Path: utzoo!attcan!uunet!bu.edu!rpi!zaphod.mps.ohio-state.edu!usc!wuarchive!psuvax1!ukma!usenet.ins.cwru.edu!ncoast!catfood
From: catfood@NCoast.ORG (Mark W. Schumann)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Porting UNIX apps. to MS-DOS
Message-ID: <1990Oct26.223541.26634@NCoast.ORG>
Date: 26 Oct 90 22:35:41 GMT
References: <90296.205211DLV101@psuvm.psu.edu>
Organization: North Coast Public Access *NIX, Cleveland, OH
Lines: 30

DLV101@psuvm.psu.edu (Dwaine VanBibber) writes:
>Does anyone have some general rules for porting C programs developed under
>UNIX to MS-DOS? I've developed a small language interpreter that I would
>like to be able to run under DOS. I have already attempted this, and it
>compiles fine using TC++, however I keep getting stack overflow. I am
>using the large memory model. Setting TC++'s  _stklen variable to something
>large doesn't seem to help any either. I should also point out that the
>program contains a recursive descent parser and function calls are often
>nested quite deep. Compiling with TC 2.01 yields the same results. Do I
>have to do a complete rewrite (ie. eliminate deep function calls or resort
>to bottom-up parsing), or can it be coerced to work? Any comments or
>volunteers to examine code? Thanks in advance.
>--Dwaine

You have a problem with the Intel '86 architecture.  No matter what you
do in C on an '86 machine, the stack segment cannot exceed 64K.  That's
because the SS register is (wierd exceptions aside) held constant through
execution of a program.  Since an Intel offset is a 16-bit pointer, you
are limited to the 64K.

Sigh...I think you may have to rewrite.  Sorry.



-- 
============================================================
Mark W. Schumann  3111 Mapledale Avenue, Cleveland 44109 USA
Domain: catfood@ncoast.org
UseNet: ...usenet.ins.cwru.edu!ncoast!catfood
============================================================