diff --git a/crates/hir-def/src/lib.rs b/crates/hir-def/src/lib.rs
index d07c5fb67c6..2aab1ccd914 100644
--- a/crates/hir-def/src/lib.rs
+++ b/crates/hir-def/src/lib.rs
@@ -128,7 +128,7 @@ impl ModuleId {
     }
 }
 
-/// An ID of a module, **local** to a specific crate
+/// An ID of a module, **local** to a `DefMap`.
 pub type LocalModuleId = Idx<nameres::ModuleData>;
 
 #[derive(Debug)]
diff --git a/crates/hir-def/src/nameres.rs b/crates/hir-def/src/nameres.rs
index 393747d304b..a7ce0360516 100644
--- a/crates/hir-def/src/nameres.rs
+++ b/crates/hir-def/src/nameres.rs
@@ -342,7 +342,7 @@ impl DefMap {
     }
 
     pub(crate) fn block_id(&self) -> Option<BlockId> {
-        self.block.as_ref().map(|block| block.block)
+        self.block.map(|block| block.block)
     }
 
     pub(crate) fn prelude(&self) -> Option<ModuleId> {
@@ -354,7 +354,7 @@ impl DefMap {
     }
 
     pub fn module_id(&self, local_id: LocalModuleId) -> ModuleId {
-        let block = self.block.as_ref().map(|b| b.block);
+        let block = self.block.map(|b| b.block);
         ModuleId { krate: self.krate, local_id, block }
     }
 
@@ -432,9 +432,9 @@ impl DefMap {
     /// Returns the module containing `local_mod`, either the parent `mod`, or the module containing
     /// the block, if `self` corresponds to a block expression.
     pub fn containing_module(&self, local_mod: LocalModuleId) -> Option<ModuleId> {
-        match &self[local_mod].parent {
-            Some(parent) => Some(self.module_id(*parent)),
-            None => self.block.as_ref().map(|block| block.parent),
+        match self[local_mod].parent {
+            Some(parent) => Some(self.module_id(parent)),
+            None => self.block.map(|block| block.parent),
         }
     }
 
@@ -444,11 +444,11 @@ impl DefMap {
         let mut buf = String::new();
         let mut arc;
         let mut current_map = self;
-        while let Some(block) = &current_map.block {
+        while let Some(block) = current_map.block {
             go(&mut buf, current_map, "block scope", current_map.root);
             buf.push('\n');
             arc = block.parent.def_map(db);
-            current_map = &*arc;
+            current_map = &arc;
         }
         go(&mut buf, current_map, "crate", current_map.root);
         return buf;
@@ -472,10 +472,10 @@ impl DefMap {
         let mut buf = String::new();
         let mut arc;
         let mut current_map = self;
-        while let Some(block) = &current_map.block {
+        while let Some(block) = current_map.block {
             format_to!(buf, "{:?} in {:?}\n", block.block, block.parent);
             arc = block.parent.def_map(db);
-            current_map = &*arc;
+            current_map = &arc;
         }
 
         format_to!(buf, "crate scope\n");
diff --git a/crates/hir-def/src/visibility.rs b/crates/hir-def/src/visibility.rs
index 087268a9ece..eee73b9f373 100644
--- a/crates/hir-def/src/visibility.rs
+++ b/crates/hir-def/src/visibility.rs
@@ -11,7 +11,7 @@ use crate::{
     nameres::DefMap,
     path::{ModPath, PathKind},
     resolver::HasResolver,
-    ConstId, FunctionId, HasModule, LocalFieldId, ModuleId, VariantId,
+    ConstId, FunctionId, HasModule, LocalFieldId, LocalModuleId, ModuleId, VariantId,
 };
 
 /// Visibility of an item, not yet resolved.
@@ -142,7 +142,8 @@ impl Visibility {
                 arc = to_module.def_map(db);
                 &arc
             };
-        let is_block_root = matches!(to_module.block, Some(_) if to_module_def_map[to_module.local_id].parent.is_none());
+        let is_block_root =
+            to_module.block.is_some() && 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();
         }
diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index 0d19420127f..830d261d786 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs
@@ -50,7 +50,7 @@ impl HirDisplay for Function {
 
         let write_self_param = |ty: &TypeRef, f: &mut HirFormatter<'_>| match ty {
             TypeRef::Path(p) if p.is_self_type() => f.write_str("self"),
-            TypeRef::Reference(inner, lifetime, mut_) if matches!(&**inner,TypeRef::Path(p) if p.is_self_type()) =>
+            TypeRef::Reference(inner, lifetime, mut_) if matches!(&**inner, TypeRef::Path(p) if p.is_self_type()) =>
             {
                 f.write_char('&')?;
                 if let Some(lifetime) = lifetime {