2 * Copyright 2016 Facebook, Inc.
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #ifndef FOLLY_PORTABILITY_H_
18 #define FOLLY_PORTABILITY_H_
20 // @nocommit invalidate ccache 20151125 (see #8764509)
26 #ifndef FOLLY_NO_CONFIG
27 #include <folly/folly-config.h>
30 #ifdef FOLLY_PLATFORM_CONFIG
31 #include FOLLY_PLATFORM_CONFIG
34 #if FOLLY_HAVE_FEATURES_H
38 #include <folly/CPortability.h>
41 # include <malloc/malloc.h>
44 #if FOLLY_HAVE_SCHED_H
46 #ifndef FOLLY_HAVE_PTHREAD_YIELD
47 #define pthread_yield sched_yield
51 #ifndef FOLLY_HAVE_UNALIGNED_READS
52 #define FOLLY_HAVE_UNALIGNED_READS 0
55 // A change in folly/MemoryMapping.cpp uses MAP_ANONYMOUS, which is named
56 // MAP_ANON on OSX/BSD.
57 #if defined(__APPLE__) || defined(__FreeBSD__)
61 #define MAP_ANONYMOUS MAP_ANON
66 // compiler specific attribute translation
67 // msvc should come first, so if clang is in msvc mode it gets the right defines
69 #if defined(__clang__) || defined(__GNUC__)
70 # define FOLLY_ALIGNED(size) __attribute__((__aligned__(size)))
71 #elif defined(_MSC_VER)
72 # define FOLLY_ALIGNED(size) __declspec(align(size))
74 # error Cannot define FOLLY_ALIGNED on this platform
76 #define FOLLY_ALIGNED_MAX FOLLY_ALIGNED(alignof(std::max_align_t))
78 // NOTE: this will only do checking in msvc with versions that support /analyze
80 # ifdef _USE_ATTRIBUTES_FOR_SAL
81 # undef _USE_ATTRIBUTES_FOR_SAL
84 # define _USE_ATTRIBUTES_FOR_SAL 1
86 # define FOLLY_PRINTF_FORMAT _Printf_format_string_
87 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) /**/
89 # define FOLLY_PRINTF_FORMAT /**/
90 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) \
91 __attribute__((__format__(__printf__, format_param, dots_param)))
95 #if defined(__clang__) || defined(__GNUC__)
96 # define FOLLY_DEPRECATED(msg) __attribute__((__deprecated__(msg)))
97 #elif defined(_MSC_VER)
98 # define FOLLY_DEPRECATED(msg) __declspec(deprecated(msg))
100 # define FOLLY_DEPRECATED(msg)
104 #if defined(_MSC_VER)
105 # define FOLLY_NORETURN __declspec(noreturn)
106 #elif defined(__clang__) || defined(__GNUC__)
107 # define FOLLY_NORETURN __attribute__((__noreturn__))
109 # define FOLLY_NORETURN
114 # define FOLLY_NOINLINE __declspec(noinline)
115 #elif defined(__clang__) || defined(__GNUC__)
116 # define FOLLY_NOINLINE __attribute__((__noinline__))
118 # define FOLLY_NOINLINE
123 # define FOLLY_ALWAYS_INLINE __forceinline
124 #elif defined(__clang__) || defined(__GNUC__)
125 # define FOLLY_ALWAYS_INLINE inline __attribute__((__always_inline__))
127 # define FOLLY_ALWAYS_INLINE inline
130 // detection for 64 bit
131 #if defined(__x86_64__) || defined(_M_X64)
137 #if defined(__aarch64__)
143 #if defined (__powerpc64__)
144 # define FOLLY_PPC64 1
146 # define FOLLY_PPC64 0
149 // packing is very ugly in msvc
151 # define FOLLY_PACK_ATTR /**/
152 # define FOLLY_PACK_PUSH __pragma(pack(push, 1))
153 # define FOLLY_PACK_POP __pragma(pack(pop))
154 #elif defined(__clang__) || defined(__GNUC__)
155 # define FOLLY_PACK_ATTR __attribute__((__packed__))
156 # define FOLLY_PACK_PUSH /**/
157 # define FOLLY_PACK_POP /**/
159 # define FOLLY_PACK_ATTR /**/
160 # define FOLLY_PACK_PUSH /**/
161 # define FOLLY_PACK_POP /**/
164 // Generalize warning push/pop.
165 #if defined(_MSC_VER)
166 # define FOLLY_PUSH_WARNING __pragma(warning(push))
167 # define FOLLY_POP_WARNING __pragma(warning(pop))
168 // Disable the GCC warnings.
169 # define FOLLY_GCC_DISABLE_WARNING(warningName)
170 # define FOLLY_MSVC_DISABLE_WARNING(warningNumber) __pragma(warning(disable: warningNumber))
171 #elif defined(__clang__) || defined(__GNUC__)
172 # define FOLLY_PUSH_WARNING _Pragma("GCC diagnostic push")
173 # define FOLLY_POP_WARNING _Pragma("GCC diagnostic pop")
174 #define FOLLY_GCC_DISABLE_WARNING_INTERNAL3(warningName) #warningName
175 #define FOLLY_GCC_DISABLE_WARNING_INTERNAL2(warningName) \
176 FOLLY_GCC_DISABLE_WARNING_INTERNAL3(warningName)
177 #define FOLLY_GCC_DISABLE_WARNING(warningName) \
178 _Pragma(FOLLY_GCC_DISABLE_WARNING_INTERNAL2(GCC diagnostic ignored \
179 FOLLY_GCC_DISABLE_WARNING_INTERNAL3(-W##warningName)))
180 // Disable the MSVC warnings.
181 # define FOLLY_MSVC_DISABLE_WARNING(warningNumber)
183 # define FOLLY_PUSH_WARNING
184 # define FOLLY_POP_WARNING
185 # define FOLLY_GCC_DISABLE_WARNING(warningName)
186 # define FOLLY_MSVC_DISABLE_WARNING(warningNumber)
189 // portable version check
190 #ifndef __GNUC_PREREQ
191 # if defined __GNUC__ && defined __GNUC_MINOR__
193 # define __GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= \
194 ((maj) << 16) + (min))
197 # define __GNUC_PREREQ(maj, min) 0
201 #if defined(__GNUC__) && !defined(__APPLE__) && !__GNUC_PREREQ(4,9)
202 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56019
203 // gcc 4.8.x incorrectly placed max_align_t in the root namespace
204 // Alias it into std (where it's found in 4.9 and later)
205 namespace std { typedef ::max_align_t max_align_t; }
208 // portable version check for clang
209 #ifndef __CLANG_PREREQ
210 # if defined __clang__ && defined __clang_major__ && defined __clang_minor__
212 # define __CLANG_PREREQ(maj, min) \
213 ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
216 # define __CLANG_PREREQ(maj, min) 0
220 /* Platform specific TLS support
221 * gcc implements __thread
222 * msvc implements __declspec(thread)
223 * the semantics are the same
224 * (but remember __thread has different semantics when using emutls (ex. apple))
226 #if defined(_MSC_VER)
227 # define FOLLY_TLS __declspec(thread)
228 #elif defined(__GNUC__) || defined(__clang__)
229 # define FOLLY_TLS __thread
231 # error cannot define platform specific thread local storage
234 #if defined(__APPLE__) && (TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE)
238 // Define to 1 if you have the `preadv' and `pwritev' functions, respectively
239 #if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
240 # if defined(__GLIBC_PREREQ)
241 # if __GLIBC_PREREQ(2, 10)
242 # define FOLLY_HAVE_PREADV 1
243 # define FOLLY_HAVE_PWRITEV 1
248 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
249 // the 'std' namespace; the latter uses inline namespaces. Wrap this decision
250 // up in a macro to make forward-declarations easier.
253 #define FOLLY_NAMESPACE_STD_BEGIN _LIBCPP_BEGIN_NAMESPACE_STD
254 #define FOLLY_NAMESPACE_STD_END _LIBCPP_END_NAMESPACE_STD
256 #define FOLLY_NAMESPACE_STD_BEGIN namespace std {
257 #define FOLLY_NAMESPACE_STD_END }
260 // If the new c++ ABI is used, __cxx11 inline namespace needs to be added to
261 // some types, e.g. std::list.
262 #if _GLIBCXX_USE_CXX11_ABI
263 # define FOLLY_GLIBCXX_NAMESPACE_CXX11_BEGIN _GLIBCXX_BEGIN_NAMESPACE_CXX11
264 # define FOLLY_GLIBCXX_NAMESPACE_CXX11_END _GLIBCXX_END_NAMESPACE_CXX11
266 # define FOLLY_GLIBCXX_NAMESPACE_CXX11_BEGIN
267 # define FOLLY_GLIBCXX_NAMESPACE_CXX11_END
270 // Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
271 // versions of these into the global namespace.
272 #if FOLLY_HAVE_CLOCK_GETTIME
275 #include <folly/detail/Clock.h>
278 // Provide our own std::__throw_* wrappers for platforms that don't have them
279 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
280 #include <bits/functexcept.h>
282 #include <folly/detail/FunctionalExcept.h>
285 #if defined(__cplusplus)
286 // Unfortunately, boost::has_trivial_copy<T> is broken in libc++ due to its
287 // usage of __has_trivial_copy(), so we can't use it as a
288 // least-common-denominator for C++11 implementations that don't support
289 // std::is_trivially_copyable<T>.
291 // http://stackoverflow.com/questions/12754886/has-trivial-copy-behaves-differently-in-clang-and-gcc-whos-right
293 // As a result, use std::is_trivially_copyable() where it exists, and fall back
294 // to Boost otherwise.
295 #if FOLLY_HAVE_STD__IS_TRIVIALLY_COPYABLE
296 #include <type_traits>
297 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
298 (std::is_trivially_copyable<T>::value)
300 #include <boost/type_traits.hpp>
301 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
302 (boost::has_trivial_copy<T>::value && \
303 boost::has_trivial_destructor<T>::value)
305 #endif // __cplusplus
307 // MSVC specific defines
308 // mainly for posix compat
311 // this definition is in a really silly place with a silly name
312 // and ifdefing it every time we want it is painful
314 typedef SSIZE_T ssize_t;
316 // sprintf semantics are not exactly identical
317 // but current usage is not a problem
318 # define snprintf _snprintf
320 // semantics here are identical
321 # define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
323 // compiler specific to compiler specific
325 # define __PRETTY_FUNCTION__ __FUNCSIG__
327 // Hide a GCC specific thing that breaks MSVC if left alone.
328 # define __extension__
331 # define FOLLY_SSE _M_IX86_FP
332 # define FOLLY_SSE_MINOR 0
340 constexpr auto kIsDebug = false;
342 constexpr auto kIsDebug = true;
349 // It's MSVC, so we just have to guess ... and allow an override
350 #ifdef FOLLY_ENDIAN_BE
351 constexpr auto kIsLittleEndian = false;
353 constexpr auto kIsLittleEndian = true;
356 constexpr auto kIsLittleEndian = __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__;
358 constexpr auto kIsBigEndian = !kIsLittleEndian;
362 # if defined(__SSE4_2__)
364 # define FOLLY_SSE_MINOR 2
365 # elif defined(__SSE4_1__)
367 # define FOLLY_SSE_MINOR 1
368 # elif defined(__SSE4__)
370 # define FOLLY_SSE_MINOR 0
371 # elif defined(__SSE3__)
373 # define FOLLY_SSE_MINOR 0
374 # elif defined(__SSE2__)
376 # define FOLLY_SSE_MINOR 0
377 # elif defined(__SSE__)
379 # define FOLLY_SSE_MINOR 0
382 # define FOLLY_SSE_MINOR 0
386 #define FOLLY_SSE_PREREQ(major, minor) \
387 (FOLLY_SSE > major || FOLLY_SSE == major && FOLLY_SSE_MINOR >= minor)
389 #if FOLLY_UNUSUAL_GFLAGS_NAMESPACE
390 namespace FOLLY_GFLAGS_NAMESPACE { }
392 using namespace FOLLY_GFLAGS_NAMESPACE;
393 } // namespace gflags
396 // for TARGET_OS_IPHONE
398 #include <TargetConditionals.h>
401 // MacOS doesn't have malloc_usable_size()
402 #if defined(__APPLE__) && !defined(FOLLY_HAVE_MALLOC_USABLE_SIZE)
403 inline size_t malloc_usable_size(void* ptr) {
404 return malloc_size(ptr);
408 // RTTI may not be enabled for this compilation unit.
409 #if defined(__GXX_RTTI) || defined(__cpp_rtti) || \
410 (defined(_MSC_VER) && defined(_CPPRTTI))
411 # define FOLLY_HAS_RTTI 1
420 inline void asm_volatile_memory() {
421 #if defined(__clang__) || defined(__GNUC__)
422 asm volatile("" : : : "memory");
423 #elif defined(_MSC_VER)
424 ::_ReadWriteBarrier();
428 inline void asm_volatile_pause() {
429 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
431 #elif defined(__i386__) || FOLLY_X64
432 asm volatile ("pause");
433 #elif FOLLY_A64 || defined(__arm__)
434 asm volatile ("yield");
436 asm volatile("or 27,27,27");
439 inline void asm_pause() {
440 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
442 #elif defined(__i386__) || FOLLY_X64
444 #elif FOLLY_A64 || defined(__arm__)
451 #if defined(__APPLE__) || defined(_MSC_VER)
452 #define MAX_STATIC_CONSTRUCTOR_PRIORITY
454 // 101 is the highest priority allowed by the init_priority attribute.
455 // This priority is already used by JEMalloc and other memory allocators so
456 // we will take the next one.
457 #define MAX_STATIC_CONSTRUCTOR_PRIORITY __attribute__ ((__init_priority__(102)))
461 #endif // FOLLY_PORTABILITY_H_