Force passing Source when creating a SourceAnalyzer

crates/ra_syntax/src/lib.rs

@@ -176,9 +176,11 @@ impl SourceFile {
 /// ```
 #[macro_export]
 macro_rules! match_ast {
-    (match $node:ident {
+    (match $node:ident { $($tt:tt)* }) => { match_ast!(match ($node) { $($tt)* }) };
+
+    (match ($node:expr) {
         $( ast::$ast:ident($it:ident) => $res:block, )*
-        _ => $catch_all:expr,
+        _ => $catch_all:expr $(,)?
     }) => {{
         $( if let Some($it) = ast::$ast::cast($node.clone()) $res else )*
         { $catch_all }