Auto merge of #13174 - Veykril:resolver, r=Veykril

Lift out the module scope into a field in the Resolver

A Resolver *always* has a module scope at the end of its scope stack,
instead of encoding this as an invariant we can just lift this scope
out into a field, allowing us to skip going through the scope vec
indirection entirely.

6 files changed, 211 insertions, 159 deletions

diff --git a/crates/hir-def/src/body.rs b/crates/hir-def/src/body.rs
index d572d46e8b0..22f5fb99266 100644
--- a/crates/hir-def/src/body.rs
+++ b/crates/hir-def/src/body.rs
@@ -250,6 +250,10 @@ pub type PatSource = InFile<PatPtr>;
 
 pub type LabelPtr = AstPtr<ast::Label>;
 pub type LabelSource = InFile<LabelPtr>;
+
+pub type FieldPtr = AstPtr<ast::RecordExprField>;
+pub type FieldSource = InFile<FieldPtr>;
+
 /// An item body together with the mapping from syntax nodes to HIR expression
 /// IDs. This is needed to go from e.g. a position in a file to the HIR
 /// expression containing it; but for type inference etc., we want to operate on
@@ -274,8 +278,8 @@ pub struct BodySourceMap {
 
     /// We don't create explicit nodes for record fields (`S { record_field: 92 }`).
     /// Instead, we use id of expression (`92`) to identify the field.
-    field_map: FxHashMap<InFile<AstPtr<ast::RecordExprField>>, ExprId>,
-    field_map_back: FxHashMap<ExprId, InFile<AstPtr<ast::RecordExprField>>>,
+    field_map: FxHashMap<FieldSource, ExprId>,
+    field_map_back: FxHashMap<ExprId, FieldSource>,
 
     expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>,
 
@@ -456,9 +460,10 @@ impl BodySourceMap {
         self.label_map.get(&src).cloned()
     }
 
-    pub fn field_syntax(&self, expr: ExprId) -> InFile<AstPtr<ast::RecordExprField>> {
+    pub fn field_syntax(&self, expr: ExprId) -> FieldSource {
         self.field_map_back[&expr].clone()
     }
+
     pub fn node_field(&self, node: InFile<&ast::RecordExprField>) -> Option<ExprId> {
         let src = node.map(AstPtr::new);
         self.field_map.get(&src).cloned()
diff --git a/crates/hir-def/src/body/lower.rs b/crates/hir-def/src/body/lower.rs
index df536e09fde..3b3297f7811 100644
--- a/crates/hir-def/src/body/lower.rs
+++ b/crates/hir-def/src/body/lower.rs
@@ -24,7 +24,7 @@ use syntax::{
 
 use crate::{
     adt::StructKind,
-    body::{Body, BodySourceMap, Expander, LabelSource, PatPtr},
+    body::{Body, BodySourceMap, Expander, ExprPtr, LabelPtr, LabelSource, PatPtr},
     body::{BodyDiagnostic, ExprSource, PatSource},
     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
     db::DefDatabase,
@@ -150,7 +150,7 @@ impl ExprCollector<'_> {
         LowerCtx::new(self.db, self.expander.current_file_id)
     }
 
-    fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
+    fn alloc_expr(&mut self, expr: Expr, ptr: ExprPtr) -> ExprId {
         let src = self.expander.to_source(ptr);
         let id = self.make_expr(expr, src.clone());
         self.source_map.expr_map.insert(src, id);
@@ -185,7 +185,7 @@ impl ExprCollector<'_> {
         id
     }
 
-    fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
+    fn alloc_label(&mut self, label: Label, ptr: LabelPtr) -> LabelId {
         let src = self.expander.to_source(ptr);
         let id = self.make_label(label, src.clone());
         self.source_map.label_map.insert(src, id);
diff --git a/crates/hir-def/src/body/scope.rs b/crates/hir-def/src/body/scope.rs
index 9b28e38029e..45f64ebb060 100644
--- a/crates/hir-def/src/body/scope.rs
+++ b/crates/hir-def/src/body/scope.rs
@@ -47,16 +47,9 @@ pub struct ScopeData {
 impl ExprScopes {
     pub(crate) fn expr_scopes_query(db: &dyn DefDatabase, def: DefWithBodyId) -> Arc<ExprScopes> {
         let body = db.body(def);
-        Arc::new(ExprScopes::new(&*body))
-    }
-
-    fn new(body: &Body) -> ExprScopes {
-        let mut scopes =
-            ExprScopes { scopes: Arena::default(), scope_by_expr: FxHashMap::default() };
-        let mut root = scopes.root_scope();
-        scopes.add_params_bindings(body, root, &body.params);
-        compute_expr_scopes(body.body_expr, body, &mut scopes, &mut root);
-        scopes
+        let mut scopes = ExprScopes::new(&*body);
+        scopes.shrink_to_fit();
+        Arc::new(scopes)
     }
 
     pub fn entries(&self, scope: ScopeId) -> &[ScopeEntry] {
@@ -89,6 +82,17 @@ impl ExprScopes {
     pub fn scope_by_expr(&self) -> &FxHashMap<ExprId, ScopeId> {
         &self.scope_by_expr
     }
+}
+
+impl ExprScopes {
+    fn new(body: &Body) -> ExprScopes {
+        let mut scopes =
+            ExprScopes { scopes: Arena::default(), scope_by_expr: FxHashMap::default() };
+        let mut root = scopes.root_scope();
+        scopes.add_params_bindings(body, root, &body.params);
+        compute_expr_scopes(body.body_expr, body, &mut scopes, &mut root);
+        scopes
+    }
 
     fn root_scope(&mut self) -> ScopeId {
         self.scopes.alloc(ScopeData { parent: None, block: None, label: None, entries: vec![] })
@@ -138,6 +142,13 @@ impl ExprScopes {
     fn set_scope(&mut self, node: ExprId, scope: ScopeId) {
         self.scope_by_expr.insert(node, scope);
     }
+
+    fn shrink_to_fit(&mut self) {
+        let ExprScopes { scopes, scope_by_expr } = self;
+        scopes.shrink_to_fit();
+        scopes.values_mut().for_each(|it| it.entries.shrink_to_fit());
+        scope_by_expr.shrink_to_fit();
+    }
 }
 
 fn compute_block_scopes(
diff --git a/crates/hir-def/src/resolver.rs b/crates/hir-def/src/resolver.rs
index 3163fa0f93f..769aa9dcb0c 100644
--- a/crates/hir-def/src/resolver.rs
+++ b/crates/hir-def/src/resolver.rs
@@ -31,12 +31,10 @@ pub struct Resolver {
     ///
     /// When using, you generally want to process the scopes in reverse order,
     /// there's `scopes` *method* for that.
-    ///
-    /// Invariant: There exists at least one Scope::ModuleScope at the start of the vec.
     scopes: Vec<Scope>,
+    module_scope: ModuleItemMap,
 }
 
-// FIXME how to store these best
 #[derive(Debug, Clone)]
 struct ModuleItemMap {
     def_map: Arc<DefMap>,
@@ -53,7 +51,7 @@ struct ExprScope {
 #[derive(Debug, Clone)]
 enum Scope {
     /// All the items and imported names of a module
-    ModuleScope(ModuleItemMap),
+    BlockScope(ModuleItemMap),
     /// Brings the generic parameters of an item into scope
     GenericParams { def: GenericDefId, params: Interned<GenericParams> },
     /// Brings `Self` in `impl` block into scope
@@ -127,24 +125,6 @@ impl Resolver {
         }
     }
 
-    fn scopes(&self) -> impl Iterator<Item = &Scope> {
-        self.scopes.iter().rev()
-    }
-
-    fn resolve_module_path(
-        &self,
-        db: &dyn DefDatabase,
-        path: &ModPath,
-        shadow: BuiltinShadowMode,
-    ) -> PerNs {
-        let (item_map, module) = self.module_scope();
-        let (module_res, segment_index) = item_map.resolve_path(db, module, path, shadow);
-        if segment_index.is_some() {
-            return PerNs::none();
-        }
-        module_res
-    }
-
     pub fn resolve_module_path_in_items(&self, db: &dyn DefDatabase, path: &ModPath) -> PerNs {
         self.resolve_module_path(db, path, BuiltinShadowMode::Module)
     }
@@ -155,7 +135,7 @@ impl Resolver {
         db: &dyn DefDatabase,
         path: &ModPath,
     ) -> Option<PerNs> {
-        let (item_map, module) = self.module_scope();
+        let (item_map, module) = self.item_scope();
         let (module_res, idx) = item_map.resolve_path(db, module, path, BuiltinShadowMode::Module);
         match module_res.take_types()? {
             ModuleDefId::TraitId(it) => {
@@ -183,37 +163,38 @@ impl Resolver {
     ) -> Option<(TypeNs, Option<usize>)> {
         let first_name = path.segments().first()?;
         let skip_to_mod = path.kind != PathKind::Plain;
+        if skip_to_mod {
+            return self.module_scope.resolve_path_in_type_ns(db, path);
+        }
+
+        let remaining_idx = || if path.segments().len() == 1 { None } else { Some(1) };
+
         for scope in self.scopes() {
             match scope {
                 Scope::ExprScope(_) => continue,
-                Scope::GenericParams { .. } | Scope::ImplDefScope(_) if skip_to_mod => continue,
-
                 Scope::GenericParams { params, def } => {
                     if let Some(id) = params.find_type_by_name(first_name, *def) {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
-                        return Some((TypeNs::GenericParam(id), idx));
+                        return Some((TypeNs::GenericParam(id), remaining_idx()));
                     }
                 }
-                Scope::ImplDefScope(impl_) => {
+                &Scope::ImplDefScope(impl_) => {
                     if first_name == &name![Self] {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
-                        return Some((TypeNs::SelfType(*impl_), idx));
+                        return Some((TypeNs::SelfType(impl_), remaining_idx()));
                     }
                 }
-                Scope::AdtScope(adt) => {
+                &Scope::AdtScope(adt) => {
                     if first_name == &name![Self] {
-                        let idx = if path.segments().len() == 1 { None } else { Some(1) };
-                        return Some((TypeNs::AdtSelfType(*adt), idx));
+                        return Some((TypeNs::AdtSelfType(adt), remaining_idx()));
                     }
                 }
-                Scope::ModuleScope(m) => {
+                Scope::BlockScope(m) => {
                     if let Some(res) = m.resolve_path_in_type_ns(db, path) {
                         return Some(res);
                     }
                 }
             }
         }
-        None
+        self.module_scope.resolve_path_in_type_ns(db, path)
     }
 
     pub fn resolve_path_in_type_ns_fully(
@@ -235,7 +216,7 @@ impl Resolver {
     ) -> Option<Visibility> {
         match visibility {
             RawVisibility::Module(_) => {
-                let (item_map, module) = self.module_scope();
+                let (item_map, module) = self.item_scope();
                 item_map.resolve_visibility(db, module, visibility)
             }
             RawVisibility::Public => Some(Visibility::Public),
@@ -251,18 +232,14 @@ impl Resolver {
         let tmp = name![self];
         let first_name = if path.is_self() { &tmp } else { path.segments().first()? };
         let skip_to_mod = path.kind != PathKind::Plain && !path.is_self();
+        if skip_to_mod {
+            return self.module_scope.resolve_path_in_value_ns(db, path);
+        }
+
         for scope in self.scopes() {
             match scope {
-                Scope::AdtScope(_)
-                | Scope::ExprScope(_)
-                | Scope::GenericParams { .. }
-                | Scope::ImplDefScope(_)
-                    if skip_to_mod =>
-                {
-                    continue
-                }
-
-                Scope::ExprScope(scope) if n_segments <= 1 => {
+                Scope::ExprScope(_) if n_segments > 1 => continue,
+                Scope::ExprScope(scope) => {
                     let entry = scope
                         .expr_scopes
                         .entries(scope.scope_id)
@@ -273,44 +250,39 @@ impl Resolver {
                         return Some(ResolveValueResult::ValueNs(ValueNs::LocalBinding(e.pat())));
                     }
                 }
-                Scope::ExprScope(_) => continue,
-
                 Scope::GenericParams { params, def } if n_segments > 1 => {
                     if let Some(id) = params.find_type_by_name(first_name, *def) {
                         let ty = TypeNs::GenericParam(id);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
-                Scope::GenericParams { params, def } if n_segments == 1 => {
+                Scope::GenericParams { .. } if n_segments != 1 => continue,
+                Scope::GenericParams { params, def } => {
                     if let Some(id) = params.find_const_by_name(first_name, *def) {
                         let val = ValueNs::GenericParam(id);
                         return Some(ResolveValueResult::ValueNs(val));
                     }
                 }
-                Scope::GenericParams { .. } => continue,
 
-                Scope::ImplDefScope(impl_) => {
+                &Scope::ImplDefScope(impl_) => {
                     if first_name == &name![Self] {
-                        if n_segments > 1 {
-                            let ty = TypeNs::SelfType(*impl_);
-                            return Some(ResolveValueResult::Partial(ty, 1));
+                        return Some(if n_segments > 1 {
+                            ResolveValueResult::Partial(TypeNs::SelfType(impl_), 1)
                         } else {
-                            return Some(ResolveValueResult::ValueNs(ValueNs::ImplSelf(*impl_)));
-                        }
+                            ResolveValueResult::ValueNs(ValueNs::ImplSelf(impl_))
+                        });
                     }
                 }
+                // bare `Self` doesn't work in the value namespace in a struct/enum definition
+                Scope::AdtScope(_) if n_segments == 1 => continue,
                 Scope::AdtScope(adt) => {
-                    if n_segments == 1 {
-                        // bare `Self` doesn't work in the value namespace in a struct/enum definition
-                        continue;
-                    }
                     if first_name == &name![Self] {
                         let ty = TypeNs::AdtSelfType(*adt);
                         return Some(ResolveValueResult::Partial(ty, 1));
                     }
                 }
 
-                Scope::ModuleScope(m) => {
+                Scope::BlockScope(m) => {
                     if let Some(def) = m.resolve_path_in_value_ns(db, path) {
                         return Some(def);
                     }
@@ -318,15 +290,16 @@ impl Resolver {
             }
         }
 
+        if let res @ Some(_) = self.module_scope.resolve_path_in_value_ns(db, path) {
+            return res;
+        }
+
         // If a path of the shape `u16::from_le_bytes` failed to resolve at all, then we fall back
         // to resolving to the primitive type, to allow this to still work in the presence of
         // `use core::u16;`.
         if path.kind == PathKind::Plain && path.segments().len() > 1 {
-            match BuiltinType::by_name(&path.segments()[0]) {
-                Some(builtin) => {
-                    return Some(ResolveValueResult::Partial(TypeNs::BuiltinType(builtin), 1));
-                }
-                None => {}
+            if let Some(builtin) = BuiltinType::by_name(&path.segments()[0]) {
+                return Some(ResolveValueResult::Partial(TypeNs::BuiltinType(builtin), 1));
             }
         }
 
@@ -345,7 +318,7 @@ impl Resolver {
     }
 
     pub fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroId> {
-        let (item_map, module) = self.module_scope();
+        let (item_map, module) = self.item_scope();
         item_map.resolve_path(db, module, path, BuiltinShadowMode::Other).0.take_macros()
     }
 
@@ -395,30 +368,34 @@ impl Resolver {
         for scope in self.scopes() {
             scope.process_names(&mut res, db);
         }
+        process_module_scope_names(&mut res, db, &self.module_scope);
         res.map
     }
 
     pub fn traits_in_scope(&self, db: &dyn DefDatabase) -> FxHashSet<TraitId> {
         let mut traits = FxHashSet::default();
-        for scope in self.scopes() {
-            match scope {
-                Scope::ModuleScope(m) => {
-                    if let Some(prelude) = m.def_map.prelude() {
-                        let prelude_def_map = prelude.def_map(db);
-                        traits.extend(prelude_def_map[prelude.local_id].scope.traits());
-                    }
-                    traits.extend(m.def_map[m.module_id].scope.traits());
 
-                    // Add all traits that are in scope because of the containing DefMaps
-                    m.def_map.with_ancestor_maps(db, m.module_id, &mut |def_map, module| {
-                        if let Some(prelude) = def_map.prelude() {
-                            let prelude_def_map = prelude.def_map(db);
-                            traits.extend(prelude_def_map[prelude.local_id].scope.traits());
-                        }
-                        traits.extend(def_map[module].scope.traits());
-                        None::<()>
-                    });
+        let collect_module_traits = |traits: &mut FxHashSet<_>, m: &ModuleItemMap| {
+            if let Some(prelude) = m.def_map.prelude() {
+                let prelude_def_map = prelude.def_map(db);
+                traits.extend(prelude_def_map[prelude.local_id].scope.traits());
+            }
+            traits.extend(m.def_map[m.module_id].scope.traits());
+
+            // Add all traits that are in scope because of the containing DefMaps
+            m.def_map.with_ancestor_maps(db, m.module_id, &mut |def_map, module| {
+                if let Some(prelude) = def_map.prelude() {
+                    let prelude_def_map = prelude.def_map(db);
+                    traits.extend(prelude_def_map[prelude.local_id].scope.traits());
                 }
+                traits.extend(def_map[module].scope.traits());
+                None::<()>
+            });
+        };
+
+        for scope in self.scopes() {
+            match scope {
+                Scope::BlockScope(m) => collect_module_traits(&mut traits, m),
                 &Scope::ImplDefScope(impl_) => {
                     if let Some(target_trait) = &db.impl_data(impl_).target_trait {
                         if let Some(TypeNs::TraitId(trait_)) =
@@ -431,35 +408,22 @@ impl Resolver {
                 _ => (),
             }
         }
-        traits
-    }
 
-    fn module_scope(&self) -> (&DefMap, LocalModuleId) {
-        self.scopes()
-            .find_map(|scope| match scope {
-                Scope::ModuleScope(m) => Some((&*m.def_map, m.module_id)),
-                _ => None,
-            })
-            .expect("module scope invariant violated")
+        collect_module_traits(&mut traits, &self.module_scope);
+        traits
     }
 
     pub fn module(&self) -> ModuleId {
-        let (def_map, local_id) = self.module_scope();
+        let (def_map, local_id) = self.item_scope();
         def_map.module_id(local_id)
     }
 
     pub fn krate(&self) -> CrateId {
-        self.def_map().krate()
+        self.module_scope.def_map.krate()
     }
 
     pub fn def_map(&self) -> &DefMap {
-        self.scopes
-            .get(0)
-            .and_then(|scope| match scope {
-                Scope::ModuleScope(m) => Some(&m.def_map),
-                _ => None,
-            })
-            .expect("module scope invariant violated")
+        self.item_scope().0
     }
 
     pub fn where_predicates_in_scope(
@@ -488,6 +452,36 @@ impl Resolver {
     }
 }
 
+impl Resolver {
+    fn scopes(&self) -> impl Iterator<Item = &Scope> {
+        self.scopes.iter().rev()
+    }
+
+    fn resolve_module_path(
+        &self,
+        db: &dyn DefDatabase,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
+    ) -> PerNs {
+        let (item_map, module) = self.item_scope();
+        let (module_res, segment_index) = item_map.resolve_path(db, module, path, shadow);
+        if segment_index.is_some() {
+            return PerNs::none();
+        }
+        module_res
+    }
+
+    /// The innermost block scope that contains items or the module scope that contains this resolver.
+    fn item_scope(&self) -> (&DefMap, LocalModuleId) {
+        self.scopes()
+            .find_map(|scope| match scope {
+                Scope::BlockScope(m) => Some((&*m.def_map, m.module_id)),
+                _ => None,
+            })
+            .unwrap_or((&self.module_scope.def_map, self.module_scope.module_id))
+    }
+}
+
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum ScopeDef {
     ModuleDef(ModuleDefId),
@@ -499,41 +493,42 @@ pub enum ScopeDef {
     Label(LabelId),
 }
 
+fn process_module_scope_names(acc: &mut ScopeNames, db: &dyn DefDatabase, m: &ModuleItemMap) {
+    // FIXME: should we provide `self` here?
+    // f(
+    //     Name::self_param(),
+    //     PerNs::types(Resolution::Def {
+    //         def: m.module.into(),
+    //     }),
+    // );
+    m.def_map[m.module_id].scope.entries().for_each(|(name, def)| {
+        acc.add_per_ns(name, def);
+    });
+    m.def_map[m.module_id].scope.legacy_macros().for_each(|(name, macs)| {
+        macs.iter().for_each(|&mac| {
+            acc.add(name, ScopeDef::ModuleDef(ModuleDefId::MacroId(MacroId::from(mac))));
+        })
+    });
+    m.def_map.extern_prelude().for_each(|(name, &def)| {
+        acc.add(name, ScopeDef::ModuleDef(ModuleDefId::ModuleId(def)));
+    });
+    if m.def_map.block_id().is_none() {
+        BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
+            acc.add_per_ns(name, def);
+        });
+    }
+    if let Some(prelude) = m.def_map.prelude() {
+        let prelude_def_map = prelude.def_map(db);
+        for (name, def) in prelude_def_map[prelude.local_id].scope.entries() {
+            acc.add_per_ns(name, def)
+        }
+    }
+}
+
 impl Scope {
     fn process_names(&self, acc: &mut ScopeNames, db: &dyn DefDatabase) {
         match self {
-            Scope::ModuleScope(m) => {
-                // FIXME: should we provide `self` here?
-                // f(
-                //     Name::self_param(),
-                //     PerNs::types(Resolution::Def {
-                //         def: m.module.into(),
-                //     }),
-                // );
-                m.def_map[m.module_id].scope.entries().for_each(|(name, def)| {
-                    acc.add_per_ns(name, def);
-                });
-                m.def_map[m.module_id].scope.legacy_macros().for_each(|(name, macs)| {
-                    macs.iter().for_each(|&mac| {
-                        acc.add(
-                            name,
-                            ScopeDef::ModuleDef(ModuleDefId::MacroId(MacroId::from(mac))),
-                        );
-                    })
-                });
-                m.def_map.extern_prelude().for_each(|(name, &def)| {
-                    acc.add(name, ScopeDef::ModuleDef(ModuleDefId::ModuleId(def)));
-                });
-                BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
-                    acc.add_per_ns(name, def);
-                });
-                if let Some(prelude) = m.def_map.prelude() {
-                    let prelude_def_map = prelude.def_map(db);
-                    for (name, def) in prelude_def_map[prelude.local_id].scope.entries() {
-                        acc.add_per_ns(name, def)
-                    }
-                }
-            }
+            Scope::BlockScope(m) => process_module_scope_names(acc, db, m),
             Scope::GenericParams { params, def: parent } => {
                 let parent = *parent;
                 for (local_id, param) in params.type_or_consts.iter() {
@@ -596,7 +591,7 @@ pub fn resolver_for_scope(
         if let Some(block) = scopes.block(scope) {
             if let Some(def_map) = db.block_def_map(block) {
                 let root = def_map.root();
-                r = r.push_module_scope(def_map, root);
+                r = r.push_block_scope(def_map, root);
                 // FIXME: This adds as many module scopes as there are blocks, but resolving in each
                 // already traverses all parents, so this is O(n²). I think we could only store the
                 // innermost module scope instead?
@@ -623,8 +618,8 @@ impl Resolver {
         self.push_scope(Scope::ImplDefScope(impl_def))
     }
 
-    fn push_module_scope(self, def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
-        self.push_scope(Scope::ModuleScope(ModuleItemMap { def_map, module_id }))
+    fn push_block_scope(self, def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
+        self.push_scope(Scope::BlockScope(ModuleItemMap { def_map, module_id }))
     }
 
     fn push_expr_scope(
@@ -768,14 +763,19 @@ pub trait HasResolver: Copy {
 impl HasResolver for ModuleId {
     fn resolver(self, db: &dyn DefDatabase) -> Resolver {
         let mut def_map = self.def_map(db);
-        let mut modules: SmallVec<[_; 2]> = smallvec![(def_map.clone(), self.local_id)];
+        let mut modules: SmallVec<[_; 1]> = smallvec![];
+        let mut module_id = self.local_id;
         while let Some(parent) = def_map.parent() {
+            modules.push((def_map, module_id));
             def_map = parent.def_map(db);
-            modules.push((def_map.clone(), parent.local_id));
+            module_id = parent.local_id;
         }
-        let mut resolver = Resolver { scopes: Vec::with_capacity(modules.len()) };
+        let mut resolver = Resolver {
+            scopes: Vec::with_capacity(modules.len()),
+            module_scope: ModuleItemMap { def_map, module_id },
+        };
         for (def_map, module) in modules.into_iter().rev() {
-            resolver = resolver.push_module_scope(def_map, module);
+            resolver = resolver.push_block_scope(def_map, module);
         }
         resolver
     }
diff --git a/crates/hir-ty/src/autoderef.rs b/crates/hir-ty/src/autoderef.rs
index b6f226dbfd2..344036dd813 100644
--- a/crates/hir-ty/src/autoderef.rs
+++ b/crates/hir-ty/src/autoderef.rs
@@ -104,8 +104,7 @@ pub(crate) fn deref(table: &mut InferenceTable<'_>, ty: Ty) -> Option<Ty> {
 
 fn builtin_deref(ty: &Ty) -> Option<&Ty> {
     match ty.kind(Interner) {
-        TyKind::Ref(.., ty) => Some(ty),
-        TyKind::Raw(.., ty) => Some(ty),
+        TyKind::Ref(.., ty) | TyKind::Raw(.., ty) => Some(ty),
         _ => None,
     }
 }
diff --git a/lib/la-arena/src/lib.rs b/lib/la-arena/src/lib.rs
index 50e8d06b660..ccaaf399176 100644
--- a/lib/la-arena/src/lib.rs
+++ b/lib/la-arena/src/lib.rs
@@ -322,6 +322,43 @@ impl<T> Arena<T> {
             .map(|(idx, value)| (Idx::from_raw(RawIdx(idx as u32)), value))
     }
 
+    /// Returns an iterator over the arena’s values.
+    ///
+    /// ```
+    /// let mut arena = la_arena::Arena::new();
+    /// let idx1 = arena.alloc(20);
+    /// let idx2 = arena.alloc(40);
+    /// let idx3 = arena.alloc(60);
+    ///
+    /// let mut iterator = arena.values();
+    /// assert_eq!(iterator.next(), Some(&20));
+    /// assert_eq!(iterator.next(), Some(&40));
+    /// assert_eq!(iterator.next(), Some(&60));
+    /// ```
+    pub fn values(&mut self) -> impl Iterator<Item = &T> + ExactSizeIterator + DoubleEndedIterator {
+        self.data.iter()
+    }
+
+    /// Returns an iterator over the arena’s mutable values.
+    ///
+    /// ```
+    /// let mut arena = la_arena::Arena::new();
+    /// let idx1 = arena.alloc(20);
+    ///
+    /// assert_eq!(arena[idx1], 20);
+    ///
+    /// let mut iterator = arena.values_mut();
+    /// *iterator.next().unwrap() = 10;
+    /// drop(iterator);
+    ///
+    /// assert_eq!(arena[idx1], 10);
+    /// ```
+    pub fn values_mut(
+        &mut self,
+    ) -> impl Iterator<Item = &mut T> + ExactSizeIterator + DoubleEndedIterator {
+        self.data.iter_mut()
+    }
+
     /// Reallocates the arena to make it take up as little space as possible.
     pub fn shrink_to_fit(&mut self) {
         self.data.shrink_to_fit();