libobjc/objc/objc-api.h

   1 /* GNU Objective-C Runtime API.
   2    Copyright (C) 1993, 1995, 1996, 1997, 2002, 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC 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 GCC 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 GCC; 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 "objc/objc-decls.h"
  34 #include <stdio.h>
  35 #include <stdarg.h>
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif /* __cplusplus */
  40
  41
  42 /* For functions which return Method_t */
  43 #define METHOD_NULL     (Method_t)0
  44                                                 /* Boolean typedefs */
  45 /*
  46 ** Method descriptor returned by introspective Object methods.
  47 ** This is really just the first part of the more complete objc_method
  48 ** structure defined below and used internally by the runtime.
  49 */
  50 struct objc_method_description
  51 {
  52     SEL name;                   /* this is a selector, not a string */
  53     char *types;                /* type encoding */
  54 };
  55
  56 /* Filer types used to describe Ivars and Methods.  */
  57 #define _C_ID       '@'
  58 #define _C_CLASS    '#'
  59 #define _C_SEL      ':'
  60 #define _C_CHR      'c'
  61 #define _C_UCHR     'C'
  62 #define _C_SHT      's'
  63 #define _C_USHT     'S'
  64 #define _C_INT      'i'
  65 #define _C_UINT     'I'
  66 #define _C_LNG      'l'
  67 #define _C_ULNG     'L'
  68 #define _C_LNG_LNG  'q'
  69 #define _C_ULNG_LNG 'Q'
  70 #define _C_FLT      'f'
  71 #define _C_DBL      'd'
  72 #define _C_BFLD     'b'
  73 #define _C_VOID     'v'
  74 #define _C_UNDEF    '?'
  75 #define _C_PTR      '^'
  76 #define _C_CHARPTR  '*'
  77 #define _C_ATOM     '%'
  78 #define _C_ARY_B    '['
  79 #define _C_ARY_E    ']'
  80 #define _C_UNION_B  '('
  81 #define _C_UNION_E  ')'
  82 #define _C_STRUCT_B '{'
  83 #define _C_STRUCT_E '}'
  84 #define _C_VECTOR   '!'
  85
  86
  87 /*
  88 ** Error handling
  89 **
  90 ** Call objc_error() or objc_verror() to record an error; this error
  91 ** routine will generally exit the program but not necessarily if the
  92 ** user has installed his own error handler.
  93 **
  94 ** Call objc_set_error_handler to assign your own function for
  95 ** handling errors.  The function should return YES if it is ok
  96 ** to continue execution, or return NO or just abort if the
  97 ** program should be stopped.  The default error handler is just to
  98 ** print a message on stderr.
  99 **
 100 ** The error handler function should be of type objc_error_handler
 101 ** The first parameter is an object instance of relevance.
 102 ** The second parameter is an error code.
 103 ** The third parameter is a format string in the printf style.
 104 ** The fourth parameter is a variable list of arguments.
 105 */
 106 extern void objc_error(id object, int code, const char* fmt, ...);
 107 extern void objc_verror(id object, int code, const char* fmt, va_list ap);
 108 typedef BOOL (*objc_error_handler)(id, int code, const char *fmt, va_list ap);
 109 extern objc_error_handler objc_set_error_handler(objc_error_handler func);
 110
 111 /*
 112 ** Error codes
 113 ** These are used by the runtime library, and your
 114 ** error handling may use them to determine if the error is
 115 ** hard or soft thus whether execution can continue or abort.
 116 */
 117 #define OBJC_ERR_UNKNOWN 0             /* Generic error */
 118
 119 #define OBJC_ERR_OBJC_VERSION 1        /* Incorrect runtime version */
 120 #define OBJC_ERR_GCC_VERSION 2         /* Incorrect compiler version */
 121 #define OBJC_ERR_MODULE_SIZE 3         /* Bad module size */
 122 #define OBJC_ERR_PROTOCOL_VERSION 4    /* Incorrect protocol version */
 123
 124 #define OBJC_ERR_MEMORY 10             /* Out of memory */
 125
 126 #define OBJC_ERR_RECURSE_ROOT 20       /* Attempt to archive the root
 127                                           object more than once. */
 128 #define OBJC_ERR_BAD_DATA 21           /* Didn't read expected data */
 129 #define OBJC_ERR_BAD_KEY 22            /* Bad key for object */
 130 #define OBJC_ERR_BAD_CLASS 23          /* Unknown class */
 131 #define OBJC_ERR_BAD_TYPE 24           /* Bad type specification */
 132 #define OBJC_ERR_NO_READ 25            /* Cannot read stream */
 133 #define OBJC_ERR_NO_WRITE 26           /* Cannot write stream */
 134 #define OBJC_ERR_STREAM_VERSION 27     /* Incorrect stream version */
 135 #define OBJC_ERR_BAD_OPCODE 28         /* Bad opcode */
 136
 137 #define OBJC_ERR_UNIMPLEMENTED 30      /* Method is not implemented */
 138
 139 #define OBJC_ERR_BAD_STATE 40          /* Bad thread state */
 140
 141 /*
 142 ** Set this variable nonzero to print a line describing each
 143 ** message that is sent.  (this is currently disabled)
 144 */
 145 extern BOOL objc_trace;
 146
 147
 148 /* For every class which happens to have statically allocated instances in
 149    this module, one OBJC_STATIC_INSTANCES is allocated by the compiler.
 150    INSTANCES is NULL terminated and points to all statically allocated
 151    instances of this class.  */
 152 struct objc_static_instances
 153 {
 154   char *class_name;
 155   id instances[0];
 156 };
 157
 158 /*
 159 ** Whereas a Module (defined further down) is the root (typically) of a file,
 160 ** a Symtab is the root of the class and category definitions within the
 161 ** module.
 162 **
 163 ** A Symtab contains a variable length array of pointers to classes and
 164 ** categories  defined in the module.
 165 */
 166 typedef struct objc_symtab {
 167   unsigned long sel_ref_cnt;                     /* Unknown. */
 168   SEL        refs;                              /* Unknown. */
 169   unsigned short cls_def_cnt;                   /* Number of classes compiled
 170                                                   (defined) in the module. */
 171   unsigned short cat_def_cnt;                   /* Number of categories
 172                                                   compiled (defined) in the
 173                                                   module. */
 174
 175   void      *defs[1];                           /* Variable array of pointers.
 176                                                   cls_def_cnt of type Class
 177                                                   followed by cat_def_cnt of
 178                                                   type Category_t, followed
 179                                                   by a NULL terminated array
 180                                                   of objc_static_instances. */
 181 } Symtab,   *Symtab_t;
 182
 183
 184 /*
 185 ** The compiler generates one of these structures for each module that
 186 ** composes the executable (eg main.m).
 187 **
 188 ** This data structure is the root of the definition tree for the module.
 189 **
 190 ** A collect program runs between ld stages and creates a ObjC ctor array.
 191 ** That array holds a pointer to each module structure of the executable.
 192 */
 193 typedef struct objc_module {
 194   unsigned long version;                        /* Compiler revision. */
 195   unsigned long size;                           /* sizeof(Module). */
 196   const char* name;                             /* Name of the file where the
 197                                                   module was generated.   The
 198                                                   name includes the path. */
 199
 200   Symtab_t    symtab;                           /* Pointer to the Symtab of
 201                                                   the module.  The Symtab
 202                                                   holds an array of
 203                                                   pointers to
 204                                                   the classes and categories
 205                                                   defined in the module. */
 206 } Module, *Module_t;
 207
 208
 209 /*
 210 ** The compiler generates one of these structures for a class that has
 211 ** instance variables defined in its specification.
 212 */
 213 typedef struct objc_ivar* Ivar_t;
 214 typedef struct objc_ivar_list {
 215   int   ivar_count;                             /* Number of structures (Ivar)
 216                                                   contained in the list.  One
 217                                                   structure per instance
 218                                                   variable defined in the
 219                                                   class. */
 220   struct objc_ivar {
 221     const char* ivar_name;                      /* Name of the instance
 222                                                   variable as entered in the
 223                                                   class definition. */
 224     const char* ivar_type;                      /* Description of the Ivar's
 225                                                   type.  Useful for
 226                                                   debuggers. */
 227     int        ivar_offset;                    /* Byte offset from the base
 228                                                   address of the instance
 229                                                   structure to the variable. */
 230
 231   } ivar_list[1];                               /* Variable length
 232                                                   structure. */
 233 } IvarList, *IvarList_t;
 234
 235
 236 /*
 237 ** The compiler generates one (or more) of these structures for a class that
 238 ** has methods defined in its specification.
 239 **
 240 ** The implementation of a class can be broken into separate pieces in a file
 241 ** and categories can break them across modules. To handle this problem is a
 242 ** singly linked list of methods.
 243 */
 244 typedef struct objc_method Method;
 245 typedef Method* Method_t;
 246 typedef struct objc_method_list {
 247   struct objc_method_list*  method_next;      /* This variable is used to link
 248                                                 a method list to another.  It
 249                                                 is a singly linked list. */
 250   int            method_count;               /* Number of methods defined in
 251                                                 this structure. */
 252   struct objc_method {
 253     SEL         method_name;                  /* This variable is the method's
 254                                                 name.  It is a char*.
 255                                                   The unique integer passed to
 256                                                 objc_msg_send is a char* too.
 257                                                 It is compared against
 258                                                 method_name using strcmp. */
 259     const char* method_types;                 /* Description of the method's
 260                                                 parameter list.  Useful for
 261                                                 debuggers. */
 262     IMP         method_imp;                   /* Address of the method in the
 263                                                 executable. */
 264   } method_list[1];                           /* Variable length
 265                                                 structure. */
 266 } MethodList, *MethodList_t;
 267
 268 struct objc_protocol_list {
 269   struct objc_protocol_list *next;
 270   size_t count;
 271   Protocol *list[1];
 272 };
 273
 274 /*
 275 ** This is used to assure consistent access to the info field of
 276 ** classes
 277 */
 278 #ifndef HOST_BITS_PER_LONG
 279 #define HOST_BITS_PER_LONG  (sizeof(long)*8)
 280 #endif
 281
 282 #define __CLS_INFO(cls) ((cls)->info)
 283 #define __CLS_ISINFO(cls, mask) ((__CLS_INFO(cls)&mask)==mask)
 284 #define __CLS_SETINFO(cls, mask) (__CLS_INFO(cls) |= mask)
 285
 286 /* The structure is of type MetaClass */
 287 #define _CLS_META 0x2L
 288 #define CLS_ISMETA(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_META))
 289
 290
 291 /* The structure is of type Class */
 292 #define _CLS_CLASS 0x1L
 293 #define CLS_ISCLASS(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_CLASS))
 294
 295 /*
 296 ** The class is initialized within the runtime.  This means that
 297 ** it has had correct super and sublinks assigned
 298 */
 299 #define _CLS_RESOLV 0x8L
 300 #define CLS_ISRESOLV(cls) __CLS_ISINFO(cls, _CLS_RESOLV)
 301 #define CLS_SETRESOLV(cls) __CLS_SETINFO(cls, _CLS_RESOLV)
 302
 303 /*
 304 ** The class has been send a +initialize message or a such is not
 305 ** defined for this class
 306 */
 307 #define _CLS_INITIALIZED 0x04L
 308 #define CLS_ISINITIALIZED(cls) __CLS_ISINFO(cls, _CLS_INITIALIZED)
 309 #define CLS_SETINITIALIZED(cls) __CLS_SETINFO(cls, _CLS_INITIALIZED)
 310
 311 /*
 312 ** The class number of this class.  This must be the same for both the
 313 ** class and its meta class object
 314 */
 315 #define CLS_GETNUMBER(cls) (__CLS_INFO(cls) >> (HOST_BITS_PER_LONG/2))
 316 #define CLS_SETNUMBER(cls, num) \
 317   ({ (cls)->info <<= (HOST_BITS_PER_LONG/2); \
 318      (cls)->info >>= (HOST_BITS_PER_LONG/2); \
 319      __CLS_SETINFO(cls, (((unsigned long)num) << (HOST_BITS_PER_LONG/2))); })
 320
 321 /*
 322 ** The compiler generates one of these structures for each category.  A class
 323 ** may have many categories and contain both instance and factory methods.
 324 */
 325 typedef struct objc_category {
 326   const char*   category_name;                /* Name of the category.  Name
 327                                                 contained in the () of the
 328                                                 category definition. */
 329   const char*   class_name;                   /* Name of the class to which
 330                                                 the category belongs. */
 331   MethodList_t  instance_methods;             /* Linked list of instance
 332                                                 methods defined in the
 333                                                 category. NULL indicates no
 334                                                 instance methods defined. */
 335   MethodList_t  class_methods;                /* Linked list of factory
 336                                                 methods defined in the
 337                                                 category.  NULL indicates no
 338                                                 class methods defined. */
 339   struct objc_protocol_list *protocols;       /* List of Protocols
 340                                                  conformed to */
 341 } Category, *Category_t;
 342
 343 /*
 344 ** Structure used when a message is send to a class's super class.  The
 345 ** compiler generates one of these structures and passes it to
 346 ** objc_msg_super.
 347 */
 348 typedef struct objc_super {
 349   id      self;                           /* Id of the object sending
 350                                                 the message. */
 351 #ifdef __cplusplus
 352   Class super_class;
 353 #else
 354   Class class;                              /* Object's super class. */
 355 #endif
 356 } Super, *Super_t;
 357
 358 IMP objc_msg_lookup_super(Super_t super, SEL sel);
 359
 360 retval_t objc_msg_sendv(id, SEL, arglist_t);
 361
 362
 363
 364 /*
 365 ** This is a hook which is called by objc_lookup_class and
 366 ** objc_get_class if the runtime is not able to find the class.
 367 ** This may e.g. try to load in the class using dynamic loading.
 368 ** The function is guaranteed to be passed a non-NULL name string.
 369 */
 370 objc_EXPORT Class (*_objc_lookup_class)(const char *name);
 371
 372 /*
 373 ** This is a hook which is called by __objc_exec_class every time a class
 374 ** or a category is loaded into the runtime.  This may e.g. help a
 375 ** dynamic loader determine the classes that have been loaded when
 376 ** an object file is dynamically linked in.
 377 */
 378 objc_EXPORT void (*_objc_load_callback)(Class class, Category* category);
 379
 380 /*
 381 ** Hook functions for allocating, copying and disposing of instances
 382 */
 383 objc_EXPORT id (*_objc_object_alloc)(Class class);
 384 objc_EXPORT id (*_objc_object_copy)(id object);
 385 objc_EXPORT id (*_objc_object_dispose)(id object);
 386
 387 /*
 388 ** Standard functions for memory allocation and disposal.
 389 ** Users should use these functions in their ObjC programs so
 390 ** that they work properly with garbage collectors as well as
 391 ** can take advantage of the exception/error handling available.
 392 */
 393 void *
 394 objc_malloc(size_t size);
 395
 396 void *
 397 objc_atomic_malloc(size_t size);
 398
 399 void *
 400 objc_valloc(size_t size);
 401
 402 void *
 403 objc_realloc(void *mem, size_t size);
 404
 405 void *
 406 objc_calloc(size_t nelem, size_t size);
 407
 408 void
 409 objc_free(void *mem);
 410
 411 /*
 412 ** Hook functions for memory allocation and disposal.
 413 ** This makes it easy to substitute garbage collection systems
 414 ** such as Boehm's GC by assigning these function pointers
 415 ** to the GC's allocation routines.  By default these point
 416 ** to the ANSI standard malloc, realloc, free, etc.
 417 **
 418 ** Users should call the normal objc routines above for
 419 ** memory allocation and disposal within their programs.
 420 */
 421 objc_EXPORT void *(*_objc_malloc)(size_t);
 422 objc_EXPORT void *(*_objc_atomic_malloc)(size_t);
 423 objc_EXPORT void *(*_objc_valloc)(size_t);
 424 objc_EXPORT void *(*_objc_realloc)(void *, size_t);
 425 objc_EXPORT void *(*_objc_calloc)(size_t, size_t);
 426 objc_EXPORT void (*_objc_free)(void *);
 427
 428 /*
 429 **  Hook for method forwarding. This makes it easy to substitute a
 430 **  library, such as ffcall, that implements closures, thereby avoiding
 431 **  gcc's __builtin_apply problems.
 432 */
 433 objc_EXPORT IMP (*__objc_msg_forward)(SEL);
 434
 435 Method_t class_get_class_method(MetaClass class, SEL aSel);
 436
 437 Method_t class_get_instance_method(Class class, SEL aSel);
 438
 439 Class class_pose_as(Class impostor, Class superclass);
 440
 441 Class objc_get_class(const char *name);
 442
 443 Class objc_lookup_class(const char *name);
 444
 445 Class objc_next_class(void **enum_state);
 446
 447 const char *sel_get_name(SEL selector);
 448
 449 const char *sel_get_type(SEL selector);
 450
 451 SEL sel_get_uid(const char *name);
 452
 453 SEL sel_get_any_uid(const char *name);
 454
 455 SEL sel_get_any_typed_uid(const char *name);
 456
 457 SEL sel_get_typed_uid(const char *name, const char*);
 458
 459 SEL sel_register_name(const char *name);
 460
 461 SEL sel_register_typed_name(const char *name, const char*type);
 462
 463
 464 BOOL sel_is_mapped (SEL aSel);
 465
 466 extern id class_create_instance(Class class);
 467
 468 static inline const char *
 469 class_get_class_name(Class class)
 470 {
 471   return CLS_ISCLASS(class)?class->name:((class==Nil)?"Nil":0);
 472 }
 473
 474 static inline long
 475 class_get_instance_size(Class class)
 476 {
 477   return CLS_ISCLASS(class)?class->instance_size:0;
 478 }
 479
 480 static inline MetaClass
 481 class_get_meta_class(Class class)
 482 {
 483   return CLS_ISCLASS(class)?class->class_pointer:Nil;
 484 }
 485
 486 static inline Class
 487 class_get_super_class(Class class)
 488 {
 489   return CLS_ISCLASS(class)?class->super_class:Nil;
 490 }
 491
 492 static inline int
 493 class_get_version(Class class)
 494 {
 495   return CLS_ISCLASS(class)?class->version:-1;
 496 }
 497
 498 static inline BOOL
 499 class_is_class(Class class)
 500 {
 501   return CLS_ISCLASS(class);
 502 }
 503
 504 static inline BOOL
 505 class_is_meta_class(Class class)
 506 {
 507   return CLS_ISMETA(class);
 508 }
 509
 510
 511 static inline void
 512 class_set_version(Class class, long version)
 513 {
 514   if (CLS_ISCLASS(class))
 515     class->version = version;
 516 }
 517
 518 static inline void *
 519 class_get_gc_object_type (Class class)
 520 {
 521   return CLS_ISCLASS(class) ? class->gc_object_type : NULL;
 522 }
 523
 524 /* Mark the instance variable as innaccessible to the garbage collector */
 525 extern void class_ivar_set_gcinvisible (Class class,
 526                                         const char* ivarname,
 527                                         BOOL gcInvisible);
 528
 529 static inline IMP
 530 method_get_imp(Method_t method)
 531 {
 532   return (method!=METHOD_NULL)?method->method_imp:(IMP)0;
 533 }
 534
 535 IMP get_imp (Class class, SEL sel);
 536
 537 /* Redefine on NeXTSTEP so as not to conflict with system function */
 538 #ifdef __NeXT__
 539 #define object_copy     gnu_object_copy
 540 #define object_dispose  gnu_object_dispose
 541 #endif
 542
 543 id object_copy(id object);
 544
 545 id object_dispose(id object);
 546
 547 static inline Class
 548 object_get_class(id object)
 549 {
 550   return ((object!=nil)
 551           ? (CLS_ISCLASS(object->class_pointer)
 552              ? object->class_pointer
 553              : (CLS_ISMETA(object->class_pointer)
 554                 ? (Class)object
 555                 : Nil))
 556           : Nil);
 557 }
 558
 559 static inline const char *
 560 object_get_class_name(id object)
 561 {
 562   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 563                          ?object->class_pointer->name
 564                          :((Class)object)->name)
 565                        :"Nil");
 566 }
 567
 568 static inline MetaClass
 569 object_get_meta_class(id object)
 570 {
 571   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 572                          ?object->class_pointer->class_pointer
 573                          :(CLS_ISMETA(object->class_pointer)
 574                            ?object->class_pointer
 575                            :Nil))
 576                        :Nil);
 577 }
 578
 579 static inline Class
 580 object_get_super_class
 581 (id object)
 582 {
 583   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 584                          ?object->class_pointer->super_class
 585                          :(CLS_ISMETA(object->class_pointer)
 586                            ?((Class)object)->super_class
 587                            :Nil))
 588                        :Nil);
 589 }
 590
 591 static inline BOOL
 592 object_is_class (id object)
 593 {
 594   return ((object != nil)  &&  CLS_ISMETA (object->class_pointer));
 595 }
 596
 597 static inline BOOL
 598 object_is_instance (id object)
 599 {
 600   return ((object != nil)  &&  CLS_ISCLASS (object->class_pointer));
 601 }
 602
 603 static inline BOOL
 604 object_is_meta_class (id object)
 605 {
 606   return ((object != nil)
 607           &&  !object_is_instance (object)
 608           &&  !object_is_class (object));
 609 }
 610
 611 struct sarray*
 612 objc_get_uninstalled_dtable(void);
 613
 614 #ifdef __cplusplus
 615 }
 616 #endif /* __cplusplus */
 617
 618
 619 #endif /* not __objc_api_INCLUDE_GNU */
 620
 621
 622