Re: gdb can't print array element for fortran

[Joel Brobecker <brobecker at adacore dot com>]

> This mail pertains to the discussion had on gdb mailing list sometime
> back here  http://sourceware.org/ml/gdb-patches/2009-01/msg00251.html.
> After a small discussion with Jan I made the following changes and 
> these didn't seem to work. Any inputs or thoughts would be helpful. 

Does anyone else have an opinion on this patch.  It looks wrong to me
(sorry Chandru): Arrays with a high bound that's less than the low bound
can exist, at least in Ada. It's just an empty array.

I haven't looked at Jan's work for the Fortran VLA stuff in a while,
so I can't remember how he dealt with this issue.  But I think his
approach might be more correct.

> --- src/gdb/gdbtypes.c.orig	2010-02-25 00:00:19.000000000 +0530
> +++ src/gdb/gdbtypes.c	2010-02-25 00:03:16.000000000 +0530
> @@ -727,6 +727,14 @@ create_range_type (struct type *result_t
>    if (low_bound >= 0)
>      TYPE_UNSIGNED (result_type) = 1;
>  
> +  if (high_bound < low_bound)
> +    {
> +      if (high_bound == -1)
> +        TYPE_HIGH_BOUND_UNDEFINED(result_type) = 1;
> +      else
> +        TYPE_HIGH_BOUND_UNDEFINED(result_type) = 0;
> +    }
> +
>    return result_type;
>  }
>  
> --- src/gdb/valarith.c.orig	2010-02-25 00:00:26.000000000 +0530
> +++ src/gdb/valarith.c	2010-02-25 00:04:37.000000000 +0530
> @@ -198,7 +198,7 @@ value_subscripted_rvalue (struct value *
>    unsigned int elt_offs = elt_size * longest_to_int (index - lowerbound);
>    struct value *v;
>  
> -  if (index < lowerbound || elt_offs >= TYPE_LENGTH (array_type))
> +  if (index < lowerbound || ((elt_offs >= TYPE_LENGTH (array_type)) && !TYPE_HIGH_BOUND_UNDEFINED(array_type)))
>      error (_("no such vector element"));
>  
>    v = allocate_value (elt_type);

-- 
Joel