runtime/objc-class.h

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