Re: Putting C++ code into gcc front end

[Neil Booth <neil at daikokuya dot co dot uk>]

Geoff Keating wrote:-

> > Every front end should have it's own representation, which should be
> > lowered to something common like GIMPLE that is simple, well-
> > documented, and yet expressive enough to be useful to everyone.  I
> > feel we can't make real progress any other way.  Imagine how
> > maintainable each front-end having its own high-level IR with real
> > distinct C structs and unions would be.
> 
> Well... When I tried to imagine, I started thinking "and, yes, we
> could have completely different representations for exceptions and
> structures and references and function calls between the C, C++, Ada,
> and Java frontends" which didn't sound quite so great.  After all,
> another project which is also a good idea and not making much progress
> recently is to commonize more of the C and C++ frontends.

Clearly things that are similar should have some kind of similar,
or common base specification.  But C++ has little in common with
Fortran; forcing them to use the same "stuff" as a high level
representation is clearly a loser.

IMO other telling signs of deep design problems is the middle
end telling the front end how to manage its symbol table: that's
basically what all the decl langhooks are about.

I think your point has more merit for a mid-level representation, like
I intimated in my post.

> Maybe a better solution would be to document what the tree structure
> is actually supposed to look like, and then try to ensure that?

I'm not willing to spend (a truly huge) amount of time on something I
don't think is the way forwards.  Particularly as I'm not being paid for
it.

Neil.