xref: /llvm-project/libcxx/include/__cxx03/__config (revision b3ad84b534bf17311b92fbfe142c0542c6e95332)
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___CXX03___CONFIG
11#define _LIBCPP___CXX03___CONFIG
12
13#include <__cxx03/__configuration/abi.h>
14#include <__cxx03/__configuration/availability.h>
15#include <__cxx03/__configuration/compiler.h>
16#include <__cxx03/__configuration/config_site_shim.h>
17#include <__cxx03/__configuration/platform.h>
18
19#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
20#  pragma GCC system_header
21#endif
22
23#ifdef __cplusplus
24
25// The attributes supported by clang are documented at https://clang.llvm.org/docs/AttributeReference.html
26
27// _LIBCPP_VERSION represents the version of libc++, which matches the version of LLVM.
28// Given a LLVM release LLVM XX.YY.ZZ (e.g. LLVM 17.0.1 == 17.00.01), _LIBCPP_VERSION is
29// defined to XXYYZZ.
30#  define _LIBCPP_VERSION 190100
31
32#  define _LIBCPP_CONCAT_IMPL(_X, _Y) _X##_Y
33#  define _LIBCPP_CONCAT(_X, _Y) _LIBCPP_CONCAT_IMPL(_X, _Y)
34
35#  if __STDC_HOSTED__ == 0
36#    define _LIBCPP_FREESTANDING
37#  endif
38
39// HARDENING {
40
41// This is for backward compatibility -- make enabling `_LIBCPP_ENABLE_ASSERTIONS` (which predates hardening modes)
42// equivalent to setting the extensive mode. This is deprecated and will be removed in LLVM 20.
43#  ifdef _LIBCPP_ENABLE_ASSERTIONS
44#    warning "_LIBCPP_ENABLE_ASSERTIONS is deprecated, please use _LIBCPP_HARDENING_MODE instead"
45#    if _LIBCPP_ENABLE_ASSERTIONS != 0 && _LIBCPP_ENABLE_ASSERTIONS != 1
46#      error "_LIBCPP_ENABLE_ASSERTIONS must be set to 0 or 1"
47#    endif
48#    if _LIBCPP_ENABLE_ASSERTIONS
49#      define _LIBCPP_HARDENING_MODE _LIBCPP_HARDENING_MODE_EXTENSIVE
50#    endif
51#  endif
52
53// The library provides the macro `_LIBCPP_HARDENING_MODE` which can be set to one of the following values:
54//
55// - `_LIBCPP_HARDENING_MODE_NONE`;
56// - `_LIBCPP_HARDENING_MODE_FAST`;
57// - `_LIBCPP_HARDENING_MODE_EXTENSIVE`;
58// - `_LIBCPP_HARDENING_MODE_DEBUG`.
59//
60// These values have the following effects:
61//
62// - `_LIBCPP_HARDENING_MODE_NONE` -- sets the hardening mode to "none" which disables all runtime hardening checks;
63//
64// - `_LIBCPP_HARDENING_MODE_FAST` -- sets that hardening mode to "fast". The fast mode enables security-critical checks
65//   that can be done with relatively little runtime overhead in constant time;
66//
67// - `_LIBCPP_HARDENING_MODE_EXTENSIVE` -- sets the hardening mode to "extensive". The extensive mode is a superset of
68//   the fast mode that additionally enables checks that are relatively cheap and prevent common types of logic errors
69//   but are not necessarily security-critical;
70//
71// - `_LIBCPP_HARDENING_MODE_DEBUG` -- sets the hardening mode to "debug". The debug mode is a superset of the extensive
72//   mode and enables all checks available in the library, including internal assertions. Checks that are part of the
73//   debug mode can be very expensive and thus the debug mode is intended to be used for testing, not in production.
74
75// Inside the library, assertions are categorized so they can be cherry-picked based on the chosen hardening mode. These
76// macros are only for internal use -- users should only pick one of the high-level hardening modes described above.
77//
78// - `_LIBCPP_ASSERT_VALID_INPUT_RANGE` -- checks that ranges (whether expressed as an iterator pair, an iterator and
79//   a sentinel, an iterator and a count, or a `std::range`) given as input to library functions are valid:
80//   - the sentinel is reachable from the begin iterator;
81//   - TODO(hardening): both iterators refer to the same container.
82//
83// - `_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS` -- checks that any attempts to access a container element, whether through
84//   the container object or through an iterator, are valid and do not attempt to go out of bounds or otherwise access
85//   a non-existent element. For iterator checks to work, bounded iterators must be enabled in the ABI. Types like
86//   `optional` and `function` are considered one-element containers for the purposes of this check.
87//
88// - `_LIBCPP_ASSERT_NON_NULL` -- checks that the pointer being dereferenced is not null. On most modern platforms zero
89//   address does not refer to an actual location in memory, so a null pointer dereference would not compromize the
90//   memory security of a program (however, it is still undefined behavior that can result in strange errors due to
91//   compiler optimizations).
92//
93// - `_LIBCPP_ASSERT_NON_OVERLAPPING_RANGES` -- for functions that take several ranges as arguments, checks that the
94//   given ranges do not overlap.
95//
96// - `_LIBCPP_ASSERT_VALID_DEALLOCATION` -- checks that an attempt to deallocate memory is valid (e.g. the given object
97//   was allocated by the given allocator). Violating this category typically results in a memory leak.
98//
99// - `_LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL` -- checks that a call to an external API doesn't fail in
100//   an unexpected manner. This includes triggering documented cases of undefined behavior in an external library (like
101//   attempting to unlock an unlocked mutex in pthreads). Any API external to the library falls under this category
102//   (from system calls to compiler intrinsics). We generally don't expect these failures to compromize memory safety or
103//   otherwise create an immediate security issue.
104//
105// - `_LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR` -- checks any operations that exchange nodes between containers to make sure
106//   the containers have compatible allocators.
107//
108// - `_LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN` -- checks that the given argument is within the domain of valid arguments
109//   for the function. Violating this typically produces an incorrect result (e.g. the clamp algorithm returns the
110//   original value without clamping it due to incorrect functors) or puts an object into an invalid state (e.g.
111//   a string view where only a subset of elements is possible to access). This category is for assertions violating
112//   which doesn't cause any immediate issues in the library -- whatever the consequences are, they will happen in the
113//   user code.
114//
115// - `_LIBCPP_ASSERT_PEDANTIC` -- checks prerequisites which are imposed by the Standard, but violating which happens to
116//   be benign in our implementation.
117//
118// - `_LIBCPP_ASSERT_SEMANTIC_REQUIREMENT` -- checks that the given argument satisfies the semantic requirements imposed
119//   by the Standard. Typically, there is no simple way to completely prove that a semantic requirement is satisfied;
120//   thus, this would often be a heuristic check and it might be quite expensive.
121//
122// - `_LIBCPP_ASSERT_INTERNAL` -- checks that internal invariants of the library hold. These assertions don't depend on
123//   user input.
124//
125// - `_LIBCPP_ASSERT_UNCATEGORIZED` -- for assertions that haven't been properly classified yet.
126
127// clang-format off
128#  define _LIBCPP_HARDENING_MODE_NONE      (1 << 1)
129#  define _LIBCPP_HARDENING_MODE_FAST      (1 << 2)
130#  define _LIBCPP_HARDENING_MODE_EXTENSIVE (1 << 4) // Deliberately not ordered.
131#  define _LIBCPP_HARDENING_MODE_DEBUG     (1 << 3)
132// clang-format on
133
134#  ifndef _LIBCPP_HARDENING_MODE
135
136#    ifndef _LIBCPP_HARDENING_MODE_DEFAULT
137#      error _LIBCPP_HARDENING_MODE_DEFAULT is not defined. This definition should be set at configuration time in the \
138`__config_site` header, please make sure your installation of libc++ is not broken.
139#    endif
140
141#    define _LIBCPP_HARDENING_MODE _LIBCPP_HARDENING_MODE_DEFAULT
142#  endif
143
144#  if _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_NONE &&                                                         \
145      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_FAST &&                                                         \
146      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_EXTENSIVE &&                                                    \
147      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_DEBUG
148#    error _LIBCPP_HARDENING_MODE must be set to one of the following values: \
149_LIBCPP_HARDENING_MODE_NONE, \
150_LIBCPP_HARDENING_MODE_FAST, \
151_LIBCPP_HARDENING_MODE_EXTENSIVE, \
152_LIBCPP_HARDENING_MODE_DEBUG
153#  endif
154
155// } HARDENING
156
157#  define _LIBCPP_TOSTRING2(x) #x
158#  define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)
159
160// NOLINTNEXTLINE(libcpp-cpp-version-check)
161#  if __cplusplus < 201103L
162#    define _LIBCPP_CXX03_LANG
163#  endif
164
165#  ifndef __has_constexpr_builtin
166#    define __has_constexpr_builtin(x) 0
167#  endif
168
169// This checks wheter a Clang module is built
170#  ifndef __building_module
171#    define __building_module(...) 0
172#  endif
173
174// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
175// the compiler and '1' otherwise.
176#  ifndef __is_identifier
177#    define __is_identifier(__x) 1
178#  endif
179
180#  ifndef __has_declspec_attribute
181#    define __has_declspec_attribute(__x) 0
182#  endif
183
184#  define __has_keyword(__x) !(__is_identifier(__x))
185
186#  ifndef __has_warning
187#    define __has_warning(...) 0
188#  endif
189
190#  if !defined(_LIBCPP_COMPILER_CLANG_BASED) && __cplusplus < 201103L
191#    error "libc++ only supports C++03 with Clang-based compilers. Please enable C++11"
192#  endif
193
194// FIXME: ABI detection should be done via compiler builtin macros. This
195// is just a placeholder until Clang implements such macros. For now assume
196// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
197// and allow the user to explicitly specify the ABI to handle cases where this
198// heuristic falls short.
199#  if defined(_LIBCPP_ABI_FORCE_ITANIUM) && defined(_LIBCPP_ABI_FORCE_MICROSOFT)
200#    error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be defined"
201#  elif defined(_LIBCPP_ABI_FORCE_ITANIUM)
202#    define _LIBCPP_ABI_ITANIUM
203#  elif defined(_LIBCPP_ABI_FORCE_MICROSOFT)
204#    define _LIBCPP_ABI_MICROSOFT
205#  else
206#    if defined(_WIN32) && defined(_MSC_VER)
207#      define _LIBCPP_ABI_MICROSOFT
208#    else
209#      define _LIBCPP_ABI_ITANIUM
210#    endif
211#  endif
212
213#  if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
214#    define _LIBCPP_ABI_VCRUNTIME
215#  endif
216
217#  if __has_feature(experimental_library)
218#    ifndef _LIBCPP_ENABLE_EXPERIMENTAL
219#      define _LIBCPP_ENABLE_EXPERIMENTAL
220#    endif
221#  endif
222
223// Incomplete features get their own specific disabling flags. This makes it
224// easier to grep for target specific flags once the feature is complete.
225#  if !defined(_LIBCPP_ENABLE_EXPERIMENTAL) && !defined(_LIBCPP_BUILDING_LIBRARY)
226#    define _LIBCPP_HAS_NO_INCOMPLETE_PSTL
227#    define _LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN
228#    define _LIBCPP_HAS_NO_EXPERIMENTAL_TZDB
229#    define _LIBCPP_HAS_NO_EXPERIMENTAL_SYNCSTREAM
230#  endif
231
232#  if defined(__MVS__)
233#    include <features.h> // for __NATIVE_ASCII_F
234#  endif
235
236#  if defined(_WIN32)
237#    define _LIBCPP_WIN32API
238#    define _LIBCPP_SHORT_WCHAR 1
239// Both MinGW and native MSVC provide a "MSVC"-like environment
240#    define _LIBCPP_MSVCRT_LIKE
241// If mingw not explicitly detected, assume using MS C runtime only if
242// a MS compatibility version is specified.
243#    if defined(_MSC_VER) && !defined(__MINGW32__)
244#      define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
245#    endif
246#    if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
247#      define _LIBCPP_HAS_BITSCAN64
248#    endif
249#    define _LIBCPP_HAS_OPEN_WITH_WCHAR
250#  endif // defined(_WIN32)
251
252#  if defined(_AIX) && !defined(__64BIT__)
253// The size of wchar is 2 byte on 32-bit mode on AIX.
254#    define _LIBCPP_SHORT_WCHAR 1
255#  endif
256
257// Libc++ supports various implementations of std::random_device.
258//
259// _LIBCPP_USING_DEV_RANDOM
260//      Read entropy from the given file, by default `/dev/urandom`.
261//      If a token is provided, it is assumed to be the path to a file
262//      to read entropy from. This is the default behavior if nothing
263//      else is specified. This implementation requires storing state
264//      inside `std::random_device`.
265//
266// _LIBCPP_USING_ARC4_RANDOM
267//      Use arc4random(). This allows obtaining random data even when
268//      using sandboxing mechanisms. On some platforms like Apple, this
269//      is the recommended source of entropy for user-space programs.
270//      When this option is used, the token passed to `std::random_device`'s
271//      constructor *must* be "/dev/urandom" -- anything else is an error.
272//
273// _LIBCPP_USING_GETENTROPY
274//      Use getentropy().
275//      When this option is used, the token passed to `std::random_device`'s
276//      constructor *must* be "/dev/urandom" -- anything else is an error.
277//
278// _LIBCPP_USING_FUCHSIA_CPRNG
279//      Use Fuchsia's zx_cprng_draw() system call, which is specified to
280//      deliver high-quality entropy and cannot fail.
281//      When this option is used, the token passed to `std::random_device`'s
282//      constructor *must* be "/dev/urandom" -- anything else is an error.
283//
284// _LIBCPP_USING_NACL_RANDOM
285//      NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
286//      including accesses to the special files under `/dev`. This implementation
287//      uses the NaCL syscall `nacl_secure_random_init()` to get entropy.
288//      When this option is used, the token passed to `std::random_device`'s
289//      constructor *must* be "/dev/urandom" -- anything else is an error.
290//
291// _LIBCPP_USING_WIN32_RANDOM
292//      Use rand_s(), for use on Windows.
293//      When this option is used, the token passed to `std::random_device`'s
294//      constructor *must* be "/dev/urandom" -- anything else is an error.
295#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||                     \
296      defined(__DragonFly__)
297#    define _LIBCPP_USING_ARC4_RANDOM
298#  elif defined(__wasi__) || defined(__EMSCRIPTEN__)
299#    define _LIBCPP_USING_GETENTROPY
300#  elif defined(__Fuchsia__)
301#    define _LIBCPP_USING_FUCHSIA_CPRNG
302#  elif defined(__native_client__)
303#    define _LIBCPP_USING_NACL_RANDOM
304#  elif defined(_LIBCPP_WIN32API)
305#    define _LIBCPP_USING_WIN32_RANDOM
306#  else
307#    define _LIBCPP_USING_DEV_RANDOM
308#  endif
309
310#  ifndef _LIBCPP_CXX03_LANG
311
312#    define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
313#    define _ALIGNAS_TYPE(x) alignas(x)
314#    define _ALIGNAS(x) alignas(x)
315#    define _LIBCPP_NORETURN [[noreturn]]
316#    define _NOEXCEPT noexcept
317#    define _NOEXCEPT_(...) noexcept(__VA_ARGS__)
318#    define _LIBCPP_CONSTEXPR constexpr
319
320#  else
321
322#    define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
323#    define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
324#    define _ALIGNAS(x) __attribute__((__aligned__(x)))
325#    define _LIBCPP_NORETURN __attribute__((__noreturn__))
326#    define _LIBCPP_HAS_NO_NOEXCEPT
327#    define nullptr __nullptr
328#    define _NOEXCEPT throw()
329#    define _NOEXCEPT_(...)
330#    define static_assert(...) _Static_assert(__VA_ARGS__)
331#    define decltype(...) __decltype(__VA_ARGS__)
332#    define _LIBCPP_CONSTEXPR
333
334typedef __char16_t char16_t;
335typedef __char32_t char32_t;
336
337#  endif
338
339#  define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)
340
341// Objective-C++ features (opt-in)
342#  if __has_feature(objc_arc)
343#    define _LIBCPP_HAS_OBJC_ARC
344#  endif
345
346#  if __has_feature(objc_arc_weak)
347#    define _LIBCPP_HAS_OBJC_ARC_WEAK
348#  endif
349
350#  if __has_extension(blocks)
351#    define _LIBCPP_HAS_EXTENSION_BLOCKS
352#  endif
353
354#  if defined(_LIBCPP_HAS_EXTENSION_BLOCKS) && defined(__APPLE__)
355#    define _LIBCPP_HAS_BLOCKS_RUNTIME
356#  endif
357
358#  if !__has_feature(address_sanitizer)
359#    define _LIBCPP_HAS_NO_ASAN
360#  endif
361
362#  define _LIBCPP_ALWAYS_INLINE __attribute__((__always_inline__))
363
364#  define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__
365
366#  if defined(_LIBCPP_OBJECT_FORMAT_COFF)
367
368#    ifdef _DLL
369#      define _LIBCPP_CRT_FUNC __declspec(dllimport)
370#    else
371#      define _LIBCPP_CRT_FUNC
372#    endif
373
374#    if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) || (defined(__MINGW32__) && !defined(_LIBCPP_BUILDING_LIBRARY))
375#      define _LIBCPP_DLL_VIS
376#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
377#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
378#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
379#      define _LIBCPP_EXPORTED_FROM_ABI
380#    elif defined(_LIBCPP_BUILDING_LIBRARY)
381#      define _LIBCPP_DLL_VIS __declspec(dllexport)
382#      if defined(__MINGW32__)
383#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
384#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
385#      else
386#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
387#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
388#      endif
389#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
390#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
391#    else
392#      define _LIBCPP_DLL_VIS __declspec(dllimport)
393#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
394#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
395#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
396#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
397#    endif
398
399#    define _LIBCPP_HIDDEN
400#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
401#    define _LIBCPP_TEMPLATE_VIS
402#    define _LIBCPP_TEMPLATE_DATA_VIS
403#    define _LIBCPP_TYPE_VISIBILITY_DEFAULT
404
405#  else
406
407#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
408#      define _LIBCPP_VISIBILITY(vis) __attribute__((__visibility__(vis)))
409#    else
410#      define _LIBCPP_VISIBILITY(vis)
411#    endif
412
413#    define _LIBCPP_HIDDEN _LIBCPP_VISIBILITY("hidden")
414#    define _LIBCPP_TEMPLATE_DATA_VIS _LIBCPP_VISIBILITY("default")
415#    define _LIBCPP_EXPORTED_FROM_ABI _LIBCPP_VISIBILITY("default")
416#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_VISIBILITY("default")
417#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
418
419// TODO: Make this a proper customization point or remove the option to override it.
420#    ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
421#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_VISIBILITY("default")
422#    endif
423
424#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
425// The inline should be removed once PR32114 is resolved
426#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS inline _LIBCPP_HIDDEN
427#    else
428#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
429#    endif
430
431// GCC doesn't support the type_visibility attribute, so we have to keep the visibility attribute on templates
432#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && !__has_attribute(__type_visibility__)
433#      define _LIBCPP_TEMPLATE_VIS __attribute__((__visibility__("default")))
434#    else
435#      define _LIBCPP_TEMPLATE_VIS
436#    endif
437
438#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
439#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT __attribute__((__type_visibility__("default")))
440#    else
441#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT
442#    endif
443
444#  endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
445
446#  if __has_attribute(exclude_from_explicit_instantiation)
447#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__((__exclude_from_explicit_instantiation__))
448#  else
449// Try to approximate the effect of exclude_from_explicit_instantiation
450// (which is that entities are not assumed to be provided by explicit
451// template instantiations in the dylib) by always inlining those entities.
452#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
453#  endif
454
455#  ifdef _LIBCPP_COMPILER_CLANG_BASED
456#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
457#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
458#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
459#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
460#  elif defined(_LIBCPP_COMPILER_GCC)
461#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
462#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
463#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
464#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
465#  else
466#    define _LIBCPP_DIAGNOSTIC_PUSH
467#    define _LIBCPP_DIAGNOSTIC_POP
468#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
469#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
470#  endif
471
472#  if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_FAST
473#    define _LIBCPP_HARDENING_SIG f
474#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_EXTENSIVE
475#    define _LIBCPP_HARDENING_SIG s
476#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
477#    define _LIBCPP_HARDENING_SIG d
478#  else
479#    define _LIBCPP_HARDENING_SIG n // "none"
480#  endif
481
482#  ifdef _LIBCPP_HAS_NO_EXCEPTIONS
483#    define _LIBCPP_EXCEPTIONS_SIG n
484#  else
485#    define _LIBCPP_EXCEPTIONS_SIG e
486#  endif
487
488#  define _LIBCPP_ODR_SIGNATURE                                                                                        \
489    _LIBCPP_CONCAT(_LIBCPP_CONCAT(_LIBCPP_HARDENING_SIG, _LIBCPP_EXCEPTIONS_SIG), _LIBCPP_VERSION)
490
491// This macro marks a symbol as being hidden from libc++'s ABI. This is achieved
492// on two levels:
493// 1. The symbol is given hidden visibility, which ensures that users won't start exporting
494//    symbols from their dynamic library by means of using the libc++ headers. This ensures
495//    that those symbols stay private to the dynamic library in which it is defined.
496//
497// 2. The symbol is given an ABI tag that encodes the ODR-relevant properties of the library.
498//    This ensures that no ODR violation can arise from mixing two TUs compiled with different
499//    versions or configurations of libc++ (such as exceptions vs no-exceptions). Indeed, if the
500//    program contains two definitions of a function, the ODR requires them to be token-by-token
501//    equivalent, and the linker is allowed to pick either definition and discard the other one.
502//
503//    For example, if a program contains a copy of `vector::at()` compiled with exceptions enabled
504//    *and* a copy of `vector::at()` compiled with exceptions disabled (by means of having two TUs
505//    compiled with different settings), the two definitions are both visible by the linker and they
506//    have the same name, but they have a meaningfully different implementation (one throws an exception
507//    and the other aborts the program). This violates the ODR and makes the program ill-formed, and in
508//    practice what will happen is that the linker will pick one of the definitions at random and will
509//    discard the other one. This can quite clearly lead to incorrect program behavior.
510//
511//    A similar reasoning holds for many other properties that are ODR-affecting. Essentially any
512//    property that causes the code of a function to differ from the code in another configuration
513//    can be considered ODR-affecting. In practice, we don't encode all such properties in the ABI
514//    tag, but we encode the ones that we think are most important: library version, exceptions, and
515//    hardening mode.
516//
517//    Note that historically, solving this problem has been achieved in various ways, including
518//    force-inlining all functions or giving internal linkage to all functions. Both these previous
519//    solutions suffer from drawbacks that lead notably to code bloat.
520//
521// Note that we use _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION to ensure that we don't depend
522// on _LIBCPP_HIDE_FROM_ABI methods of classes explicitly instantiated in the dynamic library.
523//
524// Also note that the _LIBCPP_HIDE_FROM_ABI_VIRTUAL macro should be used on virtual functions
525// instead of _LIBCPP_HIDE_FROM_ABI. That macro does not use an ABI tag. Indeed, the mangled
526// name of a virtual function is part of its ABI, since some architectures like arm64e can sign
527// the virtual function pointer in the vtable based on the mangled name of the function. Since
528// we use an ABI tag that changes with each released version, the mangled name of the virtual
529// function would change, which is incorrect. Note that it doesn't make much sense to change
530// the implementation of a virtual function in an ABI-incompatible way in the first place,
531// since that would be an ABI break anyway. Hence, the lack of ABI tag should not be noticeable.
532//
533// The macro can be applied to record and enum types. When the tagged type is nested in
534// a record this "parent" record needs to have the macro too. Another use case for applying
535// this macro to records and unions is to apply an ABI tag to inline constexpr variables.
536// This can be useful for inline variables that are implementation details which are expected
537// to change in the future.
538//
539// TODO: We provide a escape hatch with _LIBCPP_NO_ABI_TAG for folks who want to avoid increasing
540//       the length of symbols with an ABI tag. In practice, we should remove the escape hatch and
541//       use compression mangling instead, see https://github.com/itanium-cxx-abi/cxx-abi/issues/70.
542#  ifndef _LIBCPP_NO_ABI_TAG
543#    define _LIBCPP_HIDE_FROM_ABI                                                                                      \
544      _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION                                                       \
545      __attribute__((__abi_tag__(_LIBCPP_TOSTRING(_LIBCPP_ODR_SIGNATURE))))
546#  else
547#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
548#  endif
549#  define _LIBCPP_HIDE_FROM_ABI_VIRTUAL _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
550
551#  ifdef _LIBCPP_BUILDING_LIBRARY
552#    if _LIBCPP_ABI_VERSION > 1
553#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
554#    else
555#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
556#    endif
557#  else
558#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
559#  endif
560
561// TODO: Remove this workaround once we drop support for Clang 16
562#  if __has_warning("-Wc++23-extensions")
563#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
564#  else
565#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++2b-extensions")
566#  endif
567
568// Clang modules take a significant compile time hit when pushing and popping diagnostics.
569// Since all the headers are marked as system headers in the modulemap, we can simply disable this
570// pushing and popping when building with clang modules.
571#  if !__has_feature(modules)
572#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                                                         \
573      _LIBCPP_DIAGNOSTIC_PUSH                                                                                          \
574      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++11-extensions")                                                           \
575      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                           \
576      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                           \
577      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                           \
578      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION                                                                 \
579      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                             \
580      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                             \
581      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                             \
582      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
583#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS _LIBCPP_DIAGNOSTIC_POP
584#  else
585#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS
586#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS
587#  endif
588
589// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
590// clang-format off
591#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                               \
592                                      namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {                                  \
593                               inline namespace _LIBCPP_ABI_NAMESPACE {
594#  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
595
596#ifdef _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
597#  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD namespace filesystem {
598#  define _LIBCPP_END_NAMESPACE_FILESYSTEM } _LIBCPP_END_NAMESPACE_STD
599#else
600#  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD                                               \
601                                             inline namespace __fs { namespace filesystem {
602
603#  define _LIBCPP_END_NAMESPACE_FILESYSTEM }} _LIBCPP_END_NAMESPACE_STD
604#endif
605
606// clang-format on
607
608#  if __has_attribute(__enable_if__)
609#    define _LIBCPP_PREFERRED_OVERLOAD __attribute__((__enable_if__(true, "")))
610#  endif
611
612#  if !defined(__SIZEOF_INT128__) || defined(_MSC_VER)
613#    define _LIBCPP_HAS_NO_INT128
614#  endif
615
616#  ifdef _LIBCPP_CXX03_LANG
617#    define _LIBCPP_DECLARE_STRONG_ENUM(x)                                                                             \
618      struct _LIBCPP_EXPORTED_FROM_ABI x {                                                                             \
619        enum __lx
620// clang-format off
621#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)                                                                      \
622      __lx __v_;                                                                                                       \
623      _LIBCPP_HIDE_FROM_ABI x(__lx __v) : __v_(__v) {}                                                                 \
624      _LIBCPP_HIDE_FROM_ABI explicit x(int __v) : __v_(static_cast<__lx>(__v)) {}                                      \
625      _LIBCPP_HIDE_FROM_ABI operator int() const { return __v_; }                                                      \
626      };
627// clang-format on
628
629#  else // _LIBCPP_CXX03_LANG
630#    define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class x
631#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
632#  endif // _LIBCPP_CXX03_LANG
633
634#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || defined(__NetBSD__)
635#    define _LIBCPP_LOCALE__L_EXTENSIONS 1
636#  endif
637
638#  ifdef __FreeBSD__
639#    define _DECLARE_C99_LDBL_MATH 1
640#  endif
641
642// If we are getting operator new from the MSVC CRT, then allocation overloads
643// for align_val_t were added in 19.12, aka VS 2017 version 15.3.
644#  if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
645#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
646#  elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
647// We're deferring to Microsoft's STL to provide aligned new et al. We don't
648// have it unless the language feature test macro is defined.
649#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
650#  elif defined(__MVS__)
651#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
652#  endif
653
654#  if defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) || (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
655#    define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
656#  endif
657
658// It is not yet possible to use aligned_alloc() on all Apple platforms since
659// 10.15 was the first version to ship an implementation of aligned_alloc().
660#  if defined(__APPLE__)
661#    if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                                                     \
662         __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101500)
663#      define _LIBCPP_HAS_NO_C11_ALIGNED_ALLOC
664#    endif
665#  elif defined(__ANDROID__) && __ANDROID_API__ < 28
666// Android only provides aligned_alloc when targeting API 28 or higher.
667#    define _LIBCPP_HAS_NO_C11_ALIGNED_ALLOC
668#  endif
669
670#  if defined(__APPLE__) || defined(__FreeBSD__)
671#    define _LIBCPP_HAS_DEFAULTRUNELOCALE
672#  endif
673
674#  if defined(__APPLE__) || defined(__FreeBSD__)
675#    define _LIBCPP_WCTYPE_IS_MASK
676#  endif
677
678#  if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
679#    define _LIBCPP_HAS_NO_CHAR8_T
680#  endif
681
682// Deprecation macros.
683//
684// Deprecations warnings are always enabled, except when users explicitly opt-out
685// by defining _LIBCPP_DISABLE_DEPRECATION_WARNINGS.
686#  if !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
687#    if __has_attribute(__deprecated__)
688#      define _LIBCPP_DEPRECATED __attribute__((__deprecated__))
689#      define _LIBCPP_DEPRECATED_(m) __attribute__((__deprecated__(m)))
690#    elif _LIBCPP_STD_VER >= 14
691#      define _LIBCPP_DEPRECATED [[deprecated]]
692#      define _LIBCPP_DEPRECATED_(m) [[deprecated(m)]]
693#    else
694#      define _LIBCPP_DEPRECATED
695#      define _LIBCPP_DEPRECATED_(m)
696#    endif
697#  else
698#    define _LIBCPP_DEPRECATED
699#    define _LIBCPP_DEPRECATED_(m)
700#  endif
701
702#  if _LIBCPP_STD_VER < 20
703#    define _LIBCPP_DEPRECATED_ATOMIC_SYNC                                                                             \
704      _LIBCPP_DEPRECATED_("The C++20 synchronization library has been deprecated prior to C++20. Please update to "    \
705                          "using -std=c++20 if you need to use these facilities.")
706#  else
707#    define _LIBCPP_DEPRECATED_ATOMIC_SYNC /* nothing */
708#  endif
709
710#  if !defined(_LIBCPP_CXX03_LANG)
711#    define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
712#  else
713#    define _LIBCPP_DEPRECATED_IN_CXX11
714#  endif
715
716#  if _LIBCPP_STD_VER >= 14
717#    define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
718#  else
719#    define _LIBCPP_DEPRECATED_IN_CXX14
720#  endif
721
722#  if _LIBCPP_STD_VER >= 17
723#    define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
724#  else
725#    define _LIBCPP_DEPRECATED_IN_CXX17
726#  endif
727
728#  if _LIBCPP_STD_VER >= 20
729#    define _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_DEPRECATED
730#  else
731#    define _LIBCPP_DEPRECATED_IN_CXX20
732#  endif
733
734#  if _LIBCPP_STD_VER >= 23
735#    define _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_DEPRECATED
736#  else
737#    define _LIBCPP_DEPRECATED_IN_CXX23
738#  endif
739
740#  if _LIBCPP_STD_VER >= 26
741#    define _LIBCPP_DEPRECATED_IN_CXX26 _LIBCPP_DEPRECATED
742#  else
743#    define _LIBCPP_DEPRECATED_IN_CXX26
744#  endif
745
746#  if !defined(_LIBCPP_HAS_NO_CHAR8_T)
747#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T _LIBCPP_DEPRECATED
748#  else
749#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T
750#  endif
751
752// Macros to enter and leave a state where deprecation warnings are suppressed.
753#  if defined(_LIBCPP_COMPILER_CLANG_BASED) || defined(_LIBCPP_COMPILER_GCC)
754#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH                                                                           \
755      _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated\"")                                \
756          _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
757#    define _LIBCPP_SUPPRESS_DEPRECATED_POP _Pragma("GCC diagnostic pop")
758#  else
759#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH
760#    define _LIBCPP_SUPPRESS_DEPRECATED_POP
761#  endif
762
763#  if _LIBCPP_STD_VER <= 11
764#    define _LIBCPP_EXPLICIT_SINCE_CXX14
765#  else
766#    define _LIBCPP_EXPLICIT_SINCE_CXX14 explicit
767#  endif
768
769#  if _LIBCPP_STD_VER >= 23
770#    define _LIBCPP_EXPLICIT_SINCE_CXX23 explicit
771#  else
772#    define _LIBCPP_EXPLICIT_SINCE_CXX23
773#  endif
774
775#  if _LIBCPP_STD_VER >= 14
776#    define _LIBCPP_CONSTEXPR_SINCE_CXX14 constexpr
777#  else
778#    define _LIBCPP_CONSTEXPR_SINCE_CXX14
779#  endif
780
781#  if _LIBCPP_STD_VER >= 17
782#    define _LIBCPP_CONSTEXPR_SINCE_CXX17 constexpr
783#  else
784#    define _LIBCPP_CONSTEXPR_SINCE_CXX17
785#  endif
786
787#  if _LIBCPP_STD_VER >= 20
788#    define _LIBCPP_CONSTEXPR_SINCE_CXX20 constexpr
789#  else
790#    define _LIBCPP_CONSTEXPR_SINCE_CXX20
791#  endif
792
793#  if _LIBCPP_STD_VER >= 23
794#    define _LIBCPP_CONSTEXPR_SINCE_CXX23 constexpr
795#  else
796#    define _LIBCPP_CONSTEXPR_SINCE_CXX23
797#  endif
798
799#  ifndef _LIBCPP_WEAK
800#    define _LIBCPP_WEAK __attribute__((__weak__))
801#  endif
802
803// Thread API
804// clang-format off
805#  if !defined(_LIBCPP_HAS_NO_THREADS) &&                                                                              \
806      !defined(_LIBCPP_HAS_THREAD_API_PTHREAD) &&                                                                      \
807      !defined(_LIBCPP_HAS_THREAD_API_WIN32) &&                                                                        \
808      !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
809
810#    if defined(__FreeBSD__) ||                                                                                        \
811        defined(__wasi__) ||                                                                                           \
812        defined(__NetBSD__) ||                                                                                         \
813        defined(__OpenBSD__) ||                                                                                        \
814        defined(__NuttX__) ||                                                                                          \
815        defined(__linux__) ||                                                                                          \
816        defined(__GNU__) ||                                                                                            \
817        defined(__APPLE__) ||                                                                                          \
818        defined(__MVS__) ||                                                                                            \
819        defined(_AIX) ||                                                                                               \
820        defined(__EMSCRIPTEN__)
821// clang-format on
822#      define _LIBCPP_HAS_THREAD_API_PTHREAD
823#    elif defined(__Fuchsia__)
824// TODO(44575): Switch to C11 thread API when possible.
825#      define _LIBCPP_HAS_THREAD_API_PTHREAD
826#    elif defined(_LIBCPP_WIN32API)
827#      define _LIBCPP_HAS_THREAD_API_WIN32
828#    else
829#      error "No thread API"
830#    endif // _LIBCPP_HAS_THREAD_API
831#  endif   // _LIBCPP_HAS_NO_THREADS
832
833#  if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
834#    if defined(__ANDROID__) && __ANDROID_API__ >= 30
835#      define _LIBCPP_HAS_COND_CLOCKWAIT
836#    elif defined(_LIBCPP_GLIBC_PREREQ)
837#      if _LIBCPP_GLIBC_PREREQ(2, 30)
838#        define _LIBCPP_HAS_COND_CLOCKWAIT
839#      endif
840#    endif
841#  endif
842
843#  if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
844#    error _LIBCPP_HAS_THREAD_API_PTHREAD may only be defined when \
845       _LIBCPP_HAS_NO_THREADS is not defined.
846#  endif
847
848#  if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
849#    error _LIBCPP_HAS_THREAD_API_EXTERNAL may not be defined when \
850       _LIBCPP_HAS_NO_THREADS is defined.
851#  endif
852
853#  if defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(_LIBCPP_HAS_NO_THREADS)
854#    error _LIBCPP_HAS_NO_MONOTONIC_CLOCK may only be defined when \
855       _LIBCPP_HAS_NO_THREADS is defined.
856#  endif
857
858#  if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(__STDCPP_THREADS__)
859#    define __STDCPP_THREADS__ 1
860#  endif
861
862// The glibc and Bionic implementation of pthreads implements
863// pthread_mutex_destroy as nop for regular mutexes. Additionally, Win32
864// mutexes have no destroy mechanism.
865//
866// This optimization can't be performed on Apple platforms, where
867// pthread_mutex_destroy can allow the kernel to release resources.
868// See https://llvm.org/D64298 for details.
869//
870// TODO(EricWF): Enable this optimization on Bionic after speaking to their
871//               respective stakeholders.
872// clang-format off
873#  if (defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && defined(__GLIBC__)) ||                                               \
874      (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) ||                                                 \
875       defined(_LIBCPP_HAS_THREAD_API_WIN32)
876// clang-format on
877#    define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION
878#  endif
879
880// Destroying a condvar is a nop on Windows.
881//
882// This optimization can't be performed on Apple platforms, where
883// pthread_cond_destroy can allow the kernel to release resources.
884// See https://llvm.org/D64298 for details.
885//
886// TODO(EricWF): This is potentially true for some pthread implementations
887// as well.
888#  if (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) || defined(_LIBCPP_HAS_THREAD_API_WIN32)
889#    define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
890#  endif
891
892#  if defined(__BIONIC__) || defined(__NuttX__) || defined(__Fuchsia__) || defined(__wasi__) ||                        \
893      defined(_LIBCPP_HAS_MUSL_LIBC) || defined(__OpenBSD__)
894#    define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
895#  endif
896
897#  if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
898#    define _LIBCPP_HAS_C_ATOMIC_IMP
899#  elif defined(_LIBCPP_COMPILER_GCC)
900#    define _LIBCPP_HAS_GCC_ATOMIC_IMP
901#  endif
902
903#  if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) &&                                    \
904      !defined(_LIBCPP_HAS_EXTERNAL_ATOMIC_IMP)
905#    define _LIBCPP_HAS_NO_ATOMIC_HEADER
906#  else
907#    ifndef _LIBCPP_ATOMIC_FLAG_TYPE
908#      define _LIBCPP_ATOMIC_FLAG_TYPE bool
909#    endif
910#  endif
911
912#  if defined(__FreeBSD__) && defined(__clang__) && __has_attribute(__no_thread_safety_analysis__)
913#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS __attribute__((__no_thread_safety_analysis__))
914#  else
915#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
916#  endif
917
918#  if defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS)
919#    if defined(__clang__) && __has_attribute(acquire_capability)
920// Work around the attribute handling in clang.  When both __declspec and
921// __attribute__ are present, the processing goes awry preventing the definition
922// of the types. In MinGW mode, __declspec evaluates to __attribute__, and thus
923// combining the two does work.
924#      if !defined(_MSC_VER)
925#        define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
926#      endif
927#    endif
928#  endif
929
930#  ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
931#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
932#  else
933#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
934#  endif
935
936#  if _LIBCPP_STD_VER >= 20
937#    define _LIBCPP_CONSTINIT constinit
938#  elif __has_attribute(__require_constant_initialization__)
939#    define _LIBCPP_CONSTINIT __attribute__((__require_constant_initialization__))
940#  else
941#    define _LIBCPP_CONSTINIT
942#  endif
943
944#  if defined(__CUDACC__) || defined(__CUDA_ARCH__) || defined(__CUDA_LIBDEVICE__)
945// The CUDA SDK contains an unfortunate definition for the __noinline__ macro,
946// which breaks the regular __attribute__((__noinline__)) syntax. Therefore,
947// when compiling for CUDA we use the non-underscored version of the noinline
948// attribute.
949//
950// This is a temporary workaround and we still expect the CUDA SDK team to solve
951// this issue properly in the SDK headers.
952//
953// See https://github.com/llvm/llvm-project/pull/73838 for more details.
954#    define _LIBCPP_NOINLINE __attribute__((noinline))
955#  elif __has_attribute(__noinline__)
956#    define _LIBCPP_NOINLINE __attribute__((__noinline__))
957#  else
958#    define _LIBCPP_NOINLINE
959#  endif
960
961// We often repeat things just for handling wide characters in the library.
962// When wide characters are disabled, it can be useful to have a quick way of
963// disabling it without having to resort to #if-#endif, which has a larger
964// impact on readability.
965#  if defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
966#    define _LIBCPP_IF_WIDE_CHARACTERS(...)
967#  else
968#    define _LIBCPP_IF_WIDE_CHARACTERS(...) __VA_ARGS__
969#  endif
970
971// clang-format off
972#  define _LIBCPP_PUSH_MACROS _Pragma("push_macro(\"min\")") _Pragma("push_macro(\"max\")") _Pragma("push_macro(\"refresh\")") _Pragma("push_macro(\"move\")") _Pragma("push_macro(\"erase\")")
973#  define _LIBCPP_POP_MACROS _Pragma("pop_macro(\"min\")") _Pragma("pop_macro(\"max\")") _Pragma("pop_macro(\"refresh\")") _Pragma("pop_macro(\"move\")") _Pragma("pop_macro(\"erase\")")
974// clang-format on
975
976#  ifndef _LIBCPP_NO_AUTO_LINK
977#    if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
978#      if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
979#        pragma comment(lib, "c++.lib")
980#      else
981#        pragma comment(lib, "libc++.lib")
982#      endif
983#    endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
984#  endif   // _LIBCPP_NO_AUTO_LINK
985
986// Configures the fopen close-on-exec mode character, if any. This string will
987// be appended to any mode string used by fstream for fopen/fdopen.
988//
989// Not all platforms support this, but it helps avoid fd-leaks on platforms that
990// do.
991#  if defined(__BIONIC__)
992#    define _LIBCPP_FOPEN_CLOEXEC_MODE "e"
993#  else
994#    define _LIBCPP_FOPEN_CLOEXEC_MODE
995#  endif
996
997#  if __has_cpp_attribute(msvc::no_unique_address)
998// MSVC implements [[no_unique_address]] as a silent no-op currently.
999// (If/when MSVC breaks its C++ ABI, it will be changed to work as intended.)
1000// However, MSVC implements [[msvc::no_unique_address]] which does what
1001// [[no_unique_address]] is supposed to do, in general.
1002
1003// Clang-cl does not yet (14.0) implement either [[no_unique_address]] or
1004// [[msvc::no_unique_address]] though. If/when it does implement
1005// [[msvc::no_unique_address]], this should be preferred though.
1006#    define _LIBCPP_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
1007#  elif __has_cpp_attribute(no_unique_address)
1008#    define _LIBCPP_NO_UNIQUE_ADDRESS [[__no_unique_address__]]
1009#  else
1010#    define _LIBCPP_NO_UNIQUE_ADDRESS /* nothing */
1011// Note that this can be replaced by #error as soon as clang-cl
1012// implements msvc::no_unique_address, since there should be no C++20
1013// compiler that doesn't support one of the two attributes at that point.
1014// We generally don't want to use this macro outside of C++20-only code,
1015// because using it conditionally in one language version only would make
1016// the ABI inconsistent.
1017#  endif
1018
1019// c8rtomb() and mbrtoc8() were added in C++20 and C23. Support for these
1020// functions is gradually being added to existing C libraries. The conditions
1021// below check for known C library versions and conditions under which these
1022// functions are declared by the C library.
1023#  define _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8
1024// GNU libc 2.36 and newer declare c8rtomb() and mbrtoc8() in C++ modes if
1025// __cpp_char8_t is defined or if C2X extensions are enabled. Determining
1026// the latter depends on internal GNU libc details that are not appropriate
1027// to depend on here, so any declarations present when __cpp_char8_t is not
1028// defined are ignored.
1029#  if defined(_LIBCPP_GLIBC_PREREQ)
1030#    if _LIBCPP_GLIBC_PREREQ(2, 36) && defined(__cpp_char8_t)
1031#      undef _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8
1032#    endif
1033#  endif
1034
1035// There are a handful of public standard library types that are intended to
1036// support CTAD but don't need any explicit deduction guides to do so. This
1037// macro is used to mark them as such, which suppresses the
1038// '-Wctad-maybe-unsupported' compiler warning when CTAD is used in user code
1039// with these classes.
1040#  if _LIBCPP_STD_VER >= 17
1041#    ifdef _LIBCPP_COMPILER_CLANG_BASED
1042#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName)                                                              \
1043        template <class... _Tag>                                                                                       \
1044        [[maybe_unused]] _ClassName(typename _Tag::__allow_ctad...)->_ClassName<_Tag...>
1045#    else
1046#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(ClassName)                                                               \
1047        template <class... _Tag>                                                                                       \
1048        ClassName(typename _Tag::__allow_ctad...)->ClassName<_Tag...>
1049#    endif
1050#  else
1051#    define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName) static_assert(true, "")
1052#  endif
1053
1054// TODO(varconst): currently, there are bugs in Clang's intrinsics when handling Objective-C++ `id`, so don't use
1055// compiler intrinsics in the Objective-C++ mode.
1056#  ifdef __OBJC__
1057#    define _LIBCPP_WORKAROUND_OBJCXX_COMPILER_INTRINSICS
1058#  endif
1059
1060#  define _PSTL_PRAGMA(x) _Pragma(#x)
1061
1062// Enable SIMD for compilers that support OpenMP 4.0
1063#  if (defined(_OPENMP) && _OPENMP >= 201307)
1064
1065#    define _PSTL_UDR_PRESENT
1066#    define _PSTL_PRAGMA_SIMD _PSTL_PRAGMA(omp simd)
1067#    define _PSTL_PRAGMA_DECLARE_SIMD _PSTL_PRAGMA(omp declare simd)
1068#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _PSTL_PRAGMA(omp simd reduction(PRM))
1069#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
1070#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
1071#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
1072
1073// Declaration of reduction functor, where
1074// NAME - the name of the functor
1075// OP - type of the callable object with the reduction operation
1076// omp_in - refers to the local partial result
1077// omp_out - refers to the final value of the combiner operator
1078// omp_priv - refers to the private copy of the initial value
1079// omp_orig - refers to the original variable to be reduced
1080#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)                                                                   \
1081      _PSTL_PRAGMA(omp declare reduction(NAME:OP : omp_out(omp_in)) initializer(omp_priv = omp_orig))
1082
1083#  elif defined(_LIBCPP_COMPILER_CLANG_BASED)
1084
1085#    define _PSTL_PRAGMA_SIMD _Pragma("clang loop vectorize(enable) interleave(enable)")
1086#    define _PSTL_PRAGMA_DECLARE_SIMD
1087#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1088#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1089#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1090#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1091#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1092
1093#  else // (defined(_OPENMP) && _OPENMP >= 201307)
1094
1095#    define _PSTL_PRAGMA_SIMD
1096#    define _PSTL_PRAGMA_DECLARE_SIMD
1097#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM)
1098#    define _PSTL_PRAGMA_SIMD_SCAN(PRM)
1099#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1100#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1101#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1102
1103#  endif // (defined(_OPENMP) && _OPENMP >= 201307)
1104
1105#  define _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
1106
1107// Optional attributes - these are useful for a better QoI, but not required to be available
1108
1109#  if __has_attribute(__no_sanitize__) && !defined(_LIBCPP_COMPILER_GCC)
1110#    define _LIBCPP_NO_CFI __attribute__((__no_sanitize__("cfi")))
1111#  else
1112#    define _LIBCPP_NO_CFI
1113#  endif
1114
1115#  if __has_attribute(__malloc__)
1116#    define _LIBCPP_NOALIAS __attribute__((__malloc__))
1117#  else
1118#    define _LIBCPP_NOALIAS
1119#  endif
1120
1121#  if __has_attribute(__using_if_exists__)
1122#    define _LIBCPP_USING_IF_EXISTS __attribute__((__using_if_exists__))
1123#  else
1124#    define _LIBCPP_USING_IF_EXISTS
1125#  endif
1126
1127#  if __has_cpp_attribute(__nodiscard__)
1128#    define _LIBCPP_NODISCARD [[__nodiscard__]]
1129#  else
1130// We can't use GCC's [[gnu::warn_unused_result]] and
1131// __attribute__((warn_unused_result)), because GCC does not silence them via
1132// (void) cast.
1133#    define _LIBCPP_NODISCARD
1134#  endif
1135
1136#  if __has_attribute(__no_destroy__)
1137#    define _LIBCPP_NO_DESTROY __attribute__((__no_destroy__))
1138#  else
1139#    define _LIBCPP_NO_DESTROY
1140#  endif
1141
1142#  if __has_attribute(__diagnose_if__)
1143#    define _LIBCPP_DIAGNOSE_WARNING(...) __attribute__((__diagnose_if__(__VA_ARGS__, "warning")))
1144#  else
1145#    define _LIBCPP_DIAGNOSE_WARNING(...)
1146#  endif
1147
1148// Use a function like macro to imply that it must be followed by a semicolon
1149#  if __has_cpp_attribute(fallthrough)
1150#    define _LIBCPP_FALLTHROUGH() [[fallthrough]]
1151#  elif __has_attribute(__fallthrough__)
1152#    define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
1153#  else
1154#    define _LIBCPP_FALLTHROUGH() ((void)0)
1155#  endif
1156
1157#  if __has_cpp_attribute(_Clang::__lifetimebound__)
1158#    define _LIBCPP_LIFETIMEBOUND [[_Clang::__lifetimebound__]]
1159#  else
1160#    define _LIBCPP_LIFETIMEBOUND
1161#  endif
1162
1163#  if __has_attribute(__nodebug__)
1164#    define _LIBCPP_NODEBUG __attribute__((__nodebug__))
1165#  else
1166#    define _LIBCPP_NODEBUG
1167#  endif
1168
1169#  if __has_attribute(__standalone_debug__)
1170#    define _LIBCPP_STANDALONE_DEBUG __attribute__((__standalone_debug__))
1171#  else
1172#    define _LIBCPP_STANDALONE_DEBUG
1173#  endif
1174
1175#  if __has_attribute(__preferred_name__)
1176#    define _LIBCPP_PREFERRED_NAME(x) __attribute__((__preferred_name__(x)))
1177#  else
1178#    define _LIBCPP_PREFERRED_NAME(x)
1179#  endif
1180
1181#  if __has_attribute(__no_sanitize__)
1182#    define _LIBCPP_NO_SANITIZE(...) __attribute__((__no_sanitize__(__VA_ARGS__)))
1183#  else
1184#    define _LIBCPP_NO_SANITIZE(...)
1185#  endif
1186
1187#  if __has_attribute(__init_priority__)
1188#    define _LIBCPP_INIT_PRIORITY_MAX __attribute__((__init_priority__(100)))
1189#  else
1190#    define _LIBCPP_INIT_PRIORITY_MAX
1191#  endif
1192
1193#  if __has_attribute(__format__)
1194// The attribute uses 1-based indices for ordinary and static member functions.
1195// The attribute uses 2-based indices for non-static member functions.
1196#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index)                           \
1197      __attribute__((__format__(archetype, format_string_index, first_format_arg_index)))
1198#  else
1199#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index) /* nothing */
1200#  endif
1201
1202#  if __has_attribute(__packed__)
1203#    define _LIBCPP_PACKED __attribute__((__packed__))
1204#  else
1205#    define _LIBCPP_PACKED
1206#  endif
1207
1208#  if defined(_LIBCPP_ABI_MICROSOFT) && __has_declspec_attribute(empty_bases)
1209#    define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
1210#  else
1211#    define _LIBCPP_DECLSPEC_EMPTY_BASES
1212#  endif
1213
1214// Allow for build-time disabling of unsigned integer sanitization
1215#  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
1216#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
1217#  else
1218#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1219#  endif
1220
1221// Clang-18 has support for deducing this, but it does not set the FTM.
1222#  if defined(__cpp_explicit_this_parameter) || (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1800)
1223#    define _LIBCPP_HAS_EXPLICIT_THIS_PARAMETER
1224#  endif
1225
1226#endif // __cplusplus
1227
1228#endif // _LIBCPP___CXX03___CONFIG
1229