Remove the `Forest` type

8 files changed, 51 insertions, 78 deletions

diff --git a/src/librustc/arena.rs b/src/librustc/arena.rs
index 92f5bf87535..dd242686d26 100644
--- a/src/librustc/arena.rs
+++ b/src/librustc/arena.rs
@@ -127,7 +127,7 @@ macro_rules! arena_types {
             [] tys: rustc::ty::TyS<$tcx>,
 
             // HIR types
-            [few] hir_forest: rustc::hir::map::Forest<$tcx>,
+            [few] hir_krate: rustc_hir::Crate<$tcx>,
             [] arm: rustc_hir::Arm<$tcx>,
             [] attribute: syntax::ast::Attribute,
             [] block: rustc_hir::Block<$tcx>,
diff --git a/src/librustc/hir/map/hir_id_validator.rs b/src/librustc/hir/map/hir_id_validator.rs
index da9695ec08a..c721faafbec 100644
--- a/src/librustc/hir/map/hir_id_validator.rs
+++ b/src/librustc/hir/map/hir_id_validator.rs
@@ -12,7 +12,7 @@ pub fn check_crate(hir_map: &Map<'_>) {
 
     let errors = Lock::new(Vec::new());
 
-    par_iter(&hir_map.forest.krate.modules).for_each(|(module_id, _)| {
+    par_iter(&hir_map.krate.modules).for_each(|(module_id, _)| {
         let local_def_id = hir_map.local_def_id(*module_id);
         hir_map.visit_item_likes_in_module(
             local_def_id,
diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index 0e74ccc63b8..7e0e85ea586 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -129,25 +129,6 @@ impl<'hir> Entry<'hir> {
     }
 }
 
-/// Stores a crate and any number of inlined items from other crates.
-pub struct Forest<'hir> {
-    krate: Crate<'hir>,
-    pub dep_graph: DepGraph,
-}
-
-impl Forest<'hir> {
-    pub fn new(krate: Crate<'hir>, dep_graph: &DepGraph) -> Forest<'hir> {
-        Forest { krate, dep_graph: dep_graph.clone() }
-    }
-
-    /// This is used internally in the dependency tracking system.
-    /// Use the `krate` method to ensure your dependency on the
-    /// crate is tracked.
-    pub fn untracked_krate(&self) -> &Crate<'hir> {
-        &self.krate
-    }
-}
-
 /// This type is effectively a `HashMap<HirId, Entry<'hir>>`,
 /// but it is implemented as 2 layers of arrays.
 /// - first we have `A = IndexVec<DefIndex, B>` mapping `DefIndex`s to an inner value
@@ -157,11 +138,8 @@ pub(super) type HirEntryMap<'hir> = IndexVec<DefIndex, IndexVec<ItemLocalId, Opt
 /// Represents a mapping from `NodeId`s to AST elements and their parent `NodeId`s.
 #[derive(Clone)]
 pub struct Map<'hir> {
-    /// The backing storage for all the AST nodes.
-    pub forest: &'hir Forest<'hir>,
+    pub krate: &'hir Crate<'hir>,
 
-    /// Same as the dep_graph in forest, just available with one fewer
-    /// deref. This is a gratuitous micro-optimization.
     pub dep_graph: DepGraph,
 
     /// The SVH of the local crate.
@@ -212,6 +190,13 @@ impl<'hir> Iterator for ParentHirIterator<'_, 'hir> {
 }
 
 impl<'hir> Map<'hir> {
+    /// This is used internally in the dependency tracking system.
+    /// Use the `krate` method to ensure your dependency on the
+    /// crate is tracked.
+    pub fn untracked_krate(&self) -> &Crate<'hir> {
+        &self.krate
+    }
+
     #[inline]
     fn lookup(&self, id: HirId) -> Option<&Entry<'hir>> {
         let local_map = self.map.get(id.owner)?;
@@ -399,33 +384,33 @@ impl<'hir> Map<'hir> {
     pub fn item(&self, id: HirId) -> &'hir Item<'hir> {
         self.read(id);
 
-        // N.B., intentionally bypass `self.forest.krate()` so that we
+        // N.B., intentionally bypass `self.krate()` so that we
         // do not trigger a read of the whole krate here
-        self.forest.krate.item(id)
+        self.krate.item(id)
     }
 
     pub fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
         self.read(id.hir_id);
 
-        // N.B., intentionally bypass `self.forest.krate()` so that we
+        // N.B., intentionally bypass `self.krate()` so that we
         // do not trigger a read of the whole krate here
-        self.forest.krate.trait_item(id)
+        self.krate.trait_item(id)
     }
 
     pub fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
         self.read(id.hir_id);
 
-        // N.B., intentionally bypass `self.forest.krate()` so that we
+        // N.B., intentionally bypass `self.krate()` so that we
         // do not trigger a read of the whole krate here
-        self.forest.krate.impl_item(id)
+        self.krate.impl_item(id)
     }
 
     pub fn body(&self, id: BodyId) -> &'hir Body<'hir> {
         self.read(id.hir_id);
 
-        // N.B., intentionally bypass `self.forest.krate()` so that we
+        // N.B., intentionally bypass `self.krate()` so that we
         // do not trigger a read of the whole krate here
-        self.forest.krate.body(id)
+        self.krate.body(id)
     }
 
     pub fn fn_decl_by_hir_id(&self, hir_id: HirId) -> Option<&'hir FnDecl<'hir>> {
@@ -521,9 +506,9 @@ impl<'hir> Map<'hir> {
     pub fn trait_impls(&self, trait_did: DefId) -> &'hir [HirId] {
         self.dep_graph.read(DepNode::new_no_params(DepKind::AllLocalTraitImpls));
 
-        // N.B., intentionally bypass `self.forest.krate()` so that we
+        // N.B., intentionally bypass `self.krate()` so that we
         // do not trigger a read of the whole krate here
-        self.forest.krate.trait_impls.get(&trait_did).map_or(&[], |xs| &xs[..])
+        self.krate.trait_impls.get(&trait_did).map_or(&[], |xs| &xs[..])
     }
 
     /// Gets the attributes on the crate. This is preferable to
@@ -533,7 +518,7 @@ impl<'hir> Map<'hir> {
         let def_path_hash = self.definitions.def_path_hash(CRATE_DEF_INDEX);
 
         self.dep_graph.read(def_path_hash.to_dep_node(DepKind::Hir));
-        &self.forest.krate.attrs
+        &self.krate.attrs
     }
 
     pub fn get_module(&self, module: DefId) -> (&'hir Mod<'hir>, Span, HirId) {
@@ -541,7 +526,7 @@ impl<'hir> Map<'hir> {
         self.read(hir_id);
         match self.find_entry(hir_id).unwrap().node {
             Node::Item(&Item { span, kind: ItemKind::Mod(ref m), .. }) => (m, span, hir_id),
-            Node::Crate => (&self.forest.krate.module, self.forest.krate.span, hir_id),
+            Node::Crate => (&self.krate.module, self.krate.span, hir_id),
             node => panic!("not a module: {:?}", node),
         }
     }
@@ -558,7 +543,7 @@ impl<'hir> Map<'hir> {
         // in the expect_* calls the loops below
         self.read(hir_id);
 
-        let module = &self.forest.krate.modules[&hir_id];
+        let module = &self.krate.modules[&hir_id];
 
         for id in &module.items {
             visitor.visit_item(self.expect_item(*id));
@@ -975,7 +960,7 @@ impl<'hir> Map<'hir> {
             // Unit/tuple structs/variants take the attributes straight from
             // the struct/variant definition.
             Some(Node::Ctor(..)) => return self.attrs(self.get_parent_item(id)),
-            Some(Node::Crate) => Some(&self.forest.krate.attrs[..]),
+            Some(Node::Crate) => Some(&self.krate.attrs[..]),
             _ => None,
         };
         attrs.unwrap_or(&[])
@@ -1054,7 +1039,7 @@ impl<'hir> Map<'hir> {
             Some(Node::Visibility(v)) => bug!("unexpected Visibility {:?}", v),
             Some(Node::Local(local)) => local.span,
             Some(Node::MacroDef(macro_def)) => macro_def.span,
-            Some(Node::Crate) => self.forest.krate.span,
+            Some(Node::Crate) => self.krate.span,
             None => bug!("hir::map::Map::span: id not in map: {:?}", hir_id),
         }
     }
@@ -1222,7 +1207,8 @@ impl Named for ImplItem<'_> {
 pub fn map_crate<'hir>(
     sess: &rustc_session::Session,
     cstore: &CrateStoreDyn,
-    forest: &'hir Forest<'hir>,
+    krate: &'hir Crate<'hir>,
+    dep_graph: DepGraph,
     definitions: Definitions,
 ) -> Map<'hir> {
     let _prof_timer = sess.prof.generic_activity("build_hir_map");
@@ -1235,31 +1221,18 @@ pub fn map_crate<'hir>(
         .collect();
 
     let (map, crate_hash) = {
-        let hcx = crate::ich::StableHashingContext::new(sess, &forest.krate, &definitions, cstore);
-
-        let mut collector = NodeCollector::root(
-            sess,
-            &forest.krate,
-            &forest.dep_graph,
-            &definitions,
-            &hir_to_node_id,
-            hcx,
-        );
-        intravisit::walk_crate(&mut collector, &forest.krate);
+        let hcx = crate::ich::StableHashingContext::new(sess, krate, &definitions, cstore);
+
+        let mut collector =
+            NodeCollector::root(sess, krate, &dep_graph, &definitions, &hir_to_node_id, hcx);
+        intravisit::walk_crate(&mut collector, krate);
 
         let crate_disambiguator = sess.local_crate_disambiguator();
         let cmdline_args = sess.opts.dep_tracking_hash();
         collector.finalize_and_compute_crate_hash(crate_disambiguator, cstore, cmdline_args)
     };
 
-    let map = Map {
-        forest,
-        dep_graph: forest.dep_graph.clone(),
-        crate_hash,
-        map,
-        hir_to_node_id,
-        definitions,
-    };
+    let map = Map { krate, dep_graph, crate_hash, map, hir_to_node_id, definitions };
 
     sess.time("validate_HIR_map", || {
         hir_id_validator::check_crate(&map);
diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs
index 259cee47160..2e7e8fdd724 100644
--- a/src/librustc/hir/mod.rs
+++ b/src/librustc/hir/mod.rs
@@ -49,6 +49,6 @@ impl<'tcx> TyCtxt<'tcx> {
 }
 
 pub fn provide(providers: &mut Providers<'_>) {
-    providers.hir_crate = |tcx, _| tcx.hir_map.forest.untracked_krate();
+    providers.hir_crate = |tcx, _| tcx.hir_map.untracked_krate();
     map::provide(providers);
 }
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 5a0cb45d0bb..8979292c86d 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -1323,7 +1323,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     #[inline(always)]
     pub fn create_stable_hashing_context(self) -> StableHashingContext<'tcx> {
-        let krate = self.gcx.hir_map.forest.untracked_krate();
+        let krate = self.gcx.hir_map.untracked_krate();
 
         StableHashingContext::new(self.sess, krate, self.hir().definitions(), &*self.cstore)
     }
diff --git a/src/librustc_interface/passes.rs b/src/librustc_interface/passes.rs
index bf8bcd71efa..6224c4654d6 100644
--- a/src/librustc_interface/passes.rs
+++ b/src/librustc_interface/passes.rs
@@ -25,6 +25,7 @@ use rustc_data_structures::{box_region_allow_access, declare_box_region_type, pa
 use rustc_errors::PResult;
 use rustc_expand::base::ExtCtxt;
 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
+use rustc_hir::Crate;
 use rustc_lint::LintStore;
 use rustc_mir as mir;
 use rustc_mir_build as mir_build;
@@ -422,7 +423,7 @@ pub fn lower_to_hir<'res, 'tcx>(
     dep_graph: &'res DepGraph,
     krate: &'res ast::Crate,
     arena: &'tcx Arena<'tcx>,
-) -> Result<map::Forest<'tcx>> {
+) -> Crate<'tcx> {
     // Lower AST to HIR.
     let hir_crate = rustc_ast_lowering::lower_crate(
         sess,
@@ -437,8 +438,6 @@ pub fn lower_to_hir<'res, 'tcx>(
         hir_stats::print_hir_stats(&hir_crate);
     }
 
-    let hir_forest = map::Forest::new(hir_crate, &dep_graph);
-
     sess.time("early_lint_checks", || {
         rustc_lint::check_ast_crate(
             sess,
@@ -455,7 +454,7 @@ pub fn lower_to_hir<'res, 'tcx>(
         rustc_span::hygiene::clear_syntax_context_map();
     }
 
-    Ok(hir_forest)
+    hir_crate
 }
 
 // Returns all the paths that correspond to generated files.
@@ -705,7 +704,8 @@ impl<'tcx> QueryContext<'tcx> {
 pub fn create_global_ctxt<'tcx>(
     compiler: &'tcx Compiler,
     lint_store: Lrc<LintStore>,
-    hir_forest: &'tcx map::Forest<'tcx>,
+    krate: &'tcx Crate<'tcx>,
+    dep_graph: DepGraph,
     mut resolver_outputs: ResolverOutputs,
     outputs: OutputFilenames,
     crate_name: &str,
@@ -716,7 +716,7 @@ pub fn create_global_ctxt<'tcx>(
     let defs = mem::take(&mut resolver_outputs.definitions);
 
     // Construct the HIR map.
-    let hir_map = map::map_crate(sess, &*resolver_outputs.cstore, &hir_forest, defs);
+    let hir_map = map::map_crate(sess, &*resolver_outputs.cstore, krate, dep_graph, defs);
 
     let query_result_on_disk_cache = rustc_incremental::load_query_result_cache(sess);
 
diff --git a/src/librustc_interface/queries.rs b/src/librustc_interface/queries.rs
index 2ac2845be91..720d162ac81 100644
--- a/src/librustc_interface/queries.rs
+++ b/src/librustc_interface/queries.rs
@@ -3,7 +3,6 @@ use crate::passes::{self, BoxedResolver, QueryContext};
 
 use rustc::arena::Arena;
 use rustc::dep_graph::DepGraph;
-use rustc::hir::map;
 use rustc::session::config::{OutputFilenames, OutputType};
 use rustc::session::Session;
 use rustc::ty::steal::Steal;
@@ -12,6 +11,7 @@ use rustc::util::common::ErrorReported;
 use rustc_codegen_utils::codegen_backend::CodegenBackend;
 use rustc_data_structures::sync::{Lrc, Once, WorkerLocal};
 use rustc_hir::def_id::LOCAL_CRATE;
+use rustc_hir::Crate;
 use rustc_incremental::DepGraphFuture;
 use rustc_lint::LintStore;
 use std::any::Any;
@@ -74,7 +74,7 @@ pub struct Queries<'tcx> {
     register_plugins: Query<(ast::Crate, Lrc<LintStore>)>,
     expansion: Query<(ast::Crate, Steal<Rc<RefCell<BoxedResolver>>>, Lrc<LintStore>)>,
     dep_graph: Query<DepGraph>,
-    lower_to_hir: Query<(&'tcx map::Forest<'tcx>, Steal<ResolverOutputs>)>,
+    lower_to_hir: Query<(&'tcx Crate<'tcx>, Steal<ResolverOutputs>)>,
     prepare_outputs: Query<OutputFilenames>,
     global_ctxt: Query<QueryContext<'tcx>>,
     ongoing_codegen: Query<Box<dyn Any>>,
@@ -207,9 +207,7 @@ impl<'tcx> Queries<'tcx> {
         })
     }
 
-    pub fn lower_to_hir(
-        &'tcx self,
-    ) -> Result<&Query<(&'tcx map::Forest<'tcx>, Steal<ResolverOutputs>)>> {
+    pub fn lower_to_hir(&'tcx self) -> Result<&Query<(&'tcx Crate<'tcx>, Steal<ResolverOutputs>)>> {
         self.lower_to_hir.compute(|| {
             let expansion_result = self.expansion()?;
             let peeked = expansion_result.peek();
@@ -217,14 +215,14 @@ impl<'tcx> Queries<'tcx> {
             let resolver = peeked.1.steal();
             let lint_store = &peeked.2;
             let hir = resolver.borrow_mut().access(|resolver| {
-                passes::lower_to_hir(
+                Ok(passes::lower_to_hir(
                     self.session(),
                     lint_store,
                     resolver,
                     &*self.dep_graph()?.peek(),
                     &krate,
                     &self.arena,
-                )
+                ))
             })?;
             let hir = self.arena.alloc(hir);
             Ok((hir, Steal::new(BoxedResolver::to_resolver_outputs(resolver))))
@@ -253,12 +251,14 @@ impl<'tcx> Queries<'tcx> {
             let outputs = self.prepare_outputs()?.peek().clone();
             let lint_store = self.expansion()?.peek().2.clone();
             let hir = self.lower_to_hir()?.peek();
-            let (ref hir_forest, ref resolver_outputs) = &*hir;
+            let dep_graph = self.dep_graph()?.peek().clone();
+            let (ref krate, ref resolver_outputs) = &*hir;
             let _timer = self.session().timer("create_global_ctxt");
             Ok(passes::create_global_ctxt(
                 self.compiler,
                 lint_store,
-                hir_forest,
+                krate,
+                dep_graph,
                 resolver_outputs.steal(),
                 outputs,
                 &crate_name,
diff --git a/src/librustdoc/test.rs b/src/librustdoc/test.rs
index 80d3cc05fb7..d3e53e18812 100644
--- a/src/librustdoc/test.rs
+++ b/src/librustdoc/test.rs
@@ -87,7 +87,7 @@ pub fn run(options: Options) -> i32 {
         compiler.enter(|queries| {
             let lower_to_hir = queries.lower_to_hir()?;
 
-            let mut opts = scrape_test_config(lower_to_hir.peek().0.untracked_krate());
+            let mut opts = scrape_test_config(lower_to_hir.peek().0);
             opts.display_warnings |= options.display_warnings;
             let enable_per_target_ignores = options.enable_per_target_ignores;
             let mut collector = Collector::new(