On 10 Jan 2024 10:53, Corinna Vinschen wrote:
> Maybe we should switch newlib/cygwin to 2.71 as well, eventually?
> 
> We're in the process of preparing the next Cygwin release which should
> be due end of this month.  After that I don't see any reason that we
> can't bumb the configury to the latest autotools.

i'm not a fan of diverging from the rest of the source projects.  i want
the rest of gcc/binutils/gdb move to autoconf-2.71 & automake-1.16, but
i don't have the cycles to drive that.  i'm also not sure what their
preference is when it comes to release timings.
	autoconf-2.69:   Apr 2012
	         2.70:   Dec 2020
	         2.71:   Jan 2021
	automake-1.15:   Dec 2014
	         1.15.1: Jun 2017
	         1.16:   Feb 2018
	         1.16.5: Oct 2021
personally i think 2 years is enough for the dev population who actually
work on these projects, but who knows.

gcc is currently on autoconf-2.69.  it enforces this:
config/override.m4:
	dnl Ensure exactly this Autoconf version is used
	m4_ifndef([_GCC_AUTOCONF_VERSION],
	  [m4_define([_GCC_AUTOCONF_VERSION], [2.69])])
	dnl Test for the exact version when AC_INIT is expanded.

$ autoconf-2.71
...
configure.ac:4: error: Please use exactly Autoconf 2.69 instead of 2.71.
../config/override.m4:12: _GCC_AUTOCONF_VERSION_CHECK is expanded from...
configure.ac:4: the top level
autom4te-2.71: error: /usr/bin/m4 failed with exit status: 1

now, override.m4 does have an override, but it's meant for testing purposes,
and it doesn't mean anything else in the config/ macro tree has been tested.
	dnl This allows to update the tree in steps (for testing)
	dnl by putting
	dnl   m4_define([_GCC_AUTOCONF_VERSION], [X.Y])
	dnl in configure.ac before AC_INIT,
	dnl without rewriting this file.

which we can see:
$ cd newlib
$ sed -i '1im4_define([_GCC_AUTOCONF_VERSION], [2.71])' configure.ac
$ autoreconf -f
configure.ac:317: warning: The macro `AC_OUTPUT_COMMANDS' is obsolete.
configure.ac:317: You should run autoupdate.
./lib/autoconf/status.m4:1025: AC_OUTPUT_COMMANDS is expanded from...
../config/multi.m4:14: AM_ENABLE_MULTILIB is expanded from...
configure.ac:317: the top level
configure.ac:317: warning: The macro `AC_OUTPUT_COMMANDS' is obsolete.
configure.ac:317: You should run autoupdate.
./lib/autoconf/status.m4:1025: AC_OUTPUT_COMMANDS is expanded from...
../config/multi.m4:14: AM_ENABLE_MULTILIB is expanded from...
configure.ac:317: the top level
configure.ac:317: warning: The macro `AC_OUTPUT_COMMANDS' is obsolete.
configure.ac:317: You should run autoupdate.
./lib/autoconf/status.m4:1025: AC_OUTPUT_COMMANDS is expanded from...
../config/multi.m4:14: AM_ENABLE_MULTILIB is expanded from...
configure.ac:317: the top level
-mike