string/bits/string3.h

   1 /* Copyright (C) 2004-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   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
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _STRING_H
  19 # error "Never use <bits/string3.h> directly; include <string.h> instead."
  20 #endif
  21
  22 __warndecl (__warn_memset_zero_len,
  23             "memset used with constant zero length parameter; this could be due to transposed parameters");
  24
  25 #ifndef __cplusplus
  26 /* XXX This is temporarily.  We should not redefine any of the symbols
  27    and instead integrate the error checking into the original
  28    definitions.  */
  29 # undef memcpy
  30 # undef memmove
  31 # undef memset
  32 # undef strcat
  33 # undef strcpy
  34 # undef strncat
  35 # undef strncpy
  36 # ifdef __USE_GNU
  37 #  undef mempcpy
  38 #  undef stpcpy
  39 # endif
  40 # ifdef __USE_BSD
  41 #  undef bcopy
  42 #  undef bzero
  43 # endif
  44 #endif
  45
  46
  47 __fortify_function void *
  48 __NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
  49                size_t __len))
  50 {
  51   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
  52 }
  53
  54 __fortify_function void *
  55 __NTH (memmove (void *__dest, const void *__src, size_t __len))
  56 {
  57   return __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
  58 }
  59
  60 #ifdef __USE_GNU
  61 __fortify_function void *
  62 __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
  63                 size_t __len))
  64 {
  65   return __builtin___mempcpy_chk (__dest, __src, __len, __bos0 (__dest));
  66 }
  67 #endif
  68
  69
  70 /* The first two tests here help to catch a somewhat common problem
  71    where the second and third parameter are transposed.  This is
  72    especially problematic if the intended fill value is zero.  In this
  73    case no work is done at all.  We detect these problems by referring
  74    non-existing functions.  */
  75 __fortify_function void *
  76 __NTH (memset (void *__dest, int __ch, size_t __len))
  77 {
  78   if (__builtin_constant_p (__len) && __len == 0
  79       && (!__builtin_constant_p (__ch) || __ch != 0))
  80     {
  81       __warn_memset_zero_len ();
  82       return __dest;
  83     }
  84   return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
  85 }
  86
  87 #ifdef __USE_BSD
  88 __fortify_function void
  89 __NTH (bcopy (const void *__src, void *__dest, size_t __len))
  90 {
  91   (void) __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
  92 }
  93
  94 __fortify_function void
  95 __NTH (bzero (void *__dest, size_t __len))
  96 {
  97   (void) __builtin___memset_chk (__dest, '\0', __len, __bos0 (__dest));
  98 }
  99 #endif
 100
 101 __fortify_function char *
 102 __NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
 103 {
 104   return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
 105 }
 106
 107 #ifdef __USE_GNU
 108 __fortify_function char *
 109 __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
 110 {
 111   return __builtin___stpcpy_chk (__dest, __src, __bos (__dest));
 112 }
 113 #endif
 114
 115
 116 __fortify_function char *
 117 __NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
 118                 size_t __len))
 119 {
 120   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
 121 }
 122
 123 // XXX We have no corresponding builtin yet.
 124 extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
 125                             size_t __destlen) __THROW;
 126 extern char *__REDIRECT_NTH (__stpncpy_alias, (char *__dest, const char *__src,
 127                                                size_t __n), stpncpy);
 128
 129 __fortify_function char *
 130 __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
 131 {
 132   if (__bos (__dest) != (size_t) -1
 133       && (!__builtin_constant_p (__n) || __n <= __bos (__dest)))
 134     return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
 135   return __stpncpy_alias (__dest, __src, __n);
 136 }
 137
 138
 139 __fortify_function char *
 140 __NTH (strcat (char *__restrict __dest, const char *__restrict __src))
 141 {
 142   return __builtin___strcat_chk (__dest, __src, __bos (__dest));
 143 }
 144
 145
 146 __fortify_function char *
 147 __NTH (strncat (char *__restrict __dest, const char *__restrict __src,
 148                 size_t __len))
 149 {
 150   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
 151 }