Merging upstream version 1.70.0+dfsg1.

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

8 files changed, 298 insertions, 345 deletions

diff --git a/src/librustdoc/clean/blanket_impl.rs b/src/librustdoc/clean/blanket_impl.rs
index bcdbbcacc..3a3bf6a7a 100644
--- a/src/librustdoc/clean/blanket_impl.rs
+++ b/src/librustdoc/clean/blanket_impl.rs
@@ -1,6 +1,6 @@
 use crate::rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt;
 use rustc_hir as hir;
-use rustc_infer::infer::{InferOk, TyCtxtInferExt};
+use rustc_infer::infer::{DefineOpaqueTypes, InferOk, TyCtxtInferExt};
 use rustc_infer::traits;
 use rustc_middle::ty::ToPredicate;
 use rustc_span::DUMMY_SP;
@@ -47,8 +47,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
 
                 // Require the type the impl is implemented on to match
                 // our type, and ignore the impl if there was a mismatch.
-                let cause = traits::ObligationCause::dummy();
-                let Ok(eq_result) = infcx.at(&cause, param_env).eq(impl_trait_ref.self_ty(), impl_ty) else {
+                let Ok(eq_result) = infcx.at(&traits::ObligationCause::dummy(), param_env).eq(DefineOpaqueTypes::No, impl_trait_ref.self_ty(), impl_ty) else {
                         continue
                     };
                 let InferOk { value: (), obligations } = eq_result;
diff --git a/src/librustdoc/clean/cfg.rs b/src/librustdoc/clean/cfg.rs
index dd58a5b51..5177cffe6 100644
--- a/src/librustdoc/clean/cfg.rs
+++ b/src/librustdoc/clean/cfg.rs
@@ -517,6 +517,7 @@ impl<'a> fmt::Display for Display<'a> {
                         "aarch64" => "AArch64",
                         "arm" => "ARM",
                         "asmjs" => "JavaScript",
+                        "loongarch64" => "LoongArch LA64",
                         "m68k" => "M68k",
                         "mips" => "MIPS",
                         "mips64" => "MIPS-64",
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 148243683..cc5d13808 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -36,15 +36,11 @@ use crate::formats::item_type::ItemType;
 ///
 /// The returned value is `None` if the definition could not be inlined,
 /// and `Some` of a vector of items if it was successfully expanded.
-///
-/// `parent_module` refers to the parent of the *re-export*, not the original item.
 pub(crate) fn try_inline(
     cx: &mut DocContext<'_>,
-    parent_module: DefId,
-    import_def_id: Option<DefId>,
     res: Res,
     name: Symbol,
-    attrs: Option<&[ast::Attribute]>,
+    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
     visited: &mut DefIdSet,
 ) -> Option<Vec<clean::Item>> {
     let did = res.opt_def_id()?;
@@ -55,38 +51,17 @@ pub(crate) fn try_inline(
 
     debug!("attrs={:?}", attrs);
 
-    let attrs_without_docs = attrs.map(|attrs| {
-        attrs.into_iter().filter(|a| a.doc_str().is_none()).cloned().collect::<Vec<_>>()
+    let attrs_without_docs = attrs.map(|(attrs, def_id)| {
+        (attrs.into_iter().filter(|a| a.doc_str().is_none()).cloned().collect::<Vec<_>>(), def_id)
     });
-    // We need this ugly code because:
-    //
-    // ```
-    // attrs_without_docs.map(|a| a.as_slice())
-    // ```
-    //
-    // will fail because it returns a temporary slice and:
-    //
-    // ```
-    // attrs_without_docs.map(|s| {
-    //     vec = s.as_slice();
-    //     vec
-    // })
-    // ```
-    //
-    // will fail because we're moving an uninitialized variable into a closure.
-    let vec;
-    let attrs_without_docs = match attrs_without_docs {
-        Some(s) => {
-            vec = s;
-            Some(vec.as_slice())
-        }
-        None => None,
-    };
+    let attrs_without_docs =
+        attrs_without_docs.as_ref().map(|(attrs, def_id)| (&attrs[..], *def_id));
 
+    let import_def_id = attrs.and_then(|(_, def_id)| def_id);
     let kind = match res {
         Res::Def(DefKind::Trait, did) => {
             record_extern_fqn(cx, did, ItemType::Trait);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::TraitItem(Box::new(build_external_trait(cx, did)))
         }
         Res::Def(DefKind::Fn, did) => {
@@ -95,27 +70,27 @@ pub(crate) fn try_inline(
         }
         Res::Def(DefKind::Struct, did) => {
             record_extern_fqn(cx, did, ItemType::Struct);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::StructItem(build_struct(cx, did))
         }
         Res::Def(DefKind::Union, did) => {
             record_extern_fqn(cx, did, ItemType::Union);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::UnionItem(build_union(cx, did))
         }
         Res::Def(DefKind::TyAlias, did) => {
             record_extern_fqn(cx, did, ItemType::Typedef);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::TypedefItem(build_type_alias(cx, did))
         }
         Res::Def(DefKind::Enum, did) => {
             record_extern_fqn(cx, did, ItemType::Enum);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::EnumItem(build_enum(cx, did))
         }
         Res::Def(DefKind::ForeignTy, did) => {
             record_extern_fqn(cx, did, ItemType::ForeignType);
-            build_impls(cx, Some(parent_module), did, attrs_without_docs, &mut ret);
+            build_impls(cx, did, attrs_without_docs, &mut ret);
             clean::ForeignTypeItem
         }
         // Never inline enum variants but leave them shown as re-exports.
@@ -136,7 +111,7 @@ pub(crate) fn try_inline(
             clean::ConstantItem(build_const(cx, did))
         }
         Res::Def(DefKind::Macro(kind), did) => {
-            let mac = build_macro(cx, did, name, import_def_id);
+            let mac = build_macro(cx, did, name, import_def_id, kind);
 
             let type_kind = match kind {
                 MacroKind::Bang => ItemType::Macro,
@@ -149,7 +124,7 @@ pub(crate) fn try_inline(
         _ => return None,
     };
 
-    let (attrs, cfg) = merge_attrs(cx, Some(parent_module), load_attrs(cx, did), attrs);
+    let (attrs, cfg) = merge_attrs(cx, load_attrs(cx, did), attrs);
     cx.inlined.insert(did.into());
     let mut item =
         clean::Item::from_def_id_and_attrs_and_parts(did, Some(name), kind, Box::new(attrs), cfg);
@@ -177,8 +152,7 @@ pub(crate) fn try_inline_glob(
             // reexported by the glob, e.g. because they are shadowed by something else.
             let reexports = cx
                 .tcx
-                .module_reexports(current_mod)
-                .unwrap_or_default()
+                .module_children_reexports(current_mod)
                 .iter()
                 .filter_map(|child| child.res.opt_def_id())
                 .collect();
@@ -316,9 +290,8 @@ fn build_type_alias(cx: &mut DocContext<'_>, did: DefId) -> Box<clean::Typedef>
 /// Builds all inherent implementations of an ADT (struct/union/enum) or Trait item/path/reexport.
 pub(crate) fn build_impls(
     cx: &mut DocContext<'_>,
-    parent_module: Option<DefId>,
     did: DefId,
-    attrs: Option<&[ast::Attribute]>,
+    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
     ret: &mut Vec<clean::Item>,
 ) {
     let _prof_timer = cx.tcx.sess.prof.generic_activity("build_inherent_impls");
@@ -326,7 +299,7 @@ pub(crate) fn build_impls(
 
     // for each implementation of an item represented by `did`, build the clean::Item for that impl
     for &did in tcx.inherent_impls(did).iter() {
-        build_impl(cx, parent_module, did, attrs, ret);
+        build_impl(cx, did, attrs, ret);
     }
 
     // This pretty much exists expressly for `dyn Error` traits that exist in the `alloc` crate.
@@ -340,28 +313,26 @@ pub(crate) fn build_impls(
         let type_ =
             if tcx.is_trait(did) { TraitSimplifiedType(did) } else { AdtSimplifiedType(did) };
         for &did in tcx.incoherent_impls(type_) {
-            build_impl(cx, parent_module, did, attrs, ret);
+            build_impl(cx, did, attrs, ret);
         }
     }
 }
 
-/// `parent_module` refers to the parent of the re-export, not the original item
 pub(crate) fn merge_attrs(
     cx: &mut DocContext<'_>,
-    parent_module: Option<DefId>,
     old_attrs: &[ast::Attribute],
-    new_attrs: Option<&[ast::Attribute]>,
+    new_attrs: Option<(&[ast::Attribute], Option<DefId>)>,
 ) -> (clean::Attributes, Option<Arc<clean::cfg::Cfg>>) {
     // NOTE: If we have additional attributes (from a re-export),
     // always insert them first. This ensure that re-export
     // doc comments show up before the original doc comments
     // when we render them.
-    if let Some(inner) = new_attrs {
+    if let Some((inner, item_id)) = new_attrs {
         let mut both = inner.to_vec();
         both.extend_from_slice(old_attrs);
         (
-            if let Some(new_id) = parent_module {
-                Attributes::from_ast_with_additional(old_attrs, (inner, new_id))
+            if let Some(item_id) = item_id {
+                Attributes::from_ast_with_additional(old_attrs, (inner, item_id))
             } else {
                 Attributes::from_ast(&both)
             },
@@ -375,9 +346,8 @@ pub(crate) fn merge_attrs(
 /// Inline an `impl`, inherent or of a trait. The `did` must be for an `impl`.
 pub(crate) fn build_impl(
     cx: &mut DocContext<'_>,
-    parent_module: Option<DefId>,
     did: DefId,
-    attrs: Option<&[ast::Attribute]>,
+    attrs: Option<(&[ast::Attribute], Option<DefId>)>,
     ret: &mut Vec<clean::Item>,
 ) {
     if !cx.inlined.insert(did.into()) {
@@ -539,7 +509,7 @@ pub(crate) fn build_impl(
         record_extern_trait(cx, did);
     }
 
-    let (merged_attrs, cfg) = merge_attrs(cx, parent_module, load_attrs(cx, did), attrs);
+    let (merged_attrs, cfg) = merge_attrs(cx, load_attrs(cx, did), attrs);
     trace!("merged_attrs={:?}", merged_attrs);
 
     trace!(
@@ -587,7 +557,7 @@ fn build_module_items(
     // If we're re-exporting a re-export it may actually re-export something in
     // two namespaces, so the target may be listed twice. Make sure we only
     // visit each node at most once.
-    for &item in cx.tcx.module_children(did).iter() {
+    for item in cx.tcx.module_children(did).iter() {
         if item.vis.is_public() {
             let res = item.res.expect_non_local();
             if let Some(def_id) = res.opt_def_id()
@@ -635,7 +605,7 @@ fn build_module_items(
                     cfg: None,
                     inline_stmt_id: None,
                 });
-            } else if let Some(i) = try_inline(cx, did, None, res, item.ident.name, None, visited) {
+            } else if let Some(i) = try_inline(cx, res, item.ident.name, None, visited) {
                 items.extend(i)
             }
         }
@@ -681,18 +651,24 @@ fn build_macro(
     def_id: DefId,
     name: Symbol,
     import_def_id: Option<DefId>,
+    macro_kind: MacroKind,
 ) -> clean::ItemKind {
     match CStore::from_tcx(cx.tcx).load_macro_untracked(def_id, cx.sess()) {
-        LoadedMacro::MacroDef(item_def, _) => {
-            if let ast::ItemKind::MacroDef(ref def) = item_def.kind {
-                let vis = cx.tcx.visibility(import_def_id.unwrap_or(def_id));
-                clean::MacroItem(clean::Macro {
-                    source: utils::display_macro_source(cx, name, def, def_id, vis),
-                })
-            } else {
-                unreachable!()
+        LoadedMacro::MacroDef(item_def, _) => match macro_kind {
+            MacroKind::Bang => {
+                if let ast::ItemKind::MacroDef(ref def) = item_def.kind {
+                    let vis = cx.tcx.visibility(import_def_id.unwrap_or(def_id));
+                    clean::MacroItem(clean::Macro {
+                        source: utils::display_macro_source(cx, name, def, def_id, vis),
+                    })
+                } else {
+                    unreachable!()
+                }
             }
-        }
+            MacroKind::Derive | MacroKind::Attr => {
+                clean::ProcMacroItem(clean::ProcMacro { kind: macro_kind, helpers: Vec::new() })
+            }
+        },
         LoadedMacro::ProcMacro(ext) => clean::ProcMacroItem(clean::ProcMacro {
             kind: ext.macro_kind(),
             helpers: ext.helper_attrs,
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 3edc2cd2e..5fa0c120f 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -21,25 +21,24 @@ use rustc_hir::def_id::{DefId, DefIdMap, DefIdSet, LocalDefId, LOCAL_CRATE};
 use rustc_hir::PredicateOrigin;
 use rustc_hir_analysis::hir_ty_to_ty;
 use rustc_infer::infer::region_constraints::{Constraint, RegionConstraintData};
+use rustc_middle::metadata::Reexport;
 use rustc_middle::middle::resolve_bound_vars as rbv;
 use rustc_middle::ty::fold::TypeFolder;
 use rustc_middle::ty::InternalSubsts;
 use rustc_middle::ty::TypeVisitableExt;
-use rustc_middle::ty::{self, AdtKind, DefIdTree, EarlyBinder, Ty, TyCtxt};
+use rustc_middle::ty::{self, AdtKind, EarlyBinder, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_span::hygiene::{AstPass, MacroKind};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{self, ExpnKind};
 
-use std::assert_matches::assert_matches;
+use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 use std::collections::BTreeMap;
-use std::default::Default;
 use std::hash::Hash;
 use std::mem;
 use thin_vec::ThinVec;
 
-use crate::clean::inline::merge_attrs;
 use crate::core::{self, DocContext, ImplTraitParam};
 use crate::formats::item_type::ItemType;
 use crate::visit_ast::Module as DocModule;
@@ -270,15 +269,7 @@ fn clean_where_predicate<'tcx>(
             let bound_params = wbp
                 .bound_generic_params
                 .iter()
-                .map(|param| {
-                    // Higher-ranked params must be lifetimes.
-                    // Higher-ranked lifetimes can't have bounds.
-                    assert_matches!(
-                        param,
-                        hir::GenericParam { kind: hir::GenericParamKind::Lifetime { .. }, .. }
-                    );
-                    Lifetime(param.name.ident().name)
-                })
+                .map(|param| clean_generic_param(cx, None, param))
                 .collect();
             WherePredicate::BoundPredicate {
                 ty: clean_ty(wbp.bounded_ty, cx),
@@ -324,7 +315,7 @@ pub(crate) fn clean_predicate<'tcx>(
         ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
         ty::PredicateKind::Subtype(..)
-        | ty::PredicateKind::AliasEq(..)
+        | ty::PredicateKind::AliasRelate(..)
         | ty::PredicateKind::Coerce(..)
         | ty::PredicateKind::ObjectSafe(..)
         | ty::PredicateKind::ClosureKind(..)
@@ -410,7 +401,7 @@ fn clean_projection_predicate<'tcx>(
         .collect_referenced_late_bound_regions(&pred)
         .into_iter()
         .filter_map(|br| match br {
-            ty::BrNamed(_, name) if br.is_named() => Some(Lifetime(name)),
+            ty::BrNamed(_, name) if br.is_named() => Some(GenericParamDef::lifetime(name)),
             _ => None,
         })
         .collect();
@@ -427,7 +418,7 @@ fn clean_projection<'tcx>(
     cx: &mut DocContext<'tcx>,
     def_id: Option<DefId>,
 ) -> Type {
-    if cx.tcx.def_kind(ty.skip_binder().def_id) == DefKind::ImplTraitPlaceholder {
+    if cx.tcx.is_impl_trait_in_trait(ty.skip_binder().def_id) {
         let bounds = cx
             .tcx
             .explicit_item_bounds(ty.skip_binder().def_id)
@@ -508,7 +499,6 @@ fn clean_generic_param_def<'tcx>(
         ty::GenericParamDefKind::Const { has_default } => (
             def.name,
             GenericParamDefKind::Const {
-                did: def.def_id,
                 ty: Box::new(clean_middle_ty(
                     ty::Binder::dummy(
                         cx.tcx
@@ -578,7 +568,6 @@ fn clean_generic_param<'tcx>(
         hir::GenericParamKind::Const { ty, default } => (
             param.name.ident().name,
             GenericParamDefKind::Const {
-                did: param.def_id.to_def_id(),
                 ty: Box::new(clean_ty(ty, cx)),
                 default: default
                     .map(|ct| Box::new(ty::Const::from_anon_const(cx.tcx, ct.def_id).to_string())),
@@ -831,7 +820,7 @@ fn clean_ty_generics<'tcx>(
                         p.get_bound_params()
                             .into_iter()
                             .flatten()
-                            .map(|param| GenericParamDef::lifetime(param.0))
+                            .cloned()
                             .collect(),
                     ));
                 }
@@ -919,6 +908,38 @@ fn clean_ty_generics<'tcx>(
     }
 }
 
+fn clean_proc_macro<'tcx>(
+    item: &hir::Item<'tcx>,
+    name: &mut Symbol,
+    kind: MacroKind,
+    cx: &mut DocContext<'tcx>,
+) -> ItemKind {
+    let attrs = cx.tcx.hir().attrs(item.hir_id());
+    if kind == MacroKind::Derive &&
+        let Some(derive_name) = attrs
+            .lists(sym::proc_macro_derive)
+            .find_map(|mi| mi.ident())
+    {
+        *name = derive_name.name;
+    }
+
+    let mut helpers = Vec::new();
+    for mi in attrs.lists(sym::proc_macro_derive) {
+        if !mi.has_name(sym::attributes) {
+            continue;
+        }
+
+        if let Some(list) = mi.meta_item_list() {
+            for inner_mi in list {
+                if let Some(ident) = inner_mi.ident() {
+                    helpers.push(ident.name);
+                }
+            }
+        }
+    }
+    ProcMacroItem(ProcMacro { kind, helpers })
+}
+
 fn clean_fn_or_proc_macro<'tcx>(
     item: &hir::Item<'tcx>,
     sig: &hir::FnSig<'tcx>,
@@ -940,31 +961,7 @@ fn clean_fn_or_proc_macro<'tcx>(
         }
     });
     match macro_kind {
-        Some(kind) => {
-            if kind == MacroKind::Derive {
-                *name = attrs
-                    .lists(sym::proc_macro_derive)
-                    .find_map(|mi| mi.ident())
-                    .expect("proc-macro derives require a name")
-                    .name;
-            }
-
-            let mut helpers = Vec::new();
-            for mi in attrs.lists(sym::proc_macro_derive) {
-                if !mi.has_name(sym::attributes) {
-                    continue;
-                }
-
-                if let Some(list) = mi.meta_item_list() {
-                    for inner_mi in list {
-                        if let Some(ident) = inner_mi.ident() {
-                            helpers.push(ident.name);
-                        }
-                    }
-                }
-            }
-            ProcMacroItem(ProcMacro { kind, helpers })
-        }
+        Some(kind) => clean_proc_macro(item, name, kind, cx),
         None => {
             let mut func = clean_function(cx, sig, generics, FunctionArgs::Body(body_id));
             clean_fn_decl_legacy_const_generics(&mut func, attrs);
@@ -2013,7 +2010,8 @@ fn clean_generic_args<'tcx>(
     generic_args: &hir::GenericArgs<'tcx>,
     cx: &mut DocContext<'tcx>,
 ) -> GenericArgs {
-    if generic_args.parenthesized {
+    // FIXME(return_type_notation): Fix RTN parens rendering
+    if generic_args.parenthesized == hir::GenericArgsParentheses::ParenSugar {
         let output = clean_ty(generic_args.bindings[0].ty(), cx);
         let output = if output != Type::Tuple(Vec::new()) { Some(Box::new(output)) } else { None };
         let inputs =
@@ -2066,110 +2064,44 @@ fn clean_bare_fn_ty<'tcx>(
     BareFunctionDecl { unsafety: bare_fn.unsafety, abi: bare_fn.abi, decl, generic_params }
 }
 
-/// This visitor is used to go through only the "top level" of a item and not enter any sub
-/// item while looking for a given `Ident` which is stored into `item` if found.
-struct OneLevelVisitor<'hir> {
-    map: rustc_middle::hir::map::Map<'hir>,
-    item: Option<&'hir hir::Item<'hir>>,
-    looking_for: Ident,
+pub(crate) fn reexport_chain<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    import_def_id: LocalDefId,
     target_def_id: LocalDefId,
-}
-
-impl<'hir> OneLevelVisitor<'hir> {
-    fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
-        Self { map, item: None, looking_for: Ident::empty(), target_def_id }
-    }
-
-    fn reset(&mut self, looking_for: Ident) {
-        self.looking_for = looking_for;
-        self.item = None;
-    }
-}
-
-impl<'hir> hir::intravisit::Visitor<'hir> for OneLevelVisitor<'hir> {
-    type NestedFilter = rustc_middle::hir::nested_filter::All;
-
-    fn nested_visit_map(&mut self) -> Self::Map {
-        self.map
-    }
-
-    fn visit_item(&mut self, item: &'hir hir::Item<'hir>) {
-        if self.item.is_none()
-            && item.ident == self.looking_for
-            && (matches!(item.kind, hir::ItemKind::Use(_, _))
-                || item.owner_id.def_id == self.target_def_id)
+) -> &'tcx [Reexport] {
+    for child in tcx.module_children_reexports(tcx.local_parent(import_def_id)) {
+        if child.res.opt_def_id() == Some(target_def_id.to_def_id())
+            && child.reexport_chain[0].id() == Some(import_def_id.to_def_id())
         {
-            self.item = Some(item);
+            return &child.reexport_chain;
         }
     }
+    &[]
 }
 
-/// Because a `Use` item directly links to the imported item, we need to manually go through each
-/// import one by one. To do so, we go to the parent item and look for the `Ident` into it. Then,
-/// if we found the "end item" (the imported one), we stop there because we don't need its
-/// documentation. Otherwise, we repeat the same operation until we find the "end item".
+/// Collect attributes from the whole import chain.
 fn get_all_import_attributes<'hir>(
-    mut item: &hir::Item<'hir>,
-    tcx: TyCtxt<'hir>,
+    cx: &mut DocContext<'hir>,
+    import_def_id: LocalDefId,
     target_def_id: LocalDefId,
-    attributes: &mut Vec<ast::Attribute>,
     is_inline: bool,
-) {
+) -> Vec<(Cow<'hir, ast::Attribute>, Option<DefId>)> {
+    let mut attrs = Vec::new();
     let mut first = true;
-    let hir_map = tcx.hir();
-    let mut visitor = OneLevelVisitor::new(hir_map, target_def_id);
-    let mut visited = FxHashSet::default();
-
-    // If the item is an import and has at least a path with two parts, we go into it.
-    while let hir::ItemKind::Use(path, _) = item.kind && visited.insert(item.hir_id()) {
+    for def_id in reexport_chain(cx.tcx, import_def_id, target_def_id)
+        .iter()
+        .flat_map(|reexport| reexport.id())
+    {
+        let import_attrs = inline::load_attrs(cx, def_id);
         if first {
             // This is the "original" reexport so we get all its attributes without filtering them.
-            attributes.extend_from_slice(hir_map.attrs(item.hir_id()));
+            attrs = import_attrs.iter().map(|attr| (Cow::Borrowed(attr), Some(def_id))).collect();
             first = false;
         } else {
-            add_without_unwanted_attributes(attributes, hir_map.attrs(item.hir_id()), is_inline);
-        }
-
-        let def_id = if let [.., parent_segment, _] = &path.segments {
-            match parent_segment.res {
-                hir::def::Res::Def(_, def_id) => def_id,
-                _ if parent_segment.ident.name == kw::Crate => {
-                    // In case the "parent" is the crate, it'll give `Res::Err` so we need to
-                    // circumvent it this way.
-                    tcx.parent(item.owner_id.def_id.to_def_id())
-                }
-                _ => break,
-            }
-        } else {
-            // If the path doesn't have a parent, then the parent is the current module.
-            tcx.parent(item.owner_id.def_id.to_def_id())
-        };
-
-        let Some(parent) = hir_map.get_if_local(def_id) else { break };
-
-        // We get the `Ident` we will be looking for into `item`.
-        let looking_for = path.segments[path.segments.len() - 1].ident;
-        visitor.reset(looking_for);
-
-        match parent {
-            hir::Node::Item(parent_item) => {
-                hir::intravisit::walk_item(&mut visitor, parent_item);
-            }
-            hir::Node::Crate(m) => {
-                hir::intravisit::walk_mod(
-                    &mut visitor,
-                    m,
-                    tcx.local_def_id_to_hir_id(def_id.as_local().unwrap()),
-                );
-            }
-            _ => break,
-        }
-        if let Some(i) = visitor.item {
-            item = i;
-        } else {
-            break;
+            add_without_unwanted_attributes(&mut attrs, import_attrs, is_inline, Some(def_id));
         }
     }
+    attrs
 }
 
 fn filter_tokens_from_list(
@@ -2215,17 +2147,24 @@ fn filter_tokens_from_list(
 /// * `doc(inline)`
 /// * `doc(no_inline)`
 /// * `doc(hidden)`
-fn add_without_unwanted_attributes(
-    attrs: &mut Vec<ast::Attribute>,
-    new_attrs: &[ast::Attribute],
+fn add_without_unwanted_attributes<'hir>(
+    attrs: &mut Vec<(Cow<'hir, ast::Attribute>, Option<DefId>)>,
+    new_attrs: &'hir [ast::Attribute],
     is_inline: bool,
+    import_parent: Option<DefId>,
 ) {
-    // If it's `#[doc(inline)]`, we don't want all attributes, otherwise we keep everything.
+    // If it's not `#[doc(inline)]`, we don't want all attributes, otherwise we keep everything.
     if !is_inline {
-        attrs.extend_from_slice(new_attrs);
+        for attr in new_attrs {
+            attrs.push((Cow::Borrowed(attr), import_parent));
+        }
         return;
     }
     for attr in new_attrs {
+        if matches!(attr.kind, ast::AttrKind::DocComment(..)) {
+            attrs.push((Cow::Borrowed(attr), import_parent));
+            continue;
+        }
         let mut attr = attr.clone();
         match attr.kind {
             ast::AttrKind::Normal(ref mut normal) => {
@@ -2252,18 +2191,15 @@ fn add_without_unwanted_attributes(
                                     )
                                 });
                             args.tokens = TokenStream::new(tokens);
-                            attrs.push(attr);
+                            attrs.push((Cow::Owned(attr), import_parent));
                         }
                         ast::AttrArgs::Empty | ast::AttrArgs::Eq(..) => {
-                            attrs.push(attr);
-                            continue;
+                            attrs.push((Cow::Owned(attr), import_parent));
                         }
                     }
                 }
             }
-            ast::AttrKind::DocComment(..) => {
-                attrs.push(attr);
-            }
+            _ => unreachable!(),
         }
     }
 }
@@ -2318,16 +2254,17 @@ fn clean_maybe_renamed_item<'tcx>(
                 fields: variant_data.fields().iter().map(|x| clean_field(x, cx)).collect(),
             }),
             ItemKind::Impl(impl_) => return clean_impl(impl_, item.owner_id.def_id, cx),
-            // proc macros can have a name set by attributes
-            ItemKind::Fn(ref sig, generics, body_id) => {
-                clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
-            }
-            ItemKind::Macro(ref macro_def, _) => {
+            ItemKind::Macro(ref macro_def, MacroKind::Bang) => {
                 let ty_vis = cx.tcx.visibility(def_id);
                 MacroItem(Macro {
                     source: display_macro_source(cx, name, macro_def, def_id, ty_vis),
                 })
             }
+            ItemKind::Macro(_, macro_kind) => clean_proc_macro(item, &mut name, macro_kind, cx),
+            // proc macros can have a name set by attributes
+            ItemKind::Fn(ref sig, generics, body_id) => {
+                clean_fn_or_proc_macro(item, sig, generics, body_id, &mut name, cx)
+            }
             ItemKind::Trait(_, _, generics, bounds, item_ids) => {
                 let items = item_ids
                     .iter()
@@ -2350,26 +2287,28 @@ fn clean_maybe_renamed_item<'tcx>(
             _ => unreachable!("not yet converted"),
         };
 
-        let mut import_attrs = Vec::new();
-        let mut target_attrs = Vec::new();
-        if let Some(import_id) = import_id &&
-            let Some(hir::Node::Item(use_node)) = cx.tcx.hir().find_by_def_id(import_id)
-        {
-            let is_inline = inline::load_attrs(cx, import_id.to_def_id()).lists(sym::doc).get_word_attr(sym::inline).is_some();
-            // Then we get all the various imports' attributes.
-            get_all_import_attributes(use_node, cx.tcx, item.owner_id.def_id, &mut import_attrs, is_inline);
-            add_without_unwanted_attributes(&mut target_attrs, inline::load_attrs(cx, def_id), is_inline);
+        let target_attrs = inline::load_attrs(cx, def_id);
+        let attrs = if let Some(import_id) = import_id {
+            let is_inline = inline::load_attrs(cx, import_id.to_def_id())
+                .lists(sym::doc)
+                .get_word_attr(sym::inline)
+                .is_some();
+            let mut attrs =
+                get_all_import_attributes(cx, import_id, item.owner_id.def_id, is_inline);
+            add_without_unwanted_attributes(&mut attrs, target_attrs, is_inline, None);
+            attrs
         } else {
             // We only keep the item's attributes.
-            target_attrs.extend_from_slice(inline::load_attrs(cx, def_id));
-        }
+            target_attrs.iter().map(|attr| (Cow::Borrowed(attr), None)).collect()
+        };
 
-        let import_parent = import_id.map(|import_id| cx.tcx.local_parent(import_id).to_def_id());
-        let (attrs, cfg) =  merge_attrs(cx, import_parent, &target_attrs, Some(&import_attrs));
+        let cfg = attrs.cfg(cx.tcx, &cx.cache.hidden_cfg);
+        let attrs =
+            Attributes::from_ast_iter(attrs.iter().map(|(attr, did)| (&**attr, *did)), false);
 
         let mut item =
             Item::from_def_id_and_attrs_and_parts(def_id, Some(name), kind, Box::new(attrs), cfg);
-        item.inline_stmt_id = import_id.map(|def_id| def_id.to_def_id());
+        item.inline_stmt_id = import_id.map(|local| local.to_def_id());
         vec![item]
     })
 }
@@ -2450,22 +2389,17 @@ fn clean_extern_crate<'tcx>(
                     Some(l) => attr::list_contains_name(&l, sym::inline),
                     None => false,
                 }
-        });
+        })
+        && !cx.output_format.is_json();
 
     let krate_owner_def_id = krate.owner_id.to_def_id();
     if please_inline {
-        let mut visited = DefIdSet::default();
-
-        let res = Res::Def(DefKind::Mod, crate_def_id);
-
         if let Some(items) = inline::try_inline(
             cx,
-            cx.tcx.parent_module(krate.hir_id()).to_def_id(),
-            Some(krate_owner_def_id),
-            res,
+            Res::Def(DefKind::Mod, crate_def_id),
             name,
-            Some(attrs),
-            &mut visited,
+            Some((attrs, Some(krate_owner_def_id))),
+            &mut Default::default(),
         ) {
             return items;
         }
@@ -2589,17 +2523,13 @@ fn clean_use_statement_inner<'tcx>(
             denied = true;
         }
         if !denied {
-            let mut visited = DefIdSet::default();
             let import_def_id = import.owner_id.to_def_id();
-
             if let Some(mut items) = inline::try_inline(
                 cx,
-                cx.tcx.parent_module(import.hir_id()).to_def_id(),
-                Some(import_def_id),
                 path.res,
                 name,
-                Some(attrs),
-                &mut visited,
+                Some((attrs, Some(import_def_id))),
+                &mut Default::default(),
             ) {
                 items.push(Item::from_def_id_and_parts(
                     import_def_id,
diff --git a/src/librustdoc/clean/simplify.rs b/src/librustdoc/clean/simplify.rs
index dbbc25739..3c72b0bf9 100644
--- a/src/librustdoc/clean/simplify.rs
+++ b/src/librustdoc/clean/simplify.rs
@@ -49,11 +49,7 @@ pub(crate) fn where_clauses(cx: &DocContext<'_>, clauses: Vec<WP>) -> ThinVec<WP
     equalities.retain(|(lhs, rhs, bound_params)| {
         let Some((ty, trait_did, name)) = lhs.projection() else { return true; };
         let Some((bounds, _)) = tybounds.get_mut(ty) else { return true };
-        let bound_params = bound_params
-            .into_iter()
-            .map(|param| clean::GenericParamDef::lifetime(param.0))
-            .collect();
-        merge_bounds(cx, bounds, bound_params, trait_did, name, rhs)
+        merge_bounds(cx, bounds, bound_params.clone(), trait_did, name, rhs)
     });
 
     // And finally, let's reassemble everything
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 27d18aad7..6d2ce9e28 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1,5 +1,5 @@
+use std::borrow::Cow;
 use std::cell::RefCell;
-use std::default::Default;
 use std::hash::Hash;
 use std::path::PathBuf;
 use std::rc::Rc;
@@ -22,7 +22,7 @@ use rustc_hir::{BodyId, Mutability};
 use rustc_hir_analysis::check::intrinsic::intrinsic_operation_unsafety;
 use rustc_index::vec::IndexVec;
 use rustc_middle::ty::fast_reject::SimplifiedType;
-use rustc_middle::ty::{self, DefIdTree, TyCtxt, Visibility};
+use rustc_middle::ty::{self, TyCtxt, Visibility};
 use rustc_resolve::rustdoc::{add_doc_fragment, attrs_to_doc_fragments, inner_docs, DocFragment};
 use rustc_session::Session;
 use rustc_span::hygiene::MacroKind;
@@ -231,14 +231,6 @@ impl ExternalCrate {
                         hir::ItemKind::Mod(_) => {
                             as_keyword(Res::Def(DefKind::Mod, id.owner_id.to_def_id()))
                         }
-                        hir::ItemKind::Use(path, hir::UseKind::Single)
-                            if tcx.visibility(id.owner_id).is_public() =>
-                        {
-                            path.res
-                                .iter()
-                                .find_map(|res| as_keyword(res.expect_non_local()))
-                                .map(|(_, prim)| (id.owner_id.to_def_id(), prim))
-                        }
                         _ => None,
                     }
                 })
@@ -256,38 +248,24 @@ impl ExternalCrate {
         //
         // Note that this loop only searches the top-level items of the crate,
         // and this is intentional. If we were to search the entire crate for an
-        // item tagged with `#[doc(primitive)]` then we would also have to
+        // item tagged with `#[rustc_doc_primitive]` then we would also have to
         // search the entirety of external modules for items tagged
-        // `#[doc(primitive)]`, which is a pretty inefficient process (decoding
+        // `#[rustc_doc_primitive]`, which is a pretty inefficient process (decoding
         // all that metadata unconditionally).
         //
         // In order to keep the metadata load under control, the
-        // `#[doc(primitive)]` feature is explicitly designed to only allow the
+        // `#[rustc_doc_primitive]` feature is explicitly designed to only allow the
         // primitive tags to show up as the top level items in a crate.
         //
         // Also note that this does not attempt to deal with modules tagged
         // duplicately for the same primitive. This is handled later on when
         // rendering by delegating everything to a hash map.
         let as_primitive = |res: Res<!>| {
-            if let Res::Def(DefKind::Mod, def_id) = res {
-                let mut prim = None;
-                let meta_items = tcx
-                    .get_attrs(def_id, sym::doc)
-                    .flat_map(|attr| attr.meta_item_list().unwrap_or_default());
-                for meta in meta_items {
-                    if let Some(v) = meta.value_str() {
-                        if meta.has_name(sym::primitive) {
-                            prim = PrimitiveType::from_symbol(v);
-                            if prim.is_some() {
-                                break;
-                            }
-                            // FIXME: should warn on unknown primitives?
-                        }
-                    }
-                }
-                return prim.map(|p| (def_id, p));
-            }
-            None
+            let Res::Def(DefKind::Mod, def_id) = res else { return None };
+            tcx.get_attrs(def_id, sym::rustc_doc_primitive).find_map(|attr| {
+                // FIXME: should warn on unknown primitives?
+                Some((def_id, PrimitiveType::from_symbol(attr.value_str()?)?))
+            })
         };
 
         if root.is_local() {
@@ -301,15 +279,6 @@ impl ExternalCrate {
                         hir::ItemKind::Mod(_) => {
                             as_primitive(Res::Def(DefKind::Mod, id.owner_id.to_def_id()))
                         }
-                        hir::ItemKind::Use(path, hir::UseKind::Single)
-                            if tcx.visibility(id.owner_id).is_public() =>
-                        {
-                            path.res
-                                .iter()
-                                .find_map(|res| as_primitive(res.expect_non_local()))
-                                // Pretend the primitive is local.
-                                .map(|(_, prim)| (id.owner_id.to_def_id(), prim))
-                        }
                         _ => None,
                     }
                 })
@@ -482,10 +451,12 @@ impl Item {
     pub(crate) fn links(&self, cx: &Context<'_>) -> Vec<RenderedLink> {
         use crate::html::format::{href, link_tooltip};
 
-        cx.cache()
+        let Some(links) = cx.cache()
             .intra_doc_links
-            .get(&self.item_id)
-            .map_or(&[][..], |v| v.as_slice())
+            .get(&self.item_id) else {
+                return vec![]
+            };
+        links
             .iter()
             .filter_map(|ItemLink { link: s, link_text, page_id: id, ref fragment }| {
                 debug!(?id);
@@ -513,10 +484,12 @@ impl Item {
     /// the link text, but does need to know which `[]`-bracketed names
     /// are actually links.
     pub(crate) fn link_names(&self, cache: &Cache) -> Vec<RenderedLink> {
-        cache
+        let Some(links) = cache
             .intra_doc_links
-            .get(&self.item_id)
-            .map_or(&[][..], |v| v.as_slice())
+            .get(&self.item_id) else {
+                return vec![];
+            };
+        links
             .iter()
             .map(|ItemLink { link: s, link_text, .. }| RenderedLink {
                 original_text: s.clone(),
@@ -713,7 +686,7 @@ impl Item {
                 return None;
             }
             // Variants always inherit visibility
-            VariantItem(..) => return None,
+            VariantItem(..) | ImplItem(..) => return None,
             // Trait items inherit the trait's visibility
             AssocConstItem(..) | TyAssocConstItem(..) | AssocTypeItem(..) | TyAssocTypeItem(..)
             | TyMethodItem(..) | MethodItem(..) => {
@@ -869,28 +842,13 @@ pub(crate) trait AttributesExt {
     type AttributeIterator<'a>: Iterator<Item = ast::NestedMetaItem>
     where
         Self: 'a;
+    type Attributes<'a>: Iterator<Item = &'a ast::Attribute>
+    where
+        Self: 'a;
 
     fn lists<'a>(&'a self, name: Symbol) -> Self::AttributeIterator<'a>;
 
-    fn span(&self) -> Option<rustc_span::Span>;
-
-    fn cfg(&self, tcx: TyCtxt<'_>, hidden_cfg: &FxHashSet<Cfg>) -> Option<Arc<Cfg>>;
-}
-
-impl AttributesExt for [ast::Attribute] {
-    type AttributeIterator<'a> = impl Iterator<Item = ast::NestedMetaItem> + 'a;
-
-    fn lists<'a>(&'a self, name: Symbol) -> Self::AttributeIterator<'a> {
-        self.iter()
-            .filter(move |attr| attr.has_name(name))
-            .filter_map(ast::Attribute::meta_item_list)
-            .flatten()
-    }
-
-    /// Return the span of the first doc-comment, if it exists.
-    fn span(&self) -> Option<rustc_span::Span> {
-        self.iter().find(|attr| attr.doc_str().is_some()).map(|attr| attr.span)
-    }
+    fn iter<'a>(&'a self) -> Self::Attributes<'a>;
 
     fn cfg(&self, tcx: TyCtxt<'_>, hidden_cfg: &FxHashSet<Cfg>) -> Option<Arc<Cfg>> {
         let sess = tcx.sess;
@@ -980,11 +938,48 @@ impl AttributesExt for [ast::Attribute] {
     }
 }
 
+impl AttributesExt for [ast::Attribute] {
+    type AttributeIterator<'a> = impl Iterator<Item = ast::NestedMetaItem> + 'a;
+    type Attributes<'a> = impl Iterator<Item = &'a ast::Attribute> + 'a;
+
+    fn lists<'a>(&'a self, name: Symbol) -> Self::AttributeIterator<'a> {
+        self.iter()
+            .filter(move |attr| attr.has_name(name))
+            .filter_map(ast::Attribute::meta_item_list)
+            .flatten()
+    }
+
+    fn iter<'a>(&'a self) -> Self::Attributes<'a> {
+        self.into_iter()
+    }
+}
+
+impl AttributesExt for [(Cow<'_, ast::Attribute>, Option<DefId>)] {
+    type AttributeIterator<'a> = impl Iterator<Item = ast::NestedMetaItem> + 'a
+        where Self: 'a;
+    type Attributes<'a> = impl Iterator<Item = &'a ast::Attribute> + 'a
+        where Self: 'a;
+
+    fn lists<'a>(&'a self, name: Symbol) -> Self::AttributeIterator<'a> {
+        AttributesExt::iter(self)
+            .filter(move |attr| attr.has_name(name))
+            .filter_map(ast::Attribute::meta_item_list)
+            .flatten()
+    }
+
+    fn iter<'a>(&'a self) -> Self::Attributes<'a> {
+        self.into_iter().map(move |(attr, _)| match attr {
+            Cow::Borrowed(attr) => *attr,
+            Cow::Owned(attr) => attr,
+        })
+    }
+}
+
 pub(crate) trait NestedAttributesExt {
     /// Returns `true` if the attribute list contains a specific `word`
     fn has_word(self, word: Symbol) -> bool
     where
-        Self: std::marker::Sized,
+        Self: Sized,
     {
         <Self as NestedAttributesExt>::get_word_attr(self, word).is_some()
     }
@@ -1014,7 +1009,7 @@ pub(crate) fn collapse_doc_fragments(doc_strings: &[DocFragment]) -> String {
 /// A link that has not yet been rendered.
 ///
 /// This link will be turned into a rendered link by [`Item::links`].
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub(crate) struct ItemLink {
     /// The original link written in the markdown
     pub(crate) link: Box<str>,
@@ -1213,9 +1208,9 @@ impl Lifetime {
 
 #[derive(Clone, Debug)]
 pub(crate) enum WherePredicate {
-    BoundPredicate { ty: Type, bounds: Vec<GenericBound>, bound_params: Vec<Lifetime> },
+    BoundPredicate { ty: Type, bounds: Vec<GenericBound>, bound_params: Vec<GenericParamDef> },
     RegionPredicate { lifetime: Lifetime, bounds: Vec<GenericBound> },
-    EqPredicate { lhs: Box<Type>, rhs: Box<Term>, bound_params: Vec<Lifetime> },
+    EqPredicate { lhs: Box<Type>, rhs: Box<Term>, bound_params: Vec<GenericParamDef> },
 }
 
 impl WherePredicate {
@@ -1227,7 +1222,7 @@ impl WherePredicate {
         }
     }
 
-    pub(crate) fn get_bound_params(&self) -> Option<&[Lifetime]> {
+    pub(crate) fn get_bound_params(&self) -> Option<&[GenericParamDef]> {
         match self {
             Self::BoundPredicate { bound_params, .. } | Self::EqPredicate { bound_params, .. } => {
                 Some(bound_params)
@@ -1241,7 +1236,7 @@ impl WherePredicate {
 pub(crate) enum GenericParamDefKind {
     Lifetime { outlives: Vec<Lifetime> },
     Type { did: DefId, bounds: Vec<GenericBound>, default: Option<Box<Type>>, synthetic: bool },
-    Const { did: DefId, ty: Box<Type>, default: Option<Box<String>> },
+    Const { ty: Box<Type>, default: Option<Box<String>> },
 }
 
 impl GenericParamDefKind {
@@ -1471,27 +1466,68 @@ impl Type {
         result
     }
 
-    /// Check if two types are "potentially the same".
+    pub(crate) fn is_borrowed_ref(&self) -> bool {
+        matches!(self, Type::BorrowedRef { .. })
+    }
+
+    /// Check if two types are "the same" for documentation purposes.
+    ///
     /// This is different from `Eq`, because it knows that things like
     /// `Placeholder` are possible matches for everything.
-    pub(crate) fn is_same(&self, other: &Self, cache: &Cache) -> bool {
-        match (self, other) {
+    ///
+    /// This relation is not commutative when generics are involved:
+    ///
+    /// ```ignore(private)
+    /// # // see types/tests.rs:is_same_generic for the real test
+    /// use rustdoc::format::cache::Cache;
+    /// use rustdoc::clean::types::{Type, PrimitiveType};
+    /// let cache = Cache::new(false);
+    /// let generic = Type::Generic(rustc_span::symbol::sym::Any);
+    /// let unit = Type::Primitive(PrimitiveType::Unit);
+    /// assert!(!generic.is_same(&unit, &cache));
+    /// assert!(unit.is_same(&generic, &cache));
+    /// ```
+    ///
+    /// An owned type is also the same as its borrowed variants (this is commutative),
+    /// but `&T` is not the same as `&mut T`.
+    pub(crate) fn is_doc_subtype_of(&self, other: &Self, cache: &Cache) -> bool {
+        // Strip the references so that it can compare the actual types, unless both are references.
+        // If both are references, leave them alone and compare the mutabilities later.
+        let (self_cleared, other_cleared) = if !self.is_borrowed_ref() || !other.is_borrowed_ref() {
+            (self.without_borrowed_ref(), other.without_borrowed_ref())
+        } else {
+            (self, other)
+        };
+        match (self_cleared, other_cleared) {
             // Recursive cases.
             (Type::Tuple(a), Type::Tuple(b)) => {
-                a.len() == b.len() && a.iter().zip(b).all(|(a, b)| a.is_same(b, cache))
+                a.len() == b.len() && a.iter().zip(b).all(|(a, b)| a.is_doc_subtype_of(b, cache))
             }
-            (Type::Slice(a), Type::Slice(b)) => a.is_same(b, cache),
-            (Type::Array(a, al), Type::Array(b, bl)) => al == bl && a.is_same(b, cache),
+            (Type::Slice(a), Type::Slice(b)) => a.is_doc_subtype_of(b, cache),
+            (Type::Array(a, al), Type::Array(b, bl)) => al == bl && a.is_doc_subtype_of(b, cache),
             (Type::RawPointer(mutability, type_), Type::RawPointer(b_mutability, b_type_)) => {
-                mutability == b_mutability && type_.is_same(b_type_, cache)
+                mutability == b_mutability && type_.is_doc_subtype_of(b_type_, cache)
             }
             (
                 Type::BorrowedRef { mutability, type_, .. },
                 Type::BorrowedRef { mutability: b_mutability, type_: b_type_, .. },
-            ) => mutability == b_mutability && type_.is_same(b_type_, cache),
-            // Placeholders and generics are equal to all other types.
+            ) => mutability == b_mutability && type_.is_doc_subtype_of(b_type_, cache),
+            // Placeholders are equal to all other types.
             (Type::Infer, _) | (_, Type::Infer) => true,
-            (Type::Generic(_), _) | (_, Type::Generic(_)) => true,
+            // Generics match everything on the right, but not on the left.
+            // If both sides are generic, this returns true.
+            (_, Type::Generic(_)) => true,
+            (Type::Generic(_), _) => false,
+            // Paths account for both the path itself and its generics.
+            (Type::Path { path: a }, Type::Path { path: b }) => {
+                a.def_id() == b.def_id()
+                    && a.generics()
+                        .zip(b.generics())
+                        .map(|(ag, bg)| {
+                            ag.iter().zip(bg.iter()).all(|(at, bt)| at.is_doc_subtype_of(bt, cache))
+                        })
+                        .unwrap_or(true)
+            }
             // Other cases, such as primitives, just use recursion.
             (a, b) => a
                 .def_id(cache)
@@ -1782,13 +1818,17 @@ impl PrimitiveType {
         }
     }
 
-    /// Returns the DefId of the module with `doc(primitive)` for this primitive type.
+    /// Returns the DefId of the module with `rustc_doc_primitive` for this primitive type.
     /// Panics if there is no such module.
     ///
-    /// This gives precedence to primitives defined in the current crate, and deprioritizes primitives defined in `core`,
-    /// but otherwise, if multiple crates define the same primitive, there is no guarantee of which will be picked.
-    /// In particular, if a crate depends on both `std` and another crate that also defines `doc(primitive)`, then
-    /// it's entirely random whether `std` or the other crate is picked. (no_std crates are usually fine unless multiple dependencies define a primitive.)
+    /// This gives precedence to primitives defined in the current crate, and deprioritizes
+    /// primitives defined in `core`,
+    /// but otherwise, if multiple crates define the same primitive, there is no guarantee of which
+    /// will be picked.
+    ///
+    /// In particular, if a crate depends on both `std` and another crate that also defines
+    /// `rustc_doc_primitive`, then it's entirely random whether `std` or the other crate is picked.
+    /// (no_std crates are usually fine unless multiple dependencies define a primitive.)
     pub(crate) fn primitive_locations(tcx: TyCtxt<'_>) -> &FxHashMap<PrimitiveType, DefId> {
         static PRIMITIVE_LOCATIONS: OnceCell<FxHashMap<PrimitiveType, DefId>> = OnceCell::new();
         PRIMITIVE_LOCATIONS.get_or_init(|| {
@@ -1978,7 +2018,7 @@ impl Variant {
 
 #[derive(Clone, Debug)]
 pub(crate) struct Discriminant {
-    // In the case of cross crate re-exports, we don't have the nessesary information
+    // In the case of cross crate re-exports, we don't have the necessary information
     // to reconstruct the expression of the discriminant, only the value.
     pub(super) expr: Option<BodyId>,
     pub(super) value: DefId,
diff --git a/src/librustdoc/clean/types/tests.rs b/src/librustdoc/clean/types/tests.rs
index 20627c2cf..d8c91a968 100644
--- a/src/librustdoc/clean/types/tests.rs
+++ b/src/librustdoc/clean/types/tests.rs
@@ -10,7 +10,7 @@ use rustc_span::symbol::Symbol;
 fn create_doc_fragment(s: &str) -> Vec<DocFragment> {
     vec![DocFragment {
         span: DUMMY_SP,
-        parent_module: None,
+        item_id: None,
         doc: Symbol::intern(s),
         kind: DocFragmentKind::SugaredDoc,
         indent: 0,
@@ -69,3 +69,14 @@ fn should_not_trim() {
     run_test("\t    line1  \n\t    line2", "line1  \nline2");
     run_test("    \tline1  \n    \tline2", "line1  \nline2");
 }
+
+#[test]
+fn is_same_generic() {
+    use crate::clean::types::{PrimitiveType, Type};
+    use crate::formats::cache::Cache;
+    let cache = Cache::new(false);
+    let generic = Type::Generic(rustc_span::symbol::sym::Any);
+    let unit = Type::Primitive(PrimitiveType::Unit);
+    assert!(!generic.is_doc_subtype_of(&unit, &cache));
+    assert!(unit.is_doc_subtype_of(&generic, &cache));
+}
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index c9c1c2c45..cca50df0d 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -17,7 +17,7 @@ use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_middle::mir;
 use rustc_middle::mir::interpret::ConstValue;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
-use rustc_middle::ty::{self, DefIdTree, TyCtxt};
+use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::symbol::{kw, sym, Symbol};
 use std::fmt::Write as _;
 use std::mem;
@@ -195,12 +195,12 @@ pub(crate) fn build_deref_target_impls(
         if let Some(prim) = target.primitive_type() {
             let _prof_timer = cx.tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
             for did in prim.impls(tcx).filter(|did| !did.is_local()) {
-                inline::build_impl(cx, None, did, None, ret);
+                inline::build_impl(cx, did, None, ret);
             }
         } else if let Type::Path { path } = target {
             let did = path.def_id();
             if !did.is_local() {
-                inline::build_impls(cx, None, did, None, ret);
+                inline::build_impls(cx, did, None, ret);
             }
         }
     }