Importing rustc-1.44.0
Change-Id: Ib8f3d986a69f3856ec01ad24097ce18f1654009e
diff --git a/src/librustc_query_system/dep_graph/query.rs b/src/librustc_query_system/dep_graph/query.rs
new file mode 100644
index 0000000..fb313d2
--- /dev/null
+++ b/src/librustc_query_system/dep_graph/query.rs
@@ -0,0 +1,74 @@
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::graph::implementation::{
+ Direction, Graph, NodeIndex, INCOMING, OUTGOING,
+};
+
+use super::{DepKind, DepNode};
+
+pub struct DepGraphQuery<K> {
+ pub graph: Graph<DepNode<K>, ()>,
+ pub indices: FxHashMap<DepNode<K>, NodeIndex>,
+}
+
+impl<K: DepKind> DepGraphQuery<K> {
+ pub fn new(nodes: &[DepNode<K>], edges: &[(DepNode<K>, DepNode<K>)]) -> DepGraphQuery<K> {
+ let mut graph = Graph::with_capacity(nodes.len(), edges.len());
+ let mut indices = FxHashMap::default();
+ for node in nodes {
+ indices.insert(*node, graph.add_node(*node));
+ }
+
+ for &(ref source, ref target) in edges {
+ let source = indices[source];
+ let target = indices[target];
+ graph.add_edge(source, target, ());
+ }
+
+ DepGraphQuery { graph, indices }
+ }
+
+ pub fn contains_node(&self, node: &DepNode<K>) -> bool {
+ self.indices.contains_key(&node)
+ }
+
+ pub fn nodes(&self) -> Vec<&DepNode<K>> {
+ self.graph.all_nodes().iter().map(|n| &n.data).collect()
+ }
+
+ pub fn edges(&self) -> Vec<(&DepNode<K>, &DepNode<K>)> {
+ self.graph
+ .all_edges()
+ .iter()
+ .map(|edge| (edge.source(), edge.target()))
+ .map(|(s, t)| (self.graph.node_data(s), self.graph.node_data(t)))
+ .collect()
+ }
+
+ fn reachable_nodes(&self, node: &DepNode<K>, direction: Direction) -> Vec<&DepNode<K>> {
+ if let Some(&index) = self.indices.get(node) {
+ self.graph.depth_traverse(index, direction).map(|s| self.graph.node_data(s)).collect()
+ } else {
+ vec![]
+ }
+ }
+
+ /// All nodes reachable from `node`. In other words, things that
+ /// will have to be recomputed if `node` changes.
+ pub fn transitive_successors(&self, node: &DepNode<K>) -> Vec<&DepNode<K>> {
+ self.reachable_nodes(node, OUTGOING)
+ }
+
+ /// All nodes that can reach `node`.
+ pub fn transitive_predecessors(&self, node: &DepNode<K>) -> Vec<&DepNode<K>> {
+ self.reachable_nodes(node, INCOMING)
+ }
+
+ /// Just the outgoing edges from `node`.
+ pub fn immediate_successors(&self, node: &DepNode<K>) -> Vec<&DepNode<K>> {
+ if let Some(&index) = self.indices.get(&node) {
+ self.graph.successor_nodes(index).map(|s| self.graph.node_data(s)).collect()
+ } else {
+ vec![]
+ }
+ }
+}
