xref: /llvm-project/libcxx/include/__config (revision 3bd3e06f3fe418e24af65457877f40cee0544f9d)
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/language.h>
18#include <__configuration/platform.h>
19
20#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
21#  pragma GCC system_header
22#endif
23
24#ifdef __cplusplus
25
26// The attributes supported by clang are documented at https://clang.llvm.org/docs/AttributeReference.html
27
28// _LIBCPP_VERSION represents the version of libc++, which matches the version of LLVM.
29// Given a LLVM release LLVM XX.YY.ZZ (e.g. LLVM 17.0.1 == 17.00.01), _LIBCPP_VERSION is
30// defined to XXYYZZ.
31#  define _LIBCPP_VERSION 210000
32
33#  define _LIBCPP_CONCAT_IMPL(_X, _Y) _X##_Y
34#  define _LIBCPP_CONCAT(_X, _Y) _LIBCPP_CONCAT_IMPL(_X, _Y)
35#  define _LIBCPP_CONCAT3(X, Y, Z) _LIBCPP_CONCAT(X, _LIBCPP_CONCAT(Y, Z))
36
37#  if __STDC_HOSTED__ == 0
38#    define _LIBCPP_FREESTANDING
39#  endif
40
41// HARDENING {
42
43// TODO: Remove in LLVM 21. We're making this an error to catch folks who might not have migrated.
44#  ifdef _LIBCPP_ENABLE_ASSERTIONS
45#    error "_LIBCPP_ENABLE_ASSERTIONS has been removed, please use _LIBCPP_HARDENING_MODE instead"
46#  endif
47
48// The library provides the macro `_LIBCPP_HARDENING_MODE` which can be set to one of the following values:
49//
50// - `_LIBCPP_HARDENING_MODE_NONE`;
51// - `_LIBCPP_HARDENING_MODE_FAST`;
52// - `_LIBCPP_HARDENING_MODE_EXTENSIVE`;
53// - `_LIBCPP_HARDENING_MODE_DEBUG`.
54//
55// These values have the following effects:
56//
57// - `_LIBCPP_HARDENING_MODE_NONE` -- sets the hardening mode to "none" which disables all runtime hardening checks;
58//
59// - `_LIBCPP_HARDENING_MODE_FAST` -- sets that hardening mode to "fast". The fast mode enables security-critical checks
60//   that can be done with relatively little runtime overhead in constant time;
61//
62// - `_LIBCPP_HARDENING_MODE_EXTENSIVE` -- sets the hardening mode to "extensive". The extensive mode is a superset of
63//   the fast mode that additionally enables checks that are relatively cheap and prevent common types of logic errors
64//   but are not necessarily security-critical;
65//
66// - `_LIBCPP_HARDENING_MODE_DEBUG` -- sets the hardening mode to "debug". The debug mode is a superset of the extensive
67//   mode and enables all checks available in the library, including internal assertions. Checks that are part of the
68//   debug mode can be very expensive and thus the debug mode is intended to be used for testing, not in production.
69
70// Inside the library, assertions are categorized so they can be cherry-picked based on the chosen hardening mode. These
71// macros are only for internal use -- users should only pick one of the high-level hardening modes described above.
72//
73// - `_LIBCPP_ASSERT_VALID_INPUT_RANGE` -- checks that ranges (whether expressed as an iterator pair, an iterator and
74//   a sentinel, an iterator and a count, or a `std::range`) given as input to library functions are valid:
75//   - the sentinel is reachable from the begin iterator;
76//   - TODO(hardening): both iterators refer to the same container.
77//
78// - `_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS` -- checks that any attempts to access a container element, whether through
79//   the container object or through an iterator, are valid and do not attempt to go out of bounds or otherwise access
80//   a non-existent element. For iterator checks to work, bounded iterators must be enabled in the ABI. Types like
81//   `optional` and `function` are considered one-element containers for the purposes of this check.
82//
83// - `_LIBCPP_ASSERT_NON_NULL` -- checks that the pointer being dereferenced is not null. On most modern platforms zero
84//   address does not refer to an actual location in memory, so a null pointer dereference would not compromize the
85//   memory security of a program (however, it is still undefined behavior that can result in strange errors due to
86//   compiler optimizations).
87//
88// - `_LIBCPP_ASSERT_NON_OVERLAPPING_RANGES` -- for functions that take several ranges as arguments, checks that the
89//   given ranges do not overlap.
90//
91// - `_LIBCPP_ASSERT_VALID_DEALLOCATION` -- checks that an attempt to deallocate memory is valid (e.g. the given object
92//   was allocated by the given allocator). Violating this category typically results in a memory leak.
93//
94// - `_LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL` -- checks that a call to an external API doesn't fail in
95//   an unexpected manner. This includes triggering documented cases of undefined behavior in an external library (like
96//   attempting to unlock an unlocked mutex in pthreads). Any API external to the library falls under this category
97//   (from system calls to compiler intrinsics). We generally don't expect these failures to compromize memory safety or
98//   otherwise create an immediate security issue.
99//
100// - `_LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR` -- checks any operations that exchange nodes between containers to make sure
101//   the containers have compatible allocators.
102//
103// - `_LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN` -- checks that the given argument is within the domain of valid arguments
104//   for the function. Violating this typically produces an incorrect result (e.g. the clamp algorithm returns the
105//   original value without clamping it due to incorrect functors) or puts an object into an invalid state (e.g.
106//   a string view where only a subset of elements is possible to access). This category is for assertions violating
107//   which doesn't cause any immediate issues in the library -- whatever the consequences are, they will happen in the
108//   user code.
109//
110// - `_LIBCPP_ASSERT_PEDANTIC` -- checks prerequisites which are imposed by the Standard, but violating which happens to
111//   be benign in our implementation.
112//
113// - `_LIBCPP_ASSERT_SEMANTIC_REQUIREMENT` -- checks that the given argument satisfies the semantic requirements imposed
114//   by the Standard. Typically, there is no simple way to completely prove that a semantic requirement is satisfied;
115//   thus, this would often be a heuristic check and it might be quite expensive.
116//
117// - `_LIBCPP_ASSERT_INTERNAL` -- checks that internal invariants of the library hold. These assertions don't depend on
118//   user input.
119//
120// - `_LIBCPP_ASSERT_UNCATEGORIZED` -- for assertions that haven't been properly classified yet.
121
122// clang-format off
123#  define _LIBCPP_HARDENING_MODE_NONE      (1 << 1)
124#  define _LIBCPP_HARDENING_MODE_FAST      (1 << 2)
125#  define _LIBCPP_HARDENING_MODE_EXTENSIVE (1 << 4) // Deliberately not ordered.
126#  define _LIBCPP_HARDENING_MODE_DEBUG     (1 << 3)
127// clang-format on
128
129#  ifndef _LIBCPP_HARDENING_MODE
130
131#    ifndef _LIBCPP_HARDENING_MODE_DEFAULT
132#      error _LIBCPP_HARDENING_MODE_DEFAULT is not defined. This definition should be set at configuration time in the \
133`__config_site` header, please make sure your installation of libc++ is not broken.
134#    endif
135
136#    define _LIBCPP_HARDENING_MODE _LIBCPP_HARDENING_MODE_DEFAULT
137#  endif
138
139#  if _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_NONE &&                                                         \
140      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_FAST &&                                                         \
141      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_EXTENSIVE &&                                                    \
142      _LIBCPP_HARDENING_MODE != _LIBCPP_HARDENING_MODE_DEBUG
143#    error _LIBCPP_HARDENING_MODE must be set to one of the following values: \
144_LIBCPP_HARDENING_MODE_NONE, \
145_LIBCPP_HARDENING_MODE_FAST, \
146_LIBCPP_HARDENING_MODE_EXTENSIVE, \
147_LIBCPP_HARDENING_MODE_DEBUG
148#  endif
149
150// } HARDENING
151
152#  define _LIBCPP_TOSTRING2(x) #x
153#  define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)
154
155// NOLINTNEXTLINE(libcpp-cpp-version-check)
156#  if __cplusplus < 201103L
157#    define _LIBCPP_CXX03_LANG
158#  endif
159
160#  ifndef __has_constexpr_builtin
161#    define __has_constexpr_builtin(x) 0
162#  endif
163
164// This checks wheter a Clang module is built
165#  ifndef __building_module
166#    define __building_module(...) 0
167#  endif
168
169// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
170// the compiler and '1' otherwise.
171#  ifndef __is_identifier
172#    define __is_identifier(__x) 1
173#  endif
174
175#  ifndef __has_declspec_attribute
176#    define __has_declspec_attribute(__x) 0
177#  endif
178
179#  define __has_keyword(__x) !(__is_identifier(__x))
180
181#  ifndef __has_warning
182#    define __has_warning(...) 0
183#  endif
184
185#  if !defined(_LIBCPP_COMPILER_CLANG_BASED) && __cplusplus < 201103L
186#    error "libc++ only supports C++03 with Clang-based compilers. Please enable C++11"
187#  endif
188
189#  if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
190#    define _LIBCPP_ABI_VCRUNTIME
191#  endif
192
193#  if __has_feature(experimental_library)
194#    ifndef _LIBCPP_ENABLE_EXPERIMENTAL
195#      define _LIBCPP_ENABLE_EXPERIMENTAL
196#    endif
197#  endif
198
199// Incomplete features get their own specific disabling flags. This makes it
200// easier to grep for target specific flags once the feature is complete.
201#  if defined(_LIBCPP_ENABLE_EXPERIMENTAL) || defined(_LIBCPP_BUILDING_LIBRARY)
202#    define _LIBCPP_HAS_EXPERIMENTAL_LIBRARY 1
203#  else
204#    define _LIBCPP_HAS_EXPERIMENTAL_LIBRARY 0
205#  endif
206
207#  define _LIBCPP_HAS_EXPERIMENTAL_PSTL _LIBCPP_HAS_EXPERIMENTAL_LIBRARY
208#  define _LIBCPP_HAS_EXPERIMENTAL_TZDB _LIBCPP_HAS_EXPERIMENTAL_LIBRARY
209#  define _LIBCPP_HAS_EXPERIMENTAL_SYNCSTREAM _LIBCPP_HAS_EXPERIMENTAL_LIBRARY
210
211#  if defined(__MVS__)
212#    include <features.h> // for __NATIVE_ASCII_F
213#  endif
214
215#  if defined(_WIN32)
216#    define _LIBCPP_WIN32API
217#    define _LIBCPP_SHORT_WCHAR 1
218// Both MinGW and native MSVC provide a "MSVC"-like environment
219#    define _LIBCPP_MSVCRT_LIKE
220// If mingw not explicitly detected, assume using MS C runtime only if
221// a MS compatibility version is specified.
222#    if defined(_MSC_VER) && !defined(__MINGW32__)
223#      define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
224#    endif
225#    if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
226#      define _LIBCPP_HAS_BITSCAN64 1
227#    else
228#      define _LIBCPP_HAS_BITSCAN64 0
229#    endif
230#    define _LIBCPP_HAS_OPEN_WITH_WCHAR 1
231#  else
232#    define _LIBCPP_HAS_OPEN_WITH_WCHAR 0
233#    define _LIBCPP_HAS_BITSCAN64 0
234#  endif // defined(_WIN32)
235
236#  if defined(_AIX) && !defined(__64BIT__)
237// The size of wchar is 2 byte on 32-bit mode on AIX.
238#    define _LIBCPP_SHORT_WCHAR 1
239#  endif
240
241// Libc++ supports various implementations of std::random_device.
242//
243// _LIBCPP_USING_DEV_RANDOM
244//      Read entropy from the given file, by default `/dev/urandom`.
245//      If a token is provided, it is assumed to be the path to a file
246//      to read entropy from. This is the default behavior if nothing
247//      else is specified. This implementation requires storing state
248//      inside `std::random_device`.
249//
250// _LIBCPP_USING_ARC4_RANDOM
251//      Use arc4random(). This allows obtaining random data even when
252//      using sandboxing mechanisms. On some platforms like Apple, this
253//      is the recommended source of entropy for user-space programs.
254//      When this option is used, the token passed to `std::random_device`'s
255//      constructor *must* be "/dev/urandom" -- anything else is an error.
256//
257// _LIBCPP_USING_GETENTROPY
258//      Use getentropy().
259//      When this option is used, the token passed to `std::random_device`'s
260//      constructor *must* be "/dev/urandom" -- anything else is an error.
261//
262// _LIBCPP_USING_FUCHSIA_CPRNG
263//      Use Fuchsia's zx_cprng_draw() system call, which is specified to
264//      deliver high-quality entropy and cannot fail.
265//      When this option is used, the token passed to `std::random_device`'s
266//      constructor *must* be "/dev/urandom" -- anything else is an error.
267//
268// _LIBCPP_USING_NACL_RANDOM
269//      NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
270//      including accesses to the special files under `/dev`. This implementation
271//      uses the NaCL syscall `nacl_secure_random_init()` to get entropy.
272//      When this option is used, the token passed to `std::random_device`'s
273//      constructor *must* be "/dev/urandom" -- anything else is an error.
274//
275// _LIBCPP_USING_WIN32_RANDOM
276//      Use rand_s(), for use on Windows.
277//      When this option is used, the token passed to `std::random_device`'s
278//      constructor *must* be "/dev/urandom" -- anything else is an error.
279#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||                     \
280      defined(__DragonFly__)
281#    define _LIBCPP_USING_ARC4_RANDOM
282#  elif defined(__wasi__) || defined(__EMSCRIPTEN__)
283#    define _LIBCPP_USING_GETENTROPY
284#  elif defined(__Fuchsia__)
285#    define _LIBCPP_USING_FUCHSIA_CPRNG
286#  elif defined(__native_client__)
287#    define _LIBCPP_USING_NACL_RANDOM
288#  elif defined(_LIBCPP_WIN32API)
289#    define _LIBCPP_USING_WIN32_RANDOM
290#  else
291#    define _LIBCPP_USING_DEV_RANDOM
292#  endif
293
294#  ifndef _LIBCPP_CXX03_LANG
295
296#    define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
297#    define _ALIGNAS_TYPE(x) alignas(x)
298#    define _ALIGNAS(x) alignas(x)
299#    define _NOEXCEPT noexcept
300#    define _NOEXCEPT_(...) noexcept(__VA_ARGS__)
301#    define _LIBCPP_CONSTEXPR constexpr
302
303#  else
304
305#    define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
306#    define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
307#    define _ALIGNAS(x) __attribute__((__aligned__(x)))
308#    define nullptr __nullptr
309#    define _NOEXCEPT throw()
310#    define _NOEXCEPT_(...)
311#    define static_assert(...) _Static_assert(__VA_ARGS__)
312#    define decltype(...) __decltype(__VA_ARGS__)
313#    define _LIBCPP_CONSTEXPR
314
315typedef __char16_t char16_t;
316typedef __char32_t char32_t;
317
318#  endif
319
320#  define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)
321
322// Objective-C++ features (opt-in)
323#  if __has_feature(objc_arc)
324#    define _LIBCPP_HAS_OBJC_ARC 1
325#  else
326#    define _LIBCPP_HAS_OBJC_ARC 0
327#  endif
328
329#  if __has_feature(objc_arc_weak)
330#    define _LIBCPP_HAS_OBJC_ARC_WEAK 1
331#  else
332#    define _LIBCPP_HAS_OBJC_ARC_WEAK 0
333#  endif
334
335#  if __has_extension(blocks)
336#    define _LIBCPP_HAS_EXTENSION_BLOCKS 1
337#  else
338#    define _LIBCPP_HAS_EXTENSION_BLOCKS 0
339#  endif
340
341#  if _LIBCPP_HAS_EXTENSION_BLOCKS && defined(__APPLE__)
342#    define _LIBCPP_HAS_BLOCKS_RUNTIME 1
343#  else
344#    define _LIBCPP_HAS_BLOCKS_RUNTIME 0
345#  endif
346
347#  if __has_feature(address_sanitizer)
348#    define _LIBCPP_HAS_ASAN 1
349#  else
350#    define _LIBCPP_HAS_ASAN 0
351#  endif
352
353#  define _LIBCPP_ALWAYS_INLINE __attribute__((__always_inline__))
354
355#  define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__
356
357#  if defined(_LIBCPP_OBJECT_FORMAT_COFF)
358
359#    ifdef _DLL
360#      define _LIBCPP_CRT_FUNC __declspec(dllimport)
361#    else
362#      define _LIBCPP_CRT_FUNC
363#    endif
364
365#    if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) || (defined(__MINGW32__) && !defined(_LIBCPP_BUILDING_LIBRARY))
366#      define _LIBCPP_DLL_VIS
367#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
368#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
369#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
370#      define _LIBCPP_EXPORTED_FROM_ABI
371#    elif defined(_LIBCPP_BUILDING_LIBRARY)
372#      define _LIBCPP_DLL_VIS __declspec(dllexport)
373#      if defined(__MINGW32__)
374#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
375#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
376#      else
377#        define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
378#        define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
379#      endif
380#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
381#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
382#    else
383#      define _LIBCPP_DLL_VIS __declspec(dllimport)
384#      define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
385#      define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
386#      define _LIBCPP_OVERRIDABLE_FUNC_VIS
387#      define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
388#    endif
389
390#    define _LIBCPP_HIDDEN
391#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
392#    define _LIBCPP_TEMPLATE_VIS
393#    define _LIBCPP_TEMPLATE_DATA_VIS
394#    define _LIBCPP_TYPE_VISIBILITY_DEFAULT
395
396#  else
397
398#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
399#      define _LIBCPP_VISIBILITY(vis) __attribute__((__visibility__(vis)))
400#    else
401#      define _LIBCPP_VISIBILITY(vis)
402#    endif
403
404#    define _LIBCPP_HIDDEN _LIBCPP_VISIBILITY("hidden")
405#    define _LIBCPP_TEMPLATE_DATA_VIS _LIBCPP_VISIBILITY("default")
406#    define _LIBCPP_EXPORTED_FROM_ABI _LIBCPP_VISIBILITY("default")
407#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_VISIBILITY("default")
408#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
409
410// TODO: Make this a proper customization point or remove the option to override it.
411#    ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
412#      define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_VISIBILITY("default")
413#    endif
414
415#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
416// The inline should be removed once PR32114 is resolved
417#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS inline _LIBCPP_HIDDEN
418#    else
419#      define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
420#    endif
421
422// GCC doesn't support the type_visibility attribute, so we have to keep the visibility attribute on templates
423#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && !__has_attribute(__type_visibility__)
424#      define _LIBCPP_TEMPLATE_VIS __attribute__((__visibility__("default")))
425#    else
426#      define _LIBCPP_TEMPLATE_VIS
427#    endif
428
429#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
430#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT __attribute__((__type_visibility__("default")))
431#    else
432#      define _LIBCPP_TYPE_VISIBILITY_DEFAULT
433#    endif
434
435#  endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
436
437#  if __has_attribute(exclude_from_explicit_instantiation)
438#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__((__exclude_from_explicit_instantiation__))
439#  else
440// Try to approximate the effect of exclude_from_explicit_instantiation
441// (which is that entities are not assumed to be provided by explicit
442// template instantiations in the dylib) by always inlining those entities.
443#    define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
444#  endif
445
446#  ifdef _LIBCPP_COMPILER_CLANG_BASED
447#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
448#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
449#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
450#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
451#  elif defined(_LIBCPP_COMPILER_GCC)
452#    define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
453#    define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
454#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
455#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
456#  else
457#    define _LIBCPP_DIAGNOSTIC_PUSH
458#    define _LIBCPP_DIAGNOSTIC_POP
459#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
460#    define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
461#  endif
462
463#  if _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_FAST
464#    define _LIBCPP_HARDENING_SIG f
465#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_EXTENSIVE
466#    define _LIBCPP_HARDENING_SIG s
467#  elif _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG
468#    define _LIBCPP_HARDENING_SIG d
469#  else
470#    define _LIBCPP_HARDENING_SIG n // "none"
471#  endif
472
473#  if !_LIBCPP_HAS_EXCEPTIONS
474#    define _LIBCPP_EXCEPTIONS_SIG n
475#  else
476#    define _LIBCPP_EXCEPTIONS_SIG e
477#  endif
478
479#  define _LIBCPP_ODR_SIGNATURE                                                                                        \
480    _LIBCPP_CONCAT(_LIBCPP_CONCAT(_LIBCPP_HARDENING_SIG, _LIBCPP_EXCEPTIONS_SIG), _LIBCPP_VERSION)
481
482// This macro marks a symbol as being hidden from libc++'s ABI. This is achieved
483// on two levels:
484// 1. The symbol is given hidden visibility, which ensures that users won't start exporting
485//    symbols from their dynamic library by means of using the libc++ headers. This ensures
486//    that those symbols stay private to the dynamic library in which it is defined.
487//
488// 2. The symbol is given an ABI tag that encodes the ODR-relevant properties of the library.
489//    This ensures that no ODR violation can arise from mixing two TUs compiled with different
490//    versions or configurations of libc++ (such as exceptions vs no-exceptions). Indeed, if the
491//    program contains two definitions of a function, the ODR requires them to be token-by-token
492//    equivalent, and the linker is allowed to pick either definition and discard the other one.
493//
494//    For example, if a program contains a copy of `vector::at()` compiled with exceptions enabled
495//    *and* a copy of `vector::at()` compiled with exceptions disabled (by means of having two TUs
496//    compiled with different settings), the two definitions are both visible by the linker and they
497//    have the same name, but they have a meaningfully different implementation (one throws an exception
498//    and the other aborts the program). This violates the ODR and makes the program ill-formed, and in
499//    practice what will happen is that the linker will pick one of the definitions at random and will
500//    discard the other one. This can quite clearly lead to incorrect program behavior.
501//
502//    A similar reasoning holds for many other properties that are ODR-affecting. Essentially any
503//    property that causes the code of a function to differ from the code in another configuration
504//    can be considered ODR-affecting. In practice, we don't encode all such properties in the ABI
505//    tag, but we encode the ones that we think are most important: library version, exceptions, and
506//    hardening mode.
507//
508//    Note that historically, solving this problem has been achieved in various ways, including
509//    force-inlining all functions or giving internal linkage to all functions. Both these previous
510//    solutions suffer from drawbacks that lead notably to code bloat.
511//
512// Note that we use _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION to ensure that we don't depend
513// on _LIBCPP_HIDE_FROM_ABI methods of classes explicitly instantiated in the dynamic library.
514//
515// Also note that the _LIBCPP_HIDE_FROM_ABI_VIRTUAL macro should be used on virtual functions
516// instead of _LIBCPP_HIDE_FROM_ABI. That macro does not use an ABI tag. Indeed, the mangled
517// name of a virtual function is part of its ABI, since some architectures like arm64e can sign
518// the virtual function pointer in the vtable based on the mangled name of the function. Since
519// we use an ABI tag that changes with each released version, the mangled name of the virtual
520// function would change, which is incorrect. Note that it doesn't make much sense to change
521// the implementation of a virtual function in an ABI-incompatible way in the first place,
522// since that would be an ABI break anyway. Hence, the lack of ABI tag should not be noticeable.
523//
524// The macro can be applied to record and enum types. When the tagged type is nested in
525// a record this "parent" record needs to have the macro too. Another use case for applying
526// this macro to records and unions is to apply an ABI tag to inline constexpr variables.
527// This can be useful for inline variables that are implementation details which are expected
528// to change in the future.
529//
530// TODO: We provide a escape hatch with _LIBCPP_NO_ABI_TAG for folks who want to avoid increasing
531//       the length of symbols with an ABI tag. In practice, we should remove the escape hatch and
532//       use compression mangling instead, see https://github.com/itanium-cxx-abi/cxx-abi/issues/70.
533#  ifndef _LIBCPP_NO_ABI_TAG
534#    define _LIBCPP_HIDE_FROM_ABI                                                                                      \
535      _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION                                                       \
536      __attribute__((__abi_tag__(_LIBCPP_TOSTRING(_LIBCPP_ODR_SIGNATURE))))
537#  else
538#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
539#  endif
540#  define _LIBCPP_HIDE_FROM_ABI_VIRTUAL _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
541
542#  ifdef _LIBCPP_BUILDING_LIBRARY
543#    if _LIBCPP_ABI_VERSION > 1
544#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
545#    else
546#      define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
547#    endif
548#  else
549#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
550#  endif
551
552// TODO: Remove this workaround once we drop support for Clang 16
553#  if __has_warning("-Wc++23-extensions")
554#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
555#  else
556#    define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++2b-extensions")
557#  endif
558
559// Clang modules take a significant compile time hit when pushing and popping diagnostics.
560// Since all the headers are marked as system headers in the modulemap, we can simply disable this
561// pushing and popping when building with clang modules.
562#  if !__has_feature(modules)
563#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                                                         \
564      _LIBCPP_DIAGNOSTIC_PUSH                                                                                          \
565      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++11-extensions")                                                           \
566      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                           \
567      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                           \
568      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                           \
569      _LIBCPP_CLANG_DIAGNOSTIC_IGNORED_CXX23_EXTENSION                                                                 \
570      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++14-extensions")                                                             \
571      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++17-extensions")                                                             \
572      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++20-extensions")                                                             \
573      _LIBCPP_GCC_DIAGNOSTIC_IGNORED("-Wc++23-extensions")
574#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS _LIBCPP_DIAGNOSTIC_POP
575#  else
576#    define _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS
577#    define _LIBCPP_POP_EXTENSION_DIAGNOSTICS
578#  endif
579
580// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
581// clang-format off
582#  define _LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_PUSH_EXTENSION_DIAGNOSTICS                                               \
583                                      namespace _LIBCPP_TYPE_VISIBILITY_DEFAULT std {                                  \
584                               inline namespace _LIBCPP_ABI_NAMESPACE {
585#  define _LIBCPP_END_NAMESPACE_STD }} _LIBCPP_POP_EXTENSION_DIAGNOSTICS
586
587#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace std { namespace experimental {
588#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL }}
589
590#define _LIBCPP_BEGIN_NAMESPACE_LFTS _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v1 {
591#define _LIBCPP_END_NAMESPACE_LFTS } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
592
593#define _LIBCPP_BEGIN_NAMESPACE_LFTS_V2 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v2 {
594#define _LIBCPP_END_NAMESPACE_LFTS_V2 } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
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_INT128 0
614#  else
615#    define _LIBCPP_HAS_INT128 1
616#  endif
617
618#  ifdef _LIBCPP_CXX03_LANG
619#    define _LIBCPP_DECLARE_STRONG_ENUM(x)                                                                             \
620      struct _LIBCPP_EXPORTED_FROM_ABI x {                                                                             \
621        enum __lx
622// clang-format off
623#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)                                                                      \
624      __lx __v_;                                                                                                       \
625      _LIBCPP_HIDE_FROM_ABI x(__lx __v) : __v_(__v) {}                                                                 \
626      _LIBCPP_HIDE_FROM_ABI explicit x(int __v) : __v_(static_cast<__lx>(__v)) {}                                      \
627      _LIBCPP_HIDE_FROM_ABI operator int() const { return __v_; }                                                      \
628      };
629// clang-format on
630
631#  else // _LIBCPP_CXX03_LANG
632#    define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class x
633#    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
634#  endif // _LIBCPP_CXX03_LANG
635
636#  ifdef __FreeBSD__
637#    define _DECLARE_C99_LDBL_MATH 1
638#  endif
639
640// If we are getting operator new from the MSVC CRT, then allocation overloads
641// for align_val_t were added in 19.12, aka VS 2017 version 15.3.
642#  if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
643#    define _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION 0
644#  elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
645// We're deferring to Microsoft's STL to provide aligned new et al. We don't
646// have it unless the language feature test macro is defined.
647#    define _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION 0
648#  elif defined(__MVS__)
649#    define _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION 0
650#  else
651#    define _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION 1
652#  endif
653
654#  if !_LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION || (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
655#    define _LIBCPP_HAS_ALIGNED_ALLOCATION 0
656#  else
657#    define _LIBCPP_HAS_ALIGNED_ALLOCATION 1
658#  endif
659
660// It is not yet possible to use aligned_alloc() on all Apple platforms since
661// 10.15 was the first version to ship an implementation of aligned_alloc().
662#  if defined(__APPLE__)
663#    if (defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                                                     \
664         __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101500) ||                                                    \
665        (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) &&                                                    \
666         __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 130000)
667#      define _LIBCPP_HAS_C11_ALIGNED_ALLOC 0
668#    else
669#      define _LIBCPP_HAS_C11_ALIGNED_ALLOC 1
670#    endif
671#  elif defined(__ANDROID__) && __ANDROID_API__ < 28
672// Android only provides aligned_alloc when targeting API 28 or higher.
673#    define _LIBCPP_HAS_C11_ALIGNED_ALLOC 0
674#  else
675#    define _LIBCPP_HAS_C11_ALIGNED_ALLOC 1
676#  endif
677
678#  if defined(__APPLE__) || defined(__FreeBSD__)
679#    define _LIBCPP_HAS_DEFAULTRUNELOCALE
680#  endif
681
682#  if defined(__APPLE__) || defined(__FreeBSD__)
683#    define _LIBCPP_WCTYPE_IS_MASK
684#  endif
685
686#  if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
687#    define _LIBCPP_HAS_CHAR8_T 0
688#  else
689#    define _LIBCPP_HAS_CHAR8_T 1
690#  endif
691
692// Deprecation macros.
693//
694// Deprecations warnings are always enabled, except when users explicitly opt-out
695// by defining _LIBCPP_DISABLE_DEPRECATION_WARNINGS.
696#  if !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
697#    if __has_attribute(__deprecated__)
698#      define _LIBCPP_DEPRECATED __attribute__((__deprecated__))
699#      define _LIBCPP_DEPRECATED_(m) __attribute__((__deprecated__(m)))
700#    elif _LIBCPP_STD_VER >= 14
701#      define _LIBCPP_DEPRECATED [[deprecated]]
702#      define _LIBCPP_DEPRECATED_(m) [[deprecated(m)]]
703#    else
704#      define _LIBCPP_DEPRECATED
705#      define _LIBCPP_DEPRECATED_(m)
706#    endif
707#  else
708#    define _LIBCPP_DEPRECATED
709#    define _LIBCPP_DEPRECATED_(m)
710#  endif
711
712#  if !defined(_LIBCPP_CXX03_LANG)
713#    define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
714#  else
715#    define _LIBCPP_DEPRECATED_IN_CXX11
716#  endif
717
718#  if _LIBCPP_STD_VER >= 14
719#    define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
720#  else
721#    define _LIBCPP_DEPRECATED_IN_CXX14
722#  endif
723
724#  if _LIBCPP_STD_VER >= 17
725#    define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
726#  else
727#    define _LIBCPP_DEPRECATED_IN_CXX17
728#  endif
729
730#  if _LIBCPP_STD_VER >= 20
731#    define _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_DEPRECATED
732#  else
733#    define _LIBCPP_DEPRECATED_IN_CXX20
734#  endif
735
736#  if _LIBCPP_STD_VER >= 23
737#    define _LIBCPP_DEPRECATED_IN_CXX23 _LIBCPP_DEPRECATED
738#  else
739#    define _LIBCPP_DEPRECATED_IN_CXX23
740#  endif
741
742#  if _LIBCPP_STD_VER >= 26
743#    define _LIBCPP_DEPRECATED_IN_CXX26 _LIBCPP_DEPRECATED
744#  else
745#    define _LIBCPP_DEPRECATED_IN_CXX26
746#  endif
747
748#  if _LIBCPP_HAS_CHAR8_T
749#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T _LIBCPP_DEPRECATED
750#  else
751#    define _LIBCPP_DEPRECATED_WITH_CHAR8_T
752#  endif
753
754// Macros to enter and leave a state where deprecation warnings are suppressed.
755#  if defined(_LIBCPP_COMPILER_CLANG_BASED) || defined(_LIBCPP_COMPILER_GCC)
756#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH                                                                           \
757      _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wdeprecated\"")                                \
758          _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
759#    define _LIBCPP_SUPPRESS_DEPRECATED_POP _Pragma("GCC diagnostic pop")
760#  else
761#    define _LIBCPP_SUPPRESS_DEPRECATED_PUSH
762#    define _LIBCPP_SUPPRESS_DEPRECATED_POP
763#  endif
764
765#  if _LIBCPP_STD_VER <= 11
766#    define _LIBCPP_EXPLICIT_SINCE_CXX14
767#  else
768#    define _LIBCPP_EXPLICIT_SINCE_CXX14 explicit
769#  endif
770
771#  if _LIBCPP_STD_VER >= 23
772#    define _LIBCPP_EXPLICIT_SINCE_CXX23 explicit
773#  else
774#    define _LIBCPP_EXPLICIT_SINCE_CXX23
775#  endif
776
777#  if _LIBCPP_STD_VER >= 14
778#    define _LIBCPP_CONSTEXPR_SINCE_CXX14 constexpr
779#  else
780#    define _LIBCPP_CONSTEXPR_SINCE_CXX14
781#  endif
782
783#  if _LIBCPP_STD_VER >= 17
784#    define _LIBCPP_CONSTEXPR_SINCE_CXX17 constexpr
785#  else
786#    define _LIBCPP_CONSTEXPR_SINCE_CXX17
787#  endif
788
789#  if _LIBCPP_STD_VER >= 20
790#    define _LIBCPP_CONSTEXPR_SINCE_CXX20 constexpr
791#  else
792#    define _LIBCPP_CONSTEXPR_SINCE_CXX20
793#  endif
794
795#  if _LIBCPP_STD_VER >= 23
796#    define _LIBCPP_CONSTEXPR_SINCE_CXX23 constexpr
797#  else
798#    define _LIBCPP_CONSTEXPR_SINCE_CXX23
799#  endif
800
801#  if _LIBCPP_STD_VER >= 26
802#    define _LIBCPP_CONSTEXPR_SINCE_CXX26 constexpr
803#  else
804#    define _LIBCPP_CONSTEXPR_SINCE_CXX26
805#  endif
806
807#  ifndef _LIBCPP_WEAK
808#    define _LIBCPP_WEAK __attribute__((__weak__))
809#  endif
810
811// Thread API
812// clang-format off
813#  if _LIBCPP_HAS_THREADS &&                                                                                           \
814      !_LIBCPP_HAS_THREAD_API_PTHREAD &&                                                                               \
815      !_LIBCPP_HAS_THREAD_API_WIN32 &&                                                                                 \
816      !_LIBCPP_HAS_THREAD_API_EXTERNAL
817
818#    if defined(__FreeBSD__) ||                                                                                        \
819        defined(__wasi__) ||                                                                                           \
820        defined(__NetBSD__) ||                                                                                         \
821        defined(__OpenBSD__) ||                                                                                        \
822        defined(__NuttX__) ||                                                                                          \
823        defined(__linux__) ||                                                                                          \
824        defined(__GNU__) ||                                                                                            \
825        defined(__APPLE__) ||                                                                                          \
826        defined(__MVS__) ||                                                                                            \
827        defined(_AIX) ||                                                                                               \
828        defined(__EMSCRIPTEN__)
829// clang-format on
830#      undef _LIBCPP_HAS_THREAD_API_PTHREAD
831#      define _LIBCPP_HAS_THREAD_API_PTHREAD 1
832#    elif defined(__Fuchsia__)
833// TODO(44575): Switch to C11 thread API when possible.
834#      undef _LIBCPP_HAS_THREAD_API_PTHREAD
835#      define _LIBCPP_HAS_THREAD_API_PTHREAD 1
836#    elif defined(_LIBCPP_WIN32API)
837#      undef _LIBCPP_HAS_THREAD_API_WIN32
838#      define _LIBCPP_HAS_THREAD_API_WIN32 1
839#    else
840#      error "No thread API"
841#    endif // _LIBCPP_HAS_THREAD_API
842#  endif   // _LIBCPP_HAS_THREADS
843
844#  if _LIBCPP_HAS_THREAD_API_PTHREAD
845#    if defined(__ANDROID__) && __ANDROID_API__ >= 30
846#      define _LIBCPP_HAS_COND_CLOCKWAIT 1
847#    elif defined(_LIBCPP_GLIBC_PREREQ)
848#      if _LIBCPP_GLIBC_PREREQ(2, 30)
849#        define _LIBCPP_HAS_COND_CLOCKWAIT 1
850#      else
851#        define _LIBCPP_HAS_COND_CLOCKWAIT 0
852#      endif
853#    else
854#      define _LIBCPP_HAS_COND_CLOCKWAIT 0
855#    endif
856#  else
857#    define _LIBCPP_HAS_COND_CLOCKWAIT 0
858#  endif
859
860#  if !_LIBCPP_HAS_THREADS && _LIBCPP_HAS_THREAD_API_PTHREAD
861#    error _LIBCPP_HAS_THREAD_API_PTHREAD may only be true when _LIBCPP_HAS_THREADS is true.
862#  endif
863
864#  if !_LIBCPP_HAS_THREADS && _LIBCPP_HAS_THREAD_API_EXTERNAL
865#    error _LIBCPP_HAS_THREAD_API_EXTERNAL may only be true when _LIBCPP_HAS_THREADS is true.
866#  endif
867
868#  if !_LIBCPP_HAS_MONOTONIC_CLOCK && _LIBCPP_HAS_THREADS
869#    error _LIBCPP_HAS_MONOTONIC_CLOCK may only be false when _LIBCPP_HAS_THREADS is false.
870#  endif
871
872#  if _LIBCPP_HAS_THREADS && !defined(__STDCPP_THREADS__)
873#    define __STDCPP_THREADS__ 1
874#  endif
875
876// The glibc and Bionic implementation of pthreads implements
877// pthread_mutex_destroy as nop for regular mutexes. Additionally, Win32
878// mutexes have no destroy mechanism.
879//
880// This optimization can't be performed on Apple platforms, where
881// pthread_mutex_destroy can allow the kernel to release resources.
882// See https://llvm.org/D64298 for details.
883//
884// TODO(EricWF): Enable this optimization on Bionic after speaking to their
885//               respective stakeholders.
886// clang-format off
887#  if (_LIBCPP_HAS_THREAD_API_PTHREAD && defined(__GLIBC__)) ||                                                        \
888      (_LIBCPP_HAS_THREAD_API_C11 && defined(__Fuchsia__)) ||                                                          \
889       _LIBCPP_HAS_THREAD_API_WIN32
890// clang-format on
891#    define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION 1
892#  else
893#    define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION 0
894#  endif
895
896// Destroying a condvar is a nop on Windows.
897//
898// This optimization can't be performed on Apple platforms, where
899// pthread_cond_destroy can allow the kernel to release resources.
900// See https://llvm.org/D64298 for details.
901//
902// TODO(EricWF): This is potentially true for some pthread implementations
903// as well.
904#  if (_LIBCPP_HAS_THREAD_API_C11 && defined(__Fuchsia__)) || _LIBCPP_HAS_THREAD_API_WIN32
905#    define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION 1
906#  else
907#    define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION 0
908#  endif
909
910#  if defined(__BIONIC__) || defined(__NuttX__) || defined(__Fuchsia__) || defined(__wasi__) ||                        \
911      _LIBCPP_HAS_MUSL_LIBC || defined(__OpenBSD__) || defined(__LLVM_LIBC__)
912#    define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
913#  endif
914
915#  if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
916#    define _LIBCPP_HAS_C_ATOMIC_IMP 1
917#    define _LIBCPP_HAS_GCC_ATOMIC_IMP 0
918#    define _LIBCPP_HAS_EXTERNAL_ATOMIC_IMP 0
919#  elif defined(_LIBCPP_COMPILER_GCC)
920#    define _LIBCPP_HAS_C_ATOMIC_IMP 0
921#    define _LIBCPP_HAS_GCC_ATOMIC_IMP 1
922#    define _LIBCPP_HAS_EXTERNAL_ATOMIC_IMP 0
923#  endif
924
925#  if !_LIBCPP_HAS_C_ATOMIC_IMP && !_LIBCPP_HAS_GCC_ATOMIC_IMP && !_LIBCPP_HAS_EXTERNAL_ATOMIC_IMP
926#    define _LIBCPP_HAS_ATOMIC_HEADER 0
927#  else
928#    define _LIBCPP_HAS_ATOMIC_HEADER 1
929#    ifndef _LIBCPP_ATOMIC_FLAG_TYPE
930#      define _LIBCPP_ATOMIC_FLAG_TYPE bool
931#    endif
932#  endif
933
934#  if defined(__FreeBSD__) && defined(__clang__) && __has_attribute(__no_thread_safety_analysis__)
935#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS __attribute__((__no_thread_safety_analysis__))
936#  else
937#    define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
938#  endif
939
940// Work around the attribute handling in clang.  When both __declspec and
941// __attribute__ are present, the processing goes awry preventing the definition
942// of the types. In MinGW mode, __declspec evaluates to __attribute__, and thus
943// combining the two does work.
944#  if defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS) && defined(__clang__) &&                                       \
945      __has_attribute(acquire_capability) && !defined(_MSC_VER)
946#    define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS 1
947#  else
948#    define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS 0
949#  endif
950
951#  if _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
952#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
953#  else
954#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
955#  endif
956
957#  if _LIBCPP_STD_VER >= 20
958#    define _LIBCPP_CONSTINIT constinit
959#  elif __has_attribute(__require_constant_initialization__)
960#    define _LIBCPP_CONSTINIT __attribute__((__require_constant_initialization__))
961#  else
962#    define _LIBCPP_CONSTINIT
963#  endif
964
965#  if defined(__CUDACC__) || defined(__CUDA_ARCH__) || defined(__CUDA_LIBDEVICE__)
966// The CUDA SDK contains an unfortunate definition for the __noinline__ macro,
967// which breaks the regular __attribute__((__noinline__)) syntax. Therefore,
968// when compiling for CUDA we use the non-underscored version of the noinline
969// attribute.
970//
971// This is a temporary workaround and we still expect the CUDA SDK team to solve
972// this issue properly in the SDK headers.
973//
974// See https://github.com/llvm/llvm-project/pull/73838 for more details.
975#    define _LIBCPP_NOINLINE __attribute__((noinline))
976#  elif __has_attribute(__noinline__)
977#    define _LIBCPP_NOINLINE __attribute__((__noinline__))
978#  else
979#    define _LIBCPP_NOINLINE
980#  endif
981
982// We often repeat things just for handling wide characters in the library.
983// When wide characters are disabled, it can be useful to have a quick way of
984// disabling it without having to resort to #if-#endif, which has a larger
985// impact on readability.
986#  if !_LIBCPP_HAS_WIDE_CHARACTERS
987#    define _LIBCPP_IF_WIDE_CHARACTERS(...)
988#  else
989#    define _LIBCPP_IF_WIDE_CHARACTERS(...) __VA_ARGS__
990#  endif
991
992// clang-format off
993#  define _LIBCPP_PUSH_MACROS _Pragma("push_macro(\"min\")") _Pragma("push_macro(\"max\")") _Pragma("push_macro(\"refresh\")") _Pragma("push_macro(\"move\")") _Pragma("push_macro(\"erase\")")
994#  define _LIBCPP_POP_MACROS _Pragma("pop_macro(\"min\")") _Pragma("pop_macro(\"max\")") _Pragma("pop_macro(\"refresh\")") _Pragma("pop_macro(\"move\")") _Pragma("pop_macro(\"erase\")")
995// clang-format on
996
997#  ifndef _LIBCPP_NO_AUTO_LINK
998#    if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
999#      if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
1000#        pragma comment(lib, "c++.lib")
1001#      else
1002#        pragma comment(lib, "libc++.lib")
1003#      endif
1004#    endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
1005#  endif   // _LIBCPP_NO_AUTO_LINK
1006
1007// Configures the fopen close-on-exec mode character, if any. This string will
1008// be appended to any mode string used by fstream for fopen/fdopen.
1009//
1010// Not all platforms support this, but it helps avoid fd-leaks on platforms that
1011// do.
1012#  if defined(__BIONIC__)
1013#    define _LIBCPP_FOPEN_CLOEXEC_MODE "e"
1014#  else
1015#    define _LIBCPP_FOPEN_CLOEXEC_MODE
1016#  endif
1017
1018#  if __has_cpp_attribute(msvc::no_unique_address)
1019// MSVC implements [[no_unique_address]] as a silent no-op currently.
1020// (If/when MSVC breaks its C++ ABI, it will be changed to work as intended.)
1021// However, MSVC implements [[msvc::no_unique_address]] which does what
1022// [[no_unique_address]] is supposed to do, in general.
1023#    define _LIBCPP_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
1024#  else
1025#    define _LIBCPP_NO_UNIQUE_ADDRESS [[__no_unique_address__]]
1026#  endif
1027
1028// c8rtomb() and mbrtoc8() were added in C++20 and C23. Support for these
1029// functions is gradually being added to existing C libraries. The conditions
1030// below check for known C library versions and conditions under which these
1031// functions are declared by the C library.
1032//
1033// GNU libc 2.36 and newer declare c8rtomb() and mbrtoc8() in C++ modes if
1034// __cpp_char8_t is defined or if C2X extensions are enabled. Determining
1035// the latter depends on internal GNU libc details that are not appropriate
1036// to depend on here, so any declarations present when __cpp_char8_t is not
1037// defined are ignored.
1038#  if defined(_LIBCPP_GLIBC_PREREQ)
1039#    if _LIBCPP_GLIBC_PREREQ(2, 36) && defined(__cpp_char8_t)
1040#      define _LIBCPP_HAS_C8RTOMB_MBRTOC8 1
1041#    else
1042#      define _LIBCPP_HAS_C8RTOMB_MBRTOC8 0
1043#    endif
1044#  else
1045#    define _LIBCPP_HAS_C8RTOMB_MBRTOC8 0
1046#  endif
1047
1048// There are a handful of public standard library types that are intended to
1049// support CTAD but don't need any explicit deduction guides to do so. This
1050// macro is used to mark them as such, which suppresses the
1051// '-Wctad-maybe-unsupported' compiler warning when CTAD is used in user code
1052// with these classes.
1053#  if _LIBCPP_STD_VER >= 17
1054#    ifdef _LIBCPP_COMPILER_CLANG_BASED
1055#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName)                                                              \
1056        template <class... _Tag>                                                                                       \
1057        [[maybe_unused]] _ClassName(typename _Tag::__allow_ctad...)->_ClassName<_Tag...>
1058#    else
1059#      define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(ClassName)                                                               \
1060        template <class... _Tag>                                                                                       \
1061        ClassName(typename _Tag::__allow_ctad...)->ClassName<_Tag...>
1062#    endif
1063#  else
1064#    define _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(_ClassName) static_assert(true, "")
1065#  endif
1066
1067// TODO(varconst): currently, there are bugs in Clang's intrinsics when handling Objective-C++ `id`, so don't use
1068// compiler intrinsics in the Objective-C++ mode.
1069#  ifdef __OBJC__
1070#    define _LIBCPP_WORKAROUND_OBJCXX_COMPILER_INTRINSICS
1071#  endif
1072
1073#  define _PSTL_PRAGMA(x) _Pragma(#x)
1074
1075// Enable SIMD for compilers that support OpenMP 4.0
1076#  if (defined(_OPENMP) && _OPENMP >= 201307)
1077
1078#    define _PSTL_UDR_PRESENT
1079#    define _PSTL_PRAGMA_SIMD _PSTL_PRAGMA(omp simd)
1080#    define _PSTL_PRAGMA_DECLARE_SIMD _PSTL_PRAGMA(omp declare simd)
1081#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _PSTL_PRAGMA(omp simd reduction(PRM))
1082#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
1083#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
1084#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
1085
1086// Declaration of reduction functor, where
1087// NAME - the name of the functor
1088// OP - type of the callable object with the reduction operation
1089// omp_in - refers to the local partial result
1090// omp_out - refers to the final value of the combiner operator
1091// omp_priv - refers to the private copy of the initial value
1092// omp_orig - refers to the original variable to be reduced
1093#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)                                                                   \
1094      _PSTL_PRAGMA(omp declare reduction(NAME:OP : omp_out(omp_in)) initializer(omp_priv = omp_orig))
1095
1096#  elif defined(_LIBCPP_COMPILER_CLANG_BASED)
1097
1098#    define _PSTL_PRAGMA_SIMD _Pragma("clang loop vectorize(enable) interleave(enable)")
1099#    define _PSTL_PRAGMA_DECLARE_SIMD
1100#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1101#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _Pragma("clang loop vectorize(enable) interleave(enable)")
1102#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1103#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1104#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1105
1106#  else // (defined(_OPENMP) && _OPENMP >= 201307)
1107
1108#    define _PSTL_PRAGMA_SIMD
1109#    define _PSTL_PRAGMA_DECLARE_SIMD
1110#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM)
1111#    define _PSTL_PRAGMA_SIMD_SCAN(PRM)
1112#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
1113#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
1114#    define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)
1115
1116#  endif // (defined(_OPENMP) && _OPENMP >= 201307)
1117
1118#  define _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
1119
1120// Optional attributes - these are useful for a better QoI, but not required to be available
1121
1122#  if __has_attribute(__no_sanitize__) && !defined(_LIBCPP_COMPILER_GCC)
1123#    define _LIBCPP_NO_CFI __attribute__((__no_sanitize__("cfi")))
1124#  else
1125#    define _LIBCPP_NO_CFI
1126#  endif
1127
1128#  if __has_attribute(__malloc__)
1129#    define _LIBCPP_NOALIAS __attribute__((__malloc__))
1130#  else
1131#    define _LIBCPP_NOALIAS
1132#  endif
1133
1134#  if __has_attribute(__using_if_exists__)
1135#    define _LIBCPP_USING_IF_EXISTS __attribute__((__using_if_exists__))
1136#  else
1137#    define _LIBCPP_USING_IF_EXISTS
1138#  endif
1139
1140#  if __has_attribute(__no_destroy__)
1141#    define _LIBCPP_NO_DESTROY __attribute__((__no_destroy__))
1142#  else
1143#    define _LIBCPP_NO_DESTROY
1144#  endif
1145
1146#  if __has_attribute(__diagnose_if__)
1147#    define _LIBCPP_DIAGNOSE_WARNING(...) __attribute__((__diagnose_if__(__VA_ARGS__, "warning")))
1148#  else
1149#    define _LIBCPP_DIAGNOSE_WARNING(...)
1150#  endif
1151
1152// Use a function like macro to imply that it must be followed by a semicolon
1153#  if __has_cpp_attribute(fallthrough)
1154#    define _LIBCPP_FALLTHROUGH() [[fallthrough]]
1155#  elif __has_attribute(__fallthrough__)
1156#    define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
1157#  else
1158#    define _LIBCPP_FALLTHROUGH() ((void)0)
1159#  endif
1160
1161#  if __has_cpp_attribute(_Clang::__lifetimebound__)
1162#    define _LIBCPP_LIFETIMEBOUND [[_Clang::__lifetimebound__]]
1163#  else
1164#    define _LIBCPP_LIFETIMEBOUND
1165#  endif
1166
1167#  if __has_cpp_attribute(_Clang::__noescape__)
1168#    define _LIBCPP_NOESCAPE [[_Clang::__noescape__]]
1169#  else
1170#    define _LIBCPP_NOESCAPE
1171#  endif
1172
1173#  define _LIBCPP_NODEBUG [[__gnu__::__nodebug__]]
1174
1175#  if __has_cpp_attribute(_Clang::__no_specializations__)
1176#    define _LIBCPP_NO_SPECIALIZATIONS                                                                                 \
1177      [[_Clang::__no_specializations__("Users are not allowed to specialize this standard library entity")]]
1178#  else
1179#    define _LIBCPP_NO_SPECIALIZATIONS
1180#  endif
1181
1182#  if __has_attribute(__standalone_debug__)
1183#    define _LIBCPP_STANDALONE_DEBUG __attribute__((__standalone_debug__))
1184#  else
1185#    define _LIBCPP_STANDALONE_DEBUG
1186#  endif
1187
1188#  if __has_attribute(__preferred_name__)
1189#    define _LIBCPP_PREFERRED_NAME(x) __attribute__((__preferred_name__(x)))
1190#  else
1191#    define _LIBCPP_PREFERRED_NAME(x)
1192#  endif
1193
1194#  if __has_attribute(__no_sanitize__)
1195#    define _LIBCPP_NO_SANITIZE(...) __attribute__((__no_sanitize__(__VA_ARGS__)))
1196#  else
1197#    define _LIBCPP_NO_SANITIZE(...)
1198#  endif
1199
1200#  if __has_attribute(__init_priority__)
1201#    define _LIBCPP_INIT_PRIORITY_MAX __attribute__((__init_priority__(100)))
1202#  else
1203#    define _LIBCPP_INIT_PRIORITY_MAX
1204#  endif
1205
1206#  if __has_attribute(__format__)
1207// The attribute uses 1-based indices for ordinary and static member functions.
1208// The attribute uses 2-based indices for non-static member functions.
1209#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index)                           \
1210      __attribute__((__format__(archetype, format_string_index, first_format_arg_index)))
1211#  else
1212#    define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index) /* nothing */
1213#  endif
1214
1215#  if __has_attribute(__packed__)
1216#    define _LIBCPP_PACKED __attribute__((__packed__))
1217#  else
1218#    define _LIBCPP_PACKED
1219#  endif
1220
1221#  if defined(_LIBCPP_ABI_MICROSOFT) && __has_declspec_attribute(empty_bases)
1222#    define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
1223#  else
1224#    define _LIBCPP_DECLSPEC_EMPTY_BASES
1225#  endif
1226
1227// Allow for build-time disabling of unsigned integer sanitization
1228#  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
1229#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
1230#  else
1231#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
1232#  endif
1233
1234// Clang-18 has support for deducing this, but it does not set the FTM.
1235#  if defined(__cpp_explicit_this_parameter) || (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER >= 1800)
1236#    define _LIBCPP_HAS_EXPLICIT_THIS_PARAMETER 1
1237#  else
1238#    define _LIBCPP_HAS_EXPLICIT_THIS_PARAMETER 0
1239#  endif
1240
1241#endif // __cplusplus
1242
1243#endif // _LIBCPP___CONFIG
1244