Re: Possible compiler bug with this simple program

[Adam Beneschan <adam@irvine.com>]

On Sep 3, 6:31 pm, "Jeffrey R. Carter"
<spam.jrcarter....@spam.acm.org> wrote:

> Ada needs to know what the lower bound of this array parameter is, and
> apparently your compiler is getting it wrong.

One other thing that probably ought to be mentioned: It's possible
that the compiler is trying to determine the lower bound by looking at
some memory location where it expects the lower bound to be, but in
reality (since the Ada routine is being called from C) contains a
random value previously used for something else.  My experience is
that memory locations with random values contain zero a high
percentage of the time, so it would make sense that the program would
happen to work on some platforms, or on some targets.  If I understood
the original post correctly, the program seemed to be working on some
platforms but not others, and it could well be because of this random
factor.  It doesn't mean the compiler or the program were correct on
those platforms.


> Using a constrained array type

or subtype, I think.


> with a lower bound of zero and an upper bound as large or larger than can occur
> would be the best choice for this situation.

                                -- Adam