newlib/libc/sys/linux/dl/dl-librecon.h

   1 /* Optional code to distinguish library flavours.
   2    Copyright (C) 1998, 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _DL_LIBRECON_H
  22 #define _DL_LIBRECON_H  1
  23
  24 #define DISTINGUISH_LIB_VERSIONS \
  25   do                                                                          \
  26     {                                                                         \
  27       /* We have to find out whether the binary is linked against             \
  28          libc 5 or glibc.  We do this by looking at all the DT_NEEDED         \
  29          entries.  If one is libc.so.5 this is a libc 5 linked binary.  */    \
  30       if (_dl_loaded->l_info[DT_NEEDED])                                      \
  31         {                                                                     \
  32           /* We have dependencies.  */                                        \
  33           const ElfW(Dyn) *d;                                                 \
  34           const char *strtab;                                                 \
  35                                                                               \
  36           strtab = (const char *) D_PTR (_dl_loaded, l_info[DT_STRTAB]);      \
  37                                                                               \
  38           for (d = _dl_loaded->l_ld; d->d_tag != DT_NULL; ++d)                \
  39             if (d->d_tag == DT_NEEDED                                         \
  40                 && strcmp (strtab + d->d_un.d_val, "libc.so.5") == 0)         \
  41               break;                                                          \
  42                                                                               \
  43           /* We print a `5' or `6' depending on the outcome.  */              \
  44           _dl_printf (d->d_tag != DT_NULL ? "5\n" : "6\n");                   \
  45         }                                                                     \
  46     }                                                                         \
  47   while (0)
  48
  49 /* Recognizing extra environment variables.  */
  50 #define EXTRA_LD_ENVVARS \
  51   case 13:                                                                    \
  52     if (memcmp (envline, "ASSUME_KERNEL", 13) == 0)                           \
  53       {                                                                       \
  54         unsigned long int i, j, osversion = 0;                                \
  55         char *p = &envline[14], *q;                                           \
  56                                                                               \
  57         for (i = 0; i < 3; i++, p = q + 1)                                    \
  58           {                                                                   \
  59             j = __strtoul_internal (p, &q, 0, 0);                             \
  60             if (j >= 255 || p == q || (i < 2 && *q && *q != '.'))             \
  61               {                                                               \
  62                 osversion = 0;                                                \
  63                 break;                                                        \
  64               }                                                               \
  65             osversion |= j << (16 - 8 * i);                                   \
  66             if (!*q)                                                          \
  67               break;                                                          \
  68           }                                                                   \
  69         if (osversion)                                                        \
  70           _dl_osversion = osversion;                                          \
  71         break;                                                                \
  72       }                                                                       \
  73                                                                               \
  74   case 15:                                                                    \
  75     if (memcmp (envline, "LIBRARY_VERSION", 15) == 0)                         \
  76       {                                                                       \
  77         _dl_correct_cache_id = envline[16] == '5' ? 2 : 3;                    \
  78         break;                                                                \
  79       }
  80
  81 /* Extra unsecure variables.  The names are all stuffed in a single
  82    string which means they have to be terminated with a '\0' explicitly.  */
  83 #define EXTRA_UNSECURE_ENVVARS \
  84   "LD_AOUT_LIBRARY_PATH\0"                                                    \
  85   "LD_AOUT_PRELOAD\0"
  86
  87 #endif /* dl-librecon.h */