[PATCH] Verify GIMPLE_MODIFY_STMT

[Richard Guenther <rguenther at suse dot de>]

This is not verified at all and fails badly.  The following patch adds
the verification and fixes the most obvious problems (nested functions
remain broken).  It seems like the DECL_GIMPLE_FORMAL_TEMP_P concept
is broken somewhat.

I'm currently bootstrapping the patch, I know that 
gcc.c-torture/compile/20030418-1.c fails (nested functions with invalid
gimple).

Ok for trunk if this doesn't break bootstrap?

Thanks,
Richard.

2008-07-02  Richard Guenther  <rguenther@suse.de>

	* tree-gimple.c (is_gimple_addressable): Allow TARGET_MEM_REF.
	* gimplify.c (pop_gimplify_context): Do not reset
	DECL_GIMPLE_FORMAL_TEMP_P.
	(build_stack_save_restore): Set DECL_GIMPLE_FORMAL_TEMP_P on the temp.
	* tree-cfg.c (verify_expr): Verify GIMPLE_MODIFY_STMT properly.

Index: tree-gimple.c
===================================================================
*** tree-gimple.c	(revision 137252)
--- tree-gimple.c	(working copy)
*************** bool
*** 162,168 ****
  is_gimple_addressable (tree t)
  {
    return (is_gimple_id (t) || handled_component_p (t)
! 	  || INDIRECT_REF_P (t));
  }

  /* Return true if T is a valid gimple constant.  */
--- 162,169 ----
  is_gimple_addressable (tree t)
  {
    return (is_gimple_id (t) || handled_component_p (t)
! 	  || INDIRECT_REF_P (t)
! 	  || TREE_CODE (t) == TARGET_MEM_REF);
  }

  /* Return true if T is a valid gimple constant.  */
Index: gimplify.c
===================================================================
*** gimplify.c	(revision 137252)
--- gimplify.c	(working copy)
*************** pop_gimplify_context (tree body)
*** 194,202 ****
    gcc_assert (c && !c->current_bind_expr);
    gimplify_ctxp = c->prev_context;

-   for (t = c->temps; t ; t = TREE_CHAIN (t))
-     DECL_GIMPLE_FORMAL_TEMP_P (t) = 0;
-
    if (body)
      declare_vars (c->temps, body, false);
    else
--- 194,199 ----
*************** build_stack_save_restore (tree *save, tr
*** 1070,1075 ****
--- 1067,1073 ----
    save_call =
      build_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE], 0);
    tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
+   DECL_GIMPLE_FORMAL_TEMP_P (tmp_var) = 1;

    *save = build_gimple_modify_stmt (tmp_var, save_call);
    *restore =
Index: tree-cfg.c
===================================================================
*** tree-cfg.c	(revision 137252)
--- tree-cfg.c	(working copy)
*************** verify_expr (tree *tp, int *walk_subtree
*** 3197,3202 ****
--- 3197,3207 ----
        gcc_unreachable ();

      case GIMPLE_MODIFY_STMT:
+       if (!rhs_predicate_for (GIMPLE_STMT_OPERAND (t, 0))(GIMPLE_STMT_OPERAND (t, 1)))
+ 	{
+ 	  error ("Invalid rhs for GIMPLE_MODIFY_STMT lhs");
+ 	  return t;
+ 	}
        x = GIMPLE_STMT_OPERAND (t, 0);
        if (TREE_CODE (x) == BIT_FIELD_REF
  	  && is_gimple_reg (TREE_OPERAND (x, 0)))