gcc/objc/objc-api.h

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