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 /* For functions which return Method_t */
  42 #define METHOD_NULL     (Method_t)0
  43                                                 /* Boolean typedefs */
  44 /*
  45 ** Method descriptor returned by introspective Object methods.
  46 ** This is really just the first part of the more complete objc_method
  47 ** structure defined below and used internally by the runtime.
  48 */
  49 struct objc_method_description
  50 {
  51     SEL name;                   /* this is a selector, not a string */
  52     char *types;                /* type encoding */
  53 };
  54
  55 /* Filer types used to describe Ivars and Methods.  */
  56 #define _C_ID       '@'
  57 #define _C_CLASS    '#'
  58 #define _C_SEL      ':'
  59 #define _C_CHR      'c'
  60 #define _C_UCHR     'C'
  61 #define _C_SHT      's'
  62 #define _C_USHT     'S'
  63 #define _C_INT      'i'
  64 #define _C_UINT     'I'
  65 #define _C_LNG      'l'
  66 #define _C_ULNG     'L'
  67 #define _C_LNG_LNG  'q'
  68 #define _C_ULNG_LNG 'Q'
  69 #define _C_FLT      'f'
  70 #define _C_DBL      'd'
  71 #define _C_BFLD     'b'
  72 #define _C_VOID     'v'
  73 #define _C_UNDEF    '?'
  74 #define _C_PTR      '^'
  75 #define _C_CHARPTR  '*'
  76 #define _C_ATOM     '%'
  77 #define _C_ARY_B    '['
  78 #define _C_ARY_E    ']'
  79 #define _C_UNION_B  '('
  80 #define _C_UNION_E  ')'
  81 #define _C_STRUCT_B '{'
  82 #define _C_STRUCT_E '}'
  83 #define _C_VECTOR   '!'
  84
  85
  86 /*
  87 ** Error handling
  88 **
  89 ** Call objc_error() or objc_verror() to record an error; this error
  90 ** routine will generally exit the program but not necessarily if the
  91 ** user has installed his own error handler.
  92 **
  93 ** Call objc_set_error_handler to assign your own function for
  94 ** handling errors.  The function should return YES if it is ok
  95 ** to continue execution, or return NO or just abort if the
  96 ** program should be stopped.  The default error handler is just to
  97 ** print a message on stderr.
  98 **
  99 ** The error handler function should be of type objc_error_handler
 100 ** The first parameter is an object instance of relevance.
 101 ** The second parameter is an error code.
 102 ** The third parameter is a format string in the printf style.
 103 ** The fourth parameter is a variable list of arguments.
 104 */
 105 extern void objc_error(id object, int code, const char* fmt, ...);
 106 extern void objc_verror(id object, int code, const char* fmt, va_list ap);
 107 typedef BOOL (*objc_error_handler)(id, int code, const char *fmt, va_list ap);
 108 extern objc_error_handler objc_set_error_handler(objc_error_handler func);
 109
 110 /*
 111 ** Error codes
 112 ** These are used by the runtime library, and your
 113 ** error handling may use them to determine if the error is
 114 ** hard or soft thus whether execution can continue or abort.
 115 */
 116 #define OBJC_ERR_UNKNOWN 0             /* Generic error */
 117
 118 #define OBJC_ERR_OBJC_VERSION 1        /* Incorrect runtime version */
 119 #define OBJC_ERR_GCC_VERSION 2         /* Incorrect compiler version */
 120 #define OBJC_ERR_MODULE_SIZE 3         /* Bad module size */
 121 #define OBJC_ERR_PROTOCOL_VERSION 4    /* Incorrect protocol version */
 122
 123 #define OBJC_ERR_MEMORY 10             /* Out of memory */
 124
 125 #define OBJC_ERR_RECURSE_ROOT 20       /* Attempt to archive the root
 126                                           object more than once. */
 127 #define OBJC_ERR_BAD_DATA 21           /* Didn't read expected data */
 128 #define OBJC_ERR_BAD_KEY 22            /* Bad key for object */
 129 #define OBJC_ERR_BAD_CLASS 23          /* Unknown class */
 130 #define OBJC_ERR_BAD_TYPE 24           /* Bad type specification */
 131 #define OBJC_ERR_NO_READ 25            /* Cannot read stream */
 132 #define OBJC_ERR_NO_WRITE 26           /* Cannot write stream */
 133 #define OBJC_ERR_STREAM_VERSION 27     /* Incorrect stream version */
 134 #define OBJC_ERR_BAD_OPCODE 28         /* Bad opcode */
 135
 136 #define OBJC_ERR_UNIMPLEMENTED 30      /* Method is not implemented */
 137
 138 #define OBJC_ERR_BAD_STATE 40          /* Bad thread state */
 139
 140 /*
 141 ** Set this variable nonzero to print a line describing each
 142 ** message that is sent.  (this is currently disabled)
 143 */
 144 extern BOOL objc_trace;
 145
 146
 147 /* For every class which happens to have statically allocated instances in
 148    this module, one OBJC_STATIC_INSTANCES is allocated by the compiler.
 149    INSTANCES is NULL terminated and points to all statically allocated
 150    instances of this class.  */
 151 struct objc_static_instances
 152 {
 153   char *class_name;
 154 #ifdef __cplusplus
 155   id instances[1];
 156 #else
 157   id instances[0];
 158 #endif
 159 };
 160
 161 /*
 162 ** Whereas a Module (defined further down) is the root (typically) of a file,
 163 ** a Symtab is the root of the class and category definitions within the
 164 ** module.
 165 **
 166 ** A Symtab contains a variable length array of pointers to classes and
 167 ** categories  defined in the module.
 168 */
 169 typedef struct objc_symtab {
 170   unsigned long sel_ref_cnt;                     /* Unknown. */
 171   SEL        refs;                              /* Unknown. */
 172   unsigned short cls_def_cnt;                   /* Number of classes compiled
 173                                                   (defined) in the module. */
 174   unsigned short cat_def_cnt;                   /* Number of categories
 175                                                   compiled (defined) in the
 176                                                   module. */
 177
 178   void      *defs[1];                           /* Variable array of pointers.
 179                                                   cls_def_cnt of type Class
 180                                                   followed by cat_def_cnt of
 181                                                   type Category_t, followed
 182                                                   by a NULL terminated array
 183                                                   of objc_static_instances. */
 184 } Symtab,   *Symtab_t;
 185
 186
 187 /*
 188 ** The compiler generates one of these structures for each module that
 189 ** composes the executable (eg main.m).
 190 **
 191 ** This data structure is the root of the definition tree for the module.
 192 **
 193 ** A collect program runs between ld stages and creates a ObjC ctor array.
 194 ** That array holds a pointer to each module structure of the executable.
 195 */
 196 typedef struct objc_module {
 197   unsigned long version;                        /* Compiler revision. */
 198   unsigned long size;                           /* sizeof(Module). */
 199   const char* name;                             /* Name of the file where the
 200                                                   module was generated.   The
 201                                                   name includes the path. */
 202
 203   Symtab_t    symtab;                           /* Pointer to the Symtab of
 204                                                   the module.  The Symtab
 205                                                   holds an array of
 206                                                   pointers to
 207                                                   the classes and categories
 208                                                   defined in the module. */
 209 } Module, *Module_t;
 210
 211
 212 /*
 213 ** The compiler generates one of these structures for a class that has
 214 ** instance variables defined in its specification.
 215 */
 216 typedef struct objc_ivar* Ivar_t;
 217 typedef struct objc_ivar_list {
 218   int   ivar_count;                             /* Number of structures (Ivar)
 219                                                   contained in the list.  One
 220                                                   structure per instance
 221                                                   variable defined in the
 222                                                   class. */
 223   struct objc_ivar {
 224     const char* ivar_name;                      /* Name of the instance
 225                                                   variable as entered in the
 226                                                   class definition. */
 227     const char* ivar_type;                      /* Description of the Ivar's
 228                                                   type.  Useful for
 229                                                   debuggers. */
 230     int        ivar_offset;                    /* Byte offset from the base
 231                                                   address of the instance
 232                                                   structure to the variable. */
 233
 234   } ivar_list[1];                               /* Variable length
 235                                                   structure. */
 236 } IvarList, *IvarList_t;
 237
 238
 239 /*
 240 ** The compiler generates one (or more) of these structures for a class that
 241 ** has methods defined in its specification.
 242 **
 243 ** The implementation of a class can be broken into separate pieces in a file
 244 ** and categories can break them across modules. To handle this problem is a
 245 ** singly linked list of methods.
 246 */
 247 typedef struct objc_method {
 248   SEL         method_name;                  /* This variable is the method's
 249                                                name.  It is a char*.
 250                                                The unique integer passed to
 251                                                objc_msg_send is a char* too.
 252                                                It is compared against
 253                                                method_name using strcmp. */
 254   const char* method_types;                 /* Description of the method's
 255                                                parameter list.  Useful for
 256                                                debuggers. */
 257   IMP         method_imp;                   /* Address of the method in the
 258                                                executable. */
 259 } Method, *Method_t;
 260
 261 typedef struct objc_method_list {
 262   struct objc_method_list*  method_next;    /* This variable is used to link
 263                                                a method list to another.  It
 264                                                is a singly linked list. */
 265   int            method_count;              /* Number of methods defined in
 266                                                this structure. */
 267   Method method_list[1];                    /* Variable length
 268                                                structure. */
 269 } MethodList, *MethodList_t;
 270
 271 struct objc_protocol_list {
 272   struct objc_protocol_list *next;
 273   size_t count;
 274   Protocol *list[1];
 275 };
 276
 277 /*
 278 ** This is used to assure consistent access to the info field of
 279 ** classes
 280 */
 281 #ifndef HOST_BITS_PER_LONG
 282 #define HOST_BITS_PER_LONG  (sizeof(long)*8)
 283 #endif
 284
 285 #define __CLS_INFO(cls) ((cls)->info)
 286 #define __CLS_ISINFO(cls, mask) ((__CLS_INFO(cls)&mask)==mask)
 287 #define __CLS_SETINFO(cls, mask) (__CLS_INFO(cls) |= mask)
 288
 289 /* The structure is of type MetaClass */
 290 #define _CLS_META 0x2L
 291 #define CLS_ISMETA(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_META))
 292
 293
 294 /* The structure is of type Class */
 295 #define _CLS_CLASS 0x1L
 296 #define CLS_ISCLASS(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_CLASS))
 297
 298 /*
 299 ** The class is initialized within the runtime.  This means that
 300 ** it has had correct super and sublinks assigned
 301 */
 302 #define _CLS_RESOLV 0x8L
 303 #define CLS_ISRESOLV(cls) __CLS_ISINFO(cls, _CLS_RESOLV)
 304 #define CLS_SETRESOLV(cls) __CLS_SETINFO(cls, _CLS_RESOLV)
 305
 306 /*
 307 ** The class has been send a +initialize message or a such is not
 308 ** defined for this class
 309 */
 310 #define _CLS_INITIALIZED 0x04L
 311 #define CLS_ISINITIALIZED(cls) __CLS_ISINFO(cls, _CLS_INITIALIZED)
 312 #define CLS_SETINITIALIZED(cls) __CLS_SETINFO(cls, _CLS_INITIALIZED)
 313
 314 /*
 315 ** The class number of this class.  This must be the same for both the
 316 ** class and its meta class object
 317 */
 318 #define CLS_GETNUMBER(cls) (__CLS_INFO(cls) >> (HOST_BITS_PER_LONG/2))
 319 #define CLS_SETNUMBER(cls, num) \
 320   ({ (cls)->info <<= (HOST_BITS_PER_LONG/2); \
 321      (cls)->info >>= (HOST_BITS_PER_LONG/2); \
 322      __CLS_SETINFO(cls, (((unsigned long)num) << (HOST_BITS_PER_LONG/2))); })
 323
 324 /*
 325 ** The compiler generates one of these structures for each category.  A class
 326 ** may have many categories and contain both instance and factory methods.
 327 */
 328 typedef struct objc_category {
 329   const char*   category_name;                /* Name of the category.  Name
 330                                                 contained in the () of the
 331                                                 category definition. */
 332   const char*   class_name;                   /* Name of the class to which
 333                                                 the category belongs. */
 334   MethodList_t  instance_methods;             /* Linked list of instance
 335                                                 methods defined in the
 336                                                 category. NULL indicates no
 337                                                 instance methods defined. */
 338   MethodList_t  class_methods;                /* Linked list of factory
 339                                                 methods defined in the
 340                                                 category.  NULL indicates no
 341                                                 class methods defined. */
 342   struct objc_protocol_list *protocols;       /* List of Protocols
 343                                                  conformed to */
 344 } Category, *Category_t;
 345
 346 /*
 347 ** Structure used when a message is send to a class's super class.  The
 348 ** compiler generates one of these structures and passes it to
 349 ** objc_msg_super.
 350 */
 351 typedef struct objc_super {
 352   id      self;                           /* Id of the object sending
 353                                                 the message. */
 354 #ifdef __cplusplus
 355   Class super_class;
 356 #else
 357   Class class;                              /* Object's super class. */
 358 #endif
 359 } Super, *Super_t;
 360
 361 IMP objc_msg_lookup_super(Super_t super, SEL sel);
 362
 363 retval_t objc_msg_sendv(id, SEL, arglist_t);
 364
 365
 366
 367 /*
 368 ** This is a hook which is called by objc_lookup_class and
 369 ** objc_get_class if the runtime is not able to find the class.
 370 ** This may e.g. try to load in the class using dynamic loading.
 371 ** The function is guaranteed to be passed a non-NULL name string.
 372 */
 373 objc_EXPORT Class (*_objc_lookup_class)(const char *name);
 374
 375 /*
 376 ** This is a hook which is called by __objc_exec_class every time a class
 377 ** or a category is loaded into the runtime.  This may e.g. help a
 378 ** dynamic loader determine the classes that have been loaded when
 379 ** an object file is dynamically linked in.
 380 */
 381 objc_EXPORT void (*_objc_load_callback)(Class _class, Category* category);
 382
 383 /*
 384 ** Hook functions for allocating, copying and disposing of instances
 385 */
 386 objc_EXPORT id (*_objc_object_alloc)(Class _class);
 387 objc_EXPORT id (*_objc_object_copy)(id object);
 388 objc_EXPORT id (*_objc_object_dispose)(id object);
 389
 390 /*
 391 ** Standard functions for memory allocation and disposal.
 392 ** Users should use these functions in their ObjC programs so
 393 ** that they work properly with garbage collectors as well as
 394 ** can take advantage of the exception/error handling available.
 395 */
 396 void *
 397 objc_malloc(size_t size);
 398
 399 void *
 400 objc_atomic_malloc(size_t size);
 401
 402 void *
 403 objc_valloc(size_t size);
 404
 405 void *
 406 objc_realloc(void *mem, size_t size);
 407
 408 void *
 409 objc_calloc(size_t nelem, size_t size);
 410
 411 void
 412 objc_free(void *mem);
 413
 414 /*
 415 ** Hook functions for memory allocation and disposal.
 416 ** This makes it easy to substitute garbage collection systems
 417 ** such as Boehm's GC by assigning these function pointers
 418 ** to the GC's allocation routines.  By default these point
 419 ** to the ANSI standard malloc, realloc, free, etc.
 420 **
 421 ** Users should call the normal objc routines above for
 422 ** memory allocation and disposal within their programs.
 423 */
 424 objc_EXPORT void *(*_objc_malloc)(size_t);
 425 objc_EXPORT void *(*_objc_atomic_malloc)(size_t);
 426 objc_EXPORT void *(*_objc_valloc)(size_t);
 427 objc_EXPORT void *(*_objc_realloc)(void *, size_t);
 428 objc_EXPORT void *(*_objc_calloc)(size_t, size_t);
 429 objc_EXPORT void (*_objc_free)(void *);
 430
 431 /*
 432 **  Hook for method forwarding. This makes it easy to substitute a
 433 **  library, such as ffcall, that implements closures, thereby avoiding
 434 **  gcc's __builtin_apply problems.
 435 */
 436 objc_EXPORT IMP (*__objc_msg_forward)(SEL);
 437
 438 Method_t class_get_class_method(MetaClass _class, SEL aSel);
 439
 440 Method_t class_get_instance_method(Class _class, SEL aSel);
 441
 442 Class class_pose_as(Class impostor, Class superclass);
 443
 444 Class objc_get_class(const char *name);
 445
 446 Class objc_lookup_class(const char *name);
 447
 448 Class objc_next_class(void **enum_state);
 449
 450 const char *sel_get_name(SEL selector);
 451
 452 const char *sel_get_type(SEL selector);
 453
 454 SEL sel_get_uid(const char *name);
 455
 456 SEL sel_get_any_uid(const char *name);
 457
 458 SEL sel_get_any_typed_uid(const char *name);
 459
 460 SEL sel_get_typed_uid(const char *name, const char*);
 461
 462 SEL sel_register_name(const char *name);
 463
 464 SEL sel_register_typed_name(const char *name, const char*type);
 465
 466
 467 BOOL sel_is_mapped (SEL aSel);
 468
 469 extern id class_create_instance(Class _class);
 470
 471 static inline const char *
 472 class_get_class_name(Class _class)
 473 {
 474   return CLS_ISCLASS(_class)?_class->name:((_class==Nil)?"Nil":0);
 475 }
 476
 477 static inline long
 478 class_get_instance_size(Class _class)
 479 {
 480   return CLS_ISCLASS(_class)?_class->instance_size:0;
 481 }
 482
 483 static inline MetaClass
 484 class_get_meta_class(Class _class)
 485 {
 486   return CLS_ISCLASS(_class)?_class->class_pointer:Nil;
 487 }
 488
 489 static inline Class
 490 class_get_super_class(Class _class)
 491 {
 492   return CLS_ISCLASS(_class)?_class->super_class:Nil;
 493 }
 494
 495 static inline int
 496 class_get_version(Class _class)
 497 {
 498   return CLS_ISCLASS(_class)?_class->version:-1;
 499 }
 500
 501 static inline BOOL
 502 class_is_class(Class _class)
 503 {
 504   return CLS_ISCLASS(_class);
 505 }
 506
 507 static inline BOOL
 508 class_is_meta_class(Class _class)
 509 {
 510   return CLS_ISMETA(_class);
 511 }
 512
 513
 514 static inline void
 515 class_set_version(Class _class, long version)
 516 {
 517   if (CLS_ISCLASS(_class))
 518     _class->version = version;
 519 }
 520
 521 static inline void *
 522 class_get_gc_object_type (Class _class)
 523 {
 524   return CLS_ISCLASS(_class) ? _class->gc_object_type : NULL;
 525 }
 526
 527 /* Mark the instance variable as innaccessible to the garbage collector */
 528 extern void class_ivar_set_gcinvisible (Class _class,
 529                                         const char* ivarname,
 530                                         BOOL gcInvisible);
 531
 532 static inline IMP
 533 method_get_imp(Method_t method)
 534 {
 535   return (method!=METHOD_NULL)?method->method_imp:(IMP)0;
 536 }
 537
 538 IMP get_imp (Class _class, SEL sel);
 539
 540 /* Redefine on NeXTSTEP so as not to conflict with system function */
 541 #ifdef __NeXT__
 542 #define object_copy     gnu_object_copy
 543 #define object_dispose  gnu_object_dispose
 544 #endif
 545
 546 id object_copy(id object);
 547
 548 id object_dispose(id object);
 549
 550 static inline Class
 551 object_get_class(id object)
 552 {
 553   return ((object!=nil)
 554           ? (CLS_ISCLASS(object->class_pointer)
 555              ? object->class_pointer
 556              : (CLS_ISMETA(object->class_pointer)
 557                 ? (Class)object
 558                 : Nil))
 559           : Nil);
 560 }
 561
 562 static inline const char *
 563 object_get_class_name(id object)
 564 {
 565   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 566                          ?object->class_pointer->name
 567                          :((Class)object)->name)
 568                        :"Nil");
 569 }
 570
 571 static inline MetaClass
 572 object_get_meta_class(id object)
 573 {
 574   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 575                          ?object->class_pointer->class_pointer
 576                          :(CLS_ISMETA(object->class_pointer)
 577                            ?object->class_pointer
 578                            :Nil))
 579                        :Nil);
 580 }
 581
 582 static inline Class
 583 object_get_super_class
 584 (id object)
 585 {
 586   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 587                          ?object->class_pointer->super_class
 588                          :(CLS_ISMETA(object->class_pointer)
 589                            ?((Class)object)->super_class
 590                            :Nil))
 591                        :Nil);
 592 }
 593
 594 static inline BOOL
 595 object_is_class (id object)
 596 {
 597   return ((object != nil)  &&  CLS_ISMETA (object->class_pointer));
 598 }
 599
 600 static inline BOOL
 601 object_is_instance (id object)
 602 {
 603   return ((object != nil)  &&  CLS_ISCLASS (object->class_pointer));
 604 }
 605
 606 static inline BOOL
 607 object_is_meta_class (id object)
 608 {
 609   return ((object != nil)
 610           &&  !object_is_instance (object)
 611           &&  !object_is_class (object));
 612 }
 613
 614 struct sarray*
 615 objc_get_uninstalled_dtable(void);
 616
 617 #ifdef __cplusplus
 618 }
 619 #endif /* __cplusplus */
 620
 621 #endif /* not __objc_api_INCLUDE_GNU */
 622
 623
 624