1 files changed, 27 insertions, 9 deletions

diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 042e119b1..6b79e7bad 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -21,7 +21,7 @@ use crate::{
     nameres::ModuleSource,
     path::{ModPath, PathKind},
     src::HasChildSource,
-    AdtId, AttrDefId, Lookup,
+    AdtId, AttrDefId, GenericParamId, Lookup,
 };
 
 /// Holds documentation
@@ -235,6 +235,25 @@ impl Attrs {
             AttrDefId::StaticId(it) => attrs_from_item_tree(it.lookup(db).id, db),
             AttrDefId::FunctionId(it) => attrs_from_item_tree(it.lookup(db).id, db),
             AttrDefId::TypeAliasId(it) => attrs_from_item_tree(it.lookup(db).id, db),
+            AttrDefId::GenericParamId(it) => match it {
+                GenericParamId::TypeParamId(it) => {
+                    let src = it.parent.child_source(db);
+                    RawAttrs::from_attrs_owner(
+                        db,
+                        src.with_value(
+                            src.value[it.local_id].as_ref().either(|it| it as _, |it| it as _),
+                        ),
+                    )
+                }
+                GenericParamId::LifetimeParamId(it) => {
+                    let src = it.parent.child_source(db);
+                    RawAttrs::from_attrs_owner(db, src.with_value(&src.value[it.local_id]))
+                }
+                GenericParamId::ConstParamId(it) => {
+                    let src = it.parent.child_source(db);
+                    RawAttrs::from_attrs_owner(db, src.with_value(&src.value[it.local_id]))
+                }
+            },
         };
 
         raw_attrs.filter(db, def.krate(db))
@@ -260,14 +279,13 @@ impl Attrs {
     }
 
     pub fn docs(&self) -> Option<Documentation> {
-        let docs = self
-            .by_key("doc")
-            .attrs()
-            .flat_map(|attr| match attr.input.as_ref()? {
-                AttrInput::Literal(s) => Some(s),
-                AttrInput::TokenTree(_) => None,
-            })
-            .intersperse(&SmolStr::new_inline("\n"))
+        let docs = self.by_key("doc").attrs().flat_map(|attr| match attr.input.as_ref()? {
+            AttrInput::Literal(s) => Some(s),
+            AttrInput::TokenTree(_) => None,
+        });
+        // FIXME: Replace `Itertools::intersperse` with `Iterator::intersperse[_with]` until the
+        // libstd api gets stabilized (https://github.com/rust-lang/rust/issues/79524).
+        let docs = Itertools::intersperse(docs, &SmolStr::new_inline("\n"))
             .map(|it| it.as_str())
             .collect::<String>();
         if docs.is_empty() {