!oidcmp(old_oid, new_oid) && (old_mode == new_mode))
                return;
 
-       if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
+       if (opt->flags.reverse_diff) {
                SWAP(old_mode, new_mode);
                SWAP(old_oid, new_oid);
                SWAP(old_path, new_path);
        rev.diffopt.stat_graph_width = -1;
 
        /* Default to let external and textconv be used */
-       DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
-       DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
+       rev.diffopt.flags.allow_external = 1;
+       rev.diffopt.flags.allow_textconv = 1;
 
        if (nongit)
                die(_("Not a git repository"));
                diff_setup_done(&rev.diffopt);
        }
 
-       DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
+       rev.diffopt.flags.recursive = 1;
 
        setup_diff_pager(&rev.diffopt);
 
                                add_head_to_pending(&rev);
                                if (!rev.pending.nr) {
                                        struct tree *tree;
-                                       tree = lookup_tree(&empty_tree_oid);
+                                       tree = lookup_tree(the_hash_algo->empty_tree);
                                        add_pending_object(&rev, &tree->object, "HEAD");
                                }
                                break;