>It gets quite far, but in mozilla/xpcom/tests/dynamic, two symbols cannot be
>found from RegFactory.o. They are _hex__FR3ios and _dec__FR3ios.
>The strange thing is, they are not variables or functions in RegFactory.cpp

Keeping in mind that it is C++, feed those names into demangle and you get:

$ demangle
_hex__FR3ios
hex(ios &)
_dec__FR3ios
dec(ios &)

Now you can see what to look for.

BTW demangle.c is part of gcc, years ago I wrote a main() for it so that 
collect2 could issue meaningful errors.  If interested grab
ftp://ftp.quick.com.au/pub/unix/demangle.shar.Z

--sjg