Auto merge of #44012 - michaelwoerister:cache-hir-dep-node-index, r=n…

…ikomatsakis

incr.comp.: Cache Hir-DepNodeIndices in the HIR map.

In preparation for red/green. This should also be faster than before without any additional memory cost.

r? @nikomatsakis

src/librustc/dep_graph/edges.rs

@@ -244,8 +244,8 @@ impl DepGraphEdges {
         self.edges.insert((source, target));
     }
 
-    pub fn add_node(&mut self, node: DepNode) {
-        self.get_or_create_node(node);
+    pub fn add_node(&mut self, node: DepNode) -> DepNodeIndex {
+        self.get_or_create_node(node)
     }
 
     #[inline]

src/librustc/dep_graph/graph.rs

@@ -166,6 +166,14 @@ impl DepGraph {
         self.data.as_ref().unwrap().edges.borrow_mut().add_node(node);
     }
 
+    pub fn alloc_input_node(&self, node: DepNode) -> DepNodeIndex {
+        if let Some(ref data) = self.data {
+            data.edges.borrow_mut().add_node(node)
+        } else {
+            DepNodeIndex::INVALID
+        }
+    }
+
     /// Indicates that a previous work product exists for `v`. This is
     /// invoked during initial start-up based on what nodes are clean
     /// (and what files exist in the incr. directory).

src/librustc/hir/intravisit.rs

@@ -835,7 +835,16 @@ pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref:
 
 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
     // NB: Deliberately force a compilation error if/when new fields are added.
-    let ImplItem { id: _, name, ref vis, ref defaultness, ref attrs, ref node, span } = *impl_item;
+    let ImplItem {
+        id: _,
+        hir_id: _,
+        name,
+        ref vis,
+        ref defaultness,
+        ref attrs,
+        ref node,
+        span
+    } = *impl_item;
 
     visitor.visit_name(span, name);
     visitor.visit_vis(vis);

src/librustc/hir/lowering.rs

@@ -1268,7 +1268,12 @@ impl<'a> LoweringContext<'a> {
                             path.span = span;
 
                             self.allocate_hir_id_counter(import.id, import);
-                            self.with_hir_id_owner(import.id, |this| {
+                            let LoweredNodeId {
+                                node_id: import_node_id,
+                                hir_id: import_hir_id,
+                            } = self.lower_node_id(import.id);
+
+                            self.with_hir_id_owner(import_node_id, |this| {
                                 let vis = match *vis {
                                     hir::Visibility::Public => hir::Visibility::Public,
                                     hir::Visibility::Crate => hir::Visibility::Crate,
@@ -1282,8 +1287,9 @@ impl<'a> LoweringContext<'a> {
                                     }
                                 };
 
-                                this.items.insert(import.id, hir::Item {
-                                    id: import.id,
+                                this.items.insert(import_node_id, hir::Item {
+                                    id: import_node_id,
+                                    hir_id: import_hir_id,
                                     name: import.rename.unwrap_or(ident).name,
                                     attrs: attrs.clone(),
                                     node: hir::ItemUse(P(path), hir::UseKind::Single),
@@ -1414,8 +1420,11 @@ impl<'a> LoweringContext<'a> {
 
     fn lower_trait_item(&mut self, i: &TraitItem) -> hir::TraitItem {
         self.with_parent_def(i.id, |this| {
+            let LoweredNodeId { node_id, hir_id } = this.lower_node_id(i.id);
+
             hir::TraitItem {
-                id: this.lower_node_id(i.id).node_id,
+                id: node_id,
+                hir_id,
                 name: this.lower_ident(i.ident),
                 attrs: this.lower_attrs(&i.attrs),
                 node: match i.node {
@@ -1475,8 +1484,11 @@ impl<'a> LoweringContext<'a> {
 
     fn lower_impl_item(&mut self, i: &ImplItem) -> hir::ImplItem {
         self.with_parent_def(i.id, |this| {
+            let LoweredNodeId { node_id, hir_id } = this.lower_node_id(i.id);
+
             hir::ImplItem {
-                id: this.lower_node_id(i.id).node_id,
+                id: node_id,
+                hir_id,
                 name: this.lower_ident(i.ident),
                 attrs: this.lower_attrs(&i.attrs),
                 vis: this.lower_visibility(&i.vis, None),
@@ -1567,8 +1579,11 @@ impl<'a> LoweringContext<'a> {
             this.lower_item_kind(i.id, &mut name, &attrs, &mut vis, &i.node)
         });
 
+        let LoweredNodeId { node_id, hir_id } = self.lower_node_id(i.id);
+
         Some(hir::Item {
-            id: self.lower_node_id(i.id).node_id,
+            id: node_id,
+            hir_id,
             name,
             attrs,
             node,

src/librustc/hir/map/collector.rs

@@ -10,33 +10,55 @@
 
 use super::*;
 
+use dep_graph::{DepGraph, DepKind, DepNodeIndex};
 use hir::intravisit::{Visitor, NestedVisitorMap};
 use std::iter::repeat;
 use syntax::ast::{NodeId, CRATE_NODE_ID};
 use syntax_pos::Span;
 
 /// A Visitor that walks over the HIR and collects Nodes into a HIR map
-pub struct NodeCollector<'hir> {
+pub(super) struct NodeCollector<'a, 'hir> {
     /// The crate
-    pub krate: &'hir Crate,
+    krate: &'hir Crate,
     /// The node map
-    pub(super) map: Vec<MapEntry<'hir>>,
+    map: Vec<MapEntry<'hir>>,
     /// The parent of this node
-    pub parent_node: NodeId,
+    parent_node: NodeId,
+
+    current_dep_node_owner: DefIndex,
+    current_dep_node_index: DepNodeIndex,
+
+    dep_graph: &'a DepGraph,
+    definitions: &'a definitions::Definitions,
 }
 
-impl<'hir> NodeCollector<'hir> {
-    pub fn root(krate: &'hir Crate) -> NodeCollector<'hir> {
+impl<'a, 'hir> NodeCollector<'a, 'hir> {
+    pub(super) fn root(krate: &'hir Crate,
+                dep_graph: &'a DepGraph,
+                definitions: &'a definitions::Definitions)
+                -> NodeCollector<'a, 'hir> {
+        let root_mod_def_path_hash = definitions.def_path_hash(CRATE_DEF_INDEX);
+        let root_mod_dep_node = root_mod_def_path_hash.to_dep_node(DepKind::Hir);
+        let root_mod_dep_node_index = dep_graph.alloc_input_node(root_mod_dep_node);
+
         let mut collector = NodeCollector {
             krate,
             map: vec![],
             parent_node: CRATE_NODE_ID,
+            current_dep_node_index: root_mod_dep_node_index,
+            current_dep_node_owner: CRATE_DEF_INDEX,
+            dep_graph,
+            definitions,
         };
-        collector.insert_entry(CRATE_NODE_ID, RootCrate);
+        collector.insert_entry(CRATE_NODE_ID, RootCrate(root_mod_dep_node_index));
 
         collector
     }
 
+    pub(super) fn into_map(self) -> Vec<MapEntry<'hir>> {
+        self.map
+    }
+
     fn insert_entry(&mut self, id: NodeId, entry: MapEntry<'hir>) {
         debug!("hir_map: {:?} => {:?}", id, entry);
         let len = self.map.len();
@@ -47,8 +69,55 @@ impl<'hir> NodeCollector<'hir> {
     }
 
     fn insert(&mut self, id: NodeId, node: Node<'hir>) {
-        let entry = MapEntry::from_node(self.parent_node, node);
+        let parent = self.parent_node;
+        let dep_node_index = self.current_dep_node_index;
+
+        let entry = match node {
+            NodeItem(n) => EntryItem(parent, dep_node_index, n),
+            NodeForeignItem(n) => EntryForeignItem(parent, dep_node_index, n),
+            NodeTraitItem(n) => EntryTraitItem(parent, dep_node_index, n),
+            NodeImplItem(n) => EntryImplItem(parent, dep_node_index, n),
+            NodeVariant(n) => EntryVariant(parent, dep_node_index, n),
+            NodeField(n) => EntryField(parent, dep_node_index, n),
+            NodeExpr(n) => EntryExpr(parent, dep_node_index, n),
+            NodeStmt(n) => EntryStmt(parent, dep_node_index, n),
+            NodeTy(n) => EntryTy(parent, dep_node_index, n),
+            NodeTraitRef(n) => EntryTraitRef(parent, dep_node_index, n),
+            NodeBinding(n) => EntryBinding(parent, dep_node_index, n),
+            NodePat(n) => EntryPat(parent, dep_node_index, n),
+            NodeBlock(n) => EntryBlock(parent, dep_node_index, n),
+            NodeStructCtor(n) => EntryStructCtor(parent, dep_node_index, n),
+            NodeLifetime(n) => EntryLifetime(parent, dep_node_index, n),
+            NodeTyParam(n) => EntryTyParam(parent, dep_node_index, n),
+            NodeVisibility(n) => EntryVisibility(parent, dep_node_index, n),
+            NodeLocal(n) => EntryLocal(parent, dep_node_index, n),
+        };
+
+        // Make sure that the DepNode of some node coincides with the HirId
+        // owner of that node.
+        if cfg!(debug_assertions) {
+            let hir_id_owner = self.definitions.node_to_hir_id(id).owner;
+
+            if hir_id_owner != self.current_dep_node_owner {
+                let node_str = match self.definitions.opt_def_index(id) {
+                    Some(def_index) => {
+                        self.definitions.def_path(def_index).to_string_no_crate()
+                    }
+                    None => format!("{:?}", node)
+                };
+
+                bug!("inconsistent DepNode for `{}`: \
+                      current_dep_node_owner={}, hir_id.owner={}",
+                    node_str,
+                    self.definitions
+                        .def_path(self.current_dep_node_owner)
+                        .to_string_no_crate(),
+                    self.definitions.def_path(hir_id_owner).to_string_no_crate())
+            }
+        }
+
         self.insert_entry(id, entry);
+
     }
 
     fn with_parent<F: FnOnce(&mut Self)>(&mut self, parent_id: NodeId, f: F) {
@@ -57,9 +126,27 @@ impl<'hir> NodeCollector<'hir> {
         f(self);
         self.parent_node = parent_node;
     }
+
+    fn with_dep_node_owner<F: FnOnce(&mut Self)>(&mut self,
+                                                 dep_node_owner: DefIndex,
+                                                 f: F) {
+        let prev_owner = self.current_dep_node_owner;
+        let prev_index = self.current_dep_node_index;
+
+        // When we enter a new owner (item, impl item, or trait item), we always
+        // start out again with DepKind::Hir.
+        let new_dep_node = self.definitions
+                               .def_path_hash(dep_node_owner)
+                               .to_dep_node(DepKind::Hir);
+        self.current_dep_node_index = self.dep_graph.alloc_input_node(new_dep_node);
+        self.current_dep_node_owner = dep_node_owner;
+        f(self);
+        self.current_dep_node_index = prev_index;
+        self.current_dep_node_owner = prev_owner;
+    }
 }
 
-impl<'hir> Visitor<'hir> for NodeCollector<'hir> {
+impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     /// Because we want to track parent items and so forth, enable
     /// deep walking so that we walk nested items in the context of
     /// their outer items.
@@ -82,25 +169,37 @@ impl<'hir> Visitor<'hir> for NodeCollector<'hir> {
     }
 
     fn visit_nested_body(&mut self, id: BodyId) {
+        // When we enter a body, we switch to DepKind::HirBody.
+        // Note that current_dep_node_index might already be DepKind::HirBody,
+        // e.g. when entering the body of a closure that is already part of a
+        // surrounding body. That's expected and not a problem.
+        let prev_index = self.current_dep_node_index;
+        let new_dep_node = self.definitions
+                               .def_path_hash(self.current_dep_node_owner)
+                               .to_dep_node(DepKind::HirBody);
+        self.current_dep_node_index = self.dep_graph.alloc_input_node(new_dep_node);
         self.visit_body(self.krate.body(id));
+        self.current_dep_node_index = prev_index;
     }
 
     fn visit_item(&mut self, i: &'hir Item) {
         debug!("visit_item: {:?}", i);
-
-        self.insert(i.id, NodeItem(i));
-
-        self.with_parent(i.id, |this| {
-            match i.node {
-                ItemStruct(ref struct_def, _) => {
-                    // If this is a tuple-like struct, register the constructor.
-                    if !struct_def.is_struct() {
-                        this.insert(struct_def.id(), NodeStructCtor(struct_def));
+        debug_assert_eq!(i.hir_id.owner,
+                         self.definitions.opt_def_index(i.id).unwrap());
+        self.with_dep_node_owner(i.hir_id.owner, |this| {
+            this.insert(i.id, NodeItem(i));
+            this.with_parent(i.id, |this| {
+                match i.node {
+                    ItemStruct(ref struct_def, _) => {
+                        // If this is a tuple-like struct, register the constructor.
+                        if !struct_def.is_struct() {
+                            this.insert(struct_def.id(), NodeStructCtor(struct_def));
+                        }
                     }
+                    _ => {}
                 }
-                _ => {}
-            }
-            intravisit::walk_item(this, i);
+                intravisit::walk_item(this, i);
+            });
         });
     }
 
@@ -121,18 +220,26 @@ impl<'hir> Visitor<'hir> for NodeCollector<'hir> {
     }
 
     fn visit_trait_item(&mut self, ti: &'hir TraitItem) {
-        self.insert(ti.id, NodeTraitItem(ti));
-
-        self.with_parent(ti.id, |this| {
-            intravisit::walk_trait_item(this, ti);
+        debug_assert_eq!(ti.hir_id.owner,
+                         self.definitions.opt_def_index(ti.id).unwrap());
+        self.with_dep_node_owner(ti.hir_id.owner, |this| {
+            this.insert(ti.id, NodeTraitItem(ti));
+
+            this.with_parent(ti.id, |this| {
+                intravisit::walk_trait_item(this, ti);
+            });
         });
     }
 
     fn visit_impl_item(&mut self, ii: &'hir ImplItem) {
-        self.insert(ii.id, NodeImplItem(ii));
-
-        self.with_parent(ii.id, |this| {
-            intravisit::walk_impl_item(this, ii);
+        debug_assert_eq!(ii.hir_id.owner,
+                         self.definitions.opt_def_index(ii.id).unwrap());
+        self.with_dep_node_owner(ii.hir_id.owner, |this| {
+            this.insert(ii.id, NodeImplItem(ii));
+
+            this.with_parent(ii.id, |this| {
+                intravisit::walk_impl_item(this, ii);
+            });
         });
     }
 
@@ -238,4 +345,33 @@ impl<'hir> Visitor<'hir> for NodeCollector<'hir> {
             intravisit::walk_struct_field(this, field);
         });
     }
+
+    fn visit_trait_item_ref(&mut self, ii: &'hir TraitItemRef) {
+        // Do not visit the duplicate information in TraitItemRef. We want to
+        // map the actual nodes, not the duplicate ones in the *Ref.
+        let TraitItemRef {
+            id,
+            name: _,
+            kind: _,
+            span: _,
+            defaultness: _,
+        } = *ii;
+
+        self.visit_nested_trait_item(id);
+    }
+
+    fn visit_impl_item_ref(&mut self, ii: &'hir ImplItemRef) {
+        // Do not visit the duplicate information in ImplItemRef. We want to
+        // map the actual nodes, not the duplicate ones in the *Ref.
+        let ImplItemRef {
+            id,
+            name: _,
+            kind: _,
+            span: _,
+            vis: _,
+            defaultness: _,
+        } = *ii;
+
+        self.visit_nested_impl_item(id);
+    }
 }