third-party-mirror / GRTEv4 / cf41cedf52c87cf4f27c61e4eb8444ecb811ab13 / . / google3 / third_party / grte / v4_src / glibc-2.19 / debug / strncat_chk.c

/* Copyright (C) 1991-2014 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, see | |

<http://www.gnu.org/licenses/>. */ | |

#include <string.h> | |

#include <memcopy.h> | |

char * | |

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

char *s1; | |

const char *s2; | |

size_t n; | |

size_t s1len; | |

{ | |

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; | |

} |