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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 #ifndef RBIMPL_STDALIGN_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_STDALIGN_H /** * @file * @author Ruby developers * @copyright This file is a part of the programming language Ruby. * Permission is hereby granted, to either redistribute and/or * modify this file, provided that the conditions mentioned in the * file COPYING are met. Consult the file for details. * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are * implementation details. Don't take them as canon. They could * rapidly appear then vanish. The name (path) of this header file * is also an implementation detail. Do not expect it to persist * at the place it is now. Developers are free to move it anywhere * anytime at will. * @note To ruby-core: remember that this header can be possibly * recursively included from extension libraries written in C++. * Do not expect for instance `__VA_ARGS__` is always available. * We assume C99 for ruby itself but we don't assume languages of * extension libraries. They could be written in C++98. * @brief Defines #RBIMPL_ALIGNAS / #RBIMPL_ALIGNOF */ #include "ruby/impl/config.h" #ifdef HAVE_STDALIGN_H # include #endif #include "ruby/impl/compiler_is.h" #include "ruby/impl/compiler_since.h" #include "ruby/impl/has/feature.h" #include "ruby/impl/has/extension.h" #include "ruby/impl/has/attribute.h" #include "ruby/impl/has/declspec_attribute.h" /** * Wraps (or simulates) `alignas`. This is C++11's `alignas` and is _different_ * from C11 `_Alignas`. For instance, * * ```CXX * typedef struct alignas(128) foo { int foo } foo; * ``` * * is a valid C++ while * * ```C * typedef struct _Alignas(128) foo { int foo } foo; * ``` * * is an invalid C because: * * - You cannot `struct _Alignas`. * - A `typedef` cannot have alignments. */ #if defined(__cplusplus) && RBIMPL_HAS_FEATURE(cxx_alignas) # define RBIMPL_ALIGNAS alignas #elif defined(__cplusplus) && (__cplusplus >= 201103L) # define RBIMPL_ALIGNAS alignas #elif defined(__INTEL_CXX11_MODE__) # define RBIMPL_ALIGNAS alignas #elif defined(__GXX_EXPERIMENTAL_CXX0X__) # define RBIMPL_ALIGNAS alignas #elif RBIMPL_HAS_DECLSPEC_ATTRIBUTE(align) # define RBIMPL_ALIGNAS(_) __declspec(align(_)) #elif RBIMPL_HAS_ATTRIBUTE(aliged) # define RBIMPL_ALIGNAS(_) __attribute__((__aligned__(_))) #else # define RBIMPL_ALIGNAS(_) /* void */ #endif /** * Wraps (or simulates) `alignof`. Unlike #RBIMPL_ALIGNAS, we can safely say * both C/C++ definitions are effective. */ #if defined(__cplusplus) && RBIMPL_HAS_EXTENSION(cxx_alignof) # define RBIMPL_ALIGNOF __extension__ alignof #elif defined(__cplusplus) && (__cplusplus >= 201103L) # define RBIMPL_ALIGNOF alignof #elif defined(__INTEL_CXX11_MODE__) # define RBIMPL_ALIGNOF alignof #elif defined(__GXX_EXPERIMENTAL_CXX0X__) # define RBIMPL_ALIGNOF alignof #elif defined(__STDC_VERSION__) && RBIMPL_HAS_EXTENSION(c_alignof) # define RBIMPL_ALIGNOF __extension__ _Alignof #elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) # define RBIMPL_ALIGNOF _Alignof #elif RBIMPL_COMPILER_IS(MSVC) # define RBIMPL_ALIGNOF __alignof #elif defined(__GNUC__) # /* At least GCC 2.95 had this. */ # define RBIMPL_ALIGNOF __extension__ __alignof__ #elif defined(__alignof_is_defined) || defined(__DOXYGEN__) # /* OK, we can safely take definition. */ # define RBIMPL_ALIGNOF alignof #elif RBIMPL_COMPILER_SINCE(SunPro, 5, 9, 0) # /* According to their manual, Sun Studio 12 introduced __alignof__ for both # * C/C++. */ # define RBIMPL_ALIGNOF __alignof__ #elif 0 # /* THIS IS NG, you cannot define a new type inside of offsetof. */ # /* see: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm */ # define RBIMPL_ALIGNOF(T) offsetof(struct { char _; T t; }, t) #else # error :FIXME: add your compiler here to obtain an alignment. #endif #endif /* RBIMPL_STDALIGN_H */