runtime/objc-class.h

   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  *      objc-class.h
  27  *      Copyright 1988-1996, NeXT Software, Inc.
  28  */
  29
  30 #ifndef _OBJC_CLASS_H_
  31 #define _OBJC_CLASS_H_
  32
  33 #import <objc/objc.h>
  34 /*
  35  *      Class Template
  36  */
  37 struct objc_class {
  38         struct objc_class *isa;
  39         struct objc_class *super_class;
  40         const char *name;
  41         long version;
  42         long info;
  43         long instance_size;
  44         struct objc_ivar_list *ivars;
  45
  46         struct objc_method_list **methodLists;
  47
  48         struct objc_cache *cache;
  49         struct objc_protocol_list *protocols;
  50 };
  51 #define CLS_GETINFO(cls,infomask)       ((cls)->info & (infomask))
  52 #define CLS_SETINFO(cls,infomask)       ((cls)->info |= (infomask))
  53
  54 #define CLS_CLASS               0x1L
  55 #define CLS_META                0x2L
  56 #define CLS_INITIALIZED         0x4L
  57 #define CLS_POSING              0x8L
  58 #define CLS_MAPPED              0x10L
  59 #define CLS_FLUSH_CACHE         0x20L
  60 #define CLS_GROW_CACHE          0x40L
  61 #define CLS_NEED_BIND           0x80L
  62 #define CLS_METHOD_ARRAY        0x100L
  63 // the JavaBridge constructs classes with these markers
  64 #define CLS_JAVA_HYBRID         0x200L
  65 #define CLS_JAVA_CLASS          0x400L
  66 // thread-safe +initialize
  67 #define CLS_INITIALIZING        0x800
  68
  69 /*
  70  * (true as of 2001-9-24)
  71  * Thread-safety note: changes to these flags are not atomic, so
  72  * the only thing preventing lost updates is the timing of the changes.
  73  *
  74  * As long as the following are isolated from each other for any one class,
  75  * nearly all flag updates will be safe:
  76  * - compile-time
  77  * - loading in one thread (not including +load) without messaging
  78  * - initializing in one thread with messaging from that thread only
  79  * - multi-threaded messaging with method caching
  80  *
  81  * The current code doesn't protect loading yet.
  82  *
  83  * Times when the flags may change:
  84  * CLS_CLASS: compile-time, hand-built classes
  85  * CLS_META: compile time, hand-built classes
  86  * CLS_INITIALIZED: initialize
  87  * CLS_POSING: unsafe, but posing has other thread-safety problems
  88  * CLS_MAPPED: compile-time
  89  * CLS_FLUSH_CACHE: messaging
  90  * CLS_GROW_CACHE: messaging
  91  *   FLUSH_CACHE and GROW_CACHE are protected from each other by the
  92  *   cacheUpdateLock.
  93  * CLS_NEED_BIND: load, initialize
  94  * CLS_METHOD_ARRAY: load
  95  * CLS_JAVA_HYBRID: hand-built classes
  96  * CLS_JAVA_CLASS: hand-built classes, initialize
  97  * CLS_INITIALIZING: initialize
  98  *
  99  * The only unsafe updates are:
 100  * - posing (unsafe anyway)
 101  * - hand-built classes (including JavaBridge classes)
 102  *   There is a short time between objc_addClass inserts the new class
 103  *   into the class_hash and the builder setting the right flags.
 104  *   A thread looking at the class_hash could send a message to the class
 105  *   and trigger initialization, and the changes to the initialization
 106  *   flags and the hand-adjusted flags could collide.
 107  *   Solution: don't do that.
 108  */
 109
 110
 111 /*
 112  *      Category Template
 113  */
 114 typedef struct objc_category *Category;
 115
 116 struct objc_category {
 117         char *category_name;
 118         char *class_name;
 119         struct objc_method_list *instance_methods;
 120         struct objc_method_list *class_methods;
 121         struct objc_protocol_list *protocols;
 122 };
 123
 124 /*
 125  *      Instance Variable Template
 126  */
 127 typedef struct objc_ivar *Ivar;
 128
 129 struct objc_ivar {
 130         char *ivar_name;
 131         char *ivar_type;
 132         int ivar_offset;
 133 #ifdef __alpha__
 134         int space;
 135 #endif
 136 };
 137
 138 struct objc_ivar_list {
 139         int ivar_count;
 140 #ifdef __alpha__
 141         int space;
 142 #endif
 143         struct objc_ivar ivar_list[1];          /* variable length structure */
 144 };
 145
 146 OBJC_EXPORT Ivar object_setInstanceVariable(id, const char *name, void *);
 147 OBJC_EXPORT Ivar object_getInstanceVariable(id, const char *name, void **);
 148
 149 /*
 150  *      Method Template
 151  */
 152 typedef struct objc_method *Method;
 153
 154 struct objc_method {
 155         SEL method_name;
 156         char *method_types;
 157         IMP method_imp;
 158 };
 159
 160 struct objc_method_list {
 161         struct objc_method_list *obsolete;
 162
 163         int method_count;
 164 #ifdef __alpha__
 165         int space;
 166 #endif
 167         struct objc_method method_list[1];      /* variable length structure */
 168 };
 169
 170 /* Protocol support */
 171
 172 @class Protocol;
 173
 174 struct objc_protocol_list {
 175         struct objc_protocol_list *next;
 176         int count;
 177         Protocol *list[1];
 178 };
 179
 180 /* Definitions of filer types */
 181
 182 #define _C_ID           '@'
 183 #define _C_CLASS        '#'
 184 #define _C_SEL          ':'
 185 #define _C_CHR          'c'
 186 #define _C_UCHR         'C'
 187 #define _C_SHT          's'
 188 #define _C_USHT         'S'
 189 #define _C_INT          'i'
 190 #define _C_UINT         'I'
 191 #define _C_LNG          'l'
 192 #define _C_ULNG         'L'
 193 #define _C_FLT          'f'
 194 #define _C_DBL          'd'
 195 #define _C_BFLD         'b'
 196 #define _C_VOID         'v'
 197 #define _C_UNDEF        '?'
 198 #define _C_PTR          '^'
 199 #define _C_CHARPTR      '*'
 200 #define _C_ARY_B        '['
 201 #define _C_ARY_E        ']'
 202 #define _C_UNION_B      '('
 203 #define _C_UNION_E      ')'
 204 #define _C_STRUCT_B     '{'
 205 #define _C_STRUCT_E     '}'
 206
 207 /* Structure for method cache - allocated/sized at runtime */
 208
 209 typedef struct objc_cache *     Cache;
 210
 211 #define CACHE_BUCKET_NAME(B)  ((B)->method_name)
 212 #define CACHE_BUCKET_IMP(B)   ((B)->method_imp)
 213 #define CACHE_BUCKET_VALID(B) (B)
 214 #define CACHE_HASH(sel, mask) (((uarith_t)(sel)>>2) & (mask))
 215 struct objc_cache {
 216         unsigned int mask;            /* total = mask + 1 */
 217         unsigned int occupied;
 218         Method buckets[1];
 219 };
 220
 221 /* operations */
 222 OBJC_EXPORT id class_createInstance(Class, unsigned idxIvars);
 223 OBJC_EXPORT id class_createInstanceFromZone(Class, unsigned idxIvars, void *z);
 224
 225 OBJC_EXPORT void class_setVersion(Class, int);
 226 OBJC_EXPORT int class_getVersion(Class);
 227
 228 OBJC_EXPORT Ivar class_getInstanceVariable(Class, const char *);
 229 OBJC_EXPORT Method class_getInstanceMethod(Class, SEL);
 230 OBJC_EXPORT Method class_getClassMethod(Class, SEL);
 231
 232 OBJC_EXPORT void class_addMethods(Class, struct objc_method_list *);
 233 OBJC_EXPORT void class_removeMethods(Class, struct objc_method_list *);
 234
 235 OBJC_EXPORT Class class_poseAs(Class imposter, Class original);
 236
 237 OBJC_EXPORT unsigned method_getNumberOfArguments(Method);
 238 OBJC_EXPORT unsigned method_getSizeOfArguments(Method);
 239 OBJC_EXPORT unsigned method_getArgumentInfo(Method m, int arg, const char **type, int *offset);
 240
 241 // usage for nextMethodList
 242 //
 243 // void *iterator = 0;
 244 // struct objc_method_list *mlist;
 245 // while ( mlist = class_nextMethodList( cls, &iterator ) )
 246 //    ;
 247 #define OBJC_NEXT_METHOD_LIST 1
 248 OBJC_EXPORT struct objc_method_list *class_nextMethodList(Class, void **);
 249
 250 typedef void *marg_list;
 251
 252 #if defined(__ppc__) || defined(ppc)
 253 #define marg_prearg_size        128
 254 #else
 255 #define marg_prearg_size        0
 256 #endif
 257
 258 #define marg_malloc(margs, method) \
 259         do { \
 260                 margs = (marg_list *)malloc (marg_prearg_size + ((7 + method_getSizeOfArguments(method)) & ~7)); \
 261         } while (0)
 262
 263
 264 #define marg_free(margs) \
 265         do { \
 266                 free(margs); \
 267         } while (0)
 268
 269 #define marg_adjustedOffset(method, offset) \
 270         (marg_prearg_size + offset)
 271
 272
 273
 274
 275 #define marg_getRef(margs, offset, type) \
 276         ( (type *)((char *)margs + marg_adjustedOffset(method,offset) ) )
 277
 278 #define marg_getValue(margs, offset, type) \
 279         ( *marg_getRef(margs, offset, type) )
 280
 281 #define marg_setValue(margs, offset, type, value) \
 282         ( marg_getValue(margs, offset, type) = (value) )
 283
 284 /* Load categories and non-referenced classes from libraries. */
 285
 286 #endif /* _OBJC_CLASS_H_ */