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_
20 #ifndef FOLLY_NO_CONFIG
21 #include <folly/folly-config.h>
24 #ifdef FOLLY_PLATFORM_CONFIG
25 #include FOLLY_PLATFORM_CONFIG
28 #if FOLLY_HAVE_FEATURES_H
32 #include <folly/CPortability.h>
35 # include <malloc/malloc.h>
38 #if FOLLY_HAVE_SCHED_H
40 #ifndef FOLLY_HAVE_PTHREAD_YIELD
41 #define pthread_yield sched_yield
45 // A change in folly/MemoryMapping.cpp uses MAP_ANONYMOUS, which is named
46 // MAP_ANON on OSX/BSD.
47 #if defined(__APPLE__) || defined(__FreeBSD__)
51 #define MAP_ANONYMOUS MAP_ANON
56 // MaxAlign: max_align_t isn't supported by gcc
58 struct MaxAlign { char c; } __attribute__((__aligned__));
60 # error Cannot define MaxAlign on this platform
63 // compiler specific attribute translation
64 // msvc should come first, so if clang is in msvc mode it gets the right defines
66 // NOTE: this will only do checking in msvc with versions that support /analyze
68 # ifdef _USE_ATTRIBUTES_FOR_SAL
69 # undef _USE_ATTRIBUTES_FOR_SAL
72 # define _USE_ATTRIBUTES_FOR_SAL 1
74 # define FOLLY_PRINTF_FORMAT _Printf_format_string_
75 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) /**/
77 # define FOLLY_PRINTF_FORMAT /**/
78 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) \
79 __attribute__((__format__(__printf__, format_param, dots_param)))
83 #if defined(__clang__) || defined(__GNUC__)
84 # define FOLLY_DEPRECATED(msg) __attribute__((__deprecated__(msg)))
85 #elif defined(_MSC_VER)
86 # define FOLLY_DEPRECATED(msg) __declspec(deprecated(msg))
88 # define FOLLY_DEPRECATED
93 # define FOLLY_NORETURN __declspec(noreturn)
94 #elif defined(__clang__) || defined(__GNUC__)
95 # define FOLLY_NORETURN __attribute__((__noreturn__))
97 # define FOLLY_NORETURN
102 # define FOLLY_NOINLINE __declspec(noinline)
103 #elif defined(__clang__) || defined(__GNUC__)
104 # define FOLLY_NOINLINE __attribute__((__noinline__))
106 # define FOLLY_NOINLINE
111 # define FOLLY_ALWAYS_INLINE __forceinline
112 #elif defined(__clang__) || defined(__GNUC__)
113 # define FOLLY_ALWAYS_INLINE inline __attribute__((__always_inline__))
115 # define FOLLY_ALWAYS_INLINE
118 // detection for 64 bit
119 #if defined(__x86_64__) || defined(_M_X64)
125 #if defined(__aarch64__)
131 // packing is very ugly in msvc
133 # define FOLLY_PACK_ATTR /**/
134 # define FOLLY_PACK_PUSH __pragma(pack(push, 1))
135 # define FOLLY_PACK_POP __pragma(pack(pop))
136 #elif defined(__clang__) || defined(__GNUC__)
137 # define FOLLY_PACK_ATTR __attribute__((__packed__))
138 # define FOLLY_PACK_PUSH /**/
139 # define FOLLY_PACK_POP /**/
141 # define FOLLY_PACK_ATTR /**/
142 # define FOLLY_PACK_PUSH /**/
143 # define FOLLY_PACK_POP /**/
146 // portable version check
147 #ifndef __GNUC_PREREQ
148 # if defined __GNUC__ && defined __GNUC_MINOR__
150 # define __GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= \
151 ((maj) << 16) + (min))
154 # define __GNUC_PREREQ(maj, min) 0
159 /* Define macro wrappers for C++11's "final" and "override" keywords, which
160 * are supported in gcc 4.7 but not gcc 4.6. */
161 #if !defined(FOLLY_FINAL) && !defined(FOLLY_OVERRIDE)
162 # if defined(__clang__) || __GNUC_PREREQ(4, 7)
163 # define FOLLY_FINAL final
164 # define FOLLY_OVERRIDE override
165 # elif defined(_MSC_VER) && _MSC_VER >= 1600
166 # define FOLLY_FINAL final
167 # define FOLLY_OVERRIDE override
169 # define FOLLY_FINAL /**/
170 # define FOLLY_OVERRIDE /**/
174 /* Platform specific TLS support
175 * gcc implements __thread
176 * msvc implements __declspec(thread)
177 * the semantics are the same
178 * (but remember __thread has different semantics when using emutls (ex. apple))
180 #if defined(_MSC_VER)
181 # define FOLLY_TLS __declspec(thread)
182 #elif defined(__GNUC__) || defined(__clang__)
183 # define FOLLY_TLS __thread
185 # error cannot define platform specific thread local storage
188 // Define to 1 if you have the `preadv' and `pwritev' functions, respectively
189 #if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
190 # if defined(__GLIBC_PREREQ)
191 # if __GLIBC_PREREQ(2, 10)
192 # define FOLLY_HAVE_PREADV 1
193 # define FOLLY_HAVE_PWRITEV 1
198 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
199 // the 'std' namespace; the latter uses inline namepsaces. Wrap this decision
200 // up in a macro to make forward-declarations easier.
203 #define FOLLY_NAMESPACE_STD_BEGIN _LIBCPP_BEGIN_NAMESPACE_STD
204 #define FOLLY_NAMESPACE_STD_END _LIBCPP_END_NAMESPACE_STD
206 #define FOLLY_NAMESPACE_STD_BEGIN namespace std {
207 #define FOLLY_NAMESPACE_STD_END }
210 // Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
211 // versions of these into the global namespace.
212 #if FOLLY_HAVE_CLOCK_GETTIME
215 #include <folly/detail/Clock.h>
218 // Provide our own std::__throw_* wrappers for platforms that don't have them
219 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
220 #include <bits/functexcept.h>
222 #include <folly/detail/FunctionalExcept.h>
225 #if defined(__cplusplus)
226 // Unfortunately, boost::has_trivial_copy<T> is broken in libc++ due to its
227 // usage of __has_trivial_copy(), so we can't use it as a
228 // least-common-denominator for C++11 implementations that don't support
229 // std::is_trivially_copyable<T>.
231 // http://stackoverflow.com/questions/12754886/has-trivial-copy-behaves-differently-in-clang-and-gcc-whos-right
233 // As a result, use std::is_trivially_copyable() where it exists, and fall back
234 // to Boost otherwise.
235 #if FOLLY_HAVE_STD__IS_TRIVIALLY_COPYABLE
236 #include <type_traits>
237 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
238 (std::is_trivially_copyable<T>::value)
240 #include <boost/type_traits.hpp>
241 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
242 (boost::has_trivial_copy<T>::value && \
243 boost::has_trivial_destructor<T>::value)
245 #endif // __cplusplus
247 // MSVC specific defines
248 // mainly for posix compat
251 // this definition is in a really silly place with a silly name
252 // and ifdefing it every time we want it is painful
254 typedef SSIZE_T ssize_t;
256 // sprintf semantics are not exactly identical
257 // but current usage is not a problem
258 # define snprintf _snprintf
260 // semantics here are identical
261 # define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
263 // compiler specific to compiler specific
265 # define __PRETTY_FUNCTION__ __FUNCSIG__
267 // Hide a GCC specific thing that breaks MSVC if left alone.
268 # define __extension__
271 # define FOLLY_SSE _M_IX86_FP
277 # if defined(__SSE4_2__)
278 # define FOLLY_SSE 4.2
279 # elif defined(__SSE4_1__)
280 # define FOLLY_SSE 4.1
281 # elif defined(__SSE4__)
283 # elif defined(__SSE3__)
285 # elif defined(__SSE2__)
287 # elif defined(__SSE__)
294 #if FOLLY_UNUSUAL_GFLAGS_NAMESPACE
295 namespace FOLLY_GFLAGS_NAMESPACE { }
297 using namespace FOLLY_GFLAGS_NAMESPACE;
298 } // namespace gflags
301 // for TARGET_OS_IPHONE
303 #include <TargetConditionals.h>
306 // MacOS doesn't have malloc_usable_size()
307 #if defined(__APPLE__) && !defined(FOLLY_HAVE_MALLOC_USABLE_SIZE)
308 inline size_t malloc_usable_size(void* ptr) {
309 return malloc_size(ptr);
313 // RTTI may not be enabled for this compilation unit.
314 #if defined(__GXX_RTTI) || defined(__cpp_rtti) || \
315 (defined(_MSC_VER) && defined(_CPPRTTI))
316 # define FOLLY_HAS_RTTI 1
325 inline void asm_volatile_pause() {
326 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
328 #elif defined(__i386__) || FOLLY_X64
329 asm volatile ("pause");
331 asm volatile ("wfe");
334 inline void asm_pause() {
335 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
337 #elif defined(__i386__) || FOLLY_X64
346 #endif // FOLLY_PORTABILITY_H_