1 files changed, 36 insertions, 10 deletions

diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index b0a3f1784..1aa9a9b7d 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -225,22 +225,48 @@ fn collect_impl_items_in_macros(
     let mut expander = Expander::new(db, impl_block.file_id, module_id);
     let mut res = Vec::new();
 
+    // We set a limit to protect against infinite recursion
+    let limit = 100;
+
     for m in impl_block.value.syntax().children().filter_map(ast::MacroCall::cast) {
-        if let Some((mark, items)) = expander.enter_expand(db, m) {
-            let items: InFile<ast::MacroItems> = expander.to_source(items);
-            expander.exit(db, mark);
-            res.extend(collect_impl_items(
-                db,
-                items.value.items().filter_map(|it| ImplItem::cast(it.syntax().clone())),
-                items.file_id,
-                id,
-            ));
-        }
+        res.extend(collect_impl_items_in_macro(db, &mut expander, m, id, limit))
     }
 
     res
 }
 
+fn collect_impl_items_in_macro(
+    db: &impl DefDatabase,
+    expander: &mut Expander,
+    m: ast::MacroCall,
+    id: ImplId,
+    limit: usize,
+) -> Vec<AssocItemId> {
+    if limit == 0 {
+        return Vec::new();
+    }
+
+    if let Some((mark, items)) = expander.enter_expand(db, m) {
+        let items: InFile<ast::MacroItems> = expander.to_source(items);
+        let mut res = collect_impl_items(
+            db,
+            items.value.items().filter_map(|it| ImplItem::cast(it.syntax().clone())),
+            items.file_id,
+            id,
+        );
+        // Recursive collect macros
+        // Note that ast::ModuleItem do not include ast::MacroCall
+        // We cannot use ModuleItemOwner::items here
+        for it in items.value.syntax().children().filter_map(ast::MacroCall::cast) {
+            res.extend(collect_impl_items_in_macro(db, expander, it, id, limit - 1))
+        }
+        expander.exit(db, mark);
+        res
+    } else {
+        Vec::new()
+    }
+}
+
 fn collect_impl_items(
     db: &impl DefDatabase,
     impl_items: impl Iterator<Item = ImplItem>,