Auto merge of #107000 - GuillaumeGomez:fix-items-in-doc-hidden-block, r=notriddle,petrochenkov

Fix handling of items inside a `doc(hidden)` block

Fixes #106373.

cc `@aDotInTheVoid`
r? `@notriddle`

11 files changed, 357 insertions, 111 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index e2ced191a00..80493b100bb 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2213,21 +2213,17 @@ fn clean_maybe_renamed_item<'tcx>(
             get_all_import_attributes(use_node, cx.tcx, item.owner_id.def_id, &mut extra_attrs);
         }
 
-        if !extra_attrs.is_empty() {
+        let mut item = if !extra_attrs.is_empty() {
             extra_attrs.extend_from_slice(inline::load_attrs(cx, def_id));
             let attrs = Attributes::from_ast(&extra_attrs);
             let cfg = extra_attrs.cfg(cx.tcx, &cx.cache.hidden_cfg);
 
-            vec![Item::from_def_id_and_attrs_and_parts(
-                def_id,
-                Some(name),
-                kind,
-                Box::new(attrs),
-                cfg,
-            )]
+            Item::from_def_id_and_attrs_and_parts(def_id, Some(name), kind, Box::new(attrs), cfg)
         } else {
-            vec![Item::from_def_id_and_parts(def_id, Some(name), kind, cx)]
-        }
+            Item::from_def_id_and_parts(def_id, Some(name), kind, cx)
+        };
+        item.inline_stmt_id = import_id.map(|def_id| def_id.to_def_id());
+        vec![item]
     })
 }
 
diff --git a/src/librustdoc/html/render/write_shared.rs b/src/librustdoc/html/render/write_shared.rs
index 6b71ecc24bd..54749e9a317 100644
--- a/src/librustdoc/html/render/write_shared.rs
+++ b/src/librustdoc/html/render/write_shared.rs
@@ -138,7 +138,7 @@ pub(super) fn write_shared(
         Ok((ret, krates))
     }
 
-    /// Read a file and return all lines that match the <code>"{crate}":{data},\</code> format,
+    /// Read a file and return all lines that match the <code>"{crate}":{data},\ </code> format,
     /// and return a tuple `(Vec<DataString>, Vec<CrateNameString>)`.
     ///
     /// This forms the payload of files that look like this:
diff --git a/src/librustdoc/passes/strip_hidden.rs b/src/librustdoc/passes/strip_hidden.rs
index e07a788a72a..8c733ddefc0 100644
--- a/src/librustdoc/passes/strip_hidden.rs
+++ b/src/librustdoc/passes/strip_hidden.rs
@@ -1,4 +1,6 @@
 //! Strip all doc(hidden) items from the output.
+
+use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::sym;
 use std::mem;
 
@@ -7,6 +9,7 @@ use crate::clean::{Item, ItemIdSet, NestedAttributesExt};
 use crate::core::DocContext;
 use crate::fold::{strip_item, DocFolder};
 use crate::passes::{ImplStripper, Pass};
+use crate::visit_ast::inherits_doc_hidden;
 
 pub(crate) const STRIP_HIDDEN: Pass = Pass {
     name: "strip-hidden",
@@ -21,7 +24,12 @@ pub(crate) fn strip_hidden(krate: clean::Crate, cx: &mut DocContext<'_>) -> clea
 
     // strip all #[doc(hidden)] items
     let krate = {
-        let mut stripper = Stripper { retained: &mut retained, update_retained: true };
+        let mut stripper = Stripper {
+            retained: &mut retained,
+            update_retained: true,
+            tcx: cx.tcx,
+            is_in_hidden_item: false,
+        };
         stripper.fold_crate(krate)
     };
 
@@ -36,40 +44,89 @@ pub(crate) fn strip_hidden(krate: clean::Crate, cx: &mut DocContext<'_>) -> clea
     stripper.fold_crate(krate)
 }
 
-struct Stripper<'a> {
+struct Stripper<'a, 'tcx> {
     retained: &'a mut ItemIdSet,
     update_retained: bool,
+    tcx: TyCtxt<'tcx>,
+    is_in_hidden_item: bool,
+}
+
+impl<'a, 'tcx> Stripper<'a, 'tcx> {
+    fn set_is_in_hidden_item_and_fold(&mut self, is_in_hidden_item: bool, i: Item) -> Item {
+        let prev = self.is_in_hidden_item;
+        self.is_in_hidden_item |= is_in_hidden_item;
+        let ret = self.fold_item_recur(i);
+        self.is_in_hidden_item = prev;
+        ret
+    }
+
+    /// In case `i` is a non-hidden impl block, then we special-case it by changing the value
+    /// of `is_in_hidden_item` to `true` because the impl children inherit its visibility.
+    fn recurse_in_impl(&mut self, i: Item) -> Item {
+        let prev = mem::replace(&mut self.is_in_hidden_item, false);
+        let ret = self.fold_item_recur(i);
+        self.is_in_hidden_item = prev;
+        ret
+    }
 }
 
-impl<'a> DocFolder for Stripper<'a> {
+impl<'a, 'tcx> DocFolder for Stripper<'a, 'tcx> {
     fn fold_item(&mut self, i: Item) -> Option<Item> {
-        if i.attrs.lists(sym::doc).has_word(sym::hidden) {
-            debug!("strip_hidden: stripping {:?} {:?}", i.type_(), i.name);
-            // Use a dedicated hidden item for fields, variants, and modules.
-            // We need to keep private fields and variants, so that the docs
-            // can show a placeholder "// some variants omitted". We need to keep
-            // private modules, because they can contain impl blocks, and impl
-            // block privacy is inherited from the type and trait, not from the
-            // module it's defined in. Both of these are marked "stripped," and
-            // not included in the final docs, but since they still have an effect
-            // on the final doc, cannot be completely removed from the Clean IR.
-            match *i.kind {
-                clean::StructFieldItem(..) | clean::ModuleItem(..) | clean::VariantItem(..) => {
-                    // We need to recurse into stripped modules to
-                    // strip things like impl methods but when doing so
-                    // we must not add any items to the `retained` set.
-                    let old = mem::replace(&mut self.update_retained, false);
-                    let ret = strip_item(self.fold_item_recur(i));
-                    self.update_retained = old;
-                    return Some(ret);
-                }
-                _ => return None,
+        let has_doc_hidden = i.attrs.lists(sym::doc).has_word(sym::hidden);
+        let is_impl = matches!(*i.kind, clean::ImplItem(..));
+        let mut is_hidden = has_doc_hidden;
+        if !is_impl {
+            is_hidden = self.is_in_hidden_item || has_doc_hidden;
+            if !is_hidden && i.inline_stmt_id.is_none() {
+                // We don't need to check if it's coming from a reexport since the reexport itself was
+                // already checked.
+                is_hidden = i
+                    .item_id
+                    .as_def_id()
+                    .and_then(|def_id| def_id.as_local())
+                    .map(|def_id| inherits_doc_hidden(self.tcx, def_id))
+                    .unwrap_or(false);
             }
-        } else {
+        }
+        if !is_hidden {
             if self.update_retained {
                 self.retained.insert(i.item_id);
             }
+            return Some(if is_impl {
+                self.recurse_in_impl(i)
+            } else {
+                self.set_is_in_hidden_item_and_fold(false, i)
+            });
+        }
+        debug!("strip_hidden: stripping {:?} {:?}", i.type_(), i.name);
+        // Use a dedicated hidden item for fields, variants, and modules.
+        // We need to keep private fields and variants, so that the docs
+        // can show a placeholder "// some variants omitted". We need to keep
+        // private modules, because they can contain impl blocks, and impl
+        // block privacy is inherited from the type and trait, not from the
+        // module it's defined in. Both of these are marked "stripped," and
+        // not included in the final docs, but since they still have an effect
+        // on the final doc, cannot be completely removed from the Clean IR.
+        match *i.kind {
+            clean::StructFieldItem(..) | clean::ModuleItem(..) | clean::VariantItem(..) => {
+                // We need to recurse into stripped modules to
+                // strip things like impl methods but when doing so
+                // we must not add any items to the `retained` set.
+                let old = mem::replace(&mut self.update_retained, false);
+                let ret = strip_item(self.set_is_in_hidden_item_and_fold(true, i));
+                self.update_retained = old;
+                Some(ret)
+            }
+            _ => {
+                let ret = self.set_is_in_hidden_item_and_fold(true, i);
+                if has_doc_hidden {
+                    // If the item itself has `#[doc(hidden)]`, then we simply remove it.
+                    None
+                } else {
+                    // However if it's a "descendant" of a `#[doc(hidden)]` item, then we strip it.
+                    Some(strip_item(ret))
+                }
+            }
         }
-        Some(self.fold_item_recur(i))
     }
 }
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index a89d6fa8398..088cb3f3394 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -5,7 +5,9 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, DefIdMap, LocalDefId, LocalDefIdSet};
+use rustc_hir::intravisit::{walk_item, Visitor};
 use rustc_hir::{Node, CRATE_HIR_ID};
+use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{DefIdTree, TyCtxt};
 use rustc_span::def_id::{CRATE_DEF_ID, LOCAL_CRATE};
 use rustc_span::symbol::{kw, sym, Symbol};
@@ -53,19 +55,26 @@ fn def_id_to_path(tcx: TyCtxt<'_>, did: DefId) -> Vec<Symbol> {
     std::iter::once(crate_name).chain(relative).collect()
 }
 
-pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut node: LocalDefId) -> bool {
-    while let Some(id) = tcx.opt_local_parent(node) {
-        node = id;
-        if tcx.is_doc_hidden(node.to_def_id()) {
+pub(crate) fn inherits_doc_hidden(tcx: TyCtxt<'_>, mut def_id: LocalDefId) -> bool {
+    let hir = tcx.hir();
+    while let Some(id) = tcx.opt_local_parent(def_id) {
+        def_id = id;
+        if tcx.is_doc_hidden(def_id.to_def_id()) {
             return true;
+        } else if let Some(node) = hir.find_by_def_id(def_id) &&
+            matches!(
+                node,
+                hir::Node::Item(hir::Item { kind: hir::ItemKind::Impl(_), .. }),
+            )
+        {
+            // `impl` blocks stand a bit on their own: unless they have `#[doc(hidden)]` directly
+            // on them, they don't inherit it from the parent context.
+            return false;
         }
     }
     false
 }
 
-// Also, is there some reason that this doesn't use the 'visit'
-// framework from syntax?.
-
 pub(crate) struct RustdocVisitor<'a, 'tcx> {
     cx: &'a mut core::DocContext<'tcx>,
     view_item_stack: LocalDefIdSet,
@@ -73,6 +82,7 @@ pub(crate) struct RustdocVisitor<'a, 'tcx> {
     /// Are the current module and all of its parents public?
     inside_public_path: bool,
     exact_paths: DefIdMap<Vec<Symbol>>,
+    modules: Vec<Module<'tcx>>,
 }
 
 impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
@@ -80,12 +90,19 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         // If the root is re-exported, terminate all recursion.
         let mut stack = LocalDefIdSet::default();
         stack.insert(CRATE_DEF_ID);
+        let om = Module::new(
+            cx.tcx.crate_name(LOCAL_CRATE),
+            CRATE_DEF_ID,
+            cx.tcx.hir().root_module().spans.inner_span,
+        );
+
         RustdocVisitor {
             cx,
             view_item_stack: stack,
             inlining: false,
             inside_public_path: true,
             exact_paths: Default::default(),
+            modules: vec![om],
         }
     }
 
@@ -95,12 +112,10 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
     }
 
     pub(crate) fn visit(mut self) -> Module<'tcx> {
-        let mut top_level_module = self.visit_mod_contents(
-            CRATE_DEF_ID,
-            self.cx.tcx.hir().root_module(),
-            self.cx.tcx.crate_name(LOCAL_CRATE),
-            None,
-        );
+        let root_module = self.cx.tcx.hir().root_module();
+        self.visit_mod_contents(CRATE_DEF_ID, root_module);
+
+        let mut top_level_module = self.modules.pop().unwrap();
 
         // `#[macro_export] macro_rules!` items are reexported at the top level of the
         // crate, regardless of where they're defined. We want to document the
@@ -115,15 +130,13 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         // macro in the same module.
         let mut inserted = FxHashSet::default();
         for export in self.cx.tcx.module_reexports(CRATE_DEF_ID).unwrap_or(&[]) {
-            if let Res::Def(DefKind::Macro(_), def_id) = export.res {
-                if let Some(local_def_id) = def_id.as_local() {
-                    if self.cx.tcx.has_attr(def_id, sym::macro_export) {
-                        if inserted.insert(def_id) {
-                            let item = self.cx.tcx.hir().expect_item(local_def_id);
-                            top_level_module.items.push((item, None, None));
-                        }
-                    }
-                }
+            if let Res::Def(DefKind::Macro(_), def_id) = export.res &&
+                let Some(local_def_id) = def_id.as_local() &&
+                self.cx.tcx.has_attr(def_id, sym::macro_export) &&
+                inserted.insert(def_id)
+            {
+                    let item = self.cx.tcx.hir().expect_item(local_def_id);
+                    top_level_module.items.push((item, None, None));
             }
         }
 
@@ -157,23 +170,22 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         top_level_module
     }
 
-    fn visit_mod_contents(
-        &mut self,
-        def_id: LocalDefId,
-        m: &'tcx hir::Mod<'tcx>,
-        name: Symbol,
-        parent_id: Option<LocalDefId>,
-    ) -> Module<'tcx> {
-        let mut om = Module::new(name, def_id, m.spans.inner_span);
+    /// This method will go through the given module items in two passes:
+    /// 1. The items which are not glob imports/reexports.
+    /// 2. The glob imports/reexports.
+    fn visit_mod_contents(&mut self, def_id: LocalDefId, m: &'tcx hir::Mod<'tcx>) {
+        debug!("Going through module {:?}", m);
         // Keep track of if there were any private modules in the path.
         let orig_inside_public_path = self.inside_public_path;
         self.inside_public_path &= self.cx.tcx.local_visibility(def_id).is_public();
+
+        // Reimplementation of `walk_mod` because we need to do it in two passes (explanations in
+        // the second loop):
         for &i in m.item_ids {
             let item = self.cx.tcx.hir().item(i);
-            if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
-                continue;
+            if !matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
+                self.visit_item(item);
             }
-            self.visit_item(item, None, &mut om, parent_id);
         }
         for &i in m.item_ids {
             let item = self.cx.tcx.hir().item(i);
@@ -181,11 +193,11 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             // Later passes in rustdoc will de-duplicate by name and kind, so if glob-
             // imported items appear last, then they'll be the ones that get discarded.
             if matches!(item.kind, hir::ItemKind::Use(_, hir::UseKind::Glob)) {
-                self.visit_item(item, None, &mut om, parent_id);
+                self.visit_item(item);
             }
         }
         self.inside_public_path = orig_inside_public_path;
-        om
+        debug!("Leaving module {:?}", m);
     }
 
     /// Tries to resolve the target of a `pub use` statement and inlines the
@@ -203,7 +215,6 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         res: Res,
         renamed: Option<Symbol>,
         glob: bool,
-        om: &mut Module<'tcx>,
         please_inline: bool,
     ) -> bool {
         debug!("maybe_inline_local res: {:?}", res);
@@ -213,33 +224,30 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         }
 
         let tcx = self.cx.tcx;
-        let Some(res_did) = res.opt_def_id() else {
+        let Some(ori_res_did) = res.opt_def_id() else {
             return false;
         };
 
         let use_attrs = tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(def_id));
         // Don't inline `doc(hidden)` imports so they can be stripped at a later stage.
         let is_no_inline = use_attrs.lists(sym::doc).has_word(sym::no_inline)
-            || tcx.is_doc_hidden(def_id.to_def_id());
+            || use_attrs.lists(sym::doc).has_word(sym::hidden);
 
         // For cross-crate impl inlining we need to know whether items are
         // reachable in documentation -- a previously unreachable item can be
         // made reachable by cross-crate inlining which we're checking here.
         // (this is done here because we need to know this upfront).
-        if !res_did.is_local() && !is_no_inline {
-            crate::visit_lib::lib_embargo_visit_item(self.cx, res_did);
+        if !ori_res_did.is_local() && !is_no_inline {
+            crate::visit_lib::lib_embargo_visit_item(self.cx, ori_res_did);
             return false;
         }
 
-        let Some(res_did) = res_did.as_local() else {
+        let Some(res_did) = ori_res_did.as_local() else {
             return false;
         };
 
-        let is_private = !self
-            .cx
-            .cache
-            .effective_visibilities
-            .is_directly_public(self.cx.tcx, res_did.to_def_id());
+        let is_private =
+            !self.cx.cache.effective_visibilities.is_directly_public(self.cx.tcx, ori_res_did);
         let is_hidden = inherits_doc_hidden(self.cx.tcx, res_did);
 
         // Only inline if requested or if the item would otherwise be stripped.
@@ -256,20 +264,20 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 let prev = mem::replace(&mut self.inlining, true);
                 for &i in m.item_ids {
                     let i = self.cx.tcx.hir().item(i);
-                    self.visit_item(i, None, om, Some(def_id));
+                    self.visit_item_inner(i, None, Some(def_id));
                 }
                 self.inlining = prev;
                 true
             }
             Node::Item(it) if !glob => {
                 let prev = mem::replace(&mut self.inlining, true);
-                self.visit_item(it, renamed, om, Some(def_id));
+                self.visit_item_inner(it, renamed, Some(def_id));
                 self.inlining = prev;
                 true
             }
             Node::ForeignItem(it) if !glob => {
                 let prev = mem::replace(&mut self.inlining, true);
-                self.visit_foreign_item(it, renamed, om);
+                self.visit_foreign_item_inner(it, renamed);
                 self.inlining = prev;
                 true
             }
@@ -279,18 +287,28 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         ret
     }
 
-    fn visit_item(
+    #[inline]
+    fn add_to_current_mod(
         &mut self,
         item: &'tcx hir::Item<'_>,
         renamed: Option<Symbol>,
-        om: &mut Module<'tcx>,
         parent_id: Option<LocalDefId>,
     ) {
+        self.modules.last_mut().unwrap().items.push((item, renamed, parent_id))
+    }
+
+    fn visit_item_inner(
+        &mut self,
+        item: &'tcx hir::Item<'_>,
+        renamed: Option<Symbol>,
+        import_id: Option<LocalDefId>,
+    ) -> bool {
         debug!("visiting item {:?}", item);
         let name = renamed.unwrap_or(item.ident.name);
+        let tcx = self.cx.tcx;
 
         let def_id = item.owner_id.to_def_id();
-        let is_pub = self.cx.tcx.visibility(def_id).is_public();
+        let is_pub = tcx.visibility(def_id).is_public();
 
         if is_pub {
             self.store_path(item.owner_id.to_def_id());
@@ -299,8 +317,8 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         match item.kind {
             hir::ItemKind::ForeignMod { items, .. } => {
                 for item in items {
-                    let item = self.cx.tcx.hir().foreign_item(item.id);
-                    self.visit_foreign_item(item, None, om);
+                    let item = tcx.hir().foreign_item(item.id);
+                    self.visit_foreign_item_inner(item, None);
                 }
             }
             // If we're inlining, skip private items or item reexported as "_".
@@ -315,7 +333,8 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                         continue;
                     }
 
-                    let attrs = self.cx.tcx.hir().attrs(item.hir_id());
+                    let attrs =
+                        tcx.hir().attrs(tcx.hir().local_def_id_to_hir_id(item.owner_id.def_id));
 
                     // If there was a private module in the current path then don't bother inlining
                     // anything as it will probably be stripped anyway.
@@ -333,14 +352,13 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                             res,
                             ident,
                             is_glob,
-                            om,
                             please_inline,
                         ) {
                             continue;
                         }
                     }
 
-                    om.items.push((item, renamed, parent_id))
+                    self.add_to_current_mod(item, renamed, import_id);
                 }
             }
             hir::ItemKind::Macro(ref macro_def, _) => {
@@ -357,14 +375,14 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
 
                 let def_id = item.owner_id.to_def_id();
                 let is_macro_2_0 = !macro_def.macro_rules;
-                let nonexported = !self.cx.tcx.has_attr(def_id, sym::macro_export);
+                let nonexported = !tcx.has_attr(def_id, sym::macro_export);
 
                 if is_macro_2_0 || nonexported || self.inlining {
-                    om.items.push((item, renamed, None));
+                    self.add_to_current_mod(item, renamed, None);
                 }
             }
             hir::ItemKind::Mod(ref m) => {
-                om.mods.push(self.visit_mod_contents(item.owner_id.def_id, m, name, parent_id));
+                self.enter_mod(item.owner_id.def_id, m, name);
             }
             hir::ItemKind::Fn(..)
             | hir::ItemKind::ExternCrate(..)
@@ -375,33 +393,87 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             | hir::ItemKind::OpaqueTy(..)
             | hir::ItemKind::Static(..)
             | hir::ItemKind::Trait(..)
-            | hir::ItemKind::TraitAlias(..) => om.items.push((item, renamed, parent_id)),
+            | hir::ItemKind::TraitAlias(..) => {
+                self.add_to_current_mod(item, renamed, import_id);
+            }
             hir::ItemKind::Const(..) => {
                 // Underscore constants do not correspond to a nameable item and
                 // so are never useful in documentation.
                 if name != kw::Underscore {
-                    om.items.push((item, renamed, parent_id));
+                    self.add_to_current_mod(item, renamed, import_id);
                 }
             }
             hir::ItemKind::Impl(impl_) => {
                 // Don't duplicate impls when inlining or if it's implementing a trait, we'll pick
                 // them up regardless of where they're located.
                 if !self.inlining && impl_.of_trait.is_none() {
-                    om.items.push((item, None, None));
+                    self.add_to_current_mod(item, None, None);
                 }
             }
         }
+        true
     }
 
-    fn visit_foreign_item(
+    fn visit_foreign_item_inner(
         &mut self,
         item: &'tcx hir::ForeignItem<'_>,
         renamed: Option<Symbol>,
-        om: &mut Module<'tcx>,
     ) {
         // If inlining we only want to include public functions.
         if !self.inlining || self.cx.tcx.visibility(item.owner_id).is_public() {
-            om.foreigns.push((item, renamed));
+            self.modules.last_mut().unwrap().foreigns.push((item, renamed));
+        }
+    }
+
+    /// This method will create a new module and push it onto the "modules stack" then call
+    /// `visit_mod_contents`. Once done, it'll remove it from the "modules stack" and instead
+    /// add into the list of modules of the current module.
+    fn enter_mod(&mut self, id: LocalDefId, m: &'tcx hir::Mod<'tcx>, name: Symbol) {
+        self.modules.push(Module::new(name, id, m.spans.inner_span));
+
+        self.visit_mod_contents(id, m);
+
+        let last = self.modules.pop().unwrap();
+        self.modules.last_mut().unwrap().mods.push(last);
+    }
+}
+
+// We need to implement this visitor so it'll go everywhere and retrieve items we're interested in
+// such as impl blocks in const blocks.
+impl<'a, 'tcx> Visitor<'tcx> for RustdocVisitor<'a, 'tcx> {
+    type NestedFilter = nested_filter::All;
+
+    fn nested_visit_map(&mut self) -> Self::Map {
+        self.cx.tcx.hir()
+    }
+
+    fn visit_item(&mut self, i: &'tcx hir::Item<'tcx>) {
+        if self.visit_item_inner(i, None, None) {
+            walk_item(self, i);
         }
     }
+
+    fn visit_mod(&mut self, _: &hir::Mod<'tcx>, _: Span, _: hir::HirId) {
+        // Handled in `visit_item_inner`
+    }
+
+    fn visit_use(&mut self, _: &hir::UsePath<'tcx>, _: hir::HirId) {
+        // Handled in `visit_item_inner`
+    }
+
+    fn visit_path(&mut self, _: &hir::Path<'tcx>, _: hir::HirId) {
+        // Handled in `visit_item_inner`
+    }
+
+    fn visit_label(&mut self, _: &rustc_ast::Label) {
+        // Unneeded.
+    }
+
+    fn visit_infer(&mut self, _: &hir::InferArg) {
+        // Unneeded.
+    }
+
+    fn visit_lifetime(&mut self, _: &hir::Lifetime) {
+        // Unneeded.
+    }
 }
diff --git a/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.rs b/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.rs
index 4b1e04234c8..939da186fbc 100644
--- a/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.rs
+++ b/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.rs
@@ -1,12 +1,10 @@
-// check-pass
 // normalize-stderr-test: "`.*`" -> "`DEF_ID`"
 // normalize-stdout-test: "`.*`" -> "`DEF_ID`"
 // edition:2018
 
 pub async fn f() -> impl std::fmt::Debug {
-    // rustdoc doesn't care that this is infinitely sized
     #[derive(Debug)]
-    enum E {
+    enum E { //~ ERROR
         This(E),
         Unit,
     }
diff --git a/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.stderr b/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.stderr
new file mode 100644
index 00000000000..aff7402bc91
--- /dev/null
+++ b/tests/rustdoc-ui/infinite-recursive-type-impl-trait-return.stderr
@@ -0,0 +1,16 @@
+error[E0072]: recursive type `DEF_ID` has infinite size
+  --> $DIR/infinite-recursive-type-impl-trait-return.rs:7:5
+   |
+LL |     enum E {
+   |     ^^^^^^
+LL |         This(E),
+   |              - recursive without indirection
+   |
+help: insert some indirection (e.g., a `DEF_ID`) to break the cycle
+   |
+LL |         This(Box<E>),
+   |              ++++ +
+
+error: aborting due to previous error
+
+For more information about this error, try `DEF_ID`.
diff --git a/tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs b/tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs
index ac79582fb3f..ac517257498 100644
--- a/tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs
+++ b/tests/rustdoc-ui/infinite-recursive-type-impl-trait.rs
@@ -1,8 +1,5 @@
-// check-pass
-
 fn f() -> impl Sized {
-    // rustdoc doesn't care that this is infinitely sized
-    enum E {
+    enum E { //~ ERROR
         V(E),
     }
     unimplemented!()
diff --git a/tests/rustdoc-ui/infinite-recursive-type-impl-trait.stderr b/tests/rustdoc-ui/infinite-recursive-type-impl-trait.stderr
new file mode 100644
index 00000000000..a61577bd14a
--- /dev/null
+++ b/tests/rustdoc-ui/infinite-recursive-type-impl-trait.stderr
@@ -0,0 +1,16 @@
+error[E0072]: recursive type `f::E` has infinite size
+  --> $DIR/infinite-recursive-type-impl-trait.rs:2:5
+   |
+LL |     enum E {
+   |     ^^^^^^
+LL |         V(E),
+   |           - recursive without indirection
+   |
+help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to break the cycle
+   |
+LL |         V(Box<E>),
+   |           ++++ +
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0072`.
diff --git a/tests/rustdoc/hidden-private.rs b/tests/rustdoc/hidden-private.rs
new file mode 100644
index 00000000000..834ba5231a1
--- /dev/null
+++ b/tests/rustdoc/hidden-private.rs
@@ -0,0 +1,50 @@
+// This is a regression test for <https://github.com/rust-lang/rust/issues/106373>.
+// It ensures that the items in the `doc(hidden)` const block don't show up in the
+// generated docs.
+
+// compile-flags: --document-private-items
+
+#![crate_name = "foo"]
+
+// @has 'foo/index.html'
+// @count - '//*[@class="item-table"]//a[@class="struct"]' 2
+// @count - '//*[@class="item-table"]//a[@class="trait"]' 1
+// @count - '//*[@class="item-table"]//a[@class="macro"]' 0
+#[doc(hidden)]
+const _: () = {
+    macro_rules! stry {
+        () => {};
+    }
+
+    struct ShouldBeHidden;
+
+    // @has 'foo/struct.Foo.html'
+    // @!has - '//*[@class="code-header"]' 'impl Bar for Foo'
+    #[doc(hidden)]
+    impl Bar for Foo {
+        fn bar(&self) {
+            struct SHouldAlsoBeHidden;
+        }
+    }
+
+    // @has 'foo/struct.Private.html'
+    // @has - '//*[@id="impl-Bar-for-Private"]/*[@class="code-header"]' 'impl Bar for Private'
+    // @has - '//*[@id="method.bar"]/*[@class="code-header"]' 'fn bar(&self)'
+    impl Bar for Private {
+        fn bar(&self) {}
+    }
+
+    // @has - '//*[@id="impl-Private"]/*[@class="code-header"]' 'impl Private'
+    // @has - '//*[@id="method.tralala"]/*[@class="code-header"]' 'fn tralala()'
+    impl Private {
+        fn tralala() {}
+    }
+};
+
+
+struct Private;
+pub struct Foo;
+
+pub trait Bar {
+    fn bar(&self);
+}
diff --git a/tests/rustdoc/impl-in-const-block.rs b/tests/rustdoc/impl-in-const-block.rs
new file mode 100644
index 00000000000..b44e7135246
--- /dev/null
+++ b/tests/rustdoc/impl-in-const-block.rs
@@ -0,0 +1,43 @@
+// Regression test for #83026.
+// The goal of this test is to ensure that impl blocks inside
+// const expressions are documented as well.
+
+#![crate_name = "foo"]
+
+// @has 'foo/struct.A.html'
+// @has - '//*[@id="method.new"]/*[@class="code-header"]' 'pub fn new() -> A'
+// @has - '//*[@id="method.bar"]/*[@class="code-header"]' 'pub fn bar(&self)'
+// @has - '//*[@id="method.woo"]/*[@class="code-header"]' 'pub fn woo(&self)'
+// @has - '//*[@id="method.yoo"]/*[@class="code-header"]' 'pub fn yoo()'
+// @has - '//*[@id="method.yuu"]/*[@class="code-header"]' 'pub fn yuu()'
+pub struct A;
+
+const _: () = {
+    impl A {
+        const FOO: () = {
+            impl A {
+                pub fn woo(&self) {}
+            }
+        };
+
+        pub fn new() -> A {
+            A
+        }
+    }
+};
+pub const X: () = {
+    impl A {
+        pub fn bar(&self) {}
+    }
+};
+
+fn foo() {
+    impl A {
+        pub fn yoo() {}
+    }
+    const _: () = {
+        impl A {
+            pub fn yuu() {}
+        }
+    };
+}
diff --git a/tests/rustdoc/redirect.rs b/tests/rustdoc/redirect.rs
index e3a14c7a74a..5b7a76e1a77 100644
--- a/tests/rustdoc/redirect.rs
+++ b/tests/rustdoc/redirect.rs
@@ -9,9 +9,10 @@ pub trait Foo {}
 // @has redirect/index.html
 // @has - '//code' 'pub use reexp_stripped::Bar'
 // @has - '//code/a' 'Bar'
+// @has - '//a[@href="../reexp_stripped/hidden/struct.Bar.html"]' 'Bar'
 // @has reexp_stripped/hidden/struct.Bar.html
-// @has - '//p/a' '../../reexp_stripped/struct.Bar.html'
 // @has 'reexp_stripped/struct.Bar.html'
+// @has - '//a[@href="struct.Bar.html"]' 'Bar'
 #[doc(no_inline)]
 pub use reexp_stripped::Bar;
 impl Foo for Bar {}