libcxx/include/__configuration/availability.h

   1 // -*- C++ -*-
   2 //===----------------------------------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #ifndef _LIBCPP___CONFIGURATION_AVAILABILITY_H
  11 #define _LIBCPP___CONFIGURATION_AVAILABILITY_H
  12
  13 #include <__configuration/compiler.h>
  14 #include <__configuration/language.h>
  15
  16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  17 #  pragma GCC system_header
  18 #endif
  19
  20 // Libc++ is shipped by various vendors. In particular, it is used as a system
  21 // library on macOS, iOS and other Apple platforms. In order for users to be
  22 // able to compile a binary that is intended to be deployed to an older version
  23 // of a platform, Clang provides availability attributes [1]. These attributes
  24 // can be placed on declarations and are used to describe the life cycle of a
  25 // symbol in the library.
  26 //
  27 // The main goal is to ensure a compile-time error if a symbol that hasn't been
  28 // introduced in a previously released library is used in a program that targets
  29 // that previously released library. Normally, this would be a load-time error
  30 // when one tries to launch the program against the older library.
  31 //
  32 // For example, the filesystem library was introduced in the dylib in LLVM 9.
  33 // On Apple platforms, this corresponds to macOS 10.15. If a user compiles on
  34 // a macOS 10.15 host but targets macOS 10.13 with their program, the compiler
  35 // would normally not complain (because the required declarations are in the
  36 // headers), but the dynamic loader would fail to find the symbols when actually
  37 // trying to launch the program on macOS 10.13. To turn this into a compile-time
  38 // issue instead, declarations are annotated with when they were introduced, and
  39 // the compiler can produce a diagnostic if the program references something that
  40 // isn't available on the deployment target.
  41 //
  42 // This mechanism is general in nature, and any vendor can add their markup to
  43 // the library (see below). Whenever a new feature is added that requires support
  44 // in the shared library, two macros are added below to allow marking the feature
  45 // as unavailable:
  46 // 1. A macro named `_LIBCPP_AVAILABILITY_HAS_<feature>` which must be defined
  47 //    to `_LIBCPP_INTRODUCED_IN_<version>` for the appropriate LLVM version.
  48 // 2. A macro named `_LIBCPP_AVAILABILITY_<feature>`, which must be defined to
  49 //    `_LIBCPP_INTRODUCED_IN_<version>_MARKUP` for the appropriate LLVM version.
  50 //
  51 // When vendors decide to ship the feature as part of their shared library, they
  52 // can update the `_LIBCPP_INTRODUCED_IN_<version>` macro (and the markup counterpart)
  53 // based on the platform version they shipped that version of LLVM in. The library
  54 // will then use this markup to provide an optimal user experience on these platforms.
  55 //
  56 // Furthermore, many features in the standard library have corresponding
  57 // feature-test macros. The `_LIBCPP_AVAILABILITY_HAS_<feature>` macros
  58 // are checked by the corresponding feature-test macros generated by
  59 // generate_feature_test_macro_components.py to ensure that the library
  60 // doesn't announce a feature as being implemented if it is unavailable on
  61 // the deployment target.
  62 //
  63 // Note that this mechanism is disabled by default in the "upstream" libc++.
  64 // Availability annotations are only meaningful when shipping libc++ inside
  65 // a platform (i.e. as a system library), and so vendors that want them should
  66 // turn those annotations on at CMake configuration time.
  67 //
  68 // [1]: https://clang.llvm.org/docs/AttributeReference.html#availability
  69
  70 // For backwards compatibility, allow users to define _LIBCPP_DISABLE_AVAILABILITY
  71 // for a while.
  72 #if defined(_LIBCPP_DISABLE_AVAILABILITY)
  73 #  undef _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS
  74 #  define _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS 0
  75 #endif
  76
  77 // Availability markup is disabled when building the library, or when a non-Clang
  78 // compiler is used because only Clang supports the necessary attributes.
  79 #if defined(_LIBCPP_BUILDING_LIBRARY) || defined(_LIBCXXABI_BUILDING_LIBRARY) || !defined(_LIBCPP_COMPILER_CLANG_BASED)
  80 #  undef _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS
  81 #  define _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS 0
  82 #endif
  83
  84 // When availability annotations are disabled, we take for granted that features introduced
  85 // in all versions of the library are available.
  86 #if !_LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS
  87
  88 #  define _LIBCPP_INTRODUCED_IN_LLVM_20 1
  89 #  define _LIBCPP_INTRODUCED_IN_LLVM_20_ATTRIBUTE /* nothing */
  90
  91 #  define _LIBCPP_INTRODUCED_IN_LLVM_19 1
  92 #  define _LIBCPP_INTRODUCED_IN_LLVM_19_ATTRIBUTE /* nothing */
  93
  94 #  define _LIBCPP_INTRODUCED_IN_LLVM_18 1
  95 #  define _LIBCPP_INTRODUCED_IN_LLVM_18_ATTRIBUTE /* nothing */
  96
  97 #  define _LIBCPP_INTRODUCED_IN_LLVM_17 1
  98 #  define _LIBCPP_INTRODUCED_IN_LLVM_17_ATTRIBUTE /* nothing */
  99
 100 #  define _LIBCPP_INTRODUCED_IN_LLVM_16 1
 101 #  define _LIBCPP_INTRODUCED_IN_LLVM_16_ATTRIBUTE /* nothing */
 102
 103 #  define _LIBCPP_INTRODUCED_IN_LLVM_15 1
 104 #  define _LIBCPP_INTRODUCED_IN_LLVM_15_ATTRIBUTE /* nothing */
 105
 106 #  define _LIBCPP_INTRODUCED_IN_LLVM_14 1
 107 #  define _LIBCPP_INTRODUCED_IN_LLVM_14_ATTRIBUTE /* nothing */
 108
 109 #  define _LIBCPP_INTRODUCED_IN_LLVM_13 1
 110 #  define _LIBCPP_INTRODUCED_IN_LLVM_13_ATTRIBUTE /* nothing */
 111
 112 #  define _LIBCPP_INTRODUCED_IN_LLVM_12 1
 113 #  define _LIBCPP_INTRODUCED_IN_LLVM_12_ATTRIBUTE /* nothing */
 114
 115 #  define _LIBCPP_INTRODUCED_IN_LLVM_11 1
 116 #  define _LIBCPP_INTRODUCED_IN_LLVM_11_ATTRIBUTE /* nothing */
 117
 118 #  define _LIBCPP_INTRODUCED_IN_LLVM_10 1
 119 #  define _LIBCPP_INTRODUCED_IN_LLVM_10_ATTRIBUTE /* nothing */
 120
 121 #  define _LIBCPP_INTRODUCED_IN_LLVM_9 1
 122 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE      /* nothing */
 123 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_PUSH /* nothing */
 124 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_POP  /* nothing */
 125
 126 #  define _LIBCPP_INTRODUCED_IN_LLVM_8 1
 127 #  define _LIBCPP_INTRODUCED_IN_LLVM_8_ATTRIBUTE /* nothing */
 128
 129 #  define _LIBCPP_INTRODUCED_IN_LLVM_4 1
 130 #  define _LIBCPP_INTRODUCED_IN_LLVM_4_ATTRIBUTE /* nothing */
 131
 132 #elif defined(__APPLE__)
 133
 134 // clang-format off
 135
 136 // LLVM 20
 137 // TODO: Fill this in
 138 #  define _LIBCPP_INTRODUCED_IN_LLVM_20 0
 139 #  define _LIBCPP_INTRODUCED_IN_LLVM_20_ATTRIBUTE __attribute__((unavailable))
 140
 141 // LLVM 19
 142 // TODO: Fill this in
 143 #  define _LIBCPP_INTRODUCED_IN_LLVM_19 0
 144 #  define _LIBCPP_INTRODUCED_IN_LLVM_19_ATTRIBUTE __attribute__((unavailable))
 145
 146 // LLVM 18
 147 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 150000) ||       \
 148       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 180000) ||     \
 149       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 180000) ||             \
 150       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 110000) ||       \
 151       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 90000) ||      \
 152       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 240000)
 153 #    define _LIBCPP_INTRODUCED_IN_LLVM_18 0
 154 #  else
 155 #    define _LIBCPP_INTRODUCED_IN_LLVM_18 1
 156 #  endif
 157 #  define _LIBCPP_INTRODUCED_IN_LLVM_18_ATTRIBUTE                                                                 \
 158     __attribute__((availability(macos, strict, introduced = 15.0)))                                               \
 159     __attribute__((availability(ios, strict, introduced = 18.0)))                                                 \
 160     __attribute__((availability(tvos, strict, introduced = 18.0)))                                                \
 161     __attribute__((availability(watchos, strict, introduced = 11.0)))                                             \
 162     __attribute__((availability(bridgeos, strict, introduced = 9.0)))                                             \
 163     __attribute__((availability(driverkit, strict, introduced = 24.0)))
 164
 165 // LLVM 17
 166 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 140400) ||       \
 167       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 170400) ||     \
 168       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 170400) ||             \
 169       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 100400) ||       \
 170       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 80400) ||      \
 171       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 230400)
 172 #    define _LIBCPP_INTRODUCED_IN_LLVM_17 0
 173 #  else
 174 #    define _LIBCPP_INTRODUCED_IN_LLVM_17 1
 175 #  endif
 176 #  define _LIBCPP_INTRODUCED_IN_LLVM_17_ATTRIBUTE                                                                 \
 177     __attribute__((availability(macos, strict, introduced = 14.4)))                                               \
 178     __attribute__((availability(ios, strict, introduced = 17.4)))                                                 \
 179     __attribute__((availability(tvos, strict, introduced = 17.4)))                                                \
 180     __attribute__((availability(watchos, strict, introduced = 10.4)))                                             \
 181     __attribute__((availability(bridgeos, strict, introduced = 8.4)))                                             \
 182     __attribute__((availability(driverkit, strict, introduced = 23.4)))
 183
 184 // LLVM 16
 185 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 140000) ||       \
 186       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 170000) ||     \
 187       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 170000) ||             \
 188       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 100000) ||       \
 189       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 80000) ||      \
 190       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 230000)
 191 #    define _LIBCPP_INTRODUCED_IN_LLVM_16 0
 192 #  else
 193 #    define _LIBCPP_INTRODUCED_IN_LLVM_16 1
 194 #  endif
 195 #  define _LIBCPP_INTRODUCED_IN_LLVM_16_ATTRIBUTE                                                                 \
 196     __attribute__((availability(macos, strict, introduced = 14.0)))                                               \
 197     __attribute__((availability(ios, strict, introduced = 17.0)))                                                 \
 198     __attribute__((availability(tvos, strict, introduced = 17.0)))                                                \
 199     __attribute__((availability(watchos, strict, introduced = 10.0)))                                             \
 200     __attribute__((availability(bridgeos, strict, introduced = 8.0)))                                             \
 201     __attribute__((availability(driverkit, strict, introduced = 23.0)))
 202
 203 // LLVM 15
 204 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 130400) ||   \
 205       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 160500) || \
 206       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 160500) ||         \
 207       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 90500) ||    \
 208       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 70500) ||  \
 209       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 220400)
 210 #    define _LIBCPP_INTRODUCED_IN_LLVM_15 0
 211 #  else
 212 #    define _LIBCPP_INTRODUCED_IN_LLVM_15 1
 213 #  endif
 214 #  define _LIBCPP_INTRODUCED_IN_LLVM_15_ATTRIBUTE                                                                 \
 215     __attribute__((availability(macos, strict, introduced = 13.4)))                                               \
 216     __attribute__((availability(ios, strict, introduced = 16.5)))                                                 \
 217     __attribute__((availability(tvos, strict, introduced = 16.5)))                                                \
 218     __attribute__((availability(watchos, strict, introduced = 9.5)))                                              \
 219     __attribute__((availability(bridgeos, strict, introduced = 7.5)))                                             \
 220     __attribute__((availability(driverkit, strict, introduced = 22.4)))
 221
 222 // LLVM 14
 223 #  define _LIBCPP_INTRODUCED_IN_LLVM_14 _LIBCPP_INTRODUCED_IN_LLVM_15
 224 #  define _LIBCPP_INTRODUCED_IN_LLVM_14_ATTRIBUTE _LIBCPP_INTRODUCED_IN_LLVM_15_ATTRIBUTE
 225
 226 // LLVM 13
 227 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 130000) ||   \
 228       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 160000) || \
 229       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 160000) ||         \
 230       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 90000) ||    \
 231       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 70000) ||  \
 232       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 220000)
 233 #    define _LIBCPP_INTRODUCED_IN_LLVM_13 0
 234 #  else
 235 #    define _LIBCPP_INTRODUCED_IN_LLVM_13 1
 236 #  endif
 237 #  define _LIBCPP_INTRODUCED_IN_LLVM_13_ATTRIBUTE                                                                 \
 238     __attribute__((availability(macos, strict, introduced = 13.0)))                                               \
 239     __attribute__((availability(ios, strict, introduced = 16.0)))                                                 \
 240     __attribute__((availability(tvos, strict, introduced = 16.0)))                                                \
 241     __attribute__((availability(watchos, strict, introduced = 9.0)))                                              \
 242     __attribute__((availability(bridgeos, strict, introduced = 7.0)))                                             \
 243     __attribute__((availability(driverkit, strict, introduced = 22.0)))
 244
 245 // LLVM 12
 246 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 120300)   ||     \
 247       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 150300) ||     \
 248       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 150300)         ||     \
 249       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 80300)    ||     \
 250       (defined(__ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_BRIDGE_OS_VERSION_MIN_REQUIRED__ < 60000)  ||     \
 251       (defined(__ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_DRIVERKIT_VERSION_MIN_REQUIRED__ < 210300)
 252 #    define _LIBCPP_INTRODUCED_IN_LLVM_12 0
 253 #  else
 254 #    define _LIBCPP_INTRODUCED_IN_LLVM_12 1
 255 #  endif
 256 #  define _LIBCPP_INTRODUCED_IN_LLVM_12_ATTRIBUTE                                                                 \
 257     __attribute__((availability(macos, strict, introduced = 12.3)))                                               \
 258     __attribute__((availability(ios, strict, introduced = 15.3)))                                                 \
 259     __attribute__((availability(tvos, strict, introduced = 15.3)))                                                \
 260     __attribute__((availability(watchos, strict, introduced = 8.3)))                                              \
 261     __attribute__((availability(bridgeos, strict, introduced = 6.0)))                                             \
 262     __attribute__((availability(driverkit, strict, introduced = 21.3)))
 263
 264 // LLVM 11
 265 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 110000) ||   \
 266       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 140000) || \
 267       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 140000) ||         \
 268       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 70000)
 269 #    define _LIBCPP_INTRODUCED_IN_LLVM_11 0
 270 #  else
 271 #    define _LIBCPP_INTRODUCED_IN_LLVM_11 1
 272 #  endif
 273 #  define _LIBCPP_INTRODUCED_IN_LLVM_11_ATTRIBUTE                                                                 \
 274     __attribute__((availability(macos, strict, introduced = 11.0)))                                               \
 275     __attribute__((availability(ios, strict, introduced = 14.0)))                                                 \
 276     __attribute__((availability(tvos, strict, introduced = 14.0)))                                                \
 277     __attribute__((availability(watchos, strict, introduced = 7.0)))
 278
 279 // LLVM 10
 280 #  define _LIBCPP_INTRODUCED_IN_LLVM_10 _LIBCPP_INTRODUCED_IN_LLVM_11
 281 #  define _LIBCPP_INTRODUCED_IN_LLVM_10_ATTRIBUTE _LIBCPP_INTRODUCED_IN_LLVM_11_ATTRIBUTE
 282
 283 // LLVM 9
 284 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101500) ||   \
 285       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 130000) || \
 286       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 130000) ||         \
 287       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 60000)
 288 #    define _LIBCPP_INTRODUCED_IN_LLVM_9 0
 289 #  else
 290 #    define _LIBCPP_INTRODUCED_IN_LLVM_9 1
 291 #  endif
 292 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE                                                                  \
 293     __attribute__((availability(macos, strict, introduced = 10.15)))                                              \
 294     __attribute__((availability(ios, strict, introduced = 13.0)))                                                 \
 295     __attribute__((availability(tvos, strict, introduced = 13.0)))                                                \
 296     __attribute__((availability(watchos, strict, introduced = 6.0)))
 297 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_PUSH                                                                            \
 298     _Pragma("clang attribute push(__attribute__((availability(macos,strict,introduced=10.15))), apply_to=any(function,record))") \
 299     _Pragma("clang attribute push(__attribute__((availability(ios,strict,introduced=13.0))), apply_to=any(function,record))")    \
 300     _Pragma("clang attribute push(__attribute__((availability(tvos,strict,introduced=13.0))), apply_to=any(function,record))")   \
 301     _Pragma("clang attribute push(__attribute__((availability(watchos,strict,introduced=6.0))), apply_to=any(function,record))")
 302 #  define _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_POP                                                                    \
 303     _Pragma("clang attribute pop") \
 304     _Pragma("clang attribute pop") \
 305     _Pragma("clang attribute pop") \
 306     _Pragma("clang attribute pop")
 307
 308 // LLVM 4
 309 #  if defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 50000
 310 #    define _LIBCPP_INTRODUCED_IN_LLVM_4 0
 311 #  else
 312 #    define _LIBCPP_INTRODUCED_IN_LLVM_4 1
 313 #  endif
 314 #  define _LIBCPP_INTRODUCED_IN_LLVM_4_ATTRIBUTE __attribute__((availability(watchos, strict, introduced = 5.0)))
 315
 316 // clang-format on
 317
 318 #else
 319
 320 // ...New vendors can add availability markup here...
 321
 322 #  error                                                                                                               \
 323       "It looks like you're trying to enable vendor availability markup, but you haven't defined the corresponding macros yet!"
 324
 325 #endif
 326
 327 // These macros control the availability of std::bad_optional_access and
 328 // other exception types. These were put in the shared library to prevent
 329 // code bloat from every user program defining the vtable for these exception
 330 // types.
 331 //
 332 // Note that when exceptions are disabled, the methods that normally throw
 333 // these exceptions can be used even on older deployment targets, but those
 334 // methods will abort instead of throwing.
 335 #define _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4
 336 #define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4_ATTRIBUTE
 337
 338 #define _LIBCPP_AVAILABILITY_HAS_BAD_VARIANT_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4
 339 #define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4_ATTRIBUTE
 340
 341 #define _LIBCPP_AVAILABILITY_HAS_BAD_ANY_CAST _LIBCPP_INTRODUCED_IN_LLVM_4
 342 #define _LIBCPP_AVAILABILITY_BAD_ANY_CAST _LIBCPP_INTRODUCED_IN_LLVM_4_ATTRIBUTE
 343
 344 // These macros control the availability of all parts of <filesystem> that
 345 // depend on something in the dylib.
 346 #define _LIBCPP_AVAILABILITY_HAS_FILESYSTEM_LIBRARY _LIBCPP_INTRODUCED_IN_LLVM_9
 347 #define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE
 348 #define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_PUSH _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_PUSH
 349 #define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_POP _LIBCPP_INTRODUCED_IN_LLVM_9_ATTRIBUTE_POP
 350
 351 // This controls the availability of the C++20 synchronization library,
 352 // which requires shared library support for various operations
 353 // (see libcxx/src/atomic.cpp). This includes <barier>, <latch>,
 354 // <semaphore>, and notification functions on std::atomic.
 355 #define _LIBCPP_AVAILABILITY_HAS_SYNC _LIBCPP_INTRODUCED_IN_LLVM_11
 356 #define _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INTRODUCED_IN_LLVM_11_ATTRIBUTE
 357
 358 // Enable additional explicit instantiations of iostreams components. This
 359 // reduces the number of weak definitions generated in programs that use
 360 // iostreams by providing a single strong definition in the shared library.
 361 //
 362 // TODO: Enable additional explicit instantiations on GCC once it supports exclude_from_explicit_instantiation,
 363 //       or once libc++ doesn't use the attribute anymore.
 364 // TODO: Enable them on Windows once https://llvm.org/PR41018 has been fixed.
 365 #if !defined(_LIBCPP_COMPILER_GCC) && !defined(_WIN32)
 366 #  define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 _LIBCPP_INTRODUCED_IN_LLVM_12
 367 #else
 368 #  define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 0
 369 #endif
 370
 371 // This controls the availability of floating-point std::to_chars functions.
 372 // These overloads were added later than the integer overloads.
 373 #define _LIBCPP_AVAILABILITY_HAS_TO_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_14
 374 #define _LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_14_ATTRIBUTE
 375
 376 // This controls whether the library claims to provide a default verbose
 377 // termination function, and consequently whether the headers will try
 378 // to use it when the mechanism isn't overriden at compile-time.
 379 #define _LIBCPP_AVAILABILITY_HAS_VERBOSE_ABORT _LIBCPP_INTRODUCED_IN_LLVM_15
 380 #define _LIBCPP_AVAILABILITY_VERBOSE_ABORT _LIBCPP_INTRODUCED_IN_LLVM_15_ATTRIBUTE
 381
 382 // This controls the availability of the C++17 std::pmr library,
 383 // which is implemented in large part in the built library.
 384 //
 385 // TODO: Enable std::pmr markup once https://github.com/llvm/llvm-project/issues/40340 has been fixed
 386 //       Until then, it is possible for folks to try to use `std::pmr` when back-deploying to targets that don't support
 387 //       it and it'll be a load-time error, but we don't have a good alternative because the library won't compile if we
 388 //       use availability annotations until that bug has been fixed.
 389 #define _LIBCPP_AVAILABILITY_HAS_PMR _LIBCPP_INTRODUCED_IN_LLVM_16
 390 #define _LIBCPP_AVAILABILITY_PMR
 391
 392 // These macros controls the availability of __cxa_init_primary_exception
 393 // in the built library, which std::make_exception_ptr might use
 394 // (see libcxx/include/__exception/exception_ptr.h).
 395 #define _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION _LIBCPP_INTRODUCED_IN_LLVM_18
 396 #define _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION _LIBCPP_INTRODUCED_IN_LLVM_18_ATTRIBUTE
 397
 398 // This controls the availability of C++23 <print>, which
 399 // has a dependency on the built library (it needs access to
 400 // the underlying buffer types of std::cout, std::cerr, and std::clog.
 401 #define _LIBCPP_AVAILABILITY_HAS_PRINT _LIBCPP_INTRODUCED_IN_LLVM_18
 402 #define _LIBCPP_AVAILABILITY_PRINT _LIBCPP_INTRODUCED_IN_LLVM_18_ATTRIBUTE
 403
 404 // This controls the availability of the C++20 time zone database.
 405 // The parser code is built in the library.
 406 #define _LIBCPP_AVAILABILITY_HAS_TZDB _LIBCPP_INTRODUCED_IN_LLVM_19
 407 #define _LIBCPP_AVAILABILITY_TZDB _LIBCPP_INTRODUCED_IN_LLVM_19_ATTRIBUTE
 408
 409 // These macros determine whether we assume that std::bad_function_call and
 410 // std::bad_expected_access provide a key function in the dylib. This allows
 411 // centralizing their vtable and typeinfo instead of having all TUs provide
 412 // a weak definition that then gets deduplicated.
 413 #define _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19
 414 #define _LIBCPP_AVAILABILITY_BAD_FUNCTION_CALL_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19_ATTRIBUTE
 415 #define _LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19
 416 #define _LIBCPP_AVAILABILITY_BAD_EXPECTED_ACCESS_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19_ATTRIBUTE
 417
 418 // This controls the availability of floating-point std::from_chars functions.
 419 // These overloads were added later than the integer overloads.
 420 #define _LIBCPP_AVAILABILITY_HAS_FROM_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_20
 421 #define _LIBCPP_AVAILABILITY_FROM_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_20_ATTRIBUTE
 422
 423 // Define availability attributes that depend on _LIBCPP_HAS_EXCEPTIONS.
 424 // Those are defined in terms of the availability attributes above, and
 425 // should not be vendor-specific.
 426 #if !_LIBCPP_HAS_EXCEPTIONS
 427 #  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
 428 #  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
 429 #  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
 430 #else
 431 #  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST _LIBCPP_AVAILABILITY_BAD_ANY_CAST
 432 #  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
 433 #  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
 434 #endif
 435
 436 // Define availability attributes that depend on both
 437 // _LIBCPP_HAS_EXCEPTIONS and _LIBCPP_HAS_RTTI.
 438 #if !_LIBCPP_HAS_EXCEPTIONS || !_LIBCPP_HAS_RTTI
 439 #  undef _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION
 440 #  undef _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION
 441 #  define _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION 0
 442 #  define _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION
 443 #endif
 444
 445 #endif // _LIBCPP___CONFIGURATION_AVAILABILITY_H