GCC: virtual memory exhausted?

[Wes Brown <wbrown_(_at_)_calliope_(_dot_)_nix_(_dot_)_neosoft_(_dot_)_com>]

I'd been compiling KDE out of the ports selections -- after some modifications
and the like, to fit it in the OpenBSD enviroment -- and after a long build,
I run into this:

g++ -DHAVE_CONFIG_H -I. -I. -I.. -I/usr/local/kde/include -I/usr/local/include -I/usr/X11R6/include/X11/qt -I/usr/X11R6/include -I/usr/local/include -I/usr/local/include/giflib  -O -c kfmgui.cpp
In file included from kfmgui.cpp:26:
kfmprops.h:56: virtual memory exhausted
*** Error code 1

Stop.
*** Error code 1

Stop.
*** Error code 1

Stop.
*** Error code 1

Stop.
*** Error code 1

Stop.
*** Error code 1

Stop.

What is this 'virtual memory exhausted'? I had plenty of swap left, during
this compile -- about 150MB or so free.  This leads me to believe that GCC
has some sort of internal stack space, or storage area that's running out
during the compilation of this large C++ file?  This has happened to me before
when  I compile large C or C++ files.  Most especially C++ files that have a
/lot/ of includes, and recursive includes.  The preprocessor output alone is
500K.

When I try to separate the stages -- i.e. in one pass, only preprocess the
C++ file, I seem to be able to go further.  

Any suggestions as to how to fix this?

Wes Brown
wbrown_(_at_)_nix_(_dot_)_neosoft_(_dot_)_com