1/* Safe version of strerror for GDB, the GNU debugger.
2
3   Copyright (C) 2006-2023 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "common-defs.h"
21#include <string.h>
22
23/* There are two different versions of strerror_r; one is GNU-specific, the
24   other XSI-compliant.  They differ in the return type.  This overload lets
25   us choose the right behavior for each return type.  We cannot rely on Gnulib
26   to solve this for us because IPA does not use Gnulib but uses this
27   function.  */
28
29/* Called if we have a XSI-compliant strerror_r.  */
30ATTRIBUTE_UNUSED static char *
31select_strerror_r (int res, char *buf)
32{
33  return res == 0 ? buf : nullptr;
34}
35
36/* Called if we have a GNU strerror_r.  */
37ATTRIBUTE_UNUSED static char *
38select_strerror_r (char *res, char *)
39{
40  return res;
41}
42
43/* Implementation of safe_strerror as defined in common-utils.h.  */
44
45const char *
46safe_strerror (int errnum)
47{
48  static thread_local char buf[1024];
49
50  char *res = select_strerror_r (strerror_r (errnum, buf, sizeof (buf)), buf);
51  if (res != nullptr)
52    return res;
53
54  xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum);
55  return buf;
56}
57