#ifndef RBIMPL_ATTR_ARTIFICIAL_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ATTR_ARTIFICIAL_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_ATTR_ARTIFICIAL.
*
* ### Q&A ###
*
* - Q: What is this attribute? I don't get what GCC manual is talking about.
*
* - A: In short it is an attribute to manipulate GDB backtraces. The
* attribute makes the best sense when it comes with
* __attribute__((always_inline)). When a function annotated with this
* attribute gets inlined, and when you somehow look at a backtrace which
* includes such inlined call site, then the backtrace shows the caller
* and not the callee. This is handy for instance when an identical
* function is inlined more than once in a single big function. On such
* case it gets vital to know where the inlining happened in the callee.
* See also https://stackoverflow.com/a/21936099
*/
#include "ruby/internal/has/attribute.h"
/** Wraps (or simulates) `__attribute__((artificial))` */
#if RBIMPL_HAS_ATTRIBUTE(artificial)
# define RBIMPL_ATTR_ARTIFICIAL() __attribute__((__artificial__))
#else
# define RBIMPL_ATTR_ARTIFICIAL() /* void */
#endif
#endif /* RBIMPL_ATTR_ARTIFICIAL_H */
