[Patch, Fortran, 66035, v1] [5/6 Regression] gfortran ICE segfault

[Mikael Morin]

Le 08/05/2015 15:29, Andre Vehreschild a écrit :
> Hi all,
> 
> please find attached a patch for 66035. An ICE occurred when in a structure
> constructor an allocatable component of type class was initialized with an
> existing class object. This was caused by 
> 
> - the size of the memory to allocate for the component was miscalculated,
> - the vptr was not set correctly, and
> - when the class object to be used for init was allocatable already, it was
>   copied wasting some memory instead of a view_convert inserted.
> 
> All of the above are fixed by the attached patch.
> 
> Bootstraps and regtests ok on x86_64-linux-gnu/f21 for trunk and gcc-5-trunk.
> 
> Ok for trunk and gcc-5-trunk?
> 
> Regards,
> 	Andre
> 
> 
> pr66035_1.patch
> 
> diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
> index cf607d0..402d9b9 100644
> --- a/gcc/fortran/trans-expr.c
> +++ b/gcc/fortran/trans-expr.c
> @@ -6881,6 +6881,30 @@ alloc_scalar_allocatable_for_subcomponent_assignment (stmtblock_t *block,
>  				       TREE_TYPE (tmp), tmp,
>  				       fold_convert (TREE_TYPE (tmp), size));
>      }
> +  else if (cm->ts.type == BT_CLASS)
> +    {
> +      gcc_assert (expr2->ts.type == BT_CLASS || expr2->ts.type == BT_DERIVED);
> +      if (expr2->ts.type == BT_DERIVED)
> +	{
> +	  tmp = gfc_get_symbol_decl (gfc_find_vtab (&expr2->ts));
> +	  tmp = gfc_build_addr_expr (NULL_TREE, tmp);
> +	  size = fold_convert (size_type_node, gfc_vptr_size_get (tmp));
> +	}
Use TYPE_SIZE_UNIT of the rhs in this case, in the same way as in the
else branch further below.

> +      else
> +	{
> +	  gfc_expr *e2vtab;
> +	  gfc_se se;
> +	  e2vtab = gfc_find_and_cut_at_last_class_ref (expr2);
> +	  gfc_add_vptr_component (e2vtab);
> +	  gfc_add_size_component (e2vtab);
> +	  gfc_init_se (&se, NULL);
> +	  gfc_conv_expr (&se, e2vtab);
> +	  gfc_add_block_to_block (block, &se.pre);
> +	  size = fold_convert (size_type_node, se.expr);
> +	  gfc_free_expr (e2vtab);
> +	}
> +      size_in_bytes = size;
> +    }
>    else
>      {
>        /* Otherwise use the length in bytes of the rhs.  */
> @@ -7008,7 +7032,9 @@ gfc_trans_subcomponent_assign (tree dest, gfc_component * cm, gfc_expr * expr,
>        gfc_add_expr_to_block (&block, tmp);
>      }
>    else if (init && (cm->attr.allocatable
> -	   || (cm->ts.type == BT_CLASS && CLASS_DATA (cm)->attr.allocatable)))
> +	   || (cm->ts.type == BT_CLASS && CLASS_DATA (cm)->attr.allocatable
> +	       && (expr->ts.type != BT_CLASS
> +		   || CLASS_DATA (expr)->attr.allocatable))))
maybe:             || !CLASS_DATA (expr)->attr.allocatable
(with a '!')?

Mikael