1/* _Unwind_Resume wrapper for ARM EABI.
2 Copyright (C) 2015-2022 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 License as
7 published by the Free Software Foundation; either version 2.1 of the
8 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#include <sysdep.h>
20
21/* This is equivalent to the following C implementation:
22
23 void
24 _Unwind_Resume (struct _Unwind_Exception *exc)
25 {
26 __unwind_link_get_resume () (exc);
27 }
28
29 We do it in assembly just to ensure that we get an unmolested tail
30 call to the libgcc function, which is necessary for the ARM unwinder. */
31
32ENTRY (_Unwind_Resume)
33 /* We need to save and restore LR (for our own return address)
34 and R0 (for the argument to _Unwind_Resume) around the call. */
35 push {r0, lr}
36 cfi_adjust_cfa_offset (8)
37 cfi_rel_offset (r0, 0)
38 cfi_rel_offset (lr, 4)
39 bl __unwind_link_get_resume
40 mov r3, r0
41 pop {r0, lr}
42 cfi_adjust_cfa_offset (-8)
43 cfi_restore (r4)
44 cfi_restore (lr)
45 bx r3
46END (_Unwind_Resume)
47

source code of glibc/sysdeps/arm/arm-unwind-resume.S