Re: Ada Operating System

["Marin David Condic" <dont.bother.mcondic.auntie.spam@[acm.org>]

1) Which Ada compiler? There is no "The Ada Compiler". Each one is going to
be implemented differently. Given that, some compilers may be written in C,
others in Ada, some possibly in obscure languages like BLISS - did DEC do
that with their compiler? The first validated compiler was written in SETL.

2) Note that Gnat is developed in Ada. Sure, it has the gcc back end and all
that, but that's just leveraging some existing body of code. Ada can be, and
has been, used to implement Ada compilers.

3) Assuming for a moment that a given Ada compiler is developed in C - and
that the implementation (being in C) is particularly buggy, how does that
have anything to do with the quality of the output? Even a buggy program
might make highly reliable output - if and when it works.

4) The ACVC doesn't really have much to do with the "quality" of an Ada
compiler. What it does is test it for conformance to the rules - which may
act as a useful test suite & help you produce a better quality product.
(Conformance to the rules being one aspect of "quality", I suppose we could
consider it an aid to getting there.) A compiler can pass the ACVC and still
produce inefficient, buggy code, so its no guarantee.

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/


"Adrian Hoe" <byhoe@greenlime.com> wrote in message
news:9ff447f2.0202222044.78c44b25@posting.google.com...
>
> Sometime ago, I was thrown a question while giving talks in
> Universities. "What language do they use to build the Ada compiler?"
> and an (assumed) answer from the audience was "C". Then raised another
> question: "If Ada has many safety features that C does not have and
> the Ada compiler was written in C, how exactly safe is Ada?"
>
> I know there is ACVC test suite out there to certify Ada compilers
> before they reach out the market. But then, why still use C to write
> an Ada compiler?
>