runtime/objc-config.h

   1 /*
   2  * Copyright (c) 1999-2002, 2005-2008 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 #ifndef _OBJC_CONFIG_H_
  25 #define _OBJC_CONFIG_H_
  26
  27 #include <TargetConditionals.h>
  28
  29 // Define __OBJC2__ for the benefit of our asm files.
  30 #ifndef __OBJC2__
  31 #   if TARGET_OS_OSX  &&  !TARGET_OS_IOSMAC  &&  __i386__
  32         // old ABI
  33 #   else
  34 #       define __OBJC2__ 1
  35 #   endif
  36 #endif
  37
  38 // Avoid the !NDEBUG double negative.
  39 #if !NDEBUG
  40 #   define DEBUG 1
  41 #else
  42 #   define DEBUG 0
  43 #endif
  44
  45 // Define SUPPORT_GC_COMPAT=1 to enable compatibility where GC once was.
  46 // OBJC_NO_GC and OBJC_NO_GC_API in objc-api.h mean something else.
  47 #if !TARGET_OS_OSX
  48 #   define SUPPORT_GC_COMPAT 0
  49 #else
  50 #   define SUPPORT_GC_COMPAT 1
  51 #endif
  52
  53 // Define SUPPORT_ZONES=1 to enable malloc zone support in NXHashTable.
  54 #if !(TARGET_OS_OSX || TARGET_OS_IOSMAC)
  55 #   define SUPPORT_ZONES 0
  56 #else
  57 #   define SUPPORT_ZONES 1
  58 #endif
  59
  60 // Define SUPPORT_MOD=1 to use the mod operator in NXHashTable and objc-sel-set
  61 #if defined(__arm__)
  62 #   define SUPPORT_MOD 0
  63 #else
  64 #   define SUPPORT_MOD 1
  65 #endif
  66
  67 // Define SUPPORT_PREOPT=1 to enable dyld shared cache optimizations
  68 #if TARGET_OS_WIN32
  69 #   define SUPPORT_PREOPT 0
  70 #else
  71 #   define SUPPORT_PREOPT 1
  72 #endif
  73
  74 // Define SUPPORT_TAGGED_POINTERS=1 to enable tagged pointer objects
  75 // Be sure to edit tagged pointer SPI in objc-internal.h as well.
  76 #if !(__OBJC2__  &&  __LP64__)
  77 #   define SUPPORT_TAGGED_POINTERS 0
  78 #else
  79 #   define SUPPORT_TAGGED_POINTERS 1
  80 #endif
  81
  82 // Define SUPPORT_MSB_TAGGED_POINTERS to use the MSB
  83 // as the tagged pointer marker instead of the LSB.
  84 // Be sure to edit tagged pointer SPI in objc-internal.h as well.
  85 #if !SUPPORT_TAGGED_POINTERS  ||  (TARGET_OS_OSX || TARGET_OS_IOSMAC)
  86 #   define SUPPORT_MSB_TAGGED_POINTERS 0
  87 #else
  88 #   define SUPPORT_MSB_TAGGED_POINTERS 1
  89 #endif
  90
  91 // Define SUPPORT_INDEXED_ISA=1 on platforms that store the class in the isa
  92 // field as an index into a class table.
  93 // Note, keep this in sync with any .s files which also define it.
  94 // Be sure to edit objc-abi.h as well.
  95 #if __ARM_ARCH_7K__ >= 2  ||  (__arm64__ && !__LP64__)
  96 #   define SUPPORT_INDEXED_ISA 1
  97 #else
  98 #   define SUPPORT_INDEXED_ISA 0
  99 #endif
 100
 101 // Define SUPPORT_PACKED_ISA=1 on platforms that store the class in the isa
 102 // field as a maskable pointer with other data around it.
 103 #if (!__LP64__  ||  TARGET_OS_WIN32  ||  \
 104      (TARGET_OS_SIMULATOR && !TARGET_OS_IOSMAC))
 105 #   define SUPPORT_PACKED_ISA 0
 106 #else
 107 #   define SUPPORT_PACKED_ISA 1
 108 #endif
 109
 110 // Define SUPPORT_NONPOINTER_ISA=1 on any platform that may store something
 111 // in the isa field that is not a raw pointer.
 112 #if !SUPPORT_INDEXED_ISA  &&  !SUPPORT_PACKED_ISA
 113 #   define SUPPORT_NONPOINTER_ISA 0
 114 #else
 115 #   define SUPPORT_NONPOINTER_ISA 1
 116 #endif
 117
 118 // Define SUPPORT_FIXUP=1 to repair calls sites for fixup dispatch.
 119 // Fixup messaging itself is no longer supported.
 120 // Be sure to edit objc-abi.h as well (objc_msgSend*_fixup)
 121 #if !(defined(__x86_64__) && (TARGET_OS_OSX || TARGET_OS_SIMULATOR))
 122 #   define SUPPORT_FIXUP 0
 123 #else
 124 #   define SUPPORT_FIXUP 1
 125 #endif
 126
 127 // Define SUPPORT_ZEROCOST_EXCEPTIONS to use "zero-cost" exceptions for OBJC2.
 128 // Be sure to edit objc-exception.h as well (objc_add/removeExceptionHandler)
 129 #if !__OBJC2__  ||  (defined(__arm__)  &&  __USING_SJLJ_EXCEPTIONS__)
 130 #   define SUPPORT_ZEROCOST_EXCEPTIONS 0
 131 #else
 132 #   define SUPPORT_ZEROCOST_EXCEPTIONS 1
 133 #endif
 134
 135 // Define SUPPORT_ALT_HANDLERS if you're using zero-cost exceptions
 136 // but also need to support AppKit's alt-handler scheme
 137 // Be sure to edit objc-exception.h as well (objc_add/removeExceptionHandler)
 138 #if !SUPPORT_ZEROCOST_EXCEPTIONS  ||  !TARGET_OS_OSX
 139 #   define SUPPORT_ALT_HANDLERS 0
 140 #else
 141 #   define SUPPORT_ALT_HANDLERS 1
 142 #endif
 143
 144 // Define SUPPORT_RETURN_AUTORELEASE to optimize autoreleased return values
 145 #if TARGET_OS_WIN32
 146 #   define SUPPORT_RETURN_AUTORELEASE 0
 147 #else
 148 #   define SUPPORT_RETURN_AUTORELEASE 1
 149 #endif
 150
 151 // Define SUPPORT_STRET on architectures that need separate struct-return ABI.
 152 #if defined(__arm64__)
 153 #   define SUPPORT_STRET 0
 154 #else
 155 #   define SUPPORT_STRET 1
 156 #endif
 157
 158 // Define SUPPORT_MESSAGE_LOGGING to enable NSObjCMessageLoggingEnabled
 159 #if !TARGET_OS_OSX
 160 #   define SUPPORT_MESSAGE_LOGGING 0
 161 #else
 162 #   define SUPPORT_MESSAGE_LOGGING 1
 163 #endif
 164
 165 // Define HAVE_TASK_RESTARTABLE_RANGES to enable usage of
 166 // task_restartable_ranges_synchronize()
 167 #if TARGET_OS_SIMULATOR || defined(__i386__) || defined(__arm__) || !TARGET_OS_MAC
 168 #   define HAVE_TASK_RESTARTABLE_RANGES 0
 169 #else
 170 #   define HAVE_TASK_RESTARTABLE_RANGES 1
 171 #endif
 172
 173 // OBJC_INSTRUMENTED controls whether message dispatching is dynamically
 174 // monitored.  Monitoring introduces substantial overhead.
 175 // NOTE: To define this condition, do so in the build command, NOT by
 176 // uncommenting the line here.  This is because objc-class.h heeds this
 177 // condition, but objc-class.h can not #include this file (objc-config.h)
 178 // because objc-class.h is public and objc-config.h is not.
 179 //#define OBJC_INSTRUMENTED
 180
 181 // In __OBJC2__, the runtimeLock is a mutex always held
 182 // hence the cache lock is redundant and can be elided.
 183 //
 184 // If the runtime lock ever becomes a rwlock again,
 185 // the cache lock would need to be used again
 186 #if __OBJC2__
 187 #define CONFIG_USE_CACHE_LOCK 0
 188 #else
 189 #define CONFIG_USE_CACHE_LOCK 1
 190 #endif
 191
 192 // Determine how the method cache stores IMPs.
 193 #define CACHE_IMP_ENCODING_NONE 1 // Method cache contains raw IMP.
 194 #define CACHE_IMP_ENCODING_ISA_XOR 2 // Method cache contains ISA ^ IMP.
 195 #define CACHE_IMP_ENCODING_PTRAUTH 3 // Method cache contains ptrauth'd IMP.
 196
 197 #if __PTRAUTH_INTRINSICS__
 198 // Always use ptrauth when it's supported.
 199 #define CACHE_IMP_ENCODING CACHE_IMP_ENCODING_PTRAUTH
 200 #elif defined(__arm__)
 201 // 32-bit ARM uses no encoding.
 202 #define CACHE_IMP_ENCODING CACHE_IMP_ENCODING_NONE
 203 #else
 204 // Everything else uses ISA ^ IMP.
 205 #define CACHE_IMP_ENCODING CACHE_IMP_ENCODING_ISA_XOR
 206 #endif
 207
 208 #define CACHE_MASK_STORAGE_OUTLINED 1
 209 #define CACHE_MASK_STORAGE_HIGH_16 2
 210 #define CACHE_MASK_STORAGE_LOW_4 3
 211
 212 #if defined(__arm64__) && __LP64__
 213 #define CACHE_MASK_STORAGE CACHE_MASK_STORAGE_HIGH_16
 214 #elif defined(__arm64__) && !__LP64__
 215 #define CACHE_MASK_STORAGE CACHE_MASK_STORAGE_LOW_4
 216 #else
 217 #define CACHE_MASK_STORAGE CACHE_MASK_STORAGE_OUTLINED
 218 #endif
 219
 220 #endif