[PATCH] fortran/66043 -- Check for NULL() in STORAGE_SIZE()

[Steve Kargl]

On Fri, May 15, 2015 at 05:34:14PM +0200, FX wrote:
> Hi Steve,
> 
> +      gfc_error ("%qs argument of %qs intrinsic at %L shall not be an "
> +		 "unallocated allocatable variable or a disassociated or "
> +		 "undefined pointer???,
> 
> Given that we know explicitly that the expr is NULL, wouldn't
> it be nicer to give only the relevant condition (here, I guess
> it's "undefined pointer")?

The text above is essentially the wording from the standard.
I was unsure if I could catch all types of errors when I wrote
the error string.

I can change the error to something like

"Intrinsic function NULL() cannot be an actual argument to
STORAGE_SIZE because it returns a disassociated pointer"

>
> Regarding the other example mention in the PR's comment #2,
> I guess there's no requirement for the compiler to diagnose
> this, is there?
>

No.  This isn't a numbered constraint.  I spent an hour or so
tracing though parent namespaces and symbol trees to see if
I could catch the problem in comment #2.  I think that this
would require a runtime error (or adding an internal attribute
that explicitly tracks associate/disassociation and
allocation/deallocation).

-- 
Steve