Function removeAliasesRecursive

src/Analyzer/Resolve/QueryAnalyzer.cpp:207–222

Recursively clears aliases from `node` and all of its descendants, stopping at nested-scope boundaries (`QUERY`, `UNION`, `LAMBDA`). Background: during identifier resolution, when an identifier resolves to an alias (e.g. `cond` in `PREWHERE cond` resolves to the projection alias `cond`), the alias body is deep-cloned and the clone replaces the identifier. Only the clone's root is registered for l

/// scopes that are responsible for their own alias cleanup, so the walk stops at their
/// boundary.
void removeAliasesRecursive(QueryTreeNodePtr & node)
{
    if (!node)
        return;

    node->removeAlias();

    auto node_type = node->getNodeType();
    if (node_type == QueryTreeNodeType::QUERY
        || node_type == QueryTreeNodeType::UNION
        || node_type == QueryTreeNodeType::LAMBDA)
        return;

    for (auto & child : node->getChildren())
        removeAliasesRecursive(child);
}

}