xref: /aosp_15_r20/external/openscreen/third_party/abseil/src/absl/base/config.h (revision 3f982cf4871df8771c9d4abe6e9a6f8d829b2736)
1 //
2 // Copyright 2017 The Abseil Authors.
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 //      https://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16 // -----------------------------------------------------------------------------
17 // File: config.h
18 // -----------------------------------------------------------------------------
19 //
20 // This header file defines a set of macros for checking the presence of
21 // important compiler and platform features. Such macros can be used to
22 // produce portable code by parameterizing compilation based on the presence or
23 // lack of a given feature.
24 //
25 // We define a "feature" as some interface we wish to program to: for example,
26 // a library function or system call. A value of `1` indicates support for
27 // that feature; any other value indicates the feature support is undefined.
28 //
29 // Example:
30 //
31 // Suppose a programmer wants to write a program that uses the 'mmap()' system
32 // call. The Abseil macro for that feature (`ABSL_HAVE_MMAP`) allows you to
33 // selectively include the `mmap.h` header and bracket code using that feature
34 // in the macro:
35 //
36 //   #include "absl/base/config.h"
37 //
38 //   #ifdef ABSL_HAVE_MMAP
39 //   #include "sys/mman.h"
40 //   #endif  //ABSL_HAVE_MMAP
41 //
42 //   ...
43 //   #ifdef ABSL_HAVE_MMAP
44 //   void *ptr = mmap(...);
45 //   ...
46 //   #endif  // ABSL_HAVE_MMAP
47 
48 #ifndef ABSL_BASE_CONFIG_H_
49 #define ABSL_BASE_CONFIG_H_
50 
51 // Included for the __GLIBC__ macro (or similar macros on other systems).
52 #include <limits.h>
53 
54 #ifdef __cplusplus
55 // Included for __GLIBCXX__, _LIBCPP_VERSION
56 #include <cstddef>
57 #endif  // __cplusplus
58 
59 #if defined(__APPLE__)
60 // Included for TARGET_OS_IPHONE, __IPHONE_OS_VERSION_MIN_REQUIRED,
61 // __IPHONE_8_0.
62 #include <Availability.h>
63 #include <TargetConditionals.h>
64 #endif
65 
66 #include "absl/base/options.h"
67 #include "absl/base/policy_checks.h"
68 
69 // Helper macro to convert a CPP variable to a string literal.
70 #define ABSL_INTERNAL_DO_TOKEN_STR(x) #x
71 #define ABSL_INTERNAL_TOKEN_STR(x) ABSL_INTERNAL_DO_TOKEN_STR(x)
72 
73 // -----------------------------------------------------------------------------
74 // Abseil namespace annotations
75 // -----------------------------------------------------------------------------
76 
77 // ABSL_NAMESPACE_BEGIN/ABSL_NAMESPACE_END
78 //
79 // An annotation placed at the beginning/end of each `namespace absl` scope.
80 // This is used to inject an inline namespace.
81 //
82 // The proper way to write Abseil code in the `absl` namespace is:
83 //
84 // namespace absl {
85 // ABSL_NAMESPACE_BEGIN
86 //
87 // void Foo();  // absl::Foo().
88 //
89 // ABSL_NAMESPACE_END
90 // }  // namespace absl
91 //
92 // Users of Abseil should not use these macros, because users of Abseil should
93 // not write `namespace absl {` in their own code for any reason.  (Abseil does
94 // not support forward declarations of its own types, nor does it support
95 // user-provided specialization of Abseil templates.  Code that violates these
96 // rules may be broken without warning.)
97 #if !defined(ABSL_OPTION_USE_INLINE_NAMESPACE) || \
98     !defined(ABSL_OPTION_INLINE_NAMESPACE_NAME)
99 #error options.h is misconfigured.
100 #endif
101 
102 // Check that ABSL_OPTION_INLINE_NAMESPACE_NAME is neither "head" nor ""
103 #if defined(__cplusplus) && ABSL_OPTION_USE_INLINE_NAMESPACE == 1
104 
105 #define ABSL_INTERNAL_INLINE_NAMESPACE_STR \
106   ABSL_INTERNAL_TOKEN_STR(ABSL_OPTION_INLINE_NAMESPACE_NAME)
107 
108 static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != '\0',
109               "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must "
110               "not be empty.");
111 static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
112                   ABSL_INTERNAL_INLINE_NAMESPACE_STR[1] != 'e' ||
113                   ABSL_INTERNAL_INLINE_NAMESPACE_STR[2] != 'a' ||
114                   ABSL_INTERNAL_INLINE_NAMESPACE_STR[3] != 'd' ||
115                   ABSL_INTERNAL_INLINE_NAMESPACE_STR[4] != '\0',
116               "options.h misconfigured: ABSL_OPTION_INLINE_NAMESPACE_NAME must "
117               "be changed to a new, unique identifier name.");
118 
119 #endif
120 
121 #if ABSL_OPTION_USE_INLINE_NAMESPACE == 0
122 #define ABSL_NAMESPACE_BEGIN
123 #define ABSL_NAMESPACE_END
124 #elif ABSL_OPTION_USE_INLINE_NAMESPACE == 1
125 #define ABSL_NAMESPACE_BEGIN \
126   inline namespace ABSL_OPTION_INLINE_NAMESPACE_NAME {
127 #define ABSL_NAMESPACE_END }
128 #else
129 #error options.h is misconfigured.
130 #endif
131 
132 // -----------------------------------------------------------------------------
133 // Compiler Feature Checks
134 // -----------------------------------------------------------------------------
135 
136 // ABSL_HAVE_BUILTIN()
137 //
138 // Checks whether the compiler supports a Clang Feature Checking Macro, and if
139 // so, checks whether it supports the provided builtin function "x" where x
140 // is one of the functions noted in
141 // https://clang.llvm.org/docs/LanguageExtensions.html
142 //
143 // Note: Use this macro to avoid an extra level of #ifdef __has_builtin check.
144 // http://releases.llvm.org/3.3/tools/clang/docs/LanguageExtensions.html
145 #ifdef __has_builtin
146 #define ABSL_HAVE_BUILTIN(x) __has_builtin(x)
147 #else
148 #define ABSL_HAVE_BUILTIN(x) 0
149 #endif
150 
151 #if defined(__is_identifier)
152 #define ABSL_INTERNAL_HAS_KEYWORD(x) !(__is_identifier(x))
153 #else
154 #define ABSL_INTERNAL_HAS_KEYWORD(x) 0
155 #endif
156 
157 #ifdef __has_feature
158 #define ABSL_HAVE_FEATURE(f) __has_feature(f)
159 #else
160 #define ABSL_HAVE_FEATURE(f) 0
161 #endif
162 
163 // ABSL_HAVE_TLS is defined to 1 when __thread should be supported.
164 // We assume __thread is supported on Linux when compiled with Clang or compiled
165 // against libstdc++ with _GLIBCXX_HAVE_TLS defined.
166 #ifdef ABSL_HAVE_TLS
167 #error ABSL_HAVE_TLS cannot be directly set
168 #elif defined(__linux__) && (defined(__clang__) || defined(_GLIBCXX_HAVE_TLS))
169 #define ABSL_HAVE_TLS 1
170 #endif
171 
172 // ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
173 //
174 // Checks whether `std::is_trivially_destructible<T>` is supported.
175 //
176 // Notes: All supported compilers using libc++ support this feature, as does
177 // gcc >= 4.8.1 using libstdc++, and Visual Studio.
178 #ifdef ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
179 #error ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE cannot be directly set
180 #elif defined(_LIBCPP_VERSION) ||                                        \
181     (!defined(__clang__) && defined(__GNUC__) && defined(__GLIBCXX__) && \
182      (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) ||        \
183     defined(_MSC_VER)
184 #define ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE 1
185 #endif
186 
187 // ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE
188 //
189 // Checks whether `std::is_trivially_default_constructible<T>` and
190 // `std::is_trivially_copy_constructible<T>` are supported.
191 
192 // ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE
193 //
194 // Checks whether `std::is_trivially_copy_assignable<T>` is supported.
195 
196 // Notes: Clang with libc++ supports these features, as does gcc >= 5.1 with
197 // either libc++ or libstdc++, and Visual Studio (but not NVCC).
198 #if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE)
199 #error ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE cannot be directly set
200 #elif defined(ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE)
201 #error ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE cannot directly set
202 #elif (defined(__clang__) && defined(_LIBCPP_VERSION)) ||        \
203     (!defined(__clang__) && defined(__GNUC__) &&                 \
204      (__GNUC__ > 7 || (__GNUC__ == 7 && __GNUC_MINOR__ >= 4)) && \
205      (defined(_LIBCPP_VERSION) || defined(__GLIBCXX__))) ||      \
206     (defined(_MSC_VER) && !defined(__NVCC__))
207 #define ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE 1
208 #define ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE 1
209 #endif
210 
211 // ABSL_HAVE_SOURCE_LOCATION_CURRENT
212 //
213 // Indicates whether `absl::SourceLocation::current()` will return useful
214 // information in some contexts.
215 #ifndef ABSL_HAVE_SOURCE_LOCATION_CURRENT
216 #if ABSL_INTERNAL_HAS_KEYWORD(__builtin_LINE) && \
217     ABSL_INTERNAL_HAS_KEYWORD(__builtin_FILE)
218 #define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1
219 #endif
220 #endif
221 
222 // ABSL_HAVE_THREAD_LOCAL
223 //
224 // Checks whether C++11's `thread_local` storage duration specifier is
225 // supported.
226 #ifdef ABSL_HAVE_THREAD_LOCAL
227 #error ABSL_HAVE_THREAD_LOCAL cannot be directly set
228 #elif defined(__APPLE__)
229 // Notes:
230 // * Xcode's clang did not support `thread_local` until version 8, and
231 //   even then not for all iOS < 9.0.
232 // * Xcode 9.3 started disallowing `thread_local` for 32-bit iOS simulator
233 //   targeting iOS 9.x.
234 // * Xcode 10 moves the deployment target check for iOS < 9.0 to link time
235 //   making ABSL_HAVE_FEATURE unreliable there.
236 //
237 #if ABSL_HAVE_FEATURE(cxx_thread_local) && \
238     !(TARGET_OS_IPHONE && __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_9_0)
239 #define ABSL_HAVE_THREAD_LOCAL 1
240 #endif
241 #else  // !defined(__APPLE__)
242 #define ABSL_HAVE_THREAD_LOCAL 1
243 #endif
244 
245 // There are platforms for which TLS should not be used even though the compiler
246 // makes it seem like it's supported (Android NDK < r12b for example).
247 // This is primarily because of linker problems and toolchain misconfiguration:
248 // Abseil does not intend to support this indefinitely. Currently, the newest
249 // toolchain that we intend to support that requires this behavior is the
250 // r11 NDK - allowing for a 5 year support window on that means this option
251 // is likely to be removed around June of 2021.
252 // TLS isn't supported until NDK r12b per
253 // https://developer.android.com/ndk/downloads/revision_history.html
254 // Since NDK r16, `__NDK_MAJOR__` and `__NDK_MINOR__` are defined in
255 // <android/ndk-version.h>. For NDK < r16, users should define these macros,
256 // e.g. `-D__NDK_MAJOR__=11 -D__NKD_MINOR__=0` for NDK r11.
257 #if defined(__ANDROID__) && defined(__clang__)
258 #if __has_include(<android/ndk-version.h>)
259 #include <android/ndk-version.h>
260 #endif  // __has_include(<android/ndk-version.h>)
261 #if defined(__ANDROID__) && defined(__clang__) && defined(__NDK_MAJOR__) && \
262     defined(__NDK_MINOR__) &&                                               \
263     ((__NDK_MAJOR__ < 12) || ((__NDK_MAJOR__ == 12) && (__NDK_MINOR__ < 1)))
264 #undef ABSL_HAVE_TLS
265 #undef ABSL_HAVE_THREAD_LOCAL
266 #endif
267 #endif  // defined(__ANDROID__) && defined(__clang__)
268 
269 // ABSL_HAVE_INTRINSIC_INT128
270 //
271 // Checks whether the __int128 compiler extension for a 128-bit integral type is
272 // supported.
273 //
274 // Note: __SIZEOF_INT128__ is defined by Clang and GCC when __int128 is
275 // supported, but we avoid using it in certain cases:
276 // * On Clang:
277 //   * Building using Clang for Windows, where the Clang runtime library has
278 //     128-bit support only on LP64 architectures, but Windows is LLP64.
279 // * On Nvidia's nvcc:
280 //   * nvcc also defines __GNUC__ and __SIZEOF_INT128__, but not all versions
281 //     actually support __int128.
282 #ifdef ABSL_HAVE_INTRINSIC_INT128
283 #error ABSL_HAVE_INTRINSIC_INT128 cannot be directly set
284 #elif defined(__SIZEOF_INT128__)
285 #if (defined(__clang__) && !defined(_WIN32)) || \
286     (defined(__CUDACC__) && __CUDACC_VER_MAJOR__ >= 9) ||                \
287     (defined(__GNUC__) && !defined(__clang__) && !defined(__CUDACC__))
288 #define ABSL_HAVE_INTRINSIC_INT128 1
289 #elif defined(__CUDACC__)
290 // __CUDACC_VER__ is a full version number before CUDA 9, and is defined to a
291 // string explaining that it has been removed starting with CUDA 9. We use
292 // nested #ifs because there is no short-circuiting in the preprocessor.
293 // NOTE: `__CUDACC__` could be undefined while `__CUDACC_VER__` is defined.
294 #if __CUDACC_VER__ >= 70000
295 #define ABSL_HAVE_INTRINSIC_INT128 1
296 #endif  // __CUDACC_VER__ >= 70000
297 #endif  // defined(__CUDACC__)
298 #endif  // ABSL_HAVE_INTRINSIC_INT128
299 
300 // ABSL_HAVE_EXCEPTIONS
301 //
302 // Checks whether the compiler both supports and enables exceptions. Many
303 // compilers support a "no exceptions" mode that disables exceptions.
304 //
305 // Generally, when ABSL_HAVE_EXCEPTIONS is not defined:
306 //
307 // * Code using `throw` and `try` may not compile.
308 // * The `noexcept` specifier will still compile and behave as normal.
309 // * The `noexcept` operator may still return `false`.
310 //
311 // For further details, consult the compiler's documentation.
312 #ifdef ABSL_HAVE_EXCEPTIONS
313 #error ABSL_HAVE_EXCEPTIONS cannot be directly set.
314 
315 #elif defined(__clang__)
316 
317 #if __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6)
318 // Clang >= 3.6
319 #if ABSL_HAVE_FEATURE(cxx_exceptions)
320 #define ABSL_HAVE_EXCEPTIONS 1
321 #endif  // ABSL_HAVE_FEATURE(cxx_exceptions)
322 #else
323 // Clang < 3.6
324 // http://releases.llvm.org/3.6.0/tools/clang/docs/ReleaseNotes.html#the-exceptions-macro
325 #if defined(__EXCEPTIONS) && ABSL_HAVE_FEATURE(cxx_exceptions)
326 #define ABSL_HAVE_EXCEPTIONS 1
327 #endif  // defined(__EXCEPTIONS) && ABSL_HAVE_FEATURE(cxx_exceptions)
328 #endif  // __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 6)
329 
330 // Handle remaining special cases and default to exceptions being supported.
331 #elif !(defined(__GNUC__) && (__GNUC__ < 5) && !defined(__EXCEPTIONS)) &&    \
332     !(defined(__GNUC__) && (__GNUC__ >= 5) && !defined(__cpp_exceptions)) && \
333     !(defined(_MSC_VER) && !defined(_CPPUNWIND))
334 #define ABSL_HAVE_EXCEPTIONS 1
335 #endif
336 
337 // -----------------------------------------------------------------------------
338 // Platform Feature Checks
339 // -----------------------------------------------------------------------------
340 
341 // Currently supported operating systems and associated preprocessor
342 // symbols:
343 //
344 //   Linux and Linux-derived           __linux__
345 //   Android                           __ANDROID__ (implies __linux__)
346 //   Linux (non-Android)               __linux__ && !__ANDROID__
347 //   Darwin (macOS and iOS)            __APPLE__
348 //   Akaros (http://akaros.org)        __ros__
349 //   Windows                           _WIN32
350 //   NaCL                              __native_client__
351 //   AsmJS                             __asmjs__
352 //   WebAssembly                       __wasm__
353 //   Fuchsia                           __Fuchsia__
354 //
355 // Note that since Android defines both __ANDROID__ and __linux__, one
356 // may probe for either Linux or Android by simply testing for __linux__.
357 
358 // ABSL_HAVE_MMAP
359 //
360 // Checks whether the platform has an mmap(2) implementation as defined in
361 // POSIX.1-2001.
362 #ifdef ABSL_HAVE_MMAP
363 #error ABSL_HAVE_MMAP cannot be directly set
364 #elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) ||   \
365     defined(__ros__) || defined(__native_client__) || defined(__asmjs__) || \
366     defined(__wasm__) || defined(__Fuchsia__) || defined(__sun) || \
367     defined(__ASYLO__) || defined(__myriad2__)
368 #define ABSL_HAVE_MMAP 1
369 #endif
370 
371 // ABSL_HAVE_PTHREAD_GETSCHEDPARAM
372 //
373 // Checks whether the platform implements the pthread_(get|set)schedparam(3)
374 // functions as defined in POSIX.1-2001.
375 #ifdef ABSL_HAVE_PTHREAD_GETSCHEDPARAM
376 #error ABSL_HAVE_PTHREAD_GETSCHEDPARAM cannot be directly set
377 #elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) || \
378     defined(__ros__)
379 #define ABSL_HAVE_PTHREAD_GETSCHEDPARAM 1
380 #endif
381 
382 // ABSL_HAVE_SCHED_YIELD
383 //
384 // Checks whether the platform implements sched_yield(2) as defined in
385 // POSIX.1-2001.
386 #ifdef ABSL_HAVE_SCHED_YIELD
387 #error ABSL_HAVE_SCHED_YIELD cannot be directly set
388 #elif defined(__linux__) || defined(__ros__) || defined(__native_client__)
389 #define ABSL_HAVE_SCHED_YIELD 1
390 #endif
391 
392 // ABSL_HAVE_SEMAPHORE_H
393 //
394 // Checks whether the platform supports the <semaphore.h> header and sem_init(3)
395 // family of functions as standardized in POSIX.1-2001.
396 //
397 // Note: While Apple provides <semaphore.h> for both iOS and macOS, it is
398 // explicitly deprecated and will cause build failures if enabled for those
399 // platforms.  We side-step the issue by not defining it here for Apple
400 // platforms.
401 #ifdef ABSL_HAVE_SEMAPHORE_H
402 #error ABSL_HAVE_SEMAPHORE_H cannot be directly set
403 #elif defined(__linux__) || defined(__ros__)
404 #define ABSL_HAVE_SEMAPHORE_H 1
405 #endif
406 
407 // ABSL_HAVE_ALARM
408 //
409 // Checks whether the platform supports the <signal.h> header and alarm(2)
410 // function as standardized in POSIX.1-2001.
411 #ifdef ABSL_HAVE_ALARM
412 #error ABSL_HAVE_ALARM cannot be directly set
413 #elif defined(__GOOGLE_GRTE_VERSION__)
414 // feature tests for Google's GRTE
415 #define ABSL_HAVE_ALARM 1
416 #elif defined(__GLIBC__)
417 // feature test for glibc
418 #define ABSL_HAVE_ALARM 1
419 #elif defined(_MSC_VER)
420 // feature tests for Microsoft's library
421 #elif defined(__MINGW32__)
422 // mingw32 doesn't provide alarm(2):
423 // https://osdn.net/projects/mingw/scm/git/mingw-org-wsl/blobs/5.2-trunk/mingwrt/include/unistd.h
424 // mingw-w64 provides a no-op implementation:
425 // https://sourceforge.net/p/mingw-w64/mingw-w64/ci/master/tree/mingw-w64-crt/misc/alarm.c
426 #elif defined(__EMSCRIPTEN__)
427 // emscripten doesn't support signals
428 #elif defined(__Fuchsia__)
429 // Signals don't exist on fuchsia.
430 #elif defined(__native_client__)
431 #else
432 // other standard libraries
433 #define ABSL_HAVE_ALARM 1
434 #endif
435 
436 // ABSL_IS_LITTLE_ENDIAN
437 // ABSL_IS_BIG_ENDIAN
438 //
439 // Checks the endianness of the platform.
440 //
441 // Notes: uses the built in endian macros provided by GCC (since 4.6) and
442 // Clang (since 3.2); see
443 // https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html.
444 // Otherwise, if _WIN32, assume little endian. Otherwise, bail with an error.
445 #if defined(ABSL_IS_BIG_ENDIAN)
446 #error "ABSL_IS_BIG_ENDIAN cannot be directly set."
447 #endif
448 #if defined(ABSL_IS_LITTLE_ENDIAN)
449 #error "ABSL_IS_LITTLE_ENDIAN cannot be directly set."
450 #endif
451 
452 #if (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
453      __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
454 #define ABSL_IS_LITTLE_ENDIAN 1
455 #elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
456     __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
457 #define ABSL_IS_BIG_ENDIAN 1
458 #elif defined(_WIN32)
459 #define ABSL_IS_LITTLE_ENDIAN 1
460 #else
461 #error "absl endian detection needs to be set up for your compiler"
462 #endif
463 
464 // macOS 10.13 and iOS 10.11 don't let you use <any>, <optional>, or <variant>
465 // even though the headers exist and are publicly noted to work.  See
466 // https://github.com/abseil/abseil-cpp/issues/207 and
467 // https://developer.apple.com/documentation/xcode_release_notes/xcode_10_release_notes
468 // libc++ spells out the availability requirements in the file
469 // llvm-project/libcxx/include/__config via the #define
470 // _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS.
471 #if defined(__APPLE__) && defined(_LIBCPP_VERSION) && \
472   ((defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && \
473    __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101400) || \
474   (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) && \
475    __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 120000) || \
476   (defined(__ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__) && \
477    __ENVIRONMENT_WATCH_OS_VERSION_MIN_REQUIRED__ < 50000) || \
478   (defined(__ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__) && \
479    __ENVIRONMENT_TV_OS_VERSION_MIN_REQUIRED__ < 120000))
480 #define ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE 1
481 #else
482 #define ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE 0
483 #endif
484 
485 // ABSL_HAVE_STD_ANY
486 //
487 // Checks whether C++17 std::any is available by checking whether <any> exists.
488 #ifdef ABSL_HAVE_STD_ANY
489 #error "ABSL_HAVE_STD_ANY cannot be directly set."
490 #endif
491 
492 #ifdef __has_include
493 #if __has_include(<any>) && __cplusplus >= 201703L && \
494     !ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE
495 #define ABSL_HAVE_STD_ANY 1
496 #endif
497 #endif
498 
499 // ABSL_HAVE_STD_OPTIONAL
500 //
501 // Checks whether C++17 std::optional is available.
502 #ifdef ABSL_HAVE_STD_OPTIONAL
503 #error "ABSL_HAVE_STD_OPTIONAL cannot be directly set."
504 #endif
505 
506 #ifdef __has_include
507 #if __has_include(<optional>) && __cplusplus >= 201703L && \
508     !ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE
509 #define ABSL_HAVE_STD_OPTIONAL 1
510 #endif
511 #endif
512 
513 // ABSL_HAVE_STD_VARIANT
514 //
515 // Checks whether C++17 std::variant is available.
516 #ifdef ABSL_HAVE_STD_VARIANT
517 #error "ABSL_HAVE_STD_VARIANT cannot be directly set."
518 #endif
519 
520 #ifdef __has_include
521 #if __has_include(<variant>) && __cplusplus >= 201703L && \
522     !ABSL_INTERNAL_APPLE_CXX17_TYPES_UNAVAILABLE
523 #define ABSL_HAVE_STD_VARIANT 1
524 #endif
525 #endif
526 
527 // ABSL_HAVE_STD_STRING_VIEW
528 //
529 // Checks whether C++17 std::string_view is available.
530 #ifdef ABSL_HAVE_STD_STRING_VIEW
531 #error "ABSL_HAVE_STD_STRING_VIEW cannot be directly set."
532 #endif
533 
534 #ifdef __has_include
535 #if __has_include(<string_view>) && __cplusplus >= 201703L
536 #define ABSL_HAVE_STD_STRING_VIEW 1
537 #endif
538 #endif
539 
540 // For MSVC, `__has_include` is supported in VS 2017 15.3, which is later than
541 // the support for <optional>, <any>, <string_view>, <variant>. So we use
542 // _MSC_VER to check whether we have VS 2017 RTM (when <optional>, <any>,
543 // <string_view>, <variant> is implemented) or higher. Also, `__cplusplus` is
544 // not correctly set by MSVC, so we use `_MSVC_LANG` to check the language
545 // version.
546 // TODO(zhangxy): fix tests before enabling aliasing for `std::any`.
547 #if defined(_MSC_VER) && _MSC_VER >= 1910 && \
548     ((defined(_MSVC_LANG) && _MSVC_LANG > 201402) || __cplusplus > 201402)
549 // #define ABSL_HAVE_STD_ANY 1
550 #define ABSL_HAVE_STD_OPTIONAL 1
551 #define ABSL_HAVE_STD_VARIANT 1
552 #define ABSL_HAVE_STD_STRING_VIEW 1
553 #endif
554 
555 // ABSL_USES_STD_ANY
556 //
557 // Indicates whether absl::any is an alias for std::any.
558 #if !defined(ABSL_OPTION_USE_STD_ANY)
559 #error options.h is misconfigured.
560 #elif ABSL_OPTION_USE_STD_ANY == 0 || \
561     (ABSL_OPTION_USE_STD_ANY == 2 && !defined(ABSL_HAVE_STD_ANY))
562 #undef ABSL_USES_STD_ANY
563 #elif ABSL_OPTION_USE_STD_ANY == 1 || \
564     (ABSL_OPTION_USE_STD_ANY == 2 && defined(ABSL_HAVE_STD_ANY))
565 #define ABSL_USES_STD_ANY 1
566 #else
567 #error options.h is misconfigured.
568 #endif
569 
570 // ABSL_USES_STD_OPTIONAL
571 //
572 // Indicates whether absl::optional is an alias for std::optional.
573 #if !defined(ABSL_OPTION_USE_STD_OPTIONAL)
574 #error options.h is misconfigured.
575 #elif ABSL_OPTION_USE_STD_OPTIONAL == 0 || \
576     (ABSL_OPTION_USE_STD_OPTIONAL == 2 && !defined(ABSL_HAVE_STD_OPTIONAL))
577 #undef ABSL_USES_STD_OPTIONAL
578 #elif ABSL_OPTION_USE_STD_OPTIONAL == 1 || \
579     (ABSL_OPTION_USE_STD_OPTIONAL == 2 && defined(ABSL_HAVE_STD_OPTIONAL))
580 #define ABSL_USES_STD_OPTIONAL 1
581 #else
582 #error options.h is misconfigured.
583 #endif
584 
585 // ABSL_USES_STD_VARIANT
586 //
587 // Indicates whether absl::variant is an alias for std::variant.
588 #if !defined(ABSL_OPTION_USE_STD_VARIANT)
589 #error options.h is misconfigured.
590 #elif ABSL_OPTION_USE_STD_VARIANT == 0 || \
591     (ABSL_OPTION_USE_STD_VARIANT == 2 && !defined(ABSL_HAVE_STD_VARIANT))
592 #undef ABSL_USES_STD_VARIANT
593 #elif ABSL_OPTION_USE_STD_VARIANT == 1 || \
594     (ABSL_OPTION_USE_STD_VARIANT == 2 && defined(ABSL_HAVE_STD_VARIANT))
595 #define ABSL_USES_STD_VARIANT 1
596 #else
597 #error options.h is misconfigured.
598 #endif
599 
600 // ABSL_USES_STD_STRING_VIEW
601 //
602 // Indicates whether absl::string_view is an alias for std::string_view.
603 #if !defined(ABSL_OPTION_USE_STD_STRING_VIEW)
604 #error options.h is misconfigured.
605 #elif ABSL_OPTION_USE_STD_STRING_VIEW == 0 || \
606     (ABSL_OPTION_USE_STD_STRING_VIEW == 2 &&  \
607      !defined(ABSL_HAVE_STD_STRING_VIEW))
608 #undef ABSL_USES_STD_STRING_VIEW
609 #elif ABSL_OPTION_USE_STD_STRING_VIEW == 1 || \
610     (ABSL_OPTION_USE_STD_STRING_VIEW == 2 &&  \
611      defined(ABSL_HAVE_STD_STRING_VIEW))
612 #define ABSL_USES_STD_STRING_VIEW 1
613 #else
614 #error options.h is misconfigured.
615 #endif
616 
617 // In debug mode, MSVC 2017's std::variant throws a EXCEPTION_ACCESS_VIOLATION
618 // SEH exception from emplace for variant<SomeStruct> when constructing the
619 // struct can throw. This defeats some of variant_test and
620 // variant_exception_safety_test.
621 #if defined(_MSC_VER) && _MSC_VER >= 1700 && defined(_DEBUG)
622 #define ABSL_INTERNAL_MSVC_2017_DBG_MODE
623 #endif
624 
625 // ABSL_INTERNAL_MANGLED_NS
626 // ABSL_INTERNAL_MANGLED_BACKREFERENCE
627 //
628 // Internal macros for building up mangled names in our internal fork of CCTZ.
629 // This implementation detail is only needed and provided for the MSVC build.
630 //
631 // These macros both expand to string literals.  ABSL_INTERNAL_MANGLED_NS is
632 // the mangled spelling of the `absl` namespace, and
633 // ABSL_INTERNAL_MANGLED_BACKREFERENCE is a back-reference integer representing
634 // the proper count to skip past the CCTZ fork namespace names.  (This number
635 // is one larger when there is an inline namespace name to skip.)
636 #if defined(_MSC_VER)
637 #if ABSL_OPTION_USE_INLINE_NAMESPACE == 0
638 #define ABSL_INTERNAL_MANGLED_NS "absl"
639 #define ABSL_INTERNAL_MANGLED_BACKREFERENCE "5"
640 #else
641 #define ABSL_INTERNAL_MANGLED_NS \
642   ABSL_INTERNAL_TOKEN_STR(ABSL_OPTION_INLINE_NAMESPACE_NAME) "@absl"
643 #define ABSL_INTERNAL_MANGLED_BACKREFERENCE "6"
644 #endif
645 #endif
646 
647 #undef ABSL_INTERNAL_HAS_KEYWORD
648 
649 // ABSL_DLL
650 //
651 // When building Abseil as a DLL, this macro expands to `__declspec(dllexport)`
652 // so we can annotate symbols appropriately as being exported. When used in
653 // headers consuming a DLL, this macro expands to `__declspec(dllimport)` so
654 // that consumers know the symbol is defined inside the DLL. In all other cases,
655 // the macro expands to nothing.
656 #if defined(_MSC_VER)
657 #if defined(ABSL_BUILD_DLL)
658 #define ABSL_DLL __declspec(dllexport)
659 #elif defined(ABSL_CONSUME_DLL)
660 #define ABSL_DLL __declspec(dllimport)
661 #else
662 #define ABSL_DLL
663 #endif
664 #else
665 #define ABSL_DLL
666 #endif  // defined(_MSC_VER)
667 
668 // ABSL_HAVE_MEMORY_SANITIZER
669 //
670 // MemorySanitizer (MSan) is a detector of uninitialized reads. It consists of
671 // a compiler instrumentation module and a run-time library.
672 #ifdef ABSL_HAVE_MEMORY_SANITIZER
673 #error "ABSL_HAVE_MEMORY_SANITIZER cannot be directly set."
674 #elif defined(MEMORY_SANITIZER)
675 // The MEMORY_SANITIZER macro is deprecated but we will continue to honor it
676 // for now.
677 #define ABSL_HAVE_MEMORY_SANITIZER 1
678 #elif defined(__SANITIZE_MEMORY__)
679 #define ABSL_HAVE_MEMORY_SANITIZER 1
680 #elif !defined(__native_client__) && ABSL_HAVE_FEATURE(memory_sanitizer)
681 #define ABSL_HAVE_MEMORY_SANITIZER 1
682 #endif
683 
684 // ABSL_HAVE_THREAD_SANITIZER
685 //
686 // ThreadSanitizer (TSan) is a fast data race detector.
687 #ifdef ABSL_HAVE_THREAD_SANITIZER
688 #error "ABSL_HAVE_THREAD_SANITIZER cannot be directly set."
689 #elif defined(THREAD_SANITIZER)
690 // The THREAD_SANITIZER macro is deprecated but we will continue to honor it
691 // for now.
692 #define ABSL_HAVE_THREAD_SANITIZER 1
693 #elif defined(__SANITIZE_THREAD__)
694 #define ABSL_HAVE_THREAD_SANITIZER 1
695 #elif ABSL_HAVE_FEATURE(thread_sanitizer)
696 #define ABSL_HAVE_THREAD_SANITIZER 1
697 #endif
698 
699 // ABSL_HAVE_ADDRESS_SANITIZER
700 //
701 // AddressSanitizer (ASan) is a fast memory error detector.
702 #ifdef ABSL_HAVE_ADDRESS_SANITIZER
703 #error "ABSL_HAVE_ADDRESS_SANITIZER cannot be directly set."
704 #elif defined(ADDRESS_SANITIZER)
705 // The ADDRESS_SANITIZER macro is deprecated but we will continue to honor it
706 // for now.
707 #define ABSL_HAVE_ADDRESS_SANITIZER 1
708 #elif defined(__SANITIZE_ADDRESS__)
709 #define ABSL_HAVE_ADDRESS_SANITIZER 1
710 #elif ABSL_HAVE_FEATURE(address_sanitizer)
711 #define ABSL_HAVE_ADDRESS_SANITIZER 1
712 #endif
713 
714 #endif  // ABSL_BASE_CONFIG_H_
715