1# Enable large files on systems where this is not the default.
2# Enable support for files on Linux file systems with 64-bit inode numbers.
3
4# Copyright 1992-1996, 1998-2021 Free Software Foundation, Inc.
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9# The following macro works around a problem in Autoconf's AC_FUNC_FSEEKO:
10# It does not set _LARGEFILE_SOURCE=1 on HP-UX/ia64 32-bit, although this
11# setting of _LARGEFILE_SOURCE is needed so that <stdio.h> declares fseeko
12# and ftello in C++ mode as well.
13AC_DEFUN([gl_SET_LARGEFILE_SOURCE],
14[
15  AC_REQUIRE([AC_CANONICAL_HOST])
16  AC_FUNC_FSEEKO
17  case "$host_os" in
18    hpux*)
19      AC_DEFINE([_LARGEFILE_SOURCE], [1],
20        [Define to 1 to make fseeko visible on some hosts (e.g. glibc 2.2).])
21      ;;
22  esac
23])
24
25# The following implementation works around a problem in autoconf <= 2.69;
26# AC_SYS_LARGEFILE does not configure for large inodes on Mac OS X 10.5,
27# or configures them incorrectly in some cases.
28m4_version_prereq([2.70], [], [
29
30# _AC_SYS_LARGEFILE_TEST_INCLUDES
31# -------------------------------
32m4_define([_AC_SYS_LARGEFILE_TEST_INCLUDES],
33[#include <sys/types.h>
34 /* Check that off_t can represent 2**63 - 1 correctly.
35    We can't simply define LARGE_OFF_T to be 9223372036854775807,
36    since some C++ compilers masquerading as C compilers
37    incorrectly reject 9223372036854775807.  */
38#define LARGE_OFF_T (((off_t) 1 << 31 << 31) - 1 + ((off_t) 1 << 31 << 31))
39  int off_t_is_large[[(LARGE_OFF_T % 2147483629 == 721
40                       && LARGE_OFF_T % 2147483647 == 1)
41                      ? 1 : -1]];[]dnl
42])
43
44
45# _AC_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE,
46#                               CACHE-VAR,
47#                               DESCRIPTION,
48#                               PROLOGUE, [FUNCTION-BODY])
49# --------------------------------------------------------
50m4_define([_AC_SYS_LARGEFILE_MACRO_VALUE],
51[AC_CACHE_CHECK([for $1 value needed for large files], [$3],
52[while :; do
53  m4_ifval([$6], [AC_LINK_IFELSE], [AC_COMPILE_IFELSE])(
54    [AC_LANG_PROGRAM([$5], [$6])],
55    [$3=no; break])
56  m4_ifval([$6], [AC_LINK_IFELSE], [AC_COMPILE_IFELSE])(
57    [AC_LANG_PROGRAM([#define $1 $2
58$5], [$6])],
59    [$3=$2; break])
60  $3=unknown
61  break
62done])
63case $$3 in #(
64  no | unknown) ;;
65  *) AC_DEFINE_UNQUOTED([$1], [$$3], [$4]);;
66esac
67rm -rf conftest*[]dnl
68])# _AC_SYS_LARGEFILE_MACRO_VALUE
69
70
71# AC_SYS_LARGEFILE
72# ----------------
73# By default, many hosts won't let programs access large files;
74# one must use special compiler options to get large-file access to work.
75# For more details about this brain damage please see:
76# http://www.unix.org/version2/whatsnew/lfs20mar.html
77# Additionally, on Linux file systems with 64-bit inodes a file that happens
78# to have a 64-bit inode number cannot be accessed by 32-bit applications on
79# Linux x86/x86_64.  This can occur with file systems such as XFS and NFS.
80AC_DEFUN([AC_SYS_LARGEFILE],
81[AC_ARG_ENABLE(largefile,
82               [  --disable-largefile     omit support for large files])
83if test "$enable_largefile" != no; then
84
85  AC_CACHE_CHECK([for special C compiler options needed for large files],
86    ac_cv_sys_largefile_CC,
87    [ac_cv_sys_largefile_CC=no
88     if test "$GCC" != yes; then
89       ac_save_CC=$CC
90       while :; do
91         # IRIX 6.2 and later do not support large files by default,
92         # so use the C compiler's -n32 option if that helps.
93         AC_LANG_CONFTEST([AC_LANG_PROGRAM([_AC_SYS_LARGEFILE_TEST_INCLUDES])])
94         AC_COMPILE_IFELSE([], [break])
95         CC="$CC -n32"
96         AC_COMPILE_IFELSE([], [ac_cv_sys_largefile_CC=' -n32'; break])
97         break
98       done
99       CC=$ac_save_CC
100       rm -f conftest.$ac_ext
101    fi])
102  if test "$ac_cv_sys_largefile_CC" != no; then
103    CC=$CC$ac_cv_sys_largefile_CC
104  fi
105
106  _AC_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64,
107    ac_cv_sys_file_offset_bits,
108    [Number of bits in a file offset, on hosts where this is settable.],
109    [_AC_SYS_LARGEFILE_TEST_INCLUDES])
110  if test $ac_cv_sys_file_offset_bits = unknown; then
111    _AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1,
112      ac_cv_sys_large_files,
113      [Define for large files, on AIX-style hosts.],
114      [_AC_SYS_LARGEFILE_TEST_INCLUDES])
115  fi
116fi
117])# AC_SYS_LARGEFILE
118])# m4_version_prereq 2.70
119
120# Enable large files on systems where this is implemented by Gnulib, not by the
121# system headers.
122# Set the variables WINDOWS_64_BIT_OFF_T, WINDOWS_64_BIT_ST_SIZE if Gnulib
123# overrides ensure that off_t or 'struct size.st_size' are 64-bit, respectively.
124AC_DEFUN([gl_LARGEFILE],
125[
126  AC_REQUIRE([AC_CANONICAL_HOST])
127  case "$host_os" in
128    mingw*)
129      dnl Native Windows.
130      dnl mingw64 defines off_t to a 64-bit type already, if
131      dnl _FILE_OFFSET_BITS=64, which is ensured by AC_SYS_LARGEFILE.
132      AC_CACHE_CHECK([for 64-bit off_t], [gl_cv_type_off_t_64],
133        [AC_COMPILE_IFELSE(
134           [AC_LANG_PROGRAM(
135              [[#include <sys/types.h>
136                int verify_off_t_size[sizeof (off_t) >= 8 ? 1 : -1];
137              ]],
138              [[]])],
139           [gl_cv_type_off_t_64=yes], [gl_cv_type_off_t_64=no])
140        ])
141      if test $gl_cv_type_off_t_64 = no; then
142        WINDOWS_64_BIT_OFF_T=1
143      else
144        WINDOWS_64_BIT_OFF_T=0
145      fi
146      dnl Some mingw versions define, if _FILE_OFFSET_BITS=64, 'struct stat'
147      dnl to 'struct _stat32i64' or 'struct _stat64' (depending on
148      dnl _USE_32BIT_TIME_T), which has a 32-bit st_size member.
149      AC_CACHE_CHECK([for 64-bit st_size], [gl_cv_member_st_size_64],
150        [AC_COMPILE_IFELSE(
151           [AC_LANG_PROGRAM(
152              [[#include <sys/types.h>
153                struct stat buf;
154                int verify_st_size_size[sizeof (buf.st_size) >= 8 ? 1 : -1];
155              ]],
156              [[]])],
157           [gl_cv_member_st_size_64=yes], [gl_cv_member_st_size_64=no])
158        ])
159      if test $gl_cv_member_st_size_64 = no; then
160        WINDOWS_64_BIT_ST_SIZE=1
161      else
162        WINDOWS_64_BIT_ST_SIZE=0
163      fi
164      ;;
165    *)
166      dnl Nothing to do on gnulib's side.
167      dnl A 64-bit off_t is
168      dnl   - already the default on Mac OS X, FreeBSD, NetBSD, OpenBSD, IRIX,
169      dnl     OSF/1, Cygwin,
170      dnl   - enabled by _FILE_OFFSET_BITS=64 (ensured by AC_SYS_LARGEFILE) on
171      dnl     glibc, HP-UX, Solaris,
172      dnl   - enabled by _LARGE_FILES=1 (ensured by AC_SYS_LARGEFILE) on AIX,
173      dnl   - impossible to achieve on Minix 3.1.8.
174      WINDOWS_64_BIT_OFF_T=0
175      WINDOWS_64_BIT_ST_SIZE=0
176      ;;
177  esac
178])
179