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Diffstat (limited to 'include/ruby/internal/has/c_attribute.h')
| -rw-r--r-- | include/ruby/internal/has/c_attribute.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/include/ruby/internal/has/c_attribute.h b/include/ruby/internal/has/c_attribute.h new file mode 100644 index 0000000000..69b0f402cd --- /dev/null +++ b/include/ruby/internal/has/c_attribute.h @@ -0,0 +1,50 @@ +#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 */ |