Path: utzoo!yunexus!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!sdd.hp.com!apollo!rehrauer
From: rehrauer@apollo.HP.COM (Steve Rehrauer)
Newsgroups: comp.sys.apollo
Subject: Re: dde and entry points
Message-ID: <4ab905c4.20b6d@apollo.HP.COM>
Date: 31 May 90 15:16:00 GMT
Article-I.D.: apollo.4ab905c4.20b6d
References: <1990May27.225011.8276@caen.engin.umich.edu>
Sender: root@apollo.HP.COM
Reply-To: rehrauer@apollo.HP.COM (Steve Rehrauer)
Organization: Hewlett-Packard Apollo Division - Chelmsford, MA
Lines: 56

In article <1990May27.225011.8276@caen.engin.umich.edu> sjw_nc@caen.engin.umich.edu (Scott J Wilderman) writes:
>I have had nothing but trouble with dde and entry points, and
>I am wondering if others have had the same problems.  I can not
>understand the following things:
>
>1. I can not set a break point on an entry point name.

Have you APR'd this problem?  What exactly do you mean by "can not
set a break point on an entry point" -- does DDE complain in some
fashion, or do you just never hit the breakpoint during execution
of your code?  I ask because problems of this nature are often
*compiler* bugs, not DDE bugs.  If the compilers feed incorrect
debug information into the object file, it's usually poor ol' DDE
who appears to be at fault.  (In fact, I just found & fixed an
apparently VERY old bug of this nature in the 68k code-generator.
You could set a DDE entry breakpoint, but due to a compiler bug,
DDE believed that the first user-visible executable instruction
in the procedure in question was an instruction that actually was
unreachable from any execution path!)

To determine if this is really a compiler problem, you might try
using the -dba compiler option (-W0,-dba for /bin/compilers); I assume
you're using -dbs or -db now.  -dba disables all but the most trivial
of optimizations.  If it does what you expect in DDE when compiled
with -dba, then it's almost certainly a compiler problem.

Caveat: I'm using a more recent OS, compilers and DDE than you are,
so I may just be blowing smoke.

>2. I can not 'step' from a main program to an entry point - it's
>treated as 'go'.

Ummm, not to insult your intelligence or anything, but I assume the
entrypoint lives within the module, or if not, has also been compiled
for debugging?  Assuming you're not doing anything silly, then this
also sounds like it may be a compiler problem.  Again, please APR it
so we can [a] determine if it's already been fixed, and in what
release if so, or [b] fix it in a future release.

>In general, I'm not sure I think OS 10's 'dde' is an improvement
>over 9.7's 'debug'.  There are a few 'neat' features, but
>in addition to introducing some bugs (on 10.1) that make things 
>hell (all floating points less than 10**-5 print as 0. - what
>a travesty), 'dde' removed some features of 'debug' that I used 
>and liked have disappeared.  At least it's better than dbx.

Hmmm, are you sure about the floating-point business?  I suppose
a DDE person should really answer that one for you, but I've never
had a problem like that.  (I HAVE had problems where values assigned
to registers sometimes don't get properly tracked through a DDE
session -- again, this may be a compiler problem.  In which case I
guess that means I should fix it... :-)

--
   >>"Aaiiyeeee!  Death from above!"<<     | (Steve) rehrauer@apollo.hp.com
"Spontaneous human combustion - what luck!"| Apollo Computer (Hewlett-Packard)