C++ front end

[Richard Earnshaw]

> Hi,
> 
> On Tue, 25 Jun 2002, Geert Bosch wrote:
> 
> > > We would need to go to a four-stage build to support this (or not do a
> > > compare on those front ends that required C++).
> >
> > I don't see that. In stage 2 you build the front end for language X
> > using the stage1 C++ compiler.
> 
> There is no stage1 C++ compiler.  There only the C compiler is built.
> Remember that the above statement was meant under the condition of not
> requiring a preexisting native compiler for other languages than C.
> 
> You could build X in stage2 by the stage2 C++ compiler itself (i.e. first
> make the C++ compiler, then use it to build X), the same for stage3.
> Then, if the stage2 and stage3 C++ compilers are the same, we are in good
> condition.  But that has it's difficulties, as the target libs are not
> built until after stage3.
> 

Right, but this is just a waste of cpu cycles.  If the stage2 and stage3 
C++ compilers compare identically, then anything built with them will also 
compare identically (since they are, effectively the same compiler).

So we might as well just defer building X to stage3.

R.