#ifndef RBIMPL_HAS_C_ATTRIBUTE_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_HAS_C_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 `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 */
|