Use LocalDefId directly in Resolver::export_map and `module_expor…

…ts` query

This is to avoid the final conversion from `NodeId` to `HirId`
during call to `Resolver::(clone|into)_outputs`.

src/librustc_metadata/rmeta/encoder.rs

@@ -693,16 +693,25 @@ impl EncodeContext<'tcx> {
         vis: &hir::Visibility<'_>,
     ) {
         let tcx = self.tcx;
-        let def_id = tcx.hir().local_def_id(id).to_def_id();
+        let def_id = tcx.hir().local_def_id(id);
         debug!("EncodeContext::encode_info_for_mod({:?})", def_id);
 
         let data = ModData {
             reexports: match tcx.module_exports(def_id) {
-                Some(exports) => self.lazy(exports),
+                Some(exports) => {
+                    let hir_map = self.tcx.hir();
+                    self.lazy(
+                        exports
+                            .iter()
+                            .map(|export| export.map_id(|id| hir_map.as_local_hir_id(id))),
+                    )
+                }
                 _ => Lazy::empty(),
             },
         };
 
+        let def_id = def_id.to_def_id();
+
         record!(self.tables.kind[def_id] <- EntryKind::Mod(self.lazy(data)));
         record!(self.tables.visibility[def_id] <- ty::Visibility::from_hir(vis, id, self.tcx));
         record!(self.tables.span[def_id] <- self.tcx.def_span(def_id));

src/librustc_middle/hir/exports.rs

@@ -1,7 +1,8 @@
 use crate::ty;
 
+use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::Res;
-use rustc_hir::def_id::DefIdMap;
+use rustc_hir::def_id::LocalDefId;
 use rustc_macros::HashStable;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
@@ -10,7 +11,7 @@ use std::fmt::Debug;
 
 /// This is the replacement export map. It maps a module to all of the exports
 /// within.
-pub type ExportMap<Id> = DefIdMap<Vec<Export<Id>>>;
+pub type ExportMap<Id> = FxHashMap<LocalDefId, Vec<Export<Id>>>;
 
 #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]
 pub struct Export<Id> {

src/librustc_middle/query/mod.rs

@@ -865,8 +865,8 @@ rustc_queries! {
     }
 
     Other {
-        query module_exports(def_id: DefId) -> Option<&'tcx [Export<hir::HirId>]> {
-            desc { |tcx| "looking up items exported by `{}`", tcx.def_path_str(def_id) }
+        query module_exports(def_id: LocalDefId) -> Option<&'tcx [Export<LocalDefId>]> {
+            desc { |tcx| "looking up items exported by `{}`", tcx.def_path_str(def_id.to_def_id()) }
             eval_always
         }
     }

src/librustc_middle/ty/context.rs

@@ -2,7 +2,7 @@
 
 use crate::arena::Arena;
 use crate::dep_graph::{self, DepConstructor, DepGraph};
-use crate::hir::exports::Export;
+use crate::hir::exports::ExportMap;
 use crate::ich::{NodeIdHashingMode, StableHashingContext};
 use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
 use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintSource};
@@ -919,7 +919,7 @@ pub struct GlobalCtxt<'tcx> {
     trait_map: FxHashMap<LocalDefId, FxHashMap<ItemLocalId, StableVec<TraitCandidate>>>,
 
     /// Export map produced by name resolution.
-    export_map: FxHashMap<DefId, Vec<Export<hir::HirId>>>,
+    export_map: ExportMap<LocalDefId>,
 
     pub(crate) untracked_crate: &'tcx hir::Crate<'tcx>,
     pub(crate) definitions: &'tcx Definitions,

src/librustc_middle/ty/mod.rs

@@ -124,7 +124,7 @@ pub struct ResolverOutputs {
     pub trait_map: FxHashMap<hir::HirId, Vec<hir::TraitCandidate<hir::HirId>>>,
     pub maybe_unused_trait_imports: FxHashSet<LocalDefId>,
     pub maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
-    pub export_map: ExportMap<hir::HirId>,
+    pub export_map: ExportMap<LocalDefId>,
     pub glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
     /// Extern prelude entries. The value is `true` if the entry was introduced
     /// via `extern crate` item and not `--extern` option or compiler built-in.

src/librustc_resolve/imports.rs

@@ -1393,8 +1393,8 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
             let is_good_import =
                 binding.is_import() && !binding.is_ambiguity() && !ident.span.from_expansion();
             if is_good_import || binding.is_macro_def() {
-                let res = binding.res();
-                if res != Res::Err {
+                let res = binding.res().map_id(|id| this.definitions.local_def_id(id));
+                if res != def::Res::Err {
                     reexports.push(Export { ident, res, span: binding.span, vis: binding.vis });
                 }
             }
@@ -1467,7 +1467,9 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
 
         if !reexports.is_empty() {
             if let Some(def_id) = module.def_id() {
-                self.r.export_map.insert(def_id, reexports);
+                // Call to `expect_local` should be fine because current
+                // code is only called for local modules.
+                self.r.export_map.insert(def_id.expect_local(), reexports);
             }
         }
     }

src/librustc_resolve/lib.rs

@@ -878,7 +878,7 @@ pub struct Resolver<'a> {
 
     /// `CrateNum` resolutions of `extern crate` items.
     extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
-    export_map: ExportMap<NodeId>,
+    export_map: ExportMap<LocalDefId>,
     trait_map: TraitMap<NodeId>,
 
     /// A map from nodes to anonymous modules.
@@ -1281,18 +1281,7 @@ impl<'a> Resolver<'a> {
     pub fn into_outputs(self) -> ResolverOutputs {
         let definitions = self.definitions;
         let extern_crate_map = self.extern_crate_map;
-        let export_map = self
-            .export_map
-            .into_iter()
-            .map(|(k, v)| {
-                (
-                    k,
-                    v.into_iter()
-                        .map(|e| e.map_id(|id| definitions.node_id_to_hir_id(id)))
-                        .collect(),
-                )
-            })
-            .collect();
+        let export_map = self.export_map;
         let trait_map = self
             .trait_map
             .into_iter()
@@ -1330,18 +1319,7 @@ impl<'a> Resolver<'a> {
             definitions: self.definitions.clone(),
             cstore: Box::new(self.cstore().clone()),
             extern_crate_map: self.extern_crate_map.clone(),
-            export_map: self
-                .export_map
-                .iter()
-                .map(|(&k, v)| {
-                    (
-                        k,
-                        v.iter()
-                            .map(|e| e.map_id(|id| self.definitions.node_id_to_hir_id(id)))
-                            .collect(),
-                    )
-                })
-                .collect(),
+            export_map: self.export_map.clone(),
             trait_map: self
                 .trait_map
                 .iter()