57 files changed, 3268 insertions, 2395 deletions
diff --git a/Cargo.lock b/Cargo.lock
index 0314735da..6f4c4f767 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -62,7 +62,7 @@ name = "backtrace-sys"
 version = "0.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cc 1.0.30 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.50 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -118,7 +118,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "cargo_metadata"
-version = "0.7.1"
+version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -130,7 +130,7 @@ dependencies = [
 [[package]]
 name = "cc"
-version = "1.0.30"
+version = "1.0.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -265,7 +265,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -338,7 +338,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -563,7 +563,7 @@ name = "jemalloc-sys"
 version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cc 1.0.30 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)",
 "fs_extra 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "libc 0.2.50 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -755,7 +755,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -847,7 +847,7 @@ dependencies = [
 "pest_meta 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1083,7 +1083,7 @@ dependencies = [
 name = "ra_project_model"
 version = "0.1.0"
 dependencies = [
- "cargo_metadata 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cargo_metadata 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_arena 0.1.0",
@@ -1395,7 +1395,7 @@ dependencies = [
 "heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1440,7 +1440,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1523,7 +1523,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "syn"
-version = "0.15.27"
+version = "0.15.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1538,7 +1538,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.27 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)",
 "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1905,8 +1905,8 @@ dependencies = [
 "checksum block-buffer 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a076c298b9ecdb530ed9d967e74a6027d6a7478924520acddcddc24c1c8ab3ab"
 "checksum byte-tools 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "560c32574a12a89ecd91f5e742165893f86e3ab98d21f8ea548658eb9eef5f40"
 "checksum byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a019b10a2a7cdeb292db131fc8113e57ea2a908f6e7894b0c3c671893b65dbeb"
-"checksum cargo_metadata 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "585784cac9b05c93a53b17a0b24a5cdd1dfdda5256f030e089b549d2390cc720"
+"checksum cargo_metadata 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "bc796c7161c220089dfc7159e13324979181532850a237576b8fb907dd087c0d"
-"checksum cc 1.0.30 (registry+https://github.com/rust-lang/crates.io-index)" = "d01c69d08ff207f231f07196e30f84c70f1c815b04f980f8b7b01ff01f05eb92"
+"checksum cc 1.0.31 (registry+https://github.com/rust-lang/crates.io-index)" = "c9ce8bb087aacff865633f0bd5aeaed910fe2fe55b55f4739527f2e023a2e53d"
 "checksum cfg-if 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "11d43355396e872eefb45ce6342e4374ed7bc2b3a502d1b28e36d6e23c05d1f4"
 "checksum chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
 "checksum ci_info 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e5e881307a989a3a5e20d52a32cc05950e3c2178cccfcc9428271a6cde09f902"
@@ -2042,7 +2042,7 @@ dependencies = [
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
 "checksum superslice 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ab16ced94dbd8a46c82fd81e3ed9a8727dac2977ea869d217bcc4ea1f122e81f"
-"checksum syn 0.15.27 (registry+https://github.com/rust-lang/crates.io-index)" = "525bd55255f03c816e5d7f615587bd13030c7103354fadb104993dcee6a788ec"
+"checksum syn 0.15.29 (registry+https://github.com/rust-lang/crates.io-index)" = "1825685f977249735d510a242a6727b46efe914bb67e38d30c071b1b72b1d5c2"
 "checksum synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "73687139bf99285483c96ac0add482c3776528beac1d97d444f6e91f203a2015"
 "checksum tempfile 3.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "b86c784c88d98c801132806dadd3819ed29d8600836c4088e855cdf3e178ed8a"
 "checksum tera 0.11.20 (registry+https://github.com/rust-lang/crates.io-index)" = "4b505279e19d8f7d24b1a9dc58327c9c36174b1a2c7ebdeac70792d017cb64f3"
diff --git a/crates/ra_assists/src/add_missing_impl_members.rs b/crates/ra_assists/src/add_missing_impl_members.rs
new file mode 100644
index 000000000..4435c4b5d
--- /dev/null
+++ b/crates/ra_assists/src/add_missing_impl_members.rs
@@ -0,0 +1,283 @@
+use crate::{Assist, AssistId, AssistCtx};
+use hir::Resolver;
+use hir::db::HirDatabase;
+use ra_syntax::{SmolStr, SyntaxKind, TextRange, TextUnit, TreeArc};
+use ra_syntax::ast::{self, AstNode, FnDef, ImplItem, ImplItemKind, NameOwner};
+use ra_db::FilePosition;
+use ra_fmt::{leading_indent, reindent};
+use itertools::Itertools;
+pub(crate) fn add_missing_impl_members(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
+    let impl_node = ctx.node_at_offset::<ast::ImplBlock>()?;
+    let impl_item_list = impl_node.item_list()?;
+    let trait_def = {
+        let file_id = ctx.frange.file_id;
+        let position = FilePosition { file_id, offset: impl_node.syntax().range().start() };
+        let resolver = hir::source_binder::resolver_for_position(ctx.db, position);
+        resolve_target_trait_def(ctx.db, &resolver, impl_node)?
+    };
+    let missing_fns: Vec<_> = {
+        let fn_def_opt = |kind| if let ImplItemKind::FnDef(def) = kind { Some(def) } else { None };
+        let def_name = |def| -> Option<&SmolStr> { FnDef::name(def).map(ast::Name::text) };
+        let trait_items =
+            trait_def.syntax().descendants().find_map(ast::ItemList::cast)?.impl_items();
+        let impl_items = impl_item_list.impl_items();
+        let trait_fns = trait_items.map(ImplItem::kind).filter_map(fn_def_opt).collect::<Vec<_>>();
+        let impl_fns = impl_items.map(ImplItem::kind).filter_map(fn_def_opt).collect::<Vec<_>>();
+        trait_fns
+            .into_iter()
+            .filter(|t| def_name(t).is_some())
+            .filter(|t| impl_fns.iter().all(|i| def_name(i) != def_name(t)))
+            .collect()
+    };
+    if missing_fns.is_empty() {
+        return None;
+    }
+    ctx.add_action(AssistId("add_impl_missing_members"), "add missing impl members", |edit| {
+        let (parent_indent, indent) = {
+            // FIXME: Find a way to get the indent already used in the file.
+            // Now, we copy the indent of first item or indent with 4 spaces relative to impl block
+            const DEFAULT_INDENT: &str = "    ";
+            let first_item = impl_item_list.impl_items().next();
+            let first_item_indent =
+                first_item.and_then(|i| leading_indent(i.syntax())).map(ToOwned::to_owned);
+            let impl_block_indent = leading_indent(impl_node.syntax()).unwrap_or_default();
+            (
+                impl_block_indent.to_owned(),
+                first_item_indent.unwrap_or_else(|| impl_block_indent.to_owned() + DEFAULT_INDENT),
+            )
+        };
+        let changed_range = {
+            let children = impl_item_list.syntax().children();
+            let last_whitespace = children.filter_map(ast::Whitespace::cast).last();
+            last_whitespace.map(|w| w.syntax().range()).unwrap_or_else(|| {
+                let in_brackets = impl_item_list.syntax().range().end() - TextUnit::of_str("}");
+                TextRange::from_to(in_brackets, in_brackets)
+            })
+        };
+        let func_bodies = format!("\n{}", missing_fns.into_iter().map(build_func_body).join("\n"));
+        let trailing_whitespace = format!("\n{}", parent_indent);
+        let func_bodies = reindent(&func_bodies, &indent) + &trailing_whitespace;
+        let replaced_text_range = TextUnit::of_str(&func_bodies);
+        edit.replace(changed_range, func_bodies);
+        edit.set_cursor(
+            changed_range.start() + replaced_text_range - TextUnit::of_str(&trailing_whitespace),
+        );
+    });
+    ctx.build()
+}
+/// Given an `ast::ImplBlock`, resolves the target trait (the one being
+/// implemented) to a `ast::TraitDef`.
+fn resolve_target_trait_def(
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    impl_block: &ast::ImplBlock,
+) -> Option<TreeArc<ast::TraitDef>> {
+    let ast_path = impl_block.target_trait().map(AstNode::syntax).and_then(ast::PathType::cast)?;
+    let hir_path = ast_path.path().and_then(hir::Path::from_ast)?;
+    match resolver.resolve_path(db, &hir_path).take_types() {
+        Some(hir::Resolution::Def(hir::ModuleDef::Trait(def))) => Some(def.source(db).1),
+        _ => None,
+    }
+}
+fn build_func_body(def: &ast::FnDef) -> String {
+    let mut buf = String::new();
+    for child in def.syntax().children() {
+        if child.kind() == SyntaxKind::SEMI {
+            buf.push_str(" { unimplemented!() }")
+        } else {
+            child.text().push_to(&mut buf);
+        }
+    }
+    buf.trim_end().to_string()
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::helpers::{check_assist, check_assist_not_applicable};
+    #[test]
+    fn test_add_missing_impl_members() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo {
+    fn foo(&self);
+    fn bar(&self);
+    fn baz(&self);
+}
+struct S;
+impl Foo for S {
+    fn bar(&self) {}
+    <|>
+}",
+            "
+trait Foo {
+    fn foo(&self);
+    fn bar(&self);
+    fn baz(&self);
+}
+struct S;
+impl Foo for S {
+    fn bar(&self) {}
+    fn foo(&self) { unimplemented!() }
+    fn baz(&self) { unimplemented!() }<|>
+}",
+        );
+    }
+    #[test]
+    fn test_copied_overriden_members() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo {
+    fn foo(&self);
+    fn bar(&self) -> bool { true }
+    fn baz(&self) -> u32 { 42 }
+}
+struct S;
+impl Foo for S {
+    fn bar(&self) {}
+    <|>
+}",
+            "
+trait Foo {
+    fn foo(&self);
+    fn bar(&self) -> bool { true }
+    fn baz(&self) -> u32 { 42 }
+}
+struct S;
+impl Foo for S {
+    fn bar(&self) {}
+    fn foo(&self) { unimplemented!() }
+    fn baz(&self) -> u32 { 42 }<|>
+}",
+        );
+    }
+    #[test]
+    fn test_empty_impl_block() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo { fn foo(&self); }
+struct S;
+impl Foo for S {<|>}",
+            "
+trait Foo { fn foo(&self); }
+struct S;
+impl Foo for S {
+    fn foo(&self) { unimplemented!() }<|>
+}",
+        );
+    }
+    #[test]
+    fn test_cursor_after_empty_impl_block() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo { fn foo(&self); }
+struct S;
+impl Foo for S {}<|>",
+            "
+trait Foo { fn foo(&self); }
+struct S;
+impl Foo for S {
+    fn foo(&self) { unimplemented!() }<|>
+}",
+        )
+    }
+    #[test]
+    fn test_empty_trait() {
+        check_assist_not_applicable(
+            add_missing_impl_members,
+            "
+trait Foo;
+struct S;
+impl Foo for S { <|> }",
+        )
+    }
+    #[test]
+    fn test_ignore_unnamed_trait_members() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo {
+    fn (arg: u32);
+    fn valid(some: u32) -> bool { false }
+}
+struct S;
+impl Foo for S { <|> }",
+            "
+trait Foo {
+    fn (arg: u32);
+    fn valid(some: u32) -> bool { false }
+}
+struct S;
+impl Foo for S {
+    fn valid(some: u32) -> bool { false }<|>
+}",
+        )
+    }
+    #[test]
+    fn test_indented_impl_block() {
+        check_assist(
+            add_missing_impl_members,
+            "
+trait Foo {
+    fn valid(some: u32) -> bool { false }
+}
+struct S;
+mod my_mod {
+    impl crate::Foo for S { <|> }
+}",
+            "
+trait Foo {
+    fn valid(some: u32) -> bool { false }
+}
+struct S;
+mod my_mod {
+    impl crate::Foo for S {
+        fn valid(some: u32) -> bool { false }<|>
+    }
+}",
+        )
+    }
+}
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 5efc5025e..871b37f58 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -96,6 +96,7 @@ mod replace_if_let_with_match;
 mod split_import;
 mod remove_dbg;
 mod auto_import;
+mod add_missing_impl_members;
 fn all_assists<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assist>] {
    &[
@@ -110,6 +111,7 @@ fn all_assists<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assis
        split_import::split_import,
        remove_dbg::remove_dbg,
        auto_import::auto_import,
+        add_missing_impl_members::add_missing_impl_members,
    ]
 }
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index e45a510b3..2b1001d48 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -124,6 +124,10 @@ impl CrateGraph {
        self.arena.is_empty()
    }
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = CrateId> + 'a {
+        self.arena.keys().map(|it| *it)
+    }
    pub fn crate_root(&self, crate_id: CrateId) -> FileId {
        self.arena[&crate_id].file_id
    }
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 87a7195e6..b00481cd5 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -8,13 +8,12 @@ use crate::{
    Name, ScopesWithSourceMap, Ty, HirFileId,
    HirDatabase, PersistentHirDatabase,
    type_ref::TypeRef,
-    nameres::{ModuleScope, Namespace, lower::ImportId},
+    nameres::{ModuleScope, Namespace, ImportId, CrateModuleId},
    expr::{Body, BodySourceMap},
    ty::InferenceResult,
    adt::{EnumVariantId, StructFieldId, VariantDef},
    generics::GenericParams,
    docs::{Documentation, Docs, docs_from_ast},
-    module_tree::ModuleId,
    ids::{FunctionId, StructId, EnumId, AstItemDef, ConstId, StaticId, TraitId, TypeId},
    impl_block::ImplBlock,
    resolve::Resolver,
@@ -65,7 +64,7 @@ impl Crate {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct Module {
    pub(crate) krate: Crate,
-    pub(crate) module_id: ModuleId,
+    pub(crate) module_id: CrateModuleId,
 }
 /// The defs which can be visible in the module.
@@ -173,7 +172,7 @@ impl Module {
    /// Returns a `ModuleScope`: a set of items, visible in this module.
    pub fn scope(&self, db: &impl HirDatabase) -> ModuleScope {
-        db.item_map(self.krate)[self.module_id].clone()
+        db.crate_def_map(self.krate)[self.module_id].scope.clone()
    }
    pub fn problems(&self, db: &impl HirDatabase) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
@@ -181,16 +180,16 @@ impl Module {
    }
    pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
-        let item_map = db.item_map(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        Resolver::default().push_module_scope(item_map, *self)
+        Resolver::default().push_module_scope(def_map, self.module_id)
    }
    pub fn declarations(self, db: &impl HirDatabase) -> Vec<ModuleDef> {
-        let lowered_module = db.lower_module(self);
+        let def_map = db.crate_def_map(self.krate);
-        lowered_module
+        def_map[self.module_id]
-            .declarations
+            .scope
-            .values()
+            .entries()
-            .cloned()
+            .filter_map(|(_name, res)| if res.import.is_none() { Some(res.def) } else { None })
            .flat_map(|per_ns| {
                per_ns.take_types().into_iter().chain(per_ns.take_values().into_iter())
            })
diff --git a/crates/ra_hir/src/code_model_impl/krate.rs b/crates/ra_hir/src/code_model_impl/krate.rs
index 161ae6e18..cc87c6f14 100644
--- a/crates/ra_hir/src/code_model_impl/krate.rs
+++ b/crates/ra_hir/src/code_model_impl/krate.rs
@@ -18,9 +18,7 @@ impl Crate {
            .collect()
    }
    pub(crate) fn root_module_impl(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
-        let module_tree = db.module_tree(*self);
+        let module_id = db.crate_def_map(*self).root();
-        let module_id = module_tree.modules().next()?;
        let module = Module { krate: *self, module_id };
        Some(module)
    }
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index 437f96942..f7d15c55e 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -1,33 +1,61 @@
-use ra_syntax::{ast, SyntaxNode, TreeArc};
+use ra_db::FileId;
+use ra_syntax::{ast, SyntaxNode, TreeArc, AstNode};
 use crate::{
-    Module, ModuleSource, Problem,
+    Module, ModuleSource, Problem, Name,
-    Name,
+    nameres::{CrateModuleId, ImportId},
-    module_tree::ModuleId,
-    nameres::lower::ImportId,
    HirDatabase, PersistentHirDatabase,
-    HirFileId
+    HirFileId, SourceItemId,
 };
+impl ModuleSource {
+    pub(crate) fn new(
+        db: &impl PersistentHirDatabase,
+        file_id: Option<FileId>,
+        decl_id: Option<SourceItemId>,
+    ) -> ModuleSource {
+        match (file_id, decl_id) {
+            (Some(file_id), _) => {
+                let source_file = db.parse(file_id);
+                ModuleSource::SourceFile(source_file)
+            }
+            (None, Some(item_id)) => {
+                let module = db.file_item(item_id);
+                let module = ast::Module::cast(&*module).unwrap();
+                assert!(module.item_list().is_some(), "expected inline module");
+                ModuleSource::Module(module.to_owned())
+            }
+            (None, None) => panic!(),
+        }
+    }
+}
 impl Module {
-    fn with_module_id(&self, module_id: ModuleId) -> Module {
+    fn with_module_id(&self, module_id: CrateModuleId) -> Module {
        Module { module_id, krate: self.krate }
    }
    pub(crate) fn name_impl(&self, db: &impl HirDatabase) -> Option<Name> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let link = self.module_id.parent_link(&module_tree)?;
+        let parent = def_map[self.module_id].parent?;
-        Some(link.name(&module_tree).clone())
+        def_map[parent].children.iter().find_map(|(name, module_id)| {
+            if *module_id == self.module_id {
+                Some(name.clone())
+            } else {
+                None
+            }
+        })
    }
    pub(crate) fn definition_source_impl(
        &self,
        db: &impl PersistentHirDatabase,
    ) -> (HirFileId, ModuleSource) {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let file_id = self.module_id.file_id(&module_tree);
+        let decl_id = def_map[self.module_id].declaration;
-        let decl_id = self.module_id.decl_id(&module_tree);
+        let file_id = def_map[self.module_id].definition;
        let module_source = ModuleSource::new(db, file_id, decl_id);
+        let file_id = file_id.map(HirFileId::from).unwrap_or_else(|| decl_id.unwrap().file_id);
        (file_id, module_source)
    }
@@ -35,11 +63,11 @@ impl Module {
        &self,
        db: &impl HirDatabase,
    ) -> Option<(HirFileId, TreeArc<ast::Module>)> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let link = self.module_id.parent_link(&module_tree)?;
+        let decl = def_map[self.module_id].declaration?;
-        let file_id = link.owner(&module_tree).file_id(&module_tree);
+        let syntax_node = db.file_item(decl);
-        let src = link.source(&module_tree, db);
+        let ast = ast::Module::cast(&syntax_node).unwrap().to_owned();
-        Some((file_id, src))
+        Some((decl.file_id, ast))
    }
    pub(crate) fn import_source_impl(
@@ -47,22 +75,21 @@ impl Module {
        db: &impl HirDatabase,
        import: ImportId,
    ) -> TreeArc<ast::PathSegment> {
-        let (_, source_map) = db.lower_module_with_source_map(*self);
+        let (file_id, source) = self.definition_source(db);
-        let (_, source) = self.definition_source(db);
+        let (_, source_map) = db.raw_items_with_source_map(file_id.original_file(db));
        source_map.get(&source, import)
    }
    pub(crate) fn crate_root_impl(&self, db: &impl PersistentHirDatabase) -> Module {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let module_id = self.module_id.crate_root(&module_tree);
+        self.with_module_id(def_map.root())
-        self.with_module_id(module_id)
    }
    /// Finds a child module with the specified name.
    pub(crate) fn child_impl(&self, db: &impl HirDatabase, name: &Name) -> Option<Module> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let child_id = self.module_id.child(&module_tree, name)?;
+        let child_id = def_map[self.module_id].children.get(name)?;
-        Some(self.with_module_id(child_id))
+        Some(self.with_module_id(*child_id))
    }
    /// Iterates over all child modules.
@@ -70,18 +97,18 @@ impl Module {
        &self,
        db: &impl PersistentHirDatabase,
    ) -> impl Iterator<Item = Module> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let children = self
+        let children = def_map[self.module_id]
-            .module_id
+            .children
-            .children(&module_tree)
+            .iter()
-            .map(|(_, module_id)| self.with_module_id(module_id))
+            .map(|(_, module_id)| self.with_module_id(*module_id))
            .collect::<Vec<_>>();
        children.into_iter()
    }
    pub(crate) fn parent_impl(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        let parent_id = self.module_id.parent(&module_tree)?;
+        let parent_id = def_map[self.module_id].parent?;
        Some(self.with_module_id(parent_id))
    }
@@ -89,7 +116,14 @@ impl Module {
        &self,
        db: &impl HirDatabase,
    ) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
-        let module_tree = db.module_tree(self.krate);
+        let def_map = db.crate_def_map(self.krate);
-        self.module_id.problems(&module_tree, db)
+        let (my_file_id, _) = self.definition_source(db);
+        // FIXME: not entirely corret filterint by module
+        def_map
+            .problems()
+            .iter()
+            .filter(|(source_item_id, _problem)| my_file_id == source_item_id.file_id)
+            .map(|(source_item_id, problem)| (db.file_item(*source_item_id), problem.clone()))
+            .collect()
    }
 }
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 21d22aa7f..c7bad7e2b 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,23 +1,18 @@
 use std::sync::Arc;
 use ra_syntax::{SyntaxNode, TreeArc, SourceFile};
-use ra_db::{SourceDatabase, salsa};
+use ra_db::{SourceDatabase, salsa, FileId};
 use crate::{
-    MacroCallId, HirFileId,
+    HirFileId, SourceFileItems, SourceItemId, Crate, Module, HirInterner,
-    SourceFileItems, SourceItemId, Crate, Module, HirInterner,
    Function, FnSignature, ExprScopes, TypeAlias,
    Struct, Enum, StructField,
    Const, ConstSignature, Static,
-    macros::MacroExpansion,
+    nameres::{Namespace, ImportSourceMap, RawItems, CrateDefMap},
-    module_tree::ModuleTree,
+    ty::{InferenceResult, Ty, method_resolution::CrateImplBlocks, TypableDef, CallableDef, FnSig},
-    nameres::{ItemMap, lower::{LoweredModule, ImportSourceMap}},
-    ty::{InferenceResult, Ty, method_resolution::CrateImplBlocks, TypableDef},
    adt::{StructData, EnumData},
    impl_block::{ModuleImplBlocks, ImplSourceMap},
    generics::{GenericParams, GenericDef},
-    ids::SourceFileItemId,
-    nameres::Namespace,
    type_ref::TypeRef,
 };
@@ -26,9 +21,6 @@ pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
    #[salsa::invoke(HirFileId::hir_parse)]
    fn hir_parse(&self, file_id: HirFileId) -> TreeArc<SourceFile>;
-    #[salsa::invoke(crate::macros::expand_macro_invocation)]
-    fn expand_macro_invocation(&self, invoc: MacroCallId) -> Option<Arc<MacroExpansion>>;
    #[salsa::invoke(crate::adt::StructData::struct_data_query)]
    fn struct_data(&self, s: Struct) -> Arc<StructData>;
@@ -41,27 +33,14 @@ pub trait PersistentHirDatabase: SourceDatabase + AsRef<HirInterner> {
    #[salsa::invoke(crate::ids::SourceFileItems::file_item_query)]
    fn file_item(&self, source_item_id: SourceItemId) -> TreeArc<SyntaxNode>;
-    #[salsa::invoke(crate::module_tree::Submodule::submodules_query)]
+    #[salsa::invoke(RawItems::raw_items_query)]
-    fn submodules(
+    fn raw_items(&self, file_id: FileId) -> Arc<RawItems>;
-        &self,
-        file_id: HirFileId,
-        delc_id: Option<SourceFileItemId>,
-    ) -> Arc<Vec<crate::module_tree::Submodule>>;
-    #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_with_source_map_query)]
+    #[salsa::invoke(RawItems::raw_items_with_source_map_query)]
-    fn lower_module_with_source_map(
+    fn raw_items_with_source_map(&self, file_id: FileId) -> (Arc<RawItems>, Arc<ImportSourceMap>);
-        &self,
-        module: Module,
-    ) -> (Arc<LoweredModule>, Arc<ImportSourceMap>);
-    #[salsa::invoke(crate::nameres::lower::LoweredModule::lower_module_query)]
+    #[salsa::invoke(CrateDefMap::crate_def_map_query)]
-    fn lower_module(&self, module: Module) -> Arc<LoweredModule>;
+    fn crate_def_map(&self, krate: Crate) -> Arc<CrateDefMap>;
-    #[salsa::invoke(crate::nameres::ItemMap::item_map_query)]
-    fn item_map(&self, krate: Crate) -> Arc<ItemMap>;
-    #[salsa::invoke(crate::module_tree::ModuleTree::module_tree_query)]
-    fn module_tree(&self, krate: Crate) -> Arc<ModuleTree>;
    #[salsa::invoke(crate::impl_block::impls_in_module)]
    fn impls_in_module(&self, module: Module) -> Arc<ModuleImplBlocks>;
@@ -105,6 +84,9 @@ pub trait HirDatabase: PersistentHirDatabase {
    #[salsa::invoke(crate::ty::type_for_field)]
    fn type_for_field(&self, field: StructField) -> Ty;
+    #[salsa::invoke(crate::ty::callable_item_sig)]
+    fn callable_item_signature(&self, def: CallableDef) -> FnSig;
    #[salsa::invoke(crate::expr::body_with_source_map_query)]
    fn body_with_source_map(
        &self,
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 5b00330c6..9596488d3 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -83,30 +83,37 @@ impl HirFileId {
        }
    }
-    pub(crate) fn as_macro_call_id(self) -> Option<MacroCallId> {
-        match self.0 {
-            HirFileIdRepr::Macro(it) => Some(it),
-            _ => None,
-        }
-    }
    pub(crate) fn hir_parse(
        db: &impl PersistentHirDatabase,
        file_id: HirFileId,
    ) -> TreeArc<SourceFile> {
        match file_id.0 {
            HirFileIdRepr::File(file_id) => db.parse(file_id),
-            HirFileIdRepr::Macro(m) => {
+            HirFileIdRepr::Macro(macro_call_id) => {
-                if let Some(exp) = db.expand_macro_invocation(m) {
-                    return exp.file();
-                }
                // returning an empty string looks fishy...
-                SourceFile::parse("")
+                parse_macro(db, macro_call_id).unwrap_or_else(|| SourceFile::parse(""))
            }
        }
    }
 }
+fn parse_macro(
+    db: &impl PersistentHirDatabase,
+    macro_call_id: MacroCallId,
+) -> Option<TreeArc<SourceFile>> {
+    let loc = macro_call_id.loc(db);
+    let syntax = db.file_item(loc.source_item_id);
+    let macro_call = ast::MacroCall::cast(&syntax).unwrap();
+    let (macro_arg, _) = macro_call.token_tree().and_then(mbe::ast_to_token_tree)?;
+    let def_map = db.crate_def_map(loc.module.krate);
+    let (krate, macro_id) = def_map.resolve_macro(macro_call_id)?;
+    let def_map = db.crate_def_map(krate);
+    let macro_rules = &def_map[macro_id];
+    let tt = macro_rules.expand(&macro_arg).ok()?;
+    Some(mbe::token_tree_to_ast_item_list(&tt))
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 enum HirFileIdRepr {
    File(FileId),
@@ -200,8 +207,14 @@ pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<N>, Self>;
    fn from_ast(ctx: LocationCtx<&impl PersistentHirDatabase>, ast: &N) -> Self {
        let items = ctx.db.file_items(ctx.file_id);
-        let raw =
+        let item_id = items.id_of(ctx.file_id, ast.syntax());
-            SourceItemId { file_id: ctx.file_id, item_id: items.id_of(ctx.file_id, ast.syntax()) };
+        Self::from_source_item_id_unchecked(ctx, item_id)
+    }
+    fn from_source_item_id_unchecked(
+        ctx: LocationCtx<&impl PersistentHirDatabase>,
+        item_id: SourceFileItemId,
+    ) -> Self {
+        let raw = SourceItemId { file_id: ctx.file_id, item_id };
        let loc = ItemLoc { module: ctx.module, raw, _ty: PhantomData };
        Self::interner(ctx.db.as_ref()).loc2id(&loc)
@@ -290,6 +303,12 @@ impl AstItemDef<ast::TypeAliasDef> for TypeId {
 pub struct SourceFileItemId(RawId);
 impl_arena_id!(SourceFileItemId);
+impl SourceFileItemId {
+    pub(crate) fn with_file_id(self, file_id: HirFileId) -> SourceItemId {
+        SourceItemId { file_id, item_id: self }
+    }
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct SourceItemId {
    pub(crate) file_id: HirFileId,
@@ -309,9 +328,7 @@ impl SourceFileItems {
        file_id: HirFileId,
    ) -> Arc<SourceFileItems> {
        let source_file = db.hir_parse(file_id);
-        let mut res = SourceFileItems { file_id, arena: Arena::default() };
+        Arc::new(SourceFileItems::from_source_file(&source_file, file_id))
-        res.init(&source_file);
-        Arc::new(res)
    }
    pub(crate) fn file_item_query(
@@ -324,18 +341,23 @@ impl SourceFileItems {
            .to_owned()
    }
-    fn init(&mut self, source_file: &SourceFile) {
+    pub(crate) fn from_source_file(
+        source_file: &SourceFile,
+        file_id: HirFileId,
+    ) -> SourceFileItems {
+        let mut res = SourceFileItems { file_id, arena: Arena::default() };
        // By walking the tree in bread-first order we make sure that parents
        // get lower ids then children. That is, adding a new child does not
        // change parent's id. This means that, say, adding a new function to a
        // trait does not change ids of top-level items, which helps caching.
        bfs(source_file.syntax(), |it| {
            if let Some(module_item) = ast::ModuleItem::cast(it) {
-                self.alloc(module_item.syntax());
+                res.alloc(module_item.syntax());
            } else if let Some(macro_call) = ast::MacroCall::cast(it) {
-                self.alloc(macro_call.syntax());
+                res.alloc(macro_call.syntax());
            }
-        })
+        });
+        res
    }
    fn alloc(&mut self, item: &SyntaxNode) -> SourceFileItemId {
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index eb2d4ed8d..8807a4b56 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -4,7 +4,8 @@ use rustc_hash::FxHashMap;
 use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
 use ra_syntax::{
    AstPtr, SourceFile, TreeArc,
-ast::{self, AstNode}};
+    ast::{self, AstNode}
+};
 use crate::{
    Const, TypeAlias, Function, HirFileId,
@@ -13,7 +14,7 @@ use crate::{
    type_ref::TypeRef,
    ids::LocationCtx,
    resolve::Resolver,
-    ty::Ty, generics::GenericParams
+    ty::Ty, generics::GenericParams,
 };
 use crate::code_model_api::{Module, ModuleSource};
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index ac5f33079..75c977d32 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -24,9 +24,7 @@ mod path;
 pub mod source_binder;
 mod ids;
-mod macros;
 mod name;
-mod module_tree;
 mod nameres;
 mod adt;
 mod type_alias;
@@ -54,9 +52,8 @@ pub use self::{
    path::{Path, PathKind},
    name::Name,
    ids::{HirFileId, MacroCallId, MacroCallLoc, HirInterner},
-    macros::{MacroDef, MacroInput, MacroExpansion},
+    nameres::{PerNs, Namespace},
-    nameres::{ItemMap, PerNs, Namespace},
+    ty::{Ty, Substs, display::HirDisplay},
-    ty::{Ty, Substs},
    impl_block::{ImplBlock, ImplItem},
    docs::{Docs, Documentation},
    adt::AdtDef,
diff --git a/crates/ra_hir/src/macros.rs b/crates/ra_hir/src/macros.rs
deleted file mode 100644
index 45128c7df..000000000
--- a/crates/ra_hir/src/macros.rs
+++ /dev/null
@@ -1,135 +0,0 @@
-/// Machinery for macro expansion.
-///
-/// One of the more complicated things about macros is managing the source code
-/// that is produced after expansion. See `HirFileId` and `MacroCallId` for how
-/// do we do that.
-///
-/// When the file-management question is resolved, all that is left is a
-/// token-tree-to-token-tree transformation plus hygiene. We don't have either of
-/// those yet, so all macros are string based at the moment!
-use std::sync::Arc;
-use ra_syntax::{
-    TextRange, TextUnit, SourceFile, AstNode, SyntaxNode, TreeArc, SyntaxNodePtr,
-    ast,
-};
-use crate::{MacroCallId, PersistentHirDatabase};
-// Hard-coded defs for now :-(
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum MacroDef {
-    Vec,
-}
-impl MacroDef {
-    /// Expands macro call, returning the expansion and offset to be used to
-    /// convert ranges between expansion and original source.
-    pub fn ast_expand(macro_call: &ast::MacroCall) -> Option<(TextUnit, MacroExpansion)> {
-        let (def, input) = MacroDef::from_call(macro_call)?;
-        let exp = def.expand(input)?;
-        let off = macro_call.token_tree()?.syntax().range().start();
-        Some((off, exp))
-    }
-    fn from_call(macro_call: &ast::MacroCall) -> Option<(MacroDef, MacroInput)> {
-        let def = {
-            let path = macro_call.path()?;
-            let name_ref = path.segment()?.name_ref()?;
-            if name_ref.text() == "vec" {
-                MacroDef::Vec
-            } else {
-                return None;
-            }
-        };
-        let input = {
-            let arg = macro_call.token_tree()?.syntax();
-            MacroInput { text: arg.text().to_string() }
-        };
-        Some((def, input))
-    }
-    fn expand(self, input: MacroInput) -> Option<MacroExpansion> {
-        match self {
-            MacroDef::Vec => self.expand_vec(input),
-        }
-    }
-    fn expand_vec(self, input: MacroInput) -> Option<MacroExpansion> {
-        let text = format!(r"fn dummy() {{ {}; }}", input.text);
-        let file = SourceFile::parse(&text);
-        let array_expr = file.syntax().descendants().find_map(ast::ArrayExpr::cast)?;
-        let ptr = SyntaxNodePtr::new(array_expr.syntax());
-        let src_range = TextRange::offset_len(0.into(), TextUnit::of_str(&input.text));
-        let ranges_map = vec![(src_range, array_expr.syntax().range())];
-        let res = MacroExpansion { text, ranges_map, ptr };
-        Some(res)
-    }
-}
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MacroInput {
-    // Should be token trees
-    pub text: String,
-}
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct MacroExpansion {
-    /// The result of macro expansion. Should be token tree as well.
-    text: String,
-    /// Correspondence between ranges in the original source code and ranges in
-    /// the macro.
-    ranges_map: Vec<(TextRange, TextRange)>,
-    /// Implementation detail: internally, a macro is expanded to the whole file,
-    /// even if it is an expression. This `ptr` selects the actual expansion from
-    /// the expanded file.
-    ptr: SyntaxNodePtr,
-}
-impl MacroExpansion {
-    // FIXME: does not really make sense, macro expansion is not necessary a
-    // whole file. See `MacroExpansion::ptr` as well.
-    pub(crate) fn file(&self) -> TreeArc<SourceFile> {
-        SourceFile::parse(&self.text)
-    }
-    pub fn syntax(&self) -> TreeArc<SyntaxNode> {
-        self.ptr.to_node(&self.file()).to_owned()
-    }
-    /// Maps range in the source code to the range in the expanded code.
-    pub fn map_range_forward(&self, src_range: TextRange) -> Option<TextRange> {
-        for (s_range, t_range) in self.ranges_map.iter() {
-            if src_range.is_subrange(&s_range) {
-                let src_at_zero_range = src_range - src_range.start();
-                let src_range_offset = src_range.start() - s_range.start();
-                let src_range = src_at_zero_range + src_range_offset + t_range.start();
-                return Some(src_range);
-            }
-        }
-        None
-    }
-    /// Maps range in the expanded code to the range in the source code.
-    pub fn map_range_back(&self, tgt_range: TextRange) -> Option<TextRange> {
-        for (s_range, t_range) in self.ranges_map.iter() {
-            if tgt_range.is_subrange(&t_range) {
-                let tgt_at_zero_range = tgt_range - tgt_range.start();
-                let tgt_range_offset = tgt_range.start() - t_range.start();
-                let src_range = tgt_at_zero_range + tgt_range_offset + s_range.start();
-                return Some(src_range);
-            }
-        }
-        None
-    }
-}
-pub(crate) fn expand_macro_invocation(
-    db: &impl PersistentHirDatabase,
-    invoc: MacroCallId,
-) -> Option<Arc<MacroExpansion>> {
-    let loc = invoc.loc(db);
-    let syntax = db.file_item(loc.source_item_id);
-    let macro_call = ast::MacroCall::cast(&syntax).unwrap();
-    let (def, input) = MacroDef::from_call(macro_call)?;
-    def.expand(input).map(Arc::new)
-}
diff --git a/crates/ra_hir/src/marks.rs b/crates/ra_hir/src/marks.rs
index 16852a6a1..5b6400042 100644
--- a/crates/ra_hir/src/marks.rs
+++ b/crates/ra_hir/src/marks.rs
@@ -1,10 +1,12 @@
 test_utils::marks!(
+    bogus_paths
    name_res_works_for_broken_modules
-    item_map_enum_importing
+    can_import_enum_variant
    type_var_cycles_resolve_completely
    type_var_cycles_resolve_as_possible
    type_var_resolves_to_int_var
    glob_enum
    glob_across_crates
    std_prelude
+    match_ergonomics_ref
 );
diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index 99c2115e1..e69de29bb 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -1,331 +0,0 @@
-use std::sync::Arc;
-use arrayvec::ArrayVec;
-use relative_path::RelativePathBuf;
-use ra_db::{FileId, SourceRoot};
-use ra_syntax::{
-    SyntaxNode, TreeArc,
-    algo::generate,
-    ast::{self, AstNode, NameOwner},
-};
-use ra_arena::{Arena, RawId, impl_arena_id};
-use test_utils::tested_by;
-use crate::{
-    Name, AsName, HirDatabase, SourceItemId, HirFileId, Problem, SourceFileItems, ModuleSource,
-    PersistentHirDatabase,
-    Crate,
-    ids::SourceFileItemId,
-};
-impl ModuleSource {
-    pub(crate) fn new(
-        db: &impl PersistentHirDatabase,
-        file_id: HirFileId,
-        decl_id: Option<SourceFileItemId>,
-    ) -> ModuleSource {
-        match decl_id {
-            Some(item_id) => {
-                let module = db.file_item(SourceItemId { file_id, item_id });
-                let module = ast::Module::cast(&*module).unwrap();
-                assert!(module.item_list().is_some(), "expected inline module");
-                ModuleSource::Module(module.to_owned())
-            }
-            None => {
-                let source_file = db.hir_parse(file_id);
-                ModuleSource::SourceFile(source_file)
-            }
-        }
-    }
-}
-#[derive(Clone, Hash, PartialEq, Eq, Debug)]
-pub struct Submodule {
-    name: Name,
-    is_declaration: bool,
-    decl_id: SourceFileItemId,
-}
-impl Submodule {
-    pub(crate) fn submodules_query(
-        db: &impl PersistentHirDatabase,
-        file_id: HirFileId,
-        decl_id: Option<SourceFileItemId>,
-    ) -> Arc<Vec<Submodule>> {
-        db.check_canceled();
-        let file_items = db.file_items(file_id);
-        let module_source = ModuleSource::new(db, file_id, decl_id);
-        let submodules = match module_source {
-            ModuleSource::SourceFile(source_file) => {
-                collect_submodules(file_id, &file_items, &*source_file)
-            }
-            ModuleSource::Module(module) => {
-                collect_submodules(file_id, &file_items, module.item_list().unwrap())
-            }
-        };
-        return Arc::new(submodules);
-        fn collect_submodules(
-            file_id: HirFileId,
-            file_items: &SourceFileItems,
-            root: &impl ast::ModuleItemOwner,
-        ) -> Vec<Submodule> {
-            root.items()
-                .filter_map(|item| match item.kind() {
-                    ast::ModuleItemKind::Module(m) => Some(m),
-                    _ => None,
-                })
-                .filter_map(|module| {
-                    let name = module.name()?.as_name();
-                    if !module.has_semi() && module.item_list().is_none() {
-                        tested_by!(name_res_works_for_broken_modules);
-                        return None;
-                    }
-                    let sub = Submodule {
-                        name,
-                        is_declaration: module.has_semi(),
-                        decl_id: file_items.id_of(file_id, module.syntax()),
-                    };
-                    Some(sub)
-                })
-                .collect()
-        }
-    }
-}
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct ModuleId(RawId);
-impl_arena_id!(ModuleId);
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct LinkId(RawId);
-impl_arena_id!(LinkId);
-/// Physically, rust source is organized as a set of files, but logically it is
-/// organized as a tree of modules. Usually, a single file corresponds to a
-/// single module, but it is not neccessarily always the case.
-///
-/// `ModuleTree` encapsulates the logic of transitioning from the fuzzy world of files
-/// (which can have multiple parents) to the precise world of modules (which
-/// always have one parent).
-#[derive(Default, Debug, PartialEq, Eq)]
-pub struct ModuleTree {
-    mods: Arena<ModuleId, ModuleData>,
-    links: Arena<LinkId, LinkData>,
-}
-#[derive(Debug, PartialEq, Eq)]
-pub struct ModuleData {
-    file_id: HirFileId,
-    /// Points to `ast::Module`, `None` for the whole file.
-    decl_id: Option<SourceFileItemId>,
-    parent: Option<LinkId>,
-    children: Vec<LinkId>,
-}
-#[derive(Hash, Debug, PartialEq, Eq)]
-struct LinkData {
-    source: SourceItemId,
-    owner: ModuleId,
-    name: Name,
-    points_to: Vec<ModuleId>,
-    problem: Option<Problem>,
-}
-impl ModuleTree {
-    pub(crate) fn module_tree_query(
-        db: &impl PersistentHirDatabase,
-        krate: Crate,
-    ) -> Arc<ModuleTree> {
-        db.check_canceled();
-        let mut res = ModuleTree::default();
-        res.init_crate(db, krate);
-        Arc::new(res)
-    }
-    pub(crate) fn modules<'a>(&'a self) -> impl Iterator<Item = ModuleId> + 'a {
-        self.mods.iter().map(|(id, _)| id)
-    }
-    pub(crate) fn find_module_by_source(
-        &self,
-        file_id: HirFileId,
-        decl_id: Option<SourceFileItemId>,
-    ) -> Option<ModuleId> {
-        let (res, _) =
-            self.mods.iter().find(|(_, m)| (m.file_id, m.decl_id) == (file_id, decl_id))?;
-        Some(res)
-    }
-    fn init_crate(&mut self, db: &impl PersistentHirDatabase, krate: Crate) {
-        let crate_graph = db.crate_graph();
-        let file_id = crate_graph.crate_root(krate.crate_id);
-        let source_root_id = db.file_source_root(file_id);
-        let source_root = db.source_root(source_root_id);
-        self.init_subtree(db, &source_root, None, file_id.into(), None);
-    }
-    fn init_subtree(
-        &mut self,
-        db: &impl PersistentHirDatabase,
-        source_root: &SourceRoot,
-        parent: Option<LinkId>,
-        file_id: HirFileId,
-        decl_id: Option<SourceFileItemId>,
-    ) -> ModuleId {
-        let is_root = parent.is_none();
-        let id = self.alloc_mod(ModuleData { file_id, decl_id, parent, children: Vec::new() });
-        for sub in db.submodules(file_id, decl_id).iter() {
-            let link = self.alloc_link(LinkData {
-                source: SourceItemId { file_id, item_id: sub.decl_id },
-                name: sub.name.clone(),
-                owner: id,
-                points_to: Vec::new(),
-                problem: None,
-            });
-            let (points_to, problem) = if sub.is_declaration {
-                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name, is_root);
-                let points_to = points_to
-                    .into_iter()
-                    .map(|file_id| {
-                        self.init_subtree(db, source_root, Some(link), file_id.into(), None)
-                    })
-                    .collect::<Vec<_>>();
-                (points_to, problem)
-            } else {
-                let points_to =
-                    self.init_subtree(db, source_root, Some(link), file_id, Some(sub.decl_id));
-                (vec![points_to], None)
-            };
-            self.links[link].points_to = points_to;
-            self.links[link].problem = problem;
-        }
-        id
-    }
-    fn alloc_mod(&mut self, data: ModuleData) -> ModuleId {
-        self.mods.alloc(data)
-    }
-    fn alloc_link(&mut self, data: LinkData) -> LinkId {
-        let owner = data.owner;
-        let id = self.links.alloc(data);
-        self.mods[owner].children.push(id);
-        id
-    }
-}
-impl ModuleId {
-    pub(crate) fn file_id(self, tree: &ModuleTree) -> HirFileId {
-        tree.mods[self].file_id
-    }
-    pub(crate) fn decl_id(self, tree: &ModuleTree) -> Option<SourceFileItemId> {
-        tree.mods[self].decl_id
-    }
-    pub(crate) fn parent_link(self, tree: &ModuleTree) -> Option<LinkId> {
-        tree.mods[self].parent
-    }
-    pub(crate) fn parent(self, tree: &ModuleTree) -> Option<ModuleId> {
-        let link = self.parent_link(tree)?;
-        Some(tree.links[link].owner)
-    }
-    pub(crate) fn crate_root(self, tree: &ModuleTree) -> ModuleId {
-        generate(Some(self), move |it| it.parent(tree)).last().unwrap()
-    }
-    pub(crate) fn child(self, tree: &ModuleTree, name: &Name) -> Option<ModuleId> {
-        let link = tree.mods[self]
-            .children
-            .iter()
-            .map(|&it| &tree.links[it])
-            .find(|it| it.name == *name)?;
-        Some(*link.points_to.first()?)
-    }
-    pub(crate) fn children<'a>(
-        self,
-        tree: &'a ModuleTree,
-    ) -> impl Iterator<Item = (Name, ModuleId)> + 'a {
-        tree.mods[self].children.iter().filter_map(move |&it| {
-            let link = &tree.links[it];
-            let module = *link.points_to.first()?;
-            Some((link.name.clone(), module))
-        })
-    }
-    pub(crate) fn problems(
-        self,
-        tree: &ModuleTree,
-        db: &impl HirDatabase,
-    ) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
-        tree.mods[self]
-            .children
-            .iter()
-            .filter_map(|&link| {
-                let p = tree.links[link].problem.clone()?;
-                let s = link.source(tree, db);
-                let s = s.name().unwrap().syntax().to_owned();
-                Some((s, p))
-            })
-            .collect()
-    }
-}
-impl LinkId {
-    pub(crate) fn owner(self, tree: &ModuleTree) -> ModuleId {
-        tree.links[self].owner
-    }
-    pub(crate) fn name(self, tree: &ModuleTree) -> &Name {
-        &tree.links[self].name
-    }
-    pub(crate) fn source(
-        self,
-        tree: &ModuleTree,
-        db: &impl PersistentHirDatabase,
-    ) -> TreeArc<ast::Module> {
-        let syntax_node = db.file_item(tree.links[self].source);
-        ast::Module::cast(&syntax_node).unwrap().to_owned()
-    }
-}
-fn resolve_submodule(
-    db: &impl PersistentHirDatabase,
-    file_id: HirFileId,
-    name: &Name,
-    is_root: bool,
-) -> (Vec<FileId>, Option<Problem>) {
-    // FIXME: handle submodules of inline modules properly
-    let file_id = file_id.original_file(db);
-    let source_root_id = db.file_source_root(file_id);
-    let path = db.file_relative_path(file_id);
-    let root = RelativePathBuf::default();
-    let dir_path = path.parent().unwrap_or(&root);
-    let mod_name = path.file_stem().unwrap_or("unknown");
-    let is_dir_owner = is_root || mod_name == "mod";
-    let file_mod = dir_path.join(format!("{}.rs", name));
-    let dir_mod = dir_path.join(format!("{}/mod.rs", name));
-    let file_dir_mod = dir_path.join(format!("{}/{}.rs", mod_name, name));
-    let mut candidates = ArrayVec::<[_; 2]>::new();
-    if is_dir_owner {
-        candidates.push(file_mod.clone());
-        candidates.push(dir_mod);
-    } else {
-        candidates.push(file_dir_mod.clone());
-    };
-    let sr = db.source_root(source_root_id);
-    let points_to = candidates
-        .into_iter()
-        .filter_map(|path| sr.files.get(&path))
-        .map(|&it| it)
-        .collect::<Vec<_>>();
-    let problem = if points_to.is_empty() {
-        Some(Problem::UnresolvedModule {
-            candidate: if is_dir_owner { file_mod } else { file_dir_mod },
-        })
-    } else {
-        None
-    };
-    (points_to, problem)
-}
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 8d786d2ac..06bafa6f0 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -64,6 +64,7 @@ impl Name {
            "str" => KnownName::Str,
            "Self" => KnownName::SelfType,
            "self" => KnownName::SelfParam,
+            "macro_rules" => KnownName::MacroRules,
            _ => return None,
        };
        Some(name)
@@ -122,4 +123,6 @@ pub(crate) enum KnownName {
    SelfType,
    SelfParam,
+    MacroRules,
 }
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index 73919ee37..edd2f25f7 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -1,60 +1,148 @@
-//! Name resolution algorithm. The end result of the algorithm is an `ItemMap`:
+/// This module implements import-resolution/macro expansion algorithm.
-//! a map which maps each module to its scope: the set of items visible in the
+///
-//! module. That is, we only resolve imports here, name resolution of item
+/// The result of this module is `CrateDefMap`: a datastructure which contains:
-//! bodies will be done in a separate step.
+///
-//!
+///   * a tree of modules for the crate
-//! Like Rustc, we use an interactive per-crate algorithm: we start with scopes
+///   * for each module, a set of items visible in the module (directly declared
-//! containing only directly defined items, and then iteratively resolve
+///     or imported)
-//! imports.
+///
-//!
+/// Note that `CrateDefMap` contains fully macro expanded code.
-//! To make this work nicely in the IDE scenario, we place `InputModuleItems`
+///
-//! in between raw syntax and name resolution. `InputModuleItems` are computed
+/// Computing `CrateDefMap` can be partitioned into several logically
-//! using only the module's syntax, and it is all directly defined items plus
+/// independent "phases". The phases are mutually recursive though, there's no
-//! imports. The plan is to make `InputModuleItems` independent of local
+/// strict ordering.
-//! modifications (that is, typing inside a function should not change IMIs),
+///
-//! so that the results of name resolution can be preserved unless the module
+/// ## Collecting RawItems
-//! structure itself is modified.
+///
-pub(crate) mod lower;
+///  This happens in the `raw` module, which parses a single source file into a
+///  set of top-level items. Nested imports are desugared to flat imports in
-use std::{time, sync::Arc};
+///  this phase. Macro calls are represented as a triple of (Path, Option<Name>,
+///  TokenTree).
-use rustc_hash::{FxHashMap, FxHashSet};
+///
+/// ## Collecting Modules
-use ra_arena::map::ArenaMap;
+///
-use ra_db::Edition;
+/// This happens in the `collector` module. In this phase, we recursively walk
+/// tree of modules, collect raw items from submodules, populate module scopes
+/// with defined items (so, we assign item ids in this phase) and record the set
+/// of unresolved imports and macros.
+///
+/// While we walk tree of modules, we also record macro_rules definitions and
+/// expand calls to macro_rules defined macros.
+///
+/// ## Resolving Imports
+///
+/// We maintain a list of currently unresolved imports. On every iteration, we
+/// try to resolve some imports from this list. If the import is resolved, we
+/// record it, by adding an item to current module scope and, if necessary, by
+/// recursively populating glob imports.
+///
+/// ## Resolving Macros
+///
+/// macro_rules from the same crate use a global mutable namespace. We expand
+/// them immediately, when we collect modules.
+///
+/// Macros from other crates (including proc-macros) can be used with
+/// `foo::bar!` syntax. We handle them similarly to imports. There's a list of
+/// unexpanded macros. On every iteration, we try to resolve each macro call
+/// path and, upon success, we run macro expansion and "collect module" phase
+/// on the result
+mod per_ns;
+mod raw;
+mod collector;
+#[cfg(test)]
+mod tests;
+use std::sync::Arc;
+use rustc_hash::FxHashMap;
+use ra_arena::{Arena, RawId, impl_arena_id};
+use ra_db::{FileId, Edition};
 use test_utils::tested_by;
 use crate::{
-    Module, ModuleDef,
+    ModuleDef, Name, Crate, Module, Problem,
-    Path, PathKind, PersistentHirDatabase,
+    PersistentHirDatabase, Path, PathKind, HirFileId,
-    Crate, Name,
+    ids::{SourceItemId, SourceFileItemId, MacroCallId},
-    module_tree::{ModuleId, ModuleTree},
-    nameres::lower::{ImportId, LoweredModule, ImportData},
 };
-/// `ItemMap` is the result of module name resolution. It contains, for each
+pub(crate) use self::raw::{RawItems, ImportId, ImportSourceMap};
-/// module, the set of visible items.
+pub use self::per_ns::{PerNs, Namespace};
+/// Contans all top-level defs from a macro-expanded crate
 #[derive(Debug, PartialEq, Eq)]
-pub struct ItemMap {
+pub struct CrateDefMap {
+    krate: Crate,
    edition: Edition,
    /// 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<Module>,
+    prelude: Option<Module>,
-    pub(crate) extern_prelude: FxHashMap<Name, ModuleDef>,
+    extern_prelude: FxHashMap<Name, ModuleDef>,
-    per_module: ArenaMap<ModuleId, ModuleScope>,
+    root: CrateModuleId,
+    modules: Arena<CrateModuleId, ModuleData>,
+    macros: Arena<CrateMacroId, mbe::MacroRules>,
+    public_macros: FxHashMap<Name, CrateMacroId>,
+    macro_resolutions: FxHashMap<MacroCallId, (Crate, CrateMacroId)>,
+    problems: CrateDefMapProblems,
+}
+impl std::ops::Index<CrateModuleId> for CrateDefMap {
+    type Output = ModuleData;
+    fn index(&self, id: CrateModuleId) -> &ModuleData {
+        &self.modules[id]
+    }
+}
+impl std::ops::Index<CrateMacroId> for CrateDefMap {
+    type Output = mbe::MacroRules;
+    fn index(&self, id: CrateMacroId) -> &mbe::MacroRules {
+        &self.macros[id]
+    }
+}
+/// An ID of a macro, **local** to a specific crate
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) struct CrateMacroId(RawId);
+impl_arena_id!(CrateMacroId);
+/// An ID of a module, **local** to a specific crate
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub(crate) struct CrateModuleId(RawId);
+impl_arena_id!(CrateModuleId);
+#[derive(Default, Debug, PartialEq, Eq)]
+pub(crate) struct ModuleData {
+    pub(crate) parent: Option<CrateModuleId>,
+    pub(crate) children: FxHashMap<Name, CrateModuleId>,
+    pub(crate) scope: ModuleScope,
+    /// None for root
+    pub(crate) declaration: Option<SourceItemId>,
+    /// None for inline modules.
+    ///
+    /// Note that non-inline modules, by definition, live inside non-macro file.
+    pub(crate) definition: Option<FileId>,
+}
+#[derive(Default, Debug, PartialEq, Eq)]
+pub(crate) struct CrateDefMapProblems {
+    problems: Vec<(SourceItemId, Problem)>,
 }
-impl std::ops::Index<ModuleId> for ItemMap {
+impl CrateDefMapProblems {
-    type Output = ModuleScope;
+    fn add(&mut self, source_item_id: SourceItemId, problem: Problem) {
-    fn index(&self, id: ModuleId) -> &ModuleScope {
+        self.problems.push((source_item_id, problem))
-        &self.per_module[id]
+    }
+    pub(crate) fn iter<'a>(&'a self) -> impl Iterator<Item = (&'a SourceItemId, &'a Problem)> + 'a {
+        self.problems.iter().map(|(s, p)| (s, p))
    }
 }
 #[derive(Debug, Default, PartialEq, Eq, Clone)]
 pub struct ModuleScope {
-    pub(crate) items: FxHashMap<Name, Resolution>,
+    items: FxHashMap<Name, Resolution>,
 }
 impl ModuleScope {
@@ -66,8 +154,6 @@ impl ModuleScope {
    }
 }
-/// `Resolution` is basically `DefId` atm, but it should account for stuff like
-/// multiple namespaces, ambiguity and errors.
 #[derive(Debug, Clone, PartialEq, Eq, Default)]
 pub struct Resolution {
    /// None for unresolved
@@ -76,372 +162,6 @@ pub struct Resolution {
    pub import: Option<ImportId>,
 }
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Namespace {
-    Types,
-    Values,
-}
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub struct PerNs<T> {
-    pub types: Option<T>,
-    pub values: Option<T>,
-}
-impl<T> Default for PerNs<T> {
-    fn default() -> Self {
-        PerNs { types: None, values: None }
-    }
-}
-impl<T> PerNs<T> {
-    pub fn none() -> PerNs<T> {
-        PerNs { types: None, values: None }
-    }
-    pub fn values(t: T) -> PerNs<T> {
-        PerNs { types: None, values: Some(t) }
-    }
-    pub fn types(t: T) -> PerNs<T> {
-        PerNs { types: Some(t), values: None }
-    }
-    pub fn both(types: T, values: T) -> PerNs<T> {
-        PerNs { types: Some(types), values: Some(values) }
-    }
-    pub fn is_none(&self) -> bool {
-        self.types.is_none() && self.values.is_none()
-    }
-    pub fn is_both(&self) -> bool {
-        self.types.is_some() && self.values.is_some()
-    }
-    pub fn take(self, namespace: Namespace) -> Option<T> {
-        match namespace {
-            Namespace::Types => self.types,
-            Namespace::Values => self.values,
-        }
-    }
-    pub fn take_types(self) -> Option<T> {
-        self.take(Namespace::Types)
-    }
-    pub fn take_values(self) -> Option<T> {
-        self.take(Namespace::Values)
-    }
-    pub fn get(&self, namespace: Namespace) -> Option<&T> {
-        self.as_ref().take(namespace)
-    }
-    pub fn as_ref(&self) -> PerNs<&T> {
-        PerNs { types: self.types.as_ref(), values: self.values.as_ref() }
-    }
-    pub fn or(self, other: PerNs<T>) -> PerNs<T> {
-        PerNs { types: self.types.or(other.types), values: self.values.or(other.values) }
-    }
-    pub fn and_then<U>(self, f: impl Fn(T) -> Option<U>) -> PerNs<U> {
-        PerNs { types: self.types.and_then(&f), values: self.values.and_then(&f) }
-    }
-    pub fn map<U>(self, f: impl Fn(T) -> U) -> PerNs<U> {
-        PerNs { types: self.types.map(&f), values: self.values.map(&f) }
-    }
-}
-struct Resolver<'a, DB> {
-    db: &'a DB,
-    input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
-    krate: Crate,
-    module_tree: Arc<ModuleTree>,
-    processed_imports: FxHashSet<(ModuleId, ImportId)>,
-    /// If module `a` has `use b::*`, then this contains the mapping b -> a (and the import)
-    glob_imports: FxHashMap<ModuleId, Vec<(ModuleId, ImportId)>>,
-    result: ItemMap,
-}
-impl<'a, DB> Resolver<'a, DB>
-where
-    DB: PersistentHirDatabase,
-{
-    fn new(
-        db: &'a DB,
-        input: &'a FxHashMap<ModuleId, Arc<LoweredModule>>,
-        krate: Crate,
-    ) -> Resolver<'a, DB> {
-        let module_tree = db.module_tree(krate);
-        Resolver {
-            db,
-            input,
-            krate,
-            module_tree,
-            processed_imports: FxHashSet::default(),
-            glob_imports: FxHashMap::default(),
-            result: ItemMap {
-                edition: krate.edition(db),
-                prelude: None,
-                extern_prelude: FxHashMap::default(),
-                per_module: ArenaMap::default(),
-            },
-        }
-    }
-    pub(crate) fn resolve(mut self) -> ItemMap {
-        self.populate_extern_prelude();
-        for (&module_id, items) in self.input.iter() {
-            self.populate_module(module_id, Arc::clone(items));
-        }
-        let mut iter = 0;
-        loop {
-            iter += 1;
-            if iter > 1000 {
-                panic!("failed to reach fixedpoint after 1000 iters")
-            }
-            let processed_imports_count = self.processed_imports.len();
-            for &module_id in self.input.keys() {
-                self.db.check_canceled();
-                self.resolve_imports(module_id);
-            }
-            if processed_imports_count == self.processed_imports.len() {
-                // no new imports resolved
-                break;
-            }
-        }
-        self.result
-    }
-    fn populate_extern_prelude(&mut self) {
-        for dep in self.krate.dependencies(self.db) {
-            log::debug!("crate dep {:?} -> {:?}", dep.name, dep.krate);
-            if let Some(module) = dep.krate.root_module(self.db) {
-                self.result.extern_prelude.insert(dep.name.clone(), module.into());
-            }
-            // look for the prelude
-            if self.result.prelude.is_none() {
-                let item_map = self.db.item_map(dep.krate);
-                if item_map.prelude.is_some() {
-                    self.result.prelude = item_map.prelude;
-                }
-            }
-        }
-    }
-    fn populate_module(&mut self, module_id: ModuleId, input: Arc<LoweredModule>) {
-        let mut module_items = ModuleScope::default();
-        for (import_id, import_data) in input.imports.iter() {
-            if let Some(last_segment) = import_data.path.segments.iter().last() {
-                if !import_data.is_glob {
-                    let name =
-                        import_data.alias.clone().unwrap_or_else(|| last_segment.name.clone());
-                    module_items
-                        .items
-                        .insert(name, Resolution { def: PerNs::none(), import: Some(import_id) });
-                }
-            }
-        }
-        // Populate explicitly declared items, except modules
-        for (name, &def) in input.declarations.iter() {
-            let resolution = Resolution { def, import: None };
-            module_items.items.insert(name.clone(), resolution);
-        }
-        // Populate modules
-        for (name, module_id) in module_id.children(&self.module_tree) {
-            let module = Module { module_id, krate: self.krate };
-            self.add_module_item(&mut module_items, name, PerNs::types(module.into()));
-        }
-        self.result.per_module.insert(module_id, module_items);
-    }
-    fn add_module_item(&self, module_items: &mut ModuleScope, name: Name, def: PerNs<ModuleDef>) {
-        let resolution = Resolution { def, import: None };
-        module_items.items.insert(name, resolution);
-    }
-    fn resolve_imports(&mut self, module_id: ModuleId) {
-        for (import_id, import_data) in self.input[&module_id].imports.iter() {
-            if self.processed_imports.contains(&(module_id, import_id)) {
-                // already done
-                continue;
-            }
-            if self.resolve_import(module_id, import_id, import_data) == ReachedFixedPoint::Yes {
-                log::debug!("import {:?} resolved (or definite error)", import_id);
-                self.processed_imports.insert((module_id, import_id));
-            }
-        }
-    }
-    fn resolve_import(
-        &mut self,
-        module_id: ModuleId,
-        import_id: ImportId,
-        import: &ImportData,
-    ) -> ReachedFixedPoint {
-        log::debug!("resolving import: {:?} ({:?})", import, self.result.edition);
-        let original_module = Module { krate: self.krate, module_id };
-        let (def, reached_fixedpoint) = if import.is_extern_crate {
-            let res = self.result.resolve_name_in_extern_prelude(
-                &import
-                    .path
-                    .as_ident()
-                    .expect("extern crate should have been desugared to one-element path"),
-            );
-            (res, if res.is_none() { ReachedFixedPoint::No } else { ReachedFixedPoint::Yes })
-        } else {
-            let res = self.result.resolve_path_fp(
-                self.db,
-                ResolveMode::Import,
-                original_module,
-                &import.path,
-            );
-            (res.resolved_def, res.reached_fixedpoint)
-        };
-        if reached_fixedpoint != ReachedFixedPoint::Yes {
-            return reached_fixedpoint;
-        }
-        if import.is_glob {
-            log::debug!("glob import: {:?}", import);
-            match def.take_types() {
-                Some(ModuleDef::Module(m)) => {
-                    if import.is_prelude {
-                        tested_by!(std_prelude);
-                        self.result.prelude = Some(m);
-                    } else if m.krate != self.krate {
-                        tested_by!(glob_across_crates);
-                        // glob import from other crate => we can just import everything once
-                        let item_map = self.db.item_map(m.krate);
-                        let scope = &item_map[m.module_id];
-                        let items = scope
-                            .items
-                            .iter()
-                            .map(|(name, res)| (name.clone(), res.clone()))
-                            .collect::<Vec<_>>();
-                        self.update(module_id, Some(import_id), &items);
-                    } else {
-                        // glob import from same crate => we do an initial
-                        // import, and then need to propagate any further
-                        // additions
-                        let scope = &self.result[m.module_id];
-                        let items = scope
-                            .items
-                            .iter()
-                            .map(|(name, res)| (name.clone(), res.clone()))
-                            .collect::<Vec<_>>();
-                        self.update(module_id, Some(import_id), &items);
-                        // record the glob import in case we add further items
-                        self.glob_imports
-                            .entry(m.module_id)
-                            .or_default()
-                            .push((module_id, import_id));
-                    }
-                }
-                Some(ModuleDef::Enum(e)) => {
-                    tested_by!(glob_enum);
-                    // glob import from enum => just import all the variants
-                    let variants = e.variants(self.db);
-                    let resolutions = variants
-                        .into_iter()
-                        .filter_map(|variant| {
-                            let res = Resolution {
-                                def: PerNs::both(variant.into(), variant.into()),
-                                import: Some(import_id),
-                            };
-                            let name = variant.name(self.db)?;
-                            Some((name, res))
-                        })
-                        .collect::<Vec<_>>();
-                    self.update(module_id, Some(import_id), &resolutions);
-                }
-                Some(d) => {
-                    log::debug!("glob import {:?} from non-module/enum {:?}", import, d);
-                }
-                None => {
-                    log::debug!("glob import {:?} didn't resolve as type", import);
-                }
-            }
-        } else {
-            let last_segment = import.path.segments.last().unwrap();
-            let name = import.alias.clone().unwrap_or_else(|| last_segment.name.clone());
-            log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
-            // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
-            if let Some(root_module) = self.krate.root_module(self.db) {
-                if import.is_extern_crate && module_id == root_module.module_id {
-                    if let Some(def) = def.take_types() {
-                        self.result.extern_prelude.insert(name.clone(), def);
-                    }
-                }
-            }
-            let resolution = Resolution { def, import: Some(import_id) };
-            self.update(module_id, None, &[(name, resolution)]);
-        }
-        reached_fixedpoint
-    }
-    fn update(
-        &mut self,
-        module_id: ModuleId,
-        import: Option<ImportId>,
-        resolutions: &[(Name, Resolution)],
-    ) {
-        self.update_recursive(module_id, import, resolutions, 0)
-    }
-    fn update_recursive(
-        &mut self,
-        module_id: ModuleId,
-        import: Option<ImportId>,
-        resolutions: &[(Name, Resolution)],
-        depth: usize,
-    ) {
-        if depth > 100 {
-            // prevent stack overflows (but this shouldn't be possible)
-            panic!("infinite recursion in glob imports!");
-        }
-        let module_items = self.result.per_module.get_mut(module_id).unwrap();
-        let mut changed = false;
-        for (name, res) in resolutions {
-            let existing = module_items.items.entry(name.clone()).or_default();
-            if existing.def.types.is_none() && res.def.types.is_some() {
-                existing.def.types = res.def.types;
-                existing.import = import.or(res.import);
-                changed = true;
-            }
-            if existing.def.values.is_none() && res.def.values.is_some() {
-                existing.def.values = res.def.values;
-                existing.import = import.or(res.import);
-                changed = true;
-            }
-        }
-        if !changed {
-            return;
-        }
-        let glob_imports = self
-            .glob_imports
-            .get(&module_id)
-            .into_iter()
-            .flat_map(|v| v.iter())
-            .cloned()
-            .collect::<Vec<_>>();
-        for (glob_importing_module, glob_import) in glob_imports {
-            // We pass the glob import so that the tracked import in those modules is that glob import
-            self.update_recursive(glob_importing_module, Some(glob_import), resolutions, depth + 1);
-        }
-    }
-}
 #[derive(Debug, Clone)]
 struct ResolvePathResult {
    resolved_def: PerNs<ModuleDef>,
@@ -475,84 +195,85 @@ enum ReachedFixedPoint {
    No,
 }
-impl ItemMap {
+impl CrateDefMap {
-    pub(crate) fn item_map_query(db: &impl PersistentHirDatabase, krate: Crate) -> Arc<ItemMap> {
+    pub(crate) fn crate_def_map_query(
-        let start = time::Instant::now();
+        db: &impl PersistentHirDatabase,
-        let module_tree = db.module_tree(krate);
+        krate: Crate,
-        let input = module_tree
+    ) -> Arc<CrateDefMap> {
-            .modules()
+        let start = std::time::Instant::now();
-            .map(|module_id| (module_id, db.lower_module(Module { krate, module_id })))
+        let def_map = {
-            .collect::<FxHashMap<_, _>>();
+            let edition = krate.edition(db);
+            let mut modules: Arena<CrateModuleId, ModuleData> = Arena::default();
-        let resolver = Resolver::new(db, &input, krate);
+            let root = modules.alloc(ModuleData::default());
-        let res = resolver.resolve();
+            CrateDefMap {
-        let elapsed = start.elapsed();
+                krate,
-        log::info!("item_map: {:?}", elapsed);
+                edition,
-        Arc::new(res)
+                extern_prelude: FxHashMap::default(),
+                prelude: None,
+                root,
+                modules,
+                macros: Arena::default(),
+                public_macros: FxHashMap::default(),
+                macro_resolutions: FxHashMap::default(),
+                problems: CrateDefMapProblems::default(),
+            }
+        };
+        let def_map = collector::collect_defs(db, def_map);
+        log::info!("crate_def_map_query: {:?}", start.elapsed());
+        Arc::new(def_map)
    }
-    pub(crate) fn resolve_path(
+    pub(crate) fn root(&self) -> CrateModuleId {
-        &self,
+        self.root
-        db: &impl PersistentHirDatabase,
-        original_module: Module,
-        path: &Path,
-    ) -> (PerNs<ModuleDef>, Option<usize>) {
-        let res = self.resolve_path_fp(db, ResolveMode::Other, original_module, path);
-        (res.resolved_def, res.segment_index)
    }
-    fn resolve_in_prelude(
+    pub(crate) fn problems(&self) -> &CrateDefMapProblems {
-        &self,
+        &self.problems
-        db: &impl PersistentHirDatabase,
-        original_module: Module,
-        name: &Name,
-    ) -> PerNs<ModuleDef> {
-        if let Some(prelude) = self.prelude {
-            let resolution = if prelude.krate == original_module.krate {
-                self[prelude.module_id].items.get(name).cloned()
-            } else {
-                db.item_map(prelude.krate)[prelude.module_id].items.get(name).cloned()
-            };
-            resolution.map(|r| r.def).unwrap_or_else(PerNs::none)
-        } else {
-            PerNs::none()
-        }
    }
-    pub(crate) fn resolve_name_in_module(
+    pub(crate) fn mk_module(&self, module_id: CrateModuleId) -> Module {
-        &self,
+        Module { krate: self.krate, module_id }
-        db: &impl PersistentHirDatabase,
+    }
-        module: Module,
-        name: &Name,
-    ) -> PerNs<ModuleDef> {
-        // Resolve in:
-        //  - current module / scope
-        //  - extern prelude
-        //  - std prelude
-        let from_scope = self[module.module_id].items.get(name).map_or(PerNs::none(), |it| it.def);
-        let from_extern_prelude =
-            self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it));
-        let from_prelude = self.resolve_in_prelude(db, module, name);
-        from_scope.or(from_extern_prelude).or(from_prelude)
+    pub(crate) fn prelude(&self) -> Option<Module> {
+        self.prelude
    }
-    fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
+    pub(crate) fn extern_prelude(&self) -> &FxHashMap<Name, ModuleDef> {
-        self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it))
+        &self.extern_prelude
    }
-    fn resolve_name_in_crate_root_or_extern_prelude(
+    pub(crate) fn resolve_macro(
        &self,
-        db: &impl PersistentHirDatabase,
+        macro_call_id: MacroCallId,
-        module: Module,
+    ) -> Option<(Crate, CrateMacroId)> {
-        name: &Name,
+        self.macro_resolutions.get(&macro_call_id).map(|&it| it)
-    ) -> PerNs<ModuleDef> {
+    }
-        let crate_root = module.crate_root(db);
-        let from_crate_root =
-            self[crate_root.module_id].items.get(name).map_or(PerNs::none(), |it| it.def);
-        let from_extern_prelude = self.resolve_name_in_extern_prelude(name);
-        from_crate_root.or(from_extern_prelude)
+    pub(crate) fn find_module_by_source(
+        &self,
+        file_id: HirFileId,
+        decl_id: Option<SourceFileItemId>,
+    ) -> Option<CrateModuleId> {
+        let decl_id = decl_id.map(|it| it.with_file_id(file_id));
+        let (module_id, _module_data) = self.modules.iter().find(|(_module_id, module_data)| {
+            if decl_id.is_some() {
+                module_data.declaration == decl_id
+            } else {
+                module_data.definition.map(|it| it.into()) == Some(file_id)
+            }
+        })?;
+        Some(module_id)
+    }
+    pub(crate) fn resolve_path(
+        &self,
+        db: &impl PersistentHirDatabase,
+        original_module: CrateModuleId,
+        path: &Path,
+    ) -> (PerNs<ModuleDef>, Option<usize>) {
+        let res = self.resolve_path_fp(db, ResolveMode::Other, original_module, path);
+        (res.resolved_def, res.segment_index)
    }
    // Returns Yes if we are sure that additions to `ItemMap` wouldn't change
@@ -561,13 +282,17 @@ impl ItemMap {
        &self,
        db: &impl PersistentHirDatabase,
        mode: ResolveMode,
-        original_module: Module,
+        original_module: CrateModuleId,
        path: &Path,
    ) -> ResolvePathResult {
        let mut segments = path.segments.iter().enumerate();
        let mut curr_per_ns: PerNs<ModuleDef> = match path.kind {
-            PathKind::Crate => PerNs::types(original_module.crate_root(db).into()),
+            PathKind::Crate => {
-            PathKind::Self_ => PerNs::types(original_module.into()),
+                PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
+            }
+            PathKind::Self_ => {
+                PerNs::types(Module { krate: self.krate, module_id: original_module }.into())
+            }
            // plain import or absolute path in 2015: crate-relative with
            // fallback to extern prelude (with the simplification in
            // rust-lang/rust#57745)
@@ -581,11 +306,7 @@ impl ItemMap {
                    None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                };
                log::debug!("resolving {:?} in crate root (+ extern prelude)", segment);
-                self.resolve_name_in_crate_root_or_extern_prelude(
+                self.resolve_name_in_crate_root_or_extern_prelude(&segment.name)
-                    db,
-                    original_module,
-                    &segment.name,
-                )
            }
            PathKind::Plain => {
                let segment = match segments.next() {
@@ -596,8 +317,8 @@ impl ItemMap {
                self.resolve_name_in_module(db, original_module, &segment.name)
            }
            PathKind::Super => {
-                if let Some(p) = original_module.parent(db) {
+                if let Some(p) = self.modules[original_module].parent {
-                    PerNs::types(p.into())
+                    PerNs::types(Module { krate: self.krate, module_id: p }.into())
                } else {
                    log::debug!("super path in root module");
                    return ResolvePathResult::empty(ReachedFixedPoint::Yes);
@@ -634,14 +355,14 @@ impl ItemMap {
            curr_per_ns = match curr {
                ModuleDef::Module(module) => {
-                    if module.krate != original_module.krate {
+                    if module.krate != self.krate {
                        let path = Path {
                            segments: path.segments[i..].iter().cloned().collect(),
                            kind: PathKind::Self_,
                        };
                        log::debug!("resolving {:?} in other crate", path);
-                        let item_map = db.item_map(module.krate);
+                        let defp_map = db.crate_def_map(module.krate);
-                        let (def, s) = item_map.resolve_path(db, *module, &path);
+                        let (def, s) = defp_map.resolve_path(db, module.module_id, &path);
                        return ResolvePathResult::with(
                            def,
                            ReachedFixedPoint::Yes,
@@ -649,7 +370,7 @@ impl ItemMap {
                        );
                    }
-                    match self[module.module_id].items.get(&segment.name) {
+                    match self[module.module_id].scope.items.get(&segment.name) {
                        Some(res) if !res.def.is_none() => res.def,
                        _ => {
                            log::debug!("path segment {:?} not found", segment.name);
@@ -659,7 +380,7 @@ impl ItemMap {
                }
                ModuleDef::Enum(e) => {
                    // enum variant
-                    tested_by!(item_map_enum_importing);
+                    tested_by!(can_import_enum_variant);
                    match e.variant(db, &segment.name) {
                        Some(variant) => PerNs::both(variant.into(), variant.into()),
                        None => {
@@ -690,7 +411,47 @@ impl ItemMap {
        }
        ResolvePathResult::with(curr_per_ns, ReachedFixedPoint::Yes, None)
    }
-}
-#[cfg(test)]
+    fn resolve_name_in_crate_root_or_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
-mod tests;
+        let from_crate_root =
+            self[self.root].scope.items.get(name).map_or(PerNs::none(), |it| it.def);
+        let from_extern_prelude = self.resolve_name_in_extern_prelude(name);
+        from_crate_root.or(from_extern_prelude)
+    }
+    pub(crate) fn resolve_name_in_module(
+        &self,
+        db: &impl PersistentHirDatabase,
+        module: CrateModuleId,
+        name: &Name,
+    ) -> PerNs<ModuleDef> {
+        // Resolve in:
+        //  - current module / scope
+        //  - extern prelude
+        //  - std prelude
+        let from_scope = self[module].scope.items.get(name).map_or(PerNs::none(), |it| it.def);
+        let from_extern_prelude =
+            self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it));
+        let from_prelude = self.resolve_in_prelude(db, name);
+        from_scope.or(from_extern_prelude).or(from_prelude)
+    }
+    fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
+        self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it))
+    }
+    fn resolve_in_prelude(&self, db: &impl PersistentHirDatabase, name: &Name) -> PerNs<ModuleDef> {
+        if let Some(prelude) = self.prelude {
+            let resolution = if prelude.krate == self.krate {
+                self[prelude.module_id].scope.items.get(name).cloned()
+            } else {
+                db.crate_def_map(prelude.krate)[prelude.module_id].scope.items.get(name).cloned()
+            };
+            resolution.map(|r| r.def).unwrap_or_else(PerNs::none)
+        } else {
+            PerNs::none()
+        }
+    }
+}
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
new file mode 100644
index 000000000..12ed49a0a
--- /dev/null
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -0,0 +1,564 @@
+use arrayvec::ArrayVec;
+use rustc_hash::FxHashMap;
+use relative_path::RelativePathBuf;
+use test_utils::tested_by;
+use ra_db::FileId;
+use crate::{
+    Function, Module, Struct, Enum, Const, Static, Trait, TypeAlias,
+    PersistentHirDatabase, HirFileId, Name, Path, Problem, Crate,
+    KnownName,
+    nameres::{Resolution, PerNs, ModuleDef, ReachedFixedPoint, ResolveMode, raw},
+    ids::{AstItemDef, LocationCtx, MacroCallLoc, SourceItemId, MacroCallId},
+};
+use super::{CrateDefMap, CrateModuleId, ModuleData, CrateMacroId};
+pub(super) fn collect_defs(
+    db: &impl PersistentHirDatabase,
+    mut def_map: CrateDefMap,
+) -> CrateDefMap {
+    // populate external prelude
+    for dep in def_map.krate.dependencies(db) {
+        log::debug!("crate dep {:?} -> {:?}", dep.name, dep.krate);
+        if let Some(module) = dep.krate.root_module(db) {
+            def_map.extern_prelude.insert(dep.name.clone(), module.into());
+        }
+        // look for the prelude
+        if def_map.prelude.is_none() {
+            let map = db.crate_def_map(dep.krate);
+            if map.prelude.is_some() {
+                def_map.prelude = map.prelude;
+            }
+        }
+    }
+    let mut collector = DefCollector {
+        db,
+        def_map,
+        glob_imports: FxHashMap::default(),
+        unresolved_imports: Vec::new(),
+        unexpanded_macros: Vec::new(),
+        global_macro_scope: FxHashMap::default(),
+    };
+    collector.collect();
+    collector.finish()
+}
+/// Walks the tree of module recursively
+struct DefCollector<DB> {
+    db: DB,
+    def_map: CrateDefMap,
+    glob_imports: FxHashMap<CrateModuleId, Vec<(CrateModuleId, raw::ImportId)>>,
+    unresolved_imports: Vec<(CrateModuleId, raw::ImportId, raw::ImportData)>,
+    unexpanded_macros: Vec<(CrateModuleId, MacroCallId, Path, tt::Subtree)>,
+    global_macro_scope: FxHashMap<Name, CrateMacroId>,
+}
+impl<'a, DB> DefCollector<&'a DB>
+where
+    DB: PersistentHirDatabase,
+{
+    fn collect(&mut self) {
+        let crate_graph = self.db.crate_graph();
+        let file_id = crate_graph.crate_root(self.def_map.krate.crate_id());
+        let raw_items = self.db.raw_items(file_id);
+        let module_id = self.def_map.root;
+        self.def_map.modules[module_id].definition = Some(file_id);
+        ModCollector {
+            def_collector: &mut *self,
+            module_id,
+            file_id: file_id.into(),
+            raw_items: &raw_items,
+        }
+        .collect(raw_items.items());
+        // main name resolution fixed-point loop.
+        let mut i = 0;
+        loop {
+            match (self.resolve_imports(), self.resolve_macros()) {
+                (ReachedFixedPoint::Yes, ReachedFixedPoint::Yes) => break,
+                _ => i += 1,
+            }
+            if i == 1000 {
+                log::error!("diverging name resolution");
+                break;
+            }
+        }
+        let unresolved_imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
+        // show unresolved imports in completion, etc
+        for (module_id, import, import_data) in unresolved_imports {
+            self.record_resolved_import(module_id, PerNs::none(), import, &import_data)
+        }
+    }
+    fn define_macro(&mut self, name: Name, tt: &tt::Subtree, export: bool) {
+        if let Ok(rules) = mbe::MacroRules::parse(tt) {
+            let macro_id = self.def_map.macros.alloc(rules);
+            if export {
+                self.def_map.public_macros.insert(name.clone(), macro_id);
+            }
+            self.global_macro_scope.insert(name, macro_id);
+        }
+    }
+    fn resolve_imports(&mut self) -> ReachedFixedPoint {
+        let mut imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
+        let mut resolved = Vec::new();
+        imports.retain(|(module_id, import, import_data)| {
+            let (def, fp) = self.resolve_import(*module_id, import_data);
+            if fp == ReachedFixedPoint::Yes {
+                resolved.push((*module_id, def, *import, import_data.clone()))
+            }
+            fp == ReachedFixedPoint::No
+        });
+        self.unresolved_imports = imports;
+        // Resolves imports, filling-in module scopes
+        let result =
+            if resolved.is_empty() { ReachedFixedPoint::Yes } else { ReachedFixedPoint::No };
+        for (module_id, def, import, import_data) in resolved {
+            self.record_resolved_import(module_id, def, import, &import_data)
+        }
+        result
+    }
+    fn resolve_import(
+        &mut self,
+        module_id: CrateModuleId,
+        import: &raw::ImportData,
+    ) -> (PerNs<ModuleDef>, ReachedFixedPoint) {
+        log::debug!("resolving import: {:?} ({:?})", import, self.def_map.edition);
+        if import.is_extern_crate {
+            let res = self.def_map.resolve_name_in_extern_prelude(
+                &import
+                    .path
+                    .as_ident()
+                    .expect("extern crate should have been desugared to one-element path"),
+            );
+            (res, ReachedFixedPoint::Yes)
+        } else {
+            let res =
+                self.def_map.resolve_path_fp(self.db, ResolveMode::Import, module_id, &import.path);
+            (res.resolved_def, res.reached_fixedpoint)
+        }
+    }
+    fn record_resolved_import(
+        &mut self,
+        module_id: CrateModuleId,
+        def: PerNs<ModuleDef>,
+        import_id: raw::ImportId,
+        import: &raw::ImportData,
+    ) {
+        if import.is_glob {
+            log::debug!("glob import: {:?}", import);
+            match def.take_types() {
+                Some(ModuleDef::Module(m)) => {
+                    if import.is_prelude {
+                        tested_by!(std_prelude);
+                        self.def_map.prelude = Some(m);
+                    } else if m.krate != self.def_map.krate {
+                        tested_by!(glob_across_crates);
+                        // glob import from other crate => we can just import everything once
+                        let item_map = self.db.crate_def_map(m.krate);
+                        let scope = &item_map[m.module_id].scope;
+                        let items = scope
+                            .items
+                            .iter()
+                            .map(|(name, res)| (name.clone(), res.clone()))
+                            .collect::<Vec<_>>();
+                        self.update(module_id, Some(import_id), &items);
+                    } else {
+                        // glob import from same crate => we do an initial
+                        // import, and then need to propagate any further
+                        // additions
+                        let scope = &self.def_map[m.module_id].scope;
+                        let items = scope
+                            .items
+                            .iter()
+                            .map(|(name, res)| (name.clone(), res.clone()))
+                            .collect::<Vec<_>>();
+                        self.update(module_id, Some(import_id), &items);
+                        // record the glob import in case we add further items
+                        self.glob_imports
+                            .entry(m.module_id)
+                            .or_default()
+                            .push((module_id, import_id));
+                    }
+                }
+                Some(ModuleDef::Enum(e)) => {
+                    tested_by!(glob_enum);
+                    // glob import from enum => just import all the variants
+                    let variants = e.variants(self.db);
+                    let resolutions = variants
+                        .into_iter()
+                        .filter_map(|variant| {
+                            let res = Resolution {
+                                def: PerNs::both(variant.into(), variant.into()),
+                                import: Some(import_id),
+                            };
+                            let name = variant.name(self.db)?;
+                            Some((name, res))
+                        })
+                        .collect::<Vec<_>>();
+                    self.update(module_id, Some(import_id), &resolutions);
+                }
+                Some(d) => {
+                    log::debug!("glob import {:?} from non-module/enum {:?}", import, d);
+                }
+                None => {
+                    log::debug!("glob import {:?} didn't resolve as type", import);
+                }
+            }
+        } else {
+            match import.path.segments.last() {
+                Some(last_segment) => {
+                    let name = import.alias.clone().unwrap_or_else(|| last_segment.name.clone());
+                    log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
+                    // extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
+                    if import.is_extern_crate && module_id == self.def_map.root {
+                        if let Some(def) = def.take_types() {
+                            self.def_map.extern_prelude.insert(name.clone(), def);
+                        }
+                    }
+                    let resolution = Resolution { def, import: Some(import_id) };
+                    self.update(module_id, Some(import_id), &[(name, resolution)]);
+                }
+                None => tested_by!(bogus_paths),
+            }
+        }
+    }
+    fn update(
+        &mut self,
+        module_id: CrateModuleId,
+        import: Option<raw::ImportId>,
+        resolutions: &[(Name, Resolution)],
+    ) {
+        self.update_recursive(module_id, import, resolutions, 0)
+    }
+    fn update_recursive(
+        &mut self,
+        module_id: CrateModuleId,
+        import: Option<raw::ImportId>,
+        resolutions: &[(Name, Resolution)],
+        depth: usize,
+    ) {
+        if depth > 100 {
+            // prevent stack overflows (but this shouldn't be possible)
+            panic!("infinite recursion in glob imports!");
+        }
+        let module_items = &mut self.def_map.modules[module_id].scope;
+        let mut changed = false;
+        for (name, res) in resolutions {
+            let existing = module_items.items.entry(name.clone()).or_default();
+            if existing.def.types.is_none() && res.def.types.is_some() {
+                existing.def.types = res.def.types;
+                existing.import = import.or(res.import);
+                changed = true;
+            }
+            if existing.def.values.is_none() && res.def.values.is_some() {
+                existing.def.values = res.def.values;
+                existing.import = import.or(res.import);
+                changed = true;
+            }
+            if existing.def.is_none()
+                && res.def.is_none()
+                && existing.import.is_none()
+                && res.import.is_some()
+            {
+                existing.import = res.import;
+            }
+        }
+        if !changed {
+            return;
+        }
+        let glob_imports = self
+            .glob_imports
+            .get(&module_id)
+            .into_iter()
+            .flat_map(|v| v.iter())
+            .cloned()
+            .collect::<Vec<_>>();
+        for (glob_importing_module, glob_import) in glob_imports {
+            // We pass the glob import so that the tracked import in those modules is that glob import
+            self.update_recursive(glob_importing_module, Some(glob_import), resolutions, depth + 1);
+        }
+    }
+    // XXX: this is just a pile of hacks now, because `PerNs` does not handle
+    // macro namespace.
+    fn resolve_macros(&mut self) -> ReachedFixedPoint {
+        let mut macros = std::mem::replace(&mut self.unexpanded_macros, Vec::new());
+        let mut resolved = Vec::new();
+        let mut res = ReachedFixedPoint::Yes;
+        macros.retain(|(module_id, call_id, path, tt)| {
+            if path.segments.len() != 2 {
+                return true;
+            }
+            let crate_name = &path.segments[0].name;
+            let krate = match self.def_map.resolve_name_in_extern_prelude(crate_name).take_types() {
+                Some(ModuleDef::Module(m)) => m.krate(self.db),
+                _ => return true,
+            };
+            let krate = match krate {
+                Some(it) => it,
+                _ => return true,
+            };
+            res = ReachedFixedPoint::No;
+            let def_map = self.db.crate_def_map(krate);
+            if let Some(macro_id) = def_map.public_macros.get(&path.segments[1].name).cloned() {
+                resolved.push((*module_id, *call_id, (krate, macro_id), tt.clone()));
+            }
+            false
+        });
+        for (module_id, macro_call_id, macro_def_id, arg) in resolved {
+            self.collect_macro_expansion(module_id, macro_call_id, macro_def_id, arg);
+        }
+        res
+    }
+    fn collect_macro_expansion(
+        &mut self,
+        module_id: CrateModuleId,
+        macro_call_id: MacroCallId,
+        macro_def_id: (Crate, CrateMacroId),
+        macro_arg: tt::Subtree,
+    ) {
+        let (macro_krate, macro_id) = macro_def_id;
+        let dm;
+        let rules = if macro_krate == self.def_map.krate {
+            &self.def_map[macro_id]
+        } else {
+            dm = self.db.crate_def_map(macro_krate);
+            &dm[macro_id]
+        };
+        if let Ok(expansion) = rules.expand(&macro_arg) {
+            self.def_map.macro_resolutions.insert(macro_call_id, macro_def_id);
+            // XXX: this **does not** go through a database, because we can't
+            // identify macro_call without adding the whole state of name resolution
+            // as a parameter to the query.
+            //
+            // So, we run the queries "manually" and we must ensure that
+            // `db.hir_parse(macro_call_id)` returns the same source_file.
+            let file_id: HirFileId = macro_call_id.into();
+            let source_file = mbe::token_tree_to_ast_item_list(&expansion);
+            let raw_items = raw::RawItems::from_source_file(&source_file, file_id);
+            ModCollector { def_collector: &mut *self, file_id, module_id, raw_items: &raw_items }
+                .collect(raw_items.items())
+        }
+    }
+    fn finish(self) -> CrateDefMap {
+        self.def_map
+    }
+}
+/// Walks a single module, populating defs, imports and macros
+struct ModCollector<'a, D> {
+    def_collector: D,
+    module_id: CrateModuleId,
+    file_id: HirFileId,
+    raw_items: &'a raw::RawItems,
+}
+impl<DB> ModCollector<'_, &'_ mut DefCollector<&'_ DB>>
+where
+    DB: PersistentHirDatabase,
+{
+    fn collect(&mut self, items: &[raw::RawItem]) {
+        for item in items {
+            match *item {
+                raw::RawItem::Module(m) => self.collect_module(&self.raw_items[m]),
+                raw::RawItem::Import(import) => self.def_collector.unresolved_imports.push((
+                    self.module_id,
+                    import,
+                    self.raw_items[import].clone(),
+                )),
+                raw::RawItem::Def(def) => self.define_def(&self.raw_items[def]),
+                raw::RawItem::Macro(mac) => self.collect_macro(&self.raw_items[mac]),
+            }
+        }
+    }
+    fn collect_module(&mut self, module: &raw::ModuleData) {
+        match module {
+            // inline module, just recurse
+            raw::ModuleData::Definition { name, items, source_item_id } => {
+                let module_id = self.push_child_module(
+                    name.clone(),
+                    source_item_id.with_file_id(self.file_id),
+                    None,
+                );
+                ModCollector {
+                    def_collector: &mut *self.def_collector,
+                    module_id,
+                    file_id: self.file_id,
+                    raw_items: self.raw_items,
+                }
+                .collect(&*items);
+            }
+            // out of line module, resovle, parse and recurse
+            raw::ModuleData::Declaration { name, source_item_id } => {
+                let source_item_id = source_item_id.with_file_id(self.file_id);
+                let is_root = self.def_collector.def_map.modules[self.module_id].parent.is_none();
+                let (file_ids, problem) =
+                    resolve_submodule(self.def_collector.db, self.file_id, name, is_root);
+                if let Some(problem) = problem {
+                    self.def_collector.def_map.problems.add(source_item_id, problem)
+                }
+                if let Some(&file_id) = file_ids.first() {
+                    let module_id =
+                        self.push_child_module(name.clone(), source_item_id, Some(file_id));
+                    let raw_items = self.def_collector.db.raw_items(file_id);
+                    ModCollector {
+                        def_collector: &mut *self.def_collector,
+                        module_id,
+                        file_id: file_id.into(),
+                        raw_items: &raw_items,
+                    }
+                    .collect(raw_items.items())
+                }
+            }
+        }
+    }
+    fn push_child_module(
+        &mut self,
+        name: Name,
+        declaration: SourceItemId,
+        definition: Option<FileId>,
+    ) -> CrateModuleId {
+        let modules = &mut self.def_collector.def_map.modules;
+        let res = modules.alloc(ModuleData::default());
+        modules[res].parent = Some(self.module_id);
+        modules[res].declaration = Some(declaration);
+        modules[res].definition = definition;
+        modules[self.module_id].children.insert(name.clone(), res);
+        let resolution = Resolution {
+            def: PerNs::types(
+                Module { krate: self.def_collector.def_map.krate, module_id: res }.into(),
+            ),
+            import: None,
+        };
+        self.def_collector.update(self.module_id, None, &[(name, resolution)]);
+        res
+    }
+    fn define_def(&mut self, def: &raw::DefData) {
+        let module = Module { krate: self.def_collector.def_map.krate, module_id: self.module_id };
+        let ctx = LocationCtx::new(self.def_collector.db, module, self.file_id.into());
+        macro_rules! id {
+            () => {
+                AstItemDef::from_source_item_id_unchecked(ctx, def.source_item_id)
+            };
+        }
+        let name = def.name.clone();
+        let def: PerNs<ModuleDef> = match def.kind {
+            raw::DefKind::Function => PerNs::values(Function { id: id!() }.into()),
+            raw::DefKind::Struct => {
+                let s = Struct { id: id!() }.into();
+                PerNs::both(s, s)
+            }
+            raw::DefKind::Enum => PerNs::types(Enum { id: id!() }.into()),
+            raw::DefKind::Const => PerNs::values(Const { id: id!() }.into()),
+            raw::DefKind::Static => PerNs::values(Static { id: id!() }.into()),
+            raw::DefKind::Trait => PerNs::types(Trait { id: id!() }.into()),
+            raw::DefKind::TypeAlias => PerNs::types(TypeAlias { id: id!() }.into()),
+        };
+        let resolution = Resolution { def, import: None };
+        self.def_collector.update(self.module_id, None, &[(name, resolution)])
+    }
+    fn collect_macro(&mut self, mac: &raw::MacroData) {
+        // Case 1: macro rules, define a macro in crate-global mutable scope
+        if is_macro_rules(&mac.path) {
+            if let Some(name) = &mac.name {
+                self.def_collector.define_macro(name.clone(), &mac.arg, mac.export)
+            }
+            return;
+        }
+        let source_item_id = SourceItemId { file_id: self.file_id, item_id: mac.source_item_id };
+        let macro_call_id = MacroCallLoc {
+            module: Module { krate: self.def_collector.def_map.krate, module_id: self.module_id },
+            source_item_id,
+        }
+        .id(self.def_collector.db);
+        // Case 2: try to expand macro_rules from this crate, triggering
+        // recursive item collection.
+        if let Some(&macro_id) =
+            mac.path.as_ident().and_then(|name| self.def_collector.global_macro_scope.get(name))
+        {
+            self.def_collector.collect_macro_expansion(
+                self.module_id,
+                macro_call_id,
+                (self.def_collector.def_map.krate, macro_id),
+                mac.arg.clone(),
+            );
+            return;
+        }
+        // Case 3: path to a macro from another crate, expand during name resolution
+        self.def_collector.unexpanded_macros.push((
+            self.module_id,
+            macro_call_id,
+            mac.path.clone(),
+            mac.arg.clone(),
+        ))
+    }
+}
+fn is_macro_rules(path: &Path) -> bool {
+    path.as_ident().and_then(Name::as_known_name) == Some(KnownName::MacroRules)
+}
+fn resolve_submodule(
+    db: &impl PersistentHirDatabase,
+    file_id: HirFileId,
+    name: &Name,
+    is_root: bool,
+) -> (Vec<FileId>, Option<Problem>) {
+    // FIXME: handle submodules of inline modules properly
+    let file_id = file_id.original_file(db);
+    let source_root_id = db.file_source_root(file_id);
+    let path = db.file_relative_path(file_id);
+    let root = RelativePathBuf::default();
+    let dir_path = path.parent().unwrap_or(&root);
+    let mod_name = path.file_stem().unwrap_or("unknown");
+    let is_dir_owner = is_root || mod_name == "mod";
+    let file_mod = dir_path.join(format!("{}.rs", name));
+    let dir_mod = dir_path.join(format!("{}/mod.rs", name));
+    let file_dir_mod = dir_path.join(format!("{}/{}.rs", mod_name, name));
+    let mut candidates = ArrayVec::<[_; 2]>::new();
+    if is_dir_owner {
+        candidates.push(file_mod.clone());
+        candidates.push(dir_mod);
+    } else {
+        candidates.push(file_dir_mod.clone());
+    };
+    let sr = db.source_root(source_root_id);
+    let points_to = candidates
+        .into_iter()
+        .filter_map(|path| sr.files.get(&path))
+        .map(|&it| it)
+        .collect::<Vec<_>>();
+    let problem = if points_to.is_empty() {
+        Some(Problem::UnresolvedModule {
+            candidate: if is_dir_owner { file_mod } else { file_dir_mod },
+        })
+    } else {
+        None
+    };
+    (points_to, problem)
+}
diff --git a/crates/ra_hir/src/nameres/lower.rs b/crates/ra_hir/src/nameres/lower.rs
deleted file mode 100644
index 56262ad6d..000000000
--- a/crates/ra_hir/src/nameres/lower.rs
+++ /dev/null
@@ -1,222 +0,0 @@
-use std::sync::Arc;
-use ra_syntax::{
-    AstNode, SourceFile, TreeArc, AstPtr,
-    ast::{self, ModuleItemOwner, NameOwner, AttrsOwner},
-};
-use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
-use rustc_hash::FxHashMap;
-use crate::{
-    SourceItemId, Path, ModuleSource, Name,
-    HirFileId, MacroCallLoc, AsName, PerNs, Function,
-    ModuleDef, Module, Struct, Enum, Const, Static, Trait, TypeAlias,
-    ids::LocationCtx, PersistentHirDatabase,
-};
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ImportId(RawId);
-impl_arena_id!(ImportId);
-#[derive(Debug, PartialEq, Eq)]
-pub(super) struct ImportData {
-    pub(super) path: Path,
-    pub(super) alias: Option<Name>,
-    pub(super) is_glob: bool,
-    pub(super) is_prelude: bool,
-    pub(super) is_extern_crate: bool,
-}
-/// A set of items and imports declared inside a module, without relation to
-/// other modules.
-///
-/// This sits in-between raw syntax and name resolution and allows us to avoid
-/// recomputing name res: if two instance of `InputModuleItems` are the same, we
-/// can avoid redoing name resolution.
-#[derive(Debug, Default, PartialEq, Eq)]
-pub struct LoweredModule {
-    pub(crate) declarations: FxHashMap<Name, PerNs<ModuleDef>>,
-    pub(super) imports: Arena<ImportId, ImportData>,
-}
-#[derive(Debug, Default, PartialEq, Eq)]
-pub struct ImportSourceMap {
-    map: ArenaMap<ImportId, AstPtr<ast::PathSegment>>,
-}
-impl ImportSourceMap {
-    fn insert(&mut self, import: ImportId, segment: &ast::PathSegment) {
-        self.map.insert(import, AstPtr::new(segment))
-    }
-    pub fn get(&self, source: &ModuleSource, import: ImportId) -> TreeArc<ast::PathSegment> {
-        let file = match source {
-            ModuleSource::SourceFile(file) => &*file,
-            ModuleSource::Module(m) => m.syntax().ancestors().find_map(SourceFile::cast).unwrap(),
-        };
-        self.map[import].to_node(file).to_owned()
-    }
-}
-impl LoweredModule {
-    pub(crate) fn lower_module_query(
-        db: &impl PersistentHirDatabase,
-        module: Module,
-    ) -> Arc<LoweredModule> {
-        db.lower_module_with_source_map(module).0
-    }
-    pub(crate) fn lower_module_with_source_map_query(
-        db: &impl PersistentHirDatabase,
-        module: Module,
-    ) -> (Arc<LoweredModule>, Arc<ImportSourceMap>) {
-        let (file_id, source) = module.definition_source(db);
-        let file_id: HirFileId = file_id.into();
-        let mut source_map = ImportSourceMap::default();
-        let mut res = LoweredModule::default();
-        match source {
-            ModuleSource::SourceFile(it) => {
-                res.fill(&mut source_map, db, module, file_id, &mut it.items_with_macros())
-            }
-            ModuleSource::Module(it) => {
-                if let Some(item_list) = it.item_list() {
-                    res.fill(
-                        &mut source_map,
-                        db,
-                        module,
-                        file_id,
-                        &mut item_list.items_with_macros(),
-                    )
-                }
-            }
-        };
-        (Arc::new(res), Arc::new(source_map))
-    }
-    fn fill(
-        &mut self,
-        source_map: &mut ImportSourceMap,
-        db: &impl PersistentHirDatabase,
-        module: Module,
-        file_id: HirFileId,
-        items: &mut Iterator<Item = ast::ItemOrMacro>,
-    ) {
-        let file_items = db.file_items(file_id);
-        for item in items {
-            match item {
-                ast::ItemOrMacro::Item(it) => {
-                    self.add_def_id(source_map, db, module, file_id, it);
-                }
-                ast::ItemOrMacro::Macro(macro_call) => {
-                    let item_id = file_items.id_of_unchecked(macro_call.syntax());
-                    let loc =
-                        MacroCallLoc { module, source_item_id: SourceItemId { file_id, item_id } };
-                    let id = loc.id(db);
-                    let file_id = HirFileId::from(id);
-                    //FIXME: expand recursively
-                    for item in db.hir_parse(file_id).items() {
-                        self.add_def_id(source_map, db, module, file_id, item);
-                    }
-                }
-            }
-        }
-    }
-    fn add_def_id(
-        &mut self,
-        source_map: &mut ImportSourceMap,
-        db: &impl PersistentHirDatabase,
-        module: Module,
-        file_id: HirFileId,
-        item: &ast::ModuleItem,
-    ) {
-        let ctx = LocationCtx::new(db, module, file_id);
-        match item.kind() {
-            ast::ModuleItemKind::StructDef(it) => {
-                if let Some(name) = it.name() {
-                    let s = Struct { id: ctx.to_def(it) };
-                    let s: ModuleDef = s.into();
-                    self.declarations.insert(name.as_name(), PerNs::both(s, s));
-                }
-            }
-            ast::ModuleItemKind::EnumDef(it) => {
-                if let Some(name) = it.name() {
-                    let e = Enum { id: ctx.to_def(it) };
-                    let e: ModuleDef = e.into();
-                    self.declarations.insert(name.as_name(), PerNs::types(e));
-                }
-            }
-            ast::ModuleItemKind::FnDef(it) => {
-                if let Some(name) = it.name() {
-                    let func = Function { id: ctx.to_def(it) };
-                    self.declarations.insert(name.as_name(), PerNs::values(func.into()));
-                }
-            }
-            ast::ModuleItemKind::TraitDef(it) => {
-                if let Some(name) = it.name() {
-                    let t = Trait { id: ctx.to_def(it) };
-                    self.declarations.insert(name.as_name(), PerNs::types(t.into()));
-                }
-            }
-            ast::ModuleItemKind::TypeAliasDef(it) => {
-                if let Some(name) = it.name() {
-                    let t = TypeAlias { id: ctx.to_def(it) };
-                    self.declarations.insert(name.as_name(), PerNs::types(t.into()));
-                }
-            }
-            ast::ModuleItemKind::ImplBlock(_) => {
-                // impls don't define items
-            }
-            ast::ModuleItemKind::UseItem(it) => {
-                self.add_use_item(source_map, it);
-            }
-            ast::ModuleItemKind::ExternCrateItem(it) => {
-                if let Some(name_ref) = it.name_ref() {
-                    let path = Path::from_name_ref(name_ref);
-                    let alias = it.alias().and_then(|a| a.name()).map(AsName::as_name);
-                    self.imports.alloc(ImportData {
-                        path,
-                        alias,
-                        is_glob: false,
-                        is_prelude: false,
-                        is_extern_crate: true,
-                    });
-                }
-            }
-            ast::ModuleItemKind::ConstDef(it) => {
-                if let Some(name) = it.name() {
-                    let c = Const { id: ctx.to_def(it) };
-                    self.declarations.insert(name.as_name(), PerNs::values(c.into()));
-                }
-            }
-            ast::ModuleItemKind::StaticDef(it) => {
-                if let Some(name) = it.name() {
-                    let s = Static { id: ctx.to_def(it) };
-                    self.declarations.insert(name.as_name(), PerNs::values(s.into()));
-                }
-            }
-            ast::ModuleItemKind::Module(_) => {
-                // modules are handled separately directly by name res
-            }
-        };
-    }
-    fn add_use_item(&mut self, source_map: &mut ImportSourceMap, item: &ast::UseItem) {
-        let is_prelude =
-            item.attrs().any(|attr| attr.as_atom().map(|s| s == "prelude_import").unwrap_or(false));
-        Path::expand_use_item(item, |path, segment, alias| {
-            let import = self.imports.alloc(ImportData {
-                path,
-                alias,
-                is_glob: segment.is_none(),
-                is_prelude,
-                is_extern_crate: false,
-            });
-            if let Some(segment) = segment {
-                source_map.insert(import, segment)
-            }
-        })
-    }
-}
diff --git a/crates/ra_hir/src/nameres/per_ns.rs b/crates/ra_hir/src/nameres/per_ns.rs
new file mode 100644
index 000000000..c40a3ff9d
--- /dev/null
+++ b/crates/ra_hir/src/nameres/per_ns.rs
@@ -0,0 +1,78 @@
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Namespace {
+    Types,
+    Values,
+}
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct PerNs<T> {
+    pub types: Option<T>,
+    pub values: Option<T>,
+}
+impl<T> Default for PerNs<T> {
+    fn default() -> Self {
+        PerNs { types: None, values: None }
+    }
+}
+impl<T> PerNs<T> {
+    pub fn none() -> PerNs<T> {
+        PerNs { types: None, values: None }
+    }
+    pub fn values(t: T) -> PerNs<T> {