Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!rutgers!ames!cit-vax!news
From: news@cit-vax.UUCP
Newsgroups: comp.arch
Subject: Re: catering to bad code
Message-ID: <1834@cit-vax.Caltech.Edu>
Date: Fri, 20-Feb-87 07:34:48 EST
Article-I.D.: cit-vax.1834
Posted: Fri Feb 20 07:34:48 1987
Date-Received: Sat, 21-Feb-87 06:18:15 EST
References: <14833@amdcad.UUCP> <954@uw-nsr.UUCP>
Reply-To: jon@oddhack.UUCP (Jon Leech)
Organization: California Institute of Technology
Lines: 24

Organization : California Institute of Technology
Keywords: 
From: jon@oddhack.Caltech.Edu (Jon Leech)
Path: oddhack!jon

In article <954@uw-nsr.UUCP> john@uw-nsr.UUCP (John Sambrook 5-7433) writes:
>Many of the programs that I have ported have tried to dereference
>through NULL.  On the MV series this does not work, at all.  However 
>a much larger number of C programs are sloppy and don't cast pointer 
>types appropriately.  On the MV series this causes a protection violation
>and you are left looking at a few lines of traceback information.  

	I'm glad they fixed this. When I was using an early version
of DG/UX a few years ago, an incorrectly cast pointer in one program
resulted in a system crash. This made the debugging turnaround cycle 
rather long until the cast was corrected. On the bright side, making 
the program in question (a screen editor) run on the MV architecture 
nailed almost every remaining portability bug. Putting the same program
on an 80286 Xenix got the rest. I recommend this technique for developing 
truly portable C code.

    -- Jon Leech (jon@csvax.caltech.edu || ...seismo!cit-vax!jon)
    Caltech Computer Science Graphics Group
    __@/