Re: Idea: use JGNAT for memory debugging?

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

porton@ex-code.com (Victor Porton) writes:

> I have a problem with an Ada program, which is possibly access to a 
> dangling reference (e.g. after Unchecked_Deallocation).
> 
> Do I guess rightly that JGNAT (as opposed to normal Gnat) will detect 
> this problem for me? 

No. Instead, it will silently "fix" it for you; it won't actually
deallocate the object until all the references are truly gone.

> Is JGNAT free?

Yes, in both the license and cost sense.

> In general how to find dereferencing dangling references in Ada? I
> would use an OO wrapper around accesses which would do reference
> counting (in debug mode), but living entirely without accesses seems
> bad.

I agree, living without accesses is bad. But apparently you are also
copying accesses; that takes more care.

Reference counting is probably the best way to go here. But done
right, it will only mask your problem (since the reference count will
be incremented by the copy).

So it depends on what you think "the problem" is; have you made an
unnecessary copy of a pointer, or have you deallocated something
before you were truly done with it? A careful review of your
allocation/deallocation/copying policies and design will help.

-- 
-- Stephe