BEGIN { 
sub DB::sub { 
        my ($r, @r, $s);
        $s = $DB::sub;
        $s=~/^T::/ or goto &$s;
        warn "entering $s\n"; 
        if (wantarray) 
                { @r = &$s; }
        elsif (defined wantarray)
                { $r = &$s; }
        else
                { &$s; }
        warn "exitting $s\n";
        wantarray ? @r : $r;
        }
$^P |= 1;
} 
{ 
package T;
$r = "r";
sub f { $_[0].$r.n(); }
sub n { @l = l(); 2, chr(@l); }
sub l { -5..4; }
}
sub g { T::f($_[0]."a"); }; 
print g("b");