3 files changed, 10 insertions, 1 deletions

diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index 9f9d6e63c..73e1c407c 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -1129,6 +1129,7 @@ impl ast::NameOwner for FnDef {}
 impl ast::TypeParamsOwner for FnDef {}
 impl ast::AttrsOwner for FnDef {}
 impl ast::DocCommentsOwner for FnDef {}
+impl ast::AsyncOwner for FnDef {}
 impl FnDef {
     pub fn param_list(&self) -> Option<ParamList> {
         AstChildren::new(&self.syntax).next()
diff --git a/crates/ra_syntax/src/ast/traits.rs b/crates/ra_syntax/src/ast/traits.rs
index f99984fe0..8bf6aa2f0 100644
--- a/crates/ra_syntax/src/ast/traits.rs
+++ b/crates/ra_syntax/src/ast/traits.rs
@@ -8,6 +8,7 @@ use crate::{
     ast::{self, child_opt, children, AstChildren, AstNode, AstToken},
     match_ast,
     syntax_node::{SyntaxElementChildren, SyntaxNodeChildren},
+    SyntaxKind,
 };
 
 pub trait TypeAscriptionOwner: AstNode {
@@ -105,6 +106,12 @@ pub trait AttrsOwner: AstNode {
     }
 }
 
+pub trait AsyncOwner: AstNode {
+    fn is_async(&self) -> bool {
+        self.syntax().children_with_tokens().any(|t| t.kind() == SyntaxKind::ASYNC_KW)
+    }
+}
+
 pub trait DocCommentsOwner: AstNode {
     fn doc_comments(&self) -> CommentIter {
         CommentIter { iter: self.syntax().children_with_tokens() }
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 08aafb610..7d11f0176 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -275,7 +275,8 @@ Grammar(
                 "NameOwner",
                 "TypeParamsOwner",
                 "AttrsOwner",
-                "DocCommentsOwner"
+                "DocCommentsOwner",
+                "AsyncOwner"
             ],
             options: [ "ParamList", ["body", "BlockExpr"], "RetType" ],
         ),