2 files changed, 9 insertions, 12 deletions

diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 27a297e8b..5f9d53ecb 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -30,6 +30,7 @@ pub(crate) struct Expander {
     hygiene: Hygiene,
     ast_id_map: Arc<AstIdMap>,
     module: ModuleId,
+    recursive_limit: usize,
 }
 
 impl Expander {
@@ -41,7 +42,7 @@ impl Expander {
         let crate_def_map = db.crate_def_map(module.krate);
         let hygiene = Hygiene::new(db.upcast(), current_file_id);
         let ast_id_map = db.ast_id_map(current_file_id);
-        Expander { crate_def_map, current_file_id, hygiene, ast_id_map, module }
+        Expander { crate_def_map, current_file_id, hygiene, ast_id_map, module, recursive_limit: 0 }
     }
 
     pub(crate) fn enter_expand<T: ast::AstNode>(
@@ -50,6 +51,10 @@ impl Expander {
         local_scope: Option<&ItemScope>,
         macro_call: ast::MacroCall,
     ) -> Option<(Mark, T)> {
+        if self.recursive_limit > 1024 {
+            return None;
+        }
+
         let macro_call = InFile::new(self.current_file_id, &macro_call);
 
         if let Some(call_id) = macro_call.as_call_id(db, |path| {
@@ -73,6 +78,7 @@ impl Expander {
                     self.hygiene = Hygiene::new(db.upcast(), file_id);
                     self.current_file_id = file_id;
                     self.ast_id_map = db.ast_id_map(file_id);
+                    self.recursive_limit += 1;
 
                     return Some((mark, expr));
                 }
@@ -88,6 +94,7 @@ impl Expander {
         self.hygiene = Hygiene::new(db.upcast(), mark.file_id);
         self.current_file_id = mark.file_id;
         self.ast_id_map = mem::take(&mut mark.ast_id_map);
+        self.recursive_limit -= 1;
         mark.bomb.defuse();
     }
 
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index e8c58ed32..3cf0c66ea 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -453,7 +453,7 @@ impl ExprCollector<'_> {
                 }
             }
             ast::Expr::MacroCall(e) => {
-                if let Some(name) = is_macro_rules(&e) {
+                if let Some(name) = e.is_macro_rules().map(|it| it.as_name()) {
                     let mac = MacroDefId {
                         krate: Some(self.expander.module.krate),
                         ast_id: Some(self.expander.ast_id(&e)),
@@ -697,16 +697,6 @@ impl ExprCollector<'_> {
     }
 }
 
-fn is_macro_rules(m: &ast::MacroCall) -> Option<Name> {
-    let name = m.path()?.segment()?.name_ref()?.as_name();
-
-    if name == name![macro_rules] {
-        Some(m.name()?.as_name())
-    } else {
-        None
-    }
-}
-
 impl From<ast::BinOp> for BinaryOp {
     fn from(ast_op: ast::BinOp) -> Self {
         match ast_op {