| /* Copyright (C) 1991, 1997, 2004 Free Software Foundation, Inc. |

| This file is part of the GNU C Library. |

| |

| The GNU C Library is free software; you can redistribute it and/or |

| modify it under the terms of the GNU Lesser General Public |

| License as published by the Free Software Foundation; either |

| version 2.1 of the License, or (at your option) any later version. |

| |

| The GNU C Library 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 |

| Lesser General Public License for more details. |

| |

| You should have received a copy of the GNU Lesser General Public |

| License along with the GNU C Library; if not, write to the Free |

| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |

| 02111-1307 USA. */ |

| |

| #include <string.h> |

| |

| #include <memcopy.h> |

| |

| |

| char * |

| __strncat_chk (s1, s2, n, s1len) |

| char *s1; |

| const char *s2; |

| size_t n; |

| size_t s1len; |

| { |

| reg_char c; |

| char *s = s1; |

| |

| /* Find the end of S1. */ |

| do |

| { |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s1++; |

| } |

| while (c != '\0'); |

| |

| /* Make S1 point before next character, so we can increment |

| it while memory is read (wins on pipelined cpus). */ |

| ++s1len; |

| s1 -= 2; |

| |

| if (n >= 4) |

| { |

| size_t n4 = n >> 2; |

| do |

| { |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s2++; |

| *++s1 = c; |

| if (c == '\0') |

| return s; |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s2++; |

| *++s1 = c; |

| if (c == '\0') |

| return s; |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s2++; |

| *++s1 = c; |

| if (c == '\0') |

| return s; |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s2++; |

| *++s1 = c; |

| if (c == '\0') |

| return s; |

| } while (--n4 > 0); |

| n &= 3; |

| } |

| |

| while (n > 0) |

| { |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| c = *s2++; |

| *++s1 = c; |

| if (c == '\0') |

| return s; |

| n--; |

| } |

| |

| if (c != '\0') |

| { |

| if (__builtin_expect (s1len-- == 0, 0)) |

| __chk_fail (); |

| *++s1 = '\0'; |

| } |

| |

| return s; |

| } |