Retire stability_index query.

Author: cjgillot

compiler/rustc_interface/src/passes.rs

@@ -1065,7 +1065,6 @@ fn run_required_analyses(tcx: TyCtxt<'_>) {
                 // This marks the corresponding crate-level attributes
                 // as used, and ensures that their values are valid.
                 tcx.ensure_ok().limits(());
-                tcx.ensure_ok().stability_index(());
             }
         );
     });

compiler/rustc_middle/src/middle/stability.rs

@@ -7,7 +7,6 @@ use rustc_ast::NodeId;
 use rustc_attr_data_structures::{
     self as attrs, ConstStability, DefaultBodyStability, DeprecatedSince, Deprecation, Stability,
 };
-use rustc_data_structures::unord::UnordMap;
 use rustc_errors::{Applicability, Diag, EmissionGuarantee};
 use rustc_feature::GateIssue;
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -65,24 +64,6 @@ impl DeprecationEntry {
     }
 }
 
-/// A stability index, giving the stability level for items and methods.
-#[derive(HashStable, Debug)]
-pub struct Index {
-    /// Mapping from feature name to feature name based on the `implied_by` field of `#[unstable]`
-    /// attributes. If a `#[unstable(feature = "implier", implied_by = "impliee")]` attribute
-    /// exists, then this map will have a `impliee -> implier` entry.
-    ///
-    /// This mapping is necessary unless both the `#[stable]` and `#[unstable]` attributes should
-    /// specify their implications (both `implies` and `implied_by`). If only one of the two
-    /// attributes do (as in the current implementation, `implied_by` in `#[unstable]`), then this
-    /// mapping is necessary for diagnostics. When a "unnecessary feature attribute" error is
-    /// reported, only the `#[stable]` attribute information is available, so the map is necessary
-    /// to know that the feature implies another feature. If it were reversed, and the `#[stable]`
-    /// attribute had an `implies` meta item, then a map would be necessary when avoiding a "use of
-    /// unstable feature" error for a feature that was implied.
-    pub implications: UnordMap<Symbol, Symbol>,
-}
-
 pub fn report_unstable(
     sess: &Session,
     feature: Symbol,

compiler/rustc_middle/src/query/mod.rs

@@ -112,7 +112,7 @@ use crate::middle::exported_symbols::{ExportedSymbol, SymbolExportInfo};
 use crate::middle::lib_features::LibFeatures;
 use crate::middle::privacy::EffectiveVisibilities;
 use crate::middle::resolve_bound_vars::{ObjectLifetimeDefault, ResolveBoundVars, ResolvedArg};
-use crate::middle::stability::{self, DeprecationEntry};
+use crate::middle::stability::DeprecationEntry;
 use crate::mir::interpret::{
     EvalStaticInitializerRawResult, EvalToAllocationRawResult, EvalToConstValueResult,
     EvalToValTreeResult, GlobalId, LitToConstInput,
@@ -2162,6 +2162,18 @@ rustc_queries! {
         separate_provide_extern
         arena_cache
     }
+    /// Mapping from feature name to feature name based on the `implied_by` field of `#[unstable]`
+    /// attributes. If a `#[unstable(feature = "implier", implied_by = "impliee")]` attribute
+    /// exists, then this map will have a `impliee -> implier` entry.
+    ///
+    /// This mapping is necessary unless both the `#[stable]` and `#[unstable]` attributes should
+    /// specify their implications (both `implies` and `implied_by`). If only one of the two
+    /// attributes do (as in the current implementation, `implied_by` in `#[unstable]`), then this
+    /// mapping is necessary for diagnostics. When a "unnecessary feature attribute" error is
+    /// reported, only the `#[stable]` attribute information is available, so the map is necessary
+    /// to know that the feature implies another feature. If it were reversed, and the `#[stable]`
+    /// attribute had an `implies` meta item, then a map would be necessary when avoiding a "use of
+    /// unstable feature" error for a feature that was implied.
     query stability_implications(_: CrateNum) -> &'tcx UnordMap<Symbol, Symbol> {
         arena_cache
         desc { "calculating the implications between `#[unstable]` features defined in a crate" }
@@ -2268,11 +2280,6 @@ rustc_queries! {
         desc { "fetching potentially unused trait imports" }
     }
 
-    query stability_index(_: ()) -> &'tcx stability::Index {
-        arena_cache
-        eval_always
-        desc { "calculating the stability index for the local crate" }
-    }
     /// All available crates in the graph, including those that should not be user-facing
     /// (such as private crates).
     query crates(_: ()) -> &'tcx [CrateNum] {

compiler/rustc_middle/src/ty/context.rs

@@ -65,7 +65,7 @@ use crate::infer::canonical::{CanonicalParamEnvCache, CanonicalVarKind, Canonica
 use crate::lint::lint_level;
 use crate::metadata::ModChild;
 use crate::middle::codegen_fn_attrs::{CodegenFnAttrs, TargetFeature};
-use crate::middle::{resolve_bound_vars, stability};
+use crate::middle::resolve_bound_vars;
 use crate::mir::interpret::{self, Allocation, ConstAllocation};
 use crate::mir::{Body, Local, Place, PlaceElem, ProjectionKind, Promoted};
 use crate::query::plumbing::QuerySystem;
@@ -1799,10 +1799,6 @@ impl<'tcx> TyCtxt<'tcx> {
         )
     }
 
-    pub fn stability(self) -> &'tcx stability::Index {
-        self.stability_index(())
-    }
-
     pub fn features(self) -> &'tcx rustc_feature::Features {
         self.features_query(())
     }

compiler/rustc_passes/src/stability.rs

@@ -19,10 +19,8 @@ use rustc_hir::{self as hir, AmbigArg, FieldDef, Item, ItemKind, TraitRef, Ty, T
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::lib_features::{FeatureStability, LibFeatures};
 use rustc_middle::middle::privacy::EffectiveVisibilities;
-use rustc_middle::middle::stability::{
-    AllowUnstable, Deprecated, DeprecationEntry, EvalResult, Index,
-};
-use rustc_middle::query::Providers;
+use rustc_middle::middle::stability::{AllowUnstable, Deprecated, DeprecationEntry, EvalResult};
+use rustc_middle::query::{LocalCrate, Providers};
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_session::lint;
@@ -317,12 +315,12 @@ fn lookup_const_stability(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<ConstSt
 }
 
 /// A private tree-walker for producing an `Index`.
-struct Annotator<'a, 'tcx> {
+struct Annotator<'tcx> {
     tcx: TyCtxt<'tcx>,
-    index: &'a mut Index,
+    implications: UnordMap<Symbol, Symbol>,
 }
 
-impl<'a, 'tcx> Annotator<'a, 'tcx> {
+impl<'tcx> Annotator<'tcx> {
     /// Determine the stability for a node based on its attributes and inherited stability. The
     /// stability is recorded in the index and used as the parent. If the node is a function,
     /// `fn_sig` is its signature.
@@ -335,18 +333,18 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
         if let Some(stability) = self.tcx.lookup_stability(def_id)
             && let StabilityLevel::Unstable { implied_by: Some(implied_by), .. } = stability.level
         {
-            self.index.implications.insert(implied_by, stability.feature);
+            self.implications.insert(implied_by, stability.feature);
         }
 
         if let Some(stability) = self.tcx.lookup_const_stability(def_id)
             && let StabilityLevel::Unstable { implied_by: Some(implied_by), .. } = stability.level
         {
-            self.index.implications.insert(implied_by, stability.feature);
+            self.implications.insert(implied_by, stability.feature);
         }
     }
 }
 
-impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
+impl<'tcx> Visitor<'tcx> for Annotator<'tcx> {
     /// Because stability levels are scoped lexically, we want to walk
     /// nested items in the context of the outer item, so enable
     /// deep-walking.
@@ -610,12 +608,11 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
     }
 }
 
-fn stability_index(tcx: TyCtxt<'_>, (): ()) -> Index {
-    let mut index = Index { implications: Default::default() };
-    let mut annotator = Annotator { tcx, index: &mut index };
+fn stability_implications(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> UnordMap<Symbol, Symbol> {
+    let mut annotator = Annotator { tcx, implications: Default::default() };
     annotator.annotate(CRATE_DEF_ID);
     tcx.hir_walk_toplevel_module(&mut annotator);
-    index
+    annotator.implications
 }
 
 /// Cross-references the feature names of unstable APIs with enabled
@@ -627,8 +624,7 @@ fn check_mod_unstable_api_usage(tcx: TyCtxt<'_>, module_def_id: LocalModDefId) {
 pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers {
         check_mod_unstable_api_usage,
-        stability_index,
-        stability_implications: |tcx, _| tcx.stability().implications.clone(),
+        stability_implications,
         lookup_stability,
         lookup_const_stability,
         lookup_default_body_stability,