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 typedef unsigned char  BOOL;
  43 #endif
  44 #define YES   (BOOL)1
  45 #define NO    (BOOL)0
  46
  47 /*
  48 ** Definition of a selector.  Selectors themselves are not unique, but
  49 ** the sel_id is a unique identifier.
  50 */
  51 typedef const struct objc_selector
  52 {
  53   void *sel_id;
  54   const char *sel_types;
  55 } *SEL;
  56
  57 inline static BOOL
  58 sel_eq (SEL s1, SEL s2)
  59 {
  60   if (s1 == 0 || s2 == 0)
  61     return s1 == s2;
  62   else
  63     return s1->sel_id == s2->sel_id;
  64 }
  65
  66
  67 /*
  68 ** ObjC uses this typedef for untyped instances.
  69 */
  70 typedef struct objc_object {
  71   struct objc_class*  class_pointer;
  72 } *id;
  73
  74 /*
  75 ** Definition of method type.  When retrieving the implementation of a
  76 ** method, this is type of the pointer returned.  The idea of the
  77 ** definition of IMP is to represent a 'pointer to a general function
  78 ** taking an id, a SEL, followed by other unspecified arguments'.  You
  79 ** must always cast an IMP to a pointer to a function taking the
  80 ** appropriate, specific types for that function, before calling it -
  81 ** to make sure the appropriate arguments are passed to it.  The code
  82 ** generated by the compiler to perform method calls automatically
  83 ** does this cast inside method calls.
  84 */
  85 typedef id (*IMP)(id, SEL, ...);
  86
  87 /*
  88 ** More simple types...
  89 */
  90 #define nil (id)0                               /* id of Nil instance */
  91 #define Nil (Class)0                            /* id of Nil class */
  92 typedef char *STR;                              /* String alias */
  93
  94 /*
  95 ** The compiler generates one of these structures for each class.
  96 **
  97 ** This structure is the definition for classes.
  98 **
  99 ** This structure is generated by the compiler in the executable and used by
 100 ** the run-time during normal messaging operations.  Therefore some members
 101 ** change type. The compiler generates "char* const" and places a string in
 102 ** the following member variables:  super_class.
 103 */
 104 typedef struct objc_class *MetaClass;
 105 typedef struct objc_class *Class;
 106 struct objc_class {
 107   MetaClass           class_pointer;          /* Pointer to the class's
 108                                                 meta class. */
 109   struct objc_class*  super_class;            /* Pointer to the super
 110                                                 class. NULL for class
 111                                                 Object. */
 112   const char*         name;                   /* Name of the class. */
 113   long                version;                /* Unknown. */
 114   unsigned long       info;                   /* Bit mask.  See class masks
 115                                                 defined above. */
 116   long                instance_size;          /* Size in bytes of the class.
 117                                                 The sum of the class
 118                                                 definition and all super
 119                                                 class definitions. */
 120   struct objc_ivar_list* ivars;               /* Pointer to a structure that
 121                                                 describes the instance
 122                                                 variables in the class
 123                                                 definition.  NULL indicates
 124                                                 no instance variables.  Does
 125                                                 not include super class
 126                                                 variables. */
 127   struct objc_method_list*  methods;          /* Linked list of instance
 128                                                 methods defined for the
 129                                                 class. */
 130   struct sarray *    dtable;                  /* Pointer to instance
 131                                                  method dispatch table. */
 132   struct objc_class* subclass_list;           /* Subclasses */
 133   struct objc_class* sibling_class;
 134
 135   struct objc_protocol_list *protocols;       /* Protocols conformed to */
 136   void* gc_object_type;
 137 };
 138
 139 #ifndef __OBJC__
 140 typedef struct objc_protocol {
 141   struct objc_class* class_pointer;
 142   char *protocol_name;
 143   struct objc_protocol_list *protocol_list;
 144   struct objc_method_description_list *instance_methods, *class_methods;
 145 } Protocol;
 146
 147 #else /* __OBJC__ */
 148 @class Protocol;
 149 #endif
 150
 151 typedef void* retval_t;         /* return value */
 152 typedef void(*apply_t)(void);   /* function pointer */
 153 typedef union arglist {
 154   char *arg_ptr;
 155   char arg_regs[sizeof (char*)];
 156 } *arglist_t;                   /* argument frame */
 157
 158
 159 IMP objc_msg_lookup(id receiver, SEL op);
 160
 161 #ifdef __cplusplus
 162 }
 163 #endif
 164
 165 #endif /* not __objc_INCLUDE_GNU */