libobjc/objc/objc-api.h

   1 /* GNU Objective-C Runtime API.
   2    Copyright (C) 1993, 1995, 1996, 1997 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GNU CC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  14 License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* As a special exception, if you link this library with files compiled
  22    with GCC to produce an executable, this does not cause the resulting
  23    executable to be covered by the GNU General Public License.  This
  24    exception does not however invalidate any other reasons why the
  25    executable file might be covered by the GNU General Public License. */
  26
  27 #ifndef __objc_api_INCLUDE_GNU
  28 #define __objc_api_INCLUDE_GNU
  29
  30 #include "objc/objc.h"
  31 #include "objc/hash.h"
  32 #include "objc/thr.h"
  33 #include <stdio.h>
  34 #include <stdarg.h>
  35
  36 /* For functions which return Method_t */
  37 #define METHOD_NULL     (Method_t)0
  38                                                 /* Boolean typedefs */
  39 /*
  40 ** Method descriptor returned by introspective Object methods.
  41 ** This is really just the first part of the more complete objc_method
  42 ** structure defined below and used internally by the runtime.
  43 */
  44 struct objc_method_description
  45 {
  46     SEL name;                   /* this is a selector, not a string */
  47     char *types;                /* type encoding */
  48 };
  49
  50 /* Filer types used to describe Ivars and Methods.  */
  51 #define _C_ID       '@'
  52 #define _C_CLASS    '#'
  53 #define _C_SEL      ':'
  54 #define _C_CHR      'c'
  55 #define _C_UCHR     'C'
  56 #define _C_SHT      's'
  57 #define _C_USHT     'S'
  58 #define _C_INT      'i'
  59 #define _C_UINT     'I'
  60 #define _C_LNG      'l'
  61 #define _C_ULNG     'L'
  62 #define _C_LNG_LNG  'q'
  63 #define _C_ULNG_LNG 'Q'
  64 #define _C_FLT      'f'
  65 #define _C_DBL      'd'
  66 #define _C_BFLD     'b'
  67 #define _C_VOID     'v'
  68 #define _C_UNDEF    '?'
  69 #define _C_PTR      '^'
  70 #define _C_CHARPTR  '*'
  71 #define _C_ATOM     '%'
  72 #define _C_ARY_B    '['
  73 #define _C_ARY_E    ']'
  74 #define _C_UNION_B  '('
  75 #define _C_UNION_E  ')'
  76 #define _C_STRUCT_B '{'
  77 #define _C_STRUCT_E '}'
  78
  79
  80 /*
  81 ** Error handling
  82 **
  83 ** Call objc_error() or objc_verror() to record an error; this error
  84 ** routine will generally exit the program but not necessarily if the
  85 ** user has installed his own error handler.
  86 **
  87 ** Call objc_set_error_handler to assign your own function for
  88 ** handling errors.  The function should return YES if it is ok
  89 ** to continue execution, or return NO or just abort if the
  90 ** program should be stopped.  The default error handler is just to
  91 ** print a message on stderr.
  92 **
  93 ** The error handler function should be of type objc_error_handler
  94 ** The first parameter is an object instance of relevance.
  95 ** The second parameter is an error code.
  96 ** The third parameter is a format string in the printf style.
  97 ** The fourth parameter is a variable list of arguments.
  98 */
  99 extern void objc_error(id object, int code, const char* fmt, ...);
 100 extern void objc_verror(id object, int code, const char* fmt, va_list ap);
 101 typedef BOOL (*objc_error_handler)(id, int code, const char *fmt, va_list ap);
 102 objc_error_handler objc_set_error_handler(objc_error_handler func);
 103
 104 /*
 105 ** Error codes
 106 ** These are used by the runtime library, and your
 107 ** error handling may use them to determine if the error is
 108 ** hard or soft thus whether execution can continue or abort.
 109 */
 110 #define OBJC_ERR_UNKNOWN 0             /* Generic error */
 111
 112 #define OBJC_ERR_OBJC_VERSION 1        /* Incorrect runtime version */
 113 #define OBJC_ERR_GCC_VERSION 2         /* Incorrect compiler version */
 114 #define OBJC_ERR_MODULE_SIZE 3         /* Bad module size */
 115 #define OBJC_ERR_PROTOCOL_VERSION 4    /* Incorrect protocol version */
 116
 117 #define OBJC_ERR_MEMORY 10             /* Out of memory */
 118
 119 #define OBJC_ERR_RECURSE_ROOT 20       /* Attempt to archive the root
 120                                           object more than once. */
 121 #define OBJC_ERR_BAD_DATA 21           /* Didn't read expected data */
 122 #define OBJC_ERR_BAD_KEY 22            /* Bad key for object */
 123 #define OBJC_ERR_BAD_CLASS 23          /* Unknown class */
 124 #define OBJC_ERR_BAD_TYPE 24           /* Bad type specification */
 125 #define OBJC_ERR_NO_READ 25            /* Cannot read stream */
 126 #define OBJC_ERR_NO_WRITE 26           /* Cannot write stream */
 127 #define OBJC_ERR_STREAM_VERSION 27     /* Incorrect stream version */
 128 #define OBJC_ERR_BAD_OPCODE 28         /* Bad opcode */
 129
 130 #define OBJC_ERR_UNIMPLEMENTED 30      /* Method is not implemented */
 131
 132 #define OBJC_ERR_BAD_STATE 40          /* Bad thread state */
 133
 134 /*
 135 ** Set this variable nonzero to print a line describing each
 136 ** message that is sent.  (this is currently disabled)
 137 */
 138 extern BOOL objc_trace;
 139
 140
 141 /* For every class which happens to have statically allocated instances in
 142    this module, one OBJC_STATIC_INSTANCES is allocated by the compiler.
 143    INSTANCES is NULL terminated and points to all statically allocated
 144    instances of this class.  */
 145 struct objc_static_instances
 146 {
 147   char *class_name;
 148   id instances[0];
 149 };
 150
 151 /*
 152 ** Whereas a Module (defined further down) is the root (typically) of a file,
 153 ** a Symtab is the root of the class and category definitions within the
 154 ** module.
 155 **
 156 ** A Symtab contains a variable length array of pointers to classes and
 157 ** categories  defined in the module.
 158 */
 159 typedef struct objc_symtab {
 160   unsigned long sel_ref_cnt;                     /* Unknown. */
 161   SEL        refs;                              /* Unknown. */
 162   unsigned short cls_def_cnt;                   /* Number of classes compiled
 163                                                   (defined) in the module. */
 164   unsigned short cat_def_cnt;                   /* Number of categories
 165                                                   compiled (defined) in the
 166                                                   module. */
 167
 168   void      *defs[1];                           /* Variable array of pointers.
 169                                                   cls_def_cnt of type Class
 170                                                   followed by cat_def_cnt of
 171                                                   type Category_t, followed
 172                                                   by a NULL terminated array
 173                                                   of objc_static_instances. */
 174 } Symtab,   *Symtab_t;
 175
 176
 177 /*
 178 ** The compiler generates one of these structures for each module that
 179 ** composes the executable (eg main.m).
 180 **
 181 ** This data structure is the root of the definition tree for the module.
 182 **
 183 ** A collect program runs between ld stages and creates a ObjC ctor array.
 184 ** That array holds a pointer to each module structure of the executable.
 185 */
 186 typedef struct objc_module {
 187   unsigned long version;                        /* Compiler revision. */
 188   unsigned long size;                           /* sizeof(Module). */
 189   const char* name;                             /* Name of the file where the
 190                                                   module was generated.   The
 191                                                   name includes the path. */
 192
 193   Symtab_t    symtab;                           /* Pointer to the Symtab of
 194                                                   the module.  The Symtab
 195                                                   holds an array of
 196                                                   pointers to
 197                                                   the classes and categories
 198                                                   defined in the module. */
 199 } Module, *Module_t;
 200
 201
 202 /*
 203 ** The compiler generates one of these structures for a class that has
 204 ** instance variables defined in its specification.
 205 */
 206 typedef struct objc_ivar* Ivar_t;
 207 typedef struct objc_ivar_list {
 208   int   ivar_count;                             /* Number of structures (Ivar)
 209                                                   contained in the list.  One
 210                                                   structure per instance
 211                                                   variable defined in the
 212                                                   class. */
 213   struct objc_ivar {
 214     const char* ivar_name;                      /* Name of the instance
 215                                                   variable as entered in the
 216                                                   class definition. */
 217     const char* ivar_type;                      /* Description of the Ivar's
 218                                                   type.  Useful for
 219                                                   debuggers. */
 220     int        ivar_offset;                    /* Byte offset from the base
 221                                                   address of the instance
 222                                                   structure to the variable. */
 223
 224   } ivar_list[1];                               /* Variable length
 225                                                   structure. */
 226 } IvarList, *IvarList_t;
 227
 228
 229 /*
 230 ** The compiler generates one (or more) of these structures for a class that
 231 ** has methods defined in its specification.
 232 **
 233 ** The implementation of a class can be broken into separate pieces in a file
 234 ** and categories can break them across modules. To handle this problem is a
 235 ** singly linked list of methods.
 236 */
 237 typedef struct objc_method Method;
 238 typedef Method* Method_t;
 239 typedef struct objc_method_list {
 240   struct objc_method_list*  method_next;      /* This variable is used to link
 241                                                 a method list to another.  It
 242                                                 is a singly linked list. */
 243   int            method_count;               /* Number of methods defined in
 244                                                 this structure. */
 245   struct objc_method {
 246     SEL         method_name;                  /* This variable is the method's
 247                                                 name.  It is a char*.
 248                                                   The unique integer passed to
 249                                                 objc_msg_send is a char* too.
 250                                                 It is compared against
 251                                                 method_name using strcmp. */
 252     const char* method_types;                 /* Description of the method's
 253                                                 parameter list.  Useful for
 254                                                 debuggers. */
 255     IMP         method_imp;                   /* Address of the method in the
 256                                                 executable. */
 257   } method_list[1];                           /* Variable length
 258                                                 structure. */
 259 } MethodList, *MethodList_t;
 260
 261 struct objc_protocol_list {
 262   struct objc_protocol_list *next;
 263   int count;
 264   Protocol *list[1];
 265 };
 266
 267 /*
 268 ** This is used to assure consistent access to the info field of
 269 ** classes
 270 */
 271 #ifndef HOST_BITS_PER_LONG
 272 #define HOST_BITS_PER_LONG  (sizeof(long)*8)
 273 #endif
 274
 275 #define __CLS_INFO(cls) ((cls)->info)
 276 #define __CLS_ISINFO(cls, mask) ((__CLS_INFO(cls)&mask)==mask)
 277 #define __CLS_SETINFO(cls, mask) (__CLS_INFO(cls) |= mask)
 278
 279 /* The structure is of type MetaClass */
 280 #define _CLS_META 0x2L
 281 #define CLS_ISMETA(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_META))
 282
 283
 284 /* The structure is of type Class */
 285 #define _CLS_CLASS 0x1L
 286 #define CLS_ISCLASS(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_CLASS))
 287
 288 /*
 289 ** The class is initialized within the runtime.  This means that
 290 ** it has had correct super and sublinks assigned
 291 */
 292 #define _CLS_RESOLV 0x8L
 293 #define CLS_ISRESOLV(cls) __CLS_ISINFO(cls, _CLS_RESOLV)
 294 #define CLS_SETRESOLV(cls) __CLS_SETINFO(cls, _CLS_RESOLV)
 295
 296 /*
 297 ** The class has been send a +initialize message or a such is not
 298 ** defined for this class
 299 */
 300 #define _CLS_INITIALIZED 0x04L
 301 #define CLS_ISINITIALIZED(cls) __CLS_ISINFO(cls, _CLS_INITIALIZED)
 302 #define CLS_SETINITIALIZED(cls) __CLS_SETINFO(cls, _CLS_INITIALIZED)
 303
 304 /*
 305 ** The class number of this class.  This must be the same for both the
 306 ** class and its meta class object
 307 */
 308 #define CLS_GETNUMBER(cls) (__CLS_INFO(cls) >> (HOST_BITS_PER_LONG/2))
 309 #define CLS_SETNUMBER(cls, num) \
 310   ({ (cls)->info <<= (HOST_BITS_PER_LONG/2); \
 311      (cls)->info >>= (HOST_BITS_PER_LONG/2); \
 312      __CLS_SETINFO(cls, (((unsigned long)num) << (HOST_BITS_PER_LONG/2))); })
 313
 314 /*
 315 ** The compiler generates one of these structures for each category.  A class
 316 ** may have many categories and contain both instance and factory methods.
 317 */
 318 typedef struct objc_category {
 319   const char*   category_name;                /* Name of the category.  Name
 320                                                 contained in the () of the
 321                                                 category definition. */
 322   const char*   class_name;                   /* Name of the class to which
 323                                                 the category belongs. */
 324   MethodList_t  instance_methods;             /* Linked list of instance
 325                                                 methods defined in the
 326                                                 category. NULL indicates no
 327                                                 instance methods defined. */
 328   MethodList_t  class_methods;                /* Linked list of factory
 329                                                 methods defined in the
 330                                                 category.  NULL indicates no
 331                                                 class methods defined. */
 332   struct objc_protocol_list *protocols;       /* List of Protocols
 333                                                  conformed to */
 334 } Category, *Category_t;
 335
 336 /*
 337 ** Structure used when a message is send to a class's super class.  The
 338 ** compiler generates one of these structures and passes it to
 339 ** objc_msg_super.
 340 */
 341 typedef struct objc_super {
 342   id      self;                           /* Id of the object sending
 343                                                 the message. */
 344   Class class;                              /* Object's super class. */
 345 } Super, *Super_t;
 346
 347 IMP objc_msg_lookup_super(Super_t super, SEL sel);
 348
 349 retval_t objc_msg_sendv(id, SEL, arglist_t);
 350
 351
 352
 353 /*
 354 ** This is a hook which is called by objc_lookup_class and
 355 ** objc_get_class if the runtime is not able to find the class.
 356 ** This may e.g. try to load in the class using dynamic loading.
 357 ** The function is guaranteed to be passed a non-NULL name string.
 358 */
 359 extern Class (*_objc_lookup_class)(const char *name);
 360
 361 /*
 362 ** This is a hook which is called by __objc_exec_class every time a class
 363 ** or a category is loaded into the runtime.  This may e.g. help a
 364 ** dynamic loader determine the classes that have been loaded when
 365 ** an object file is dynamically linked in.
 366 */
 367 extern void (*_objc_load_callback)(Class class, Category* category);
 368
 369 /*
 370 ** Hook functions for allocating, copying and disposing of instances
 371 */
 372 extern id (*_objc_object_alloc)(Class class);
 373 extern id (*_objc_object_copy)(id object);
 374 extern id (*_objc_object_dispose)(id object);
 375
 376 /*
 377 ** Standard functions for memory allocation and disposal.
 378 ** Users should use these functions in their ObjC programs so
 379 ** that they work properly with garbage collectors as well as
 380 ** can take advantage of the exception/error handling available.
 381 */
 382 void *
 383 objc_malloc(size_t size);
 384
 385 void *
 386 objc_atomic_malloc(size_t size);
 387
 388 void *
 389 objc_valloc(size_t size);
 390
 391 void *
 392 objc_realloc(void *mem, size_t size);
 393
 394 void *
 395 objc_calloc(size_t nelem, size_t size);
 396
 397 void
 398 objc_free(void *mem);
 399
 400 /*
 401 ** Hook functions for memory allocation and disposal.
 402 ** This makes it easy to substitute garbage collection systems
 403 ** such as Boehm's GC by assigning these function pointers
 404 ** to the GC's allocation routines.  By default these point
 405 ** to the ANSI standard malloc, realloc, free, etc.
 406 **
 407 ** Users should call the normal objc routines above for
 408 ** memory allocation and disposal within their programs.
 409 */
 410 extern void *(*_objc_malloc)(size_t);
 411 extern void *(*_objc_atomic_malloc)(size_t);
 412 extern void *(*_objc_valloc)(size_t);
 413 extern void *(*_objc_realloc)(void *, size_t);
 414 extern void *(*_objc_calloc)(size_t, size_t);
 415 extern void (*_objc_free)(void *);
 416
 417 Method_t class_get_class_method(MetaClass class, SEL aSel);
 418
 419 Method_t class_get_instance_method(Class class, SEL aSel);
 420
 421 Class class_pose_as(Class impostor, Class superclass);
 422
 423 Class objc_get_class(const char *name);
 424
 425 Class objc_lookup_class(const char *name);
 426
 427 Class objc_next_class(void **enum_state);
 428
 429 const char *sel_get_name(SEL selector);
 430
 431 const char *sel_get_type(SEL selector);
 432
 433 SEL sel_get_uid(const char *name);
 434
 435 SEL sel_get_any_uid(const char *name);
 436
 437 SEL sel_get_any_typed_uid(const char *name);
 438
 439 SEL sel_get_typed_uid(const char *name, const char*);
 440
 441 SEL sel_register_name(const char *name);
 442
 443 SEL sel_register_typed_name(const char *name, const char*type);
 444
 445
 446 BOOL sel_is_mapped (SEL aSel);
 447
 448 extern id class_create_instance(Class class);
 449
 450 static inline const char *
 451 class_get_class_name(Class class)
 452 {
 453   return CLS_ISCLASS(class)?class->name:((class==Nil)?"Nil":0);
 454 }
 455
 456 static inline long
 457 class_get_instance_size(Class class)
 458 {
 459   return CLS_ISCLASS(class)?class->instance_size:0;
 460 }
 461
 462 static inline MetaClass
 463 class_get_meta_class(Class class)
 464 {
 465   return CLS_ISCLASS(class)?class->class_pointer:Nil;
 466 }
 467
 468 static inline Class
 469 class_get_super_class(Class class)
 470 {
 471   return CLS_ISCLASS(class)?class->super_class:Nil;
 472 }
 473
 474 static inline int
 475 class_get_version(Class class)
 476 {
 477   return CLS_ISCLASS(class)?class->version:-1;
 478 }
 479
 480 static inline BOOL
 481 class_is_class(Class class)
 482 {
 483   return CLS_ISCLASS(class);
 484 }
 485
 486 static inline BOOL
 487 class_is_meta_class(Class class)
 488 {
 489   return CLS_ISMETA(class);
 490 }
 491
 492
 493 static inline void
 494 class_set_version(Class class, long version)
 495 {
 496   if (CLS_ISCLASS(class))
 497     class->version = version;
 498 }
 499
 500 static inline void *
 501 class_get_gc_object_type (Class class)
 502 {
 503   return CLS_ISCLASS(class) ? class->gc_object_type : NULL;
 504 }
 505
 506 /* Mark the instance variable as innaccessible to the garbage collector */
 507 extern void class_ivar_set_gcinvisible (Class class,
 508                                         const char* ivarname,
 509                                         BOOL gcInvisible);
 510
 511 static inline IMP
 512 method_get_imp(Method_t method)
 513 {
 514   return (method!=METHOD_NULL)?method->method_imp:(IMP)0;
 515 }
 516
 517 IMP get_imp (Class class, SEL sel);
 518
 519 /* Redefine on NeXTSTEP so as not to conflict with system function */
 520 #ifdef __NeXT__
 521 #define object_copy     gnu_object_copy
 522 #define object_dispose  gnu_object_dispose
 523 #endif
 524
 525 id object_copy(id object);
 526
 527 id object_dispose(id object);
 528
 529 static inline Class
 530 object_get_class(id object)
 531 {
 532   return ((object!=nil)
 533           ? (CLS_ISCLASS(object->class_pointer)
 534              ? object->class_pointer
 535              : (CLS_ISMETA(object->class_pointer)
 536                 ? (Class)object
 537                 : Nil))
 538           : Nil);
 539 }
 540
 541 static inline const char *
 542 object_get_class_name(id object)
 543 {
 544   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 545                          ?object->class_pointer->name
 546                          :((Class)object)->name)
 547                        :"Nil");
 548 }
 549
 550 static inline MetaClass
 551 object_get_meta_class(id object)
 552 {
 553   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 554                          ?object->class_pointer->class_pointer
 555                          :(CLS_ISMETA(object->class_pointer)
 556                            ?object->class_pointer
 557                            :Nil))
 558                        :Nil);
 559 }
 560
 561 static inline Class
 562 object_get_super_class
 563 (id object)
 564 {
 565   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 566                          ?object->class_pointer->super_class
 567                          :(CLS_ISMETA(object->class_pointer)
 568                            ?((Class)object)->super_class
 569                            :Nil))
 570                        :Nil);
 571 }
 572
 573 static inline BOOL
 574 object_is_class(id object)
 575 {
 576   return CLS_ISCLASS((Class)object);
 577 }
 578
 579 static inline BOOL
 580 object_is_instance(id object)
 581 {
 582   return (object!=nil)&&CLS_ISCLASS(object->class_pointer);
 583 }
 584
 585 static inline BOOL
 586 object_is_meta_class(id object)
 587 {
 588   return CLS_ISMETA((Class)object);
 589 }
 590
 591 struct sarray*
 592 objc_get_uninstalled_dtable(void);
 593
 594 #endif /* not __objc_api_INCLUDE_GNU */
 595
 596
 597