Enable potential_query_instability lint in rustc_hir_typeck.

Fix linting errors by using FxIndex(Map|Set) and Unord(Map|Set) as appropriate.

Author: michaelwoerister

compiler/rustc_data_structures/src/unord.rs

@@ -31,6 +31,7 @@ use crate::{
 ///
 /// It's still possible to do the same thing with an `Fn` by using interior mutability,
 /// but the chance of doing it accidentally is reduced.
+#[derive(Clone)]
 pub struct UnordItems<T, I: Iterator<Item = T>>(I);
 
 impl<T, I: Iterator<Item = T>> UnordItems<T, I> {
@@ -194,6 +195,11 @@ impl<V: Eq + Hash> UnordSet<V> {
         Self { inner: Default::default() }
     }
 
+    #[inline]
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self { inner: FxHashSet::with_capacity_and_hasher(capacity, Default::default()) }
+    }
+
     #[inline]
     pub fn len(&self) -> usize {
         self.inner.len()
@@ -258,9 +264,9 @@ impl<V: Eq + Hash> UnordSet<V> {
     #[inline]
     pub fn to_sorted_stable_ord(&self) -> Vec<V>
     where
-        V: Ord + StableOrd + Copy,
+        V: Ord + StableOrd + Clone,
     {
-        let mut items: Vec<V> = self.inner.iter().copied().collect();
+        let mut items: Vec<V> = self.inner.iter().cloned().collect();
         items.sort_unstable();
         items
     }
@@ -312,6 +318,12 @@ impl<V: Hash + Eq> From<FxHashSet<V>> for UnordSet<V> {
     }
 }
 
+impl<V: Hash + Eq, I: Iterator<Item = V>> From<UnordItems<V, I>> for UnordSet<V> {
+    fn from(value: UnordItems<V, I>) -> Self {
+        UnordSet { inner: FxHashSet::from_iter(value.0) }
+    }
+}
+
 impl<HCX, V: Hash + Eq + HashStable<HCX>> HashStable<HCX> for UnordSet<V> {
     #[inline]
     fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) {
@@ -362,6 +374,11 @@ impl<K: Hash + Eq, V, I: Iterator<Item = (K, V)>> From<UnordItems<(K, V), I>> fo
 }
 
 impl<K: Eq + Hash, V> UnordMap<K, V> {
+    #[inline]
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self { inner: FxHashMap::with_capacity_and_hasher(capacity, Default::default()) }
+    }
+
     #[inline]
     pub fn len(&self) -> usize {
         self.inner.len()

compiler/rustc_hir_typeck/src/fallback.rs

@@ -1,8 +1,8 @@
 use crate::FnCtxt;
 use rustc_data_structures::{
-    fx::{FxHashMap, FxHashSet},
     graph::WithSuccessors,
     graph::{iterate::DepthFirstSearch, vec_graph::VecGraph},
+    unord::{UnordBag, UnordMap, UnordSet},
 };
 use rustc_middle::ty::{self, Ty};
 
@@ -83,7 +83,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     fn fallback_if_possible(
         &self,
         ty: Ty<'tcx>,
-        diverging_fallback: &FxHashMap<Ty<'tcx>, Ty<'tcx>>,
+        diverging_fallback: &UnordMap<Ty<'tcx>, Ty<'tcx>>,
     ) {
         // Careful: we do NOT shallow-resolve `ty`. We know that `ty`
         // is an unsolved variable, and we determine its fallback
@@ -193,7 +193,7 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
     fn calculate_diverging_fallback(
         &self,
         unsolved_variables: &[Ty<'tcx>],
-    ) -> FxHashMap<Ty<'tcx>, Ty<'tcx>> {
+    ) -> UnordMap<Ty<'tcx>, Ty<'tcx>> {
         debug!("calculate_diverging_fallback({:?})", unsolved_variables);
 
         // Construct a coercion graph where an edge `A -> B` indicates
@@ -210,10 +210,10 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
         //
         // These variables are the ones that are targets for fallback to
         // either `!` or `()`.
-        let diverging_roots: FxHashSet<ty::TyVid> = self
+        let diverging_roots: UnordSet<ty::TyVid> = self
             .diverging_type_vars
             .borrow()
-            .iter()
+            .items()
             .map(|&ty| self.shallow_resolve(ty))
             .filter_map(|ty| ty.ty_vid())
             .map(|vid| self.root_var(vid))
@@ -284,23 +284,27 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
         // For each diverging variable, figure out whether it can
         // reach a member of N. If so, it falls back to `()`. Else
         // `!`.
-        let mut diverging_fallback = FxHashMap::default();
-        diverging_fallback.reserve(diverging_vids.len());
+        let mut diverging_fallback = UnordMap::with_capacity(diverging_vids.len());
         for &diverging_vid in &diverging_vids {
             let diverging_ty = Ty::new_var(self.tcx, diverging_vid);
             let root_vid = self.root_var(diverging_vid);
             let can_reach_non_diverging = coercion_graph
                 .depth_first_search(root_vid)
                 .any(|n| roots_reachable_from_non_diverging.visited(n));
 
-            let mut found_infer_var_info = ty::InferVarInfo { self_in_trait: false, output: false };
+            let infer_var_infos: UnordBag<_> = self
+                .inh
+                .infer_var_info
+                .borrow()
+                .items()
+                .filter(|&(vid, _)| self.infcx.root_var(*vid) == root_vid)
+                .map(|(_, info)| *info)
+                .collect();
 
-            for (vid, info) in self.inh.infer_var_info.borrow().iter() {
-                if self.infcx.root_var(*vid) == root_vid {
-                    found_infer_var_info.self_in_trait |= info.self_in_trait;
-                    found_infer_var_info.output |= info.output;
-                }
-            }
+            let found_infer_var_info = ty::InferVarInfo {
+                self_in_trait: infer_var_infos.items().any(|info| info.self_in_trait),
+                output: infer_var_infos.items().any(|info| info.output),
+            };
 
             if found_infer_var_info.self_in_trait && found_infer_var_info.output {
                 // This case falls back to () to ensure that the code pattern in

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs

@@ -6,7 +6,7 @@ use hir::{
     intravisit::{self, Visitor},
     Body, Expr, ExprKind, Guard, HirId, LoopIdError,
 };
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_hir as hir;
 use rustc_index::IndexVec;
 use rustc_infer::infer::InferCtxt;
@@ -28,7 +28,7 @@ pub(super) fn build_control_flow_graph<'tcx>(
     consumed_borrowed_places: ConsumedAndBorrowedPlaces,
     body: &'tcx Body<'tcx>,
     num_exprs: usize,
-) -> (DropRangesBuilder, FxHashSet<HirId>) {
+) -> (DropRangesBuilder, UnordSet<HirId>) {
     let mut drop_range_visitor = DropRangeVisitor::new(
         infcx,
         typeck_results,
@@ -528,7 +528,7 @@ impl DropRangesBuilder {
         hir: Map<'_>,
         num_exprs: usize,
     ) -> Self {
-        let mut tracked_value_map = FxHashMap::<_, TrackedValueIndex>::default();
+        let mut tracked_value_map = UnordMap::<_, TrackedValueIndex>::default();
         let mut next = <_>::from(0u32);
         for value in tracked_values {
             for_each_consumable(hir, value, |value| {

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs

@@ -17,7 +17,7 @@ use self::record_consumed_borrow::find_consumed_and_borrowed;
 use crate::FnCtxt;
 use hir::def_id::DefId;
 use hir::{Body, HirId, HirIdMap, Node};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_hir as hir;
 use rustc_index::bit_set::BitSet;
 use rustc_index::IndexVec;
@@ -63,7 +63,7 @@ pub fn compute_drop_ranges<'a, 'tcx>(
         // If drop range tracking is not enabled, skip all the analysis and produce an
         // empty set of DropRanges.
         DropRanges {
-            tracked_value_map: FxHashMap::default(),
+            tracked_value_map: UnordMap::default(),
             nodes: IndexVec::new(),
             borrowed_temporaries: None,
         }
@@ -182,9 +182,9 @@ impl TryFrom<&PlaceWithHirId<'_>> for TrackedValue {
 }
 
 pub struct DropRanges {
-    tracked_value_map: FxHashMap<TrackedValue, TrackedValueIndex>,
+    tracked_value_map: UnordMap<TrackedValue, TrackedValueIndex>,
     nodes: IndexVec<PostOrderId, NodeInfo>,
-    borrowed_temporaries: Option<FxHashSet<HirId>>,
+    borrowed_temporaries: Option<UnordSet<HirId>>,
 }
 
 impl DropRanges {
@@ -227,7 +227,7 @@ struct DropRangesBuilder {
     /// (see NodeInfo::drop_state). The hir_id_map field stores the mapping
     /// from HirIds to the HirIdIndex that is used to represent that value in
     /// bitvector.
-    tracked_value_map: FxHashMap<TrackedValue, TrackedValueIndex>,
+    tracked_value_map: UnordMap<TrackedValue, TrackedValueIndex>,
 
     /// When building the control flow graph, we don't always know the
     /// post-order index of the target node at the point we encounter it.

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs

@@ -4,7 +4,7 @@ use crate::{
     FnCtxt,
 };
 use hir::{def_id::DefId, Body, HirId, HirIdMap};
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::{fx::FxIndexSet, unord::UnordSet};
 use rustc_hir as hir;
 use rustc_middle::ty::{ParamEnv, TyCtxt};
 use rustc_middle::{
@@ -30,13 +30,13 @@ pub(super) struct ConsumedAndBorrowedPlaces {
     ///
     /// Note that this set excludes "partial drops" -- for example, a statement like `drop(x.y)` is
     /// not considered a drop of `x`, although it would be a drop of `x.y`.
-    pub(super) consumed: HirIdMap<FxHashSet<TrackedValue>>,
+    pub(super) consumed: HirIdMap<FxIndexSet<TrackedValue>>,
 
     /// A set of hir-ids of values or variables that are borrowed at some point within the body.
-    pub(super) borrowed: FxHashSet<TrackedValue>,
+    pub(super) borrowed: UnordSet<TrackedValue>,
 
     /// A set of hir-ids of values or variables that are borrowed at some point within the body.
-    pub(super) borrowed_temporaries: FxHashSet<HirId>,
+    pub(super) borrowed_temporaries: UnordSet<HirId>,
 }
 
 /// Works with ExprUseVisitor to find interesting values for the drop range analysis.

compiler/rustc_hir_typeck/src/inherited.rs

@@ -1,6 +1,6 @@
 use super::callee::DeferredCallResolution;
 
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::HirIdMap;
@@ -61,9 +61,9 @@ pub struct Inherited<'tcx> {
     /// Whenever we introduce an adjustment from `!` into a type variable,
     /// we record that type variable here. This is later used to inform
     /// fallback. See the `fallback` module for details.
-    pub(super) diverging_type_vars: RefCell<FxHashSet<Ty<'tcx>>>,
+    pub(super) diverging_type_vars: RefCell<UnordSet<Ty<'tcx>>>,
 
-    pub(super) infer_var_info: RefCell<FxHashMap<ty::TyVid, ty::InferVarInfo>>,
+    pub(super) infer_var_info: RefCell<UnordMap<ty::TyVid, ty::InferVarInfo>>,
 }
 
 impl<'tcx> Deref for Inherited<'tcx> {

compiler/rustc_hir_typeck/src/lib.rs

@@ -6,7 +6,6 @@
 #![feature(min_specialization)]
 #![feature(control_flow_enum)]
 #![feature(option_as_slice)]
-#![allow(rustc::potential_query_instability)]
 #![recursion_limit = "256"]
 
 #[macro_use]

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -7,7 +7,9 @@ use crate::errors::NoAssociatedItem;
 use crate::Expectation;
 use crate::FnCtxt;
 use rustc_ast::ast::Mutability;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::fx::FxIndexSet;
+use rustc_data_structures::unord::UnordSet;
 use rustc_errors::StashKey;
 use rustc_errors::{
     pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed,
@@ -31,6 +33,7 @@ use rustc_middle::ty::fast_reject::{simplify_type, TreatParams};
 use rustc_middle::ty::print::{with_crate_prefix, with_forced_trimmed_paths};
 use rustc_middle::ty::IsSuggestable;
 use rustc_middle::ty::{self, GenericArgKind, Ty, TyCtxt, TypeVisitableExt};
+use rustc_span::def_id::DefIdSet;
 use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::Symbol;
 use rustc_span::{edit_distance, source_map, ExpnKind, FileName, MacroKind, Span};
@@ -536,11 +539,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 ));
             }
         } else if !unsatisfied_predicates.is_empty() {
-            let mut type_params = FxHashMap::default();
+            let mut type_params = FxIndexMap::default();
 
             // Pick out the list of unimplemented traits on the receiver.
             // This is used for custom error messages with the `#[rustc_on_unimplemented]` attribute.
-            let mut unimplemented_traits = FxHashMap::default();
+            let mut unimplemented_traits = FxIndexMap::default();
             let mut unimplemented_traits_only = true;
             for (predicate, _parent_pred, cause) in unsatisfied_predicates {
                 if let (ty::PredicateKind::Clause(ty::ClauseKind::Trait(p)), Some(cause)) =
@@ -606,7 +609,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             );
                             type_params
                                 .entry(key)
-                                .or_insert_with(FxHashSet::default)
+                                .or_insert_with(UnordSet::default)
                                 .insert(obligation.to_owned());
                             return true;
                         }
@@ -680,8 +683,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             };
 
             // Find all the requirements that come from a local `impl` block.
-            let mut skip_list: FxHashSet<_> = Default::default();
-            let mut spanned_predicates = FxHashMap::default();
+            let mut skip_list: UnordSet<_> = Default::default();
+            let mut spanned_predicates = FxIndexMap::default();
             for (p, parent_p, cause) in unsatisfied_predicates {
                 // Extract the predicate span and parent def id of the cause,
                 // if we have one.
@@ -723,7 +726,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         let span = self_ty.span.ctxt().outer_expn_data().call_site;
                         let entry = spanned_predicates.entry(span);
                         let entry = entry.or_insert_with(|| {
-                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                            (FxIndexSet::default(), FxIndexSet::default(), Vec::new())
                         });
                         entry.0.insert(span);
                         entry.1.insert((
@@ -771,7 +774,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         skip_list.insert(p);
                         let entry = spanned_predicates.entry(self_ty.span);
                         let entry = entry.or_insert_with(|| {
-                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                            (FxIndexSet::default(), FxIndexSet::default(), Vec::new())
                         });
                         entry.2.push(p);
                         if cause_span != *item_span {
@@ -806,7 +809,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         skip_list.insert(p);
                         let entry = spanned_predicates.entry(ident.span);
                         let entry = entry.or_insert_with(|| {
-                            (FxHashSet::default(), FxHashSet::default(), Vec::new())
+                            (FxIndexSet::default(), FxIndexSet::default(), Vec::new())
                         });
                         entry.0.insert(cause_span);
                         entry.1.insert((ident.span, ""));
@@ -840,7 +843,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 unsatisfied_bounds = true;
             }
 
-            let mut suggested_bounds = FxHashSet::default();
+            let mut suggested_bounds = UnordSet::default();
             // The requirements that didn't have an `impl` span to show.
             let mut bound_list = unsatisfied_predicates
                 .iter()
@@ -889,8 +892,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             for ((span, add_where_or_comma), obligations) in type_params.into_iter() {
                 restrict_type_params = true;
                 // #74886: Sort here so that the output is always the same.
-                let mut obligations = obligations.into_iter().collect::<Vec<_>>();
-                obligations.sort();
+                let obligations = obligations.to_sorted_stable_ord();
                 err.span_suggestion_verbose(
                     span,
                     format!(
@@ -2053,7 +2055,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 ty::Adt(def, _) => Some(def.did()),
                 _ => None,
             })
-            .collect::<FxHashSet<_>>();
+            .collect::<FxIndexSet<_>>();
         let mut spans: MultiSpan = def_ids
             .iter()
             .filter_map(|def_id| {
@@ -2669,7 +2671,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 Nothing,
                             }
                             let ast_generics = hir.get_generics(id.owner.def_id).unwrap();
-                            let trait_def_ids: FxHashSet<DefId> = ast_generics
+                            let trait_def_ids: DefIdSet = ast_generics
                                 .bounds_for_param(def_id)
                                 .flat_map(|bp| bp.bounds.iter())
                                 .filter_map(|bound| bound.trait_ref()?.trait_def_id())