Adding debian version 1.65.0+dfsg1-2.debian/1.65.0+dfsg1-2

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

11 files changed, 1017 insertions, 405 deletions

diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index a2ac329f2..b3f15ba7c 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -16,6 +16,7 @@ use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{self, FnSig, ForeignItem, HirId, Item, ItemKind, TraitItem, CRATE_HIR_ID};
 use rustc_hir::{MethodKind, Target};
 use rustc_middle::hir::nested_filter;
+use rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::{
@@ -130,6 +131,7 @@ impl CheckAttrVisitor<'_> {
                 | sym::rustc_if_this_changed
                 | sym::rustc_then_this_would_need => self.check_rustc_dirty_clean(&attr),
                 sym::cmse_nonsecure_entry => self.check_cmse_nonsecure_entry(attr, span, target),
+                sym::collapse_debuginfo => self.check_collapse_debuginfo(attr, span, target),
                 sym::const_trait => self.check_const_trait(attr, span, target),
                 sym::must_not_suspend => self.check_must_not_suspend(&attr, span, target),
                 sym::must_use => self.check_must_use(hir_id, &attr, span, target),
@@ -146,6 +148,7 @@ impl CheckAttrVisitor<'_> {
                 | sym::stable
                 | sym::rustc_allowed_through_unstable_modules
                 | sym::rustc_promotable => self.check_stability_promotable(&attr, span, target),
+                sym::link_ordinal => self.check_link_ordinal(&attr, span, target),
                 _ => true,
             };
             is_valid &= attr_is_valid;
@@ -171,6 +174,7 @@ impl CheckAttrVisitor<'_> {
                 sym::no_implicit_prelude => {
                     self.check_generic_attr(hir_id, attr, target, &[Target::Mod])
                 }
+                sym::rustc_object_lifetime_default => self.check_object_lifetime_default(hir_id),
                 _ => {}
             }
 
@@ -209,7 +213,14 @@ impl CheckAttrVisitor<'_> {
         }
 
         // FIXME(@lcnr): this doesn't belong here.
-        if matches!(target, Target::Closure | Target::Fn | Target::Method(_) | Target::ForeignFn) {
+        if matches!(
+            target,
+            Target::Closure
+                | Target::Fn
+                | Target::Method(_)
+                | Target::ForeignFn
+                | Target::ForeignStatic
+        ) {
             self.tcx.ensure().codegen_fn_attrs(self.tcx.hir().local_def_id(hir_id));
         }
 
@@ -402,6 +413,38 @@ impl CheckAttrVisitor<'_> {
         }
     }
 
+    /// Debugging aid for `object_lifetime_default` query.
+    fn check_object_lifetime_default(&self, hir_id: HirId) {
+        let tcx = self.tcx;
+        if let Some(generics) = tcx.hir().get_generics(tcx.hir().local_def_id(hir_id)) {
+            for p in generics.params {
+                let hir::GenericParamKind::Type { .. } = p.kind else { continue };
+                let param_id = tcx.hir().local_def_id(p.hir_id);
+                let default = tcx.object_lifetime_default(param_id);
+                let repr = match default {
+                    ObjectLifetimeDefault::Empty => "BaseDefault".to_owned(),
+                    ObjectLifetimeDefault::Static => "'static".to_owned(),
+                    ObjectLifetimeDefault::Param(def_id) => tcx.item_name(def_id).to_string(),
+                    ObjectLifetimeDefault::Ambiguous => "Ambiguous".to_owned(),
+                };
+                tcx.sess.span_err(p.span, &repr);
+            }
+        }
+    }
+
+    /// Checks if `#[collapse_debuginfo]` is applied to a macro.
+    fn check_collapse_debuginfo(&self, attr: &Attribute, span: Span, target: Target) -> bool {
+        match target {
+            Target::MacroDef => true,
+            _ => {
+                self.tcx
+                    .sess
+                    .emit_err(errors::CollapseDebuginfo { attr_span: attr.span, defn_span: span });
+                false
+            }
+        }
+    }
+
     /// Checks if a `#[track_caller]` is applied to a non-naked function. Returns `true` if valid.
     fn check_track_caller(
         &self,
@@ -632,6 +675,7 @@ impl CheckAttrVisitor<'_> {
             | Target::GlobalAsm
             | Target::TyAlias
             | Target::OpaqueTy
+            | Target::ImplTraitPlaceholder
             | Target::Enum
             | Target::Variant
             | Target::Struct
@@ -644,7 +688,9 @@ impl CheckAttrVisitor<'_> {
             | Target::ForeignStatic
             | Target::ForeignTy
             | Target::GenericParam(..)
-            | Target::MacroDef => None,
+            | Target::MacroDef
+            | Target::PatField
+            | Target::ExprField => None,
         } {
             tcx.sess.emit_err(errors::DocAliasBadLocation { span, attr_str, location });
             return false;
@@ -1620,6 +1666,8 @@ impl CheckAttrVisitor<'_> {
                         E0552,
                         "unrecognized representation hint"
                     )
+                    .help("valid reprs are `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, \
+                          `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`")
                     .emit();
 
                     continue;
@@ -1886,6 +1934,16 @@ impl CheckAttrVisitor<'_> {
         }
     }
 
+    fn check_link_ordinal(&self, attr: &Attribute, _span: Span, target: Target) -> bool {
+        match target {
+            Target::ForeignFn | Target::ForeignStatic => true,
+            _ => {
+                self.tcx.sess.emit_err(errors::LinkOrdinal { attr_span: attr.span });
+                false
+            }
+        }
+    }
+
     fn check_deprecated(&self, hir_id: HirId, attr: &Attribute, _span: Span, target: Target) {
         match target {
             Target::Closure | Target::Expression | Target::Statement | Target::Arm => {
@@ -2048,14 +2106,14 @@ impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
         intravisit::walk_expr(self, expr)
     }
 
-    fn visit_variant(
-        &mut self,
-        variant: &'tcx hir::Variant<'tcx>,
-        generics: &'tcx hir::Generics<'tcx>,
-        item_id: HirId,
-    ) {
+    fn visit_expr_field(&mut self, field: &'tcx hir::ExprField<'tcx>) {
+        self.check_attributes(field.hir_id, field.span, Target::ExprField, None);
+        intravisit::walk_expr_field(self, field)
+    }
+
+    fn visit_variant(&mut self, variant: &'tcx hir::Variant<'tcx>) {
         self.check_attributes(variant.id, variant.span, Target::Variant, None);
-        intravisit::walk_variant(self, variant, generics, item_id)
+        intravisit::walk_variant(self, variant)
     }
 
     fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
@@ -2063,6 +2121,11 @@ impl<'tcx> Visitor<'tcx> for CheckAttrVisitor<'tcx> {
 
         intravisit::walk_param(self, param);
     }
+
+    fn visit_pat_field(&mut self, field: &'tcx hir::PatField<'tcx>) {
+        self.check_attributes(field.hir_id, field.span, Target::PatField, None);
+        intravisit::walk_pat_field(self, field);
+    }
 }
 
 fn is_c_like_enum(item: &Item<'_>) -> bool {
@@ -2092,6 +2155,7 @@ fn check_invalid_crate_level_attr(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
         sym::automatically_derived,
         sym::start,
         sym::rustc_main,
+        sym::unix_sigpipe,
         sym::derive,
         sym::test,
         sym::test_case,
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 1e2fbeb38..f141d7bee 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -226,19 +226,16 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
         lhs: &hir::Pat<'_>,
         res: Res,
         pats: &[hir::Pat<'_>],
-        dotdot: Option<usize>,
+        dotdot: hir::DotDotPos,
     ) {
         let variant = match self.typeck_results().node_type(lhs.hir_id).kind() {
             ty::Adt(adt, _) => adt.variant_of_res(res),
             _ => span_bug!(lhs.span, "non-ADT in tuple struct pattern"),
         };
-        let first_n = pats.iter().enumerate().take(dotdot.unwrap_or(pats.len()));
+        let dotdot = dotdot.as_opt_usize().unwrap_or(pats.len());
+        let first_n = pats.iter().enumerate().take(dotdot);
         let missing = variant.fields.len() - pats.len();
-        let last_n = pats
-            .iter()
-            .enumerate()
-            .skip(dotdot.unwrap_or(pats.len()))
-            .map(|(idx, pat)| (idx + missing, pat));
+        let last_n = pats.iter().enumerate().skip(dotdot).map(|(idx, pat)| (idx + missing, pat));
         for (idx, pat) in first_n.chain(last_n) {
             if let PatKind::Wild = pat.kind {
                 continue;
@@ -368,14 +365,7 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
         self.maybe_typeck_results = old_maybe_typeck_results;
     }
 
-    fn visit_variant_data(
-        &mut self,
-        def: &'tcx hir::VariantData<'tcx>,
-        _: Symbol,
-        _: &hir::Generics<'_>,
-        _: hir::HirId,
-        _: rustc_span::Span,
-    ) {
+    fn visit_variant_data(&mut self, def: &'tcx hir::VariantData<'tcx>) {
         let tcx = self.tcx;
         let has_repr_c = self.repr_has_repr_c;
         let has_repr_simd = self.repr_has_repr_simd;
@@ -457,7 +447,7 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
     }
 
     fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) {
-        if let TyKind::OpaqueDef(item_id, _) = ty.kind {
+        if let TyKind::OpaqueDef(item_id, _, _) = ty.kind {
             let item = self.tcx.hir().item(item_id);
             intravisit::walk_item(self, item);
         }
diff --git a/compiler/rustc_passes/src/entry.rs b/compiler/rustc_passes/src/entry.rs
index 7381019a6..cd10170d3 100644
--- a/compiler/rustc_passes/src/entry.rs
+++ b/compiler/rustc_passes/src/entry.rs
@@ -1,11 +1,11 @@
-use rustc_ast::{entry::EntryPointType, Attribute};
+use rustc_ast::entry::EntryPointType;
 use rustc_errors::struct_span_err;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId, CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_hir::{ItemId, Node, CRATE_HIR_ID};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{DefIdTree, TyCtxt};
-use rustc_session::config::{CrateType, EntryFnType};
+use rustc_session::config::{sigpipe, CrateType, EntryFnType};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol, DUMMY_SP};
@@ -71,14 +71,12 @@ fn entry_point_type(ctxt: &EntryContext<'_>, id: ItemId, at_root: bool) -> Entry
     }
 }
 
-fn err_if_attr_found(ctxt: &EntryContext<'_>, attrs: &[Attribute], sym: Symbol) {
+fn err_if_attr_found(ctxt: &EntryContext<'_>, id: ItemId, sym: Symbol, details: &str) {
+    let attrs = ctxt.tcx.hir().attrs(id.hir_id());
     if let Some(attr) = ctxt.tcx.sess.find_by_name(attrs, sym) {
         ctxt.tcx
             .sess
-            .struct_span_err(
-                attr.span,
-                &format!("`{}` attribute can only be used on functions", sym),
-            )
+            .struct_span_err(attr.span, &format!("`{}` attribute {}", sym, details))
             .emit();
     }
 }
@@ -87,14 +85,16 @@ fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
     let at_root = ctxt.tcx.opt_local_parent(id.def_id) == Some(CRATE_DEF_ID);
 
     match entry_point_type(ctxt, id, at_root) {
-        EntryPointType::None => (),
+        EntryPointType::None => {
+            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on `fn main()`");
+        }
         _ if !matches!(ctxt.tcx.def_kind(id.def_id), DefKind::Fn) => {
-            let attrs = ctxt.tcx.hir().attrs(id.hir_id());
-            err_if_attr_found(ctxt, attrs, sym::start);
-            err_if_attr_found(ctxt, attrs, sym::rustc_main);
+            err_if_attr_found(ctxt, id, sym::start, "can only be used on functions");
+            err_if_attr_found(ctxt, id, sym::rustc_main, "can only be used on functions");
         }
         EntryPointType::MainNamed => (),
         EntryPointType::OtherMain => {
+            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on root `fn main()`");
             ctxt.non_main_fns.push(ctxt.tcx.def_span(id.def_id));
         }
         EntryPointType::RustcMainAttr => {
@@ -116,6 +116,7 @@ fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
             }
         }
         EntryPointType::Start => {
+            err_if_attr_found(ctxt, id, sym::unix_sigpipe, "can only be used on `fn main()`");
             if ctxt.start_fn.is_none() {
                 ctxt.start_fn = Some((id.def_id, ctxt.tcx.def_span(id.def_id.to_def_id())));
             } else {
@@ -136,8 +137,9 @@ fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
 fn configure_main(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) -> Option<(DefId, EntryFnType)> {
     if let Some((def_id, _)) = visitor.start_fn {
         Some((def_id.to_def_id(), EntryFnType::Start))
-    } else if let Some((def_id, _)) = visitor.attr_main_fn {
-        Some((def_id.to_def_id(), EntryFnType::Main))
+    } else if let Some((local_def_id, _)) = visitor.attr_main_fn {
+        let def_id = local_def_id.to_def_id();
+        Some((def_id, EntryFnType::Main { sigpipe: sigpipe(tcx, def_id) }))
     } else {
         if let Some(main_def) = tcx.resolutions(()).main_def && let Some(def_id) = main_def.opt_fn_def_id() {
             // non-local main imports are handled below
@@ -161,13 +163,39 @@ fn configure_main(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) -> Option<(DefId,
                 )
                 .emit();
             }
-            return Some((def_id, EntryFnType::Main));
+            return Some((def_id, EntryFnType::Main { sigpipe: sigpipe(tcx, def_id) }));
         }
         no_main_err(tcx, visitor);
         None
     }
 }
 
+fn sigpipe(tcx: TyCtxt<'_>, def_id: DefId) -> u8 {
+    if let Some(attr) = tcx.get_attr(def_id, sym::unix_sigpipe) {
+        match (attr.value_str(), attr.meta_item_list()) {
+            (Some(sym::inherit), None) => sigpipe::INHERIT,
+            (Some(sym::sig_ign), None) => sigpipe::SIG_IGN,
+            (Some(sym::sig_dfl), None) => sigpipe::SIG_DFL,
+            (_, Some(_)) => {
+                // Keep going so that `fn emit_malformed_attribute()` can print
+                // an excellent error message
+                sigpipe::DEFAULT
+            }
+            _ => {
+                tcx.sess
+                    .struct_span_err(
+                        attr.span,
+                        "valid values for `#[unix_sigpipe = \"...\"]` are `inherit`, `sig_ign`, or `sig_dfl`",
+                    )
+                    .emit();
+                sigpipe::DEFAULT
+            }
+        }
+    } else {
+        sigpipe::DEFAULT
+    }
+}
+
 fn no_main_err(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) {
     let sp = tcx.def_span(CRATE_DEF_ID);
     if *tcx.sess.parse_sess.reached_eof.borrow() {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 5feb0e295..96cc8ae98 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -3,37 +3,37 @@ use rustc_macros::{LintDiagnostic, SessionDiagnostic, SessionSubdiagnostic};
 use rustc_span::{Span, Symbol};
 
 #[derive(LintDiagnostic)]
-#[lint(passes::outer_crate_level_attr)]
+#[diag(passes::outer_crate_level_attr)]
 pub struct OuterCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inner_crate_level_attr)]
+#[diag(passes::inner_crate_level_attr)]
 pub struct InnerCrateLevelAttr;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::ignored_attr_with_macro)]
+#[diag(passes::ignored_attr_with_macro)]
 pub struct IgnoredAttrWithMacro<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::ignored_attr)]
+#[diag(passes::ignored_attr)]
 pub struct IgnoredAttr<'a> {
     pub sym: &'a str,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inline_ignored_function_prototype)]
+#[diag(passes::inline_ignored_function_prototype)]
 pub struct IgnoredInlineAttrFnProto;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::inline_ignored_constants)]
-#[warn_]
+#[diag(passes::inline_ignored_constants)]
+#[warning]
 #[note]
 pub struct IgnoredInlineAttrConstants;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::inline_not_fn_or_closure, code = "E0518")]
+#[diag(passes::inline_not_fn_or_closure, code = "E0518")]
 pub struct InlineNotFnOrClosure {
     #[primary_span]
     pub attr_span: Span,
@@ -42,19 +42,19 @@ pub struct InlineNotFnOrClosure {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_ignored_function_prototype)]
+#[diag(passes::no_coverage_ignored_function_prototype)]
 pub struct IgnoredNoCoverageFnProto;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_propagate)]
+#[diag(passes::no_coverage_propagate)]
 pub struct IgnoredNoCoveragePropagate;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_coverage_fn_defn)]
+#[diag(passes::no_coverage_fn_defn)]
 pub struct IgnoredNoCoverageFnDefn;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::no_coverage_not_coverable, code = "E0788")]
+#[diag(passes::no_coverage_not_coverable, code = "E0788")]
 pub struct IgnoredNoCoverageNotCoverable {
     #[primary_span]
     pub attr_span: Span,
@@ -63,7 +63,7 @@ pub struct IgnoredNoCoverageNotCoverable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_fn)]
+#[diag(passes::should_be_applied_to_fn)]
 pub struct AttrShouldBeAppliedToFn {
     #[primary_span]
     pub attr_span: Span,
@@ -72,14 +72,14 @@ pub struct AttrShouldBeAppliedToFn {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::naked_tracked_caller, code = "E0736")]
+#[diag(passes::naked_tracked_caller, code = "E0736")]
 pub struct NakedTrackedCaller {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_fn, code = "E0739")]
+#[diag(passes::should_be_applied_to_fn, code = "E0739")]
 pub struct TrackedCallerWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -88,7 +88,7 @@ pub struct TrackedCallerWrongLocation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_struct_enum, code = "E0701")]
+#[diag(passes::should_be_applied_to_struct_enum, code = "E0701")]
 pub struct NonExhaustiveWrongLocation {
     #[primary_span]
     pub attr_span: Span,
@@ -97,7 +97,7 @@ pub struct NonExhaustiveWrongLocation {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_trait)]
+#[diag(passes::should_be_applied_to_trait)]
 pub struct AttrShouldBeAppliedToTrait {
     #[primary_span]
     pub attr_span: Span,
@@ -106,11 +106,11 @@ pub struct AttrShouldBeAppliedToTrait {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::target_feature_on_statement)]
+#[diag(passes::target_feature_on_statement)]
 pub struct TargetFeatureOnStatement;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::should_be_applied_to_static)]
+#[diag(passes::should_be_applied_to_static)]
 pub struct AttrShouldBeAppliedToStatic {
     #[primary_span]
     pub attr_span: Span,
@@ -119,7 +119,7 @@ pub struct AttrShouldBeAppliedToStatic {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_expect_str)]
+#[diag(passes::doc_expect_str)]
 pub struct DocExpectStr<'a> {
     #[primary_span]
     pub attr_span: Span,
@@ -127,7 +127,7 @@ pub struct DocExpectStr<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_empty)]
+#[diag(passes::doc_alias_empty)]
 pub struct DocAliasEmpty<'a> {
     #[primary_span]
     pub span: Span,
@@ -135,7 +135,7 @@ pub struct DocAliasEmpty<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_bad_char)]
+#[diag(passes::doc_alias_bad_char)]
 pub struct DocAliasBadChar<'a> {
     #[primary_span]
     pub span: Span,
@@ -144,7 +144,7 @@ pub struct DocAliasBadChar<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_start_end)]
+#[diag(passes::doc_alias_start_end)]
 pub struct DocAliasStartEnd<'a> {
     #[primary_span]
     pub span: Span,
@@ -152,7 +152,7 @@ pub struct DocAliasStartEnd<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_bad_location)]
+#[diag(passes::doc_alias_bad_location)]
 pub struct DocAliasBadLocation<'a> {
     #[primary_span]
     pub span: Span,
@@ -161,7 +161,7 @@ pub struct DocAliasBadLocation<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_not_an_alias)]
+#[diag(passes::doc_alias_not_an_alias)]
 pub struct DocAliasNotAnAlias<'a> {
     #[primary_span]
     pub span: Span,
@@ -169,42 +169,42 @@ pub struct DocAliasNotAnAlias<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_alias_duplicated)]
+#[diag(passes::doc_alias_duplicated)]
 pub struct DocAliasDuplicated {
     #[label]
     pub first_defn: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_not_string_literal)]
+#[diag(passes::doc_alias_not_string_literal)]
 pub struct DocAliasNotStringLiteral {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_alias_malformed)]
+#[diag(passes::doc_alias_malformed)]
 pub struct DocAliasMalformed {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_empty_mod)]
+#[diag(passes::doc_keyword_empty_mod)]
 pub struct DocKeywordEmptyMod {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_not_mod)]
+#[diag(passes::doc_keyword_not_mod)]
 pub struct DocKeywordNotMod {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_invalid_ident)]
+#[diag(passes::doc_keyword_invalid_ident)]
 pub struct DocKeywordInvalidIdent {
     #[primary_span]
     pub span: Span,
@@ -212,21 +212,21 @@ pub struct DocKeywordInvalidIdent {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_fake_variadic_not_valid)]
+#[diag(passes::doc_fake_variadic_not_valid)]
 pub struct DocFakeVariadicNotValid {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_keyword_only_impl)]
+#[diag(passes::doc_keyword_only_impl)]
 pub struct DocKeywordOnlyImpl {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_inline_conflict)]
+#[diag(passes::doc_inline_conflict)]
 #[help]
 pub struct DocKeywordConflict {
     #[primary_span]
@@ -234,7 +234,7 @@ pub struct DocKeywordConflict {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_inline_only_use)]
+#[diag(passes::doc_inline_only_use)]
 #[note]
 pub struct DocInlineOnlyUse {
     #[label]
@@ -244,7 +244,7 @@ pub struct DocInlineOnlyUse {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::doc_attr_not_crate_level)]
+#[diag(passes::doc_attr_not_crate_level)]
 pub struct DocAttrNotCrateLevel<'a> {
     #[primary_span]
     pub span: Span,
@@ -252,27 +252,27 @@ pub struct DocAttrNotCrateLevel<'a> {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown)]
+#[diag(passes::doc_test_unknown)]
 pub struct DocTestUnknown {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_takes_list)]
+#[diag(passes::doc_test_takes_list)]
 pub struct DocTestTakesList;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_primitive)]
+#[diag(passes::doc_primitive)]
 pub struct DocPrimitive;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_any)]
+#[diag(passes::doc_test_unknown_any)]
 pub struct DocTestUnknownAny {
     pub path: String,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_spotlight)]
+#[diag(passes::doc_test_unknown_spotlight)]
 #[note]
 #[note(passes::no_op_note)]
 pub struct DocTestUnknownSpotlight {
@@ -282,7 +282,7 @@ pub struct DocTestUnknownSpotlight {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_test_unknown_include)]
+#[diag(passes::doc_test_unknown_include)]
 pub struct DocTestUnknownInclude {
     pub path: String,
     pub value: String,
@@ -292,11 +292,11 @@ pub struct DocTestUnknownInclude {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::doc_invalid)]
+#[diag(passes::doc_invalid)]
 pub struct DocInvalid;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::pass_by_value)]
+#[diag(passes::pass_by_value)]
 pub struct PassByValue {
     #[primary_span]
     pub attr_span: Span,
@@ -305,7 +305,7 @@ pub struct PassByValue {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::allow_incoherent_impl)]
+#[diag(passes::allow_incoherent_impl)]
 pub struct AllowIncoherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -314,7 +314,7 @@ pub struct AllowIncoherentImpl {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::has_incoherent_inherent_impl)]
+#[diag(passes::has_incoherent_inherent_impl)]
 pub struct HasIncoherentInherentImpl {
     #[primary_span]
     pub attr_span: Span,
@@ -323,21 +323,21 @@ pub struct HasIncoherentInherentImpl {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::must_use_async)]
+#[diag(passes::must_use_async)]
 pub struct MustUseAsync {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::must_use_no_effect)]
+#[diag(passes::must_use_no_effect)]
 pub struct MustUseNoEffect {
     pub article: &'static str,
     pub target: rustc_hir::Target,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::must_not_suspend)]
+#[diag(passes::must_not_suspend)]
 pub struct MustNotSuspend {
     #[primary_span]
     pub attr_span: Span,
@@ -346,24 +346,24 @@ pub struct MustNotSuspend {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::cold)]
-#[warn_]
+#[diag(passes::cold)]
+#[warning]
 pub struct Cold {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link)]
-#[warn_]
+#[diag(passes::link)]
+#[warning]
 pub struct Link {
     #[label]
     pub span: Option<Span>,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link_name)]
-#[warn_]
+#[diag(passes::link_name)]
+#[warning]
 pub struct LinkName<'a> {
     #[help]
     pub attr_span: Option<Span>,
@@ -373,7 +373,7 @@ pub struct LinkName<'a> {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::no_link)]
+#[diag(passes::no_link)]
 pub struct NoLink {
     #[primary_span]
     pub attr_span: Span,
@@ -382,7 +382,7 @@ pub struct NoLink {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::export_name)]
+#[diag(passes::export_name)]
 pub struct ExportName {
     #[primary_span]
     pub attr_span: Span,
@@ -391,7 +391,7 @@ pub struct ExportName {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_layout_scalar_valid_range_not_struct)]
+#[diag(passes::rustc_layout_scalar_valid_range_not_struct)]
 pub struct RustcLayoutScalarValidRangeNotStruct {
     #[primary_span]
     pub attr_span: Span,
@@ -400,14 +400,14 @@ pub struct RustcLayoutScalarValidRangeNotStruct {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_layout_scalar_valid_range_arg)]
+#[diag(passes::rustc_layout_scalar_valid_range_arg)]
 pub struct RustcLayoutScalarValidRangeArg {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_only)]
+#[diag(passes::rustc_legacy_const_generics_only)]
 pub struct RustcLegacyConstGenericsOnly {
     #[primary_span]
     pub attr_span: Span,
@@ -416,7 +416,7 @@ pub struct RustcLegacyConstGenericsOnly {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index)]
+#[diag(passes::rustc_legacy_const_generics_index)]
 pub struct RustcLegacyConstGenericsIndex {
     #[primary_span]
     pub attr_span: Span,
@@ -425,7 +425,7 @@ pub struct RustcLegacyConstGenericsIndex {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index_exceed)]
+#[diag(passes::rustc_legacy_const_generics_index_exceed)]
 pub struct RustcLegacyConstGenericsIndexExceed {
     #[primary_span]
     #[label]
@@ -434,30 +434,30 @@ pub struct RustcLegacyConstGenericsIndexExceed {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_legacy_const_generics_index_negative)]
+#[diag(passes::rustc_legacy_const_generics_index_negative)]
 pub struct RustcLegacyConstGenericsIndexNegative {
     #[primary_span]
     pub invalid_args: Vec<Span>,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_dirty_clean)]
+#[diag(passes::rustc_dirty_clean)]
 pub struct RustcDirtyClean {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::link_section)]
-#[warn_]
+#[diag(passes::link_section)]
+#[warning]
 pub struct LinkSection {
     #[label]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_mangle_foreign)]
-#[warn_]
+#[diag(passes::no_mangle_foreign)]
+#[warning]
 #[note]
 pub struct NoMangleForeign {
     #[label]
@@ -468,40 +468,40 @@ pub struct NoMangleForeign {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::no_mangle)]
-#[warn_]
+#[diag(passes::no_mangle)]
+#[warning]
 pub struct NoMangle {
     #[label]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::repr_ident, code = "E0565")]
+#[diag(passes::repr_ident, code = "E0565")]
 pub struct ReprIdent {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::repr_conflicting, code = "E0566")]
+#[diag(passes::repr_conflicting, code = "E0566")]
 pub struct ReprConflicting;
 
 #[derive(SessionDiagnostic)]
-#[error(passes::used_static)]
+#[diag(passes::used_static)]
 pub struct UsedStatic {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::used_compiler_linker)]
+#[diag(passes::used_compiler_linker)]
 pub struct UsedCompilerLinker {
     #[primary_span]
     pub spans: Vec<Span>,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::allow_internal_unstable)]
+#[diag(passes::allow_internal_unstable)]
 pub struct AllowInternalUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -510,14 +510,14 @@ pub struct AllowInternalUnstable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::debug_visualizer_placement)]
+#[diag(passes::debug_visualizer_placement)]
 pub struct DebugVisualizerPlacement {
     #[primary_span]
     pub span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::debug_visualizer_invalid)]
+#[diag(passes::debug_visualizer_invalid)]
 #[note(passes::note_1)]
 #[note(passes::note_2)]
 #[note(passes::note_3)]
@@ -527,7 +527,7 @@ pub struct DebugVisualizerInvalid {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_allow_const_fn_unstable)]
+#[diag(passes::rustc_allow_const_fn_unstable)]
 pub struct RustcAllowConstFnUnstable {
     #[primary_span]
     pub attr_span: Span,
@@ -536,7 +536,7 @@ pub struct RustcAllowConstFnUnstable {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_std_internal_symbol)]
+#[diag(passes::rustc_std_internal_symbol)]
 pub struct RustcStdInternalSymbol {
     #[primary_span]
     pub attr_span: Span,
@@ -545,35 +545,42 @@ pub struct RustcStdInternalSymbol {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::const_trait)]
+#[diag(passes::const_trait)]
 pub struct ConstTrait {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::stability_promotable)]
+#[diag(passes::link_ordinal)]
+pub struct LinkOrdinal {
+    #[primary_span]
+    pub attr_span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(passes::stability_promotable)]
 pub struct StabilityPromotable {
     #[primary_span]
     pub attr_span: Span,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::deprecated)]
+#[diag(passes::deprecated)]
 pub struct Deprecated;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::macro_use)]
+#[diag(passes::macro_use)]
 pub struct MacroUse {
     pub name: Symbol,
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::macro_export)]
+#[diag(passes::macro_export)]
 pub struct MacroExport;
 
 #[derive(LintDiagnostic)]
-#[lint(passes::plugin_registrar)]
+#[diag(passes::plugin_registrar)]
 pub struct PluginRegistrar;
 
 #[derive(SessionSubdiagnostic)]
@@ -587,7 +594,7 @@ pub enum UnusedNote {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::unused)]
+#[diag(passes::unused)]
 pub struct Unused {
     #[suggestion(applicability = "machine-applicable")]
     pub attr_span: Span,
@@ -596,7 +603,7 @@ pub struct Unused {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::non_exported_macro_invalid_attrs, code = "E0518")]
+#[diag(passes::non_exported_macro_invalid_attrs, code = "E0518")]
 pub struct NonExportedMacroInvalidAttrs {
     #[primary_span]
     #[label]
@@ -604,19 +611,18 @@ pub struct NonExportedMacroInvalidAttrs {
 }
 
 #[derive(LintDiagnostic)]
-#[lint(passes::unused_duplicate)]
+#[diag(passes::unused_duplicate)]
 pub struct UnusedDuplicate {
-    #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
     pub this: Span,
     #[note]
     pub other: Span,
-    #[warn_]
+    #[warning]
     pub warning: Option<()>,
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::unused_multiple)]
+#[diag(passes::unused_multiple)]
 pub struct UnusedMultiple {
     #[primary_span]
     #[suggestion(code = "", applicability = "machine-applicable")]
@@ -627,7 +633,7 @@ pub struct UnusedMultiple {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_lint_opt_ty)]
+#[diag(passes::rustc_lint_opt_ty)]
 pub struct RustcLintOptTy {
     #[primary_span]
     pub attr_span: Span,
@@ -636,10 +642,19 @@ pub struct RustcLintOptTy {
 }
 
 #[derive(SessionDiagnostic)]
-#[error(passes::rustc_lint_opt_deny_field_access)]
+#[diag(passes::rustc_lint_opt_deny_field_access)]
 pub struct RustcLintOptDenyFieldAccess {
     #[primary_span]
     pub attr_span: Span,
     #[label]
     pub span: Span,
 }
+
+#[derive(SessionDiagnostic)]
+#[diag(passes::collapse_debuginfo)]
+pub struct CollapseDebuginfo {
+    #[primary_span]
+    pub attr_span: Span,
+    #[label]
+    pub defn_span: Span,
+}
diff --git a/compiler/rustc_passes/src/hir_id_validator.rs b/compiler/rustc_passes/src/hir_id_validator.rs
index 212ea9e57..3bb8c0bb4 100644
--- a/compiler/rustc_passes/src/hir_id_validator.rs
+++ b/compiler/rustc_passes/src/hir_id_validator.rs
@@ -103,7 +103,7 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
             self.error(|| {
                 format!(
                     "ItemLocalIds not assigned densely in {}. \
-                Max ItemLocalId = {}, missing IDs = {:?}; seens IDs = {:?}",
+                Max ItemLocalId = {}, missing IDs = {:#?}; seens IDs = {:#?}",
                     self.hir_map.def_path(owner).to_string_no_crate_verbose(),
                     max,
                     missing_items,
diff --git a/compiler/rustc_passes/src/hir_stats.rs b/compiler/rustc_passes/src/hir_stats.rs
index a3be827a7..0be2fc053 100644
--- a/compiler/rustc_passes/src/hir_stats.rs
+++ b/compiler/rustc_passes/src/hir_stats.rs
@@ -21,75 +21,169 @@ enum Id {
     None,
 }
 
-struct NodeData {
+struct NodeStats {
     count: usize,
     size: usize,
 }
 
+impl NodeStats {
+    fn new() -> NodeStats {
+        NodeStats { count: 0, size: 0 }
+    }
+}
+
+struct Node {
+    stats: NodeStats,
+    subnodes: FxHashMap<&'static str, NodeStats>,
+}
+
+impl Node {
+    fn new() -> Node {
+        Node { stats: NodeStats::new(), subnodes: FxHashMap::default() }
+    }
+}
+
+/// This type measures the size of AST and HIR nodes, by implementing the AST
+/// and HIR `Visitor` traits. But we don't measure every visited type because
+/// that could cause double counting.
+///
+/// For example, `ast::Visitor` has `visit_ident`, but `Ident`s are always
+/// stored inline within other AST nodes, so we don't implement `visit_ident`
+/// here. In contrast, we do implement `visit_expr` because `ast::Expr` is
+/// always stored as `P<ast::Expr>`, and every such expression should be
+/// measured separately.
+///
+/// In general, a `visit_foo` method should be implemented here if the
+/// corresponding `Foo` type is always stored on its own, e.g.: `P<Foo>`,
+/// `Box<Foo>`, `Vec<Foo>`, `Box<[Foo]>`.
+///
+/// There are some types in the AST and HIR tree that the visitors do not have
+/// a `visit_*` method for, and so we cannot measure these, which is
+/// unfortunate.
 struct StatCollector<'k> {
     krate: Option<Map<'k>>,
-    data: FxHashMap<&'static str, NodeData>,
+    nodes: FxHashMap<&'static str, Node>,
     seen: FxHashSet<Id>,
 }
 
 pub fn print_hir_stats(tcx: TyCtxt<'_>) {
     let mut collector = StatCollector {
         krate: Some(tcx.hir()),
-        data: FxHashMap::default(),
+        nodes: FxHashMap::default(),
         seen: FxHashSet::default(),
     };
     tcx.hir().walk_toplevel_module(&mut collector);
     tcx.hir().walk_attributes(&mut collector);
-    collector.print("HIR STATS");
+    collector.print("HIR STATS", "hir-stats");
 }
 
-pub fn print_ast_stats(krate: &ast::Crate, title: &str) {
+pub fn print_ast_stats(krate: &ast::Crate, title: &str, prefix: &str) {
+    use rustc_ast::visit::Visitor;
+
     let mut collector =
-        StatCollector { krate: None, data: FxHashMap::default(), seen: FxHashSet::default() };
-    ast_visit::walk_crate(&mut collector, krate);
-    collector.print(title);
+        StatCollector { krate: None, nodes: FxHashMap::default(), seen: FxHashSet::default() };
+    collector.visit_crate(krate);
+    collector.print(title, prefix);
 }
 
 impl<'k> StatCollector<'k> {
-    fn record<T>(&mut self, label: &'static str, id: Id, node: &T) {
+    // Record a top-level node.
+    fn record<T>(&mut self, label: &'static str, id: Id, val: &T) {
+        self.record_inner(label, None, id, val);
+    }
+
+    // Record a two-level entry, with a top-level enum type and a variant.
+    fn record_variant<T>(&mut self, label1: &'static str, label2: &'static str, id: Id, val: &T) {
+        self.record_inner(label1, Some(label2), id, val);
+    }
+
+    fn record_inner<T>(
+        &mut self,
+        label1: &'static str,
+        label2: Option<&'static str>,
+        id: Id,
+        val: &T,
+    ) {
         if id != Id::None && !self.seen.insert(id) {
             return;
         }
 
-        let entry = self.data.entry(label).or_insert(NodeData { count: 0, size: 0 });
+        let node = self.nodes.entry(label1).or_insert(Node::new());
+        node.stats.count += 1;
+        node.stats.size = std::mem::size_of_val(val);
 
-        entry.count += 1;
-        entry.size = std::mem::size_of_val(node);
+        if let Some(label2) = label2 {
+            let subnode = node.subnodes.entry(label2).or_insert(NodeStats::new());
+            subnode.count += 1;
+            subnode.size = std::mem::size_of_val(val);
+        }
     }
 
-    fn print(&self, title: &str) {
-        let mut stats: Vec<_> = self.data.iter().collect();
-
-        stats.sort_by_key(|&(_, ref d)| d.count * d.size);
+    fn print(&self, title: &str, prefix: &str) {
+        let mut nodes: Vec<_> = self.nodes.iter().collect();
+        nodes.sort_by_key(|&(_, ref node)| node.stats.count * node.stats.size);
 
-        let mut total_size = 0;
+        let total_size = nodes.iter().map(|(_, node)| node.stats.count * node.stats.size).sum();
 
-        eprintln!("\n{}\n", title);
+        eprintln!("{} {}", prefix, title);
+        eprintln!(
+            "{} {:<18}{:>18}{:>14}{:>14}",
+            prefix, "Name", "Accumulated Size", "Count", "Item Size"
+        );
+        eprintln!("{} ----------------------------------------------------------------", prefix);
 
-        eprintln!("{:<18}{:>18}{:>14}{:>14}", "Name", "Accumulated Size", "Count", "Item Size");
-        eprintln!("----------------------------------------------------------------");
+        let percent = |m, n| (m * 100) as f64 / n as f64;
 
-        for (label, data) in stats {
+        for (label, node) in nodes {
+            let size = node.stats.count * node.stats.size;
             eprintln!(
-                "{:<18}{:>18}{:>14}{:>14}",
+                "{} {:<18}{:>10} ({:4.1}%){:>14}{:>14}",
+                prefix,
                 label,
-                to_readable_str(data.count * data.size),
-                to_readable_str(data.count),
-                to_readable_str(data.size)
+                to_readable_str(size),
+                percent(size, total_size),
+                to_readable_str(node.stats.count),
+                to_readable_str(node.stats.size)
             );
-
-            total_size += data.count * data.size;
+            if !node.subnodes.is_empty() {
+                let mut subnodes: Vec<_> = node.subnodes.iter().collect();
+                subnodes.sort_by_key(|&(_, ref subnode)| subnode.count * subnode.size);
+
+                for (label, subnode) in subnodes {
+                    let size = subnode.count * subnode.size;
+                    eprintln!(
+                        "{} - {:<18}{:>10} ({:4.1}%){:>14}",
+                        prefix,
+                        label,
+                        to_readable_str(size),
+                        percent(size, total_size),
+                        to_readable_str(subnode.count),
+                    );
+                }
+            }
         }
-        eprintln!("----------------------------------------------------------------");
-        eprintln!("{:<18}{:>18}\n", "Total", to_readable_str(total_size));
+        eprintln!("{} ----------------------------------------------------------------", prefix);
+        eprintln!("{} {:<18}{:>10}", prefix, "Total", to_readable_str(total_size));
+        eprintln!("{}", prefix);
     }
 }
 
+// Used to avoid boilerplate for types with many variants.
+macro_rules! record_variants {
+    (
+        ($self:ident, $val:expr, $kind:expr, $id:expr, $mod:ident, $ty:ty, $tykind:ident),
+        [$($variant:ident),*]
+    ) => {
+        match $kind {
+            $(
+                $mod::$tykind::$variant { .. } => {
+                    $self.record_variant(stringify!($ty), stringify!($variant), $id, $val)
+                }
+            )*
+        }
+    };
+}
+
 impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_param(&mut self, param: &'v hir::Param<'v>) {
         self.record("Param", Id::Node(param.hir_id), param);
@@ -122,12 +216,46 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     }
 
     fn visit_item(&mut self, i: &'v hir::Item<'v>) {
-        self.record("Item", Id::Node(i.hir_id()), i);
+        record_variants!(
+            (self, i, i.kind, Id::Node(i.hir_id()), hir, Item, ItemKind),
+            [
+                ExternCrate,
+                Use,
+                Static,
+                Const,
+                Fn,
+                Macro,
+                Mod,
+                ForeignMod,
+                GlobalAsm,
+                TyAlias,
+                OpaqueTy,
+                Enum,
+                Struct,
+                Union,
+                Trait,
+                TraitAlias,
+                Impl
+            ]
+        );
         hir_visit::walk_item(self, i)
     }
 
+    fn visit_body(&mut self, b: &'v hir::Body<'v>) {
+        self.record("Body", Id::None, b);
+        hir_visit::walk_body(self, b);
+    }
+
+    fn visit_mod(&mut self, m: &'v hir::Mod<'v>, _s: Span, n: HirId) {
+        self.record("Mod", Id::None, m);
+        hir_visit::walk_mod(self, m, n)
+    }
+
     fn visit_foreign_item(&mut self, i: &'v hir::ForeignItem<'v>) {
-        self.record("ForeignItem", Id::Node(i.hir_id()), i);
+        record_variants!(
+            (self, i, i.kind, Id::Node(i.hir_id()), hir, ForeignItem, ForeignItemKind),
+            [Fn, Static, Type]
+        );
         hir_visit::walk_foreign_item(self, i)
     }
 
@@ -142,7 +270,10 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     }
 
     fn visit_stmt(&mut self, s: &'v hir::Stmt<'v>) {
-        self.record("Stmt", Id::Node(s.hir_id), s);
+        record_variants!(
+            (self, s, s.kind, Id::Node(s.hir_id), hir, Stmt, StmtKind),
+            [Local, Item, Expr, Semi]
+        );
         hir_visit::walk_stmt(self, s)
     }
 
@@ -152,50 +283,135 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     }
 
     fn visit_pat(&mut self, p: &'v hir::Pat<'v>) {
-        self.record("Pat", Id::Node(p.hir_id), p);
+        record_variants!(
+            (self, p, p.kind, Id::Node(p.hir_id), hir, Pat, PatKind),
+            [Wild, Binding, Struct, TupleStruct, Or, Path, Tuple, Box, Ref, Lit, Range, Slice]
+        );
         hir_visit::walk_pat(self, p)
     }
 
-    fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) {
-        self.record("Expr", Id::Node(ex.hir_id), ex);
-        hir_visit::walk_expr(self, ex)
+    fn visit_pat_field(&mut self, f: &'v hir::PatField<'v>) {
+        self.record("PatField", Id::Node(f.hir_id), f);
+        hir_visit::walk_pat_field(self, f)
+    }
+
+    fn visit_expr(&mut self, e: &'v hir::Expr<'v>) {
+        record_variants!(
+            (self, e, e.kind, Id::Node(e.hir_id), hir, Expr, ExprKind),
+            [
+                Box, ConstBlock, Array, Call, MethodCall, Tup, Binary, Unary, Lit, Cast, Type,
+                DropTemps, Let, If, Loop, Match, Closure, Block, Assign, AssignOp, Field, Index,
+                Path, AddrOf, Break, Continue, Ret, InlineAsm, Struct, Repeat, Yield, Err
+            ]
+        );
+        hir_visit::walk_expr(self, e)
+    }
+
+    fn visit_let_expr(&mut self, lex: &'v hir::Let<'v>) {
+        self.record("Let", Id::Node(lex.hir_id), lex);
+        hir_visit::walk_let_expr(self, lex)
+    }
+
+    fn visit_expr_field(&mut self, f: &'v hir::ExprField<'v>) {
+        self.record("ExprField", Id::Node(f.hir_id), f);
+        hir_visit::walk_expr_field(self, f)
     }
 
     fn visit_ty(&mut self, t: &'v hir::Ty<'v>) {
-        self.record("Ty", Id::Node(t.hir_id), t);
+        record_variants!(
+            (self, t, t.kind, Id::Node(t.hir_id), hir, Ty, TyKind),
+            [
+                Slice,
+                Array,
+                Ptr,
+                Rptr,
+                BareFn,
+                Never,
+                Tup,
+                Path,
+                OpaqueDef,
+                TraitObject,
+                Typeof,
+                Infer,
+                Err
+            ]
+        );
         hir_visit::walk_ty(self, t)
     }
 
+    fn visit_generic_param(&mut self, p: &'v hir::GenericParam<'v>) {
+        self.record("GenericParam", Id::Node(p.hir_id), p);
+        hir_visit::walk_generic_param(self, p)
+    }
+
+    fn visit_generics(&mut self, g: &'v hir::Generics<'v>) {
+        self.record("Generics", Id::None, g);
+        hir_visit::walk_generics(self, g)
+    }
+
+    fn visit_where_predicate(&mut self, p: &'v hir::WherePredicate<'v>) {
+        record_variants!(
+            (self, p, p, Id::None, hir, WherePredicate, WherePredicate),
+            [BoundPredicate, RegionPredicate, EqPredicate]
+        );
+        hir_visit::walk_where_predicate(self, p)
+    }
+
     fn visit_fn(
         &mut self,
         fk: hir_visit::FnKind<'v>,
         fd: &'v hir::FnDecl<'v>,
         b: hir::BodyId,
-        s: Span,
+        _: Span,
         id: hir::HirId,
     ) {
         self.record("FnDecl", Id::None, fd);
-        hir_visit::walk_fn(self, fk, fd, b, s, id)
+        hir_visit::walk_fn(self, fk, fd, b, id)
     }
 
-    fn visit_where_predicate(&mut self, predicate: &'v hir::WherePredicate<'v>) {
-        self.record("WherePredicate", Id::None, predicate);
-        hir_visit::walk_where_predicate(self, predicate)
+    fn visit_use(&mut self, p: &'v hir::Path<'v>, hir_id: hir::HirId) {
+        // This is `visit_use`, but the type is `Path` so record it that way.
+        self.record("Path", Id::None, p);
+        hir_visit::walk_use(self, p, hir_id)
     }
 
     fn visit_trait_item(&mut self, ti: &'v hir::TraitItem<'v>) {
-        self.record("TraitItem", Id::Node(ti.hir_id()), ti);
+        record_variants!(
+            (self, ti, ti.kind, Id::Node(ti.hir_id()), hir, TraitItem, TraitItemKind),
+            [Const, Fn, Type]
+        );
         hir_visit::walk_trait_item(self, ti)
     }
 
+    fn visit_trait_item_ref(&mut self, ti: &'v hir::TraitItemRef) {
+        self.record("TraitItemRef", Id::Node(ti.id.hir_id()), ti);
+        hir_visit::walk_trait_item_ref(self, ti)
+    }
+
     fn visit_impl_item(&mut self, ii: &'v hir::ImplItem<'v>) {
-        self.record("ImplItem", Id::Node(ii.hir_id()), ii);
+        record_variants!(
+            (self, ii, ii.kind, Id::Node(ii.hir_id()), hir, ImplItem, ImplItemKind),
+            [Const, Fn, TyAlias]
+        );
         hir_visit::walk_impl_item(self, ii)
     }
 
-    fn visit_param_bound(&mut self, bounds: &'v hir::GenericBound<'v>) {
-        self.record("GenericBound", Id::None, bounds);
-        hir_visit::walk_param_bound(self, bounds)
+    fn visit_foreign_item_ref(&mut self, fi: &'v hir::ForeignItemRef) {
+        self.record("ForeignItemRef", Id::Node(fi.id.hir_id()), fi);
+        hir_visit::walk_foreign_item_ref(self, fi)
+    }
+
+    fn visit_impl_item_ref(&mut self, ii: &'v hir::ImplItemRef) {
+        self.record("ImplItemRef", Id::Node(ii.id.hir_id()), ii);
+        hir_visit::walk_impl_item_ref(self, ii)
+    }
+
+    fn visit_param_bound(&mut self, b: &'v hir::GenericBound<'v>) {
+        record_variants!(
+            (self, b, b, Id::None, hir, GenericBound, GenericBound),
+            [Trait, LangItemTrait, Outlives]
+        );
+        hir_visit::walk_param_bound(self, b)
     }
 
     fn visit_field_def(&mut self, s: &'v hir::FieldDef<'v>) {
@@ -203,14 +419,22 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
         hir_visit::walk_field_def(self, s)
     }
 
-    fn visit_variant(
-        &mut self,
-        v: &'v hir::Variant<'v>,
-        g: &'v hir::Generics<'v>,
-        item_id: hir::HirId,
-    ) {
+    fn visit_variant(&mut self, v: &'v hir::Variant<'v>) {
         self.record("Variant", Id::None, v);
-        hir_visit::walk_variant(self, v, g, item_id)
+        hir_visit::walk_variant(self, v)
+    }
+
+    fn visit_generic_arg(&mut self, ga: &'v hir::GenericArg<'v>) {
+        record_variants!(
+            (self, ga, ga, Id::Node(ga.hir_id()), hir, GenericArg, GenericArg),
+            [Lifetime, Type, Const, Infer]
+        );
+        match ga {
+            hir::GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
+            hir::GenericArg::Type(ty) => self.visit_ty(ty),
+            hir::GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
+            hir::GenericArg::Infer(inf) => self.visit_infer(inf),
+        }
     }
 
     fn visit_lifetime(&mut self, lifetime: &'v hir::Lifetime) {
@@ -218,19 +442,19 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
         hir_visit::walk_lifetime(self, lifetime)
     }
 
-    fn visit_qpath(&mut self, qpath: &'v hir::QPath<'v>, id: hir::HirId, span: Span) {
-        self.record("QPath", Id::None, qpath);
-        hir_visit::walk_qpath(self, qpath, id, span)
-    }
-
     fn visit_path(&mut self, path: &'v hir::Path<'v>, _id: hir::HirId) {
         self.record("Path", Id::None, path);
         hir_visit::walk_path(self, path)
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v hir::PathSegment<'v>) {
+    fn visit_path_segment(&mut self, path_segment: &'v hir::PathSegment<'v>) {
         self.record("PathSegment", Id::None, path_segment);
-        hir_visit::walk_path_segment(self, path_span, path_segment)
+        hir_visit::walk_path_segment(self, path_segment)
+    }
+
+    fn visit_generic_args(&mut self, ga: &'v hir::GenericArgs<'v>) {
+        self.record("GenericArgs", Id::None, ga);
+        hir_visit::walk_generic_args(self, ga)
     }
 
     fn visit_assoc_type_binding(&mut self, type_binding: &'v hir::TypeBinding<'v>) {
@@ -241,16 +465,45 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_attribute(&mut self, attr: &'v ast::Attribute) {
         self.record("Attribute", Id::Attr(attr.id), attr);
     }
+
+    fn visit_inline_asm(&mut self, asm: &'v hir::InlineAsm<'v>, id: HirId) {
+        self.record("InlineAsm", Id::None, asm);
+        hir_visit::walk_inline_asm(self, asm, id);
+    }
 }
 
 impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
     fn visit_foreign_item(&mut self, i: &'v ast::ForeignItem) {
-        self.record("ForeignItem", Id::None, i);
+        record_variants!(
+            (self, i, i.kind, Id::None, ast, ForeignItem, ForeignItemKind),
+            [Static, Fn, TyAlias, MacCall]
+        );
         ast_visit::walk_foreign_item(self, i)
     }
 
     fn visit_item(&mut self, i: &'v ast::Item) {
-        self.record("Item", Id::None, i);
+        record_variants!(
+            (self, i, i.kind, Id::None, ast, Item, ItemKind),
+            [
+                ExternCrate,
+                Use,
+                Static,
+                Const,
+                Fn,
+                Mod,
+                ForeignMod,
+                GlobalAsm,
+                TyAlias,
+                Enum,
+                Struct,
+                Union,
+                Trait,
+                TraitAlias,
+                Impl,
+                MacCall,
+                MacroDef
+            ]
+        );
         ast_visit::walk_item(self, i)
     }
 
@@ -265,47 +518,119 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
     }
 
     fn visit_stmt(&mut self, s: &'v ast::Stmt) {
-        self.record("Stmt", Id::None, s);
+        record_variants!(
+            (self, s, s.kind, Id::None, ast, Stmt, StmtKind),
+            [Local, Item, Expr, Semi, Empty, MacCall]
+        );
         ast_visit::walk_stmt(self, s)
     }
 
+    fn visit_param(&mut self, p: &'v ast::Param) {
+        self.record("Param", Id::None, p);
+        ast_visit::walk_param(self, p)
+    }
+
     fn visit_arm(&mut self, a: &'v ast::Arm) {
         self.record("Arm", Id::None, a);
         ast_visit::walk_arm(self, a)
     }
 
     fn visit_pat(&mut self, p: &'v ast::Pat) {
-        self.record("Pat", Id::None, p);
+        record_variants!(
+            (self, p, p.kind, Id::None, ast, Pat, PatKind),
+            [
+                Wild,
+                Ident,
+                Struct,
+                TupleStruct,
+                Or,
+                Path,
+                Tuple,
+                Box,
+                Ref,
+                Lit,
+                Range,
+                Slice,
+                Rest,
+                Paren,
+                MacCall
+            ]
+        );
         ast_visit::walk_pat(self, p)
     }
 
-    fn visit_expr(&mut self, ex: &'v ast::Expr) {
-        self.record("Expr", Id::None, ex);
-        ast_visit::walk_expr(self, ex)
+    fn visit_expr(&mut self, e: &'v ast::Expr) {
+        record_variants!(
+            (self, e, e.kind, Id::None, ast, Expr, ExprKind),
+            [
+                Box, Array, ConstBlock, Call, MethodCall, Tup, Binary, Unary, Lit, Cast, Type, Let,
+                If, While, ForLoop, Loop, Match, Closure, Block, Async, Await, TryBlock, Assign,
+                AssignOp, Field, Index, Range, Underscore, Path, AddrOf, Break, Continue, Ret,
+                InlineAsm, MacCall, Struct, Repeat, Paren, Try, Yield, Yeet, Err
+            ]
+        );
+        ast_visit::walk_expr(self, e)
     }
 
     fn visit_ty(&mut self, t: &'v ast::Ty) {
-        self.record("Ty", Id::None, t);
+        record_variants!(
+            (self, t, t.kind, Id::None, ast, Ty, TyKind),
+            [
+                Slice,
+                Array,
+                Ptr,
+                Rptr,
+                BareFn,
+                Never,
+                Tup,
+                Path,
+                TraitObject,
+                ImplTrait,
+                Paren,
+                Typeof,
+                Infer,
+                ImplicitSelf,
+                MacCall,
+                Err,
+                CVarArgs
+            ]
+        );
+
         ast_visit::walk_ty(self, t)
     }
 
-    fn visit_fn(&mut self, fk: ast_visit::FnKind<'v>, s: Span, _: NodeId) {
+    fn visit_generic_param(&mut self, g: &'v ast::GenericParam) {
+        self.record("GenericParam", Id::None, g);
+        ast_visit::walk_generic_param(self, g)
+    }
+
+    fn visit_where_predicate(&mut self, p: &'v ast::WherePredicate) {
+        record_variants!(
+            (self, p, p, Id::None, ast, WherePredicate, WherePredicate),
+            [BoundPredicate, RegionPredicate, EqPredicate]
+        );
+        ast_visit::walk_where_predicate(self, p)
+    }
+
+    fn visit_fn(&mut self, fk: ast_visit::FnKind<'v>, _: Span, _: NodeId) {
         self.record("FnDecl", Id::None, fk.decl());
-        ast_visit::walk_fn(self, fk, s)
+        ast_visit::walk_fn(self, fk)
     }
 
-    fn visit_assoc_item(&mut self, item: &'v ast::AssocItem, ctxt: ast_visit::AssocCtxt) {
-        let label = match ctxt {
-            ast_visit::AssocCtxt::Trait => "TraitItem",
-            ast_visit::AssocCtxt::Impl => "ImplItem",
-        };
-        self.record(label, Id::None, item);
-        ast_visit::walk_assoc_item(self, item, ctxt);
+    fn visit_assoc_item(&mut self, i: &'v ast::AssocItem, ctxt: ast_visit::AssocCtxt) {
+        record_variants!(
+            (self, i, i.kind, Id::None, ast, AssocItem, AssocItemKind),
+            [Const, Fn, TyAlias, MacCall]
+        );
+        ast_visit::walk_assoc_item(self, i, ctxt);
     }
 
-    fn visit_param_bound(&mut self, bounds: &'v ast::GenericBound, _ctxt: BoundKind) {
-        self.record("GenericBound", Id::None, bounds);
-        ast_visit::walk_param_bound(self, bounds)
+    fn visit_param_bound(&mut self, b: &'v ast::GenericBound, _ctxt: BoundKind) {
+        record_variants!(
+            (self, b, b, Id::None, ast, GenericBound, GenericBound),
+            [Trait, Outlives]
+        );
+        ast_visit::walk_param_bound(self, b)
     }
 
     fn visit_field_def(&mut self, s: &'v ast::FieldDef) {
@@ -318,27 +643,52 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
         ast_visit::walk_variant(self, v)
     }
 
-    fn visit_lifetime(&mut self, lifetime: &'v ast::Lifetime, _: ast_visit::LifetimeCtxt) {
-        self.record("Lifetime", Id::None, lifetime);
-        ast_visit::walk_lifetime(self, lifetime)
+    // `UseTree` has one inline use (in `ast::ItemKind::Use`) and one
+    // non-inline use (in `ast::UseTreeKind::Nested). The former case is more
+    // common, so we don't implement `visit_use_tree` and tolerate the missed
+    // coverage in the latter case.
+
+    // `PathSegment` has one inline use (in `ast::ExprKind::MethodCall`) and
+    // one non-inline use (in `ast::Path::segments`). The latter case is more
+    // common than the former case, so we implement this visitor and tolerate
+    // the double counting in the former case.
+    fn visit_path_segment(&mut self, path_segment: &'v ast::PathSegment) {
+        self.record("PathSegment", Id::None, path_segment);
+        ast_visit::walk_path_segment(self, path_segment)
     }
 
-    fn visit_mac_call(&mut self, mac: &'v ast::MacCall) {
-        self.record("MacCall", Id::None, mac);
-        ast_visit::walk_mac(self, mac)
+    // `GenericArgs` has one inline use (in `ast::AssocConstraint::gen_args`) and one
+    // non-inline use (in `ast::PathSegment::args`). The latter case is more
+    // common, so we implement `visit_generic_args` and tolerate the double
+    // counting in the former case.
+    fn visit_generic_args(&mut self, g: &'v ast::GenericArgs) {
+        record_variants!(
+            (self, g, g, Id::None, ast, GenericArgs, GenericArgs),
+            [AngleBracketed, Parenthesized]
+        );
+        ast_visit::walk_generic_args(self, g)
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v ast::PathSegment) {
-        self.record("PathSegment", Id::None, path_segment);
-        ast_visit::walk_path_segment(self, path_span, path_segment)
+    fn visit_attribute(&mut self, attr: &'v ast::Attribute) {
+        record_variants!(
+            (self, attr, attr.kind, Id::None, ast, Attribute, AttrKind),
+            [Normal, DocComment]
+        );
+        ast_visit::walk_attribute(self, attr)
     }
 
-    fn visit_assoc_constraint(&mut self, constraint: &'v ast::AssocConstraint) {
-        self.record("AssocConstraint", Id::None, constraint);
-        ast_visit::walk_assoc_constraint(self, constraint)
+    fn visit_expr_field(&mut self, f: &'v ast::ExprField) {
+        self.record("ExprField", Id::None, f);
+        ast_visit::walk_expr_field(self, f)
     }
 
-    fn visit_attribute(&mut self, attr: &'v ast::Attribute) {
-        self.record("Attribute", Id::None, attr);
+    fn visit_crate(&mut self, krate: &'v ast::Crate) {
+        self.record("Crate", Id::None, krate);
+        ast_visit::walk_crate(self, krate)
+    }
+
+    fn visit_inline_asm(&mut self, asm: &'v ast::InlineAsm) {
+        self.record("InlineAsm", Id::None, asm);
+        ast_visit::walk_inline_asm(self, asm)
     }
 }
diff --git a/compiler/rustc_passes/src/lib.rs b/compiler/rustc_passes/src/lib.rs
index 7b2f83958..39ebb8db2 100644
--- a/compiler/rustc_passes/src/lib.rs
+++ b/compiler/rustc_passes/src/lib.rs
@@ -8,7 +8,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![feature(let_else)]
+#![cfg_attr(bootstrap, feature(let_else))]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
 #![feature(try_blocks)]
diff --git a/compiler/rustc_passes/src/lib_features.rs b/compiler/rustc_passes/src/lib_features.rs
index e05994f13..04173c792 100644
--- a/compiler/rustc_passes/src/lib_features.rs
+++ b/compiler/rustc_passes/src/lib_features.rs
@@ -5,6 +5,7 @@
 //! collect them instead.
 
 use rustc_ast::{Attribute, MetaItemKind};
+use rustc_attr::{rust_version_symbol, VERSION_PLACEHOLDER};
 use rustc_errors::struct_span_err;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
@@ -29,11 +30,16 @@ impl<'tcx> LibFeatureCollector<'tcx> {
     }
 
     fn extract(&self, attr: &Attribute) -> Option<(Symbol, Option<Symbol>, Span)> {
-        let stab_attrs =
-            [sym::stable, sym::unstable, sym::rustc_const_stable, sym::rustc_const_unstable];
+        let stab_attrs = [
+            sym::stable,
+            sym::unstable,
+            sym::rustc_const_stable,
+            sym::rustc_const_unstable,
+            sym::rustc_default_body_unstable,
+        ];
 
         // Find a stability attribute: one of #[stable(…)], #[unstable(…)],
-        // #[rustc_const_stable(…)], or #[rustc_const_unstable(…)].
+        // #[rustc_const_stable(…)], #[rustc_const_unstable(…)] or #[rustc_default_body_unstable].
         if let Some(stab_attr) = stab_attrs.iter().find(|stab_attr| attr.has_name(**stab_attr)) {
             let meta_kind = attr.meta_kind();
             if let Some(MetaItemKind::List(ref metas)) = meta_kind {
@@ -49,12 +55,21 @@ impl<'tcx> LibFeatureCollector<'tcx> {
                         }
                     }
                 }
+
+                if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
+                    since = Some(rust_version_symbol());
+                }
+
                 if let Some(feature) = feature {
                     // This additional check for stability is to make sure we
                     // don't emit additional, irrelevant errors for malformed
                     // attributes.
-                    let is_unstable =
-                        matches!(*stab_attr, sym::unstable | sym::rustc_const_unstable);
+                    let is_unstable = matches!(
+                        *stab_attr,
+                        sym::unstable
+                            | sym::rustc_const_unstable
+                            | sym::rustc_default_body_unstable
+                    );
                     if since.is_some() || is_unstable {
                         return Some((feature, since, attr.span));
                     }
diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 461dd52b9..6a4cd79cd 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -89,16 +89,15 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_hir::def::*;
-use rustc_hir::def_id::LocalDefId;
+use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Expr, HirId, HirIdMap, HirIdSet};
 use rustc_index::vec::IndexVec;
-use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, DefIdTree, RootVariableMinCaptureList, Ty, TyCtxt};
 use rustc_session::lint;
 use rustc_span::symbol::{kw, sym, Symbol};
-use rustc_span::Span;
+use rustc_span::{BytePos, Span};
 
 use std::collections::VecDeque;
 use std::io;
@@ -139,12 +138,54 @@ fn live_node_kind_to_string(lnk: LiveNodeKind, tcx: TyCtxt<'_>) -> String {
     }
 }
 
-fn check_mod_liveness(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
-    tcx.hir().visit_item_likes_in_module(module_def_id, &mut IrMaps::new(tcx));
+fn check_liveness(tcx: TyCtxt<'_>, def_id: DefId) {
+    let local_def_id = match def_id.as_local() {
+        None => return,
+        Some(def_id) => def_id,
+    };
+
+    // Don't run unused pass for #[derive()]
+    let parent = tcx.local_parent(local_def_id);
+    if let DefKind::Impl = tcx.def_kind(parent)
+        && tcx.has_attr(parent.to_def_id(), sym::automatically_derived)
+    {
+        return;
+    }
+
+    // Don't run unused pass for #[naked]
+    if tcx.has_attr(def_id, sym::naked) {
+        return;
+    }
+
+    let mut maps = IrMaps::new(tcx);
+    let body_id = tcx.hir().body_owned_by(local_def_id);
+    let hir_id = tcx.hir().body_owner(body_id);
+    let body = tcx.hir().body(body_id);
+
+    if let Some(upvars) = tcx.upvars_mentioned(def_id) {
+        for &var_hir_id in upvars.keys() {
+            let var_name = tcx.hir().name(var_hir_id);
+            maps.add_variable(Upvar(var_hir_id, var_name));
+        }
+    }
+
+    // gather up the various local variables, significant expressions,
+    // and so forth:
+    maps.visit_body(body);
+
+    // compute liveness
+    let mut lsets = Liveness::new(&mut maps, local_def_id);
+    let entry_ln = lsets.compute(&body, hir_id);
+    lsets.log_liveness(entry_ln, body_id.hir_id);
+
+    // check for various error conditions
+    lsets.visit_body(body);
+    lsets.warn_about_unused_upvars(entry_ln);
+    lsets.warn_about_unused_args(body, entry_ln);
 }
 
 pub fn provide(providers: &mut Providers) {
-    *providers = Providers { check_mod_liveness, ..*providers };
+    *providers = Providers { check_liveness, ..*providers };
 }
 
 // ______________________________________________________________________
@@ -188,6 +229,19 @@ enum VarKind {
     Upvar(HirId, Symbol),
 }
 
+struct CollectLitsVisitor<'tcx> {
+    lit_exprs: Vec<&'tcx hir::Expr<'tcx>>,
+}
+
+impl<'tcx> Visitor<'tcx> for CollectLitsVisitor<'tcx> {
+    fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+        if let hir::ExprKind::Lit(_) = expr.kind {
+            self.lit_exprs.push(expr);
+        }
+        intravisit::walk_expr(self, expr);
+    }
+}
+
 struct IrMaps<'tcx> {
     tcx: TyCtxt<'tcx>,
     live_node_map: HirIdMap<LiveNode>,
@@ -316,56 +370,6 @@ impl<'tcx> IrMaps<'tcx> {
 }
 
 impl<'tcx> Visitor<'tcx> for IrMaps<'tcx> {
-    type NestedFilter = nested_filter::OnlyBodies;
-
-    fn nested_visit_map(&mut self) -> Self::Map {
-        self.tcx.hir()
-    }
-
-    fn visit_body(&mut self, body: &'tcx hir::Body<'tcx>) {
-        debug!("visit_body {:?}", body.id());
-
-        // swap in a new set of IR maps for this body
-        let mut maps = IrMaps::new(self.tcx);
-        let hir_id = maps.tcx.hir().body_owner(body.id());
-        let local_def_id = maps.tcx.hir().local_def_id(hir_id);
-        let def_id = local_def_id.to_def_id();
-
-        // Don't run unused pass for #[derive()]
-        let parent = self.tcx.local_parent(local_def_id);
-        if let DefKind::Impl = self.tcx.def_kind(parent)
-            && self.tcx.has_attr(parent.to_def_id(), sym::automatically_derived)
-        {
-            return;
-        }
-
-        // Don't run unused pass for #[naked]
-        if self.tcx.has_attr(def_id, sym::naked) {
-            return;
-        }
-
-        if let Some(upvars) = maps.tcx.upvars_mentioned(def_id) {
-            for &var_hir_id in upvars.keys() {
-                let var_name = maps.tcx.hir().name(var_hir_id);
-                maps.add_variable(Upvar(var_hir_id, var_name));
-            }
-        }
-
-        // gather up the various local variables, significant expressions,
-        // and so forth:
-        intravisit::walk_body(&mut maps, body);
-
-        // compute liveness
-        let mut lsets = Liveness::new(&mut maps, local_def_id);
-        let entry_ln = lsets.compute(&body, hir_id);
-        lsets.log_liveness(entry_ln, body.id().hir_id);
-
-        // check for various error conditions
-        lsets.visit_body(body);
-        lsets.warn_about_unused_upvars(entry_ln);
-        lsets.warn_about_unused_args(body, entry_ln);
-    }
-
     fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
         self.add_from_pat(&local.pat);
         if local.els.is_some() {
@@ -1035,9 +1039,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 self.propagate_through_expr(&f, succ)
             }
 
-            hir::ExprKind::MethodCall(.., ref args, _) => {
+            hir::ExprKind::MethodCall(.., receiver, ref args, _) => {
                 let succ = self.check_is_ty_uninhabited(expr, succ);
-                self.propagate_through_exprs(args, succ)
+                let succ = self.propagate_through_exprs(args, succ);
+                self.propagate_through_expr(receiver, succ)
             }
 
             hir::ExprKind::Tup(ref exprs) => self.propagate_through_exprs(exprs, succ),
@@ -1342,7 +1347,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
 
 impl<'a, 'tcx> Visitor<'tcx> for Liveness<'a, 'tcx> {
     fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
-        self.check_unused_vars_in_pat(&local.pat, None, |spans, hir_id, ln, var| {
+        self.check_unused_vars_in_pat(&local.pat, None, None, |spans, hir_id, ln, var| {
             if local.init.is_some() {
                 self.warn_about_dead_assign(spans, hir_id, ln, var);
             }
@@ -1357,7 +1362,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Liveness<'a, 'tcx> {
     }
 
     fn visit_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) {
-        self.check_unused_vars_in_pat(&arm.pat, None, |_, _, _, _| {});
+        self.check_unused_vars_in_pat(&arm.pat, None, None, |_, _, _, _| {});
         intravisit::walk_arm(self, arm);
     }
 }
@@ -1396,7 +1401,7 @@ fn check_expr<'tcx>(this: &mut Liveness<'_, 'tcx>, expr: &'tcx Expr<'tcx>) {
         }
 
         hir::ExprKind::Let(let_expr) => {
-            this.check_unused_vars_in_pat(let_expr.pat, None, |_, _, _, _| {});
+            this.check_unused_vars_in_pat(let_expr.pat, None, None, |_, _, _, _| {});
         }
 
         // no correctness conditions related to liveness
@@ -1517,13 +1522,18 @@ impl<'tcx> Liveness<'_, 'tcx> {
 
     fn warn_about_unused_args(&self, body: &hir::Body<'_>, entry_ln: LiveNode) {
         for p in body.params {
-            self.check_unused_vars_in_pat(&p.pat, Some(entry_ln), |spans, hir_id, ln, var| {
-                if !self.live_on_entry(ln, var) {
-                    self.report_unused_assign(hir_id, spans, var, |name| {
-                        format!("value passed to `{}` is never read", name)
-                    });
-                }
-            });
+            self.check_unused_vars_in_pat(
+                &p.pat,
+                Some(entry_ln),
+                Some(body),
+                |spans, hir_id, ln, var| {
+                    if !self.live_on_entry(ln, var) {
+                        self.report_unused_assign(hir_id, spans, var, |name| {
+                            format!("value passed to `{}` is never read", name)
+                        });
+                    }
+                },
+            );
         }
     }
 
@@ -1531,6 +1541,7 @@ impl<'tcx> Liveness<'_, 'tcx> {
         &self,
         pat: &hir::Pat<'_>,
         entry_ln: Option<LiveNode>,
+        opt_body: Option<&hir::Body<'_>>,
         on_used_on_entry: impl Fn(Vec<Span>, HirId, LiveNode, Variable),
     ) {
         // In an or-pattern, only consider the variable; any later patterns must have the same
@@ -1549,6 +1560,8 @@ impl<'tcx> Liveness<'_, 'tcx> {
                 .or_insert_with(|| (ln, var, vec![id_and_sp]));
         });
 
+        let can_remove = matches!(&pat.kind, hir::PatKind::Struct(_, _, true));
+
         for (_, (ln, var, hir_ids_and_spans)) in vars {
             if self.used_on_entry(ln, var) {
                 let id = hir_ids_and_spans[0].0;
@@ -1556,16 +1569,20 @@ impl<'tcx> Liveness<'_, 'tcx> {
                     hir_ids_and_spans.into_iter().map(|(_, _, ident_span)| ident_span).collect();
                 on_used_on_entry(spans, id, ln, var);
             } else {
-                self.report_unused(hir_ids_and_spans, ln, var);
+                self.report_unused(hir_ids_and_spans, ln, var, can_remove, pat, opt_body);
             }
         }
     }
 
+    #[instrument(skip(self), level = "INFO")]
     fn report_unused(
         &self,
         hir_ids_and_spans: Vec<(HirId, Span, Span)>,
         ln: LiveNode,
         var: Variable,
+        can_remove: bool,
+        pat: &hir::Pat<'_>,
+        opt_body: Option<&hir::Body<'_>>,
     ) {
         let first_hir_id = hir_ids_and_spans[0].0;
 
@@ -1590,6 +1607,32 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             .emit();
                     },
                 )
+            } else if can_remove {
+                self.ir.tcx.struct_span_lint_hir(
+                    lint::builtin::UNUSED_VARIABLES,
+                    first_hir_id,
+                    hir_ids_and_spans.iter().map(|(_, pat_span, _)| *pat_span).collect::<Vec<_>>(),
+                    |lint| {
+                        let mut err = lint.build(&format!("unused variable: `{}`", name));
+                        err.multipart_suggestion(
+                            "try removing the field",
+                            hir_ids_and_spans
+                                .iter()
+                                .map(|(_, pat_span, _)| {
+                                    let span = self
+                                        .ir
+                                        .tcx
+                                        .sess
+                                        .source_map()
+                                        .span_extend_to_next_char(*pat_span, ',', true);
+                                    (span.with_hi(BytePos(span.hi().0 + 1)), String::new())
+                                })
+                                .collect(),
+                            Applicability::MachineApplicable,
+                        );
+                        err.emit();
+                    },
+                );
             } else {
                 let (shorthands, non_shorthands): (Vec<_>, Vec<_>) =
                     hir_ids_and_spans.iter().copied().partition(|(hir_id, _, ident_span)| {
@@ -1643,6 +1686,9 @@ impl<'tcx> Liveness<'_, 'tcx> {
                             .collect::<Vec<_>>(),
                         |lint| {
                             let mut err = lint.build(&format!("unused variable: `{}`", name));
+                            if self.has_added_lit_match_name_span(&name, opt_body, &mut err) {
+                                err.span_label(pat.span, "unused variable");
+                            }
                             err.multipart_suggestion(
                                 "if this is intentional, prefix it with an underscore",
                                 non_shorthands,
@@ -1656,6 +1702,42 @@ impl<'tcx> Liveness<'_, 'tcx> {
         }
     }
 
+    fn has_added_lit_match_name_span(
+        &self,
+        name: &str,
+        opt_body: Option<&hir::Body<'_>>,
+        err: &mut rustc_errors::DiagnosticBuilder<'_, ()>,
+    ) -> bool {
+        let mut has_litstring = false;
+        let Some(opt_body) = opt_body else {return false;};
+        let mut visitor = CollectLitsVisitor { lit_exprs: vec![] };
+        intravisit::walk_body(&mut visitor, opt_body);
+        for lit_expr in visitor.lit_exprs {
+            let hir::ExprKind::Lit(litx) = &lit_expr.kind else { continue };
+            let rustc_ast::LitKind::Str(syb, _) = litx.node else{ continue; };
+            let name_str: &str = syb.as_str();
+            let mut name_pa = String::from("{");
+            name_pa.push_str(&name);
+            name_pa.push('}');
+            if name_str.contains(&name_pa) {
+                err.span_label(
+                    lit_expr.span,
+                    "you might have meant to use string interpolation in this string literal",
+                );
+                err.multipart_suggestion(
+                    "string interpolation only works in `format!` invocations",
+                    vec![
+                        (lit_expr.span.shrink_to_lo(), "format!(".to_string()),
+                        (lit_expr.span.shrink_to_hi(), ")".to_string()),
+                    ],
+                    Applicability::MachineApplicable,
+                );
+                has_litstring = true;
+            }
+        }
+        has_litstring
+    }
+
     fn warn_about_dead_assign(&self, spans: Vec<Span>, hir_id: HirId, ln: LiveNode, var: Variable) {
         if !self.live_on_exit(ln, var) {
             self.report_unused_assign(hir_id, spans, var, |name| {
diff --git a/compiler/rustc_passes/src/naked_functions.rs b/compiler/rustc_passes/src/naked_functions.rs
index 20765abf3..607973446 100644
--- a/compiler/rustc_passes/src/naked_functions.rs
+++ b/compiler/rustc_passes/src/naked_functions.rs
@@ -1,11 +1,12 @@
 //! Checks validity of naked functions.
 
-use rustc_ast::{Attribute, InlineAsmOptions};
+use rustc_ast::InlineAsmOptions;
 use rustc_errors::{struct_span_err, Applicability};
 use rustc_hir as hir;
+use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
-use rustc_hir::intravisit::{FnKind, Visitor};
-use rustc_hir::{ExprKind, HirId, InlineAsmOperand, StmtKind};
+use rustc_hir::intravisit::Visitor;
+use rustc_hir::{ExprKind, InlineAsmOperand, StmtKind};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::UNDEFINED_NAKED_FUNCTION_ABI;
@@ -13,71 +14,58 @@ use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_target::spec::abi::Abi;
 
-fn check_mod_naked_functions(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
-    tcx.hir().visit_item_likes_in_module(module_def_id, &mut CheckNakedFunctions { tcx });
-}
-
 pub(crate) fn provide(providers: &mut Providers) {
     *providers = Providers { check_mod_naked_functions, ..*providers };
 }
 
-struct CheckNakedFunctions<'tcx> {
-    tcx: TyCtxt<'tcx>,
-}
-
-impl<'tcx> Visitor<'tcx> for CheckNakedFunctions<'tcx> {
-    fn visit_fn(
-        &mut self,
-        fk: FnKind<'_>,
-        _fd: &'tcx hir::FnDecl<'tcx>,
-        body_id: hir::BodyId,
-        span: Span,
-        hir_id: HirId,
-    ) {
-        let ident_span;
-        let fn_header;
-
-        match fk {
-            FnKind::Closure => {
-                // Closures with a naked attribute are rejected during attribute
-                // check. Don't validate them any further.
-                return;
-            }
-            FnKind::ItemFn(ident, _, ref header, ..) => {
-                ident_span = ident.span;
-                fn_header = header;
-            }
-
-            FnKind::Method(ident, ref sig, ..) => {
-                ident_span = ident.span;
-                fn_header = &sig.header;
-            }
+fn check_mod_naked_functions(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
+    let items = tcx.hir_module_items(module_def_id);
+    for def_id in items.definitions() {
+        if !matches!(tcx.def_kind(def_id), DefKind::Fn | DefKind::AssocFn) {
+            continue;
         }
 
-        let attrs = self.tcx.hir().attrs(hir_id);
-        let naked = attrs.iter().any(|attr| attr.has_name(sym::naked));
-        if naked {
-            let body = self.tcx.hir().body(body_id);
-            check_abi(self.tcx, hir_id, fn_header.abi, ident_span);
-            check_no_patterns(self.tcx, body.params);
-            check_no_parameters_use(self.tcx, body);
-            check_asm(self.tcx, body, span);
-            check_inline(self.tcx, attrs);
+        let naked = tcx.has_attr(def_id.to_def_id(), sym::naked);
+        if !naked {
+            continue;
         }
+
+        let (fn_header, body_id) = match tcx.hir().get_by_def_id(def_id) {
+            hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn(sig, _, body_id), .. })
+            | hir::Node::TraitItem(hir::TraitItem {
+                kind: hir::TraitItemKind::Fn(sig, hir::TraitFn::Provided(body_id)),
+                ..
+            })
+            | hir::Node::ImplItem(hir::ImplItem {
+                kind: hir::ImplItemKind::Fn(sig, body_id),
+                ..
+            }) => (sig.header, *body_id),
+            _ => continue,
+        };
+
+        let body = tcx.hir().body(body_id);
+        check_abi(tcx, def_id, fn_header.abi);
+        check_no_patterns(tcx, body.params);
+        check_no_parameters_use(tcx, body);
+        check_asm(tcx, def_id, body);
+        check_inline(tcx, def_id);
     }
 }
 
 /// Check that the function isn't inlined.
-fn check_inline(tcx: TyCtxt<'_>, attrs: &[Attribute]) {
-    for attr in attrs.iter().filter(|attr| attr.has_name(sym::inline)) {
+fn check_inline(tcx: TyCtxt<'_>, def_id: LocalDefId) {
+    let attrs = tcx.get_attrs(def_id.to_def_id(), sym::inline);
+    for attr in attrs {
         tcx.sess.struct_span_err(attr.span, "naked functions cannot be inlined").emit();
     }
 }
 
 /// Checks that function uses non-Rust ABI.
-fn check_abi(tcx: TyCtxt<'_>, hir_id: HirId, abi: Abi, fn_ident_span: Span) {
+fn check_abi(tcx: TyCtxt<'_>, def_id: LocalDefId, abi: Abi) {
     if abi == Abi::Rust {
-        tcx.struct_span_lint_hir(UNDEFINED_NAKED_FUNCTION_ABI, hir_id, fn_ident_span, |lint| {
+        let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
+        let span = tcx.def_span(def_id);
+        tcx.struct_span_lint_hir(UNDEFINED_NAKED_FUNCTION_ABI, hir_id, span, |lint| {
             lint.build("Rust ABI is unsupported in naked functions").emit();
         });
     }
@@ -88,7 +76,7 @@ fn check_no_patterns(tcx: TyCtxt<'_>, params: &[hir::Param<'_>]) {
     for param in params {
         match param.pat.kind {
             hir::PatKind::Wild
-            | hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, _, None) => {}
+            | hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, _, None) => {}
             _ => {
                 tcx.sess
                     .struct_span_err(
@@ -141,7 +129,7 @@ impl<'tcx> Visitor<'tcx> for CheckParameters<'tcx> {
 }
 
 /// Checks that function body contains a single inline assembly block.
-fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, body: &'tcx hir::Body<'tcx>, fn_span: Span) {
+fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &'tcx hir::Body<'tcx>) {
     let mut this = CheckInlineAssembly { tcx, items: Vec::new() };
     this.visit_body(body);
     if let [(ItemKind::Asm | ItemKind::Err, _)] = this.items[..] {
@@ -149,7 +137,7 @@ fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, body: &'tcx hir::Body<'tcx>, fn_span: Span
     } else {
         let mut diag = struct_span_err!(
             tcx.sess,
-            fn_span,
+            tcx.def_span(def_id),
             E0787,
             "naked functions must contain a single asm block"
         );
diff --git a/compiler/rustc_passes/src/stability.rs b/compiler/rustc_passes/src/stability.rs
index ca6a2ac3d..9ba127609 100644
--- a/compiler/rustc_passes/src/stability.rs
+++ b/compiler/rustc_passes/src/stability.rs
@@ -1,8 +1,10 @@
 //! A pass that annotates every item and method with its stability level,
 //! propagating default levels lexically from parent to children ast nodes.
 
-use attr::StabilityLevel;
-use rustc_attr::{self as attr, ConstStability, Stability, Unstable, UnstableReason};
+use rustc_attr::{
+    self as attr, rust_version_symbol, ConstStability, Stability, StabilityLevel, Unstable,
+    UnstableReason, VERSION_PLACEHOLDER,
+};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_errors::{struct_span_err, Applicability};
 use rustc_hir as hir;
@@ -10,7 +12,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID};
 use rustc_hir::hir_id::CRATE_HIR_ID;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{FieldDef, Generics, HirId, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
+use rustc_hir::{FieldDef, Item, ItemKind, TraitRef, Ty, TyKind, Variant};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::privacy::AccessLevels;
 use rustc_middle::middle::stability::{AllowUnstable, DeprecationEntry, Index};
@@ -161,7 +163,7 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
             return;
         }
 
-        let (stab, const_stab) = attr::find_stability(&self.tcx.sess, attrs, item_sp);
+        let (stab, const_stab, body_stab) = attr::find_stability(&self.tcx.sess, attrs, item_sp);
         let mut const_span = None;
 
         let const_stab = const_stab.map(|(const_stab, const_span_node)| {
@@ -209,6 +211,13 @@ impl<'a, 'tcx> Annotator<'a, 'tcx> {
             }
         }
 
+        if let Some((body_stab, _span)) = body_stab {
+            // FIXME: check that this item can have body stability
+
+            self.index.default_body_stab_map.insert(def_id, body_stab);
+            debug!(?self.index.default_body_stab_map);
+        }
+
         let stab = stab.map(|(stab, span)| {
             // Error if prohibited, or can't inherit anything from a container.
             if kind == AnnotationKind::Prohibited
@@ -434,7 +443,7 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
         );
     }
 
-    fn visit_variant(&mut self, var: &'tcx Variant<'tcx>, g: &'tcx Generics<'tcx>, item_id: HirId) {
+    fn visit_variant(&mut self, var: &'tcx Variant<'tcx>) {
         self.annotate(
             self.tcx.hir().local_def_id(var.id),
             var.span,
@@ -452,12 +461,12 @@ impl<'a, 'tcx> Visitor<'tcx> for Annotator<'a, 'tcx> {
                         AnnotationKind::Required,
                         InheritDeprecation::Yes,
                         InheritConstStability::No,
-                        InheritStability::No,
+                        InheritStability::Yes,
                         |_| {},
                     );
                 }
 
-                intravisit::walk_variant(v, var, g, item_id)
+                intravisit::walk_variant(v, var)
             },
         )
     }
@@ -590,9 +599,12 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
         intravisit::walk_impl_item(self, ii);
     }
 
-    fn visit_variant(&mut self, var: &'tcx Variant<'tcx>, g: &'tcx Generics<'tcx>, item_id: HirId) {
+    fn visit_variant(&mut self, var: &'tcx Variant<'tcx>) {
         self.check_missing_stability(self.tcx.hir().local_def_id(var.id), var.span);
-        intravisit::walk_variant(self, var, g, item_id);
+        if let Some(ctor_hir_id) = var.data.ctor_hir_id() {
+            self.check_missing_stability(self.tcx.hir().local_def_id(ctor_hir_id), var.span);
+        }
+        intravisit::walk_variant(self, var);
     }
 
     fn visit_field_def(&mut self, s: &'tcx FieldDef<'tcx>) {
@@ -613,6 +625,7 @@ fn stability_index(tcx: TyCtxt<'_>, (): ()) -> Index {
     let mut index = Index {
         stab_map: Default::default(),
         const_stab_map: Default::default(),
+        default_body_stab_map: Default::default(),
         depr_map: Default::default(),
         implications: Default::default(),
     };
@@ -673,6 +686,9 @@ pub(crate) fn provide(providers: &mut Providers) {
         stability_implications: |tcx, _| tcx.stability().implications.clone(),
         lookup_stability: |tcx, id| tcx.stability().local_stability(id.expect_local()),
         lookup_const_stability: |tcx, id| tcx.stability().local_const_stability(id.expect_local()),
+        lookup_default_body_stability: |tcx, id| {
+            tcx.stability().local_default_body_stability(id.expect_local())
+        },
         lookup_deprecation_entry: |tcx, id| {
             tcx.stability().local_deprecation_entry(id.expect_local())
         },
@@ -723,7 +739,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                 let features = self.tcx.features();
                 if features.staged_api {
                     let attrs = self.tcx.hir().attrs(item.hir_id());
-                    let (stab, const_stab) = attr::find_stability(&self.tcx.sess, attrs, item.span);
+                    let (stab, const_stab, _) =
+                        attr::find_stability(&self.tcx.sess, attrs, item.span);
 
                     // If this impl block has an #[unstable] attribute, give an
                     // error if all involved types and traits are stable, because
@@ -816,7 +833,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'tcx> {
                 // added, such as `core::intrinsics::transmute`
                 let parents = path.segments.iter().rev().skip(1);
                 for path_segment in parents {
-                    if let Some(def_id) = path_segment.res.as_ref().and_then(Res::opt_def_id) {
+                    if let Some(def_id) = path_segment.res.opt_def_id() {
                         // use `None` for id to prevent deprecation check
                         self.tcx.check_stability_allow_unstable(
                             def_id,
@@ -949,51 +966,90 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
     remaining_lib_features.remove(&sym::libc);
     remaining_lib_features.remove(&sym::test);
 
-    // We always collect the lib features declared in the current crate, even if there are
-    // no unknown features, because the collection also does feature attribute validation.
-    let local_defined_features = tcx.lib_features(());
-    let mut all_lib_features: FxHashMap<_, _> =
-        local_defined_features.to_vec().iter().map(|el| *el).collect();
-    let mut implications = tcx.stability_implications(rustc_hir::def_id::LOCAL_CRATE).clone();
-    for &cnum in tcx.crates(()) {
-        implications.extend(tcx.stability_implications(cnum));
-        all_lib_features.extend(tcx.defined_lib_features(cnum).iter().map(|el| *el));
-    }
-
-    // Check that every feature referenced by an `implied_by` exists (for features defined in the
-    // local crate).
-    for (implied_by, feature) in tcx.stability_implications(rustc_hir::def_id::LOCAL_CRATE) {
-        // Only `implied_by` needs to be checked, `feature` is guaranteed to exist.
-        if !all_lib_features.contains_key(implied_by) {
-            let span = local_defined_features
-                .stable
-                .get(feature)
-                .map(|(_, span)| span)
-                .or_else(|| local_defined_features.unstable.get(feature))
-                .expect("feature that implied another does not exist");
-            tcx.sess
-                .struct_span_err(
-                    *span,
-                    format!("feature `{implied_by}` implying `{feature}` does not exist"),
-                )
-                .emit();
-        }
-    }
-
-    if !remaining_lib_features.is_empty() {
-        for (feature, since) in all_lib_features.iter() {
+    /// For each feature in `defined_features`..
+    ///
+    /// - If it is in `remaining_lib_features` (those features with `#![feature(..)]` attributes in
+    ///   the current crate), check if it is stable (or partially stable) and thus an unnecessary
+    ///   attribute.
+    /// - If it is in `remaining_implications` (a feature that is referenced by an `implied_by`
+    ///   from the current crate), then remove it from the remaining implications.
+    ///
+    /// Once this function has been invoked for every feature (local crate and all extern crates),
+    /// then..
+    ///
+    /// - If features remain in `remaining_lib_features`, then the user has enabled a feature that
+    ///   does not exist.
+    /// - If features remain in `remaining_implications`, the `implied_by` refers to a feature that
+    ///   does not exist.
+    ///
+    /// By structuring the code in this way: checking the features defined from each crate one at a
+    /// time, less loading from metadata is performed and thus compiler performance is improved.
+    fn check_features<'tcx>(
+        tcx: TyCtxt<'tcx>,
+        remaining_lib_features: &mut FxIndexMap<&Symbol, Span>,
+        remaining_implications: &mut FxHashMap<Symbol, Symbol>,
+        defined_features: &[(Symbol, Option<Symbol>)],
+        all_implications: &FxHashMap<Symbol, Symbol>,
+    ) {
+        for (feature, since) in defined_features {
             if let Some(since) = since && let Some(span) = remaining_lib_features.get(&feature) {
                 // Warn if the user has enabled an already-stable lib feature.
-                if let Some(implies) = implications.get(&feature) {
+                if let Some(implies) = all_implications.get(&feature) {
                     unnecessary_partially_stable_feature_lint(tcx, *span, *feature, *implies, *since);
                 } else {
                     unnecessary_stable_feature_lint(tcx, *span, *feature, *since);
                 }
+
+            }
+            remaining_lib_features.remove(feature);
+
+            // `feature` is the feature doing the implying, but `implied_by` is the feature with
+            // the attribute that establishes this relationship. `implied_by` is guaranteed to be a
+            // feature defined in the local crate because `remaining_implications` is only the
+            // implications from this crate.
+            remaining_implications.remove(feature);
+
+            if remaining_lib_features.is_empty() && remaining_implications.is_empty() {
+                break;
             }
-            remaining_lib_features.remove(&feature);
-            if remaining_lib_features.is_empty() {
+        }
+    }
+
+    // All local crate implications need to have the feature that implies it confirmed to exist.
+    let mut remaining_implications =
+        tcx.stability_implications(rustc_hir::def_id::LOCAL_CRATE).clone();
+
+    // We always collect the lib features declared in the current crate, even if there are
+    // no unknown features, because the collection also does feature attribute validation.
+    let local_defined_features = tcx.lib_features(()).to_vec();
+    if !remaining_lib_features.is_empty() || !remaining_implications.is_empty() {
+        // Loading the implications of all crates is unavoidable to be able to emit the partial
+        // stabilization diagnostic, but it can be avoided when there are no
+        // `remaining_lib_features`.
+        let mut all_implications = remaining_implications.clone();
+        for &cnum in tcx.crates(()) {
+            all_implications.extend(tcx.stability_implications(cnum));
+        }
+
+        check_features(
+            tcx,
+            &mut remaining_lib_features,
+            &mut remaining_implications,
+            local_defined_features.as_slice(),
+            &all_implications,
+        );
+
+        for &cnum in tcx.crates(()) {
+            if remaining_lib_features.is_empty() && remaining_implications.is_empty() {
                 break;
             }
+            check_features(
+                tcx,
+                &mut remaining_lib_features,
+                &mut remaining_implications,
+                tcx.defined_lib_features(cnum).to_vec().as_slice(),
+                &all_implications,
+            );
         }
     }
 
@@ -1001,6 +1057,22 @@ pub fn check_unused_or_stable_features(tcx: TyCtxt<'_>) {
         struct_span_err!(tcx.sess, span, E0635, "unknown feature `{}`", feature).emit();
     }
 
+    for (implied_by, feature) in remaining_implications {
+        let local_defined_features = tcx.lib_features(());
+        let span = local_defined_features
+            .stable
+            .get(&feature)
+            .map(|(_, span)| span)
+            .or_else(|| local_defined_features.unstable.get(&feature))
+            .expect("feature that implied another does not exist");
+        tcx.sess
+            .struct_span_err(
+                *span,
+                format!("feature `{implied_by}` implying `{feature}` does not exist"),
+            )
+            .emit();
+    }
+
     // FIXME(#44232): the `used_features` table no longer exists, so we
     // don't lint about unused features. We should re-enable this one day!
 }
@@ -1035,7 +1107,15 @@ fn unnecessary_partially_stable_feature_lint(
     });
 }
 
-fn unnecessary_stable_feature_lint(tcx: TyCtxt<'_>, span: Span, feature: Symbol, since: Symbol) {
+fn unnecessary_stable_feature_lint(
+    tcx: TyCtxt<'_>,
+    span: Span,
+    feature: Symbol,
+    mut since: Symbol,
+) {
+    if since.as_str() == VERSION_PLACEHOLDER {
+        since = rust_version_symbol();
+    }
     tcx.struct_span_lint_hir(lint::builtin::STABLE_FEATURES, hir::CRATE_HIR_ID, span, |lint| {
         lint.build(&format!(
             "the feature `{feature}` has been stable since {since} and no longer requires an \