2 * Copyright 2015 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_
22 #ifndef FOLLY_NO_CONFIG
23 #include <folly/folly-config.h>
26 #ifdef FOLLY_PLATFORM_CONFIG
27 #include FOLLY_PLATFORM_CONFIG
30 #if FOLLY_HAVE_FEATURES_H
34 #include <folly/CPortability.h>
37 # include <malloc/malloc.h>
40 #if FOLLY_HAVE_SCHED_H
42 #ifndef FOLLY_HAVE_PTHREAD_YIELD
43 #define pthread_yield sched_yield
47 // A change in folly/MemoryMapping.cpp uses MAP_ANONYMOUS, which is named
48 // MAP_ANON on OSX/BSD.
49 #if defined(__APPLE__) || defined(__FreeBSD__)
53 #define MAP_ANONYMOUS MAP_ANON
58 // compiler specific attribute translation
59 // msvc should come first, so if clang is in msvc mode it gets the right defines
61 #if defined(__clang__) || defined(__GNUC__)
62 # define FOLLY_ALIGNED(size) __attribute__((__aligned__(size)))
63 #elif defined(_MSC_VER)
64 # define FOLLY_ALIGNED(size) __declspec(align(size))
66 # error Cannot define FOLLY_ALIGNED on this platform
68 #define FOLLY_ALIGNED_MAX FOLLY_ALIGNED(alignof(std::max_align_t))
70 // NOTE: this will only do checking in msvc with versions that support /analyze
72 # ifdef _USE_ATTRIBUTES_FOR_SAL
73 # undef _USE_ATTRIBUTES_FOR_SAL
76 # define _USE_ATTRIBUTES_FOR_SAL 1
78 # define FOLLY_PRINTF_FORMAT _Printf_format_string_
79 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) /**/
81 # define FOLLY_PRINTF_FORMAT /**/
82 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) \
83 __attribute__((__format__(__printf__, format_param, dots_param)))
87 #if defined(__clang__) || defined(__GNUC__)
88 # define FOLLY_DEPRECATED(msg) __attribute__((__deprecated__(msg)))
89 #elif defined(_MSC_VER)
90 # define FOLLY_DEPRECATED(msg) __declspec(deprecated(msg))
92 # define FOLLY_DEPRECATED(msg)
97 # define FOLLY_NORETURN __declspec(noreturn)
98 #elif defined(__clang__) || defined(__GNUC__)
99 # define FOLLY_NORETURN __attribute__((__noreturn__))
101 # define FOLLY_NORETURN
106 # define FOLLY_NOINLINE __declspec(noinline)
107 #elif defined(__clang__) || defined(__GNUC__)
108 # define FOLLY_NOINLINE __attribute__((__noinline__))
110 # define FOLLY_NOINLINE
115 # define FOLLY_ALWAYS_INLINE __forceinline
116 #elif defined(__clang__) || defined(__GNUC__)
117 # define FOLLY_ALWAYS_INLINE inline __attribute__((__always_inline__))
119 # define FOLLY_ALWAYS_INLINE
122 // detection for 64 bit
123 #if defined(__x86_64__) || defined(_M_X64)
129 #if defined(__aarch64__)
135 // packing is very ugly in msvc
137 # define FOLLY_PACK_ATTR /**/
138 # define FOLLY_PACK_PUSH __pragma(pack(push, 1))
139 # define FOLLY_PACK_POP __pragma(pack(pop))
140 #elif defined(__clang__) || defined(__GNUC__)
141 # define FOLLY_PACK_ATTR __attribute__((__packed__))
142 # define FOLLY_PACK_PUSH /**/
143 # define FOLLY_PACK_POP /**/
145 # define FOLLY_PACK_ATTR /**/
146 # define FOLLY_PACK_PUSH /**/
147 # define FOLLY_PACK_POP /**/
150 // portable version check
151 #ifndef __GNUC_PREREQ
152 # if defined __GNUC__ && defined __GNUC_MINOR__
154 # define __GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= \
155 ((maj) << 16) + (min))
158 # define __GNUC_PREREQ(maj, min) 0
162 #if defined(__GNUC__) && !__GNUC_PREREQ(4,9)
163 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56019
164 // gcc 4.8.x incorrectly placed max_align_t in the root namespace
165 // Alias it into std (where it's found in 4.9 and later)
166 namespace std { typedef ::max_align_t max_align_t; }
169 /* Define macro wrappers for C++11's "final" and "override" keywords, which
170 * are supported in gcc 4.7 but not gcc 4.6. */
171 #if !defined(FOLLY_FINAL) && !defined(FOLLY_OVERRIDE)
172 # if defined(__clang__) || __GNUC_PREREQ(4, 7)
173 # define FOLLY_FINAL final
174 # define FOLLY_OVERRIDE override
175 # elif defined(_MSC_VER) && _MSC_VER >= 1600
176 # define FOLLY_FINAL final
177 # define FOLLY_OVERRIDE override
179 # define FOLLY_FINAL /**/
180 # define FOLLY_OVERRIDE /**/
184 /* Platform specific TLS support
185 * gcc implements __thread
186 * msvc implements __declspec(thread)
187 * the semantics are the same
188 * (but remember __thread has different semantics when using emutls (ex. apple))
190 #if defined(_MSC_VER)
191 # define FOLLY_TLS __declspec(thread)
192 #elif defined(__GNUC__) || defined(__clang__)
193 # define FOLLY_TLS __thread
195 # error cannot define platform specific thread local storage
198 // Define to 1 if you have the `preadv' and `pwritev' functions, respectively
199 #if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
200 # if defined(__GLIBC_PREREQ)
201 # if __GLIBC_PREREQ(2, 10)
202 # define FOLLY_HAVE_PREADV 1
203 # define FOLLY_HAVE_PWRITEV 1
208 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
209 // the 'std' namespace; the latter uses inline namepsaces. Wrap this decision
210 // up in a macro to make forward-declarations easier.
213 #define FOLLY_NAMESPACE_STD_BEGIN _LIBCPP_BEGIN_NAMESPACE_STD
214 #define FOLLY_NAMESPACE_STD_END _LIBCPP_END_NAMESPACE_STD
216 #define FOLLY_NAMESPACE_STD_BEGIN namespace std {
217 #define FOLLY_NAMESPACE_STD_END }
220 // Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
221 // versions of these into the global namespace.
222 #if FOLLY_HAVE_CLOCK_GETTIME
225 #include <folly/detail/Clock.h>
228 // Provide our own std::__throw_* wrappers for platforms that don't have them
229 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
230 #include <bits/functexcept.h>
232 #include <folly/detail/FunctionalExcept.h>
235 #if defined(__cplusplus)
236 // Unfortunately, boost::has_trivial_copy<T> is broken in libc++ due to its
237 // usage of __has_trivial_copy(), so we can't use it as a
238 // least-common-denominator for C++11 implementations that don't support
239 // std::is_trivially_copyable<T>.
241 // http://stackoverflow.com/questions/12754886/has-trivial-copy-behaves-differently-in-clang-and-gcc-whos-right
243 // As a result, use std::is_trivially_copyable() where it exists, and fall back
244 // to Boost otherwise.
245 #if FOLLY_HAVE_STD__IS_TRIVIALLY_COPYABLE
246 #include <type_traits>
247 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
248 (std::is_trivially_copyable<T>::value)
250 #include <boost/type_traits.hpp>
251 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
252 (boost::has_trivial_copy<T>::value && \
253 boost::has_trivial_destructor<T>::value)
255 #endif // __cplusplus
257 // MSVC specific defines
258 // mainly for posix compat
261 // this definition is in a really silly place with a silly name
262 // and ifdefing it every time we want it is painful
264 typedef SSIZE_T ssize_t;
266 // sprintf semantics are not exactly identical
267 // but current usage is not a problem
268 # define snprintf _snprintf
270 // semantics here are identical
271 # define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
273 // compiler specific to compiler specific
275 # define __PRETTY_FUNCTION__ __FUNCSIG__
277 // Hide a GCC specific thing that breaks MSVC if left alone.
278 # define __extension__
281 # define FOLLY_SSE _M_IX86_FP
282 # define FOLLY_SSE_MINOR 0
288 # if defined(__SSE4_2__)
290 # define FOLLY_SSE_MINOR 2
291 # elif defined(__SSE4_1__)
293 # define FOLLY_SSE_MINOR 1
294 # elif defined(__SSE4__)
296 # define FOLLY_SSE_MINOR 0
297 # elif defined(__SSE3__)
299 # define FOLLY_SSE_MINOR 0
300 # elif defined(__SSE2__)
302 # define FOLLY_SSE_MINOR 0
303 # elif defined(__SSE__)
305 # define FOLLY_SSE_MINOR 0
308 # define FOLLY_SSE_MINOR 0
312 #if FOLLY_UNUSUAL_GFLAGS_NAMESPACE
313 namespace FOLLY_GFLAGS_NAMESPACE { }
315 using namespace FOLLY_GFLAGS_NAMESPACE;
316 } // namespace gflags
319 // for TARGET_OS_IPHONE
321 #include <TargetConditionals.h>
324 // MacOS doesn't have malloc_usable_size()
325 #if defined(__APPLE__) && !defined(FOLLY_HAVE_MALLOC_USABLE_SIZE)
326 inline size_t malloc_usable_size(void* ptr) {
327 return malloc_size(ptr);
331 // RTTI may not be enabled for this compilation unit.
332 #if defined(__GXX_RTTI) || defined(__cpp_rtti) || \
333 (defined(_MSC_VER) && defined(_CPPRTTI))
334 # define FOLLY_HAS_RTTI 1
343 inline void asm_volatile_memory() {
344 #if defined(__clang__) || defined(__GNUC__)
345 asm volatile("" : : : "memory");
346 #elif defined(_MSC_VER)
347 ::_ReadWriteBarrier();
351 inline void asm_volatile_pause() {
352 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
354 #elif defined(__i386__) || FOLLY_X64
355 asm volatile ("pause");
357 asm volatile ("wfe");
360 inline void asm_pause() {
361 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
363 #elif defined(__i386__) || FOLLY_X64
372 #endif // FOLLY_PORTABILITY_H_