1// (C) Copyright Douglas Gregor 2010
2//
3// Use, modification and distribution are subject to the
4// Boost Software License, Version 1.0. (See accompanying file
5// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6
7// See http://www.boost.org for most recent version.
8
9// Clang compiler setup.
10
11#define BOOST_HAS_PRAGMA_ONCE
12
13// Detecting `-fms-extension` compiler flag assuming that _MSC_VER defined when that flag is used.
14#if defined (_MSC_VER) && (__clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 4))
15# define BOOST_HAS_PRAGMA_DETECT_MISMATCH
16#endif
17
18// When compiling with clang before __has_extension was defined,
19// even if one writes 'defined(__has_extension) && __has_extension(xxx)',
20// clang reports a compiler error. So the only workaround found is:
21
22#ifndef __has_extension
23#define __has_extension __has_feature
24#endif
25
26#ifndef __has_attribute
27#define __has_attribute(x) 0
28#endif
29
30#if !__has_feature(cxx_exceptions) && !defined(BOOST_NO_EXCEPTIONS)
31# define BOOST_NO_EXCEPTIONS
32#endif
33
34#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_RTTI)
35# define BOOST_NO_RTTI
36#endif
37
38#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_TYPEID)
39# define BOOST_NO_TYPEID
40#endif
41
42#if defined(__int64) && !defined(__GNUC__)
43# define BOOST_HAS_MS_INT64
44#endif
45
46#define BOOST_HAS_NRVO
47
48// Branch prediction hints
49#if defined(__has_builtin)
50#if __has_builtin(__builtin_expect)
51#define BOOST_LIKELY(x) __builtin_expect(x, 1)
52#define BOOST_UNLIKELY(x) __builtin_expect(x, 0)
53#endif
54#endif
55
56// Clang supports "long long" in all compilation modes.
57#define BOOST_HAS_LONG_LONG
58
59//
60// We disable this if the compiler is really nvcc as it
61// doesn't actually support __int128 as of CUDA_VERSION=5000
62// even though it defines __SIZEOF_INT128__.
63// See https://svn.boost.org/trac/boost/ticket/10418
64// Only re-enable this for nvcc if you're absolutely sure
65// of the circumstances under which it's supported.
66// Similarly __SIZEOF_INT128__ is defined when targetting msvc
67// compatibility even though the required support functions are absent.
68//
69#if defined(__SIZEOF_INT128__) && !defined(__CUDACC__) && !defined(_MSC_VER)
70# define BOOST_HAS_INT128
71#endif
72
73
74//
75// Dynamic shared object (DSO) and dynamic-link library (DLL) support
76//
77#if !defined(_WIN32) && !defined(__WIN32__) && !defined(WIN32)
78# define BOOST_SYMBOL_EXPORT __attribute__((__visibility__("default")))
79# define BOOST_SYMBOL_IMPORT
80# define BOOST_SYMBOL_VISIBLE __attribute__((__visibility__("default")))
81#endif
82
83//
84// The BOOST_FALLTHROUGH macro can be used to annotate implicit fall-through
85// between switch labels.
86//
87#if __cplusplus >= 201103L && defined(__has_warning)
88# if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
89# define BOOST_FALLTHROUGH [[clang::fallthrough]]
90# endif
91#endif
92
93#if !__has_feature(cxx_auto_type)
94# define BOOST_NO_CXX11_AUTO_DECLARATIONS
95# define BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS
96#endif
97
98//
99// Currently clang on Windows using VC++ RTL does not support C++11's char16_t or char32_t
100//
101#if defined(_MSC_VER) || !(defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L)
102# define BOOST_NO_CXX11_CHAR16_T
103# define BOOST_NO_CXX11_CHAR32_T
104#endif
105
106#if !__has_feature(cxx_constexpr)
107# define BOOST_NO_CXX11_CONSTEXPR
108#endif
109
110#if !__has_feature(cxx_decltype)
111# define BOOST_NO_CXX11_DECLTYPE
112#endif
113
114#if !__has_feature(cxx_decltype_incomplete_return_types)
115# define BOOST_NO_CXX11_DECLTYPE_N3276
116#endif
117
118#if !__has_feature(cxx_defaulted_functions)
119# define BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
120#endif
121
122#if !__has_feature(cxx_deleted_functions)
123# define BOOST_NO_CXX11_DELETED_FUNCTIONS
124#endif
125
126#if !__has_feature(cxx_explicit_conversions)
127# define BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS
128#endif
129
130#if !__has_feature(cxx_default_function_template_args)
131# define BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS
132#endif
133
134#if !__has_feature(cxx_generalized_initializers)
135# define BOOST_NO_CXX11_HDR_INITIALIZER_LIST
136#endif
137
138#if !__has_feature(cxx_lambdas)
139# define BOOST_NO_CXX11_LAMBDAS
140#endif
141
142#if !__has_feature(cxx_local_type_template_args)
143# define BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS
144#endif
145
146#if !__has_feature(cxx_noexcept)
147# define BOOST_NO_CXX11_NOEXCEPT
148#endif
149
150#if !__has_feature(cxx_nullptr)
151# define BOOST_NO_CXX11_NULLPTR
152#endif
153
154#if !__has_feature(cxx_range_for)
155# define BOOST_NO_CXX11_RANGE_BASED_FOR
156#endif
157
158#if !__has_feature(cxx_raw_string_literals)
159# define BOOST_NO_CXX11_RAW_LITERALS
160#endif
161
162#if !__has_feature(cxx_reference_qualified_functions)
163# define BOOST_NO_CXX11_REF_QUALIFIERS
164#endif
165
166#if !__has_feature(cxx_generalized_initializers)
167# define BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
168#endif
169
170#if !__has_feature(cxx_rvalue_references)
171# define BOOST_NO_CXX11_RVALUE_REFERENCES
172#endif
173
174#if !__has_feature(cxx_strong_enums)
175# define BOOST_NO_CXX11_SCOPED_ENUMS
176#endif
177
178#if !__has_feature(cxx_static_assert)
179# define BOOST_NO_CXX11_STATIC_ASSERT
180#endif
181
182#if !__has_feature(cxx_alias_templates)
183# define BOOST_NO_CXX11_TEMPLATE_ALIASES
184#endif
185
186#if !__has_feature(cxx_unicode_literals)
187# define BOOST_NO_CXX11_UNICODE_LITERALS
188#endif
189
190#if !__has_feature(cxx_variadic_templates)
191# define BOOST_NO_CXX11_VARIADIC_TEMPLATES
192#endif
193
194#if !__has_feature(cxx_user_literals)
195# define BOOST_NO_CXX11_USER_DEFINED_LITERALS
196#endif
197
198#if !__has_feature(cxx_alignas)
199# define BOOST_NO_CXX11_ALIGNAS
200#endif
201
202#if !__has_feature(cxx_trailing_return)
203# define BOOST_NO_CXX11_TRAILING_RESULT_TYPES
204#endif
205
206#if !__has_feature(cxx_inline_namespaces)
207# define BOOST_NO_CXX11_INLINE_NAMESPACES
208#endif
209
210#if !__has_feature(cxx_override_control)
211# define BOOST_NO_CXX11_FINAL
212#endif
213
214#if !(__has_feature(__cxx_binary_literals__) || __has_extension(__cxx_binary_literals__))
215# define BOOST_NO_CXX14_BINARY_LITERALS
216#endif
217
218#if !__has_feature(__cxx_decltype_auto__)
219# define BOOST_NO_CXX14_DECLTYPE_AUTO
220#endif
221
222#if !__has_feature(__cxx_aggregate_nsdmi__)
223# define BOOST_NO_CXX14_AGGREGATE_NSDMI
224#endif
225
226#if !__has_feature(__cxx_init_captures__)
227# define BOOST_NO_CXX14_INITIALIZED_LAMBDA_CAPTURES
228#endif
229
230#if !__has_feature(__cxx_generic_lambdas__)
231# define BOOST_NO_CXX14_GENERIC_LAMBDAS
232#endif
233
234// clang < 3.5 has a defect with dependent type, like following.
235//
236// template <class T>
237// constexpr typename enable_if<pred<T> >::type foo(T &)
238// { } // error: no return statement in constexpr function
239//
240// This issue also affects C++11 mode, but C++11 constexpr requires return stmt.
241// Therefore we don't care such case.
242//
243// Note that we can't check Clang version directly as the numbering system changes depending who's
244// creating the Clang release (see https://github.com/boostorg/config/pull/39#issuecomment-59927873)
245// so instead verify that we have a feature that was introduced at the same time as working C++14
246// constexpr (generic lambda's in this case):
247//
248#if !__has_feature(__cxx_generic_lambdas__) || !__has_feature(__cxx_relaxed_constexpr__)
249# define BOOST_NO_CXX14_CONSTEXPR
250#endif
251
252#if !__has_feature(__cxx_return_type_deduction__)
253# define BOOST_NO_CXX14_RETURN_TYPE_DEDUCTION
254#endif
255
256#if !__has_feature(__cxx_variable_templates__)
257# define BOOST_NO_CXX14_VARIABLE_TEMPLATES
258#endif
259
260#if __cplusplus < 201400
261// All versions with __cplusplus above this value seem to support this:
262# define BOOST_NO_CXX14_DIGIT_SEPARATORS
263#endif
264//
265// __builtin_unreachable:
266#if defined(__has_builtin) && __has_builtin(__builtin_unreachable)
267#define BOOST_UNREACHABLE_RETURN(x) __builtin_unreachable();
268#endif
269
270// Clang has supported the 'unused' attribute since the first release.
271#define BOOST_ATTRIBUTE_UNUSED __attribute__((__unused__))
272
273#ifndef BOOST_COMPILER
274# define BOOST_COMPILER "Clang version " __clang_version__
275#endif
276
277// Macro used to identify the Clang compiler.
278#define BOOST_CLANG 1
279
280