Also, arrange for a @command{configure} option @code{--enable-year2038}
to request widening the type @code{time_t} as needed to represent file
-wand other timestamps after January 2038. This widening is possible
+wand other timestamps after mid-January 2038. This widening is possible
only on 32-bit GNU/Linux x86 and ARM systems with glibc 2.34 or later.
If year-2038 support is requested but @command{configure} fails to find a way
to widen @code{time_t} and inspection of the system suggests that
this feature is available somehow, @command{configure} will error out.
If you want the default to be @code{--enable-year2038}, you can use
-@code{AC_SYS_YEAR2038} instead of @code{AC_SYS_LARGEFILE}.
+@code{AC_SYS_YEAR2038} or @code{AC_SYS_YEAR2038_RECOMMENDED}
+instead of @code{AC_SYS_LARGEFILE}.
In other words, older packages that have long used @code{AC_SYS_LARGEFILE}
can have year-2038 support on 32-bit GNU/Linux x86 and ARM systems either by
regenerating @file{configure} with current Autoconf and configuring with
-@option{--enable-year2038}, or by using @code{AC_SYS_YEAR2038} and
-configuring without @option{--disable-year2038}.
+@option{--enable-year2038}, or by using @code{AC_SYS_YEAR2038} or
+@code{AC_SYS_YEAR2038_RECOMMENDED} and configuring without
+@option{--disable-year2038}.
A future version of Autoconf might change the @code{AC_SYS_LARGEFILE}
default to @code{--enable-year2038}; if and when that happens,
@code{AC_SYS_LARGEFILE} and @code{AC_SYS_YEAR2038} will become equivalent.
break binary compatibility with that library.
@end defmac
-@defmac AC_SYS_LARGEFILE_REQUIRED
-@acindex{SYS_LARGEFILE_REQUIRED}
-This macro has the same effect as @code{AC_SYS_LARGEFILE},
-but also declares that the program being configured
-requires support for large files.
-If a large @code{off_t} is unavailable,
-@command{configure} will error out.
-The @option{--disable-largefile} option will not be available.
-
-Large-file and year-2038 support for applications and libraries should
-be configured compatibly. @xref{AC_SYS_LARGEFILE}.
-@end defmac
-
@anchor{AC_SYS_LONG_FILE_NAMES}
@defmac AC_SYS_LONG_FILE_NAMES
@acindex{SYS_LONG_FILE_NAMES}
@xref{AC_SYS_LARGEFILE}.
@end defmac
-@defmac AC_SYS_YEAR2038_REQUIRED
-@acindex{SYS_YEAR2038_REQUIRED}
+@defmac AC_SYS_YEAR2038_RECOMMENDED
+@acindex{SYS_YEAR2038_RECOMMENDED}
This macro has the same effect as @code{AC_SYS_YEAR2038},
but also declares that the program being configured
-requires support for timestamps after mid-January of 2038.
-If a large @code{time_t} is unavailable,
-@command{configure} will unconditionally error out.
-The @option{--disable-year2038} option will not be available.
+should support timestamps after mid-January 2038.
+If a large @code{time_t} is unavailable, @command{configure} will error
+out unless the @option{--disable-year2038} option is specified.
Year-2038 support for applications and libraries should be configured
compatibly. @xref{AC_SYS_YEAR2038}.
dnl 32-bit MinGW (misconfiguration)
))
-# _AC_SYS_YEAR2038_PROBE([IF-NOT-DETECTED])
-# -----------------------------------------
+# _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
# AC_TRY_RUN. Note also that some systems only support large time_t
# together with large off_t.
#
-# If support is not detected, the behavior depends on which of the
-# top-level AC_SYS_YEAR2038 macros was used (see below).
-#
# 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 $CC option to enable timestamps after Jan 2038],
+[AC_CACHE_CHECK([for $CC option for timestamps after 2038],
[ac_cv_sys_year2038_opts],
[ac_save_CPPFLAGS="$CPPFLAGS"
ac_opt_found=no
AS_CASE([$ac_cv_sys_year2038_opts],
["none needed"], [],
["support not detected"],
- [ac_have_year2038=no
- AS_CASE([$ac_year2038_required,$enable_year2038],
- [yes,*],
- [AC_MSG_FAILURE([support for timestamps after Jan 2038 is required])],
- [*,yes],
- [# 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([test $cross_compiling = no],
- [AS_IF([TZ=UTC0 touch -t 210602070628.15 conftest.time 2>/dev/null],
- [AS_CASE([`TZ=UTC0 LC_ALL=C ls -l conftest.time 2>/dev/null`],
- [*'Feb 7 2106'* | *'Feb 7 17:10'*],
- [AC_MSG_FAILURE(m4_text_wrap(
- [this system appears to support timestamps after January 2038,
- but no mechanism for enabling wide 'time_t' was detected.
- Did you mean to build a 64-bit binary? (e.g. 'CC="${CC} -m64"'.)
- To proceed with 32-bit time_t, configure with '--disable-year2038'.],
- [], [], [55]))])])])])],
+ [ac_have_year2038=no],
["-D_TIME_BITS=64"],
[AC_DEFINE([_TIME_BITS], [64],
["-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 January 2038.
+ It will stop working after mid-January 2038.
Remove _USE_32BIT_TIME_T from the compiler flags.],
[], [], [55]))],
# _AC_SYS_YEAR2038_ENABLE
# -----------------------
-# Subroutine of AC_SYS_YEAR2038 and _AC_SYS_YEAR2038_OPT_IN.
# Depending on which of the YEAR2038 macros was used, add either an
-# --enable-year2038, or a --disable-year2038, or no option at all to
-# the configure script. Note that this is expanded very late and
+# --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_REQUIRED],
- [ac_year2038_required=yes],
- [ac_year2038_required=no]))dnl
-m4_divert_text([DEFAULTS],
m4_provide_if([AC_SYS_YEAR2038],
[enable_year2038=yes],
[enable_year2038=no]))]dnl
-[m4_provide_if([AC_SYS_YEAR2038_REQUIRED], [],
[AC_ARG_ENABLE([year2038],
m4_provide_if([AC_SYS_YEAR2038],
[AS_HELP_STRING([--disable-year2038],
- [omit support for dates after Jan 2038])],
+ [don't support timestamps after 2038])],
[AS_HELP_STRING([--enable-year2038],
- [include support for dates after Jan 2038])]))])])
-
-# _AC_SYS_YEAR2038_OPT_IN
-# -----------------------
-# If the --enable-year2038 option is given to configure, attempt to
-# detect and activate support for large time_t on 32-bit systems.
-# This macro is automatically invoked by AC_SYS_LARGEFILE when large
-# *file* support is detected. It does not AC_REQUIRE AC_SYS_LARGEFILE
-# to avoid a dependency loop, and is therefore unsafe to expose as a
-# documented macro.
-AC_DEFUN([_AC_SYS_YEAR2038_OPT_IN],
-[m4_provide_if([_AC_SYS_YEAR2038_PROBE], [], [dnl
- AS_IF([test "$ac_year2038_required,$enable_year2038" != no,no],
- [_AC_SYS_YEAR2038_PROBE])
- AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])
-])])
+ [support timestamps after 2038])]))])
# AC_SYS_YEAR2038
# ---------------
# 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],
-[m4_provide_if([AC_SYS_LARGEFILE_REQUIRED], [],
- [AC_REQUIRE([AC_SYS_LARGEFILE])])]dnl
-[m4_provide_if([_AC_SYS_YEAR2038_PROBE], [], [dnl
- AS_IF([test "$ac_year2038_required,$enable_year2038" != no,no],
- [_AC_SYS_YEAR2038_PROBE])
- AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])
-])])
-
-# AC_SYS_YEAR2038_REQUIRED
-# ------------------------
-# Same as AC_SYS_YEAR2038, but declares that this program *requires*
-# support for large time_t. If we cannot find any way to make time_t
-# capable of representing values larger than 2**31 - 1, configure will
-# error out. Furthermore, no --enable-year2038 nor --disable-year2038
-# option will be available.
-AC_DEFUN([AC_SYS_YEAR2038_REQUIRED],
-[m4_provide_if([AC_SYS_LARGEFILE_REQUIRED], [],
- [AC_REQUIRE([AC_SYS_LARGEFILE])])]dnl
-[m4_provide_if([_AC_SYS_YEAR2038_PROBE], [], [dnl
- _AC_SYS_YEAR2038_PROBE
- AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])
-])])
+[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.
+ 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_LARGEFILE_TEST_CODE
# ---------------------------
["none needed"], [],
["supported through gnulib"], [],
["support not detected"],
- [ac_have_largefile=no
- AS_IF([test $ac_largefile_required,$ac_year2038_required != no,no],
- [AC_MSG_FAILURE([support for large files is required])])],
+ [ac_have_largefile=no],
["-D_FILE_OFFSET_BITS=64"],
[AC_DEFINE([_FILE_OFFSET_BITS], [64],
[AC_MSG_ERROR(
[internal error: bad value for \$ac_cv_sys_largefile_opts])])
-_AC_SYS_YEAR2038_OPT_IN
-])
-
-# _AC_SYS_LARGEFILE_ENABLE
-# ------------------------
-# Subroutine of AC_SYS_LARGEFILE. If AC_SYS_LARGEFILE_REQUIRED was
-# not used at any point in this configure script, add a
-# --disable-largefile option to the configure script. Note that this
-# is expanded very late and therefore there cannot be any code in the
-# AC_ARG_ENABLE. The default value for 'enable_largefile' is emitted
-# unconditionally because the generated shell code always looks at
-# this variable.
-m4_define([_AC_SYS_LARGEFILE_ENABLE],
-[m4_divert_text([DEFAULTS],
- m4_provide_if([AC_SYS_LARGEFILE_REQUIRED],
- [ac_largefile_required=yes],
- [ac_largefile_required=no]))dnl
-m4_divert_text([DEFAULTS],
- [enable_largefile=yes])]dnl
-[m4_provide_if([AC_SYS_LARGEFILE_REQUIRED], [],
- [m4_provide_if([AC_SYS_YEAR2038_REQUIRED], [],
- [AC_ARG_ENABLE([largefile],
- [AS_HELP_STRING([--disable-largefile],
- [omit support for large files])])])])])
+AS_IF([test "$enable_year2038" != no],
+ [_AC_SYS_YEAR2038_PROBE])
+AC_CONFIG_COMMANDS_PRE([_AC_SYS_YEAR2038_ENABLE])])
# AC_SYS_LARGEFILE
# ----------------
# Additionally, on Linux file systems with 64-bit inodes a file that happens
# to have a 64-bit inode number cannot be accessed by 32-bit applications on
# Linux x86/x86_64. This can occur with file systems such as XFS and NFS.
-# This macro allows configuration to continue if the system doesn't support
-# large files; see also AC_SYS_LARGEFILE_REQUIRED.
AC_DEFUN([AC_SYS_LARGEFILE],
-[m4_provide_if([_AC_SYS_LARGEFILE_PROBE], [], [dnl
- AS_IF([test "$ac_largefile_required,$enable_largefile,$ac_year2038_required" != no,no,no],
- [_AC_SYS_LARGEFILE_PROBE])
- AC_CONFIG_COMMANDS_PRE([_AC_SYS_LARGEFILE_ENABLE])
-])])
-
-# AC_SYS_LARGEFILE_REQUIRED
-# -------------------------
-# Same as AC_SYS_LARGEFILE, but declares that this program *requires*
-# support for large files. If we cannot find a combination of compiler
-# options and #defines that makes 'off_t' capable of representing 2**63 - 1,
-# 'configure' will error out. Furthermore, 'configure' will not offer a
-# --disable-largefile command line option.
-# If both AC_SYS_LARGEFILE and AC_SYS_LARGEFILE_REQUIRED are used in the
-# same configure script -- in either order -- AC_SYS_LARGEFILE_REQUIRED wins.
-AC_DEFUN([AC_SYS_LARGEFILE_REQUIRED],
-[m4_provide_if([_AC_SYS_LARGEFILE_PROBE], [], [dnl
- _AC_SYS_LARGEFILE_PROBE
- AC_CONFIG_COMMANDS_PRE([_AC_SYS_LARGEFILE_ENABLE])
-])])
+[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])])
# AC_SYS_LONG_FILE_NAMES
# ----------------------
projects / thirdparty / autoconf.git / commitdiff
