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      1 /*
      2  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef WTF_Compiler_h
     27 #define WTF_Compiler_h
     28 
     29 /* COMPILER() - the compiler being used to build the project */
     30 #define COMPILER(WTF_FEATURE) (defined WTF_COMPILER_##WTF_FEATURE  && WTF_COMPILER_##WTF_FEATURE)
     31 
     32 /* COMPILER_SUPPORTS() - whether the compiler being used to build the project supports the given feature. */
     33 #define COMPILER_SUPPORTS(WTF_COMPILER_FEATURE) (defined WTF_COMPILER_SUPPORTS_##WTF_COMPILER_FEATURE  && WTF_COMPILER_SUPPORTS_##WTF_COMPILER_FEATURE)
     34 
     35 /* COMPILER_QUIRK() - whether the compiler being used to build the project requires a given quirk. */
     36 #define COMPILER_QUIRK(WTF_COMPILER_QUIRK) (defined WTF_COMPILER_QUIRK_##WTF_COMPILER_QUIRK  && WTF_COMPILER_QUIRK_##WTF_COMPILER_QUIRK)
     37 
     38 /* ==== COMPILER() - the compiler being used to build the project ==== */
     39 
     40 /* COMPILER(CLANG) - Clang  */
     41 #if defined(__clang__)
     42 #define WTF_COMPILER_CLANG 1
     43 
     44 #define CLANG_PRAGMA(PRAGMA) _Pragma(PRAGMA)
     45 
     46 /* Specific compiler features */
     47 #define WTF_COMPILER_SUPPORTS_CXX_VARIADIC_TEMPLATES __has_extension(cxx_variadic_templates)
     48 
     49 /* There is a bug in clang that comes with Xcode 4.2 where AtomicStrings can't be implicitly converted to Strings
     50    in the presence of move constructors and/or move assignment operators. This bug has been fixed in Xcode 4.3 clang, so we
     51    check for both cxx_rvalue_references as well as the unrelated cxx_nonstatic_member_init feature which we know was added in 4.3 */
     52 #define WTF_COMPILER_SUPPORTS_CXX_RVALUE_REFERENCES __has_extension(cxx_rvalue_references) && __has_extension(cxx_nonstatic_member_init)
     53 
     54 #define WTF_COMPILER_SUPPORTS_CXX_DELETED_FUNCTIONS __has_extension(cxx_deleted_functions)
     55 #define WTF_COMPILER_SUPPORTS_CXX_NULLPTR __has_feature(cxx_nullptr)
     56 #define WTF_COMPILER_SUPPORTS_CXX_EXPLICIT_CONVERSIONS __has_feature(cxx_explicit_conversions)
     57 #define WTF_COMPILER_SUPPORTS_BLOCKS __has_feature(blocks)
     58 #define WTF_COMPILER_SUPPORTS_C_STATIC_ASSERT __has_extension(c_static_assert)
     59 #define WTF_COMPILER_SUPPORTS_CXX_STATIC_ASSERT __has_extension(cxx_static_assert)
     60 #define WTF_COMPILER_SUPPORTS_CXX_OVERRIDE_CONTROL __has_extension(cxx_override_control)
     61 #define WTF_COMPILER_SUPPORTS_HAS_TRIVIAL_DESTRUCTOR __has_extension(has_trivial_destructor)
     62 #define WTF_COMPILER_SUPPORTS_CXX_STRONG_ENUMS __has_extension(cxx_strong_enums)
     63 
     64 #endif
     65 
     66 #ifndef CLANG_PRAGMA
     67 #define CLANG_PRAGMA(PRAGMA)
     68 #endif
     69 
     70 /* COMPILER(MSVC) - Microsoft Visual C++ */
     71 #if defined(_MSC_VER)
     72 #define WTF_COMPILER_MSVC 1
     73 
     74 /* Specific compiler features */
     75 #if !COMPILER(CLANG) && _MSC_VER >= 1600
     76 #define WTF_COMPILER_SUPPORTS_CXX_NULLPTR 1
     77 #endif
     78 
     79 #if COMPILER(CLANG)
     80 /* Keep strong enums turned off when building with clang-cl: We cannot yet build all of Blink without fallback to cl.exe, and strong enums are exposed at ABI boundaries. */
     81 #undef WTF_COMPILER_SUPPORTS_CXX_STRONG_ENUMS
     82 #else
     83 #define WTF_COMPILER_SUPPORTS_CXX_OVERRIDE_CONTROL 1
     84 #endif
     85 
     86 #endif
     87 
     88 /* COMPILER(GCC) - GNU Compiler Collection */
     89 #if defined(__GNUC__)
     90 #define WTF_COMPILER_GCC 1
     91 #define GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
     92 #define GCC_VERSION_AT_LEAST(major, minor, patch) (GCC_VERSION >= (major * 10000 + minor * 100 + patch))
     93 #else
     94 /* Define this for !GCC compilers, just so we can write things like GCC_VERSION_AT_LEAST(4, 1, 0). */
     95 #define GCC_VERSION_AT_LEAST(major, minor, patch) 0
     96 #endif
     97 
     98 /* Specific compiler features */
     99 #if COMPILER(GCC) && !COMPILER(CLANG)
    100 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
    101 /* C11 support */
    102 #define WTF_COMPILER_SUPPORTS_C_STATIC_ASSERT 1
    103 #endif
    104 #if defined(__GXX_EXPERIMENTAL_CXX0X__) || (defined(__cplusplus) && __cplusplus >= 201103L)
    105 /* C++11 support */
    106 #if GCC_VERSION_AT_LEAST(4, 3, 0)
    107 #define WTF_COMPILER_SUPPORTS_CXX_RVALUE_REFERENCES 1
    108 #define WTF_COMPILER_SUPPORTS_CXX_STATIC_ASSERT 1
    109 #define WTF_COMPILER_SUPPORTS_CXX_VARIADIC_TEMPLATES 1
    110 #endif
    111 #if GCC_VERSION_AT_LEAST(4, 4, 0)
    112 #define WTF_COMPILER_SUPPORTS_CXX_DELETED_FUNCTIONS 1
    113 #endif
    114 #if GCC_VERSION_AT_LEAST(4, 5, 0)
    115 #define WTF_COMPILER_SUPPORTS_CXX_EXPLICIT_CONVERSIONS 1
    116 #endif
    117 #if GCC_VERSION_AT_LEAST(4, 6, 0)
    118 #define WTF_COMPILER_SUPPORTS_CXX_NULLPTR 1
    119 /* Strong enums should work from gcc 4.4, but doesn't seem to support some operators */
    120 #define WTF_COMPILER_SUPPORTS_CXX_STRONG_ENUMS 1
    121 #endif
    122 #if GCC_VERSION_AT_LEAST(4, 7, 0)
    123 #define WTF_COMPILER_SUPPORTS_CXX_OVERRIDE_CONTROL 1
    124 #endif
    125 #endif /* defined(__GXX_EXPERIMENTAL_CXX0X__) || (defined(__cplusplus) && __cplusplus >= 201103L) */
    126 #endif /* COMPILER(GCC) */
    127 
    128 /* ==== Compiler features ==== */
    129 
    130 
    131 /* ALWAYS_INLINE */
    132 
    133 #ifndef ALWAYS_INLINE
    134 #if COMPILER(GCC) && defined(NDEBUG) && !COMPILER(MINGW)
    135 #define ALWAYS_INLINE inline __attribute__((__always_inline__))
    136 #elif COMPILER(MSVC) && defined(NDEBUG)
    137 #define ALWAYS_INLINE __forceinline
    138 #else
    139 #define ALWAYS_INLINE inline
    140 #endif
    141 #endif
    142 
    143 
    144 /* NEVER_INLINE */
    145 
    146 #ifndef NEVER_INLINE
    147 #if COMPILER(GCC)
    148 #define NEVER_INLINE __attribute__((__noinline__))
    149 #elif COMPILER(MSVC)
    150 #define NEVER_INLINE __declspec(noinline)
    151 #else
    152 #define NEVER_INLINE
    153 #endif
    154 #endif
    155 
    156 
    157 /* UNLIKELY */
    158 
    159 #ifndef UNLIKELY
    160 #if COMPILER(GCC)
    161 #define UNLIKELY(x) __builtin_expect((x), 0)
    162 #else
    163 #define UNLIKELY(x) (x)
    164 #endif
    165 #endif
    166 
    167 
    168 /* LIKELY */
    169 
    170 #ifndef LIKELY
    171 #if COMPILER(GCC)
    172 #define LIKELY(x) __builtin_expect((x), 1)
    173 #else
    174 #define LIKELY(x) (x)
    175 #endif
    176 #endif
    177 
    178 
    179 /* NO_RETURN */
    180 
    181 
    182 #ifndef NO_RETURN
    183 #if COMPILER(GCC)
    184 #define NO_RETURN __attribute((__noreturn__))
    185 #elif COMPILER(MSVC)
    186 #define NO_RETURN __declspec(noreturn)
    187 #else
    188 #define NO_RETURN
    189 #endif
    190 #endif
    191 
    192 
    193 /* WARN_UNUSED_RETURN */
    194 
    195 #if COMPILER(GCC)
    196 #define WARN_UNUSED_RETURN __attribute__ ((warn_unused_result))
    197 #else
    198 #define WARN_UNUSED_RETURN
    199 #endif
    200 
    201 /* ALLOW_UNUSED */
    202 
    203 #if COMPILER(GCC)
    204 #define ALLOW_UNUSED __attribute__((unused))
    205 #else
    206 #define ALLOW_UNUSED
    207 #endif
    208 
    209 /* OVERRIDE and FINAL */
    210 
    211 #if COMPILER_SUPPORTS(CXX_OVERRIDE_CONTROL)
    212 #define OVERRIDE override
    213 #define FINAL final
    214 #else
    215 #define OVERRIDE
    216 #define FINAL
    217 #endif
    218 
    219 /* WTF_DELETED_FUNCTION */
    220 
    221 #if COMPILER_SUPPORTS(CXX_DELETED_FUNCTIONS)
    222 #define WTF_DELETED_FUNCTION = delete
    223 #else
    224 #define WTF_DELETED_FUNCTION
    225 #endif
    226 
    227 /* REFERENCED_FROM_ASM */
    228 
    229 #ifndef REFERENCED_FROM_ASM
    230 #if COMPILER(GCC)
    231 #define REFERENCED_FROM_ASM __attribute__((used))
    232 #else
    233 #define REFERENCED_FROM_ASM
    234 #endif
    235 #endif
    236 
    237 /* OBJC_CLASS */
    238 
    239 #ifndef OBJC_CLASS
    240 #ifdef __OBJC__
    241 #define OBJC_CLASS @class
    242 #else
    243 #define OBJC_CLASS class
    244 #endif
    245 #endif
    246 
    247 /* WTF_PRETTY_FUNCTION */
    248 
    249 #if COMPILER(GCC)
    250 #define WTF_COMPILER_SUPPORTS_PRETTY_FUNCTION 1
    251 #define WTF_PRETTY_FUNCTION __PRETTY_FUNCTION__
    252 #elif COMPILER(MSVC)
    253 #define WTF_COMPILER_SUPPORTS_PRETTY_FUNCTION 1
    254 #define WTF_PRETTY_FUNCTION __FUNCDNAME__
    255 #else
    256 #define WTF_PRETTY_FUNCTION __FUNCTION__
    257 #endif
    258 
    259 #endif /* WTF_Compiler_h */
    260