#ifndef RBIMPL_HAS_C_ATTRIBUTE_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_HAS_C_ATTRIBUTE_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_HAS_C_ATTRIBUTE. */ #include "ruby/internal/has/extension.h" #include "ruby/internal/has/warning.h" /** Wraps (or simulates) `__has_c_attribute`. */ #if defined(__cplusplus) # /* Makes no sense. */ # define RBIMPL_HAS_C_ATTRIBUTE(_) 0 #elif RBIMPL_HAS_EXTENSION(c_attributes) # /* Hmm. It seems Clang 17 has this macro defined even when -std=c99 mode, # * _and_ fails to compile complaining that attributes are C2X feature. We # * need to work around this nonsense. */ # define RBIMPL_HAS_C_ATTRIBUTE(_) __has_c_attribute(_) #elif RBIMPL_HAS_WARNING("-Wc2x-extensions") # define RBIMPL_HAS_C_ATTRIBUTE(_) 0 #elif defined(__has_c_attribute) # define RBIMPL_HAS_C_ATTRIBUTE(_) __has_c_attribute(_) #else # /* As of writing everything that lacks __has_c_attribute also completely # * lacks C2x attributes as well. Might change in future? */ # define RBIMPL_HAS_C_ATTRIBUTE(_) 0 #endif #endif /* RBIMPL_HAS_C_ATTRIBUTE_H */