rustc_middle/dep_graph/
retained.rs

1use rustc_data_structures::fx::FxHashMap;
2use rustc_data_structures::graph::linked_graph::{Direction, INCOMING, LinkedGraph, NodeIndex};
3
4use super::{DepNode, DepNodeIndex};
5
6/// An in-memory copy of the current session's query dependency graph, which
7/// is only enabled when `-Zquery-dep-graph` is set (for debugging/testing).
8///
9/// Normally, dependencies recorded during the current session are written to
10/// disk and then forgotten, to avoid wasting memory on information that is
11/// not needed when the compiler is working correctly.
12pub struct RetainedDepGraph {
13    pub inner: LinkedGraph<DepNode, ()>,
14    pub indices: FxHashMap<DepNode, NodeIndex>,
15}
16
17impl RetainedDepGraph {
18    pub fn new(prev_node_count: usize) -> Self {
19        let node_count = prev_node_count + prev_node_count / 4;
20        let edge_count = 6 * node_count;
21
22        let inner = LinkedGraph::with_capacity(node_count, edge_count);
23        let indices = FxHashMap::default();
24
25        Self { inner, indices }
26    }
27
28    pub fn push(&mut self, index: DepNodeIndex, node: DepNode, edges: &[DepNodeIndex]) {
29        let source = NodeIndex(index.as_usize());
30        self.inner.add_node_with_idx(source, node);
31        self.indices.insert(node, source);
32
33        for &target in edges.iter() {
34            self.inner.add_edge(source, NodeIndex(target.as_usize()), ());
35        }
36    }
37
38    pub fn nodes(&self) -> Vec<&DepNode> {
39        self.inner.all_nodes().iter().map(|n| n.data.as_ref().unwrap()).collect()
40    }
41
42    pub fn edges(&self) -> Vec<(&DepNode, &DepNode)> {
43        self.inner
44            .all_edges()
45            .iter()
46            .map(|edge| (edge.source(), edge.target()))
47            .map(|(s, t)| (self.inner.node_data(s), self.inner.node_data(t)))
48            .collect()
49    }
50
51    fn reachable_nodes(&self, node: &DepNode, direction: Direction) -> Vec<&DepNode> {
52        if let Some(&index) = self.indices.get(node) {
53            self.inner.depth_traverse(index, direction).map(|s| self.inner.node_data(s)).collect()
54        } else {
55            ::alloc::vec::Vec::new()vec![]
56        }
57    }
58
59    /// All nodes that can reach `node`.
60    pub fn transitive_predecessors(&self, node: &DepNode) -> Vec<&DepNode> {
61        self.reachable_nodes(node, INCOMING)
62    }
63}
rustc_middle/dep_graph/retained.rs

rustc_middle/dep_graph/
retained.rs
