Re: GNAT Opinions

[Steven Hovater <nh-ho@mediaone.net>]

Well, speaking from a Rational viewpoint ( I'm a technical representative for
Rational, spend all
my time supporting the VADS and Apex accounts in our area), I'm a little taken
aback by your
comment regarding support for Verdix (now Rational) products on Digital Unix. I
can say for certain
that we have a version of the self-hosted VADS compiler (6.2.5)  that runs on
4.0d.

I have heard nothing officially regarding a pending termination of support for
this product. It it true
that our new technology (including Ada95) is going into the Apex product
line(both Unix and NT).

Suggest you contact your local Rational representative for further information.
(see www.rational.com).

Cheers,
Steve

Pascal MALAISE wrote:

> choboy@calspan.com wrote:
> > I'm looking for opinions from people
> > who may have used GNAT in a large-scale development effort such as ours or
> > perhaps did some trade studies that resulted in a GNAT go/no-go decision.
>
> Knowing that Verdix products will soon not be supported (on Digital Unix
> at least)
> and considering the price of the APEX package, we are starting a similar
> study.
> At present, this is just a study which involves a double migration, from
> DU 4.0 to Linux and from Verdix to Gnat (in 95 mode).
>
> For the compiler quality, nothing to say, except that
> - gnat compiling policy is restrictive, and despite the *nice* gnatchop,
> it is difficult to maintain both versions with unique sources. It is
> difficult
> to insert gnat compilation within an existing (and Verdix oriented) ada
> CASE
> environment.
> - gnat reliability, as a compiler, looks good. It better detects unused
> and
> non initialized variables. No compiler bugs have been detected so far.
> - gnat has some (specific or ada 95?) constraints on representation
> clauses
> which have to be defined before the usage of the type which forbids to
> put
> them in private parts, by instance.
>
> For the scale and progress of our study,
> - we migrate the middleware (which is mainly in C with ADA interfaces)
> - we migrate a demonstration program in Ada 83 to Gnat in 95
> - everything compiles so far, but no attempt hs been made to run the
> result,
> which tempers my remark about gnat reliability, but we forsee to achieve
> the migration by the end of Feb.
> - we don't use Ada Core Tech support
>
> As a conclusion, so far so good. This migration does not raise more
> problems
> than other migration (to decada or Aonix).
>
> --
> Pascal MALAISE
> (priv) mailto:malaise@magic.fr
> (prof) mailto:malaise@fr.airsysatm.thomson-csf.com

--
Steven
Hovater
svh@rational.com
Software Engineering Consultant
Phone/fax:781-676-2565/2500
Rational
Software
Pager: 888-906-2209
83 Hartwell Ave, Lexington, MA
Amateur radio: AA1YH