sysdeps/unix/sysv/linux/dl-librecon.h

   1 /* Optional code to distinguish library flavours.
   2    Copyright (C) 2001-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Jakub Jelinek <jakub@redhat.com>, 2001.
   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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _DL_LIBRECON_H
  21 #define _DL_LIBRECON_H  1
  22
  23 static inline void __attribute__ ((unused, always_inline))
  24 _dl_osversion_init (char *assume_kernel)
  25 {
  26   unsigned long int i, j, osversion = 0;
  27   char *p = assume_kernel, *q;
  28
  29   for (i = 0; i < 3; i++, p = q + 1)
  30     {
  31       j = __strtoul_internal (p, &q, 0, 0);
  32       if (j >= 255 || p == q || (i < 2 && *q && *q != '.'))
  33         {
  34           osversion = 0;
  35           break;
  36         }
  37       osversion |= j << (16 - 8 * i);
  38       if (!*q)
  39         break;
  40     }
  41   if (osversion)
  42     GLRO(dl_osversion) = osversion;
  43 }
  44
  45 /* Recognizing extra environment variables.  */
  46 #define EXTRA_LD_ENVVARS_13 \
  47     if (memcmp (envline, "ASSUME_KERNEL", 13) == 0)                           \
  48       {                                                                       \
  49         _dl_osversion_init (&envline[14]);                                    \
  50         break;                                                                \
  51       }
  52
  53 #define DL_OSVERSION_INIT \
  54   do {                                                                        \
  55     char *assume_kernel = getenv ("LD_ASSUME_KERNEL");                        \
  56     if (assume_kernel)                                                        \
  57       _dl_osversion_init (assume_kernel);                                     \
  58   } while (0)
  59
  60 #endif /* dl-librecon.h */