kernel - Handle spinlock indefinite wait edge case
[dragonfly.git] / contrib / grep / lib / strerror.c
blobadba738b7b40e84611e02d4a392a83ca7637f30c
1 /* strerror.c --- POSIX compatible system error routine
3 Copyright (C) 2007-2015 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program 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
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 #include <config.h>
20 /* Specification. */
21 #include <string.h>
23 #include <errno.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
28 #include "intprops.h"
29 #include "strerror-override.h"
30 #include "verify.h"
32 /* Use the system functions, not the gnulib overrides in this file. */
33 #undef sprintf
35 char *
36 strerror (int n)
37 #undef strerror
39 static char buf[STACKBUF_LEN];
40 size_t len;
42 /* Cast away const, due to the historical signature of strerror;
43 callers should not be modifying the string. */
44 const char *msg = strerror_override (n);
45 if (msg)
46 return (char *) msg;
48 msg = strerror (n);
50 /* Our strerror_r implementation might use the system's strerror
51 buffer, so all other clients of strerror have to see the error
52 copied into a buffer that we manage. This is not thread-safe,
53 even if the system strerror is, but portable programs shouldn't
54 be using strerror if they care about thread-safety. */
55 if (!msg || !*msg)
57 static char const fmt[] = "Unknown error %d";
58 verify (sizeof buf >= sizeof (fmt) + INT_STRLEN_BOUND (n));
59 sprintf (buf, fmt, n);
60 errno = EINVAL;
61 return buf;
64 /* Fix STACKBUF_LEN if this ever aborts. */
65 len = strlen (msg);
66 if (sizeof buf <= len)
67 abort ();
69 return memcpy (buf, msg, len + 1);