[Fortran, Patch, pr65795, v1] Segfault (invalid write) for ALLOCATE statement involving COARRAYS

[Jerry DeLisle]

On 04/03/2016 06:35 AM, Andre Vehreschild wrote:
> Hi all,
> 
> attached patch fixes a segfault when allocating a coarray of a type
> that has allocatable components. Before the patch the compiler tried
> to ref the component to nullify from the coarray's base address and not
> from its .data component. The proposed patch fixes this by preventing
> the nullify of the components in the array_allocate() for coarrays,
> because the components are nullified again afterwards by copying a
> fully nullified copy of the type to the coarray's data component.
> 
> There albeit is an alternative to this patch:
> 
> trans-array.c: 5556+
> 
> -       tmp = gfc_nullify_alloc_comp (expr->ts.u.derived, se->expr,
> +       tmp = gfc_nullify_alloc_comp (expr->ts.u.derived, coarray ?
> +  						pointer : se->expr, 
> 				      ref->u.ar.as->rank);
> 
> The above adds a second nullify to the generated code before the one
> done the object copy mentioned above. 
> 
> Because I am unsure which patch is best, I propose both. I do favor of
> course the one without the duplicate nullify as attached.
> 
> Bootstrapped and regtested ok on x86_64-linux-gnu/F23. Ok for trunk?
> 
> The patch also applies (with a small delta) to gcc-5 w/o any
> regressions. Ok for gcc-5-branch?
> 
> Regards,
> 	Andre
> 

OK for trunk and gcc-5. Go with your preferred.

Jerry