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Re: Pascal front-end integration
- From: ja2morri at csclub dot uwaterloo dot ca (James A. Morrison)
- To: Ed Smith-Rowland <3dw4rd at verizon dot net>
- Cc: gcc at gcc dot gnu dot org
- Date: 01 Mar 2005 22:20:30 -0500
- Subject: Re: Pascal front-end integration
- References: <42252379.1060505@verizon.net>
Ed Smith-Rowland <3dw4rd@verizon.net> writes:
> On 1 Mar 2005 at 8:17, James A. Morrison wrote:
>
> > Hi,
> > I've decided I'm going to try to take the time and cleanup and
> > update
> > the
> > Pascal frontend for gcc and try it get it integrated into the upstream
> > source. I'm doing this because I wouldn't like to see GPC work with GCC
> > 4+. I don't care at all at supporting GPC on anything less than GCC 4.1
> > so I've started by ripping out as much obviously compatibility code as I
> > can and removing any traces of GPC being a separate project.
>
> My guess is that inclusion of Pascal into gcc would give that language
> more exposure and would lead to faster development.
>
> By many accounts gcc-4 is getting faster. It would be nice to see pascal
> take advantage of this rather than being marooned on 3.x.
>
> I, for one, am more likely to play with a gpascal that bootstraps with
> mainline than to try to build one with, perhaps unusual, dependencies
> and some different version of gcc.
>
> I am learning gcc internals slowly (this is a part-time after-work effort :-P)
> but I would be interested in helping wherever I can.
Grab the source and see what you can do.
> > So far I have only accomplished converting lang-options.h to
> > lang.opt. I'm going
> > to continue cleaning up the GPC code, then once I am happy with how the code
> > looks with respect to the rest of the GCC code, I'm going to get it to
> > compile with
> > the current version of GCC mainline. I'm starting with the boring
> > conflict happy
> > whitespace changes first so the code is easier for me to read and so that I can
> > try to get an idea what the GPC frontend is doing.
>
> Before we get too far with this I think we should keep an eye on a trend in gcc
> at least through 3.4 and 4.0: Front ends are increasingly written by hand rather
> than with flex and bison. This is true for C++ as of 3.4 and for C as of 4.1.
> I'm pretty sure it's true for gfortran too. I think this is true for gcjx too.
> The latter is written in C++ to boot.
>
> My understandng is that gpc uses flex/bison in a p2c - a pascal to C translator.
> I would like to know why folks think hand written parsers are better. My guess is that
> they are easier to maintain and that they support more lookahead.
>
> A gpascal front end effort might do well to take a hard look at the new front ends
> for C and C++ (and Java) and consider a rewrite from scratch using these as models.
Feel free to write your own parser, I have no desire to do that.
> > My current changes are available through bazaar (an arch implementation) which
> > people can get with:
> > baz register-archive http://www.csclub.uwaterloo.ca/~ja2morri/arch <http://www.csclub.uwaterloo.ca/%7Eja2morri/arch>
> > baz get phython@gcc.gnu.org--pascal/gcc-pascal--mainline--0.3
>
> There is another trend in gcc: a move toward Subversion from CVS. I realize this
> is a first-try effort but there would probably be less regret later if we adopt
> the standard toolchain. The decision to go to Subversion was not taken lightly.
>
> Ed Smith-Rowland
I don't think it makes a difference. If this little project of mine does
start moving I'll put the code in CVS/SVN at that time. Until then, I'm
taking an opportunity to play with bazaar.
--
Thanks,
Jim
http://www.student.cs.uwaterloo.ca/~ja2morri/
http://phython.blogspot.com
http://open.nit.ca/wiki/?page=jim