From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23030 invoked by alias); 7 Mar 2003 22:50:39 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 23023 invoked from network); 7 Mar 2003 22:50:39 -0000 Received: from unknown (HELO desire.geoffk.org) (12.235.57.148) by 172.16.49.205 with SMTP; 7 Mar 2003 22:50:39 -0000 Received: (from geoffk@localhost) by desire.geoffk.org (8.11.6/8.11.6) id h27MoK706172; Fri, 7 Mar 2003 14:50:20 -0800 Date: Fri, 07 Mar 2003 22:57:00 -0000 From: Geoff Keating Message-Id: <200303072250.h27MoK706172@desire.geoffk.org> To: neil@daikokuya.co.uk CC: per@bothner.com, tromey@redhat.com, gcc@gcc.gnu.org In-reply-to: <20030307222021.GE31657@daikokuya.co.uk> (message from Neil Booth on Fri, 7 Mar 2003 22:20:21 +0000) Subject: Re: Putting C++ code into gcc front end References: <3E64C09A.9070500@comsys.se> <87isuzjb71.fsf@fleche.redhat.com> <3E67FBA6.1000907@bothner.com> <20030307125056.GA23848@gauvain.u-strasbg.fr> <20030307202316.GD31657@daikokuya.co.uk> <20030307222021.GE31657@daikokuya.co.uk> X-SW-Source: 2003-03/txt/msg00540.txt.bz2 > Date: Fri, 7 Mar 2003 22:20:21 +0000 > From: Neil Booth > It would be much easier if you didn't have to worry about 6 different > front ends for every dinky little change you make to some tree. Or > if you had something that documented the quirks of how every field was > used by every front end. We have nothing close to that. It's almost > impossible to make significant changes to trees: not only do they > represent everything, but they represent everything in every goddamn > front end. It's a really nasty situation to be in. > > 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. Maybe a better solution would be to document what the tree structure is actually supposed to look like, and then try to ensure that? -- - Geoffrey Keating