(x)emacs settings for gnu style perl?

[Alex Hornby]

Hi,

I'm updating my 6 month old automake tree to try and get the patsubst
and built source patches going again, and have noticed that all the
newer code is in true GNU indent style rather than the earlier
approximation.

e.g. new style
        if (/AM_PATH_PYTHON/)
          {
            $seen_pythondir = 1;
          }

What are the emacs settings to get this to happen automatically? In
xemacs 20.4 I've tried c-set-style to gnu in cperl-mode, but it
doesn't do the trick.

Thanks,
Alex.