libobjc/objc/objc.h

   1 /* Basic data types for Objective C.
   2    Copyright (C) 1993, 1995, 1996, 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
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public 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
  22    compiled with GCC to produce an executable, this does not cause
  23    the resulting executable to be covered by the GNU General Public License.
  24    This exception does not however invalidate any other reasons why
  25    the executable file might be covered by the GNU General Public License.  */
  26
  27 #ifndef __objc_INCLUDE_GNU
  28 #define __objc_INCLUDE_GNU
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 #include <stddef.h>
  35
  36 /*
  37 ** Definition of the boolean type.
  38 */
  39 #ifdef __vxworks
  40 typedef int BOOL;
  41 #else
  42 #undef BOOL
  43 typedef unsigned char  BOOL;
  44 #endif
  45 #define YES   (BOOL)1
  46 #define NO    (BOOL)0
  47
  48 /*
  49 ** Definition of a selector.  Selectors themselves are not unique, but
  50 ** the sel_id is a unique identifier.
  51 */
  52 typedef const struct objc_selector
  53 {
  54   void *sel_id;
  55   const char *sel_types;
  56 } *SEL;
  57
  58 inline static BOOL
  59 sel_eq (SEL s1, SEL s2)
  60 {
  61   if (s1 == 0 || s2 == 0)
  62     return s1 == s2;
  63   else
  64     return s1->sel_id == s2->sel_id;
  65 }
  66
  67
  68 /*
  69 ** ObjC uses this typedef for untyped instances.
  70 */
  71 typedef struct objc_object {
  72   struct objc_class*  class_pointer;
  73 } *id;
  74
  75 /*
  76 ** Definition of method type.  When retrieving the implementation of a
  77 ** method, this is type of the pointer returned.  The idea of the
  78 ** definition of IMP is to represent a 'pointer to a general function
  79 ** taking an id, a SEL, followed by other unspecified arguments'.  You
  80 ** must always cast an IMP to a pointer to a function taking the
  81 ** appropriate, specific types for that function, before calling it -
  82 ** to make sure the appropriate arguments are passed to it.  The code
  83 ** generated by the compiler to perform method calls automatically
  84 ** does this cast inside method calls.
  85 */
  86 typedef id (*IMP)(id, SEL, ...);
  87
  88 /*
  89 ** More simple types...
  90 */
  91 #define nil (id)0                               /* id of Nil instance */
  92 #define Nil (Class)0                            /* id of Nil class */
  93 typedef char *STR;                              /* String alias */
  94
  95 /*
  96 ** The compiler generates one of these structures for each class.
  97 **
  98 ** This structure is the definition for classes.
  99 **
 100 ** This structure is generated by the compiler in the executable and used by
 101 ** the run-time during normal messaging operations.  Therefore some members
 102 ** change type. The compiler generates "char* const" and places a string in
 103 ** the following member variables:  super_class.
 104 */
 105 typedef struct objc_class *MetaClass;
 106 typedef struct objc_class *Class;
 107 struct objc_class {
 108   MetaClass           class_pointer;          /* Pointer to the class's
 109                                                 meta class. */
 110   struct objc_class*  super_class;            /* Pointer to the super
 111                                                 class. NULL for class
 112                                                 Object. */
 113   const char*         name;                   /* Name of the class. */
 114   long                version;                /* Unknown. */
 115   unsigned long       info;                   /* Bit mask.  See class masks
 116                                                 defined above. */
 117   long                instance_size;          /* Size in bytes of the class.
 118                                                 The sum of the class
 119                                                 definition and all super
 120                                                 class definitions. */
 121   struct objc_ivar_list* ivars;               /* Pointer to a structure that
 122                                                 describes the instance
 123                                                 variables in the class
 124                                                 definition.  NULL indicates
 125                                                 no instance variables.  Does
 126                                                 not include super class
 127                                                 variables. */
 128   struct objc_method_list*  methods;          /* Linked list of instance
 129                                                 methods defined for the
 130                                                 class. */
 131   struct sarray *    dtable;                  /* Pointer to instance
 132                                                  method dispatch table. */
 133   struct objc_class* subclass_list;           /* Subclasses */
 134   struct objc_class* sibling_class;
 135
 136   struct objc_protocol_list *protocols;       /* Protocols conformed to */
 137   void* gc_object_type;
 138 };
 139
 140 #ifndef __OBJC__
 141 typedef struct objc_protocol {
 142   struct objc_class* class_pointer;
 143   char *protocol_name;
 144   struct objc_protocol_list *protocol_list;
 145   struct objc_method_description_list *instance_methods, *class_methods;
 146 } Protocol;
 147
 148 #else /* __OBJC__ */
 149 @class Protocol;
 150 #endif
 151
 152 typedef void* retval_t;         /* return value */
 153 typedef void(*apply_t)(void);   /* function pointer */
 154 typedef union arglist {
 155   char *arg_ptr;
 156   char arg_regs[sizeof (char*)];
 157 } *arglist_t;                   /* argument frame */
 158
 159
 160 IMP objc_msg_lookup(id receiver, SEL op);
 161
 162 #ifdef __cplusplus
 163 }
 164 #endif
 165
 166 #endif /* not __objc_INCLUDE_GNU */