Merging debian version 1.65.0+dfsg1-2.

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

12 files changed, 608 insertions, 862 deletions

diff --git a/compiler/rustc_resolve/src/access_levels.rs b/compiler/rustc_resolve/src/access_levels.rs
index 3fba923d9..0a3add2e0 100644
--- a/compiler/rustc_resolve/src/access_levels.rs
+++ b/compiler/rustc_resolve/src/access_levels.rs
@@ -1,25 +1,21 @@
+use crate::imports::ImportKind;
+use crate::NameBinding;
+use crate::NameBindingKind;
+use crate::Resolver;
 use rustc_ast::ast;
 use rustc_ast::visit;
 use rustc_ast::visit::Visitor;
 use rustc_ast::Crate;
 use rustc_ast::EnumDef;
-use rustc_ast::ForeignMod;
 use rustc_ast::NodeId;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_middle::middle::privacy::AccessLevel;
-use rustc_middle::ty::Visibility;
+use rustc_middle::ty::DefIdTree;
 use rustc_span::sym;
 
-use crate::imports::ImportKind;
-use crate::BindingKey;
-use crate::NameBinding;
-use crate::NameBindingKind;
-use crate::Resolver;
-
 pub struct AccessLevelsVisitor<'r, 'a> {
     r: &'r mut Resolver<'a>,
-    prev_level: Option<AccessLevel>,
     changed: bool,
 }
 
@@ -28,31 +24,32 @@ impl<'r, 'a> AccessLevelsVisitor<'r, 'a> {
     /// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we
     /// need access to a TyCtxt for that.
     pub fn compute_access_levels<'c>(r: &'r mut Resolver<'a>, krate: &'c Crate) {
-        let mut visitor =
-            AccessLevelsVisitor { r, changed: false, prev_level: Some(AccessLevel::Public) };
+        let mut visitor = AccessLevelsVisitor { r, changed: false };
 
         visitor.set_access_level_def_id(CRATE_DEF_ID, Some(AccessLevel::Public));
-        visitor.set_exports_access_level(CRATE_DEF_ID);
+        visitor.set_bindings_access_level(CRATE_DEF_ID);
 
         while visitor.changed {
             visitor.reset();
             visit::walk_crate(&mut visitor, krate);
         }
 
-        tracing::info!("resolve::access_levels: {:#?}", r.access_levels);
+        info!("resolve::access_levels: {:#?}", r.access_levels);
     }
 
     fn reset(&mut self) {
         self.changed = false;
-        self.prev_level = Some(AccessLevel::Public);
     }
 
-    /// Update the access level of the exports of the given module accordingly. The module access
+    /// Update the access level of the bindings in the given module accordingly. The module access
     /// level has to be Exported or Public.
     /// This will also follow `use` chains (see PrivacyVisitor::set_import_binding_access_level).
-    fn set_exports_access_level(&mut self, module_id: LocalDefId) {
+    fn set_bindings_access_level(&mut self, module_id: LocalDefId) {
         assert!(self.r.module_map.contains_key(&&module_id.to_def_id()));
-
+        let module_level = self.r.access_levels.map.get(&module_id).copied();
+        if !module_level.is_some() {
+            return;
+        }
         // Set the given binding access level to `AccessLevel::Public` and
         // sets the rest of the `use` chain to `AccessLevel::Exported` until
         // we hit the actual exported item.
@@ -72,28 +69,20 @@ impl<'r, 'a> AccessLevelsVisitor<'r, 'a> {
                 }
             };
 
-        let module_level = self.r.access_levels.map.get(&module_id).copied();
-        assert!(module_level >= Some(AccessLevel::Exported));
-
-        if let Some(exports) = self.r.reexport_map.get(&module_id) {
-            let pub_exports = exports
-                .iter()
-                .filter(|ex| ex.vis == Visibility::Public)
-                .cloned()
-                .collect::<Vec<_>>();
-
-            let module = self.r.get_module(module_id.to_def_id()).unwrap();
-            for export in pub_exports.into_iter() {
-                if let Some(export_def_id) = export.res.opt_def_id().and_then(|id| id.as_local()) {
-                    self.set_access_level_def_id(export_def_id, Some(AccessLevel::Exported));
-                }
-
-                if let Some(ns) = export.res.ns() {
-                    let key = BindingKey { ident: export.ident, ns, disambiguator: 0 };
-                    let name_res = self.r.resolution(module, key);
-                    if let Some(binding) = name_res.borrow().binding() {
-                        set_import_binding_access_level(self, binding, module_level)
-                    }
+        let module = self.r.get_module(module_id.to_def_id()).unwrap();
+        let resolutions = self.r.resolutions(module);
+
+        for (.., name_resolution) in resolutions.borrow().iter() {
+            if let Some(binding) = name_resolution.borrow().binding() && binding.vis.is_public() && !binding.is_ambiguity() {
+                let access_level = match binding.is_import() {
+                    true => {
+                        set_import_binding_access_level(self, binding, module_level);
+                        Some(AccessLevel::Exported)
+                    },
+                    false => module_level,
+                };
+                if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
+                    self.set_access_level_def_id(def_id, access_level);
                 }
             }
         }
@@ -127,97 +116,59 @@ impl<'r, 'a> AccessLevelsVisitor<'r, 'a> {
 
 impl<'r, 'ast> Visitor<'ast> for AccessLevelsVisitor<'ast, 'r> {
     fn visit_item(&mut self, item: &'ast ast::Item) {
-        let inherited_item_level = match item.kind {
+        let def_id = self.r.local_def_id(item.id);
+        // Set access level of nested items.
+        // If it's a mod, also make the visitor walk all of its items
+        match item.kind {
             // Resolved in rustc_privacy when types are available
             ast::ItemKind::Impl(..) => return,
 
-            // Only exported `macro_rules!` items are public, but they always are
-            ast::ItemKind::MacroDef(ref macro_def) if macro_def.macro_rules => {
-                let is_macro_export =
-                    item.attrs.iter().any(|attr| attr.has_name(sym::macro_export));
-                if is_macro_export { Some(AccessLevel::Public) } else { None }
-            }
-
-            // Foreign modules inherit level from parents.
-            ast::ItemKind::ForeignMod(..) => self.prev_level,
-
-            // Other `pub` items inherit levels from parents.
-            ast::ItemKind::ExternCrate(..)
-            | ast::ItemKind::Use(..)
-            | ast::ItemKind::Static(..)
-            | ast::ItemKind::Const(..)
-            | ast::ItemKind::Fn(..)
-            | ast::ItemKind::Mod(..)
-            | ast::ItemKind::GlobalAsm(..)
-            | ast::ItemKind::TyAlias(..)
-            | ast::ItemKind::Enum(..)
-            | ast::ItemKind::Struct(..)
-            | ast::ItemKind::Union(..)
-            | ast::ItemKind::Trait(..)
-            | ast::ItemKind::TraitAlias(..)
-            | ast::ItemKind::MacroDef(..) => {
-                if item.vis.kind.is_pub() {
-                    self.prev_level
-                } else {
-                    None
-                }
-            }
-
             // Should be unreachable at this stage
             ast::ItemKind::MacCall(..) => panic!(
                 "ast::ItemKind::MacCall encountered, this should not anymore appear at this stage"
             ),
-        };
 
-        let access_level = self.set_access_level(item.id, inherited_item_level);
+            // Foreign modules inherit level from parents.
+            ast::ItemKind::ForeignMod(..) => {
+                let parent_level =
+                    self.r.access_levels.map.get(&self.r.local_parent(def_id)).copied();
+                self.set_access_level(item.id, parent_level);
+            }
 
-        // Set access level of nested items.
-        // If it's a mod, also make the visitor walk all of its items
-        match item.kind {
-            ast::ItemKind::Mod(..) => {
-                if access_level.is_some() {
-                    self.set_exports_access_level(self.r.local_def_id(item.id));
+            // Only exported `macro_rules!` items are public, but they always are
+            ast::ItemKind::MacroDef(ref macro_def) if macro_def.macro_rules => {
+                if item.attrs.iter().any(|attr| attr.has_name(sym::macro_export)) {
+                    self.set_access_level(item.id, Some(AccessLevel::Public));
                 }
+            }
 
-                let orig_level = std::mem::replace(&mut self.prev_level, access_level);
+            ast::ItemKind::Mod(..) => {
+                self.set_bindings_access_level(def_id);
                 visit::walk_item(self, item);
-                self.prev_level = orig_level;
             }
 
-            ast::ItemKind::ForeignMod(ForeignMod { ref items, .. }) => {
-                for nested in items {
-                    if nested.vis.kind.is_pub() {
-                        self.set_access_level(nested.id, access_level);
-                    }
-                }
-            }
             ast::ItemKind::Enum(EnumDef { ref variants }, _) => {
+                self.set_bindings_access_level(def_id);
                 for variant in variants {
-                    let variant_level = self.set_access_level(variant.id, access_level);
-                    if let Some(ctor_id) = variant.data.ctor_id() {
-                        self.set_access_level(ctor_id, access_level);
-                    }
-
+                    let variant_def_id = self.r.local_def_id(variant.id);
+                    let variant_level = self.r.access_levels.map.get(&variant_def_id).copied();
                     for field in variant.data.fields() {
                         self.set_access_level(field.id, variant_level);
                     }
                 }
             }
-            ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
-                if let Some(ctor_id) = def.ctor_id() {
-                    self.set_access_level(ctor_id, access_level);
-                }
 
+            ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
+                let inherited_level = self.r.access_levels.map.get(&def_id).copied();
                 for field in def.fields() {
                     if field.vis.kind.is_pub() {
-                        self.set_access_level(field.id, access_level);
+                        self.set_access_level(field.id, inherited_level);
                     }
                 }
             }
-            ast::ItemKind::Trait(ref trait_kind) => {
-                for nested in trait_kind.items.iter() {
-                    self.set_access_level(nested.id, access_level);
-                }
+
+            ast::ItemKind::Trait(..) => {
+                self.set_bindings_access_level(def_id);
             }
 
             ast::ItemKind::ExternCrate(..)
@@ -229,9 +180,6 @@ impl<'r, 'ast> Visitor<'ast> for AccessLevelsVisitor<'ast, 'r> {
             | ast::ItemKind::TraitAlias(..)
             | ast::ItemKind::MacroDef(..)
             | ast::ItemKind::Fn(..) => return,
-
-            // Unreachable kinds
-            ast::ItemKind::Impl(..) | ast::ItemKind::MacCall(..) => unreachable!(),
         }
     }
 }
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index e955a1798..81b67b758 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -36,28 +36,29 @@ use rustc_span::Span;
 
 use std::cell::Cell;
 use std::ptr;
-use tracing::debug;
 
 type Res = def::Res<NodeId>;
 
-impl<'a> ToNameBinding<'a> for (Module<'a>, ty::Visibility, Span, LocalExpnId) {
+impl<'a, Id: Into<DefId>> ToNameBinding<'a>
+    for (Module<'a>, ty::Visibility<Id>, Span, LocalExpnId)
+{
     fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
         arenas.alloc_name_binding(NameBinding {
             kind: NameBindingKind::Module(self.0),
             ambiguity: None,
-            vis: self.1,
+            vis: self.1.to_def_id(),
             span: self.2,
             expansion: self.3,
         })
     }
 }
 
-impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, LocalExpnId) {
+impl<'a, Id: Into<DefId>> ToNameBinding<'a> for (Res, ty::Visibility<Id>, Span, LocalExpnId) {
     fn to_name_binding(self, arenas: &'a ResolverArenas<'a>) -> &'a NameBinding<'a> {
         arenas.alloc_name_binding(NameBinding {
             kind: NameBindingKind::Res(self.0, false),
             ambiguity: None,
-            vis: self.1,
+            vis: self.1.to_def_id(),
             span: self.2,
             expansion: self.3,
         })
@@ -71,7 +72,7 @@ impl<'a> ToNameBinding<'a> for (Res, ty::Visibility, Span, LocalExpnId, IsMacroE
         arenas.alloc_name_binding(NameBinding {
             kind: NameBindingKind::Res(self.0, true),
             ambiguity: None,
-            vis: self.1,
+            vis: self.1.to_def_id(),
             span: self.2,
             expansion: self.3,
         })
@@ -261,7 +262,9 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         self.r.visibilities[&def_id.expect_local()]
                     }
                     // Otherwise, the visibility is restricted to the nearest parent `mod` item.
-                    _ => ty::Visibility::Restricted(self.parent_scope.module.nearest_parent_mod()),
+                    _ => ty::Visibility::Restricted(
+                        self.parent_scope.module.nearest_parent_mod().expect_local(),
+                    ),
                 })
             }
             ast::VisibilityKind::Restricted { ref path, id, .. } => {
@@ -312,7 +315,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                             } else {
                                 let vis = ty::Visibility::Restricted(res.def_id());
                                 if self.r.is_accessible_from(vis, parent_scope.module) {
-                                    Ok(vis)
+                                    Ok(vis.expect_local())
                                 } else {
                                     Err(VisResolutionError::AncestorOnly(path.span))
                                 }
@@ -380,7 +383,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             has_attributes: !item.attrs.is_empty(),
             root_span,
             root_id,
-            vis: Cell::new(vis),
+            vis: Cell::new(Some(vis)),
             used: Cell::new(false),
         });
 
@@ -588,7 +591,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             ast::UseTreeKind::Glob => {
                 let kind = ImportKind::Glob {
                     is_prelude: self.r.session.contains_name(&item.attrs, sym::prelude_import),
-                    max_vis: Cell::new(ty::Visibility::Invisible),
+                    max_vis: Cell::new(None),
                 };
                 self.r.visibilities.insert(self.r.local_def_id(id), vis);
                 self.add_import(prefix, kind, use_tree.span, id, item, root_span, item.id, vis);
@@ -650,7 +653,9 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         true,
                         // The whole `use` item
                         item,
-                        ty::Visibility::Invisible,
+                        ty::Visibility::Restricted(
+                            self.parent_scope.module.nearest_parent_mod().expect_local(),
+                        ),
                         root_span,
                     );
                 }
@@ -766,10 +771,10 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 if let Some(ctor_node_id) = vdata.ctor_id() {
                     // If the structure is marked as non_exhaustive then lower the visibility
                     // to within the crate.
-                    let mut ctor_vis = if vis == ty::Visibility::Public
+                    let mut ctor_vis = if vis.is_public()
                         && self.r.session.contains_name(&item.attrs, sym::non_exhaustive)
                     {
-                        ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())
+                        ty::Visibility::Restricted(CRATE_DEF_ID)
                     } else {
                         vis
                     };
@@ -786,7 +791,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         if ctor_vis.is_at_least(field_vis, &*self.r) {
                             ctor_vis = field_vis;
                         }
-                        ret_fields.push(field_vis);
+                        ret_fields.push(field_vis.to_def_id());
                     }
                     let ctor_def_id = self.r.local_def_id(ctor_node_id);
                     let ctor_res = Res::Def(
@@ -796,7 +801,9 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                     self.r.define(parent, ident, ValueNS, (ctor_res, ctor_vis, sp, expansion));
                     self.r.visibilities.insert(ctor_def_id, ctor_vis);
 
-                    self.r.struct_constructors.insert(def_id, (ctor_res, ctor_vis, ret_fields));
+                    self.r
+                        .struct_constructors
+                        .insert(def_id, (ctor_res, ctor_vis.to_def_id(), ret_fields));
                 }
             }
 
@@ -868,8 +875,8 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
         }
         .map(|module| {
             let used = self.process_macro_use_imports(item, module);
-            let binding =
-                (module, ty::Visibility::Public, sp, expansion).to_name_binding(self.r.arenas);
+            let vis = ty::Visibility::<LocalDefId>::Public;
+            let binding = (module, vis, sp, expansion).to_name_binding(self.r.arenas);
             (used, Some(ModuleOrUniformRoot::Module(module)), binding)
         })
         .unwrap_or((true, None, self.r.dummy_binding));
@@ -885,7 +892,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             root_span: item.span,
             span: item.span,
             module_path: Vec::new(),
-            vis: Cell::new(vis),
+            vis: Cell::new(Some(vis)),
             used: Cell::new(used),
         });
         self.r.potentially_unused_imports.push(import);
@@ -965,6 +972,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 | DefKind::TyAlias
                 | DefKind::ForeignTy
                 | DefKind::OpaqueTy
+                | DefKind::ImplTraitPlaceholder
                 | DefKind::TraitAlias
                 | DefKind::AssocTy,
                 _,
@@ -1030,7 +1038,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 self.insert_field_names(def_id, field_names);
             }
             Res::Def(DefKind::AssocFn, def_id) => {
-                if cstore.fn_has_self_parameter_untracked(def_id) {
+                if cstore.fn_has_self_parameter_untracked(def_id, self.r.session) {
                     self.r.has_self.insert(def_id);
                 }
             }
@@ -1118,7 +1126,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 root_span: span,
                 span,
                 module_path: Vec::new(),
-                vis: Cell::new(ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())),
+                vis: Cell::new(Some(ty::Visibility::Restricted(CRATE_DEF_ID))),
                 used: Cell::new(false),
             })
         };
@@ -1264,7 +1272,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             let vis = if is_macro_export {
                 ty::Visibility::Public
             } else {
-                ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())
+                ty::Visibility::Restricted(CRATE_DEF_ID)
             };
             let binding = (res, vis, span, expansion).to_name_binding(self.r.arenas);
             self.r.set_binding_parent_module(binding, parent_scope.module);
@@ -1295,7 +1303,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 }
                 _ => self.resolve_visibility(&item.vis),
             };
-            if vis != ty::Visibility::Public {
+            if !vis.is_public() {
                 self.insert_unused_macro(ident, def_id, item.id, &rule_spans);
             }
             self.r.define(module, ident, MacroNS, (res, vis, span, expansion));
@@ -1508,10 +1516,10 @@ impl<'a, 'b> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b> {
         self.r.visibilities.insert(def_id, vis);
 
         // If the variant is marked as non_exhaustive then lower the visibility to within the crate.
-        let ctor_vis = if vis == ty::Visibility::Public
+        let ctor_vis = if vis.is_public()
             && self.r.session.contains_name(&variant.attrs, sym::non_exhaustive)
         {
-            ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())
+            ty::Visibility::Restricted(CRATE_DEF_ID)
         } else {
             vis
         };
diff --git a/compiler/rustc_resolve/src/check_unused.rs b/compiler/rustc_resolve/src/check_unused.rs
index f2f6f1d89..8b58b32b6 100644
--- a/compiler/rustc_resolve/src/check_unused.rs
+++ b/compiler/rustc_resolve/src/check_unused.rs
@@ -227,7 +227,7 @@ impl Resolver<'_> {
         for import in self.potentially_unused_imports.iter() {
             match import.kind {
                 _ if import.used.get()
-                    || import.vis.get().is_public()
+                    || import.expect_vis().is_public()
                     || import.span.is_dummy() =>
                 {
                     if let ImportKind::MacroUse = import.kind {
diff --git a/compiler/rustc_resolve/src/def_collector.rs b/compiler/rustc_resolve/src/def_collector.rs
index 66641fb2c..3f88f44ff 100644
--- a/compiler/rustc_resolve/src/def_collector.rs
+++ b/compiler/rustc_resolve/src/def_collector.rs
@@ -8,7 +8,6 @@ use rustc_hir::definitions::*;
 use rustc_span::hygiene::LocalExpnId;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
-use tracing::debug;
 
 pub(crate) fn collect_definitions(
     resolver: &mut Resolver<'_>,
@@ -155,7 +154,7 @@ impl<'a, 'b> visit::Visitor<'a> for DefCollector<'a, 'b> {
             }
         }
 
-        visit::walk_fn(self, fn_kind, span);
+        visit::walk_fn(self, fn_kind);
     }
 
     fn visit_use_tree(&mut self, use_tree: &'a UseTree, id: NodeId, _nested: bool) {
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 8839fb1a1..ab71fa0bc 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -25,7 +25,6 @@ use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{BytePos, Span};
-use tracing::debug;
 
 use crate::imports::{Import, ImportKind, ImportResolver};
 use crate::late::{PatternSource, Rib};
@@ -511,7 +510,7 @@ impl<'a> Resolver<'a> {
                 err.span_label(span, "use of generic parameter from outer function");
 
                 let sm = self.session.source_map();
-                match outer_res {
+                let def_id = match outer_res {
                     Res::SelfTy { trait_: maybe_trait_defid, alias_to: maybe_impl_defid } => {
                         if let Some(impl_span) =
                             maybe_impl_defid.and_then(|(def_id, _)| self.opt_span(def_id))
@@ -536,11 +535,13 @@ impl<'a> Resolver<'a> {
                         if let Some(span) = self.opt_span(def_id) {
                             err.span_label(span, "type parameter from outer function");
                         }
+                        def_id
                     }
                     Res::Def(DefKind::ConstParam, def_id) => {
                         if let Some(span) = self.opt_span(def_id) {
                             err.span_label(span, "const parameter from outer function");
                         }
+                        def_id
                     }
                     _ => {
                         bug!(
@@ -548,28 +549,23 @@ impl<'a> Resolver<'a> {
                             DefKind::TyParam or DefKind::ConstParam"
                         );
                     }
-                }
+                };
 
-                if has_generic_params == HasGenericParams::Yes {
+                if let HasGenericParams::Yes(span) = has_generic_params {
                     // Try to retrieve the span of the function signature and generate a new
                     // message with a local type or const parameter.
                     let sugg_msg = "try using a local generic parameter instead";
-                    if let Some((sugg_span, snippet)) = sm.generate_local_type_param_snippet(span) {
-                        // Suggest the modification to the user
-                        err.span_suggestion(
-                            sugg_span,
-                            sugg_msg,
-                            snippet,
-                            Applicability::MachineApplicable,
-                        );
-                    } else if let Some(sp) = sm.generate_fn_name_span(span) {
-                        err.span_label(
-                            sp,
-                            "try adding a local generic parameter in this method instead",
-                        );
+                    let name = self.opt_name(def_id).unwrap_or(sym::T);
+                    let (span, snippet) = if span.is_empty() {
+                        let snippet = format!("<{}>", name);
+                        (span, snippet)
                     } else {
-                        err.help("try using a local generic parameter instead");
-                    }
+                        let span = sm.span_through_char(span, '<').shrink_to_hi();
+                        let snippet = format!("{}, ", name);
+                        (span, snippet)
+                    };
+                    // Suggest the modification to the user
+                    err.span_suggestion(span, sugg_msg, snippet, Applicability::MaybeIncorrect);
                 }
 
                 err
@@ -1175,16 +1171,6 @@ impl<'a> Resolver<'a> {
                 Scope::Module(module, _) => {
                     this.add_module_candidates(module, &mut suggestions, filter_fn);
                 }
-                Scope::RegisteredAttrs => {
-                    let res = Res::NonMacroAttr(NonMacroAttrKind::Registered);
-                    if filter_fn(res) {
-                        suggestions.extend(
-                            this.registered_attrs
-                                .iter()
-                                .map(|ident| TypoSuggestion::typo_from_res(ident.name, res)),
-                        );
-                    }
-                }
                 Scope::MacroUsePrelude => {
                     suggestions.extend(this.macro_use_prelude.iter().filter_map(
                         |(name, binding)| {
@@ -1407,7 +1393,7 @@ impl<'a> Resolver<'a> {
 
         // If only some candidates are accessible, take just them
         if !candidates.iter().all(|v: &ImportSuggestion| !v.accessible) {
-            candidates = candidates.into_iter().filter(|x| x.accessible).collect();
+            candidates.retain(|x| x.accessible)
         }
 
         candidates
@@ -2544,12 +2530,15 @@ fn show_candidates(
                 Applicability::MaybeIncorrect,
             );
             if let [first, .., last] = &path[..] {
-                err.span_suggestion_verbose(
-                    first.ident.span.until(last.ident.span),
-                    &format!("if you import `{}`, refer to it directly", last.ident),
-                    "",
-                    Applicability::Unspecified,
-                );
+                let sp = first.ident.span.until(last.ident.span);
+                if sp.can_be_used_for_suggestions() {
+                    err.span_suggestion_verbose(
+                        sp,
+                        &format!("if you import `{}`, refer to it directly", last.ident),
+                        "",
+                        Applicability::Unspecified,
+                    );
+                }
             }
         } else {
             msg.push(':');
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index 6e6782881..2287aa1eb 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -6,6 +6,7 @@ use rustc_middle::bug;
 use rustc_middle::ty;
 use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK;
 use rustc_session::lint::BuiltinLintDiagnostics;
+use rustc_span::def_id::LocalDefId;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext};
 use rustc_span::symbol::{kw, Ident};
@@ -13,7 +14,9 @@ use rustc_span::{Span, DUMMY_SP};
 
 use std::ptr;
 
-use crate::late::{ConstantItemKind, HasGenericParams, PathSource, Rib, RibKind};
+use crate::late::{
+    ConstantHasGenerics, ConstantItemKind, HasGenericParams, PathSource, Rib, RibKind,
+};
 use crate::macros::{sub_namespace_match, MacroRulesScope};
 use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, Determinacy, Finalize};
 use crate::{ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot};
@@ -24,6 +27,8 @@ use Determinacy::*;
 use Namespace::*;
 use RibKind::*;
 
+type Visibility = ty::Visibility<LocalDefId>;
+
 impl<'a> Resolver<'a> {
     /// A generic scope visitor.
     /// Visits scopes in order to resolve some identifier in them or perform other actions.
@@ -125,7 +130,6 @@ impl<'a> Resolver<'a> {
                 }
                 Scope::CrateRoot => true,
                 Scope::Module(..) => true,
-                Scope::RegisteredAttrs => use_prelude,
                 Scope::MacroUsePrelude => use_prelude || rust_2015,
                 Scope::BuiltinAttrs => true,
                 Scope::ExternPrelude => use_prelude || is_absolute_path,
@@ -185,12 +189,11 @@ impl<'a> Resolver<'a> {
                             match ns {
                                 TypeNS => Scope::ExternPrelude,
                                 ValueNS => Scope::StdLibPrelude,
-                                MacroNS => Scope::RegisteredAttrs,
+                                MacroNS => Scope::MacroUsePrelude,
                             }
                         }
                     }
                 }
-                Scope::RegisteredAttrs => Scope::MacroUsePrelude,
                 Scope::MacroUsePrelude => Scope::StdLibPrelude,
                 Scope::BuiltinAttrs => break, // nowhere else to search
                 Scope::ExternPrelude if is_absolute_path => break,
@@ -273,7 +276,7 @@ impl<'a> Resolver<'a> {
     ///
     /// Invariant: This must only be called during main resolution, not during
     /// import resolution.
-    #[tracing::instrument(level = "debug", skip(self, ribs))]
+    #[instrument(level = "debug", skip(self, ribs))]
     pub(crate) fn resolve_ident_in_lexical_scope(
         &mut self,
         mut ident: Ident,
@@ -367,7 +370,7 @@ impl<'a> Resolver<'a> {
     /// expansion and import resolution (perhaps they can be merged in the future).
     /// The function is used for resolving initial segments of macro paths (e.g., `foo` in
     /// `foo::bar!(); or `foo!();`) and also for import paths on 2018 edition.
-    #[tracing::instrument(level = "debug", skip(self, scope_set))]
+    #[instrument(level = "debug", skip(self, scope_set))]
     pub(crate) fn early_resolve_ident_in_lexical_scope(
         &mut self,
         orig_ident: Ident,
@@ -424,8 +427,7 @@ impl<'a> Resolver<'a> {
                 let ident = Ident::new(orig_ident.name, orig_ident.span.with_ctxt(ctxt));
                 let ok = |res, span, arenas| {
                     Ok((
-                        (res, ty::Visibility::Public, span, LocalExpnId::ROOT)
-                            .to_name_binding(arenas),
+                        (res, Visibility::Public, span, LocalExpnId::ROOT).to_name_binding(arenas),
                         Flags::empty(),
                     ))
                 };
@@ -438,7 +440,7 @@ impl<'a> Resolver<'a> {
                         {
                             let binding = (
                                 Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper),
-                                ty::Visibility::Public,
+                                Visibility::Public,
                                 attr.span,
                                 expn_id,
                             )
@@ -554,14 +556,6 @@ impl<'a> Resolver<'a> {
                             Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
                         }
                     }
-                    Scope::RegisteredAttrs => match this.registered_attrs.get(&ident).cloned() {
-                        Some(ident) => ok(
-                            Res::NonMacroAttr(NonMacroAttrKind::Registered),
-                            ident.span,
-                            this.arenas,
-                        ),
-                        None => Err(Determinacy::Determined),
-                    },
                     Scope::MacroUsePrelude => {
                         match this.macro_use_prelude.get(&ident.name).cloned() {
                             Some(binding) => Ok((binding, Flags::MISC_FROM_PRELUDE)),
@@ -716,7 +710,7 @@ impl<'a> Resolver<'a> {
         Err(Determinacy::determined(determinacy == Determinacy::Determined || force))
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     pub(crate) fn maybe_resolve_ident_in_module(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -728,7 +722,7 @@ impl<'a> Resolver<'a> {
             .map_err(|(determinacy, _)| determinacy)
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     pub(crate) fn resolve_ident_in_module(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -742,7 +736,7 @@ impl<'a> Resolver<'a> {
             .map_err(|(determinacy, _)| determinacy)
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_ident_in_module_ext(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -780,7 +774,7 @@ impl<'a> Resolver<'a> {
         )
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_ident_in_module_unadjusted(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -804,7 +798,7 @@ impl<'a> Resolver<'a> {
 
     /// Attempts to resolve `ident` in namespaces `ns` of `module`.
     /// Invariant: if `finalize` is `Some`, expansion and import resolution must be complete.
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_ident_in_module_unadjusted_ext(
         &mut self,
         module: ModuleOrUniformRoot<'a>,
@@ -849,9 +843,8 @@ impl<'a> Resolver<'a> {
                 if ns == TypeNS {
                     if ident.name == kw::Crate || ident.name == kw::DollarCrate {
                         let module = self.resolve_crate_root(ident);
-                        let binding =
-                            (module, ty::Visibility::Public, module.span, LocalExpnId::ROOT)
-                                .to_name_binding(self.arenas);
+                        let binding = (module, Visibility::Public, module.span, LocalExpnId::ROOT)
+                            .to_name_binding(self.arenas);
                         return Ok(binding);
                     } else if ident.name == kw::Super || ident.name == kw::SelfLower {
                         // FIXME: Implement these with renaming requirements so that e.g.
@@ -951,7 +944,10 @@ impl<'a> Resolver<'a> {
         // Check if one of single imports can still define the name,
         // if it can then our result is not determined and can be invalidated.
         for single_import in &resolution.single_imports {
-            if !self.is_accessible_from(single_import.vis.get(), parent_scope.module) {
+            let Some(import_vis) = single_import.vis.get() else {
+                continue;
+            };
+            if !self.is_accessible_from(import_vis, parent_scope.module) {
                 continue;
             }
             let Some(module) = single_import.imported_module.get() else {
@@ -1016,7 +1012,10 @@ impl<'a> Resolver<'a> {
         // Check if one of glob imports can still define the name,
         // if it can then our "no resolution" result is not determined and can be invalidated.
         for glob_import in module.globs.borrow().iter() {
-            if !self.is_accessible_from(glob_import.vis.get(), parent_scope.module) {
+            let Some(import_vis) = glob_import.vis.get() else {
+                continue;
+            };
+            if !self.is_accessible_from(import_vis, parent_scope.module) {
                 continue;
             }
             let module = match glob_import.imported_module.get() {
@@ -1061,7 +1060,7 @@ impl<'a> Resolver<'a> {
     }
 
     /// Validate a local resolution (from ribs).
-    #[tracing::instrument(level = "debug", skip(self, all_ribs))]
+    #[instrument(level = "debug", skip(self, all_ribs))]
     fn validate_res_from_ribs(
         &mut self,
         rib_index: usize,
@@ -1103,7 +1102,7 @@ impl<'a> Resolver<'a> {
                         | ForwardGenericParamBanRibKind => {
                             // Nothing to do. Continue.
                         }
-                        ItemRibKind(_) | FnItemRibKind | AssocItemRibKind => {
+                        ItemRibKind(_) | AssocItemRibKind => {
                             // This was an attempt to access an upvar inside a
                             // named function item. This is not allowed, so we
                             // report an error.
@@ -1168,10 +1167,10 @@ impl<'a> Resolver<'a> {
                     let has_generic_params: HasGenericParams = match rib.kind {
                         NormalRibKind
                         | ClosureOrAsyncRibKind
-                        | AssocItemRibKind
                         | ModuleRibKind(..)
                         | MacroDefinition(..)
                         | InlineAsmSymRibKind
+                        | AssocItemRibKind
                         | ForwardGenericParamBanRibKind => {
                             // Nothing to do. Continue.
                             continue;
@@ -1180,7 +1179,9 @@ impl<'a> Resolver<'a> {
                         ConstantItemRibKind(trivial, _) => {
                             let features = self.session.features_untracked();
                             // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
-                            if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) {
+                            if !(trivial == ConstantHasGenerics::Yes
+                                || features.generic_const_exprs)
+                            {
                                 // HACK(min_const_generics): If we encounter `Self` in an anonymous constant
                                 // we can't easily tell if it's generic at this stage, so we instead remember
                                 // this and then enforce the self type to be concrete later on.
@@ -1207,7 +1208,6 @@ impl<'a> Resolver<'a> {
 
                         // This was an attempt to use a type parameter outside its scope.
                         ItemRibKind(has_generic_params) => has_generic_params,
-                        FnItemRibKind => HasGenericParams::Yes,
                         ConstParamTyRibKind => {
                             if let Some(span) = finalize {
                                 self.report_error(
@@ -1232,28 +1232,22 @@ impl<'a> Resolver<'a> {
                 }
             }
             Res::Def(DefKind::ConstParam, _) => {
-                let mut ribs = ribs.iter().peekable();
-                if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() {
-                    // When declaring const parameters inside function signatures, the first rib
-                    // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it
-                    // (spuriously) conflicting with the const param.
-                    ribs.next();
-                }
-
                 for rib in ribs {
                     let has_generic_params = match rib.kind {
                         NormalRibKind
                         | ClosureOrAsyncRibKind
-                        | AssocItemRibKind
                         | ModuleRibKind(..)
                         | MacroDefinition(..)
                         | InlineAsmSymRibKind
+                        | AssocItemRibKind
                         | ForwardGenericParamBanRibKind => continue,
 
                         ConstantItemRibKind(trivial, _) => {
                             let features = self.session.features_untracked();
                             // HACK(min_const_generics): We currently only allow `N` or `{ N }`.
-                            if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) {
+                            if !(trivial == ConstantHasGenerics::Yes
+                                || features.generic_const_exprs)
+                            {
                                 if let Some(span) = finalize {
                                     self.report_error(
                                         span,
@@ -1272,7 +1266,6 @@ impl<'a> Resolver<'a> {
                         }
 
                         ItemRibKind(has_generic_params) => has_generic_params,
-                        FnItemRibKind => HasGenericParams::Yes,
                         ConstParamTyRibKind => {
                             if let Some(span) = finalize {
                                 self.report_error(
@@ -1302,7 +1295,7 @@ impl<'a> Resolver<'a> {
         res
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     pub(crate) fn maybe_resolve_path(
         &mut self,
         path: &[Segment],
@@ -1312,7 +1305,7 @@ impl<'a> Resolver<'a> {
         self.resolve_path_with_ribs(path, opt_ns, parent_scope, None, None, None)
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     pub(crate) fn resolve_path(
         &mut self,
         path: &[Segment],
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index b89273990..c133c272b 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -23,15 +23,13 @@ use rustc_span::lev_distance::find_best_match_for_name;
 use rustc_span::symbol::{kw, Ident, Symbol};
 use rustc_span::Span;
 
-use tracing::*;
-
 use std::cell::Cell;
 use std::{mem, ptr};
 
 type Res = def::Res<NodeId>;
 
 /// Contains data for specific kinds of imports.
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub enum ImportKind<'a> {
     Single {
         /// `source` in `use prefix::source as target`.
@@ -52,8 +50,8 @@ pub enum ImportKind<'a> {
     },
     Glob {
         is_prelude: bool,
-        max_vis: Cell<ty::Visibility>, // The visibility of the greatest re-export.
-                                       // n.b. `max_vis` is only used in `finalize_import` to check for re-export errors.
+        max_vis: Cell<Option<ty::Visibility>>, // The visibility of the greatest re-export.
+                                               // n.b. `max_vis` is only used in `finalize_import` to check for re-export errors.
     },
     ExternCrate {
         source: Option<Symbol>,
@@ -62,6 +60,44 @@ pub enum ImportKind<'a> {
     MacroUse,
 }
 
+/// Manually implement `Debug` for `ImportKind` because the `source/target_bindings`
+/// contain `Cell`s which can introduce infinite loops while printing.
+impl<'a> std::fmt::Debug for ImportKind<'a> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use ImportKind::*;
+        match self {
+            Single {
+                ref source,
+                ref target,
+                ref type_ns_only,
+                ref nested,
+                ref additional_ids,
+                // Ignore the following to avoid an infinite loop while printing.
+                source_bindings: _,
+                target_bindings: _,
+            } => f
+                .debug_struct("Single")
+                .field("source", source)
+                .field("target", target)
+                .field("type_ns_only", type_ns_only)
+                .field("nested", nested)
+                .field("additional_ids", additional_ids)
+                .finish_non_exhaustive(),
+            Glob { ref is_prelude, ref max_vis } => f
+                .debug_struct("Glob")
+                .field("is_prelude", is_prelude)
+                .field("max_vis", max_vis)
+                .finish(),
+            ExternCrate { ref source, ref target } => f
+                .debug_struct("ExternCrate")
+                .field("source", source)
+                .field("target", target)
+                .finish(),
+            MacroUse => f.debug_struct("MacroUse").finish(),
+        }
+    }
+}
+
 /// One import.
 #[derive(Debug, Clone)]
 pub(crate) struct Import<'a> {
@@ -106,7 +142,7 @@ pub(crate) struct Import<'a> {
     pub module_path: Vec<Segment>,
     /// The resolution of `module_path`.
     pub imported_module: Cell<Option<ModuleOrUniformRoot<'a>>>,
-    pub vis: Cell<ty::Visibility>,
+    pub vis: Cell<Option<ty::Visibility>>,
     pub used: Cell<bool>,
 }
 
@@ -121,6 +157,10 @@ impl<'a> Import<'a> {
             _ => false,
         }
     }
+
+    pub(crate) fn expect_vis(&self) -> ty::Visibility {
+        self.vis.get().expect("encountered cleared import visibility")
+    }
 }
 
 /// Records information about the resolution of a name in a namespace of a module.
@@ -161,7 +201,7 @@ fn pub_use_of_private_extern_crate_hack(import: &Import<'_>, binding: &NameBindi
                 import: Import { kind: ImportKind::ExternCrate { .. }, .. },
                 ..
             },
-        ) => import.vis.get().is_public(),
+        ) => import.expect_vis().is_public(),
         _ => false,
     }
 }
@@ -174,17 +214,20 @@ impl<'a> Resolver<'a> {
         binding: &'a NameBinding<'a>,
         import: &'a Import<'a>,
     ) -> &'a NameBinding<'a> {
-        let vis = if binding.vis.is_at_least(import.vis.get(), self)
+        let import_vis = import.expect_vis().to_def_id();
+        let vis = if binding.vis.is_at_least(import_vis, self)
             || pub_use_of_private_extern_crate_hack(import, binding)
         {
-            import.vis.get()
+            import_vis
         } else {
             binding.vis
         };
 
         if let ImportKind::Glob { ref max_vis, .. } = import.kind {
-            if vis == import.vis.get() || vis.is_at_least(max_vis.get(), self) {
-                max_vis.set(vis)
+            if vis == import_vis
+                || max_vis.get().map_or(true, |max_vis| vis.is_at_least(max_vis, self))
+            {
+                max_vis.set(Some(vis.expect_local()))
             }
         }
 
@@ -498,7 +541,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
         } else {
             // For better failure detection, pretend that the import will
             // not define any names while resolving its module path.
-            let orig_vis = import.vis.replace(ty::Visibility::Invisible);
+            let orig_vis = import.vis.take();
             let path_res =
                 self.r.maybe_resolve_path(&import.module_path, None, &import.parent_scope);
             import.vis.set(orig_vis);
@@ -533,7 +576,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                 if let Err(Undetermined) = source_bindings[ns].get() {
                     // For better failure detection, pretend that the import will
                     // not define any names while resolving its module path.
-                    let orig_vis = import.vis.replace(ty::Visibility::Invisible);
+                    let orig_vis = import.vis.take();
                     let binding = this.resolve_ident_in_module(
                         module,
                         source,
@@ -582,7 +625,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
     /// Optionally returns an unresolved import error. This error is buffered and used to
     /// consolidate multiple unresolved import errors into a single diagnostic.
     fn finalize_import(&mut self, import: &'b Import<'b>) -> Option<UnresolvedImportError> {
-        let orig_vis = import.vis.replace(ty::Visibility::Invisible);
+        let orig_vis = import.vis.take();
         let ignore_binding = match &import.kind {
             ImportKind::Single { target_bindings, .. } => target_bindings[TypeNS].get(),
             _ => None,
@@ -689,9 +732,9 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
                         });
                     }
                 }
-                if !is_prelude &&
-                   max_vis.get() != ty::Visibility::Invisible && // Allow empty globs.
-                   !max_vis.get().is_at_least(import.vis.get(), &*self.r)
+                if !is_prelude
+                    && let Some(max_vis) = max_vis.get()
+                    && !max_vis.is_at_least(import.expect_vis(), &*self.r)
                 {
                     let msg = "glob import doesn't reexport anything because no candidate is public enough";
                     self.r.lint_buffer.buffer_lint(UNUSED_IMPORTS, import.id, import.span, msg);
@@ -704,7 +747,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
         let mut all_ns_err = true;
         self.r.per_ns(|this, ns| {
             if !type_ns_only || ns == TypeNS {
-                let orig_vis = import.vis.replace(ty::Visibility::Invisible);
+                let orig_vis = import.vis.take();
                 let binding = this.resolve_ident_in_module(
                     module,
                     ident,
@@ -868,8 +911,7 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
         let mut crate_private_reexport = false;
         self.r.per_ns(|this, ns| {
             if let Ok(binding) = source_bindings[ns].get() {
-                let vis = import.vis.get();
-                if !binding.vis.is_at_least(vis, &*this) {
+                if !binding.vis.is_at_least(import.expect_vis(), &*this) {
                     reexport_error = Some((ns, binding));
                     if let ty::Visibility::Restricted(binding_def_id) = binding.vis {
                         if binding_def_id.is_top_level_module() {
@@ -1091,24 +1133,15 @@ impl<'a, 'b> ImportResolver<'a, 'b> {
         if let Some(def_id) = module.opt_def_id() {
             let mut reexports = Vec::new();
 
-            module.for_each_child(self.r, |_, ident, _, binding| {
-                // FIXME: Consider changing the binding inserted by `#[macro_export] macro_rules`
-                // into the crate root to actual `NameBindingKind::Import`.
-                if binding.is_import()
-                    || matches!(binding.kind, NameBindingKind::Res(_, _is_macro_export @ true))
-                {
-                    let res = binding.res().expect_non_local();
-                    // Ambiguous imports are treated as errors at this point and are
-                    // not exposed to other crates (see #36837 for more details).
-                    if res != def::Res::Err && !binding.is_ambiguity() {
-                        reexports.push(ModChild {
-                            ident,
-                            res,
-                            vis: binding.vis,
-                            span: binding.span,
-                            macro_rules: false,
-                        });
-                    }
+            module.for_each_child(self.r, |this, ident, _, binding| {
+                if let Some(res) = this.is_reexport(binding) {
+                    reexports.push(ModChild {
+                        ident,
+                        res,
+                        vis: binding.vis,
+                        span: binding.span,
+                        macro_rules: false,
+                    });
                 }
             });
 
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index dea3eaecd..d8d82e125 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -20,7 +20,7 @@ use rustc_errors::DiagnosticId;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, PartialRes, PerNS};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
-use rustc_hir::{PrimTy, TraitCandidate};
+use rustc_hir::{BindingAnnotation, PrimTy, TraitCandidate};
 use rustc_middle::middle::resolve_lifetime::Set1;
 use rustc_middle::ty::DefIdTree;
 use rustc_middle::{bug, span_bug};
@@ -30,9 +30,9 @@ use rustc_span::{BytePos, Span};
 use smallvec::{smallvec, SmallVec};
 
 use rustc_span::source_map::{respan, Spanned};
+use std::assert_matches::debug_assert_matches;
 use std::collections::{hash_map::Entry, BTreeSet};
 use std::mem::{replace, take};
-use tracing::debug;
 
 mod diagnostics;
 pub(crate) mod lifetimes;
@@ -51,7 +51,7 @@ use diagnostics::{
 #[derive(Copy, Clone, Debug)]
 struct BindingInfo {
     span: Span,
-    binding_mode: BindingMode,
+    annotation: BindingAnnotation,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
@@ -91,13 +91,20 @@ enum PatBoundCtx {
 }
 
 /// Does this the item (from the item rib scope) allow generic parameters?
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug)]
 pub(crate) enum HasGenericParams {
+    Yes(Span),
+    No,
+}
+
+/// May this constant have generics?
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub(crate) enum ConstantHasGenerics {
     Yes,
     No,
 }
 
-impl HasGenericParams {
+impl ConstantHasGenerics {
     fn force_yes_if(self, b: bool) -> Self {
         if b { Self::Yes } else { self }
     }
@@ -125,10 +132,6 @@ pub(crate) enum RibKind<'a> {
     /// We passed through a closure. Disallow labels.
     ClosureOrAsyncRibKind,
 
-    /// We passed through a function definition. Disallow upvars.
-    /// Permit only those const parameters that are specified in the function's generics.
-    FnItemRibKind,
-
     /// We passed through an item scope. Disallow upvars.
     ItemRibKind(HasGenericParams),
 
@@ -136,7 +139,7 @@ pub(crate) enum RibKind<'a> {
     ///
     /// The item may reference generic parameters in trivial constant expressions.
     /// All other constants aren't allowed to use generic params at all.
-    ConstantItemRibKind(HasGenericParams, Option<(Ident, ConstantItemKind)>),
+    ConstantItemRibKind(ConstantHasGenerics, Option<(Ident, ConstantItemKind)>),
 
     /// We passed through a module.
     ModuleRibKind(Module<'a>),
@@ -165,7 +168,6 @@ impl RibKind<'_> {
         match self {
             NormalRibKind
             | ClosureOrAsyncRibKind
-            | FnItemRibKind
             | ConstantItemRibKind(..)
             | ModuleRibKind(_)
             | MacroDefinition(_)
@@ -182,7 +184,6 @@ impl RibKind<'_> {
 
             AssocItemRibKind
             | ClosureOrAsyncRibKind
-            | FnItemRibKind
             | ItemRibKind(..)
             | ConstantItemRibKind(..)
             | ModuleRibKind(..)
@@ -557,7 +558,7 @@ struct LateResolutionVisitor<'a, 'b, 'ast> {
     /// They will be used to determine the correct lifetime for the fn return type.
     /// The `LifetimeElisionCandidate` is used for diagnostics, to suggest introducing named
     /// lifetimes.
-    lifetime_elision_candidates: Option<FxIndexMap<LifetimeRes, LifetimeElisionCandidate>>,
+    lifetime_elision_candidates: Option<Vec<(LifetimeRes, LifetimeElisionCandidate)>>,
 
     /// The trait that the current context can refer to.
     current_trait_ref: Option<(Module<'a>, TraitRef)>,
@@ -629,7 +630,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                 // Elided lifetime in reference: we resolve as if there was some lifetime `'_` with
                 // NodeId `ty.id`.
                 // This span will be used in case of elision failure.
-                let span = self.r.session.source_map().next_point(ty.span.shrink_to_lo());
+                let span = self.r.session.source_map().start_point(ty.span);
                 self.resolve_elided_lifetime(ty.id, span);
                 visit::walk_ty(self, ty);
             }
@@ -723,7 +724,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
         self.diagnostic_metadata.current_trait_object = prev;
         self.diagnostic_metadata.current_type_path = prev_ty;
     }
-    fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef, _: &'ast TraitBoundModifier) {
+    fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef) {
         let span = tref.span.shrink_to_lo().to(tref.trait_ref.path.span.shrink_to_lo());
         self.with_generic_param_rib(
             &tref.bound_generic_params,
@@ -751,7 +752,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                 self.with_lifetime_rib(LifetimeRibKind::Item, |this| {
                     this.with_generic_param_rib(
                         &generics.params,
-                        ItemRibKind(HasGenericParams::Yes),
+                        ItemRibKind(HasGenericParams::Yes(generics.span)),
                         LifetimeRibKind::Generics {
                             binder: foreign_item.id,
                             kind: LifetimeBinderKind::Item,
@@ -765,7 +766,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                 self.with_lifetime_rib(LifetimeRibKind::Item, |this| {
                     this.with_generic_param_rib(
                         &generics.params,
-                        ItemRibKind(HasGenericParams::Yes),
+                        ItemRibKind(HasGenericParams::Yes(generics.span)),
                         LifetimeRibKind::Generics {
                             binder: foreign_item.id,
                             kind: LifetimeBinderKind::Function,
@@ -786,7 +787,8 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
         }
     }
     fn visit_fn(&mut self, fn_kind: FnKind<'ast>, sp: Span, fn_id: NodeId) {
-        let rib_kind = match fn_kind {
+        let previous_value = self.diagnostic_metadata.current_function;
+        match fn_kind {
             // Bail if the function is foreign, and thus cannot validly have
             // a body, or if there's no body for some other reason.
             FnKind::Fn(FnCtxt::Foreign, _, sig, _, generics, _)
@@ -809,20 +811,18 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                 );
                 return;
             }
-            FnKind::Fn(FnCtxt::Free, ..) => FnItemRibKind,
-            FnKind::Fn(FnCtxt::Assoc(_), ..) => NormalRibKind,
-            FnKind::Closure(..) => ClosureOrAsyncRibKind,
+            FnKind::Fn(..) => {
+                self.diagnostic_metadata.current_function = Some((fn_kind, sp));
+            }
+            // Do not update `current_function` for closures: it suggests `self` parameters.
+            FnKind::Closure(..) => {}
         };
-        let previous_value = self.diagnostic_metadata.current_function;
-        if matches!(fn_kind, FnKind::Fn(..)) {
-            self.diagnostic_metadata.current_function = Some((fn_kind, sp));
-        }
         debug!("(resolving function) entering function");
 
         // Create a value rib for the function.
-        self.with_rib(ValueNS, rib_kind, |this| {
+        self.with_rib(ValueNS, ClosureOrAsyncRibKind, |this| {
             // Create a label rib for the function.
-            this.with_label_rib(FnItemRibKind, |this| {
+            this.with_label_rib(ClosureOrAsyncRibKind, |this| {
                 match fn_kind {
                     FnKind::Fn(_, _, sig, _, generics, body) => {
                         this.visit_generics(generics);
@@ -852,7 +852,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                         // We include all lifetime parameters, either named or "Fresh".
                         // The order of those parameters does not matter, as long as it is
                         // deterministic.
-                        if let Some(async_node_id) = async_node_id {
+                        if let Some((async_node_id, _)) = async_node_id {
                             let mut extra_lifetime_params = this
                                 .r
                                 .extra_lifetime_params_map
@@ -995,7 +995,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                             // non-trivial constants this is doesn't matter.
                             self.with_constant_rib(
                                 IsRepeatExpr::No,
-                                HasGenericParams::Yes,
+                                ConstantHasGenerics::Yes,
                                 None,
                                 |this| {
                                     this.smart_resolve_path(
@@ -1031,7 +1031,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
         if let Some(ref gen_args) = constraint.gen_args {
             // Forbid anonymous lifetimes in GAT parameters until proper semantics are decided.
             self.with_lifetime_rib(LifetimeRibKind::AnonymousReportError, |this| {
-                this.visit_generic_args(gen_args.span(), gen_args)
+                this.visit_generic_args(gen_args)
             });
         }
         match constraint.kind {
@@ -1045,10 +1045,10 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
         }
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
+    fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) {
         if let Some(ref args) = path_segment.args {
             match &**args {
-                GenericArgs::AngleBracketed(..) => visit::walk_generic_args(self, path_span, args),
+                GenericArgs::AngleBracketed(..) => visit::walk_generic_args(self, args),
                 GenericArgs::Parenthesized(p_args) => {
                     // Probe the lifetime ribs to know how to behave.
                     for rib in self.lifetime_ribs.iter().rev() {
@@ -1079,7 +1079,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
                             // We have nowhere to introduce generics.  Code is malformed,
                             // so use regular lifetime resolution to avoid spurious errors.
                             LifetimeRibKind::Item | LifetimeRibKind::Generics { .. } => {
-                                visit::walk_generic_args(self, path_span, args);
+                                visit::walk_generic_args(self, args);
                                 break;
                             }
                             LifetimeRibKind::AnonymousCreateParameter { .. }
@@ -1390,7 +1390,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         })
     }
 
-    #[tracing::instrument(level = "debug", skip(self, work))]
+    #[instrument(level = "debug", skip(self, work))]
     fn with_lifetime_rib<T>(
         &mut self,
         kind: LifetimeRibKind,
@@ -1404,7 +1404,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         ret
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_lifetime(&mut self, lifetime: &'ast Lifetime, use_ctxt: visit::LifetimeCtxt) {
         let ident = lifetime.ident;
 
@@ -1508,7 +1508,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         self.record_lifetime_res(lifetime.id, LifetimeRes::Error, LifetimeElisionCandidate::Named);
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_anonymous_lifetime(&mut self, lifetime: &Lifetime, elided: bool) {
         debug_assert_eq!(lifetime.ident.name, kw::UnderscoreLifetime);
 
@@ -1573,7 +1573,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         self.report_missing_lifetime_specifiers(vec![missing_lifetime], None);
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_elided_lifetime(&mut self, anchor_id: NodeId, span: Span) {
         let id = self.r.next_node_id();
         let lt = Lifetime { id, ident: Ident::new(kw::UnderscoreLifetime, span) };
@@ -1586,7 +1586,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         self.resolve_anonymous_lifetime(&lt, true);
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn create_fresh_lifetime(&mut self, id: NodeId, ident: Ident, binder: NodeId) -> LifetimeRes {
         debug_assert_eq!(ident.name, kw::UnderscoreLifetime);
         debug!(?ident.span);
@@ -1604,7 +1604,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         res
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_elided_lifetimes_in_path(
         &mut self,
         path_id: NodeId,
@@ -1804,7 +1804,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         }
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn record_lifetime_res(
         &mut self,
         id: NodeId,
@@ -1820,14 +1820,14 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         match res {
             LifetimeRes::Param { .. } | LifetimeRes::Fresh { .. } | LifetimeRes::Static => {
                 if let Some(ref mut candidates) = self.lifetime_elision_candidates {
-                    candidates.insert(res, candidate);
+                    candidates.push((res, candidate));
                 }
             }
             LifetimeRes::Infer | LifetimeRes::Error | LifetimeRes::ElidedAnchor { .. } => {}
         }
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn record_lifetime_param(&mut self, id: NodeId, res: LifetimeRes) {
         if let Some(prev_res) = self.r.lifetimes_res_map.insert(id, res) {
             panic!(
@@ -1838,7 +1838,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
     }
 
     /// Perform resolution of a function signature, accounting for lifetime elision.
-    #[tracing::instrument(level = "debug", skip(self, inputs))]
+    #[instrument(level = "debug", skip(self, inputs))]
     fn resolve_fn_signature(
         &mut self,
         fn_id: NodeId,
@@ -1873,12 +1873,25 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         has_self: bool,
         inputs: impl Iterator<Item = (Option<&'ast Pat>, &'ast Ty)>,
     ) -> Result<LifetimeRes, (Vec<MissingLifetime>, Vec<ElisionFnParameter>)> {
-        let outer_candidates =
-            replace(&mut self.lifetime_elision_candidates, Some(Default::default()));
+        enum Elision {
+            /// We have not found any candidate.
+            None,
+            /// We have a candidate bound to `self`.
+            Self_(LifetimeRes),
+            /// We have a candidate bound to a parameter.
+            Param(LifetimeRes),
+            /// We failed elision.
+            Err,
+        }
+
+        // Save elision state to reinstate it later.
+        let outer_candidates = self.lifetime_elision_candidates.take();
 
-        let mut elision_lifetime = None;
-        let mut lifetime_count = 0;
+        // Result of elision.
+        let mut elision_lifetime = Elision::None;
+        // Information for diagnostics.
         let mut parameter_info = Vec::new();
+        let mut all_candidates = Vec::new();
 
         let mut bindings = smallvec![(PatBoundCtx::Product, Default::default())];
         for (index, (pat, ty)) in inputs.enumerate() {
@@ -1886,12 +1899,17 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             if let Some(pat) = pat {
                 self.resolve_pattern(pat, PatternSource::FnParam, &mut bindings);
             }
+
+            // Record elision candidates only for this parameter.
+            debug_assert_matches!(self.lifetime_elision_candidates, None);
+            self.lifetime_elision_candidates = Some(Default::default());
             self.visit_ty(ty);
+            let local_candidates = self.lifetime_elision_candidates.take();
 
-            if let Some(ref candidates) = self.lifetime_elision_candidates {
-                let new_count = candidates.len();
-                let local_count = new_count - lifetime_count;
-                if local_count != 0 {
+            if let Some(candidates) = local_candidates {
+                let distinct: FxHashSet<_> = candidates.iter().map(|(res, _)| *res).collect();
+                let lifetime_count = distinct.len();
+                if lifetime_count != 0 {
                     parameter_info.push(ElisionFnParameter {
                         index,
                         ident: if let Some(pat) = pat && let PatKind::Ident(_, ident, _) = pat.kind {
@@ -1899,48 +1917,64 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                         } else {
                             None
                         },
-                        lifetime_count: local_count,
+                        lifetime_count,
                         span: ty.span,
                     });
+                    all_candidates.extend(candidates.into_iter().filter_map(|(_, candidate)| {
+                        match candidate {
+                            LifetimeElisionCandidate::Ignore | LifetimeElisionCandidate::Named => {
+                                None
+                            }
+                            LifetimeElisionCandidate::Missing(missing) => Some(missing),
+                        }
+                    }));
+                }
+                let mut distinct_iter = distinct.into_iter();
+                if let Some(res) = distinct_iter.next() {
+                    match elision_lifetime {
+                        // We are the first parameter to bind lifetimes.
+                        Elision::None => {
+                            if distinct_iter.next().is_none() {
+                                // We have a single lifetime => success.
+                                elision_lifetime = Elision::Param(res)
+                            } else {
+                                // We have have multiple lifetimes => error.
+                                elision_lifetime = Elision::Err;
+                            }
+                        }
+                        // We have 2 parameters that bind lifetimes => error.
+                        Elision::Param(_) => elision_lifetime = Elision::Err,
+                        // `self` elision takes precedence over everything else.
+                        Elision::Self_(_) | Elision::Err => {}
+                    }
                 }
-                lifetime_count = new_count;
             }
 
             // Handle `self` specially.
             if index == 0 && has_self {
                 let self_lifetime = self.find_lifetime_for_self(ty);
                 if let Set1::One(lifetime) = self_lifetime {
-                    elision_lifetime = Some(lifetime);
-                    self.lifetime_elision_candidates = None;
+                    // We found `self` elision.
+                    elision_lifetime = Elision::Self_(lifetime);
                 } else {
-                    self.lifetime_elision_candidates = Some(Default::default());
-                    lifetime_count = 0;
+                    // We do not have `self` elision: disregard the `Elision::Param` that we may
+                    // have found.
+                    elision_lifetime = Elision::None;
                 }
             }
             debug!("(resolving function / closure) recorded parameter");
         }
 
-        let all_candidates = replace(&mut self.lifetime_elision_candidates, outer_candidates);
-        debug!(?all_candidates);
+        // Reinstate elision state.
+        debug_assert_matches!(self.lifetime_elision_candidates, None);
+        self.lifetime_elision_candidates = outer_candidates;
 
-        if let Some(res) = elision_lifetime {
+        if let Elision::Param(res) | Elision::Self_(res) = elision_lifetime {
             return Ok(res);
         }
 
-        // We do not have a `self` candidate, look at the full list.
-        let all_candidates = all_candidates.unwrap();
-        if all_candidates.len() == 1 {
-            Ok(*all_candidates.first().unwrap().0)
-        } else {
-            let all_candidates = all_candidates
-                .into_iter()
-                .filter_map(|(_, candidate)| match candidate {
-                    LifetimeElisionCandidate::Ignore | LifetimeElisionCandidate::Named => None,
-                    LifetimeElisionCandidate::Missing(missing) => Some(missing),
-                })
-                .collect();
-            Err((all_candidates, parameter_info))
-        }
+        // We do not have a candidate.
+        Err((all_candidates, parameter_info))
     }
 
     /// List all the lifetimes that appear in the provided type.
@@ -2071,7 +2105,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         self.with_current_self_item(item, |this| {
             this.with_generic_param_rib(
                 &generics.params,
-                ItemRibKind(HasGenericParams::Yes),
+                ItemRibKind(HasGenericParams::Yes(generics.span)),
                 LifetimeRibKind::Generics {
                     binder: item.id,
                     kind: LifetimeBinderKind::Item,
@@ -2141,7 +2175,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             ItemKind::TyAlias(box TyAlias { ref generics, .. }) => {
                 self.with_generic_param_rib(
                     &generics.params,
-                    ItemRibKind(HasGenericParams::Yes),
+                    ItemRibKind(HasGenericParams::Yes(generics.span)),
                     LifetimeRibKind::Generics {
                         binder: item.id,
                         kind: LifetimeBinderKind::Item,
@@ -2154,7 +2188,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
             ItemKind::Fn(box Fn { ref generics, .. }) => {
                 self.with_generic_param_rib(
                     &generics.params,
-                    ItemRibKind(HasGenericParams::Yes),
+                    ItemRibKind(HasGenericParams::Yes(generics.span)),
                     LifetimeRibKind::Generics {
                         binder: item.id,
                         kind: LifetimeBinderKind::Function,
@@ -2186,7 +2220,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 // Create a new rib for the trait-wide type parameters.
                 self.with_generic_param_rib(
                     &generics.params,
-                    ItemRibKind(HasGenericParams::Yes),
+                    ItemRibKind(HasGenericParams::Yes(generics.span)),
                     LifetimeRibKind::Generics {
                         binder: item.id,
                         kind: LifetimeBinderKind::Item,
@@ -2210,7 +2244,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 // Create a new rib for the trait-wide type parameters.
                 self.with_generic_param_rib(
                     &generics.params,
-                    ItemRibKind(HasGenericParams::Yes),
+                    ItemRibKind(HasGenericParams::Yes(generics.span)),
                     LifetimeRibKind::Generics {
                         binder: item.id,
                         kind: LifetimeBinderKind::Item,
@@ -2251,7 +2285,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                             // so it doesn't matter whether this is a trivial constant.
                             this.with_constant_rib(
                                 IsRepeatExpr::No,
-                                HasGenericParams::Yes,
+                                ConstantHasGenerics::Yes,
                                 Some((item.ident, constant_item_kind)),
                                 |this| this.visit_expr(expr),
                             );
@@ -2412,7 +2446,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         // Do not account for the parameters we just bound for function lifetime elision.
         if let Some(ref mut candidates) = self.lifetime_elision_candidates {
             for (_, res) in function_lifetime_rib.bindings.values() {
-                candidates.remove(res);
+                candidates.retain(|(r, _)| r != res);
             }
         }
 
@@ -2450,7 +2484,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
     fn with_constant_rib(
         &mut self,
         is_repeat: IsRepeatExpr,
-        may_use_generics: HasGenericParams,
+        may_use_generics: ConstantHasGenerics,
         item: Option<(Ident, ConstantItemKind)>,
         f: impl FnOnce(&mut Self),
     ) {
@@ -2517,7 +2551,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                             |this| {
                                 this.with_constant_rib(
                                     IsRepeatExpr::No,
-                                    HasGenericParams::Yes,
+                                    ConstantHasGenerics::Yes,
                                     None,
                                     |this| this.visit_expr(expr),
                                 )
@@ -2598,7 +2632,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         // If applicable, create a rib for the type parameters.
         self.with_generic_param_rib(
             &generics.params,
-            ItemRibKind(HasGenericParams::Yes),
+            ItemRibKind(HasGenericParams::Yes(generics.span)),
             LifetimeRibKind::Generics {
                 span: generics.span,
                 binder: item_id,
@@ -2689,7 +2723,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                     self.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Infer), |this| {
                         this.with_constant_rib(
                             IsRepeatExpr::No,
-                            HasGenericParams::Yes,
+                            ConstantHasGenerics::Yes,
                             None,
                             |this| this.visit_expr(expr),
                         )
@@ -2866,10 +2900,10 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
         pat.walk(&mut |pat| {
             match pat.kind {
-                PatKind::Ident(binding_mode, ident, ref sub_pat)
+                PatKind::Ident(annotation, ident, ref sub_pat)
                     if sub_pat.is_some() || self.is_base_res_local(pat.id) =>
                 {
-                    binding_map.insert(ident, BindingInfo { span: ident.span, binding_mode });
+                    binding_map.insert(ident, BindingInfo { span: ident.span, annotation });
                 }
                 PatKind::Or(ref ps) => {
                     // Check the consistency of this or-pattern and
@@ -2926,7 +2960,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                         binding_error.target.insert(pat_outer.span);
                     }
                     Some(binding_outer) => {
-                        if binding_outer.binding_mode != binding_inner.binding_mode {
+                        if binding_outer.annotation != binding_inner.annotation {
                             // The binding modes in the outer and inner bindings differ.
                             inconsistent_vars
                                 .entry(name)
@@ -3147,14 +3181,14 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
     fn try_resolve_as_non_binding(
         &mut self,
         pat_src: PatternSource,
-        bm: BindingMode,
+        ann: BindingAnnotation,
         ident: Ident,
         has_sub: bool,
     ) -> Option<Res> {
         // An immutable (no `mut`) by-value (no `ref`) binding pattern without
         // a sub pattern (no `@ $pat`) is syntactically ambiguous as it could
         // also be interpreted as a path to e.g. a constant, variant, etc.
-        let is_syntactic_ambiguity = !has_sub && bm == BindingMode::ByValue(Mutability::Not);
+        let is_syntactic_ambiguity = !has_sub && ann == BindingAnnotation::NONE;
 
         let ls_binding = self.maybe_resolve_ident_in_lexical_scope(ident, ValueNS)?;
         let (res, binding) = match ls_binding {
@@ -3268,11 +3302,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         source: PathSource<'ast>,
         finalize: Finalize,
     ) -> PartialRes {
-        tracing::debug!(
+        debug!(
             "smart_resolve_path_fragment(qself={:?}, path={:?}, finalize={:?})",
-            qself,
-            path,
-            finalize,
+            qself, path, finalize,
         );
         let ns = source.namespace();
 
@@ -3696,9 +3728,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
         self.with_constant_rib(
             is_repeat,
             if constant.value.is_potential_trivial_const_param() {
-                HasGenericParams::Yes
+                ConstantHasGenerics::Yes
             } else {
-                HasGenericParams::No
+                ConstantHasGenerics::No
             },
             None,
             |this| visit::walk_anon_const(this, constant),
@@ -3707,8 +3739,8 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
 
     fn resolve_inline_const(&mut self, constant: &'ast AnonConst) {
         debug!("resolve_anon_const {constant:?}");
-        self.with_constant_rib(IsRepeatExpr::No, HasGenericParams::Yes, None, |this| {
-            visit::walk_anon_const(this, constant);
+        self.with_constant_rib(IsRepeatExpr::No, ConstantHasGenerics::Yes, None, |this| {
+            visit::walk_anon_const(this, constant)
         });
     }
 
@@ -3802,7 +3834,7 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                 for argument in arguments {
                     self.resolve_expr(argument, None);
                 }
-                self.visit_path_segment(expr.span, segment);
+                self.visit_path_segment(segment);
             }
 
             ExprKind::Call(ref callee, ref arguments) => {
@@ -3815,9 +3847,9 @@ impl<'a: 'ast, 'b, 'ast> LateResolutionVisitor<'a, 'b, 'ast> {
                         self.with_constant_rib(
                             IsRepeatExpr::No,
                             if argument.is_potential_trivial_const_param() {
-                                HasGenericParams::Yes
+                                ConstantHasGenerics::Yes
                             } else {
-                                HasGenericParams::No
+                                ConstantHasGenerics::No
                             },
                             None,
                             |this| {
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 2b1f2b88e..3b095eeeb 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -33,8 +33,6 @@ use rustc_span::{BytePos, Span};
 use std::iter;
 use std::ops::Deref;
 
-use tracing::debug;
-
 type Res = def::Res<ast::NodeId>;
 
 /// A field or associated item from self type suggested in case of resolution failure.
@@ -161,6 +159,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             msg: String,
             fallback_label: String,
             span: Span,
+            span_label: Option<(Span, &'a str)>,
             could_be_expr: bool,
             suggestion: Option<(Span, &'a str, String)>,
         }
@@ -172,6 +171,12 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 msg: format!("expected {}, found {} `{}`", expected, res.descr(), path_str),
                 fallback_label: format!("not a {expected}"),
                 span,
+                span_label: match res {
+                    Res::Def(kind, def_id) if kind == DefKind::TyParam => {
+                        self.def_span(def_id).map(|span| (span, "found this type parameter"))
+                    }
+                    _ => None,
+                },
                 could_be_expr: match res {
                     Res::Def(DefKind::Fn, _) => {
                         // Verify whether this is a fn call or an Fn used as a type.
@@ -243,14 +248,32 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 .map_or_else(String::new, |res| format!("{} ", res.descr()));
                 (mod_prefix, format!("`{}`", Segment::names_to_string(mod_path)), None)
             };
+
+            let (fallback_label, suggestion) = if path_str == "async"
+                && expected.starts_with("struct")
+            {
+                ("`async` blocks are only allowed in Rust 2018 or later".to_string(), suggestion)
+            } else {
+                // check if we are in situation of typo like `True` instead of `true`.
+                let override_suggestion =
+                    if ["true", "false"].contains(&item_str.to_string().to_lowercase().as_str()) {
+                        let item_typo = item_str.to_string().to_lowercase();
+                        Some((
+                            item_span,
+                            "you may want to use a bool value instead",
+                            format!("{}", item_typo),
+                        ))
+                    } else {
+                        suggestion
+                    };
+                (format!("not found in {mod_str}"), override_suggestion)
+            };
+
             BaseError {
                 msg: format!("cannot find {expected} `{item_str}` in {mod_prefix}{mod_str}"),
-                fallback_label: if path_str == "async" && expected.starts_with("struct") {
-                    "`async` blocks are only allowed in Rust 2018 or later".to_string()
-                } else {
-                    format!("not found in {mod_str}")
-                },
+                fallback_label,
                 span: item_span,
+                span_label: None,
                 could_be_expr: false,
                 suggestion,
             }
@@ -262,6 +285,10 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
 
         self.suggest_swapping_misplaced_self_ty_and_trait(&mut err, source, res, base_error.span);
 
+        if let Some((span, label)) = base_error.span_label {
+            err.span_label(span, label);
+        }
+
         if let Some(sugg) = base_error.suggestion {
             err.span_suggestion_verbose(sugg.0, sugg.1, sugg.2, Applicability::MaybeIncorrect);
         }
@@ -590,9 +617,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                         .filter(|&sp| sp != base_error.span)
                         .collect();
 
-                    let start_span = bounds.iter().map(|bound| bound.span()).next().unwrap();
+                    let start_span = bounds[0].span();
                     // `end_span` is the end of the poly trait ref (Foo + 'baz + Bar><)
-                    let end_span = bounds.iter().map(|bound| bound.span()).last().unwrap();
+                    let end_span = bounds.last().unwrap().span();
                     // `last_bound_span` is the last bound of the poly trait ref (Foo + >'baz< + Bar)
                     let last_bound_span = spans.last().cloned().unwrap();
                     let mut multi_span: MultiSpan = spans.clone().into();
@@ -985,27 +1012,45 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
         let ns = source.namespace();
         let is_expected = &|res| source.is_expected(res);
 
-        let path_sep = |err: &mut Diagnostic, expr: &Expr| match expr.kind {
-            ExprKind::Field(_, ident) => {
+        let path_sep = |err: &mut Diagnostic, expr: &Expr, kind: DefKind| {
+            const MESSAGE: &str = "use the path separator to refer to an item";
+
+            let (lhs_span, rhs_span) = match &expr.kind {
+                ExprKind::Field(base, ident) => (base.span, ident.span),
+                ExprKind::MethodCall(_, args, span) => (args[0].span, *span),
+                _ => return false,
+            };
+
+            if lhs_span.eq_ctxt(rhs_span) {
                 err.span_suggestion(
-                    expr.span,
-                    "use the path separator to refer to an item",
-                    format!("{}::{}", path_str, ident),
+                    lhs_span.between(rhs_span),
+                    MESSAGE,
+                    "::",
                     Applicability::MaybeIncorrect,
                 );
                 true
-            }
-            ExprKind::MethodCall(ref segment, ..) => {
-                let span = expr.span.with_hi(segment.ident.span.hi());
-                err.span_suggestion(
-                    span,
-                    "use the path separator to refer to an item",
-                    format!("{}::{}", path_str, segment.ident),
+            } else if kind == DefKind::Struct
+            && let Some(lhs_source_span) = lhs_span.find_ancestor_inside(expr.span)
+            && let Ok(snippet) = self.r.session.source_map().span_to_snippet(lhs_source_span)
+            {
+                // The LHS is a type that originates from a macro call.
+                // We have to add angle brackets around it.
+
+                err.span_suggestion_verbose(
+                    lhs_source_span.until(rhs_span),
+                    MESSAGE,
+                    format!("<{snippet}>::"),
                     Applicability::MaybeIncorrect,
                 );
                 true
+            } else {
+                // Either we were unable to obtain the source span / the snippet or
+                // the LHS originates from a macro call and it is not a type and thus
+                // there is no way to replace `.` with `::` and still somehow suggest
+                // valid Rust code.
+
+                false
             }
-            _ => false,
         };
 
         let find_span = |source: &PathSource<'_>, err: &mut Diagnostic| {
@@ -1027,7 +1072,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
             match source {
                 PathSource::Expr(Some(
                     parent @ Expr { kind: ExprKind::Field(..) | ExprKind::MethodCall(..), .. },
-                )) if path_sep(err, &parent) => {}
+                )) if path_sep(err, &parent, DefKind::Struct) => {}
                 PathSource::Expr(
                     None
                     | Some(Expr {
@@ -1143,8 +1188,11 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                     }
                 }
             }
-            (Res::Def(DefKind::Mod, _), PathSource::Expr(Some(parent))) => {
-                if !path_sep(err, &parent) {
+            (
+                Res::Def(kind @ (DefKind::Mod | DefKind::Trait), _),
+                PathSource::Expr(Some(parent)),
+            ) => {
+                if !path_sep(err, &parent, kind) {
                     return false;
                 }
             }
@@ -1742,7 +1790,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 }
             };
 
-            let mut suggestable_variants = variants
+            let suggestable_variants = variants
                 .iter()
                 .filter(|(_, def_id, kind)| !needs_placeholder(*def_id, *kind))
                 .map(|(variant, _, kind)| (path_names_to_string(variant), kind))
@@ -1752,8 +1800,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                     CtorKind::Fictive => format!("({} {{}})", variant),
                 })
                 .collect::<Vec<_>>();
+            let no_suggestable_variant = suggestable_variants.is_empty();
 
-            if !suggestable_variants.is_empty() {
+            if !no_suggestable_variant {
                 let msg = if suggestable_variants.len() == 1 {
                     "you might have meant to use the following enum variant"
                 } else {
@@ -1763,7 +1812,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 err.span_suggestions(
                     span,
                     msg,
-                    suggestable_variants.drain(..),
+                    suggestable_variants.into_iter(),
                     Applicability::MaybeIncorrect,
                 );
             }
@@ -1780,15 +1829,15 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 .collect::<Vec<_>>();
 
             if !suggestable_variants_with_placeholders.is_empty() {
-                let msg = match (
-                    suggestable_variants.is_empty(),
-                    suggestable_variants_with_placeholders.len(),
-                ) {
-                    (true, 1) => "the following enum variant is available",
-                    (true, _) => "the following enum variants are available",
-                    (false, 1) => "alternatively, the following enum variant is available",
-                    (false, _) => "alternatively, the following enum variants are also available",
-                };
+                let msg =
+                    match (no_suggestable_variant, suggestable_variants_with_placeholders.len()) {
+                        (true, 1) => "the following enum variant is available",
+                        (true, _) => "the following enum variants are available",
+                        (false, 1) => "alternatively, the following enum variant is available",
+                        (false, _) => {
+                            "alternatively, the following enum variants are also available"
+                        }
+                    };
 
                 err.span_suggestions(
                     span,
@@ -2021,9 +2070,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
 
     fn suggest_introducing_lifetime(
         &self,
-        err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
+        err: &mut Diagnostic,
         name: Option<&str>,
-        suggest: impl Fn(&mut DiagnosticBuilder<'_, ErrorGuaranteed>, bool, Span, &str, String) -> bool,
+        suggest: impl Fn(&mut Diagnostic, bool, Span, &str, String) -> bool,
     ) {
         let mut suggest_note = true;
         for rib in self.lifetime_ribs.iter().rev() {
@@ -2147,9 +2196,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
         err.emit()
     }
 
-    pub(crate) fn add_missing_lifetime_specifiers_label(
+    fn add_missing_lifetime_specifiers_label(
         &mut self,
-        err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
+        err: &mut Diagnostic,
         lifetime_refs: Vec<MissingLifetime>,
         function_param_lifetimes: Option<(Vec<MissingLifetime>, Vec<ElisionFnParameter>)>,
     ) {
@@ -2300,7 +2349,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                         err.multipart_suggestion_verbose(
                             message,
                             std::iter::once((span, intro_sugg))
-                                .chain(spans_suggs.clone())
+                                .chain(spans_suggs.iter().cloned())
                                 .collect(),
                             Applicability::MaybeIncorrect,
                         );
diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs
index 94460e33d..4d9704617 100644
--- a/compiler/rustc_resolve/src/late/lifetimes.rs
+++ b/compiler/rustc_resolve/src/late/lifetimes.rs
@@ -11,23 +11,21 @@ use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
-use rustc_hir::def_id::{DefIdMap, LocalDefId};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{GenericArg, GenericParam, GenericParamKind, HirIdMap, LifetimeName, Node};
 use rustc_middle::bug;
 use rustc_middle::hir::map::Map;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::resolve_lifetime::*;
-use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt};
+use rustc_middle::ty::{self, DefIdTree, TyCtxt};
 use rustc_span::def_id::DefId;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
-use std::borrow::Cow;
 use std::fmt;
-use std::mem::take;
 
 trait RegionExt {
-    fn early(hir_map: Map<'_>, index: &mut u32, param: &GenericParam<'_>) -> (LocalDefId, Region);
+    fn early(hir_map: Map<'_>, param: &GenericParam<'_>) -> (LocalDefId, Region);
 
     fn late(index: u32, hir_map: Map<'_>, param: &GenericParam<'_>) -> (LocalDefId, Region);
 
@@ -36,19 +34,13 @@ trait RegionExt {
     fn shifted(self, amount: u32) -> Region;
 
     fn shifted_out_to_binder(self, binder: ty::DebruijnIndex) -> Region;
-
-    fn subst<'a, L>(self, params: L, map: &NamedRegionMap) -> Option<Region>
-    where
-        L: Iterator<Item = &'a hir::Lifetime>;
 }
 
 impl RegionExt for Region {
-    fn early(hir_map: Map<'_>, index: &mut u32, param: &GenericParam<'_>) -> (LocalDefId, Region) {
-        let i = *index;
-        *index += 1;
+    fn early(hir_map: Map<'_>, param: &GenericParam<'_>) -> (LocalDefId, Region) {
         let def_id = hir_map.local_def_id(param.hir_id);
-        debug!("Region::early: index={} def_id={:?}", i, def_id);
-        (def_id, Region::EarlyBound(i, def_id.to_def_id()))
+        debug!("Region::early: def_id={:?}", def_id);
+        (def_id, Region::EarlyBound(def_id.to_def_id()))
     }
 
     fn late(idx: u32, hir_map: Map<'_>, param: &GenericParam<'_>) -> (LocalDefId, Region) {
@@ -65,9 +57,7 @@ impl RegionExt for Region {
         match *self {
             Region::Static => None,
 
-            Region::EarlyBound(_, id) | Region::LateBound(_, _, id) | Region::Free(_, id) => {
-                Some(id)
-            }
+            Region::EarlyBound(id) | Region::LateBound(_, _, id) | Region::Free(_, id) => Some(id),
         }
     }
 
@@ -88,17 +78,6 @@ impl RegionExt for Region {
             _ => self,
         }
     }
-
-    fn subst<'a, L>(self, mut params: L, map: &NamedRegionMap) -> Option<Region>
-    where
-        L: Iterator<Item = &'a hir::Lifetime>,
-    {
-        if let Region::EarlyBound(index, _) = self {
-            params.nth(index as usize).and_then(|lifetime| map.defs.get(&lifetime.hir_id).cloned())
-        } else {
-            Some(self)
-        }
-    }
 }
 
 /// Maps the id of each lifetime reference to the lifetime decl
@@ -131,9 +110,6 @@ pub(crate) struct LifetimeContext<'a, 'tcx> {
     /// be false if the `Item` we are resolving lifetimes for is not a trait or
     /// we eventually need lifetimes resolve for trait items.
     trait_definition_only: bool,
-
-    /// Cache for cross-crate per-definition object lifetime defaults.
-    xcrate_object_lifetime_defaults: DefIdMap<Vec<ObjectLifetimeDefault>>,
 }
 
 #[derive(Debug)]
@@ -147,25 +123,6 @@ enum Scope<'a> {
         /// for diagnostics.
         lifetimes: FxIndexMap<LocalDefId, Region>,
 
-        /// if we extend this scope with another scope, what is the next index
-        /// we should use for an early-bound region?
-        next_early_index: u32,
-
-        /// Whether or not this binder would serve as the parent
-        /// binder for opaque types introduced within. For example:
-        ///
-        /// ```text
-        ///     fn foo<'a>() -> impl for<'b> Trait<Item = impl Trait2<'a>>
-        /// ```
-        ///
-        /// Here, the opaque types we create for the `impl Trait`
-        /// and `impl Trait2` references will both have the `foo` item
-        /// as their parent. When we get to `impl Trait2`, we find
-        /// that it is nested within the `for<>` binder -- this flag
-        /// allows us to skip that when looking for the parent binder
-        /// of the resulting opaque type.
-        opaque_type_parent: bool,
-
         scope_type: BinderScopeType,
 
         /// The late bound vars for a given item are stored by `HirId` to be
@@ -245,19 +202,9 @@ struct TruncatedScopeDebug<'a>(&'a Scope<'a>);
 impl<'a> fmt::Debug for TruncatedScopeDebug<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.0 {
-            Scope::Binder {
-                lifetimes,
-                next_early_index,
-                opaque_type_parent,
-                scope_type,
-                hir_id,
-                where_bound_origin,
-                s: _,
-            } => f
+            Scope::Binder { lifetimes, scope_type, hir_id, where_bound_origin, s: _ } => f
                 .debug_struct("Binder")
                 .field("lifetimes", lifetimes)
-                .field("next_early_index", next_early_index)
-                .field("opaque_type_parent", opaque_type_parent)
                 .field("scope_type", scope_type)
                 .field("hir_id", hir_id)
                 .field("where_bound_origin", where_bound_origin)
@@ -294,10 +241,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
 
         named_region_map: |tcx, id| resolve_lifetimes_for(tcx, id).defs.get(&id),
         is_late_bound_map,
-        object_lifetime_defaults: |tcx, id| match tcx.hir().find_by_def_id(id) {
-            Some(Node::Item(item)) => compute_object_lifetime_defaults(tcx, item),
-            _ => None,
-        },
+        object_lifetime_default,
         late_bound_vars_map: |tcx, id| resolve_lifetimes_for(tcx, id).late_bound_vars.get(&id),
 
         ..*providers
@@ -334,7 +278,7 @@ pub fn provide(providers: &mut ty::query::Providers) {
 /// lifetimes into a single binder.) This requires us to resolve the
 /// *trait definition* of `Sub`; basically just enough lifetime information
 /// to look at the supertraits.
-#[tracing::instrument(level = "debug", skip(tcx))]
+#[instrument(level = "debug", skip(tcx))]
 fn resolve_lifetimes_trait_definition(
     tcx: TyCtxt<'_>,
     local_def_id: LocalDefId,
@@ -345,7 +289,7 @@ fn resolve_lifetimes_trait_definition(
 /// Computes the `ResolveLifetimes` map that contains data for an entire `Item`.
 /// You should not read the result of this query directly, but rather use
 /// `named_region_map`, `is_late_bound_map`, etc.
-#[tracing::instrument(level = "debug", skip(tcx))]
+#[instrument(level = "debug", skip(tcx))]
 fn resolve_lifetimes(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> ResolveLifetimes {
     convert_named_region_map(do_resolve(tcx, local_def_id, false))
 }
@@ -363,7 +307,6 @@ fn do_resolve(
         map: &mut named_region_map,
         scope: ROOT_SCOPE,
         trait_definition_only,
-        xcrate_object_lifetime_defaults: Default::default(),
     };
     visitor.visit_item(item);
 
@@ -432,13 +375,6 @@ fn item_for(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> LocalDefId {
     item
 }
 
-/// In traits, there is an implicit `Self` type parameter which comes before the generics.
-/// We have to account for this when computing the index of the other generic parameters.
-/// This function returns whether there is such an implicit parameter defined on the given item.
-fn sub_items_have_self_param(node: &hir::ItemKind<'_>) -> bool {
-    matches!(*node, hir::ItemKind::Trait(..) | hir::ItemKind::TraitAlias(..))
-}
-
 fn late_region_as_bound_region<'tcx>(tcx: TyCtxt<'tcx>, region: &Region) -> ty::BoundVariableKind {
     match region {
         Region::LateBound(_, _, def_id) => {
@@ -558,7 +494,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 }
             }
 
-            let next_early_index = self.next_early_index();
             let (lifetimes, binders): (FxIndexMap<LocalDefId, Region>, Vec<_>) =
                 bound_generic_params
                     .iter()
@@ -576,8 +511,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 hir_id: e.hir_id,
                 lifetimes,
                 s: self.scope,
-                next_early_index,
-                opaque_type_parent: false,
                 scope_type: BinderScopeType::Normal,
                 where_bound_origin: None,
             };
@@ -592,6 +525,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
         match &item.kind {
             hir::ItemKind::Impl(hir::Impl { of_trait, .. }) => {
@@ -603,7 +537,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
         match item.kind {
             hir::ItemKind::Fn(_, ref generics, _) => {
-                self.visit_early_late(None, item.hir_id(), generics, |this| {
+                self.visit_early_late(item.hir_id(), generics, |this| {
                     intravisit::walk_item(this, item);
                 });
             }
@@ -670,31 +604,20 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
             | hir::ItemKind::TraitAlias(ref generics, ..)
             | hir::ItemKind::Impl(hir::Impl { ref generics, .. }) => {
                 // These kinds of items have only early-bound lifetime parameters.
-                let mut index = if sub_items_have_self_param(&item.kind) {
-                    1 // Self comes before lifetimes
-                } else {
-                    0
-                };
-                let mut non_lifetime_count = 0;
                 let lifetimes = generics
                     .params
                     .iter()
                     .filter_map(|param| match param.kind {
                         GenericParamKind::Lifetime { .. } => {
-                            Some(Region::early(self.tcx.hir(), &mut index, param))
-                        }
-                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
-                            non_lifetime_count += 1;
-                            None
+                            Some(Region::early(self.tcx.hir(), param))
                         }
+                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => None,
                     })
                     .collect();
                 self.map.late_bound_vars.insert(item.hir_id(), vec![]);
                 let scope = Scope::Binder {
                     hir_id: item.hir_id(),
                     lifetimes,
-                    next_early_index: index + non_lifetime_count,
-                    opaque_type_parent: true,
                     scope_type: BinderScopeType::Normal,
                     s: ROOT_SCOPE,
                     where_bound_origin: None,
@@ -712,7 +635,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
     fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
         match item.kind {
             hir::ForeignItemKind::Fn(_, _, ref generics) => {
-                self.visit_early_late(None, item.hir_id(), generics, |this| {
+                self.visit_early_late(item.hir_id(), generics, |this| {
                     intravisit::walk_foreign_item(this, item);
                 })
             }
@@ -725,11 +648,10 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) {
         match ty.kind {
             hir::TyKind::BareFn(ref c) => {
-                let next_early_index = self.next_early_index();
                 let (lifetimes, binders): (FxIndexMap<LocalDefId, Region>, Vec<_>) = c
                     .generic_params
                     .iter()
@@ -746,8 +668,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                     hir_id: ty.hir_id,
                     lifetimes,
                     s: self.scope,
-                    next_early_index,
-                    opaque_type_parent: false,
                     scope_type: BinderScopeType::Normal,
                     where_bound_origin: None,
                 };
@@ -762,7 +682,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 let scope = Scope::TraitRefBoundary { s: self.scope };
                 self.with(scope, |this| {
                     for bound in bounds {
-                        this.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);
+                        this.visit_poly_trait_ref(bound);
                     }
                 });
                 match lifetime.name {
@@ -795,7 +715,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 };
                 self.with(scope, |this| this.visit_ty(&mt.ty));
             }
-            hir::TyKind::OpaqueDef(item_id, lifetimes) => {
+            hir::TyKind::OpaqueDef(item_id, lifetimes, _in_trait) => {
                 // Resolve the lifetimes in the bounds to the lifetime defs in the generics.
                 // `fn foo<'a>() -> impl MyTrait<'a> { ... }` desugars to
                 // `type MyAnonTy<'b> = impl MyTrait<'b>;`
@@ -886,32 +806,23 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
 
                 // We want to start our early-bound indices at the end of the parent scope,
                 // not including any parent `impl Trait`s.
-                let mut index = self.next_early_index_for_opaque_type();
-                debug!(?index);
-
                 let mut lifetimes = FxIndexMap::default();
-                let mut non_lifetime_count = 0;
                 debug!(?generics.params);
                 for param in generics.params {
                     match param.kind {
                         GenericParamKind::Lifetime { .. } => {
-                            let (def_id, reg) = Region::early(self.tcx.hir(), &mut index, &param);
+                            let (def_id, reg) = Region::early(self.tcx.hir(), &param);
                             lifetimes.insert(def_id, reg);
                         }
-                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
-                            non_lifetime_count += 1;
-                        }
+                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {}
                     }
                 }
-                let next_early_index = index + non_lifetime_count;
                 self.map.late_bound_vars.insert(ty.hir_id, vec![]);
 
                 let scope = Scope::Binder {
                     hir_id: ty.hir_id,
                     lifetimes,
-                    next_early_index,
                     s: self.scope,
-                    opaque_type_parent: false,
                     scope_type: BinderScopeType::Normal,
                     where_bound_origin: None,
                 };
@@ -929,43 +840,32 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
         use self::hir::TraitItemKind::*;
         match trait_item.kind {
             Fn(_, _) => {
-                let tcx = self.tcx;
-                self.visit_early_late(
-                    Some(tcx.hir().get_parent_item(trait_item.hir_id())),
-                    trait_item.hir_id(),
-                    &trait_item.generics,
-                    |this| intravisit::walk_trait_item(this, trait_item),
-                );
+                self.visit_early_late(trait_item.hir_id(), &trait_item.generics, |this| {
+                    intravisit::walk_trait_item(this, trait_item)
+                });
             }
             Type(bounds, ref ty) => {
                 let generics = &trait_item.generics;
-                let mut index = self.next_early_index();
-                debug!("visit_ty: index = {}", index);
-                let mut non_lifetime_count = 0;
                 let lifetimes = generics
                     .params
                     .iter()
                     .filter_map(|param| match param.kind {
                         GenericParamKind::Lifetime { .. } => {
-                            Some(Region::early(self.tcx.hir(), &mut index, param))
-                        }
-                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
-                            non_lifetime_count += 1;
-                            None
+                            Some(Region::early(self.tcx.hir(), param))
                         }
+                        GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => None,
                     })
                     .collect();
                 self.map.late_bound_vars.insert(trait_item.hir_id(), vec![]);
                 let scope = Scope::Binder {
                     hir_id: trait_item.hir_id(),
                     lifetimes,
-                    next_early_index: index + non_lifetime_count,
                     s: self.scope,
-                    opaque_type_parent: true,
                     scope_type: BinderScopeType::Normal,
                     where_bound_origin: None,
                 };
@@ -990,43 +890,30 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
         use self::hir::ImplItemKind::*;
         match impl_item.kind {
-            Fn(..) => {
-                let tcx = self.tcx;
-                self.visit_early_late(
-                    Some(tcx.hir().get_parent_item(impl_item.hir_id())),
-                    impl_item.hir_id(),
-                    &impl_item.generics,
-                    |this| intravisit::walk_impl_item(this, impl_item),
-                );
-            }
+            Fn(..) => self.visit_early_late(impl_item.hir_id(), &impl_item.generics, |this| {
+                intravisit::walk_impl_item(this, impl_item)
+            }),
             TyAlias(ref ty) => {
                 let generics = &impl_item.generics;
-                let mut index = self.next_early_index();
-                let mut non_lifetime_count = 0;
-                debug!("visit_ty: index = {}", index);
                 let lifetimes: FxIndexMap<LocalDefId, Region> = generics
                     .params
                     .iter()
                     .filter_map(|param| match param.kind {
                         GenericParamKind::Lifetime { .. } => {
-                            Some(Region::early(self.tcx.hir(), &mut index, param))
-                        }
-                        GenericParamKind::Const { .. } | GenericParamKind::Type { .. } => {
-                            non_lifetime_count += 1;
-                            None
+                            Some(Region::early(self.tcx.hir(), param))
                         }
+                        GenericParamKind::Const { .. } | GenericParamKind::Type { .. } => None,
                     })
                     .collect();
                 self.map.late_bound_vars.insert(ty.hir_id, vec![]);
                 let scope = Scope::Binder {
                     hir_id: ty.hir_id,
                     lifetimes,
-                    next_early_index: index + non_lifetime_count,
                     s: self.scope,
-                    opaque_type_parent: true,
                     scope_type: BinderScopeType::Normal,
                     where_bound_origin: None,
                 };
@@ -1046,7 +933,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn visit_lifetime(&mut self, lifetime_ref: &'tcx hir::Lifetime) {
         match lifetime_ref.name {
             hir::LifetimeName::Static => self.insert_lifetime(lifetime_ref, Region::Static),
@@ -1129,7 +1016,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                                 })
                                 .unzip();
                         this.map.late_bound_vars.insert(bounded_ty.hir_id, binders.clone());
-                        let next_early_index = this.next_early_index();
                         // Even if there are no lifetimes defined here, we still wrap it in a binder
                         // scope. If there happens to be a nested poly trait ref (an error), that
                         // will be `Concatenating` anyways, so we don't have to worry about the depth
@@ -1138,8 +1024,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                             hir_id: bounded_ty.hir_id,
                             lifetimes,
                             s: this.scope,
-                            next_early_index,
-                            opaque_type_parent: false,
                             scope_type: BinderScopeType::Normal,
                             where_bound_origin: Some(origin),
                         };
@@ -1210,8 +1094,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                     hir_id: *hir_id,
                     lifetimes: FxIndexMap::default(),
                     s: self.scope,
-                    next_early_index: self.next_early_index(),
-                    opaque_type_parent: false,
                     scope_type,
                     where_bound_origin: None,
                 };
@@ -1223,14 +1105,9 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
         }
     }
 
-    fn visit_poly_trait_ref(
-        &mut self,
-        trait_ref: &'tcx hir::PolyTraitRef<'tcx>,
-        _modifier: hir::TraitBoundModifier,
-    ) {
+    fn visit_poly_trait_ref(&mut self, trait_ref: &'tcx hir::PolyTraitRef<'tcx>) {
         debug!("visit_poly_trait_ref(trait_ref={:?})", trait_ref);
 
-        let next_early_index = self.next_early_index();
         let (mut binders, scope_type) = self.poly_trait_ref_binder_info();
 
         let initial_bound_vars = binders.len() as u32;
@@ -1260,8 +1137,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
             hir_id: trait_ref.trait_ref.hir_ref_id,
             lifetimes,
             s: self.scope,
-            next_early_index,
-            opaque_type_parent: false,
             scope_type,
             where_bound_origin: None,
         };
@@ -1272,139 +1147,49 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
     }
 }
 
-fn compute_object_lifetime_defaults<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    item: &hir::Item<'_>,
-) -> Option<&'tcx [ObjectLifetimeDefault]> {
-    match item.kind {
-        hir::ItemKind::Struct(_, ref generics)
-        | hir::ItemKind::Union(_, ref generics)
-        | hir::ItemKind::Enum(_, ref generics)
-        | hir::ItemKind::OpaqueTy(hir::OpaqueTy {
-            ref generics,
-            origin: hir::OpaqueTyOrigin::TyAlias,
-            ..
-        })
-        | hir::ItemKind::TyAlias(_, ref generics)
-        | hir::ItemKind::Trait(_, _, ref generics, ..) => {
-            let result = object_lifetime_defaults_for_item(tcx, generics);
-
-            // Debugging aid.
-            let attrs = tcx.hir().attrs(item.hir_id());
-            if tcx.sess.contains_name(attrs, sym::rustc_object_lifetime_default) {
-                let object_lifetime_default_reprs: String = result
-                    .iter()
-                    .map(|set| match *set {
-                        Set1::Empty => "BaseDefault".into(),
-                        Set1::One(Region::Static) => "'static".into(),
-                        Set1::One(Region::EarlyBound(mut i, _)) => generics
-                            .params
-                            .iter()
-                            .find_map(|param| match param.kind {
-                                GenericParamKind::Lifetime { .. } => {
-                                    if i == 0 {
-                                        return Some(param.name.ident().to_string().into());
-                                    }
-                                    i -= 1;
-                                    None
-                                }
-                                _ => None,
-                            })
-                            .unwrap(),
-                        Set1::One(_) => bug!(),
-                        Set1::Many => "Ambiguous".into(),
-                    })
-                    .collect::<Vec<Cow<'static, str>>>()
-                    .join(",");
-                tcx.sess.span_err(item.span, &object_lifetime_default_reprs);
-            }
-
-            Some(result)
-        }
-        _ => None,
-    }
-}
-
-/// Scan the bounds and where-clauses on parameters to extract bounds
-/// of the form `T:'a` so as to determine the `ObjectLifetimeDefault`
-/// for each type parameter.
-fn object_lifetime_defaults_for_item<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    generics: &hir::Generics<'_>,
-) -> &'tcx [ObjectLifetimeDefault] {
-    fn add_bounds(set: &mut Set1<hir::LifetimeName>, bounds: &[hir::GenericBound<'_>]) {
-        for bound in bounds {
-            if let hir::GenericBound::Outlives(ref lifetime) = *bound {
-                set.insert(lifetime.name.normalize_to_macros_2_0());
-            }
-        }
-    }
-
-    let process_param = |param: &hir::GenericParam<'_>| match param.kind {
-        GenericParamKind::Lifetime { .. } => None,
+fn object_lifetime_default<'tcx>(tcx: TyCtxt<'tcx>, param_def_id: DefId) -> ObjectLifetimeDefault {
+    debug_assert_eq!(tcx.def_kind(param_def_id), DefKind::TyParam);
+    let param_def_id = param_def_id.expect_local();
+    let parent_def_id = tcx.local_parent(param_def_id);
+    let generics = tcx.hir().get_generics(parent_def_id).unwrap();
+    let param_hir_id = tcx.local_def_id_to_hir_id(param_def_id);
+    let param = generics.params.iter().find(|p| p.hir_id == param_hir_id).unwrap();
+
+    // Scan the bounds and where-clauses on parameters to extract bounds
+    // of the form `T:'a` so as to determine the `ObjectLifetimeDefault`
+    // for each type parameter.
+    match param.kind {
         GenericParamKind::Type { .. } => {
             let mut set = Set1::Empty;
 
-            let param_def_id = tcx.hir().local_def_id(param.hir_id);
-            for predicate in generics.predicates {
-                // Look for `type: ...` where clauses.
-                let hir::WherePredicate::BoundPredicate(ref data) = *predicate else { continue };
-
+            // Look for `type: ...` where clauses.
+            for bound in generics.bounds_for_param(param_def_id) {
                 // Ignore `for<'a> type: ...` as they can change what
                 // lifetimes mean (although we could "just" handle it).
-                if !data.bound_generic_params.is_empty() {
+                if !bound.bound_generic_params.is_empty() {
                     continue;
                 }
 
-                let res = match data.bounded_ty.kind {
-                    hir::TyKind::Path(hir::QPath::Resolved(None, ref path)) => path.res,
-                    _ => continue,
-                };
-
-                if res == Res::Def(DefKind::TyParam, param_def_id.to_def_id()) {
-                    add_bounds(&mut set, &data.bounds);
+                for bound in bound.bounds {
+                    if let hir::GenericBound::Outlives(ref lifetime) = *bound {
+                        set.insert(lifetime.name.normalize_to_macros_2_0());
+                    }
                 }
             }
 
-            Some(match set {
-                Set1::Empty => Set1::Empty,
-                Set1::One(name) => {
-                    if name == hir::LifetimeName::Static {
-                        Set1::One(Region::Static)
-                    } else {
-                        generics
-                            .params
-                            .iter()
-                            .filter_map(|param| match param.kind {
-                                GenericParamKind::Lifetime { .. } => {
-                                    let param_def_id = tcx.hir().local_def_id(param.hir_id);
-                                    Some((
-                                        param_def_id,
-                                        hir::LifetimeName::Param(param_def_id, param.name),
-                                    ))
-                                }
-                                _ => None,
-                            })
-                            .enumerate()
-                            .find(|&(_, (_, lt_name))| lt_name == name)
-                            .map_or(Set1::Many, |(i, (def_id, _))| {
-                                Set1::One(Region::EarlyBound(i as u32, def_id.to_def_id()))
-                            })
-                    }
+            match set {
+                Set1::Empty => ObjectLifetimeDefault::Empty,
+                Set1::One(hir::LifetimeName::Static) => ObjectLifetimeDefault::Static,
+                Set1::One(hir::LifetimeName::Param(param_def_id, _)) => {
+                    ObjectLifetimeDefault::Param(param_def_id.to_def_id())
                 }
-                Set1::Many => Set1::Many,
-            })
+                _ => ObjectLifetimeDefault::Ambiguous,
+            }
         }
-        GenericParamKind::Const { .. } => {
-            // Generic consts don't impose any constraints.
-            //
-            // We still store a dummy value here to allow generic parameters
-            // in an arbitrary order.
-            Some(Set1::Empty)
+        _ => {
+            bug!("object_lifetime_default_raw must only be called on a type parameter")
         }
-    };
-
-    tcx.arena.alloc_from_iter(generics.params.iter().filter_map(process_param))
+    }
 }
 
 impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
@@ -1413,20 +1198,17 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         F: for<'b> FnOnce(&mut LifetimeContext<'b, 'tcx>),
     {
         let LifetimeContext { tcx, map, .. } = self;
-        let xcrate_object_lifetime_defaults = take(&mut self.xcrate_object_lifetime_defaults);
         let mut this = LifetimeContext {
             tcx: *tcx,
             map,
             scope: &wrap_scope,
             trait_definition_only: self.trait_definition_only,
-            xcrate_object_lifetime_defaults,
         };
-        let span = tracing::debug_span!("scope", scope = ?TruncatedScopeDebug(&this.scope));
+        let span = debug_span!("scope", scope = ?TruncatedScopeDebug(&this.scope));
         {
             let _enter = span.enter();
             f(&mut this);
         }
-        self.xcrate_object_lifetime_defaults = this.xcrate_object_lifetime_defaults;
     }
 
     /// Visits self by adding a scope and handling recursive walk over the contents with `walk`.
@@ -1449,30 +1231,12 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
     /// ordering is not important there.
     fn visit_early_late<F>(
         &mut self,
-        parent_id: Option<LocalDefId>,
         hir_id: hir::HirId,
         generics: &'tcx hir::Generics<'tcx>,
         walk: F,
     ) where
         F: for<'b, 'c> FnOnce(&'b mut LifetimeContext<'c, 'tcx>),
     {
-        // Find the start of nested early scopes, e.g., in methods.
-        let mut next_early_index = 0;
-        if let Some(parent_id) = parent_id {
-            let parent = self.tcx.hir().expect_item(parent_id);
-            if sub_items_have_self_param(&parent.kind) {
-                next_early_index += 1; // Self comes before lifetimes
-            }
-            match parent.kind {
-                hir::ItemKind::Trait(_, _, ref generics, ..)
-                | hir::ItemKind::Impl(hir::Impl { ref generics, .. }) => {
-                    next_early_index += generics.params.len() as u32;
-                }
-                _ => {}
-            }
-        }
-
-        let mut non_lifetime_count = 0;
         let mut named_late_bound_vars = 0;
         let lifetimes: FxIndexMap<LocalDefId, Region> = generics
             .params
@@ -1484,16 +1248,12 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                         named_late_bound_vars += 1;
                         Some(Region::late(late_bound_idx, self.tcx.hir(), param))
                     } else {
-                        Some(Region::early(self.tcx.hir(), &mut next_early_index, param))
+                        Some(Region::early(self.tcx.hir(), param))
                     }
                 }
-                GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => {
-                    non_lifetime_count += 1;
-                    None
-                }
+                GenericParamKind::Type { .. } | GenericParamKind::Const { .. } => None,
             })
             .collect();
-        let next_early_index = next_early_index + non_lifetime_count;
 
         let binders: Vec<_> = generics
             .params
@@ -1512,52 +1272,14 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         let scope = Scope::Binder {
             hir_id,
             lifetimes,
-            next_early_index,
             s: self.scope,
-            opaque_type_parent: true,
             scope_type: BinderScopeType::Normal,
             where_bound_origin: None,
         };
         self.with(scope, walk);
     }
 
-    fn next_early_index_helper(&self, only_opaque_type_parent: bool) -> u32 {
-        let mut scope = self.scope;
-        loop {
-            match *scope {
-                Scope::Root => return 0,
-
-                Scope::Binder { next_early_index, opaque_type_parent, .. }
-                    if (!only_opaque_type_parent || opaque_type_parent) =>
-                {
-                    return next_early_index;
-                }
-
-                Scope::Binder { s, .. }
-                | Scope::Body { s, .. }
-                | Scope::Elision { s, .. }
-                | Scope::ObjectLifetimeDefault { s, .. }
-                | Scope::Supertrait { s, .. }
-                | Scope::TraitRefBoundary { s, .. } => scope = s,
-            }
-        }
-    }
-
-    /// Returns the next index one would use for an early-bound-region
-    /// if extending the current scope.
-    fn next_early_index(&self) -> u32 {
-        self.next_early_index_helper(true)
-    }
-
-    /// Returns the next index one would use for an `impl Trait` that
-    /// is being converted into an opaque type alias `impl Trait`. This will be the
-    /// next early index from the enclosing item, for the most
-    /// part. See the `opaque_type_parent` field for more info.
-    fn next_early_index_for_opaque_type(&self) -> u32 {
-        self.next_early_index_helper(false)
-    }
-
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn resolve_lifetime_ref(
         &mut self,
         region_def_id: LocalDefId,
@@ -1638,7 +1360,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             return;
         }
 
-        // We may fail to resolve higher-ranked lifetimes that are mentionned by APIT.
+        // We may fail to resolve higher-ranked lifetimes that are mentioned by APIT.
         // AST-based resolution does not care for impl-trait desugaring, which are the
         // responibility of lowering.  This may create a mismatch between the resolution
         // AST found (`region_def_id`) which points to HRTB, and what HIR allows.
@@ -1679,17 +1401,13 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         );
     }
 
+    #[instrument(level = "debug", skip(self))]
     fn visit_segment_args(
         &mut self,
         res: Res,
         depth: usize,
         generic_args: &'tcx hir::GenericArgs<'tcx>,
     ) {
-        debug!(
-            "visit_segment_args(res={:?}, depth={:?}, generic_args={:?})",
-            res, depth, generic_args,
-        );
-
         if generic_args.parenthesized {
             self.visit_fn_like_elision(
                 generic_args.inputs(),
@@ -1707,13 +1425,9 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
 
         // Figure out if this is a type/trait segment,
         // which requires object lifetime defaults.
-        let parent_def_id = |this: &mut Self, def_id: DefId| {
-            let def_key = this.tcx.def_key(def_id);
-            DefId { krate: def_id.krate, index: def_key.parent.expect("missing parent") }
-        };
         let type_def_id = match res {
-            Res::Def(DefKind::AssocTy, def_id) if depth == 1 => Some(parent_def_id(self, def_id)),
-            Res::Def(DefKind::Variant, def_id) if depth == 0 => Some(parent_def_id(self, def_id)),
+            Res::Def(DefKind::AssocTy, def_id) if depth == 1 => Some(self.tcx.parent(def_id)),
+            Res::Def(DefKind::Variant, def_id) if depth == 0 => Some(self.tcx.parent(def_id)),
             Res::Def(
                 DefKind::Struct
                 | DefKind::Union
@@ -1725,7 +1439,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             _ => None,
         };
 
-        debug!("visit_segment_args: type_def_id={:?}", type_def_id);
+        debug!(?type_def_id);
 
         // Compute a vector of defaults, one for each type parameter,
         // per the rules given in RFCs 599 and 1156. Example:
@@ -1763,55 +1477,52 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             };
 
             let map = &self.map;
-            let set_to_region = |set: &ObjectLifetimeDefault| match *set {
-                Set1::Empty => {
+            let generics = self.tcx.generics_of(def_id);
+
+            // `type_def_id` points to an item, so there is nothing to inherit generics from.
+            debug_assert_eq!(generics.parent_count, 0);
+
+            let set_to_region = |set: ObjectLifetimeDefault| match set {
+                ObjectLifetimeDefault::Empty => {
                     if in_body {
                         None
                     } else {
                         Some(Region::Static)
                     }
                 }
-                Set1::One(r) => {
-                    let lifetimes = generic_args.args.iter().filter_map(|arg| match arg {
-                        GenericArg::Lifetime(lt) => Some(lt),
+                ObjectLifetimeDefault::Static => Some(Region::Static),
+                ObjectLifetimeDefault::Param(param_def_id) => {
+                    // This index can be used with `generic_args` since `parent_count == 0`.
+                    let index = generics.param_def_id_to_index[&param_def_id] as usize;
+                    generic_args.args.get(index).and_then(|arg| match arg {
+                        GenericArg::Lifetime(lt) => map.defs.get(&lt.hir_id).copied(),
                         _ => None,
-                    });
-                    r.subst(lifetimes, map)
+                    })
                 }
-                Set1::Many => None,
+                ObjectLifetimeDefault::Ambiguous => None,
             };
-            if let Some(def_id) = def_id.as_local() {
-                let id = self.tcx.hir().local_def_id_to_hir_id(def_id);
-                self.tcx
-                    .object_lifetime_defaults(id.owner)
-                    .unwrap()
-                    .iter()
-                    .map(set_to_region)
-                    .collect()
-            } else {
-                let tcx = self.tcx;
-                self.xcrate_object_lifetime_defaults
-                    .entry(def_id)
-                    .or_insert_with(|| {
-                        tcx.generics_of(def_id)
-                            .params
-                            .iter()
-                            .filter_map(|param| match param.kind {
-                                GenericParamDefKind::Type { object_lifetime_default, .. } => {
-                                    Some(object_lifetime_default)
-                                }
-                                GenericParamDefKind::Const { .. } => Some(Set1::Empty),
-                                GenericParamDefKind::Lifetime => None,
-                            })
-                            .collect()
-                    })
-                    .iter()
-                    .map(set_to_region)
-                    .collect()
-            }
+            generics
+                .params
+                .iter()
+                .filter_map(|param| {
+                    match self.tcx.def_kind(param.def_id) {
+                        // Generic consts don't impose any constraints.
+                        //
+                        // We still store a dummy value here to allow generic parameters
+                        // in an arbitrary order.
+                        DefKind::ConstParam => Some(ObjectLifetimeDefault::Empty),
+                        DefKind::TyParam => Some(self.tcx.object_lifetime_default(param.def_id)),
+                        // We may also get a `Trait` or `TraitAlias` because of how generics `Self` parameter
+                        // works.  Ignore it because it can't have a meaningful lifetime default.
+                        DefKind::LifetimeParam | DefKind::Trait | DefKind::TraitAlias => None,
+                        dk => bug!("unexpected def_kind {:?}", dk),
+                    }
+                })
+                .map(set_to_region)
+                .collect()
         });
 
-        debug!("visit_segment_args: object_lifetime_defaults={:?}", object_lifetime_defaults);
+        debug!(?object_lifetime_defaults);
 
         let mut i = 0;
         for arg in generic_args.args {
@@ -1953,7 +1664,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         }
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn visit_fn_like_elision(
         &mut self,
         inputs: &'tcx [hir::Ty<'tcx>],
@@ -2001,7 +1712,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         self.insert_lifetime(lifetime_ref, lifetime.shifted(late_depth));
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
+    #[instrument(level = "debug", skip(self))]
     fn insert_lifetime(&mut self, lifetime_ref: &'tcx hir::Lifetime, def: Region) {
         debug!(
             node = ?self.tcx.hir().node_to_string(lifetime_ref.hir_id),
@@ -2112,7 +1823,7 @@ fn is_late_bound_map(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<&FxIndexSet<
                     // is, those would be potentially inputs to
                     // projections
                     if let Some(last_segment) = path.segments.last() {
-                        self.visit_path_segment(path.span, last_segment);
+                        self.visit_path_segment(last_segment);
                     }
                 }
 
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 62843c651..26b9284fe 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -7,12 +7,13 @@
 //! Type-relative name resolution (methods, fields, associated items) happens in `rustc_typeck`.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(drain_filter)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![feature(let_else)]
+#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(never_type)]
 #![recursion_limit = "256"]
 #![allow(rustdoc::private_intra_doc_links)]
@@ -57,8 +58,7 @@ use rustc_span::{Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 use std::cell::{Cell, RefCell};
 use std::collections::BTreeSet;
-use std::{cmp, fmt, ptr};
-use tracing::debug;
+use std::{fmt, ptr};
 
 use diagnostics::{ImportSuggestion, LabelSuggestion, Suggestion};
 use imports::{Import, ImportKind, ImportResolver, NameResolution};
@@ -108,7 +108,6 @@ enum Scope<'a> {
     // The node ID is for reporting the `PROC_MACRO_DERIVE_RESOLUTION_FALLBACK`
     // lint if it should be reported.
     Module(Module<'a>, Option<NodeId>),
-    RegisteredAttrs,
     MacroUsePrelude,
     BuiltinAttrs,
     ExternPrelude,
@@ -165,7 +164,6 @@ enum ImplTraitContext {
     Universal(LocalDefId),
 }
 
-#[derive(Eq)]
 struct BindingError {
     name: Symbol,
     origin: BTreeSet<Span>,
@@ -173,24 +171,6 @@ struct BindingError {
     could_be_path: bool,
 }
 
-impl PartialOrd for BindingError {
-    fn partial_cmp(&self, other: &BindingError) -> Option<cmp::Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl PartialEq for BindingError {
-    fn eq(&self, other: &BindingError) -> bool {
-        self.name == other.name
-    }
-}
-
-impl Ord for BindingError {
-    fn cmp(&self, other: &BindingError) -> cmp::Ordering {
-        self.name.cmp(&other.name)
-    }
-}
-
 enum ResolutionError<'a> {
     /// Error E0401: can't use type or const parameters from outer function.
     GenericParamsFromOuterFunction(Res, HasGenericParams),
@@ -650,7 +630,7 @@ pub struct NameBinding<'a> {
     ambiguity: Option<(&'a NameBinding<'a>, AmbiguityKind)>,
     expansion: LocalExpnId,
     span: Span,
-    vis: ty::Visibility,
+    vis: ty::Visibility<DefId>,
 }
 
 pub trait ToNameBinding<'a> {
@@ -847,7 +827,7 @@ impl<'a> NameBinding<'a> {
     }
 }
 
-#[derive(Debug, Default, Clone)]
+#[derive(Default, Clone)]
 pub struct ExternPreludeEntry<'a> {
     extern_crate_item: Option<&'a NameBinding<'a>>,
     pub introduced_by_item: bool,
@@ -913,11 +893,6 @@ pub struct Resolver<'a> {
     label_res_map: NodeMap<NodeId>,
     /// Resolutions for lifetimes.
     lifetimes_res_map: NodeMap<LifetimeRes>,
-    /// Mapping from generics `def_id`s to TAIT generics `def_id`s.
-    /// For each captured lifetime (e.g., 'a), we create a new lifetime parameter that is a generic
-    /// defined on the TAIT, so we have type Foo<'a1> = ... and we establish a mapping in this
-    /// field from the original parameter 'a to the new parameter 'a1.
-    generics_def_id_map: Vec<FxHashMap<LocalDefId, LocalDefId>>,
     /// Lifetime parameters that lowering will have to introduce.
     extra_lifetime_params_map: NodeMap<Vec<(Ident, NodeId, LifetimeRes)>>,
 
@@ -976,7 +951,6 @@ pub struct Resolver<'a> {
     /// A small map keeping true kinds of built-in macros that appear to be fn-like on
     /// the surface (`macro` items in libcore), but are actually attributes or derives.
     builtin_macro_kinds: FxHashMap<LocalDefId, MacroKind>,
-    registered_attrs: FxHashSet<Ident>,
     registered_tools: RegisteredTools,
     macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
     macro_map: FxHashMap<DefId, MacroData>,
@@ -1020,7 +994,7 @@ pub struct Resolver<'a> {
     /// Table for mapping struct IDs into struct constructor IDs,
     /// it's not used during normal resolution, only for better error reporting.
     /// Also includes of list of each fields visibility
-    struct_constructors: DefIdMap<(Res, ty::Visibility, Vec<ty::Visibility>)>,
+    struct_constructors: DefIdMap<(Res, ty::Visibility<DefId>, Vec<ty::Visibility<DefId>>)>,
 
     /// Features enabled for this crate.
     active_features: FxHashSet<Symbol>,
@@ -1253,8 +1227,7 @@ impl<'a> Resolver<'a> {
             }
         }
 
-        let (registered_attrs, registered_tools) =
-            macros::registered_attrs_and_tools(session, &krate.attrs);
+        let registered_tools = macros::registered_tools(session, &krate.attrs);
 
         let features = session.features_untracked();
 
@@ -1282,7 +1255,6 @@ impl<'a> Resolver<'a> {
             import_res_map: Default::default(),
             label_res_map: Default::default(),
             lifetimes_res_map: Default::default(),
-            generics_def_id_map: Vec::new(),
             extra_lifetime_params_map: Default::default(),
             extern_crate_map: Default::default(),
             reexport_map: FxHashMap::default(),
@@ -1319,7 +1291,6 @@ impl<'a> Resolver<'a> {
             macro_names: FxHashSet::default(),
             builtin_macros: Default::default(),
             builtin_macro_kinds: Default::default(),
-            registered_attrs,
             registered_tools,
             macro_use_prelude: FxHashMap::default(),
             macro_map: FxHashMap::default(),
@@ -1450,7 +1421,6 @@ impl<'a> Resolver<'a> {
             import_res_map: self.import_res_map,
             label_res_map: self.label_res_map,
             lifetimes_res_map: self.lifetimes_res_map,
-            generics_def_id_map: self.generics_def_id_map,
             extra_lifetime_params_map: self.extra_lifetime_params_map,
             next_node_id: self.next_node_id,
             node_id_to_def_id: self.node_id_to_def_id,
@@ -1495,7 +1465,6 @@ impl<'a> Resolver<'a> {
             import_res_map: self.import_res_map.clone(),
             label_res_map: self.label_res_map.clone(),
             lifetimes_res_map: self.lifetimes_res_map.clone(),
-            generics_def_id_map: self.generics_def_id_map.clone(),
             extra_lifetime_params_map: self.extra_lifetime_params_map.clone(),
             next_node_id: self.next_node_id.clone(),
             node_id_to_def_id: self.node_id_to_def_id.clone(),
@@ -1821,7 +1790,11 @@ impl<'a> Resolver<'a> {
         self.pat_span_map.insert(node, span);
     }
 
-    fn is_accessible_from(&self, vis: ty::Visibility, module: Module<'a>) -> bool {
+    fn is_accessible_from(
+        &self,
+        vis: ty::Visibility<impl Into<DefId>>,
+        module: Module<'a>,
+    ) -> bool {
         vis.is_accessible_from(module.nearest_parent_mod(), self)
     }
 
@@ -1875,10 +1848,8 @@ impl<'a> Resolver<'a> {
                     self.crate_loader.maybe_process_path_extern(ident.name)?
                 };
                 let crate_root = self.expect_module(crate_id.as_def_id());
-                Some(
-                    (crate_root, ty::Visibility::Public, DUMMY_SP, LocalExpnId::ROOT)
-                        .to_name_binding(self.arenas),
-                )
+                let vis = ty::Visibility::<LocalDefId>::Public;
+                Some((crate_root, vis, DUMMY_SP, LocalExpnId::ROOT).to_name_binding(self.arenas))
             }
         })
     }
@@ -1946,6 +1917,16 @@ impl<'a> Resolver<'a> {
         def_id.as_local().map(|def_id| self.source_span[def_id])
     }
 
+    /// Retrieves the name of the given `DefId`.
+    #[inline]
+    pub fn opt_name(&self, def_id: DefId) -> Option<Symbol> {
+        let def_key = match def_id.as_local() {
+            Some(def_id) => self.definitions.def_key(def_id),
+            None => self.cstore().def_key(def_id),
+        };
+        def_key.get_opt_name()
+    }
+
     /// Checks if an expression refers to a function marked with
     /// `#[rustc_legacy_const_generics]` and returns the argument index list
     /// from the attribute.
@@ -1985,7 +1966,7 @@ impl<'a> Resolver<'a> {
                         _ => panic!("invalid arg index"),
                     }
                 }
-                // Cache the lookup to avoid parsing attributes for an iterm multiple times.
+                // Cache the lookup to avoid parsing attributes for an item multiple times.
                 self.legacy_const_generic_args.insert(def_id, Some(ret.clone()));
                 return Some(ret);
             }
@@ -2015,6 +1996,24 @@ impl<'a> Resolver<'a> {
         }
         self.main_def = Some(MainDefinition { res, is_import, span });
     }
+
+    // Items that go to reexport table encoded to metadata and visible through it to other crates.
+    fn is_reexport(&self, binding: &NameBinding<'a>) -> Option<def::Res<!>> {
+        // FIXME: Consider changing the binding inserted by `#[macro_export] macro_rules`
+        // into the crate root to actual `NameBindingKind::Import`.
+        if binding.is_import()
+            || matches!(binding.kind, NameBindingKind::Res(_, _is_macro_export @ true))
+        {
+            let res = binding.res().expect_non_local();
+            // Ambiguous imports are treated as errors at this point and are
+            // not exposed to other crates (see #36837 for more details).
+            if res != def::Res::Err && !binding.is_ambiguity() {
+                return Some(res);
+            }
+        }
+
+        return None;
+    }
 }
 
 fn names_to_string(names: &[Symbol]) -> String {
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index 070fb9c72..dafa10e9e 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -112,47 +112,32 @@ fn fast_print_path(path: &ast::Path) -> Symbol {
     }
 }
 
-/// The code common between processing `#![register_tool]` and `#![register_attr]`.
-fn registered_idents(
-    sess: &Session,
-    attrs: &[ast::Attribute],
-    attr_name: Symbol,
-    descr: &str,
-) -> FxHashSet<Ident> {
-    let mut registered = FxHashSet::default();
-    for attr in sess.filter_by_name(attrs, attr_name) {
+pub(crate) fn registered_tools(sess: &Session, attrs: &[ast::Attribute]) -> FxHashSet<Ident> {
+    let mut registered_tools = FxHashSet::default();
+    for attr in sess.filter_by_name(attrs, sym::register_tool) {
         for nested_meta in attr.meta_item_list().unwrap_or_default() {
             match nested_meta.ident() {
                 Some(ident) => {
-                    if let Some(old_ident) = registered.replace(ident) {
-                        let msg = format!("{} `{}` was already registered", descr, ident);
+                    if let Some(old_ident) = registered_tools.replace(ident) {
+                        let msg = format!("{} `{}` was already registered", "tool", ident);
                         sess.struct_span_err(ident.span, &msg)
                             .span_label(old_ident.span, "already registered here")
                             .emit();
                     }
                 }
                 None => {
-                    let msg = format!("`{}` only accepts identifiers", attr_name);
+                    let msg = format!("`{}` only accepts identifiers", sym::register_tool);
                     let span = nested_meta.span();
                     sess.struct_span_err(span, &msg).span_label(span, "not an identifier").emit();
                 }
             }
         }
     }
-    registered
-}
-
-pub(crate) fn registered_attrs_and_tools(
-    sess: &Session,
-    attrs: &[ast::Attribute],
-) -> (FxHashSet<Ident>, FxHashSet<Ident>) {
-    let registered_attrs = registered_idents(sess, attrs, sym::register_attr, "attribute");
-    let mut registered_tools = registered_idents(sess, attrs, sym::register_tool, "tool");
     // We implicitly add `rustfmt` and `clippy` to known tools,
     // but it's not an error to register them explicitly.
     let predefined_tools = [sym::clippy, sym::rustfmt];
     registered_tools.extend(predefined_tools.iter().cloned().map(Ident::with_dummy_span));
-    (registered_attrs, registered_tools)
+    registered_tools
 }
 
 // Some feature gates for inner attributes are reported as lints for backward compatibility.
@@ -456,7 +441,7 @@ impl<'a> ResolverExpand for Resolver<'a> {
                 }
                 PathResult::Indeterminate => indeterminate = true,
                 // We can only be sure that a path doesn't exist after having tested all the
-                // posibilities, only at that time we can return false.
+                // possibilities, only at that time we can return false.
                 PathResult::Failed { .. } => {}
                 PathResult::Module(_) => panic!("unexpected path resolution"),
             }