misc/sys/param.h

   1 /* Compatibility header for old-style Unix parameters and limits.
   2    Copyright (C) 1995-2020 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 _SYS_PARAM_H
  20 #define _SYS_PARAM_H    1
  21
  22 #define __need_NULL
  23 #include <stddef.h>
  24
  25 #include <sys/types.h>
  26 #include <limits.h>
  27 #include <endian.h>                     /* Define BYTE_ORDER et al.  */
  28 #include <signal.h>                     /* Define NSIG.  */
  29
  30 /* This file defines some things in system-specific ways.  */
  31 #include <bits/param.h>
  32
  33
  34 /* BSD names for some <limits.h> values.  */
  35
  36 #define NBBY            CHAR_BIT
  37
  38 #if !defined NGROUPS && defined NGROUPS_MAX
  39 # define NGROUPS        NGROUPS_MAX
  40 #endif
  41 #if !defined MAXSYMLINKS && defined SYMLOOP_MAX
  42 # define MAXSYMLINKS    SYMLOOP_MAX
  43 #endif
  44 #if !defined CANBSIZ && defined MAX_CANON
  45 # define CANBSIZ        MAX_CANON
  46 #endif
  47 #if !defined MAXPATHLEN && defined PATH_MAX
  48 # define MAXPATHLEN     PATH_MAX
  49 #endif
  50 #if !defined NOFILE && defined OPEN_MAX
  51 # define NOFILE         OPEN_MAX
  52 #endif
  53 #if !defined MAXHOSTNAMELEN && defined HOST_NAME_MAX
  54 # define MAXHOSTNAMELEN HOST_NAME_MAX
  55 #endif
  56 #ifndef NCARGS
  57 # ifdef ARG_MAX
  58 #  define NCARGS        ARG_MAX
  59 # else
  60 /* ARG_MAX is unlimited, but we define NCARGS for BSD programs that want to
  61    compare against some fixed limit.  */
  62 # define NCARGS         INT_MAX
  63 # endif
  64 #endif
  65
  66
  67 /* Magical constants.  */
  68 #ifndef NOGROUP
  69 # define NOGROUP        65535     /* Marker for empty group set member.  */
  70 #endif
  71 #ifndef NODEV
  72 # define NODEV          ((dev_t) -1)    /* Non-existent device.  */
  73 #endif
  74
  75
  76 /* Unit of `st_blocks'.  */
  77 #ifndef DEV_BSIZE
  78 # define DEV_BSIZE      512
  79 #endif
  80
  81
  82 /* Bit map related macros.  */
  83 #define setbit(a,i)     ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
  84 #define clrbit(a,i)     ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
  85 #define isset(a,i)      ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
  86 #define isclr(a,i)      (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
  87
  88 /* Macros for counting and rounding.  */
  89 #ifndef howmany
  90 # define howmany(x, y)  (((x) + ((y) - 1)) / (y))
  91 #endif
  92 #ifdef __GNUC__
  93 # define roundup(x, y)  (__builtin_constant_p (y) && powerof2 (y)             \
  94                          ? (((x) + (y) - 1) & ~((y) - 1))                     \
  95                          : ((((x) + ((y) - 1)) / (y)) * (y)))
  96 #else
  97 # define roundup(x, y)  ((((x) + ((y) - 1)) / (y)) * (y))
  98 #endif
  99 #define powerof2(x)     ((((x) - 1) & (x)) == 0)
 100
 101 /* Macros for min/max.  */
 102 #define MIN(a,b) (((a)<(b))?(a):(b))
 103 #define MAX(a,b) (((a)>(b))?(a):(b))
 104
 105
 106 #endif  /* sys/param.h */