| /* Checking strncat. |
| Copyright (C) 1991-2018 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC 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, or (at your option) any later |
| version. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combine |
| executable.) |
| |
| GCC 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. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| |
| #include "config.h" |
| #include <ssp/ssp.h> |
| #ifdef HAVE_STRING_H |
| # include <string.h> |
| #endif |
| |
| extern void __chk_fail (void) __attribute__((__noreturn__)); |
| |
| char * |
| __strncat_chk (char *__restrict__ dest, const char *__restrict__ src, |
| size_t n, size_t slen) |
| { |
| char c; |
| char *s = dest; |
| |
| do |
| { |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *dest++; |
| } |
| while (c != '\0'); |
| |
| ++slen; |
| dest -= 2; |
| |
| if (n >= 4) |
| { |
| size_t n4 = n >> 2; |
| do |
| { |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *src++; |
| *++dest = c; |
| if (c == '\0') |
| return s; |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *src++; |
| *++dest = c; |
| if (c == '\0') |
| return s; |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *src++; |
| *++dest = c; |
| if (c == '\0') |
| return s; |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *src++; |
| *++dest = c; |
| if (c == '\0') |
| return s; |
| } while (--n4 > 0); |
| n &= 3; |
| } |
| |
| while (n > 0) |
| { |
| if (slen-- == 0) |
| __chk_fail (); |
| c = *src++; |
| *++dest = c; |
| if (c == '\0') |
| return s; |
| n--; |
| } |
| |
| if (c != '\0') |
| { |
| if (slen-- == 0) |
| __chk_fail (); |
| *++dest = '\0'; |
| } |
| |
| return s; |
| } |