1 files changed, 47 insertions, 2 deletions

diff --git a/crates/ra_hir_def/src/generics.rs b/crates/ra_hir_def/src/generics.rs
index ed4f60c66..c4b9f626f 100644
--- a/crates/ra_hir_def/src/generics.rs
+++ b/crates/ra_hir_def/src/generics.rs
@@ -74,8 +74,53 @@ impl GenericParams {
         def: GenericDefId,
     ) -> Arc<GenericParams> {
         let _p = profile("generic_params_query");
-        let (params, _source_map) = GenericParams::new(db, def);
-        Arc::new(params)
+
+        let generics = match def {
+            GenericDefId::FunctionId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::AdtId(AdtId::StructId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::AdtId(AdtId::EnumId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::AdtId(AdtId::UnionId(id)) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::TraitId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::TypeAliasId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::ImplId(id) => {
+                let id = id.lookup(db).id;
+                let tree = db.item_tree(id.file_id);
+                let item = &tree[id.value];
+                item.generic_params.clone()
+            }
+            GenericDefId::EnumVariantId(_) | GenericDefId::ConstId(_) => GenericParams::default(),
+        };
+        Arc::new(generics)
     }
 
     fn new(db: &dyn DefDatabase, def: GenericDefId) -> (GenericParams, InFile<SourceMap>) {