Re: [PATCH] PR fortran/101536 - ICE in gfc_conv_expr_descriptor, at fortran/trans-array.c:7324

[Tobias Burnus <tobias@codesourcery.com>]

Hi Harald,

On 21.07.21 22:22, Harald Anlauf via Fortran wrote:
> Another one of Gerhard's infamous testcases.  We did not properly detect
> and reject array elements of type CLASS as argument to an intrinsic when
> it should be an array.
>
> Regtested on x86_64-pc-linux-gnu.  OK for mainline / 11-branch when it
> reopens?
...
> +    class(t), allocatable :: x(:)
> +    f = size (x(1)) ! { dg-error "must be an array" }
...
>    if (e->ts.type == BT_CLASS && gfc_expr_attr (e).class_ok
>          && CLASS_DATA (e)->attr.dimension
>          && CLASS_DATA (e)->as->rank)
>      {
> +      if (e->ref && e->ref->type == REF_ARRAY
> +       && e->ref->u.ar.type == AR_ELEMENT)
> +     goto error;

I think that one is wrong. While CLASS_DATA (e) accesses e->ts.u.derived->components,
which always works, your code assumes that there is only 'c' and not 'x%c' where
'c' is of type BT_CLASS and 'x' is of type BT_DERIVED.

I wonder whether it works if you simply remove 'return true;'
as gfc_add_class_array_ref sets 'e->rank = CLASS(e)->rank (and
adds an AR_FULL ref, if needed). In the nonerror case, the
'return true' is obtained via:
    if (e->rank != 0 && e->ts.type != BT_PROCEDURE)
      return true;
And, otherwise, it falls through to the error.

OK if that works – but please also add a test like

type t
   class(*), allocatable :: c(:)
end type t
type(t) :: x
x%c = [1,2,3,4]
print *, size(x%c)
print *, size(x%c(1)) ! { dg-error ... }
end

Thanks,

Tobias

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