Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 428 insertions, 323 deletions

diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index 175472797..764a6d3aa 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -148,7 +148,7 @@ where
             })
             .collect();
         // We are only interested in case the type *doesn't* implement the Sized trait.
-        if !ty.is_sized(tcx.at(rustc_span::DUMMY_SP), param_env) {
+        if !ty.is_sized(tcx, param_env) {
             // In case `#![no_core]` is used, `sized_trait` returns nothing.
             if let Some(item) = tcx.lang_items().sized_trait().and_then(|sized_trait_did| {
                 self.generate_for_trait(ty, sized_trait_did, param_env, item_def_id, &f, true)
@@ -475,6 +475,12 @@ where
 
         let mut ty_to_fn: FxHashMap<Type, (PolyTrait, Option<Type>)> = Default::default();
 
+        // FIXME: This code shares much of the logic found in `clean_ty_generics` and
+        //        `simplify::where_clause`. Consider deduplicating it to avoid diverging
+        //        implementations.
+        //        Further, the code below does not merge (partially re-sugared) bounds like
+        //        `Tr<A = T>` & `Tr<B = U>` and it does not render higher-ranked parameters
+        //        originating from equality predicates.
         for p in clean_where_predicates {
             let (orig_p, p) = (p, clean_predicate(p, self.cx));
             if p.is_none() {
@@ -549,8 +555,8 @@ where
                 WherePredicate::RegionPredicate { lifetime, bounds } => {
                     lifetime_to_bounds.entry(lifetime).or_default().extend(bounds);
                 }
-                WherePredicate::EqPredicate { lhs, rhs } => {
-                    match lhs {
+                WherePredicate::EqPredicate { lhs, rhs, bound_params } => {
+                    match *lhs {
                         Type::QPath(box QPathData {
                             ref assoc, ref self_type, ref trait_, ..
                         }) => {
@@ -585,13 +591,14 @@ where
                                 GenericArgs::AngleBracketed { ref mut bindings, .. } => {
                                     bindings.push(TypeBinding {
                                         assoc: assoc.clone(),
-                                        kind: TypeBindingKind::Equality { term: rhs },
+                                        kind: TypeBindingKind::Equality { term: *rhs },
                                     });
                                 }
                                 GenericArgs::Parenthesized { .. } => {
                                     existing_predicates.push(WherePredicate::EqPredicate {
                                         lhs: lhs.clone(),
                                         rhs,
+                                        bound_params,
                                     });
                                     continue; // If something other than a Fn ends up
                                     // with parentheses, leave it alone
diff --git a/src/librustdoc/clean/blanket_impl.rs b/src/librustdoc/clean/blanket_impl.rs
index cc734389e..8b63c3db3 100644
--- a/src/librustdoc/clean/blanket_impl.rs
+++ b/src/librustdoc/clean/blanket_impl.rs
@@ -2,7 +2,6 @@ use crate::rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtE
 use rustc_hir as hir;
 use rustc_infer::infer::{InferOk, TyCtxtInferExt};
 use rustc_infer::traits;
-use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::ToPredicate;
 use rustc_span::DUMMY_SP;
 
@@ -14,122 +13,124 @@ pub(crate) struct BlanketImplFinder<'a, 'tcx> {
 
 impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
     pub(crate) fn get_blanket_impls(&mut self, item_def_id: DefId) -> Vec<Item> {
-        let param_env = self.cx.tcx.param_env(item_def_id);
-        let ty = self.cx.tcx.bound_type_of(item_def_id);
+        let cx = &mut self.cx;
+        let param_env = cx.tcx.param_env(item_def_id);
+        let ty = cx.tcx.bound_type_of(item_def_id);
 
         trace!("get_blanket_impls({:?})", ty);
         let mut impls = Vec::new();
-        self.cx.with_all_traits(|cx, all_traits| {
-            for &trait_def_id in all_traits {
-                if !cx.cache.access_levels.is_public(trait_def_id)
-                    || cx.generated_synthetics.get(&(ty.0, trait_def_id)).is_some()
-                {
+        for trait_def_id in cx.tcx.all_traits() {
+            if !cx.cache.effective_visibilities.is_directly_public(trait_def_id)
+                || cx.generated_synthetics.get(&(ty.0, trait_def_id)).is_some()
+            {
+                continue;
+            }
+            // NOTE: doesn't use `for_each_relevant_impl` to avoid looking at anything besides blanket impls
+            let trait_impls = cx.tcx.trait_impls_of(trait_def_id);
+            'blanket_impls: for &impl_def_id in trait_impls.blanket_impls() {
+                trace!(
+                    "get_blanket_impls: Considering impl for trait '{:?}' {:?}",
+                    trait_def_id,
+                    impl_def_id
+                );
+                let trait_ref = cx.tcx.bound_impl_trait_ref(impl_def_id).unwrap();
+                if !matches!(trait_ref.0.self_ty().kind(), ty::Param(_)) {
                     continue;
                 }
-                // NOTE: doesn't use `for_each_relevant_impl` to avoid looking at anything besides blanket impls
-                let trait_impls = cx.tcx.trait_impls_of(trait_def_id);
-                for &impl_def_id in trait_impls.blanket_impls() {
-                    trace!(
-                        "get_blanket_impls: Considering impl for trait '{:?}' {:?}",
-                        trait_def_id,
-                        impl_def_id
-                    );
-                    let trait_ref = cx.tcx.bound_impl_trait_ref(impl_def_id).unwrap();
-                    let is_param = matches!(trait_ref.0.self_ty().kind(), ty::Param(_));
-                    let may_apply = is_param && cx.tcx.infer_ctxt().enter(|infcx| {
-                        let substs = infcx.fresh_substs_for_item(DUMMY_SP, item_def_id);
-                        let ty = ty.subst(infcx.tcx, substs);
-                        let param_env = EarlyBinder(param_env).subst(infcx.tcx, substs);
+                let infcx = cx.tcx.infer_ctxt().build();
+                let substs = infcx.fresh_substs_for_item(DUMMY_SP, item_def_id);
+                let impl_ty = ty.subst(infcx.tcx, substs);
+                let param_env = EarlyBinder(param_env).subst(infcx.tcx, substs);
 
-                        let impl_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id);
-                        let trait_ref = trait_ref.subst(infcx.tcx, impl_substs);
+                let impl_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl_def_id);
+                let impl_trait_ref = trait_ref.subst(infcx.tcx, impl_substs);
 
-                        // Require the type the impl is implemented on to match
-                        // our type, and ignore the impl if there was a mismatch.
-                        let cause = traits::ObligationCause::dummy();
-                        let eq_result = infcx.at(&cause, param_env).eq(trait_ref.self_ty(), ty);
-                        if let Ok(InferOk { value: (), obligations }) = eq_result {
-                            // FIXME(eddyb) ignoring `obligations` might cause false positives.
-                            drop(obligations);
+                // Require the type the impl is implemented on to match
+                // our type, and ignore the impl if there was a mismatch.
+                let cause = traits::ObligationCause::dummy();
+                let Ok(eq_result) = infcx.at(&cause, param_env).eq(impl_trait_ref.self_ty(), impl_ty) else {
+                        continue
+                    };
+                let InferOk { value: (), obligations } = eq_result;
+                // FIXME(eddyb) ignoring `obligations` might cause false positives.
+                drop(obligations);
 
-                            trace!(
-                                "invoking predicate_may_hold: param_env={:?}, trait_ref={:?}, ty={:?}",
-                                param_env,
-                                trait_ref,
-                                ty
-                            );
-                            let predicates = cx
-                                .tcx
-                                .predicates_of(impl_def_id)
-                                .instantiate(cx.tcx, impl_substs)
-                                .predicates
-                                .into_iter()
-                                .chain(Some(
-                                    ty::Binder::dummy(trait_ref)
-                                        .to_poly_trait_predicate()
-                                        .map_bound(ty::PredicateKind::Trait)
-                                        .to_predicate(infcx.tcx),
-                                ));
-                            for predicate in predicates {
-                                debug!("testing predicate {:?}", predicate);
-                                let obligation = traits::Obligation::new(
-                                    traits::ObligationCause::dummy(),
-                                    param_env,
-                                    predicate,
-                                );
-                                match infcx.evaluate_obligation(&obligation) {
-                                    Ok(eval_result) if eval_result.may_apply() => {}
-                                    Err(traits::OverflowError::Canonical) => {}
-                                    Err(traits::OverflowError::ErrorReporting) => {}
-                                    _ => {
-                                        return false;
-                                    }
-                                }
-                            }
-                            true
-                        } else {
-                            false
-                        }
-                    });
-                    debug!(
-                        "get_blanket_impls: found applicable impl: {} for trait_ref={:?}, ty={:?}",
-                        may_apply, trait_ref, ty
+                trace!(
+                    "invoking predicate_may_hold: param_env={:?}, impl_trait_ref={:?}, impl_ty={:?}",
+                    param_env,
+                    impl_trait_ref,
+                    impl_ty
+                );
+                let predicates = cx
+                    .tcx
+                    .predicates_of(impl_def_id)
+                    .instantiate(cx.tcx, impl_substs)
+                    .predicates
+                    .into_iter()
+                    .chain(Some(
+                        ty::Binder::dummy(impl_trait_ref)
+                            .to_poly_trait_predicate()
+                            .map_bound(ty::PredicateKind::Trait)
+                            .to_predicate(infcx.tcx),
+                    ));
+                for predicate in predicates {
+                    debug!("testing predicate {:?}", predicate);
+                    let obligation = traits::Obligation::new(
+                        traits::ObligationCause::dummy(),
+                        param_env,
+                        predicate,
                     );
-                    if !may_apply {
-                        continue;
+                    match infcx.evaluate_obligation(&obligation) {
+                        Ok(eval_result) if eval_result.may_apply() => {}
+                        Err(traits::OverflowError::Canonical) => {}
+                        Err(traits::OverflowError::ErrorReporting) => {}
+                        _ => continue 'blanket_impls,
                     }
+                }
+                debug!(
+                    "get_blanket_impls: found applicable impl for trait_ref={:?}, ty={:?}",
+                    trait_ref, ty
+                );
 
-                    cx.generated_synthetics.insert((ty.0, trait_def_id));
+                cx.generated_synthetics.insert((ty.0, trait_def_id));
 
-                    impls.push(Item {
-                        name: None,
-                        attrs: Default::default(),
-                        visibility: Inherited,
-                        item_id: ItemId::Blanket { impl_id: impl_def_id, for_: item_def_id },
-                        kind: Box::new(ImplItem(Box::new(Impl {
-                            unsafety: hir::Unsafety::Normal,
-                            generics: clean_ty_generics(
-                                cx,
-                                cx.tcx.generics_of(impl_def_id),
-                                cx.tcx.explicit_predicates_of(impl_def_id),
-                            ),
-                            // FIXME(eddyb) compute both `trait_` and `for_` from
-                            // the post-inference `trait_ref`, as it's more accurate.
-                            trait_: Some(clean_trait_ref_with_bindings(cx, trait_ref.0, ThinVec::new())),
-                            for_: clean_middle_ty(ty.0, cx, None),
-                            items: cx.tcx
-                                .associated_items(impl_def_id)
-                                .in_definition_order()
-                                .map(|x| clean_middle_assoc_item(x, cx))
-                                .collect::<Vec<_>>(),
-                            polarity: ty::ImplPolarity::Positive,
-                            kind: ImplKind::Blanket(Box::new(clean_middle_ty(trait_ref.0.self_ty(), cx, None))),
-                        }))),
-                        cfg: None,
-                    });
-                }
+                impls.push(Item {
+                    name: None,
+                    attrs: Default::default(),
+                    visibility: Inherited,
+                    item_id: ItemId::Blanket { impl_id: impl_def_id, for_: item_def_id },
+                    kind: Box::new(ImplItem(Box::new(Impl {
+                        unsafety: hir::Unsafety::Normal,
+                        generics: clean_ty_generics(
+                            cx,
+                            cx.tcx.generics_of(impl_def_id),
+                            cx.tcx.explicit_predicates_of(impl_def_id),
+                        ),
+                        // FIXME(eddyb) compute both `trait_` and `for_` from
+                        // the post-inference `trait_ref`, as it's more accurate.
+                        trait_: Some(clean_trait_ref_with_bindings(
+                            cx,
+                            trait_ref.0,
+                            ThinVec::new(),
+                        )),
+                        for_: clean_middle_ty(ty.0, cx, None),
+                        items: cx
+                            .tcx
+                            .associated_items(impl_def_id)
+                            .in_definition_order()
+                            .map(|x| clean_middle_assoc_item(x, cx))
+                            .collect::<Vec<_>>(),
+                        polarity: ty::ImplPolarity::Positive,
+                        kind: ImplKind::Blanket(Box::new(clean_middle_ty(
+                            trait_ref.0.self_ty(),
+                            cx,
+                            None,
+                        ))),
+                    }))),
+                    cfg: None,
+                });
             }
-        });
+        }
 
         impls
     }
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index df0e9f7cc..4e2031a91 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -55,12 +55,39 @@ pub(crate) fn try_inline(
     let mut ret = Vec::new();
 
     debug!("attrs={:?}", attrs);
-    let attrs_clone = attrs;
+
+    let attrs_without_docs = attrs.map(|attrs| {
+        attrs.into_iter().filter(|a| a.doc_str().is_none()).cloned().collect::<Vec<_>>()
+    });
+    // We need this ugly code because:
+    //
+    // ```
+    // attrs_without_docs.map(|a| a.as_slice())
+    // ```
+    //
+    // will fail because it returns a temporary slice and:
+    //
+    // ```
+    // attrs_without_docs.map(|s| {
+    //     vec = s.as_slice();
+    //     vec
+    // })
+    // ```
+    //
+    // will fail because we're moving an uninitialized variable into a closure.
+    let vec;
+    let attrs_without_docs = match attrs_without_docs {
+        Some(s) => {
+            vec = s;
+            Some(vec.as_slice())
+        }
+        None => None,
+    };
 
     let kind = match res {
         Res::Def(DefKind::Trait, did) => {
             record_extern_fqn(cx, did, ItemType::Trait);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::TraitItem(Box::new(build_external_trait(cx, did)))
         }
         Res::Def(DefKind::Fn, did) => {
@@ -69,27 +96,27 @@ pub(crate) fn try_inline(
         }
         Res::Def(DefKind::Struct, did) => {
             record_extern_fqn(cx, did, ItemType::Struct);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::StructItem(build_struct(cx, did))
         }
         Res::Def(DefKind::Union, did) => {
             record_extern_fqn(cx, did, ItemType::Union);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::UnionItem(build_union(cx, did))
         }
         Res::Def(DefKind::TyAlias, did) => {
             record_extern_fqn(cx, did, ItemType::Typedef);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::TypedefItem(build_type_alias(cx, did))
         }
         Res::Def(DefKind::Enum, did) => {
             record_extern_fqn(cx, did, ItemType::Enum);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::EnumItem(build_enum(cx, did))
         }
         Res::Def(DefKind::ForeignTy, did) => {
             record_extern_fqn(cx, did, ItemType::ForeignType);
-            build_impls(cx, Some(parent_module), did, attrs, &mut ret);
+            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
             clean::ForeignTypeItem
         }
         // Never inline enum variants but leave them shown as re-exports.
@@ -123,7 +150,7 @@ pub(crate) fn try_inline(
         _ => return None,
     };
 
-    let (attrs, cfg) = merge_attrs(cx, Some(parent_module), load_attrs(cx, did), attrs_clone);
+    let (attrs, cfg) = merge_attrs(cx, Some(parent_module), load_attrs(cx, did), attrs);
     cx.inlined.insert(did.into());
     let mut item = clean::Item::from_def_id_and_attrs_and_parts(
         did,
@@ -362,7 +389,7 @@ pub(crate) fn build_impl(
     if !did.is_local() {
         if let Some(traitref) = associated_trait {
             let did = traitref.def_id;
-            if !cx.cache.access_levels.is_public(did) {
+            if !cx.cache.effective_visibilities.is_directly_public(did) {
                 return;
             }
 
@@ -391,7 +418,7 @@ pub(crate) fn build_impl(
     // reachable in rustdoc generated documentation
     if !did.is_local() {
         if let Some(did) = for_.def_id(&cx.cache) {
-            if !cx.cache.access_levels.is_public(did) {
+            if !cx.cache.effective_visibilities.is_directly_public(did) {
                 return;
             }
 
@@ -425,7 +452,7 @@ pub(crate) fn build_impl(
                         let assoc_kind = match item.kind {
                             hir::ImplItemKind::Const(..) => ty::AssocKind::Const,
                             hir::ImplItemKind::Fn(..) => ty::AssocKind::Fn,
-                            hir::ImplItemKind::TyAlias(..) => ty::AssocKind::Type,
+                            hir::ImplItemKind::Type(..) => ty::AssocKind::Type,
                         };
                         let trait_item = tcx
                             .associated_items(associated_trait.def_id)
@@ -733,10 +760,6 @@ pub(crate) fn record_extern_trait(cx: &mut DocContext<'_>, did: DefId) {
     debug!("record_extern_trait: {:?}", did);
     let trait_ = build_external_trait(cx, did);
 
-    let trait_ = clean::TraitWithExtraInfo {
-        trait_,
-        is_notable: clean::utils::has_doc_flag(cx.tcx, did, sym::notable_trait),
-    };
     cx.external_traits.borrow_mut().insert(did, trait_);
     cx.active_extern_traits.remove(&did);
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index c8875c272..64a18757b 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -17,16 +17,16 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::PredicateOrigin;
+use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
 use rustc_middle::middle::resolve_lifetime as rl;
 use rustc_middle::ty::fold::TypeFolder;
-use rustc_middle::ty::subst::{InternalSubsts, Subst};
-use rustc_middle::ty::{self, AdtKind, DefIdTree, EarlyBinder, Lift, Ty, TyCtxt};
+use rustc_middle::ty::InternalSubsts;
+use rustc_middle::ty::{self, AdtKind, DefIdTree, EarlyBinder, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_span::hygiene::{AstPass, MacroKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{self, ExpnKind};
-use rustc_typeck::hir_ty_to_ty;
 
 use std::assert_matches::assert_matches;
 use std::collections::hash_map::Entry;
@@ -176,8 +176,6 @@ fn clean_poly_trait_ref_with_bindings<'tcx>(
     poly_trait_ref: ty::PolyTraitRef<'tcx>,
     bindings: ThinVec<TypeBinding>,
 ) -> GenericBound {
-    let poly_trait_ref = poly_trait_ref.lift_to_tcx(cx.tcx).unwrap();
-
     // collect any late bound regions
     let late_bound_regions: Vec<_> = cx
         .tcx
@@ -292,8 +290,9 @@ fn clean_where_predicate<'tcx>(
         },
 
         hir::WherePredicate::EqPredicate(ref wrp) => WherePredicate::EqPredicate {
-            lhs: clean_ty(wrp.lhs_ty, cx),
-            rhs: clean_ty(wrp.rhs_ty, cx).into(),
+            lhs: Box::new(clean_ty(wrp.lhs_ty, cx)),
+            rhs: Box::new(clean_ty(wrp.rhs_ty, cx).into()),
+            bound_params: Vec::new(),
         },
     })
 }
@@ -309,7 +308,9 @@ pub(crate) fn clean_predicate<'tcx>(
         }
         ty::PredicateKind::RegionOutlives(pred) => clean_region_outlives_predicate(pred),
         ty::PredicateKind::TypeOutlives(pred) => clean_type_outlives_predicate(pred, cx),
-        ty::PredicateKind::Projection(pred) => Some(clean_projection_predicate(pred, cx)),
+        ty::PredicateKind::Projection(pred) => {
+            Some(clean_projection_predicate(bound_predicate.rebind(pred), cx))
+        }
         ty::PredicateKind::ConstEvaluatable(..) => None,
         ty::PredicateKind::WellFormed(..) => None,
 
@@ -387,13 +388,25 @@ fn clean_hir_term<'tcx>(term: &hir::Term<'tcx>, cx: &mut DocContext<'tcx>) -> Te
 }
 
 fn clean_projection_predicate<'tcx>(
-    pred: ty::ProjectionPredicate<'tcx>,
+    pred: ty::Binder<'tcx, ty::ProjectionPredicate<'tcx>>,
     cx: &mut DocContext<'tcx>,
 ) -> WherePredicate {
-    let ty::ProjectionPredicate { projection_ty, term } = pred;
+    let late_bound_regions = cx
+        .tcx
+        .collect_referenced_late_bound_regions(&pred)
+        .into_iter()
+        .filter_map(|br| match br {
+            ty::BrNamed(_, name) if name != kw::UnderscoreLifetime => Some(Lifetime(name)),
+            _ => None,
+        })
+        .collect();
+
+    let ty::ProjectionPredicate { projection_ty, term } = pred.skip_binder();
+
     WherePredicate::EqPredicate {
-        lhs: clean_projection(projection_ty, cx, None),
-        rhs: clean_middle_term(term, cx),
+        lhs: Box::new(clean_projection(projection_ty, cx, None)),
+        rhs: Box::new(clean_middle_term(term, cx)),
+        bound_params: late_bound_regions,
     }
 }
 
@@ -402,8 +415,17 @@ fn clean_projection<'tcx>(
     cx: &mut DocContext<'tcx>,
     def_id: Option<DefId>,
 ) -> Type {
-    let lifted = ty.lift_to_tcx(cx.tcx).unwrap();
-    let trait_ = clean_trait_ref_with_bindings(cx, lifted.trait_ref(cx.tcx), ThinVec::new());
+    if cx.tcx.def_kind(ty.item_def_id) == DefKind::ImplTraitPlaceholder {
+        let bounds = cx
+            .tcx
+            .explicit_item_bounds(ty.item_def_id)
+            .iter()
+            .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, ty.substs))
+            .collect::<Vec<_>>();
+        return clean_middle_opaque_bounds(cx, bounds);
+    }
+
+    let trait_ = clean_trait_ref_with_bindings(cx, ty.trait_ref(cx.tcx), ThinVec::new());
     let self_type = clean_middle_ty(ty.self_ty(), cx, None);
     let self_def_id = if let Some(def_id) = def_id {
         cx.tcx.opt_parent(def_id).or(Some(def_id))
@@ -632,7 +654,7 @@ fn clean_ty_generics<'tcx>(
     let mut impl_trait = BTreeMap::<ImplTraitParam, Vec<GenericBound>>::default();
 
     // Bounds in the type_params and lifetimes fields are repeated in the
-    // predicates field (see rustc_typeck::collect::ty_generics), so remove
+    // predicates field (see rustc_hir_analysis::collect::ty_generics), so remove
     // them.
     let stripped_params = gens
         .params
@@ -655,8 +677,9 @@ fn clean_ty_generics<'tcx>(
         })
         .collect::<Vec<GenericParamDef>>();
 
-    // param index -> [(DefId of trait, associated type name and generics, type)]
-    let mut impl_trait_proj = FxHashMap::<u32, Vec<(DefId, PathSegment, Ty<'_>)>>::default();
+    // param index -> [(trait DefId, associated type name & generics, type, higher-ranked params)]
+    let mut impl_trait_proj =
+        FxHashMap::<u32, Vec<(DefId, PathSegment, Ty<'_>, Vec<GenericParamDef>)>>::default();
 
     let where_predicates = preds
         .predicates
@@ -715,6 +738,14 @@ fn clean_ty_generics<'tcx>(
                             trait_did,
                             name,
                             rhs.ty().unwrap(),
+                            p.get_bound_params()
+                                .into_iter()
+                                .flatten()
+                                .map(|param| GenericParamDef {
+                                    name: param.0,
+                                    kind: GenericParamDefKind::Lifetime { outlives: Vec::new() },
+                                })
+                                .collect(),
                         ));
                     }
 
@@ -730,15 +761,19 @@ fn clean_ty_generics<'tcx>(
         // Move trait bounds to the front.
         bounds.sort_by_key(|b| !matches!(b, GenericBound::TraitBound(..)));
 
-        if let crate::core::ImplTraitParam::ParamIndex(idx) = param {
-            if let Some(proj) = impl_trait_proj.remove(&idx) {
-                for (trait_did, name, rhs) in proj {
-                    let rhs = clean_middle_ty(rhs, cx, None);
-                    simplify::merge_bounds(cx, &mut bounds, trait_did, name, &Term::Type(rhs));
-                }
+        let crate::core::ImplTraitParam::ParamIndex(idx) = param else { unreachable!() };
+        if let Some(proj) = impl_trait_proj.remove(&idx) {
+            for (trait_did, name, rhs, bound_params) in proj {
+                let rhs = clean_middle_ty(rhs, cx, None);
+                simplify::merge_bounds(
+                    cx,
+                    &mut bounds,
+                    bound_params,
+                    trait_did,
+                    name,
+                    &Term::Type(rhs),
+                );
             }
-        } else {
-            unreachable!();
         }
 
         cx.impl_trait_bounds.insert(param, bounds);
@@ -749,31 +784,36 @@ fn clean_ty_generics<'tcx>(
     let mut where_predicates =
         where_predicates.into_iter().flat_map(|p| clean_predicate(*p, cx)).collect::<Vec<_>>();
 
-    // Type parameters have a Sized bound by default unless removed with
-    // ?Sized. Scan through the predicates and mark any type parameter with
-    // a Sized bound, removing the bounds as we find them.
+    // In the surface language, all type parameters except `Self` have an
+    // implicit `Sized` bound unless removed with `?Sized`.
+    // However, in the list of where-predicates below, `Sized` appears like a
+    // normal bound: It's either present (the type is sized) or
+    // absent (the type is unsized) but never *maybe* (i.e. `?Sized`).
+    //
+    // This is unsuitable for rendering.
+    // Thus, as a first step remove all `Sized` bounds that should be implicit.
     //
-    // Note that associated types also have a sized bound by default, but we
+    // Note that associated types also have an implicit `Sized` bound but we
     // don't actually know the set of associated types right here so that's
-    // handled in cleaning associated types
+    // handled when cleaning associated types.
     let mut sized_params = FxHashSet::default();
-    where_predicates.retain(|pred| match *pred {
-        WherePredicate::BoundPredicate { ty: Generic(ref g), ref bounds, .. } => {
-            if bounds.iter().any(|b| b.is_sized_bound(cx)) {
-                sized_params.insert(*g);
-                false
-            } else {
-                true
-            }
+    where_predicates.retain(|pred| {
+        if let WherePredicate::BoundPredicate { ty: Generic(g), bounds, .. } = pred
+        && *g != kw::SelfUpper
+        && bounds.iter().any(|b| b.is_sized_bound(cx))
+        {
+            sized_params.insert(*g);
+            false
+        } else {
+            true
         }
-        _ => true,
     });
 
-    // Run through the type parameters again and insert a ?Sized
-    // unbound for any we didn't find to be Sized.
+    // As a final step, go through the type parameters again and insert a
+    // `?Sized` bound for each one we didn't find to be `Sized`.
     for tp in &stripped_params {
-        if matches!(tp.kind, types::GenericParamDefKind::Type { .. })
-            && !sized_params.contains(&tp.name)
+        if let types::GenericParamDefKind::Type { .. } = tp.kind
+        && !sized_params.contains(&tp.name)
         {
             where_predicates.push(WherePredicate::BoundPredicate {
                 ty: Type::Generic(tp.name),
@@ -1002,7 +1042,7 @@ fn clean_poly_trait_ref<'tcx>(
 }
 
 fn clean_trait_item<'tcx>(trait_item: &hir::TraitItem<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
-    let local_did = trait_item.def_id.to_def_id();
+    let local_did = trait_item.owner_id.to_def_id();
     cx.with_param_env(local_did, |cx| {
         let inner = match trait_item.kind {
             hir::TraitItemKind::Const(ty, Some(default)) => AssocConstItem(
@@ -1054,7 +1094,7 @@ pub(crate) fn clean_impl_item<'tcx>(
     impl_: &hir::ImplItem<'tcx>,
     cx: &mut DocContext<'tcx>,
 ) -> Item {
-    let local_did = impl_.def_id.to_def_id();
+    let local_did = impl_.owner_id.to_def_id();
     cx.with_param_env(local_did, |cx| {
         let inner = match impl_.kind {
             hir::ImplItemKind::Const(ty, expr) => {
@@ -1063,10 +1103,10 @@ pub(crate) fn clean_impl_item<'tcx>(
             }
             hir::ImplItemKind::Fn(ref sig, body) => {
                 let m = clean_function(cx, sig, impl_.generics, body);
-                let defaultness = cx.tcx.impl_defaultness(impl_.def_id);
+                let defaultness = cx.tcx.impl_defaultness(impl_.owner_id);
                 MethodItem(m, Some(defaultness))
             }
-            hir::ImplItemKind::TyAlias(hir_ty) => {
+            hir::ImplItemKind::Type(hir_ty) => {
                 let type_ = clean_ty(hir_ty, cx);
                 let generics = clean_generics(impl_.generics, cx);
                 let item_type = clean_middle_ty(hir_ty_to_ty(cx.tcx, hir_ty), cx, None);
@@ -1080,7 +1120,7 @@ pub(crate) fn clean_impl_item<'tcx>(
         let mut what_rustc_thinks =
             Item::from_def_id_and_parts(local_did, Some(impl_.ident.name), inner, cx);
 
-        let impl_ref = cx.tcx.impl_trait_ref(cx.tcx.local_parent(impl_.def_id));
+        let impl_ref = cx.tcx.impl_trait_ref(cx.tcx.local_parent(impl_.owner_id.def_id));
 
         // Trait impl items always inherit the impl's visibility --
         // we don't want to show `pub`.
@@ -1177,11 +1217,18 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
 
             if let ty::TraitContainer = assoc_item.container {
                 let bounds = tcx.explicit_item_bounds(assoc_item.def_id);
-                let predicates = ty::GenericPredicates { parent: None, predicates: bounds };
-                let mut generics =
-                    clean_ty_generics(cx, tcx.generics_of(assoc_item.def_id), predicates);
-                // Filter out the bounds that are (likely?) directly attached to the associated type,
-                // as opposed to being located in the where clause.
+                let predicates = tcx.explicit_predicates_of(assoc_item.def_id).predicates;
+                let predicates =
+                    tcx.arena.alloc_from_iter(bounds.into_iter().chain(predicates).copied());
+                let mut generics = clean_ty_generics(
+                    cx,
+                    tcx.generics_of(assoc_item.def_id),
+                    ty::GenericPredicates { parent: None, predicates },
+                );
+                // Move bounds that are (likely) directly attached to the associated type
+                // from the where clause to the associated type.
+                // There is no guarantee that this is what the user actually wrote but we have
+                // no way of knowing.
                 let mut bounds = generics
                     .where_predicates
                     .drain_filter(|pred| match *pred {
@@ -1239,6 +1286,24 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                     }
                     None => bounds.push(GenericBound::maybe_sized(cx)),
                 }
+                // Move bounds that are (likely) directly attached to the parameters of the
+                // (generic) associated type from the where clause to the respective parameter.
+                // There is no guarantee that this is what the user actually wrote but we have
+                // no way of knowing.
+                let mut where_predicates = Vec::new();
+                for mut pred in generics.where_predicates {
+                    if let WherePredicate::BoundPredicate { ty: Generic(arg), bounds, .. } = &mut pred
+                    && let Some(GenericParamDef {
+                        kind: GenericParamDefKind::Type { bounds: param_bounds, .. },
+                        ..
+                    }) = generics.params.iter_mut().find(|param| &param.name == arg)
+                    {
+                        param_bounds.extend(mem::take(bounds));
+                    } else {
+                        where_predicates.push(pred);
+                    }
+                }
+                generics.where_predicates = where_predicates;
 
                 if tcx.impl_defaultness(assoc_item.def_id).has_value() {
                     AssocTypeItem(
@@ -1325,7 +1390,7 @@ fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type
                 segments: trait_segments.iter().map(|x| clean_path_segment(x, cx)).collect(),
             };
             register_res(cx, trait_.res);
-            let self_def_id = DefId::local(qself.hir_id.owner.local_def_index);
+            let self_def_id = DefId::local(qself.hir_id.owner.def_id.local_def_index);
             let self_type = clean_ty(qself, cx);
             let should_show_cast = compute_should_show_cast(Some(self_def_id), &trait_, &self_type);
             Type::QPath(Box::new(QPathData {
@@ -1366,7 +1431,7 @@ fn maybe_expand_private_type_alias<'tcx>(
     let Res::Def(DefKind::TyAlias, def_id) = path.res else { return None };
     // Substitute private type aliases
     let def_id = def_id.as_local()?;
-    let alias = if !cx.cache.access_levels.is_exported(def_id.to_def_id()) {
+    let alias = if !cx.cache.effective_visibilities.is_exported(def_id.to_def_id()) {
         &cx.tcx.hir().expect_item(def_id).kind
     } else {
         return None;
@@ -1480,7 +1545,7 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
                     // as we currently do not supply the parent generics to anonymous constants
                     // but do allow `ConstKind::Param`.
                     //
-                    // `const_eval_poly` tries to to first substitute generic parameters which
+                    // `const_eval_poly` tries to first substitute generic parameters which
                     // results in an ICE while manually constructing the constant and using `eval`
                     // does nothing for `ConstKind::Param`.
                     let ct = ty::Const::from_anon_const(cx.tcx, def_id);
@@ -1509,13 +1574,12 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
         }
         TyKind::BareFn(barefn) => BareFunction(Box::new(clean_bare_fn_ty(barefn, cx))),
         // Rustdoc handles `TyKind::Err`s by turning them into `Type::Infer`s.
-        TyKind::Infer | TyKind::Err => Infer,
-        TyKind::Typeof(..) => panic!("unimplemented type {:?}", ty.kind),
+        TyKind::Infer | TyKind::Err | TyKind::Typeof(..) => Infer,
     }
 }
 
 /// Returns `None` if the type could not be normalized
-fn normalize<'tcx>(cx: &mut DocContext<'tcx>, ty: Ty<'_>) -> Option<Ty<'tcx>> {
+fn normalize<'tcx>(cx: &mut DocContext<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
     // HACK: low-churn fix for #79459 while we wait for a trait normalization fix
     if !cx.tcx.sess.opts.unstable_opts.normalize_docs {
         return None;
@@ -1526,13 +1590,11 @@ fn normalize<'tcx>(cx: &mut DocContext<'tcx>, ty: Ty<'_>) -> Option<Ty<'tcx>> {
     use rustc_middle::traits::ObligationCause;
 
     // Try to normalize `<X as Y>::T` to a type
-    let lifted = ty.lift_to_tcx(cx.tcx).unwrap();
-    let normalized = cx.tcx.infer_ctxt().enter(|infcx| {
-        infcx
-            .at(&ObligationCause::dummy(), cx.param_env)
-            .normalize(lifted)
-            .map(|resolved| infcx.resolve_vars_if_possible(resolved.value))
-    });
+    let infcx = cx.tcx.infer_ctxt().build();
+    let normalized = infcx
+        .at(&ObligationCause::dummy(), cx.param_env)
+        .normalize(ty)
+        .map(|resolved| infcx.resolve_vars_if_possible(resolved.value));
     match normalized {
         Ok(normalized_value) => {
             debug!("normalized {:?} to {:?}", ty, normalized_value);
@@ -1546,12 +1608,12 @@ fn normalize<'tcx>(cx: &mut DocContext<'tcx>, ty: Ty<'_>) -> Option<Ty<'tcx>> {
 }
 
 pub(crate) fn clean_middle_ty<'tcx>(
-    this: Ty<'tcx>,
+    ty: Ty<'tcx>,
     cx: &mut DocContext<'tcx>,
     def_id: Option<DefId>,
 ) -> Type {
-    trace!("cleaning type: {:?}", this);
-    let ty = normalize(cx, this).unwrap_or(this);
+    trace!("cleaning type: {:?}", ty);
+    let ty = normalize(cx, ty).unwrap_or(ty);
     match *ty.kind() {
         ty::Never => Primitive(PrimitiveType::Never),
         ty::Bool => Primitive(PrimitiveType::Bool),
@@ -1561,8 +1623,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
         ty::Float(float_ty) => Primitive(float_ty.into()),
         ty::Str => Primitive(PrimitiveType::Str),
         ty::Slice(ty) => Slice(Box::new(clean_middle_ty(ty, cx, None))),
-        ty::Array(ty, n) => {
-            let mut n = cx.tcx.lift(n).expect("array lift failed");
+        ty::Array(ty, mut n) => {
             n = n.eval(cx.tcx, ty::ParamEnv::reveal_all());
             let n = print_const(cx, n);
             Array(Box::new(clean_middle_ty(ty, cx, None)), n)
@@ -1574,7 +1635,6 @@ pub(crate) fn clean_middle_ty<'tcx>(
             type_: Box::new(clean_middle_ty(ty, cx, None)),
         },
         ty::FnDef(..) | ty::FnPtr(_) => {
-            let ty = cx.tcx.lift(this).expect("FnPtr lift failed");
             let sig = ty.fn_sig(cx.tcx);
             let decl = clean_fn_decl_from_did_and_sig(cx, None, sig);
             BareFunction(Box::new(BareFunctionDecl {
@@ -1608,7 +1668,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
             let did = obj
                 .principal_def_id()
                 .or_else(|| dids.next())
-                .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", this));
+                .unwrap_or_else(|| panic!("found trait object `{:?}` with no traits?", ty));
             let substs = match obj.principal() {
                 Some(principal) => principal.skip_binder().substs,
                 // marker traits have no substs.
@@ -1632,8 +1692,6 @@ pub(crate) fn clean_middle_ty<'tcx>(
                 .map(|pb| TypeBinding {
                     assoc: projection_to_path_segment(
                         pb.skip_binder()
-                            .lift_to_tcx(cx.tcx)
-                            .unwrap()
                             // HACK(compiler-errors): Doesn't actually matter what self
                             // type we put here, because we're only using the GAT's substs.
                             .with_self_ty(cx.tcx, cx.tcx.types.self_param)
@@ -1666,66 +1724,13 @@ pub(crate) fn clean_middle_ty<'tcx>(
         ty::Opaque(def_id, substs) => {
             // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
             // by looking up the bounds associated with the def_id.
-            let substs = cx.tcx.lift(substs).expect("Opaque lift failed");
             let bounds = cx
                 .tcx
                 .explicit_item_bounds(def_id)
                 .iter()
                 .map(|(bound, _)| EarlyBinder(*bound).subst(cx.tcx, substs))
                 .collect::<Vec<_>>();
-            let mut regions = vec![];
-            let mut has_sized = false;
-            let mut bounds = bounds
-                .iter()
-                .filter_map(|bound| {
-                    let bound_predicate = bound.kind();
-                    let trait_ref = match bound_predicate.skip_binder() {
-                        ty::PredicateKind::Trait(tr) => bound_predicate.rebind(tr.trait_ref),
-                        ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
-                            if let Some(r) = clean_middle_region(reg) {
-                                regions.push(GenericBound::Outlives(r));
-                            }
-                            return None;
-                        }
-                        _ => return None,
-                    };
-
-                    if let Some(sized) = cx.tcx.lang_items().sized_trait() {
-                        if trait_ref.def_id() == sized {
-                            has_sized = true;
-                            return None;
-                        }
-                    }
-
-                    let bindings: ThinVec<_> = bounds
-                        .iter()
-                        .filter_map(|bound| {
-                            if let ty::PredicateKind::Projection(proj) = bound.kind().skip_binder()
-                            {
-                                if proj.projection_ty.trait_ref(cx.tcx) == trait_ref.skip_binder() {
-                                    Some(TypeBinding {
-                                        assoc: projection_to_path_segment(proj.projection_ty, cx),
-                                        kind: TypeBindingKind::Equality {
-                                            term: clean_middle_term(proj.term, cx),
-                                        },
-                                    })
-                                } else {
-                                    None
-                                }
-                            } else {
-                                None
-                            }
-                        })
-                        .collect();
-
-                    Some(clean_poly_trait_ref_with_bindings(cx, trait_ref, bindings))
-                })
-                .collect::<Vec<_>>();
-            bounds.extend(regions);
-            if !has_sized && !bounds.is_empty() {
-                bounds.insert(0, GenericBound::maybe_sized(cx));
-            }
-            ImplTrait(bounds)
+            clean_middle_opaque_bounds(cx, bounds)
         }
 
         ty::Closure(..) => panic!("Closure"),
@@ -1738,6 +1743,64 @@ pub(crate) fn clean_middle_ty<'tcx>(
     }
 }
 
+fn clean_middle_opaque_bounds<'tcx>(
+    cx: &mut DocContext<'tcx>,
+    bounds: Vec<ty::Predicate<'tcx>>,
+) -> Type {
+    let mut regions = vec![];
+    let mut has_sized = false;
+    let mut bounds = bounds
+        .iter()
+        .filter_map(|bound| {
+            let bound_predicate = bound.kind();
+            let trait_ref = match bound_predicate.skip_binder() {
+                ty::PredicateKind::Trait(tr) => bound_predicate.rebind(tr.trait_ref),
+                ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
+                    if let Some(r) = clean_middle_region(reg) {
+                        regions.push(GenericBound::Outlives(r));
+                    }
+                    return None;
+                }
+                _ => return None,
+            };
+
+            if let Some(sized) = cx.tcx.lang_items().sized_trait() {
+                if trait_ref.def_id() == sized {
+                    has_sized = true;
+                    return None;
+                }
+            }
+
+            let bindings: ThinVec<_> = bounds
+                .iter()
+                .filter_map(|bound| {
+                    if let ty::PredicateKind::Projection(proj) = bound.kind().skip_binder() {
+                        if proj.projection_ty.trait_ref(cx.tcx) == trait_ref.skip_binder() {
+                            Some(TypeBinding {
+                                assoc: projection_to_path_segment(proj.projection_ty, cx),
+                                kind: TypeBindingKind::Equality {
+                                    term: clean_middle_term(proj.term, cx),
+                                },
+                            })
+                        } else {
+                            None
+                        }
+                    } else {
+                        None
+                    }
+                })
+                .collect();
+
+            Some(clean_poly_trait_ref_with_bindings(cx, trait_ref, bindings))
+        })
+        .collect::<Vec<_>>();
+    bounds.extend(regions);
+    if !has_sized && !bounds.is_empty() {
+        bounds.insert(0, GenericBound::maybe_sized(cx));
+    }
+    ImplTrait(bounds)
+}
+
 pub(crate) fn clean_field<'tcx>(field: &hir::FieldDef<'tcx>, cx: &mut DocContext<'tcx>) -> Item {
     let def_id = cx.tcx.hir().local_def_id(field.hir_id).to_def_id();
     clean_field_with_def_id(def_id, field.ident.name, clean_ty(field.ty, cx), cx)
@@ -1895,7 +1958,7 @@ fn clean_maybe_renamed_item<'tcx>(
 ) -> Vec<Item> {
     use hir::ItemKind;
 
-    let def_id = item.def_id.to_def_id();
+    let def_id = item.owner_id.to_def_id();
     let mut name = renamed.unwrap_or_else(|| cx.tcx.hir().name(item.hir_id()));
     cx.with_param_env(def_id, |cx| {
         let kind = match item.kind {
@@ -2037,11 +2100,11 @@ fn clean_extern_crate<'tcx>(
     cx: &mut DocContext<'tcx>,
 ) -> Vec<Item> {
     // this is the ID of the `extern crate` statement
-    let cnum = cx.tcx.extern_mod_stmt_cnum(krate.def_id).unwrap_or(LOCAL_CRATE);
+    let cnum = cx.tcx.extern_mod_stmt_cnum(krate.owner_id.def_id).unwrap_or(LOCAL_CRATE);
     // this is the ID of the crate itself
     let crate_def_id = cnum.as_def_id();
     let attrs = cx.tcx.hir().attrs(krate.hir_id());
-    let ty_vis = cx.tcx.visibility(krate.def_id);
+    let ty_vis = cx.tcx.visibility(krate.owner_id);
     let please_inline = ty_vis.is_public()
         && attrs.iter().any(|a| {
             a.has_name(sym::doc)
@@ -2059,7 +2122,7 @@ fn clean_extern_crate<'tcx>(
         if let Some(items) = inline::try_inline(
             cx,
             cx.tcx.parent_module(krate.hir_id()).to_def_id(),
-            Some(krate.def_id.to_def_id()),
+            Some(krate.owner_id.to_def_id()),
             res,
             name,
             Some(attrs),
@@ -2095,11 +2158,11 @@ fn clean_use_statement<'tcx>(
         return Vec::new();
     }
 
-    let visibility = cx.tcx.visibility(import.def_id);
+    let visibility = cx.tcx.visibility(import.owner_id);
     let attrs = cx.tcx.hir().attrs(import.hir_id());
     let inline_attr = attrs.lists(sym::doc).get_word_attr(sym::inline);
     let pub_underscore = visibility.is_public() && name == kw::Underscore;
-    let current_mod = cx.tcx.parent_module_from_def_id(import.def_id);
+    let current_mod = cx.tcx.parent_module_from_def_id(import.owner_id.def_id);
 
     // The parent of the module in which this import resides. This
     // is the same as `current_mod` if that's already the top
@@ -2170,7 +2233,7 @@ fn clean_use_statement<'tcx>(
         }
         if !denied {
             let mut visited = FxHashSet::default();
-            let import_def_id = import.def_id.to_def_id();
+            let import_def_id = import.owner_id.to_def_id();
 
             if let Some(mut items) = inline::try_inline(
                 cx,
@@ -2193,7 +2256,7 @@ fn clean_use_statement<'tcx>(
         Import::new_simple(name, resolve_use_source(cx, path), true)
     };
 
-    vec![Item::from_def_id_and_parts(import.def_id.to_def_id(), None, ImportItem(inner), cx)]
+    vec![Item::from_def_id_and_parts(import.owner_id.to_def_id(), None, ImportItem(inner), cx)]
 }
 
 fn clean_maybe_renamed_foreign_item<'tcx>(
@@ -2201,7 +2264,7 @@ fn clean_maybe_renamed_foreign_item<'tcx>(
     item: &hir::ForeignItem<'tcx>,
     renamed: Option<Symbol>,
 ) -> Item {
-    let def_id = item.def_id.to_def_id();
+    let def_id = item.owner_id.to_def_id();
     cx.with_param_env(def_id, |cx| {
         let kind = match item.kind {
             hir::ForeignItemKind::Fn(decl, names, generics) => {
diff --git a/src/librustdoc/clean/simplify.rs b/src/librustdoc/clean/simplify.rs
index af7813a77..1bcb9fcd5 100644
--- a/src/librustdoc/clean/simplify.rs
+++ b/src/librustdoc/clean/simplify.rs
@@ -14,7 +14,6 @@
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty;
-use rustc_span::Symbol;
 
 use crate::clean;
 use crate::clean::GenericArgs as PP;
@@ -26,38 +25,37 @@ pub(crate) fn where_clauses(cx: &DocContext<'_>, clauses: Vec<WP>) -> Vec<WP> {
     //
     // We use `FxIndexMap` so that the insertion order is preserved to prevent messing up to
     // the order of the generated bounds.
-    let mut params: FxIndexMap<Symbol, (Vec<_>, Vec<_>)> = FxIndexMap::default();
+    let mut tybounds = FxIndexMap::default();
     let mut lifetimes = Vec::new();
     let mut equalities = Vec::new();
-    let mut tybounds = Vec::new();
 
     for clause in clauses {
         match clause {
-            WP::BoundPredicate { ty, bounds, bound_params } => match ty {
-                clean::Generic(s) => {
-                    let (b, p) = params.entry(s).or_default();
-                    b.extend(bounds);
-                    p.extend(bound_params);
-                }
-                t => tybounds.push((t, (bounds, bound_params))),
-            },
+            WP::BoundPredicate { ty, bounds, bound_params } => {
+                let (b, p): &mut (Vec<_>, Vec<_>) = tybounds.entry(ty).or_default();
+                b.extend(bounds);
+                p.extend(bound_params);
+            }
             WP::RegionPredicate { lifetime, bounds } => {
                 lifetimes.push((lifetime, bounds));
             }
-            WP::EqPredicate { lhs, rhs } => equalities.push((lhs, rhs)),
+            WP::EqPredicate { lhs, rhs, bound_params } => equalities.push((lhs, rhs, bound_params)),
         }
     }
 
     // Look for equality predicates on associated types that can be merged into
-    // general bound predicates
-    equalities.retain(|&(ref lhs, ref rhs)| {
-        let Some((self_, trait_did, name)) = lhs.projection() else {
-            return true;
-        };
-        let clean::Generic(generic) = self_ else { return true };
-        let Some((bounds, _)) = params.get_mut(generic) else { return true };
-
-        merge_bounds(cx, bounds, trait_did, name, rhs)
+    // general bound predicates.
+    equalities.retain(|&(ref lhs, ref rhs, ref bound_params)| {
+        let Some((ty, trait_did, name)) = lhs.projection() else { return true; };
+        let Some((bounds, _)) = tybounds.get_mut(ty) else { return true };
+        let bound_params = bound_params
+            .into_iter()
+            .map(|param| clean::GenericParamDef {
+                name: param.0,
+                kind: clean::GenericParamDefKind::Lifetime { outlives: Vec::new() },
+            })
+            .collect();
+        merge_bounds(cx, bounds, bound_params, trait_did, name, rhs)
     });
 
     // And finally, let's reassemble everything
@@ -65,23 +63,23 @@ pub(crate) fn where_clauses(cx: &DocContext<'_>, clauses: Vec<WP>) -> Vec<WP> {
     clauses.extend(
         lifetimes.into_iter().map(|(lt, bounds)| WP::RegionPredicate { lifetime: lt, bounds }),
     );
-    clauses.extend(params.into_iter().map(|(k, (bounds, params))| WP::BoundPredicate {
-        ty: clean::Generic(k),
-        bounds,
-        bound_params: params,
-    }));
     clauses.extend(tybounds.into_iter().map(|(ty, (bounds, bound_params))| WP::BoundPredicate {
         ty,
         bounds,
         bound_params,
     }));
-    clauses.extend(equalities.into_iter().map(|(lhs, rhs)| WP::EqPredicate { lhs, rhs }));
+    clauses.extend(equalities.into_iter().map(|(lhs, rhs, bound_params)| WP::EqPredicate {
+        lhs,
+        rhs,
+        bound_params,
+    }));
     clauses
 }
 
 pub(crate) fn merge_bounds(
     cx: &clean::DocContext<'_>,
     bounds: &mut Vec<clean::GenericBound>,
+    mut bound_params: Vec<clean::GenericParamDef>,
     trait_did: DefId,
     assoc: clean::PathSegment,
     rhs: &clean::Term,
@@ -98,6 +96,14 @@ pub(crate) fn merge_bounds(
             return false;
         }
         let last = trait_ref.trait_.segments.last_mut().expect("segments were empty");
+
+        trait_ref.generic_params.append(&mut bound_params);
+        // Since the parameters (probably) originate from `tcx.collect_*_late_bound_regions` which
+        // returns a hash set, sort them alphabetically to guarantee a stable and deterministic
+        // output (and to fully deduplicate them).
+        trait_ref.generic_params.sort_unstable_by(|p, q| p.name.as_str().cmp(q.name.as_str()));
+        trait_ref.generic_params.dedup_by_key(|p| p.name);
+
         match last.args {
             PP::AngleBracketed { ref mut bindings, .. } => {
                 bindings.push(clean::TypeBinding {
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index f973fd088..cd1f972dc 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -21,6 +21,7 @@ use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{BodyId, Mutability};
+use rustc_hir_analysis::check::intrinsic::intrinsic_operation_unsafety;
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::{self, TyCtxt};
@@ -31,7 +32,6 @@ use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{self, FileName, Loc};
 use rustc_target::abi::VariantIdx;
 use rustc_target::spec::abi::Abi;
-use rustc_typeck::check::intrinsic::intrinsic_operation_unsafety;
 
 use crate::clean::cfg::Cfg;
 use crate::clean::clean_visibility;
@@ -119,7 +119,7 @@ pub(crate) struct Crate {
     pub(crate) module: Item,
     pub(crate) primitives: ThinVec<(DefId, PrimitiveType)>,
     /// Only here so that they can be filtered through the rustdoc passes.
-    pub(crate) external_traits: Rc<RefCell<FxHashMap<DefId, TraitWithExtraInfo>>>,
+    pub(crate) external_traits: Rc<RefCell<FxHashMap<DefId, Trait>>>,
 }
 
 impl Crate {
@@ -132,13 +132,6 @@ impl Crate {
     }
 }
 
-/// This struct is used to wrap additional information added by rustdoc on a `trait` item.
-#[derive(Clone, Debug)]
-pub(crate) struct TraitWithExtraInfo {
-    pub(crate) trait_: Trait,
-    pub(crate) is_notable: bool,
-}
-
 #[derive(Copy, Clone, Debug)]
 pub(crate) struct ExternalCrate {
     pub(crate) crate_num: CrateNum,
@@ -247,13 +240,13 @@ impl ExternalCrate {
                     let item = tcx.hir().item(id);
                     match item.kind {
                         hir::ItemKind::Mod(_) => {
-                            as_keyword(Res::Def(DefKind::Mod, id.def_id.to_def_id()))
+                            as_keyword(Res::Def(DefKind::Mod, id.owner_id.to_def_id()))
                         }
                         hir::ItemKind::Use(path, hir::UseKind::Single)
-                            if tcx.visibility(id.def_id).is_public() =>
+                            if tcx.visibility(id.owner_id).is_public() =>
                         {
                             as_keyword(path.res.expect_non_local())
-                                .map(|(_, prim)| (id.def_id.to_def_id(), prim))
+                                .map(|(_, prim)| (id.owner_id.to_def_id(), prim))
                         }
                         _ => None,
                     }
@@ -315,14 +308,14 @@ impl ExternalCrate {
                     let item = tcx.hir().item(id);
                     match item.kind {
                         hir::ItemKind::Mod(_) => {
-                            as_primitive(Res::Def(DefKind::Mod, id.def_id.to_def_id()))
+                            as_primitive(Res::Def(DefKind::Mod, id.owner_id.to_def_id()))
                         }
                         hir::ItemKind::Use(path, hir::UseKind::Single)
-                            if tcx.visibility(id.def_id).is_public() =>
+                            if tcx.visibility(id.owner_id).is_public() =>
                         {
                             as_primitive(path.res.expect_non_local()).map(|(_, prim)| {
                                 // Pretend the primitive is local.
-                                (id.def_id.to_def_id(), prim)
+                                (id.owner_id.to_def_id(), prim)
                             })
                         }
                         _ => None,
@@ -689,7 +682,7 @@ impl Item {
                 let abi = tcx.fn_sig(self.item_id.as_def_id().unwrap()).abi();
                 hir::FnHeader {
                     unsafety: if abi == Abi::RustIntrinsic {
-                        intrinsic_operation_unsafety(self.name.unwrap())
+                        intrinsic_operation_unsafety(tcx, self.item_id.as_def_id().unwrap())
                     } else {
                         hir::Unsafety::Unsafe
                     },
@@ -1357,7 +1350,7 @@ impl Lifetime {
 pub(crate) enum WherePredicate {
     BoundPredicate { ty: Type, bounds: Vec<GenericBound>, bound_params: Vec<Lifetime> },
     RegionPredicate { lifetime: Lifetime, bounds: Vec<GenericBound> },
-    EqPredicate { lhs: Type, rhs: Term },
+    EqPredicate { lhs: Box<Type>, rhs: Box<Term>, bound_params: Vec<Lifetime> },
 }
 
 impl WherePredicate {
@@ -1368,6 +1361,15 @@ impl WherePredicate {
             _ => None,
         }
     }
+
+    pub(crate) fn get_bound_params(&self) -> Option<&[Lifetime]> {
+        match self {
+            Self::BoundPredicate { bound_params, .. } | Self::EqPredicate { bound_params, .. } => {
+                Some(bound_params)
+            }
+            _ => None,
+        }
+    }
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -1530,6 +1532,9 @@ impl Trait {
     pub(crate) fn is_auto(&self, tcx: TyCtxt<'_>) -> bool {
         tcx.trait_is_auto(self.def_id)
     }
+    pub(crate) fn is_notable_trait(&self, tcx: TyCtxt<'_>) -> bool {
+        tcx.is_doc_notable_trait(self.def_id)
+    }
     pub(crate) fn unsafety(&self, tcx: TyCtxt<'_>) -> hir::Unsafety {
         tcx.trait_def(self.def_id).unsafety
     }
@@ -2201,8 +2206,11 @@ impl Path {
     /// Checks if this is a `T::Name` path for an associated type.
     pub(crate) fn is_assoc_ty(&self) -> bool {
         match self.res {
-            Res::SelfTy { .. } if self.segments.len() != 1 => true,
-            Res::Def(DefKind::TyParam, _) if self.segments.len() != 1 => true,
+            Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::Def(DefKind::TyParam, _)
+                if self.segments.len() != 1 =>
+            {
+                true
+            }
             Res::Def(DefKind::AssocTy, _) => true,
             _ => false,
         }
@@ -2532,15 +2540,15 @@ impl SubstParam {
 mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
-    // These are in alphabetical order, which is easy to maintain.
+    // tidy-alphabetical-start
     static_assert_size!(Crate, 72); // frequently moved by-value
     static_assert_size!(DocFragment, 32);
-    #[cfg(not(bootstrap))]
-    static_assert_size!(GenericArg, 56);
+    static_assert_size!(GenericArg, 48);
     static_assert_size!(GenericArgs, 32);
     static_assert_size!(GenericParamDef, 56);
     static_assert_size!(Item, 56);
-    static_assert_size!(ItemKind, 96);
+    static_assert_size!(ItemKind, 88);
     static_assert_size!(PathSegment, 40);
-    static_assert_size!(Type, 56);
+    static_assert_size!(Type, 48);
+    // tidy-alphabetical-end
 }
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index 3eaedaf10..58767d3a4 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -7,7 +7,6 @@ use crate::clean::{
     PathSegment, Primitive, PrimitiveType, Type, TypeBinding, Visibility,
 };
 use crate::core::DocContext;
-use crate::formats::item_type::ItemType;
 use crate::visit_lib::LibEmbargoVisitor;
 
 use rustc_ast as ast;
@@ -234,8 +233,7 @@ pub(crate) fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
 
 pub(crate) fn print_const(cx: &DocContext<'_>, n: ty::Const<'_>) -> String {
     match n.kind() {
-        ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) => {
-            assert_eq!(promoted, ());
+        ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs: _ }) => {
             let s = if let Some(def) = def.as_local() {
                 print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(def.did))
             } else {
@@ -305,9 +303,9 @@ fn format_integer_with_underscore_sep(num: &str) -> String {
         .collect()
 }
 
-fn print_const_with_custom_print_scalar(
-    tcx: TyCtxt<'_>,
-    ct: mir::ConstantKind<'_>,
+fn print_const_with_custom_print_scalar<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    ct: mir::ConstantKind<'tcx>,
     underscores_and_type: bool,
 ) -> String {
     // Use a slightly different format for integer types which always shows the actual value.
@@ -321,7 +319,7 @@ fn print_const_with_custom_print_scalar(
             }
         }
         (mir::ConstantKind::Val(ConstValue::Scalar(int), _), ty::Int(i)) => {
-            let ty = tcx.lift(ct.ty()).unwrap();
+            let ty = ct.ty();
             let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
             let data = int.assert_bits(size);
             let sign_extended_data = size.sign_extend(data) as i128;
@@ -455,7 +453,9 @@ pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
 
     match path.res {
         Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
-        Res::SelfTy { .. } if path.segments.len() == 1 => Generic(kw::SelfUpper),
+        Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } if path.segments.len() == 1 => {
+            Generic(kw::SelfUpper)
+        }
         Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
         _ => {
             let _ = register_res(cx, path.res);
@@ -503,9 +503,6 @@ pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
         return did;
     }
     inline::record_extern_fqn(cx, did, kind);
-    if let ItemType::Trait = kind {
-        inline::record_extern_trait(cx, did);
-    }
     did
 }