mirror of
https://github.com/ruby/ruby.git
synced 2022-11-09 12:17:21 -05:00
46 lines
2.4 KiB
C++
46 lines
2.4 KiB
C++
#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 */
|