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Diffstat (limited to 'include/ruby/impl/has/cpp_attribute.h')
| -rw-r--r-- | include/ruby/impl/has/cpp_attribute.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/ruby/impl/has/cpp_attribute.h b/include/ruby/impl/has/cpp_attribute.h new file mode 100644 index 0000000000..941f7ddca3 --- /dev/null +++ b/include/ruby/impl/has/cpp_attribute.h @@ -0,0 +1,79 @@ +#ifndef RUBY3_HAS_CPP_ATTRIBUTE_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RUBY3_HAS_CPP_ATTRIBUTE_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 `RUBY3` or `ruby3` 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 #RUBY3_HAS_CPP_ATTRIBUTE. + */ +#include "ruby/3/compiler_is.h" +#include "ruby/3/compiler_since.h" +#include "ruby/3/token_paste.h" + +/** @cond INTERNAL_MACRO */ +#if defined(__has_cpp_attribute) +# define RUBY3_HAS_CPP_ATTRIBUTE0(_) __has_cpp_attribute(_) + +#elif RUBY3_COMPILER_IS(MSVC) +# /* MSVC has never updated its __cplusplus since forever (unless specified +# * explicitly by a compiler flag). They also lack __has_cpp_attribute until +# * 2019. However, they do have attributes since 2015 or so. */ +# /* https://docs.microsoft.com/en-us/cpp/overview/visual-cpp-language-conformance */ +# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _) +# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn 200809 * RUBY3_COMPILER_SINCE(MSVC, 19, 00, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_carries_dependency 200809 * RUBY3_COMPILER_SINCE(MSVC, 19, 00, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated 201309 * RUBY3_COMPILER_SINCE(MSVC, 19, 10, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_fallthrough 201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 10, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_maybe_unused 201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 11, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_nodiscard 201603 * RUBY3_COMPILER_SINCE(MSVC, 19, 11, 0) + +#elif RUBY3_COMPILER_BEFORE(Clang, 3, 6, 0) +# /* Clang 3.6.0 introduced __has_cpp_attribute. Prior to that following +# * attributes were already there. */ +# /* https://clang.llvm.org/cxx_status.html */ +# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _) +# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn 200809 * RUBY3_COMPILER_SINCE(Clang, 3, 3, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated 201309 * RUBY3_COMPILER_SINCE(Clang, 3, 4, 0) + +#elif RUBY3_COMPILER_BEFORE(GCC, 5, 0, 0) +# /* GCC 5+ have __has_cpp_attribute, while 4.x had following attributes. */ +# /* https://gcc.gnu.org/projects/cxx-status.html */ +# define RUBY3_HAS_CPP_ATTRIBUTE0(_) RUBY3_TOKEN_PASTE(RUBY3_HAS_CPP_ATTRIBUTE_, _) +# define RUBY3_HAS_CPP_ATTRIBUTE_noreturn 200809 * RUBY3_COMPILER_SINCE(GCC, 4, 8, 0) +# define RUBY3_HAS_CPP_ATTRIBUTE_deprecated 201309 * RUBY3_COMPILER_SINCE(GCC, 4, 9, 0) + +#else +# /* :FIXME: +# * Candidate compilers to list here: +# * - icpc: They have __INTEL_CXX11_MODE__. +# * - SunPro: Seems they support C++11. +# */ +# define RUBY3_HAS_CPP_ATTRIBUTE0(_) 0 +#endif +/** @endcond */ + +/** Wraps (or simulates) `__has_cpp_attribute`. */ +#if ! defined(__cplusplus) +# /* Makes no sense. */ +# define RUBY3_HAS_CPP_ATTRIBUTE(_) 0 +#else +# /* GCC needs workarounds. See https://gcc.godbolt.org/z/jdz3pa */ +# define RUBY3_HAS_CPP_ATTRIBUTE(_) \ + ((RUBY3_HAS_CPP_ATTRIBUTE0(_) <= __cplusplus) ? RUBY3_HAS_CPP_ATTRIBUTE0(_) : 0) +#endif + +#endif /* RUBY3_HAS_CPP_ATTRIBUTE_H */ |