Auto merge of #111425 - Bryanskiy:privacy_ef, r=petrochenkov

Populate effective visibilities in `rustc_privacy` (take 2)

Same as https://github.com/rust-lang/rust/pull/110907 + regressions fixes.
Fixes https://github.com/rust-lang/rust/issues/111359.

r? `@petrochenkov`

7 files changed, 243 insertions, 147 deletions

diff --git a/compiler/rustc_lint/src/builtin.rs b/compiler/rustc_lint/src/builtin.rs
index b1c45eaf601..9b74d108546 100644
--- a/compiler/rustc_lint/src/builtin.rs
+++ b/compiler/rustc_lint/src/builtin.rs
@@ -647,7 +647,9 @@ declare_lint_pass!(MissingCopyImplementations => [MISSING_COPY_IMPLEMENTATIONS])
 
 impl<'tcx> LateLintPass<'tcx> for MissingCopyImplementations {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
-        if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) {
+        if !(cx.effective_visibilities.is_reachable(item.owner_id.def_id)
+            && cx.tcx.local_visibility(item.owner_id.def_id).is_public())
+        {
             return;
         }
         let (def, ty) = match item.kind {
@@ -766,7 +768,9 @@ impl_lint_pass!(MissingDebugImplementations => [MISSING_DEBUG_IMPLEMENTATIONS]);
 
 impl<'tcx> LateLintPass<'tcx> for MissingDebugImplementations {
     fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) {
-        if !cx.effective_visibilities.is_reachable(item.owner_id.def_id) {
+        if !(cx.effective_visibilities.is_reachable(item.owner_id.def_id)
+            && cx.tcx.local_visibility(item.owner_id.def_id).is_public())
+        {
             return;
         }
 
diff --git a/compiler/rustc_middle/src/middle/privacy.rs b/compiler/rustc_middle/src/middle/privacy.rs
index 967fed687b6..aeb6a1601fc 100644
--- a/compiler/rustc_middle/src/middle/privacy.rs
+++ b/compiler/rustc_middle/src/middle/privacy.rs
@@ -64,7 +64,7 @@ impl EffectiveVisibility {
         self.at_level(level).is_public()
     }
 
-    pub fn from_vis(vis: Visibility) -> EffectiveVisibility {
+    pub const fn from_vis(vis: Visibility) -> EffectiveVisibility {
         EffectiveVisibility {
             direct: vis,
             reexported: vis,
@@ -72,6 +72,18 @@ impl EffectiveVisibility {
             reachable_through_impl_trait: vis,
         }
     }
+
+    #[must_use]
+    pub fn min(mut self, lhs: EffectiveVisibility, tcx: TyCtxt<'_>) -> Self {
+        for l in Level::all_levels() {
+            let rhs_vis = self.at_level_mut(l);
+            let lhs_vis = *lhs.at_level(l);
+            if rhs_vis.is_at_least(lhs_vis, tcx) {
+                *rhs_vis = lhs_vis;
+            };
+        }
+        self
+    }
 }
 
 /// Holds a map of effective visibilities for reachable HIR nodes.
@@ -137,24 +149,6 @@ impl EffectiveVisibilities {
         };
     }
 
-    pub fn set_public_at_level(
-        &mut self,
-        id: LocalDefId,
-        lazy_private_vis: impl FnOnce() -> Visibility,
-        level: Level,
-    ) {
-        let mut effective_vis = self
-            .effective_vis(id)
-            .copied()
-            .unwrap_or_else(|| EffectiveVisibility::from_vis(lazy_private_vis()));
-        for l in Level::all_levels() {
-            if l <= level {
-                *effective_vis.at_level_mut(l) = Visibility::Public;
-            }
-        }
-        self.map.insert(id, effective_vis);
-    }
-
     pub fn check_invariants(&self, tcx: TyCtxt<'_>, early: bool) {
         if !cfg!(debug_assertions) {
             return;
@@ -219,7 +213,7 @@ impl<Id: Eq + Hash> EffectiveVisibilities<Id> {
     pub fn update(
         &mut self,
         id: Id,
-        nominal_vis: Visibility,
+        nominal_vis: Option<Visibility>,
         lazy_private_vis: impl FnOnce() -> Visibility,
         inherited_effective_vis: EffectiveVisibility,
         level: Level,
@@ -243,12 +237,11 @@ impl<Id: Eq + Hash> EffectiveVisibilities<Id> {
                 if !(inherited_effective_vis_at_prev_level == inherited_effective_vis_at_level
                     && level != l)
                 {
-                    calculated_effective_vis =
-                        if nominal_vis.is_at_least(inherited_effective_vis_at_level, tcx) {
-                            inherited_effective_vis_at_level
-                        } else {
-                            nominal_vis
-                        };
+                    calculated_effective_vis = if let Some(nominal_vis) = nominal_vis && !nominal_vis.is_at_least(inherited_effective_vis_at_level, tcx) {
+                        nominal_vis
+                    } else {
+                        inherited_effective_vis_at_level
+                    }
                 }
                 // effective visibility can't be decreased at next update call for the
                 // same id
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index d6eb5463870..817f304e8ef 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -25,7 +25,7 @@ use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{AssocItemKind, HirIdSet, ItemId, Node, PatKind};
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
-use rustc_middle::middle::privacy::{EffectiveVisibilities, Level};
+use rustc_middle::middle::privacy::{EffectiveVisibilities, EffectiveVisibility, Level};
 use rustc_middle::span_bug;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::subst::InternalSubsts;
@@ -38,7 +38,7 @@ use rustc_span::Span;
 
 use std::marker::PhantomData;
 use std::ops::ControlFlow;
-use std::{cmp, fmt, mem};
+use std::{fmt, mem};
 
 use errors::{
     FieldIsPrivate, FieldIsPrivateLabel, FromPrivateDependencyInPublicInterface, InPublicInterface,
@@ -408,8 +408,9 @@ impl VisibilityLike for ty::Visibility {
         min(find.tcx.local_visibility(def_id), find.min, find.tcx)
     }
 }
-impl VisibilityLike for Option<Level> {
-    const MAX: Self = Some(Level::Direct);
+
+impl VisibilityLike for Option<EffectiveVisibility> {
+    const MAX: Self = Some(EffectiveVisibility::from_vis(ty::Visibility::Public));
     // Type inference is very smart sometimes.
     // It can make an impl reachable even some components of its type or trait are unreachable.
     // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
@@ -421,7 +422,13 @@ impl VisibilityLike for Option<Level> {
     // (which require reaching the `DefId`s in them).
     const SHALLOW: bool = true;
     fn new_min(find: &FindMin<'_, '_, Self>, def_id: LocalDefId) -> Self {
-        cmp::min(find.effective_visibilities.public_at_level(def_id), find.min)
+        if let Some(min) = find.min {
+            return find
+                .effective_visibilities
+                .effective_vis(def_id)
+                .map(|eff_vis| min.min(*eff_vis, find.tcx));
+        }
+        None
     }
 }
 
@@ -447,49 +454,79 @@ struct EmbargoVisitor<'tcx> {
     ///     n::p::f()
     /// }
     macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
-    /// Previous visibility level; `None` means unreachable.
-    prev_level: Option<Level>,
     /// Has something changed in the level map?
     changed: bool,
 }
 
 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
-    level: Option<Level>,
+    effective_vis: Option<EffectiveVisibility>,
     item_def_id: LocalDefId,
     ev: &'a mut EmbargoVisitor<'tcx>,
+    level: Level,
 }
 
 impl<'tcx> EmbargoVisitor<'tcx> {
-    fn get(&self, def_id: LocalDefId) -> Option<Level> {
-        self.effective_visibilities.public_at_level(def_id)
-    }
-
-    /// Updates node level and returns the updated level.
-    fn update(&mut self, def_id: LocalDefId, level: Option<Level>) -> Option<Level> {
-        let old_level = self.get(def_id);
-        // Visibility levels can only grow.
-        if level > old_level {
-            self.effective_visibilities.set_public_at_level(
-                def_id,
-                || ty::Visibility::Restricted(self.tcx.parent_module_from_def_id(def_id)),
-                level.unwrap(),
-            );
-            self.changed = true;
-            level
-        } else {
-            old_level
+    fn get(&self, def_id: LocalDefId) -> Option<EffectiveVisibility> {
+        self.effective_visibilities.effective_vis(def_id).copied()
+    }
+
+    // Updates node effective visibility.
+    fn update(
+        &mut self,
+        def_id: LocalDefId,
+        inherited_effective_vis: Option<EffectiveVisibility>,
+        level: Level,
+    ) {
+        let nominal_vis = self.tcx.local_visibility(def_id);
+        self.update_eff_vis(def_id, inherited_effective_vis, Some(nominal_vis), level);
+    }
+
+    fn update_eff_vis(
+        &mut self,
+        def_id: LocalDefId,
+        inherited_effective_vis: Option<EffectiveVisibility>,
+        nominal_vis: Option<ty::Visibility>,
+        level: Level,
+    ) {
+        if let Some(inherited_effective_vis) = inherited_effective_vis {
+            let private_vis =
+                ty::Visibility::Restricted(self.tcx.parent_module_from_def_id(def_id));
+            if Some(private_vis) != nominal_vis {
+                self.changed |= self.effective_visibilities.update(
+                    def_id,
+                    nominal_vis,
+                    || private_vis,
+                    inherited_effective_vis,
+                    level,
+                    self.tcx,
+                );
+            }
         }
     }
 
     fn reach(
         &mut self,
         def_id: LocalDefId,
-        level: Option<Level>,
+        effective_vis: Option<EffectiveVisibility>,
     ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
         ReachEverythingInTheInterfaceVisitor {
-            level: cmp::min(level, Some(Level::Reachable)),
+            effective_vis,
             item_def_id: def_id,
             ev: self,
+            level: Level::Reachable,
+        }
+    }
+
+    fn reach_through_impl_trait(
+        &mut self,
+        def_id: LocalDefId,
+        effective_vis: Option<EffectiveVisibility>,
+    ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
+        ReachEverythingInTheInterfaceVisitor {
+            effective_vis,
+            item_def_id: def_id,
+            ev: self,
+            level: Level::ReachableThroughImplTrait,
         }
     }
 
@@ -510,16 +547,18 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             return;
         }
 
-        if self.get(local_def_id).is_none() {
+        if self.effective_visibilities.public_at_level(local_def_id).is_none() {
             return;
         }
 
         // Since we are starting from an externally visible module,
         // all the parents in the loop below are also guaranteed to be modules.
         let mut module_def_id = macro_module_def_id;
+        let macro_ev = self.get(local_def_id);
+        assert!(macro_ev.is_some());
         loop {
             let changed_reachability =
-                self.update_macro_reachable(module_def_id, macro_module_def_id);
+                self.update_macro_reachable(module_def_id, macro_module_def_id, macro_ev);
             if changed_reachability || module_def_id == CRATE_DEF_ID {
                 break;
             }
@@ -533,21 +572,33 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         &mut self,
         module_def_id: LocalDefId,
         defining_mod: LocalDefId,
+        macro_ev: Option<EffectiveVisibility>,
     ) -> bool {
         if self.macro_reachable.insert((module_def_id, defining_mod)) {
-            self.update_macro_reachable_mod(module_def_id, defining_mod);
+            self.update_macro_reachable_mod(module_def_id, defining_mod, macro_ev);
             true
         } else {
             false
         }
     }
 
-    fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
+    fn update_macro_reachable_mod(
+        &mut self,
+        module_def_id: LocalDefId,
+        defining_mod: LocalDefId,
+        macro_ev: Option<EffectiveVisibility>,
+    ) {
         let module = self.tcx.hir().get_module(module_def_id).0;
         for item_id in module.item_ids {
             let def_kind = self.tcx.def_kind(item_id.owner_id);
             let vis = self.tcx.local_visibility(item_id.owner_id.def_id);
-            self.update_macro_reachable_def(item_id.owner_id.def_id, def_kind, vis, defining_mod);
+            self.update_macro_reachable_def(
+                item_id.owner_id.def_id,
+                def_kind,
+                vis,
+                defining_mod,
+                macro_ev,
+            );
         }
         for child in self.tcx.module_children_local(module_def_id) {
             // FIXME: Use module children for the logic above too.
@@ -556,7 +607,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
                 && let Res::Def(def_kind, def_id) = child.res
                 && let Some(def_id) = def_id.as_local() {
                 let vis = self.tcx.local_visibility(def_id);
-                self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
+                self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod, macro_ev);
             }
         }
     }
@@ -567,16 +618,14 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         def_kind: DefKind,
         vis: ty::Visibility,
         module: LocalDefId,
+        macro_ev: Option<EffectiveVisibility>,
     ) {
-        let level = Some(Level::Reachable);
-        if vis.is_public() {
-            self.update(def_id, level);
-        }
+        self.update(def_id, macro_ev, Level::Reachable);
         match def_kind {
             // No type privacy, so can be directly marked as reachable.
             DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias => {
                 if vis.is_accessible_from(module, self.tcx) {
-                    self.update(def_id, level);
+                    self.update(def_id, macro_ev, Level::Reachable);
                 }
             }
 
@@ -588,7 +637,7 @@ impl<'tcx> EmbargoVisitor<'tcx> {
                 let item = self.tcx.hir().expect_item(def_id);
                 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }, _) = item.kind {
                     if vis.is_accessible_from(module, self.tcx) {
-                        self.update(def_id, level);
+                        self.update(def_id, macro_ev, Level::Reachable);
                     }
                 }
             }
@@ -599,26 +648,24 @@ impl<'tcx> EmbargoVisitor<'tcx> {
             // the module, however may be reachable.
             DefKind::Mod => {
                 if vis.is_accessible_from(module, self.tcx) {
-                    self.update_macro_reachable(def_id, module);
+                    self.update_macro_reachable(def_id, module, macro_ev);
                 }
             }
 
             DefKind::Struct | DefKind::Union => {
                 // While structs and unions have type privacy, their fields do not.
-                if vis.is_public() {
-                    let item = self.tcx.hir().expect_item(def_id);
-                    if let hir::ItemKind::Struct(ref struct_def, _)
-                    | hir::ItemKind::Union(ref struct_def, _) = item.kind
-                    {
-                        for field in struct_def.fields() {
-                            let field_vis = self.tcx.local_visibility(field.def_id);
-                            if field_vis.is_accessible_from(module, self.tcx) {
-                                self.reach(field.def_id, level).ty();
-                            }
+                let item = self.tcx.hir().expect_item(def_id);
+                if let hir::ItemKind::Struct(ref struct_def, _)
+                | hir::ItemKind::Union(ref struct_def, _) = item.kind
+                {
+                    for field in struct_def.fields() {
+                        let field_vis = self.tcx.local_visibility(field.def_id);
+                        if field_vis.is_accessible_from(module, self.tcx) {
+                            self.reach(field.def_id, macro_ev).ty();
                         }
-                    } else {
-                        bug!("item {:?} with DefKind {:?}", item, def_kind);
                     }
+                } else {
+                    bug!("item {:?} with DefKind {:?}", item, def_kind);
                 }
             }
 
@@ -662,14 +709,16 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
     }
 
     fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
-        let item_level = match item.kind {
+        let item_ev = match item.kind {
             hir::ItemKind::Impl { .. } => {
-                let impl_level = Option::<Level>::of_impl(
+                let impl_ev = Option::<EffectiveVisibility>::of_impl(
                     item.owner_id.def_id,
                     self.tcx,
                     &self.effective_visibilities,
                 );
-                self.update(item.owner_id.def_id, impl_level)
+
+                self.update_eff_vis(item.owner_id.def_id, impl_ev, None, Level::Direct);
+                impl_ev
             }
             _ => self.get(item.owner_id.def_id),
         };
@@ -678,38 +727,35 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
         match item.kind {
             hir::ItemKind::Enum(ref def, _) => {
                 for variant in def.variants {
-                    let variant_level = self.update(variant.def_id, item_level);
+                    self.update(variant.def_id, item_ev, Level::Reachable);
+                    let variant_ev = self.get(variant.def_id);
                     if let Some(ctor_def_id) = variant.data.ctor_def_id() {
-                        self.update(ctor_def_id, item_level);
+                        self.update(ctor_def_id, variant_ev, Level::Reachable);
                     }
                     for field in variant.data.fields() {
-                        self.update(field.def_id, variant_level);
+                        self.update(field.def_id, variant_ev, Level::Reachable);
                     }
                 }
             }
             hir::ItemKind::Impl(ref impl_) => {
                 for impl_item_ref in impl_.items {
-                    if impl_.of_trait.is_some()
-                        || self.tcx.visibility(impl_item_ref.id.owner_id).is_public()
-                    {
-                        self.update(impl_item_ref.id.owner_id.def_id, item_level);
-                    }
+                    let def_id = impl_item_ref.id.owner_id.def_id;
+                    let nominal_vis =
+                        impl_.of_trait.is_none().then(|| self.tcx.local_visibility(def_id));
+                    self.update_eff_vis(def_id, item_ev, nominal_vis, Level::Direct);
                 }
             }
             hir::ItemKind::Trait(.., trait_item_refs) => {
                 for trait_item_ref in trait_item_refs {
-                    self.update(trait_item_ref.id.owner_id.def_id, item_level);
+                    self.update(trait_item_ref.id.owner_id.def_id, item_ev, Level::Reachable);
                 }
             }
             hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
                 if let Some(ctor_def_id) = def.ctor_def_id() {
-                    self.update(ctor_def_id, item_level);
+                    self.update(ctor_def_id, item_ev, Level::Reachable);
                 }
                 for field in def.fields() {
-                    let vis = self.tcx.visibility(field.def_id);
-                    if vis.is_public() {
-                        self.update(field.def_id, item_level);
-                    }
+                    self.update(field.def_id, item_ev, Level::Reachable);
                 }
             }
             hir::ItemKind::Macro(ref macro_def, _) => {
@@ -717,9 +763,7 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
             }
             hir::ItemKind::ForeignMod { items, .. } => {
                 for foreign_item in items {
-                    if self.tcx.visibility(foreign_item.id.owner_id).is_public() {
-                        self.update(foreign_item.id.owner_id.def_id, item_level);
-                    }
+                    self.update(foreign_item.id.owner_id.def_id, item_ev, Level::Reachable);
                 }
             }
 
@@ -754,8 +798,11 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
                     // FIXME: This is some serious pessimization intended to workaround deficiencies
                     // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
                     // reachable if they are returned via `impl Trait`, even from private functions.
-                    let exist_level = cmp::max(item_level, Some(Level::ReachableThroughImplTrait));
-                    self.reach(item.owner_id.def_id, exist_level).generics().predicates().ty();
+                    let exist_ev = Some(EffectiveVisibility::from_vis(ty::Visibility::Public));
+                    self.reach_through_impl_trait(item.owner_id.def_id, exist_ev)
+                        .generics()
+                        .predicates()
+                        .ty();
                 }
             }
             // Visit everything.
@@ -763,17 +810,18 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
             | hir::ItemKind::Static(..)
             | hir::ItemKind::Fn(..)
             | hir::ItemKind::TyAlias(..) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level).generics().predicates().ty();
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev).generics().predicates().ty();
                 }
             }
             hir::ItemKind::Trait(.., trait_item_refs) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level).generics().predicates();
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev).generics().predicates();
 
                     for trait_item_ref in trait_item_refs {
                         let tcx = self.tcx;
-                        let mut reach = self.reach(trait_item_ref.id.owner_id.def_id, item_level);
+                        let mut reach = self.reach(trait_item_ref.id.owner_id.def_id, item_ev);
+
                         reach.generics().predicates();
 
                         if trait_item_ref.kind == AssocItemKind::Type
@@ -787,23 +835,24 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
                 }
             }
             hir::ItemKind::TraitAlias(..) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level).generics().predicates();
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev).generics().predicates();
                 }
             }
             // Visit everything except for private impl items.
             hir::ItemKind::Impl(ref impl_) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level)
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev)
                         .generics()
                         .predicates()
                         .ty()
                         .trait_ref();
 
                     for impl_item_ref in impl_.items {
-                        let impl_item_level = self.get(impl_item_ref.id.owner_id.def_id);
-                        if impl_item_level.is_some() {
-                            self.reach(impl_item_ref.id.owner_id.def_id, impl_item_level)
+                        let impl_item_ev = self.get(impl_item_ref.id.owner_id.def_id);
+
+                        if impl_item_ev.is_some() {
+                            self.reach(impl_item_ref.id.owner_id.def_id, impl_item_ev)
                                 .generics()
                                 .predicates()
                                 .ty();
@@ -814,23 +863,23 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
 
             // Visit everything, but enum variants have their own levels.
             hir::ItemKind::Enum(ref def, _) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level).generics().predicates();
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev).generics().predicates();
                 }
                 for variant in def.variants {
-                    let variant_level = self.get(variant.def_id);
-                    if variant_level.is_some() {
+                    let variant_ev = self.get(variant.def_id);
+                    if variant_ev.is_some() {
                         for field in variant.data.fields() {
-                            self.reach(field.def_id, variant_level).ty();
+                            self.reach(field.def_id, variant_ev).ty();
                         }
                         // Corner case: if the variant is reachable, but its
                         // enum is not, make the enum reachable as well.
-                        self.reach(item.owner_id.def_id, variant_level).ty();
+                        self.reach(item.owner_id.def_id, variant_ev).ty();
                     }
                     if let Some(ctor_def_id) = variant.data.ctor_def_id() {
-                        let ctor_level = self.get(ctor_def_id);
-                        if ctor_level.is_some() {
-                            self.reach(item.owner_id.def_id, ctor_level).ty();
+                        let ctor_ev = self.get(ctor_def_id);
+                        if ctor_ev.is_some() {
+                            self.reach(item.owner_id.def_id, ctor_ev).ty();
                         }
                     }
                 }
@@ -838,9 +887,9 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
             // Visit everything, but foreign items have their own levels.
             hir::ItemKind::ForeignMod { items, .. } => {
                 for foreign_item in items {
-                    let foreign_item_level = self.get(foreign_item.id.owner_id.def_id);
-                    if foreign_item_level.is_some() {
-                        self.reach(foreign_item.id.owner_id.def_id, foreign_item_level)
+                    let foreign_item_ev = self.get(foreign_item.id.owner_id.def_id);
+                    if foreign_item_ev.is_some() {
+                        self.reach(foreign_item.id.owner_id.def_id, foreign_item_ev)
                             .generics()
                             .predicates()
                             .ty();
@@ -849,36 +898,32 @@ impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
             }
             // Visit everything except for private fields.
             hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
-                if item_level.is_some() {
-                    self.reach(item.owner_id.def_id, item_level).generics().predicates();
+                if item_ev.is_some() {
+                    self.reach(item.owner_id.def_id, item_ev).generics().predicates();
                     for field in struct_def.fields() {
-                        let field_level = self.get(field.def_id);
-                        if field_level.is_some() {
-                            self.reach(field.def_id, field_level).ty();
+                        let field_ev = self.get(field.def_id);
+                        if field_ev.is_some() {
+                            self.reach(field.def_id, field_ev).ty();
                         }
                     }
                 }
                 if let Some(ctor_def_id) = struct_def.ctor_def_id() {
-                    let ctor_level = self.get(ctor_def_id);
-                    if ctor_level.is_some() {
-                        self.reach(item.owner_id.def_id, ctor_level).ty();
+                    let ctor_ev = self.get(ctor_def_id);
+                    if ctor_ev.is_some() {
+                        self.reach(item.owner_id.def_id, ctor_ev).ty();
                     }
                 }
             }
         }
 
-        let orig_level = mem::replace(&mut self.prev_level, item_level);
         intravisit::walk_item(self, item);
-        self.prev_level = orig_level;
     }
 
     fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
         // Blocks can have public items, for example impls, but they always
         // start as completely private regardless of publicity of a function,
         // constant, type, field, etc., in which this block resides.
-        let orig_level = mem::replace(&mut self.prev_level, None);
         intravisit::walk_block(self, b);
-        self.prev_level = orig_level;
     }
 }
 
@@ -932,11 +977,7 @@ impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx>
         _descr: &dyn fmt::Display,
     ) -> ControlFlow<Self::BreakTy> {
         if let Some(def_id) = def_id.as_local() {
-            if let (ty::Visibility::Public, _) | (_, Some(Level::ReachableThroughImplTrait)) =
-                (self.tcx().visibility(def_id.to_def_id()), self.level)
-            {
-                self.ev.update(def_id, self.level);
-            }
+            self.ev.update_eff_vis(def_id, self.effective_vis, None, self.level);
         }
         ControlFlow::Continue(())
     }
@@ -2164,7 +2205,6 @@ fn effective_visibilities(tcx: TyCtxt<'_>, (): ()) -> &EffectiveVisibilities {
         tcx,
         effective_visibilities: tcx.resolutions(()).effective_visibilities.clone(),
         macro_reachable: Default::default(),
-        prev_level: Some(Level::Direct),
         changed: false,
     };
 
diff --git a/compiler/rustc_resolve/src/effective_visibilities.rs b/compiler/rustc_resolve/src/effective_visibilities.rs
index 87067189a77..7393bdb388a 100644
--- a/compiler/rustc_resolve/src/effective_visibilities.rs
+++ b/compiler/rustc_resolve/src/effective_visibilities.rs
@@ -199,7 +199,7 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
         let tcx = self.r.tcx;
         self.changed |= self.import_effective_visibilities.update(
             binding,
-            nominal_vis,
+            Some(nominal_vis),
             || cheap_private_vis.unwrap_or_else(|| self.r.private_vis_import(binding)),
             inherited_eff_vis,
             parent_id.level(),
@@ -213,7 +213,7 @@ impl<'r, 'a, 'tcx> EffectiveVisibilitiesVisitor<'r, 'a, 'tcx> {
         let tcx = self.r.tcx;
         self.changed |= self.def_effective_visibilities.update(
             def_id,
-            nominal_vis,
+            Some(nominal_vis),
             || cheap_private_vis.unwrap_or_else(|| self.r.private_vis_def(def_id)),
             inherited_eff_vis,
             parent_id.level(),
diff --git a/library/core/src/iter/adapters/flatten.rs b/library/core/src/iter/adapters/flatten.rs
index 520ec9abcf0..2568aaf34f3 100644
--- a/library/core/src/iter/adapters/flatten.rs
+++ b/library/core/src/iter/adapters/flatten.rs
@@ -310,6 +310,7 @@ where
 /// Real logic of both `Flatten` and `FlatMap` which simply delegate to
 /// this type.
 #[derive(Clone, Debug)]
+#[unstable(feature = "trusted_len", issue = "37572")]
 struct FlattenCompat<I, U> {
     iter: Fuse<I>,
     frontiter: Option<U>,
@@ -463,6 +464,7 @@ where
     }
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
 impl<I, U> Iterator for FlattenCompat<I, U>
 where
     I: Iterator<Item: IntoIterator<IntoIter = U, Item = U::Item>>,
@@ -577,6 +579,7 @@ where
     }
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
 impl<I, U> DoubleEndedIterator for FlattenCompat<I, U>
 where
     I: DoubleEndedIterator<Item: IntoIterator<IntoIter = U, Item = U::Item>>,
@@ -646,6 +649,7 @@ where
     }
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
 unsafe impl<const N: usize, I, T> TrustedLen
     for FlattenCompat<I, <[T; N] as IntoIterator>::IntoIter>
 where
@@ -653,6 +657,7 @@ where
 {
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
 unsafe impl<'a, const N: usize, I, T> TrustedLen
     for FlattenCompat<I, <&'a [T; N] as IntoIterator>::IntoIter>
 where
@@ -660,6 +665,7 @@ where
 {
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
 unsafe impl<'a, const N: usize, I, T> TrustedLen
     for FlattenCompat<I, <&'a mut [T; N] as IntoIterator>::IntoIter>
 where
diff --git a/tests/ui/lint/issue-111359.rs b/tests/ui/lint/issue-111359.rs
new file mode 100644
index 00000000000..e390c3fc565
--- /dev/null
+++ b/tests/ui/lint/issue-111359.rs
@@ -0,0 +1,27 @@
+#[deny(missing_debug_implementations)]
+#[deny(missing_copy_implementations)]
+
+mod priv_mod {
+    use std::convert::TryFrom;
+
+    pub struct BarPub;
+    //~^ ERROR type does not implement `Debug`; consider adding `#[derive(Debug)]` or a manual implementation
+    //~| ERROR type could implement `Copy`; consider adding `impl Copy`
+    struct BarPriv;
+
+    impl<'a> TryFrom<BarPriv> for u8 {
+        type Error = ();
+        fn try_from(o: BarPriv) -> Result<Self, ()> {
+            unimplemented!()
+        }
+    }
+
+    impl<'a> TryFrom<BarPub> for u8 {
+        type Error = ();
+        fn try_from(o: BarPub) -> Result<Self, ()> {
+            unimplemented!()
+        }
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/lint/issue-111359.stderr b/tests/ui/lint/issue-111359.stderr
new file mode 100644
index 00000000000..2296d8413d6
--- /dev/null
+++ b/tests/ui/lint/issue-111359.stderr
@@ -0,0 +1,26 @@
+error: type does not implement `Debug`; consider adding `#[derive(Debug)]` or a manual implementation
+  --> $DIR/issue-111359.rs:7:5
+   |
+LL |     pub struct BarPub;
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/issue-111359.rs:1:8
+   |
+LL | #[deny(missing_debug_implementations)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: type could implement `Copy`; consider adding `impl Copy`
+  --> $DIR/issue-111359.rs:7:5
+   |
+LL |     pub struct BarPub;
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/issue-111359.rs:2:8
+   |
+LL | #[deny(missing_copy_implementations)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+