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Editing: artificial.h
#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 */
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