Re: New Ada portable GUI Library?

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

Gautier <gautier@fakeaddress.nil> writes:

> Ah, so it was just a question of switching -gnatE !!
> I guess that even seasoned Ada programmers using GNAT don't wake up each
> morning saying "Oh, without -gnatE, GNAT is not an Ada compiler legally
> speaking. G'morning, Darling, by the way".

:-)

If you develop code from scratch, you probably don't want -gnatE.
GNAT will impose some fairly minor restrictions on you,
and in return you get a statically determined elaboration
order that will work, and you don't have to mess around
with the various elaboration control pragmas.  And you
can avoid the run-time overhead of elaboration checks on
every call.

If you also want to port to non-GNAT compilers, there's an option in
GNAT that will tell you where to put those pragmas.  It's nearly
impossible to do it correctly without that help!

If you have code developed on a non-GNAT compiler, then you might well
want -gnatE.  On the other hand, you might want to fix the code so it
works without -gnatE, but that can be a lot of work!

If anybody is confused about elaboration, there's a long section in the
GNAT User's Guide that explains it all quite nicely (much more clearly
than the Ada RM!).

- Bob