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