1/* Definition of __INDIRECT_RETURN.  x86 version.
 2   Copyright (C) 2018-2025 Free Software Foundation, Inc.
 3   This file is part of the GNU C Library.
 4
 5   The GNU C Library is free software; you can redistribute it and/or
 6   modify it under the terms of the GNU Lesser General Public
 7   License as published by the Free Software Foundation; either
 8   version 2.1 of the License, or (at your option) any later version.
 9
10   The GNU C Library is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   Lesser General Public License for more details.
14
15   You should have received a copy of the GNU Lesser General Public
16   License along with the GNU C Library; if not, see
17   <https://www.gnu.org/licenses/>.  */
18
19#ifndef _UCONTEXT_H
20# error "Never include <bits/indirect-return.h> directly; use <ucontext.h> instead."
21#endif
22
23/* On x86, swapcontext returns via indirect branch when the shadow stack
24   is enabled.  Define __INDIRECT_RETURN to indicate whether swapcontext
25   returns via indirect branch.  */
26#if defined __CET__ && (__CET__ & 2) != 0
27# if __glibc_has_attribute (__indirect_return__)
28#  define __INDIRECT_RETURN __attribute__ ((__indirect_return__))
29# else
30/* Newer compilers provide the indirect_return attribute, but without
31   it we can use returns_twice to affect the optimizer in the same
32   way and avoid unsafe optimizations.  */
33#  define __INDIRECT_RETURN __attribute__ ((__returns_twice__))
34# endif
35#else
36# define __INDIRECT_RETURN
37#endif