Merge from rustc

24 files changed, 675 insertions, 343 deletions

diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index cc86a3d7475..dd43ee03383 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -20,7 +20,8 @@ use rustc_span::symbol::{kw, sym, Symbol};
 use crate::clean::{
     self, clean_fn_decl_from_did_and_sig, clean_generics, clean_impl_item, clean_middle_assoc_item,
     clean_middle_field, clean_middle_ty, clean_trait_ref_with_bindings, clean_ty,
-    clean_ty_generics, clean_variant_def, utils, Attributes, AttributesExt, ImplKind, ItemId, Type,
+    clean_ty_alias_inner_type, clean_ty_generics, clean_variant_def, utils, Attributes,
+    AttributesExt, ImplKind, ItemId, Type,
 };
 use crate::core::DocContext;
 use crate::formats::item_type::ItemType;
@@ -289,16 +290,14 @@ fn build_union(cx: &mut DocContext<'_>, did: DefId) -> clean::Union {
 
 fn build_type_alias(cx: &mut DocContext<'_>, did: DefId) -> Box<clean::TypeAlias> {
     let predicates = cx.tcx.explicit_predicates_of(did);
-    let type_ = clean_middle_ty(
-        ty::Binder::dummy(cx.tcx.type_of(did).instantiate_identity()),
-        cx,
-        Some(did),
-        None,
-    );
+    let ty = cx.tcx.type_of(did).instantiate_identity();
+    let type_ = clean_middle_ty(ty::Binder::dummy(ty), cx, Some(did), None);
+    let inner_type = clean_ty_alias_inner_type(ty, cx);
 
     Box::new(clean::TypeAlias {
         type_,
         generics: clean_ty_generics(cx, cx.tcx.generics_of(did), predicates),
+        inner_type,
         item_type: None,
     })
 }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index b584c32a4c7..f30384701cb 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -24,6 +24,7 @@ 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::GenericArgsRef;
 use rustc_middle::ty::TypeVisitableExt;
 use rustc_middle::ty::{self, AdtKind, EarlyBinder, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
@@ -541,7 +542,7 @@ fn clean_generic_param_def<'tcx>(
                 },
             )
         }
-        ty::GenericParamDefKind::Const { has_default } => (
+        ty::GenericParamDefKind::Const { has_default, .. } => (
             def.name,
             GenericParamDefKind::Const {
                 ty: Box::new(clean_middle_ty(
@@ -955,6 +956,43 @@ fn clean_ty_generics<'tcx>(
     }
 }
 
+fn clean_ty_alias_inner_type<'tcx>(
+    ty: Ty<'tcx>,
+    cx: &mut DocContext<'tcx>,
+) -> Option<TypeAliasInnerType> {
+    let ty::Adt(adt_def, args) = ty.kind() else {
+        return None;
+    };
+
+    Some(if adt_def.is_enum() {
+        let variants: rustc_index::IndexVec<_, _> = adt_def
+            .variants()
+            .iter()
+            .map(|variant| clean_variant_def_with_args(variant, args, cx))
+            .collect();
+
+        TypeAliasInnerType::Enum {
+            variants,
+            is_non_exhaustive: adt_def.is_variant_list_non_exhaustive(),
+        }
+    } else {
+        let variant = adt_def
+            .variants()
+            .iter()
+            .next()
+            .unwrap_or_else(|| bug!("a struct or union should always have one variant def"));
+
+        let fields: Vec<_> =
+            clean_variant_def_with_args(variant, args, cx).kind.inner_items().cloned().collect();
+
+        if adt_def.is_struct() {
+            TypeAliasInnerType::Struct { ctor_kind: variant.ctor_kind(), fields }
+        } else {
+            TypeAliasInnerType::Union { fields }
+        }
+    })
+}
+
 fn clean_proc_macro<'tcx>(
     item: &hir::Item<'tcx>,
     name: &mut Symbol,
@@ -1222,6 +1260,7 @@ fn clean_trait_item<'tcx>(trait_item: &hir::TraitItem<'tcx>, cx: &mut DocContext
                     Box::new(TypeAlias {
                         type_: clean_ty(default, cx),
                         generics,
+                        inner_type: None,
                         item_type: Some(item_type),
                     }),
                     bounds,
@@ -1264,7 +1303,12 @@ pub(crate) fn clean_impl_item<'tcx>(
                     None,
                 );
                 AssocTypeItem(
-                    Box::new(TypeAlias { type_, generics, item_type: Some(item_type) }),
+                    Box::new(TypeAlias {
+                        type_,
+                        generics,
+                        inner_type: None,
+                        item_type: Some(item_type),
+                    }),
                     Vec::new(),
                 )
             }
@@ -1471,6 +1515,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                                 None,
                             ),
                             generics,
+                            inner_type: None,
                             item_type: None,
                         }),
                         bounds,
@@ -1490,6 +1535,7 @@ pub(crate) fn clean_middle_assoc_item<'tcx>(
                             None,
                         ),
                         generics,
+                        inner_type: None,
                         item_type: None,
                     }),
                     // Associated types inside trait or inherent impls are not allowed to have
@@ -2363,6 +2409,83 @@ pub(crate) fn clean_variant_def<'tcx>(variant: &ty::VariantDef, cx: &mut DocCont
     )
 }
 
+pub(crate) fn clean_variant_def_with_args<'tcx>(
+    variant: &ty::VariantDef,
+    args: &GenericArgsRef<'tcx>,
+    cx: &mut DocContext<'tcx>,
+) -> Item {
+    let discriminant = match variant.discr {
+        ty::VariantDiscr::Explicit(def_id) => Some(Discriminant { expr: None, value: def_id }),
+        ty::VariantDiscr::Relative(_) => None,
+    };
+
+    use rustc_middle::traits::ObligationCause;
+    use rustc_trait_selection::infer::TyCtxtInferExt;
+    use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
+
+    let infcx = cx.tcx.infer_ctxt().build();
+    let kind = match variant.ctor_kind() {
+        Some(CtorKind::Const) => VariantKind::CLike,
+        Some(CtorKind::Fn) => VariantKind::Tuple(
+            variant
+                .fields
+                .iter()
+                .map(|field| {
+                    let ty = cx.tcx.type_of(field.did).instantiate(cx.tcx, args);
+
+                    // normalize the type to only show concrete types
+                    // note: we do not use try_normalize_erasing_regions since we
+                    // do care about showing the regions
+                    let ty = infcx
+                        .at(&ObligationCause::dummy(), cx.param_env)
+                        .query_normalize(ty)
+                        .map(|normalized| normalized.value)
+                        .unwrap_or(ty);
+
+                    clean_field_with_def_id(
+                        field.did,
+                        field.name,
+                        clean_middle_ty(ty::Binder::dummy(ty), cx, Some(field.did), None),
+                        cx,
+                    )
+                })
+                .collect(),
+        ),
+        None => VariantKind::Struct(VariantStruct {
+            fields: variant
+                .fields
+                .iter()
+                .map(|field| {
+                    let ty = cx.tcx.type_of(field.did).instantiate(cx.tcx, args);
+
+                    // normalize the type to only show concrete types
+                    // note: we do not use try_normalize_erasing_regions since we
+                    // do care about showing the regions
+                    let ty = infcx
+                        .at(&ObligationCause::dummy(), cx.param_env)
+                        .query_normalize(ty)
+                        .map(|normalized| normalized.value)
+                        .unwrap_or(ty);
+
+                    clean_field_with_def_id(
+                        field.did,
+                        field.name,
+                        clean_middle_ty(ty::Binder::dummy(ty), cx, Some(field.did), None),
+                        cx,
+                    )
+                })
+                .collect(),
+        }),
+    };
+
+    Item::from_def_id_and_parts(
+        variant.def_id,
+        Some(variant.name),
+        VariantItem(Variant { kind, discriminant }),
+        cx,
+    )
+}
+
 fn clean_variant_data<'tcx>(
     variant: &hir::VariantData<'tcx>,
     disr_expr: &Option<hir::AnonConst>,
@@ -2617,7 +2740,7 @@ fn clean_maybe_renamed_item<'tcx>(
             ItemKind::TyAlias(hir_ty, generics) => {
                 *cx.current_type_aliases.entry(def_id).or_insert(0) += 1;
                 let rustdoc_ty = clean_ty(hir_ty, cx);
-                let ty = clean_middle_ty(
+                let type_ = clean_middle_ty(
                     ty::Binder::dummy(hir_ty_to_ty(cx.tcx, hir_ty)),
                     cx,
                     None,
@@ -2630,10 +2753,15 @@ fn clean_maybe_renamed_item<'tcx>(
                         cx.current_type_aliases.remove(&def_id);
                     }
                 }
+
+                let ty = cx.tcx.type_of(def_id).instantiate_identity();
+                let inner_type = clean_ty_alias_inner_type(ty, cx);
+
                 TypeAliasItem(Box::new(TypeAlias {
-                    type_: rustdoc_ty,
                     generics,
-                    item_type: Some(ty),
+                    inner_type,
+                    type_: rustdoc_ty,
+                    item_type: Some(type_),
                 }))
             }
             ItemKind::Enum(ref def, generics) => EnumItem(Enum {
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 9134d5268da..b276745f317 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -25,7 +25,9 @@ use rustc_index::IndexVec;
 use rustc_metadata::rendered_const;
 use rustc_middle::ty::fast_reject::SimplifiedType;
 use rustc_middle::ty::{self, TyCtxt, Visibility};
-use rustc_resolve::rustdoc::{add_doc_fragment, attrs_to_doc_fragments, inner_docs, DocFragment};
+use rustc_resolve::rustdoc::{
+    add_doc_fragment, attrs_to_doc_fragments, inner_docs, span_of_fragments, DocFragment,
+};
 use rustc_session::Session;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
@@ -397,7 +399,7 @@ impl Item {
     }
 
     pub(crate) fn attr_span(&self, tcx: TyCtxt<'_>) -> rustc_span::Span {
-        crate::passes::span_of_attrs(&self.attrs)
+        span_of_fragments(&self.attrs.doc_strings)
             .unwrap_or_else(|| self.span(tcx).map_or(rustc_span::DUMMY_SP, |span| span.inner()))
     }
 
@@ -2231,9 +2233,19 @@ pub(crate) struct PathSegment {
 }
 
 #[derive(Clone, Debug)]
+pub(crate) enum TypeAliasInnerType {
+    Enum { variants: IndexVec<VariantIdx, Item>, is_non_exhaustive: bool },
+    Union { fields: Vec<Item> },
+    Struct { ctor_kind: Option<CtorKind>, fields: Vec<Item> },
+}
+
+#[derive(Clone, Debug)]
 pub(crate) struct TypeAlias {
     pub(crate) type_: Type,
     pub(crate) generics: Generics,
+    /// Inner `AdtDef` type, ie `type TyKind = IrTyKind<Adt, Ty>`,
+    /// to be shown directly on the typedef page.
+    pub(crate) inner_type: Option<TypeAliasInnerType>,
     /// `type_` can come from either the HIR or from metadata. If it comes from HIR, it may be a type
     /// alias instead of the final type. This will always have the final type, regardless of whether
     /// `type_` came from HIR or from metadata.
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 1ce7efdfc20..974dc1c5135 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -157,6 +157,12 @@ pub(crate) struct Options {
     /// Note: this field is duplicated in `RenderOptions` because it's useful
     /// to have it in both places.
     pub(crate) unstable_features: rustc_feature::UnstableFeatures,
+
+    /// All commandline args used to invoke the compiler, with @file args fully expanded.
+    /// This will only be used within debug info, e.g. in the pdb file on windows
+    /// This is mainly useful for other tools that reads that debuginfo to figure out
+    /// how to call the compiler with the same arguments.
+    pub(crate) expanded_args: Vec<String>,
 }
 
 impl fmt::Debug for Options {
@@ -744,6 +750,7 @@ impl Options {
             json_unused_externs,
             scrape_examples_options,
             unstable_features,
+            expanded_args: args,
         };
         let render_options = RenderOptions {
             output,
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index eadff37b592..7cd25ef444b 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -194,6 +194,7 @@ pub(crate) fn create_config(
         describe_lints,
         lint_cap,
         scrape_examples_options,
+        expanded_args,
         ..
     }: RustdocOptions,
     RenderOptions { document_private, .. }: &RenderOptions,
@@ -291,6 +292,7 @@ pub(crate) fn create_config(
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
         ice_file: None,
+        expanded_args,
     }
 }
 
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 36d5adb6304..ea87268877f 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -10,6 +10,7 @@ use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::TyCtxt;
 use rustc_parse::maybe_new_parser_from_source_str;
 use rustc_parse::parser::attr::InnerAttrPolicy;
+use rustc_resolve::rustdoc::span_of_fragments;
 use rustc_session::config::{self, CrateType, ErrorOutputType};
 use rustc_session::parse::ParseSess;
 use rustc_session::{lint, EarlyErrorHandler, Session};
@@ -33,7 +34,6 @@ use crate::clean::{types::AttributesExt, Attributes};
 use crate::config::Options as RustdocOptions;
 use crate::html::markdown::{self, ErrorCodes, Ignore, LangString};
 use crate::lint::init_lints;
-use crate::passes::span_of_attrs;
 
 /// Options that apply to all doctests in a crate or Markdown file (for `rustdoc foo.md`).
 #[derive(Clone, Default)]
@@ -109,6 +109,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
         ice_file: None,
+        expanded_args: options.expanded_args.clone(),
     };
 
     let test_args = options.test_args.clone();
@@ -1240,7 +1241,7 @@ impl<'a, 'hir, 'tcx> HirCollector<'a, 'hir, 'tcx> {
                 Some(&crate::html::markdown::ExtraInfo::new(
                     self.tcx,
                     def_id.to_def_id(),
-                    span_of_attrs(&attrs).unwrap_or(sp),
+                    span_of_fragments(&attrs.doc_strings).unwrap_or(sp),
                 )),
             );
         }
diff --git a/src/librustdoc/fold.rs b/src/librustdoc/fold.rs
index ceba643ed5f..cf11e2d7899 100644
--- a/src/librustdoc/fold.rs
+++ b/src/librustdoc/fold.rs
@@ -52,10 +52,31 @@ pub(crate) trait DocFolder: Sized {
 
                 VariantItem(Variant { kind, discriminant })
             }
+            TypeAliasItem(mut typealias) => {
+                typealias.inner_type = typealias.inner_type.map(|inner_type| match inner_type {
+                    TypeAliasInnerType::Enum { variants, is_non_exhaustive } => {
+                        let variants = variants
+                            .into_iter_enumerated()
+                            .filter_map(|(_, x)| self.fold_item(x))
+                            .collect();
+
+                        TypeAliasInnerType::Enum { variants, is_non_exhaustive }
+                    }
+                    TypeAliasInnerType::Union { fields } => {
+                        let fields = fields.into_iter().filter_map(|x| self.fold_item(x)).collect();
+                        TypeAliasInnerType::Union { fields }
+                    }
+                    TypeAliasInnerType::Struct { ctor_kind, fields } => {
+                        let fields = fields.into_iter().filter_map(|x| self.fold_item(x)).collect();
+                        TypeAliasInnerType::Struct { ctor_kind, fields }
+                    }
+                });
+
+                TypeAliasItem(typealias)
+            }
             ExternCrateItem { src: _ }
             | ImportItem(_)
             | FunctionItem(_)
-            | TypeAliasItem(_)
             | OpaqueTyItem(_)
             | StaticItem(_)
             | ConstantItem(_)
diff --git a/src/librustdoc/formats/cache.rs b/src/librustdoc/formats/cache.rs
index 9a34e7cce8a..4c6e7dfb987 100644
--- a/src/librustdoc/formats/cache.rs
+++ b/src/librustdoc/formats/cache.rs
@@ -457,6 +457,7 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
             | clean::StructItem(..)
             | clean::UnionItem(..)
             | clean::VariantItem(..)
+            | clean::TypeAliasItem(..)
             | clean::ImplItem(..) => {
                 self.cache.parent_stack.push(ParentStackItem::new(&item));
                 (self.fold_item_recur(item), true)
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 98cc38a10d4..b28019e3f91 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -1574,7 +1574,6 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("crate-search-div".into(), 1);
     // This is the list of IDs used in HTML generated in Rust (including the ones
     // used in tera template files).
-    map.insert("mainThemeStyle".into(), 1);
     map.insert("themeStyle".into(), 1);
     map.insert("settings-menu".into(), 1);
     map.insert("help-button".into(), 1);
@@ -1610,6 +1609,7 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("blanket-implementations-list".into(), 1);
     map.insert("deref-methods".into(), 1);
     map.insert("layout".into(), 1);
+    map.insert("aliased-type".into(), 1);
     map
 }
 
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index bb1c186668c..0bc10c5e10f 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -7,8 +7,10 @@ use std::sync::mpsc::{channel, Receiver};
 
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::{DefIdMap, LOCAL_CRATE};
+use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
+use rustc_span::def_id::DefId;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::FileName;
 use rustc_span::{sym, Symbol};
@@ -22,13 +24,13 @@ use super::{
     sidebar::{sidebar_module_like, Sidebar},
     AllTypes, LinkFromSrc, StylePath,
 };
-use crate::clean::{self, types::ExternalLocation, ExternalCrate};
+use crate::clean::{self, types::ExternalLocation, ExternalCrate, TypeAliasItem};
 use crate::config::{ModuleSorting, RenderOptions};
 use crate::docfs::{DocFS, PathError};
 use crate::error::Error;
 use crate::formats::cache::Cache;
 use crate::formats::item_type::ItemType;
-use crate::formats::FormatRenderer;
+use crate::formats::{self, FormatRenderer};
 use crate::html::escape::Escape;
 use crate::html::format::{join_with_double_colon, Buffer};
 use crate::html::markdown::{self, plain_text_summary, ErrorCodes, IdMap};
@@ -147,6 +149,53 @@ impl SharedContext<'_> {
     pub(crate) fn edition(&self) -> Edition {
         self.tcx.sess.edition()
     }
+
+    /// Returns a list of impls on the given type, and, if it's a type alias,
+    /// other types that it aliases.
+    pub(crate) fn all_impls_for_item<'a>(
+        &'a self,
+        it: &clean::Item,
+        did: DefId,
+    ) -> Vec<&'a formats::Impl> {
+        let tcx = self.tcx;
+        let cache = &self.cache;
+        let mut saw_impls = FxHashSet::default();
+        let mut v: Vec<&formats::Impl> = cache
+            .impls
+            .get(&did)
+            .map(Vec::as_slice)
+            .unwrap_or(&[])
+            .iter()
+            .filter(|i| saw_impls.insert(i.def_id()))
+            .collect();
+        if let TypeAliasItem(ait) = &*it.kind &&
+            let aliased_clean_type = ait.item_type.as_ref().unwrap_or(&ait.type_) &&
+            let Some(aliased_type_defid) = aliased_clean_type.def_id(cache) &&
+            let Some(av) = cache.impls.get(&aliased_type_defid) &&
+            let Some(alias_def_id) = it.item_id.as_def_id()
+        {
+            // This branch of the compiler compares types structually, but does
+            // not check trait bounds. That's probably fine, since type aliases
+            // don't normally constrain on them anyway.
+            // https://github.com/rust-lang/rust/issues/21903
+            //
+            // FIXME(lazy_type_alias): Once the feature is complete or stable, rewrite this to use type unification.
+            // Be aware of `tests/rustdoc/issue-112515-impl-ty-alias.rs` which might regress.
+            let aliased_ty = tcx.type_of(alias_def_id).skip_binder();
+            let reject_cx = DeepRejectCtxt {
+                treat_obligation_params: TreatParams::AsCandidateKey,
+            };
+            v.extend(av.iter().filter(|impl_| {
+                if let Some(impl_def_id) = impl_.impl_item.item_id.as_def_id() {
+                    reject_cx.types_may_unify(aliased_ty, tcx.type_of(impl_def_id).skip_binder())
+                        && saw_impls.insert(impl_def_id)
+                } else {
+                    false
+                }
+            }));
+        }
+        v
+    }
 }
 
 impl<'tcx> Context<'tcx> {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index aef8f1a74fb..5adbecd6d04 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -1117,13 +1117,13 @@ pub(crate) fn render_all_impls(
 fn render_assoc_items<'a, 'cx: 'a>(
     cx: &'a mut Context<'cx>,
     containing_item: &'a clean::Item,
-    it: DefId,
+    did: DefId,
     what: AssocItemRender<'a>,
 ) -> impl fmt::Display + 'a + Captures<'cx> {
     let mut derefs = DefIdSet::default();
-    derefs.insert(it);
+    derefs.insert(did);
     display_fn(move |f| {
-        render_assoc_items_inner(f, cx, containing_item, it, what, &mut derefs);
+        render_assoc_items_inner(f, cx, containing_item, did, what, &mut derefs);
         Ok(())
     })
 }
@@ -1132,15 +1132,17 @@ fn render_assoc_items_inner(
     mut w: &mut dyn fmt::Write,
     cx: &mut Context<'_>,
     containing_item: &clean::Item,
-    it: DefId,
+    did: DefId,
     what: AssocItemRender<'_>,
     derefs: &mut DefIdSet,
 ) {
     info!("Documenting associated items of {:?}", containing_item.name);
     let shared = Rc::clone(&cx.shared);
-    let cache = &shared.cache;
-    let Some(v) = cache.impls.get(&it) else { return };
-    let (non_trait, traits): (Vec<_>, _) = v.iter().partition(|i| i.inner_impl().trait_.is_none());
+    let v = shared.all_impls_for_item(containing_item, did);
+    let v = v.as_slice();
+    let (non_trait, traits): (Vec<&Impl>, _) =
+        v.iter().partition(|i| i.inner_impl().trait_.is_none());
+    let mut saw_impls = FxHashSet::default();
     if !non_trait.is_empty() {
         let mut tmp_buf = Buffer::html();
         let (render_mode, id, class_html) = match what {
@@ -1169,6 +1171,9 @@ fn render_assoc_items_inner(
         };
         let mut impls_buf = Buffer::html();
         for i in &non_trait {
+            if !saw_impls.insert(i.def_id()) {
+                continue;
+            }
             render_impl(
                 &mut impls_buf,
                 cx,
@@ -1214,8 +1219,10 @@ fn render_assoc_items_inner(
 
         let (synthetic, concrete): (Vec<&Impl>, Vec<&Impl>) =
             traits.into_iter().partition(|t| t.inner_impl().kind.is_auto());
-        let (blanket_impl, concrete): (Vec<&Impl>, _) =
-            concrete.into_iter().partition(|t| t.inner_impl().kind.is_blanket());
+        let (blanket_impl, concrete): (Vec<&Impl>, _) = concrete
+            .into_iter()
+            .filter(|t| saw_impls.insert(t.def_id()))
+            .partition(|t| t.inner_impl().kind.is_blanket());
 
         render_all_impls(w, cx, containing_item, &concrete, &synthetic, &blanket_impl);
     }
diff --git a/src/librustdoc/html/render/print_item.rs b/src/librustdoc/html/render/print_item.rs
index cb78f903462..c6751c9585e 100644
--- a/src/librustdoc/html/render/print_item.rs
+++ b/src/librustdoc/html/render/print_item.rs
@@ -1237,6 +1237,75 @@ fn item_type_alias(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &c
 
     write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
 
+    if let Some(inner_type) = &t.inner_type {
+        write!(
+            w,
+            "<h2 id=\"aliased-type\" class=\"small-section-header\">\
+                Aliased Type<a href=\"#aliased-type\" class=\"anchor\">§</a></h2>"
+        );
+
+        match inner_type {
+            clean::TypeAliasInnerType::Enum { variants, is_non_exhaustive } => {
+                let variants_iter = || variants.iter().filter(|i| !i.is_stripped());
+                wrap_item(w, |w| {
+                    let variants_len = variants.len();
+                    let variants_count = variants_iter().count();
+                    let has_stripped_entries = variants_len != variants_count;
+
+                    write!(w, "enum {}{}", it.name.unwrap(), t.generics.print(cx));
+                    render_enum_fields(
+                        w,
+                        cx,
+                        Some(&t.generics),
+                        variants_iter(),
+                        variants_count,
+                        has_stripped_entries,
+                        *is_non_exhaustive,
+                    )
+                });
+                item_variants(w, cx, it, variants_iter());
+            }
+            clean::TypeAliasInnerType::Union { fields } => {
+                wrap_item(w, |w| {
+                    let fields_count = fields.iter().filter(|i| !i.is_stripped()).count();
+                    let has_stripped_fields = fields.len() != fields_count;
+
+                    write!(w, "union {}{}", it.name.unwrap(), t.generics.print(cx));
+                    render_struct_fields(
+                        w,
+                        Some(&t.generics),
+                        None,
+                        fields,
+                        "",
+                        true,
+                        has_stripped_fields,
+                        cx,
+                    );
+                });
+                item_fields(w, cx, it, fields, None);
+            }
+            clean::TypeAliasInnerType::Struct { ctor_kind, fields } => {
+                wrap_item(w, |w| {
+                    let fields_count = fields.iter().filter(|i| !i.is_stripped()).count();
+                    let has_stripped_fields = fields.len() != fields_count;
+
+                    write!(w, "struct {}{}", it.name.unwrap(), t.generics.print(cx));
+                    render_struct_fields(
+                        w,
+                        Some(&t.generics),
+                        *ctor_kind,
+                        fields,
+                        "",
+                        true,
+                        has_stripped_fields,
+                        cx,
+                    );
+                });
+                item_fields(w, cx, it, fields, None);
+            }
+        }
+    }
+
     let def_id = it.item_id.expect_def_id();
     // Render any items associated directly to this alias, as otherwise they
     // won't be visible anywhere in the docs. It would be nice to also show
@@ -1315,6 +1384,12 @@ fn print_tuple_struct_fields<'a, 'cx: 'a>(
     s: &'a [clean::Item],
 ) -> impl fmt::Display + 'a + Captures<'cx> {
     display_fn(|f| {
+        if s.iter()
+            .all(|field| matches!(*field.kind, clean::StrippedItem(box clean::StructFieldItem(..))))
+        {
+            return f.write_str("/* private fields */");
+        }
+
         for (i, ty) in s.iter().enumerate() {
             if i > 0 {
                 f.write_str(", ")?;
@@ -1332,7 +1407,7 @@ fn print_tuple_struct_fields<'a, 'cx: 'a>(
 fn item_enum(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, e: &clean::Enum) {
     let tcx = cx.tcx();
     let count_variants = e.variants().count();
-    wrap_item(w, |mut w| {
+    wrap_item(w, |w| {
         render_attributes_in_code(w, it, tcx);
         write!(
             w,
@@ -1341,148 +1416,179 @@ fn item_enum(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, e: &clean::
             it.name.unwrap(),
             e.generics.print(cx),
         );
-        if !print_where_clause_and_check(w, &e.generics, cx) {
-            // If there wasn't a `where` clause, we add a whitespace.
-            w.write_str(" ");
-        }
+        render_enum_fields(
+            w,
+            cx,
+            Some(&e.generics),
+            e.variants(),
+            count_variants,
+            e.has_stripped_entries(),
+            it.is_non_exhaustive(),
+        );
+    });
 
-        let variants_stripped = e.has_stripped_entries();
-        if count_variants == 0 && !variants_stripped {
-            w.write_str("{}");
-        } else {
-            w.write_str("{\n");
-            let toggle = should_hide_fields(count_variants);
-            if toggle {
-                toggle_open(&mut w, format_args!("{count_variants} variants"));
-            }
-            for v in e.variants() {
-                w.write_str("    ");
-                let name = v.name.unwrap();
-                match *v.kind {
-                    // FIXME(#101337): Show discriminant
-                    clean::VariantItem(ref var) => match var.kind {
-                        clean::VariantKind::CLike => w.write_str(name.as_str()),
-                        clean::VariantKind::Tuple(ref s) => {
-                            write!(w, "{name}({})", print_tuple_struct_fields(cx, s),);
-                        }
-                        clean::VariantKind::Struct(ref s) => {
-                            render_struct(w, v, None, None, &s.fields, "    ", false, cx);
-                        }
-                    },
-                    _ => unreachable!(),
-                }
-                w.write_str(",\n");
-            }
+    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
 
-            if variants_stripped && !it.is_non_exhaustive() {
-                w.write_str("    // some variants omitted\n");
-            }
-            if toggle {
-                toggle_close(&mut w);
+    if count_variants != 0 {
+        item_variants(w, cx, it, e.variants());
+    }
+    let def_id = it.item_id.expect_def_id();
+    write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All));
+    write!(w, "{}", document_type_layout(cx, def_id));
+}
+
+fn render_enum_fields<'a>(
+    mut w: &mut Buffer,
+    cx: &mut Context<'_>,
+    g: Option<&clean::Generics>,
+    variants: impl Iterator<Item = &'a clean::Item>,
+    count_variants: usize,
+    has_stripped_entries: bool,
+    is_non_exhaustive: bool,
+) {
+    if !g.is_some_and(|g| print_where_clause_and_check(w, g, cx)) {
+        // If there wasn't a `where` clause, we add a whitespace.
+        w.write_str(" ");
+    }
+
+    let variants_stripped = has_stripped_entries;
+    if count_variants == 0 && !variants_stripped {
+        w.write_str("{}");
+    } else {
+        w.write_str("{\n");
+        let toggle = should_hide_fields(count_variants);
+        if toggle {
+            toggle_open(&mut w, format_args!("{count_variants} variants"));
+        }
+        const TAB: &str = "    ";
+        for v in variants {
+            w.write_str(TAB);
+            let name = v.name.unwrap();
+            match *v.kind {
+                // FIXME(#101337): Show discriminant
+                clean::VariantItem(ref var) => match var.kind {
+                    clean::VariantKind::CLike => w.write_str(name.as_str()),
+                    clean::VariantKind::Tuple(ref s) => {
+                        write!(w, "{name}({})", print_tuple_struct_fields(cx, s),);
+                    }
+                    clean::VariantKind::Struct(ref s) => {
+                        render_struct(w, v, None, None, &s.fields, TAB, false, cx);
+                    }
+                },
+                _ => unreachable!(),
             }
-            w.write_str("}");
+            w.write_str(",\n");
         }
-    });
 
-    write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
+        if variants_stripped && !is_non_exhaustive {
+            w.write_str("    // some variants omitted\n");
+        }
+        if toggle {
+            toggle_close(&mut w);
+        }
+        w.write_str("}");
+    }
+}
 
-    if count_variants != 0 {
+fn item_variants<'a>(
+    w: &mut Buffer,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    variants: impl Iterator<Item = &'a clean::Item>,
+) {
+    let tcx = cx.tcx();
+    write!(
+        w,
+        "<h2 id=\"variants\" class=\"variants small-section-header\">\
+            Variants{}<a href=\"#variants\" class=\"anchor\">§</a>\
+        </h2>\
+        {}\
+        <div class=\"variants\">",
+        document_non_exhaustive_header(it),
+        document_non_exhaustive(it)
+    );
+    for variant in variants {
+        let id = cx.derive_id(format!("{}.{}", ItemType::Variant, variant.name.unwrap()));
         write!(
             w,
-            "<h2 id=\"variants\" class=\"variants small-section-header\">\
-                Variants{}<a href=\"#variants\" class=\"anchor\">§</a>\
-            </h2>\
-            {}\
-            <div class=\"variants\">",
-            document_non_exhaustive_header(it),
-            document_non_exhaustive(it)
+            "<section id=\"{id}\" class=\"variant\">\
+                <a href=\"#{id}\" class=\"anchor\">§</a>",
         );
-        for variant in e.variants() {
-            let id = cx.derive_id(format!("{}.{}", ItemType::Variant, variant.name.unwrap()));
-            write!(
-                w,
-                "<section id=\"{id}\" class=\"variant\">\
-                    <a href=\"#{id}\" class=\"anchor\">§</a>",
-            );
-            render_stability_since_raw_with_extra(
-                w,
-                variant.stable_since(tcx),
-                variant.const_stability(tcx),
-                it.stable_since(tcx),
-                it.const_stable_since(tcx),
-                " rightside",
-            );
-            write!(w, "<h3 class=\"code-header\">{name}", name = variant.name.unwrap());
+        render_stability_since_raw_with_extra(
+            w,
+            variant.stable_since(tcx),
+            variant.const_stability(tcx),
+            it.stable_since(tcx),
+            it.const_stable_since(tcx),
+            " rightside",
+        );
+        write!(w, "<h3 class=\"code-header\">{name}", name = variant.name.unwrap());
 
-            let clean::VariantItem(variant_data) = &*variant.kind else { unreachable!() };
+        let clean::VariantItem(variant_data) = &*variant.kind else { unreachable!() };
 
-            if let clean::VariantKind::Tuple(ref s) = variant_data.kind {
-                write!(w, "({})", print_tuple_struct_fields(cx, s));
-            }
-            w.write_str("</h3></section>");
-
-            let heading_and_fields = match &variant_data.kind {
-                clean::VariantKind::Struct(s) => Some(("Fields", &s.fields)),
-                clean::VariantKind::Tuple(fields) => {
-                    // Documentation on tuple variant fields is rare, so to reduce noise we only emit
-                    // the section if at least one field is documented.
-                    if fields.iter().any(|f| !f.doc_value().is_empty()) {
-                        Some(("Tuple Fields", fields))
-                    } else {
-                        None
-                    }
+        if let clean::VariantKind::Tuple(ref s) = variant_data.kind {
+            write!(w, "({})", print_tuple_struct_fields(cx, s));
+        }
+        w.write_str("</h3></section>");
+
+        let heading_and_fields = match &variant_data.kind {
+            clean::VariantKind::Struct(s) => Some(("Fields", &s.fields)),
+            clean::VariantKind::Tuple(fields) => {
+                // Documentation on tuple variant fields is rare, so to reduce noise we only emit
+                // the section if at least one field is documented.
+                if fields.iter().any(|f| !f.doc_value().is_empty()) {
+                    Some(("Tuple Fields", fields))
+                } else {
+                    None
                 }
-                clean::VariantKind::CLike => None,
-            };
+            }
+            clean::VariantKind::CLike => None,
+        };
 
-            if let Some((heading, fields)) = heading_and_fields {
-                let variant_id =
-                    cx.derive_id(format!("{}.{}.fields", ItemType::Variant, variant.name.unwrap()));
-                write!(
-                    w,
-                    "<div class=\"sub-variant\" id=\"{variant_id}\">\
-                        <h4>{heading}</h4>\
-                        {}",
-                    document_non_exhaustive(variant)
-                );
-                for field in fields {
-                    match *field.kind {
-                        clean::StrippedItem(box clean::StructFieldItem(_)) => {}
-                        clean::StructFieldItem(ref ty) => {
-                            let id = cx.derive_id(format!(
-                                "variant.{}.field.{}",
-                                variant.name.unwrap(),
-                                field.name.unwrap()
-                            ));
-                            write!(
-                                w,
-                                "<div class=\"sub-variant-field\">\
+        if let Some((heading, fields)) = heading_and_fields {
+            let variant_id =
+                cx.derive_id(format!("{}.{}.fields", ItemType::Variant, variant.name.unwrap()));
+            write!(
+                w,
+                "<div class=\"sub-variant\" id=\"{variant_id}\">\
+                    <h4>{heading}</h4>\
+                    {}",
+                document_non_exhaustive(variant)
+            );
+            for field in fields {
+                match *field.kind {
+                    clean::StrippedItem(box clean::StructFieldItem(_)) => {}
+                    clean::StructFieldItem(ref ty) => {
+                        let id = cx.derive_id(format!(
+                            "variant.{}.field.{}",
+                            variant.name.unwrap(),
+                            field.name.unwrap()
+                        ));
+                        write!(
+                            w,
+                            "<div class=\"sub-variant-field\">\
                                  <span id=\"{id}\" class=\"small-section-header\">\
                                      <a href=\"#{id}\" class=\"anchor field\">§</a>\
                                      <code>{f}: {t}</code>\
                                  </span>",
-                                f = field.name.unwrap(),
-                                t = ty.print(cx),
-                            );
-                            write!(
-                                w,
-                                "{}</div>",
-                                document(cx, field, Some(variant), HeadingOffset::H5)
-                            );
-                        }
-                        _ => unreachable!(),
+                            f = field.name.unwrap(),
+                            t = ty.print(cx),
+                        );
+                        write!(
+                            w,
+                            "{}</div>",
+                            document(cx, field, Some(variant), HeadingOffset::H5)
+                        );
                     }
+                    _ => unreachable!(),
                 }
-                w.write_str("</div>");
             }
-
-            write!(w, "{}", document(cx, variant, Some(it), HeadingOffset::H4));
+            w.write_str("</div>");
         }
-        write!(w, "</div>");
+
+        write!(w, "{}", document(cx, variant, Some(it), HeadingOffset::H4));
     }
-    let def_id = it.item_id.expect_def_id();
-    write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All));
-    write!(w, "{}", document_type_layout(cx, def_id));
+    write!(w, "</div>");
 }
 
 fn item_macro(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean::Macro) {
@@ -1593,15 +1699,28 @@ fn item_struct(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean
 
     write!(w, "{}", document(cx, it, None, HeadingOffset::H2));
 
-    let mut fields = s
-        .fields
+    item_fields(w, cx, it, &s.fields, s.ctor_kind);
+
+    let def_id = it.item_id.expect_def_id();
+    write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All));
+    write!(w, "{}", document_type_layout(cx, def_id));
+}
+
+fn item_fields(
+    w: &mut Buffer,
+    cx: &mut Context<'_>,
+    it: &clean::Item,
+    fields: &Vec<clean::Item>,
+    ctor_kind: Option<CtorKind>,
+) {
+    let mut fields = fields
         .iter()
         .filter_map(|f| match *f.kind {
             clean::StructFieldItem(ref ty) => Some((f, ty)),
             _ => None,
         })
         .peekable();
-    if let None | Some(CtorKind::Fn) = s.ctor_kind {
+    if let None | Some(CtorKind::Fn) = ctor_kind {
         if fields.peek().is_some() {
             write!(
                 w,
@@ -1609,7 +1728,7 @@ fn item_struct(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean
                      {}{}<a href=\"#fields\" class=\"anchor\">§</a>\
                  </h2>\
                  {}",
-                if s.ctor_kind.is_none() { "Fields" } else { "Tuple Fields" },
+                if ctor_kind.is_none() { "Fields" } else { "Tuple Fields" },
                 document_non_exhaustive_header(it),
                 document_non_exhaustive(it)
             );
@@ -1630,9 +1749,6 @@ fn item_struct(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, s: &clean
             }
         }
     }
-    let def_id = it.item_id.expect_def_id();
-    write!(w, "{}", render_assoc_items(cx, it, def_id, AssocItemRender::All));
-    write!(w, "{}", document_type_layout(cx, def_id));
 }
 
 fn item_static(w: &mut impl fmt::Write, cx: &mut Context<'_>, it: &clean::Item, s: &clean::Static) {
@@ -1871,7 +1987,7 @@ fn render_union<'a, 'cx: 'a>(
 }
 
 fn render_struct(
-    mut w: &mut Buffer,
+    w: &mut Buffer,
     it: &clean::Item,
     g: Option<&clean::Generics>,
     ty: Option<CtorKind>,
@@ -1891,6 +2007,29 @@ fn render_struct(
     if let Some(g) = g {
         write!(w, "{}", g.print(cx))
     }
+    render_struct_fields(
+        w,
+        g,
+        ty,
+        fields,
+        tab,
+        structhead,
+        it.has_stripped_entries().unwrap_or(false),
+        cx,
+    )
+}
+
+fn render_struct_fields(
+    mut w: &mut Buffer,
+    g: Option<&clean::Generics>,
+    ty: Option<CtorKind>,
+    fields: &[clean::Item],
+    tab: &str,
+    structhead: bool,
+    has_stripped_entries: bool,
+    cx: &Context<'_>,
+) {
+    let tcx = cx.tcx();
     match ty {
         None => {
             let where_displayed =
@@ -1922,11 +2061,11 @@ fn render_struct(
             }
 
             if has_visible_fields {
-                if it.has_stripped_entries().unwrap() {
+                if has_stripped_entries {
                     write!(w, "\n{tab}    /* private fields */");
                 }
                 write!(w, "\n{tab}");
-            } else if it.has_stripped_entries().unwrap() {
+            } else if has_stripped_entries {
                 write!(w, " /* private fields */ ");
             }
             if toggle {
@@ -1936,21 +2075,31 @@ fn render_struct(
         }
         Some(CtorKind::Fn) => {
             w.write_str("(");
-            for (i, field) in fields.iter().enumerate() {
-                if i > 0 {
-                    w.write_str(", ");
-                }
-                match *field.kind {
-                    clean::StrippedItem(box clean::StructFieldItem(..)) => write!(w, "_"),
-                    clean::StructFieldItem(ref ty) => {
-                        write!(
-                            w,
-                            "{}{}",
-                            visibility_print_with_space(field.visibility(tcx), field.item_id, cx),
-                            ty.print(cx),
-                        )
+            if fields.iter().all(|field| {
+                matches!(*field.kind, clean::StrippedItem(box clean::StructFieldItem(..)))
+            }) {
+                write!(w, "/* private fields */");
+            } else {
+                for (i, field) in fields.iter().enumerate() {
+                    if i > 0 {
+                        w.write_str(", ");
+                    }
+                    match *field.kind {
+                        clean::StrippedItem(box clean::StructFieldItem(..)) => write!(w, "_"),
+                        clean::StructFieldItem(ref ty) => {
+                            write!(
+                                w,
+                                "{}{}",
+                                visibility_print_with_space(
+                                    field.visibility(tcx),
+                                    field.item_id,
+                                    cx
+                                ),
+                                ty.print(cx),
+                            )
+                        }
+                        _ => unreachable!(),
                     }
-                    _ => unreachable!(),
                 }
             }
             w.write_str(")");
diff --git a/src/librustdoc/html/render/sidebar.rs b/src/librustdoc/html/render/sidebar.rs
index b96b1536156..76f63c6f63e 100644
--- a/src/librustdoc/html/render/sidebar.rs
+++ b/src/librustdoc/html/render/sidebar.rs
@@ -82,7 +82,7 @@ pub(super) fn print_sidebar(cx: &Context<'_>, it: &clean::Item, buffer: &mut Buf
         clean::PrimitiveItem(_) => sidebar_primitive(cx, it),
         clean::UnionItem(ref u) => sidebar_union(cx, it, u),
         clean::EnumItem(ref e) => sidebar_enum(cx, it, e),
-        clean::TypeAliasItem(_) => sidebar_type_alias(cx, it),
+        clean::TypeAliasItem(ref t) => sidebar_type_alias(cx, it, t),
         clean::ModuleItem(ref m) => vec![sidebar_module(&m.items)],
         clean::ForeignTypeItem => sidebar_foreign_type(cx, it),
         _ => vec![],
@@ -230,8 +230,33 @@ fn sidebar_primitive<'a>(cx: &'a Context<'_>, it: &'a clean::Item) -> Vec<LinkBl
     }
 }
 
-fn sidebar_type_alias<'a>(cx: &'a Context<'_>, it: &'a clean::Item) -> Vec<LinkBlock<'a>> {
+fn sidebar_type_alias<'a>(
+    cx: &'a Context<'_>,
+    it: &'a clean::Item,
+    t: &'a clean::TypeAlias,
+) -> Vec<LinkBlock<'a>> {
     let mut items = vec![];
+    if let Some(inner_type) = &t.inner_type {
+        items.push(LinkBlock::forced(Link::new("aliased-type", "Aliased type")));
+        match inner_type {
+            clean::TypeAliasInnerType::Enum { variants, is_non_exhaustive: _ } => {
+                let mut variants = variants
+                    .iter()
+                    .filter(|i| !i.is_stripped())
+                    .filter_map(|v| v.name)
+                    .map(|name| Link::new(format!("variant.{name}"), name.to_string()))
+                    .collect::<Vec<_>>();
+                variants.sort_unstable();
+
+                items.push(LinkBlock::new(Link::new("variants", "Variants"), variants));
+            }
+            clean::TypeAliasInnerType::Union { fields }
+            | clean::TypeAliasInnerType::Struct { ctor_kind: _, fields } => {
+                let fields = get_struct_fields_name(fields);
+                items.push(LinkBlock::new(Link::new("fields", "Fields"), fields));
+            }
+        }
+    }
     sidebar_assoc_items(cx, it, &mut items);
     items
 }
@@ -254,11 +279,12 @@ fn sidebar_assoc_items<'a>(
     links: &mut Vec<LinkBlock<'a>>,
 ) {
     let did = it.item_id.expect_def_id();
-    let cache = cx.cache();
+    let v = cx.shared.all_impls_for_item(it, it.item_id.expect_def_id());
+    let v = v.as_slice();
 
     let mut assoc_consts = Vec::new();
     let mut methods = Vec::new();
-    if let Some(v) = cache.impls.get(&did) {
+    if !v.is_empty() {
         let mut used_links = FxHashSet::default();
         let mut id_map = IdMap::new();
 
@@ -294,7 +320,7 @@ fn sidebar_assoc_items<'a>(
                     cx,
                     &mut deref_methods,
                     impl_,
-                    v,
+                    v.iter().copied(),
                     &mut derefs,
                     &mut used_links,
                 );
@@ -324,7 +350,7 @@ fn sidebar_deref_methods<'a>(
     cx: &'a Context<'_>,
     out: &mut Vec<LinkBlock<'a>>,
     impl_: &Impl,
-    v: &[Impl],
+    v: impl Iterator<Item = &'a Impl>,
     derefs: &mut DefIdSet,
     used_links: &mut FxHashSet<String>,
 ) {
@@ -349,7 +375,7 @@ fn sidebar_deref_methods<'a>(
             // Avoid infinite cycles
             return;
         }
-        let deref_mut = v.iter().any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
+        let deref_mut = { v }.any(|i| i.trait_did() == cx.tcx().lang_items().deref_mut_trait());
         let inner_impl = target
             .def_id(c)
             .or_else(|| {
@@ -400,7 +426,7 @@ fn sidebar_deref_methods<'a>(
                 cx,
                 out,
                 target_deref_impl,
-                target_impls,
+                target_impls.iter(),
                 derefs,
                 used_links,
             );
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index cb653d6b8df..a5ae988f348 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -852,14 +852,14 @@ function preLoadCss(cssUrl) {
         window.CURRENT_TOOLTIP_ELEMENT = wrapper;
         window.CURRENT_TOOLTIP_ELEMENT.TOOLTIP_BASE = e;
         clearTooltipHoverTimeout(window.CURRENT_TOOLTIP_ELEMENT);
-        wrapper.onpointerenter = function(ev) {
+        wrapper.onpointerenter = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
             }
             clearTooltipHoverTimeout(e);
         };
-        wrapper.onpointerleave = function(ev) {
+        wrapper.onpointerleave = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
@@ -963,38 +963,38 @@ function preLoadCss(cssUrl) {
     }
 
     onEachLazy(document.getElementsByClassName("tooltip"), e => {
-        e.onclick = function() {
-            this.TOOLTIP_FORCE_VISIBLE = this.TOOLTIP_FORCE_VISIBLE ? false : true;
-            if (window.CURRENT_TOOLTIP_ELEMENT && !this.TOOLTIP_FORCE_VISIBLE) {
+        e.onclick = () => {
+            e.TOOLTIP_FORCE_VISIBLE = e.TOOLTIP_FORCE_VISIBLE ? false : true;
+            if (window.CURRENT_TOOLTIP_ELEMENT && !e.TOOLTIP_FORCE_VISIBLE) {
                 hideTooltip(true);
             } else {
-                showTooltip(this);
+                showTooltip(e);
                 window.CURRENT_TOOLTIP_ELEMENT.setAttribute("tabindex", "0");
                 window.CURRENT_TOOLTIP_ELEMENT.focus();
                 window.CURRENT_TOOLTIP_ELEMENT.onblur = tooltipBlurHandler;
             }
             return false;
         };
-        e.onpointerenter = function(ev) {
+        e.onpointerenter = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            setTooltipHoverTimeout(this, true);
+            setTooltipHoverTimeout(e, true);
         };
-        e.onpointermove = function(ev) {
+        e.onpointermove = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            setTooltipHoverTimeout(this, true);
+            setTooltipHoverTimeout(e, true);
         };
-        e.onpointerleave = function(ev) {
+        e.onpointerleave = ev => {
             // If this is a synthetic touch event, ignore it. A click event will be along shortly.
             if (ev.pointerType !== "mouse") {
                 return;
             }
-            if (!this.TOOLTIP_FORCE_VISIBLE &&
+            if (!e.TOOLTIP_FORCE_VISIBLE &&
                 !elemIsInParent(ev.relatedTarget, window.CURRENT_TOOLTIP_ELEMENT)) {
                 // Tooltip pointer leave gesture:
                 //
@@ -1139,7 +1139,7 @@ href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
      *
      * Pass "true" to reset focus for tooltip popovers.
      */
-    window.hideAllModals = function(switchFocus) {
+    window.hideAllModals = switchFocus => {
         hideSidebar();
         window.hidePopoverMenus();
         hideTooltip(switchFocus);
@@ -1148,7 +1148,7 @@ href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
     /**
      * Hide all the popover menus.
      */
-    window.hidePopoverMenus = function() {
+    window.hidePopoverMenus = () => {
         onEachLazy(document.querySelectorAll(".search-form .popover"), elem => {
             elem.style.display = "none";
         });
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 2cba32c1b50..63947789c54 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -59,8 +59,8 @@
             if (settingValue !== null) {
                 toggle.checked = settingValue === "true";
             }
-            toggle.onchange = function() {
-                changeSetting(this.id, this.checked);
+            toggle.onchange = () => {
+                changeSetting(toggle.id, toggle.checked);
             };
         });
         onEachLazy(settingsElement.querySelectorAll("input[type=\"radio\"]"), elem => {
@@ -224,14 +224,14 @@
 
     if (isSettingsPage) {
         // We replace the existing "onclick" callback to do nothing if clicked.
-        getSettingsButton().onclick = function(event) {
+        getSettingsButton().onclick = event => {
             event.preventDefault();
         };
     } else {
         // We replace the existing "onclick" callback.
         const settingsButton = getSettingsButton();
         const settingsMenu = document.getElementById("settings");
-        settingsButton.onclick = function(event) {
+        settingsButton.onclick = event => {
             if (elemIsInParent(event.target, settingsMenu)) {
                 return;
             }
diff --git a/src/librustdoc/html/templates/page.html b/src/librustdoc/html/templates/page.html
index 60ccfe4da44..8cb43634377 100644
--- a/src/librustdoc/html/templates/page.html
+++ b/src/librustdoc/html/templates/page.html
@@ -15,8 +15,7 @@
     <link rel="stylesheet" {#+ #}
           href="{{static_root_path|safe}}{{files.normalize_css}}"> {# #}
     <link rel="stylesheet" {#+ #}
-          href="{{static_root_path|safe}}{{files.rustdoc_css}}" {#+ #}
-          id="mainThemeStyle"> {# #}
+          href="{{static_root_path|safe}}{{files.rustdoc_css}}"> {# #}
     {% if !layout.default_settings.is_empty() %}
     <script id="default-settings" {#+ #}
       {%~ for (k, v) in layout.default_settings ~%}
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 0c18f5687f5..08865015960 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -789,7 +789,7 @@ pub(crate) fn from_macro_kind(kind: rustc_span::hygiene::MacroKind) -> MacroKind
 
 impl FromWithTcx<Box<clean::TypeAlias>> for TypeAlias {
     fn from_tcx(type_alias: Box<clean::TypeAlias>, tcx: TyCtxt<'_>) -> Self {
-        let clean::TypeAlias { type_, generics, item_type: _ } = *type_alias;
+        let clean::TypeAlias { type_, generics, item_type: _, inner_type: _ } = *type_alias;
         TypeAlias { type_: type_.into_tcx(tcx), generics: generics.into_tcx(tcx) }
     }
 }
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 7b0a7a90d31..0db846bfc7e 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -16,7 +16,9 @@ use rustc_hir::Mutability;
 use rustc_middle::ty::{Ty, TyCtxt};
 use rustc_middle::{bug, span_bug, ty};
 use rustc_resolve::rustdoc::{has_primitive_or_keyword_docs, prepare_to_doc_link_resolution};
-use rustc_resolve::rustdoc::{strip_generics_from_path, MalformedGenerics};
+use rustc_resolve::rustdoc::{
+    source_span_for_markdown_range, strip_generics_from_path, MalformedGenerics,
+};
 use rustc_session::lint::Lint;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -1211,11 +1213,11 @@ impl LinkCollector<'_, '_> {
         ori_link: &MarkdownLinkRange,
         item: &Item,
     ) {
-        let span = super::source_span_for_markdown_range(
+        let span = source_span_for_markdown_range(
             self.cx.tcx,
             dox,
             ori_link.inner_range(),
-            &item.attrs,
+            &item.attrs.doc_strings,
         )
         .unwrap_or_else(|| item.attr_span(self.cx.tcx));
         rustc_session::parse::feature_err(
@@ -1702,26 +1704,27 @@ fn report_diagnostic(
         let (span, link_range) = match link_range {
             MarkdownLinkRange::Destination(md_range) => {
                 let mut md_range = md_range.clone();
-                let sp = super::source_span_for_markdown_range(tcx, dox, &md_range, &item.attrs)
-                    .map(|mut sp| {
-                        while dox.as_bytes().get(md_range.start) == Some(&b' ')
-                            || dox.as_bytes().get(md_range.start) == Some(&b'`')
-                        {
-                            md_range.start += 1;
-                            sp = sp.with_lo(sp.lo() + BytePos(1));
-                        }
-                        while dox.as_bytes().get(md_range.end - 1) == Some(&b' ')
-                            || dox.as_bytes().get(md_range.end - 1) == Some(&b'`')
-                        {
-                            md_range.end -= 1;
-                            sp = sp.with_hi(sp.hi() - BytePos(1));
-                        }
-                        sp
-                    });
+                let sp =
+                    source_span_for_markdown_range(tcx, dox, &md_range, &item.attrs.doc_strings)
+                        .map(|mut sp| {
+                            while dox.as_bytes().get(md_range.start) == Some(&b' ')
+                                || dox.as_bytes().get(md_range.start) == Some(&b'`')
+                            {
+                                md_range.start += 1;
+                                sp = sp.with_lo(sp.lo() + BytePos(1));
+                            }
+                            while dox.as_bytes().get(md_range.end - 1) == Some(&b' ')
+                                || dox.as_bytes().get(md_range.end - 1) == Some(&b'`')
+                            {
+                                md_range.end -= 1;
+                                sp = sp.with_hi(sp.hi() - BytePos(1));
+                            }
+                            sp
+                        });
                 (sp, MarkdownLinkRange::Destination(md_range))
             }
             MarkdownLinkRange::WholeLink(md_range) => (
-                super::source_span_for_markdown_range(tcx, dox, &md_range, &item.attrs),
+                source_span_for_markdown_range(tcx, dox, &md_range, &item.attrs.doc_strings),
                 link_range.clone(),
             ),
         };
diff --git a/src/librustdoc/passes/lint/bare_urls.rs b/src/librustdoc/passes/lint/bare_urls.rs
index 97078a5cb16..0c5cfffe1be 100644
--- a/src/librustdoc/passes/lint/bare_urls.rs
+++ b/src/librustdoc/passes/lint/bare_urls.rs
@@ -4,11 +4,11 @@
 use crate::clean::*;
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
-use crate::passes::source_span_for_markdown_range;
 use core::ops::Range;
 use pulldown_cmark::{Event, Parser, Tag};
 use regex::Regex;
 use rustc_errors::Applicability;
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use std::mem;
 use std::sync::LazyLock;
 
@@ -21,8 +21,9 @@ pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item) {
     if !dox.is_empty() {
         let report_diag =
             |cx: &DocContext<'_>, msg: &'static str, url: &str, range: Range<usize>| {
-                let sp = source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs)
-                    .unwrap_or_else(|| item.attr_span(cx.tcx));
+                let sp =
+                    source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs.doc_strings)
+                        .unwrap_or_else(|| item.attr_span(cx.tcx));
                 cx.tcx.struct_span_lint_hir(crate::lint::BARE_URLS, hir_id, sp, msg, |lint| {
                     lint.note("bare URLs are not automatically turned into clickable links")
                         .span_suggestion(
diff --git a/src/librustdoc/passes/lint/check_code_block_syntax.rs b/src/librustdoc/passes/lint/check_code_block_syntax.rs
index 37e28e1fbca..316b1a41c7d 100644
--- a/src/librustdoc/passes/lint/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/lint/check_code_block_syntax.rs
@@ -6,6 +6,7 @@ use rustc_errors::{
     Applicability, Diagnostic, Handler, LazyFallbackBundle,
 };
 use rustc_parse::parse_stream_from_source_str;
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use rustc_session::parse::ParseSess;
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
 use rustc_span::source_map::{FilePathMapping, SourceMap};
@@ -14,7 +15,6 @@ use rustc_span::{FileName, InnerSpan, DUMMY_SP};
 use crate::clean;
 use crate::core::DocContext;
 use crate::html::markdown::{self, RustCodeBlock};
-use crate::passes::source_span_for_markdown_range;
 
 pub(crate) fn visit_item(cx: &DocContext<'_>, item: &clean::Item) {
     if let Some(dox) = &item.opt_doc_value() {
@@ -77,11 +77,15 @@ fn check_rust_syntax(
     let is_ignore = code_block.lang_string.ignore != markdown::Ignore::None;
 
     // The span and whether it is precise or not.
-    let (sp, precise_span) =
-        match source_span_for_markdown_range(cx.tcx, dox, &code_block.range, &item.attrs) {
-            Some(sp) => (sp, true),
-            None => (item.attr_span(cx.tcx), false),
-        };
+    let (sp, precise_span) = match source_span_for_markdown_range(
+        cx.tcx,
+        dox,
+        &code_block.range,
+        &item.attrs.doc_strings,
+    ) {
+        Some(sp) => (sp, true),
+        None => (item.attr_span(cx.tcx), false),
+    };
 
     let msg = if buffer.has_errors {
         "could not parse code block as Rust code"
diff --git a/src/librustdoc/passes/lint/html_tags.rs b/src/librustdoc/passes/lint/html_tags.rs
index c135c584cec..79fc599e176 100644
--- a/src/librustdoc/passes/lint/html_tags.rs
+++ b/src/librustdoc/passes/lint/html_tags.rs
@@ -2,9 +2,9 @@
 use crate::clean::*;
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
-use crate::passes::source_span_for_markdown_range;
 
 use pulldown_cmark::{BrokenLink, Event, LinkType, Parser, Tag};
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
 
 use std::iter::Peekable;
 use std::ops::Range;
@@ -20,7 +20,8 @@ pub(crate) fn visit_item(cx: &DocContext<'_>, item: &Item) {
     let dox = item.doc_value();
     if !dox.is_empty() {
         let report_diag = |msg: String, range: &Range<usize>, is_open_tag: bool| {
-            let sp = match source_span_for_markdown_range(tcx, &dox, range, &item.attrs) {
+            let sp = match source_span_for_markdown_range(tcx, &dox, range, &item.attrs.doc_strings)
+            {
                 Some(sp) => sp,
                 None => item.attr_span(tcx),
             };
@@ -60,7 +61,7 @@ pub(crate) fn visit_item(cx: &DocContext<'_>, item: &Item) {
                             tcx,
                             &dox,
                             &(generics_start..generics_end),
-                            &item.attrs,
+                            &item.attrs.doc_strings,
                         ) {
                             Some(sp) => sp,
                             None => item.attr_span(tcx),
diff --git a/src/librustdoc/passes/lint/redundant_explicit_links.rs b/src/librustdoc/passes/lint/redundant_explicit_links.rs
index 67cd2cc9732..0c15bf5f764 100644
--- a/src/librustdoc/passes/lint/redundant_explicit_links.rs
+++ b/src/librustdoc/passes/lint/redundant_explicit_links.rs
@@ -6,6 +6,7 @@ use rustc_errors::SuggestionStyle;
 use rustc_hir::def::{DefKind, DocLinkResMap, Namespace, Res};
 use rustc_hir::HirId;
 use rustc_lint_defs::Applicability;
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use rustc_span::Symbol;
 
 use crate::clean::utils::find_nearest_parent_module;
@@ -13,7 +14,6 @@ use crate::clean::utils::inherits_doc_hidden;
 use crate::clean::Item;
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
-use crate::passes::source_span_for_markdown_range;
 
 #[derive(Debug)]
 struct LinkData {
@@ -160,16 +160,21 @@ fn check_inline_or_reference_unknown_redundancy(
         (find_resolution(resolutions, &dest)?, find_resolution(resolutions, resolvable_link)?);
 
     if dest_res == display_res {
-        let link_span = source_span_for_markdown_range(cx.tcx, &doc, &link_range, &item.attrs)
-            .unwrap_or(item.attr_span(cx.tcx));
+        let link_span =
+            source_span_for_markdown_range(cx.tcx, &doc, &link_range, &item.attrs.doc_strings)
+                .unwrap_or(item.attr_span(cx.tcx));
         let explicit_span = source_span_for_markdown_range(
             cx.tcx,
             &doc,
             &offset_explicit_range(doc, link_range, open, close),
-            &item.attrs,
+            &item.attrs.doc_strings,
+        )?;
+        let display_span = source_span_for_markdown_range(
+            cx.tcx,
+            &doc,
+            &resolvable_link_range,
+            &item.attrs.doc_strings,
         )?;
-        let display_span =
-            source_span_for_markdown_range(cx.tcx, &doc, &resolvable_link_range, &item.attrs)?;
 
         cx.tcx.struct_span_lint_hir(crate::lint::REDUNDANT_EXPLICIT_LINKS, hir_id, explicit_span, "redundant explicit link target", |lint| {
             lint.span_label(explicit_span, "explicit target is redundant")
@@ -201,21 +206,26 @@ fn check_reference_redundancy(
         (find_resolution(resolutions, &dest)?, find_resolution(resolutions, resolvable_link)?);
 
     if dest_res == display_res {
-        let link_span = source_span_for_markdown_range(cx.tcx, &doc, &link_range, &item.attrs)
-            .unwrap_or(item.attr_span(cx.tcx));
+        let link_span =
+            source_span_for_markdown_range(cx.tcx, &doc, &link_range, &item.attrs.doc_strings)
+                .unwrap_or(item.attr_span(cx.tcx));
         let explicit_span = source_span_for_markdown_range(
             cx.tcx,
             &doc,
             &offset_explicit_range(doc, link_range.clone(), b'[', b']'),
-            &item.attrs,
+            &item.attrs.doc_strings,
+        )?;
+        let display_span = source_span_for_markdown_range(
+            cx.tcx,
+            &doc,
+            &resolvable_link_range,
+            &item.attrs.doc_strings,
         )?;
-        let display_span =
-            source_span_for_markdown_range(cx.tcx, &doc, &resolvable_link_range, &item.attrs)?;
         let def_span = source_span_for_markdown_range(
             cx.tcx,
             &doc,
             &offset_reference_def_range(doc, dest, link_range),
-            &item.attrs,
+            &item.attrs.doc_strings,
         )?;
 
         cx.tcx.struct_span_lint_hir(crate::lint::REDUNDANT_EXPLICIT_LINKS, hir_id, explicit_span, "redundant explicit link target", |lint| {
diff --git a/src/librustdoc/passes/lint/unescaped_backticks.rs b/src/librustdoc/passes/lint/unescaped_backticks.rs
index 256958d7160..8b7fdd6ab1f 100644
--- a/src/librustdoc/passes/lint/unescaped_backticks.rs
+++ b/src/librustdoc/passes/lint/unescaped_backticks.rs
@@ -3,10 +3,10 @@
 use crate::clean::Item;
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
-use crate::passes::source_span_for_markdown_range;
 use pulldown_cmark::{BrokenLink, Event, Parser};
 use rustc_errors::DiagnosticBuilder;
 use rustc_lint_defs::Applicability;
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use std::ops::Range;
 
 pub(crate) fn visit_item(cx: &DocContext<'_>, item: &Item) {
@@ -52,7 +52,7 @@ pub(crate) fn visit_item(cx: &DocContext<'_>, item: &Item) {
                     tcx,
                     &dox,
                     &(backtick_index..backtick_index + 1),
-                    &item.attrs,
+                    &item.attrs.doc_strings,
                 )
                 .unwrap_or_else(|| item.attr_span(tcx));
 
@@ -378,9 +378,12 @@ fn suggest_insertion(
     /// Maximum bytes of context to show around the insertion.
     const CONTEXT_MAX_LEN: usize = 80;
 
-    if let Some(span) =
-        source_span_for_markdown_range(cx.tcx, &dox, &(insert_index..insert_index), &item.attrs)
-    {
+    if let Some(span) = source_span_for_markdown_range(
+        cx.tcx,
+        &dox,
+        &(insert_index..insert_index),
+        &item.attrs.doc_strings,
+    ) {
         lint.span_suggestion(span, message, suggestion, Applicability::MaybeIncorrect);
     } else {
         let line_start = dox[..insert_index].rfind('\n').map_or(0, |idx| idx + 1);
diff --git a/src/librustdoc/passes/mod.rs b/src/librustdoc/passes/mod.rs
index 4b1ff68df50..bb678e33888 100644
--- a/src/librustdoc/passes/mod.rs
+++ b/src/librustdoc/passes/mod.rs
@@ -1,11 +1,6 @@
 //! Contains information about "passes", used to modify crate information during the documentation
 //! process.
 
-use rustc_middle::ty::TyCtxt;
-use rustc_resolve::rustdoc::DocFragmentKind;
-use rustc_span::{InnerSpan, Span, DUMMY_SP};
-use std::ops::Range;
-
 use self::Condition::*;
 use crate::clean;
 use crate::core::DocContext;
@@ -115,89 +110,3 @@ impl ConditionalPass {
 pub(crate) fn defaults(show_coverage: bool) -> &'static [ConditionalPass] {
     if show_coverage { COVERAGE_PASSES } else { DEFAULT_PASSES }
 }
-
-/// Returns a span encompassing all the given attributes.
-pub(crate) fn span_of_attrs(attrs: &clean::Attributes) -> Option<Span> {
-    if attrs.doc_strings.is_empty() {
-        return None;
-    }
-    let start = attrs.doc_strings[0].span;
-    if start == DUMMY_SP {
-        return None;
-    }
-    let end = attrs.doc_strings.last().expect("no doc strings provided").span;
-    Some(start.to(end))
-}
-
-/// Attempts to match a range of bytes from parsed markdown to a `Span` in the source code.
-///
-/// This method will return `None` if we cannot construct a span from the source map or if the
-/// attributes are not all sugared doc comments. It's difficult to calculate the correct span in
-/// that case due to escaping and other source features.
-pub(crate) fn source_span_for_markdown_range(
-    tcx: TyCtxt<'_>,
-    markdown: &str,
-    md_range: &Range<usize>,
-    attrs: &clean::Attributes,
-) -> Option<Span> {
-    let is_all_sugared_doc =
-        attrs.doc_strings.iter().all(|frag| frag.kind == DocFragmentKind::SugaredDoc);
-
-    if !is_all_sugared_doc {
-        return None;
-    }
-
-    let snippet = tcx.sess.source_map().span_to_snippet(span_of_attrs(attrs)?).ok()?;
-
-    let starting_line = markdown[..md_range.start].matches('\n').count();
-    let ending_line = starting_line + markdown[md_range.start..md_range.end].matches('\n').count();
-
-    // We use `split_terminator('\n')` instead of `lines()` when counting bytes so that we treat
-    // CRLF and LF line endings the same way.
-    let mut src_lines = snippet.split_terminator('\n');
-    let md_lines = markdown.split_terminator('\n');
-
-    // The number of bytes from the source span to the markdown span that are not part
-    // of the markdown, like comment markers.
-    let mut start_bytes = 0;
-    let mut end_bytes = 0;
-
-    'outer: for (line_no, md_line) in md_lines.enumerate() {
-        loop {
-            let source_line = src_lines.next()?;
-            match source_line.find(md_line) {
-                Some(offset) => {
-                    if line_no == starting_line {
-                        start_bytes += offset;
-
-                        if starting_line == ending_line {
-                            break 'outer;
-                        }
-                    } else if line_no == ending_line {
-                        end_bytes += offset;
-                        break 'outer;
-                    } else if line_no < starting_line {
-                        start_bytes += source_line.len() - md_line.len();
-                    } else {
-                        end_bytes += source_line.len() - md_line.len();
-                    }
-                    break;
-                }
-                None => {
-                    // Since this is a source line that doesn't include a markdown line,
-                    // we have to count the newline that we split from earlier.
-                    if line_no <= starting_line {
-                        start_bytes += source_line.len() + 1;
-                    } else {
-                        end_bytes += source_line.len() + 1;
-                    }
-                }
-            }
-        }
-    }
-
-    Some(span_of_attrs(attrs)?.from_inner(InnerSpan::new(
-        md_range.start + start_bytes,
-        md_range.end + start_bytes + end_bytes,
-    )))
-}