incr.comp.: Add new DepGraph implementation.

src/librustc/dep_graph/dep_node.rs

@@ -60,7 +60,7 @@
 //! user of the `DepNode` API of having to know how to compute the expected
 //! fingerprint for a given set of node parameters.
 
-use hir::def_id::{CrateNum, DefId, DefIndex};
+use hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX};
 use hir::map::DefPathHash;
 use hir::{HirId, ItemLocalId};
 
@@ -420,7 +420,7 @@ define_dep_nodes!( <'tcx>
     [input] Hir(DefId),
 
     // Represents metadata from an extern crate.
-    [input] MetaData(DefId),
+    [input] CrateMetadata(CrateNum),
 
     // Represents some artifact that we save to disk. Note that these
     // do not have a def-id as part of their identifier.
@@ -678,6 +678,22 @@ impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefIndex,
     }
 }
 
+impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (CrateNum,) {
+    const CAN_RECONSTRUCT_QUERY_KEY: bool = true;
+
+    fn to_fingerprint(&self, tcx: TyCtxt) -> Fingerprint {
+        let def_id = DefId {
+            krate: self.0,
+            index: CRATE_DEF_INDEX,
+        };
+        tcx.def_path_hash(def_id).0
+    }
+
+    fn to_debug_str(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> String {
+        tcx.crate_name(self.0).as_str().to_string()
+    }
+}
+
 impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefId, DefId) {
     const CAN_RECONSTRUCT_QUERY_KEY: bool = false;
 

src/librustc/dep_graph/edges.rs

@@ -17,7 +17,7 @@ use std::mem;
 use super::{DepGraphQuery, DepKind, DepNode};
 use super::debug::EdgeFilter;
 
-pub struct DepGraphEdges {
+pub(super) struct DepGraphEdges {
     nodes: Vec<DepNode>,
     indices: FxHashMap<DepNode, DepNodeIndex>,
     edges: FxHashSet<(DepNodeIndex, DepNodeIndex)>,
@@ -31,8 +31,8 @@ pub struct DepGraphEdges {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-pub struct DepNodeIndex {
-    index: u32
+pub(super) struct DepNodeIndex {
+    index: u32,
 }
 
 impl DepNodeIndex {