Method cloneAndReplace

src/Analyzer/IQueryTreeNode.cpp:244–337

}

QueryTreeNodePtr IQueryTreeNode::cloneAndReplace(const ReplacementMap & replacement_map) const
{
    /** Clone tree with this node as root.
      *
      * Algorithm
      * For each node we clone state and also create mapping old pointer to new pointer.
      * For each cloned node we update weak pointers array.
      *
      * After that we can update pointer in weak pointers array using old pointer to new pointer mapping.
      */
    std::unordered_map<const IQueryTreeNode *, QueryTreeNodePtr> old_pointer_to_new_pointer;
    std::vector<QueryTreeNodeWeakPtr *> weak_pointers_to_update_after_clone;

    QueryTreeNodePtr result_cloned_node_place;

    std::vector<std::pair<const IQueryTreeNode *, QueryTreeNodePtr *>> nodes_to_clone;
    nodes_to_clone.emplace_back(this, &result_cloned_node_place);

    while (!nodes_to_clone.empty())
    {
        const auto [node_to_clone, place_for_cloned_node] = nodes_to_clone.back();
        nodes_to_clone.pop_back();

        auto already_cloned_node_it = old_pointer_to_new_pointer.find(node_to_clone);
        if (already_cloned_node_it != old_pointer_to_new_pointer.end())
        {
            *place_for_cloned_node = already_cloned_node_it->second;
            continue;
        }

        auto it = replacement_map.find(node_to_clone);
        auto node_clone = it != replacement_map.end() ? it->second : node_to_clone->cloneImpl();
        *place_for_cloned_node = node_clone;

        old_pointer_to_new_pointer.emplace(node_to_clone, node_clone);

        if (it != replacement_map.end())
            continue;

        node_clone->original_ast = node_to_clone->original_ast;
        node_clone->setAlias(node_to_clone->alias);
        node_clone->parenthesized = node_to_clone->parenthesized;
        node_clone->children = node_to_clone->children;
        node_clone->weak_pointers = node_to_clone->weak_pointers;

        for (auto & child : node_clone->children)
        {
            if (!child)
                continue;

            nodes_to_clone.emplace_back(child.get(), &child);
        }

        for (auto & weak_pointer : node_clone->weak_pointers)
        {
            weak_pointers_to_update_after_clone.push_back(&weak_pointer);
        }
    }