Re: GNAT 3.3 vs 3.15

[Stephen Leake <Stephen.A.Leake@nasa.gov>]

David Holm <david@realityrift.com> writes:

> What are the problems of using GNAT 3.3 over 3.15? 

I'm not clear what you mean by "GNAT 3.3"; there is no such thing
according to ACT. I guess you mean "The Ada compiler that comes with
GCC 3.3". What does "gnatmake -v" say about the version?

> What is new since 3.15? 

Bugs. The main difference is the gcc 3.x backend; it has a lot of
changes since the gcc 2.8 that gnat 3.15 is based on. Some of those
changes break GNAT. To be fair, some of them improve GNAT :). ACT is
working on fixing things, but it's a slow process.

For example, the ACT candidate release of GNAT based on gcc 3.x
(called GNAT 5.00a) is now available for customer testing; it has a
bug that stopped me cold. They are fixing it, but I won't be using
GNAT 5.00 (or GCC 3.3) until there is another release from ACT.

> I've been using 3.3 for a while and run it through my test suites
> (some simple floating-point stuff) and so far have had nog problems.

Then you are ok; that's what tests are for, after all!

You should improve your test suite to truly test your application;
that may make you feel more comfortable.

But keep GNAT 3.15 handy; if you encounter a weird problem, try it on
3.15 before you blame your code :).

-- 
-- Stephe