Merging upstream version 1.70.0+dfsg1.

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

14 files changed, 687 insertions, 429 deletions

diff --git a/compiler/rustc_resolve/locales/en-US.ftl b/compiler/rustc_resolve/messages.ftl
index 817bb83ed..01f002c94 100644
--- a/compiler/rustc_resolve/locales/en-US.ftl
+++ b/compiler/rustc_resolve/messages.ftl
@@ -42,7 +42,7 @@ resolve_try_adding_local_generic_param_on_method =
     try adding a local generic parameter in this method instead
 
 resolve_help_try_using_local_generic_param =
-    try using a local generic paramter instead
+    try using a local generic parameter instead
 
 resolve_name_is_already_used_as_generic_parameter =
     the name `{$name}` is already used for a generic parameter in this item's generic parameters
@@ -207,5 +207,19 @@ resolve_expected_found =
 resolve_indeterminate =
     cannot determine resolution for the visibility
 
+resolve_tool_module_imported =
+    cannot use a tool module through an import
+    .note = the tool module imported here
+
 resolve_module_only =
     visibility must resolve to a module
+
+resolve_macro_expected_found =
+    expected {$expected}, found {$found} `{$macro_path}`
+
+resolve_remove_surrounding_derive =
+    remove from the surrounding `derive()`
+
+resolve_add_as_non_derive =
+    add as non-Derive macro
+    `#[{$macro_path}]`
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index b1e023f2c..ff0f1f559 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -25,12 +25,9 @@ use rustc_expand::expand::AstFragment;
 use rustc_hir::def::{self, *};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
 use rustc_metadata::creader::LoadedMacro;
-use rustc_middle::bug;
 use rustc_middle::metadata::ModChild;
-use rustc_middle::ty::{self, DefIdTree};
-use rustc_session::cstore::CrateStore;
+use rustc_middle::{bug, ty};
 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind};
-use rustc_span::source_map::respan;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::Span;
 
@@ -99,7 +96,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         loop {
             match self.get_module(def_id) {
                 Some(module) => return module,
-                None => def_id = self.parent(def_id),
+                None => def_id = self.tcx.parent(def_id),
             }
         }
     }
@@ -117,35 +114,28 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
 
         if !def_id.is_local() {
-            let def_kind = self.cstore().def_kind(def_id);
-            match def_kind {
-                DefKind::Mod | DefKind::Enum | DefKind::Trait => {
-                    let def_key = self.cstore().def_key(def_id);
-                    let parent = def_key.parent.map(|index| {
-                        self.get_nearest_non_block_module(DefId { index, krate: def_id.krate })
-                    });
-                    let name = if let Some(cnum) = def_id.as_crate_root() {
-                        self.cstore().crate_name(cnum)
-                    } else {
-                        def_key.disambiguated_data.data.get_opt_name().expect("module without name")
-                    };
-
-                    let expn_id = self.cstore().module_expansion_untracked(def_id, &self.tcx.sess);
-                    let span = self.cstore().get_span_untracked(def_id, &self.tcx.sess);
-                    Some(self.new_module(
-                        parent,
-                        ModuleKind::Def(def_kind, def_id, name),
-                        expn_id,
-                        span,
-                        // FIXME: Account for `#[no_implicit_prelude]` attributes.
-                        parent.map_or(false, |module| module.no_implicit_prelude),
-                    ))
-                }
-                _ => None,
+            // Query `def_kind` is not used because query system overhead is too expensive here.
+            let def_kind = self.cstore().def_kind_untracked(def_id);
+            if let DefKind::Mod | DefKind::Enum | DefKind::Trait = def_kind {
+                let parent = self
+                    .tcx
+                    .opt_parent(def_id)
+                    .map(|parent_id| self.get_nearest_non_block_module(parent_id));
+                // Query `expn_that_defined` is not used because
+                // hashing spans in its result is expensive.
+                let expn_id = self.cstore().expn_that_defined_untracked(def_id, &self.tcx.sess);
+                return Some(self.new_module(
+                    parent,
+                    ModuleKind::Def(def_kind, def_id, self.tcx.item_name(def_id)),
+                    expn_id,
+                    self.def_span(def_id),
+                    // FIXME: Account for `#[no_implicit_prelude]` attributes.
+                    parent.map_or(false, |module| module.no_implicit_prelude),
+                ));
             }
-        } else {
-            None
         }
+
+        None
     }
 
     pub(crate) fn expn_def_scope(&mut self, expn_id: ExpnId) -> Module<'a> {
@@ -207,6 +197,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     }
 
     pub(crate) fn build_reduced_graph_external(&mut self, module: Module<'a>) {
+        // Query `module_children` is not used because hashing spans in its result is expensive.
         let children =
             Vec::from_iter(self.cstore().module_children_untracked(module.def_id(), self.tcx.sess));
         for child in children {
@@ -329,13 +320,13 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         }
     }
 
-    fn insert_field_names_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
-        let field_names = vdata
-            .fields()
-            .iter()
-            .map(|field| respan(field.span, field.ident.map_or(kw::Empty, |ident| ident.name)))
-            .collect();
-        self.r.field_names.insert(def_id, field_names);
+    fn insert_field_def_ids(&mut self, def_id: LocalDefId, vdata: &ast::VariantData) {
+        if vdata.fields().iter().any(|field| field.is_placeholder) {
+            // The fields are not expanded yet.
+            return;
+        }
+        let def_ids = vdata.fields().iter().map(|field| self.r.local_def_id(field.id).to_def_id());
+        self.r.field_def_ids.insert(def_id, self.r.tcx.arena.alloc_from_iter(def_ids));
     }
 
     fn insert_field_visibilities_local(&mut self, def_id: DefId, vdata: &ast::VariantData) {
@@ -347,12 +338,6 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         self.r.field_visibility_spans.insert(def_id, field_vis);
     }
 
-    fn insert_field_names_extern(&mut self, def_id: DefId) {
-        let field_names =
-            self.r.cstore().struct_field_names_untracked(def_id, self.r.tcx.sess).collect();
-        self.r.field_names.insert(def_id, field_names);
-    }
-
     fn block_needs_anonymous_module(&mut self, block: &Block) -> bool {
         // If any statements are items, we need to create an anonymous module
         block
@@ -579,7 +564,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             }
             ast::UseTreeKind::Glob => {
                 let kind = ImportKind::Glob {
-                    is_prelude: self.r.tcx.sess.contains_name(&item.attrs, sym::prelude_import),
+                    is_prelude: attr::contains_name(&item.attrs, sym::prelude_import),
                     max_vis: Cell::new(None),
                     id,
                 };
@@ -694,7 +679,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                     expansion.to_expn_id(),
                     item.span,
                     parent.no_implicit_prelude
-                        || self.r.tcx.sess.contains_name(&item.attrs, sym::no_implicit_prelude),
+                        || attr::contains_name(&item.attrs, sym::no_implicit_prelude),
                 );
                 self.r.define(parent, ident, TypeNS, (module, vis, sp, expansion));
 
@@ -703,8 +688,8 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             }
 
             // These items live in the value namespace.
-            ItemKind::Static(_, mt, _) => {
-                let res = Res::Def(DefKind::Static(mt), def_id);
+            ItemKind::Static(box ast::StaticItem { mutability, .. }) => {
+                let res = Res::Def(DefKind::Static(mutability), def_id);
                 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
             }
             ItemKind::Const(..) => {
@@ -750,7 +735,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
 
                 // Record field names for error reporting.
-                self.insert_field_names_local(def_id, vdata);
+                self.insert_field_def_ids(local_def_id, vdata);
                 self.insert_field_visibilities_local(def_id, vdata);
 
                 // If this is a tuple or unit struct, define a name
@@ -759,7 +744,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                     // If the structure is marked as non_exhaustive then lower the visibility
                     // to within the crate.
                     let mut ctor_vis = if vis.is_public()
-                        && self.r.tcx.sess.contains_name(&item.attrs, sym::non_exhaustive)
+                        && attr::contains_name(&item.attrs, sym::non_exhaustive)
                     {
                         ty::Visibility::Restricted(CRATE_DEF_ID)
                     } else {
@@ -775,7 +760,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                         let field_vis = self
                             .try_resolve_visibility(&field.vis, false)
                             .unwrap_or(ty::Visibility::Public);
-                        if ctor_vis.is_at_least(field_vis, &*self.r) {
+                        if ctor_vis.is_at_least(field_vis, self.r.tcx) {
                             ctor_vis = field_vis;
                         }
                         ret_fields.push(field_vis.to_def_id());
@@ -790,7 +775,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
                     self.r
                         .struct_constructors
-                        .insert(def_id, (ctor_res, ctor_vis.to_def_id(), ret_fields));
+                        .insert(local_def_id, (ctor_res, ctor_vis.to_def_id(), ret_fields));
                 }
             }
 
@@ -799,7 +784,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 self.r.define(parent, ident, TypeNS, (res, vis, sp, expansion));
 
                 // Record field names for error reporting.
-                self.insert_field_names_local(def_id, vdata);
+                self.insert_field_def_ids(local_def_id, vdata);
                 self.insert_field_visibilities_local(def_id, vdata);
             }
 
@@ -946,7 +931,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
     /// Builds the reduced graph for a single item in an external crate.
     fn build_reduced_graph_for_external_crate_res(&mut self, child: ModChild) {
         let parent = self.parent_scope.module;
-        let ModChild { ident, res, vis, span, macro_rules } = child;
+        let ModChild { ident, res, vis, span, .. } = child;
         let res = res.expect_non_local();
         let expansion = self.parent_scope.expansion;
         // Record primary definitions.
@@ -979,9 +964,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 _,
             ) => self.r.define(parent, ident, ValueNS, (res, vis, span, expansion)),
             Res::Def(DefKind::Macro(..), _) | Res::NonMacroAttr(..) => {
-                if !macro_rules {
-                    self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
-                }
+                self.r.define(parent, ident, MacroNS, (res, vis, span, expansion))
             }
             Res::Def(
                 DefKind::TyParam
@@ -1005,32 +988,6 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             | Res::SelfCtor(..)
             | Res::Err => bug!("unexpected resolution: {:?}", res),
         }
-        // Record some extra data for better diagnostics.
-        match res {
-            Res::Def(DefKind::Struct, def_id) => {
-                let cstore = self.r.cstore();
-                if let Some((ctor_kind, ctor_def_id)) = cstore.ctor_untracked(def_id) {
-                    let ctor_res = Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
-                    let ctor_vis = cstore.visibility_untracked(ctor_def_id);
-                    let field_visibilities =
-                        cstore.struct_field_visibilities_untracked(def_id).collect();
-                    drop(cstore);
-                    self.r
-                        .struct_constructors
-                        .insert(def_id, (ctor_res, ctor_vis, field_visibilities));
-                } else {
-                    drop(cstore);
-                }
-                self.insert_field_names_extern(def_id)
-            }
-            Res::Def(DefKind::Union, def_id) => self.insert_field_names_extern(def_id),
-            Res::Def(DefKind::AssocFn, def_id) => {
-                if self.r.cstore().fn_has_self_parameter_untracked(def_id, self.r.tcx.sess) {
-                    self.r.has_self.insert(def_id);
-                }
-            }
-            _ => {}
-        }
     }
 
     fn add_macro_use_binding(
@@ -1203,12 +1160,11 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
     }
 
     fn proc_macro_stub(&self, item: &ast::Item) -> Option<(MacroKind, Ident, Span)> {
-        if self.r.tcx.sess.contains_name(&item.attrs, sym::proc_macro) {
+        if attr::contains_name(&item.attrs, sym::proc_macro) {
             return Some((MacroKind::Bang, item.ident, item.span));
-        } else if self.r.tcx.sess.contains_name(&item.attrs, sym::proc_macro_attribute) {
+        } else if attr::contains_name(&item.attrs, sym::proc_macro_attribute) {
             return Some((MacroKind::Attr, item.ident, item.span));
-        } else if let Some(attr) = self.r.tcx.sess.find_by_name(&item.attrs, sym::proc_macro_derive)
-        {
+        } else if let Some(attr) = attr::find_by_name(&item.attrs, sym::proc_macro_derive) {
             if let Some(nested_meta) = attr.meta_item_list().and_then(|list| list.get(0).cloned()) {
                 if let Some(ident) = nested_meta.ident() {
                     return Some((MacroKind::Derive, ident, ident.span));
@@ -1263,7 +1219,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         if macro_rules {
             let ident = ident.normalize_to_macros_2_0();
             self.r.macro_names.insert(ident);
-            let is_macro_export = self.r.tcx.sess.contains_name(&item.attrs, sym::macro_export);
+            let is_macro_export = attr::contains_name(&item.attrs, sym::macro_export);
             let vis = if is_macro_export {
                 ty::Visibility::Public
             } else {
@@ -1414,10 +1370,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
 
         if !(ctxt == AssocCtxt::Impl
             && matches!(item.vis.kind, ast::VisibilityKind::Inherited)
-            && self
-                .r
-                .trait_impl_items
-                .contains(&ty::DefIdTree::local_parent(&*self.r, local_def_id)))
+            && self.r.trait_impl_items.contains(&self.r.tcx.local_parent(local_def_id)))
         {
             // Trait impl item visibility is inherited from its trait when not specified
             // explicitly. In that case we cannot determine it here in early resolve,
@@ -1430,7 +1383,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
                 AssocItemKind::Const(..) => (DefKind::AssocConst, ValueNS),
                 AssocItemKind::Fn(box Fn { ref sig, .. }) => {
                     if sig.decl.has_self() {
-                        self.r.has_self.insert(def_id);
+                        self.r.has_self.insert(local_def_id);
                     }
                     (DefKind::AssocFn, ValueNS)
                 }
@@ -1526,13 +1479,12 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         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.is_public()
-            && self.r.tcx.sess.contains_name(&variant.attrs, sym::non_exhaustive)
-        {
-            ty::Visibility::Restricted(CRATE_DEF_ID)
-        } else {
-            vis
-        };
+        let ctor_vis =
+            if vis.is_public() && attr::contains_name(&variant.attrs, sym::non_exhaustive) {
+                ty::Visibility::Restricted(CRATE_DEF_ID)
+            } else {
+                vis
+            };
 
         // Define a constructor name in the value namespace.
         if let Some((ctor_kind, ctor_node_id)) = CtorKind::from_ast(&variant.data) {
@@ -1544,7 +1496,7 @@ impl<'a, 'b, 'tcx> Visitor<'b> for BuildReducedGraphVisitor<'a, 'b, 'tcx> {
         }
 
         // Record field names for error reporting.
-        self.insert_field_names_local(def_id.to_def_id(), &variant.data);
+        self.insert_field_def_ids(def_id, &variant.data);
         self.insert_field_visibilities_local(def_id.to_def_id(), &variant.data);
 
         visit::walk_variant(self, variant);
diff --git a/compiler/rustc_resolve/src/check_unused.rs b/compiler/rustc_resolve/src/check_unused.rs
index b2578e4c4..ae3fd0ede 100644
--- a/compiler/rustc_resolve/src/check_unused.rs
+++ b/compiler/rustc_resolve/src/check_unused.rs
@@ -32,9 +32,10 @@ use rustc_ast::visit::{self, Visitor};
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_data_structures::unord::UnordSet;
 use rustc_errors::{pluralize, MultiSpan};
+use rustc_hir::def::{DefKind, Res};
 use rustc_session::lint::builtin::{MACRO_USE_EXTERN_CRATE, UNUSED_EXTERN_CRATES, UNUSED_IMPORTS};
 use rustc_session::lint::BuiltinLintDiagnostics;
-use rustc_span::symbol::Ident;
+use rustc_span::symbol::{kw, Ident};
 use rustc_span::{Span, DUMMY_SP};
 
 struct UnusedImport<'a> {
@@ -58,6 +59,7 @@ struct UnusedImportCheckVisitor<'a, 'b, 'tcx> {
     base_use_tree: Option<&'a ast::UseTree>,
     base_id: ast::NodeId,
     item_span: Span,
+    base_use_is_pub: bool,
 }
 
 struct ExternCrateToLint {
@@ -110,6 +112,35 @@ impl<'a, 'b, 'tcx> UnusedImportCheckVisitor<'a, 'b, 'tcx> {
             unused: Default::default(),
         })
     }
+
+    fn check_import_as_underscore(&mut self, item: &ast::UseTree, id: ast::NodeId) {
+        match item.kind {
+            ast::UseTreeKind::Simple(Some(ident)) => {
+                if ident.name == kw::Underscore
+                    && !self
+                        .r
+                        .import_res_map
+                        .get(&id)
+                        .map(|per_ns| {
+                            per_ns.iter().filter_map(|res| res.as_ref()).any(|res| {
+                                matches!(res, Res::Def(DefKind::Trait | DefKind::TraitAlias, _))
+                            })
+                        })
+                        .unwrap_or(false)
+                {
+                    self.unused_import(self.base_id).add(id);
+                }
+            }
+            ast::UseTreeKind::Nested(ref items) => self.check_imports_as_underscore(items),
+            _ => {}
+        }
+    }
+
+    fn check_imports_as_underscore(&mut self, items: &[(ast::UseTree, ast::NodeId)]) {
+        for (item, id) in items {
+            self.check_import_as_underscore(item, *id);
+        }
+    }
 }
 
 impl<'a, 'b, 'tcx> Visitor<'a> for UnusedImportCheckVisitor<'a, 'b, 'tcx> {
@@ -119,7 +150,8 @@ impl<'a, 'b, 'tcx> Visitor<'a> for UnusedImportCheckVisitor<'a, 'b, 'tcx> {
             // whether they're used or not. Also ignore imports with a dummy span
             // because this means that they were generated in some fashion by the
             // compiler and we don't need to consider them.
-            ast::ItemKind::Use(..) if item.vis.kind.is_pub() || item.span.is_dummy() => return,
+            ast::ItemKind::Use(..) if item.span.is_dummy() => return,
+            ast::ItemKind::Use(..) => self.base_use_is_pub = item.vis.kind.is_pub(),
             ast::ItemKind::ExternCrate(orig_name) => {
                 self.extern_crate_items.push(ExternCrateToLint {
                     id: item.id,
@@ -146,6 +178,11 @@ impl<'a, 'b, 'tcx> Visitor<'a> for UnusedImportCheckVisitor<'a, 'b, 'tcx> {
             self.base_use_tree = Some(use_tree);
         }
 
+        if self.base_use_is_pub {
+            self.check_import_as_underscore(use_tree, id);
+            return;
+        }
+
         if let ast::UseTreeKind::Nested(ref items) = use_tree.kind {
             if items.is_empty() {
                 self.unused_import(self.base_id).add(id);
@@ -300,6 +337,7 @@ impl Resolver<'_, '_> {
             base_use_tree: None,
             base_id: ast::DUMMY_NODE_ID,
             item_span: DUMMY_SP,
+            base_use_is_pub: false,
         };
         visit::walk_crate(&mut visitor, krate);
 
@@ -355,7 +393,7 @@ impl Resolver<'_, '_> {
             // If we are in the `--test` mode, suppress a help that adds the `#[cfg(test)]`
             // attribute; however, if not, suggest adding the attribute. There is no way to
             // retrieve attributes here because we do not have a `TyCtxt` yet.
-            let test_module_span = if tcx.sess.opts.test {
+            let test_module_span = if tcx.sess.is_test_crate() {
                 None
             } else {
                 let parent_module = visitor.r.get_nearest_non_block_module(
diff --git a/compiler/rustc_resolve/src/def_collector.rs b/compiler/rustc_resolve/src/def_collector.rs
index e7ff236f8..356d7f365 100644
--- a/compiler/rustc_resolve/src/def_collector.rs
+++ b/compiler/rustc_resolve/src/def_collector.rs
@@ -260,9 +260,7 @@ impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> {
                     Async::No => closure_def,
                 }
             }
-            ExprKind::Async(_, async_id, _) => {
-                self.create_def(async_id, DefPathData::ClosureExpr, expr.span)
-            }
+            ExprKind::Async(_, _) => self.create_def(expr.id, DefPathData::ClosureExpr, expr.span),
             _ => self.parent_def,
         };
 
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 7add59ac6..0c9d30608 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -12,10 +12,10 @@ use rustc_errors::{struct_span_err, SuggestionStyle};
 use rustc_feature::BUILTIN_ATTRIBUTES;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, CtorOf, DefKind, NonMacroAttrKind, PerNS};
-use rustc_hir::def_id::{DefId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
 use rustc_hir::PrimTy;
 use rustc_middle::bug;
-use rustc_middle::ty::{DefIdTree, TyCtxt};
+use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::ABSOLUTE_PATHS_NOT_STARTING_WITH_CRATE;
 use rustc_session::lint::builtin::MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS;
 use rustc_session::lint::BuiltinLintDiagnostics;
@@ -555,25 +555,22 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         return err;
                     }
                     Res::SelfTyAlias { alias_to: def_id, .. } => {
-                        if let Some(impl_span) = self.opt_span(def_id) {
-                            err.span_label(
-                                reduce_impl_span_to_impl_keyword(sm, impl_span),
-                                "`Self` type implicitly declared here, by this `impl`",
-                            );
-                        }
+                        err.span_label(
+                            reduce_impl_span_to_impl_keyword(sm, self.def_span(def_id)),
+                            "`Self` type implicitly declared here, by this `impl`",
+                        );
                         err.span_label(span, "use a type here instead");
                         return err;
                     }
                     Res::Def(DefKind::TyParam, def_id) => {
-                        if let Some(span) = self.opt_span(def_id) {
-                            err.span_label(span, "type parameter from outer function");
-                        }
+                        err.span_label(self.def_span(def_id), "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");
-                        }
+                        err.span_label(
+                            self.def_span(def_id),
+                            "const parameter from outer function",
+                        );
                         def_id
                     }
                     _ => {
@@ -589,7 +586,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     // 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";
-                    let name = self.opt_name(def_id).unwrap_or(sym::T);
+                    let name = self.tcx.item_name(def_id);
                     let (span, snippet) = if span.is_empty() {
                         let snippet = format!("<{}>", name);
                         (span, snippet)
@@ -1197,7 +1194,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         segms.push(ast::PathSegment::from_ident(ident));
                         let path = Path { span: name_binding.span, segments: segms, tokens: None };
                         let did = match res {
-                            Res::Def(DefKind::Ctor(..), did) => this.opt_parent(did),
+                            Res::Def(DefKind::Ctor(..), did) => this.tcx.opt_parent(did),
                             _ => res.opt_def_id(),
                         };
 
@@ -1216,15 +1213,11 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                             // a note about editions
                             let note = if let Some(did) = did {
                                 let requires_note = !did.is_local()
-                                    && this.cstore().item_attrs_untracked(did, this.tcx.sess).any(
+                                    && this.tcx.get_attrs(did, sym::rustc_diagnostic_item).any(
                                         |attr| {
-                                            if attr.has_name(sym::rustc_diagnostic_item) {
-                                                [sym::TryInto, sym::TryFrom, sym::FromIterator]
-                                                    .map(|x| Some(x))
-                                                    .contains(&attr.value_str())
-                                            } else {
-                                                false
-                                            }
+                                            [sym::TryInto, sym::TryFrom, sym::FromIterator]
+                                                .map(|x| Some(x))
+                                                .contains(&attr.value_str())
                                         },
                                     );
 
@@ -1373,8 +1366,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
         if ident.name == kw::Default
             && let ModuleKind::Def(DefKind::Enum, def_id, _) = parent_scope.module.kind
-            && let Some(span) = self.opt_span(def_id)
         {
+            let span = self.def_span(def_id);
             let source_map = self.tcx.sess.source_map();
             let head_span = source_map.guess_head_span(span);
             if let Ok(head) = source_map.span_to_snippet(head_span) {
@@ -1450,11 +1443,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             Some(suggestion) if suggestion.candidate == kw::Underscore => return false,
             Some(suggestion) => suggestion,
         };
-        let def_span = suggestion.res.opt_def_id().and_then(|def_id| match def_id.krate {
-            LOCAL_CRATE => self.opt_span(def_id),
-            _ => Some(self.cstore().get_span_untracked(def_id, self.tcx.sess)),
-        });
-        if let Some(def_span) = def_span {
+        if let Some(def_span) = suggestion.res.opt_def_id().map(|def_id| self.def_span(def_id)) {
             if span.overlaps(def_span) {
                 // Don't suggest typo suggestion for itself like in the following:
                 // error[E0423]: expected function, tuple struct or tuple variant, found struct `X`
@@ -1591,9 +1580,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             ctor_def_id,
         )) = binding.kind
         {
-            let def_id = self.parent(ctor_def_id);
-            let fields = self.field_names.get(&def_id)?;
-            return fields.iter().map(|name| name.span).reduce(Span::to); // None for `struct Foo()`
+            let def_id = self.tcx.parent(ctor_def_id);
+            return self
+                .field_def_ids(def_id)?
+                .iter()
+                .map(|&field_id| self.def_span(field_id))
+                .reduce(Span::to); // None for `struct Foo()`
         }
         None
     }
@@ -1615,7 +1607,17 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         let mut err =
             struct_span_err!(self.tcx.sess, ident.span, E0603, "{} `{}` is private", descr, ident);
         err.span_label(ident.span, &format!("private {}", descr));
-        if let Some(span) = ctor_fields_span {
+
+        let mut non_exhaustive = None;
+        // If an ADT is foreign and marked as `non_exhaustive`, then that's
+        // probably why we have the privacy error.
+        // Otherwise, point out if the struct has any private fields.
+        if let Some(def_id) = res.opt_def_id()
+            && !def_id.is_local()
+            && let Some(attr) = self.tcx.get_attr(def_id, sym::non_exhaustive)
+        {
+            non_exhaustive = Some(attr.span);
+        } else if let Some(span) = ctor_fields_span {
             err.span_label(span, "a constructor is private if any of the fields is private");
             if let Res::Def(_, d) = res && let Some(fields) = self.field_visibility_spans.get(&d) {
                 err.multipart_suggestion_verbose(
@@ -1664,6 +1666,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             if !first && binding.vis.is_public() {
                 note_span.push_span_label(def_span, "consider importing it directly");
             }
+            // Final step in the import chain, point out if the ADT is `non_exhaustive`
+            // which is probably why this privacy violation occurred.
+            if next_binding.is_none() && let Some(span) = non_exhaustive {
+                note_span.push_span_label(
+                    span,
+                    format!("cannot be constructed because it is `#[non_exhaustive]`"),
+                );
+            }
             err.span_note(note_span, &msg);
         }
 
@@ -1677,8 +1687,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     ) -> Option<Symbol> {
         let mut candidates = self
             .extern_prelude
-            .iter()
-            .map(|(ident, _)| ident.name)
+            .keys()
+            .map(|ident| ident.name)
             .chain(
                 self.module_map
                     .iter()
@@ -2015,7 +2025,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         // 1) some consistent ordering for emitted diagnostics, and
         // 2) `std` suggestions before `core` suggestions.
         let mut extern_crate_names =
-            self.extern_prelude.iter().map(|(ident, _)| ident.name).collect::<Vec<_>>();
+            self.extern_prelude.keys().map(|ident| ident.name).collect::<Vec<_>>();
         extern_crate_names.sort_by(|a, b| b.as_str().partial_cmp(a.as_str()).unwrap());
 
         for name in extern_crate_names.into_iter() {
diff --git a/compiler/rustc_resolve/src/effective_visibilities.rs b/compiler/rustc_resolve/src/effective_visibilities.rs
index 7bd90d7e3..bed579f6b 100644
--- a/compiler/rustc_resolve/src/effective_visibilities.rs
+++ b/compiler/rustc_resolve/src/effective_visibilities.rs
@@ -4,12 +4,13 @@ use rustc_ast::visit;
 use rustc_ast::visit::Visitor;
 use rustc_ast::Crate;
 use rustc_ast::EnumDef;
+use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::intern::Interned;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_middle::middle::privacy::Level;
 use rustc_middle::middle::privacy::{EffectiveVisibilities, EffectiveVisibility};
-use rustc_middle::ty::{DefIdTree, Visibility};
+use rustc_middle::ty::Visibility;
 use std::mem;
 
 type ImportId<'a> = Interned<'a, NameBinding<'a>>;
@@ -60,7 +61,7 @@ impl Resolver<'_, '_> {
         // For mod items `nearest_normal_mod` returns its argument, but we actually need its parent.
         let normal_mod_id = self.nearest_normal_mod(def_id);
         if normal_mod_id == def_id {
-            self.opt_local_parent(def_id).map_or(Visibility::Public, Visibility::Restricted)
+            Visibility::Restricted(self.tcx.local_parent(def_id))
         } else {
             Visibility::Restricted(normal_mod_id)
         }
@@ -70,21 +71,20 @@ impl Resolver<'_, '_> {
 impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
     /// Fills the `Resolver::effective_visibilities` table with public & exported items
     /// For now, this doesn't resolve macros (FIXME) and cannot resolve Impl, as we
-    /// need access to a TyCtxt for that.
+    /// need access to a TyCtxt for that. Returns the set of ambiguous re-exports.
     pub(crate) fn compute_effective_visibilities<'c>(
         r: &'r mut Resolver<'a, 'tcx>,
         krate: &'c Crate,
-    ) {
+    ) -> FxHashSet<Interned<'a, NameBinding<'a>>> {
         let mut visitor = EffectiveVisibilitiesVisitor {
             r,
             def_effective_visibilities: Default::default(),
             import_effective_visibilities: Default::default(),
-            current_private_vis: Visibility::Public,
+            current_private_vis: Visibility::Restricted(CRATE_DEF_ID),
             changed: false,
         };
 
-        visitor.update(CRATE_DEF_ID, CRATE_DEF_ID);
-        visitor.current_private_vis = Visibility::Restricted(CRATE_DEF_ID);
+        visitor.def_effective_visibilities.update_root();
         visitor.set_bindings_effective_visibilities(CRATE_DEF_ID);
 
         while visitor.changed {
@@ -93,18 +93,26 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
         }
         visitor.r.effective_visibilities = visitor.def_effective_visibilities;
 
+        let mut exported_ambiguities = FxHashSet::default();
+
         // Update visibilities for import def ids. These are not used during the
         // `EffectiveVisibilitiesVisitor` pass, because we have more detailed binding-based
         // information, but are used by later passes. Effective visibility of an import def id
         // is the maximum value among visibilities of bindings corresponding to that def id.
         for (binding, eff_vis) in visitor.import_effective_visibilities.iter() {
             let NameBindingKind::Import { import, .. } = binding.kind else { unreachable!() };
-            if let Some(node_id) = import.id() {
-                r.effective_visibilities.update_eff_vis(r.local_def_id(node_id), eff_vis, r.tcx)
+            if !binding.is_ambiguity() {
+                if let Some(node_id) = import.id() {
+                    r.effective_visibilities.update_eff_vis(r.local_def_id(node_id), eff_vis, r.tcx)
+                }
+            } else if binding.ambiguity.is_some() && eff_vis.is_public_at_level(Level::Reexported) {
+                exported_ambiguities.insert(*binding);
             }
         }
 
         info!("resolve::effective_visibilities: {:#?}", r.effective_visibilities);
+
+        exported_ambiguities
     }
 
     /// Update effective visibilities of bindings in the given module,
@@ -115,30 +123,38 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
         let resolutions = self.r.resolutions(module);
 
         for (_, name_resolution) in resolutions.borrow().iter() {
-            if let Some(mut binding) = name_resolution.borrow().binding() && !binding.is_ambiguity() {
+            if let Some(mut binding) = name_resolution.borrow().binding() {
                 // Set the given effective visibility level to `Level::Direct` and
                 // sets the rest of the `use` chain to `Level::Reexported` until
                 // we hit the actual exported item.
+                //
+                // If the binding is ambiguous, put the root ambiguity binding and all reexports
+                // leading to it into the table. They are used by the `ambiguous_glob_reexports`
+                // lint. For all bindings added to the table this way `is_ambiguity` returns true.
                 let mut parent_id = ParentId::Def(module_id);
                 while let NameBindingKind::Import { binding: nested_binding, .. } = binding.kind {
                     let binding_id = ImportId::new_unchecked(binding);
                     self.update_import(binding_id, parent_id);
 
+                    if binding.ambiguity.is_some() {
+                        // Stop at the root ambiguity, further bindings in the chain should not
+                        // be reexported because the root ambiguity blocks any access to them.
+                        // (Those further bindings are most likely not ambiguities themselves.)
+                        break;
+                    }
+
                     parent_id = ParentId::Import(binding_id);
                     binding = nested_binding;
                 }
 
-                if let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
+                if binding.ambiguity.is_none()
+                    && let Some(def_id) = binding.res().opt_def_id().and_then(|id| id.as_local()) {
                     self.update_def(def_id, binding.vis.expect_local(), parent_id);
                 }
             }
         }
     }
 
-    fn cheap_private_vis(&self, parent_id: ParentId<'_>) -> Option<Visibility> {
-        matches!(parent_id, ParentId::Def(_)).then_some(self.current_private_vis)
-    }
-
     fn effective_vis_or_private(&mut self, parent_id: ParentId<'a>) -> EffectiveVisibility {
         // Private nodes are only added to the table for caching, they could be added or removed at
         // any moment without consequences, so we don't set `changed` to true when adding them.
@@ -152,15 +168,39 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
         }
     }
 
+    /// All effective visibilities for a node are larger or equal than private visibility
+    /// for that node (see `check_invariants` in middle/privacy.rs).
+    /// So if either parent or nominal visibility is the same as private visibility, then
+    /// `min(parent_vis, nominal_vis) <= private_vis`, and the update logic is guaranteed
+    /// to not update anything and we can skip it.
+    ///
+    /// We are checking this condition only if the correct value of private visibility is
+    /// cheaply available, otherwise it does't make sense performance-wise.
+    ///
+    /// `None` is returned if the update can be skipped,
+    /// and cheap private visibility is returned otherwise.
+    fn may_update(
+        &self,
+        nominal_vis: Visibility,
+        parent_id: ParentId<'_>,
+    ) -> Option<Option<Visibility>> {
+        match parent_id {
+            ParentId::Def(def_id) => (nominal_vis != self.current_private_vis
+                && self.r.visibilities[&def_id] != self.current_private_vis)
+                .then_some(Some(self.current_private_vis)),
+            ParentId::Import(_) => Some(None),
+        }
+    }
+
     fn update_import(&mut self, binding: ImportId<'a>, parent_id: ParentId<'a>) {
         let nominal_vis = binding.vis.expect_local();
-        let private_vis = self.cheap_private_vis(parent_id);
+        let Some(cheap_private_vis) = self.may_update(nominal_vis, parent_id) else { return };
         let inherited_eff_vis = self.effective_vis_or_private(parent_id);
         let tcx = self.r.tcx;
         self.changed |= self.import_effective_visibilities.update(
             binding,
             nominal_vis,
-            || private_vis.unwrap_or_else(|| self.r.private_vis_import(binding)),
+            || cheap_private_vis.unwrap_or_else(|| self.r.private_vis_import(binding)),
             inherited_eff_vis,
             parent_id.level(),
             tcx,
@@ -168,20 +208,20 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
     }
 
     fn update_def(&mut self, def_id: LocalDefId, nominal_vis: Visibility, parent_id: ParentId<'a>) {
-        let private_vis = self.cheap_private_vis(parent_id);
+        let Some(cheap_private_vis) = self.may_update(nominal_vis, parent_id) else { return };
         let inherited_eff_vis = self.effective_vis_or_private(parent_id);
         let tcx = self.r.tcx;
         self.changed |= self.def_effective_visibilities.update(
             def_id,
             nominal_vis,
-            || private_vis.unwrap_or_else(|| self.r.private_vis_def(def_id)),
+            || cheap_private_vis.unwrap_or_else(|| self.r.private_vis_def(def_id)),
             inherited_eff_vis,
             parent_id.level(),
             tcx,
         );
     }
 
-    fn update(&mut self, def_id: LocalDefId, parent_id: LocalDefId) {
+    fn update_field(&mut self, def_id: LocalDefId, parent_id: LocalDefId) {
         self.update_def(def_id, self.r.visibilities[&def_id], ParentId::Def(parent_id));
     }
 }
@@ -213,14 +253,14 @@ impl<'r, 'ast, 'tcx> Visitor<'ast> for EffectiveVisibilitiesVisitor<'ast, 'r, 't
                 for variant in variants {
                     let variant_def_id = self.r.local_def_id(variant.id);
                     for field in variant.data.fields() {
-                        self.update(self.r.local_def_id(field.id), variant_def_id);
+                        self.update_field(self.r.local_def_id(field.id), variant_def_id);
                     }
                 }
             }
 
             ast::ItemKind::Struct(ref def, _) | ast::ItemKind::Union(ref def, _) => {
                 for field in def.fields() {
-                    self.update(self.r.local_def_id(field.id), def_id);
+                    self.update_field(self.r.local_def_id(field.id), def_id);
                 }
             }
 
diff --git a/compiler/rustc_resolve/src/errors.rs b/compiler/rustc_resolve/src/errors.rs
index 867363f42..afa796cb6 100644
--- a/compiler/rustc_resolve/src/errors.rs
+++ b/compiler/rustc_resolve/src/errors.rs
@@ -470,5 +470,41 @@ pub(crate) struct ExpectedFound {
 pub(crate) struct Indeterminate(#[primary_span] pub(crate) Span);
 
 #[derive(Diagnostic)]
+#[diag(resolve_tool_module_imported)]
+pub(crate) struct ToolModuleImported {
+    #[primary_span]
+    pub(crate) span: Span,
+    #[note]
+    pub(crate) import: Span,
+}
+
+#[derive(Diagnostic)]
 #[diag(resolve_module_only)]
 pub(crate) struct ModuleOnly(#[primary_span] pub(crate) Span);
+
+#[derive(Diagnostic, Default)]
+#[diag(resolve_macro_expected_found)]
+pub(crate) struct MacroExpectedFound<'a> {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) found: &'a str,
+    pub(crate) expected: &'a str,
+    pub(crate) macro_path: &'a str,
+    #[subdiagnostic]
+    pub(crate) remove_surrounding_derive: Option<RemoveSurroundingDerive>,
+    #[subdiagnostic]
+    pub(crate) add_as_non_derive: Option<AddAsNonDerive<'a>>,
+}
+
+#[derive(Subdiagnostic)]
+#[help(resolve_remove_surrounding_derive)]
+pub(crate) struct RemoveSurroundingDerive {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
+#[derive(Subdiagnostic)]
+#[help(resolve_add_as_non_derive)]
+pub(crate) struct AddAsNonDerive<'a> {
+    pub(crate) macro_path: &'a str,
+}
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index 52f0b65fa..5a56d7b99 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -17,7 +17,7 @@ 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::{errors, AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, Determinacy, Finalize};
 use crate::{Import, ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot};
 use crate::{NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError, Res};
 use crate::{ResolutionError, Resolver, Scope, ScopeSet, Segment, ToNameBinding, Weak};
@@ -389,7 +389,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
         }
 
-        assert!(force || !finalize.is_some()); // `finalize` implies `force`
+        assert!(force || finalize.is_none()); // `finalize` implies `force`
 
         // Make sure `self`, `super` etc produce an error when passed to here.
         if orig_ident.is_path_segment_keyword() {
@@ -869,17 +869,19 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         let resolution =
             self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports.
 
-        if let Some(Finalize { path_span, report_private, .. }) = finalize {
-            // If the primary binding is unusable, search further and return the shadowed glob
-            // binding if it exists. What we really want here is having two separate scopes in
-            // a module - one for non-globs and one for globs, but until that's done use this
-            // hack to avoid inconsistent resolution ICEs during import validation.
-            let binding = [resolution.binding, resolution.shadowed_glob].into_iter().find_map(
-                |binding| match (binding, ignore_binding) {
+        // If the primary binding is unusable, search further and return the shadowed glob
+        // binding if it exists. What we really want here is having two separate scopes in
+        // a module - one for non-globs and one for globs, but until that's done use this
+        // hack to avoid inconsistent resolution ICEs during import validation.
+        let binding =
+            [resolution.binding, resolution.shadowed_glob].into_iter().find_map(|binding| {
+                match (binding, ignore_binding) {
                     (Some(binding), Some(ignored)) if ptr::eq(binding, ignored) => None,
                     _ => binding,
-                },
-            );
+                }
+            });
+
+        if let Some(Finalize { path_span, report_private, .. }) = finalize {
             let Some(binding) = binding else {
                 return Err((Determined, Weak::No));
             };
@@ -927,15 +929,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
 
         let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| {
-            if let Some(ignored) = ignore_binding && ptr::eq(binding, ignored) {
-                return Err((Determined, Weak::No));
-            }
             let usable = this.is_accessible_from(binding.vis, parent_scope.module);
             if usable { Ok(binding) } else { Err((Determined, Weak::No)) }
         };
 
         // Items and single imports are not shadowable, if we have one, then it's determined.
-        if let Some(binding) = resolution.binding {
+        if let Some(binding) = binding {
             if !binding.is_glob_import() {
                 return check_usable(self, binding);
             }
@@ -952,6 +951,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             if !self.is_accessible_from(import_vis, parent_scope.module) {
                 continue;
             }
+            if let Some(ignored) = ignore_binding &&
+                let NameBindingKind::Import { import, .. } = ignored.kind &&
+                ptr::eq(import, &**single_import) {
+                // Ignore not just the binding itself, but if it has a shadowed_glob,
+                // ignore that, too, because this loop is supposed to only process
+                // named imports.
+                continue;
+            }
             let Some(module) = single_import.imported_module.get() else {
                 return Err((Undetermined, Weak::No));
             };
@@ -989,7 +996,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         // and prohibit access to macro-expanded `macro_export` macros instead (unless restricted
         // shadowing is enabled, see `macro_expanded_macro_export_errors`).
         let unexpanded_macros = !module.unexpanded_invocations.borrow().is_empty();
-        if let Some(binding) = resolution.binding {
+        if let Some(binding) = binding {
             if !unexpanded_macros || ns == MacroNS || restricted_shadowing {
                 return check_usable(self, binding);
             } else {
@@ -1357,7 +1364,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 }
             };
 
-            let is_last = i == path.len() - 1;
+            let is_last = i + 1 == path.len();
             let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS };
             let name = ident.name;
 
@@ -1494,16 +1501,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     if let Some(next_module) = binding.module() {
                         module = Some(ModuleOrUniformRoot::Module(next_module));
                         record_segment_res(self, res);
-                    } else if res == Res::ToolMod && i + 1 != path.len() {
+                    } else if res == Res::ToolMod && !is_last && opt_ns.is_some() {
                         if binding.is_import() {
-                            self.tcx
-                                .sess
-                                .struct_span_err(
-                                    ident.span,
-                                    "cannot use a tool module through an import",
-                                )
-                                .span_note(binding.span, "the tool module imported here")
-                                .emit();
+                            self.tcx.sess.emit_err(errors::ToolModuleImported {
+                                span: ident.span,
+                                import: binding.span,
+                            });
                         }
                         let res = Res::NonMacroAttr(NonMacroAttrKind::Tool);
                         return PathResult::NonModule(PartialRes::new(res));
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 4dab0836d..3c22d51c3 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -17,14 +17,18 @@ use rustc_data_structures::intern::Interned;
 use rustc_errors::{pluralize, struct_span_err, Applicability, MultiSpan};
 use rustc_hir::def::{self, DefKind, PartialRes};
 use rustc_middle::metadata::ModChild;
+use rustc_middle::metadata::Reexport;
 use rustc_middle::span_bug;
 use rustc_middle::ty;
-use rustc_session::lint::builtin::{PUB_USE_OF_PRIVATE_EXTERN_CRATE, UNUSED_IMPORTS};
+use rustc_session::lint::builtin::{
+    AMBIGUOUS_GLOB_REEXPORTS, PUB_USE_OF_PRIVATE_EXTERN_CRATE, UNUSED_IMPORTS,
+};
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::LocalExpnId;
 use rustc_span::symbol::{kw, Ident, Symbol};
 use rustc_span::Span;
+use smallvec::SmallVec;
 
 use std::cell::Cell;
 use std::{mem, ptr};
@@ -85,20 +89,28 @@ impl<'a> std::fmt::Debug for ImportKind<'a> {
             Single {
                 ref source,
                 ref target,
+                ref source_bindings,
+                ref target_bindings,
                 ref type_ns_only,
                 ref nested,
                 ref id,
-                // Ignore the following to avoid an infinite loop while printing.
-                source_bindings: _,
-                target_bindings: _,
             } => f
                 .debug_struct("Single")
                 .field("source", source)
                 .field("target", target)
+                // Ignore the nested bindings to avoid an infinite loop while printing.
+                .field(
+                    "source_bindings",
+                    &source_bindings.clone().map(|b| b.into_inner().map(|_| format_args!(".."))),
+                )
+                .field(
+                    "target_bindings",
+                    &target_bindings.clone().map(|b| b.into_inner().map(|_| format_args!(".."))),
+                )
                 .field("type_ns_only", type_ns_only)
                 .field("nested", nested)
                 .field("id", id)
-                .finish_non_exhaustive(),
+                .finish(),
             Glob { ref is_prelude, ref max_vis, ref id } => f
                 .debug_struct("Glob")
                 .field("is_prelude", is_prelude)
@@ -180,6 +192,17 @@ impl<'a> Import<'a> {
             ImportKind::MacroUse | ImportKind::MacroExport => None,
         }
     }
+
+    fn simplify(&self, r: &Resolver<'_, '_>) -> Reexport {
+        let to_def_id = |id| r.local_def_id(id).to_def_id();
+        match self.kind {
+            ImportKind::Single { id, .. } => Reexport::Single(to_def_id(id)),
+            ImportKind::Glob { id, .. } => Reexport::Glob(to_def_id(id)),
+            ImportKind::ExternCrate { id, .. } => Reexport::ExternCrate(to_def_id(id)),
+            ImportKind::MacroUse => Reexport::MacroUse,
+            ImportKind::MacroExport => Reexport::MacroExport,
+        }
+    }
 }
 
 /// Records information about the resolution of a name in a namespace of a module.
@@ -245,7 +268,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         import: &'a Import<'a>,
     ) -> &'a NameBinding<'a> {
         let import_vis = import.expect_vis().to_def_id();
-        let vis = if binding.vis.is_at_least(import_vis, self)
+        let vis = if binding.vis.is_at_least(import_vis, self.tcx)
             || pub_use_of_private_extern_crate_hack(import, binding)
         {
             import_vis
@@ -255,7 +278,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
         if let ImportKind::Glob { ref max_vis, .. } = import.kind {
             if vis == import_vis
-                || max_vis.get().map_or(true, |max_vis| vis.is_at_least(max_vis, self))
+                || max_vis.get().map_or(true, |max_vis| vis.is_at_least(max_vis, self.tcx))
             {
                 max_vis.set(Some(vis.expect_local()))
             }
@@ -294,7 +317,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                                 old_binding,
                                 binding,
                             ));
-                        } else if !old_binding.vis.is_at_least(binding.vis, &*this) {
+                        } else if !old_binding.vis.is_at_least(binding.vis, this.tcx) {
                             // We are glob-importing the same item but with greater visibility.
                             resolution.binding = Some(binding);
                         }
@@ -415,13 +438,17 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     /// Resolves all imports for the crate. This method performs the fixed-
     /// point iteration.
     pub(crate) fn resolve_imports(&mut self) {
-        let mut prev_num_indeterminates = self.indeterminate_imports.len() + 1;
-        while self.indeterminate_imports.len() < prev_num_indeterminates {
-            prev_num_indeterminates = self.indeterminate_imports.len();
+        let mut prev_indeterminate_count = usize::MAX;
+        let mut indeterminate_count = self.indeterminate_imports.len() * 3;
+        while indeterminate_count < prev_indeterminate_count {
+            prev_indeterminate_count = indeterminate_count;
+            indeterminate_count = 0;
             for import in mem::take(&mut self.indeterminate_imports) {
-                match self.resolve_import(&import) {
-                    true => self.determined_imports.push(import),
-                    false => self.indeterminate_imports.push(import),
+                let import_indeterminate_count = self.resolve_import(&import);
+                indeterminate_count += import_indeterminate_count;
+                match import_indeterminate_count {
+                    0 => self.determined_imports.push(import),
+                    _ => self.indeterminate_imports.push(import),
                 }
             }
         }
@@ -498,6 +525,34 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
     }
 
+    pub(crate) fn check_reexport_ambiguities(
+        &mut self,
+        exported_ambiguities: FxHashSet<Interned<'a, NameBinding<'a>>>,
+    ) {
+        for module in self.arenas.local_modules().iter() {
+            module.for_each_child(self, |this, ident, ns, binding| {
+                if let NameBindingKind::Import { import, .. } = binding.kind
+                && let Some((amb_binding, _)) = binding.ambiguity
+                && binding.res() != Res::Err
+                && exported_ambiguities.contains(&Interned::new_unchecked(binding))
+                {
+                    this.lint_buffer.buffer_lint_with_diagnostic(
+                        AMBIGUOUS_GLOB_REEXPORTS,
+                        import.root_id,
+                        import.root_span,
+                        "ambiguous glob re-exports",
+                        BuiltinLintDiagnostics::AmbiguousGlobReexports {
+                            name: ident.to_string(),
+                            namespace: ns.descr().to_string(),
+                            first_reexport_span: import.root_span,
+                            duplicate_reexport_span: amb_binding.span,
+                        },
+                    );
+                }
+            });
+        }
+    }
+
     fn throw_unresolved_import_error(&self, errors: Vec<(&Import<'_>, UnresolvedImportError)>) {
         if errors.is_empty() {
             return;
@@ -573,9 +628,13 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         diag.emit();
     }
 
-    /// Attempts to resolve the given import, returning true if its resolution is determined.
-    /// If successful, the resolved bindings are written into the module.
-    fn resolve_import(&mut self, import: &'a Import<'a>) -> bool {
+    /// Attempts to resolve the given import, returning:
+    /// - `0` means its resolution is determined.
+    /// - Other values mean that indeterminate exists under certain namespaces.
+    ///
+    /// Meanwhile, if resolve successful, the resolved bindings are written
+    /// into the module.
+    fn resolve_import(&mut self, import: &'a Import<'a>) -> usize {
         debug!(
             "(resolving import for module) resolving import `{}::...` in `{}`",
             Segment::names_to_string(&import.module_path),
@@ -593,8 +652,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
             match path_res {
                 PathResult::Module(module) => module,
-                PathResult::Indeterminate => return false,
-                PathResult::NonModule(..) | PathResult::Failed { .. } => return true,
+                PathResult::Indeterminate => return 3,
+                PathResult::NonModule(..) | PathResult::Failed { .. } => return 0,
             }
         };
 
@@ -610,12 +669,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             } => (source, target, source_bindings, target_bindings, type_ns_only),
             ImportKind::Glob { .. } => {
                 self.resolve_glob_import(import);
-                return true;
+                return 0;
             }
             _ => unreachable!(),
         };
 
-        let mut indeterminate = false;
+        let mut indeterminate_count = 0;
         self.per_ns(|this, ns| {
             if !type_ns_only || ns == TypeNS {
                 if let Err(Undetermined) = source_bindings[ns].get() {
@@ -638,7 +697,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 
                 let parent = import.parent_scope.module;
                 match source_bindings[ns].get() {
-                    Err(Undetermined) => indeterminate = true,
+                    Err(Undetermined) => indeterminate_count += 1,
                     // Don't update the resolution, because it was never added.
                     Err(Determined) if target.name == kw::Underscore => {}
                     Ok(binding) if binding.is_importable() => {
@@ -662,7 +721,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             }
         });
 
-        !indeterminate
+        indeterminate_count
     }
 
     /// Performs final import resolution, consistency checks and error reporting.
@@ -786,7 +845,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     }
                     if !is_prelude
                     && let Some(max_vis) = max_vis.get()
-                    && !max_vis.is_at_least(import.expect_vis(), &*self)
+                    && !max_vis.is_at_least(import.expect_vis(), self.tcx)
                 {
                     let msg = "glob import doesn't reexport anything because no candidate is public enough";
                     self.lint_buffer.buffer_lint(UNUSED_IMPORTS, id, import.span, msg);
@@ -977,7 +1036,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         let mut crate_private_reexport = false;
         self.per_ns(|this, ns| {
             if let Ok(binding) = source_bindings[ns].get() {
-                if !binding.vis.is_at_least(import.expect_vis(), &*this) {
+                if !binding.vis.is_at_least(import.expect_vis(), this.tcx) {
                     reexport_error = Some((ns, binding));
                     if let ty::Visibility::Restricted(binding_def_id) = binding.vis {
                         if binding_def_id.is_top_level_module() {
@@ -1202,24 +1261,38 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         *module.globs.borrow_mut() = Vec::new();
 
         if let Some(def_id) = module.opt_def_id() {
+            let mut non_reexports = Vec::new();
             let mut reexports = Vec::new();
 
             module.for_each_child(self, |this, ident, _, binding| {
-                if let Some(res) = this.is_reexport(binding) {
+                let res = binding.res().expect_non_local();
+                if !binding.is_import() {
+                    non_reexports.push(res.def_id().expect_local());
+                } else if res != def::Res::Err && !binding.is_ambiguity() {
+                    let mut reexport_chain = SmallVec::new();
+                    let mut next_binding = binding;
+                    while let NameBindingKind::Import { binding, import, .. } = next_binding.kind {
+                        reexport_chain.push(import.simplify(this));
+                        next_binding = binding;
+                    }
+
                     reexports.push(ModChild {
                         ident,
                         res,
                         vis: binding.vis,
                         span: binding.span,
-                        macro_rules: false,
+                        reexport_chain,
                     });
                 }
             });
 
+            // Should be fine because this code is only called for local modules.
+            let def_id = def_id.expect_local();
+            if !non_reexports.is_empty() {
+                self.module_children_non_reexports.insert(def_id, non_reexports);
+            }
             if !reexports.is_empty() {
-                // Call to `expect_local` should be fine because current
-                // code is only called for local modules.
-                self.reexport_map.insert(def_id.expect_local(), reexports);
+                self.module_children_reexports.insert(def_id, reexports);
             }
         }
     }
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 7df17376b..90a2fa89c 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -22,7 +22,6 @@ use rustc_hir::def::{self, CtorKind, DefKind, LifetimeRes, PartialRes, PerNS};
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::{BindingAnnotation, PrimTy, TraitCandidate};
 use rustc_middle::middle::resolve_bound_vars::Set1;
-use rustc_middle::ty::DefIdTree;
 use rustc_middle::{bug, span_bug};
 use rustc_session::config::{CrateType, ResolveDocLinks};
 use rustc_session::lint;
@@ -123,6 +122,12 @@ pub(crate) enum ConstantItemKind {
     Static,
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+enum RecordPartialRes {
+    Yes,
+    No,
+}
+
 /// The rib kind restricts certain accesses,
 /// e.g. to a `Res::Local` of an outer item.
 #[derive(Copy, Clone, Debug)]
@@ -591,10 +596,9 @@ struct LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     parent_scope: ParentScope<'a>,
 
     /// The current set of local scopes for types and values.
-    /// FIXME #4948: Reuse ribs to avoid allocation.
     ribs: PerNS<Vec<Rib<'a>>>,
 
-    /// Previous poped `rib`, only used for diagnostic.
+    /// Previous popped `rib`, only used for diagnostic.
     last_block_rib: Option<Rib<'a>>,
 
     /// The current set of local scopes, for labels.
@@ -1219,7 +1223,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             lifetime_ribs: Vec::new(),
             lifetime_elision_candidates: None,
             current_trait_ref: None,
-            diagnostic_metadata: Box::new(DiagnosticMetadata::default()),
+            diagnostic_metadata: Default::default(),
             // errors at module scope should always be reported
             in_func_body: false,
             lifetime_uses: Default::default(),
@@ -1479,8 +1483,9 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                                     } else {
                                         LifetimeUseSet::Many
                                     }),
-                                    LifetimeRibKind::Generics { .. } => None,
-                                    LifetimeRibKind::ConstGeneric | LifetimeRibKind::AnonConst => {
+                                    LifetimeRibKind::Generics { .. }
+                                    | LifetimeRibKind::ConstGeneric => None,
+                                    LifetimeRibKind::AnonConst => {
                                         span_bug!(ident.span, "unexpected rib kind: {:?}", rib.kind)
                                     }
                                 })
@@ -1671,8 +1676,12 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             // Figure out if this is a type/trait segment,
             // which may need lifetime elision performed.
             let type_def_id = match partial_res.base_res() {
-                Res::Def(DefKind::AssocTy, def_id) if i + 2 == proj_start => self.r.parent(def_id),
-                Res::Def(DefKind::Variant, def_id) if i + 1 == proj_start => self.r.parent(def_id),
+                Res::Def(DefKind::AssocTy, def_id) if i + 2 == proj_start => {
+                    self.r.tcx.parent(def_id)
+                }
+                Res::Def(DefKind::Variant, def_id) if i + 1 == proj_start => {
+                    self.r.tcx.parent(def_id)
+                }
                 Res::Def(DefKind::Struct, def_id)
                 | Res::Def(DefKind::Union, def_id)
                 | Res::Def(DefKind::Enum, def_id)
@@ -2342,7 +2351,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 });
             }
 
-            ItemKind::Static(ref ty, _, ref expr) | ItemKind::Const(_, ref ty, ref expr) => {
+            ItemKind::Static(box ast::StaticItem { ref ty, ref expr, .. })
+            | ItemKind::Const(box ast::ConstItem { ref ty, ref expr, .. }) => {
                 self.with_static_rib(|this| {
                     this.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Static), |this| {
                         this.visit_ty(ty);
@@ -2417,8 +2427,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                     .iter()
                     .rfind(|r| matches!(r.kind, ItemRibKind(_)))
                     .expect("associated item outside of an item");
-                seen_bindings
-                    .extend(parent_rib.bindings.iter().map(|(ident, _)| (*ident, ident.span)));
+                seen_bindings.extend(parent_rib.bindings.keys().map(|ident| (*ident, ident.span)));
             };
             add_bindings_for_ns(ValueNS);
             add_bindings_for_ns(TypeNS);
@@ -2621,11 +2630,11 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         for item in trait_items {
             self.resolve_doc_links(&item.attrs, MaybeExported::Ok(item.id));
             match &item.kind {
-                AssocItemKind::Const(_, ty, default) => {
+                AssocItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
                     self.visit_ty(ty);
                     // Only impose the restrictions of `ConstRibKind` for an
                     // actual constant expression in a provided default.
-                    if let Some(expr) = default {
+                    if let Some(expr) = expr {
                         // We allow arbitrary const expressions inside of associated consts,
                         // even if they are potentially not const evaluatable.
                         //
@@ -2678,6 +2687,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 &path,
                 PathSource::Trait(AliasPossibility::No),
                 Finalize::new(trait_ref.ref_id, trait_ref.path.span),
+                RecordPartialRes::Yes,
             );
             self.diagnostic_metadata.currently_processing_impl_trait = None;
             if let Some(def_id) = res.expect_full_res().opt_def_id() {
@@ -2796,7 +2806,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         use crate::ResolutionError::*;
         self.resolve_doc_links(&item.attrs, MaybeExported::ImplItem(trait_id.ok_or(&item.vis)));
         match &item.kind {
-            AssocItemKind::Const(_, ty, default) => {
+            AssocItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
                 debug!("resolve_implementation AssocItemKind::Const");
                 // If this is a trait impl, ensure the const
                 // exists in trait
@@ -2811,7 +2821,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 );
 
                 self.visit_ty(ty);
-                if let Some(expr) = default {
+                if let Some(expr) = expr {
                     // We allow arbitrary const expressions inside of associated consts,
                     // even if they are potentially not const evaluatable.
                     //
@@ -3373,7 +3383,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                         participle: "defined",
                         article: res.article(),
                         shadowed_binding: res,
-                        shadowed_binding_span: self.r.opt_span(def_id).expect("const parameter defined outside of local crate"),
+                        shadowed_binding_span: self.r.def_span(def_id),
                     }
                 );
                 None
@@ -3416,6 +3426,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             &Segment::from_path(path),
             source,
             Finalize::new(id, path.span),
+            RecordPartialRes::Yes,
         );
     }
 
@@ -3426,6 +3437,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         path: &[Segment],
         source: PathSource<'ast>,
         finalize: Finalize,
+        record_partial_res: RecordPartialRes,
     ) -> PartialRes {
         let ns = source.namespace();
 
@@ -3454,8 +3466,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                         sugg.to_string(),
                         Applicability::MaybeIncorrect,
                     ))
-                } else if res.is_none() && matches!(source, PathSource::Type) {
-                    this.report_missing_type_error(path)
+                } else if res.is_none() && let PathSource::Type | PathSource::Expr(_) = source {
+                    this.suggest_adding_generic_parameter(path, source)
                 } else {
                     None
                 };
@@ -3632,7 +3644,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             _ => report_errors(self, None),
         };
 
-        if !matches!(source, PathSource::TraitItem(..)) {
+        if record_partial_res == RecordPartialRes::Yes {
             // Avoid recording definition of `A::B` in `<T as A>::B::C`.
             self.r.record_partial_res(node_id, partial_res);
             self.resolve_elided_lifetimes_in_path(node_id, partial_res, path, source, path_span);
@@ -3736,7 +3748,25 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 )));
             }
 
-            // Make sure `A::B` in `<T as A::B>::C` is a trait item.
+            let num_privacy_errors = self.r.privacy_errors.len();
+            // Make sure that `A` in `<T as A>::B::C` is a trait.
+            let trait_res = self.smart_resolve_path_fragment(
+                &None,
+                &path[..qself.position],
+                PathSource::Trait(AliasPossibility::No),
+                Finalize::new(finalize.node_id, qself.path_span),
+                RecordPartialRes::No,
+            );
+
+            if trait_res.expect_full_res() == Res::Err {
+                return Ok(Some(trait_res));
+            }
+
+            // Truncate additional privacy errors reported above,
+            // because they'll be recomputed below.
+            self.r.privacy_errors.truncate(num_privacy_errors);
+
+            // Make sure `A::B` in `<T as A>::B::C` is a trait item.
             //
             // Currently, `path` names the full item (`A::B::C`, in
             // our example). so we extract the prefix of that that is
@@ -3749,6 +3779,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 &path[..=qself.position],
                 PathSource::TraitItem(ns),
                 Finalize::with_root_span(finalize.node_id, finalize.path_span, qself.path_span),
+                RecordPartialRes::No,
             );
 
             // The remaining segments (the `C` in our example) will
@@ -4233,7 +4264,10 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             {
                 return;
             }
-            ResolveDocLinks::Exported if !maybe_exported.eval(self.r) => {
+            ResolveDocLinks::Exported
+                if !maybe_exported.eval(self.r)
+                    && !rustdoc::has_primitive_or_keyword_docs(attrs) =>
+            {
                 return;
             }
             ResolveDocLinks::ExportedMetadata
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index b8ddc4552..37fbfad2d 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -19,9 +19,8 @@ use rustc_errors::{
 use rustc_hir as hir;
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorKind, CtorOf, DefKind};
-use rustc_hir::def_id::{DefId, CRATE_DEF_ID, LOCAL_CRATE};
+use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
 use rustc_hir::PrimTy;
-use rustc_middle::ty::DefIdTree;
 use rustc_session::lint;
 use rustc_session::parse::feature_err;
 use rustc_session::Session;
@@ -167,13 +166,6 @@ impl TypoCandidate {
 }
 
 impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
-    fn def_span(&self, def_id: DefId) -> Option<Span> {
-        match def_id.krate {
-            LOCAL_CRATE => self.r.opt_span(def_id),
-            _ => Some(self.r.cstore().get_span_untracked(def_id, self.r.tcx.sess)),
-        }
-    }
-
     fn make_base_error(
         &mut self,
         path: &[Segment],
@@ -192,7 +184,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 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"))
+                        Some((self.r.def_span(def_id), "found this type parameter"))
                     }
                     _ => None,
                 },
@@ -1296,28 +1288,46 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 }
                 PathSource::Expr(_) | PathSource::TupleStruct(..) | PathSource::Pat => {
                     let span = find_span(&source, err);
-                    if let Some(span) = self.def_span(def_id) {
-                        err.span_label(span, &format!("`{}` defined here", path_str));
-                    }
-                    let (tail, descr, applicability) = match source {
-                        PathSource::Pat | PathSource::TupleStruct(..) => {
-                            ("", "pattern", Applicability::MachineApplicable)
-                        }
-                        _ => (": val", "literal", Applicability::HasPlaceholders),
-                    };
-                    let (fields, applicability) = match self.r.field_names.get(&def_id) {
-                        Some(fields) => (
-                            fields
-                                .iter()
-                                .map(|f| format!("{}{}", f.node, tail))
-                                .collect::<Vec<String>>()
-                                .join(", "),
-                            applicability,
+                    err.span_label(self.r.def_span(def_id), &format!("`{path_str}` defined here"));
+
+                    let (tail, descr, applicability, old_fields) = match source {
+                        PathSource::Pat => ("", "pattern", Applicability::MachineApplicable, None),
+                        PathSource::TupleStruct(_, args) => (
+                            "",
+                            "pattern",
+                            Applicability::MachineApplicable,
+                            Some(
+                                args.iter()
+                                    .map(|a| self.r.tcx.sess.source_map().span_to_snippet(*a).ok())
+                                    .collect::<Vec<Option<String>>>(),
+                            ),
                         ),
+                        _ => (": val", "literal", Applicability::HasPlaceholders, None),
+                    };
+                    let field_ids = self.r.field_def_ids(def_id);
+                    let (fields, applicability) = match field_ids {
+                        Some(field_ids) => {
+                            let fields = field_ids.iter().map(|&id| self.r.tcx.item_name(id));
+
+                            let fields = if let Some(old_fields) = old_fields {
+                                fields
+                                    .enumerate()
+                                    .map(|(idx, new)| (new, old_fields.get(idx)))
+                                    .map(|(new, old)| {
+                                        let new = new.to_ident_string();
+                                        if let Some(Some(old)) = old && new != *old { format!("{}: {}", new, old) } else { new }
+                                    })
+                                    .collect::<Vec<String>>()
+                            } else {
+                                fields.map(|f| format!("{f}{tail}")).collect::<Vec<String>>()
+                            };
+
+                            (fields.join(", "), applicability)
+                        }
                         None => ("/* fields */".to_string(), Applicability::HasPlaceholders),
                     };
-                    let pad = match self.r.field_names.get(&def_id) {
-                        Some(fields) if fields.is_empty() => "",
+                    let pad = match field_ids {
+                        Some(field_ids) if field_ids.is_empty() => "",
                         _ => " ",
                     };
                     err.span_suggestion(
@@ -1360,17 +1370,14 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 if self.r.tcx.sess.is_nightly_build() {
                     let msg = "you might have meant to use `#![feature(trait_alias)]` instead of a \
                                `type` alias";
-                    if let Some(span) = self.def_span(def_id) {
-                        if let Ok(snip) = self.r.tcx.sess.source_map().span_to_snippet(span) {
-                            // The span contains a type alias so we should be able to
-                            // replace `type` with `trait`.
-                            let snip = snip.replacen("type", "trait", 1);
-                            err.span_suggestion(span, msg, snip, Applicability::MaybeIncorrect);
-                        } else {
-                            err.span_help(span, msg);
-                        }
+                    let span = self.r.def_span(def_id);
+                    if let Ok(snip) = self.r.tcx.sess.source_map().span_to_snippet(span) {
+                        // The span contains a type alias so we should be able to
+                        // replace `type` with `trait`.
+                        let snip = snip.replacen("type", "trait", 1);
+                        err.span_suggestion(span, msg, snip, Applicability::MaybeIncorrect);
                     } else {
-                        err.help(msg);
+                        err.span_help(span, msg);
                     }
                 }
             }
@@ -1409,19 +1416,38 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 self.suggest_using_enum_variant(err, source, def_id, span);
             }
             (Res::Def(DefKind::Struct, def_id), source) if ns == ValueNS => {
-                let (ctor_def, ctor_vis, fields) =
-                    if let Some(struct_ctor) = self.r.struct_constructors.get(&def_id).cloned() {
-                        if let PathSource::Expr(Some(parent)) = source {
-                            if let ExprKind::Field(..) | ExprKind::MethodCall(..) = parent.kind {
-                                bad_struct_syntax_suggestion(def_id);
-                                return true;
-                            }
+                let struct_ctor = match def_id.as_local() {
+                    Some(def_id) => self.r.struct_constructors.get(&def_id).cloned(),
+                    None => {
+                        let ctor = self.r.cstore().ctor_untracked(def_id);
+                        ctor.map(|(ctor_kind, ctor_def_id)| {
+                            let ctor_res =
+                                Res::Def(DefKind::Ctor(CtorOf::Struct, ctor_kind), ctor_def_id);
+                            let ctor_vis = self.r.tcx.visibility(ctor_def_id);
+                            let field_visibilities = self
+                                .r
+                                .tcx
+                                .associated_item_def_ids(def_id)
+                                .iter()
+                                .map(|field_id| self.r.tcx.visibility(field_id))
+                                .collect();
+                            (ctor_res, ctor_vis, field_visibilities)
+                        })
+                    }
+                };
+
+                let (ctor_def, ctor_vis, fields) = if let Some(struct_ctor) = struct_ctor {
+                    if let PathSource::Expr(Some(parent)) = source {
+                        if let ExprKind::Field(..) | ExprKind::MethodCall(..) = parent.kind {
+                            bad_struct_syntax_suggestion(def_id);
+                            return true;
                         }
-                        struct_ctor
-                    } else {
-                        bad_struct_syntax_suggestion(def_id);
-                        return true;
-                    };
+                    }
+                    struct_ctor
+                } else {
+                    bad_struct_syntax_suggestion(def_id);
+                    return true;
+                };
 
                 let is_accessible = self.r.is_accessible_from(ctor_vis, self.parent_scope.module);
                 if !is_expected(ctor_def) || is_accessible {
@@ -1445,10 +1471,12 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                         );
 
                         // Use spans of the tuple struct definition.
-                        self.r
-                            .field_names
-                            .get(&def_id)
-                            .map(|fields| fields.iter().map(|f| f.span).collect::<Vec<_>>())
+                        self.r.field_def_ids(def_id).map(|field_ids| {
+                            field_ids
+                                .iter()
+                                .map(|&field_id| self.r.def_span(field_id))
+                                .collect::<Vec<_>>()
+                        })
                     }
                     _ => None,
                 };
@@ -1494,9 +1522,10 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 match source {
                     PathSource::Expr(_) | PathSource::TupleStruct(..) | PathSource::Pat => {
                         let span = find_span(&source, err);
-                        if let Some(span) = self.def_span(def_id) {
-                            err.span_label(span, &format!("`{}` defined here", path_str));
-                        }
+                        err.span_label(
+                            self.r.def_span(def_id),
+                            &format!("`{path_str}` defined here"),
+                        );
                         err.span_suggestion(
                             span,
                             "use this syntax instead",
@@ -1508,13 +1537,11 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                 }
             }
             (Res::Def(DefKind::Ctor(_, CtorKind::Fn), ctor_def_id), _) if ns == ValueNS => {
-                let def_id = self.r.parent(ctor_def_id);
-                if let Some(span) = self.def_span(def_id) {
-                    err.span_label(span, &format!("`{}` defined here", path_str));
-                }
-                let fields = self.r.field_names.get(&def_id).map_or_else(
+                let def_id = self.r.tcx.parent(ctor_def_id);
+                err.span_label(self.r.def_span(def_id), &format!("`{path_str}` defined here"));
+                let fields = self.r.field_def_ids(def_id).map_or_else(
                     || "/* fields */".to_string(),
-                    |fields| vec!["_"; fields.len()].join(", "),
+                    |field_ids| vec!["_"; field_ids.len()].join(", "),
                 );
                 err.span_suggestion(
                     span,
@@ -1595,8 +1622,11 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                     if let Some(Res::Def(DefKind::Struct | DefKind::Union, did)) =
                         resolution.full_res()
                     {
-                        if let Some(field_names) = self.r.field_names.get(&did) {
-                            if field_names.iter().any(|&field_name| ident.name == field_name.node) {
+                        if let Some(field_ids) = self.r.field_def_ids(did) {
+                            if field_ids
+                                .iter()
+                                .any(|&field_id| ident.name == self.r.tcx.item_name(field_id))
+                            {
                                 return Some(AssocSuggestion::Field);
                             }
                         }
@@ -1631,7 +1661,17 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             ) {
                 let res = binding.res();
                 if filter_fn(res) {
-                    if self.r.has_self.contains(&res.def_id()) {
+                    let def_id = res.def_id();
+                    let has_self = match def_id.as_local() {
+                        Some(def_id) => self.r.has_self.contains(&def_id),
+                        None => self
+                            .r
+                            .tcx
+                            .fn_arg_names(def_id)
+                            .first()
+                            .map_or(false, |ident| ident.name == kw::SelfLower),
+                    };
+                    if has_self {
                         return Some(AssocSuggestion::MethodWithSelf { called });
                     } else {
                         match res {
@@ -1737,7 +1777,7 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
 
         let name = path[path.len() - 1].ident.name;
         // Make sure error reporting is deterministic.
-        names.sort_by(|a, b| a.candidate.as_str().partial_cmp(b.candidate.as_str()).unwrap());
+        names.sort_by(|a, b| a.candidate.as_str().cmp(b.candidate.as_str()));
 
         match find_best_match_for_name(
             &names.iter().map(|suggestion| suggestion.candidate).collect::<Vec<Symbol>>(),
@@ -1999,12 +2039,13 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             }
         } else {
             let needs_placeholder = |ctor_def_id: DefId, kind: CtorKind| {
-                let def_id = self.r.parent(ctor_def_id);
-                let has_no_fields = self.r.field_names.get(&def_id).map_or(false, |f| f.is_empty());
+                let def_id = self.r.tcx.parent(ctor_def_id);
                 match kind {
                     CtorKind::Const => false,
-                    CtorKind::Fn if has_no_fields => false,
-                    _ => true,
+                    CtorKind::Fn => !self
+                        .r
+                        .field_def_ids(def_id)
+                        .map_or(false, |field_ids| field_ids.is_empty()),
                 }
             };
 
@@ -2065,15 +2106,14 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
         };
 
         if def_id.is_local() {
-            if let Some(span) = self.def_span(def_id) {
-                err.span_note(span, "the enum is defined here");
-            }
+            err.span_note(self.r.def_span(def_id), "the enum is defined here");
         }
     }
 
-    pub(crate) fn report_missing_type_error(
+    pub(crate) fn suggest_adding_generic_parameter(
         &self,
         path: &[Segment],
+        source: PathSource<'_>,
     ) -> Option<(Span, &'static str, String, Applicability)> {
         let (ident, span) = match path {
             [segment]
@@ -2109,7 +2149,6 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
             // Without the 2nd `true`, we'd suggest `impl <T>` for `impl T` when a type `T` isn't found
             | (Some(Item { kind: kind @ ItemKind::Impl(..), .. }), true, true)
             | (Some(Item { kind, .. }), false, _) => {
-                // Likely missing type parameter.
                 if let Some(generics) = kind.generics() {
                     if span.overlaps(generics.span) {
                         // Avoid the following:
@@ -2122,7 +2161,12 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                         //   |           not found in this scope
                         return None;
                     }
-                    let msg = "you might be missing a type parameter";
+
+                    let (msg, sugg) = match source {
+                        PathSource::Type => ("you might be missing a type parameter", ident),
+                        PathSource::Expr(_) => ("you might be missing a const parameter", format!("const {ident}: /* Type */")),
+                        _ => return None,
+                    };
                     let (span, sugg) = if let [.., param] = &generics.params[..] {
                         let span = if let [.., bound] = &param.bounds[..] {
                             bound.span()
@@ -2133,9 +2177,9 @@ impl<'a: 'ast, 'ast, 'tcx> LateResolutionVisitor<'a, '_, 'ast, 'tcx> {
                         } else {
                             param.ident.span
                         };
-                        (span, format!(", {}", ident))
+                        (span, format!(", {sugg}"))
                     } else {
-                        (generics.span, format!("<{}>", ident))
+                        (generics.span, format!("<{sugg}>"))
                     };
                     // Do not suggest if this is coming from macro expansion.
                     if span.can_be_used_for_suggestions() {
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 1fdfb1a53..b820d56b8 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -23,10 +23,11 @@ extern crate tracing;
 
 use rustc_arena::{DroplessArena, TypedArena};
 use rustc_ast::node_id::NodeMap;
-use rustc_ast::{self as ast, NodeId, CRATE_NODE_ID};
+use rustc_ast::{self as ast, attr, NodeId, CRATE_NODE_ID};
 use rustc_ast::{AngleBracketedArg, Crate, Expr, ExprKind, GenericArg, GenericArgs, LitKind, Path};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::intern::Interned;
+use rustc_data_structures::steal::Steal;
 use rustc_data_structures::sync::{Lrc, MappedReadGuard};
 use rustc_errors::{
     Applicability, DiagnosticBuilder, DiagnosticMessage, ErrorGuaranteed, SubdiagnosticMessage,
@@ -34,7 +35,7 @@ use rustc_errors::{
 use rustc_expand::base::{DeriveResolutions, SyntaxExtension, SyntaxExtensionKind};
 use rustc_hir::def::Namespace::{self, *};
 use rustc_hir::def::{self, CtorOf, DefKind, DocLinkResMap, LifetimeRes, PartialRes, PerNS};
-use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LocalDefId};
+use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LocalDefIdMap, LocalDefIdSet};
 use rustc_hir::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::definitions::DefPathData;
 use rustc_hir::TraitCandidate;
@@ -44,13 +45,11 @@ use rustc_metadata::creader::{CStore, CrateLoader};
 use rustc_middle::metadata::ModChild;
 use rustc_middle::middle::privacy::EffectiveVisibilities;
 use rustc_middle::span_bug;
-use rustc_middle::ty::{self, DefIdTree, MainDefinition, RegisteredTools, TyCtxt};
+use rustc_middle::ty::{self, MainDefinition, RegisteredTools, TyCtxt};
 use rustc_middle::ty::{ResolverGlobalCtxt, ResolverOutputs};
 use rustc_query_system::ich::StableHashingContext;
-use rustc_session::cstore::CrateStore;
 use rustc_session::lint::LintBuffer;
 use rustc_span::hygiene::{ExpnId, LocalExpnId, MacroKind, SyntaxContext, Transparency};
-use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
 
@@ -80,7 +79,7 @@ mod late;
 mod macros;
 pub mod rustdoc;
 
-fluent_messages! { "../locales/en-US.ftl" }
+fluent_messages! { "../messages.ftl" }
 
 enum Weak {
     Yes,
@@ -880,11 +879,8 @@ pub struct Resolver<'a, 'tcx> {
     extern_prelude: FxHashMap<Ident, ExternPreludeEntry<'a>>,
 
     /// N.B., this is used only for better diagnostics, not name resolution itself.
-    has_self: FxHashSet<DefId>,
-
-    /// Names of fields of an item `DefId` accessible with dot syntax.
-    /// Used for hints during error reporting.
-    field_names: FxHashMap<DefId, Vec<Spanned<Symbol>>>,
+    has_self: LocalDefIdSet,
+    field_def_ids: LocalDefIdMap<&'tcx [DefId]>,
 
     /// Span of the privacy modifier in fields of an item `DefId` accessible with dot syntax.
     /// Used for hints during error reporting.
@@ -913,7 +909,8 @@ pub struct Resolver<'a, 'tcx> {
 
     /// `CrateNum` resolutions of `extern crate` items.
     extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
-    reexport_map: FxHashMap<LocalDefId, Vec<ModChild>>,
+    module_children_non_reexports: LocalDefIdMap<Vec<LocalDefId>>,
+    module_children_reexports: LocalDefIdMap<Vec<ModChild>>,
     trait_map: NodeMap<Vec<TraitCandidate>>,
 
     /// A map from nodes to anonymous modules.
@@ -965,7 +962,7 @@ pub struct Resolver<'a, 'tcx> {
     /// 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_tools: RegisteredTools,
+    registered_tools: &'tcx RegisteredTools,
     macro_use_prelude: FxHashMap<Symbol, &'a NameBinding<'a>>,
     macro_map: FxHashMap<DefId, MacroData>,
     dummy_ext_bang: Lrc<SyntaxExtension>,
@@ -1008,7 +1005,7 @@ pub struct Resolver<'a, 'tcx> {
     /// 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<DefId>, Vec<ty::Visibility<DefId>>)>,
+    struct_constructors: LocalDefIdMap<(Res, ty::Visibility<DefId>, Vec<ty::Visibility<DefId>>)>,
 
     /// Features enabled for this crate.
     active_features: FxHashSet<Symbol>,
@@ -1117,13 +1114,6 @@ impl<'a, 'tcx> AsMut<Resolver<'a, 'tcx>> for Resolver<'a, 'tcx> {
     }
 }
 
-impl<'a, 'b, 'tcx> DefIdTree for &'a Resolver<'b, 'tcx> {
-    #[inline]
-    fn opt_parent(self, id: DefId) -> Option<DefId> {
-        self.tcx.opt_parent(id)
-    }
-}
-
 impl<'tcx> Resolver<'_, 'tcx> {
     fn opt_local_def_id(&self, node: NodeId) -> Option<LocalDefId> {
         self.node_id_to_def_id.get(&node).copied()
@@ -1179,7 +1169,7 @@ impl<'tcx> Resolver<'_, 'tcx> {
         if let Some(def_id) = def_id.as_local() {
             self.item_generics_num_lifetimes[&def_id]
         } else {
-            self.cstore().item_generics_num_lifetimes(def_id, self.tcx.sess)
+            self.tcx.generics_of(def_id).own_counts().lifetimes
         }
     }
 
@@ -1191,7 +1181,8 @@ impl<'tcx> Resolver<'_, 'tcx> {
 impl<'a, 'tcx> Resolver<'a, 'tcx> {
     pub fn new(
         tcx: TyCtxt<'tcx>,
-        krate: &Crate,
+        attrs: &[ast::Attribute],
+        crate_span: Span,
         arenas: &'a ResolverArenas<'a>,
     ) -> Resolver<'a, 'tcx> {
         let root_def_id = CRATE_DEF_ID.to_def_id();
@@ -1200,8 +1191,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             None,
             ModuleKind::Def(DefKind::Mod, root_def_id, kw::Empty),
             ExpnId::root(),
-            krate.spans.inner_span,
-            tcx.sess.contains_name(&krate.attrs, sym::no_implicit_prelude),
+            crate_span,
+            attr::contains_name(attrs, sym::no_implicit_prelude),
             &mut module_map,
         );
         let empty_module = arenas.new_module(
@@ -1233,14 +1224,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             .map(|(name, _)| (Ident::from_str(name), Default::default()))
             .collect();
 
-        if !tcx.sess.contains_name(&krate.attrs, sym::no_core) {
+        if !attr::contains_name(attrs, sym::no_core) {
             extern_prelude.insert(Ident::with_dummy_span(sym::core), Default::default());
-            if !tcx.sess.contains_name(&krate.attrs, sym::no_std) {
+            if !attr::contains_name(attrs, sym::no_std) {
                 extern_prelude.insert(Ident::with_dummy_span(sym::std), Default::default());
             }
         }
 
-        let registered_tools = macros::registered_tools(tcx.sess, &krate.attrs);
+        let registered_tools = tcx.registered_tools(());
 
         let features = tcx.sess.features_untracked();
 
@@ -1255,8 +1246,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             prelude: None,
             extern_prelude,
 
-            has_self: FxHashSet::default(),
-            field_names: FxHashMap::default(),
+            has_self: Default::default(),
+            field_def_ids: Default::default(),
             field_visibility_spans: FxHashMap::default(),
 
             determined_imports: Vec::new(),
@@ -1269,7 +1260,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             lifetimes_res_map: Default::default(),
             extra_lifetime_params_map: Default::default(),
             extern_crate_map: Default::default(),
-            reexport_map: FxHashMap::default(),
+            module_children_non_reexports: Default::default(),
+            module_children_reexports: Default::default(),
             trait_map: NodeMap::default(),
             underscore_disambiguator: 0,
             empty_module,
@@ -1396,7 +1388,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         let visibilities = self.visibilities;
         let has_pub_restricted = self.has_pub_restricted;
         let extern_crate_map = self.extern_crate_map;
-        let reexport_map = self.reexport_map;
         let maybe_unused_trait_imports = self.maybe_unused_trait_imports;
         let glob_map = self.glob_map;
         let main_def = self.main_def;
@@ -1408,14 +1399,14 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             has_pub_restricted,
             effective_visibilities,
             extern_crate_map,
-            reexport_map,
+            module_children_non_reexports: self.module_children_non_reexports,
+            module_children_reexports: self.module_children_reexports,
             glob_map,
             maybe_unused_trait_imports,
             main_def,
             trait_impls: self.trait_impls,
             proc_macros,
             confused_type_with_std_module,
-            registered_tools: self.registered_tools,
             doc_link_resolutions: self.doc_link_resolutions,
             doc_link_traits_in_scope: self.doc_link_traits_in_scope,
             all_macro_rules: self.all_macro_rules,
@@ -1433,6 +1424,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             trait_map: self.trait_map,
             builtin_macro_kinds: self.builtin_macro_kinds,
             lifetime_elision_allowed: self.lifetime_elision_allowed,
+            lint_buffer: Steal::new(self.lint_buffer),
         };
         ResolverOutputs { global_ctxt, ast_lowering }
     }
@@ -1442,9 +1434,11 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     }
 
     fn crate_loader<T>(&mut self, f: impl FnOnce(&mut CrateLoader<'_, '_>) -> T) -> T {
-        let mut cstore = self.tcx.untracked().cstore.write();
-        let cstore = cstore.untracked_as_any().downcast_mut().unwrap();
-        f(&mut CrateLoader::new(self.tcx, &mut *cstore, &mut self.used_extern_options))
+        f(&mut CrateLoader::new(
+            self.tcx,
+            &mut CStore::from_tcx_mut(self.tcx),
+            &mut self.used_extern_options,
+        ))
     }
 
     fn cstore(&self) -> MappedReadGuard<'_, CStore> {
@@ -1483,9 +1477,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     pub fn resolve_crate(&mut self, krate: &Crate) {
         self.tcx.sess.time("resolve_crate", || {
             self.tcx.sess.time("finalize_imports", || self.finalize_imports());
-            self.tcx.sess.time("compute_effective_visibilities", || {
+            let exported_ambiguities = self.tcx.sess.time("compute_effective_visibilities", || {
                 EffectiveVisibilitiesVisitor::compute_effective_visibilities(self, krate)
             });
+            self.tcx.sess.time("check_reexport_ambiguities", || {
+                self.check_reexport_ambiguities(exported_ambiguities)
+            });
             self.tcx.sess.time("finalize_macro_resolutions", || self.finalize_macro_resolutions());
             self.tcx.sess.time("late_resolve_crate", || self.late_resolve_crate(krate));
             self.tcx.sess.time("resolve_main", || self.resolve_main());
@@ -1656,7 +1653,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 misc2: AmbiguityErrorMisc::None,
             };
             if !self.matches_previous_ambiguity_error(&ambiguity_error) {
-                // avoid dumplicated span information to be emitt out
+                // avoid duplicated span information to be emitt out
                 self.ambiguity_errors.push(ambiguity_error);
             }
         }
@@ -1789,7 +1786,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         vis: ty::Visibility<impl Into<DefId>>,
         module: Module<'a>,
     ) -> bool {
-        vis.is_accessible_from(module.nearest_parent_mod(), self)
+        vis.is_accessible_from(module.nearest_parent_mod(), self.tcx)
     }
 
     fn set_binding_parent_module(&mut self, binding: &'a NameBinding<'a>, module: Module<'a>) {
@@ -1856,20 +1853,12 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         &mut self,
         path_str: &str,
         ns: Namespace,
-        mut parent_scope: ParentScope<'a>,
+        parent_scope: ParentScope<'a>,
     ) -> Option<Res> {
         let mut segments =
             Vec::from_iter(path_str.split("::").map(Ident::from_str).map(Segment::from_ident));
         if let Some(segment) = segments.first_mut() {
-            if segment.ident.name == kw::Crate {
-                // FIXME: `resolve_path` always resolves `crate` to the current crate root, but
-                // rustdoc wants it to resolve to the `parent_scope`'s crate root. This trick of
-                // replacing `crate` with `self` and changing the current module should achieve
-                // the same effect.
-                segment.ident.name = kw::SelfLower;
-                parent_scope.module =
-                    self.expect_module(parent_scope.module.def_id().krate.as_def_id());
-            } else if segment.ident.name == kw::Empty {
+            if segment.ident.name == kw::Empty {
                 segment.ident.name = kw::PathRoot;
             }
         }
@@ -1884,20 +1873,20 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
     }
 
-    /// Retrieves the span of the given `DefId` if `DefId` is in the local crate.
-    #[inline]
-    fn opt_span(&self, def_id: DefId) -> Option<Span> {
-        def_id.as_local().map(|def_id| self.tcx.source_span(def_id))
+    /// Retrieves definition span of the given `DefId`.
+    fn def_span(&self, def_id: DefId) -> Span {
+        match def_id.as_local() {
+            Some(def_id) => self.tcx.source_span(def_id),
+            // Query `def_span` is not used because hashing its result span is expensive.
+            None => self.cstore().def_span_untracked(def_id, self.tcx.sess),
+        }
     }
 
-    /// Retrieves the name of the given `DefId`.
-    #[inline]
-    fn opt_name(&self, def_id: DefId) -> Option<Symbol> {
-        let def_key = match def_id.as_local() {
-            Some(def_id) => self.tcx.definitions_untracked().def_key(def_id),
-            None => self.cstore().def_key(def_id),
-        };
-        def_key.get_opt_name()
+    fn field_def_ids(&self, def_id: DefId) -> Option<&'tcx [DefId]> {
+        match def_id.as_local() {
+            Some(def_id) => self.field_def_ids.get(&def_id).copied(),
+            None => Some(self.tcx.associated_item_def_ids(def_id)),
+        }
     }
 
     /// Checks if an expression refers to a function marked with
@@ -1924,10 +1913,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     return v.clone();
                 }
 
-                let attr = self
-                    .cstore()
-                    .item_attrs_untracked(def_id, self.tcx.sess)
-                    .find(|a| a.has_name(sym::rustc_legacy_const_generics))?;
+                let attr = self.tcx.get_attr(def_id, sym::rustc_legacy_const_generics)?;
                 let mut ret = Vec::new();
                 for meta in attr.meta_item_list()? {
                     match meta.lit()?.kind {
@@ -1965,20 +1951,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         }
         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<!>> {
-        if binding.is_import() {
-            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 {
@@ -2047,3 +2019,7 @@ impl Finalize {
         Finalize { node_id, path_span, root_span, report_private: true }
     }
 }
+
+pub fn provide(providers: &mut ty::query::Providers) {
+    providers.registered_tools = macros::registered_tools;
+}
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index b38c11e8b..22b014c06 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -1,14 +1,14 @@
 //! A bunch of methods and structures more or less related to resolving macros and
 //! interface provided by `Resolver` to macro expander.
 
+use crate::errors::{AddAsNonDerive, MacroExpectedFound, RemoveSurroundingDerive};
 use crate::Namespace::*;
 use crate::{BuiltinMacroState, Determinacy};
 use crate::{DeriveData, Finalize, ParentScope, ResolutionError, Resolver, ScopeSet};
 use crate::{ModuleKind, ModuleOrUniformRoot, NameBinding, PathResult, Segment};
-use rustc_ast::{self as ast, Inline, ItemKind, ModKind, NodeId};
+use rustc_ast::{self as ast, attr, Inline, ItemKind, ModKind, NodeId};
 use rustc_ast_pretty::pprust;
 use rustc_attr::StabilityLevel;
-use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::intern::Interned;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{struct_span_err, Applicability};
@@ -20,11 +20,11 @@ use rustc_hir::def::{self, DefKind, NonMacroAttrKind};
 use rustc_hir::def_id::{CrateNum, LocalDefId};
 use rustc_middle::middle::stability;
 use rustc_middle::ty::RegisteredTools;
+use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::{LEGACY_DERIVE_HELPERS, SOFT_UNSTABLE};
 use rustc_session::lint::builtin::{UNUSED_MACROS, UNUSED_MACRO_RULES};
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::parse::feature_err;
-use rustc_session::Session;
 use rustc_span::edition::Edition;
 use rustc_span::hygiene::{self, ExpnData, ExpnKind, LocalExpnId};
 use rustc_span::hygiene::{AstPass, MacroKind};
@@ -111,15 +111,17 @@ fn fast_print_path(path: &ast::Path) -> Symbol {
     }
 }
 
-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) {
+pub(crate) fn registered_tools(tcx: TyCtxt<'_>, (): ()) -> RegisteredTools {
+    let mut registered_tools = RegisteredTools::default();
+    let (_, pre_configured_attrs) = &*tcx.crate_for_resolver(()).borrow();
+    for attr in attr::filter_by_name(pre_configured_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_tools.replace(ident) {
                         let msg = format!("{} `{}` was already registered", "tool", ident);
-                        sess.struct_span_err(ident.span, &msg)
+                        tcx.sess
+                            .struct_span_err(ident.span, &msg)
                             .span_label(old_ident.span, "already registered here")
                             .emit();
                     }
@@ -127,7 +129,10 @@ pub(crate) fn registered_tools(sess: &Session, attrs: &[ast::Attribute]) -> FxHa
                 None => {
                     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();
+                    tcx.sess
+                        .struct_span_err(span, &msg)
+                        .span_label(span, "not an identifier")
+                        .emit();
                 }
             }
         }
@@ -539,12 +544,29 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
         };
         if let Some((article, expected)) = unexpected_res {
             let path_str = pprust::path_to_string(path);
-            let msg = format!("expected {}, found {} `{}`", expected, res.descr(), path_str);
-            self.tcx
-                .sess
-                .struct_span_err(path.span, &msg)
-                .span_label(path.span, format!("not {} {}", article, expected))
-                .emit();
+
+            let mut err = MacroExpectedFound {
+                span: path.span,
+                expected,
+                found: res.descr(),
+                macro_path: &path_str,
+                ..Default::default() // Subdiagnostics default to None
+            };
+
+            // Suggest moving the macro out of the derive() if the macro isn't Derive
+            if !path.span.from_expansion()
+                && kind == MacroKind::Derive
+                && ext.macro_kind() != MacroKind::Derive
+            {
+                err.remove_surrounding_derive = Some(RemoveSurroundingDerive { span: path.span });
+                err.add_as_non_derive = Some(AddAsNonDerive { macro_path: &path_str });
+            }
+
+            let mut err = self.tcx.sess.create_err(err);
+            err.span_label(path.span, format!("not {} {}", article, expected));
+
+            err.emit();
+
             return Ok((self.dummy_ext(kind), Res::Err));
         }
 
@@ -699,7 +721,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 PathResult::NonModule(path_res) if let Some(res) = path_res.full_res() => {
                     check_consistency(self, &path, path_span, kind, initial_res, res)
                 }
-                path_res @ PathResult::NonModule(..) | path_res @ PathResult::Failed { .. } => {
+                path_res @ (PathResult::NonModule(..) | PathResult::Failed { .. }) => {
                     let mut suggestion = None;
                     let (span, label) = if let PathResult::Failed { span, label, .. } = path_res {
                         // try to suggest if it's not a macro, maybe a function
diff --git a/compiler/rustc_resolve/src/rustdoc.rs b/compiler/rustc_resolve/src/rustdoc.rs
index b8853c174..9eae99be2 100644
--- a/compiler/rustc_resolve/src/rustdoc.rs
+++ b/compiler/rustc_resolve/src/rustdoc.rs
@@ -3,7 +3,7 @@ use rustc_ast as ast;
 use rustc_ast::util::comments::beautify_doc_string;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::def_id::DefId;
-use rustc_span::symbol::{kw, Symbol};
+use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 use std::{cmp, mem};
 
@@ -26,11 +26,13 @@ pub enum DocFragmentKind {
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct DocFragment {
     pub span: Span,
-    /// The module this doc-comment came from.
-    ///
-    /// This allows distinguishing between the original documentation and a pub re-export.
-    /// If it is `None`, the item was not re-exported.
-    pub parent_module: Option<DefId>,
+    /// The item this doc-comment came from.
+    /// Used to determine the scope in which doc links in this fragment are resolved.
+    /// Typically filled for reexport docs when they are merged into the docs of the
+    /// original reexported item.
+    /// If the id is not filled, which happens for the original reexported item, then
+    /// it has to be taken from somewhere else during doc link resolution.
+    pub item_id: Option<DefId>,
     pub doc: Symbol,
     pub kind: DocFragmentKind,
     pub indent: usize,
@@ -186,7 +188,7 @@ pub fn attrs_to_doc_fragments<'a>(
 ) -> (Vec<DocFragment>, ast::AttrVec) {
     let mut doc_fragments = Vec::new();
     let mut other_attrs = ast::AttrVec::new();
-    for (attr, parent_module) in attrs {
+    for (attr, item_id) in attrs {
         if let Some((doc_str, comment_kind)) = attr.doc_str_and_comment_kind() {
             let doc = beautify_doc_string(doc_str, comment_kind);
             let kind = if attr.is_doc_comment() {
@@ -194,7 +196,7 @@ pub fn attrs_to_doc_fragments<'a>(
             } else {
                 DocFragmentKind::RawDoc
             };
-            let fragment = DocFragment { span: attr.span, doc, kind, parent_module, indent: 0 };
+            let fragment = DocFragment { span: attr.span, doc, kind, item_id, indent: 0 };
             doc_fragments.push(fragment);
         } else if !doc_only {
             other_attrs.push(attr.clone());
@@ -216,7 +218,7 @@ pub fn prepare_to_doc_link_resolution(
 ) -> FxHashMap<Option<DefId>, String> {
     let mut res = FxHashMap::default();
     for fragment in doc_fragments {
-        let out_str = res.entry(fragment.parent_module).or_default();
+        let out_str = res.entry(fragment.item_id).or_default();
         add_doc_fragment(out_str, fragment);
     }
     res
@@ -337,6 +339,22 @@ pub fn inner_docs(attrs: &[ast::Attribute]) -> bool {
     attrs.iter().find(|a| a.doc_str().is_some()).map_or(true, |a| a.style == ast::AttrStyle::Inner)
 }
 
+/// Has `#[rustc_doc_primitive]` or `#[doc(keyword)]`.
+pub fn has_primitive_or_keyword_docs(attrs: &[ast::Attribute]) -> bool {
+    for attr in attrs {
+        if attr.has_name(sym::rustc_doc_primitive) {
+            return true;
+        } else if attr.has_name(sym::doc) && let Some(items) = attr.meta_item_list() {
+            for item in items {
+                if item.has_name(sym::keyword) {
+                    return true;
+                }
+            }
+        }
+    }
+    false
+}
+
 /// Simplified version of the corresponding function in rustdoc.
 /// If the rustdoc version returns a successful result, this function must return the same result.
 /// Otherwise this function may return anything.