gcc/objc/objc.h

   1 /* Basic data types for Objective C.
   2    Copyright (C) 1993 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
   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 GNU CC 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 GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 /* As a special exception, if you link this library with files
  21    compiled with GCC to produce an executable, this does not cause
  22    the resulting executable to be covered by the GNU General Public License.
  23    This exception does not however invalidate any other reasons why
  24    the executable file might be covered by the GNU General Public License.  */
  25
  26 #ifndef __objc_INCLUDE_GNU
  27 #define __objc_INCLUDE_GNU
  28
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 #include <stddef.h>
  34
  35 /*
  36 ** Definition of the boolean type.
  37 */
  38 typedef char  BOOL;
  39 #define YES   (BOOL)1
  40 #define NO    (BOOL)0
  41
  42 /*
  43 ** Definition of a selector.  Selectors are really of type unsigned int.
  44 ** The runtime does this mapping from SEL's to names internally in the
  45 ** sel_... operations.  You should never use the fact that it is actually
  46 ** an integer, since other Objective-C implementations use other conventions.
  47 */
  48 typedef void* SEL;
  49
  50 /*
  51 ** ObjC uses this typedef for untyped instances.
  52 */
  53 typedef struct objc_object {
  54   struct objc_class*  class_pointer;
  55 } *id;
  56
  57 /*
  58 ** Definition of method type.  When retrieving the implementation of a
  59 ** method, this is type of the pointer returned
  60 */
  61 typedef id (*IMP)(id, SEL, ...);
  62
  63 /*
  64 ** More simple types...
  65 */
  66 #define nil (id)0                               /* id of Nil instance */
  67 #define Nil (Class*)0                          /* id of Nil class */
  68 typedef char *STR;                              /* String alias */
  69
  70 /*
  71 ** The compiler generates one of these structures for each class.
  72 **
  73 ** This structure is the definition for classes.
  74 **
  75 ** This structure is generated by the compiler in the executable and used by
  76 ** the run-time during normal messaging operations.  Therefore some members
  77 ** change type. The compiler generates "char* const" and places a string in
  78 ** the following member variables:  super_class.
  79 */
  80 typedef struct objc_class MetaClass;
  81 typedef struct objc_class Class;
  82 struct objc_class {
  83   MetaClass*         class_pointer;          /* Pointer to the class's
  84                                                 meta class. */
  85   struct objc_class*  super_class;            /* Pointer to the super
  86                                                 class. NULL for class
  87                                                 Object. */
  88   const char*         name;                   /* Name of the class. */
  89   long                version;                /* Unknown. */
  90   unsigned long       info;                   /* Bit mask.  See class masks
  91                                                 defined above. */
  92   long                instance_size;          /* Size in bytes of the class.
  93                                                 The sum of the class definition
  94                                                 and all super class
  95                                                 definitions. */
  96   struct objc_ivar_list* ivars;               /* Pointer to a structure that
  97                                                 describes the instance
  98                                                 variables in the class
  99                                                 definition.  NULL indicates
 100                                                 no instance variables.  Does
 101                                                 not include super class
 102                                                 variables. */
 103   struct objc_method_list*  methods;          /* Linked list of instance
 104                                                 methods defined for the
 105                                                 class. */
 106   struct sarray *    dtable;                  /* Pointer to instance
 107                                                  method dispatch table. */
 108   struct objc_class* subclass_list;           /* Subclasses */
 109   struct objc_class* sibling_class;
 110
 111   struct objc_protocol_list *protocols;       /* Protocols conformed to */
 112 };
 113
 114 #ifndef __OBJC__
 115 typedef struct objc_protocol {
 116   struct objc_class* class_pointer;
 117   char *protocol_name;
 118   struct objc_protocol_list *protocol_list;
 119   struct objc_method_description_list *instance_methods, *class_methods;
 120 } Protocol;
 121
 122 #else /* __OBJC__ */
 123 @class Protocol;
 124 #endif
 125
 126 typedef void* retval_t;         /* return value */
 127 typedef void(*apply_t)(void);   /* function pointer */
 128 typedef union {
 129   char *arg_ptr;
 130   char arg_regs[sizeof (char*)];
 131 } *arglist_t;                   /* argument frame */
 132
 133
 134 #if defined(__OBJC__)
 135 #include "objc/sarray.h"
 136
 137 /*
 138   This is the function called when messages are send to nil.  You may
 139   set a breakpoint in your debugger at this function to catch messages
 140   too nil.
 141 */
 142 extern id nil_method(id rcv, SEL op, ...);
 143
 144 /*
 145   The messager is inlined, thus it is defined here directly.  The
 146   inlining is quite time-consuming when optimizing.  This will be
 147   taken care of later by hand-coding the messager in the compiler.
 148 */
 149 extern __inline__ IMP
 150 objc_msg_lookup(id receiver, SEL op)
 151 {
 152   if(receiver)
 153     return sarray_get(receiver->class_pointer->dtable, (size_t)(op));
 154   else
 155     return nil_method;
 156 }
 157
 158 #else
 159
 160 IMP objc_msg_lookup(id receiver, SEL op);
 161
 162 #endif
 163
 164 #ifdef __cplusplus
 165 }
 166 #endif
 167
 168 #endif /* not __objc_INCLUDE_GNU */