src/getpagesize.h

   1 /* Emulate getpagesize on systems that lack it.
   2    Copyright (C) 1986, 1992, 1995, 2001-2012 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, either version 3 of the License, or
   9 (at your option) any later version.
  10
  11 GNU Emacs 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
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef HAVE_GETPAGESIZE
  20
  21 # include <unistd.h>
  22
  23 # ifdef _SC_PAGESIZE
  24 #  define getpagesize() sysconf (_SC_PAGESIZE)
  25 # else /* no _SC_PAGESIZE */
  26 #  ifdef HAVE_SYS_PARAM_H
  27 #   include <sys/param.h>
  28 #   ifdef EXEC_PAGESIZE
  29 #    define getpagesize() EXEC_PAGESIZE
  30 #   else /* no EXEC_PAGESIZE */
  31 #    ifdef NBPG
  32 #     define getpagesize() NBPG * CLSIZE
  33 #     ifndef CLSIZE
  34 #      define CLSIZE 1
  35 #     endif /* no CLSIZE */
  36 #    else /* no NBPG */
  37 #      ifdef PAGESIZE
  38 #       define getpagesize() PAGESIZE
  39 #      endif /* PAGESIZE */
  40 #    endif /* no NBPG */
  41 #   endif /* no EXEC_PAGESIZE */
  42 #  else /* no HAVE_SYS_PARAM_H */
  43 #   define getpagesize() 8192   /* punt totally */
  44 #  endif /* no HAVE_SYS_PARAM_H */
  45 # endif /* no _SC_PAGESIZE */
  46
  47 #endif /* no HAVE_GETPAGESIZE */
  48