gnupic: Re: [gnupic] gputils development
Subject:
Re: [gnupic] gputils development
From:
"David Barnett" ####@####.####
Date:
25 May 2007 21:52:10 +0100
Message-Id: <007401c79f0d$f768cbe0$0301a8c0@barnett2>
I spent some more time today digging through the gpasm code. The two-pass
architecture seems very central to its functionality. If anyone knows much
about what happens at each pass, that could accelerate my learning process.
I could swear I've seen some documentation about it before, but I'm not
turning up anything now. It looks like all the code emission and error
reporting happens on the second pass. I'd assume the first pass is for
collecting macros and constants...?
I could be wrong on either count, but I think that a pcode-based
architecture will eliminate the need for 2 passes and I think that will
circumvent a lot of the hacks that some of the comment lines so poignantly
lament. In the interim I'll need to deal with the two-pass system
regardless to knock out some bugs and figure out what I'm doing. Maybe it
means fixing some bugs twice, but hopefully fixing them the simplest way
first will keep it pretty stable so we can make a quick bugfix release
before plunging in and making huge changes.
FYI, the bugs I have in mind are differences in directives between MPASM and
gpasm. Two that come to mind are the severe gpasm limitations on the #v
syntax and the order of evaluation for #defines inside macro bodies, as I
mentioned way back in Oct '06.
David Barnett
