fix stuck parser

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/libsyntax2/src/grammar/expressions/mod.rs b/crates/libsyntax2/src/grammar/expressions/mod.rs
index 9379ed938..f7b9f7086 100644
--- a/crates/libsyntax2/src/grammar/expressions/mod.rs
+++ b/crates/libsyntax2/src/grammar/expressions/mod.rs
@@ -376,6 +376,10 @@ fn arg_list(p: &mut Parser) {
     let m = p.start();
     p.bump();
     while !p.at(R_PAREN) && !p.at(EOF) {
+        if !EXPR_FIRST.contains(p.current()) {
+            p.error("expected expression");
+            break;
+        }
         expr(p);
         if !p.at(R_PAREN) && !p.expect(COMMA) {
             break;