Re: DEC Ada for Alpha Computers

[lpb@sei.cmu.edu (Loic Briand)]

To: weber@lglsun.epfl.ch (Mats Weber)
Subject: Re: DEC Ada for Alpha Computers
Fcc: inbox 
--------

In article <35af4b$g6@info.epfl.ch>, you write:
|> In article <1994Sep15.121515.24609@sei.cmu.edu>
|> lpb@sei.cmu.edu (Loic Briand) writes:
|> 
|> > The problem is that the debugger needs to have a couple of specific features
|> > implemented for each language. It looks like they were not implemented for Ada
|> > (as they were not implemented if I remember correctly in the first versions
|> > of DEC Ada/VMS). Note also that the debugger is working great with C. 
[snip]
|> I woudn't expect any vendor to fix debugger problems, at least no to a
|> satisfactory level. I have seen no Ada debugger correctly handling
|> programs with many generics and tasks. I have been participating in the
|> development of a project with approx. 100 KLOC, and we have almost
|> never been able to use a debugger to find the bugs.

I have used high quality Ada debuggers in the past. At least in the case of VAX
Ada, the debugger was able to set break pointw and watch points on any
specific points of specific instances of generics. We were even able (to my
surprise) to set breakpoints in instances of generics that were inside instances
of generics (double-level generics). Also, debugging multitask programs was
possible, though a breakpoint was stopping the whole process, not only one
task (this interesting feature was supposed to be available on DDC-I products). 
I have a similar positive experience with Alsys. 
These experiences were in the context of 500,000 LOCs programs on "serious" 
platforms like VAX or SUN4. 
I have to say that if we had some bad experiences with the first release(s) of
these environments, we always had terrible experiences with all versions of
several PC-based Ada environments, specially with the debuggers which could not 
be considered usable. Meridian used to insert debugging code, which resulted in
having a debug version working, but not the straight one. You can't consider
that such environments are professionnal tools. They are good enough to
learn at home or at school, to develop a couple a toy-size gizmos, but not
100s KLOC multitasking/safety critical/embedded/distributed applications. 
I know that a few teams have done that in the past, and I recognize their
talent. But they would have saved a lot of energy/frustration/money with real
environments on real platforms.
----------------------------------------------------------------------------
--   Loic Briand    lpb@sei.cmu.edu      Office 3308      (412) 268-6674  --
----------------------------------------------------------------------------