[libcxx-commits] [libcxx] 182f5e9 - [libc++] Reformulate availability in terms of LLVM releases (#87563)

via libcxx-commits libcxx-commits at lists.llvm.org
Thu Apr 25 06:27:06 PDT 2024


Author: Louis Dionne
Date: 2024-04-25T09:27:02-04:00
New Revision: 182f5e9b2f034bf8a3a6dd8a80e8fe7d8292e411

URL: https://github.com/llvm/llvm-project/commit/182f5e9b2f034bf8a3a6dd8a80e8fe7d8292e411
DIFF: https://github.com/llvm/llvm-project/commit/182f5e9b2f034bf8a3a6dd8a80e8fe7d8292e411.diff

LOG: [libc++] Reformulate availability in terms of LLVM releases (#87563)

To make it easier to maintain the availability macros for both upstream
developers and vendors, this patch reformulates availability macros as a
function of the upstream LLVM release that a feature was introduced in.
This way, upstream developers can easily use the appropriate LLVM
version, and vendors can simply fill in the platform version(s) in which
a LLVM version landed.

Added: 
    

Modified: 
    libcxx/include/__availability

Removed: 
    


################################################################################
diff  --git a/libcxx/include/__availability b/libcxx/include/__availability
index aa761eb5bfe5e3..7a02ae00846bfa 100644
--- a/libcxx/include/__availability
+++ b/libcxx/include/__availability
@@ -28,30 +28,32 @@
 // that previously released library. Normally, this would be a load-time error
 // when one tries to launch the program against the older library.
 //
-// For example, the filesystem library was introduced in the dylib in macOS 10.15.
-// If a user compiles on a macOS 10.15 host but targets macOS 10.13 with their
-// program, the compiler would normally not complain (because the required
-// declarations are in the headers), but the dynamic loader would fail to find
-// the symbols when actually trying to launch the program on macOS 10.13. To
-// turn this into a compile-time issue instead, declarations are annotated with
-// when they were introduced, and the compiler can produce a diagnostic if the
-// program references something that isn't available on the deployment target.
+// For example, the filesystem library was introduced in the dylib in LLVM 9.
+// On Apple platforms, this corresponds to macOS 10.15. If a user compiles on
+// a macOS 10.15 host but targets macOS 10.13 with their program, the compiler
+// would normally not complain (because the required declarations are in the
+// headers), but the dynamic loader would fail to find the symbols when actually
+// trying to launch the program on macOS 10.13. To turn this into a compile-time
+// issue instead, declarations are annotated with when they were introduced, and
+// the compiler can produce a diagnostic if the program references something that
+// isn't available on the deployment target.
 //
 // This mechanism is general in nature, and any vendor can add their markup to
 // the library (see below). Whenever a new feature is added that requires support
 // in the shared library, two macros are added below to allow marking the feature
 // as unavailable:
-// 1. A macro named `_LIBCPP_AVAILABILITY_HAS_NO_<feature>` which must be defined
-//    exactly when compiling for a target that doesn't support the feature.
-// 2. A macro named `_LIBCPP_AVAILABILITY_<feature>`, which must always be defined
-//    and must expand to the proper availability attribute for the platform.
+// 1. A macro named `_LIBCPP_AVAILABILITY_HAS_<feature>` which must be defined
+//    to `_LIBCPP_INTRODUCED_IN_<version>` for the appropriate LLVM version.
+// 2. A macro named `_LIBCPP_AVAILABILITY_<feature>`, which must be defined to
+//    `_LIBCPP_INTRODUCED_IN_<version>_MARKUP` for the appropriate LLVM version.
 //
 // When vendors decide to ship the feature as part of their shared library, they
-// can update these macros appropriately for their platform, and the library will
-// use those to provide an optimal user experience.
+// can update the `_LIBCPP_INTRODUCED_IN_<version>` macro (and the markup counterpart)
+// based on the platform version they shipped that version of LLVM in. The library
+// will then use this markup to provide an optimal user experience on these platforms.
 //
 // Furthermore, many features in the standard library have corresponding
-// feature-test macros. The `_LIBCPP_AVAILABILITY_HAS_NO_<feature>` macros
+// feature-test macros. The `_LIBCPP_AVAILABILITY_HAS_<feature>` macros
 // are checked by the corresponding feature-test macros generated by
 // generate_feature_test_macro_components.py to ensure that the library
 // doesn't announce a feature as being implemented if it is unavailable on
@@ -74,237 +76,181 @@
 
 // Availability markup is disabled when building the library, or when a non-Clang
 // compiler is used because only Clang supports the necessary attributes.
-// doesn't support the proper attributes.
 #if defined(_LIBCPP_BUILDING_LIBRARY) || defined(_LIBCXXABI_BUILDING_LIBRARY) || !defined(_LIBCPP_COMPILER_CLANG_BASED)
 #  if !defined(_LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS)
 #    define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS
 #  endif
 #endif
 
+// When availability annotations are disabled, we take for granted that features introduced
+// in all versions of the library are available.
 #if defined(_LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS)
 
-// These macros control the availability of std::bad_optional_access and
-// other exception types. These were put in the shared library to prevent
-// code bloat from every user program defining the vtable for these exception
-// types.
-//
-// Note that when exceptions are disabled, the methods that normally throw
-// these exceptions can be used even on older deployment targets, but those
-// methods will abort instead of throwing.
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS 1
-#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_VARIANT_ACCESS 1
-#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
+#  define _LIBCPP_INTRODUCED_IN_LLVM_4 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP /* nothing */
 
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_ANY_CAST 1
-#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST
+#  define _LIBCPP_INTRODUCED_IN_LLVM_9 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP      /* nothing */
+#  define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_PUSH /* nothing */
+#  define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_POP  /* nothing */
 
-// These macros control the availability of all parts of <filesystem> that
-// depend on something in the dylib.
-#  define _LIBCPP_AVAILABILITY_HAS_FILESYSTEM_LIBRARY 1
-#  define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY
-#  define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_PUSH
-#  define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_POP
+#  define _LIBCPP_INTRODUCED_IN_LLVM_10 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_10_MARKUP /* nothing */
 
-// This controls the availability of the C++20 synchronization library,
-// which requires shared library support for various operations
-// (see libcxx/src/atomic.cpp). This includes <barier>, <latch>,
-// <semaphore>, and notification functions on std::atomic.
-#  define _LIBCPP_AVAILABILITY_HAS_SYNC 1
-#  define _LIBCPP_AVAILABILITY_SYNC
+#  define _LIBCPP_INTRODUCED_IN_LLVM_12 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_12_MARKUP /* nothing */
 
-// Enable additional explicit instantiations of iostreams components. This
-// reduces the number of weak definitions generated in programs that use
-// iostreams by providing a single strong definition in the shared library.
-//
-// TODO: Enable additional explicit instantiations on GCC once it supports exclude_from_explicit_instantiation,
-//       or once libc++ doesn't use the attribute anymore.
-// TODO: Enable them on Windows once https://llvm.org/PR41018 has been fixed.
-#  if !defined(_LIBCPP_COMPILER_GCC) && !defined(_WIN32)
-#    define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 1
-#  else
-#    define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 0
-#  endif
+#  define _LIBCPP_INTRODUCED_IN_LLVM_14 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_14_MARKUP /* nothing */
 
-// This controls the availability of floating-point std::to_chars functions.
-// These overloads were added later than the integer overloads.
-#  define _LIBCPP_AVAILABILITY_HAS_TO_CHARS_FLOATING_POINT 1
-#  define _LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT
+#  define _LIBCPP_INTRODUCED_IN_LLVM_15 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_15_MARKUP /* nothing */
 
-// This controls whether the library claims to provide a default verbose
-// termination function, and consequently whether the headers will try
-// to use it when the mechanism isn't overriden at compile-time.
-#  define _LIBCPP_AVAILABILITY_HAS_VERBOSE_ABORT 1
-#  define _LIBCPP_AVAILABILITY_VERBOSE_ABORT
+#  define _LIBCPP_INTRODUCED_IN_LLVM_16 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_16_MARKUP /* nothing */
 
-// This controls the availability of the C++17 std::pmr library,
-// which is implemented in large part in the built library.
-#  define _LIBCPP_AVAILABILITY_HAS_PMR 1
-#  define _LIBCPP_AVAILABILITY_PMR
+#  define _LIBCPP_INTRODUCED_IN_LLVM_18 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_18_MARKUP /* nothing */
 
-// These macros controls the availability of __cxa_init_primary_exception
-// in the built library, which std::make_exception_ptr might use
-// (see libcxx/include/__exception/exception_ptr.h).
-#  define _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION 1
-#  define _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION
-
-// This controls the availability of C++23 <print>, which
-// has a dependency on the built library (it needs access to
-// the underlying buffer types of std::cout, std::cerr, and std::clog.
-#  define _LIBCPP_AVAILABILITY_HAS_PRINT 1
-#  define _LIBCPP_AVAILABILITY_PRINT
-
-// This controls the availability of the C++20 time zone database.
-// The parser code is built in the library.
-#  define _LIBCPP_AVAILABILITY_HAS_TZDB 1
-#  define _LIBCPP_AVAILABILITY_TZDB
-
-// These macros determine whether we assume that std::bad_function_call and
-// std::bad_expected_access provide a key function in the dylib. This allows
-// centralizing their vtable and typeinfo instead of having all TUs provide
-// a weak definition that then gets deduplicated.
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION 1
-#  define _LIBCPP_AVAILABILITY_BAD_FUNCTION_CALL_KEY_FUNCTION
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION 1
-#  define _LIBCPP_AVAILABILITY_BAD_EXPECTED_ACCESS_KEY_FUNCTION
+#  define _LIBCPP_INTRODUCED_IN_LLVM_19 1
+#  define _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP /* nothing */
 
 #elif defined(__APPLE__)
 
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS                                                                 \
-    (!defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) || __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ >= 50000)
-
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_VARIANT_ACCESS _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_ANY_CAST _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS
-
-#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS __attribute__((availability(watchos, strict, introduced = 5.0)))
-#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-
-// TODO: Update once this is released
-#  define _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION 0
-#  define _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION __attribute__((unavailable))
+// LLVM 4
+#  if defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 50000
+#    define _LIBCPP_INTRODUCED_IN_LLVM_4 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP __attribute__((availability(watchos, strict, introduced = 5.0)))
+#  else
+#    define _LIBCPP_INTRODUCED_IN_LLVM_4 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP /* nothing */
+#  endif
 
-// <filesystem>
+// LLVM 9
 // clang-format off
 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101500) ||   \
       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 130000) || \
       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 130000) ||         \
       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 60000)
 // clang-format on
-#    define _LIBCPP_AVAILABILITY_HAS_FILESYSTEM_LIBRARY 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP                                                                        \
+      __attribute__((availability(macos, strict, introduced = 10.15)))                                                 \
+      __attribute__((availability(ios, strict, introduced = 13.0)))                                                    \
+      __attribute__((availability(tvos, strict, introduced = 13.0)))                                                   \
+      __attribute__((availability(watchos, strict, introduced = 6.0)))
+// clang-format off
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_PUSH                                                                               \
+      _Pragma("clang attribute push(__attribute__((availability(macos,strict,introduced=10.15))), apply_to=any(function,record))") \
+      _Pragma("clang attribute push(__attribute__((availability(ios,strict,introduced=13.0))), apply_to=any(function,record))")    \
+      _Pragma("clang attribute push(__attribute__((availability(tvos,strict,introduced=13.0))), apply_to=any(function,record))")   \
+      _Pragma("clang attribute push(__attribute__((availability(watchos,strict,introduced=6.0))), apply_to=any(function,record))")
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_POP                                                                    \
+      _Pragma("clang attribute pop") \
+      _Pragma("clang attribute pop") \
+      _Pragma("clang attribute pop") \
+      _Pragma("clang attribute pop")
+// clang-format on
 #  else
-#    define _LIBCPP_AVAILABILITY_HAS_FILESYSTEM_LIBRARY 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP      /* nothing */
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_PUSH /* nothing */
+#    define _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_POP  /* nothing */
 #  endif
-#  define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY                                                                      \
-    __attribute__((availability(macos, strict, introduced = 10.15)))                                                   \
-    __attribute__((availability(ios, strict, introduced = 13.0)))                                                      \
-    __attribute__((availability(tvos, strict, introduced = 13.0)))                                                     \
-    __attribute__((availability(watchos, strict, introduced = 6.0)))
+
+// LLVM 10
 // clang-format off
-#   define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_PUSH                                 \
-        _Pragma("clang attribute push(__attribute__((availability(macos,strict,introduced=10.15))), apply_to=any(function,record))") \
-        _Pragma("clang attribute push(__attribute__((availability(ios,strict,introduced=13.0))), apply_to=any(function,record))")    \
-        _Pragma("clang attribute push(__attribute__((availability(tvos,strict,introduced=13.0))), apply_to=any(function,record))")   \
-        _Pragma("clang attribute push(__attribute__((availability(watchos,strict,introduced=6.0))), apply_to=any(function,record))")
-#   define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_POP                                  \
-        _Pragma("clang attribute pop")                                          \
-        _Pragma("clang attribute pop")                                          \
-        _Pragma("clang attribute pop")                                          \
-        _Pragma("clang attribute pop")
+#  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 110000) ||   \
+      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 140000) || \
+      (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 140000) ||         \
+      (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 70000)
 // clang-format on
+#    define _LIBCPP_INTRODUCED_IN_LLVM_10 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_10_MARKUP                                                                       \
+      __attribute__((availability(macos, strict, introduced = 11.0)))                                                  \
+      __attribute__((availability(ios, strict, introduced = 14.0)))                                                    \
+      __attribute__((availability(tvos, strict, introduced = 14.0)))                                                   \
+      __attribute__((availability(watchos, strict, introduced = 7.0)))
+#  else
+#    define _LIBCPP_INTRODUCED_IN_LLVM_10 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_10_MARKUP /* nothing */
+#  endif
 
-// std::to_chars(floating-point)
+// LLVM 12
 // clang-format off
-#  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 130300) ||   \
-      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 160300) || \
-      (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 160300) ||         \
-      (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 90300)
+#  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 120000)   || \
+      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 150000) || \
+      (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 150000)         || \
+      (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 80000)
 // clang-format on
-#    define _LIBCPP_AVAILABILITY_HAS_TO_CHARS_FLOATING_POINT 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_12 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_12_MARKUP                                                                       \
+      __attribute__((availability(macos, strict, introduced = 12.0)))                                                  \
+      __attribute__((availability(ios, strict, introduced = 15.0)))                                                    \
+      __attribute__((availability(tvos, strict, introduced = 15.0)))                                                   \
+      __attribute__((availability(watchos, strict, introduced = 8.0)))
 #  else
-#    define _LIBCPP_AVAILABILITY_HAS_TO_CHARS_FLOATING_POINT 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_12 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_12_MARKUP /* nothing */
 #  endif
-#  define _LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT                                                                 \
-    __attribute__((availability(macos, strict, introduced = 13.3)))                                                    \
-    __attribute__((availability(ios, strict, introduced = 16.3)))                                                      \
-    __attribute__((availability(tvos, strict, introduced = 16.3)))                                                     \
-    __attribute__((availability(watchos, strict, introduced = 9.3)))
 
-// c++20 synchronization library
+// LLVM 14
 // clang-format off
-#   if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 110000) ||   \
-       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 140000) || \
-       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 140000) ||         \
-       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 70000)
+#  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 130400) ||   \
+      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 160500) || \
+      (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 160500) ||         \
+      (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 90500)
 // clang-format on
-#    define _LIBCPP_AVAILABILITY_HAS_SYNC 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_14 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_14_MARKUP                                                                       \
+      __attribute__((availability(macos, strict, introduced = 13.4)))                                                  \
+      __attribute__((availability(ios, strict, introduced = 16.5)))                                                    \
+      __attribute__((availability(tvos, strict, introduced = 16.5)))                                                   \
+      __attribute__((availability(watchos, strict, introduced = 9.5)))
 #  else
-#    define _LIBCPP_AVAILABILITY_HAS_SYNC 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_14 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_14_MARKUP /* nothing */
 #  endif
-#  define _LIBCPP_AVAILABILITY_SYNC                                                                                    \
-    __attribute__((availability(macos, strict, introduced = 11.0)))                                                    \
-    __attribute__((availability(ios, strict, introduced = 14.0)))                                                      \
-    __attribute__((availability(tvos, strict, introduced = 14.0)))                                                     \
-    __attribute__((availability(watchos, strict, introduced = 7.0)))
-
-// __libcpp_verbose_abort
-// TODO: Update once this is released
-#  define _LIBCPP_AVAILABILITY_HAS_VERBOSE_ABORT 0
 
-#  define _LIBCPP_AVAILABILITY_VERBOSE_ABORT __attribute__((unavailable))
-
-// std::pmr
+// LLVM 15-16
+#  define _LIBCPP_INTRODUCED_IN_LLVM_15 _LIBCPP_INTRODUCED_IN_LLVM_16
+#  define _LIBCPP_INTRODUCED_IN_LLVM_15_MARKUP _LIBCPP_INTRODUCED_IN_LLVM_16_MARKUP
 // clang-format off
 #  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 140000) ||   \
       (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 170000) || \
       (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 170000) ||         \
       (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 100000)
 // clang-format on
-#    define _LIBCPP_AVAILABILITY_HAS_PMR 0
-#  else
-#    define _LIBCPP_AVAILABILITY_HAS_PMR 1
-#  endif
-// TODO: Enable std::pmr markup once https://github.com/llvm/llvm-project/issues/40340 has been fixed
-//       Until then, it is possible for folks to try to use `std::pmr` when back-deploying to targets that don't support
-//       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
-//       use availability annotations until that bug has been fixed.
-#  if 0
-#    define _LIBCPP_AVAILABILITY_PMR                                                                                   \
+#    define _LIBCPP_INTRODUCED_IN_LLVM_16 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_16_MARKUP                                                                       \
       __attribute__((availability(macos, strict, introduced = 14.0)))                                                  \
       __attribute__((availability(ios, strict, introduced = 17.0)))                                                    \
       __attribute__((availability(tvos, strict, introduced = 17.0)))                                                   \
       __attribute__((availability(watchos, strict, introduced = 10.0)))
 #  else
-#    define _LIBCPP_AVAILABILITY_PMR
+#    define _LIBCPP_INTRODUCED_IN_LLVM_16 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_16_MARKUP /* nothing */
 #  endif
 
-#  define _LIBCPP_AVAILABILITY_HAS_TZDB 0
-#  define _LIBCPP_AVAILABILITY_TZDB __attribute__((unavailable))
-
-// Warning: This availability macro works 
diff erently than the other macros.
-// The dylib part of print is not needed on Apple platforms. Therefore when
-// the macro is not available the code calling the dylib is commented out.
-// The macro _LIBCPP_AVAILABILITY_PRINT is not used.
-#  define _LIBCPP_AVAILABILITY_HAS_PRINT 0
-#  define _LIBCPP_AVAILABILITY_PRINT __attribute__((unavailable))
-
-// clang-format off
-#  if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 120000)   || \
-      (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 150000) || \
-      (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 150000)         || \
-      (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 80000)
-// clang-format on
-#    define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 0
+// LLVM 18
+// TODO: Fill this in
+#  if 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_18 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_18_MARKUP __attribute__((unavailable))
 #  else
-#    define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_18 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_18_MARKUP /* nothing */
 #  endif
 
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION 0
-#  define _LIBCPP_AVAILABILITY_BAD_FUNCTION_CALL_KEY_FUNCTION __attribute__((unavailable))
-
-#  define _LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION 0
-#  define _LIBCPP_AVAILABILITY_BAD_EXPECTED_ACCESS_KEY_FUNCTION __attribute__((unavailable))
+// LLVM 19
+// TODO: Fill this in
+#  if 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_19 0
+#    define _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP __attribute__((unavailable))
+#  else
+#    define _LIBCPP_INTRODUCED_IN_LLVM_19 1
+#    define _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP /* nothing */
+#  endif
 
 #else
 
@@ -315,6 +261,97 @@
 
 #endif
 
+// These macros control the availability of std::bad_optional_access and
+// other exception types. These were put in the shared library to prevent
+// code bloat from every user program defining the vtable for these exception
+// types.
+//
+// Note that when exceptions are disabled, the methods that normally throw
+// these exceptions can be used even on older deployment targets, but those
+// methods will abort instead of throwing.
+#define _LIBCPP_AVAILABILITY_HAS_BAD_OPTIONAL_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4
+#define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP
+
+#define _LIBCPP_AVAILABILITY_HAS_BAD_VARIANT_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4
+#define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP
+
+#define _LIBCPP_AVAILABILITY_HAS_BAD_ANY_CAST _LIBCPP_INTRODUCED_IN_LLVM_4
+#define _LIBCPP_AVAILABILITY_BAD_ANY_CAST _LIBCPP_INTRODUCED_IN_LLVM_4_MARKUP
+
+// These macros control the availability of all parts of <filesystem> that
+// depend on something in the dylib.
+#define _LIBCPP_AVAILABILITY_HAS_FILESYSTEM_LIBRARY _LIBCPP_INTRODUCED_IN_LLVM_9
+#define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP
+#define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_PUSH _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_PUSH
+#define _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY_POP _LIBCPP_INTRODUCED_IN_LLVM_9_MARKUP_POP
+
+// This controls the availability of the C++20 synchronization library,
+// which requires shared library support for various operations
+// (see libcxx/src/atomic.cpp). This includes <barier>, <latch>,
+// <semaphore>, and notification functions on std::atomic.
+#define _LIBCPP_AVAILABILITY_HAS_SYNC _LIBCPP_INTRODUCED_IN_LLVM_10
+#define _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INTRODUCED_IN_LLVM_10_MARKUP
+
+// Enable additional explicit instantiations of iostreams components. This
+// reduces the number of weak definitions generated in programs that use
+// iostreams by providing a single strong definition in the shared library.
+//
+// TODO: Enable additional explicit instantiations on GCC once it supports exclude_from_explicit_instantiation,
+//       or once libc++ doesn't use the attribute anymore.
+// TODO: Enable them on Windows once https://llvm.org/PR41018 has been fixed.
+#if !defined(_LIBCPP_COMPILER_GCC) && !defined(_WIN32)
+#  define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 _LIBCPP_INTRODUCED_IN_LLVM_12
+#else
+#  define _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1 0
+#endif
+
+// This controls the availability of floating-point std::to_chars functions.
+// These overloads were added later than the integer overloads.
+#define _LIBCPP_AVAILABILITY_HAS_TO_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_14
+#define _LIBCPP_AVAILABILITY_TO_CHARS_FLOATING_POINT _LIBCPP_INTRODUCED_IN_LLVM_14_MARKUP
+
+// This controls whether the library claims to provide a default verbose
+// termination function, and consequently whether the headers will try
+// to use it when the mechanism isn't overriden at compile-time.
+#define _LIBCPP_AVAILABILITY_HAS_VERBOSE_ABORT _LIBCPP_INTRODUCED_IN_LLVM_15
+#define _LIBCPP_AVAILABILITY_VERBOSE_ABORT _LIBCPP_INTRODUCED_IN_LLVM_15_MARKUP
+
+// This controls the availability of the C++17 std::pmr library,
+// which is implemented in large part in the built library.
+//
+// TODO: Enable std::pmr markup once https://github.com/llvm/llvm-project/issues/40340 has been fixed
+//       Until then, it is possible for folks to try to use `std::pmr` when back-deploying to targets that don't support
+//       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
+//       use availability annotations until that bug has been fixed.
+#define _LIBCPP_AVAILABILITY_HAS_PMR _LIBCPP_INTRODUCED_IN_LLVM_16
+#define _LIBCPP_AVAILABILITY_PMR
+
+// These macros controls the availability of __cxa_init_primary_exception
+// in the built library, which std::make_exception_ptr might use
+// (see libcxx/include/__exception/exception_ptr.h).
+#define _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION _LIBCPP_INTRODUCED_IN_LLVM_18
+#define _LIBCPP_AVAILABILITY_INIT_PRIMARY_EXCEPTION _LIBCPP_INTRODUCED_IN_LLVM_18_MARKUP
+
+// This controls the availability of C++23 <print>, which
+// has a dependency on the built library (it needs access to
+// the underlying buffer types of std::cout, std::cerr, and std::clog.
+#define _LIBCPP_AVAILABILITY_HAS_PRINT _LIBCPP_INTRODUCED_IN_LLVM_18
+#define _LIBCPP_AVAILABILITY_PRINT _LIBCPP_INTRODUCED_IN_LLVM_18_MARKUP
+
+// This controls the availability of the C++20 time zone database.
+// The parser code is built in the library.
+#define _LIBCPP_AVAILABILITY_HAS_TZDB _LIBCPP_INTRODUCED_IN_LLVM_19
+#define _LIBCPP_AVAILABILITY_TZDB _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP
+
+// These macros determine whether we assume that std::bad_function_call and
+// std::bad_expected_access provide a key function in the dylib. This allows
+// centralizing their vtable and typeinfo instead of having all TUs provide
+// a weak definition that then gets deduplicated.
+#  define _LIBCPP_AVAILABILITY_HAS_BAD_FUNCTION_CALL_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19
+#  define _LIBCPP_AVAILABILITY_BAD_FUNCTION_CALL_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP
+#  define _LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19
+#  define _LIBCPP_AVAILABILITY_BAD_EXPECTED_ACCESS_KEY_FUNCTION _LIBCPP_INTRODUCED_IN_LLVM_19_MARKUP
+
 // Define availability attributes that depend on _LIBCPP_HAS_NO_EXCEPTIONS.
 // Those are defined in terms of the availability attributes above, and
 // should not be vendor-specific.


        


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