Box TypedefItem, ImplItem, AssocTypeItem variants of ItemKind

This reduces ItemKind size from 224 bytes to 160 bytes.

Author: est31

src/librustdoc/clean/auto_trait.rs

@@ -117,15 +117,15 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
             attrs: Default::default(),
             visibility: Inherited,
             item_id: ItemId::Auto { trait_: trait_def_id, for_: item_def_id },
-            kind: Box::new(ImplItem(Impl {
+            kind: Box::new(ImplItem(Box::new(Impl {
                 unsafety: hir::Unsafety::Normal,
                 generics: new_generics,
                 trait_: Some(trait_ref.clean(self.cx)),
                 for_: clean_middle_ty(ty, self.cx, None),
                 items: Vec::new(),
                 polarity,
                 kind: ImplKind::Auto,
-            })),
+            }))),
             cfg: None,
         })
     }

src/librustdoc/clean/blanket_impl.rs

@@ -106,7 +106,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
                         attrs: Default::default(),
                         visibility: Inherited,
                         item_id: ItemId::Blanket { impl_id: impl_def_id, for_: item_def_id },
-                        kind: Box::new(ImplItem(Impl {
+                        kind: Box::new(ImplItem(Box::new(Impl {
                             unsafety: hir::Unsafety::Normal,
                             generics: clean_ty_generics(
                                 cx,
@@ -124,7 +124,7 @@ impl<'a, 'tcx> BlanketImplFinder<'a, 'tcx> {
                                 .collect::<Vec<_>>(),
                             polarity: ty::ImplPolarity::Positive,
                             kind: ImplKind::Blanket(Box::new(clean_middle_ty(trait_ref.0.self_ty(), cx, None))),
-                        })),
+                        }))),
                         cfg: None,
                     });
                 }

src/librustdoc/clean/inline.rs

@@ -260,15 +260,15 @@ fn build_union(cx: &mut DocContext<'_>, did: DefId) -> clean::Union {
     clean::Union { generics, fields }
 }
 
-fn build_type_alias(cx: &mut DocContext<'_>, did: DefId) -> clean::Typedef {
+fn build_type_alias(cx: &mut DocContext<'_>, did: DefId) -> Box<clean::Typedef> {
     let predicates = cx.tcx.explicit_predicates_of(did);
     let type_ = clean_middle_ty(cx.tcx.type_of(did), cx, Some(did));
 
-    clean::Typedef {
+    Box::new(clean::Typedef {
         type_,
         generics: clean_ty_generics(cx, cx.tcx.generics_of(did), predicates),
         item_type: None,
-    }
+    })
 }
 
 /// Builds all inherent implementations of an ADT (struct/union/enum) or Trait item/path/reexport.
@@ -493,7 +493,7 @@ pub(crate) fn build_impl(
     ret.push(clean::Item::from_def_id_and_attrs_and_parts(
         did,
         None,
-        clean::ImplItem(clean::Impl {
+        clean::ImplItem(Box::new(clean::Impl {
             unsafety: hir::Unsafety::Normal,
             generics,
             trait_,
@@ -505,7 +505,7 @@ pub(crate) fn build_impl(
             } else {
                 ImplKind::Normal
             },
-        }),
+        })),
         Box::new(merged_attrs),
         cx,
         cfg,

src/librustdoc/clean/mod.rs

@@ -1068,11 +1068,11 @@ impl<'tcx> Clean<'tcx, Item> for hir::TraitItem<'tcx> {
                     let bounds = bounds.iter().filter_map(|x| x.clean(cx)).collect();
                     let item_type = clean_middle_ty(hir_ty_to_ty(cx.tcx, default), cx, None);
                     AssocTypeItem(
-                        Typedef {
+                        Box::new(Typedef {
                             type_: clean_ty(default, cx),
                             generics,
                             item_type: Some(item_type),
-                        },
+                        }),
                         bounds,
                     )
                 }
@@ -1109,7 +1109,7 @@ impl<'tcx> Clean<'tcx, Item> for hir::ImplItem<'tcx> {
                     let generics = self.generics.clean(cx);
                     let item_type = clean_middle_ty(hir_ty_to_ty(cx.tcx, hir_ty), cx, None);
                     AssocTypeItem(
-                        Typedef { type_, generics, item_type: Some(item_type) },
+                        Box::new(Typedef { type_, generics, item_type: Some(item_type) }),
                         Vec::new(),
                     )
                 }
@@ -1282,7 +1282,7 @@ impl<'tcx> Clean<'tcx, Item> for ty::AssocItem {
 
                     if self.defaultness.has_value() {
                         AssocTypeItem(
-                            Typedef {
+                            Box::new(Typedef {
                                 type_: clean_middle_ty(
                                     tcx.type_of(self.def_id),
                                     cx,
@@ -1291,7 +1291,7 @@ impl<'tcx> Clean<'tcx, Item> for ty::AssocItem {
                                 generics,
                                 // FIXME: should we obtain the Type from HIR and pass it on here?
                                 item_type: None,
-                            },
+                            }),
                             bounds,
                         )
                     } else {
@@ -1300,11 +1300,11 @@ impl<'tcx> Clean<'tcx, Item> for ty::AssocItem {
                 } else {
                     // FIXME: when could this happen? Associated items in inherent impls?
                     AssocTypeItem(
-                        Typedef {
+                        Box::new(Typedef {
                             type_: clean_middle_ty(tcx.type_of(self.def_id), cx, Some(self.def_id)),
                             generics: Generics { params: Vec::new(), where_predicates: Vec::new() },
                             item_type: None,
-                        },
+                        }),
                         Vec::new(),
                     )
                 }
@@ -1949,11 +1949,11 @@ fn clean_maybe_renamed_item<'tcx>(
             ItemKind::TyAlias(hir_ty, generics) => {
                 let rustdoc_ty = clean_ty(hir_ty, cx);
                 let ty = clean_middle_ty(hir_ty_to_ty(cx.tcx, hir_ty), cx, None);
-                TypedefItem(Typedef {
+                TypedefItem(Box::new(Typedef {
                     type_: rustdoc_ty,
                     generics: generics.clean(cx),
                     item_type: Some(ty),
-                })
+                }))
             }
             ItemKind::Enum(ref def, generics) => EnumItem(Enum {
                 variants: def.variants.iter().map(|v| v.clean(cx)).collect(),
@@ -2041,7 +2041,7 @@ fn clean_impl<'tcx>(
         _ => None,
     });
     let mut make_item = |trait_: Option<Path>, for_: Type, items: Vec<Item>| {
-        let kind = ImplItem(Impl {
+        let kind = ImplItem(Box::new(Impl {
             unsafety: impl_.unsafety,
             generics: impl_.generics.clean(cx),
             trait_,
@@ -2053,7 +2053,7 @@ fn clean_impl<'tcx>(
             } else {
                 ImplKind::Normal
             },
-        });
+        }));
         Item::from_hir_id_and_parts(hir_id, None, kind, cx)
     };
     if let Some(type_alias) = type_alias {

src/librustdoc/clean/types.rs

@@ -430,8 +430,8 @@ impl Item {
         };
         match kind {
             ItemKind::ModuleItem(Module { span, .. }) => *span,
-            ItemKind::ImplItem(Impl { kind: ImplKind::Auto, .. }) => Span::dummy(),
-            ItemKind::ImplItem(Impl { kind: ImplKind::Blanket(_), .. }) => {
+            ItemKind::ImplItem(box Impl { kind: ImplKind::Auto, .. }) => Span::dummy(),
+            ItemKind::ImplItem(box Impl { kind: ImplKind::Blanket(_), .. }) => {
                 if let ItemId::Blanket { impl_id, .. } = self.item_id {
                     rustc_span(impl_id, tcx)
                 } else {
@@ -732,13 +732,13 @@ pub(crate) enum ItemKind {
     EnumItem(Enum),
     FunctionItem(Function),
     ModuleItem(Module),
-    TypedefItem(Typedef),
+    TypedefItem(Box<Typedef>),
     OpaqueTyItem(OpaqueTy),
     StaticItem(Static),
     ConstantItem(Constant),
     TraitItem(Trait),
     TraitAliasItem(TraitAlias),
-    ImplItem(Impl),
+    ImplItem(Box<Impl>),
     /// A required method in a trait declaration meaning it's only a function signature.
     TyMethodItem(Function),
     /// A method in a trait impl or a provided method in a trait declaration.
@@ -765,7 +765,7 @@ pub(crate) enum ItemKind {
     /// The bounds may be non-empty if there is a `where` clause.
     TyAssocTypeItem(Box<Generics>, Vec<GenericBound>),
     /// An associated type in a trait impl or a provided one in a trait declaration.
-    AssocTypeItem(Typedef, Vec<GenericBound>),
+    AssocTypeItem(Box<Typedef>, Vec<GenericBound>),
     /// An item that has been stripped by a rustdoc pass
     StrippedItem(Box<ItemKind>),
     KeywordItem,

src/librustdoc/formats/cache.rs

@@ -536,7 +536,7 @@ enum ParentStackItem {
 impl ParentStackItem {
     fn new(item: &clean::Item) -> Self {
         match &*item.kind {
-            clean::ItemKind::ImplItem(clean::Impl { for_, trait_, generics, kind, .. }) => {
+            clean::ItemKind::ImplItem(box clean::Impl { for_, trait_, generics, kind, .. }) => {
                 ParentStackItem::Impl {
                     for_: for_.clone(),
                     trait_: trait_.clone(),

src/librustdoc/html/render/mod.rs

@@ -1160,7 +1160,7 @@ fn render_deref_methods(
         .items
         .iter()
         .find_map(|item| match *item.kind {
-            clean::AssocTypeItem(ref t, _) => Some(match *t {
+            clean::AssocTypeItem(box ref t, _) => Some(match *t {
                 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
                 _ => (&t.type_, &t.type_),
             }),
@@ -2054,7 +2054,7 @@ fn sidebar_deref_methods(
     debug!("found Deref: {:?}", impl_);
     if let Some((target, real_target)) =
         impl_.inner_impl().items.iter().find_map(|item| match *item.kind {
-            clean::AssocTypeItem(ref t, _) => Some(match *t {
+            clean::AssocTypeItem(box ref t, _) => Some(match *t {
                 clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
                 _ => (&t.type_, &t.type_),
             }),

src/librustdoc/json/conversions.rs

@@ -568,10 +568,10 @@ impl FromWithTcx<clean::Trait> for Trait {
     }
 }
 
-impl FromWithTcx<clean::Impl> for Impl {
-    fn from_tcx(impl_: clean::Impl, tcx: TyCtxt<'_>) -> Self {
+impl FromWithTcx<Box<clean::Impl>> for Impl {
+    fn from_tcx(impl_: Box<clean::Impl>, tcx: TyCtxt<'_>) -> Self {
         let provided_trait_methods = impl_.provided_trait_methods(tcx);
-        let clean::Impl { unsafety, generics, trait_, for_, items, polarity, kind } = impl_;
+        let clean::Impl { unsafety, generics, trait_, for_, items, polarity, kind } = *impl_;
         // FIXME: should `trait_` be a clean::Path equivalent in JSON?
         let trait_ = trait_.map(|path| clean::Type::Path { path }.into_tcx(tcx));
         // FIXME: use something like ImplKind in JSON?
@@ -721,9 +721,9 @@ pub(crate) fn from_macro_kind(kind: rustc_span::hygiene::MacroKind) -> MacroKind
     }
 }
 
-impl FromWithTcx<clean::Typedef> for Typedef {
-    fn from_tcx(typedef: clean::Typedef, tcx: TyCtxt<'_>) -> Self {
-        let clean::Typedef { type_, generics, item_type: _ } = typedef;
+impl FromWithTcx<Box<clean::Typedef>> for Typedef {
+    fn from_tcx(typedef: Box<clean::Typedef>, tcx: TyCtxt<'_>) -> Self {
+        let clean::Typedef { type_, generics, item_type: _ } = *typedef;
         Typedef { type_: type_.into_tcx(tcx), generics: generics.into_tcx(tcx) }
     }
 }

src/librustdoc/passes/check_doc_test_visibility.rs

@@ -71,7 +71,7 @@ pub(crate) fn should_have_doc_example(cx: &DocContext<'_>, item: &clean::Item) -
                 | clean::PrimitiveItem(_)
                 | clean::KeywordItem
                 // check for trait impl
-                | clean::ImplItem(clean::Impl { trait_: Some(_), .. })
+                | clean::ImplItem(box clean::Impl { trait_: Some(_), .. })
         )
     {
         return false;

src/librustdoc/passes/collect_trait_impls.rs

@@ -146,7 +146,7 @@ pub(crate) fn collect_trait_impls(mut krate: Crate, cx: &mut DocContext<'_>) ->
 
     // scan through included items ahead of time to splice in Deref targets to the "valid" sets
     for it in new_items_external.iter().chain(new_items_local.iter()) {
-        if let ImplItem(Impl { ref for_, ref trait_, ref items, .. }) = *it.kind {
+        if let ImplItem(box Impl { ref for_, ref trait_, ref items, .. }) = *it.kind {
             if trait_.as_ref().map(|t| t.def_id()) == cx.tcx.lang_items().deref_trait()
                 && cleaner.keep_impl(for_, true)
             {
@@ -187,7 +187,7 @@ pub(crate) fn collect_trait_impls(mut krate: Crate, cx: &mut DocContext<'_>) ->
 
     // Filter out external items that are not needed
     new_items_external.retain(|it| {
-        if let ImplItem(Impl { ref for_, ref trait_, ref kind, .. }) = *it.kind {
+        if let ImplItem(box Impl { ref for_, ref trait_, ref kind, .. }) = *it.kind {
             cleaner.keep_impl(
                 for_,
                 trait_.as_ref().map(|t| t.def_id()) == cx.tcx.lang_items().deref_trait(),