Stop interning stability.

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -129,12 +129,8 @@ provide! { <'tcx> tcx, def_id, other, cdata,
     opt_def_kind => { Some(cdata.def_kind(def_id.index)) }
     def_span => { cdata.get_span(def_id.index, &tcx.sess) }
     def_ident_span => { cdata.opt_item_ident(def_id.index, &tcx.sess).map(|ident| ident.span) }
-    lookup_stability => {
+    lookup_stability => { cdata.get_stability(def_id.index) }
-        cdata.get_stability(def_id.index).map(|s| tcx.intern_stability(s))
+    lookup_const_stability => { cdata.get_const_stability(def_id.index) }
-    }
-    lookup_const_stability => {
-        cdata.get_const_stability(def_id.index).map(|s| tcx.intern_const_stability(s))
-    }
     lookup_deprecation_entry => {
         cdata.get_deprecation(def_id.index).map(DeprecationEntry::external)
     }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1661,7 +1661,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             let hir = tcx.hir();
 
             let proc_macro_decls_static = tcx.proc_macro_decls_static(()).unwrap().local_def_index;
-            let stability = tcx.lookup_stability(DefId::local(CRATE_DEF_INDEX)).copied();
+            let stability = tcx.lookup_stability(DefId::local(CRATE_DEF_INDEX));
             let macros =
                 self.lazy(tcx.resolutions(()).proc_macros.iter().map(|p| p.local_def_index));
             let spans = self.tcx.sess.parse_sess.proc_macro_quoted_spans();

compiler/rustc_middle/src/middle/stability.rs

@@ -57,11 +57,11 @@ impl DeprecationEntry {
 
 /// A stability index, giving the stability level for items and methods.
 #[derive(HashStable, Debug)]
-pub struct Index<'tcx> {
+pub struct Index {
     /// This is mostly a cache, except the stabilities of local items
     /// are filled by the annotator.
-    pub stab_map: FxHashMap<LocalDefId, &'tcx Stability>,
+    pub stab_map: FxHashMap<LocalDefId, Stability>,
-    pub const_stab_map: FxHashMap<LocalDefId, &'tcx ConstStability>,
+    pub const_stab_map: FxHashMap<LocalDefId, ConstStability>,
     pub depr_map: FxHashMap<LocalDefId, DeprecationEntry>,
 
     /// Maps for each crate whether it is part of the staged API.
@@ -71,12 +71,12 @@ pub struct Index<'tcx> {
     pub active_features: FxHashSet<Symbol>,
 }
 
-impl<'tcx> Index<'tcx> {
+impl Index {
-    pub fn local_stability(&self, def_id: LocalDefId) -> Option<&'tcx Stability> {
+    pub fn local_stability(&self, def_id: LocalDefId) -> Option<Stability> {
         self.stab_map.get(&def_id).copied()
     }
 
-    pub fn local_const_stability(&self, def_id: LocalDefId) -> Option<&'tcx ConstStability> {
+    pub fn local_const_stability(&self, def_id: LocalDefId) -> Option<ConstStability> {
         self.const_stab_map.get(&def_id).copied()
     }
 
@@ -416,7 +416,7 @@ impl<'tcx> TyCtxt<'tcx> {
         }
 
         match stability {
-            Some(&Stability {
+            Some(Stability {
                 level: attr::Unstable { reason, issue, is_soft }, feature, ..
             }) => {
                 if span.allows_unstable(feature) {

compiler/rustc_middle/src/query/mod.rs

@@ -1010,12 +1010,12 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query lookup_stability(def_id: DefId) -> Option<&'tcx attr::Stability> {
+    query lookup_stability(def_id: DefId) -> Option<attr::Stability> {
         desc { |tcx| "looking up stability of `{}`", tcx.def_path_str(def_id) }
         separate_provide_extern
     }
 
-    query lookup_const_stability(def_id: DefId) -> Option<&'tcx attr::ConstStability> {
+    query lookup_const_stability(def_id: DefId) -> Option<attr::ConstStability> {
         desc { |tcx| "looking up const stability of `{}`", tcx.def_path_str(def_id) }
         separate_provide_extern
     }
@@ -1626,7 +1626,7 @@ rustc_queries! {
         desc { |tcx| "names_imported_by_glob_use for `{}`", tcx.def_path_str(def_id.to_def_id()) }
     }
 
-    query stability_index(_: ()) -> stability::Index<'tcx> {
+    query stability_index(_: ()) -> stability::Index {
         storage(ArenaCacheSelector<'tcx>)
         eval_always
         desc { "calculating the stability index for the local crate" }

compiler/rustc_middle/src/ty/context.rs

@@ -24,7 +24,6 @@ use crate::ty::{
     RegionKind, ReprOptions, TraitObjectVisitor, Ty, TyKind, TyS, TyVar, TyVid, TypeAndMut, UintTy,
 };
 use rustc_ast as ast;
-use rustc_attr as attr;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::intern::Interned;
 use rustc_data_structures::memmap::Mmap;
@@ -116,12 +115,6 @@ pub struct CtxtInterners<'tcx> {
     bound_variable_kinds: InternedSet<'tcx, List<ty::BoundVariableKind>>,
     layout: InternedSet<'tcx, Layout>,
     adt_def: InternedSet<'tcx, AdtDef>,
-
-    /// `#[stable]` and `#[unstable]` attributes
-    stability: InternedSet<'tcx, attr::Stability>,
-
-    /// `#[rustc_const_stable]` and `#[rustc_const_unstable]` attributes
-    const_stability: InternedSet<'tcx, attr::ConstStability>,
 }
 
 impl<'tcx> CtxtInterners<'tcx> {
@@ -143,8 +136,6 @@ impl<'tcx> CtxtInterners<'tcx> {
             bound_variable_kinds: Default::default(),
             layout: Default::default(),
             adt_def: Default::default(),
-            stability: Default::default(),
-            const_stability: Default::default(),
         }
     }
 
@@ -1271,7 +1262,7 @@ impl<'tcx> TyCtxt<'tcx> {
         self.diagnostic_items(did.krate).name_to_id.get(&name) == Some(&did)
     }
 
-    pub fn stability(self) -> &'tcx stability::Index<'tcx> {
+    pub fn stability(self) -> &'tcx stability::Index {
         self.stability_index(())
     }
 
@@ -1981,12 +1972,6 @@ impl<'tcx> TyCtxt<'tcx> {
 
                 writeln!(fmt, "InternalSubsts interner: #{}", self.0.interners.substs.len())?;
                 writeln!(fmt, "Region interner: #{}", self.0.interners.region.len())?;
-                writeln!(fmt, "Stability interner: #{}", self.0.interners.stability.len())?;
-                writeln!(
-                    fmt,
-                    "Const Stability interner: #{}",
-                    self.0.interners.const_stability.len()
-                )?;
                 writeln!(
                     fmt,
                     "Const Allocation interner: #{}",
@@ -2174,8 +2159,6 @@ direct_interners_old! {
     const_allocation: intern_const_alloc(Allocation),
     layout: intern_layout(Layout),
     adt_def: intern_adt_def(AdtDef),
-    stability: intern_stability(attr::Stability),
-    const_stability: intern_const_stability(attr::ConstStability),
 }
 
 macro_rules! slice_interners {

compiler/rustc_passes/src/stability.rs

@@ -87,9 +87,9 @@ impl InheritStability {
 // A private tree-walker for producing an Index.
 struct Annotator<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    index: &'a mut Index<'tcx>,
+    index: &'a mut Index,
-    parent_stab: Option<&'tcx Stability>,
+    parent_stab: Option<Stability>,
-    parent_const_stab: Option<&'tcx ConstStability>,
+    parent_const_stab: Option<ConstStability>,
     parent_depr: Option<DeprecationEntry>,
     in_trait_impl: bool,
 }
@@ -171,7 +171,6 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
         let mut const_span = None;
 
         let const_stab = const_stab.map(|(const_stab, const_span_node)| {
-            let const_stab = self.tcx.intern_const_stability(const_stab);
             self.index.const_stab_map.insert(def_id, const_stab);
             const_span = Some(const_span_node);
             const_stab
@@ -228,7 +227,6 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
             }
 
             debug!("annotate: found {:?}", stab);
-            let stab = self.tcx.intern_stability(stab);
 
             // Check if deprecated_since < stable_since. If it is,
             // this is *almost surely* an accident.
@@ -299,8 +297,8 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
     fn recurse_with_stability_attrs(
         &mut self,
         depr: Option<DeprecationEntry>,
-        stab: Option<&'tcx Stability>,
+        stab: Option<Stability>,
-        const_stab: Option<&'tcx ConstStability>,
+        const_stab: Option<ConstStability>,
         f: impl FnOnce(&mut Self),
     ) {
         // These will be `Some` if this item changes the corresponding stability attribute.
@@ -655,7 +653,7 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
     // stable (assuming they have not inherited instability from their parent).
 }
 
-fn stability_index<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> Index<'tcx> {
+fn stability_index(tcx: TyCtxt<'_>, (): ()) -> Index {
     let is_staged_api =
         tcx.sess.opts.debugging_opts.force_unstable_if_unmarked || tcx.features().staged_api;
     let mut staged_api = FxHashMap::default();
@@ -698,14 +696,14 @@ fn stability_index<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> Index<'tcx> {
             let reason = "this crate is being loaded from the sysroot, an \
                           unstable location; did you mean to load this crate \
                           from crates.io via `Cargo.toml` instead?";
-            let stability = tcx.intern_stability(Stability {
+            let stability = Stability {
                 level: attr::StabilityLevel::Unstable {
                     reason: Some(Symbol::intern(reason)),
                     issue: NonZeroU32::new(27812),
                     is_soft: false,
                 },
                 feature: sym::rustc_private,
-            });
+            };
             annotator.parent_stab = Some(stability);
         }
 

src/librustdoc/clean/types.rs

@@ -381,12 +381,12 @@ crate fn rustc_span(def_id: DefId, tcx: TyCtxt<'_>) -> Span {
 }
 
 impl Item {
-    crate fn stability<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Option<&'tcx Stability> {
+    crate fn stability<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Option<Stability> {
         self.def_id.as_def_id().and_then(|did| tcx.lookup_stability(did))
     }
 
     crate fn const_stability<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Option<ConstStability> {
-        self.def_id.as_def_id().and_then(|did| tcx.lookup_const_stability(did)).map(|cs| *cs)
+        self.def_id.as_def_id().and_then(|did| tcx.lookup_const_stability(did))
     }
 
     crate fn deprecation(&self, tcx: TyCtxt<'_>) -> Option<Deprecation> {