runtime/objc.h

   1 /*
   2  * Copyright (c) 1999-2007 Apple Inc.  All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  *      objc.h
  25  *      Copyright 1988-1996, NeXT Software, Inc.
  26  */
  27
  28 #ifndef _OBJC_OBJC_H_
  29 #define _OBJC_OBJC_H_
  30
  31 #include <sys/types.h>      // for __DARWIN_NULL
  32 #include <Availability.h>
  33 #include <objc/objc-api.h>
  34 #include <stdbool.h>
  35
  36 #if !OBJC_TYPES_DEFINED
  37 /// An opaque type that represents an Objective-C class.
  38 typedef struct objc_class *Class;
  39
  40 /// Represents an instance of a class.
  41 struct objc_object {
  42     Class isa  OBJC_ISA_AVAILABILITY;
  43 };
  44
  45 /// A pointer to an instance of a class.
  46 typedef struct objc_object *id;
  47 #endif
  48
  49 /// An opaque type that represents a method selector.
  50 typedef struct objc_selector *SEL;
  51
  52 /// A pointer to the function of a method implementation.
  53 #if !OBJC_OLD_DISPATCH_PROTOTYPES
  54 typedef void (*IMP)(void /* id, SEL, ... */ );
  55 #else
  56 typedef id (*IMP)(id, SEL, ...);
  57 #endif
  58
  59 #define OBJC_BOOL_DEFINED
  60
  61 /// Type to represent a boolean value.
  62 #if (TARGET_OS_IPHONE && __LP64__)  ||  TARGET_OS_WATCH
  63 #define OBJC_BOOL_IS_BOOL 1
  64 typedef bool BOOL;
  65 #else
  66 #define OBJC_BOOL_IS_CHAR 1
  67 typedef signed char BOOL;
  68 // BOOL is explicitly signed so @encode(BOOL) == "c" rather than "C"
  69 // even if -funsigned-char is used.
  70 #endif
  71
  72 #if __has_feature(objc_bool)
  73 #define YES __objc_yes
  74 #define NO  __objc_no
  75 #else
  76 #define YES ((BOOL)1)
  77 #define NO  ((BOOL)0)
  78 #endif
  79
  80 #ifndef Nil
  81 # if __has_feature(cxx_nullptr)
  82 #   define Nil nullptr
  83 # else
  84 #   define Nil __DARWIN_NULL
  85 # endif
  86 #endif
  87
  88 #ifndef nil
  89 # if __has_feature(cxx_nullptr)
  90 #   define nil nullptr
  91 # else
  92 #   define nil __DARWIN_NULL
  93 # endif
  94 #endif
  95
  96 #ifndef __strong
  97 # if !__has_feature(objc_arc)
  98 #   define __strong /* empty */
  99 # endif
 100 #endif
 101
 102 #ifndef __unsafe_unretained
 103 # if !__has_feature(objc_arc)
 104 #   define __unsafe_unretained /* empty */
 105 # endif
 106 #endif
 107
 108 #ifndef __autoreleasing
 109 # if !__has_feature(objc_arc)
 110 #   define __autoreleasing /* empty */
 111 # endif
 112 #endif
 113
 114
 115 /**
 116  * Returns the name of the method specified by a given selector.
 117  *
 118  * @param sel A pointer of type \c SEL. Pass the selector whose name you wish to determine.
 119  *
 120  * @return A C string indicating the name of the selector.
 121  */
 122 OBJC_EXPORT const char *sel_getName(SEL sel)
 123     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 124
 125 /**
 126  * Registers a method with the Objective-C runtime system, maps the method
 127  * name to a selector, and returns the selector value.
 128  *
 129  * @param str A pointer to a C string. Pass the name of the method you wish to register.
 130  *
 131  * @return A pointer of type SEL specifying the selector for the named method.
 132  *
 133  * @note You must register a method name with the Objective-C runtime system to obtain the
 134  *  method’s selector before you can add the method to a class definition. If the method name
 135  *  has already been registered, this function simply returns the selector.
 136  */
 137 OBJC_EXPORT SEL sel_registerName(const char *str)
 138     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 139
 140 /**
 141  * Returns the class name of a given object.
 142  *
 143  * @param obj An Objective-C object.
 144  *
 145  * @return The name of the class of which \e obj is an instance.
 146  */
 147 OBJC_EXPORT const char *object_getClassName(id obj)
 148     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 149
 150 /**
 151  * Returns a pointer to any extra bytes allocated with an instance given object.
 152  *
 153  * @param obj An Objective-C object.
 154  *
 155  * @return A pointer to any extra bytes allocated with \e obj. If \e obj was
 156  *   not allocated with any extra bytes, then dereferencing the returned pointer is undefined.
 157  *
 158  * @note This function returns a pointer to any extra bytes allocated with the instance
 159  *  (as specified by \c class_createInstance with extraBytes>0). This memory follows the
 160  *  object's ordinary ivars, but may not be adjacent to the last ivar.
 161  * @note The returned pointer is guaranteed to be pointer-size aligned, even if the area following
 162  *  the object's last ivar is less aligned than that. Alignment greater than pointer-size is never
 163  *  guaranteed, even if the area following the object's last ivar is more aligned than that.
 164  * @note In a garbage-collected environment, the memory is scanned conservatively.
 165  */
 166 OBJC_EXPORT void *object_getIndexedIvars(id obj)
 167     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 168
 169 /**
 170  * Identifies a selector as being valid or invalid.
 171  *
 172  * @param sel The selector you want to identify.
 173  *
 174  * @return YES if selector is valid and has a function implementation, NO otherwise.
 175  *
 176  * @warning On some platforms, an invalid reference (to invalid memory addresses) can cause
 177  *  a crash.
 178  */
 179 OBJC_EXPORT BOOL sel_isMapped(SEL sel)
 180     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 181
 182 /**
 183  * Registers a method name with the Objective-C runtime system.
 184  *
 185  * @param str A pointer to a C string. Pass the name of the method you wish to register.
 186  *
 187  * @return A pointer of type SEL specifying the selector for the named method.
 188  *
 189  * @note The implementation of this method is identical to the implementation of \c sel_registerName.
 190  * @note Prior to OS X version 10.0, this method tried to find the selector mapped to the given name
 191  *  and returned \c NULL if the selector was not found. This was changed for safety, because it was
 192  *  observed that many of the callers of this function did not check the return value for \c NULL.
 193  */
 194 OBJC_EXPORT SEL sel_getUid(const char *str)
 195     OBJC_AVAILABLE(10.0, 2.0, 9.0, 1.0);
 196
 197 typedef const void* objc_objectptr_t;
 198
 199
 200 // Obsolete ARC conversions.
 201
 202 OBJC_EXPORT id objc_retainedObject(objc_objectptr_t obj)
 203     OBJC_UNAVAILABLE("use CFBridgingRelease() or a (__bridge_transfer id) cast instead");
 204 OBJC_EXPORT id objc_unretainedObject(objc_objectptr_t obj)
 205     OBJC_UNAVAILABLE("use a (__bridge id) cast instead");
 206 OBJC_EXPORT objc_objectptr_t objc_unretainedPointer(id obj)
 207     OBJC_UNAVAILABLE("use a __bridge cast instead");
 208
 209
 210 #if !__OBJC2__
 211
 212 // The following declarations are provided here for source compatibility.
 213
 214 #if defined(__LP64__)
 215     typedef long arith_t;
 216     typedef unsigned long uarith_t;
 217 #   define ARITH_SHIFT 32
 218 #else
 219     typedef int arith_t;
 220     typedef unsigned uarith_t;
 221 #   define ARITH_SHIFT 16
 222 #endif
 223
 224 typedef char *STR;
 225
 226 #define ISSELECTOR(sel) sel_isMapped(sel)
 227 #define SELNAME(sel)    sel_getName(sel)
 228 #define SELUID(str)     sel_getUid(str)
 229 #define NAMEOF(obj)     object_getClassName(obj)
 230 #define IV(obj)         object_getIndexedIvars(obj)
 231
 232 #endif
 233
 234 #endif  /* _OBJC_OBJC_H_ */