include/bits/stdlib.h

   1 /* Checking macros for stdlib functions.
   2    Copyright (C) 2005-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _STDLIB_H
  20 # error "Never include <bits/stdlib.h> directly; use <stdlib.h> instead."
  21 #endif
  22
  23 extern char *__realpath_chk (const char *__restrict __name,
  24                              char *__restrict __resolved,
  25                              size_t __resolvedlen) __THROW __wur;
  26 extern char *__REDIRECT_NTH (__realpath_alias,
  27                              (const char *__restrict __name,
  28                               char *__restrict __resolved), realpath) __wur;
  29 extern char *__REDIRECT_NTH (__realpath_chk_warn,
  30                              (const char *__restrict __name,
  31                               char *__restrict __resolved,
  32                               size_t __resolvedlen), __realpath_chk) __wur
  33      __warnattr ("second argument of realpath must be either NULL or at "
  34                  "least PATH_MAX bytes long buffer");
  35
  36 __fortify_function __wur char *
  37 __NTH (realpath (const char *__restrict __name, char *__restrict __resolved))
  38 {
  39   if (__glibc_objsize (__resolved) != (size_t) -1)
  40     {
  41 #if defined _LIBC_LIMITS_H_ && defined PATH_MAX
  42       if (__glibc_objsize (__resolved) < PATH_MAX)
  43         return __realpath_chk_warn (__name, __resolved,
  44                                     __glibc_objsize (__resolved));
  45 #endif
  46       return __realpath_chk (__name, __resolved, __glibc_objsize (__resolved));
  47     }
  48
  49   return __realpath_alias (__name, __resolved);
  50 }
  51
  52
  53 extern int __ptsname_r_chk (int __fd, char *__buf, size_t __buflen,
  54                             size_t __nreal) __THROW __nonnull ((2))
  55     __attr_access ((__write_only__, 2, 3));
  56 extern int __REDIRECT_NTH (__ptsname_r_alias, (int __fd, char *__buf,
  57                                                size_t __buflen), ptsname_r)
  58      __nonnull ((2)) __attr_access ((__write_only__, 2, 3));
  59 extern int __REDIRECT_NTH (__ptsname_r_chk_warn,
  60                            (int __fd, char *__buf, size_t __buflen,
  61                             size_t __nreal), __ptsname_r_chk)
  62      __nonnull ((2)) __warnattr ("ptsname_r called with buflen bigger than "
  63                                  "size of buf");
  64
  65 __fortify_function int
  66 __NTH (ptsname_r (int __fd, char *__buf, size_t __buflen))
  67 {
  68   if (__glibc_objsize (__buf) != (size_t) -1)
  69     {
  70       if (!__builtin_constant_p (__buflen))
  71         return __ptsname_r_chk (__fd, __buf, __buflen,
  72                                 __glibc_objsize (__buf));
  73       if (__buflen > __glibc_objsize (__buf))
  74         return __ptsname_r_chk_warn (__fd, __buf, __buflen,
  75                                      __glibc_objsize (__buf));
  76     }
  77   return __ptsname_r_alias (__fd, __buf, __buflen);
  78 }
  79
  80
  81 extern int __wctomb_chk (char *__s, wchar_t __wchar, size_t __buflen)
  82   __THROW __wur;
  83 extern int __REDIRECT_NTH (__wctomb_alias, (char *__s, wchar_t __wchar),
  84                            wctomb) __wur;
  85
  86 __fortify_function __wur int
  87 __NTH (wctomb (char *__s, wchar_t __wchar))
  88 {
  89   /* We would have to include <limits.h> to get a definition of MB_LEN_MAX.
  90      But this would only disturb the namespace.  So we define our own
  91      version here.  */
  92 #define __STDLIB_MB_LEN_MAX     16
  93 #if defined MB_LEN_MAX && MB_LEN_MAX != __STDLIB_MB_LEN_MAX
  94 # error "Assumed value of MB_LEN_MAX wrong"
  95 #endif
  96   if (__glibc_objsize (__s) != (size_t) -1
  97       && __STDLIB_MB_LEN_MAX > __glibc_objsize (__s))
  98     return __wctomb_chk (__s, __wchar, __glibc_objsize (__s));
  99   return __wctomb_alias (__s, __wchar);
 100 }
 101
 102
 103 extern size_t __mbstowcs_chk (wchar_t *__restrict __dst,
 104                               const char *__restrict __src,
 105                               size_t __len, size_t __dstlen) __THROW
 106     __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
 107 extern size_t __REDIRECT_NTH (__mbstowcs_alias,
 108                               (wchar_t *__restrict __dst,
 109                                const char *__restrict __src,
 110                                size_t __len), mbstowcs)
 111     __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
 112 extern size_t __REDIRECT_NTH (__mbstowcs_chk_warn,
 113                               (wchar_t *__restrict __dst,
 114                                const char *__restrict __src,
 115                                size_t __len, size_t __dstlen), __mbstowcs_chk)
 116      __warnattr ("mbstowcs called with dst buffer smaller than len "
 117                  "* sizeof (wchar_t)");
 118
 119 __fortify_function size_t
 120 __NTH (mbstowcs (wchar_t *__restrict __dst, const char *__restrict __src,
 121                  size_t __len))
 122 {
 123   if (__glibc_objsize (__dst) != (size_t) -1)
 124     {
 125       if (!__builtin_constant_p (__len))
 126         return __mbstowcs_chk (__dst, __src, __len,
 127                                __glibc_objsize (__dst) / sizeof (wchar_t));
 128
 129       if (__len > __glibc_objsize (__dst) / sizeof (wchar_t))
 130         return __mbstowcs_chk_warn (__dst, __src, __len,
 131                                     (__glibc_objsize (__dst)
 132                                      / sizeof (wchar_t)));
 133     }
 134   return __mbstowcs_alias (__dst, __src, __len);
 135 }
 136
 137
 138 extern size_t __wcstombs_chk (char *__restrict __dst,
 139                               const wchar_t *__restrict __src,
 140                               size_t __len, size_t __dstlen) __THROW
 141   __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
 142 extern size_t __REDIRECT_NTH (__wcstombs_alias,
 143                               (char *__restrict __dst,
 144                                const wchar_t *__restrict __src,
 145                                size_t __len), wcstombs)
 146   __attr_access ((__write_only__, 1, 3)) __attr_access ((__read_only__, 2));
 147 extern size_t __REDIRECT_NTH (__wcstombs_chk_warn,
 148                               (char *__restrict __dst,
 149                                const wchar_t *__restrict __src,
 150                                size_t __len, size_t __dstlen), __wcstombs_chk)
 151      __warnattr ("wcstombs called with dst buffer smaller than len");
 152
 153 __fortify_function size_t
 154 __NTH (wcstombs (char *__restrict __dst, const wchar_t *__restrict __src,
 155                  size_t __len))
 156 {
 157   if (__glibc_objsize (__dst) != (size_t) -1)
 158     {
 159       if (!__builtin_constant_p (__len))
 160         return __wcstombs_chk (__dst, __src, __len, __glibc_objsize (__dst));
 161       if (__len > __glibc_objsize (__dst))
 162         return __wcstombs_chk_warn (__dst, __src, __len,
 163                                     __glibc_objsize (__dst));
 164     }
 165   return __wcstombs_alias (__dst, __src, __len);
 166 }