box a bunch of large types

16 files changed, 83 insertions, 79 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 985b66e6bea..14c190daf35 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -2917,11 +2917,11 @@ pub enum ItemKind {
     /// A static item (`static`).
     ///
     /// E.g., `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`.
-    Static(Static),
+    Static(Box<Static>),
     /// A constant item (`const`).
     ///
     /// E.g., `const FOO: i32 = 42;`.
-    Const(ConstItem),
+    Const(Box<ConstItem>),
     /// A function declaration (`fn`).
     ///
     /// E.g., `fn foo(bar: usize) -> usize { .. }`.
@@ -3037,7 +3037,7 @@ pub type AssocItem = Item<AssocItemKind>;
 pub enum AssocItemKind {
     /// An associated constant, `const $ident: $ty $def?;` where `def ::= "=" $expr? ;`.
     /// If `def` is parsed, then the constant is provided, and otherwise required.
-    Const(ConstItem),
+    Const(Box<ConstItem>),
     /// An associated function.
     Fn(Box<Fn>),
     /// An associated type.
@@ -3049,7 +3049,7 @@ pub enum AssocItemKind {
 impl AssocItemKind {
     pub fn defaultness(&self) -> Defaultness {
         match *self {
-            Self::Const(ConstItem { defaultness, .. })
+            Self::Const(box ConstItem { defaultness, .. })
             | Self::Fn(box Fn { defaultness, .. })
             | Self::Type(box TyAlias { defaultness, .. }) => defaultness,
             Self::MacCall(..) => Defaultness::Final,
@@ -3099,7 +3099,7 @@ impl From<ForeignItemKind> for ItemKind {
     fn from(foreign_item_kind: ForeignItemKind) -> ItemKind {
         match foreign_item_kind {
             ForeignItemKind::Static(a, b, c) => {
-                ItemKind::Static(Static { ty: a, mutability: b, expr: c })
+                ItemKind::Static(Static { ty: a, mutability: b, expr: c }.into())
             }
             ForeignItemKind::Fn(fn_kind) => ItemKind::Fn(fn_kind),
             ForeignItemKind::TyAlias(ty_alias_kind) => ItemKind::TyAlias(ty_alias_kind),
@@ -3113,7 +3113,7 @@ impl TryFrom<ItemKind> for ForeignItemKind {
 
     fn try_from(item_kind: ItemKind) -> Result<ForeignItemKind, ItemKind> {
         Ok(match item_kind {
-            ItemKind::Static(Static { ty: a, mutability: b, expr: c }) => {
+            ItemKind::Static(box Static { ty: a, mutability: b, expr: c }) => {
                 ForeignItemKind::Static(a, b, c)
             }
             ItemKind::Fn(fn_kind) => ForeignItemKind::Fn(fn_kind),
@@ -3132,8 +3132,8 @@ mod size_asserts {
     use super::*;
     use rustc_data_structures::static_assert_size;
     // tidy-alphabetical-start
-    static_assert_size!(AssocItem, 104);
-    static_assert_size!(AssocItemKind, 32);
+    static_assert_size!(AssocItem, 88);
+    static_assert_size!(AssocItemKind, 16);
     static_assert_size!(Attribute, 32);
     static_assert_size!(Block, 32);
     static_assert_size!(Expr, 72);
diff --git a/compiler/rustc_ast/src/mut_visit.rs b/compiler/rustc_ast/src/mut_visit.rs
index e99a2fee67c..4d569e0fb94 100644
--- a/compiler/rustc_ast/src/mut_visit.rs
+++ b/compiler/rustc_ast/src/mut_visit.rs
@@ -1030,7 +1030,7 @@ pub fn noop_visit_item_kind<T: MutVisitor>(kind: &mut ItemKind, vis: &mut T) {
     match kind {
         ItemKind::ExternCrate(_orig_name) => {}
         ItemKind::Use(use_tree) => vis.visit_use_tree(use_tree),
-        ItemKind::Static(Static { ty, mutability: _, expr }) => {
+        ItemKind::Static(box Static { ty, mutability: _, expr }) => {
             vis.visit_ty(ty);
             visit_opt(expr, |expr| vis.visit_expr(expr));
         }
diff --git a/compiler/rustc_ast/src/visit.rs b/compiler/rustc_ast/src/visit.rs
index 55a17efe416..970bda58f35 100644
--- a/compiler/rustc_ast/src/visit.rs
+++ b/compiler/rustc_ast/src/visit.rs
@@ -305,8 +305,8 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
     match &item.kind {
         ItemKind::ExternCrate(_) => {}
         ItemKind::Use(use_tree) => visitor.visit_use_tree(use_tree, item.id, false),
-        ItemKind::Static(Static { ty, mutability: _, expr })
-        | ItemKind::Const(ConstItem { ty, expr, .. }) => {
+        ItemKind::Static(box Static { ty, mutability: _, expr })
+        | ItemKind::Const(box ConstItem { ty, expr, .. }) => {
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_expr, expr);
         }
@@ -675,7 +675,7 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem,
     visitor.visit_ident(ident);
     walk_list!(visitor, visit_attribute, attrs);
     match kind {
-        AssocItemKind::Const(ConstItem { ty, expr, .. }) => {
+        AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
             visitor.visit_ty(ty);
             walk_list!(visitor, visit_expr, expr);
         }
diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index b41bb5017e5..803dbbffbd8 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -229,11 +229,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
                 self.lower_use_tree(use_tree, &prefix, id, vis_span, ident, attrs)
             }
-            ItemKind::Static(ast::Static { ty: t, mutability: m, expr: e }) => {
+            ItemKind::Static(box ast::Static { ty: t, mutability: m, expr: e }) => {
                 let (ty, body_id) = self.lower_const_item(t, span, e.as_deref());
                 hir::ItemKind::Static(ty, *m, body_id)
             }
-            ItemKind::Const(ast::ConstItem { ty, expr, .. }) => {
+            ItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
                 let (ty, body_id) = self.lower_const_item(ty, span, expr.as_deref());
                 hir::ItemKind::Const(ty, body_id)
             }
@@ -708,7 +708,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let trait_item_def_id = hir_id.expect_owner();
 
         let (generics, kind, has_default) = match &i.kind {
-            AssocItemKind::Const(ConstItem { ty, expr, .. }) => {
+            AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
                 let ty =
                     self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy));
                 let body = expr.as_ref().map(|x| self.lower_const_body(i.span, Some(x)));
@@ -809,7 +809,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.lower_attrs(hir_id, &i.attrs);
 
         let (generics, kind) = match &i.kind {
-            AssocItemKind::Const(ConstItem { ty, expr, .. }) => {
+            AssocItemKind::Const(box ConstItem { ty, expr, .. }) => {
                 let ty =
                     self.lower_ty(ty, &ImplTraitContext::Disallowed(ImplTraitPosition::ConstTy));
                 (
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index 43d086ec52d..431a569c1e0 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -983,14 +983,14 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                     self.err_handler().emit_err(errors::FieldlessUnion { span: item.span });
                 }
             }
-            ItemKind::Const(ConstItem { defaultness, expr: None, .. }) => {
+            ItemKind::Const(box ConstItem { defaultness, expr: None, .. }) => {
                 self.check_defaultness(item.span, *defaultness);
                 self.session.emit_err(errors::ConstWithoutBody {
                     span: item.span,
                     replace_span: self.ending_semi_or_hi(item.span),
                 });
             }
-            ItemKind::Static(Static { expr: None, .. }) => {
+            ItemKind::Static(box Static { expr: None, .. }) => {
                 self.session.emit_err(errors::StaticWithoutBody {
                     span: item.span,
                     replace_span: self.ending_semi_or_hi(item.span),
@@ -1259,7 +1259,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
 
         if ctxt == AssocCtxt::Impl {
             match &item.kind {
-                AssocItemKind::Const(ConstItem { expr: None, .. }) => {
+                AssocItemKind::Const(box ConstItem { expr: None, .. }) => {
                     self.session.emit_err(errors::AssocConstWithoutBody {
                         span: item.span,
                         replace_span: self.ending_semi_or_hi(item.span),
diff --git a/compiler/rustc_ast_pretty/src/pprust/state/item.rs b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
index 92b9c8fd766..e2d133eb233 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state/item.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state/item.rs
@@ -157,7 +157,7 @@ impl<'a> State<'a> {
                 self.print_use_tree(tree);
                 self.word(";");
             }
-            ast::ItemKind::Static(Static { ty, mutability: mutbl, expr: body }) => {
+            ast::ItemKind::Static(box Static { ty, mutability: mutbl, expr: body }) => {
                 let def = ast::Defaultness::Final;
                 self.print_item_const(
                     item.ident,
@@ -168,7 +168,7 @@ impl<'a> State<'a> {
                     def,
                 );
             }
-            ast::ItemKind::Const(ast::ConstItem { defaultness, ty, expr }) => {
+            ast::ItemKind::Const(box ast::ConstItem { defaultness, ty, expr }) => {
                 self.print_item_const(
                     item.ident,
                     None,
@@ -515,7 +515,7 @@ impl<'a> State<'a> {
             ast::AssocItemKind::Fn(box ast::Fn { defaultness, sig, generics, body }) => {
                 self.print_fn_full(sig, ident, generics, vis, *defaultness, body.as_deref(), attrs);
             }
-            ast::AssocItemKind::Const(ast::ConstItem { defaultness, ty, expr }) => {
+            ast::AssocItemKind::Const(box ast::ConstItem { defaultness, ty, expr }) => {
                 self.print_item_const(ident, None, ty, expr.as_deref(), vis, *defaultness);
             }
             ast::AssocItemKind::Type(box ast::TyAlias {
diff --git a/compiler/rustc_builtin_macros/src/global_allocator.rs b/compiler/rustc_builtin_macros/src/global_allocator.rs
index f26e2572088..34361a6d868 100644
--- a/compiler/rustc_builtin_macros/src/global_allocator.rs
+++ b/compiler/rustc_builtin_macros/src/global_allocator.rs
@@ -25,12 +25,12 @@ pub fn expand(
     // FIXME - if we get deref patterns, use them to reduce duplication here
     let (item, is_stmt, ty_span) =
         if let Annotatable::Item(item) = &item
-            && let ItemKind::Static(ast::Static { ty, ..}) = &item.kind
+            && let ItemKind::Static(box ast::Static { ty, ..}) = &item.kind
         {
             (item, false, ecx.with_def_site_ctxt(ty.span))
         } else if let Annotatable::Stmt(stmt) = &item
             && let StmtKind::Item(item) = &stmt.kind
-            && let ItemKind::Static(ast::Static { ty, ..}) = &item.kind
+            && let ItemKind::Static(box ast::Static { ty, ..}) = &item.kind
         {
             (item, true, ecx.with_def_site_ctxt(ty.span))
         } else {
diff --git a/compiler/rustc_builtin_macros/src/test.rs b/compiler/rustc_builtin_macros/src/test.rs
index ced341e5413..a76ed4ee6ce 100644
--- a/compiler/rustc_builtin_macros/src/test.rs
+++ b/compiler/rustc_builtin_macros/src/test.rs
@@ -254,25 +254,27 @@ pub fn expand_test_or_bench(
 
     let location_info = get_location_info(cx, &item);
 
-    let mut test_const = cx.item(
-        sp,
-        Ident::new(item.ident.name, sp),
-        thin_vec![
-            // #[cfg(test)]
-            cx.attr_nested_word(sym::cfg, sym::test, attr_sp),
-            // #[rustc_test_marker = "test_case_sort_key"]
-            cx.attr_name_value_str(sym::rustc_test_marker, test_path_symbol, attr_sp),
-        ],
-        // const $ident: test::TestDescAndFn =
-        ast::ItemKind::Const(ast::ConstItem {
-            defaultness: ast::Defaultness::Final,
-            ty: cx.ty(sp, ast::TyKind::Path(None, test_path("TestDescAndFn"))),
-            // test::TestDescAndFn {
-            expr: Some(
-                cx.expr_struct(
-                    sp,
-                    test_path("TestDescAndFn"),
-                    thin_vec![
+    let mut test_const =
+        cx.item(
+            sp,
+            Ident::new(item.ident.name, sp),
+            thin_vec![
+                // #[cfg(test)]
+                cx.attr_nested_word(sym::cfg, sym::test, attr_sp),
+                // #[rustc_test_marker = "test_case_sort_key"]
+                cx.attr_name_value_str(sym::rustc_test_marker, test_path_symbol, attr_sp),
+            ],
+            // const $ident: test::TestDescAndFn =
+            ast::ItemKind::Const(
+                ast::ConstItem {
+                    defaultness: ast::Defaultness::Final,
+                    ty: cx.ty(sp, ast::TyKind::Path(None, test_path("TestDescAndFn"))),
+                    // test::TestDescAndFn {
+                    expr: Some(
+                        cx.expr_struct(
+                            sp,
+                            test_path("TestDescAndFn"),
+                            thin_vec![
                         // desc: test::TestDesc {
                         field(
                             "desc",
@@ -359,10 +361,12 @@ pub fn expand_test_or_bench(
                         // testfn: test::StaticTestFn(...) | test::StaticBenchFn(...)
                         field("testfn", test_fn), // }
                     ],
-                ), // }
+                        ), // }
+                    ),
+                }
+                .into(),
             ),
-        }),
-    );
+        );
     test_const = test_const.map(|mut tc| {
         tc.vis.kind = ast::VisibilityKind::Public;
         tc
diff --git a/compiler/rustc_expand/src/build.rs b/compiler/rustc_expand/src/build.rs
index 39fed9fdd0d..59c588b3955 100644
--- a/compiler/rustc_expand/src/build.rs
+++ b/compiler/rustc_expand/src/build.rs
@@ -627,7 +627,7 @@ impl<'a> ExtCtxt<'a> {
             span,
             name,
             AttrVec::new(),
-            ast::ItemKind::Static(ast::Static { ty, mutability, expr: Some(expr) }),
+            ast::ItemKind::Static(ast::Static { ty, mutability, expr: Some(expr) }.into()),
         )
     }
 
@@ -643,7 +643,7 @@ impl<'a> ExtCtxt<'a> {
             span,
             name,
             AttrVec::new(),
-            ast::ItemKind::Const(ast::ConstItem { defaultness, ty, expr: Some(expr) }),
+            ast::ItemKind::Const(ast::ConstItem { defaultness, ty, expr: Some(expr) }.into()),
         )
     }
 
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index d920e237508..c856e973e5c 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -805,8 +805,8 @@ trait UnusedDelimLint {
     fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
         use ast::ItemKind::*;
 
-        if let Const(ast::ConstItem { expr: Some(expr), .. })
-        | Static(ast::Static { expr: Some(expr), .. }) = &item.kind
+        if let Const(box ast::ConstItem { expr: Some(expr), .. })
+        | Static(box ast::Static { expr: Some(expr), .. }) = &item.kind
         {
             self.check_unused_delims_expr(
                 cx,
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs
index f6422d30ba5..66fa9fb38d4 100644
--- a/compiler/rustc_parse/src/parser/item.rs
+++ b/compiler/rustc_parse/src/parser/item.rs
@@ -228,7 +228,7 @@ impl<'a> Parser<'a> {
             self.bump(); // `static`
             let m = self.parse_mutability();
             let (ident, ty, expr) = self.parse_item_global(Some(m))?;
-            (ident, ItemKind::Static(Static { ty, mutability: m, expr }))
+            (ident, ItemKind::Static(Box::new(Static { ty, mutability: m, expr })))
         } else if let Const::Yes(const_span) = self.parse_constness(Case::Sensitive) {
             // CONST ITEM
             if self.token.is_keyword(kw::Impl) {
@@ -237,7 +237,7 @@ impl<'a> Parser<'a> {
             } else {
                 self.recover_const_mut(const_span);
                 let (ident, ty, expr) = self.parse_item_global(None)?;
-                (ident, ItemKind::Const(ConstItem { defaultness: def_(), ty, expr }))
+                (ident, ItemKind::Const(Box::new(ConstItem { defaultness: def_(), ty, expr })))
             }
         } else if self.check_keyword(kw::Trait) || self.check_auto_or_unsafe_trait_item() {
             // TRAIT ITEM
@@ -863,13 +863,13 @@ impl<'a> Parser<'a> {
                 let kind = match AssocItemKind::try_from(kind) {
                     Ok(kind) => kind,
                     Err(kind) => match kind {
-                        ItemKind::Static(Static { ty, mutability: _, expr }) => {
+                        ItemKind::Static(box Static { ty, mutability: _, expr }) => {
                             self.sess.emit_err(errors::AssociatedStaticItemNotAllowed { span });
-                            AssocItemKind::Const(ConstItem {
+                            AssocItemKind::Const(Box::new(ConstItem {
                                 defaultness: Defaultness::Final,
                                 ty,
                                 expr,
-                            })
+                            }))
                         }
                         _ => return self.error_bad_item_kind(span, &kind, "`trait`s or `impl`s"),
                     },
@@ -1119,7 +1119,7 @@ impl<'a> Parser<'a> {
                 let kind = match ForeignItemKind::try_from(kind) {
                     Ok(kind) => kind,
                     Err(kind) => match kind {
-                        ItemKind::Const(ConstItem { ty, expr, .. }) => {
+                        ItemKind::Const(box ConstItem { ty, expr, .. }) => {
                             self.sess.emit_err(errors::ExternItemCannotBeConst {
                                 ident_span: ident.span,
                                 const_span: span.with_hi(ident.span.lo()),
diff --git a/compiler/rustc_resolve/src/build_reduced_graph.rs b/compiler/rustc_resolve/src/build_reduced_graph.rs
index 3a79ddca2eb..10d282a21a7 100644
--- a/compiler/rustc_resolve/src/build_reduced_graph.rs
+++ b/compiler/rustc_resolve/src/build_reduced_graph.rs
@@ -688,7 +688,7 @@ impl<'a, 'b, 'tcx> BuildReducedGraphVisitor<'a, 'b, 'tcx> {
             }
 
             // These items live in the value namespace.
-            ItemKind::Static(ast::Static { mutability, .. }) => {
+            ItemKind::Static(box ast::Static { mutability, .. }) => {
                 let res = Res::Def(DefKind::Static(mutability), def_id);
                 self.r.define(parent, ident, ValueNS, (res, vis, sp, expansion));
             }
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 735644ec8d5..d38bfc62abd 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -2346,8 +2346,8 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 });
             }
 
-            ItemKind::Static(ast::Static { ref ty, ref expr, .. })
-            | ItemKind::Const(ast::ConstItem { ref ty, ref expr, .. }) => {
+            ItemKind::Static(box ast::Static { ref ty, ref expr, .. })
+            | ItemKind::Const(box ast::ConstItem { ref ty, ref expr, .. }) => {
                 self.with_static_rib(|this| {
                     this.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Static), |this| {
                         this.visit_ty(ty);
@@ -2625,7 +2625,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         for item in trait_items {
             self.resolve_doc_links(&item.attrs, MaybeExported::Ok(item.id));
             match &item.kind {
-                AssocItemKind::Const(ast::ConstItem { ty, expr, .. }) => {
+                AssocItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
                     self.visit_ty(ty);
                     // Only impose the restrictions of `ConstRibKind` for an
                     // actual constant expression in a provided default.
@@ -2800,7 +2800,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         use crate::ResolutionError::*;
         self.resolve_doc_links(&item.attrs, MaybeExported::ImplItem(trait_id.ok_or(&item.vis)));
         match &item.kind {
-            AssocItemKind::Const(ast::ConstItem { ty, expr, .. }) => {
+            AssocItemKind::Const(box ast::ConstItem { ty, expr, .. }) => {
                 debug!("resolve_implementation AssocItemKind::Const");
                 // If this is a trait impl, ensure the const
                 // exists in trait
diff --git a/src/tools/clippy/clippy_lints/src/redundant_static_lifetimes.rs b/src/tools/clippy/clippy_lints/src/redundant_static_lifetimes.rs
index d41f79f8131..aa47f3aed54 100644
--- a/src/tools/clippy/clippy_lints/src/redundant_static_lifetimes.rs
+++ b/src/tools/clippy/clippy_lints/src/redundant_static_lifetimes.rs
@@ -100,13 +100,13 @@ impl EarlyLintPass for RedundantStaticLifetimes {
         }
 
         if !item.span.from_expansion() {
-            if let ItemKind::Const(ConstItem { ty: ref var_type, .. }) = item.kind {
+            if let ItemKind::Const(box ConstItem { ty: ref var_type, .. }) = item.kind {
                 Self::visit_type(var_type, cx, "constants have by default a `'static` lifetime");
                 // Don't check associated consts because `'static` cannot be elided on those (issue
                 // #2438)
             }
 
-            if let ItemKind::Static(Static{ ty: ref var_type,.. }) = item.kind {
+            if let ItemKind::Static(box Static { ty: ref var_type,.. }) = item.kind {
                 Self::visit_type(var_type, cx, "statics have by default a `'static` lifetime");
             }
         }
diff --git a/src/tools/clippy/clippy_utils/src/ast_utils.rs b/src/tools/clippy/clippy_utils/src/ast_utils.rs
index be841098dba..0d2a7440c46 100644
--- a/src/tools/clippy/clippy_utils/src/ast_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/ast_utils.rs
@@ -286,8 +286,8 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
     match (l, r) {
         (ExternCrate(l), ExternCrate(r)) => l == r,
         (Use(l), Use(r)) => eq_use_tree(l, r),
-        (Static(ast::Static{ ty: lt, mutability: lm, expr: le}), Static(ast::Static { ty: rt, mutability: rm, expr: re})) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
-        (Const(ast::ConstItem { defaultness: ld, ty: lt, expr: le}), Const(ast::ConstItem { defaultness: rd, ty: rt, expr: re} )) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
+        (Static(box ast::Static{ ty: lt, mutability: lm, expr: le}), Static(box ast::Static { ty: rt, mutability: rm, expr: re})) => lm == rm && eq_ty(lt, rt) && eq_expr_opt(le, re),
+        (Const(box ast::ConstItem { defaultness: ld, ty: lt, expr: le}), Const(box ast::ConstItem { defaultness: rd, ty: rt, expr: re} )) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
         (
             Fn(box ast::Fn {
                 defaultness: ld,
@@ -451,7 +451,7 @@ pub fn eq_foreign_item_kind(l: &ForeignItemKind, r: &ForeignItemKind) -> bool {
 pub fn eq_assoc_item_kind(l: &AssocItemKind, r: &AssocItemKind) -> bool {
     use AssocItemKind::*;
     match (l, r) {
-        (Const(ast::ConstItem { defaultness: ld, ty: lt, expr: le}), Const(ast::ConstItem { defaultness: rd, ty: rt, expr: re})) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
+        (Const(box ast::ConstItem { defaultness: ld, ty: lt, expr: le}), Const(box ast::ConstItem { defaultness: rd, ty: rt, expr: re})) => eq_defaultness(*ld, *rd) && eq_ty(lt, rt) && eq_expr_opt(le, re),
         (
             Fn(box ast::Fn {
                 defaultness: ld,
diff --git a/src/tools/rustfmt/src/items.rs b/src/tools/rustfmt/src/items.rs
index 0dc8a4e937f..43779cfaecd 100644
--- a/src/tools/rustfmt/src/items.rs
+++ b/src/tools/rustfmt/src/items.rs
@@ -1804,13 +1804,15 @@ pub(crate) struct StaticParts<'a> {
 
 impl<'a> StaticParts<'a> {
     pub(crate) fn from_item(item: &'a ast::Item) -> Self {
-        let (defaultness, prefix, ty, mutability, expr) = match item.kind {
-            ast::ItemKind::Static(ast::Static { ref ty, mutability, ref expr}) => {
-                (None, "static", ty, mutability, expr)
-            }
-            ast::ItemKind::Const(ast::ConstItem { defaultness, ref ty, ref expr}) => {
-                (Some(defaultness), "const", ty, ast::Mutability::Not, expr)
-            }
+        let (defaultness, prefix, ty, mutability, expr) = match &item.kind {
+            ast::ItemKind::Static(s) => (None, "static", &s.ty, s.mutability, &s.expr),
+            ast::ItemKind::Const(c) => (
+                Some(c.defaultness),
+                "const",
+                &c.ty,
+                ast::Mutability::Not,
+                &c.expr,
+            ),
             _ => unreachable!(),
         };
         StaticParts {
@@ -1826,10 +1828,8 @@ impl<'a> StaticParts<'a> {
     }
 
     pub(crate) fn from_trait_item(ti: &'a ast::AssocItem) -> Self {
-        let (defaultness, ty, expr_opt) = match ti.kind {
-            ast::AssocItemKind::Const(ast::ConstItem {defaultness, ref ty, ref expr}) => {
-                (defaultness, ty, expr)
-            }
+        let (defaultness, ty, expr_opt) = match &ti.kind {
+            ast::AssocItemKind::Const(c) => (c.defaultness, &c.ty, &c.expr),
             _ => unreachable!(),
         };
         StaticParts {
@@ -1845,8 +1845,8 @@ impl<'a> StaticParts<'a> {
     }
 
     pub(crate) fn from_impl_item(ii: &'a ast::AssocItem) -> Self {
-        let (defaultness, ty, expr) = match ii.kind {
-            ast::AssocItemKind::Const(ast::ConstItem { defaultness, ref ty, ref expr}) => (defaultness, ty, expr),
+        let (defaultness, ty, expr) = match &ii.kind {
+            ast::AssocItemKind::Const(c) => (c.defaultness, &c.ty, &c.expr),
             _ => unreachable!(),
         };
         StaticParts {