Upgrading lang/gcc40 using lang/gcc40?

[Mike Edenfield]

I've been running a -CURRENT system with lang/gcc40 as the base compiler 
for a couple of weeks to see if there's any major issue, and whether I 
can tell a difference in compile speed or execution speed.  (So far, no 
problems but no real noticeable speed difference either way).   I've 
specified CC=/usr/local/bin/gcc40 in /etc/make.conf, so it's being used 
for everything.

However, each time I try to portupgrade lang/gcc40 I run into a bit of a 
problem.  The gcc port's "install" target tries to compile some build 
tools using the existing compiler (not the newly built one).  Problem 
being, this target runs after "make deinstall" has run -- so I have no 
system compiler at that point.  And it's too late to change to 
/usr/bin/cc, since the path to /usr/local/bin/gcc40 has already been 
embedded into the Makefile for the stuff being built at install-time

Am I doing something wrong, or is this just how gcc works?  For now I 
have to rememeber not to try to portupgrade this one, but manually do so 
and explicitly specify CC=/usr/bin/cc.

--Mike