13 files changed, 107 insertions, 305 deletions

diff --git a/crates/hir_def/Cargo.toml b/crates/hir_def/Cargo.toml
index 2f07b6d01..c2d99280f 100644
--- a/crates/hir_def/Cargo.toml
+++ b/crates/hir_def/Cargo.toml
@@ -28,10 +28,10 @@ base_db = { path = "../base_db", version = "0.0.0" }
 syntax = { path = "../syntax", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
 hir_expand = { path = "../hir_expand", version = "0.0.0" }
-test_utils = { path = "../test_utils", version = "0.0.0" }
 mbe = { path = "../mbe", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
 
 [dev-dependencies]
+test_utils = { path = "../test_utils" }
 expect-test = "1.1"
diff --git a/crates/hir_def/src/adt.rs b/crates/hir_def/src/adt.rs
index ed36c3109..efbde17d8 100644
--- a/crates/hir_def/src/adt.rs
+++ b/crates/hir_def/src/adt.rs
@@ -21,8 +21,7 @@ use crate::{
     trace::Trace,
     type_ref::TypeRef,
     visibility::RawVisibility,
-    EnumId, HasModule, LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StructId, UnionId,
-    VariantId,
+    EnumId, LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StructId, UnionId, VariantId,
 };
 use cfg::CfgOptions;
 
@@ -92,10 +91,10 @@ fn parse_repr_tt(tt: &Subtree) -> Option<ReprKind> {
 impl StructData {
     pub(crate) fn struct_data_query(db: &dyn DefDatabase, id: StructId) -> Arc<StructData> {
         let loc = id.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let repr = repr_from_value(db, krate, &item_tree, ModItem::from(loc.id.value).into());
-        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+        let cfg_options = db.crate_graph()[loc.container.krate].cfg_options.clone();
 
         let strukt = &item_tree[loc.id.value];
         let variant_data = lower_fields(db, krate, &item_tree, &cfg_options, &strukt.fields, None);
@@ -107,10 +106,10 @@ impl StructData {
     }
     pub(crate) fn union_data_query(db: &dyn DefDatabase, id: UnionId) -> Arc<StructData> {
         let loc = id.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let repr = repr_from_value(db, krate, &item_tree, ModItem::from(loc.id.value).into());
-        let cfg_options = db.crate_graph()[loc.container.module(db).krate].cfg_options.clone();
+        let cfg_options = db.crate_graph()[loc.container.krate].cfg_options.clone();
 
         let union = &item_tree[loc.id.value];
         let variant_data = lower_fields(db, krate, &item_tree, &cfg_options, &union.fields, None);
@@ -126,7 +125,7 @@ impl StructData {
 impl EnumData {
     pub(crate) fn enum_data_query(db: &dyn DefDatabase, e: EnumId) -> Arc<EnumData> {
         let loc = e.lookup(db);
-        let krate = loc.container.module(db).krate;
+        let krate = loc.container.krate;
         let item_tree = db.item_tree(loc.id.file_id);
         let cfg_options = db.crate_graph()[krate].cfg_options.clone();
 
@@ -168,7 +167,7 @@ impl HasChildSource<LocalEnumVariantId> for EnumId {
     ) -> InFile<ArenaMap<LocalEnumVariantId, Self::Value>> {
         let src = self.lookup(db).source(db);
         let mut trace = Trace::new_for_map();
-        lower_enum(db, &mut trace, &src, self.lookup(db).container.module(db));
+        lower_enum(db, &mut trace, &src, self.lookup(db).container);
         src.with_value(trace.into_map())
     }
 }
@@ -238,10 +237,10 @@ impl HasChildSource<LocalFieldId> for VariantId {
                 // I don't really like the fact that we call into parent source
                 // here, this might add to more queries then necessary.
                 let src = it.parent.child_source(db);
-                (src.map(|map| map[it.local_id].kind()), it.parent.lookup(db).container.module(db))
+                (src.map(|map| map[it.local_id].kind()), it.parent.lookup(db).container)
             }
             VariantId::StructId(it) => {
-                (it.lookup(db).source(db).map(|it| it.kind()), it.lookup(db).container.module(db))
+                (it.lookup(db).source(db).map(|it| it.kind()), it.lookup(db).container)
             }
             VariantId::UnionId(it) => (
                 it.lookup(db).source(db).map(|it| {
@@ -249,7 +248,7 @@ impl HasChildSource<LocalFieldId> for VariantId {
                         .map(ast::StructKind::Record)
                         .unwrap_or(ast::StructKind::Unit)
                 }),
-                it.lookup(db).container.module(db),
+                it.lookup(db).container,
             ),
         };
         let mut expander = CfgExpander::new(db, src.file_id, module_id.krate);
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index b716d5f6e..97cdbbb9e 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -267,7 +267,7 @@ impl Attrs {
         db: &dyn DefDatabase,
         e: EnumId,
     ) -> Arc<ArenaMap<LocalEnumVariantId, Attrs>> {
-        let krate = e.lookup(db).container.module(db).krate;
+        let krate = e.lookup(db).container.krate;
         let src = e.child_source(db);
         let mut res = ArenaMap::default();
 
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index b1a3fe1cb..19c4eb521 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -28,11 +28,10 @@ use crate::{
     db::DefDatabase,
     expr::{Expr, ExprId, Label, LabelId, Pat, PatId},
     item_scope::BuiltinShadowMode,
-    item_scope::ItemScope,
     nameres::DefMap,
     path::{ModPath, Path},
     src::HasSource,
-    AsMacroCall, DefWithBodyId, HasModule, LocalModuleId, Lookup, ModuleId,
+    AsMacroCall, BlockId, DefWithBodyId, HasModule, LocalModuleId, Lookup, ModuleId,
 };
 
 /// A subset of Expander that only deals with cfg attributes. We only need it to
@@ -226,7 +225,8 @@ pub struct Body {
     pub params: Vec<PatId>,
     /// The `ExprId` of the actual body expression.
     pub body_expr: ExprId,
-    pub item_scope: ItemScope,
+    /// Block expressions in this body that may contain inner items.
+    pub block_scopes: Vec<BlockId>,
     _c: Count<Self>,
 }
 
@@ -295,7 +295,7 @@ impl Body {
             }
         };
         let expander = Expander::new(db, file_id, module);
-        let (body, source_map) = Body::new(db, def, expander, params, body);
+        let (body, source_map) = Body::new(db, expander, params, body);
         (Arc::new(body), Arc::new(source_map))
     }
 
@@ -305,12 +305,11 @@ impl Body {
 
     fn new(
         db: &dyn DefDatabase,
-        def: DefWithBodyId,
         expander: Expander,
         params: Option<ast::ParamList>,
         body: Option<ast::Expr>,
     ) -> (Body, BodySourceMap) {
-        lower::lower(db, def, expander, params, body)
+        lower::lower(db, expander, params, body)
     }
 }
 
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index d4abe819d..8c8eb8007 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -1,17 +1,16 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
 
-use std::{any::type_name, mem, sync::Arc};
+use std::mem;
 
 use either::Either;
 use hir_expand::{
     hygiene::Hygiene,
     name::{name, AsName, Name},
-    ExpandError, HirFileId, MacroDefId, MacroDefKind,
+    ExpandError, HirFileId,
 };
 use la_arena::Arena;
 use profile::Count;
-use rustc_hash::FxHashMap;
 use syntax::{
     ast::{
         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
@@ -32,11 +31,9 @@ use crate::{
         Statement,
     },
     item_scope::BuiltinShadowMode,
-    item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
     path::{GenericArgs, Path},
     type_ref::{Mutability, Rawness, TypeRef},
-    AdtId, BlockLoc, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern,
-    ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    AdtId, BlockLoc, ModuleDefId,
 };
 
 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
@@ -60,15 +57,12 @@ impl LowerCtx {
 
 pub(super) fn lower(
     db: &dyn DefDatabase,
-    def: DefWithBodyId,
     expander: Expander,
     params: Option<ast::ParamList>,
     body: Option<ast::Expr>,
 ) -> (Body, BodySourceMap) {
-    let item_tree = db.item_tree(expander.current_file_id);
     ExprCollector {
         db,
-        def,
         source_map: BodySourceMap::default(),
         body: Body {
             exprs: Arena::default(),
@@ -76,14 +70,9 @@ pub(super) fn lower(
             labels: Arena::default(),
             params: Vec::new(),
             body_expr: dummy_expr_id(),
-            item_scope: Default::default(),
+            block_scopes: Vec::new(),
             _c: Count::new(),
         },
-        item_trees: {
-            let mut map = FxHashMap::default();
-            map.insert(expander.current_file_id, item_tree);
-            map
-        },
         expander,
     }
     .collect(params, body)
@@ -91,12 +80,9 @@ pub(super) fn lower(
 
 struct ExprCollector<'a> {
     db: &'a dyn DefDatabase,
-    def: DefWithBodyId,
     expander: Expander,
     body: Body,
     source_map: BodySourceMap,
-
-    item_trees: FxHashMap<HirFileId, Arc<ItemTree>>,
 }
 
 impl ExprCollector<'_> {
@@ -593,9 +579,6 @@ impl ExprCollector<'_> {
                 } else {
                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 
-                    let item_tree = self.db.item_tree(self.expander.current_file_id);
-                    self.item_trees.insert(self.expander.current_file_id, item_tree);
-
                     let id = collector(self, Some(expansion));
                     self.expander.exit(self.db, mark);
                     id
@@ -605,32 +588,6 @@ impl ExprCollector<'_> {
         }
     }
 
-    fn find_inner_item<N: ItemTreeNode>(&self, ast: &N::Source) -> Option<ItemTreeId<N>> {
-        let id = self.expander.ast_id(ast);
-        let tree = &self.item_trees[&id.file_id];
-
-        // FIXME: This probably breaks with `use` items, since they produce multiple item tree nodes
-
-        // Root file (non-macro).
-        let item_tree_id = tree
-            .all_inner_items()
-            .chain(tree.top_level_items().iter().copied())
-            .filter_map(|mod_item| mod_item.downcast::<N>())
-            .find(|tree_id| tree[*tree_id].ast_id().upcast() == id.value.upcast())
-            .or_else(|| {
-                log::debug!(
-                    "couldn't find inner {} item for {:?} (AST: `{}` - {:?})",
-                    type_name::<N>(),
-                    id,
-                    ast.syntax(),
-                    ast.syntax(),
-                );
-                None
-            })?;
-
-        Some(ItemTreeId::new(id.file_id, item_tree_id))
-    }
-
     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
         if let Some(expr) = expr {
             self.collect_expr(expr)
@@ -662,7 +619,6 @@ impl ExprCollector<'_> {
                             match expansion {
                                 Some(expansion) => {
                                     let statements: ast::MacroStmts = expansion;
-                                    this.collect_stmts_items(statements.statements());
 
                                     statements.statements().for_each(|stmt| {
                                         if let Some(mut r) = this.collect_stmt(stmt) {
@@ -700,6 +656,8 @@ impl ExprCollector<'_> {
         let block_loc =
             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
         let block_id = self.db.intern_block(block_loc);
+        self.body.block_scopes.push(block_id);
+
         let opt_def_map = self.db.block_def_map(block_id);
         let has_def_map = opt_def_map.is_some();
         let def_map = opt_def_map.unwrap_or_else(|| self.expander.def_map.clone());
@@ -707,7 +665,6 @@ impl ExprCollector<'_> {
         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
         let prev_local_module = mem::replace(&mut self.expander.module, module);
 
-        self.collect_stmts_items(block.statements());
         let statements =
             block.statements().filter_map(|s| self.collect_stmt(s)).flatten().collect();
         let tail = block.tail_expr().map(|e| self.collect_expr(e));
@@ -722,108 +679,6 @@ impl ExprCollector<'_> {
         expr_id
     }
 
-    fn collect_stmts_items(&mut self, stmts: ast::AstChildren<ast::Stmt>) {
-        let container = ContainerId::DefWithBodyId(self.def);
-
-        let items = stmts
-            .filter_map(|stmt| match stmt {
-                ast::Stmt::Item(it) => Some(it),
-                ast::Stmt::LetStmt(_) | ast::Stmt::ExprStmt(_) => None,
-            })
-            .filter_map(|item| {
-                let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
-                    ast::Item::Fn(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            FunctionLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::TypeAlias(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            TypeAliasLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::Const(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (
-                            ConstLoc { container: container.into(), id }.intern(self.db).into(),
-                            def.name(),
-                        )
-                    }
-                    ast::Item::Static(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (StaticLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Struct(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (StructLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Enum(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (EnumLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Union(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (UnionLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::Trait(def) => {
-                        let id = self.find_inner_item(&def)?;
-                        (TraitLoc { container, id }.intern(self.db).into(), def.name())
-                    }
-                    ast::Item::ExternBlock(_) => return None, // FIXME: collect from extern blocks
-                    ast::Item::Impl(_)
-                    | ast::Item::Use(_)
-                    | ast::Item::ExternCrate(_)
-                    | ast::Item::Module(_)
-                    | ast::Item::MacroCall(_) => return None,
-                    ast::Item::MacroRules(def) => {
-                        return Some(Either::Right(ast::Macro::from(def)));
-                    }
-                    ast::Item::MacroDef(def) => {
-                        return Some(Either::Right(ast::Macro::from(def)));
-                    }
-                };
-
-                Some(Either::Left((def, name)))
-            })
-            .collect::<Vec<_>>();
-
-        for either in items {
-            match either {
-                Either::Left((def, name)) => {
-                    self.body.item_scope.define_def(def);
-                    if let Some(name) = name {
-                        let vis = crate::visibility::Visibility::Public; // FIXME determine correctly
-                        let has_constructor = match def {
-                            ModuleDefId::AdtId(AdtId::StructId(s)) => {
-                                self.db.struct_data(s).variant_data.kind() != StructKind::Record
-                            }
-                            _ => true,
-                        };
-                        self.body.item_scope.push_res(
-                            name.as_name(),
-                            crate::per_ns::PerNs::from_def(def, vis, has_constructor),
-                        );
-                    }
-                }
-                Either::Right(e) => {
-                    let mac = MacroDefId {
-                        krate: self.expander.def_map.krate(),
-                        ast_id: Some(self.expander.ast_id(&e)),
-                        kind: MacroDefKind::Declarative,
-                        local_inner: false,
-                    };
-                    if let Some(name) = e.name() {
-                        self.body.item_scope.define_legacy_macro(name.as_name(), mac);
-                    }
-                }
-            }
-        }
-    }
-
     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
         if let Some(block) = expr {
             self.collect_block(block)
diff --git a/crates/hir_def/src/child_by_source.rs b/crates/hir_def/src/child_by_source.rs
index 75c2d756b..2a331dcaf 100644
--- a/crates/hir_def/src/child_by_source.rs
+++ b/crates/hir_def/src/child_by_source.rs
@@ -17,13 +17,16 @@ use crate::{
 };
 
 pub trait ChildBySource {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap;
-}
-
-impl ChildBySource for TraitId {
     fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
         let mut res = DynMap::default();
+        self.child_by_source_to(db, &mut res);
+        res
+    }
+    fn child_by_source_to(&self, db: &dyn DefDatabase, map: &mut DynMap);
+}
 
+impl ChildBySource for TraitId {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let data = db.trait_data(*self);
         for (_name, item) in data.items.iter() {
             match *item {
@@ -41,15 +44,11 @@ impl ChildBySource for TraitId {
                 }
             }
         }
-
-        res
     }
 }
 
 impl ChildBySource for ImplId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let data = db.impl_data(*self);
         for &item in data.items.iter() {
             match item {
@@ -67,25 +66,21 @@ impl ChildBySource for ImplId {
                 }
             }
         }
-
-        res
     }
 }
 
 impl ChildBySource for ModuleId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let def_map = self.def_map(db);
         let module_data = &def_map[self.local_id];
-        module_data.scope.child_by_source(db)
+        module_data.scope.child_by_source_to(db, res);
     }
 }
 
 impl ChildBySource for ItemScope {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-        self.declarations().for_each(|item| add_module_def(db, &mut res, item));
-        self.impls().for_each(|imp| add_impl(db, &mut res, imp));
-        return res;
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
+        self.declarations().for_each(|item| add_module_def(db, res, item));
+        self.impls().for_each(|imp| add_impl(db, res, imp));
 
         fn add_module_def(db: &dyn DefDatabase, map: &mut DynMap, item: ModuleDefId) {
             match item {
@@ -134,9 +129,7 @@ impl ChildBySource for ItemScope {
 }
 
 impl ChildBySource for VariantId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let arena_map = self.child_source(db);
         let arena_map = arena_map.as_ref();
         for (local_id, source) in arena_map.value.iter() {
@@ -150,28 +143,27 @@ impl ChildBySource for VariantId {
                 }
             }
         }
-        res
     }
 }
 
 impl ChildBySource for EnumId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
-
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let arena_map = self.child_source(db);
         let arena_map = arena_map.as_ref();
         for (local_id, source) in arena_map.value.iter() {
             let id = EnumVariantId { parent: *self, local_id };
             res[keys::VARIANT].insert(arena_map.with_value(source.clone()), id)
         }
-
-        res
     }
 }
 
 impl ChildBySource for DefWithBodyId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let body = db.body(*self);
-        body.item_scope.child_by_source(db)
+        for def_map in body.block_scopes.iter().filter_map(|block| db.block_def_map(*block)) {
+            // All block expressions are merged into the same map, because they logically all add
+            // inner items to the containing `DefWithBodyId`.
+            def_map[def_map.root()].scope.child_by_source_to(db, res);
+        }
     }
 }
diff --git a/crates/hir_def/src/data.rs b/crates/hir_def/src/data.rs
index d3380e0f4..aea53d527 100644
--- a/crates/hir_def/src/data.rs
+++ b/crates/hir_def/src/data.rs
@@ -97,7 +97,7 @@ impl TraitData {
         let tr_def = &item_tree[tr_loc.id.value];
         let name = tr_def.name.clone();
         let auto = tr_def.auto;
-        let module_id = tr_loc.container.module(db);
+        let module_id = tr_loc.container;
         let container = AssocContainerId::TraitId(tr);
         let mut expander = Expander::new(db, tr_loc.id.file_id, module_id);
 
@@ -147,7 +147,7 @@ impl ImplData {
         let target_trait = impl_def.target_trait.map(|id| item_tree[id].clone());
         let target_type = item_tree[impl_def.target_type].clone();
         let is_negative = impl_def.is_negative;
-        let module_id = impl_loc.container.module(db);
+        let module_id = impl_loc.container;
         let container = AssocContainerId::ImplId(id);
         let mut expander = Expander::new(db, impl_loc.id.file_id, module_id);
 
diff --git a/crates/hir_def/src/generics.rs b/crates/hir_def/src/generics.rs
index 3ace3be1f..a056ab797 100644
--- a/crates/hir_def/src/generics.rs
+++ b/crates/hir_def/src/generics.rs
@@ -421,8 +421,7 @@ impl HasChildSource<LocalConstParamId> for GenericDefId {
 }
 
 impl ChildBySource for GenericDefId {
-    fn child_by_source(&self, db: &dyn DefDatabase) -> DynMap {
-        let mut res = DynMap::default();
+    fn child_by_source_to(&self, db: &dyn DefDatabase, res: &mut DynMap) {
         let (_, sm) = GenericParams::new(db, *self);
 
         let sm = sm.as_ref();
@@ -440,6 +439,5 @@ impl ChildBySource for GenericDefId {
             let id = ConstParamId { parent: *self, local_id };
             res[keys::CONST_PARAM].insert(sm.with_value(src.clone()), id);
         }
-        res
     }
 }
diff --git a/crates/hir_def/src/item_scope.rs b/crates/hir_def/src/item_scope.rs
index 919933813..aafd73b60 100644
--- a/crates/hir_def/src/item_scope.rs
+++ b/crates/hir_def/src/item_scope.rs
@@ -168,37 +168,6 @@ impl ItemScope {
         self.unnamed_trait_imports.insert(tr, vis);
     }
 
-    pub(crate) fn push_res(&mut self, name: Name, def: PerNs) -> bool {
-        let mut changed = false;
-
-        if let Some(types) = def.types {
-            self.types.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                types
-            });
-        }
-        if let Some(values) = def.values {
-            self.values.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                values
-            });
-        }
-        if let Some(macros) = def.macros {
-            self.macros.entry(name.clone()).or_insert_with(|| {
-                changed = true;
-                macros
-            });
-        }
-
-        if def.is_none() {
-            if self.unresolved.insert(name) {
-                changed = true;
-            }
-        }
-
-        changed
-    }
-
     pub(crate) fn push_res_with_import(
         &mut self,
         glob_imports: &mut PerNsGlobImports,
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index 4498d94bb..6d11c5be4 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -108,7 +108,7 @@ pub type LocalModuleId = Idx<nameres::ModuleData>;
 
 #[derive(Debug)]
 pub struct ItemLoc<N: ItemTreeNode> {
-    pub container: ContainerId,
+    pub container: ModuleId,
     pub id: ItemTreeId<N>,
 }
 
@@ -279,18 +279,12 @@ pub struct ConstParamId {
 pub type LocalConstParamId = Idx<generics::ConstParamData>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum ContainerId {
-    ModuleId(ModuleId),
-    DefWithBodyId(DefWithBodyId),
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum AssocContainerId {
-    ContainerId(ContainerId),
+    ModuleId(ModuleId),
     ImplId(ImplId),
     TraitId(TraitId),
 }
-impl_from!(ContainerId for AssocContainerId);
+impl_from!(ModuleId for AssocContainerId);
 
 /// A Data Type
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -447,21 +441,12 @@ pub trait HasModule {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId;
 }
 
-impl HasModule for ContainerId {
-    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
-        match *self {
-            ContainerId::ModuleId(it) => it,
-            ContainerId::DefWithBodyId(it) => it.module(db),
-        }
-    }
-}
-
 impl HasModule for AssocContainerId {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         match *self {
-            AssocContainerId::ContainerId(it) => it.module(db),
-            AssocContainerId::ImplId(it) => it.lookup(db).container.module(db),
-            AssocContainerId::TraitId(it) => it.lookup(db).container.module(db),
+            AssocContainerId::ModuleId(it) => it,
+            AssocContainerId::ImplId(it) => it.lookup(db).container,
+            AssocContainerId::TraitId(it) => it.lookup(db).container,
         }
     }
 }
@@ -479,16 +464,15 @@ impl HasModule for AdtId {
             AdtId::UnionId(it) => it.lookup(db).container,
             AdtId::EnumId(it) => it.lookup(db).container,
         }
-        .module(db)
     }
 }
 
 impl HasModule for VariantId {
     fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
         match self {
-            VariantId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
-            VariantId::StructId(it) => it.lookup(db).container.module(db),
-            VariantId::UnionId(it) => it.lookup(db).container.module(db),
+            VariantId::EnumVariantId(it) => it.parent.lookup(db).container,
+            VariantId::StructId(it) => it.lookup(db).container,
+            VariantId::UnionId(it) => it.lookup(db).container,
         }
     }
 }
@@ -518,18 +502,18 @@ impl HasModule for GenericDefId {
         match self {
             GenericDefId::FunctionId(it) => it.lookup(db).module(db),
             GenericDefId::AdtId(it) => it.module(db),
-            GenericDefId::TraitId(it) => it.lookup(db).container.module(db),
+            GenericDefId::TraitId(it) => it.lookup(db).container,
             GenericDefId::TypeAliasId(it) => it.lookup(db).module(db),
-            GenericDefId::ImplId(it) => it.lookup(db).container.module(db),
-            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db),
+            GenericDefId::ImplId(it) => it.lookup(db).container,
+            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container,
             GenericDefId::ConstId(it) => it.lookup(db).module(db),
         }
     }
 }
 
 impl HasModule for StaticLoc {
-    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
-        self.container.module(db)
+    fn module(&self, _db: &dyn db::DefDatabase) -> ModuleId {
+        self.container
     }
 }
 
@@ -542,10 +526,10 @@ impl ModuleDefId {
             ModuleDefId::ModuleId(id) => *id,
             ModuleDefId::FunctionId(id) => id.lookup(db).module(db),
             ModuleDefId::AdtId(id) => id.module(db),
-            ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container.module(db),
+            ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container,
             ModuleDefId::ConstId(id) => id.lookup(db).container.module(db),
-            ModuleDefId::StaticId(id) => id.lookup(db).container.module(db),
-            ModuleDefId::TraitId(id) => id.lookup(db).container.module(db),
+            ModuleDefId::StaticId(id) => id.lookup(db).container,
+            ModuleDefId::TraitId(id) => id.lookup(db).container,
             ModuleDefId::TypeAliasId(id) => id.lookup(db).module(db),
             ModuleDefId::BuiltinType(_) => return None,
         })
@@ -559,12 +543,12 @@ impl AttrDefId {
             AttrDefId::FieldId(it) => it.parent.module(db).krate,
             AttrDefId::AdtId(it) => it.module(db).krate,
             AttrDefId::FunctionId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::EnumVariantId(it) => it.parent.lookup(db).container.module(db).krate,
+            AttrDefId::EnumVariantId(it) => it.parent.lookup(db).container.krate,
             AttrDefId::StaticId(it) => it.lookup(db).module(db).krate,
             AttrDefId::ConstId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::TraitId(it) => it.lookup(db).container.module(db).krate,
+            AttrDefId::TraitId(it) => it.lookup(db).container.krate,
             AttrDefId::TypeAliasId(it) => it.lookup(db).module(db).krate,
-            AttrDefId::ImplId(it) => it.lookup(db).container.module(db).krate,
+            AttrDefId::ImplId(it) => it.lookup(db).container.krate,
             AttrDefId::GenericParamId(it) => {
                 match it {
                     GenericParamId::TypeParamId(it) => it.parent,
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 3bb69d935..9ed48c506 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -37,9 +37,9 @@ use crate::{
     path::{ImportAlias, ModPath, PathKind},
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
-    AdtId, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId, FunctionLoc,
-    ImplLoc, Intern, LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc,
-    UnionLoc, UnresolvedMacro,
+    AdtId, AstId, AstIdWithPath, ConstLoc, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
+    LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    UnresolvedMacro,
 };
 
 const GLOB_RECURSION_LIMIT: usize = 100;
@@ -1042,7 +1042,6 @@ impl ModCollector<'_, '_> {
                 }
             }
             let module = self.def_collector.def_map.module_id(self.module_id);
-            let container = ContainerId::ModuleId(module);
 
             let mut def = None;
             match item {
@@ -1109,9 +1108,9 @@ impl ModCollector<'_, '_> {
                 }
                 ModItem::Impl(imp) => {
                     let module = self.def_collector.def_map.module_id(self.module_id);
-                    let container = ContainerId::ModuleId(module);
-                    let impl_id = ImplLoc { container, id: ItemTreeId::new(self.file_id, imp) }
-                        .intern(self.def_collector.db);
+                    let impl_id =
+                        ImplLoc { container: module, id: ItemTreeId::new(self.file_id, imp) }
+                            .intern(self.def_collector.db);
                     self.def_collector.def_map.modules[self.module_id].scope.define_impl(impl_id)
                 }
                 ModItem::Function(id) => {
@@ -1121,7 +1120,7 @@ impl ModCollector<'_, '_> {
 
                     def = Some(DefData {
                         id: FunctionLoc {
-                            container: container.into(),
+                            container: module.into(),
                             id: ItemTreeId::new(self.file_id, id),
                         }
                         .intern(self.def_collector.db)
@@ -1140,7 +1139,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: StructLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: StructLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1157,7 +1156,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: UnionLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: UnionLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1174,7 +1173,7 @@ impl ModCollector<'_, '_> {
                     self.collect_derives(&attrs, it.ast_id.upcast());
 
                     def = Some(DefData {
-                        id: EnumLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: EnumLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1188,7 +1187,7 @@ impl ModCollector<'_, '_> {
                     if let Some(name) = &it.name {
                         def = Some(DefData {
                             id: ConstLoc {
-                                container: container.into(),
+                                container: module.into(),
                                 id: ItemTreeId::new(self.file_id, id),
                             }
                             .intern(self.def_collector.db)
@@ -1203,7 +1202,7 @@ impl ModCollector<'_, '_> {
                     let it = &self.item_tree[id];
 
                     def = Some(DefData {
-                        id: StaticLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: StaticLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1215,7 +1214,7 @@ impl ModCollector<'_, '_> {
                     let it = &self.item_tree[id];
 
                     def = Some(DefData {
-                        id: TraitLoc { container, id: ItemTreeId::new(self.file_id, id) }
+                        id: TraitLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
                             .intern(self.def_collector.db)
                             .into(),
                         name: &it.name,
@@ -1228,7 +1227,7 @@ impl ModCollector<'_, '_> {
 
                     def = Some(DefData {
                         id: TypeAliasLoc {
-                            container: container.into(),
+                            container: module.into(),
                             id: ItemTreeId::new(self.file_id, id),
                         }
                         .intern(self.def_collector.db)
diff --git a/crates/hir_def/src/nameres/path_resolution.rs b/crates/hir_def/src/nameres/path_resolution.rs
index 8258dcffb..db459b1ed 100644
--- a/crates/hir_def/src/nameres/path_resolution.rs
+++ b/crates/hir_def/src/nameres/path_resolution.rs
@@ -156,7 +156,7 @@ impl DefMap {
         }
     }
 
-    pub(super) fn resolve_path_fp_with_macro_single(
+    fn resolve_path_fp_with_macro_single(
         &self,
         db: &dyn DefDatabase,
         mode: ResolveMode,
@@ -384,10 +384,16 @@ impl DefMap {
                 }
             }
         };
-        let from_extern_prelude = self
-            .extern_prelude
-            .get(name)
-            .map_or(PerNs::none(), |&it| PerNs::types(it, Visibility::Public));
+        // Give precedence to names in outer `DefMap`s over the extern prelude; only check prelude
+        // from the crate DefMap.
+        let from_extern_prelude = match self.block {
+            Some(_) => PerNs::none(),
+            None => self
+                .extern_prelude
+                .get(name)
+                .map_or(PerNs::none(), |&it| PerNs::types(it, Visibility::Public)),
+        };
+
         let from_prelude = self.resolve_in_prelude(db, name);
 
         from_legacy_macro.or(from_scope_or_builtin).or(from_extern_prelude).or(from_prelude)
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 77ff21739..42736171e 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -19,10 +19,10 @@ use crate::{
     path::{ModPath, PathKind},
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
-    AdtId, AssocContainerId, ConstId, ConstParamId, ContainerId, DefWithBodyId, EnumId,
-    EnumVariantId, FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId,
-    LocalModuleId, Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
-    TypeParamId, VariantId,
+    AdtId, AssocContainerId, ConstId, ConstParamId, DefWithBodyId, EnumId, EnumVariantId,
+    FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId, LocalModuleId,
+    Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId, TypeParamId,
+    VariantId,
 };
 
 #[derive(Debug, Clone, Default)]
@@ -342,6 +342,16 @@ impl Resolver {
                     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::<()>
+                });
             }
         }
         traits
@@ -678,19 +688,10 @@ impl HasResolver for DefWithBodyId {
     }
 }
 
-impl HasResolver for ContainerId {
-    fn resolver(self, db: &dyn DefDatabase) -> Resolver {
-        match self {
-            ContainerId::ModuleId(it) => it.resolver(db),
-            ContainerId::DefWithBodyId(it) => it.module(db).resolver(db),
-        }
-    }
-}
-
 impl HasResolver for AssocContainerId {
     fn resolver(self, db: &dyn DefDatabase) -> Resolver {
         match self {
-            AssocContainerId::ContainerId(it) => it.resolver(db),
+            AssocContainerId::ModuleId(it) => it.resolver(db),
             AssocContainerId::TraitId(it) => it.resolver(db),
             AssocContainerId::ImplId(it) => it.resolver(db),
         }