Remove hir::AssocItemKind.

32 files changed, 294 insertions, 456 deletions

diff --git a/compiler/rustc_ast_lowering/src/delegation.rs b/compiler/rustc_ast_lowering/src/delegation.rs
index a8a8b2d6e1b..9bfcd232221 100644
--- a/compiler/rustc_ast_lowering/src/delegation.rs
+++ b/compiler/rustc_ast_lowering/src/delegation.rs
@@ -62,21 +62,6 @@ pub(crate) struct DelegationResults<'hir> {
 }
 
 impl<'hir> LoweringContext<'_, 'hir> {
-    /// Defines whether the delegatee is an associated function whose first parameter is `self`.
-    pub(crate) fn delegatee_is_method(
-        &self,
-        item_id: NodeId,
-        path_id: NodeId,
-        span: Span,
-        is_in_trait_impl: bool,
-    ) -> bool {
-        let sig_id = self.get_delegation_sig_id(item_id, path_id, span, is_in_trait_impl);
-        let Ok(sig_id) = sig_id else {
-            return false;
-        };
-        self.is_method(sig_id, span)
-    }
-
     fn is_method(&self, def_id: DefId, span: Span) -> bool {
         match self.tcx.def_kind(def_id) {
             DefKind::Fn => false,
diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index db67ce8dc16..a86fa49755b 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -384,7 +384,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_trait_item_ref(&mut self, ii: &'hir TraitItemRef) {
         // Do not visit the duplicate information in TraitItemRef. We want to
         // map the actual nodes, not the duplicate ones in the *Ref.
-        let TraitItemRef { id, ident: _, kind: _, span: _ } = *ii;
+        let TraitItemRef { id, ident: _, span: _ } = *ii;
 
         self.visit_nested_trait_item(id);
     }
@@ -392,7 +392,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_impl_item_ref(&mut self, ii: &'hir ImplItemRef) {
         // Do not visit the duplicate information in ImplItemRef. We want to
         // map the actual nodes, not the duplicate ones in the *Ref.
-        let ImplItemRef { id, ident: _, kind: _, span: _ } = *ii;
+        let ImplItemRef { id, ident: _, span: _ } = *ii;
 
         self.visit_nested_impl_item(id);
     }
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index b2a69c7c00f..5043995e6b9 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -393,11 +393,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
                         (trait_ref, lowered_ty)
                     });
 
-                let new_impl_items = self.arena.alloc_from_iter(
-                    impl_items
-                        .iter()
-                        .map(|item| self.lower_impl_item_ref(item, trait_ref.is_some())),
-                );
+                let new_impl_items = self
+                    .arena
+                    .alloc_from_iter(impl_items.iter().map(|item| self.lower_impl_item_ref(item)));
 
                 // `defaultness.has_value()` is never called for an `impl`, always `true` in order
                 // to not cause an assertion failure inside the `lower_defaultness` function.
@@ -973,30 +971,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
     }
 
     fn lower_trait_item_ref(&mut self, i: &AssocItem) -> hir::TraitItemRef {
-        let (ident, kind) = match &i.kind {
-            AssocItemKind::Const(box ConstItem { ident, .. }) => {
-                (*ident, hir::AssocItemKind::Const)
-            }
-            AssocItemKind::Type(box TyAlias { ident, .. }) => (*ident, hir::AssocItemKind::Type),
-            AssocItemKind::Fn(box Fn { ident, sig, .. }) => {
-                (*ident, hir::AssocItemKind::Fn { has_self: sig.decl.has_self() })
-            }
-            AssocItemKind::Delegation(box delegation) => (
-                delegation.ident,
-                hir::AssocItemKind::Fn {
-                    has_self: self.delegatee_is_method(i.id, delegation.id, i.span, false),
-                },
-            ),
-            AssocItemKind::MacCall(..) | AssocItemKind::DelegationMac(..) => {
-                panic!("macros should have been expanded by now")
-            }
-        };
         let id = hir::TraitItemId { owner_id: self.owner_id(i.id) };
         hir::TraitItemRef {
             id,
-            ident: self.lower_ident(ident),
+            ident: self.lower_ident(i.kind.ident().unwrap()),
             span: self.lower_span(i.span),
-            kind,
         }
     }
 
@@ -1137,31 +1116,13 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.arena.alloc(item)
     }
 
-    fn lower_impl_item_ref(&mut self, i: &AssocItem, is_in_trait_impl: bool) -> hir::ImplItemRef {
+    fn lower_impl_item_ref(&mut self, i: &AssocItem) -> hir::ImplItemRef {
         hir::ImplItemRef {
             id: hir::ImplItemId { owner_id: self.owner_id(i.id) },
             // `unwrap` is safe because `AssocItemKind::{MacCall,DelegationMac}` are the only
             // assoc item kinds without an identifier and they cannot reach here.
             ident: self.lower_ident(i.kind.ident().unwrap()),
             span: self.lower_span(i.span),
-            kind: match &i.kind {
-                AssocItemKind::Const(..) => hir::AssocItemKind::Const,
-                AssocItemKind::Type(..) => hir::AssocItemKind::Type,
-                AssocItemKind::Fn(box Fn { sig, .. }) => {
-                    hir::AssocItemKind::Fn { has_self: sig.decl.has_self() }
-                }
-                AssocItemKind::Delegation(box delegation) => hir::AssocItemKind::Fn {
-                    has_self: self.delegatee_is_method(
-                        i.id,
-                        delegation.id,
-                        i.span,
-                        is_in_trait_impl,
-                    ),
-                },
-                AssocItemKind::MacCall(..) | AssocItemKind::DelegationMac(..) => {
-                    panic!("macros should have been expanded by now")
-                }
-            },
         }
     }
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
index 7c69baba62e..a06540f8325 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -681,46 +681,30 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             return (false, false, None);
         }
         let my_def = self.body.source.def_id();
-        let my_hir = self.infcx.tcx.local_def_id_to_hir_id(my_def.as_local().unwrap());
         let Some(td) =
             self.infcx.tcx.impl_of_method(my_def).and_then(|x| self.infcx.tcx.trait_id_of_impl(x))
         else {
             return (false, false, None);
         };
+
+        let implemented_trait_item = self.infcx.tcx.associated_item(my_def).trait_item_def_id;
+
         (
             true,
             td.is_local(),
-            td.as_local().and_then(|tld| match self.infcx.tcx.hir_node_by_def_id(tld) {
-                Node::Item(hir::Item {
-                    kind: hir::ItemKind::Trait(_, _, _, _, _, items), ..
-                }) => {
-                    let mut f_in_trait_opt = None;
-                    for hir::TraitItemRef { id: fi, kind: k, .. } in *items {
-                        let hi = fi.hir_id();
-                        if !matches!(k, hir::AssocItemKind::Fn { .. }) {
-                            continue;
-                        }
-                        if self.infcx.tcx.hir_name(hi) != self.infcx.tcx.hir_name(my_hir) {
-                            continue;
-                        }
-                        f_in_trait_opt = Some(hi);
-                        break;
-                    }
-                    f_in_trait_opt.and_then(|f_in_trait| {
-                        if let Node::TraitItem(ti) = self.infcx.tcx.hir_node(f_in_trait)
-                            && let hir::TraitItemKind::Fn(sig, _) = ti.kind
-                            && let Some(ty) = sig.decl.inputs.get(local.index() - 1)
-                            && let hir::TyKind::Ref(_, mut_ty) = ty.kind
-                            && let hir::Mutability::Not = mut_ty.mutbl
-                            && sig.decl.implicit_self.has_implicit_self()
-                        {
-                            Some(ty.span)
-                        } else {
-                            None
-                        }
-                    })
+            implemented_trait_item.and_then(|f_in_trait| {
+                let f_in_trait = f_in_trait.as_local()?;
+                if let Node::TraitItem(ti) = self.infcx.tcx.hir_node_by_def_id(f_in_trait)
+                    && let hir::TraitItemKind::Fn(sig, _) = ti.kind
+                    && let Some(ty) = sig.decl.inputs.get(local.index() - 1)
+                    && let hir::TyKind::Ref(_, mut_ty) = ty.kind
+                    && let hir::Mutability::Not = mut_ty.mutbl
+                    && sig.decl.implicit_self.has_implicit_self()
+                {
+                    Some(ty.span)
+                } else {
+                    None
                 }
-                _ => None,
             }),
         )
     }
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index c57a8e648fb..8531003c6ac 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -4415,7 +4415,6 @@ impl ItemKind<'_> {
 pub struct TraitItemRef {
     pub id: TraitItemId,
     pub ident: Ident,
-    pub kind: AssocItemKind,
     pub span: Span,
 }
 
@@ -4429,17 +4428,9 @@ pub struct TraitItemRef {
 pub struct ImplItemRef {
     pub id: ImplItemId,
     pub ident: Ident,
-    pub kind: AssocItemKind,
     pub span: Span,
 }
 
-#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
-pub enum AssocItemKind {
-    Const,
-    Fn { has_self: bool },
-    Type,
-}
-
 // The bodies for items are stored "out of line", in a separate
 // hashmap in the `Crate`. Here we just record the hir-id of the item
 // so it can fetched later.
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index c40a6b081ef..e5a60fb5d31 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -499,9 +499,6 @@ pub trait Visitor<'v>: Sized {
     fn visit_attribute(&mut self, _attr: &'v Attribute) -> Self::Result {
         Self::Result::output()
     }
-    fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) -> Self::Result {
-        walk_associated_item_kind(self, kind)
-    }
     fn visit_defaultness(&mut self, defaultness: &'v Defaultness) -> Self::Result {
         walk_defaultness(self, defaultness)
     }
@@ -1252,10 +1249,9 @@ pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(
     visitor: &mut V,
     trait_item_ref: &'v TraitItemRef,
 ) -> V::Result {
-    let TraitItemRef { id, ident, ref kind, span: _ } = *trait_item_ref;
+    let TraitItemRef { id, ident, span: _ } = *trait_item_ref;
     try_visit!(visitor.visit_nested_trait_item(id));
-    try_visit!(visitor.visit_ident(ident));
-    visitor.visit_associated_item_kind(kind)
+    visitor.visit_ident(ident)
 }
 
 pub fn walk_impl_item<'v, V: Visitor<'v>>(
@@ -1307,10 +1303,9 @@ pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(
     visitor: &mut V,
     impl_item_ref: &'v ImplItemRef,
 ) -> V::Result {
-    let ImplItemRef { id, ident, ref kind, span: _ } = *impl_item_ref;
+    let ImplItemRef { id, ident, span: _ } = *impl_item_ref;
     try_visit!(visitor.visit_nested_impl_item(id));
-    try_visit!(visitor.visit_ident(ident));
-    visitor.visit_associated_item_kind(kind)
+    visitor.visit_ident(ident)
 }
 
 pub fn walk_trait_ref<'v, V: Visitor<'v>>(
@@ -1484,13 +1479,6 @@ pub fn walk_assoc_item_constraint<'v, V: Visitor<'v>>(
     V::Result::output()
 }
 
-pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) -> V::Result {
-    // No visitable content here: this fn exists so you can call it if
-    // the right thing to do, should content be added in the future,
-    // would be to walk it.
-    V::Result::output()
-}
-
 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) -> V::Result {
     // No visitable content here: this fn exists so you can call it if
     // the right thing to do, should content be added in the future,
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 431d99a572d..50b0146d80c 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -914,7 +914,7 @@ fn trait_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::TraitDef {
                 let item = items.iter().find(|item| item.ident == *ident);
 
                 match item {
-                    Some(item) if matches!(item.kind, hir::AssocItemKind::Fn { .. }) => {
+                    Some(item) if matches!(tcx.def_kind(item.id.owner_id), DefKind::AssocFn) => {
                         if !tcx.defaultness(item.id.owner_id).has_value() {
                             tcx.dcx().emit_err(errors::FunctionNotHaveDefaultImplementation {
                                 span: item.span,
diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index 172f3372483..255ff56f62b 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -28,7 +28,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, DefId, LocalDefId};
 use rustc_hir::intravisit::FnKind as HirFnKind;
-use rustc_hir::{Body, FnDecl, GenericParamKind, PatKind, PredicateOrigin};
+use rustc_hir::{Body, FnDecl, PatKind, PredicateOrigin};
 use rustc_middle::bug;
 use rustc_middle::lint::LevelAndSource;
 use rustc_middle::ty::layout::LayoutOf;
@@ -952,36 +952,34 @@ declare_lint! {
 
 declare_lint_pass!(InvalidNoMangleItems => [NO_MANGLE_CONST_ITEMS, NO_MANGLE_GENERIC_ITEMS]);
 
+impl InvalidNoMangleItems {
+    fn check_no_mangle_on_generic_fn(
+        &self,
+        cx: &LateContext<'_>,
+        attr_span: Span,
+        def_id: LocalDefId,
+    ) {
+        let generics = cx.tcx.generics_of(def_id);
+        if generics.requires_monomorphization(cx.tcx) {
+            cx.emit_span_lint(
+                NO_MANGLE_GENERIC_ITEMS,
+                cx.tcx.def_span(def_id),
+                BuiltinNoMangleGeneric { suggestion: attr_span },
+            );
+        }
+    }
+}
+
 impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
     fn check_item(&mut self, cx: &LateContext<'_>, it: &hir::Item<'_>) {
         let attrs = cx.tcx.hir_attrs(it.hir_id());
-        let check_no_mangle_on_generic_fn = |attr_span: Span,
-                                             impl_generics: Option<&hir::Generics<'_>>,
-                                             generics: &hir::Generics<'_>,
-                                             span| {
-            for param in
-                generics.params.iter().chain(impl_generics.map(|g| g.params).into_iter().flatten())
-            {
-                match param.kind {
-                    GenericParamKind::Lifetime { .. } => {}
-                    GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
-                        cx.emit_span_lint(
-                            NO_MANGLE_GENERIC_ITEMS,
-                            span,
-                            BuiltinNoMangleGeneric { suggestion: attr_span },
-                        );
-                        break;
-                    }
-                }
-            }
-        };
         match it.kind {
-            hir::ItemKind::Fn { generics, .. } => {
+            hir::ItemKind::Fn { .. } => {
                 if let Some(attr_span) =
                     find_attr!(attrs, AttributeKind::ExportName {span, ..} => *span)
                         .or_else(|| find_attr!(attrs, AttributeKind::NoMangle(span) => *span))
                 {
-                    check_no_mangle_on_generic_fn(attr_span, None, generics, it.span);
+                    self.check_no_mangle_on_generic_fn(cx, attr_span, it.owner_id.def_id);
                 }
             }
             hir::ItemKind::Const(..) => {
@@ -1006,24 +1004,19 @@ impl<'tcx> LateLintPass<'tcx> for InvalidNoMangleItems {
                     );
                 }
             }
-            hir::ItemKind::Impl(hir::Impl { generics, items, .. }) => {
-                for it in *items {
-                    if let hir::AssocItemKind::Fn { .. } = it.kind {
-                        let attrs = cx.tcx.hir_attrs(it.id.hir_id());
-                        if let Some(attr_span) =
-                            find_attr!(attrs, AttributeKind::ExportName {span, ..} => *span)
-                                .or_else(
-                                    || find_attr!(attrs, AttributeKind::NoMangle(span) => *span),
-                                )
-                        {
-                            check_no_mangle_on_generic_fn(
-                                attr_span,
-                                Some(generics),
-                                cx.tcx.hir_get_generics(it.id.owner_id.def_id).unwrap(),
-                                it.span,
-                            );
-                        }
-                    }
+            _ => {}
+        }
+    }
+
+    fn check_impl_item(&mut self, cx: &LateContext<'_>, it: &hir::ImplItem<'_>) {
+        let attrs = cx.tcx.hir_attrs(it.hir_id());
+        match it.kind {
+            hir::ImplItemKind::Fn { .. } => {
+                if let Some(attr_span) =
+                    find_attr!(attrs, AttributeKind::ExportName {span, ..} => *span)
+                        .or_else(|| find_attr!(attrs, AttributeKind::NoMangle(span) => *span))
+                {
+                    self.check_no_mangle_on_generic_fn(cx, attr_span, it.owner_id.def_id);
                 }
             }
             _ => {}
diff --git a/compiler/rustc_middle/src/ty/assoc.rs b/compiler/rustc_middle/src/ty/assoc.rs
index 9534d45e495..1d15e4de7b6 100644
--- a/compiler/rustc_middle/src/ty/assoc.rs
+++ b/compiler/rustc_middle/src/ty/assoc.rs
@@ -258,6 +258,16 @@ impl AssocItems {
     }
 
     /// Returns the associated item with the given identifier and `AssocKind`, if one exists.
+    /// The identifier is ignoring hygiene. This is meant to be used for lints and diagnostics.
+    pub fn filter_by_name_unhygienic_and_kind(
+        &self,
+        name: Symbol,
+        assoc_tag: AssocTag,
+    ) -> impl '_ + Iterator<Item = &ty::AssocItem> {
+        self.filter_by_name_unhygienic(name).filter(move |item| item.as_tag() == assoc_tag)
+    }
+
+    /// Returns the associated item with the given identifier and `AssocKind`, if one exists.
     /// The identifier is matched hygienically.
     pub fn find_by_ident_and_kind(
         &self,
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 9a96749f3e7..38f82de9184 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -20,8 +20,8 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalModDefId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{
-    self as hir, self, AssocItemKind, Attribute, CRATE_HIR_ID, CRATE_OWNER_ID, FnSig, ForeignItem,
-    HirId, Item, ItemKind, MethodKind, Safety, Target, TraitItem,
+    self as hir, self, Attribute, CRATE_HIR_ID, CRATE_OWNER_ID, FnSig, ForeignItem, HirId, Item,
+    ItemKind, MethodKind, Safety, Target, TraitItem,
 };
 use rustc_macros::LintDiagnostic;
 use rustc_middle::hir::nested_filter;
@@ -1151,7 +1151,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 if generics.params.len() != 0 => {}
             ItemKind::Trait(_, _, _, generics, _, items)
                 if generics.params.len() != 0
-                    || items.iter().any(|item| matches!(item.kind, AssocItemKind::Type)) => {}
+                    || items.iter().any(|item| {
+                        matches!(self.tcx.def_kind(item.id.owner_id), DefKind::AssocTy)
+                    }) => {}
             ItemKind::TyAlias(_, generics, _) if generics.params.len() != 0 => {}
             _ => {
                 self.dcx().emit_err(errors::DocSearchUnboxInvalid { span: meta.span() });
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index cdfd1a2b07e..1fd7cc25524 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -415,7 +415,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
                 hir::ItemKind::Trait(.., trait_item_refs) => {
                     // mark assoc ty live if the trait is live
                     for trait_item in trait_item_refs {
-                        if matches!(trait_item.kind, hir::AssocItemKind::Type) {
+                        if matches!(self.tcx.def_kind(trait_item.id.owner_id), DefKind::AssocTy) {
                             self.check_def_id(trait_item.id.owner_id.to_def_id());
                         }
                     }
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 963f4c77d80..a7453a659c9 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -26,7 +26,7 @@ use rustc_errors::{MultiSpan, listify};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{CRATE_DEF_ID, DefId, LocalDefId, LocalModDefId};
 use rustc_hir::intravisit::{self, InferKind, Visitor};
-use rustc_hir::{AmbigArg, AssocItemKind, ForeignItemKind, ItemId, ItemKind, PatKind};
+use rustc_hir::{AmbigArg, ForeignItemKind, ItemId, ItemKind, PatKind};
 use rustc_middle::middle::privacy::{EffectiveVisibilities, EffectiveVisibility, Level};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::print::PrintTraitRefExt as _;
@@ -678,7 +678,7 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
                         let mut reach = self.reach(trait_item_ref.id.owner_id.def_id, item_ev);
                         reach.generics().predicates();
 
-                        if trait_item_ref.kind == AssocItemKind::Type
+                        if let DefKind::AssocTy = tcx.def_kind(trait_item_ref.id.owner_id)
                             && !tcx.defaultness(trait_item_ref.id.owner_id).has_value()
                         {
                             // No type to visit.
@@ -1576,16 +1576,15 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
 
     fn check_assoc_item(
         &self,
-        def_id: LocalDefId,
-        assoc_item_kind: AssocItemKind,
+        item: &ty::AssocItem,
         vis: ty::Visibility,
         effective_vis: Option<EffectiveVisibility>,
     ) {
-        let mut check = self.check(def_id, vis, effective_vis);
+        let mut check = self.check(item.def_id.expect_local(), vis, effective_vis);
 
-        let (check_ty, is_assoc_ty) = match assoc_item_kind {
-            AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
-            AssocItemKind::Type => (self.tcx.defaultness(def_id).has_value(), true),
+        let (check_ty, is_assoc_ty) = match item.kind {
+            ty::AssocKind::Const { .. } | ty::AssocKind::Fn { .. } => (true, false),
+            ty::AssocKind::Type { .. } => (item.defaultness(self.tcx).has_value(), true),
         };
 
         check.in_assoc_ty = is_assoc_ty;
@@ -1619,30 +1618,20 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
                 self.check(def_id, item_visibility, effective_vis).generics().bounds();
             }
             DefKind::Trait => {
-                let item = tcx.hir_item(id);
-                if let hir::ItemKind::Trait(.., trait_item_refs) = item.kind {
-                    self.check_unnameable(item.owner_id.def_id, effective_vis);
+                self.check_unnameable(def_id, effective_vis);
 
-                    self.check(item.owner_id.def_id, item_visibility, effective_vis)
-                        .generics()
-                        .predicates();
+                self.check(def_id, item_visibility, effective_vis).generics().predicates();
 
-                    for trait_item_ref in trait_item_refs {
-                        self.check_assoc_item(
-                            trait_item_ref.id.owner_id.def_id,
-                            trait_item_ref.kind,
+                for assoc_item in tcx.associated_items(id.owner_id).in_definition_order() {
+                    self.check_assoc_item(assoc_item, item_visibility, effective_vis);
+
+                    if assoc_item.is_type() {
+                        self.check(
+                            assoc_item.def_id.expect_local(),
                             item_visibility,
                             effective_vis,
-                        );
-
-                        if let AssocItemKind::Type = trait_item_ref.kind {
-                            self.check(
-                                trait_item_ref.id.owner_id.def_id,
-                                item_visibility,
-                                effective_vis,
-                            )
-                            .bounds();
-                        }
+                        )
+                        .bounds();
                     }
                 }
             }
@@ -1714,69 +1703,52 @@ impl<'tcx> PrivateItemsInPublicInterfacesChecker<'_, 'tcx> {
             // Subitems of inherent impls have their own publicity.
             // A trait impl is public when both its type and its trait are public
             // Subitems of trait impls have inherited publicity.
-            DefKind::Impl { .. } => {
-                let item = tcx.hir_item(id);
-                if let hir::ItemKind::Impl(impl_) = item.kind {
-                    let impl_vis = ty::Visibility::of_impl::<false>(
-                        item.owner_id.def_id,
-                        tcx,
-                        &Default::default(),
-                    );
+            DefKind::Impl { of_trait } => {
+                let impl_vis = ty::Visibility::of_impl::<false>(def_id, tcx, &Default::default());
 
-                    // We are using the non-shallow version here, unlike when building the
-                    // effective visisibilities table to avoid large number of false positives.
-                    // For example in
-                    //
-                    // impl From<Priv> for Pub {
-                    //     fn from(_: Priv) -> Pub {...}
-                    // }
-                    //
-                    // lints shouldn't be emitted even if `from` effective visibility
-                    // is larger than `Priv` nominal visibility and if `Priv` can leak
-                    // in some scenarios due to type inference.
-                    let impl_ev = EffectiveVisibility::of_impl::<false>(
-                        item.owner_id.def_id,
-                        tcx,
-                        self.effective_visibilities,
-                    );
+                // We are using the non-shallow version here, unlike when building the
+                // effective visisibilities table to avoid large number of false positives.
+                // For example in
+                //
+                // impl From<Priv> for Pub {
+                //     fn from(_: Priv) -> Pub {...}
+                // }
+                //
+                // lints shouldn't be emitted even if `from` effective visibility
+                // is larger than `Priv` nominal visibility and if `Priv` can leak
+                // in some scenarios due to type inference.
+                let impl_ev =
+                    EffectiveVisibility::of_impl::<false>(def_id, tcx, self.effective_visibilities);
+
+                let mut check = self.check(def_id, impl_vis, Some(impl_ev));
+
+                // Generics and predicates of trait impls are intentionally not checked
+                // for private components (#90586).
+                if !of_trait {
+                    check.generics().predicates();
+                }
 
-                    let mut check = self.check(item.owner_id.def_id, impl_vis, Some(impl_ev));
-                    // Generics and predicates of trait impls are intentionally not checked
-                    // for private components (#90586).
-                    if impl_.of_trait.is_none() {
-                        check.generics().predicates();
-                    }
-                    // Skip checking private components in associated types, due to lack of full
-                    // normalization they produce very ridiculous false positives.
-                    // FIXME: Remove this when full normalization is implemented.
-                    check.skip_assoc_tys = true;
-                    check.ty().trait_ref();
-
-                    for impl_item_ref in impl_.items {
-                        let impl_item_vis = if impl_.of_trait.is_none() {
-                            min(
-                                tcx.local_visibility(impl_item_ref.id.owner_id.def_id),
-                                impl_vis,
-                                tcx,
-                            )
-                        } else {
-                            impl_vis
-                        };
+                // Skip checking private components in associated types, due to lack of full
+                // normalization they produce very ridiculous false positives.
+                // FIXME: Remove this when full normalization is implemented.
+                check.skip_assoc_tys = true;
+                check.ty().trait_ref();
 
-                        let impl_item_ev = if impl_.of_trait.is_none() {
-                            self.get(impl_item_ref.id.owner_id.def_id)
-                                .map(|ev| ev.min(impl_ev, self.tcx))
-                        } else {
-                            Some(impl_ev)
-                        };
-
-                        self.check_assoc_item(
-                            impl_item_ref.id.owner_id.def_id,
-                            impl_item_ref.kind,
-                            impl_item_vis,
-                            impl_item_ev,
-                        );
-                    }
+                for assoc_item in tcx.associated_items(id.owner_id).in_definition_order() {
+                    let impl_item_vis = if !of_trait {
+                        min(tcx.local_visibility(assoc_item.def_id.expect_local()), impl_vis, tcx)
+                    } else {
+                        impl_vis
+                    };
+
+                    let impl_item_ev = if !of_trait {
+                        self.get(assoc_item.def_id.expect_local())
+                            .map(|ev| ev.min(impl_ev, self.tcx))
+                    } else {
+                        Some(impl_ev)
+                    };
+
+                    self.check_assoc_item(assoc_item, impl_item_vis, impl_item_ev);
                 }
             }
             _ => {}
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
index bff5e9128cb..db35c988bf7 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
@@ -841,54 +841,32 @@ fn foo(&self) -> Self::T { String::new() }
 
         let param_env = tcx.param_env(body_owner_def_id);
 
-        match item {
-            hir::Node::Item(hir::Item { kind: hir::ItemKind::Trait(.., items), .. }) => {
-                // FIXME: account for `#![feature(specialization)]`
-                for item in &items[..] {
-                    match item.kind {
-                        hir::AssocItemKind::Type => {
-                            // FIXME: account for returning some type in a trait fn impl that has
-                            // an assoc type as a return type (#72076).
-                            if let hir::Defaultness::Default { has_value: true } =
-                                tcx.defaultness(item.id.owner_id)
-                            {
-                                let assoc_ty = tcx.type_of(item.id.owner_id).instantiate_identity();
-                                if self.infcx.can_eq(param_env, assoc_ty, found) {
-                                    diag.span_label(
-                                        item.span,
-                                        "associated type defaults can't be assumed inside the \
-                                            trait defining them",
-                                    );
-                                    return true;
-                                }
-                            }
+        if let DefKind::Trait | DefKind::Impl { .. } = tcx.def_kind(parent_id) {
+            let assoc_items = tcx.associated_items(parent_id);
+            // FIXME: account for `#![feature(specialization)]`
+            for assoc_item in assoc_items.in_definition_order() {
+                if assoc_item.is_type()
+                    // FIXME: account for returning some type in a trait fn impl that has
+                    // an assoc type as a return type (#72076).
+                    && let hir::Defaultness::Default { has_value: true } = assoc_item.defaultness(tcx)
+                    && let assoc_ty = tcx.type_of(assoc_item.def_id).instantiate_identity()
+                    && self.infcx.can_eq(param_env, assoc_ty, found)
+                {
+                    let msg = match assoc_item.container {
+                        ty::AssocItemContainer::Trait => {
+                            "associated type defaults can't be assumed inside the \
+                                            trait defining them"
                         }
-                        _ => {}
-                    }
-                }
-            }
-            hir::Node::Item(hir::Item {
-                kind: hir::ItemKind::Impl(hir::Impl { items, .. }),
-                ..
-            }) => {
-                for item in &items[..] {
-                    if let hir::AssocItemKind::Type = item.kind {
-                        let assoc_ty = tcx.type_of(item.id.owner_id).instantiate_identity();
-                        if let hir::Defaultness::Default { has_value: true } =
-                            tcx.defaultness(item.id.owner_id)
-                            && self.infcx.can_eq(param_env, assoc_ty, found)
-                        {
-                            diag.span_label(
-                                item.span,
-                                "associated type is `default` and may be overridden",
-                            );
-                            return true;
+                        ty::AssocItemContainer::Impl => {
+                            "associated type is `default` and may be overridden"
                         }
-                    }
+                    };
+                    diag.span_label(tcx.def_span(assoc_item.def_id), msg);
+                    return true;
                 }
             }
-            _ => {}
         }
+
         false
     }
 
diff --git a/compiler/rustc_ty_utils/src/assoc.rs b/compiler/rustc_ty_utils/src/assoc.rs
index d27f749762f..fecc56091b9 100644
--- a/compiler/rustc_ty_utils/src/assoc.rs
+++ b/compiler/rustc_ty_utils/src/assoc.rs
@@ -154,7 +154,7 @@ fn associated_types_for_impl_traits_in_trait_or_impl<'tcx>(
         ItemKind::Trait(.., trait_item_refs) => trait_item_refs
             .iter()
             .filter_map(move |item| {
-                if !matches!(item.kind, hir::AssocItemKind::Fn { .. }) {
+                if !matches!(tcx.def_kind(item.id.owner_id), DefKind::AssocFn) {
                     return None;
                 }
                 let fn_def_id = item.id.owner_id.def_id;
@@ -185,7 +185,7 @@ fn associated_types_for_impl_traits_in_trait_or_impl<'tcx>(
                 .items
                 .iter()
                 .filter_map(|item| {
-                    if !matches!(item.kind, hir::AssocItemKind::Fn { .. }) {
+                    if !matches!(tcx.def_kind(item.id.owner_id), DefKind::AssocFn) {
                         return None;
                     }
                     let did = item.id.owner_id.def_id.to_def_id();
diff --git a/src/tools/clippy/clippy_lints/src/arbitrary_source_item_ordering.rs b/src/tools/clippy/clippy_lints/src/arbitrary_source_item_ordering.rs
index 8b6bfaebbe5..ee8da707a80 100644
--- a/src/tools/clippy/clippy_lints/src/arbitrary_source_item_ordering.rs
+++ b/src/tools/clippy/clippy_lints/src/arbitrary_source_item_ordering.rs
@@ -8,9 +8,10 @@ use clippy_utils::diagnostics::span_lint_and_note;
 use clippy_utils::is_cfg_test;
 use rustc_attr_data_structures::AttributeKind;
 use rustc_hir::{
-    AssocItemKind, Attribute, FieldDef, HirId, ImplItemRef, IsAuto, Item, ItemKind, Mod, QPath, TraitItemRef, TyKind,
+    Attribute, FieldDef, HirId, ImplItemRef, IsAuto, Item, ItemKind, Mod, OwnerId, QPath, TraitItemRef, TyKind,
     Variant, VariantData,
 };
+use rustc_middle::ty::AssocKind;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_session::impl_lint_pass;
 
@@ -315,9 +316,9 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
                     }
 
                     if let Some(cur_t) = cur_t {
-                        let cur_t_kind = convert_assoc_item_kind(cur_t.kind);
+                        let cur_t_kind = convert_assoc_item_kind(cx, cur_t.id.owner_id);
                         let cur_t_kind_index = self.assoc_types_order.index_of(&cur_t_kind);
-                        let item_kind = convert_assoc_item_kind(item.kind);
+                        let item_kind = convert_assoc_item_kind(cx,item.id.owner_id);
                         let item_kind_index = self.assoc_types_order.index_of(&item_kind);
 
                         if cur_t_kind == item_kind && cur_t.ident.name.as_str() > item.ident.name.as_str() {
@@ -338,9 +339,9 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
                     }
 
                     if let Some(cur_t) = cur_t {
-                        let cur_t_kind = convert_assoc_item_kind(cur_t.kind);
+                        let cur_t_kind = convert_assoc_item_kind(cx, cur_t.id.owner_id);
                         let cur_t_kind_index = self.assoc_types_order.index_of(&cur_t_kind);
-                        let item_kind = convert_assoc_item_kind(item.kind);
+                        let item_kind = convert_assoc_item_kind(cx, item.id.owner_id);
                         let item_kind_index = self.assoc_types_order.index_of(&item_kind);
 
                         if cur_t_kind == item_kind && cur_t.ident.name.as_str() > item.ident.name.as_str() {
@@ -458,18 +459,19 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
     }
 }
 
-/// Converts a [`rustc_hir::AssocItemKind`] to a
-/// [`SourceItemOrderingTraitAssocItemKind`].
+/// Converts a [`ty::AssocKind`] to a [`SourceItemOrderingTraitAssocItemKind`].
 ///
 /// This is implemented here because `rustc_hir` is not a dependency of
 /// `clippy_config`.
-fn convert_assoc_item_kind(value: AssocItemKind) -> SourceItemOrderingTraitAssocItemKind {
+fn convert_assoc_item_kind(cx: &LateContext<'_>, owner_id: OwnerId) -> SourceItemOrderingTraitAssocItemKind {
+    let kind = cx.tcx.associated_item(owner_id.def_id).kind;
+
     #[allow(clippy::enum_glob_use)] // Very local glob use for legibility.
     use SourceItemOrderingTraitAssocItemKind::*;
-    match value {
-        AssocItemKind::Const => Const,
-        AssocItemKind::Type => Type,
-        AssocItemKind::Fn { .. } => Fn,
+    match kind {
+        AssocKind::Const{..} => Const,
+        AssocKind::Type {..}=> Type,
+        AssocKind::Fn { .. } => Fn,
     }
 }
 
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index 2cb3b32babe..db2fea1aae9 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -1,7 +1,8 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_hir;
 use rustc_abi::ExternAbi;
-use rustc_hir::{AssocItemKind, Body, FnDecl, HirId, HirIdSet, Impl, ItemKind, Node, Pat, PatKind, intravisit};
+use rustc_hir::{Body, FnDecl, HirId, HirIdSet, Node, Pat, PatKind, intravisit};
+use rustc_hir::def::DefKind;
 use rustc_hir_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::mir::FakeReadCause;
@@ -84,23 +85,18 @@ impl<'tcx> LateLintPass<'tcx> for BoxedLocal {
             .def_id;
 
         let mut trait_self_ty = None;
-        if let Node::Item(item) = cx.tcx.hir_node_by_def_id(parent_id) {
+        match cx.tcx.def_kind(parent_id) {
             // If the method is an impl for a trait, don't warn.
-            if let ItemKind::Impl(Impl { of_trait: Some(_), .. }) = item.kind {
-                return;
+            DefKind::Impl { of_trait: true } => {
+                return
             }
 
             // find `self` ty for this trait if relevant
-            if let ItemKind::Trait(_, _, _, _, _, items) = item.kind {
-                for trait_item in items {
-                    if trait_item.id.owner_id.def_id == fn_def_id
-                        // be sure we have `self` parameter in this function
-                        && trait_item.kind == (AssocItemKind::Fn { has_self: true })
-                    {
-                        trait_self_ty = Some(TraitRef::identity(cx.tcx, trait_item.id.owner_id.to_def_id()).self_ty());
-                    }
-                }
+            DefKind::Trait => {
+                trait_self_ty = Some(TraitRef::identity(cx.tcx, parent_id.to_def_id()).self_ty());
             }
+
+            _ => {}
         }
 
         let mut v = EscapeDelegate {
diff --git a/src/tools/clippy/clippy_lints/src/functions/renamed_function_params.rs b/src/tools/clippy/clippy_lints/src/functions/renamed_function_params.rs
index 2d22bb157a9..0d6191f2c97 100644
--- a/src/tools/clippy/clippy_lints/src/functions/renamed_function_params.rs
+++ b/src/tools/clippy/clippy_lints/src/functions/renamed_function_params.rs
@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use rustc_errors::{Applicability, MultiSpan};
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::hir_id::OwnerId;
-use rustc_hir::{Impl, ImplItem, ImplItemKind, ImplItemRef, ItemKind, Node, TraitRef};
+use rustc_hir::{Impl, ImplItem, ImplItemKind, ItemKind, Node, TraitRef};
 use rustc_lint::LateContext;
 use rustc_span::Span;
 use rustc_span::symbol::{Ident, kw};
@@ -15,11 +15,10 @@ pub(super) fn check_impl_item(cx: &LateContext<'_>, item: &ImplItem<'_>, ignored
         && let parent_node = cx.tcx.parent_hir_node(item.hir_id())
         && let Node::Item(parent_item) = parent_node
         && let ItemKind::Impl(Impl {
-            items,
             of_trait: Some(trait_ref),
             ..
         }) = &parent_item.kind
-        && let Some(did) = trait_item_def_id_of_impl(items, item.owner_id)
+        && let Some(did) = trait_item_def_id_of_impl(cx, item.owner_id)
         && !is_from_ignored_trait(trait_ref, ignored_traits)
     {
         let mut param_idents_iter = cx.tcx.hir_body_param_idents(body_id);
@@ -93,14 +92,8 @@ impl RenamedFnArgs {
 }
 
 /// Get the [`trait_item_def_id`](ImplItemRef::trait_item_def_id) of a relevant impl item.
-fn trait_item_def_id_of_impl(items: &[ImplItemRef], target: OwnerId) -> Option<DefId> {
-    items.iter().find_map(|item| {
-        if item.id.owner_id == target {
-            item.trait_item_def_id
-        } else {
-            None
-        }
-    })
+fn trait_item_def_id_of_impl(cx: &LateContext<'_>, target: OwnerId) -> Option<DefId> {
+    cx.tcx.associated_item(target).trait_item_def_id
 }
 
 fn is_from_ignored_trait(of_trait: &TraitRef<'_>, ignored_traits: &DefIdSet) -> bool {
diff --git a/src/tools/clippy/clippy_lints/src/infallible_try_from.rs b/src/tools/clippy/clippy_lints/src/infallible_try_from.rs
index b54c289fa7e..e79fcec6e6a 100644
--- a/src/tools/clippy/clippy_lints/src/infallible_try_from.rs
+++ b/src/tools/clippy/clippy_lints/src/infallible_try_from.rs
@@ -1,8 +1,9 @@
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::sym;
 use rustc_errors::MultiSpan;
-use rustc_hir::{AssocItemKind, Item, ItemKind};
+use rustc_hir::{Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::AssocTag;
 use rustc_session::declare_lint_pass;
 
 declare_clippy_lint! {
@@ -51,25 +52,23 @@ impl<'tcx> LateLintPass<'tcx> for InfallibleTryFrom {
         if !cx.tcx.is_diagnostic_item(sym::TryFrom, trait_def_id) {
             return;
         }
-        for ii in imp.items {
-            if ii.kind == AssocItemKind::Type {
-                let ii = cx.tcx.hir_impl_item(ii.id);
-                if ii.ident.name != sym::Error {
-                    continue;
-                }
-                let ii_ty = ii.expect_type();
-                let ii_ty_span = ii_ty.span;
-                let ii_ty = clippy_utils::ty::ty_from_hir_ty(cx, ii_ty);
-                if !ii_ty.is_inhabited_from(cx.tcx, ii.owner_id.to_def_id(), cx.typing_env()) {
-                    let mut span = MultiSpan::from_span(cx.tcx.def_span(item.owner_id.to_def_id()));
-                    span.push_span_label(ii_ty_span, "infallible error type");
-                    span_lint(
-                        cx,
-                        INFALLIBLE_TRY_FROM,
-                        span,
-                        "infallible TryFrom impl; consider implementing From, instead",
-                    );
-                }
+        for ii in cx.tcx.associated_items(item.owner_id.def_id)
+            .filter_by_name_unhygienic_and_kind(sym::Error, AssocTag::Type)
+        {
+            let ii_ty = cx.tcx.type_of(ii.def_id).instantiate_identity();
+            if !ii_ty.is_inhabited_from(cx.tcx, ii.def_id, cx.typing_env()) {
+                let mut span = MultiSpan::from_span(cx.tcx.def_span(item.owner_id.to_def_id()));
+                let ii_ty_span = cx.tcx.hir_node_by_def_id(ii.def_id.expect_local())
+                    .expect_impl_item()
+                    .expect_type()
+                    .span;
+                span.push_span_label(ii_ty_span, "infallible error type");
+                span_lint(
+                    cx,
+                    INFALLIBLE_TRY_FROM,
+                    span,
+                    "infallible TryFrom impl; consider implementing From, instead",
+                );
             }
         }
     }
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
index aded31971ce..896aa64fcdb 100644
--- a/src/tools/clippy/clippy_lints/src/len_zero.rs
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -10,7 +10,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::{
-    AssocItemKind, BinOpKind, Expr, ExprKind, FnRetTy, GenericArg, GenericBound, HirId, ImplItem, ImplItemKind,
+    BinOpKind, Expr, ExprKind, FnRetTy, GenericArg, GenericBound, HirId, ImplItem, ImplItemKind,
     ImplicitSelfKind, Item, ItemKind, Mutability, Node, OpaqueTyOrigin, PatExprKind, PatKind, PathSegment, PrimTy,
     QPath, TraitItemRef, TyKind,
 };
@@ -18,6 +18,7 @@ use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, FnSig, Ty};
 use rustc_session::declare_lint_pass;
 use rustc_span::source_map::Spanned;
+use rustc_span::symbol::kw;
 use rustc_span::{Ident, Span, Symbol};
 use rustc_trait_selection::traits::supertrait_def_ids;
 
@@ -267,19 +268,10 @@ fn span_without_enclosing_paren(cx: &LateContext<'_>, span: Span) -> Span {
 fn check_trait_items(cx: &LateContext<'_>, visited_trait: &Item<'_>, ident: Ident, trait_items: &[TraitItemRef]) {
     fn is_named_self(cx: &LateContext<'_>, item: &TraitItemRef, name: Symbol) -> bool {
         item.ident.name == name
-            && if let AssocItemKind::Fn { has_self } = item.kind {
-                has_self && {
-                    cx.tcx
-                        .fn_sig(item.id.owner_id)
-                        .skip_binder()
-                        .inputs()
-                        .skip_binder()
-                        .len()
-                        == 1
-                }
-            } else {
-                false
-            }
+            && matches!(
+                cx.tcx.fn_arg_idents(item.id.owner_id),
+                [Some(Ident { name: kw::SelfLower, .. })],
+            )
     }
 
     // fill the set with current and super traits
diff --git a/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs b/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
index e266c36b6e7..fa61d0fa11a 100644
--- a/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
+++ b/src/tools/clippy/clippy_lints/src/missing_trait_methods.rs
@@ -61,15 +61,14 @@ impl<'tcx> LateLintPass<'tcx> for MissingTraitMethods {
         if !is_lint_allowed(cx, MISSING_TRAIT_METHODS, item.hir_id())
             && span_is_local(item.span)
             && let ItemKind::Impl(Impl {
-                items,
                 of_trait: Some(trait_ref),
                 ..
             }) = item.kind
             && let Some(trait_id) = trait_ref.trait_def_id()
         {
-            let trait_item_ids: DefIdSet = items
-                .iter()
-                .filter_map(|impl_item| impl_item.trait_item_def_id)
+            let trait_item_ids: DefIdSet = cx.tcx.associated_items(item.owner_id)
+                .in_definition_order()
+                .filter_map(|assoc_item| assoc_item.trait_item_def_id)
                 .collect();
 
             for assoc in cx
diff --git a/src/tools/clippy/clippy_lints/src/new_without_default.rs b/src/tools/clippy/clippy_lints/src/new_without_default.rs
index 4b73a4455f5..3b86f1d1f59 100644
--- a/src/tools/clippy/clippy_lints/src/new_without_default.rs
+++ b/src/tools/clippy/clippy_lints/src/new_without_default.rs
@@ -6,6 +6,7 @@ use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::HirIdSet;
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::ty::AssocKind;
 use rustc_session::impl_lint_pass;
 use rustc_span::sym;
 
@@ -61,18 +62,18 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
             of_trait: None,
             generics,
             self_ty: impl_self_ty,
-            items,
             ..
         }) = item.kind
         {
-            for assoc_item in *items {
-                if assoc_item.kind == (hir::AssocItemKind::Fn { has_self: false }) {
-                    let impl_item = cx.tcx.hir_impl_item(assoc_item.id);
+            for assoc_item in cx.tcx.associated_items(item.owner_id.def_id)
+                .filter_by_name_unhygienic(sym::new)
+            {
+                if let AssocKind::Fn { has_self: false, .. } = assoc_item.kind {
+                    let impl_item = cx.tcx.hir_node_by_def_id(assoc_item.def_id.expect_local()).expect_impl_item();
                     if impl_item.span.in_external_macro(cx.sess().source_map()) {
                         return;
                     }
                     if let hir::ImplItemKind::Fn(ref sig, _) = impl_item.kind {
-                        let name = impl_item.ident.name;
                         let id = impl_item.owner_id;
                         if sig.header.is_unsafe() {
                             // can't be implemented for unsafe new
@@ -88,11 +89,9 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                             return;
                         }
                         if sig.decl.inputs.is_empty()
-                            && name == sym::new
                             && cx.effective_visibilities.is_reachable(impl_item.owner_id.def_id)
-                            && let self_def_id = cx.tcx.hir_get_parent_item(id.into())
-                            && let self_ty = cx.tcx.type_of(self_def_id).instantiate_identity()
-                            && self_ty == return_ty(cx, id)
+                            && let self_ty = cx.tcx.type_of(item.owner_id).instantiate_identity()
+                            && self_ty == return_ty(cx, impl_item.owner_id)
                             && let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default)
                         {
                             if self.impling_types.is_none() {
@@ -111,7 +110,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                             // Check if a Default implementation exists for the Self type, regardless of
                             // generics
                             if let Some(ref impling_types) = self.impling_types
-                                && let self_def = cx.tcx.type_of(self_def_id).instantiate_identity()
+                                && let self_def = cx.tcx.type_of(item.owner_id).instantiate_identity()
                                 && let Some(self_def) = self_def.ty_adt_def()
                                 && let Some(self_local_did) = self_def.did().as_local()
                                 && let self_id = cx.tcx.local_def_id_to_hir_id(self_local_did)
diff --git a/src/tools/clippy/clippy_lints/src/same_name_method.rs b/src/tools/clippy/clippy_lints/src/same_name_method.rs
index 226e8ff6adb..85fde780e68 100644
--- a/src/tools/clippy/clippy_lints/src/same_name_method.rs
+++ b/src/tools/clippy/clippy_lints/src/same_name_method.rs
@@ -3,7 +3,7 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{HirId, Impl, ItemKind, Node, Path, QPath, TraitRef, TyKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::AssocItem;
+use rustc_middle::ty::{AssocKind, AssocItem};
 use rustc_session::declare_lint_pass;
 use rustc_span::Span;
 use rustc_span::symbol::Symbol;
@@ -54,7 +54,6 @@ impl<'tcx> LateLintPass<'tcx> for SameNameMethod {
             if matches!(cx.tcx.def_kind(id.owner_id), DefKind::Impl { .. })
                 && let item = cx.tcx.hir_item(id)
                 && let ItemKind::Impl(Impl {
-                    items,
                     of_trait,
                     self_ty,
                     ..
@@ -115,13 +114,11 @@ impl<'tcx> LateLintPass<'tcx> for SameNameMethod {
                             }
                         };
 
-                        for impl_item_ref in (*items)
-                            .iter()
-                            .filter(|impl_item_ref| matches!(impl_item_ref.kind, rustc_hir::AssocItemKind::Fn { .. }))
-                        {
-                            let method_name = impl_item_ref.ident.name;
-                            methods_in_trait.remove(&method_name);
-                            check_trait_method(method_name, impl_item_ref.span);
+                        for assoc_item in cx.tcx.associated_items(id.owner_id).in_definition_order() {
+                            if let AssocKind::Fn { name, .. } = assoc_item.kind {
+                                methods_in_trait.remove(&name);
+                                check_trait_method(name, cx.tcx.def_span(assoc_item.def_id));
+                            }
                         }
 
                         for method_name in methods_in_trait {
@@ -129,14 +126,11 @@ impl<'tcx> LateLintPass<'tcx> for SameNameMethod {
                         }
                     },
                     None => {
-                        for impl_item_ref in (*items)
-                            .iter()
-                            .filter(|impl_item_ref| matches!(impl_item_ref.kind, rustc_hir::AssocItemKind::Fn { .. }))
-                        {
-                            let method_name = impl_item_ref.ident.name;
-                            let impl_span = impl_item_ref.span;
-                            let hir_id = impl_item_ref.id.hir_id();
-                            if let Some(trait_spans) = existing_name.trait_methods.get(&method_name) {
+                        for assoc_item in cx.tcx.associated_items(id.owner_id).in_definition_order() {
+                            let AssocKind::Fn { name, .. } = assoc_item.kind else { continue };
+                            let impl_span = cx.tcx.def_span(assoc_item.def_id);
+                            let hir_id = cx.tcx.local_def_id_to_hir_id(assoc_item.def_id.expect_local());
+                            if let Some(trait_spans) = existing_name.trait_methods.get(&name) {
                                 span_lint_hir_and_then(
                                     cx,
                                     SAME_NAME_METHOD,
@@ -148,12 +142,12 @@ impl<'tcx> LateLintPass<'tcx> for SameNameMethod {
                                         // iterate on trait_spans?
                                         diag.span_note(
                                             trait_spans[0],
-                                            format!("existing `{method_name}` defined here"),
+                                            format!("existing `{name}` defined here"),
                                         );
                                     },
                                 );
                             }
-                            existing_name.impl_methods.insert(method_name, (impl_span, hir_id));
+                            existing_name.impl_methods.insert(name, (impl_span, hir_id));
                         }
                     },
                 }
diff --git a/src/tools/clippy/tests/ui/same_name_method.stderr b/src/tools/clippy/tests/ui/same_name_method.stderr
index b2624ac4d26..bf7456d80e2 100644
--- a/src/tools/clippy/tests/ui/same_name_method.stderr
+++ b/src/tools/clippy/tests/ui/same_name_method.stderr
@@ -2,13 +2,13 @@ error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:20:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    |
 note: existing `foo` defined here
   --> tests/ui/same_name_method.rs:25:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    = note: `-D clippy::same-name-method` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::same_name_method)]`
 
@@ -16,7 +16,7 @@ error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:35:13
    |
 LL |             fn clone() {}
-   |             ^^^^^^^^^^^^^
+   |             ^^^^^^^^^^
    |
 note: existing `clone` defined here
   --> tests/ui/same_name_method.rs:31:18
@@ -28,19 +28,19 @@ error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:46:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    |
 note: existing `foo` defined here
   --> tests/ui/same_name_method.rs:51:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
 
 error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:61:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    |
 note: existing `foo` defined here
   --> tests/ui/same_name_method.rs:65:9
@@ -52,7 +52,7 @@ error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:74:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    |
 note: existing `foo` defined here
   --> tests/ui/same_name_method.rs:79:9
@@ -64,7 +64,7 @@ error: method's name is the same as an existing method in a trait
   --> tests/ui/same_name_method.rs:74:13
    |
 LL |             fn foo() {}
-   |             ^^^^^^^^^^^
+   |             ^^^^^^^^
    |
 note: existing `foo` defined here
   --> tests/ui/same_name_method.rs:81:9
diff --git a/tests/ui/associated-types/defaults-in-other-trait-items.stderr b/tests/ui/associated-types/defaults-in-other-trait-items.stderr
index bdcfadd3955..56abd6ebf73 100644
--- a/tests/ui/associated-types/defaults-in-other-trait-items.stderr
+++ b/tests/ui/associated-types/defaults-in-other-trait-items.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/defaults-in-other-trait-items.rs:9:13
    |
 LL |     type A = ();
-   |     ------------ associated type defaults can't be assumed inside the trait defining them
+   |     ------ associated type defaults can't be assumed inside the trait defining them
 ...
 LL |         let () = p;
    |             ^^   - this expression has type `<Self as Tr>::A`
@@ -16,7 +16,7 @@ error[E0308]: mismatched types
   --> $DIR/defaults-in-other-trait-items.rs:36:25
    |
 LL |     type Ty = u8;
-   |     ------------- associated type defaults can't be assumed inside the trait defining them
+   |     ------- associated type defaults can't be assumed inside the trait defining them
 ...
 LL |     const C: Self::Ty = 0u8;
    |                         ^^^ expected associated type, found `u8`
@@ -28,7 +28,7 @@ error[E0308]: mismatched types
   --> $DIR/defaults-in-other-trait-items.rs:54:9
    |
 LL |     type Res = isize;
-   |     ----------------- associated type defaults can't be assumed inside the trait defining them
+   |     -------- associated type defaults can't be assumed inside the trait defining them
 LL |
 LL |     fn infer_me_correctly() -> Self::Res {
    |                                --------- expected `<Self as Trait>::Res` because of return type
diff --git a/tests/ui/associated-types/defaults-specialization.stderr b/tests/ui/associated-types/defaults-specialization.stderr
index fd2a1a0c2d1..7d19ac85982 100644
--- a/tests/ui/associated-types/defaults-specialization.stderr
+++ b/tests/ui/associated-types/defaults-specialization.stderr
@@ -31,7 +31,7 @@ error[E0053]: method `make` has an incompatible type for trait
   --> $DIR/defaults-specialization.rs:35:18
    |
 LL |     default type Ty = bool;
-   |     ----------------------- associated type is `default` and may be overridden
+   |     --------------- associated type is `default` and may be overridden
 LL |
 LL |     fn make() -> bool { true }
    |                  ^^^^ expected associated type, found `bool`
@@ -53,7 +53,7 @@ error[E0308]: mismatched types
   --> $DIR/defaults-specialization.rs:10:9
    |
 LL |     type Ty = u8;
-   |     ------------- associated type defaults can't be assumed inside the trait defining them
+   |     ------- associated type defaults can't be assumed inside the trait defining them
 LL |
 LL |     fn make() -> Self::Ty {
    |                  -------- expected `<Self as Tr>::Ty` because of return type
@@ -80,7 +80,7 @@ error[E0308]: mismatched types
   --> $DIR/defaults-specialization.rs:44:29
    |
 LL |     default type Ty = bool;
-   |     ----------------------- associated type is `default` and may be overridden
+   |     --------------- associated type is `default` and may be overridden
 LL |
 LL |     fn make() -> Self::Ty { true }
    |                  --------   ^^^^ expected associated type, found `bool`
diff --git a/tests/ui/associated-types/issue-26681.stderr b/tests/ui/associated-types/issue-26681.stderr
index b64bcee07f0..5fb1a4ef3f5 100644
--- a/tests/ui/associated-types/issue-26681.stderr
+++ b/tests/ui/associated-types/issue-26681.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/issue-26681.rs:17:39
    |
 LL |     type Fv: Foo = u8;
-   |     ------------------ associated type defaults can't be assumed inside the trait defining them
+   |     ------------ associated type defaults can't be assumed inside the trait defining them
 LL |     const C: <Self::Fv as Foo>::Bar = 6665;
    |                                       ^^^^ expected associated type, found integer
    |
diff --git a/tests/ui/generics/export-name-on-generics.stderr b/tests/ui/generics/export-name-on-generics.stderr
index 7bc7b8ca559..e08b2b1c8f3 100644
--- a/tests/ui/generics/export-name-on-generics.stderr
+++ b/tests/ui/generics/export-name-on-generics.stderr
@@ -4,7 +4,7 @@ error: functions generic over types or consts must be mangled
 LL | #[export_name = "foo"]
    | ---------------------- help: remove this attribute
 LL | pub fn foo<T>() {}
-   | ^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/export-name-on-generics.rs:3:9
@@ -18,7 +18,7 @@ error: functions generic over types or consts must be mangled
 LL | #[export_name = "bar"]
    | ---------------------- help: remove this attribute
 LL | pub extern "C" fn bar<T>() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:21:5
@@ -26,7 +26,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo"]
    |     ---------------------- help: remove this attribute
 LL |     pub fn foo<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:24:5
@@ -34,7 +34,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "bar"]
    |     ---------------------- help: remove this attribute
 LL |     pub extern "C" fn bar<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:42:5
@@ -42,7 +42,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo"]
    |     ---------------------- help: remove this attribute
 LL |     fn foo<T>() {}
-   |     ^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:45:5
@@ -50,7 +50,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "bar"]
    |     ---------------------- help: remove this attribute
 LL |     extern "C" fn bar<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:64:5
@@ -58,7 +58,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo"]
    |     ---------------------- help: remove this attribute
 LL |     fn foo() {}
-   |     ^^^^^^^^^^^
+   |     ^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:67:5
@@ -66,7 +66,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo2"]
    |     ----------------------- help: remove this attribute
 LL |     fn foo2<U>() {}
-   |     ^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:70:5
@@ -74,7 +74,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "baz"]
    |     ---------------------- help: remove this attribute
 LL |     extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:73:5
@@ -82,7 +82,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "baz"]
    |     ---------------------- help: remove this attribute
 LL |     fn baz(x: &i32) -> &i32 { x }
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:76:5
@@ -90,7 +90,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "qux"]
    |     ---------------------- help: remove this attribute
 LL |     fn qux<'a>(x: &'a i32) -> &i32 { x }
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:83:5
@@ -98,7 +98,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo"]
    |     ---------------------- help: remove this attribute
 LL |     pub fn foo() {}
-   |     ^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:86:5
@@ -106,7 +106,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "bar"]
    |     ---------------------- help: remove this attribute
 LL |     pub extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:89:5
@@ -114,7 +114,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "baz"]
    |     ---------------------- help: remove this attribute
 LL |     pub fn baz<U>() {}
-   |     ^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:105:5
@@ -122,7 +122,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "foo"]
    |     ---------------------- help: remove this attribute
 LL |     fn foo() {}
-   |     ^^^^^^^^^^^
+   |     ^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:108:5
@@ -130,7 +130,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "bar"]
    |     ---------------------- help: remove this attribute
 LL |     extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/export-name-on-generics.rs:111:5
@@ -138,7 +138,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[export_name = "baz"]
    |     ---------------------- help: remove this attribute
 LL |     fn baz<U>() {}
-   |     ^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^
 
 error: aborting due to 17 previous errors
 
diff --git a/tests/ui/generics/generic-no-mangle.stderr b/tests/ui/generics/generic-no-mangle.stderr
index adfddbe9ca7..39fbe4dd76d 100644
--- a/tests/ui/generics/generic-no-mangle.stderr
+++ b/tests/ui/generics/generic-no-mangle.stderr
@@ -4,7 +4,7 @@ error: functions generic over types or consts must be mangled
 LL | #[no_mangle]
    | ------------ help: remove this attribute
 LL | pub fn foo<T>() {}
-   | ^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/generic-no-mangle.rs:3:9
@@ -18,7 +18,7 @@ error: functions generic over types or consts must be mangled
 LL | #[no_mangle]
    | ------------ help: remove this attribute
 LL | pub extern "C" fn bar<T>() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:21:5
@@ -26,7 +26,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     pub fn foo<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:24:5
@@ -34,7 +34,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     pub extern "C" fn bar<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:42:5
@@ -42,7 +42,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn foo<T>() {}
-   |     ^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:45:5
@@ -50,7 +50,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     extern "C" fn bar<T>() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:64:5
@@ -58,7 +58,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn foo() {}
-   |     ^^^^^^^^^^^
+   |     ^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:67:5
@@ -66,7 +66,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn foo2<U>() {}
-   |     ^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:70:5
@@ -74,7 +74,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:73:5
@@ -82,7 +82,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn baz(x: &i32) -> &i32 { x }
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:76:5
@@ -90,7 +90,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn qux<'a>(x: &'a i32) -> &i32 { x }
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:83:5
@@ -98,7 +98,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     pub fn foo() {}
-   |     ^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:86:5
@@ -106,7 +106,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     pub extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:89:5
@@ -114,7 +114,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     pub fn baz<U>() {}
-   |     ^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:105:5
@@ -122,7 +122,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn foo() {}
-   |     ^^^^^^^^^^^
+   |     ^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:108:5
@@ -130,7 +130,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     extern "C" fn bar() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^
 
 error: functions generic over types or consts must be mangled
   --> $DIR/generic-no-mangle.rs:111:5
@@ -138,7 +138,7 @@ error: functions generic over types or consts must be mangled
 LL |     #[no_mangle]
    |     ------------ help: remove this attribute
 LL |     fn baz<U>() {}
-   |     ^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^
 
 error: aborting due to 17 previous errors
 
diff --git a/tests/ui/lint/suggestions.stderr b/tests/ui/lint/suggestions.stderr
index a4871ead74b..c35e92f5980 100644
--- a/tests/ui/lint/suggestions.stderr
+++ b/tests/ui/lint/suggestions.stderr
@@ -65,7 +65,7 @@ LL | #[no_mangle]
    | ------------ help: remove this attribute
 LL |
 LL | pub fn defiant<T>(_t: T) {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(no_mangle_generic_items)]` on by default
 
@@ -89,7 +89,7 @@ warning: functions generic over types or consts must be mangled
   --> $DIR/suggestions.rs:26:18
    |
 LL |     #[no_mangle] pub fn val_jean<T>() {}
-   |     ------------ ^^^^^^^^^^^^^^^^^^^^^^^
+   |     ------------ ^^^^^^^^^^^^^^^^^^^^
    |     |
    |     help: remove this attribute
 
@@ -105,7 +105,7 @@ warning: functions generic over types or consts must be mangled
   --> $DIR/suggestions.rs:35:18
    |
 LL |     #[no_mangle] pub(crate) fn crossfield<T>() {}
-   |     ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     ------------ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |     |
    |     help: remove this attribute
 
diff --git a/tests/ui/specialization/specialization-default-types.current.stderr b/tests/ui/specialization/specialization-default-types.current.stderr
index 67477f9a6d5..09689681740 100644
--- a/tests/ui/specialization/specialization-default-types.current.stderr
+++ b/tests/ui/specialization/specialization-default-types.current.stderr
@@ -12,7 +12,7 @@ error[E0308]: mismatched types
   --> $DIR/specialization-default-types.rs:19:9
    |
 LL |     default type Output = Box<T>;
-   |     ----------------------------- associated type is `default` and may be overridden
+   |     ------------------- associated type is `default` and may be overridden
 LL |     default fn generate(self) -> Self::Output {
    |                                  ------------ expected `<T as Example>::Output` because of return type
 LL |         Box::new(self)
diff --git a/tests/ui/specialization/specialization-default-types.next.stderr b/tests/ui/specialization/specialization-default-types.next.stderr
index 4f7c4765446..1535c6473bd 100644
--- a/tests/ui/specialization/specialization-default-types.next.stderr
+++ b/tests/ui/specialization/specialization-default-types.next.stderr
@@ -12,7 +12,7 @@ error[E0308]: mismatched types
   --> $DIR/specialization-default-types.rs:19:9
    |
 LL |     default type Output = Box<T>;
-   |     ----------------------------- associated type is `default` and may be overridden
+   |     ------------------- associated type is `default` and may be overridden
 LL |     default fn generate(self) -> Self::Output {
    |                                  ------------ expected `<T as Example>::Output` because of return type
 LL |         Box::new(self)
diff --git a/tests/ui/stats/input-stats.stderr b/tests/ui/stats/input-stats.stderr
index 7c92044ef5f..7b3acdeb207 100644
--- a/tests/ui/stats/input-stats.stderr
+++ b/tests/ui/stats/input-stats.stderr
@@ -112,12 +112,12 @@ hir-stats Param                     64 (NN.N%)             2            32
 hir-stats GenericArg                64 (NN.N%)             4            16
 hir-stats - Type                      16 (NN.N%)             1
 hir-stats - Lifetime                  48 (NN.N%)             3
-hir-stats TraitItemRef              56 (NN.N%)             2            28
-hir-stats ImplItemRef               56 (NN.N%)             2            28
+hir-stats TraitItemRef              48 (NN.N%)             2            24
+hir-stats ImplItemRef               48 (NN.N%)             2            24
 hir-stats ExprField                 40 (NN.N%)             1            40
 hir-stats Mod                       32 (NN.N%)             1            32
 hir-stats Lifetime                  28 (NN.N%)             1            28
 hir-stats ForeignItemRef            24 (NN.N%)             1            24
 hir-stats ----------------------------------------------------------------
-hir-stats Total                  8_700                   173
+hir-stats Total                  8_684                   173
 hir-stats ================================================================