-/* strerror.c --- ANSI C compatible system error routine
+/* strerror.c --- POSIX compatible system error routine
- Copyright (C) 1986, 1988, 1989, 1991, 2002, 2003, 2006, 2007 Free
- Software Foundation, Inc.
+ Copyright (C) 2007-2012 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
-#if !HAVE_STRERROR
+/* Specification. */
+#include <string.h>
-#include <limits.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
-/* Don't include <stdio.h>, since it may or may not declare
- sys_errlist and its declarations may collide with ours. Just
- declare the stuff that we need directly. Standard hosted C89
- implementations define strerror and they don't need this strerror
- function, so take some liberties with the standard to cater to
- ancient or limited freestanding implementations. */
-int sprintf (char *, char const *, ...);
-extern int sys_nerr;
-extern char *sys_errlist[];
+#include "intprops.h"
+#include "strerror-override.h"
+#include "verify.h"
+
+/* Use the system functions, not the gnulib overrides in this file. */
+#undef sprintf
char *
strerror (int n)
+#undef strerror
{
- static char const fmt[] = "Unknown error (%d)";
- static char mesg[sizeof fmt + sizeof n * CHAR_BIT / 3];
+ static char buf[STACKBUF_LEN];
+ size_t len;
+
+ /* Cast away const, due to the historical signature of strerror;
+ callers should not be modifying the string. */
+ const char *msg = strerror_override (n);
+ if (msg)
+ return (char *) msg;
+
+ msg = strerror (n);
- if (n < 0 || n >= sys_nerr)
+ /* Our strerror_r implementation might use the system's strerror
+ buffer, so all other clients of strerror have to see the error
+ copied into a buffer that we manage. This is not thread-safe,
+ even if the system strerror is, but portable programs shouldn't
+ be using strerror if they care about thread-safety. */
+ if (!msg || !*msg)
{
- sprintf (mesg, fmt, n);
- return mesg;
+ static char const fmt[] = "Unknown error %d";
+ verify (sizeof buf >= sizeof (fmt) + INT_STRLEN_BOUND (n));
+ sprintf (buf, fmt, n);
+ errno = EINVAL;
+ return buf;
}
- else
- return sys_errlist[n];
-}
-
-#else
-/* This declaration is solely to ensure that after preprocessing
- this file is never empty. */
-typedef int dummy;
+ /* Fix STACKBUF_LEN if this ever aborts. */
+ len = strlen (msg);
+ if (sizeof buf <= len)
+ abort ();
-#endif
+ return memcpy (buf, msg, len + 1);
+}