Re: Accessibility and possible Gnat bug

[Tero Koskinen <tero.koskinen@iki.fi>]

19.12.2014, 17:35, Michael B. kirjoitti:
> In the previous discussion about accessibility I was pointed to the
> paper "Accessibility rules OK!" of John Barnes (ACM SIGAda Ada Letters
> Volume XV Issue 1, Jan./Feb. 1995) which contains the following example:
>
> procedure Example6  is
...
>           P1(Z'Access);   -- Raises Program_Error.
...
> end Example6;
>
> In the paper the program is expected to run without errors.
> I compiled it with Gnat 4.9 on Debian 8.0, ran it and got an
> Program_Error on the marked line.
>
> Is this correct in Ada 2012 or not? I would like to hear your opinion
> about that before I write a possibly unnecessary bug report to AdaCore.

I don't know what the standard actually says, but Irvine ICCAda
generates executable, which does not raise exception when
the code is compiled in Ada 2005 mode.

Also, Janus/Ada generates executable, which does not raise exception,
when Janus/Ada uses Ada 95 mode.

GNAT GPL 2013 always generates executable, which raises exception.
(Tested with -gnat95 and -gnat2012 flags).

Yours,
  Tero