Re: Separate Compilation in Programming Languages

[<adaworks@sbcglobal.net>]

"Ray Blaak" <rAYblaaK@STRIPCAPStelus.net> wrote in message 
news:uhcfv5xql.fsf@STRIPCAPStelus.net...
>
> Does the existence of gnatmake indicate corrupted dependency management in
> Ada?
>
No. It might indicate a problem with the GNAT implementation, but not
with Ada.  Not all Ada compilers are GNAT, and some handle this
more easily.   One of the issues for GNAT is that it depends on
the GNU model.  This is not true of Rational Apex, Aonix, or
even the ICC compiler.

> I program in a lot of languages, and I used to be heavily into Ada. I just do
> not encounter the problem in a serious way with the other languages.
>
I also program in a lot of languages.  I even program in Java sometimes.
However, I have not programmed any large-scale programs in Java,
as I have in Ada.

Although you have certainly made your point that my original statement
may have been too strong, this conversation has, as noted in another
contribution, led me to do some research into this issue.  What I have
found is not encouraging.  In fact, it is even a little horrifying.

As Java programs get larger, the dependency problems become more
and more messy.   Over and over this is discussed by  various forums
on the Internet.   Until I began researching this, I had not idea just how
pervasive the problem was in Java.

Apparently, for toy programs, and small projects this problem with Java
does not manifest itself.  However, as Java programs get larger, the
programmers are required to do a lot of workarounds.   Further, the
compiler does not actually trap all the kinds of errors that can occur
with dependency issues.  Third-party tools are required to analyze these
problems, and those third-party tools are not foolproof -- at least, not
so far.

> I easily agree that Ada is better at this, but in every language I use
> currently, there are always ways to readily control dependency and separate
> compilation issues.
>
This may be true in your practice, but there are hundreds of developers out
there who are find this to be a real problem.   As I see it right now, Ada
continues to be a much better solution when a software architecture is
large and needs to scale-up to even larger.

The scary thing for me, now that I am in the DoD, is that so many contractors
are naive about this issue and continue to insist on using Java for weapon
systems development. In my view, based on this week's research, Java should
not be used for safety-critical systems.  There are too many possibilities for
serious hidden problems based on these dependency issues.   It is probably
OK for Web solutions, but no one will accidentally get killed or maimed
because of a corrupted Internet solution.   Ooooops!   I forgot about SOA
where reusable components are integrated into safety-critical solutions.  I
guess it is better to be safe and not use it at all for any kind of software
where life and limb could be at risk.

Richard Riehle