protocol_list)
 116      m = lookup_instance_method(protocol_list, aSel);
 117
 118    return m;
 119 }
 120
 121 - (struct objc_method_description *) descriptionForClassMethod:(SEL)aSel
 122 {
 123    struct objc_method_description *m = lookup_method(class_methods, aSel);
 124
 125    if (!m && protocol_list)
 126      m = lookup_class_method(protocol_list, aSel);
 127
 128    return m;
 129 }
 130
 131 - (const char *)name
 132 {
 133   return protocol_name;
 134 }
 135
 136 - (BOOL)isEqual:other
 137 {
 138     return [other isKindOf:[Protocol class]] && [self conformsTo: other] && [other conformsTo: self];
 139 }
 140
 141 - (unsigned int)hash
 142 {
 143     return 23;
 144 }
 145
 146 static
 147 struct objc_method_description *
 148 lookup_method(struct objc_method_description_list *mlist, SEL aSel)
 149 {
 150    if (mlist)
 151      {
 152      int i;
 153      for (i = 0; i < mlist->count; i++)
 154        if (mlist->list[i].name == aSel)
 155          return mlist->list+i;
 156      }
 157    return 0;
 158 }
 159
 160 static
 161 struct objc_method_description *
 162 lookup_instance_method(struct objc_protocol_list *plist, SEL aSel)
 163 {
 164    int i;
 165    struct objc_method_description *m = 0;
 166
 167    for (i = 0; i < plist->count; i++)
 168      {
 169      if (plist->list[i]->instance_methods)
 170        m = lookup_method(plist->list[i]->instance_methods, aSel);
 171
 172      /* depth first search */
 173      if (!m && plist->list[i]->protocol_list)
 174        m = lookup_instance_method(plist->list[i]->protocol_list, aSel);
 175
 176      if (m)
 177        return m;
 178      }
 179    return 0;
 180 }
 181
 182 static
 183 struct objc_method_description *
 184 lookup_class_method(struct objc_protocol_list *plist, SEL aSel)
 185 {
 186    int i;
 187    struct objc_method_description *m = 0;
 188
 189    for (i = 0; i < plist->count; i++)
 190      {
 191      if (plist->list[i]->class_methods)
 192        m = lookup_method(plist->list[i]->class_methods, aSel);
 193
 194      /* depth first search */
 195      if (!m && plist->list[i]->protocol_list)
 196        m = lookup_class_method(plist->list[i]->protocol_list, aSel);
 197
 198      if (m)
 199        return m;
 200      }
 201    return 0;
 202 }
 203
 204 @end