On 05 Jan 2022 13:10, Corinna Vinschen wrote:
> On Dec 30 13:39, Mike Frysinger wrote:
> > The top-level newlib dir is already using autoconf-2.69, and all the
> > subdirs are using autoconf-2.68.  Update them all to use 2.69 as a
> > prereq and then regenerate them accordingly.
> > 
> > The README file already says to use autoconf-2.69.
> 
> Yeah, but...
> 
> The AC_PREREQ only checks for the minimum required autoconf version for
> *this* specific autoconf file.  AC_PREREQ([2.52]) doesn't mean we have to
> use 2.52, but any later version will suffice.  All current autoconf
> files are compatible with 2.69.  Neither binutils-gdb, nor gcc changed
> their files to require 2.69.  So it's note quite clear to me what this
> patch accomplishes.

that's incorrect.  gcc & binutils-gdb have config/override.m4 which requires
autoconf-2.69 exactly is used.  no older versions, no newer versions, only
2.69 is permitted.

$ cd bfd/
$ autoconf-2.68
aclocal.m4:17: warning: this file was generated for autoconf 2.69.
You have another version of autoconf.  It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically 'autoreconf'.
configure.ac:21: error: Please use exactly Autoconf 2.69 instead of 2.68.
../config/override.m4:12: _GCC_AUTOCONF_VERSION_CHECK is expanded from...
configure.ac:21: the top level
autom4te-2.68: /usr/bin/m4 failed with exit status: 1

$ cd .../gcc/gcc
$ autoconf-2.68
configure.ac:26: error: Please use exactly Autoconf 2.69 instead of 2.68.
../config/override.m4:12: _GCC_AUTOCONF_VERSION_CHECK is expanded from...
configure.ac:26: the top level
autom4te-2.68: /usr/bin/m4 failed with exit status: 1

do you want me to update newlib/ & libgloss/ to leverage this macro ?

> Autoconf 2.71 is the next version introducing backward incompatibilities.
> Wouldn't it make more sense to fix up the incompatibilities (if any)
> and update the affected files to 2.71 to be more future-proof?

since newlib keeps its top-level files & config/ files in sync with the
binutils-gdb & gcc repos, i don't think moving to a version diff from them
is a good idea.  unless you want to completely throw away all of the top
level files and have newlib/libgloss go their own completely independent
route.
-mike