Re: [tuples] dereference POINTER_PLUS_EXPR check

["Richard Guenther" <richard.guenther@gmail.com>]

On Nov 21, 2007 10:52 PM, Aldy Hernandez <aldyh@redhat.com> wrote:
> > Maybe we could make this a helper in tree.c.  Something like
> > pointed_to_type().  I don't think one exists already, but I may be wrong.
>
> Things are a bit cleaner now too, bonus!
>
> Is this OK?

No, sorry.  It doesn't make sense to check the pointed-to types.  Or do you
say the modify expr embeds a de-reference?

Richard.

>         * tree.c (pointed_to_type): New.
>         * tree.h (pointed_to_type): Protoize.
>         * tree-cfg.c (verify_types_in_gimple_assign): Use the dereferenced
>         type when checking the validity of a POINTER_PLUS_EXPR.
>
> Index: tree.c
> ===================================================================
> --- tree.c      (revision 130313)
> +++ tree.c      (working copy)
> @@ -8833,4 +8833,14 @@ block_nonartificial_location (tree block
>    return ret;
>  }
>
> +/* Given a tree type T, drill down to the type it points to and return
> +   it.  */
> +tree
> +pointed_to_type (tree t)
> +{
> +  while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
> +    t = TREE_TYPE (t);
> +  return t;
> +}
> +
>  #include "gt-tree.h"
> Index: tree.h
> ===================================================================
> --- tree.h      (revision 130313)
> +++ tree.h      (working copy)
> @@ -4918,6 +4918,7 @@ extern tree *tree_block (tree);
>  extern tree *generic_tree_operand (tree, int);
>  extern tree *generic_tree_type (tree);
>  extern location_t *block_nonartificial_location (tree);
> +extern tree pointed_to_type (tree);
>
>  /* In function.c */
>  extern void expand_main_function (void);
> Index: tree-cfg.c
> ===================================================================
> --- tree-cfg.c  (revision 130313)
> +++ tree-cfg.c  (working copy)
> @@ -3558,8 +3558,16 @@ verify_types_in_gimple_assign (gimple st
>             error ("invalid operands in pointer plus expression");
>             return true;
>           }
> -       if (!POINTER_TYPE_P (rhs1_type)
> -           || !useless_type_conversion_p (lhs_type, rhs1_type)
> +
> +       if (!POINTER_TYPE_P (lhs_type)
> +           || !POINTER_TYPE_P (rhs1_type))
> +         {
> +           error ("type mismatch in pointer plus expression");
> +           return true;
> +         }
> +
> +       if (!useless_type_conversion_p (pointed_to_type (lhs_type),
> +                                       pointed_to_type (rhs1_type))
>             || !useless_type_conversion_p (sizetype, rhs2_type))
>
>           {
>             error ("type mismatch in pointer plus expression");
>