diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 41e4bf8e8bf..9176c90ae9c 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -1701,8 +1701,9 @@ impl ModCollector<'_, '_> {
                 {
                     Ok((file_id, is_mod_rs, mod_dir)) => {
                         let item_tree = db.file_item_tree(file_id.into());
+                        let krate = self.def_collector.def_map.krate;
                         let is_enabled = item_tree
-                            .top_level_attrs(db, self.def_collector.def_map.krate)
+                            .top_level_attrs(db, krate)
                             .cfg()
                             .map_or(true, |cfg| self.is_cfg_enabled(&cfg));
                         if is_enabled {
@@ -1713,7 +1714,7 @@ impl ModCollector<'_, '_> {
                                 &self.item_tree[module.visibility],
                             );
                             ModCollector {
-                                def_collector: &mut *self.def_collector,
+                                def_collector: self.def_collector,
                                 macro_depth: self.macro_depth,
                                 module_id,
                                 tree_id: TreeId::new(file_id.into(), None),
@@ -1723,7 +1724,7 @@ impl ModCollector<'_, '_> {
                             .collect_in_top_module(item_tree.top_level_items());
                             let is_macro_use = is_macro_use
                                 || item_tree
-                                    .top_level_attrs(db, self.def_collector.def_map.krate)
+                                    .top_level_attrs(db, krate)
                                     .by_key("macro_use")
                                     .exists();
                             if is_macro_use {
@@ -1748,12 +1749,11 @@ impl ModCollector<'_, '_> {
         definition: Option<(FileId, bool)>,
         visibility: &crate::visibility::RawVisibility,
     ) -> LocalModuleId {
-        let vis = self
-            .def_collector
-            .def_map
+        let def_map = &mut self.def_collector.def_map;
+        let vis = def_map
             .resolve_visibility(self.def_collector.db, self.module_id, visibility)
             .unwrap_or(Visibility::Public);
-        let modules = &mut self.def_collector.def_map.modules;
+        let modules = &mut def_map.modules;
         let origin = match definition {
             None => ModuleOrigin::Inline { definition: declaration },
             Some((definition, is_mod_rs)) => {
@@ -1768,10 +1768,10 @@ impl ModCollector<'_, '_> {
         }
         modules[self.module_id].children.insert(name.clone(), res);
 
-        let module = self.def_collector.def_map.module_id(res);
+        let module = def_map.module_id(res);
         let def = ModuleDefId::from(module);
 
-        self.def_collector.def_map.modules[self.module_id].scope.declare(def);
+        def_map.modules[self.module_id].scope.declare(def);
         self.def_collector.update(
             self.module_id,
             &[(Some(name), PerNs::from_def(def, vis, false))],
diff --git a/crates/hir_def/src/visibility.rs b/crates/hir_def/src/visibility.rs
index 80009010c52..f76034a3e22 100644
--- a/crates/hir_def/src/visibility.rs
+++ b/crates/hir_def/src/visibility.rs
@@ -1,6 +1,6 @@
 //! Defines hir-level representation of visibility (e.g. `pub` and `pub(crate)`).
 
-use std::sync::Arc;
+use std::{iter, sync::Arc};
 
 use hir_expand::{hygiene::Hygiene, InFile};
 use la_arena::ArenaMap;
@@ -25,7 +25,7 @@ pub enum RawVisibility {
 }
 
 impl RawVisibility {
-    pub(crate) fn private() -> RawVisibility {
+    pub(crate) const fn private() -> RawVisibility {
         RawVisibility::Module(ModPath::from_kind(PathKind::Super(0)))
     }
 
@@ -113,10 +113,7 @@ impl Visibility {
     }
 
     pub(crate) fn is_visible_from_other_crate(self) -> bool {
-        match self {
-            Visibility::Module(_) => false,
-            Visibility::Public => true,
-        }
+        matches!(self, Visibility::Public)
     }
 
     pub(crate) fn is_visible_from_def_map(
@@ -145,10 +142,7 @@ impl Visibility {
                 arc = to_module.def_map(db);
                 &arc
             };
-        let is_block_root = match to_module.block {
-            Some(_) => to_module_def_map[to_module.local_id].parent.is_none(),
-            None => false,
-        };
+        let is_block_root = matches!(to_module.block, Some(_) if to_module_def_map[to_module.local_id].parent.is_none());
         if is_block_root {
             to_module = to_module_def_map.containing_module(to_module.local_id).unwrap();
         }
@@ -161,9 +155,7 @@ impl Visibility {
                 return true;
             }
             match def_map[from_module].parent {
-                Some(parent) => {
-                    from_module = parent;
-                }
+                Some(parent) => from_module = parent,
                 None => {
                     match def_map.parent() {
                         Some(module) => {
@@ -171,10 +163,8 @@ impl Visibility {
                             def_map = &*parent_arc;
                             from_module = module.local_id;
                         }
-                        None => {
-                            // Reached the root module, nothing left to check.
-                            return false;
-                        }
+                        // Reached the root module, nothing left to check.
+                        None => return false,
                     }
                 }
             }
@@ -194,12 +184,12 @@ impl Visibility {
                     return None;
                 }
 
-                let mut a_ancestors = std::iter::successors(Some(mod_a.local_id), |m| {
-                    let parent_id = def_map[*m].parent?;
+                let mut a_ancestors = iter::successors(Some(mod_a.local_id), |&m| {
+                    let parent_id = def_map[m].parent?;
                     Some(parent_id)
                 });
-                let mut b_ancestors = std::iter::successors(Some(mod_b.local_id), |m| {
-                    let parent_id = def_map[*m].parent?;
+                let mut b_ancestors = iter::successors(Some(mod_b.local_id), |&m| {
+                    let parent_id = def_map[m].parent?;
                     Some(parent_id)
                 });