Re: Dynamic allocation in the predefined language environment

[Matthias-Christian Ott <ott@mirix.org>]

On 06/07/15 13:04, G.B. wrote:
> On 06.07.15 13:13, Matthias-Christian Ott wrote:
> 
>> Unbounded-length strings do not have this limitation but requires
>> dynamic memory allocation (or at least I see no other way to implement
>> it) which in turn requires error handling of memory allocation errors.
>> However, if I'm not mistaken neither Ada 95, nor Ada 2005, nor Ada 2012
>> specify how memory allocation errors are to be reported or handled and
>> do not allow one to specify the storage pool from which unbounded-length
>> strings are allocated.
> 
> I think that LRM 13.11 might apply here (coming from LRM 4.8),
> 
> "If Storage_Pool is not specified for a type defined by an
>  access_to_object_definition, then the implementation chooses
>  a standard storage pool for it in an implementation-defined
>  manner.  In this case, the exception Storage_Error is raised
>  by an allocator if there is not enough storage."
> 
> A handler then, if possible, could be of the kind that
> does not require additional resources for its execution.
> It might be more tricky to use one with tasks, but IIUC,
> one can attach termination handlers.

That should work. But what if the implementation does not use access
types or storage pools to implement unbounded-length strings? The
standard simply doesn't specify the behaviour or implementation of the
package with regards to memory management.

- Matthias-Christian