diff --git a/src/closures.rs b/src/closures.rs
index 257b8729f45..5f1102a36fc 100644
--- a/src/closures.rs
+++ b/src/closures.rs
@@ -31,6 +31,7 @@
 //     statement without needing a semi-colon), then adding or removing braces
 //     can change whether it is treated as an expression or statement.
 
+// FIXME(topecongiro) Format async closures (#2813).
 pub fn rewrite_closure(
     capture: ast::CaptureBy,
     movability: ast::Movability,
@@ -288,7 +289,7 @@ pub fn rewrite_last_closure(
     expr: &ast::Expr,
     shape: Shape,
 ) -> Option<String> {
-    if let ast::ExprKind::Closure(capture, movability, ref fn_decl, ref body, _) = expr.node {
+    if let ast::ExprKind::Closure(capture, _, movability, ref fn_decl, ref body, _) = expr.node {
         let body = match body.node {
             ast::ExprKind::Block(ref block, _)
                 if !is_unsafe_block(block)
diff --git a/src/expr.rs b/src/expr.rs
index b8a323f73a2..ca31b0b82ef 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -183,7 +183,7 @@ pub fn format_expr(
         } else {
             Some("yield".to_string())
         },
-        ast::ExprKind::Closure(capture, movability, ref fn_decl, ref body, _) => {
+        ast::ExprKind::Closure(capture, _, movability, ref fn_decl, ref body, _) => {
             closures::rewrite_closure(
                 capture, movability, fn_decl, body, expr.span, context, shape,
             )
@@ -344,6 +344,8 @@ fn needs_space_after_range(rhs: &ast::Expr) -> bool {
         }
         // FIXME(#2743)
         ast::ExprKind::ObsoleteInPlace(..) => unimplemented!(),
+        // FIXME(topecongiro) Format async block.
+        ast::ExprKind::Async(..) => None,
     };
 
     expr_rw
diff --git a/src/items.rs b/src/items.rs
index bef8fd79599..fe638a17069 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -192,10 +192,10 @@ pub fn from_method_sig(
         generics: &'a ast::Generics,
     ) -> FnSig<'a> {
         FnSig {
-            unsafety: method_sig.unsafety,
-            constness: method_sig.constness.node,
+            unsafety: method_sig.header.unsafety,
+            constness: method_sig.header.constness.node,
             defaultness: ast::Defaultness::Final,
-            abi: method_sig.abi,
+            abi: method_sig.header.abi,
             decl: &*method_sig.decl,
             generics,
             visibility: DEFAULT_VISIBILITY,
@@ -209,13 +209,13 @@ pub fn from_fn_kind(
         defaultness: ast::Defaultness,
     ) -> FnSig<'a> {
         match *fn_kind {
-            visit::FnKind::ItemFn(_, unsafety, constness, abi, visibility, _) => FnSig {
+            visit::FnKind::ItemFn(_, fn_header, visibility, _) => FnSig {
                 decl,
                 generics,
-                abi,
-                constness: constness.node,
+                abi: fn_header.abi,
+                constness: fn_header.constness.node,
                 defaultness,
-                unsafety,
+                unsafety: fn_header.unsafety,
                 visibility: visibility.clone(),
             },
             visit::FnKind::Method(_, method_sig, vis, _) => {
diff --git a/src/visitor.rs b/src/visitor.rs
index 76fd3395ba9..2b0f08dd0c7 100644
--- a/src/visitor.rs
+++ b/src/visitor.rs
@@ -252,6 +252,7 @@ fn close_block(&mut self, unindent_comment: bool) {
 
     // Note that this only gets called for function definitions. Required methods
     // on traits do not get handled here.
+    // FIXME(topecongiro) Format async fn (#2812).
     fn visit_fn(
         &mut self,
         fk: visit::FnKind,
@@ -264,7 +265,7 @@ fn visit_fn(
         let indent = self.block_indent;
         let block;
         let rewrite = match fk {
-            visit::FnKind::ItemFn(ident, _, _, _, _, b) | visit::FnKind::Method(ident, _, _, b) => {
+            visit::FnKind::ItemFn(ident, _, _, b) | visit::FnKind::Method(ident, _, _, b) => {
                 block = b;
                 self.rewrite_fn(
                     indent,
@@ -392,10 +393,10 @@ pub fn visit_item(&mut self, item: &ast::Item) {
             ast::ItemKind::Static(..) | ast::ItemKind::Const(..) => {
                 self.visit_static(&StaticParts::from_item(item));
             }
-            ast::ItemKind::Fn(ref decl, unsafety, constness, abi, ref generics, ref body) => {
+            ast::ItemKind::Fn(ref decl, fn_header, ref generics, ref body) => {
                 let inner_attrs = inner_attributes(&item.attrs);
                 self.visit_fn(
-                    visit::FnKind::ItemFn(item.ident, unsafety, constness, abi, &item.vis, body),
+                    visit::FnKind::ItemFn(item.ident, fn_header, &item.vis, body),
                     generics,
                     decl,
                     item.span,