Stop using ty::GenericPredicates for non-predicates_of queries

compiler/rustc_hir_analysis/src/collect.rs

@@ -420,7 +420,7 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> {
         span: Span,
         def_id: LocalDefId,
         assoc_name: Ident,
-    ) -> ty::GenericPredicates<'tcx> {
+    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
         self.tcx.at(span).type_param_predicates((self.item_def_id, def_id, assoc_name))
     }
 

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -580,24 +580,24 @@ pub(super) fn explicit_predicates_of<'tcx>(
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are lowered and stored. This also ensures that
 /// the transitive super-predicates are lowered.
-pub(super) fn explicit_super_predicates_of(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_super_predicates_of<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: LocalDefId,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(tcx, trait_def_id.to_def_id(), PredicateFilter::SelfOnly)
 }
 
-pub(super) fn explicit_supertraits_containing_assoc_item(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_supertraits_containing_assoc_item<'tcx>(
+    tcx: TyCtxt<'tcx>,
     (trait_def_id, assoc_name): (DefId, Ident),
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(tcx, trait_def_id, PredicateFilter::SelfThatDefines(assoc_name))
 }
 
-pub(super) fn explicit_implied_predicates_of(
-    tcx: TyCtxt<'_>,
+pub(super) fn explicit_implied_predicates_of<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: LocalDefId,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     implied_predicates_with_filter(
         tcx,
         trait_def_id.to_def_id(),
@@ -612,11 +612,11 @@ pub(super) fn explicit_implied_predicates_of(
 /// Ensures that the super-predicates of the trait with a `DefId`
 /// of `trait_def_id` are lowered and stored. This also ensures that
 /// the transitive super-predicates are lowered.
-pub(super) fn implied_predicates_with_filter(
-    tcx: TyCtxt<'_>,
+pub(super) fn implied_predicates_with_filter<'tcx>(
+    tcx: TyCtxt<'tcx>,
     trait_def_id: DefId,
     filter: PredicateFilter,
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     let Some(trait_def_id) = trait_def_id.as_local() else {
         // if `assoc_name` is None, then the query should've been redirected to an
         // external provider
@@ -679,20 +679,16 @@ pub(super) fn implied_predicates_with_filter(
         _ => {}
     }
 
-    ty::GenericPredicates {
-        parent: None,
-        predicates: implied_bounds,
-        effects_min_tys: ty::List::empty(),
-    }
+    ty::EarlyBinder::bind(implied_bounds)
 }
 
 /// Returns the predicates defined on `item_def_id` of the form
 /// `X: Foo` where `X` is the type parameter `def_id`.
 #[instrument(level = "trace", skip(tcx))]
-pub(super) fn type_param_predicates(
-    tcx: TyCtxt<'_>,
+pub(super) fn type_param_predicates<'tcx>(
+    tcx: TyCtxt<'tcx>,
     (item_def_id, def_id, assoc_name): (LocalDefId, LocalDefId, Ident),
-) -> ty::GenericPredicates<'_> {
+) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]> {
     use rustc_hir::*;
     use rustc_middle::ty::Ty;
 
@@ -713,18 +709,20 @@ pub(super) fn type_param_predicates(
         tcx.generics_of(item_def_id).parent.map(|def_id| def_id.expect_local())
     };
 
-    let mut result = parent
-        .map(|parent| {
-            let icx = ItemCtxt::new(tcx, parent);
-            icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_name)
-        })
-        .unwrap_or_default();
+    let result = if let Some(parent) = parent {
+        let icx = ItemCtxt::new(tcx, parent);
+        icx.probe_ty_param_bounds(DUMMY_SP, def_id, assoc_name)
+    } else {
+        ty::EarlyBinder::bind(&[] as &[_])
+    };
     let mut extend = None;
 
     let item_hir_id = tcx.local_def_id_to_hir_id(item_def_id);
 
     let hir_node = tcx.hir_node(item_hir_id);
-    let Some(hir_generics) = hir_node.generics() else { return result };
+    let Some(hir_generics) = hir_node.generics() else {
+        return result;
+    };
     if let Node::Item(item) = hir_node
         && let ItemKind::Trait(..) = item.kind
         // Implied `Self: Trait` and supertrait bounds.
@@ -748,9 +746,10 @@ pub(super) fn type_param_predicates(
             _ => false,
         }),
     );
-    result.predicates =
-        tcx.arena.alloc_from_iter(result.predicates.iter().copied().chain(extra_predicates));
-    result
+
+    ty::EarlyBinder::bind(
+        tcx.arena.alloc_from_iter(result.skip_binder().iter().copied().chain(extra_predicates)),
+    )
 }
 
 impl<'tcx> ItemCtxt<'tcx> {

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1761,7 +1761,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                 break Some((bound_vars.into_iter().collect(), assoc_item));
             }
             let predicates = tcx.explicit_supertraits_containing_assoc_item((def_id, assoc_name));
-            let obligations = predicates.predicates.iter().filter_map(|&(pred, _)| {
+            let obligations = predicates.iter_identity_copied().filter_map(|(pred, _)| {
                 let bound_predicate = pred.kind();
                 match bound_predicate.skip_binder() {
                     ty::ClauseKind::Trait(data) => {

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -136,7 +136,7 @@ pub trait HirTyLowerer<'tcx> {
         span: Span,
         def_id: LocalDefId,
         assoc_name: Ident,
-    ) -> ty::GenericPredicates<'tcx>;
+    ) -> ty::EarlyBinder<'tcx, &'tcx [(ty::Clause<'tcx>, Span)]>;
 
     /// Lower an associated type to a projection.
     ///
@@ -831,13 +831,13 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         debug!(?ty_param_def_id, ?assoc_name, ?span);
         let tcx = self.tcx();
 
-        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name).predicates;
+        let predicates = &self.probe_ty_param_bounds(span, ty_param_def_id, assoc_name);
         debug!("predicates={:#?}", predicates);
 
         self.probe_single_bound_for_assoc_item(
             || {
                 let trait_refs = predicates
-                    .iter()
+                    .iter_identity_copied()
                     .filter_map(|(p, _)| Some(p.as_trait_clause()?.map_bound(|t| t.trait_ref)));
                 traits::transitive_bounds_that_define_assoc_item(tcx, trait_refs, assoc_name)
             },