2 * Copyright 2014 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-config.h"
24 #ifdef FOLLY_PLATFORM_CONFIG
25 #include FOLLY_PLATFORM_CONFIG
28 #if FOLLY_HAVE_FEATURES_H
32 #include "CPortability.h"
34 #if FOLLY_HAVE_SCHED_H
36 #ifndef FOLLY_HAVE_PTHREAD_YIELD
37 #define pthread_yield sched_yield
41 // A change in folly/MemoryMapping.cpp uses MAP_ANONYMOUS, which is named
42 // MAP_ANON on OSX/BSD.
43 #if defined(__APPLE__) || defined(__FreeBSD__)
47 #define MAP_ANONYMOUS MAP_ANON
52 // MaxAlign: max_align_t isn't supported by gcc
54 struct MaxAlign { char c; } __attribute__((aligned));
56 # error Cannot define MaxAlign on this platform
59 // compiler specific attribute translation
60 // msvc should come first, so if clang is in msvc mode it gets the right defines
62 // NOTE: this will only do checking in msvc with versions that support /analyze
64 # ifdef _USE_ATTRIBUTES_FOR_SAL
65 # undef _USE_ATTRIBUTES_FOR_SAL
67 # define _USE_ATTRIBUTES_FOR_SAL 1
69 # define FOLLY_PRINTF_FORMAT _Printf_format_string_
70 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) /**/
72 # define FOLLY_PRINTF_FORMAT /**/
73 # define FOLLY_PRINTF_FORMAT_ATTR(format_param, dots_param) \
74 __attribute__((format(printf, format_param, dots_param)))
79 # define FOLLY_NORETURN __declspec(noreturn)
80 #elif defined(__clang__) || defined(__GNUC__)
81 # define FOLLY_NORETURN __attribute__((noreturn))
83 # define FOLLY_NORETURN
88 # define FOLLY_NOINLINE __declspec(noinline)
89 #elif defined(__clang__) || defined(__GNUC__)
90 # define FOLLY_NOINLINE __attribute__((noinline))
92 # define FOLLY_NOINLINE
97 # define FOLLY_ALWAYS_INLINE __forceinline
98 #elif defined(__clang__) || defined(__GNUC__)
99 # define FOLLY_ALWAYS_INLINE inline __attribute__((always_inline))
101 # define FOLLY_ALWAYS_INLINE
104 // detection for 64 bit
105 #if defined(__x86_64__) || defined(_M_X64)
111 // packing is very ugly in msvc
113 # define FOLLY_PACK_ATTR /**/
114 # define FOLLY_PACK_PUSH __pragma(pack(push, 1))
115 # define FOLLY_PACK_POP __pragma(pack(pop))
116 #elif defined(__clang__) || defined(__GNUC__)
117 # define FOLLY_PACK_ATTR __attribute__((packed))
118 # define FOLLY_PACK_PUSH /**/
119 # define FOLLY_PACK_POP /**/
121 # define FOLLY_PACK_ATTR /**/
122 # define FOLLY_PACK_PUSH /**/
123 # define FOLLY_PACK_POP /**/
126 // portable version check
127 #ifndef __GNUC_PREREQ
128 # if defined __GNUC__ && defined __GNUC_MINOR__
129 # define __GNUC_PREREQ(maj, min) ((__GNUC__ << 16) + __GNUC_MINOR__ >= \
130 ((maj) << 16) + (min))
132 # define __GNUC_PREREQ(maj, min) 0
137 /* Define macro wrappers for C++11's "final" and "override" keywords, which
138 * are supported in gcc 4.7 but not gcc 4.6. */
139 #if !defined(FOLLY_FINAL) && !defined(FOLLY_OVERRIDE)
140 # if defined(__clang__) || __GNUC_PREREQ(4, 7)
141 # define FOLLY_FINAL final
142 # define FOLLY_OVERRIDE override
144 # define FOLLY_FINAL /**/
145 # define FOLLY_OVERRIDE /**/
149 /* Platform specific TLS support
150 * gcc implements __thread
151 * msvc implements __declspec(thread)
152 * the semantics are the same (but remember __thread is broken on apple)
154 #if defined(_MSC_VER)
155 # define FOLLY_TLS __declspec(thread)
156 #elif defined(__GNUC__) || defined(__clang__)
157 # define FOLLY_TLS __thread
159 # error cannot define platform specific thread local storage
162 // Define to 1 if you have the `preadv' and `pwritev' functions, respectively
163 #if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
164 # if defined(__GLIBC_PREREQ)
165 # if __GLIBC_PREREQ(2, 10)
166 # define FOLLY_HAVE_PREADV 1
167 # define FOLLY_HAVE_PWRITEV 1
172 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
173 // the 'std' namespace; the latter uses inline namepsaces. Wrap this decision
174 // up in a macro to make forward-declarations easier.
177 #define FOLLY_NAMESPACE_STD_BEGIN _LIBCPP_BEGIN_NAMESPACE_STD
178 #define FOLLY_NAMESPACE_STD_END _LIBCPP_END_NAMESPACE_STD
180 #define FOLLY_NAMESPACE_STD_BEGIN namespace std {
181 #define FOLLY_NAMESPACE_STD_END }
184 // Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
185 // versions of these into the global namespace.
186 #if FOLLY_HAVE_CLOCK_GETTIME
189 #include <folly/detail/Clock.h>
192 // Provide our own std::__throw_* wrappers for platforms that don't have them
193 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
194 #include <bits/functexcept.h>
196 #include <folly/detail/FunctionalExcept.h>
199 #if defined(__cplusplus)
200 // Unfortunately, boost::has_trivial_copy<T> is broken in libc++ due to its
201 // usage of __has_trivial_copy(), so we can't use it as a
202 // least-common-denominator for C++11 implementations that don't support
203 // std::is_trivially_copyable<T>.
205 // http://stackoverflow.com/questions/12754886/has-trivial-copy-behaves-differently-in-clang-and-gcc-whos-right
207 // As a result, use std::is_trivially_copyable() where it exists, and fall back
208 // to Boost otherwise.
209 #if FOLLY_HAVE_STD__IS_TRIVIALLY_COPYABLE
210 #include <type_traits>
211 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
212 (std::is_trivially_copyable<T>::value)
214 #include <boost/type_traits.hpp>
215 #define FOLLY_IS_TRIVIALLY_COPYABLE(T) \
216 (boost::has_trivial_copy<T>::value && \
217 boost::has_trivial_destructor<T>::value)
219 #endif // __cplusplus
221 // MSVC specific defines
222 // mainly for posix compat
225 // this definition is in a really silly place with a silly name
226 // and ifdefing it every time we want it is painful
228 typedef SSIZE_T ssize_t;
230 // sprintf semantics are not exactly identical
231 // but current usage is not a problem
232 # define snprintf _snprintf
234 // semantics here are identical
235 # define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
237 // compiler specific to compiler specific
238 # define __PRETTY_FUNCTION__ __FUNCSIG__
241 #if FOLLY_UNUSUAL_GFLAGS_NAMESPACE
242 namespace FOLLY_GFLAGS_NAMESPACE { }
244 using namespace FOLLY_GFLAGS_NAMESPACE;
245 } // namespace gflags
248 #endif // FOLLY_PORTABILITY_H_