indirect-return.h (1614B) - Raw
1 /* Definition of __INDIRECT_RETURN. AArch64 version. 2 Copyright (C) 2024-2025 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 /* __INDIRECT_RETURN indicates that swapcontext may return via 24 an indirect branch. This happens when GCS is enabled, so 25 add the attribute if available, otherwise returns_twice has 26 a similar effect, but it prevents some code transformations 27 that can cause build failures in some rare cases so it is 28 only used when GCS is enabled. */ 29 #if __glibc_has_attribute (__indirect_return__) 30 # define __INDIRECT_RETURN __attribute__ ((__indirect_return__)) 31 #elif __glibc_has_attribute (__returns_twice__) \ 32 && defined __ARM_FEATURE_GCS_DEFAULT 33 # define __INDIRECT_RETURN __attribute__ ((__returns_twice__)) 34 #else 35 # define __INDIRECT_RETURN 36 #endif