Re: Ada Core Technologies and Ada95 Standards

[dewar@cs.nyu.edu (Robert Dewar)]

Ken said

"Robert Dewar wrote:
>
> Ken said
>
> "> A comparison would be if 20 different vendors wrote completely different
> > F22 software, with different cockpit interfaces.
>
> Twenty sounds a little low, but that's close enough...."
>
> Are you really saying that the ENTIRE F22 software is duplicated by 20
> vendors?

Nope. Of course, that's not what you asked. See original quote above. :)

However, we've certainly had multiple vendors write the same software (N-version
programming) on previous programs. I don't like that approach myself, but
that's a different discussion.

Of course, it doesn't matter whether or not twenty vendors wrote the same
software, or different software going into the same system, with respect to
the question you asked."

OK, that makes sense -- I couldn't imagine that the F22 was indeed like
the compiler field, where we have multiple vendors generating complete
Ada systems for the same target. That IS exactly what I asked, sorry if
I was not clear, and it matters very much. We were talking about taking
failures and creating industry wide regression suites. This is very hard
to do across more than one vendor.. For example, a lot of our tests in
our suite check 

   o text of error messages generated
   o performance and behavior of GNAT specific features
   o particular GNAT choices for implementation dependent behavior

None of these are useful multi-vendor tests, at least not without a lot
of work, which would only recognize some of them.

Other tests in our suite are white-box (path coverage) type tests baed
on the specific algorithms used by GNAT. They are runnable, but not
especially useful, on other compilers.

Nevertheless there are a lot of tests in regression suites that could
be generally used. If we put a test in our suite that seems clearly
related to ACVC-type conformance testing, I send it along to the ACVC
folks for inclusion.

As an example of cross-vendor use of test suites, one of the important
aspects of our agreement with DEC is that we wlil have access to the
DEC test suite. It will take a lot of work to adapt that suite, and part
of the reason that it is feasible is that we are committed to a very
high degree of compatibility with Dec Ada.