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emacs/m4/largefile.m4
Paul Eggert c87a165040 Update from Gnulib
This incorporates:
2020-02-21 largefile: remove _DARWIN_USE_64_BIT_INODE
2020-02-21 Add ‘extern "C"’ to count-one-bits.h etc.
* lib/count-leading-zeros.h, lib/count-one-bits.h:
* lib/count-trailing-zeros.h, m4/largefile.m4: Copy from Gnulib.
2020-02-22 10:33:45 -08:00

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# Enable large files on systems where this is not the default.
# Enable support for files on Linux file systems with 64-bit inode numbers.
# Copyright 1992-1996, 1998-2020 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 macro works around a problem in Autoconf's AC_FUNC_FSEEKO:
# It does not set _LARGEFILE_SOURCE=1 on HP-UX/ia64 32-bit, although this
# setting of _LARGEFILE_SOURCE is needed so that <stdio.h> declares fseeko
# and ftello in C++ mode as well.
AC_DEFUN([gl_SET_LARGEFILE_SOURCE],
[
AC_REQUIRE([AC_CANONICAL_HOST])
AC_FUNC_FSEEKO
case "$host_os" in
hpux*)
AC_DEFINE([_LARGEFILE_SOURCE], [1],
[Define to 1 to make fseeko visible on some hosts (e.g. glibc 2.2).])
;;
esac
])
# The following implementation works around a problem in autoconf <= 2.69;
# AC_SYS_LARGEFILE does not configure for large inodes on Mac OS X 10.5,
# or configures them incorrectly in some cases.
m4_version_prereq([2.70], [] ,[
# _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], [$4]);;
esac
rm -rf conftest*[]dnl
])# _AC_SYS_LARGEFILE_MACRO_VALUE
# AC_SYS_LARGEFILE
# ----------------
# By default, many hosts won't let programs access large files;
# one must use special compiler options to get large-file access to work.
# For more details about this brain damage please see:
# http://www.unix.org/version2/whatsnew/lfs20mar.html
# Additionally, on Linux file systems with 64-bit inodes a file that happens
# to have a 64-bit inode number cannot be accessed by 32-bit applications on
# Linux x86/x86_64. This can occur with file systems such as XFS and NFS.
AC_DEFUN([AC_SYS_LARGEFILE],
[AC_ARG_ENABLE(largefile,
[ --disable-largefile omit support for large files])
if test "$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 $ac_cv_sys_file_offset_bits = unknown; then
_AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1,
ac_cv_sys_large_files,
[Define for large files, on AIX-style hosts.],
[_AC_SYS_LARGEFILE_TEST_INCLUDES])
fi
fi
])# AC_SYS_LARGEFILE
])# m4_version_prereq 2.70
# Enable large files on systems where this is implemented by Gnulib, not by the
# system headers.
# Set the variables WINDOWS_64_BIT_OFF_T, WINDOWS_64_BIT_ST_SIZE if Gnulib
# overrides ensure that off_t or 'struct size.st_size' are 64-bit, respectively.
AC_DEFUN([gl_LARGEFILE],
[
AC_REQUIRE([AC_CANONICAL_HOST])
case "$host_os" in
mingw*)
dnl Native Windows.
dnl mingw64 defines off_t to a 64-bit type already, if
dnl _FILE_OFFSET_BITS=64, which is ensured by AC_SYS_LARGEFILE.
AC_CACHE_CHECK([for 64-bit off_t], [gl_cv_type_off_t_64],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <sys/types.h>
int verify_off_t_size[sizeof (off_t) >= 8 ? 1 : -1];
]],
[[]])],
[gl_cv_type_off_t_64=yes], [gl_cv_type_off_t_64=no])
])
if test $gl_cv_type_off_t_64 = no; then
WINDOWS_64_BIT_OFF_T=1
else
WINDOWS_64_BIT_OFF_T=0
fi
dnl Some mingw versions define, if _FILE_OFFSET_BITS=64, 'struct stat'
dnl to 'struct _stat32i64' or 'struct _stat64' (depending on
dnl _USE_32BIT_TIME_T), which has a 32-bit st_size member.
AC_CACHE_CHECK([for 64-bit st_size], [gl_cv_member_st_size_64],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <sys/types.h>
struct stat buf;
int verify_st_size_size[sizeof (buf.st_size) >= 8 ? 1 : -1];
]],
[[]])],
[gl_cv_member_st_size_64=yes], [gl_cv_member_st_size_64=no])
])
if test $gl_cv_member_st_size_64 = no; then
WINDOWS_64_BIT_ST_SIZE=1
else
WINDOWS_64_BIT_ST_SIZE=0
fi
;;
*)
dnl Nothing to do on gnulib's side.
dnl A 64-bit off_t is
dnl - already the default on Mac OS X, FreeBSD, NetBSD, OpenBSD, IRIX,
dnl OSF/1, Cygwin,
dnl - enabled by _FILE_OFFSET_BITS=64 (ensured by AC_SYS_LARGEFILE) on
dnl glibc, HP-UX, Solaris,
dnl - enabled by _LARGE_FILES=1 (ensured by AC_SYS_LARGEFILE) on AIX,
dnl - impossible to achieve on Minix 3.1.8.
WINDOWS_64_BIT_OFF_T=0
WINDOWS_64_BIT_ST_SIZE=0
;;
esac
])