Making to alternate directories

[Mike Chartier]

I would like to setup my make file such that
 %.o go to $(OBJDIR)
 %.so go to $(LIBDIR)
 % (executables) go to $(BINDIR)

I can't make-then-move. The source I'm building is NFS mounted and the 
whole point is to make the binaries on locally mounted disks.

I've tried many things and this almost works:

##########################

vpath %.so $(LIBDIR)
vpath %.o $(OBJDIR)

libMylib.so : myObj1.o myObj2.o ...

%.so :
   $(CXX) -shared $(CPPFLAGS) $(CXXFLAGS) -o $(LIBDIR)/$@ $^

%.o : %.cpp %.h
   $(CXX) $(CPPFLAGS) $(CXXFLAGS) -o $(OBJDIR)/$@ -c $<

#################

The problem is of course that if the %.o files aren't made the first 
time through make can't find them when it finished making them (to make 
%.so). The second pass works perfectly but I have to be able to compile 
in one pass (at least from the developer's prospective) without 
generating errors (on good builds).

Another nice feature would be to be able to generate prerequisites 
automatically (section 4.13 of the manual) but I don't see how I can 
integrate that with what I'm doing.

Any suggestions would be greatly appriciated. Thanks!