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)))
86 # define FOLLY_DEPRECATED
91 # define FOLLY_NORETURN __declspec(noreturn)
92 #elif defined(__clang__) || defined(__GNUC__)
93 # define FOLLY_NORETURN __attribute__((__noreturn__))
95 # define FOLLY_NORETURN
100 # define FOLLY_NOINLINE __declspec(noinline)
101 #elif defined(__clang__) || defined(__GNUC__)
102 # define FOLLY_NOINLINE __attribute__((__noinline__))
104 # define FOLLY_NOINLINE
109 # define FOLLY_ALWAYS_INLINE __forceinline
110 #elif defined(__clang__) || defined(__GNUC__)
111 # define FOLLY_ALWAYS_INLINE inline __attribute__((__always_inline__))
113 # define FOLLY_ALWAYS_INLINE
116 // detection for 64 bit
117 #if defined(__x86_64__) || defined(_M_X64)
123 #if defined(__aarch64__)
129 // packing is very ugly in msvc
131 # define FOLLY_PACK_ATTR /**/
132 # define FOLLY_PACK_PUSH __pragma(pack(push, 1))
133 # define FOLLY_PACK_POP __pragma(pack(pop))
134 #elif defined(__clang__) || defined(__GNUC__)
135 # define FOLLY_PACK_ATTR __attribute__((__packed__))
136 # define FOLLY_PACK_PUSH /**/
137 # define FOLLY_PACK_POP /**/
139 # define FOLLY_PACK_ATTR /**/
140 # define FOLLY_PACK_PUSH /**/
141 # define FOLLY_PACK_POP /**/
144 // portable version check
145 #ifndef __GNUC_PREREQ
146 # if defined __GNUC__ && defined __GNUC_MINOR__
148 # define __GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= \
149 ((maj) << 16) + (min))
152 # define __GNUC_PREREQ(maj, min) 0
157 /* Define macro wrappers for C++11's "final" and "override" keywords, which
158 * are supported in gcc 4.7 but not gcc 4.6. */
159 #if !defined(FOLLY_FINAL) && !defined(FOLLY_OVERRIDE)
160 # if defined(__clang__) || __GNUC_PREREQ(4, 7)
161 # define FOLLY_FINAL final
162 # define FOLLY_OVERRIDE override
163 # elif defined(_MSC_VER) && _MSC_VER >= 1600
164 # define FOLLY_FINAL final
165 # define FOLLY_OVERRIDE override
167 # define FOLLY_FINAL /**/
168 # define FOLLY_OVERRIDE /**/
172 /* Platform specific TLS support
173 * gcc implements __thread
174 * msvc implements __declspec(thread)
175 * the semantics are the same
176 * (but remember __thread has different semantics when using emutls (ex. apple))
178 #if defined(_MSC_VER)
179 # define FOLLY_TLS __declspec(thread)
180 #elif defined(__GNUC__) || defined(__clang__)
181 # define FOLLY_TLS __thread
183 # error cannot define platform specific thread local storage
186 // Define to 1 if you have the `preadv' and `pwritev' functions, respectively
187 #if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
188 # if defined(__GLIBC_PREREQ)
189 # if __GLIBC_PREREQ(2, 10)
190 # define FOLLY_HAVE_PREADV 1
191 # define FOLLY_HAVE_PWRITEV 1
196 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
197 // the 'std' namespace; the latter uses inline namepsaces. Wrap this decision
198 // up in a macro to make forward-declarations easier.
201 #define FOLLY_NAMESPACE_STD_BEGIN _LIBCPP_BEGIN_NAMESPACE_STD
202 #define FOLLY_NAMESPACE_STD_END _LIBCPP_END_NAMESPACE_STD
204 #define FOLLY_NAMESPACE_STD_BEGIN namespace std {
205 #define FOLLY_NAMESPACE_STD_END }
208 // Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
209 // versions of these into the global namespace.
210 #if FOLLY_HAVE_CLOCK_GETTIME
213 #include <folly/detail/Clock.h>
216 // Provide our own std::__throw_* wrappers for platforms that don't have them
217 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
218 #include <bits/functexcept.h>
220 #include <folly/detail/FunctionalExcept.h>
223 #if defined(__cplusplus)
224 // Unfortunately, boost::has_trivial_copy<T> is broken in libc++ due to its
225 // usage of __has_trivial_copy(), so we can't use it as a
226 // least-common-denominator for C++11 implementations that don't support
227 // std::is_trivially_copyable<T>.
229 // http://stackoverflow.com/questions/12754886/has-trivial-copy-behaves-differently-in-clang-and-gcc-whos-right
231 // As a result, use std::is_trivially_copyable() where it exists, and fall back
232 // to Boost otherwise.
233 #if FOLLY_HAVE_STD__IS_TRIVIALLY_COPYABLE
234 #include <type_traits>
235 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
236 (std::is_trivially_copyable<T>::value)
238 #include <boost/type_traits.hpp>
239 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
240 (boost::has_trivial_copy<T>::value && \
241 boost::has_trivial_destructor<T>::value)
243 #endif // __cplusplus
245 // MSVC specific defines
246 // mainly for posix compat
249 // this definition is in a really silly place with a silly name
250 // and ifdefing it every time we want it is painful
252 typedef SSIZE_T ssize_t;
254 // sprintf semantics are not exactly identical
255 // but current usage is not a problem
256 # define snprintf _snprintf
258 // semantics here are identical
259 # define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
261 // compiler specific to compiler specific
263 # define __PRETTY_FUNCTION__ __FUNCSIG__
266 #if FOLLY_UNUSUAL_GFLAGS_NAMESPACE
267 namespace FOLLY_GFLAGS_NAMESPACE { }
269 using namespace FOLLY_GFLAGS_NAMESPACE;
270 } // namespace gflags
273 // for TARGET_OS_IPHONE
275 #include <TargetConditionals.h>
278 // MacOS doesn't have malloc_usable_size()
279 #if defined(__APPLE__) && !defined(FOLLY_HAVE_MALLOC_USABLE_SIZE)
280 inline size_t malloc_usable_size(void* ptr) {
281 return malloc_size(ptr);
285 // RTTI may not be enabled for this compilation unit.
286 #if defined(__GXX_RTTI) || defined(__cpp_rtti) || \
287 (defined(_MSC_VER) && defined(_CPPRTTI))
288 # define FOLLY_HAS_RTTI 1
297 inline void asm_volatile_pause() {
298 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
300 #elif defined(__i386__) || FOLLY_X64
301 asm volatile ("pause");
303 asm volatile ("wfe");
306 inline void asm_pause() {
307 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
309 #elif defined(__i386__) || FOLLY_X64
318 #endif // FOLLY_PORTABILITY_H_