[Patch, fortran] PR70853 - ICE on pointing to null, in gfc_add_block_to_block, at fortran/trans.c:1599

[Tobias Burnus]

LGTM. Thanks for the patch!

Tobias

PS: I assume, your patch also fixes the following test case, which also 
ICEs in gfc_trans_pointer_assignment:
integer, pointer, contiguous :: x(:)
nullify(x(1:1))
end

On 12/18/19 5:07 PM, Harald Anlauf wrote:
> The patch is self-explaining and practically obvious: pointer bounds
> remapping to NULL is not allowed, thus we shall reject it.  I hope the
> error message is fine.  If somebody prefers a formulation as in the
> standard ("data target", also used by the Intel compiler), please
> speak now.
>
> Regtested on x86_64-pc-linux-gnu.
>
> OK for trunk?
>
> Thanks,
> Harald
>
> Index: gcc/fortran/trans-expr.c
> ===================================================================
> --- gcc/fortran/trans-expr.c    (Revision 279405)
> +++ gcc/fortran/trans-expr.c    (Arbeitskopie)
> @@ -9218,6 +9218,13 @@ gfc_trans_pointer_assignment (gfc_expr * expr1, gf
>            break;
>         rank_remap = (remap && remap->u.ar.end[0]);
>
> +      if (remap && expr2->expr_type == EXPR_NULL)
> +       {
> +         gfc_error ("If bounds remapping is specified at %L, "
> +                    "the pointer target shall not be NULL", &expr1->where);
> +         return NULL_TREE;
> +       }
> +
>         gfc_init_se (&lse, NULL);
>         if (remap)
>          lse.descriptor_only = 1;
>
>
> Index: gcc/testsuite/gfortran.dg/pr70853.f90
> ===================================================================
> --- gcc/testsuite/gfortran.dg/pr70853.f90       (nicht existent)
> +++ gcc/testsuite/gfortran.dg/pr70853.f90       (Arbeitskopie)
> @@ -0,0 +1,8 @@
> +! { dg-do compile }
> +! PR fortran/70853
> +! Contributed by Gerhard Steinmetz
> +program p
> +   real, pointer :: z(:)
> +   z(1:2) => null() ! { dg-error "pointer target shall not be NULL" }
> +   z(2:1) => null() ! { dg-error "pointer target shall not be NULL" }
> +end
>
>
> 2019-12-18  Harald Anlauf  <anlauf@gmx.de>
>
>          PR fortran/92898
>          * trans-expr.c (gfc_trans_pointer_assignment): Reject bounds
>          remapping if pointer target is NULL().
>
>
> 2019-12-18  Harald Anlauf  <anlauf@gmx.de>
>
>          PR fortran/70853
>          * gfortran.dg/pr70853.f90: New test.