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Diffstat (limited to 'include/ruby/internal/cast.h')
| -rw-r--r-- | include/ruby/internal/cast.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/include/ruby/internal/cast.h b/include/ruby/internal/cast.h new file mode 100644 index 0000000000..4524d63f17 --- /dev/null +++ b/include/ruby/internal/cast.h @@ -0,0 +1,53 @@ +#ifndef RBIMPL_CAST_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RBIMPL_CAST_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_CAST. + * @cond INTERNAL_MACRO + * + * This casting macro makes sense only inside of other macros that are part of + * public headers. They could be used from C++, and C-style casts could issue + * warnings. Ruby internals are pure C so they should not bother. + */ +#include "ruby/impl/compiler_since.h" +#include "ruby/impl/has/warning.h" +#include "ruby/impl/warning_push.h" + +#if ! defined(__cplusplus) +# define RBIMPL_CAST(expr) (expr) + +#elif RBIMPL_COMPILER_SINCE(GCC, 4, 6, 0) +# /* g++ has -Wold-style-cast since 1997 or so, but its _Pragma is broken. */ +# /* See https://gcc.godbolt.org/z/XWhU6J */ +# define RBIMPL_CAST(expr) (expr) +# pragma GCC diagnostic ignored "-Wold-style-cast" + +#elif RBIMPL_HAS_WARNING("-Wold-style-cast") +# define RBIMPL_CAST(expr) \ + RBIMPL_WARNING_PUSH() \ + RBIMPL_WARNING_IGNORED(-Wold-style-cast) \ + (expr) \ + RBIMPL_WARNING_POP() + +#else +# define RBIMPL_CAST(expr) (expr) +#endif +/** @endcond */ + +#endif /* RBIMPL_CAST_H */ |