Path: utzoo!attcan!uunet!mcvax!ukc!dcl-cs!nott-cs!pyr1.cs.ucl.ac.uk!purchase
From: purchase@pyr1.cs.ucl.ac.uk
Newsgroups: comp.lang.smalltalk
Subject: Re: OO debuggers
Message-ID: <37100005@pyr1.cs.ucl.ac.uk>
Date: 16 Sep 88 19:59:00 GMT
References: <37100002@pyr1.cs.ucl.ac.uk>
Lines: 91
Nf-ID: #R:pyr1.cs.ucl.ac.uk:37100002:pyr1.cs.ucl.ac.uk:37100005:000:4113
Nf-From: pyr1.cs.ucl.ac.uk!purchase    Sep 16 19:59:00 1988


KEY:
>>> Written 09:37 pm  Sep  9, 1988 by purchase@uk.ac.ucl.cs
>>  Written 12:47 am  Sep 12, 1988 by becher@argosy.UUCP
>   Written 07:19 pm  Sep 12, 1988 by jans@tekgvs.GVS.TEK.COM 

>>>I have been surprised and disappointed to learn that most
>>>of the testing/debugging tools I have come across for OO languages seem to
>>>be merely poor conversions of procedure-oriented language debuggers. 

>>So we have poor conversions of poor products ...

>>>I might be wrong, but I think that languages of a (relatively) new paradigm
>>>like OOP need *new* innovative support tools to back them. Does any one out
>>>there have any strong opinions about this?

>>You are not wrong - you are absolutely right.
>>However, this lack of debugging tools is not confined to the OO domain.
>>I defy you to show you one generally-available debugger that is the least
>>bit "innovative".  They all seem to be stuck in the Linton dbx mold --
>>i.e. dumb terminal textual rather than multiple window graphical (no
>>offense Mark, but the time has come to move on).  From what I can gather
>>there are precious few people working on the debugging problem
>>(Zellwegger and Cargill are exceptions).

I could not agree more. During my preliminary literature survey I noticed a
distinct lack of any truly innovative work after 1985. With the exceptions
of Bruegge and Cargill. One of my colleagues conducted a survey (amongst
colleges in London University) which showed that 40% of programmers *never*
use debuggers and of these who do 25% consider that they are not very useful
because they are: too cumbersome to use; are too difficult to learn and have
inadequate user interfaces. The lack of good tools, both OO and otherwise is
a problem.

>>>With this in mind, has anyone out there used a OO debug tool (or related
>>>utility) of any real merit? 

>>No (see above).  In my humble opinion, gdb+ doesn't even come close.
>>(Although, admittedly, it's better than almost anything else).

You mean you got gdb+ to work? I could get it to debug straightforward c++
but as soon as I used the methods-display command or any of the extra "OO
facilities" it went spurious on me.

>you should look closely at the generally available Smalltalk-80 debugger, or
>even the less capable, but more generally available (meaning cheaper),
>Smalltalk-V debugger.  (I think "generally available" means you can buy it
>for a reasonable price for the most popular computing platforms.)

I have. I am preparing a few internal research reports on it now. Agreed its
better than gdb+ and one could not even begin to compare it to dbx (or
dbxtool) but it has its problems.

>C++ has a lot of catching up to do, but it seems to be evolving strictly in
>the incestuous C-Unix environment.

Agreed. Sad isn't it?

> ..execution speed, the least important metric in the present "software
> crisis" ...

I'm not sure I agree fully here. Although you are undoubtedly right
generally, one of the important properties of a debugger is that it has
minimal effect on the observable run-time behaviour of one's program.
Smalltalk's debugger (and one or two others I have used) falls over here.
Having to wait a minute for the debugger to simulate a method that
usually concludes in 200mS is unacceptable -- especially if you are
not informed of the delay in advance.

>C'mon, guys, if you're going to make things better,
>at least start with what was state-of-the art in 1980!

I'm working on it!

>>> Jan Purchase
>>  Jon Becher
>   Jan Steinman

Thanks for listening...

****************************************************************************
FROM : Jan Andrew Purchase          | Snail:     Room 208, PhD Lab.,
at   : pyr1.cs.ucl.ac.uk	    |            Computer Science Dept.,
			            |		 University College,
				    |		 London, UK.
				    |
JANET   : purchase@uk.ac.ucl.cs
ARPANET : purchase@pyr1.cs.ucl.ac.uk@nss.cs.ucl.ac.uk
****************************************************************************
      (these are my views, and are not necessarily those of UCL)
****************************************************************************