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, 51 Franklin Street, Fifth Floor,
  19 Boston, MA 02110-1301, 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.h"
  31 #include "hash.h"
  32 #include "thr.h"
  33 #include "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_BOOL     '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 #define _C_COMPLEX   'j'
  86
  87
  88 /*
  89 ** Error handling
  90 **
  91 ** Call objc_error() or objc_verror() to record an error; this error
  92 ** routine will generally exit the program but not necessarily if the
  93 ** user has installed his own error handler.
  94 **
  95 ** Call objc_set_error_handler to assign your own function for
  96 ** handling errors.  The function should return YES if it is ok
  97 ** to continue execution, or return NO or just abort if the
  98 ** program should be stopped.  The default error handler is just to
  99 ** print a message on stderr.
 100 **
 101 ** The error handler function should be of type objc_error_handler
 102 ** The first parameter is an object instance of relevance.
 103 ** The second parameter is an error code.
 104 ** The third parameter is a format string in the printf style.
 105 ** The fourth parameter is a variable list of arguments.
 106 */
 107 extern void objc_error(id object, int code, const char* fmt, ...);
 108 extern void objc_verror(id object, int code, const char* fmt, va_list ap);
 109 typedef BOOL (*objc_error_handler)(id, int code, const char *fmt, va_list ap);
 110 extern objc_error_handler objc_set_error_handler(objc_error_handler func);
 111
 112 /*
 113 ** Error codes
 114 ** These are used by the runtime library, and your
 115 ** error handling may use them to determine if the error is
 116 ** hard or soft thus whether execution can continue or abort.
 117 */
 118 #define OBJC_ERR_UNKNOWN 0             /* Generic error */
 119
 120 #define OBJC_ERR_OBJC_VERSION 1        /* Incorrect runtime version */
 121 #define OBJC_ERR_GCC_VERSION 2         /* Incorrect compiler version */
 122 #define OBJC_ERR_MODULE_SIZE 3         /* Bad module size */
 123 #define OBJC_ERR_PROTOCOL_VERSION 4    /* Incorrect protocol version */
 124
 125 #define OBJC_ERR_MEMORY 10             /* Out of memory */
 126
 127 #define OBJC_ERR_RECURSE_ROOT 20       /* Attempt to archive the root
 128                                           object more than once. */
 129 #define OBJC_ERR_BAD_DATA 21           /* Didn't read expected data */
 130 #define OBJC_ERR_BAD_KEY 22            /* Bad key for object */
 131 #define OBJC_ERR_BAD_CLASS 23          /* Unknown class */
 132 #define OBJC_ERR_BAD_TYPE 24           /* Bad type specification */
 133 #define OBJC_ERR_NO_READ 25            /* Cannot read stream */
 134 #define OBJC_ERR_NO_WRITE 26           /* Cannot write stream */
 135 #define OBJC_ERR_STREAM_VERSION 27     /* Incorrect stream version */
 136 #define OBJC_ERR_BAD_OPCODE 28         /* Bad opcode */
 137
 138 #define OBJC_ERR_UNIMPLEMENTED 30      /* Method is not implemented */
 139
 140 #define OBJC_ERR_BAD_STATE 40          /* Bad thread state */
 141
 142 /*
 143 ** Set this variable nonzero to print a line describing each
 144 ** message that is sent.  (this is currently disabled)
 145 */
 146 extern BOOL objc_trace;
 147
 148
 149 /* For every class which happens to have statically allocated instances in
 150    this module, one OBJC_STATIC_INSTANCES is allocated by the compiler.
 151    INSTANCES is NULL terminated and points to all statically allocated
 152    instances of this class.  */
 153 struct objc_static_instances
 154 {
 155   char *class_name;
 156 #ifdef __cplusplus
 157   id instances[1];
 158 #else
 159   id instances[0];
 160 #endif
 161 };
 162
 163 /*
 164 ** Whereas a Module (defined further down) is the root (typically) of a file,
 165 ** a Symtab is the root of the class and category definitions within the
 166 ** module.
 167 **
 168 ** A Symtab contains a variable length array of pointers to classes and
 169 ** categories  defined in the module.
 170 */
 171 typedef struct objc_symtab {
 172   unsigned long sel_ref_cnt;                     /* Unknown. */
 173   SEL        refs;                              /* Unknown. */
 174   unsigned short cls_def_cnt;                   /* Number of classes compiled
 175                                                   (defined) in the module. */
 176   unsigned short cat_def_cnt;                   /* Number of categories
 177                                                   compiled (defined) in the
 178                                                   module. */
 179
 180   void      *defs[1];                           /* Variable array of pointers.
 181                                                   cls_def_cnt of type Class
 182                                                   followed by cat_def_cnt of
 183                                                   type Category_t, followed
 184                                                   by a NULL terminated array
 185                                                   of objc_static_instances. */
 186 } Symtab,   *Symtab_t;
 187
 188
 189 /*
 190 ** The compiler generates one of these structures for each module that
 191 ** composes the executable (eg main.m).
 192 **
 193 ** This data structure is the root of the definition tree for the module.
 194 **
 195 ** A collect program runs between ld stages and creates a ObjC ctor array.
 196 ** That array holds a pointer to each module structure of the executable.
 197 */
 198 typedef struct objc_module {
 199   unsigned long version;                        /* Compiler revision. */
 200   unsigned long size;                           /* sizeof(Module). */
 201   const char* name;                             /* Name of the file where the
 202                                                   module was generated.   The
 203                                                   name includes the path. */
 204
 205   Symtab_t    symtab;                           /* Pointer to the Symtab of
 206                                                   the module.  The Symtab
 207                                                   holds an array of
 208                                                   pointers to
 209                                                   the classes and categories
 210                                                   defined in the module. */
 211 } Module, *Module_t;
 212
 213
 214 /*
 215 ** The compiler generates one of these structures for a class that has
 216 ** instance variables defined in its specification.
 217 */
 218 typedef struct objc_ivar {
 219     const char* ivar_name;                      /* Name of the instance
 220                                                   variable as entered in the
 221                                                   class definition. */
 222     const char* ivar_type;                      /* Description of the Ivar's
 223                                                   type.  Useful for
 224                                                   debuggers. */
 225     int        ivar_offset;                    /* Byte offset from the base
 226                                                   address of the instance
 227                                                   structure to the variable. */
 228 } *Ivar_t;
 229
 230 typedef struct objc_ivar_list {
 231   int   ivar_count;                             /* Number of structures (Ivar)
 232                                                   contained in the list.  One
 233                                                   structure per instance
 234                                                   variable defined in the
 235                                                   class. */
 236   struct objc_ivar ivar_list[1];               /* Variable length
 237                                                   structure. */
 238 } IvarList, *IvarList_t;
 239
 240
 241 /*
 242 ** The compiler generates one (or more) of these structures for a class that
 243 ** has methods defined in its specification.
 244 **
 245 ** The implementation of a class can be broken into separate pieces in a file
 246 ** and categories can break them across modules. To handle this problem is a
 247 ** singly linked list of methods.
 248 */
 249 typedef struct objc_method {
 250   SEL         method_name;                  /* This variable is the method's
 251                                                name.  It is a char*.
 252                                                The unique integer passed to
 253                                                objc_msg_send is a char* too.
 254                                                It is compared against
 255                                                method_name using strcmp. */
 256   const char* method_types;                 /* Description of the method's
 257                                                parameter list.  Useful for
 258                                                debuggers. */
 259   IMP         method_imp;                   /* Address of the method in the
 260                                                executable. */
 261 } Method, *Method_t;
 262
 263 typedef struct objc_method_list {
 264   struct objc_method_list*  method_next;    /* This variable is used to link
 265                                                a method list to another.  It
 266                                                is a singly linked list. */
 267   int            method_count;              /* Number of methods defined in
 268                                                this structure. */
 269   Method method_list[1];                    /* Variable length
 270                                                structure. */
 271 } MethodList, *MethodList_t;
 272
 273 struct objc_protocol_list {
 274   struct objc_protocol_list *next;
 275   size_t count;
 276   Protocol *list[1];
 277 };
 278
 279 /*
 280 ** This is used to assure consistent access to the info field of
 281 ** classes
 282 */
 283 #ifndef HOST_BITS_PER_LONG
 284 #define HOST_BITS_PER_LONG  (sizeof(long)*8)
 285 #endif
 286
 287 #define __CLS_INFO(cls) ((cls)->info)
 288 #define __CLS_ISINFO(cls, mask) ((__CLS_INFO(cls)&mask)==mask)
 289 #define __CLS_SETINFO(cls, mask) (__CLS_INFO(cls) |= mask)
 290
 291 /* The structure is of type MetaClass */
 292 #define _CLS_META 0x2L
 293 #define CLS_ISMETA(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_META))
 294
 295
 296 /* The structure is of type Class */
 297 #define _CLS_CLASS 0x1L
 298 #define CLS_ISCLASS(cls) ((cls)&&__CLS_ISINFO(cls, _CLS_CLASS))
 299
 300 /*
 301 ** The class is initialized within the runtime.  This means that
 302 ** it has had correct super and sublinks assigned
 303 */
 304 #define _CLS_RESOLV 0x8L
 305 #define CLS_ISRESOLV(cls) __CLS_ISINFO(cls, _CLS_RESOLV)
 306 #define CLS_SETRESOLV(cls) __CLS_SETINFO(cls, _CLS_RESOLV)
 307
 308 /*
 309 ** The class has been send a +initialize message or a such is not
 310 ** defined for this class
 311 */
 312 #define _CLS_INITIALIZED 0x04L
 313 #define CLS_ISINITIALIZED(cls) __CLS_ISINFO(cls, _CLS_INITIALIZED)
 314 #define CLS_SETINITIALIZED(cls) __CLS_SETINFO(cls, _CLS_INITIALIZED)
 315
 316 /*
 317 ** The class number of this class.  This must be the same for both the
 318 ** class and its meta class object
 319 */
 320 #define CLS_GETNUMBER(cls) (__CLS_INFO(cls) >> (HOST_BITS_PER_LONG/2))
 321 #define CLS_SETNUMBER(cls, num) \
 322   ({ (cls)->info <<= (HOST_BITS_PER_LONG/2); \
 323      (cls)->info >>= (HOST_BITS_PER_LONG/2); \
 324      __CLS_SETINFO(cls, (((unsigned long)num) << (HOST_BITS_PER_LONG/2))); })
 325
 326 /*
 327 ** The compiler generates one of these structures for each category.  A class
 328 ** may have many categories and contain both instance and factory methods.
 329 */
 330 typedef struct objc_category {
 331   const char*   category_name;                /* Name of the category.  Name
 332                                                 contained in the () of the
 333                                                 category definition. */
 334   const char*   class_name;                   /* Name of the class to which
 335                                                 the category belongs. */
 336   MethodList_t  instance_methods;             /* Linked list of instance
 337                                                 methods defined in the
 338                                                 category. NULL indicates no
 339                                                 instance methods defined. */
 340   MethodList_t  class_methods;                /* Linked list of factory
 341                                                 methods defined in the
 342                                                 category.  NULL indicates no
 343                                                 class methods defined. */
 344   struct objc_protocol_list *protocols;       /* List of Protocols
 345                                                  conformed to */
 346 } Category, *Category_t;
 347
 348 /*
 349 ** Structure used when a message is send to a class's super class.  The
 350 ** compiler generates one of these structures and passes it to
 351 ** objc_msg_super.
 352 */
 353 typedef struct objc_super {
 354   id      self;                           /* Id of the object sending
 355                                                 the message. */
 356 #ifdef __cplusplus
 357   Class super_class;
 358 #else
 359   Class class;                              /* Object's super class. */
 360 #endif
 361 } Super, *Super_t;
 362
 363 IMP objc_msg_lookup_super(Super_t super, SEL sel);
 364
 365 retval_t objc_msg_sendv(id, SEL, arglist_t);
 366
 367
 368
 369 /*
 370 ** This is a hook which is called by objc_lookup_class and
 371 ** objc_get_class if the runtime is not able to find the class.
 372 ** This may e.g. try to load in the class using dynamic loading.
 373 ** The function is guaranteed to be passed a non-NULL name string.
 374 */
 375 objc_EXPORT Class (*_objc_lookup_class)(const char *name);
 376
 377 /*
 378 ** This is a hook which is called by __objc_exec_class every time a class
 379 ** or a category is loaded into the runtime.  This may e.g. help a
 380 ** dynamic loader determine the classes that have been loaded when
 381 ** an object file is dynamically linked in.
 382 */
 383 objc_EXPORT void (*_objc_load_callback)(Class _class, Category* category);
 384
 385 /*
 386 ** Hook functions for allocating, copying and disposing of instances
 387 */
 388 objc_EXPORT id (*_objc_object_alloc)(Class _class);
 389 objc_EXPORT id (*_objc_object_copy)(id object);
 390 objc_EXPORT id (*_objc_object_dispose)(id object);
 391
 392 /*
 393 ** Standard functions for memory allocation and disposal.
 394 ** Users should use these functions in their ObjC programs so
 395 ** that they work properly with garbage collectors as well as
 396 ** can take advantage of the exception/error handling available.
 397 */
 398 void *
 399 objc_malloc(size_t size);
 400
 401 void *
 402 objc_atomic_malloc(size_t size);
 403
 404 void *
 405 objc_valloc(size_t size);
 406
 407 void *
 408 objc_realloc(void *mem, size_t size);
 409
 410 void *
 411 objc_calloc(size_t nelem, size_t size);
 412
 413 void
 414 objc_free(void *mem);
 415
 416 /*
 417 ** Hook functions for memory allocation and disposal.
 418 ** This makes it easy to substitute garbage collection systems
 419 ** such as Boehm's GC by assigning these function pointers
 420 ** to the GC's allocation routines.  By default these point
 421 ** to the ANSI standard malloc, realloc, free, etc.
 422 **
 423 ** Users should call the normal objc routines above for
 424 ** memory allocation and disposal within their programs.
 425 */
 426 objc_EXPORT void *(*_objc_malloc)(size_t);
 427 objc_EXPORT void *(*_objc_atomic_malloc)(size_t);
 428 objc_EXPORT void *(*_objc_valloc)(size_t);
 429 objc_EXPORT void *(*_objc_realloc)(void *, size_t);
 430 objc_EXPORT void *(*_objc_calloc)(size_t, size_t);
 431 objc_EXPORT void (*_objc_free)(void *);
 432
 433 /*
 434 **  Hook for method forwarding. This makes it easy to substitute a
 435 **  library, such as ffcall, that implements closures, thereby avoiding
 436 **  gcc's __builtin_apply problems.
 437 */
 438 objc_EXPORT IMP (*__objc_msg_forward)(SEL);
 439
 440 Method_t class_get_class_method(MetaClass _class, SEL aSel);
 441
 442 Method_t class_get_instance_method(Class _class, SEL aSel);
 443
 444 Class class_pose_as(Class impostor, Class superclass);
 445
 446 Class objc_get_class(const char *name);
 447
 448 Class objc_lookup_class(const char *name);
 449
 450 Class objc_next_class(void **enum_state);
 451
 452 const char *sel_get_name(SEL selector);
 453
 454 const char *sel_get_type(SEL selector);
 455
 456 SEL sel_get_uid(const char *name);
 457
 458 SEL sel_get_any_uid(const char *name);
 459
 460 SEL sel_get_any_typed_uid(const char *name);
 461
 462 SEL sel_get_typed_uid(const char *name, const char*);
 463
 464 SEL sel_register_name(const char *name);
 465
 466 SEL sel_register_typed_name(const char *name, const char*type);
 467
 468
 469 BOOL sel_is_mapped (SEL aSel);
 470
 471 extern id class_create_instance(Class _class);
 472
 473 static inline const char *
 474 class_get_class_name(Class _class)
 475 {
 476   return CLS_ISCLASS(_class)?_class->name:((_class==Nil)?"Nil":0);
 477 }
 478
 479 static inline long
 480 class_get_instance_size(Class _class)
 481 {
 482   return CLS_ISCLASS(_class)?_class->instance_size:0;
 483 }
 484
 485 static inline MetaClass
 486 class_get_meta_class(Class _class)
 487 {
 488   return CLS_ISCLASS(_class)?_class->class_pointer:Nil;
 489 }
 490
 491 static inline Class
 492 class_get_super_class(Class _class)
 493 {
 494   return CLS_ISCLASS(_class)?_class->super_class:Nil;
 495 }
 496
 497 static inline int
 498 class_get_version(Class _class)
 499 {
 500   return CLS_ISCLASS(_class)?_class->version:-1;
 501 }
 502
 503 static inline BOOL
 504 class_is_class(Class _class)
 505 {
 506   return CLS_ISCLASS(_class);
 507 }
 508
 509 static inline BOOL
 510 class_is_meta_class(Class _class)
 511 {
 512   return CLS_ISMETA(_class);
 513 }
 514
 515
 516 static inline void
 517 class_set_version(Class _class, long version)
 518 {
 519   if (CLS_ISCLASS(_class))
 520     _class->version = version;
 521 }
 522
 523 static inline void *
 524 class_get_gc_object_type (Class _class)
 525 {
 526   return CLS_ISCLASS(_class) ? _class->gc_object_type : NULL;
 527 }
 528
 529 /* Mark the instance variable as innaccessible to the garbage collector */
 530 extern void class_ivar_set_gcinvisible (Class _class,
 531                                         const char* ivarname,
 532                                         BOOL gcInvisible);
 533
 534 static inline IMP
 535 method_get_imp(Method_t method)
 536 {
 537   return (method!=METHOD_NULL)?method->method_imp:(IMP)0;
 538 }
 539
 540 IMP get_imp (Class _class, SEL sel);
 541
 542 /* Redefine on NeXTSTEP so as not to conflict with system function */
 543 #ifdef __NeXT__
 544 #define object_copy     gnu_object_copy
 545 #define object_dispose  gnu_object_dispose
 546 #endif
 547
 548 id object_copy(id object);
 549
 550 id object_dispose(id object);
 551
 552 static inline Class
 553 object_get_class(id object)
 554 {
 555   return ((object!=nil)
 556           ? (CLS_ISCLASS(object->class_pointer)
 557              ? object->class_pointer
 558              : (CLS_ISMETA(object->class_pointer)
 559                 ? (Class)object
 560                 : Nil))
 561           : Nil);
 562 }
 563
 564 static inline const char *
 565 object_get_class_name(id object)
 566 {
 567   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 568                          ?object->class_pointer->name
 569                          :((Class)object)->name)
 570                        :"Nil");
 571 }
 572
 573 static inline MetaClass
 574 object_get_meta_class(id object)
 575 {
 576   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 577                          ?object->class_pointer->class_pointer
 578                          :(CLS_ISMETA(object->class_pointer)
 579                            ?object->class_pointer
 580                            :Nil))
 581                        :Nil);
 582 }
 583
 584 static inline Class
 585 object_get_super_class
 586 (id object)
 587 {
 588   return ((object!=nil)?(CLS_ISCLASS(object->class_pointer)
 589                          ?object->class_pointer->super_class
 590                          :(CLS_ISMETA(object->class_pointer)
 591                            ?((Class)object)->super_class
 592                            :Nil))
 593                        :Nil);
 594 }
 595
 596 static inline BOOL
 597 object_is_class (id object)
 598 {
 599   return ((object != nil)  &&  CLS_ISMETA (object->class_pointer));
 600 }
 601
 602 static inline BOOL
 603 object_is_instance (id object)
 604 {
 605   return ((object != nil)  &&  CLS_ISCLASS (object->class_pointer));
 606 }
 607
 608 static inline BOOL
 609 object_is_meta_class (id object)
 610 {
 611   return ((object != nil)
 612           &&  !object_is_instance (object)
 613           &&  !object_is_class (object));
 614 }
 615
 616 struct sarray*
 617 objc_get_uninstalled_dtable(void);
 618
 619 #ifdef __cplusplus
 620 }
 621 #endif /* __cplusplus */
 622
 623 #endif /* not __objc_api_INCLUDE_GNU */
 624
 625
 626