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.
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.
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 [EMAIL PROTECTED]/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
