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Diffstat (limited to 'include/ruby/internal/stdalign.h')
| -rw-r--r-- | include/ruby/internal/stdalign.h | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/include/ruby/internal/stdalign.h b/include/ruby/internal/stdalign.h deleted file mode 100644 index ec68f6a882..0000000000 --- a/include/ruby/internal/stdalign.h +++ /dev/null @@ -1,135 +0,0 @@ -#ifndef RBIMPL_STDALIGN_H /*-*-C++-*-vi:se ft=cpp:*/ -#define RBIMPL_STDALIGN_H -/** - * @file - * @author Ruby developers <ruby-core@ruby-lang.org> - * @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/internal/config.h" - -#ifdef STDC_HEADERS -# include <stddef.h> -#endif - -#include "ruby/internal/compiler_is.h" -#include "ruby/internal/has/attribute.h" -#include "ruby/internal/has/declspec_attribute.h" -#include "ruby/internal/has/feature.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(aligned) -# define RBIMPL_ALIGNAS(_) __attribute__((__aligned__(_))) - -#else -# define RBIMPL_ALIGNAS(_) /* void */ -#endif - -/** - * Wraps (or simulates) `alignof`. - * - * We want C11's `_Alignof`. However in spite of its clear language, compilers - * (including GCC and clang) tend to have buggy implementations. We have to - * avoid such things to resort to our own version. - * - * @see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023 - * @see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69560 - * @see https://bugs.llvm.org/show_bug.cgi?id=26547 - */ -#if defined(__DOXYGEN__) -# define RBIMPL_ALIGNOF alignof -#elif defined(__cplusplus) -# /* C++11 `alignof()` can be buggy. */ -# /* see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69560 */ -# /* But don't worry, we can use templates. */ -# define RBIMPL_ALIGNOF(T) (static_cast<size_t>(ruby::rbimpl_alignof<T>::value)) - -namespace ruby { -template<typename T> -struct rbimpl_alignof { - typedef struct { - char _; - T t; - } type; - - enum { - value = offsetof(type, t) - }; -}; -} - -#elif RBIMPL_COMPILER_IS(MSVC) -# /* Windows have no alignment glitch.*/ -# define RBIMPL_ALIGNOF __alignof - -#elif defined(HAVE__ALIGNOF) -# /* Autoconf detected availability of a sane `_Alignof()`. */ -# define RBIMPL_ALIGNOF(T) RB_GNUC_EXTENSION(_Alignof(T)) - -#else -# /* :BEWARE: This is the last resort. If your compiler somehow supports -# * querying the alignment of a type, you definitely should use that instead. -# * There are 2 known pitfalls for this fallback implementation: -# * -# * First, it is either an undefined behaviour (C) or an explicit error (C++) -# * to define a struct inside of `offsetof`. C compilers tend to accept such -# * things, but AFAIK C++ has no room to allow. -# * -# * Second, there exist T such that `struct { char _; T t; }` is invalid. A -# * known example is when T is a struct with a flexible array member. Such -# * struct cannot be enclosed into another one. -# */ -# /* see: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2083.htm */ -# /* see: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm */ -# define RBIMPL_ALIGNOF(T) offsetof(struct { char _; T t; }, t) - -#endif - -#endif /* RBIMPL_STDALIGN_H */ |