gcc 4.0 front-end infrastructure for C dialects - plans?

["Gary Funck" <gary at intrepid dot com>]

The recent discussion titled "gcc integration" has me wondering if our
project (implementing an experimental dialect of C used primarily in
a distributed shared memory context) should be moving to
GCC 4.0 rather the our current focus (gcc 3.4)?  One reason we were shying
away from 4.0 was that we were under the impression that the new C++
top-down recursive descent parser technology was going to be applied to
regular C (and its dialects) as well.  This would raise the level of
difficulty for us to re-implement extensions made to the yacc-based C
parser,
making them fit into the new recursive descent parser.  We were concerned
that it might be difficult to track changes in the new parser as well,
because
fixes to that parser might propagate into the code in the parser in a less
modular way than they're made to the yacc-based parser, and thus make it
more difficult to stay in synch. with the GCC baseline.

We also have made fairly extensive changes in c-decl.c, c-typeck.c, and to
a limited degree expr.c (eventually we hope that additional language hooks
might be able to isolate those changes, but for now it is easier and faster
to make local changes).  Are the 4.0 based versions of those files
reasonably stable at this point?

To recap:

1) Will the current yacc-based parser remain for C dialects in 4.0?

2) Are the 4.0 source files such as c-decl.c, c-typeck.c, and expr.c
   sufficiently stable at this point to support changes required by
   a C dialect, without more than the usual amount of heartburn?
   (the bump from 3.3 to 3.4 was actually quite extensive, but manageable
   and understandable).

thanks.

PS; the project mentioned above is an implementation of a proposed C
dialect,
called UPC, described here: http://www.intrepid.com/upc.