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#ifndef __has_cpp_attribute
31#define __has_cpp_attribute(x) 0
32#endif
33
34#if !__has_feature(cxx_exceptions) && !defined(BOOST_NO_EXCEPTIONS)
35# define BOOST_NO_EXCEPTIONS
36#endif
37
38#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_RTTI)
39# define BOOST_NO_RTTI
40#endif
41
42#if !__has_feature(cxx_rtti) && !defined(BOOST_NO_TYPEID)
43# define BOOST_NO_TYPEID
44#endif
45
46#if !__has_feature(cxx_thread_local)
47# define BOOST_NO_CXX11_THREAD_LOCAL
48#endif
49
50#ifdef __is_identifier
51#if !__is_identifier(__int64) && !defined(__GNUC__)
52# define BOOST_HAS_MS_INT64
53#endif
54#endif
55
56#if __has_include(<stdint.h>)
57# define BOOST_HAS_STDINT_H
58#endif
59
60#if (defined(linux) || defined(__linux) || defined(__linux__) || defined(__GNU__) || defined(__GLIBC__)) && !defined(_CRAYC)
61#if (__clang_major__ >= 4) && defined(__has_include)
62#if __has_include(<quadmath.h>)
63# define BOOST_HAS_FLOAT128
64#endif
65#endif
66#endif
67
68
69#define BOOST_HAS_NRVO
70
71// Branch prediction hints
72#if !defined (__c2__) && defined(__has_builtin)
73#if __has_builtin(__builtin_expect)
74#define BOOST_LIKELY(x) __builtin_expect(x, 1)
75#define BOOST_UNLIKELY(x) __builtin_expect(x, 0)
76#endif
77#endif
78
79// Clang supports "long long" in all compilation modes.
80#define BOOST_HAS_LONG_LONG
81
82//
83// We disable this if the compiler is really nvcc with C++03 as it
84// doesn't actually support __int128 as of CUDA_VERSION=7500
85// even though it defines __SIZEOF_INT128__.
86// See https://svn.boost.org/trac/boost/ticket/10418
87// https://svn.boost.org/trac/boost/ticket/11852
88// Only re-enable this for nvcc if you're absolutely sure
89// of the circumstances under which it's supported.
90// Similarly __SIZEOF_INT128__ is defined when targetting msvc
91// compatibility even though the required support functions are absent.
92//
93#if defined(__CUDACC__)
94# if defined(BOOST_GCC_CXX11)
95# define BOOST_NVCC_CXX11
96# else
97# define BOOST_NVCC_CXX03
98# endif
99#endif
100
101#if defined(__SIZEOF_INT128__) && !defined(BOOST_NVCC_CXX03) && !defined(_MSC_VER)
102# define BOOST_HAS_INT128
103#endif
104
105
106//
107// Dynamic shared object (DSO) and dynamic-link library (DLL) support
108//
109#if defined(_WIN32) || defined(__WIN32__) || defined(WIN32) || defined(__CYGWIN__)
110# define BOOST_HAS_DECLSPEC
111# define BOOST_SYMBOL_EXPORT __attribute__((__dllexport__))
112# define BOOST_SYMBOL_IMPORT __attribute__((__dllimport__))
113#else
114# define BOOST_SYMBOL_EXPORT __attribute__((__visibility__("default")))
115# define BOOST_SYMBOL_VISIBLE __attribute__((__visibility__("default")))
116# define BOOST_SYMBOL_IMPORT
117#endif
118
119//
120// The BOOST_FALLTHROUGH macro can be used to annotate implicit fall-through
121// between switch labels.
122//
123#if __cplusplus >= 201103L && defined(__has_warning)
124# if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
125# define BOOST_FALLTHROUGH [[clang::fallthrough]]
126# endif
127#endif
128
129#if !__has_feature(cxx_auto_type)
130# define BOOST_NO_CXX11_AUTO_DECLARATIONS
131# define BOOST_NO_CXX11_AUTO_MULTIDECLARATIONS
132#endif
133
134//
135// Currently clang on Windows using VC++ RTL does not support C++11's char16_t or char32_t
136//
137#if (defined(_MSC_VER) && (_MSC_VER < 1900)) || !(defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L)
138# define BOOST_NO_CXX11_CHAR16_T
139# define BOOST_NO_CXX11_CHAR32_T
140#endif
141
142#if defined(_MSC_VER) && (_MSC_VER >= 1800) && !defined(__GNUC__)
143#define BOOST_HAS_EXPM1
144#define BOOST_HAS_LOG1P
145#endif
146
147#if !__has_feature(cxx_constexpr)
148# define BOOST_NO_CXX11_CONSTEXPR
149#endif
150
151#if !__has_feature(cxx_decltype)
152# define BOOST_NO_CXX11_DECLTYPE
153#endif
154
155#if !__has_feature(cxx_decltype_incomplete_return_types)
156# define BOOST_NO_CXX11_DECLTYPE_N3276
157#endif
158
159#if !__has_feature(cxx_defaulted_functions)
160# define BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
161#endif
162
163#if !__has_feature(cxx_deleted_functions)
164# define BOOST_NO_CXX11_DELETED_FUNCTIONS
165#endif
166
167#if !__has_feature(cxx_explicit_conversions)
168# define BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS
169#endif
170
171#if !__has_feature(cxx_default_function_template_args)
172# define BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS
173#endif
174
175#if !__has_feature(cxx_generalized_initializers)
176# define BOOST_NO_CXX11_HDR_INITIALIZER_LIST
177#endif
178
179#if !__has_feature(cxx_lambdas)
180# define BOOST_NO_CXX11_LAMBDAS
181#endif
182
183#if !__has_feature(cxx_local_type_template_args)
184# define BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS
185#endif
186
187#if !__has_feature(cxx_noexcept)
188# define BOOST_NO_CXX11_NOEXCEPT
189#endif
190
191#if !__has_feature(cxx_nullptr)
192# define BOOST_NO_CXX11_NULLPTR
193#endif
194
195#if !__has_feature(cxx_range_for)
196# define BOOST_NO_CXX11_RANGE_BASED_FOR
197#endif
198
199#if !__has_feature(cxx_raw_string_literals)
200# define BOOST_NO_CXX11_RAW_LITERALS
201#endif
202
203#if !__has_feature(cxx_reference_qualified_functions)
204# define BOOST_NO_CXX11_REF_QUALIFIERS
205#endif
206
207#if !__has_feature(cxx_generalized_initializers)
208# define BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX
209#endif
210
211#if !__has_feature(cxx_rvalue_references)
212# define BOOST_NO_CXX11_RVALUE_REFERENCES
213#endif
214
215#if !__has_feature(cxx_strong_enums)
216# define BOOST_NO_CXX11_SCOPED_ENUMS
217#endif
218
219#if !__has_feature(cxx_static_assert)
220# define BOOST_NO_CXX11_STATIC_ASSERT
221#endif
222
223#if !__has_feature(cxx_alias_templates)
224# define BOOST_NO_CXX11_TEMPLATE_ALIASES
225#endif
226
227#if !__has_feature(cxx_unicode_literals)
228# define BOOST_NO_CXX11_UNICODE_LITERALS
229#endif
230
231#if !__has_feature(cxx_variadic_templates)
232# define BOOST_NO_CXX11_VARIADIC_TEMPLATES
233#endif
234
235#if !__has_feature(cxx_user_literals)
236# define BOOST_NO_CXX11_USER_DEFINED_LITERALS
237#endif
238
239#if !__has_feature(cxx_alignas)
240# define BOOST_NO_CXX11_ALIGNAS
241#endif
242
243#if !__has_feature(cxx_trailing_return)
244# define BOOST_NO_CXX11_TRAILING_RESULT_TYPES
245#endif
246
247#if !__has_feature(cxx_inline_namespaces)
248# define BOOST_NO_CXX11_INLINE_NAMESPACES
249#endif
250
251#if !__has_feature(cxx_override_control)
252# define BOOST_NO_CXX11_FINAL
253# define BOOST_NO_CXX11_OVERRIDE
254#endif
255
256#if !__has_feature(cxx_unrestricted_unions)
257# define BOOST_NO_CXX11_UNRESTRICTED_UNION
258#endif
259
260#if !(__has_feature(__cxx_binary_literals__) || __has_extension(__cxx_binary_literals__))
261# define BOOST_NO_CXX14_BINARY_LITERALS
262#endif
263
264#if !__has_feature(__cxx_decltype_auto__)
265# define BOOST_NO_CXX14_DECLTYPE_AUTO
266#endif
267
268#if !__has_feature(__cxx_aggregate_nsdmi__)
269# define BOOST_NO_CXX14_AGGREGATE_NSDMI
270#endif
271
272#if !__has_feature(__cxx_init_captures__)
273# define BOOST_NO_CXX14_INITIALIZED_LAMBDA_CAPTURES
274#endif
275
276#if !__has_feature(__cxx_generic_lambdas__)
277# define BOOST_NO_CXX14_GENERIC_LAMBDAS
278#endif
279
280// clang < 3.5 has a defect with dependent type, like following.
281//
282// template <class T>
283// constexpr typename enable_if<pred<T> >::type foo(T &)
284// { } // error: no return statement in constexpr function
285//
286// This issue also affects C++11 mode, but C++11 constexpr requires return stmt.
287// Therefore we don't care such case.
288//
289// Note that we can't check Clang version directly as the numbering system changes depending who's
290// creating the Clang release (see https://github.com/boostorg/config/pull/39#issuecomment-59927873)
291// so instead verify that we have a feature that was introduced at the same time as working C++14
292// constexpr (generic lambda's in this case):
293//
294#if !__has_feature(__cxx_generic_lambdas__) || !__has_feature(__cxx_relaxed_constexpr__)
295# define BOOST_NO_CXX14_CONSTEXPR
296#endif
297
298#if !__has_feature(__cxx_return_type_deduction__)
299# define BOOST_NO_CXX14_RETURN_TYPE_DEDUCTION
300#endif
301
302#if !__has_feature(__cxx_variable_templates__)
303# define BOOST_NO_CXX14_VARIABLE_TEMPLATES
304#endif
305
306#if !defined(__cpp_structured_bindings) || (__cpp_structured_bindings < 201606)
307# define BOOST_NO_CXX17_STRUCTURED_BINDINGS
308#endif
309
310#if !defined(__cpp_if_constexpr) || (__cpp_if_constexpr < 201606)
311# define BOOST_NO_CXX17_IF_CONSTEXPR
312#endif
313
314// Clang 3.9+ in c++1z
315#if !__has_cpp_attribute(fallthrough) || __cplusplus < 201406L
316# define BOOST_NO_CXX17_INLINE_VARIABLES
317# define BOOST_NO_CXX17_FOLD_EXPRESSIONS
318#endif
319
320#if __cplusplus < 201103L
321#define BOOST_NO_CXX11_SFINAE_EXPR
322#endif
323
324#if __cplusplus < 201400
325// All versions with __cplusplus above this value seem to support this:
326# define BOOST_NO_CXX14_DIGIT_SEPARATORS
327#endif
328//
329// __builtin_unreachable:
330#if defined(__has_builtin) && __has_builtin(__builtin_unreachable)
331#define BOOST_UNREACHABLE_RETURN(x) __builtin_unreachable();
332#endif
333
334#if (__clang_major__ == 3) && (__clang_minor__ == 0)
335// Apparently a clang bug:
336# define BOOST_NO_CXX11_FIXED_LENGTH_VARIADIC_TEMPLATE_EXPANSION_PACKS
337#endif
338
339// Clang has supported the 'unused' attribute since the first release.
340#define BOOST_ATTRIBUTE_UNUSED __attribute__((__unused__))
341
342// Type aliasing hint.
343#if __has_attribute(__may_alias__)
344# define BOOST_MAY_ALIAS __attribute__((__may_alias__))
345#endif
346
347#ifndef BOOST_COMPILER
348# define BOOST_COMPILER "Clang version " __clang_version__
349#endif
350
351// Macro used to identify the Clang compiler.
352#define BOOST_CLANG 1
353
354

source code of include/boost/config/compiler/clang.hpp