# largefile.m4 # serial 1 dnl Copyright 1992-1996, 1998-2024 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. # Enable large files on systems where this is not the default. # Enable support for files on Linux file systems with 64-bit inode numbers. # 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 declares fseeko # and ftello in C++ mode as well. # This problem occurs in Autoconf 2.71 and earlier, which lack AC_SYS_YEAR2038. AC_DEFUN([gl_SET_LARGEFILE_SOURCE], m4_ifndef([AC_SYS_YEAR2038], [[ 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 ]]) ) dnl Remove AC_SYS_YEAR2038_RECOMMENDED if unpatched Autoconf 2.72 or earlier. dnl Autoconf 2.72 still uses -n32, which is not a C preprocessor option, dnl and which was useful only on IRIX which is no longer supported. dnl This should be fixed in Autoconf 2.73. m4_ifdef([AC_SYS_YEAR2038_RECOMMENDED], [m4_bmatch(m4_ifdef([_AC_SYS_LARGEFILE_OPTIONS], [m4_defn([_AC_SYS_LARGEFILE_OPTIONS])], ["-n32"]), ["-n32"], [m4_undefine([AC_SYS_YEAR2038_RECOMMENDED])])]) m4_ifndef([AC_SYS_YEAR2038_RECOMMENDED], [ # Fix up AC_SYS_YEAR2038_RECOMMENDED and related macros, even if # unpatched Autoconf 2.72 or earlier. This code is taken from Autoconf master. # _AC_SYS_YEAR2038_TEST_CODE # -------------------------- # C code used to probe for time_t that can represent time points more # than 2**31 - 1 seconds after the epoch. With the usual Unix epoch, # these correspond to dates after 2038-01-18 22:14:07 +0000 (Gregorian), # hence the name. AC_DEFUN([_AC_SYS_YEAR2038_TEST_CODE], [[ #include /* Check that time_t can represent 2**32 - 1 correctly. */ #define LARGE_TIME_T \\ ((time_t) (((time_t) 1 << 30) - 1 + 3 * ((time_t) 1 << 30))) int verify_time_t_range[(LARGE_TIME_T / 65537 == 65535 && LARGE_TIME_T % 65537 == 0) ? 1 : -1]; ]]) # _AC_SYS_YEAR2038_OPTIONS # ------------------------ # List of known ways to enable support for large time_t. If you change # this list you probably also need to change the AS_CASE at the end of # _AC_SYS_YEAR2038_PROBE. m4_define([_AC_SYS_YEAR2038_OPTIONS], m4_normalize( ["none needed"] dnl 64-bit and newer 32-bit Unix ["-D_TIME_BITS=64"] dnl glibc 2.34 with some 32-bit ABIs ["-D__MINGW_USE_VC2005_COMPAT"] dnl 32-bit MinGW ["-U_USE_32_BIT_TIME_T -D__MINGW_USE_VC2005_COMPAT"] dnl 32-bit MinGW (misconfiguration) )) # _AC_SYS_YEAR2038_PROBE # ---------------------- # Subroutine of AC_SYS_YEAR2038. Probe for time_t that can represent # time points more than 2**31 - 1 seconds after the epoch (dates after # 2038-01-18, see above) and set the cache variable ac_cv_sys_year2038_opts # to one of the values in the _AC_SYS_YEAR2038_OPTIONS list, or to # "support not detected" if none of them worked. Then, set compilation # options and #defines as necessary to enable large time_t support. # # Note that we do not test whether mktime, localtime, etc. handle # large values of time_t correctly, as that would require use of # AC_TRY_RUN. Note also that some systems only support large time_t # together with large off_t. # # If you change this macro you may also need to change # _AC_SYS_YEAR2038_OPTIONS. AC_DEFUN([_AC_SYS_YEAR2038_PROBE], [AC_CACHE_CHECK([for $CPPFLAGS option for timestamps after 2038], [ac_cv_sys_year2038_opts], [ac_save_CPPFLAGS="$CPPFLAGS" ac_opt_found=no for ac_opt in _AC_SYS_YEAR2038_OPTIONS; do AS_IF([test x"$ac_opt" != x"none needed"], [CPPFLAGS="$ac_save_CPPFLAGS $ac_opt"]) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([_AC_SYS_YEAR2038_TEST_CODE])], [ac_cv_sys_year2038_opts="$ac_opt" ac_opt_found=yes]) test $ac_opt_found = no || break done CPPFLAGS="$ac_save_CPPFLAGS" test $ac_opt_found = yes || ac_cv_sys_year2038_opts="support not detected"]) ac_have_year2038=yes AS_CASE([$ac_cv_sys_year2038_opts], ["none needed"], [], ["support not detected"], [ac_have_year2038=no], ["-D_TIME_BITS=64"], [AC_DEFINE([_TIME_BITS], [64], [Number of bits in time_t, on hosts where this is settable.])], ["-D__MINGW_USE_VC2005_COMPAT"], [AC_DEFINE([__MINGW_USE_VC2005_COMPAT], [1], [Define to 1 on platforms where this makes time_t a 64-bit type.])], ["-U_USE_32_BIT_TIME_T"*], [AC_MSG_FAILURE(m4_text_wrap( [the 'time_t' type is currently forced to be 32-bit. It will stop working after mid-January 2038. Remove _USE_32BIT_TIME_T from the compiler flags.], [], [], [55]))], [AC_MSG_ERROR( [internal error: bad value for \$ac_cv_sys_year2038_opts])]) ]) # _AC_SYS_YEAR2038_ENABLE # ----------------------- # Depending on which of the YEAR2038 macros was used, add either an # --enable-year2038 or a --disable-year2038 to # the configure script. This is expanded very late and # therefore there cannot be any code in the AC_ARG_ENABLE. The # default value for 'enable_year2038' is emitted unconditionally # because the generated code always looks at this variable. m4_define([_AC_SYS_YEAR2038_ENABLE], [m4_divert_text([DEFAULTS], m4_provide_if([AC_SYS_YEAR2038], [enable_year2038=yes], [enable_year2038=no]))]dnl [AC_ARG_ENABLE([year2038], m4_provide_if([AC_SYS_YEAR2038], [AS_HELP_STRING([--disable-year2038], [don't support timestamps after 2038])], [AS_HELP_STRING([--enable-year2038], [support timestamps after 2038])]))]) # AC_SYS_YEAR2038 # --------------- # Attempt to detect and activate support for large time_t. # On systems where time_t is not always 64 bits, this probe can be # skipped by passing the --disable-year2038 option to configure. AC_DEFUN([AC_SYS_YEAR2038], [AC_REQUIRE([AC_SYS_LARGEFILE])dnl AS_IF([test "$enable_year2038,$ac_have_year2038,$cross_compiling" = yes,no,no], [# If we're not cross compiling and 'touch' works with a large # timestamp, then we can presume the system supports wider time_t # *somehow* and we just weren't able to detect it. One common # case that we deliberately *don't* probe for is a system that # supports both 32- and 64-bit ABIs but only the 64-bit ABI offers # wide time_t. (It would be inappropriate for us to override an # intentional use of -m32.) Error out, demanding use of # --disable-year2038 if this is intentional. AS_IF([TZ=UTC0 touch -t 210602070628.15 conftest.time 2>/dev/null], [AS_CASE([`TZ=UTC0 LC_ALL=C ls -l conftest.time 2>/dev/null`], [*'Feb 7 2106'* | *'Feb 7 17:10'*], [AC_MSG_FAILURE(m4_text_wrap( [this system appears to support timestamps after mid-January 2038, but no mechanism for enabling wide 'time_t' was detected. Did you mean to build a 64-bit binary? (E.g., 'CC="${CC} -m64"'.) To proceed with 32-bit time_t, configure with '--disable-year2038'.], [], [], [55]))])])])]) # AC_SYS_YEAR2038_RECOMMENDED # --------------------------- # Same as AC_SYS_YEAR2038, but recommend support for large time_t. # If we cannot find any way to make time_t capable of representing # values larger than 2**31 - 1, error out unless --disable-year2038 is given. AC_DEFUN([AC_SYS_YEAR2038_RECOMMENDED], [AC_REQUIRE([AC_SYS_YEAR2038])dnl AS_IF([test "$enable_year2038,$ac_have_year2038" = yes,no], [AC_MSG_FAILURE(m4_text_wrap( [could not enable timestamps after mid-January 2038. This package recommends support for these later timestamps. However, to proceed with signed 32-bit time_t even though it will fail then, configure with '--disable-year2038'.], [], [], [55]))])]) # _AC_SYS_LARGEFILE_TEST_CODE # --------------------------- # C code used to probe for large file support. m4_define([_AC_SYS_LARGEFILE_TEST_CODE], [@%:@include @%:@ifndef FTYPE @%:@ define FTYPE off_t @%:@endif /* Check that FTYPE can represent 2**63 - 1 correctly. We can't simply define LARGE_FTYPE to be 9223372036854775807, since some C++ compilers masquerading as C compilers incorrectly reject 9223372036854775807. */ @%:@define LARGE_FTYPE (((FTYPE) 1 << 31 << 31) - 1 + ((FTYPE) 1 << 31 << 31)) int FTYPE_is_large[[(LARGE_FTYPE % 2147483629 == 721 && LARGE_FTYPE % 2147483647 == 1) ? 1 : -1]];[]dnl ]) # Defined by Autoconf 2.71 and circa 2022 Gnulib unwisely depended on it. m4_define([_AC_SYS_LARGEFILE_TEST_INCLUDES], [_AC_SYS_LARGEFILE_TEST_CODE]) # _AC_SYS_LARGEFILE_OPTIONS # ------------------------- # List of known ways to enable support for large files. If you change # this list you probably also need to change the AS_CASE at the end of # _AC_SYS_LARGEFILE_PROBE. m4_define([_AC_SYS_LARGEFILE_OPTIONS], m4_normalize( ["none needed"] dnl Most current systems ["-D_FILE_OFFSET_BITS=64"] dnl X/Open LFS spec ["-D_LARGE_FILES=1"] dnl 32-bit AIX 4.2.1+, 32-bit z/OS )) # _AC_SYS_LARGEFILE_PROBE # ----------------------- # Subroutine of AC_SYS_LARGEFILE. Probe for large file support and set # the cache variable ac_cv_sys_largefile_opts to one of the values in # the _AC_SYS_LARGEFILE_OPTIONS list, or to "support not detected" if # none of the options in that list worked. Then, set compilation # options and #defines as necessary to enable large file support. # # If large file support is not detected, the behavior depends on which of # the top-level AC_SYS_LARGEFILE macros was used (see below). # # If you change this macro you may also need to change # _AC_SYS_LARGEFILE_OPTIONS. AC_DEFUN([_AC_SYS_LARGEFILE_PROBE], [AC_CACHE_CHECK([for $CPPFLAGS option for large files], [ac_cv_sys_largefile_opts], [ac_save_CPPFLAGS=$CPPFLAGS ac_opt_found=no for ac_opt in _AC_SYS_LARGEFILE_OPTIONS; do AS_IF([test x"$ac_opt" != x"none needed"], [CPPFLAGS="$ac_save_CPPFLAGS $ac_opt"]) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([_AC_SYS_LARGEFILE_TEST_CODE])], [AS_IF([test x"$ac_opt" = x"none needed"], [# GNU/Linux s390x and alpha need _FILE_OFFSET_BITS=64 for wide ino_t. CPPFLAGS="$CPPFLAGS -DFTYPE=ino_t" AC_COMPILE_IFELSE([], [], [CPPFLAGS="$CPPFLAGS -D_FILE_OFFSET_BITS=64" AC_COMPILE_IFELSE([], [ac_opt='-D_FILE_OFFSET_BITS=64'])])]) ac_cv_sys_largefile_opts=$ac_opt ac_opt_found=yes]) test $ac_opt_found = no || break done CPPFLAGS=$ac_save_CPPFLAGS dnl Gnulib implements large file support for native Windows, based on the dnl variables WINDOWS_64_BIT_OFF_T, WINDOWS_64_BIT_ST_SIZE. m4_ifdef([gl_LARGEFILE], [ AC_REQUIRE([AC_CANONICAL_HOST]) if test $ac_opt_found != yes; then AS_CASE([$host_os], [mingw* | windows*], [ac_cv_sys_largefile_opts="supported through gnulib" ac_opt_found=yes] ) fi ]) test $ac_opt_found = yes || ac_cv_sys_largefile_opts="support not detected"]) ac_have_largefile=yes AS_CASE([$ac_cv_sys_largefile_opts], ["none needed"], [], ["supported through gnulib"], [], ["support not detected"], [ac_have_largefile=no], ["-D_FILE_OFFSET_BITS=64"], [AC_DEFINE([_FILE_OFFSET_BITS], [64], [Number of bits in a file offset, on hosts where this is settable.])], ["-D_LARGE_FILES=1"], [AC_DEFINE([_LARGE_FILES], [1], [Define to 1 on platforms where this makes off_t a 64-bit type.])], [AC_MSG_ERROR( [internal error: bad value for \$ac_cv_sys_largefile_opts])]) AS_IF([test "$enable_year2038" != no], [_AC_SYS_YEAR2038_PROBE]) AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])]) # AC_SYS_LARGEFILE # ---------------- # By default, many hosts won't let programs access large files; # one must use special compiler options to get large-file access to work. # For more details about this brain damage please see: # http://www.unix.org/version2/whatsnew/lfs20mar.html # Additionally, on Linux file systems with 64-bit inodes a file that happens # to have a 64-bit inode number cannot be accessed by 32-bit applications on # Linux x86/x86_64. This can occur with file systems such as XFS and NFS. AC_DEFUN([AC_SYS_LARGEFILE], [AC_ARG_ENABLE([largefile], [AS_HELP_STRING([--disable-largefile], [omit support for large files])])dnl AS_IF([test "$enable_largefile,$enable_year2038" != no,no], [_AC_SYS_LARGEFILE_PROBE])]) ])# m4_ifndef AC_SYS_YEAR2038_RECOMMENDED # Enable large files on systems where this is implemented by Gnulib, not by the # system headers. # Set the variables WINDOWS_64_BIT_OFF_T, WINDOWS_64_BIT_ST_SIZE if Gnulib # overrides ensure that off_t or 'struct size.st_size' are 64-bit, respectively. AC_DEFUN([gl_LARGEFILE], [ AC_REQUIRE([AC_CANONICAL_HOST]) case "$host_os" in mingw* | windows*) 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 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 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 ])