libobjc/objc/objc-api.h

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