Function rustc_incremental::build_dep_graph

pub fn build_dep_graph(
    sess: &Session,
    prev_graph: SerializedDepGraph,
    prev_work_products: FxHashMap<WorkProductId, WorkProduct>
) -> Option<DepGraph>

Builds the dependency graph.

This function creates the staging dep-graph. When the dep-graph is modified by a query execution, the new dependency information is not kept in memory but directly output to this file. save_dep_graph then finalizes the staging dep-graph and moves it to the permanent dep-graph path