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emacs/m4/largefile.m4
2011-09-03 16:08:32 -07:00

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# Enable large files on systems where this is not the default.
# Copyright 1992-1996, 1998-2011 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.
# The following implementation works around a problem in autoconf <= 2.68;
# AC_SYS_LARGEFILE does not configure for large inodes on Mac OS X 10.5.
m4_version_prereq([2.69], [] ,[
# _AC_SYS_LARGEFILE_TEST_INCLUDES
# -------------------------------
m4_define([_AC_SYS_LARGEFILE_TEST_INCLUDES],
[@%:@include <sys/types.h>
/* Check that off_t can represent 2**63 - 1 correctly.
We can't simply define LARGE_OFF_T to be 9223372036854775807,
since some C++ compilers masquerading as C compilers
incorrectly reject 9223372036854775807. */
@%:@define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
int off_t_is_large[[(LARGE_OFF_T % 2147483629 == 721
&& LARGE_OFF_T % 2147483647 == 1)
? 1 : -1]];[]dnl
])
# _AC_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE,
# CACHE-VAR,
# DESCRIPTION,
# PROLOGUE, [FUNCTION-BODY])
# --------------------------------------------------------
m4_define([_AC_SYS_LARGEFILE_MACRO_VALUE],
[AC_CACHE_CHECK([for $1 value needed for large files], [$3],
[while :; do
m4_ifval([$6], [AC_LINK_IFELSE], [AC_COMPILE_IFELSE])(
[AC_LANG_PROGRAM([$5], [$6])],
[$3=no; break])
m4_ifval([$6], [AC_LINK_IFELSE], [AC_COMPILE_IFELSE])(
[AC_LANG_PROGRAM([@%:@define $1 $2
$5], [$6])],
[$3=$2; break])
$3=unknown
break
done])
case $$3 in #(
no | unknown) ;;
*) AC_DEFINE_UNQUOTED([$1], [$$3], [$4]);;
esac
rm -rf conftest*[]dnl
])# _AC_SYS_LARGEFILE_MACRO_VALUE
# AC_SYS_LARGEFILE
# ----------------
# By default, many hosts won't let programs access large files;
# one must use special compiler options to get large-file access to work.
# For more details about this brain damage please see:
# http://www.unix-systems.org/version2/whatsnew/lfs20mar.html
AC_DEFUN([AC_SYS_LARGEFILE],
[AC_ARG_ENABLE(largefile,
[ --disable-largefile omit support for large files])
if test "$enable_largefile" != no; then
AC_CACHE_CHECK([for special C compiler options needed for large files],
ac_cv_sys_largefile_CC,
[ac_cv_sys_largefile_CC=no
if test "$GCC" != yes; then
ac_save_CC=$CC
while :; do
# IRIX 6.2 and later do not support large files by default,
# so use the C compiler's -n32 option if that helps.
AC_LANG_CONFTEST([AC_LANG_PROGRAM([_AC_SYS_LARGEFILE_TEST_INCLUDES])])
AC_COMPILE_IFELSE([], [break])
CC="$CC -n32"
AC_COMPILE_IFELSE([], [ac_cv_sys_largefile_CC=' -n32'; break])
break
done
CC=$ac_save_CC
rm -f conftest.$ac_ext
fi])
if test "$ac_cv_sys_largefile_CC" != no; then
CC=$CC$ac_cv_sys_largefile_CC
fi
_AC_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64,
ac_cv_sys_file_offset_bits,
[Number of bits in a file offset, on hosts where this is settable.],
[_AC_SYS_LARGEFILE_TEST_INCLUDES])
if test $ac_cv_sys_file_offset_bits = unknown; then
_AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1,
ac_cv_sys_large_files,
[Define for large files, on AIX-style hosts.],
[_AC_SYS_LARGEFILE_TEST_INCLUDES])
fi
AH_VERBATIM([_DARWIN_USE_64_BIT_INODE],
[/* Enable large inode numbers on Mac OS X. */
#ifndef _DARWIN_USE_64_BIT_INODE
# define _DARWIN_USE_64_BIT_INODE 1
#endif])
fi
])# AC_SYS_LARGEFILE
])# m4_version_prereq 2.69