boost/config/compiler/clang.hpp

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