runtime/Protocol.m

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25         Protocol.h
  26         Copyright 1991-1996 NeXT Software, Inc.
  27 */
  28
  29 #if defined(WIN32)
  30     #include <winnt-pdo.h>
  31 #endif
  32
  33 #include "objc-private.h"
  34 #import <objc/Protocol.h>
  35
  36 #include <objc/objc-runtime.h>
  37 #include <stdlib.h>
  38
  39 #if defined(__MACH__)
  40     #include <mach-o/dyld.h>
  41     #include <mach-o/ldsyms.h>
  42 #endif
  43
  44 /* some forward declarations */
  45
  46 static struct objc_method_description *
  47 lookup_method(struct objc_method_description_list *mlist, SEL aSel);
  48
  49 static struct objc_method_description *
  50 lookup_class_method(struct objc_protocol_list *plist, SEL aSel);
  51
  52 static struct objc_method_description *
  53 lookup_instance_method(struct objc_protocol_list *plist, SEL aSel);
  54
  55 @implementation Protocol
  56
  57
  58 + _fixup: (OBJC_PROTOCOL_PTR)protos numElements: (int) nentries
  59 {
  60   int i;
  61   for (i = 0; i < nentries; i++)
  62     {
  63       /* isa has been overloaded by the compiler to indicate version info */
  64       protos[i] OBJC_PROTOCOL_DEREF isa = self; // install the class descriptor.
  65     }
  66
  67   return self;
  68 }
  69
  70 + load
  71 {
  72   OBJC_PROTOCOL_PTR p;
  73   int size;
  74   headerType **hp;
  75   headerType **hdrs;
  76   hdrs = _getObjcHeaders();
  77
  78   for (hp = hdrs; *hp; hp++)
  79     {
  80       p = (OBJC_PROTOCOL_PTR)_getObjcProtocols((headerType*)*hp, &size);
  81       if (p && size) { [self _fixup:p numElements: size]; }
  82     }
  83   free (hdrs);
  84
  85   return self;
  86 }
  87
  88 - (BOOL) conformsTo: (Protocol *)aProtocolObj
  89 {
  90   if (!aProtocolObj)
  91     return NO;
  92
  93   if (strcmp(aProtocolObj->protocol_name, protocol_name) == 0)
  94     return YES;
  95   else if (protocol_list)
  96     {
  97     int i;
  98
  99     for (i = 0; i < protocol_list->count; i++)
 100       {
 101       Protocol *p = protocol_list->list[i];
 102
 103       if (strcmp(aProtocolObj->protocol_name, p->protocol_name) == 0)
 104         return YES;
 105
 106       if ([p conformsTo:aProtocolObj])
 107         return YES;
 108       }
 109     return NO;
 110     }
 111   else
 112     return NO;
 113 }
 114
 115 - (struct objc_method_description *) descriptionForInstanceMethod:(SEL)aSel
 116 {
 117    struct objc_method_description *m = lookup_method(instance_methods, aSel);
 118
 119    if (!m && protocol_list)
 120      m = lookup_instance_method(protocol_list, aSel);
 121
 122    return m;
 123 }
 124
 125 - (struct objc_method_description *) descriptionForClassMethod:(SEL)aSel
 126 {
 127    struct objc_method_description *m = lookup_method(class_methods, aSel);
 128
 129    if (!m && protocol_list)
 130      m = lookup_class_method(protocol_list, aSel);
 131
 132    return m;
 133 }
 134
 135 - (const char *)name
 136 {
 137   return protocol_name;
 138 }
 139
 140 - (BOOL)isEqual:other
 141 {
 142     return [other isKindOf:[Protocol class]] && [self conformsTo: other] && [other conformsTo: self];
 143 }
 144
 145 - (unsigned int)hash
 146 {
 147     return 23;
 148 }
 149
 150 static
 151 struct objc_method_description *
 152 lookup_method(struct objc_method_description_list *mlist, SEL aSel)
 153 {
 154    if (mlist)
 155      {
 156      int i;
 157      for (i = 0; i < mlist->count; i++)
 158        if (mlist->list[i].name == aSel)
 159          return mlist->list+i;
 160      }
 161    return 0;
 162 }
 163
 164 static
 165 struct objc_method_description *
 166 lookup_instance_method(struct objc_protocol_list *plist, SEL aSel)
 167 {
 168    int i;
 169    struct objc_method_description *m = 0;
 170
 171    for (i = 0; i < plist->count; i++)
 172      {
 173      if (plist->list[i]->instance_methods)
 174        m = lookup_method(plist->list[i]->instance_methods, aSel);
 175
 176      /* depth first search */
 177      if (!m && plist->list[i]->protocol_list)
 178        m = lookup_instance_method(plist->list[i]->protocol_list, aSel);
 179
 180      if (m)
 181        return m;
 182      }
 183    return 0;
 184 }
 185
 186 static
 187 struct objc_method_description *
 188 lookup_class_method(struct objc_protocol_list *plist, SEL aSel)
 189 {
 190    int i;
 191    struct objc_method_description *m = 0;
 192
 193    for (i = 0; i < plist->count; i++)
 194      {
 195      if (plist->list[i]->class_methods)
 196        m = lookup_method(plist->list[i]->class_methods, aSel);
 197
 198      /* depth first search */
 199      if (!m && plist->list[i]->protocol_list)
 200        m = lookup_class_method(plist->list[i]->protocol_list, aSel);
 201
 202      if (m)
 203        return m;
 204      }
 205    return 0;
 206 }
 207
 208 @end