19 files changed, 550 insertions, 147 deletions
diff --git a/crates/hir_def/src/attr.rs b/crates/hir_def/src/attr.rs
index 1b09ff816..c72649c41 100644
--- a/crates/hir_def/src/attr.rs
+++ b/crates/hir_def/src/attr.rs
@@ -207,6 +207,7 @@ impl Attrs {
                        mod_data.definition_source(db).as_ref().map(|src| match src {
                            ModuleSource::SourceFile(file) => file as &dyn AttrsOwner,
                            ModuleSource::Module(module) => module as &dyn AttrsOwner,
+                            ModuleSource::BlockExpr(block) => block as &dyn AttrsOwner,
                        }),
                    ),
                }
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 344f0b6c0..2c2c999dd 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -29,7 +29,7 @@ use crate::{
    expr::{Expr, ExprId, Label, LabelId, Pat, PatId},
    item_scope::BuiltinShadowMode,
    item_scope::ItemScope,
-    nameres::CrateDefMap,
+    nameres::DefMap,
    path::{ModPath, Path},
    src::HasSource,
    AsMacroCall, DefWithBodyId, HasModule, Lookup, ModuleId,
@@ -45,7 +45,7 @@ pub(crate) struct CfgExpander {
 pub(crate) struct Expander {
    cfg_expander: CfgExpander,
-    crate_def_map: Arc<CrateDefMap>,
+    crate_def_map: Arc<DefMap>,
    current_file_id: HirFileId,
    ast_id_map: Arc<AstIdMap>,
    module: ModuleId,
@@ -122,7 +122,7 @@ impl Expander {
        let mut err = None;
        let call_id =
-            macro_call.as_call_id_with_errors(db, self.crate_def_map.krate, resolver, &mut |e| {
+            macro_call.as_call_id_with_errors(db, self.crate_def_map.krate(), resolver, &mut |e| {
                err.get_or_insert(e);
            });
        let call_id = match call_id {
diff --git a/crates/hir_def/src/body/tests.rs b/crates/hir_def/src/body/tests.rs
index de77d5fc9..2e5d0a01e 100644
--- a/crates/hir_def/src/body/tests.rs
+++ b/crates/hir_def/src/body/tests.rs
@@ -6,18 +6,24 @@ use crate::{test_db::TestDB, ModuleDefId};
 use super::*;
 fn lower(ra_fixture: &str) -> Arc<Body> {
-    let (db, file_id) = crate::test_db::TestDB::with_single_file(ra_fixture);
+    let db = crate::test_db::TestDB::with_files(ra_fixture);
    let krate = db.crate_graph().iter().next().unwrap();
    let def_map = db.crate_def_map(krate);
-    let module = def_map.modules_for_file(file_id).next().unwrap();
+    let mut fn_def = None;
-    let module = &def_map[module];
+    'outer: for (_, module) in def_map.modules() {
-    let fn_def = match module.scope.declarations().next().unwrap() {
+        for decl in module.scope.declarations() {
-        ModuleDefId::FunctionId(it) => it,
+            match decl {
-        _ => panic!(),
+                ModuleDefId::FunctionId(it) => {
-    };
+                    fn_def = Some(it);
+                    break 'outer;
+                }
+                _ => {}
+            }
+        }
+    }
-    db.body(fn_def.into())
+    db.body(fn_def.unwrap().into())
 }
 fn check_diagnostics(ra_fixture: &str) {
@@ -42,6 +48,25 @@ fn main() { n_nuple!(1,2,3); }
 }
 #[test]
+fn macro_resolve() {
+    // Regression test for a path resolution bug introduced with inner item handling.
+    lower(
+        r"
+macro_rules! vec {
+    () => { () };
+    ($elem:expr; $n:expr) => { () };
+    ($($x:expr),+ $(,)?) => { () };
+}
+mod m {
+    fn outer() {
+        let _ = vec![FileSet::default(); self.len()];
+    }
+}
+      ",
+    );
+}
+#[test]
 fn cfg_diagnostics() {
    check_diagnostics(
        r"
diff --git a/crates/hir_def/src/db.rs b/crates/hir_def/src/db.rs
index 6ef9fe790..a87c80b8a 100644
--- a/crates/hir_def/src/db.rs
+++ b/crates/hir_def/src/db.rs
@@ -2,9 +2,9 @@
 use std::sync::Arc;
 use base_db::{salsa, CrateId, SourceDatabase, Upcast};
-use hir_expand::{db::AstDatabase, HirFileId};
+use hir_expand::{db::AstDatabase, AstId, HirFileId};
 use la_arena::ArenaMap;
-use syntax::SmolStr;
+use syntax::{ast, SmolStr};
 use crate::{
    adt::{EnumData, StructData},
@@ -15,7 +15,7 @@ use crate::{
    import_map::ImportMap,
    item_tree::ItemTree,
    lang_item::{LangItemTarget, LangItems},
-    nameres::CrateDefMap,
+    nameres::DefMap,
    AttrDefId, ConstId, ConstLoc, DefWithBodyId, EnumId, EnumLoc, FunctionId, FunctionLoc,
    GenericDefId, ImplId, ImplLoc, LocalEnumVariantId, LocalFieldId, StaticId, StaticLoc, StructId,
    StructLoc, TraitId, TraitLoc, TypeAliasId, TypeAliasLoc, UnionId, UnionLoc, VariantId,
@@ -50,10 +50,13 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
    #[salsa::invoke(crate_def_map_wait)]
    #[salsa::transparent]
-    fn crate_def_map(&self, krate: CrateId) -> Arc<CrateDefMap>;
+    fn crate_def_map(&self, krate: CrateId) -> Arc<DefMap>;
-    #[salsa::invoke(CrateDefMap::crate_def_map_query)]
+    #[salsa::invoke(DefMap::crate_def_map_query)]
-    fn crate_def_map_query(&self, krate: CrateId) -> Arc<CrateDefMap>;
+    fn crate_def_map_query(&self, krate: CrateId) -> Arc<DefMap>;
+    #[salsa::invoke(DefMap::block_def_map_query)]
+    fn block_def_map(&self, krate: CrateId, block: AstId<ast::BlockExpr>) -> Arc<DefMap>;
    #[salsa::invoke(StructData::struct_data_query)]
    fn struct_data(&self, id: StructId) -> Arc<StructData>;
@@ -112,7 +115,7 @@ pub trait DefDatabase: InternDatabase + AstDatabase + Upcast<dyn AstDatabase> {
    fn import_map(&self, krate: CrateId) -> Arc<ImportMap>;
 }
-fn crate_def_map_wait(db: &impl DefDatabase, krate: CrateId) -> Arc<CrateDefMap> {
+fn crate_def_map_wait(db: &impl DefDatabase, krate: CrateId) -> Arc<DefMap> {
    let _p = profile::span("crate_def_map:wait");
    db.crate_def_map_query(krate)
 }
diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index 4a212d291..db2d125ae 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -4,7 +4,7 @@ use hir_expand::name::{known, AsName, Name};
 use rustc_hash::FxHashSet;
 use test_utils::mark;
-use crate::nameres::CrateDefMap;
+use crate::nameres::DefMap;
 use crate::{
    db::DefDatabase,
    item_scope::ItemInNs,
@@ -47,11 +47,11 @@ impl ModPath {
    }
 }
-fn check_self_super(def_map: &CrateDefMap, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
+fn check_self_super(def_map: &DefMap, item: ItemInNs, from: ModuleId) -> Option<ModPath> {
    if item == ItemInNs::Types(from.into()) {
        // - if the item is the module we're in, use `self`
        Some(ModPath::from_segments(PathKind::Super(0), Vec::new()))
-    } else if let Some(parent_id) = def_map.modules[from.local_id].parent {
+    } else if let Some(parent_id) = def_map[from.local_id].parent {
        // - if the item is the parent module, use `super` (this is not used recursively, since `super::super` is ugly)
        if item
            == ItemInNs::Types(ModuleDefId::ModuleId(ModuleId {
@@ -111,7 +111,7 @@ fn find_path_inner(
    // - if the item is already in scope, return the name under which it is
    let def_map = db.crate_def_map(from.krate);
-    let from_scope: &crate::item_scope::ItemScope = &def_map.modules[from.local_id].scope;
+    let from_scope: &crate::item_scope::ItemScope = &def_map[from.local_id].scope;
    let scope_name =
        if let Some((name, _)) = from_scope.name_of(item) { Some(name.clone()) } else { None };
    if prefixed.is_none() && scope_name.is_some() {
@@ -123,7 +123,7 @@ fn find_path_inner(
    if item
        == ItemInNs::Types(ModuleDefId::ModuleId(ModuleId {
            krate: from.krate,
-            local_id: def_map.root,
+            local_id: def_map.root(),
        }))
    {
        return Some(ModPath::from_segments(PathKind::Crate, Vec::new()));
@@ -136,7 +136,7 @@ fn find_path_inner(
    }
    // - if the item is the crate root of a dependency crate, return the name from the extern prelude
-    for (name, def_id) in &def_map.extern_prelude {
+    for (name, def_id) in def_map.extern_prelude() {
        if item == ItemInNs::Types(*def_id) {
            let name = scope_name.unwrap_or_else(|| name.clone());
            return Some(ModPath::from_segments(PathKind::Plain, vec![name]));
@@ -144,10 +144,10 @@ fn find_path_inner(
    }
    // - if the item is in the prelude, return the name from there
-    if let Some(prelude_module) = def_map.prelude {
+    if let Some(prelude_module) = def_map.prelude() {
        let prelude_def_map = db.crate_def_map(prelude_module.krate);
        let prelude_scope: &crate::item_scope::ItemScope =
-            &prelude_def_map.modules[prelude_module.local_id].scope;
+            &prelude_def_map[prelude_module.local_id].scope;
        if let Some((name, vis)) = prelude_scope.name_of(item) {
            if vis.is_visible_from(db, from) {
                return Some(ModPath::from_segments(PathKind::Plain, vec![name.clone()]));
@@ -175,7 +175,7 @@ fn find_path_inner(
    // - otherwise, look for modules containing (reexporting) it and import it from one of those
-    let crate_root = ModuleId { local_id: def_map.root, krate: from.krate };
+    let crate_root = ModuleId { local_id: def_map.root(), krate: from.krate };
    let crate_attrs = db.attrs(crate_root.into());
    let prefer_no_std = crate_attrs.by_key("no_std").exists();
    let mut best_path = None;
@@ -287,7 +287,7 @@ fn find_local_import_locations(
    // Compute the initial worklist. We start with all direct child modules of `from` as well as all
    // of its (recursive) parent modules.
-    let data = &def_map.modules[from.local_id];
+    let data = &def_map[from.local_id];
    let mut worklist = data
        .children
        .values()
@@ -296,7 +296,7 @@ fn find_local_import_locations(
    let mut parent = data.parent;
    while let Some(p) = parent {
        worklist.push(ModuleId { krate: from.krate, local_id: p });
-        parent = def_map.modules[p].parent;
+        parent = def_map[p].parent;
    }
    let mut seen: FxHashSet<_> = FxHashSet::default();
diff --git a/crates/hir_def/src/import_map.rs b/crates/hir_def/src/import_map.rs
index e5368b293..0251d016b 100644
--- a/crates/hir_def/src/import_map.rs
+++ b/crates/hir_def/src/import_map.rs
@@ -75,7 +75,7 @@ impl ImportMap {
        // We look only into modules that are public(ly reexported), starting with the crate root.
        let empty = ImportPath { segments: vec![] };
-        let root = ModuleId { krate, local_id: def_map.root };
+        let root = ModuleId { krate, local_id: def_map.root() };
        let mut worklist = vec![(root, empty)];
        while let Some((module, mod_path)) = worklist.pop() {
            let ext_def_map;
@@ -263,6 +263,7 @@ pub enum ImportKind {
    Trait,
    TypeAlias,
    BuiltinType,
+    AssociatedItem,
 }
 /// A way to match import map contents against the search query.
@@ -282,6 +283,7 @@ pub struct Query {
    query: String,
    lowercased: String,
    name_only: bool,
+    assoc_items_only: bool,
    search_mode: SearchMode,
    case_sensitive: bool,
    limit: usize,
@@ -295,6 +297,7 @@ impl Query {
            query,
            lowercased,
            name_only: false,
+            assoc_items_only: false,
            search_mode: SearchMode::Contains,
            case_sensitive: false,
            limit: usize::max_value(),
@@ -309,6 +312,11 @@ impl Query {
        Self { name_only: true, ..self }
    }
+    /// Matches only the entries that are associated items, ignoring the rest.
+    pub fn assoc_items_only(self) -> Self {
+        Self { assoc_items_only: true, ..self }
+    }
    /// Specifies the way to search for the entries using the query.
    pub fn search_mode(self, search_mode: SearchMode) -> Self {
        Self { search_mode, ..self }
@@ -331,6 +339,14 @@ impl Query {
    }
    fn import_matches(&self, import: &ImportInfo, enforce_lowercase: bool) -> bool {
+        if import.is_trait_assoc_item {
+            if self.exclude_import_kinds.contains(&ImportKind::AssociatedItem) {
+                return false;
+            }
+        } else if self.assoc_items_only {
+            return false;
+        }
        let mut input = if import.is_trait_assoc_item || self.name_only {
            import.path.segments.last().unwrap().to_string()
        } else {
@@ -814,6 +830,56 @@ mod tests {
    }
    #[test]
+    fn assoc_items_filtering() {
+        let ra_fixture = r#"
+        //- /main.rs crate:main deps:dep
+        //- /dep.rs crate:dep
+        pub mod fmt {
+            pub trait Display {
+                type FmtTypeAlias;
+                const FMT_CONST: bool;
+                fn format_function();
+                fn format_method(&self);
+            }
+        }
+    "#;
+        check_search(
+            ra_fixture,
+            "main",
+            Query::new("fmt".to_string()).search_mode(SearchMode::Fuzzy).assoc_items_only(),
+            expect![[r#"
+            dep::fmt::Display::FMT_CONST (a)
+            dep::fmt::Display::format_function (a)
+            dep::fmt::Display::format_method (a)
+        "#]],
+        );
+        check_search(
+            ra_fixture,
+            "main",
+            Query::new("fmt".to_string())
+                .search_mode(SearchMode::Fuzzy)
+                .exclude_import_kind(ImportKind::AssociatedItem),
+            expect![[r#"
+            dep::fmt (t)
+            dep::fmt::Display (t)
+        "#]],
+        );
+        check_search(
+            ra_fixture,
+            "main",
+            Query::new("fmt".to_string())
+                .search_mode(SearchMode::Fuzzy)
+                .assoc_items_only()
+                .exclude_import_kind(ImportKind::AssociatedItem),
+            expect![[r#""#]],
+        );
+    }
+    #[test]
    fn search_mode() {
        let ra_fixture = r#"
            //- /main.rs crate:main deps:dep
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 9a433b61c..b8d7608e7 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -21,6 +21,7 @@ use hir_expand::{
    HirFileId, InFile,
 };
 use la_arena::{Arena, Idx, RawIdx};
+use profile::Count;
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
 use syntax::{ast, match_ast};
@@ -67,15 +68,16 @@ impl GenericParamsId {
 /// The item tree of a source file.
 #[derive(Debug, Eq, PartialEq)]
 pub struct ItemTree {
+    _c: Count<Self>,
    top_level: SmallVec<[ModItem; 1]>,
    attrs: FxHashMap<AttrOwner, RawAttrs>,
-    inner_items: FxHashMap<FileAstId<ast::Item>, SmallVec<[ModItem; 1]>>,
    data: Option<Box<ItemTreeData>>,
 }
 impl ItemTree {
-    pub fn item_tree_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<ItemTree> {
+    pub(crate) fn item_tree_query(db: &dyn DefDatabase, file_id: HirFileId) -> Arc<ItemTree> {
        let _p = profile::span("item_tree_query").detail(|| format!("{:?}", file_id));
        let syntax = if let Some(node) = db.parse_or_expand(file_id) {
            node
@@ -118,9 +120,9 @@ impl ItemTree {
    fn empty() -> Self {
        Self {
+            _c: Count::new(),
            top_level: Default::default(),
            attrs: Default::default(),
-            inner_items: Default::default(),
            data: Default::default(),
        }
    }
@@ -145,9 +147,9 @@ impl ItemTree {
                macro_calls,
                macro_rules,
                macro_defs,
-                exprs,
                vis,
                generics,
+                inner_items,
            } = &mut **data;
            imports.shrink_to_fit();
@@ -167,10 +169,11 @@ impl ItemTree {
            macro_calls.shrink_to_fit();
            macro_rules.shrink_to_fit();
            macro_defs.shrink_to_fit();
-            exprs.shrink_to_fit();
            vis.arena.shrink_to_fit();
            generics.arena.shrink_to_fit();
+            inner_items.shrink_to_fit();
        }
    }
@@ -193,16 +196,18 @@ impl ItemTree {
        self.raw_attrs(of).clone().filter(db, krate)
    }
-    /// Returns the lowered inner items that `ast` corresponds to.
+    pub fn all_inner_items(&self) -> impl Iterator<Item = ModItem> + '_ {
-    ///
+        match &self.data {
-    /// Most AST items are lowered to a single `ModItem`, but some (eg. `use` items) may be lowered
+            Some(data) => Some(data.inner_items.values().flatten().copied()).into_iter().flatten(),
-    /// to multiple items in the `ItemTree`.
+            None => None.into_iter().flatten(),
-    pub fn inner_items(&self, ast: FileAstId<ast::Item>) -> &[ModItem] {
+        }
-        &self.inner_items[&ast]
    }
-    pub fn all_inner_items(&self) -> impl Iterator<Item = ModItem> + '_ {
+    pub fn inner_items_of_block(&self, block: FileAstId<ast::BlockExpr>) -> &[ModItem] {
-        self.inner_items.values().flatten().copied()
+        match &self.data {
+            Some(data) => data.inner_items.get(&block).map(|it| &**it).unwrap_or(&[]),
+            None => &[],
+        }
    }
    pub fn source<S: ItemTreeNode>(&self, db: &dyn DefDatabase, of: ItemTreeId<S>) -> S::Source {
@@ -296,10 +301,11 @@ struct ItemTreeData {
    macro_calls: Arena<MacroCall>,
    macro_rules: Arena<MacroRules>,
    macro_defs: Arena<MacroDef>,
-    exprs: Arena<Expr>,
    vis: ItemVisibilities,
    generics: GenericParamsStorage,
+    inner_items: FxHashMap<FileAstId<ast::BlockExpr>, SmallVec<[ModItem; 1]>>,
 }
 #[derive(Debug, Eq, PartialEq, Hash)]
@@ -461,7 +467,7 @@ macro_rules! impl_index {
    };
 }
-impl_index!(fields: Field, variants: Variant, exprs: Expr);
+impl_index!(fields: Field, variants: Variant);
 impl Index<RawVisibilityId> for ItemTree {
    type Output = RawVisibility;
@@ -664,11 +670,6 @@ pub struct MacroDef {
    pub ast_id: FileAstId<ast::MacroDef>,
 }
-// NB: There's no `FileAstId` for `Expr`. The only case where this would be useful is for array
-// lengths, but we don't do much with them yet.
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct Expr;
 macro_rules! impl_froms {
    ($e:ident { $($v:ident ($t:ty)),* $(,)? }) => {
        $(
diff --git a/crates/hir_def/src/item_tree/lower.rs b/crates/hir_def/src/item_tree/lower.rs
index 5e71ca42c..ce470fc3b 100644
--- a/crates/hir_def/src/item_tree/lower.rs
+++ b/crates/hir_def/src/item_tree/lower.rs
@@ -6,7 +6,7 @@ use hir_expand::{ast_id_map::AstIdMap, hygiene::Hygiene, name::known, HirFileId}
 use smallvec::SmallVec;
 use syntax::{
    ast::{self, ModuleItemOwner},
-    SyntaxNode,
+    SyntaxNode, WalkEvent,
 };
 use crate::{
@@ -37,7 +37,6 @@ pub(super) struct Ctx {
    file: HirFileId,
    source_ast_id_map: Arc<AstIdMap>,
    body_ctx: crate::body::LowerCtx,
-    inner_items: Vec<ModItem>,
    forced_visibility: Option<RawVisibilityId>,
 }
@@ -49,7 +48,6 @@ impl Ctx {
            file,
            source_ast_id_map: db.ast_id_map(file),
            body_ctx: crate::body::LowerCtx::new(db, file),
-            inner_items: Vec::new(),
            forced_visibility: None,
        }
    }
@@ -73,8 +71,6 @@ impl Ctx {
    }
    fn lower_mod_item(&mut self, item: &ast::Item, inner: bool) -> Option<ModItems> {
-        assert!(inner || self.inner_items.is_empty());
        // Collect inner items for 1-to-1-lowered items.
        match item {
            ast::Item::Struct(_)
@@ -150,14 +146,37 @@ impl Ctx {
    fn collect_inner_items(&mut self, container: &SyntaxNode) {
        let forced_vis = self.forced_visibility.take();
-        let mut inner_items = mem::take(&mut self.tree.inner_items);
-        inner_items.extend(container.descendants().skip(1).filter_map(ast::Item::cast).filter_map(
+        let mut block_stack = Vec::new();
-            |item| {
+        for event in container.preorder().skip(1) {
-                let ast_id = self.source_ast_id_map.ast_id(&item);
+            match event {
-                Some((ast_id, self.lower_mod_item(&item, true)?.0))
+                WalkEvent::Enter(node) => {
-            },
+                    match_ast! {
-        ));
+                        match node {
-        self.tree.inner_items = inner_items;
+                            ast::BlockExpr(block) => {
+                                block_stack.push(self.source_ast_id_map.ast_id(&block));
+                            },
+                            ast::Item(item) => {
+                                let mod_items = self.lower_mod_item(&item, true);
+                                let current_block = block_stack.last();
+                                if let (Some(mod_items), Some(block)) = (mod_items, current_block) {
+                                    if !mod_items.0.is_empty() {
+                                        self.data().inner_items.entry(*block).or_default().extend(mod_items.0.iter().copied());
+                                    }
+                                }
+                            },
+                            _ => {}
+                        }
+                    }
+                }
+                WalkEvent::Leave(node) => {
+                    if ast::BlockExpr::cast(node).is_some() {
+                        block_stack.pop();
+                    }
+                }
+            }
+        }
        self.forced_visibility = forced_vis;
    }
diff --git a/crates/hir_def/src/lang_item.rs b/crates/hir_def/src/lang_item.rs
index 30188b740..9e90f745c 100644
--- a/crates/hir_def/src/lang_item.rs
+++ b/crates/hir_def/src/lang_item.rs
@@ -84,7 +84,7 @@ impl LangItems {
        let crate_def_map = db.crate_def_map(krate);
-        for (_, module_data) in crate_def_map.modules.iter() {
+        for (_, module_data) in crate_def_map.modules() {
            for impl_def in module_data.scope.impls() {
                lang_items.collect_lang_item(db, impl_def, LangItemTarget::ImplDefId)
            }
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 50acc3f54..bd3ea9b8b 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -59,9 +59,10 @@ use std::sync::Arc;
 use base_db::{CrateId, Edition, FileId};
 use hir_expand::{diagnostics::DiagnosticSink, name::Name, InFile};
 use la_arena::Arena;
+use profile::Count;
 use rustc_hash::FxHashMap;
 use stdx::format_to;
-use syntax::ast;
+use syntax::{ast, AstNode};
 use crate::{
    db::DefDatabase,
@@ -74,21 +75,23 @@ use crate::{
 /// Contains all top-level defs from a macro-expanded crate
 #[derive(Debug, PartialEq, Eq)]
-pub struct CrateDefMap {
+pub struct DefMap {
-    pub root: LocalModuleId,
+    _c: Count<Self>,
-    pub modules: Arena<ModuleData>,
+    parent: Option<Arc<DefMap>>,
-    pub(crate) krate: CrateId,
+    root: LocalModuleId,
+    modules: Arena<ModuleData>,
+    krate: CrateId,
    /// The prelude module for this crate. This either comes from an import
    /// marked with the `prelude_import` attribute, or (in the normal case) from
    /// a dependency (`std` or `core`).
-    pub(crate) prelude: Option<ModuleId>,
+    prelude: Option<ModuleId>,
-    pub(crate) extern_prelude: FxHashMap<Name, ModuleDefId>,
+    extern_prelude: FxHashMap<Name, ModuleDefId>,
    edition: Edition,
    diagnostics: Vec<DefDiagnostic>,
 }
-impl std::ops::Index<LocalModuleId> for CrateDefMap {
+impl std::ops::Index<LocalModuleId> for DefMap {
    type Output = ModuleData;
    fn index(&self, id: LocalModuleId) -> &ModuleData {
        &self.modules[id]
@@ -109,6 +112,10 @@ pub enum ModuleOrigin {
    Inline {
        definition: AstId<ast::Module>,
    },
+    /// Pseudo-module introduced by a block scope (contains only inner items).
+    BlockExpr {
+        block: AstId<ast::BlockExpr>,
+    },
 }
 impl Default for ModuleOrigin {
@@ -122,7 +129,7 @@ impl ModuleOrigin {
        match self {
            ModuleOrigin::File { declaration: module, .. }
            | ModuleOrigin::Inline { definition: module, .. } => Some(*module),
-            ModuleOrigin::CrateRoot { .. } => None,
+            ModuleOrigin::CrateRoot { .. } | ModuleOrigin::BlockExpr { .. } => None,
        }
    }
@@ -137,7 +144,7 @@ impl ModuleOrigin {
    pub fn is_inline(&self) -> bool {
        match self {
-            ModuleOrigin::Inline { .. } => true,
+            ModuleOrigin::Inline { .. } | ModuleOrigin::BlockExpr { .. } => true,
            ModuleOrigin::CrateRoot { .. } | ModuleOrigin::File { .. } => false,
        }
    }
@@ -155,6 +162,9 @@ impl ModuleOrigin {
                definition.file_id,
                ModuleSource::Module(definition.to_node(db.upcast())),
            ),
+            ModuleOrigin::BlockExpr { block } => {
+                InFile::new(block.file_id, ModuleSource::BlockExpr(block.to_node(db.upcast())))
+            }
        }
    }
 }
@@ -169,29 +179,56 @@ pub struct ModuleData {
    pub origin: ModuleOrigin,
 }
-impl CrateDefMap {
+impl DefMap {
-    pub(crate) fn crate_def_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<CrateDefMap> {
+    pub(crate) fn crate_def_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<DefMap> {
        let _p = profile::span("crate_def_map_query").detail(|| {
            db.crate_graph()[krate].display_name.as_deref().unwrap_or_default().to_string()
        });
-        let def_map = {
+        let edition = db.crate_graph()[krate].edition;
-            let edition = db.crate_graph()[krate].edition;
+        let def_map = DefMap::empty(krate, edition);
-            let mut modules: Arena<ModuleData> = Arena::default();
+        let def_map = collector::collect_defs(db, def_map, None);
-            let root = modules.alloc(ModuleData::default());
-            CrateDefMap {
-                krate,
-                edition,
-                extern_prelude: FxHashMap::default(),
-                prelude: None,
-                root,
-                modules,
-                diagnostics: Vec::new(),
-            }
-        };
-        let def_map = collector::collect_defs(db, def_map);
        Arc::new(def_map)
    }
+    pub(crate) fn block_def_map_query(
+        db: &dyn DefDatabase,
+        krate: CrateId,
+        block: AstId<ast::BlockExpr>,
+    ) -> Arc<DefMap> {
+        let item_tree = db.item_tree(block.file_id);
+        let block_items = item_tree.inner_items_of_block(block.value);
+        let parent = parent_def_map(db, krate, block);
+        if block_items.is_empty() {
+            // If there are no inner items, nothing new is brought into scope, so we can just return
+            // the parent DefMap. This keeps DefMap parent chains short.
+            return parent;
+        }
+        let mut def_map = DefMap::empty(krate, parent.edition);
+        def_map.parent = Some(parent);
+        let def_map = collector::collect_defs(db, def_map, Some(block.value));
+        Arc::new(def_map)
+    }
+    fn empty(krate: CrateId, edition: Edition) -> DefMap {
+        let mut modules: Arena<ModuleData> = Arena::default();
+        let root = modules.alloc(ModuleData::default());
+        DefMap {
+            _c: Count::new(),
+            parent: None,
+            krate,
+            edition,
+            extern_prelude: FxHashMap::default(),
+            prelude: None,
+            root,
+            modules,
+            diagnostics: Vec::new(),
+        }
+    }
    pub fn add_diagnostics(
        &self,
        db: &dyn DefDatabase,
@@ -208,6 +245,26 @@ impl CrateDefMap {
            .map(|(id, _data)| id)
    }
+    pub fn modules(&self) -> impl Iterator<Item = (LocalModuleId, &ModuleData)> + '_ {
+        self.modules.iter()
+    }
+    pub fn root(&self) -> LocalModuleId {
+        self.root
+    }
+    pub(crate) fn krate(&self) -> CrateId {
+        self.krate
+    }
+    pub(crate) fn prelude(&self) -> Option<ModuleId> {
+        self.prelude
+    }
+    pub(crate) fn extern_prelude(&self) -> impl Iterator<Item = (&Name, &ModuleDefId)> + '_ {
+        self.extern_prelude.iter()
+    }
    pub(crate) fn resolve_path(
        &self,
        db: &dyn DefDatabase,
@@ -224,10 +281,15 @@ impl CrateDefMap {
    // even), as this should be a great debugging aid.
    pub fn dump(&self) -> String {
        let mut buf = String::new();
-        go(&mut buf, self, "crate", self.root);
+        let mut current_map = self;
+        while let Some(parent) = &current_map.parent {
+            go(&mut buf, current_map, "block scope", current_map.root);
+            current_map = &**parent;
+        }
+        go(&mut buf, current_map, "crate", current_map.root);
        return buf;
-        fn go(buf: &mut String, map: &CrateDefMap, path: &str, module: LocalModuleId) {
+        fn go(buf: &mut String, map: &DefMap, path: &str, module: LocalModuleId) {
            format_to!(buf, "{}\n", path);
            let mut entries: Vec<_> = map.modules[module].scope.resolutions().collect();
@@ -276,10 +338,40 @@ impl ModuleData {
    }
 }
+fn parent_def_map(
+    db: &dyn DefDatabase,
+    krate: CrateId,
+    block: AstId<ast::BlockExpr>,
+) -> Arc<DefMap> {
+    // FIXME: store this info in the item tree instead of reparsing here
+    let ast_id_map = db.ast_id_map(block.file_id);
+    let block_ptr = ast_id_map.get(block.value);
+    let root = match db.parse_or_expand(block.file_id) {
+        Some(it) => it,
+        None => {
+            return Arc::new(DefMap::empty(krate, Edition::Edition2018));
+        }
+    };
+    let ast = block_ptr.to_node(&root);
+    for ancestor in ast.syntax().ancestors().skip(1) {
+        if let Some(block_expr) = ast::BlockExpr::cast(ancestor) {
+            let ancestor_id = ast_id_map.ast_id(&block_expr);
+            let ast_id = InFile::new(block.file_id, ancestor_id);
+            let parent_map = db.block_def_map(krate, ast_id);
+            return parent_map;
+        }
+    }
+    // No enclosing block scope, so the parent is the crate-level DefMap.
+    db.crate_def_map(krate)
+}
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ModuleSource {
    SourceFile(ast::SourceFile),
    Module(ast::Module),
+    BlockExpr(ast::BlockExpr),
 }
 mod diagnostics {
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 0cd61698c..cd68efbe6 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -31,7 +31,7 @@ use crate::{
    },
    nameres::{
        diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
-        BuiltinShadowMode, CrateDefMap, ModuleData, ModuleOrigin, ResolveMode,
+        BuiltinShadowMode, DefMap, ModuleData, ModuleOrigin, ResolveMode,
    },
    path::{ImportAlias, ModPath, PathKind},
    per_ns::PerNs,
@@ -45,7 +45,11 @@ const GLOB_RECURSION_LIMIT: usize = 100;
 const EXPANSION_DEPTH_LIMIT: usize = 128;
 const FIXED_POINT_LIMIT: usize = 8192;
-pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
+pub(super) fn collect_defs(
+    db: &dyn DefDatabase,
+    mut def_map: DefMap,
+    block: Option<FileAstId<ast::BlockExpr>>,
+) -> DefMap {
    let crate_graph = db.crate_graph();
    // populate external prelude
@@ -93,6 +97,14 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: CrateDefMap) -> Cr
        exports_proc_macros: false,
        from_glob_import: Default::default(),
    };
+    match block {
+        Some(block) => {
+            collector.seed_with_inner(block);
+        }
+        None => {
+            collector.seed_with_top_level();
+        }
+    }
    collector.collect();
    collector.finish()
 }
@@ -210,7 +222,7 @@ struct DefData<'a> {
 /// Walks the tree of module recursively
 struct DefCollector<'a> {
    db: &'a dyn DefDatabase,
-    def_map: CrateDefMap,
+    def_map: DefMap,
    glob_imports: FxHashMap<LocalModuleId, Vec<(LocalModuleId, Visibility)>>,
    unresolved_imports: Vec<ImportDirective>,
    resolved_imports: Vec<ImportDirective>,
@@ -228,7 +240,7 @@ struct DefCollector<'a> {
 }
 impl DefCollector<'_> {
-    fn collect(&mut self) {
+    fn seed_with_top_level(&mut self) {
        let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id;
        let item_tree = self.db.item_tree(file_id.into());
        let module_id = self.def_map.root;
@@ -248,7 +260,31 @@ impl DefCollector<'_> {
            }
            .collect(item_tree.top_level_items());
        }
+    }
+    fn seed_with_inner(&mut self, block: FileAstId<ast::BlockExpr>) {
+        let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id;
+        let item_tree = self.db.item_tree(file_id.into());
+        let module_id = self.def_map.root;
+        self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id };
+        if item_tree
+            .top_level_attrs(self.db, self.def_map.krate)
+            .cfg()
+            .map_or(true, |cfg| self.cfg_options.check(&cfg) != Some(false))
+        {
+            ModCollector {
+                def_collector: &mut *self,
+                macro_depth: 0,
+                module_id,
+                file_id: file_id.into(),
+                item_tree: &item_tree,
+                mod_dir: ModDir::root(),
+            }
+            .collect(item_tree.inner_items_of_block(block));
+        }
+    }
+    fn collect(&mut self) {
        // main name resolution fixed-point loop.
        let mut i = 0;
        loop {
@@ -859,7 +895,7 @@ impl DefCollector<'_> {
        .collect(item_tree.top_level_items());
    }
-    fn finish(mut self) -> CrateDefMap {
+    fn finish(mut self) -> DefMap {
        // Emit diagnostics for all remaining unexpanded macros.
        for directive in &self.unexpanded_macros {
@@ -1470,11 +1506,10 @@ impl ModCollector<'_, '_> {
 mod tests {
    use crate::{db::DefDatabase, test_db::TestDB};
    use base_db::{fixture::WithFixture, SourceDatabase};
-    use la_arena::Arena;
    use super::*;
-    fn do_collect_defs(db: &dyn DefDatabase, def_map: CrateDefMap) -> CrateDefMap {
+    fn do_collect_defs(db: &dyn DefDatabase, def_map: DefMap) -> DefMap {
        let mut collector = DefCollector {
            db,
            def_map,
@@ -1489,28 +1524,17 @@ mod tests {
            exports_proc_macros: false,
            from_glob_import: Default::default(),
        };
+        collector.seed_with_top_level();
        collector.collect();
        collector.def_map
    }
-    fn do_resolve(code: &str) -> CrateDefMap {
+    fn do_resolve(code: &str) -> DefMap {
        let (db, _file_id) = TestDB::with_single_file(&code);
        let krate = db.test_crate();
-        let def_map = {
+        let edition = db.crate_graph()[krate].edition;
-            let edition = db.crate_graph()[krate].edition;
+        let def_map = DefMap::empty(krate, edition);
-            let mut modules: Arena<ModuleData> = Arena::default();
-            let root = modules.alloc(ModuleData::default());
-            CrateDefMap {
-                krate,
-                edition,
-                extern_prelude: FxHashMap::default(),
-                prelude: None,
-                root,
-                modules,
-                diagnostics: Vec::new(),
-            }
-        };
        do_collect_defs(&db, def_map)
    }
diff --git a/crates/hir_def/src/nameres/path_resolution.rs b/crates/hir_def/src/nameres/path_resolution.rs
index 88e10574e..ec90f4e65 100644
--- a/crates/hir_def/src/nameres/path_resolution.rs
+++ b/crates/hir_def/src/nameres/path_resolution.rs
@@ -19,7 +19,7 @@ use test_utils::mark;
 use crate::{
    db::DefDatabase,
    item_scope::BUILTIN_SCOPE,
-    nameres::{BuiltinShadowMode, CrateDefMap},
+    nameres::{BuiltinShadowMode, DefMap},
    path::{ModPath, PathKind},
    per_ns::PerNs,
    visibility::{RawVisibility, Visibility},
@@ -61,7 +61,7 @@ impl ResolvePathResult {
    }
 }
-impl CrateDefMap {
+impl DefMap {
    pub(super) fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs {
        self.extern_prelude
            .get(name)
@@ -104,6 +104,43 @@ impl CrateDefMap {
        path: &ModPath,
        shadow: BuiltinShadowMode,
    ) -> ResolvePathResult {
+        let mut result = ResolvePathResult::empty(ReachedFixedPoint::No);
+        result.segment_index = Some(usize::max_value());
+        let mut current_map = self;
+        loop {
+            let new = current_map.resolve_path_fp_with_macro_single(
+                db,
+                mode,
+                original_module,
+                path,
+                shadow,
+            );
+            // Merge `new` into `result`.
+            result.resolved_def = result.resolved_def.or(new.resolved_def);
+            if result.reached_fixedpoint == ReachedFixedPoint::No {
+                result.reached_fixedpoint = new.reached_fixedpoint;
+            }
+            // FIXME: this doesn't seem right; what if the different namespace resolutions come from different crates?
+            result.krate = result.krate.or(new.krate);
+            result.segment_index = result.segment_index.min(new.segment_index);
+            match &current_map.parent {
+                Some(map) => current_map = map,
+                None => return result,
+            }
+        }
+    }
+    pub(super) fn resolve_path_fp_with_macro_single(
+        &self,
+        db: &dyn DefDatabase,
+        mode: ResolveMode,
+        original_module: LocalModuleId,
+        path: &ModPath,
+        shadow: BuiltinShadowMode,
+    ) -> ResolvePathResult {
        let mut segments = path.segments.iter().enumerate();
        let mut curr_per_ns: PerNs = match path.kind {
            PathKind::DollarCrate(krate) => {
diff --git a/crates/hir_def/src/nameres/tests.rs b/crates/hir_def/src/nameres/tests.rs
index c459fa66d..73e3a4702 100644
--- a/crates/hir_def/src/nameres/tests.rs
+++ b/crates/hir_def/src/nameres/tests.rs
@@ -4,27 +4,47 @@ mod macros;
 mod mod_resolution;
 mod diagnostics;
 mod primitives;
+mod block;
 use std::sync::Arc;
 use base_db::{fixture::WithFixture, SourceDatabase};
 use expect_test::{expect, Expect};
+use hir_expand::db::AstDatabase;
 use test_utils::mark;
 use crate::{db::DefDatabase, nameres::*, test_db::TestDB};
-fn compute_crate_def_map(ra_fixture: &str) -> Arc<CrateDefMap> {
+fn compute_crate_def_map(ra_fixture: &str) -> Arc<DefMap> {
    let db = TestDB::with_files(ra_fixture);
    let krate = db.crate_graph().iter().next().unwrap();
    db.crate_def_map(krate)
 }
+fn compute_block_def_map(ra_fixture: &str) -> Arc<DefMap> {
+    let (db, position) = TestDB::with_position(ra_fixture);
+    let module = db.module_for_file(position.file_id);
+    let ast_map = db.ast_id_map(position.file_id.into());
+    let ast = db.parse(position.file_id);
+    let block: ast::BlockExpr =
+        syntax::algo::find_node_at_offset(&ast.syntax_node(), position.offset).unwrap();
+    let block_id = ast_map.ast_id(&block);
+    db.block_def_map(module.krate, InFile::new(position.file_id.into(), block_id))
+}
 fn check(ra_fixture: &str, expect: Expect) {
    let def_map = compute_crate_def_map(ra_fixture);
    let actual = def_map.dump();
    expect.assert_eq(&actual);
 }
+fn check_at(ra_fixture: &str, expect: Expect) {
+    let def_map = compute_block_def_map(ra_fixture);
+    let actual = def_map.dump();
+    expect.assert_eq(&actual);
+}
 #[test]
 fn crate_def_map_smoke_test() {
    check(
diff --git a/crates/hir_def/src/nameres/tests/block.rs b/crates/hir_def/src/nameres/tests/block.rs
new file mode 100644
index 000000000..01d6326a7
--- /dev/null
+++ b/crates/hir_def/src/nameres/tests/block.rs
@@ -0,0 +1,97 @@
+use super::*;
+#[test]
+fn inner_item_smoke() {
+    check_at(
+        r#"
+struct inner {}
+fn outer() {
+    $0
+    fn inner() {}
+}
+"#,
+        expect![[r#"
+            block scope
+            inner: v
+            crate
+            inner: t
+            outer: v
+        "#]],
+    );
+}
+#[test]
+fn use_from_crate() {
+    check_at(
+        r#"
+struct Struct;
+fn outer() {
+    use Struct;
+    use crate::Struct as CrateStruct;
+    use self::Struct as SelfStruct;
+    $0
+}
+"#,
+        expect![[r#"
+            block scope
+            CrateStruct: t v
+            SelfStruct: t v
+            Struct: t v
+            crate
+            Struct: t v
+            outer: v
+        "#]],
+    );
+}
+#[test]
+fn merge_namespaces() {
+    check_at(
+        r#"
+struct name {}
+fn outer() {
+    fn name() {}
+    use name as imported; // should import both `name`s
+    $0
+}
+"#,
+        expect![[r#"
+            block scope
+            imported: t v
+            name: v
+            crate
+            name: t
+            outer: v
+        "#]],
+    );
+}
+#[test]
+fn nested_blocks() {
+    check_at(
+        r#"
+fn outer() {
+    struct inner1 {}
+    fn inner() {
+        use inner1;
+        use outer;
+        fn inner2() {}
+        $0
+    }
+}
+"#,
+        expect![[r#"
+            block scope
+            inner1: t
+            inner2: v
+            outer: v
+            block scope
+            inner: v
+            inner1: t
+            crate
+            outer: v
+        "#]],
+    );
+}
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index 3dd7c3cbb..e34cd7f2f 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -87,7 +87,7 @@ impl ModPath {
    /// If this path is a single identifier, like `foo`, return its name.
    pub fn as_ident(&self) -> Option<&Name> {
-        if self.kind != PathKind::Plain || self.segments.len() > 1 {
+        if !self.is_ident() {
            return None;
        }
        self.segments.first()
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 85ddc2c47..b2f577649 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -16,13 +16,14 @@ use crate::{
    expr::{ExprId, PatId},
    generics::GenericParams,
    item_scope::{BuiltinShadowMode, BUILTIN_SCOPE},
-    nameres::CrateDefMap,
+    nameres::DefMap,
    path::{ModPath, PathKind},
    per_ns::PerNs,
    visibility::{RawVisibility, Visibility},
    AdtId, AssocContainerId, ConstId, ConstParamId, ContainerId, DefWithBodyId, EnumId,
-    EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId, LocalModuleId, Lookup, ModuleDefId,
+    EnumVariantId, FunctionId, GenericDefId, GenericParamId, HasModule, ImplId, LifetimeParamId,
-    ModuleId, StaticId, StructId, TraitId, TypeAliasId, TypeParamId, VariantId,
+    LocalModuleId, Lookup, ModuleDefId, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
+    TypeParamId, VariantId,
 };
 #[derive(Debug, Clone, Default)]
@@ -34,7 +35,7 @@ pub struct Resolver {
 // FIXME how to store these best
 #[derive(Debug, Clone)]
 struct ModuleItemMap {
-    crate_def_map: Arc<CrateDefMap>,
+    crate_def_map: Arc<DefMap>,
    module_id: LocalModuleId,
 }
@@ -145,6 +146,19 @@ impl Resolver {
        self.resolve_module_path(db, path, BuiltinShadowMode::Module)
    }
+    pub fn resolve_module_path_in_trait_items(
+        &self,
+        db: &dyn DefDatabase,
+        path: &ModPath,
+    ) -> Option<TraitId> {
+        let (item_map, module) = self.module_scope()?;
+        let (module_res, ..) = item_map.resolve_path(db, module, &path, BuiltinShadowMode::Module);
+        match module_res.take_types()? {
+            ModuleDefId::TraitId(it) => Some(it),
+            _ => None,
+        }
+    }
    pub fn resolve_path_in_type_ns(
        &self,
        db: &dyn DefDatabase,
@@ -415,7 +429,7 @@ impl Resolver {
        let mut traits = FxHashSet::default();
        for scope in &self.scopes {
            if let Scope::ModuleScope(m) = scope {
-                if let Some(prelude) = m.crate_def_map.prelude {
+                if let Some(prelude) = m.crate_def_map.prelude() {
                    let prelude_def_map = db.crate_def_map(prelude.krate);
                    traits.extend(prelude_def_map[prelude.local_id].scope.traits());
                }
@@ -425,7 +439,7 @@ impl Resolver {
        traits
    }
-    fn module_scope(&self) -> Option<(&CrateDefMap, LocalModuleId)> {
+    fn module_scope(&self) -> Option<(&DefMap, LocalModuleId)> {
        self.scopes.iter().rev().find_map(|scope| match scope {
            Scope::ModuleScope(m) => Some((&*m.crate_def_map, m.module_id)),
@@ -445,11 +459,11 @@ impl Resolver {
    pub fn module(&self) -> Option<ModuleId> {
        let (def_map, local_id) = self.module_scope()?;
-        Some(ModuleId { krate: def_map.krate, local_id })
+        Some(ModuleId { krate: def_map.krate(), local_id })
    }
    pub fn krate(&self) -> Option<CrateId> {
-        self.module_scope().map(|t| t.0.krate)
+        self.module_scope().map(|t| t.0.krate())
    }
    pub fn where_predicates_in_scope<'a>(
@@ -484,7 +498,7 @@ pub enum ScopeDef {
    PerNs(PerNs),
    ImplSelfType(ImplId),
    AdtSelfType(AdtId),
-    GenericParam(TypeParamId),
+    GenericParam(GenericParamId),
    Local(PatId),
 }
@@ -508,13 +522,13 @@ impl Scope {
                    seen.insert((name.clone(), scope));
                    f(name.clone(), ScopeDef::PerNs(scope));
                });
-                m.crate_def_map.extern_prelude.iter().for_each(|(name, &def)| {
+                m.crate_def_map.extern_prelude().for_each(|(name, &def)| {
                    f(name.clone(), ScopeDef::PerNs(PerNs::types(def, Visibility::Public)));
                });
                BUILTIN_SCOPE.iter().for_each(|(name, &def)| {
                    f(name.clone(), ScopeDef::PerNs(def));
                });
-                if let Some(prelude) = m.crate_def_map.prelude {
+                if let Some(prelude) = m.crate_def_map.prelude() {
                    let prelude_def_map = db.crate_def_map(prelude.krate);
                    prelude_def_map[prelude.local_id].scope.entries().for_each(|(name, def)| {
                        let seen_tuple = (name.clone(), def);
@@ -527,15 +541,21 @@ impl Scope {
            Scope::LocalItemsScope(body) => body.item_scope.entries().for_each(|(name, def)| {
                f(name.clone(), ScopeDef::PerNs(def));
            }),
-            Scope::GenericParams { params, def } => {
+            &Scope::GenericParams { ref params, def: parent } => {
                for (local_id, param) in params.types.iter() {
-                    if let Some(name) = &param.name {
+                    if let Some(ref name) = param.name {
-                        f(
+                        let id = TypeParamId { local_id, parent };
-                            name.clone(),
+                        f(name.clone(), ScopeDef::GenericParam(id.into()))
-                            ScopeDef::GenericParam(TypeParamId { local_id, parent: *def }),
-                        )
                    }
                }
+                for (local_id, param) in params.consts.iter() {
+                    let id = ConstParamId { local_id, parent };
+                    f(param.name.clone(), ScopeDef::GenericParam(id.into()))
+                }
+                for (local_id, param) in params.lifetimes.iter() {
+                    let id = LifetimeParamId { local_id, parent };
+                    f(param.name.clone(), ScopeDef::GenericParam(id.into()))
+                }
            }
            Scope::ImplDefScope(i) => {
                f(name![Self], ScopeDef::ImplSelfType(*i));
@@ -588,11 +608,7 @@ impl Resolver {
        self.push_scope(Scope::ImplDefScope(impl_def))
    }
-    fn push_module_scope(
+    fn push_module_scope(self, crate_def_map: Arc<DefMap>, module_id: LocalModuleId) -> Resolver {
-        self,
-        crate_def_map: Arc<CrateDefMap>,
-        module_id: LocalModuleId,
-    ) -> Resolver {
        self.push_scope(Scope::ModuleScope(ModuleItemMap { crate_def_map, module_id }))
    }
diff --git a/crates/hir_def/src/test_db.rs b/crates/hir_def/src/test_db.rs
index 574c0201a..4ff219fb7 100644
--- a/crates/hir_def/src/test_db.rs
+++ b/crates/hir_def/src/test_db.rs
@@ -75,7 +75,7 @@ impl TestDB {
    pub(crate) fn module_for_file(&self, file_id: FileId) -> crate::ModuleId {
        for &krate in self.relevant_crates(file_id).iter() {
            let crate_def_map = self.crate_def_map(krate);
-            for (local_id, data) in crate_def_map.modules.iter() {
+            for (local_id, data) in crate_def_map.modules() {
                if data.origin.file_id() == Some(file_id) {
                    return crate::ModuleId { krate, local_id };
                }
@@ -110,7 +110,7 @@ impl TestDB {
        let crate_graph = self.crate_graph();
        for krate in crate_graph.iter() {
            let crate_def_map = self.crate_def_map(krate);
-            for (module_id, _) in crate_def_map.modules.iter() {
+            for (module_id, _) in crate_def_map.modules() {
                let file_id = crate_def_map[module_id].origin.file_id();
                files.extend(file_id)
            }
@@ -135,7 +135,7 @@ impl TestDB {
            let crate_def_map = self.crate_def_map(krate);
            let mut sink = DiagnosticSinkBuilder::new().build(&mut cb);
-            for (module_id, module) in crate_def_map.modules.iter() {
+            for (module_id, module) in crate_def_map.modules() {
                crate_def_map.add_diagnostics(self, module_id, &mut sink);
                for decl in module.scope.declarations() {
diff --git a/crates/hir_def/src/type_ref.rs b/crates/hir_def/src/type_ref.rs
index ae93d0d10..049b2e462 100644
--- a/crates/hir_def/src/type_ref.rs
+++ b/crates/hir_def/src/type_ref.rs
@@ -159,6 +159,8 @@ impl TypeRef {
            ast::Type::DynTraitType(inner) => {
                TypeRef::DynTrait(type_bounds_from_ast(ctx, inner.type_bound_list()))
            }
+            // FIXME: Macros in type position are not yet supported.
+            ast::Type::MacroType(_) => TypeRef::Error,
        }
    }
diff --git a/crates/hir_def/src/visibility.rs b/crates/hir_def/src/visibility.rs
index f3bc9d680..3134fa43d 100644
--- a/crates/hir_def/src/visibility.rs
+++ b/crates/hir_def/src/visibility.rs
@@ -5,7 +5,7 @@ use syntax::ast;
 use crate::{
    db::DefDatabase,
-    nameres::CrateDefMap,
+    nameres::DefMap,
    path::{ModPath, PathKind},
    ModuleId,
 };
@@ -116,7 +116,7 @@ impl Visibility {
    pub(crate) fn is_visible_from_def_map(
        self,
-        def_map: &CrateDefMap,
+        def_map: &DefMap,
        from_module: crate::LocalModuleId,
    ) -> bool {
        let to_module = match self {
@@ -135,7 +135,7 @@ impl Visibility {
    ///
    /// If there is no subset relation between `self` and `other`, returns `None` (ie. they're only
    /// visible in unrelated modules).
-    pub(crate) fn max(self, other: Visibility, def_map: &CrateDefMap) -> Option<Visibility> {
+    pub(crate) fn max(self, other: Visibility, def_map: &DefMap) -> Option<Visibility> {
        match (self, other) {
            (Visibility::Module(_), Visibility::Public)
            | (Visibility::Public, Visibility::Module(_))