emacs/m4/fsusage.m4

# serial 35
# Obtaining file system usage information.

# Copyright (C) 1997-1998, 2000-2001, 2003-2023 Free Software Foundation, Inc.
#
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

# Written by Jim Meyering.

AC_DEFUN([gl_FSUSAGE],
[
  AC_CHECK_HEADERS_ONCE([sys/param.h])
  AC_CHECK_HEADERS_ONCE([sys/vfs.h sys/fs_types.h])
  AC_CHECK_HEADERS([sys/mount.h], [], [],
    [AC_INCLUDES_DEFAULT
     [#if HAVE_SYS_PARAM_H
       #include <sys/param.h>
      #endif]])
  gl_FILE_SYSTEM_USAGE([gl_cv_fs_space=yes], [gl_cv_fs_space=no])
])

# Try to determine how a program can obtain file system usage information.
# If successful, define the appropriate symbol (see fsusage.c) and
# execute ACTION-IF-FOUND.  Otherwise, execute ACTION-IF-NOT-FOUND.
#
# gl_FILE_SYSTEM_USAGE([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])

AC_DEFUN([gl_FILE_SYSTEM_USAGE],
[
  dnl Enable large-file support. This has the effect of changing the size
  dnl of field f_blocks in 'struct statvfs' from 32 bit to 64 bit on
  dnl glibc/Hurd, HP-UX 11, Solaris (32-bit mode). It also changes the size
  dnl of field f_blocks in 'struct statfs' from 32 bit to 64 bit on
  dnl Mac OS X >= 10.5 (32-bit mode).
  AC_REQUIRE([AC_SYS_LARGEFILE])

  ac_fsusage_space=no

  # Perform only the link test since it seems there are no variants of the
  # statvfs function.  This check is more than just AC_CHECK_FUNCS([statvfs])
  # because that got a false positive on SCO OSR5.  Adding the declaration
  # of a 'struct statvfs' causes this test to fail (as it should) on such
  # systems.  That system is reported to work fine with STAT_STATFS4 which
  # is what it gets when this test fails.
  if test $ac_fsusage_space = no; then
    # glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
    # OpenBSD >= 4.4, AIX, HP-UX, IRIX, Solaris, Cygwin, Interix, BeOS.
    AC_CACHE_CHECK([for statvfs function (SVR4)],
      [fu_cv_sys_stat_statvfs],
      [AC_LINK_IFELSE(
         [AC_LANG_PROGRAM([[
#include <sys/types.h>
#ifdef __osf__
"Do not use Tru64's statvfs implementation"
#endif

#include <sys/statvfs.h>

struct statvfs fsd;

#if defined __APPLE__ && defined __MACH__
#include <limits.h>
/* On Mac OS X >= 10.5, f_blocks in 'struct statvfs' is a 32-bit quantity;
   that commonly limits file systems to 4 TiB.  Whereas f_blocks in
   'struct statfs' is a 64-bit type, thanks to the large-file support
   that was enabled above.  In this case, don't use statvfs(); use statfs()
   instead.  */
int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
#endif
]],
            [[statvfs (0, &fsd);]])],
         [fu_cv_sys_stat_statvfs=yes],
         [fu_cv_sys_stat_statvfs=no])
      ])
    if test $fu_cv_sys_stat_statvfs = yes; then
      ac_fsusage_space=yes
      # AIX >= 5.2 has statvfs64 that has a wider f_blocks field than statvfs.
      # glibc, HP-UX, IRIX, Solaris have statvfs64 as well, but on these systems
      # statvfs with large-file support is already equivalent to statvfs64.
      AC_CACHE_CHECK([whether to use statvfs64],
        [fu_cv_sys_stat_statvfs64],
        [AC_LINK_IFELSE(
           [AC_LANG_PROGRAM(
              [[#include <sys/types.h>
                #include <sys/statvfs.h>
                struct statvfs64 fsd;
                int check_f_blocks_larger_in_statvfs64
                  [sizeof (((struct statvfs64 *) 0)->f_blocks)
                   > sizeof (((struct statvfs *) 0)->f_blocks)
                   ? 1 : -1];
              ]],
              [[statvfs64 (0, &fsd);]])],
           [fu_cv_sys_stat_statvfs64=yes],
           [fu_cv_sys_stat_statvfs64=no])
        ])
      if test $fu_cv_sys_stat_statvfs64 = yes; then
        AC_DEFINE([STAT_STATVFS64], [1],
          [Define if statvfs64 should be preferred over statvfs.])
      else
        AC_DEFINE([STAT_STATVFS], [1],
          [Define if there is a function named statvfs.  (SVR4)])
      fi
    fi
  fi

  # Check for this unconditionally so we have a
  # good fallback on glibc/Linux > 2.6 < 2.6.36
  AC_CACHE_CHECK([for two-argument statfs with statfs.f_frsize member],
    [fu_cv_sys_stat_statfs2_frsize],
    [AC_RUN_IFELSE(
       [AC_LANG_SOURCE([[
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#ifdef HAVE_SYS_VFS_H
#include <sys/vfs.h>
#endif
  int
  main ()
  {
    struct statfs fsd;
    fsd.f_frsize = 0;
    return statfs (".", &fsd) != 0;
  }]])],
       [fu_cv_sys_stat_statfs2_frsize=yes],
       [fu_cv_sys_stat_statfs2_frsize=no],
       [fu_cv_sys_stat_statfs2_frsize=no])
    ])
  if test $fu_cv_sys_stat_statfs2_frsize = yes; then
    ac_fsusage_space=yes
    AC_DEFINE([STAT_STATFS2_FRSIZE], [1],
      [Define if statfs takes 2 args and struct statfs has a field named f_frsize.
       (glibc/Linux > 2.6)])
  fi

  if test $ac_fsusage_space = no; then
    # DEC Alpha running OSF/1
    AC_CACHE_CHECK([for 3-argument statfs function (DEC OSF/1)],
      [fu_cv_sys_stat_statfs3_osf1],
      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <sys/param.h>
#include <sys/types.h>
#include <sys/mount.h>
  int
  main ()
  {
    struct statfs fsd;
    fsd.f_fsize = 0;
    return statfs (".", &fsd, sizeof (struct statfs)) != 0;
  }]])],
         [fu_cv_sys_stat_statfs3_osf1=yes],
         [fu_cv_sys_stat_statfs3_osf1=no],
         [fu_cv_sys_stat_statfs3_osf1=no])
      ])
    if test $fu_cv_sys_stat_statfs3_osf1 = yes; then
      ac_fsusage_space=yes
      AC_DEFINE([STAT_STATFS3_OSF1], [1],
        [Define if statfs takes 3 args.  (DEC Alpha running OSF/1)])
    fi
  fi

  if test $ac_fsusage_space = no; then
    # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
    # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
    # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
    # (On IRIX you need to include <sys/statfs.h>, not only <sys/mount.h> and
    # <sys/vfs.h>.)
    # (On Solaris, statfs has 4 arguments.)
    AC_CACHE_CHECK([for two-argument statfs with statfs.f_bsize member (AIX, 4.3BSD)],
      [fu_cv_sys_stat_statfs2_bsize],
      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#ifdef HAVE_SYS_VFS_H
#include <sys/vfs.h>
#endif
  int
  main ()
  {
    struct statfs fsd;
    fsd.f_bsize = 0;
    return statfs (".", &fsd) != 0;
  }]])],
         [fu_cv_sys_stat_statfs2_bsize=yes],
         [fu_cv_sys_stat_statfs2_bsize=no],
         [fu_cv_sys_stat_statfs2_bsize=no])
      ])
    if test $fu_cv_sys_stat_statfs2_bsize = yes; then
      ac_fsusage_space=yes
      AC_DEFINE([STAT_STATFS2_BSIZE], [1],
        [Define if statfs takes 2 args and struct statfs has a field named f_bsize.
         (4.3BSD, SunOS 4, HP-UX)])
    fi
  fi

  if test $ac_fsusage_space = no; then
    # SVR3
    # (Solaris already handled above.)
    AC_CACHE_CHECK([for four-argument statfs (SVR3)],
      [fu_cv_sys_stat_statfs4],
      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <sys/types.h>
#include <sys/statfs.h>
  int
  main ()
  {
    struct statfs fsd;
    return statfs (".", &fsd, sizeof fsd, 0) != 0;
  }]])],
         [fu_cv_sys_stat_statfs4=yes],
         [fu_cv_sys_stat_statfs4=no],
         [fu_cv_sys_stat_statfs4=no])
      ])
    if test $fu_cv_sys_stat_statfs4 = yes; then
      ac_fsusage_space=yes
      AC_DEFINE([STAT_STATFS4], [1],
        [Define if statfs takes 4 args.  (SVR3, old Irix)])
    fi
  fi

  if test $ac_fsusage_space = no; then
    # 4.4BSD and older NetBSD
    # (OSF/1 already handled above.)
    # (On AIX, you need to include <sys/statfs.h>, not only <sys/mount.h>.)
    # (On Solaris, statfs has 4 arguments and 'struct statfs' is not declared in
    # <sys/mount.h>.)
    AC_CACHE_CHECK([for two-argument statfs with statfs.f_fsize member (4.4BSD and NetBSD)],
      [fu_cv_sys_stat_statfs2_fsize],
      [AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <sys/types.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
  int
  main ()
  {
    struct statfs fsd;
    fsd.f_fsize = 0;
    return statfs (".", &fsd) != 0;
  }]])],
         [fu_cv_sys_stat_statfs2_fsize=yes],
         [fu_cv_sys_stat_statfs2_fsize=no],
         [fu_cv_sys_stat_statfs2_fsize=no])
      ])
    if test $fu_cv_sys_stat_statfs2_fsize = yes; then
      ac_fsusage_space=yes
      AC_DEFINE([STAT_STATFS2_FSIZE], [1],
        [Define if statfs takes 2 args and struct statfs has a field named f_fsize.
         (4.4BSD, NetBSD)])
    fi
  fi

  AS_IF([test $ac_fsusage_space = yes], [$1], [$2])

])


# Check for SunOS statfs brokenness wrt partitions 2GB and larger.
# If <sys/vfs.h> exists and struct statfs has a member named f_spare,
# enable the workaround code in fsusage.c.
AC_DEFUN([gl_STATFS_TRUNCATES],
[
  AC_CACHE_CHECK([for statfs that truncates block counts],
    [fu_cv_sys_truncating_statfs],
    [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM([[
#if !defined(sun) && !defined(__sun)
choke -- this is a workaround for a Sun-specific problem
#endif
#include <sys/types.h>
#include <sys/vfs.h>
         ]],
         [[struct statfs t; long c = *(t.f_spare);
           if (c) return 0;
         ]])],
       [fu_cv_sys_truncating_statfs=yes],
       [fu_cv_sys_truncating_statfs=no])
    ])
  if test $fu_cv_sys_truncating_statfs = yes; then
    AC_DEFINE([STATFS_TRUNCATES_BLOCK_COUNTS], [1],
      [Define if the block counts reported by statfs may be truncated to 2GB
       and the correct values may be stored in the f_spare array.
       (SunOS 4.1.2, 4.1.3, and 4.1.3_U1 are reported to have this problem.
       SunOS 4.1.1 seems not to be affected.)])
  fi
])


# Prerequisites of lib/fsusage.c not done by gl_FILE_SYSTEM_USAGE.
AC_DEFUN([gl_PREREQ_FSUSAGE_EXTRA],
[
  AC_CHECK_HEADERS([sys/fs/s5param.h sys/statfs.h])
  gl_STATFS_TRUNCATES
])