debug/wcpcpy_chk.c

   1 /* Copyright (C) 1996, 1997, 2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <wchar.h>
  21
  22 #define __need_ptrdiff_t
  23 #include <stddef.h>
  24
  25
  26 /* Copy SRC to DEST, returning the address of the terminating L'\0' in
  27    DEST.  Check for overflows.  */
  28 wchar_t *
  29 __wcpcpy_chk (wchar_t *dest, const wchar_t *src, size_t destlen)
  30 {
  31   wchar_t *wcp = (wchar_t *) dest - 1;
  32   wint_t c;
  33   const ptrdiff_t off = src - dest + 1;
  34
  35   do
  36     {
  37       if (__builtin_expect (destlen-- == 0, 0))
  38         __chk_fail ();
  39       c = wcp[off];
  40       *++wcp = c;
  41     }
  42   while (c != L'\0');
  43
  44   return wcp;
  45 }