xref: /freebsd/contrib/llvm-project/libcxx/include/__config (revision 415efcecd8b80f68e76376ef2b854cb6f5c84b5a)
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___CONFIG
11#define _LIBCPP___CONFIG
12
13#include <__config_site>
14#include <__configuration/abi.h>
15#include <__configuration/availability.h>
16#include <__configuration/compiler.h>
17#include <__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 190104
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// TODO: Remove once we switch to GCC 14
166#  ifndef __has_extension
167#    define __has_extension(__x) 0
168#  endif
169
170// TODO: Remove once we switch to GCC 14
171#  ifndef __has_feature
172#    define __has_feature(__x) 0
173#  endif
174
175#  ifndef __has_constexpr_builtin
176#    define __has_constexpr_builtin(x) 0
177#  endif
178
179// This checks wheter a Clang module is built
180#  ifndef __building_module
181#    define __building_module(...) 0
182#  endif
183
184// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
185// the compiler and '1' otherwise.
186#  ifndef __is_identifier
187#    define __is_identifier(__x) 1
188#  endif
189
190#  ifndef __has_declspec_attribute
191#    define __has_declspec_attribute(__x) 0
192#  endif
193
194#  define __has_keyword(__x) !(__is_identifier(__x))
195
196#  ifndef __has_warning
197#    define __has_warning(...) 0
198#  endif
199
200#  if !defined(_LIBCPP_COMPILER_CLANG_BASED) && __cplusplus < 201103L
201#    error "libc++ only supports C++03 with Clang-based compilers. Please enable C++11"
202#  endif
203
204// FIXME: ABI detection should be done via compiler builtin macros. This
205// is just a placeholder until Clang implements such macros. For now assume
206// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
207// and allow the user to explicitly specify the ABI to handle cases where this
208// heuristic falls short.
209#  if defined(_LIBCPP_ABI_FORCE_ITANIUM) && defined(_LIBCPP_ABI_FORCE_MICROSOFT)
210#    error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be defined"
211#  elif defined(_LIBCPP_ABI_FORCE_ITANIUM)
212#    define _LIBCPP_ABI_ITANIUM
213#  elif defined(_LIBCPP_ABI_FORCE_MICROSOFT)
214#    define _LIBCPP_ABI_MICROSOFT
215#  else
216#    if defined(_WIN32) && defined(_MSC_VER)
217#      define _LIBCPP_ABI_MICROSOFT
218#    else
219#      define _LIBCPP_ABI_ITANIUM
220#    endif
221#  endif
222
223#  if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
224#    define _LIBCPP_ABI_VCRUNTIME
225#  endif
226
227#  if __has_feature(experimental_library)
228#    ifndef _LIBCPP_ENABLE_EXPERIMENTAL
229#      define _LIBCPP_ENABLE_EXPERIMENTAL
230#    endif
231#  endif
232
233// Incomplete features get their own specific disabling flags. This makes it
234// easier to grep for target specific flags once the feature is complete.
235#  if !defined(_LIBCPP_ENABLE_EXPERIMENTAL) && !defined(_LIBCPP_BUILDING_LIBRARY)
236#    define _LIBCPP_HAS_NO_INCOMPLETE_PSTL
237#    define _LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN
238#    define _LIBCPP_HAS_NO_EXPERIMENTAL_TZDB
239#    define _LIBCPP_HAS_NO_EXPERIMENTAL_SYNCSTREAM
240#  endif
241
242#  if defined(__MVS__)
243#    include <features.h> // for __NATIVE_ASCII_F
244#  endif
245
246#  if defined(_WIN32)
247#    define _LIBCPP_WIN32API
248#    define _LIBCPP_SHORT_WCHAR 1
249// Both MinGW and native MSVC provide a "MSVC"-like environment
250#    define _LIBCPP_MSVCRT_LIKE
251// If mingw not explicitly detected, assume using MS C runtime only if
252// a MS compatibility version is specified.
253#    if defined(_MSC_VER) && !defined(__MINGW32__)
254#      define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
255#    endif
256#    if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
257#      define _LIBCPP_HAS_BITSCAN64
258#    endif
259#    define _LIBCPP_HAS_OPEN_WITH_WCHAR
260#  endif // defined(_WIN32)
261
262#  if defined(_AIX) && !defined(__64BIT__)
263// The size of wchar is 2 byte on 32-bit mode on AIX.
264#    define _LIBCPP_SHORT_WCHAR 1
265#  endif
266
267// Libc++ supports various implementations of std::random_device.
268//
269// _LIBCPP_USING_DEV_RANDOM
270//      Read entropy from the given file, by default `/dev/urandom`.
271//      If a token is provided, it is assumed to be the path to a file
272//      to read entropy from. This is the default behavior if nothing
273//      else is specified. This implementation requires storing state
274//      inside `std::random_device`.
275//
276// _LIBCPP_USING_ARC4_RANDOM
277//      Use arc4random(). This allows obtaining random data even when
278//      using sandboxing mechanisms. On some platforms like Apple, this
279//      is the recommended source of entropy for user-space programs.
280//      When this option is used, the token passed to `std::random_device`'s
281//      constructor *must* be "/dev/urandom" -- anything else is an error.
282//
283// _LIBCPP_USING_GETENTROPY
284//      Use getentropy().
285//      When this option is used, the token passed to `std::random_device`'s
286//      constructor *must* be "/dev/urandom" -- anything else is an error.
287//
288// _LIBCPP_USING_FUCHSIA_CPRNG
289//      Use Fuchsia's zx_cprng_draw() system call, which is specified to
290//      deliver high-quality entropy and cannot fail.
291//      When this option is used, the token passed to `std::random_device`'s
292//      constructor *must* be "/dev/urandom" -- anything else is an error.
293//
294// _LIBCPP_USING_NACL_RANDOM
295//      NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
296//      including accesses to the special files under `/dev`. This implementation
297//      uses the NaCL syscall `nacl_secure_random_init()` to get entropy.
298//      When this option is used, the token passed to `std::random_device`'s
299//      constructor *must* be "/dev/urandom" -- anything else is an error.
300//
301// _LIBCPP_USING_WIN32_RANDOM
302//      Use rand_s(), for use on Windows.
303//      When this option is used, the token passed to `std::random_device`'s
304//      constructor *must* be "/dev/urandom" -- anything else is an error.
305#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||                     \
306      defined(__DragonFly__)
307#    define _LIBCPP_USING_ARC4_RANDOM
308#  elif defined(__wasi__) || defined(__EMSCRIPTEN__)
309#    define _LIBCPP_USING_GETENTROPY
310#  elif defined(__Fuchsia__)
311#    define _LIBCPP_USING_FUCHSIA_CPRNG
312#  elif defined(__native_client__)
313#    define _LIBCPP_USING_NACL_RANDOM
314#  elif defined(_LIBCPP_WIN32API)
315#    define _LIBCPP_USING_WIN32_RANDOM
316#  else
317#    define _LIBCPP_USING_DEV_RANDOM
318#  endif
319
320#  ifndef _LIBCPP_CXX03_LANG
321
322#    define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
323#    define _ALIGNAS_TYPE(x) alignas(x)
324#    define _ALIGNAS(x) alignas(x)
325#    define _LIBCPP_NORETURN [[noreturn]]
326#    define _NOEXCEPT noexcept
327#    define _NOEXCEPT_(...) noexcept(__VA_ARGS__)
328#    define _LIBCPP_CONSTEXPR constexpr
329
330#  else
331
332#    define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
333#    define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
334#    define _ALIGNAS(x) __attribute__((__aligned__(x)))
335#    define _LIBCPP_NORETURN __attribute__((__noreturn__))
336#    define _LIBCPP_HAS_NO_NOEXCEPT
337#    define nullptr __nullptr
338#    define _NOEXCEPT throw()
339#    define _NOEXCEPT_(...)
340#    define static_assert(...) _Static_assert(__VA_ARGS__)
341#    define decltype(...) __decltype(__VA_ARGS__)
342#    define _LIBCPP_CONSTEXPR
343
344typedef __char16_t char16_t;
345typedef __char32_t char32_t;
346
347#  endif
348
349#  define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)
350
351#  if defined(_LIBCPP_COMPILER_CLANG_BASED)
352
353// Objective-C++ features (opt-in)
354#    if __has_feature(objc_arc)
355#      define _LIBCPP_HAS_OBJC_ARC
356#    endif
357
358#    if __has_feature(objc_arc_weak)
359#      define _LIBCPP_HAS_OBJC_ARC_WEAK
360#    endif
361
362#    if __has_extension(blocks)
363#      define _LIBCPP_HAS_EXTENSION_BLOCKS
364#    endif
365
366#    if defined(_LIBCPP_HAS_EXTENSION_BLOCKS) && defined(__APPLE__)
367#      define _LIBCPP_HAS_BLOCKS_RUNTIME
368#    endif
369
370#    if !__has_feature(address_sanitizer)
371#      define _LIBCPP_HAS_NO_ASAN
372#    endif
373
374#    define _LIBCPP_ALWAYS_INLINE __attribute__((__always_inline__))
375
376#    define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__
377
378#  elif defined(_LIBCPP_COMPILER_GCC)
379
380#    if !defined(__SANITIZE_ADDRESS__)
381#      define _LIBCPP_HAS_NO_ASAN
382#    endif
383
384#    define _LIBCPP_ALWAYS_INLINE __attribute__((__always_inline__))
385
386#    define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__
387
388#  endif // _LIBCPP_COMPILER_[CLANG|GCC]
389
390#  if defined(_LIBCPP_OBJECT_FORMAT_COFF)
391
392#    ifdef _DLL
393#      define _LIBCPP_CRT_FUNC __declspec(dllimport)
394#    else
395#      define _LIBCPP_CRT_FUNC
396#    endif
397
398#    if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) || (defined(__MINGW32__) && !defined(_LIBCPP_BUILDING_LIBRARY))
399#      define _LIBCPP_DLL_VIS
400#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
401#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
402#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
403#      define _LIBCPP_EXPORTED_FROM_ABI
404#    elif defined(_LIBCPP_BUILDING_LIBRARY)
405#      define _LIBCPP_DLL_VIS __declspec(dllexport)
406#      if defined(__MINGW32__)
407#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
408#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
409#      else
410#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
411#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
412#      endif
413#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
414#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
415#    else
416#      define _LIBCPP_DLL_VIS __declspec(dllimport)
417#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
418#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
419#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
420#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
421#    endif
422
423#    define _LIBCPP_HIDDEN
424#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
425#    define _LIBCPP_TEMPLATE_VIS
426#    define _LIBCPP_TEMPLATE_DATA_VIS
427#    define _LIBCPP_TYPE_VISIBILITY_DEFAULT
428
429#  else
430
431#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
432#      define _LIBCPP_VISIBILITY(vis) __attribute__((__visibility__(vis)))
433#    else
434#      define _LIBCPP_VISIBILITY(vis)
435#    endif
436
437#    define _LIBCPP_HIDDEN _LIBCPP_VISIBILITY("hidden")
438#    define _LIBCPP_TEMPLATE_DATA_VIS _LIBCPP_VISIBILITY("default")
439#    define _LIBCPP_EXPORTED_FROM_ABI _LIBCPP_VISIBILITY("default")
440#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_VISIBILITY("default")
441#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
442
443// TODO: Make this a proper customization point or remove the option to override it.
444#    ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
445#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_VISIBILITY("default")
446#    endif
447
448#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
449// The inline should be removed once PR32114 is resolved
450#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS inline _LIBCPP_HIDDEN
451#    else
452#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
453#    endif
454
455// GCC doesn't support the type_visibility attribute, so we have to keep the visibility attribute on templates
456#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && !__has_attribute(__type_visibility__)
457#      define _LIBCPP_TEMPLATE_VIS __attribute__((__visibility__("default")))
458#    else
459#      define _LIBCPP_TEMPLATE_VIS
460#    endif
461
462#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__) && \
463        _LIBCPP_CLANG_VER >= 1500 // FreeBSD customization
464#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT __attribute__((__type_visibility__("default")))
465#    else
466#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT
467#    endif
468
469#  endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
470
471#  if __has_attribute(exclude_from_explicit_instantiation)
472#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__((__exclude_from_explicit_instantiation__))
473#  else
474// Try to approximate the effect of exclude_from_explicit_instantiation
475// (which is that entities are not assumed to be provided by explicit
476// template instantiations in the dylib) by always inlining those entities.
477#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
478#  endif
479
480#  ifdef _LIBCPP_COMPILER_CLANG_BASED
481#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
482#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
483#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
484#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
485#  elif defined(_LIBCPP_COMPILER_GCC)
486#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
487#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
488#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
489#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
490#  else
491#    define _LIBCPP_DIAGNOSTIC_PUSH
492#    define _LIBCPP_DIAGNOSTIC_POP
493#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
494#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
495#  endif
496
497#  if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_FAST
498#    define _LIBCPP_HARDENING_SIG f
499#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_EXTENSIVE
500#    define _LIBCPP_HARDENING_SIG s
501#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
502#    define _LIBCPP_HARDENING_SIG d
503#  else
504#    define _LIBCPP_HARDENING_SIG n // "none"
505#  endif
506
507#  ifdef _LIBCPP_HAS_NO_EXCEPTIONS
508#    define _LIBCPP_EXCEPTIONS_SIG n
509#  else
510#    define _LIBCPP_EXCEPTIONS_SIG e
511#  endif
512
513#  define _LIBCPP_ODR_SIGNATURE                                                                                        \
514    _LIBCPP_CONCAT(_LIBCPP_CONCAT(_LIBCPP_HARDENING_SIG, _LIBCPP_EXCEPTIONS_SIG), _LIBCPP_VERSION)
515
516// This macro marks a symbol as being hidden from libc++'s ABI. This is achieved
517// on two levels:
518// 1. The symbol is given hidden visibility, which ensures that users won't start exporting
519//    symbols from their dynamic library by means of using the libc++ headers. This ensures
520//    that those symbols stay private to the dynamic library in which it is defined.
521//
522// 2. The symbol is given an ABI tag that encodes the ODR-relevant properties of the library.
523//    This ensures that no ODR violation can arise from mixing two TUs compiled with different
524//    versions or configurations of libc++ (such as exceptions vs no-exceptions). Indeed, if the
525//    program contains two definitions of a function, the ODR requires them to be token-by-token
526//    equivalent, and the linker is allowed to pick either definition and discard the other one.
527//
528//    For example, if a program contains a copy of `vector::at()` compiled with exceptions enabled
529//    *and* a copy of `vector::at()` compiled with exceptions disabled (by means of having two TUs
530//    compiled with different settings), the two definitions are both visible by the linker and they
531//    have the same name, but they have a meaningfully different implementation (one throws an exception
532//    and the other aborts the program). This violates the ODR and makes the program ill-formed, and in
533//    practice what will happen is that the linker will pick one of the definitions at random and will
534//    discard the other one. This can quite clearly lead to incorrect program behavior.
535//
536//    A similar reasoning holds for many other properties that are ODR-affecting. Essentially any
537//    property that causes the code of a function to differ from the code in another configuration
538//    can be considered ODR-affecting. In practice, we don't encode all such properties in the ABI
539//    tag, but we encode the ones that we think are most important: library version, exceptions, and
540//    hardening mode.
541//
542//    Note that historically, solving this problem has been achieved in various ways, including
543//    force-inlining all functions or giving internal linkage to all functions. Both these previous
544//    solutions suffer from drawbacks that lead notably to code bloat.
545//
546// Note that we use _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION to ensure that we don't depend
547// on _LIBCPP_HIDE_FROM_ABI methods of classes explicitly instantiated in the dynamic library.
548//
549// Also note that the _LIBCPP_HIDE_FROM_ABI_VIRTUAL macro should be used on virtual functions
550// instead of _LIBCPP_HIDE_FROM_ABI. That macro does not use an ABI tag. Indeed, the mangled
551// name of a virtual function is part of its ABI, since some architectures like arm64e can sign
552// the virtual function pointer in the vtable based on the mangled name of the function. Since
553// we use an ABI tag that changes with each released version, the mangled name of the virtual
554// function would change, which is incorrect. Note that it doesn't make much sense to change
555// the implementation of a virtual function in an ABI-incompatible way in the first place,
556// since that would be an ABI break anyway. Hence, the lack of ABI tag should not be noticeable.
557//
558// The macro can be applied to record and enum types. When the tagged type is nested in
559// a record this "parent" record needs to have the macro too. Another use case for applying
560// this macro to records and unions is to apply an ABI tag to inline constexpr variables.
561// This can be useful for inline variables that are implementation details which are expected
562// to change in the future.
563//
564// TODO: We provide a escape hatch with _LIBCPP_NO_ABI_TAG for folks who want to avoid increasing
565//       the length of symbols with an ABI tag. In practice, we should remove the escape hatch and
566//       use compression mangling instead, see https://github.com/itanium-cxx-abi/cxx-abi/issues/70.
567#  ifndef _LIBCPP_NO_ABI_TAG
568#    define _LIBCPP_HIDE_FROM_ABI                                                                                      \
569      _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION                                                       \
570      __attribute__((__abi_tag__(_LIBCPP_TOSTRING(_LIBCPP_ODR_SIGNATURE))))
571#  else
572#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
573#  endif
574#  define _LIBCPP_HIDE_FROM_ABI_VIRTUAL _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
575
576#  ifdef _LIBCPP_BUILDING_LIBRARY
577#    if _LIBCPP_ABI_VERSION > 1
578#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
579#    else
580#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
581#    endif
582#  else
583#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
584#  endif
585
586// TODO: Remove this workaround once we drop support for Clang 16
587#  if __has_warning("-Wc++23-extensions")
588#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
589#  else
590#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++2b-extensions")
591#  endif
592
593// Clang modules take a significant compile time hit when pushing and popping diagnostics.
594// Since all the headers are marked as system headers in the modulemap, we can simply disable this
595// pushing and popping when building with clang modules.
596#  if !__has_feature(modules)
597#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                                                         \
598      _LIBCPP_DIAGNOSTIC_PUSH                                                                                          \
599      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++11-extensions")                                                           \
600      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                           \
601      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                           \
602      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                           \
603      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION                                                                 \
604      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                             \
605      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                             \
606      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                             \
607      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
608#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS _LIBCPP_DIAGNOSTIC_POP
609#  else
610#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS
611#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS
612#  endif
613
614// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
615// clang-format off
616#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                               \
617                                      namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {                                  \
618                               inline namespace _LIBCPP_ABI_NAMESPACE {
619#  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
620
621#ifdef _LIBCPP_ABI_NO_FILESYSTEM_INLINE_NAMESPACE
622#  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD namespace filesystem {
623#  define _LIBCPP_END_NAMESPACE_FILESYSTEM } _LIBCPP_END_NAMESPACE_STD
624#else
625#  define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM _LIBCPP_BEGIN_NAMESPACE_STD                                               \
626                                             inline namespace __fs { namespace filesystem {
627
628#  define _LIBCPP_END_NAMESPACE_FILESYSTEM }} _LIBCPP_END_NAMESPACE_STD
629#endif
630
631// clang-format on
632
633#  if __has_attribute(__enable_if__)
634#    define _LIBCPP_PREFERRED_OVERLOAD __attribute__((__enable_if__(true, "")))
635#  endif
636
637#  if !defined(__SIZEOF_INT128__) || defined(_MSC_VER)
638#    define _LIBCPP_HAS_NO_INT128
639#  endif
640
641#  ifdef _LIBCPP_CXX03_LANG
642#    define _LIBCPP_DECLARE_STRONG_ENUM(x)                                                                             \
643      struct _LIBCPP_EXPORTED_FROM_ABI x {                                                                             \
644        enum __lx
645// clang-format off
646#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)                                                                      \
647      __lx __v_;                                                                                                       \
648      _LIBCPP_HIDE_FROM_ABI x(__lx __v) : __v_(__v) {}                                                                 \
649      _LIBCPP_HIDE_FROM_ABI explicit x(int __v) : __v_(static_cast<__lx>(__v)) {}                                      \
650      _LIBCPP_HIDE_FROM_ABI operator int() const { return __v_; }                                                      \
651      };
652// clang-format on
653
654#  else // _LIBCPP_CXX03_LANG
655#    define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class x
656#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
657#  endif // _LIBCPP_CXX03_LANG
658
659#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || defined(__NetBSD__)
660#    define _LIBCPP_LOCALE__L_EXTENSIONS 1
661#  endif
662
663#  ifdef __FreeBSD__
664#    define _DECLARE_C99_LDBL_MATH 1
665#  endif
666
667// If we are getting operator new from the MSVC CRT, then allocation overloads
668// for align_val_t were added in 19.12, aka VS 2017 version 15.3.
669#  if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
670#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
671#  elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
672// We're deferring to Microsoft's STL to provide aligned new et al. We don't
673// have it unless the language feature test macro is defined.
674#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
675#  elif defined(__MVS__)
676#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
677#  endif
678
679#  if defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) || (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
680#    define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
681#  endif
682
683// It is not yet possible to use aligned_alloc() on all Apple platforms since
684// 10.15 was the first version to ship an implementation of aligned_alloc().
685#  if defined(__APPLE__)
686#    if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                                                     \
687         __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101500)
688#      define _LIBCPP_HAS_NO_C11_ALIGNED_ALLOC
689#    endif
690#  elif defined(__ANDROID__) && __ANDROID_API__ < 28
691// Android only provides aligned_alloc when targeting API 28 or higher.
692#    define _LIBCPP_HAS_NO_C11_ALIGNED_ALLOC
693#  endif
694
695#  if defined(__APPLE__) || defined(__FreeBSD__)
696#    define _LIBCPP_HAS_DEFAULTRUNELOCALE
697#  endif
698
699#  if defined(__APPLE__) || defined(__FreeBSD__)
700#    define _LIBCPP_WCTYPE_IS_MASK
701#  endif
702
703#  if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
704#    define _LIBCPP_HAS_NO_CHAR8_T
705#  endif
706
707// Deprecation macros.
708//
709// Deprecations warnings are always enabled, except when users explicitly opt-out
710// by defining _LIBCPP_DISABLE_DEPRECATION_WARNINGS.
711#  if !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
712#    if __has_attribute(__deprecated__)
713#      define _LIBCPP_DEPRECATED __attribute__((__deprecated__))
714#      define _LIBCPP_DEPRECATED_(m) __attribute__((__deprecated__(m)))
715#    elif _LIBCPP_STD_VER >= 14
716#      define _LIBCPP_DEPRECATED [[deprecated]]
717#      define _LIBCPP_DEPRECATED_(m) [[deprecated(m)]]
718#    else
719#      define _LIBCPP_DEPRECATED
720#      define _LIBCPP_DEPRECATED_(m)
721#    endif
722#  else
723#    define _LIBCPP_DEPRECATED
724#    define _LIBCPP_DEPRECATED_(m)
725#  endif
726
727#  if _LIBCPP_STD_VER < 20
728#    define _LIBCPP_DEPRECATED_ATOMIC_SYNC                                                                             \
729      _LIBCPP_DEPRECATED_("The C++20 synchronization library has been deprecated prior to C++20. Please update to "    \
730                          "using -std=c++20 if you need to use these facilities.")
731#  else
732#    define _LIBCPP_DEPRECATED_ATOMIC_SYNC /* nothing */
733#  endif
734
735#  if !defined(_LIBCPP_CXX03_LANG)
736#    define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
737#  else
738#    define _LIBCPP_DEPRECATED_IN_CXX11
739#  endif
740
741#  if _LIBCPP_STD_VER >= 14
742#    define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
743#  else
744#    define _LIBCPP_DEPRECATED_IN_CXX14
745#  endif
746
747#  if _LIBCPP_STD_VER >= 17
748#    define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
749#  else
750#    define _LIBCPP_DEPRECATED_IN_CXX17
751#  endif
752
753#  if _LIBCPP_STD_VER >= 20
754#    define _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_DEPRECATED
755#  else
756#    define _LIBCPP_DEPRECATED_IN_CXX20
757#  endif
758
759#  if _LIBCPP_STD_VER >= 23
760#    define _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_DEPRECATED
761#  else
762#    define _LIBCPP_DEPRECATED_IN_CXX23
763#  endif
764
765#  if _LIBCPP_STD_VER >= 26
766#    define _LIBCPP_DEPRECATED_IN_CXX26 _LIBCPP_DEPRECATED
767#  else
768#    define _LIBCPP_DEPRECATED_IN_CXX26
769#  endif
770
771#  if !defined(_LIBCPP_HAS_NO_CHAR8_T)
772#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T _LIBCPP_DEPRECATED
773#  else
774#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T
775#  endif
776
777// Macros to enter and leave a state where deprecation warnings are suppressed.
778#  if defined(_LIBCPP_COMPILER_CLANG_BASED) || defined(_LIBCPP_COMPILER_GCC)
779#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH                                                                           \
780      _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated\"")                                \
781          _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
782#    define _LIBCPP_SUPPRESS_DEPRECATED_POP _Pragma("GCC diagnostic pop")
783#  else
784#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH
785#    define _LIBCPP_SUPPRESS_DEPRECATED_POP
786#  endif
787
788#  if _LIBCPP_STD_VER <= 11
789#    define _LIBCPP_EXPLICIT_SINCE_CXX14
790#  else
791#    define _LIBCPP_EXPLICIT_SINCE_CXX14 explicit
792#  endif
793
794#  if _LIBCPP_STD_VER >= 23
795#    define _LIBCPP_EXPLICIT_SINCE_CXX23 explicit
796#  else
797#    define _LIBCPP_EXPLICIT_SINCE_CXX23
798#  endif
799
800#  if _LIBCPP_STD_VER >= 14
801#    define _LIBCPP_CONSTEXPR_SINCE_CXX14 constexpr
802#  else
803#    define _LIBCPP_CONSTEXPR_SINCE_CXX14
804#  endif
805
806#  if _LIBCPP_STD_VER >= 17
807#    define _LIBCPP_CONSTEXPR_SINCE_CXX17 constexpr
808#  else
809#    define _LIBCPP_CONSTEXPR_SINCE_CXX17
810#  endif
811
812#  if _LIBCPP_STD_VER >= 20
813#    define _LIBCPP_CONSTEXPR_SINCE_CXX20 constexpr
814#  else
815#    define _LIBCPP_CONSTEXPR_SINCE_CXX20
816#  endif
817
818#  if _LIBCPP_STD_VER >= 23
819#    define _LIBCPP_CONSTEXPR_SINCE_CXX23 constexpr
820#  else
821#    define _LIBCPP_CONSTEXPR_SINCE_CXX23
822#  endif
823
824#  ifndef _LIBCPP_WEAK
825#    define _LIBCPP_WEAK __attribute__((__weak__))
826#  endif
827
828// Thread API
829// clang-format off
830#  if !defined(_LIBCPP_HAS_NO_THREADS) &&                                                                              \
831      !defined(_LIBCPP_HAS_THREAD_API_PTHREAD) &&                                                                      \
832      !defined(_LIBCPP_HAS_THREAD_API_WIN32) &&                                                                        \
833      !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
834
835#    if defined(__FreeBSD__) ||                                                                                        \
836        defined(__wasi__) ||                                                                                           \
837        defined(__NetBSD__) ||                                                                                         \
838        defined(__OpenBSD__) ||                                                                                        \
839        defined(__NuttX__) ||                                                                                          \
840        defined(__linux__) ||                                                                                          \
841        defined(__GNU__) ||                                                                                            \
842        defined(__APPLE__) ||                                                                                          \
843        defined(__MVS__) ||                                                                                            \
844        defined(_AIX) ||                                                                                               \
845        defined(__EMSCRIPTEN__)
846// clang-format on
847#      define _LIBCPP_HAS_THREAD_API_PTHREAD
848#    elif defined(__Fuchsia__)
849// TODO(44575): Switch to C11 thread API when possible.
850#      define _LIBCPP_HAS_THREAD_API_PTHREAD
851#    elif defined(_LIBCPP_WIN32API)
852#      define _LIBCPP_HAS_THREAD_API_WIN32
853#    else
854#      error "No thread API"
855#    endif // _LIBCPP_HAS_THREAD_API
856#  endif   // _LIBCPP_HAS_NO_THREADS
857
858#  if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
859#    if defined(__ANDROID__) && __ANDROID_API__ >= 30
860#      define _LIBCPP_HAS_COND_CLOCKWAIT
861#    elif defined(_LIBCPP_GLIBC_PREREQ)
862#      if _LIBCPP_GLIBC_PREREQ(2, 30)
863#        define _LIBCPP_HAS_COND_CLOCKWAIT
864#      endif
865#    endif
866#  endif
867
868#  if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
869#    error _LIBCPP_HAS_THREAD_API_PTHREAD may only be defined when \
870       _LIBCPP_HAS_NO_THREADS is not defined.
871#  endif
872
873#  if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
874#    error _LIBCPP_HAS_THREAD_API_EXTERNAL may not be defined when \
875       _LIBCPP_HAS_NO_THREADS is defined.
876#  endif
877
878#  if defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(_LIBCPP_HAS_NO_THREADS)
879#    error _LIBCPP_HAS_NO_MONOTONIC_CLOCK may only be defined when \
880       _LIBCPP_HAS_NO_THREADS is defined.
881#  endif
882
883#  if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(__STDCPP_THREADS__)
884#    define __STDCPP_THREADS__ 1
885#  endif
886
887// The glibc and Bionic implementation of pthreads implements
888// pthread_mutex_destroy as nop for regular mutexes. Additionally, Win32
889// mutexes have no destroy mechanism.
890//
891// This optimization can't be performed on Apple platforms, where
892// pthread_mutex_destroy can allow the kernel to release resources.
893// See https://llvm.org/D64298 for details.
894//
895// TODO(EricWF): Enable this optimization on Bionic after speaking to their
896//               respective stakeholders.
897// clang-format off
898#  if (defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && defined(__GLIBC__)) ||                                               \
899      (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) ||                                                 \
900       defined(_LIBCPP_HAS_THREAD_API_WIN32)
901// clang-format on
902#    define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION
903#  endif
904
905// Destroying a condvar is a nop on Windows.
906//
907// This optimization can't be performed on Apple platforms, where
908// pthread_cond_destroy can allow the kernel to release resources.
909// See https://llvm.org/D64298 for details.
910//
911// TODO(EricWF): This is potentially true for some pthread implementations
912// as well.
913#  if (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) || defined(_LIBCPP_HAS_THREAD_API_WIN32)
914#    define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
915#  endif
916
917#  if defined(__BIONIC__) || defined(__NuttX__) || defined(__Fuchsia__) || defined(__wasi__) ||                        \
918      defined(_LIBCPP_HAS_MUSL_LIBC) || defined(__OpenBSD__)
919#    define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
920#  endif
921
922#  if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
923#    define _LIBCPP_HAS_C_ATOMIC_IMP
924#  elif defined(_LIBCPP_COMPILER_GCC)
925#    define _LIBCPP_HAS_GCC_ATOMIC_IMP
926#  endif
927
928#  if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) &&                                    \
929      !defined(_LIBCPP_HAS_EXTERNAL_ATOMIC_IMP)
930#    define _LIBCPP_HAS_NO_ATOMIC_HEADER
931#  else
932#    ifndef _LIBCPP_ATOMIC_FLAG_TYPE
933#      define _LIBCPP_ATOMIC_FLAG_TYPE bool
934#    endif
935#  endif
936
937#  if defined(__FreeBSD__) && defined(__clang__) && __has_attribute(__no_thread_safety_analysis__)
938#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS __attribute__((__no_thread_safety_analysis__))
939#  else
940#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
941#  endif
942
943#  if defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS)
944#    if defined(__clang__) && __has_attribute(acquire_capability)
945// Work around the attribute handling in clang.  When both __declspec and
946// __attribute__ are present, the processing goes awry preventing the definition
947// of the types. In MinGW mode, __declspec evaluates to __attribute__, and thus
948// combining the two does work.
949#      if !defined(_MSC_VER)
950#        define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
951#      endif
952#    endif
953#  endif
954
955#  ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
956#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
957#  else
958#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
959#  endif
960
961#  if _LIBCPP_STD_VER >= 20
962#    define _LIBCPP_CONSTINIT constinit
963#  elif __has_attribute(__require_constant_initialization__)
964#    define _LIBCPP_CONSTINIT __attribute__((__require_constant_initialization__))
965#  else
966#    define _LIBCPP_CONSTINIT
967#  endif
968
969#  if defined(__CUDACC__) || defined(__CUDA_ARCH__) || defined(__CUDA_LIBDEVICE__)
970// The CUDA SDK contains an unfortunate definition for the __noinline__ macro,
971// which breaks the regular __attribute__((__noinline__)) syntax. Therefore,
972// when compiling for CUDA we use the non-underscored version of the noinline
973// attribute.
974//
975// This is a temporary workaround and we still expect the CUDA SDK team to solve
976// this issue properly in the SDK headers.
977//
978// See https://github.com/llvm/llvm-project/pull/73838 for more details.
979#    define _LIBCPP_NOINLINE __attribute__((noinline))
980#  elif __has_attribute(__noinline__)
981#    define _LIBCPP_NOINLINE __attribute__((__noinline__))
982#  else
983#    define _LIBCPP_NOINLINE
984#  endif
985
986// We often repeat things just for handling wide characters in the library.
987// When wide characters are disabled, it can be useful to have a quick way of
988// disabling it without having to resort to #if-#endif, which has a larger
989// impact on readability.
990#  if defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
991#    define _LIBCPP_IF_WIDE_CHARACTERS(...)
992#  else
993#    define _LIBCPP_IF_WIDE_CHARACTERS(...) __VA_ARGS__
994#  endif
995
996// clang-format off
997#  define _LIBCPP_PUSH_MACROS _Pragma("push_macro(\"min\")") _Pragma("push_macro(\"max\")") _Pragma("push_macro(\"refresh\")") _Pragma("push_macro(\"move\")") _Pragma("push_macro(\"erase\")")
998#  define _LIBCPP_POP_MACROS _Pragma("pop_macro(\"min\")") _Pragma("pop_macro(\"max\")") _Pragma("pop_macro(\"refresh\")") _Pragma("pop_macro(\"move\")") _Pragma("pop_macro(\"erase\")")
999// clang-format on
1000
1001#  ifndef _LIBCPP_NO_AUTO_LINK
1002#    if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
1003#      if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
1004#        pragma comment(lib, "c++.lib")
1005#      else
1006#        pragma comment(lib, "libc++.lib")
1007#      endif
1008#    endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
1009#  endif   // _LIBCPP_NO_AUTO_LINK
1010
1011// Configures the fopen close-on-exec mode character, if any. This string will
1012// be appended to any mode string used by fstream for fopen/fdopen.
1013//
1014// Not all platforms support this, but it helps avoid fd-leaks on platforms that
1015// do.
1016#  if defined(__BIONIC__)
1017#    define _LIBCPP_FOPEN_CLOEXEC_MODE "e"
1018#  else
1019#    define _LIBCPP_FOPEN_CLOEXEC_MODE
1020#  endif
1021
1022#  if __has_cpp_attribute(msvc::no_unique_address)
1023// MSVC implements [[no_unique_address]] as a silent no-op currently.
1024// (If/when MSVC breaks its C++ ABI, it will be changed to work as intended.)
1025// However, MSVC implements [[msvc::no_unique_address]] which does what
1026// [[no_unique_address]] is supposed to do, in general.
1027
1028// Clang-cl does not yet (14.0) implement either [[no_unique_address]] or
1029// [[msvc::no_unique_address]] though. If/when it does implement
1030// [[msvc::no_unique_address]], this should be preferred though.
1031#    define _LIBCPP_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
1032#  elif __has_cpp_attribute(no_unique_address)
1033#    define _LIBCPP_NO_UNIQUE_ADDRESS [[__no_unique_address__]]
1034#  else
1035#    define _LIBCPP_NO_UNIQUE_ADDRESS /* nothing */
1036// Note that this can be replaced by #error as soon as clang-cl
1037// implements msvc::no_unique_address, since there should be no C++20
1038// compiler that doesn't support one of the two attributes at that point.
1039// We generally don't want to use this macro outside of C++20-only code,
1040// because using it conditionally in one language version only would make
1041// the ABI inconsistent.
1042#  endif
1043
1044// c8rtomb() and mbrtoc8() were added in C++20 and C23. Support for these
1045// functions is gradually being added to existing C libraries. The conditions
1046// below check for known C library versions and conditions under which these
1047// functions are declared by the C library.
1048#  define _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8
1049// GNU libc 2.36 and newer declare c8rtomb() and mbrtoc8() in C++ modes if
1050// __cpp_char8_t is defined or if C2X extensions are enabled. Determining
1051// the latter depends on internal GNU libc details that are not appropriate
1052// to depend on here, so any declarations present when __cpp_char8_t is not
1053// defined are ignored.
1054#  if defined(_LIBCPP_GLIBC_PREREQ)
1055#    if _LIBCPP_GLIBC_PREREQ(2, 36) && defined(__cpp_char8_t)
1056#      undef _LIBCPP_HAS_NO_C8RTOMB_MBRTOC8
1057#    endif
1058#  endif
1059
1060// There are a handful of public standard library types that are intended to
1061// support CTAD but don't need any explicit deduction guides to do so. This
1062// macro is used to mark them as such, which suppresses the
1063// '-Wctad-maybe-unsupported' compiler warning when CTAD is used in user code
1064// with these classes.
1065#  if _LIBCPP_STD_VER >= 17
1066#    ifdef _LIBCPP_COMPILER_CLANG_BASED
1067#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName)                                                              \
1068        template <class... _Tag>                                                                                       \
1069        [[maybe_unused]] _ClassName(typename _Tag::__allow_ctad...)->_ClassName<_Tag...>
1070#    else
1071#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(ClassName)                                                               \
1072        template <class... _Tag>                                                                                       \
1073        ClassName(typename _Tag::__allow_ctad...)->ClassName<_Tag...>
1074#    endif
1075#  else
1076#    define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName) static_assert(true, "")
1077#  endif
1078
1079// TODO(varconst): currently, there are bugs in Clang's intrinsics when handling Objective-C++ `id`, so don't use
1080// compiler intrinsics in the Objective-C++ mode.
1081#  ifdef __OBJC__
1082#    define _LIBCPP_WORKAROUND_OBJCXX_COMPILER_INTRINSICS
1083#  endif
1084
1085#  define _PSTL_PRAGMA(x) _Pragma(#x)
1086
1087// Enable SIMD for compilers that support OpenMP 4.0
1088#  if (defined(_OPENMP) && _OPENMP >= 201307)
1089
1090#    define _PSTL_UDR_PRESENT
1091#    define _PSTL_PRAGMA_SIMD _PSTL_PRAGMA(omp simd)
1092#    define _PSTL_PRAGMA_DECLARE_SIMD _PSTL_PRAGMA(omp declare simd)
1093#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _PSTL_PRAGMA(omp simd reduction(PRM))
1094#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
1095#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
1096#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
1097
1098// Declaration of reduction functor, where
1099// NAME - the name of the functor
1100// OP - type of the callable object with the reduction operation
1101// omp_in - refers to the local partial result
1102// omp_out - refers to the final value of the combiner operator
1103// omp_priv - refers to the private copy of the initial value
1104// omp_orig - refers to the original variable to be reduced
1105#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)                                                                   \
1106      _PSTL_PRAGMA(omp declare reduction(NAME:OP : omp_out(omp_in)) initializer(omp_priv = omp_orig))
1107
1108#  elif defined(_LIBCPP_COMPILER_CLANG_BASED)
1109
1110#    define _PSTL_PRAGMA_SIMD _Pragma("clang loop vectorize(enable) interleave(enable)")
1111#    define _PSTL_PRAGMA_DECLARE_SIMD
1112#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1113#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1114#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1115#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1116#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1117
1118#  else // (defined(_OPENMP) && _OPENMP >= 201307)
1119
1120#    define _PSTL_PRAGMA_SIMD
1121#    define _PSTL_PRAGMA_DECLARE_SIMD
1122#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM)
1123#    define _PSTL_PRAGMA_SIMD_SCAN(PRM)
1124#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1125#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1126#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1127
1128#  endif // (defined(_OPENMP) && _OPENMP >= 201307)
1129
1130#  define _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
1131
1132// Optional attributes - these are useful for a better QoI, but not required to be available
1133
1134#  if __has_attribute(__no_sanitize__) && !defined(_LIBCPP_COMPILER_GCC)
1135#    define _LIBCPP_NO_CFI __attribute__((__no_sanitize__("cfi")))
1136#  else
1137#    define _LIBCPP_NO_CFI
1138#  endif
1139
1140#  if __has_attribute(__malloc__)
1141#    define _LIBCPP_NOALIAS __attribute__((__malloc__))
1142#  else
1143#    define _LIBCPP_NOALIAS
1144#  endif
1145
1146#  if __has_attribute(__using_if_exists__)
1147#    define _LIBCPP_USING_IF_EXISTS __attribute__((__using_if_exists__))
1148#  else
1149#    define _LIBCPP_USING_IF_EXISTS
1150#  endif
1151
1152#  if __has_cpp_attribute(__nodiscard__)
1153#    define _LIBCPP_NODISCARD [[__nodiscard__]]
1154#  else
1155// We can't use GCC's [[gnu::warn_unused_result]] and
1156// __attribute__((warn_unused_result)), because GCC does not silence them via
1157// (void) cast.
1158#    define _LIBCPP_NODISCARD
1159#  endif
1160
1161#  if __has_attribute(__no_destroy__)
1162#    define _LIBCPP_NO_DESTROY __attribute__((__no_destroy__))
1163#  else
1164#    define _LIBCPP_NO_DESTROY
1165#  endif
1166
1167#  if __has_attribute(__diagnose_if__)
1168#    define _LIBCPP_DIAGNOSE_WARNING(...) __attribute__((__diagnose_if__(__VA_ARGS__, "warning")))
1169#  else
1170#    define _LIBCPP_DIAGNOSE_WARNING(...)
1171#  endif
1172
1173// Use a function like macro to imply that it must be followed by a semicolon
1174#  if __has_cpp_attribute(fallthrough)
1175#    define _LIBCPP_FALLTHROUGH() [[fallthrough]]
1176#  elif __has_attribute(__fallthrough__)
1177#    define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
1178#  else
1179#    define _LIBCPP_FALLTHROUGH() ((void)0)
1180#  endif
1181
1182#  if __has_cpp_attribute(_Clang::__lifetimebound__)
1183#    define _LIBCPP_LIFETIMEBOUND [[_Clang::__lifetimebound__]]
1184#  else
1185#    define _LIBCPP_LIFETIMEBOUND
1186#  endif
1187
1188#  if __has_attribute(__nodebug__)
1189#    define _LIBCPP_NODEBUG __attribute__((__nodebug__))
1190#  else
1191#    define _LIBCPP_NODEBUG
1192#  endif
1193
1194#  if __has_attribute(__standalone_debug__)
1195#    define _LIBCPP_STANDALONE_DEBUG __attribute__((__standalone_debug__))
1196#  else
1197#    define _LIBCPP_STANDALONE_DEBUG
1198#  endif
1199
1200#  if __has_attribute(__preferred_name__)
1201#    define _LIBCPP_PREFERRED_NAME(x) __attribute__((__preferred_name__(x)))
1202#  else
1203#    define _LIBCPP_PREFERRED_NAME(x)
1204#  endif
1205
1206#  if __has_attribute(__no_sanitize__)
1207#    define _LIBCPP_NO_SANITIZE(...) __attribute__((__no_sanitize__(__VA_ARGS__)))
1208#  else
1209#    define _LIBCPP_NO_SANITIZE(...)
1210#  endif
1211
1212#  if __has_attribute(__init_priority__)
1213#    define _LIBCPP_INIT_PRIORITY_MAX __attribute__((__init_priority__(100)))
1214#  else
1215#    define _LIBCPP_INIT_PRIORITY_MAX
1216#  endif
1217
1218#  if __has_attribute(__format__)
1219// The attribute uses 1-based indices for ordinary and static member functions.
1220// The attribute uses 2-based indices for non-static member functions.
1221#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index)                           \
1222      __attribute__((__format__(archetype, format_string_index, first_format_arg_index)))
1223#  else
1224#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index) /* nothing */
1225#  endif
1226
1227#  if __has_attribute(__packed__)
1228#    define _LIBCPP_PACKED __attribute__((__packed__))
1229#  else
1230#    define _LIBCPP_PACKED
1231#  endif
1232
1233#  if defined(_LIBCPP_ABI_MICROSOFT) && __has_declspec_attribute(empty_bases)
1234#    define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
1235#  else
1236#    define _LIBCPP_DECLSPEC_EMPTY_BASES
1237#  endif
1238
1239// Allow for build-time disabling of unsigned integer sanitization
1240#  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
1241#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
1242#  else
1243#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1244#  endif
1245
1246// Clang-18 has support for deducing this, but it does not set the FTM.
1247#  if defined(__cpp_explicit_this_parameter) || (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1800)
1248#    define _LIBCPP_HAS_EXPLICIT_THIS_PARAMETER
1249#  endif
1250
1251#endif // __cplusplus
1252
1253#endif // _LIBCPP___CONFIG
1254