uclibc-ng/libc/unistd/sysconf.c

/* Copyright (C) 1991, 93, 95, 96, 97, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#define _XOPEN_SOURCE  500
#include <features.h>
#include <errno.h>
#include <limits.h>
#include <grp.h>
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#ifdef __UCLIBC_HAS_REGEX__
#include <regex.h>
#endif

libc_hidden_proto(sysconf)

libc_hidden_proto(getpagesize)
libc_hidden_proto(getdtablesize)

#ifndef __UCLIBC_CLK_TCK_CONST
#error __UCLIBC_CLK_TCK_CONST not defined!
#endif

/***********************************************************************/
/*
 * Manuel Novoa III        Jan 2001
 *
 * On i386, the switch-based implementation generates 796 bytes of code.
 * However, many of the return values are repeats.  By collecting these
 * repeats and moving to a table-based implementation, we generate 283
 * bytes on i386 (-Os -fomit-frame-pointer).
 */

#ifdef _UCLIBC_GENERATE_SYSCONF_ARCH
/*
 * Set some errno's so the auto-gen code knows what it is dealing with.
 *    1) ENOSYS signifies that we're returning a default value.
 *       This is just extra info for development.
 *    2) EISNAM signifies that the value returned varies at runtime.
 *
 * Option: GETPAGESIZE_IS_DYNAMIC
 *    The current implementation of getpagesize in uClibc returns
 *    a constant.  The pagesize on the target arch should not vary,
 *    so it should be safe to set this as 0.
 */
#define RETURN_NEG_1 __set_errno(ENOSYS); return -1
#define RETURN_FUNCTION(f) __set_errno(EISNAM); return (long int) #f
#define GETPAGESIZE_IS_DYNAMIC 0
#else
#define RETURN_NEG_1 return -1
#define RETURN_FUNCTION(f) return f;
#endif /* _UCLIBC_GENERATE_SYSCONF_ARCH */

/* Get the value of the system variable NAME.  */
long int sysconf(int name)
{
  switch (name)
    {
    default:
      __set_errno(EINVAL);
      return -1;

    case _SC_ARG_MAX:
#ifdef	ARG_MAX
      return ARG_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_CHILD_MAX:
#ifdef	CHILD_MAX
      return CHILD_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_CLK_TCK:
      /* Can't use CLK_TCK here since that calls __sysconf(_SC_CLK_TCK) */
      return __UCLIBC_CLK_TCK_CONST;

    case _SC_NGROUPS_MAX:
#ifdef	NGROUPS_MAX
      return NGROUPS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_OPEN_MAX:
      RETURN_FUNCTION(getdtablesize());

    case _SC_STREAM_MAX:
#ifdef	STREAM_MAX
      return STREAM_MAX;
#else
      return FOPEN_MAX;
#endif

    case _SC_TZNAME_MAX:
      return _POSIX_TZNAME_MAX;

    case _SC_JOB_CONTROL:
#ifdef	_POSIX_JOB_CONTROL
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_SAVED_IDS:
#ifdef	_POSIX_SAVED_IDS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_REALTIME_SIGNALS:
#ifdef	_POSIX_REALTIME_SIGNALS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PRIORITY_SCHEDULING:
#ifdef	_POSIX_PRIORITY_SCHEDULING
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_TIMERS:
#ifdef	_POSIX_TIMERS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_ASYNCHRONOUS_IO:
#ifdef	_POSIX_ASYNCHRONOUS_IO
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PRIORITIZED_IO:
#ifdef	_POSIX_PRIORITIZED_IO
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_SYNCHRONIZED_IO:
#ifdef	_POSIX_SYNCHRONIZED_IO
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_FSYNC:
#ifdef	_POSIX_FSYNC
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_MAPPED_FILES:
#ifdef	_POSIX_MAPPED_FILES
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_MEMLOCK:
#ifdef	_POSIX_MEMLOCK
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_MEMLOCK_RANGE:
#ifdef	_POSIX_MEMLOCK_RANGE
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_MEMORY_PROTECTION:
#ifdef	_POSIX_MEMORY_PROTECTION
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_MESSAGE_PASSING:
#ifdef	_POSIX_MESSAGE_PASSING
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_SEMAPHORES:
#ifdef	_POSIX_SEMAPHORES
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_SHARED_MEMORY_OBJECTS:
#ifdef	_POSIX_SHARED_MEMORY_OBJECTS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_VERSION:
      return _POSIX_VERSION;

    case _SC_PAGESIZE:
#if defined(GETPAGESIZE_IS_DYNAMIC) && (GETPAGESIZE_IS_DYNAMIC == 1)
      RETURN_FUNCTION(getpagesize());
#else
      return getpagesize();		/* note: currently this is not dynamic */
#endif

    case _SC_AIO_LISTIO_MAX:
#ifdef	AIO_LISTIO_MAX
      return AIO_LISTIO_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_AIO_MAX:
#ifdef	AIO_MAX
      return AIO_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_AIO_PRIO_DELTA_MAX:
#ifdef	AIO_PRIO_DELTA_MAX
      return AIO_PRIO_DELTA_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_DELAYTIMER_MAX:
#ifdef	DELAYTIMER_MAX
      return DELAYTIMER_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_MQ_OPEN_MAX:
#ifdef	MQ_OPEN_MAX
      return MQ_OPEN_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_MQ_PRIO_MAX:
#ifdef	MQ_PRIO_MAX
      return MQ_PRIO_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_RTSIG_MAX:
#ifdef	RTSIG_MAX
      return RTSIG_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_SEM_NSEMS_MAX:
#ifdef	SEM_NSEMS_MAX
      return SEM_NSEMS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_SEM_VALUE_MAX:
#ifdef	SEM_VALUE_MAX
      return SEM_VALUE_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_SIGQUEUE_MAX:
#ifdef	SIGQUEUE_MAX
      return SIGQUEUE_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_TIMER_MAX:
#ifdef	TIMER_MAX
      return TIMER_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_BC_BASE_MAX:
#ifdef	BC_BASE_MAX
      return BC_BASE_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_BC_DIM_MAX:
#ifdef	BC_DIM_MAX
      return BC_DIM_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_BC_SCALE_MAX:
#ifdef	BC_SCALE_MAX
      return BC_SCALE_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_BC_STRING_MAX:
#ifdef	BC_STRING_MAX
      return BC_STRING_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_COLL_WEIGHTS_MAX:
#ifdef	COLL_WEIGHTS_MAX
      return COLL_WEIGHTS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_EQUIV_CLASS_MAX:
#ifdef	EQUIV_CLASS_MAX
      return EQUIV_CLASS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_EXPR_NEST_MAX:
#ifdef	EXPR_NEST_MAX
      return EXPR_NEST_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_LINE_MAX:
#ifdef	LINE_MAX
      return LINE_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_RE_DUP_MAX:
#ifdef	RE_DUP_MAX
      return RE_DUP_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_CHARCLASS_NAME_MAX:
#ifdef	CHARCLASS_NAME_MAX
      return CHARCLASS_NAME_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII:
#ifdef	_POSIX_PII
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_XTI:
#ifdef	_POSIX_PII_XTI
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_SOCKET:
#ifdef	_POSIX_PII_SOCKET
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_INTERNET:
#ifdef	_POSIX_PII_INTERNET
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_OSI:
#ifdef	_POSIX_PII_OSI
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_POLL:
#ifdef	_POSIX_POLL
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_SELECT:
#ifdef	_POSIX_SELECT
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_UIO_MAXIOV:
#ifdef	UIO_MAXIOV
      return UIO_MAXIOV;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_INTERNET_STREAM:
#ifdef	_POSIX_PII_INTERNET_STREAM
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_INTERNET_DGRAM:
#ifdef	_POSIX_PII_INTERNET_DGRAM
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_OSI_COTS:
#ifdef	_POSIX_PII_OSI_COTS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_OSI_CLTS:
#ifdef	_POSIX_PII_OSI_CLTS
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_PII_OSI_M:
#ifdef	_POSIX_PII_OSI_M
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_T_IOV_MAX:
#ifdef	_T_IOV_MAX
      return _T_IOV_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_VERSION:
      return _POSIX2_VERSION;

    case _SC_2_C_BIND:
#ifdef	_POSIX2_C_BIND
      return _POSIX2_C_BIND;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_C_DEV:
#ifdef	_POSIX2_C_DEV
      return _POSIX2_C_DEV;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_C_VERSION:
#ifdef	_POSIX2_C_VERSION
      return _POSIX2_C_VERSION;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_FORT_DEV:
#ifdef	_POSIX2_FORT_DEV
      return _POSIX2_FORT_DEV;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_FORT_RUN:
#ifdef	_POSIX2_FORT_RUN
      return _POSIX2_FORT_RUN;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_LOCALEDEF:
#ifdef	_POSIX2_LOCALEDEF
      return _POSIX2_LOCALEDEF;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_SW_DEV:
#ifdef	_POSIX2_SW_DEV
      return _POSIX2_SW_DEV;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_CHAR_TERM:
#ifdef	_POSIX2_CHAR_TERM
      return _POSIX2_CHAR_TERM;
#else
      RETURN_NEG_1;
#endif

    case _SC_2_UPE:
#ifdef	_POSIX2_UPE
      return _POSIX2_UPE;
#else
      RETURN_NEG_1;
#endif

      /* POSIX 1003.1c (POSIX Threads).  */
    case _SC_THREADS:
#ifdef __UCLIBC_HAS_THREADS__
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_SAFE_FUNCTIONS:
#ifdef __UCLIBC_HAS_THREADS__
      return 1;
#else
      RETURN_NEG_1;
#endif

/* If you change these, also change libc/pwd_grp/pwd_grp.c to match */
    case _SC_GETGR_R_SIZE_MAX:
      return __UCLIBC_GRP_BUFFER_SIZE__;

    case _SC_GETPW_R_SIZE_MAX:
      return __UCLIBC_PWD_BUFFER_SIZE__;

/* getlogin() is a worthless interface.  In uClibc we let the user specify
 * whatever they want via the LOGNAME environment variable, or we return NULL
 * if getenv() fails to find anything.  So this is merely how large a env
 * variable can be.  Lets use 256 */
    case _SC_LOGIN_NAME_MAX:
      return 256;

/* If you change this, also change _SC_TTY_NAME_MAX in libc/unistd/sysconf.c */
#define TTYNAME_BUFLEN		32
    case _SC_TTY_NAME_MAX:
      return TTYNAME_BUFLEN;

    case _SC_THREAD_DESTRUCTOR_ITERATIONS:
#ifdef	_POSIX_THREAD_DESTRUCTOR_ITERATIONS
      return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_KEYS_MAX:
#ifdef	PTHREAD_KEYS_MAX
      return PTHREAD_KEYS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_STACK_MIN:
#ifdef	PTHREAD_STACK_MIN
      return PTHREAD_STACK_MIN;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_THREADS_MAX:
#ifdef	PTHREAD_THREADS_MAX
      return PTHREAD_THREADS_MAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_ATTR_STACKADDR:
#ifdef	_POSIX_THREAD_ATTR_STACKADDR
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_ATTR_STACKSIZE:
#ifdef	_POSIX_THREAD_ATTR_STACKSIZE
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_PRIORITY_SCHEDULING:
#ifdef	_POSIX_THREAD_PRIORITY_SCHEDULING
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_PRIO_INHERIT:
#ifdef	_POSIX_THREAD_PRIO_INHERIT
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_PRIO_PROTECT:
#ifdef	_POSIX_THREAD_PRIO_PROTECT
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_THREAD_PROCESS_SHARED:
#ifdef	_POSIX_THREAD_PROCESS_SHARED
      return 1;
#else
      RETURN_NEG_1;
#endif

    case _SC_NPROCESSORS_CONF:
#if 0
      RETURN_FUNCTION(get_nprocs_conf());
#else
      /* this is a hack.  for now always claim we have exactly one cpu */
      return 1;
#endif

    case _SC_NPROCESSORS_ONLN:
#if 0
      RETURN_FUNCTION(get_nprocs());
#else
      /* this is a hack.  for now always claim we have exactly one cpu */
      return 1;
#endif

    case _SC_PHYS_PAGES:
#if 0
      RETURN_FUNCTION(get_phys_pages());
#else
      RETURN_NEG_1;
#endif

    case _SC_AVPHYS_PAGES:
#if 0
      RETURN_FUNCTION(get_avphys_pages());
#else
      RETURN_NEG_1;
#endif

    case _SC_ATEXIT_MAX:
      return __UCLIBC_MAX_ATEXIT;

    case _SC_PASS_MAX:
      /* We have no limit but since the return value might be used to
	 allocate a buffer we restrict the value.  */
      return BUFSIZ;

    case _SC_XOPEN_VERSION:
      return _XOPEN_VERSION;

    case _SC_XOPEN_XCU_VERSION:
      return _XOPEN_XCU_VERSION;

    case _SC_XOPEN_UNIX:
      return _XOPEN_UNIX;

    case _SC_XOPEN_CRYPT:
#ifdef	_XOPEN_CRYPT
      return _XOPEN_CRYPT;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_ENH_I18N:
#ifdef	_XOPEN_ENH_I18N
      return _XOPEN_ENH_I18N;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_SHM:
#ifdef	_XOPEN_SHM
      return _XOPEN_SHM;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_XPG2:
#ifdef	_XOPEN_XPG2
      return _XOPEN_XPG2;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_XPG3:
#ifdef	_XOPEN_XPG3
      return _XOPEN_XPG3;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_XPG4:
#ifdef	_XOPEN_XPG4
      return _XOPEN_XPG4;
#else
      RETURN_NEG_1;
#endif

    case _SC_CHAR_BIT:
      return CHAR_BIT;

    case _SC_CHAR_MAX:
      return CHAR_MAX;

    case _SC_CHAR_MIN:
      return CHAR_MIN;

    case _SC_INT_MAX:
      return INT_MAX;

    case _SC_INT_MIN:
      return INT_MIN;

    case _SC_LONG_BIT:
      return sizeof (long int) * CHAR_BIT;

    case _SC_WORD_BIT:
      return sizeof (int) * CHAR_BIT;

    case _SC_MB_LEN_MAX:
      return MB_LEN_MAX;

    case _SC_NZERO:
      return NZERO;

    case _SC_SSIZE_MAX:
      return _POSIX_SSIZE_MAX;

    case _SC_SCHAR_MAX:
      return SCHAR_MAX;

    case _SC_SCHAR_MIN:
      return SCHAR_MIN;

    case _SC_SHRT_MAX:
      return SHRT_MAX;

    case _SC_SHRT_MIN:
      return SHRT_MIN;

    case _SC_UCHAR_MAX:
      return UCHAR_MAX;

    case _SC_UINT_MAX:
      return UINT_MAX;

    case _SC_ULONG_MAX:
      return ULONG_MAX;

    case _SC_USHRT_MAX:
      return USHRT_MAX;

    case _SC_NL_ARGMAX:
#ifdef	NL_ARGMAX
      return NL_ARGMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_NL_LANGMAX:
#ifdef	NL_LANGMAX
      return NL_LANGMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_NL_MSGMAX:
#ifdef	NL_MSGMAX
      return NL_MSGMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_NL_NMAX:
#ifdef	NL_NMAX
      return NL_NMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_NL_SETMAX:
#ifdef	NL_SETMAX
      return NL_SETMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_NL_TEXTMAX:
#ifdef	NL_TEXTMAX
      return NL_TEXTMAX;
#else
      RETURN_NEG_1;
#endif

    case _SC_XBS5_ILP32_OFF32:
#ifdef _XBS5_ILP32_OFF32
      return _XBS5_ILP32_OFF32;
#else
      RETURN_NEG_1;
#endif
    case _SC_XBS5_ILP32_OFFBIG:
#ifdef _XBS5_ILP32_OFFBIG
      return _XBS5_ILP32_OFFBIG;
#else
      RETURN_NEG_1;
#endif
    case _SC_XBS5_LP64_OFF64:
#ifdef _XBS5_LP64_OFF64
      return _XBS5_LP64_OFF64;
#else
      RETURN_NEG_1;
#endif
    case _SC_XBS5_LPBIG_OFFBIG:
#ifdef _XBS5_LPBIG_OFFBIG
      return _XBS5_LPBIG_OFFBIG;
#else
      RETURN_NEG_1;
#endif

    case _SC_XOPEN_LEGACY:
      return _XOPEN_LEGACY;

    case _SC_XOPEN_REALTIME:
#ifdef _XOPEN_REALTIME
      return _XOPEN_REALTIME;
#else
      RETURN_NEG_1;
#endif
    case _SC_XOPEN_REALTIME_THREADS:
#ifdef _XOPEN_REALTIME_THREADS
      return _XOPEN_REALTIME_THREADS;
#else
      RETURN_NEG_1;
#endif

    case _SC_MONOTONIC_CLOCK:
#if defined __UCLIBC_HAS_REALTIME__ && defined __NR_clock_getres
      /* Check using the clock_getres system call.  */
      if (clock_getres(CLOCK_MONOTONIC, NULL) >= 0)
        return _POSIX_VERSION;
#endif

      RETURN_NEG_1;
    }
}
libc_hidden_def(sysconf)