wcscat_chk.c 1.5 KB

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  1. /* Copyright (C) 1995-2019 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <http://www.gnu.org/licenses/>. */
  15. #include <wchar.h>
  16. /* Append SRC on the end of DEST. Check for overflows. */
  17. wchar_t *
  18. __wcscat_chk (wchar_t *dest, const wchar_t *src, size_t destlen)
  19. {
  20. wchar_t *s1 = dest;
  21. const wchar_t *s2 = src;
  22. wchar_t c;
  23. /* Find the end of the string. */
  24. do
  25. {
  26. if (__glibc_unlikely (destlen-- == 0))
  27. __chk_fail ();
  28. c = *s1++;
  29. }
  30. while (c != L'\0');
  31. /* Make S1 point before the next character, so we can increment
  32. it while memory is read (wins on pipelined cpus). */
  33. s1 -= 2;
  34. ++destlen;
  35. do
  36. {
  37. if (__glibc_unlikely (destlen-- == 0))
  38. __chk_fail ();
  39. c = *s2++;
  40. *++s1 = c;
  41. }
  42. while (c != L'\0');
  43. return dest;
  44. }