1 files changed, 71 insertions, 0 deletions
diff --git a/lib/strerror.c b/lib/strerror.c
new file mode 100644
index 0000000..1a53a8b
--- /dev/null
+++ b/lib/strerror.c
@@ -0,0 +1,71 @@
+/* strerror.c --- POSIX compatible system error routine
+
+   Copyright (C) 2007-2020 Free Software Foundation, Inc.
+
+   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 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
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <string.h>
+
+#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 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);
+
+  /* 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)
+    {
+      static char const fmt[] = "Unknown error %d";
+      verify (sizeof buf >= sizeof (fmt) + INT_STRLEN_BOUND (n));
+      sprintf (buf, fmt, n);
+      errno = EINVAL;
+      return buf;
+    }
+
+  /* Fix STACKBUF_LEN if this ever aborts.  */
+  len = strlen (msg);
+  if (sizeof buf <= len)
+    abort ();
+
+  memcpy (buf, msg, len + 1);
+  return buf;
+}