maint: update copyright

[gnulib.git] / lib / strerror.c

diff --git a/lib/strerror.c b/lib/strerror.c
index 7c17f1f..e54f0cc 100644 (file)
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -1,12 +1,11 @@
-/* strerror.c --- ANSI C compatible system error routine
+/* strerror.c --- POSIX compatible system error routine
 
-   Copyright (C) 1986, 1988, 1989, 1991, 2002, 2003 Free Software
-   Foundation, Inc.
+   Copyright (C) 2007-2014 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
@@ -14,36 +13,58 @@
    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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
-#include <limits.h>
+/* Specification.  */
+#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 <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#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;
 
-  if (n < 0 || n >= sys_nerr)
+  msg = strerror (n);
+
+  /* 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];
+
+  /* Fix STACKBUF_LEN if this ever aborts.  */
+  len = strlen (msg);
+  if (sizeof buf <= len)
+    abort ();
+
+  return memcpy (buf, msg, len + 1);
 }