string/bits/string3.h

   1 /* Copyright (C) 2004-2015 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 #if !__GNUC_PREREQ (5,0)
  23 __warndecl (__warn_memset_zero_len,
  24             "memset used with constant zero length parameter; this could be due to transposed parameters");
  25 #endif
  26
  27 #ifndef __cplusplus
  28 /* XXX This is temporarily.  We should not redefine any of the symbols
  29    and instead integrate the error checking into the original
  30    definitions.  */
  31 # undef memcpy
  32 # undef memmove
  33 # undef memset
  34 # undef strcat
  35 # undef strcpy
  36 # undef strncat
  37 # undef strncpy
  38 # ifdef __USE_GNU
  39 #  undef mempcpy
  40 #  undef stpcpy
  41 # endif
  42 # ifdef __USE_MISC
  43 #  undef bcopy
  44 #  undef bzero
  45 # endif
  46 #endif
  47
  48
  49 __fortify_function void *
  50 __NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
  51                size_t __len))
  52 {
  53   return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
  54 }
  55
  56 __fortify_function void *
  57 __NTH (memmove (void *__dest, const void *__src, size_t __len))
  58 {
  59   return __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
  60 }
  61
  62 #ifdef __USE_GNU
  63 __fortify_function void *
  64 __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
  65                 size_t __len))
  66 {
  67   return __builtin___mempcpy_chk (__dest, __src, __len, __bos0 (__dest));
  68 }
  69 #endif
  70
  71
  72 /* The first two tests here help to catch a somewhat common problem
  73    where the second and third parameter are transposed.  This is
  74    especially problematic if the intended fill value is zero.  In this
  75    case no work is done at all.  We detect these problems by referring
  76    non-existing functions.  */
  77 __fortify_function void *
  78 __NTH (memset (void *__dest, int __ch, size_t __len))
  79 {
  80   /* GCC-5.0 and newer implements these checks in the compiler, so we don't
  81      need them here.  */
  82 #if !__GNUC_PREREQ (5,0)
  83   if (__builtin_constant_p (__len) && __len == 0
  84       && (!__builtin_constant_p (__ch) || __ch != 0))
  85     {
  86       __warn_memset_zero_len ();
  87       return __dest;
  88     }
  89 #endif
  90   return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
  91 }
  92
  93 #ifdef __USE_MISC
  94 __fortify_function void
  95 __NTH (bcopy (const void *__src, void *__dest, size_t __len))
  96 {
  97   (void) __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
  98 }
  99
 100 __fortify_function void
 101 __NTH (bzero (void *__dest, size_t __len))
 102 {
 103   (void) __builtin___memset_chk (__dest, '\0', __len, __bos0 (__dest));
 104 }
 105 #endif
 106
 107 __fortify_function char *
 108 __NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
 109 {
 110   return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
 111 }
 112
 113 #ifdef __USE_GNU
 114 __fortify_function char *
 115 __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
 116 {
 117   return __builtin___stpcpy_chk (__dest, __src, __bos (__dest));
 118 }
 119 #endif
 120
 121
 122 __fortify_function char *
 123 __NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
 124                 size_t __len))
 125 {
 126   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
 127 }
 128
 129 // XXX We have no corresponding builtin yet.
 130 extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
 131                             size_t __destlen) __THROW;
 132 extern char *__REDIRECT_NTH (__stpncpy_alias, (char *__dest, const char *__src,
 133                                                size_t __n), stpncpy);
 134
 135 __fortify_function char *
 136 __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
 137 {
 138   if (__bos (__dest) != (size_t) -1
 139       && (!__builtin_constant_p (__n) || __n <= __bos (__dest)))
 140     return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
 141   return __stpncpy_alias (__dest, __src, __n);
 142 }
 143
 144
 145 __fortify_function char *
 146 __NTH (strcat (char *__restrict __dest, const char *__restrict __src))
 147 {
 148   return __builtin___strcat_chk (__dest, __src, __bos (__dest));
 149 }
 150
 151
 152 __fortify_function char *
 153 __NTH (strncat (char *__restrict __dest, const char *__restrict __src,
 154                 size_t __len))
 155 {
 156   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
 157 }