diff --git a/crates/hir-def/src/body/scope.rs b/crates/hir-def/src/body/scope.rs
index 2a90a09f25e..f6946663135 100644
--- a/crates/hir-def/src/body/scope.rs
+++ b/crates/hir-def/src/body/scope.rs
@@ -1,7 +1,6 @@
 //! Name resolution for expressions.
 use hir_expand::name::Name;
-use la_arena::{Arena, Idx, IdxRange, RawIdx};
-use rustc_hash::FxHashMap;
+use la_arena::{Arena, ArenaMap, Idx, IdxRange, RawIdx};
 use triomphe::Arc;
 
 use crate::{
@@ -17,7 +16,7 @@ pub type ScopeId = Idx<ScopeData>;
 pub struct ExprScopes {
     scopes: Arena<ScopeData>,
     scope_entries: Arena<ScopeEntry>,
-    scope_by_expr: FxHashMap<ExprId, ScopeId>,
+    scope_by_expr: ArenaMap<ExprId, ScopeId>,
 }
 
 #[derive(Debug, PartialEq, Eq)]
@@ -77,10 +76,10 @@ impl ExprScopes {
     }
 
     pub fn scope_for(&self, expr: ExprId) -> Option<ScopeId> {
-        self.scope_by_expr.get(&expr).copied()
+        self.scope_by_expr.get(expr).copied()
     }
 
-    pub fn scope_by_expr(&self) -> &FxHashMap<ExprId, ScopeId> {
+    pub fn scope_by_expr(&self) -> &ArenaMap<ExprId, ScopeId> {
         &self.scope_by_expr
     }
 }
@@ -94,7 +93,7 @@ impl ExprScopes {
         let mut scopes = ExprScopes {
             scopes: Arena::default(),
             scope_entries: Arena::default(),
-            scope_by_expr: FxHashMap::default(),
+            scope_by_expr: ArenaMap::with_capacity(body.exprs.len()),
         };
         let mut root = scopes.root_scope();
         scopes.add_params_bindings(body, root, &body.params);
diff --git a/crates/hir-def/src/import_map.rs b/crates/hir-def/src/import_map.rs
index eb32c76b066..90763d4c3df 100644
--- a/crates/hir-def/src/import_map.rs
+++ b/crates/hir-def/src/import_map.rs
@@ -1,7 +1,6 @@
 //! A map of all publicly exported items in a crate.
 
-use std::collections::hash_map::Entry;
-use std::{fmt, hash::BuildHasherDefault};
+use std::{collections::hash_map::Entry, fmt, hash::BuildHasherDefault};
 
 use base_db::CrateId;
 use fst::{self, Streamer};
@@ -11,10 +10,12 @@ use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet, FxHasher};
 use triomphe::Arc;
 
-use crate::item_scope::ImportOrExternCrate;
 use crate::{
-    db::DefDatabase, item_scope::ItemInNs, nameres::DefMap, visibility::Visibility, AssocItemId,
-    ModuleDefId, ModuleId, TraitId,
+    db::DefDatabase,
+    item_scope::{ImportOrExternCrate, ItemInNs},
+    nameres::DefMap,
+    visibility::Visibility,
+    AssocItemId, ModuleDefId, ModuleId, TraitId,
 };
 
 type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;
@@ -94,7 +95,7 @@ fn collect_import_map(db: &dyn DefDatabase, krate: CrateId) -> FxIndexMap<ItemIn
 
     // We look only into modules that are public(ly reexported), starting with the crate root.
     let root = def_map.module_id(DefMap::ROOT);
-    let mut worklist = vec![(root, 0)];
+    let mut worklist = vec![(root, 0u32)];
     // Records items' minimum module depth.
     let mut depth_map = FxHashMap::default();
 
diff --git a/crates/hir-def/src/lib.rs b/crates/hir-def/src/lib.rs
index 1abcb1835fd..9c6f652f1ec 100644
--- a/crates/hir-def/src/lib.rs
+++ b/crates/hir-def/src/lib.rs
@@ -499,10 +499,7 @@ impl_from!(Macro2Id, MacroRulesId, ProcMacroId for MacroId);
 
 impl MacroId {
     pub fn is_attribute(self, db: &dyn db::DefDatabase) -> bool {
-        match self {
-            MacroId::ProcMacroId(it) => it.lookup(db).kind == ProcMacroKind::Attr,
-            _ => false,
-        }
+        matches!(self, MacroId::ProcMacroId(it) if it.lookup(db).kind == ProcMacroKind::Attr)
     }
 }
 
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index f29fb1edf00..8d8ba48ad92 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -888,7 +888,7 @@ fn scope_for_offset(
         .scope_by_expr()
         .iter()
         .filter_map(|(id, scope)| {
-            let InFile { file_id, value } = source_map.expr_syntax(*id).ok()?;
+            let InFile { file_id, value } = source_map.expr_syntax(id).ok()?;
             if from_file == file_id {
                 return Some((value.text_range(), scope));
             }
@@ -923,7 +923,7 @@ fn adjust(
         .scope_by_expr()
         .iter()
         .filter_map(|(id, scope)| {
-            let source = source_map.expr_syntax(*id).ok()?;
+            let source = source_map.expr_syntax(id).ok()?;
             // FIXME: correctly handle macro expansion
             if source.file_id != from_file {
                 return None;
diff --git a/crates/stdx/src/macros.rs b/crates/stdx/src/macros.rs
index 1a9982fa8b2..d71e418c89b 100644
--- a/crates/stdx/src/macros.rs
+++ b/crates/stdx/src/macros.rs
@@ -15,7 +15,12 @@ macro_rules! eprintln {
 macro_rules! format_to {
     ($buf:expr) => ();
     ($buf:expr, $lit:literal $($arg:tt)*) => {
-        { use ::std::fmt::Write as _; let _ = ::std::write!($buf, $lit $($arg)*); }
+        {
+            use ::std::fmt::Write as _;
+            // We can't do ::std::fmt::Write::write_fmt($buf, format_args!($lit $($arg)*))
+            // unfortunately, as that loses out on autoref behavior.
+            _ = $buf.write_fmt(format_args!($lit $($arg)*))
+        }
     };
 }
 
diff --git a/crates/stdx/src/process.rs b/crates/stdx/src/process.rs
index e5aa3436518..bca0cbc36d1 100644
--- a/crates/stdx/src/process.rs
+++ b/crates/stdx/src/process.rs
@@ -23,7 +23,7 @@ pub fn streaming_output(
         let idx = if eof {
             data.len()
         } else {
-            match data.iter().rposition(|b| *b == b'\n') {
+            match data.iter().rposition(|&b| b == b'\n') {
                 Some(i) => i + 1,
                 None => return,
             }