Re: compiler settings in AdaGIDE

[Robert A Duff <bobduff@shell01.TheWorld.com>]

sjw <simon.j.wright@mac.com> writes:

> On Jul 23, 4:22�pm, Georg Bauhaus <rm.dash-bauh...@futureapps.de>
> wrote:
>> On 23.07.10 17:16, Robert A Duff wrote:
>>
>> >> ...Or turn off all checks (-gnatp). �The program is no
>> >> standard Ada program then, but since your program is correct... :-)
>>
>> > It's still a standard Ada program.
>>
>> Without -gnato?

Sure.  How could compiler switches affect some property
("standardness") of the text of an Ada program?

> -gnato is one of the things you have to do to make GNAT a conforming
> Ada compiler.

Well, not really.  If you don't say -gnato, then GNAT is implicitly
assuming "pragma Suppress(Overflow_Check);".  That's a standard
feature of Ada, and the compiler writer gets to decide how
source text is represented.  If you don't want that text as
part of your program, say "-gnato".

Similarly, if you say "-gnatn", GNAT is implicitly including
"pragma Suppress(All_Checks);" as part of your program text.

I realize this argument is a bit of a cheat.

And I think overflow checks should be turned on by default.
But I don't think it's a conformance issue, formally speaking
-- GNAT conforms with or without -gnatn or -gnato.

Without -gnatE (dynamic elaboration checks), on the other hand, GNAT is
nonconforming, because it rejects some legal programs, and you can't
play the above "source representation" game.  I think it's good
that it's nonconforming in this case, because the default behavior
(static elaboration checks) is better than the standard way,
and it doesn't harm portability.

- Bob