Function rustc_query_system::query::plumbing::ensure_must_run

fn ensure_must_run<CTX, K, V>(
    tcx: CTX, 
    key: &K, 
    query: &QueryVtable<CTX, K, V>
) -> (bool, Option<DepNode<CTX::DepKind>>) where
    K: DepNodeParams<CTX::DepContext>,
    CTX: QueryContext, 

Ensure that either this query has all green inputs or been executed. Executing query::ensure(D) is considered a read of the dep-node D. Returns true if the query should still run.

This function is particularly useful when executing passes for their side-effects – e.g., in order to report errors for erroneous programs.

Note: The optimization is only available during incr. comp.