Remove unneeded Lrc in query results.

Author: cjgillot

src/librustc_metadata/rmeta/decoder.rs

@@ -1197,7 +1197,7 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
         }
     }
 
-    fn get_item_attrs(&self, node_id: DefIndex, sess: &Session) -> Lrc<[ast::Attribute]> {
+    fn get_item_attrs(&self, node_id: DefIndex, sess: &Session) -> Vec<ast::Attribute> {
         // The attributes for a tuple struct/variant are attached to the definition, not the ctor;
         // we assume that someone passing in a tuple struct ctor is actually wanting to
         // look at the definition
@@ -1208,15 +1208,13 @@ impl<'a, 'tcx> CrateMetadataRef<'a> {
             node_id
         };
 
-        Lrc::from(
-            self.root
-                .tables
-                .attributes
-                .get(self, item_id)
-                .unwrap_or(Lazy::empty())
-                .decode((self, sess))
-                .collect::<Vec<_>>(),
-        )
+        self.root
+            .tables
+            .attributes
+            .get(self, item_id)
+            .unwrap_or(Lazy::empty())
+            .decode((self, sess))
+            .collect::<Vec<_>>()
     }
 
     fn get_struct_field_names(&self, id: DefIndex, sess: &Session) -> Vec<Spanned<ast::Name>> {

src/librustc_metadata/rmeta/decoder/cstore_impl.rs

@@ -138,7 +138,9 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     lookup_deprecation_entry => {
         cdata.get_deprecation(def_id.index).map(DeprecationEntry::external)
     }
-    item_attrs => { cdata.get_item_attrs(def_id.index, tcx.sess) }
+    item_attrs => { tcx.arena.alloc_from_iter(
+        cdata.get_item_attrs(def_id.index, tcx.sess).into_iter()
+    ) }
     // FIXME(#38501) We've skipped a `read` on the `hir_owner_nodes` of
     // a `fn` when encoding, so the dep-tracking wouldn't work.
     // This is only used by rustdoc anyway, which shouldn't have

src/librustc_middle/arena.rs

@@ -118,6 +118,9 @@ macro_rules! arena_types {
             [] upvars: rustc_data_structures::fx::FxIndexMap<rustc_hir::HirId, rustc_hir::Upvar>,
             [] object_safety_violations: rustc_middle::traits::ObjectSafetyViolation,
             [] codegen_unit: rustc_middle::mir::mono::CodegenUnit<$tcx>,
+            [] attribute: rustc_ast::ast::Attribute,
+            [] name_set: rustc_data_structures::fx::FxHashSet<rustc_ast::ast::Name>,
+            [] hir_id_set: rustc_hir::HirIdSet,
 
             // Interned types
             [] tys: rustc_middle::ty::TyS<$tcx>,

src/librustc_middle/query/mod.rs

@@ -610,7 +610,7 @@ rustc_queries! {
     }
 
     Other {
-        query reachable_set(_: CrateNum) -> Lrc<HirIdSet> {
+        query reachable_set(_: CrateNum) -> &'tcx HirIdSet {
             desc { "reachability" }
         }
 
@@ -642,7 +642,7 @@ rustc_queries! {
         query lookup_stability(_: DefId) -> Option<&'tcx attr::Stability> {}
         query lookup_const_stability(_: DefId) -> Option<&'tcx attr::ConstStability> {}
         query lookup_deprecation_entry(_: DefId) -> Option<DeprecationEntry> {}
-        query item_attrs(_: DefId) -> Lrc<[ast::Attribute]> {}
+        query item_attrs(_: DefId) -> &'tcx [ast::Attribute] {}
     }
 
     Codegen {
@@ -1047,7 +1047,7 @@ rustc_queries! {
             desc { "looking up all possibly unused extern crates" }
         }
         query names_imported_by_glob_use(_: DefId)
-            -> Lrc<FxHashSet<ast::Name>> {
+            -> &'tcx FxHashSet<ast::Name> {
             eval_always
         }
 

src/librustc_middle/ty/context.rs

@@ -2721,7 +2721,7 @@ pub fn provide(providers: &mut ty::query::Providers<'_>) {
     };
     providers.names_imported_by_glob_use = |tcx, id| {
         assert_eq!(id.krate, LOCAL_CRATE);
-        Lrc::new(tcx.glob_map.get(&id).cloned().unwrap_or_default())
+        tcx.arena.alloc(tcx.glob_map.get(&id).cloned().unwrap_or_default())
     };
 
     providers.lookup_stability = |tcx, id| {

src/librustc_middle/ty/mod.rs

@@ -3013,7 +3013,7 @@ impl<'tcx> TyCtxt<'tcx> {
         if let Some(id) = self.hir().as_local_hir_id(did) {
             Attributes::Borrowed(self.hir().attrs(id))
         } else {
-            Attributes::Owned(self.item_attrs(did))
+            Attributes::Borrowed(self.item_attrs(did))
         }
     }
 

src/librustc_passes/reachable.rs

@@ -6,7 +6,6 @@
 // reachable as well.
 
 use rustc_data_structures::fx::FxHashSet;
-use rustc_data_structures::sync::Lrc;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::LOCAL_CRATE;
@@ -375,7 +374,7 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx
     }
 }
 
-fn reachable_set(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Lrc<HirIdSet> {
+fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) -> &'tcx HirIdSet {
     debug_assert!(crate_num == LOCAL_CRATE);
 
     let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
@@ -421,7 +420,7 @@ fn reachable_set(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Lrc<HirIdSet> {
     debug!("Inline reachability shows: {:?}", reachable_context.reachable_symbols);
 
     // Return the set of reachable symbols.
-    Lrc::new(reachable_context.reachable_symbols)
+    tcx.arena.alloc(reachable_context.reachable_symbols)
 }
 
 pub fn provide(providers: &mut Providers<'_>) {