Re: [PATCH] use m4 -g when available

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

According to Paolo Bonzini on 7/12/2009 5:51 AM:
> M4sugar requires GNU m4 extensions to be enabled.  Override
> POSIXLY_CORRECT using -g.

I see you already pushed this (by accident)?  The general idea is okay,
but we need a followup patch (I've had a partial patch to do something
similar on my branch, for some time now, but never got around to finishing
it, because the cleanups weren't trivial).

> --- a/m4/m4.m4
> +++ b/m4/m4.m4

Let's bump the serial number of this file.

> @@ -32,6 +32,17 @@ AC_PATH_PROGS_FEATURE_CHECK([M4], [m4 gm4 gnum4],
>        [AC_MSG_ERROR([no acceptable m4 could be found in \$PATH.
>  GNU M4 1.4.5 or later is required; 1.4.11 is recommended])])])
>    M4=$ac_cv_path_M4
> +  AC_CACHE_CHECK([whether $ac_cv_path_M4 accepts -g], 
> [ac_cv_prog_gnu_m4_gnu],
> +    [case `$M4 --help < /dev/null 2>&1` in

This is theoretically too late.  The earlier check relies on GNU features,
so if the user does: POSIXLY_CORRECT=: ./configure, then GNU m4 will be
rejected before you even get to the second check for accepting -g.  It
seems like we really need to consolidate the check for -g as a side effect
of the AC_PATH_PROGS_FEATURE_CHECK, rather than a later check.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkpbHfoACgkQ84KuGfSFAYAs5QCeK3eZOZMXdy/5fVvS8ug689NU
Qz8AoIfODvxAujtJlPhQU5TWypK4pG6z
=H08s
-----END PGP SIGNATURE-----