101 files changed, 2783 insertions, 1035 deletions
diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index b5160eaa3..060a05d41 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -14,8 +14,9 @@ Forum for questions: https://users.rust-lang.org/c/ide/14
 Before submitting, please make sure that you're not running into one of these known issues:
 1. on-the-fly diagnostics are mostly unimplemented (`cargo check` diagnostics will be shown when saving a file)
- 2. some settings are required for procedural macro and build script support (`rust-analyzer.cargo.loadOutDirsFromCheck`, `rust-analyzer.procMacro.enable`): #6448
+ 2. some platform-specific imports are not resolved: #6038
- 3. some platform-specific imports are not resolved: #6038
+ 3. attribute proc macros are not supported: #6029
+ 4. the version string is misleading (includes the previous week): #8571
 Otherwise please try to provide information which will help us to fix the issue faster. Minimal reproducible examples with few dependencies are especially lovely <3.
 -->
diff --git a/Cargo.lock b/Cargo.lock
index d7e6d3ac8..1bb66c66e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -259,9 +259,9 @@ dependencies = [
 [[package]]
 name = "crossbeam-channel"
-version = "0.5.0"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dca26ee1f8d361640700bde38b2c37d8c22b3ce2d360e1fc1c74ea4b0aa7d775"
+checksum = "06ed27e177f16d65f0f0c22a213e17c696ace5dd64b14258b52f9417ccb52db4"
 dependencies = [
 "cfg-if",
 "crossbeam-utils",
@@ -971,9 +971,9 @@ dependencies = [
 [[package]]
 name = "notify"
-version = "5.0.0-pre.6"
+version = "5.0.0-pre.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5fd82b93434edb9c00ae65ee741e0e081cdc8c63346ab9f687935a629aaf4c3"
+checksum = "1ebe7699a0f8c5759450716ee03d231685c22b4fe8f406c42c22e0ad94d40ce7"
 dependencies = [
 "anymap",
 "bitflags",
diff --git a/crates/base_db/src/fixture.rs b/crates/base_db/src/fixture.rs
index 04e2be390..0132565e4 100644
--- a/crates/base_db/src/fixture.rs
+++ b/crates/base_db/src/fixture.rs
@@ -35,7 +35,7 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
    fn with_position(ra_fixture: &str) -> (Self, FilePosition) {
        let (db, file_id, range_or_offset) = Self::with_range_or_offset(ra_fixture);
        let offset = match range_or_offset {
-            RangeOrOffset::Range(_) => panic!(),
+            RangeOrOffset::Range(_) => panic!("Expected a cursor position, got a range instead"),
            RangeOrOffset::Offset(it) => it,
        };
        (db, FilePosition { file_id, offset })
@@ -45,7 +45,7 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
        let (db, file_id, range_or_offset) = Self::with_range_or_offset(ra_fixture);
        let range = match range_or_offset {
            RangeOrOffset::Range(it) => it,
-            RangeOrOffset::Offset(_) => panic!(),
+            RangeOrOffset::Offset(_) => panic!("Expected a cursor range, got a position instead"),
        };
        (db, FileRange { file_id, range })
    }
@@ -54,7 +54,9 @@ pub trait WithFixture: Default + SourceDatabaseExt + 'static {
        let fixture = ChangeFixture::parse(ra_fixture);
        let mut db = Self::default();
        fixture.change.apply(&mut db);
-        let (file_id, range_or_offset) = fixture.file_position.unwrap();
+        let (file_id, range_or_offset) = fixture
+            .file_position
+            .expect("Could not find file position in fixture. Did you forget to add an `$0`?");
        (db, file_id, range_or_offset)
    }
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index eba46a056..0acfa582a 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -2066,6 +2066,18 @@ impl Type {
        self.ty.dyn_trait().map(Into::into)
    }
+    /// If a type can be represented as `dyn Trait`, returns all traits accessible via this type,
+    /// or an empty iterator otherwise.
+    pub fn applicable_inherent_traits<'a>(
+        &'a self,
+        db: &'a dyn HirDatabase,
+    ) -> impl Iterator<Item = Trait> + 'a {
+        self.autoderef(db)
+            .filter_map(|derefed_type| derefed_type.ty.dyn_trait())
+            .flat_map(move |dyn_trait_id| hir_ty::all_super_traits(db.upcast(), dyn_trait_id))
+            .map(Trait::from)
+    }
    pub fn as_impl_traits(&self, db: &dyn HirDatabase) -> Option<Vec<Trait>> {
        self.ty.impl_trait_bounds(db).map(|it| {
            it.into_iter()
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index 7955bf0b5..62500602a 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -6,10 +6,11 @@ use std::{cell::RefCell, fmt, iter::successors};
 use base_db::{FileId, FileRange};
 use hir_def::{
+    body,
    resolver::{self, HasResolver, Resolver, TypeNs},
    AsMacroCall, FunctionId, TraitId, VariantId,
 };
-use hir_expand::{hygiene::Hygiene, name::AsName, ExpansionInfo};
+use hir_expand::{name::AsName, ExpansionInfo};
 use hir_ty::associated_type_shorthand_candidates;
 use itertools::Itertools;
 use rustc_hash::{FxHashMap, FxHashSet};
@@ -853,8 +854,8 @@ impl<'a> SemanticsScope<'a> {
    /// Resolve a path as-if it was written at the given scope. This is
    /// necessary a heuristic, as it doesn't take hygiene into account.
    pub fn speculative_resolve(&self, path: &ast::Path) -> Option<PathResolution> {
-        let hygiene = Hygiene::new(self.db.upcast(), self.file_id);
+        let ctx = body::LowerCtx::new(self.db.upcast(), self.file_id);
-        let path = Path::from_src(path.clone(), &hygiene)?;
+        let path = Path::from_src(path.clone(), &ctx)?;
        resolve_hir_path(self.db, &self.resolver, &path)
    }
 }
diff --git a/crates/hir/src/source_analyzer.rs b/crates/hir/src/source_analyzer.rs
index 847d2537d..0895bd6f1 100644
--- a/crates/hir/src/source_analyzer.rs
+++ b/crates/hir/src/source_analyzer.rs
@@ -9,6 +9,7 @@ use std::{iter::once, sync::Arc};
 use hir_def::{
    body::{
+        self,
        scope::{ExprScopes, ScopeId},
        Body, BodySourceMap,
    },
@@ -202,8 +203,8 @@ impl SourceAnalyzer {
        db: &dyn HirDatabase,
        macro_call: InFile<&ast::MacroCall>,
    ) -> Option<MacroDef> {
-        let hygiene = Hygiene::new(db.upcast(), macro_call.file_id);
+        let ctx = body::LowerCtx::new(db.upcast(), macro_call.file_id);
-        let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &hygiene))?;
+        let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &ctx))?;
        self.resolver.resolve_path_as_macro(db.upcast(), path.mod_path()).map(|it| it.into())
    }
@@ -281,7 +282,9 @@ impl SourceAnalyzer {
        }
        // This must be a normal source file rather than macro file.
-        let hir_path = Path::from_src(path.clone(), &Hygiene::new(db.upcast(), self.file_id))?;
+        let hygiene = Hygiene::new(db.upcast(), self.file_id);
+        let ctx = body::LowerCtx::with_hygiene(&hygiene);
+        let hir_path = Path::from_src(path.clone(), &ctx)?;
        // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we
        // trying to resolve foo::bar.
diff --git a/crates/hir_def/src/body.rs b/crates/hir_def/src/body.rs
index 96b959967..131f424cc 100644
--- a/crates/hir_def/src/body.rs
+++ b/crates/hir_def/src/body.rs
@@ -21,7 +21,7 @@ use profile::Count;
 use rustc_hash::FxHashMap;
 use syntax::{ast, AstNode, AstPtr};
-pub(crate) use lower::LowerCtx;
+pub use lower::LowerCtx;
 use crate::{
    attr::{Attrs, RawAttrs},
@@ -37,13 +37,15 @@ use crate::{
 /// A subset of Expander that only deals with cfg attributes. We only need it to
 /// avoid cyclic queries in crate def map during enum processing.
+#[derive(Debug)]
 pub(crate) struct CfgExpander {
    cfg_options: CfgOptions,
    hygiene: Hygiene,
    krate: CrateId,
 }
-pub(crate) struct Expander {
+#[derive(Debug)]
+pub struct Expander {
    cfg_expander: CfgExpander,
    def_map: Arc<DefMap>,
    current_file_id: HirFileId,
@@ -80,11 +82,7 @@ impl CfgExpander {
 }
 impl Expander {
-    pub(crate) fn new(
+    pub fn new(db: &dyn DefDatabase, current_file_id: HirFileId, module: ModuleId) -> Expander {
-        db: &dyn DefDatabase,
-        current_file_id: HirFileId,
-        module: ModuleId,
-    ) -> Expander {
        let cfg_expander = CfgExpander::new(db, current_file_id, module.krate);
        let def_map = module.def_map(db);
        let ast_id_map = db.ast_id_map(current_file_id);
@@ -98,7 +96,7 @@ impl Expander {
        }
    }
-    pub(crate) fn enter_expand<T: ast::AstNode>(
+    pub fn enter_expand<T: ast::AstNode>(
        &mut self,
        db: &dyn DefDatabase,
        macro_call: ast::MacroCall,
@@ -170,7 +168,7 @@ impl Expander {
        Ok(ExpandResult { value: Some((mark, node)), err })
    }
-    pub(crate) fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) {
+    pub fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) {
        self.cfg_expander.hygiene = Hygiene::new(db.upcast(), mark.file_id);
        self.current_file_id = mark.file_id;
        self.ast_id_map = mem::take(&mut mark.ast_id_map);
@@ -190,8 +188,13 @@ impl Expander {
        &self.cfg_expander.cfg_options
    }
+    pub fn current_file_id(&self) -> HirFileId {
+        self.current_file_id
+    }
    fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
-        Path::from_src(path, &self.cfg_expander.hygiene)
+        let ctx = LowerCtx::with_hygiene(&self.cfg_expander.hygiene);
+        Path::from_src(path, &ctx)
    }
    fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroDefId> {
@@ -204,7 +207,8 @@ impl Expander {
    }
 }
-pub(crate) struct Mark {
+#[derive(Debug)]
+pub struct Mark {
    file_id: HirFileId,
    ast_id_map: Arc<AstIdMap>,
    bomb: DropBomb,
diff --git a/crates/hir_def/src/body/lower.rs b/crates/hir_def/src/body/lower.rs
index ed07d6928..c11da30d2 100644
--- a/crates/hir_def/src/body/lower.rs
+++ b/crates/hir_def/src/body/lower.rs
@@ -1,10 +1,11 @@
 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
 //! representation.
-use std::mem;
+use std::{mem, sync::Arc};
 use either::Either;
 use hir_expand::{
+    ast_id_map::{AstIdMap, FileAstId},
    hygiene::Hygiene,
    name::{name, AsName, Name},
    ExpandError, HirFileId,
@@ -39,20 +40,39 @@ use crate::{
 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
-pub(crate) struct LowerCtx {
+pub struct LowerCtx {
    hygiene: Hygiene,
+    file_id: Option<HirFileId>,
+    source_ast_id_map: Option<Arc<AstIdMap>>,
 }
 impl LowerCtx {
-    pub(crate) fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
+    pub fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
-        LowerCtx { hygiene: Hygiene::new(db.upcast(), file_id) }
+        LowerCtx {
+            hygiene: Hygiene::new(db.upcast(), file_id),
+            file_id: Some(file_id),
+            source_ast_id_map: Some(db.ast_id_map(file_id)),
+        }
+    }
+    pub fn with_hygiene(hygiene: &Hygiene) -> Self {
+        LowerCtx { hygiene: hygiene.clone(), file_id: None, source_ast_id_map: None }
+    }
+    pub(crate) fn hygiene(&self) -> &Hygiene {
+        &self.hygiene
    }
-    pub(crate) fn with_hygiene(hygiene: &Hygiene) -> Self {
-        LowerCtx { hygiene: hygiene.clone() }
+    pub(crate) fn file_id(&self) -> HirFileId {
+        self.file_id.unwrap()
    }
    pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
-        Path::from_src(ast, &self.hygiene)
+        Path::from_src(ast, self)
+    }
+    pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> Option<FileAstId<N>> {
+        self.source_ast_id_map.as_ref().map(|ast_id_map| ast_id_map.ast_id(item))
    }
 }
@@ -568,9 +588,13 @@ impl ExprCollector<'_> {
        let res = match res {
            Ok(res) => res,
-            Err(UnresolvedMacro) => {
+            Err(UnresolvedMacro { path }) => {
                self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall(
-                    UnresolvedMacroCall { file: outer_file, node: syntax_ptr.cast().unwrap() },
+                    UnresolvedMacroCall {
+                        file: outer_file,
+                        node: syntax_ptr.cast().unwrap(),
+                        path,
+                    },
                ));
                collector(self, None);
                return;
diff --git a/crates/hir_def/src/body/tests.rs b/crates/hir_def/src/body/tests.rs
index c1d3e998f..63f5fe88d 100644
--- a/crates/hir_def/src/body/tests.rs
+++ b/crates/hir_def/src/body/tests.rs
@@ -180,7 +180,7 @@ fn unresolved_macro_diag() {
        r#"
 fn f() {
    m!();
-  //^^^^ unresolved macro call
+  //^^^^ unresolved macro `m!`
 }
      "#,
    );
diff --git a/crates/hir_def/src/diagnostics.rs b/crates/hir_def/src/diagnostics.rs
index 97abf8653..a71ae2668 100644
--- a/crates/hir_def/src/diagnostics.rs
+++ b/crates/hir_def/src/diagnostics.rs
@@ -8,7 +8,7 @@ use hir_expand::diagnostics::{Diagnostic, DiagnosticCode, DiagnosticSink};
 use hir_expand::{HirFileId, InFile};
 use syntax::{ast, AstPtr, SyntaxNodePtr, TextRange};
-use crate::{db::DefDatabase, DefWithBodyId};
+use crate::{db::DefDatabase, path::ModPath, DefWithBodyId};
 pub fn validate_body(db: &dyn DefDatabase, owner: DefWithBodyId, sink: &mut DiagnosticSink<'_>) {
    let source_map = db.body_with_source_map(owner).1;
@@ -103,6 +103,7 @@ impl Diagnostic for UnresolvedImport {
 pub struct UnresolvedMacroCall {
    pub file: HirFileId,
    pub node: AstPtr<ast::MacroCall>,
+    pub path: ModPath,
 }
 impl Diagnostic for UnresolvedMacroCall {
@@ -110,7 +111,7 @@ impl Diagnostic for UnresolvedMacroCall {
        DiagnosticCode("unresolved-macro-call")
    }
    fn message(&self) -> String {
-        "unresolved macro call".to_string()
+        format!("unresolved macro `{}!`", self.path)
    }
    fn display_source(&self) -> InFile<SyntaxNodePtr> {
        InFile::new(self.file, self.node.clone().into())
diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index 109d3552f..2c4bbe585 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -425,106 +425,142 @@ mod tests {
    #[test]
    fn same_module() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            struct S;
+struct S;
-            $0
+$0
-        "#;
+        "#,
-        check_found_path(code, "S", "S", "crate::S", "self::S");
+            "S",
+            "S",
+            "crate::S",
+            "self::S",
+        );
    }
    #[test]
    fn enum_variant() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            enum E { A }
+enum E { A }
-            $0
+$0
-        "#;
+        "#,
-        check_found_path(code, "E::A", "E::A", "E::A", "E::A");
+            "E::A",
+            "E::A",
+            "E::A",
+            "E::A",
+        );
    }
    #[test]
    fn sub_module() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo {
+mod foo {
-                pub struct S;
+    pub struct S;
-            }
+}
-            $0
+$0
-        "#;
+        "#,
-        check_found_path(code, "foo::S", "foo::S", "crate::foo::S", "self::foo::S");
+            "foo::S",
+            "foo::S",
+            "crate::foo::S",
+            "self::foo::S",
+        );
    }
    #[test]
    fn super_module() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo;
+//- /main.rs
-            //- /foo.rs
+mod foo;
-            mod bar;
+//- /foo.rs
-            struct S;
+mod bar;
-            //- /foo/bar.rs
+struct S;
-            $0
+//- /foo/bar.rs
-        "#;
+$0
-        check_found_path(code, "super::S", "super::S", "crate::foo::S", "super::S");
+        "#,
+            "super::S",
+            "super::S",
+            "crate::foo::S",
+            "super::S",
+        );
    }
    #[test]
    fn self_module() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo;
+//- /main.rs
-            //- /foo.rs
+mod foo;
-            $0
+//- /foo.rs
-        "#;
+$0
-        check_found_path(code, "self", "self", "crate::foo", "self");
+        "#,
+            "self",
+            "self",
+            "crate::foo",
+            "self",
+        );
    }
    #[test]
    fn crate_root() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo;
+//- /main.rs
-            //- /foo.rs
+mod foo;
-            $0
+//- /foo.rs
-        "#;
+$0
-        check_found_path(code, "crate", "crate", "crate", "crate");
+        "#,
+            "crate",
+            "crate",
+            "crate",
+            "crate",
+        );
    }
    #[test]
    fn same_crate() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo;
+//- /main.rs
-            struct S;
+mod foo;
-            //- /foo.rs
+struct S;
-            $0
+//- /foo.rs
-        "#;
+$0
-        check_found_path(code, "crate::S", "crate::S", "crate::S", "crate::S");
+        "#,
+            "crate::S",
+            "crate::S",
+            "crate::S",
+            "crate::S",
+        );
    }
    #[test]
    fn different_crate() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs crate:main deps:std
+            r#"
-            $0
+//- /main.rs crate:main deps:std
-            //- /std.rs crate:std
+$0
-            pub struct S;
+//- /std.rs crate:std
-        "#;
+pub struct S;
-        check_found_path(code, "std::S", "std::S", "std::S", "std::S");
+        "#,
+            "std::S",
+            "std::S",
+            "std::S",
+            "std::S",
+        );
    }
    #[test]
    fn different_crate_renamed() {
-        let code = r#"
-            //- /main.rs crate:main deps:std
-            extern crate std as std_renamed;
-            $0
-            //- /std.rs crate:std
-            pub struct S;
-        "#;
        check_found_path(
-            code,
+            r#"
+//- /main.rs crate:main deps:std
+extern crate std as std_renamed;
+$0
+//- /std.rs crate:std
+pub struct S;
+        "#,
            "std_renamed::S",
            "std_renamed::S",
            "std_renamed::S",
@@ -537,41 +573,38 @@ mod tests {
        cov_mark::check!(partially_imported);
        // Tests that short paths are used even for external items, when parts of the path are
        // already in scope.
-        let code = r#"
+        check_found_path(
-            //- /main.rs crate:main deps:syntax
+            r#"
+//- /main.rs crate:main deps:syntax
-            use syntax::ast;
+use syntax::ast;
-            $0
+$0
-            //- /lib.rs crate:syntax
+//- /lib.rs crate:syntax
-            pub mod ast {
+pub mod ast {
-                pub enum ModuleItem {
+    pub enum ModuleItem {
-                    A, B, C,
+        A, B, C,
-                }
+    }
-            }
+}
-        "#;
+        "#,
-        check_found_path(
-            code,
            "ast::ModuleItem",
            "syntax::ast::ModuleItem",
            "syntax::ast::ModuleItem",
            "syntax::ast::ModuleItem",
        );
-        let code = r#"
-            //- /main.rs crate:main deps:syntax
-            $0
-            //- /lib.rs crate:syntax
-            pub mod ast {
-                pub enum ModuleItem {
-                    A, B, C,
-                }
-            }
-        "#;
        check_found_path(
-            code,
+            r#"
+//- /main.rs crate:main deps:syntax
+$0
+//- /lib.rs crate:syntax
+pub mod ast {
+    pub enum ModuleItem {
+        A, B, C,
+    }
+}
+        "#,
            "syntax::ast::ModuleItem",
            "syntax::ast::ModuleItem",
            "syntax::ast::ModuleItem",
@@ -581,68 +614,86 @@ mod tests {
    #[test]
    fn same_crate_reexport() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod bar {
+mod bar {
-                mod foo { pub(super) struct S; }
+    mod foo { pub(super) struct S; }
-                pub(crate) use foo::*;
+    pub(crate) use foo::*;
-            }
+}
-            $0
+$0
-        "#;
+        "#,
-        check_found_path(code, "bar::S", "bar::S", "crate::bar::S", "self::bar::S");
+            "bar::S",
+            "bar::S",
+            "crate::bar::S",
+            "self::bar::S",
+        );
    }
    #[test]
    fn same_crate_reexport_rename() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod bar {
+mod bar {
-                mod foo { pub(super) struct S; }
+    mod foo { pub(super) struct S; }
-                pub(crate) use foo::S as U;
+    pub(crate) use foo::S as U;
-            }
+}
-            $0
+$0
-        "#;
+        "#,
-        check_found_path(code, "bar::U", "bar::U", "crate::bar::U", "self::bar::U");
+            "bar::U",
+            "bar::U",
+            "crate::bar::U",
+            "self::bar::U",
+        );
    }
    #[test]
    fn different_crate_reexport() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs crate:main deps:std
+            r#"
-            $0
+//- /main.rs crate:main deps:std
-            //- /std.rs crate:std deps:core
+$0
-            pub use core::S;
+//- /std.rs crate:std deps:core
-            //- /core.rs crate:core
+pub use core::S;
-            pub struct S;
+//- /core.rs crate:core
-        "#;
+pub struct S;
-        check_found_path(code, "std::S", "std::S", "std::S", "std::S");
+        "#,
+            "std::S",
+            "std::S",
+            "std::S",
+            "std::S",
+        );
    }
    #[test]
    fn prelude() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs crate:main deps:std
+            r#"
-            $0
+//- /main.rs crate:main deps:std
-            //- /std.rs crate:std
+$0
-            pub mod prelude { pub struct S; }
+//- /std.rs crate:std
-            #[prelude_import]
+pub mod prelude { pub struct S; }
-            pub use prelude::*;
+#[prelude_import]
-        "#;
+pub use prelude::*;
-        check_found_path(code, "S", "S", "S", "S");
+        "#,
+            "S",
+            "S",
+            "S",
+            "S",
+        );
    }
    #[test]
    fn enum_variant_from_prelude() {
        let code = r#"
-            //- /main.rs crate:main deps:std
+//- /main.rs crate:main deps:std
-            $0
+$0
-            //- /std.rs crate:std
+//- /std.rs crate:std
-            pub mod prelude {
+pub mod prelude {
-                pub enum Option<T> { Some(T), None }
+    pub enum Option<T> { Some(T), None }
-                pub use Option::*;
+    pub use Option::*;
-            }
+}
-            #[prelude_import]
+#[prelude_import]
-            pub use prelude::*;
+pub use prelude::*;
        "#;
        check_found_path(code, "None", "None", "None", "None");
        check_found_path(code, "Some", "Some", "Some", "Some");
@@ -650,71 +701,85 @@ mod tests {
    #[test]
    fn shortest_path() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            pub mod foo;
+//- /main.rs
-            pub mod baz;
+pub mod foo;
-            struct S;
+pub mod baz;
-            $0
+struct S;
-            //- /foo.rs
+$0
-            pub mod bar { pub struct S; }
+//- /foo.rs
-            //- /baz.rs
+pub mod bar { pub struct S; }
-            pub use crate::foo::bar::S;
+//- /baz.rs
-        "#;
+pub use crate::foo::bar::S;
-        check_found_path(code, "baz::S", "baz::S", "crate::baz::S", "self::baz::S");
+        "#,
+            "baz::S",
+            "baz::S",
+            "crate::baz::S",
+            "self::baz::S",
+        );
    }
    #[test]
    fn discount_private_imports() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            mod foo;
+//- /main.rs
-            pub mod bar { pub struct S; }
+mod foo;
-            use bar::S;
+pub mod bar { pub struct S; }
-            //- /foo.rs
+use bar::S;
-            $0
+//- /foo.rs
-        "#;
+$0
-        // crate::S would be shorter, but using private imports seems wrong
+        "#,
-        check_found_path(code, "crate::bar::S", "crate::bar::S", "crate::bar::S", "crate::bar::S");
+            // crate::S would be shorter, but using private imports seems wrong
+            "crate::bar::S",
+            "crate::bar::S",
+            "crate::bar::S",
+            "crate::bar::S",
+        );
    }
    #[test]
    fn import_cycle() {
-        let code = r#"
+        check_found_path(
-            //- /main.rs
+            r#"
-            pub mod foo;
+//- /main.rs
-            pub mod bar;
+pub mod foo;
-            pub mod baz;
+pub mod bar;
-            //- /bar.rs
+pub mod baz;
-            $0
+//- /bar.rs
-            //- /foo.rs
+$0
-            pub use super::baz;
+//- /foo.rs
-            pub struct S;
+pub use super::baz;
-            //- /baz.rs
+pub struct S;
-            pub use super::foo;
+//- /baz.rs
-        "#;
+pub use super::foo;
-        check_found_path(code, "crate::foo::S", "crate::foo::S", "crate::foo::S", "crate::foo::S");
+        "#,
+            "crate::foo::S",
+            "crate::foo::S",
+            "crate::foo::S",
+            "crate::foo::S",
+        );
    }
    #[test]
    fn prefer_std_paths_over_alloc() {
        cov_mark::check!(prefer_std_paths);
-        let code = r#"
+        check_found_path(
-        //- /main.rs crate:main deps:alloc,std
+            r#"
-        $0
+//- /main.rs crate:main deps:alloc,std
+$0
-        //- /std.rs crate:std deps:alloc
+//- /std.rs crate:std deps:alloc
-        pub mod sync {
+pub mod sync {
-            pub use alloc::sync::Arc;
+    pub use alloc::sync::Arc;
-        }
+}
-        //- /zzz.rs crate:alloc
+//- /zzz.rs crate:alloc
-        pub mod sync {
+pub mod sync {
-            pub struct Arc;
+    pub struct Arc;
-        }
+}
-        "#;
+        "#,
-        check_found_path(
-            code,
            "std::sync::Arc",
            "std::sync::Arc",
            "std::sync::Arc",
@@ -725,26 +790,25 @@ mod tests {
    #[test]
    fn prefer_core_paths_over_std() {
        cov_mark::check!(prefer_no_std_paths);
-        let code = r#"
+        check_found_path(
-        //- /main.rs crate:main deps:core,std
+            r#"
-        #![no_std]
+//- /main.rs crate:main deps:core,std
+#![no_std]
-        $0
+$0
-        //- /std.rs crate:std deps:core
+//- /std.rs crate:std deps:core
-        pub mod fmt {
+pub mod fmt {
-            pub use core::fmt::Error;
+    pub use core::fmt::Error;
-        }
+}
-        //- /zzz.rs crate:core
+//- /zzz.rs crate:core
-        pub mod fmt {
+pub mod fmt {
-            pub struct Error;
+    pub struct Error;
-        }
+}
-        "#;
+        "#,
-        check_found_path(
-            code,
            "core::fmt::Error",
            "core::fmt::Error",
            "core::fmt::Error",
@@ -754,26 +818,25 @@ mod tests {
    #[test]
    fn prefer_alloc_paths_over_std() {
-        let code = r#"
+        check_found_path(
-        //- /main.rs crate:main deps:alloc,std
+            r#"
-        #![no_std]
+//- /main.rs crate:main deps:alloc,std
+#![no_std]
-        $0
+$0
-        //- /std.rs crate:std deps:alloc
+//- /std.rs crate:std deps:alloc
-        pub mod sync {
+pub mod sync {
-            pub use alloc::sync::Arc;
+    pub use alloc::sync::Arc;
-        }
+}
-        //- /zzz.rs crate:alloc
+//- /zzz.rs crate:alloc
-        pub mod sync {
+pub mod sync {
-            pub struct Arc;
+    pub struct Arc;
-        }
+}
-        "#;
+            "#,
-        check_found_path(
-            code,
            "alloc::sync::Arc",
            "alloc::sync::Arc",
            "alloc::sync::Arc",
@@ -783,20 +846,19 @@ mod tests {
    #[test]
    fn prefer_shorter_paths_if_not_alloc() {
-        let code = r#"
+        check_found_path(
-        //- /main.rs crate:main deps:megaalloc,std
+            r#"
-        $0
+//- /main.rs crate:main deps:megaalloc,std
+$0
-        //- /std.rs crate:std deps:megaalloc
+//- /std.rs crate:std deps:megaalloc
-        pub mod sync {
+pub mod sync {
-            pub use megaalloc::sync::Arc;
+    pub use megaalloc::sync::Arc;
-        }
+}
-        //- /zzz.rs crate:megaalloc
+//- /zzz.rs crate:megaalloc
-        pub struct Arc;
+pub struct Arc;
-        "#;
+            "#,
-        check_found_path(
-            code,
            "megaalloc::Arc",
            "megaalloc::Arc",
            "megaalloc::Arc",
@@ -807,12 +869,11 @@ mod tests {
    #[test]
    fn builtins_are_in_scope() {
        let code = r#"
-        //- /main.rs
+$0
-        $0
-        pub mod primitive {
+pub mod primitive {
-            pub use u8;
+    pub use u8;
-        }
+}
        "#;
        check_found_path(code, "u8", "u8", "u8", "u8");
        check_found_path(code, "u16", "u16", "u16", "u16");
@@ -822,10 +883,10 @@ mod tests {
    fn inner_items() {
        check_found_path(
            r#"
-            fn main() {
+fn main() {
-                struct Inner {}
+    struct Inner {}
-                $0
+    $0
-            }
+}
        "#,
            "Inner",
            "Inner",
@@ -838,12 +899,12 @@ mod tests {
    fn inner_items_from_outer_scope() {
        check_found_path(
            r#"
-            fn main() {
+fn main() {
-                struct Struct {}
+    struct Struct {}
-                {
+    {
-                    $0
+        $0
-                }
+    }
-            }
+}
        "#,
            "Struct",
            "Struct",
@@ -857,14 +918,14 @@ mod tests {
        cov_mark::check!(prefixed_in_block_expression);
        check_found_path(
            r#"
-            fn main() {
+fn main() {
-                mod module {
+    mod module {
-                    struct Struct {}
+        struct Struct {}
-                }
+    }
-                {
+    {
-                    $0
+        $0
-                }
+    }
-            }
+}
        "#,
            "module::Struct",
            "module::Struct",
@@ -877,14 +938,14 @@ mod tests {
    fn outer_items_with_inner_items_present() {
        check_found_path(
            r#"
-            mod module {
+mod module {
-                pub struct CompleteMe;
+    pub struct CompleteMe;
-            }
+}
-            fn main() {
+fn main() {
-                fn inner() {}
+    fn inner() {}
-                $0
+    $0
-            }
+}
            "#,
            "module::CompleteMe",
            "module::CompleteMe",
@@ -894,6 +955,29 @@ mod tests {
    }
    #[test]
+    fn from_inside_module() {
+        // This worked correctly, but the test suite logic was broken.
+        cov_mark::check!(submodule_in_testdb);
+        check_found_path(
+            r#"
+mod baz {
+    pub struct Foo {}
+}
+mod bar {
+    fn bar() {
+        $0
+    }
+}
+            "#,
+            "crate::baz::Foo",
+            "crate::baz::Foo",
+            "crate::baz::Foo",
+            "crate::baz::Foo",
+        )
+    }
+    #[test]
    fn recursive_pub_mod_reexport() {
        cov_mark::check!(recursive_imports);
        check_found_path(
diff --git a/crates/hir_def/src/item_tree.rs b/crates/hir_def/src/item_tree.rs
index 94e08f835..16a94a058 100644
--- a/crates/hir_def/src/item_tree.rs
+++ b/crates/hir_def/src/item_tree.rs
@@ -104,6 +104,11 @@ impl ItemTree {
                    // items and expanded during block DefMap computation
                    return Default::default();
                },
+                ast::Type(ty) => {
+                    // Types can contain inner items. We return an empty item tree in this case, but
+                    // still need to collect inner items.
+                    ctx.lower_inner_items(ty.syntax())
+                },
                ast::Expr(e) => {
                    // Macros can expand to expressions. We return an empty item tree in this case, but
                    // still need to collect inner items.
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index d69116d51..25694f037 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -66,6 +66,7 @@ use hir_expand::{
 };
 use la_arena::Idx;
 use nameres::DefMap;
+use path::ModPath;
 use syntax::ast;
 use crate::builtin_type::BuiltinType;
@@ -107,6 +108,18 @@ impl ModuleId {
    pub fn containing_module(&self, db: &dyn db::DefDatabase) -> Option<ModuleId> {
        self.def_map(db).containing_module(self.local_id)
    }
+    /// Returns `true` if this module represents a block expression.
+    ///
+    /// Returns `false` if this module is a submodule *inside* a block expression
+    /// (eg. `m` in `{ mod m {} }`).
+    pub fn is_block_root(&self, db: &dyn db::DefDatabase) -> bool {
+        if self.block.is_none() {
+            return false;
+        }
+        self.def_map(db)[self.local_id].parent.is_none()
+    }
 }
 /// An ID of a module, **local** to a specific crate
@@ -435,6 +448,16 @@ impl_from!(
    for AttrDefId
 );
+impl From<AssocContainerId> for AttrDefId {
+    fn from(acid: AssocContainerId) -> Self {
+        match acid {
+            AssocContainerId::ModuleId(mid) => AttrDefId::ModuleId(mid),
+            AssocContainerId::ImplId(iid) => AttrDefId::ImplId(iid),
+            AssocContainerId::TraitId(tid) => AttrDefId::TraitId(tid),
+        }
+    }
+}
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum VariantId {
    EnumVariantId(EnumVariantId),
@@ -665,7 +688,10 @@ impl<T: ast::AstNode> AstIdWithPath<T> {
    }
 }
-pub struct UnresolvedMacro;
+#[derive(Debug)]
+pub struct UnresolvedMacro {
+    pub path: ModPath,
+}
 fn macro_call_as_call_id(
    call: &AstIdWithPath<ast::MacroCall>,
@@ -674,7 +700,8 @@ fn macro_call_as_call_id(
    resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
    error_sink: &mut dyn FnMut(mbe::ExpandError),
 ) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
-    let def: MacroDefId = resolver(call.path.clone()).ok_or(UnresolvedMacro)?;
+    let def: MacroDefId =
+        resolver(call.path.clone()).ok_or_else(|| UnresolvedMacro { path: call.path.clone() })?;
    let res = if let MacroDefKind::BuiltInEager(..) = def.kind {
        let macro_call = InFile::new(call.ast_id.file_id, call.ast_id.to_node(db.upcast()));
@@ -704,8 +731,13 @@ fn derive_macro_as_call_id(
    krate: CrateId,
    resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
 ) -> Result<MacroCallId, UnresolvedMacro> {
-    let def: MacroDefId = resolver(item_attr.path.clone()).ok_or(UnresolvedMacro)?;
+    let def: MacroDefId = resolver(item_attr.path.clone())
-    let last_segment = item_attr.path.segments().last().ok_or(UnresolvedMacro)?;
+        .ok_or_else(|| UnresolvedMacro { path: item_attr.path.clone() })?;
+    let last_segment = item_attr
+        .path
+        .segments()
+        .last()
+        .ok_or_else(|| UnresolvedMacro { path: item_attr.path.clone() })?;
    let res = def
        .as_lazy_macro(
            db.upcast(),
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index 9e181751c..542f190a1 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -481,7 +481,7 @@ mod diagnostics {
        UnresolvedProcMacro { ast: MacroCallKind },
-        UnresolvedMacroCall { ast: AstId<ast::MacroCall> },
+        UnresolvedMacroCall { ast: AstId<ast::MacroCall>, path: ModPath },
        MacroError { ast: MacroCallKind, message: String },
    }
@@ -546,8 +546,9 @@ mod diagnostics {
        pub(super) fn unresolved_macro_call(
            container: LocalModuleId,
            ast: AstId<ast::MacroCall>,
+            path: ModPath,
        ) -> Self {
-            Self { in_module: container, kind: DiagnosticKind::UnresolvedMacroCall { ast } }
+            Self { in_module: container, kind: DiagnosticKind::UnresolvedMacroCall { ast, path } }
        }
        pub(super) fn add_to(
@@ -662,9 +663,13 @@ mod diagnostics {
                    });
                }
-                DiagnosticKind::UnresolvedMacroCall { ast } => {
+                DiagnosticKind::UnresolvedMacroCall { ast, path } => {
                    let node = ast.to_node(db.upcast());
-                    sink.push(UnresolvedMacroCall { file: ast.file_id, node: AstPtr::new(&node) });
+                    sink.push(UnresolvedMacroCall {
+                        file: ast.file_id,
+                        node: AstPtr::new(&node),
+                        path: path.clone(),
+                    });
                }
                DiagnosticKind::MacroError { ast, message } => {
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index fb4ddff5e..05ceb1efb 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -829,7 +829,7 @@ impl DefCollector<'_> {
                            res = ReachedFixedPoint::No;
                            return false;
                        }
-                        Err(UnresolvedMacro) | Ok(Err(_)) => {}
+                        Err(UnresolvedMacro { .. }) | Ok(Err(_)) => {}
                    }
                }
                MacroDirectiveKind::Derive { ast_id, derive_attr } => {
@@ -845,7 +845,7 @@ impl DefCollector<'_> {
                            res = ReachedFixedPoint::No;
                            return false;
                        }
-                        Err(UnresolvedMacro) => (),
+                        Err(UnresolvedMacro { .. }) => (),
                    }
                }
            }
@@ -943,10 +943,11 @@ impl DefCollector<'_> {
                    &mut |_| (),
                ) {
                    Ok(_) => (),
-                    Err(UnresolvedMacro) => {
+                    Err(UnresolvedMacro { path }) => {
                        self.def_map.diagnostics.push(DefDiagnostic::unresolved_macro_call(
                            directive.module_id,
                            ast_id.ast_id,
+                            path,
                        ));
                    }
                },
@@ -1530,7 +1531,7 @@ impl ModCollector<'_, '_> {
                ));
                return;
            }
-            Err(UnresolvedMacro) => (),
+            Err(UnresolvedMacro { .. }) => (),
        }
        // Case 2: resolve in module scope, expand during name resolution.
diff --git a/crates/hir_def/src/nameres/path_resolution.rs b/crates/hir_def/src/nameres/path_resolution.rs
index ccc9f22eb..c984148c3 100644
--- a/crates/hir_def/src/nameres/path_resolution.rs
+++ b/crates/hir_def/src/nameres/path_resolution.rs
@@ -387,7 +387,13 @@ impl DefMap {
            .get_legacy_macro(name)
            .map_or_else(PerNs::none, |m| PerNs::macros(m, Visibility::Public));
        let from_scope = self[module].scope.get(name);
-        let from_builtin = BUILTIN_SCOPE.get(name).copied().unwrap_or_else(PerNs::none);
+        let from_builtin = match self.block {
+            Some(_) => {
+                // Only resolve to builtins in the root `DefMap`.
+                PerNs::none()
+            }
+            None => BUILTIN_SCOPE.get(name).copied().unwrap_or_else(PerNs::none),
+        };
        let from_scope_or_builtin = match shadow {
            BuiltinShadowMode::Module => from_scope.or(from_builtin),
            BuiltinShadowMode::Other => {
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
index 1ac88fc89..543975e07 100644
--- a/crates/hir_def/src/nameres/tests/diagnostics.rs
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -170,7 +170,7 @@ fn unresolved_legacy_scope_macro() {
          m!();
          m2!();
-        //^^^^^^ unresolved macro call
+        //^^^^^^ unresolved macro `self::m2!`
        "#,
    );
 }
@@ -187,7 +187,7 @@ fn unresolved_module_scope_macro() {
          self::m!();
          self::m2!();
-        //^^^^^^^^^^^^ unresolved macro call
+        //^^^^^^^^^^^^ unresolved macro `self::m2!`
        "#,
    );
 }
diff --git a/crates/hir_def/src/path.rs b/crates/hir_def/src/path.rs
index b528ff8ba..509f77850 100644
--- a/crates/hir_def/src/path.rs
+++ b/crates/hir_def/src/path.rs
@@ -48,7 +48,8 @@ pub enum ImportAlias {
 impl ModPath {
    pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<ModPath> {
-        lower::lower_path(path, hygiene).map(|it| (*it.mod_path).clone())
+        let ctx = LowerCtx::with_hygiene(hygiene);
+        lower::lower_path(path, &ctx).map(|it| (*it.mod_path).clone())
    }
    pub fn from_segments(kind: PathKind, segments: impl IntoIterator<Item = Name>) -> ModPath {
@@ -167,8 +168,8 @@ pub enum GenericArg {
 impl Path {
    /// Converts an `ast::Path` to `Path`. Works with use trees.
    /// It correctly handles `$crate` based path from macro call.
-    pub fn from_src(path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
+    pub fn from_src(path: ast::Path, ctx: &LowerCtx) -> Option<Path> {
-        lower::lower_path(path, hygiene)
+        lower::lower_path(path, ctx)
    }
    /// Converts a known mod path to `Path`.
diff --git a/crates/hir_def/src/path/lower.rs b/crates/hir_def/src/path/lower.rs
index 7b29d9d4f..1df6db525 100644
--- a/crates/hir_def/src/path/lower.rs
+++ b/crates/hir_def/src/path/lower.rs
@@ -6,10 +6,7 @@ use crate::intern::Interned;
 use std::sync::Arc;
 use either::Either;
-use hir_expand::{
+use hir_expand::name::{name, AsName};
-    hygiene::Hygiene,
-    name::{name, AsName},
-};
 use syntax::ast::{self, AstNode, TypeBoundsOwner};
 use super::AssociatedTypeBinding;
@@ -23,12 +20,12 @@ pub(super) use lower_use::lower_use_tree;
 /// Converts an `ast::Path` to `Path`. Works with use trees.
 /// It correctly handles `$crate` based path from macro call.
-pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path> {
+pub(super) fn lower_path(mut path: ast::Path, ctx: &LowerCtx) -> Option<Path> {
    let mut kind = PathKind::Plain;
    let mut type_anchor = None;
    let mut segments = Vec::new();
    let mut generic_args = Vec::new();
-    let ctx = LowerCtx::with_hygiene(hygiene);
+    let hygiene = ctx.hygiene();
    loop {
        let segment = path.segment()?;
@@ -43,10 +40,10 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
                    Either::Left(name) => {
                        let args = segment
                            .generic_arg_list()
-                            .and_then(|it| lower_generic_args(&ctx, it))
+                            .and_then(|it| lower_generic_args(ctx, it))
                            .or_else(|| {
                                lower_generic_args_from_fn_path(
-                                    &ctx,
+                                    ctx,
                                    segment.param_list(),
                                    segment.ret_type(),
                                )
@@ -64,7 +61,7 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
            ast::PathSegmentKind::Type { type_ref, trait_ref } => {
                assert!(path.qualifier().is_none()); // this can only occur at the first segment
-                let self_type = TypeRef::from_ast(&ctx, type_ref?);
+                let self_type = TypeRef::from_ast(ctx, type_ref?);
                match trait_ref {
                    // <T>::foo
@@ -74,7 +71,7 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
                    }
                    // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
                    Some(trait_ref) => {
-                        let path = Path::from_src(trait_ref.path()?, hygiene)?;
+                        let path = Path::from_src(trait_ref.path()?, ctx)?;
                        let mod_path = (*path.mod_path).clone();
                        let num_segments = path.mod_path.segments.len();
                        kind = mod_path.kind;
diff --git a/crates/hir_def/src/test_db.rs b/crates/hir_def/src/test_db.rs
index dd36106f8..8fa703a57 100644
--- a/crates/hir_def/src/test_db.rs
+++ b/crates/hir_def/src/test_db.rs
@@ -15,7 +15,12 @@ use rustc_hash::FxHashSet;
 use syntax::{algo, ast, AstNode, TextRange, TextSize};
 use test_utils::extract_annotations;
-use crate::{db::DefDatabase, nameres::DefMap, src::HasSource, Lookup, ModuleDefId, ModuleId};
+use crate::{
+    db::DefDatabase,
+    nameres::{DefMap, ModuleSource},
+    src::HasSource,
+    LocalModuleId, Lookup, ModuleDefId, ModuleId,
+};
 #[salsa::database(
    base_db::SourceDatabaseExtStorage,
@@ -87,10 +92,11 @@ impl TestDB {
    pub(crate) fn module_at_position(&self, position: FilePosition) -> ModuleId {
        let file_module = self.module_for_file(position.file_id);
        let mut def_map = file_module.def_map(self);
+        let module = self.mod_at_position(&def_map, position);
        def_map = match self.block_at_position(&def_map, position) {
            Some(it) => it,
-            None => return file_module,
+            None => return def_map.module_id(module),
        };
        loop {
            let new_map = self.block_at_position(&def_map, position);
@@ -106,6 +112,47 @@ impl TestDB {
        }
    }
+    /// Finds the smallest/innermost module in `def_map` containing `position`.
+    fn mod_at_position(&self, def_map: &DefMap, position: FilePosition) -> LocalModuleId {
+        let mut size = None;
+        let mut res = def_map.root();
+        for (module, data) in def_map.modules() {
+            let src = data.definition_source(self);
+            if src.file_id != position.file_id.into() {
+                continue;
+            }
+            let range = match src.value {
+                ModuleSource::SourceFile(it) => it.syntax().text_range(),
+                ModuleSource::Module(it) => it.syntax().text_range(),
+                ModuleSource::BlockExpr(it) => it.syntax().text_range(),
+            };
+            if !range.contains(position.offset) {
+                continue;
+            }
+            let new_size = match size {
+                None => range.len(),
+                Some(size) => {
+                    if range.len() < size {
+                        range.len()
+                    } else {
+                        size
+                    }
+                }
+            };
+            if size != Some(new_size) {
+                cov_mark::hit!(submodule_in_testdb);
+                size = Some(new_size);
+                res = module;
+            }
+        }
+        res
+    }
    fn block_at_position(&self, def_map: &DefMap, position: FilePosition) -> Option<Arc<DefMap>> {
        // Find the smallest (innermost) function in `def_map` containing the cursor.
        let mut size = None;
diff --git a/crates/hir_def/src/type_ref.rs b/crates/hir_def/src/type_ref.rs
index 4c24aae94..ea29da5da 100644
--- a/crates/hir_def/src/type_ref.rs
+++ b/crates/hir_def/src/type_ref.rs
@@ -1,6 +1,7 @@
 //! HIR for references to types. Paths in these are not yet resolved. They can
 //! be directly created from an ast::TypeRef, without further queries.
-use hir_expand::name::Name;
+use hir_expand::{name::Name, AstId, InFile};
 use syntax::ast;
 use crate::{body::LowerCtx, path::Path};
@@ -68,6 +69,7 @@ impl TraitRef {
        }
    }
 }
 /// Compare ty::Ty
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum TypeRef {
@@ -84,6 +86,7 @@ pub enum TypeRef {
    // For
    ImplTrait(Vec<TypeBound>),
    DynTrait(Vec<TypeBound>),
+    Macro(AstId<ast::MacroCall>),
    Error,
 }
@@ -116,7 +119,7 @@ pub enum TypeBound {
 impl TypeRef {
    /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
-    pub(crate) fn from_ast(ctx: &LowerCtx, node: ast::Type) -> Self {
+    pub fn from_ast(ctx: &LowerCtx, node: ast::Type) -> Self {
        match node {
            ast::Type::ParenType(inner) => TypeRef::from_ast_opt(&ctx, inner.ty()),
            ast::Type::TupleType(inner) => {
@@ -176,8 +179,13 @@ impl TypeRef {
            ast::Type::DynTraitType(inner) => {
                TypeRef::DynTrait(type_bounds_from_ast(ctx, inner.type_bound_list()))
            }
-            // FIXME: Macros in type position are not yet supported.
+            ast::Type::MacroType(mt) => match mt.macro_call() {
-            ast::Type::MacroType(_) => TypeRef::Error,
+                Some(mc) => ctx
+                    .ast_id(&mc)
+                    .map(|mc| TypeRef::Macro(InFile::new(ctx.file_id(), mc)))
+                    .unwrap_or(TypeRef::Error),
+                None => TypeRef::Error,
+            },
        }
    }
@@ -215,7 +223,7 @@ impl TypeRef {
                    }
                }
                TypeRef::Path(path) => go_path(path, f),
-                TypeRef::Never | TypeRef::Placeholder | TypeRef::Error => {}
+                TypeRef::Never | TypeRef::Placeholder | TypeRef::Macro(_) | TypeRef::Error => {}
            };
        }
diff --git a/crates/hir_def/src/visibility.rs b/crates/hir_def/src/visibility.rs
index 9908cd926..d4b7c9970 100644
--- a/crates/hir_def/src/visibility.rs
+++ b/crates/hir_def/src/visibility.rs
@@ -123,11 +123,19 @@ impl Visibility {
        def_map: &DefMap,
        mut from_module: crate::LocalModuleId,
    ) -> bool {
-        let to_module = match self {
+        let mut to_module = match self {
            Visibility::Module(m) => m,
            Visibility::Public => return true,
        };
+        // `to_module` might be the root module of a block expression. Those have the same
+        // visibility as the containing module (even though no items are directly nameable from
+        // there, getting this right is important for method resolution).
+        // In that case, we adjust the visibility of `to_module` to point to the containing module.
+        if to_module.is_block_root(db) {
+            to_module = to_module.containing_module(db).unwrap();
+        }
        // from_module needs to be a descendant of to_module
        let mut def_map = def_map;
        let mut parent_arc;
diff --git a/crates/hir_expand/src/builtin_macro.rs b/crates/hir_expand/src/builtin_macro.rs
index 80365fc16..179de61f9 100644
--- a/crates/hir_expand/src/builtin_macro.rs
+++ b/crates/hir_expand/src/builtin_macro.rs
@@ -110,6 +110,7 @@ register_builtin! {
    (format_args_nl, FormatArgsNl) => format_args_expand,
    (llvm_asm, LlvmAsm) => asm_expand,
    (asm, Asm) => asm_expand,
+    (global_asm, GlobalAsm) => global_asm_expand,
    (cfg, Cfg) => cfg_expand,
    (core_panic, CorePanic) => panic_expand,
    (std_panic, StdPanic) => panic_expand,
@@ -274,6 +275,15 @@ fn asm_expand(
    ExpandResult::ok(expanded)
 }
+fn global_asm_expand(
+    _db: &dyn AstDatabase,
+    _id: LazyMacroId,
+    _tt: &tt::Subtree,
+) -> ExpandResult<tt::Subtree> {
+    // Expand to nothing (at item-level)
+    ExpandResult::ok(quote! {})
+}
 fn cfg_expand(
    db: &dyn AstDatabase,
    id: LazyMacroId,
diff --git a/crates/hir_expand/src/db.rs b/crates/hir_expand/src/db.rs
index ca705ee9d..1e4b0cc19 100644
--- a/crates/hir_expand/src/db.rs
+++ b/crates/hir_expand/src/db.rs
@@ -440,6 +440,7 @@ fn to_fragment_kind(db: &dyn AstDatabase, id: MacroCallId) -> FragmentKind {
        MACRO_ITEMS | SOURCE_FILE => FragmentKind::Items,
        MACRO_STMTS => FragmentKind::Statements,
        MACRO_PAT => FragmentKind::Pattern,
+        MACRO_TYPE => FragmentKind::Type,
        ITEM_LIST => FragmentKind::Items,
        LET_STMT => {
            // FIXME: Handle LHS Pattern
diff --git a/crates/hir_expand/src/eager.rs b/crates/hir_expand/src/eager.rs
index ef126e4ad..a5ac32d3c 100644
--- a/crates/hir_expand/src/eager.rs
+++ b/crates/hir_expand/src/eager.rs
@@ -31,6 +31,7 @@ use parser::FragmentKind;
 use std::sync::Arc;
 use syntax::{algo::SyntaxRewriter, SyntaxNode};
+#[derive(Debug)]
 pub struct ErrorEmitted {
    _private: (),
 }
diff --git a/crates/hir_expand/src/name.rs b/crates/hir_expand/src/name.rs
index a0f8766b0..bcfd3e524 100644
--- a/crates/hir_expand/src/name.rs
+++ b/crates/hir_expand/src/name.rs
@@ -221,6 +221,7 @@ pub mod known {
        option_env,
        llvm_asm,
        asm,
+        global_asm,
        // Builtin derives
        Copy,
        Clone,
diff --git a/crates/hir_ty/src/autoderef.rs b/crates/hir_ty/src/autoderef.rs
index 71bc436e6..2c07494a9 100644
--- a/crates/hir_ty/src/autoderef.rs
+++ b/crates/hir_ty/src/autoderef.rs
@@ -36,6 +36,7 @@ pub(crate) fn deref(
    krate: CrateId,
    ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
+    let _p = profile::span("deref");
    if let Some(derefed) = builtin_deref(&ty.goal.value) {
        Some(Canonical { value: derefed, binders: ty.goal.binders.clone() })
    } else {
@@ -56,6 +57,7 @@ fn deref_by_trait(
    krate: CrateId,
    ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
+    let _p = profile::span("deref_by_trait");
    let deref_trait = match db.lang_item(krate, "deref".into())? {
        LangItemTarget::TraitId(it) => it,
        _ => return None,
diff --git a/crates/hir_ty/src/db.rs b/crates/hir_ty/src/db.rs
index 1690926ad..cf67d4266 100644
--- a/crates/hir_ty/src/db.rs
+++ b/crates/hir_ty/src/db.rs
@@ -128,13 +128,21 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
        id: chalk_db::AssociatedTyValueId,
    ) -> Arc<chalk_db::AssociatedTyValue>;
-    #[salsa::invoke(crate::traits::trait_solve_query)]
+    #[salsa::invoke(trait_solve_wait)]
+    #[salsa::transparent]
    fn trait_solve(
        &self,
        krate: CrateId,
        goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
    ) -> Option<crate::Solution>;
+    #[salsa::invoke(crate::traits::trait_solve_query)]
+    fn trait_solve_query(
+        &self,
+        krate: CrateId,
+        goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
+    ) -> Option<crate::Solution>;
    #[salsa::invoke(chalk_db::program_clauses_for_chalk_env_query)]
    fn program_clauses_for_chalk_env(
        &self,
@@ -156,6 +164,15 @@ fn infer_wait(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult>
    db.infer_query(def)
 }
+fn trait_solve_wait(
+    db: &dyn HirDatabase,
+    krate: CrateId,
+    goal: crate::Canonical<crate::InEnvironment<crate::DomainGoal>>,
+) -> Option<crate::Solution> {
+    let _p = profile::span("trait_solve::wait");
+    db.trait_solve_query(krate, goal)
+}
 #[test]
 fn hir_database_is_object_safe() {
    fn _assert_object_safe(_: &dyn HirDatabase) {}
diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index 1c9f9ede7..075dc4131 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -35,6 +35,8 @@ use crate::{
 };
 mod allow {
+    pub(super) const BAD_STYLE: &str = "bad_style";
+    pub(super) const NONSTANDARD_STYLE: &str = "nonstandard_style";
    pub(super) const NON_SNAKE_CASE: &str = "non_snake_case";
    pub(super) const NON_UPPER_CASE_GLOBAL: &str = "non_upper_case_globals";
    pub(super) const NON_CAMEL_CASE_TYPES: &str = "non_camel_case_types";
@@ -83,10 +85,39 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
    }
    /// Checks whether not following the convention is allowed for this item.
-    ///
+    fn allowed(&self, id: AttrDefId, allow_name: &str, recursing: bool) -> bool {
-    /// Currently this method doesn't check parent attributes.
+        let is_allowed = |def_id| {
-    fn allowed(&self, id: AttrDefId, allow_name: &str) -> bool {
+            let attrs = self.db.attrs(def_id);
-        self.db.attrs(id).by_key("allow").tt_values().any(|tt| tt.to_string().contains(allow_name))
+            // don't bug the user about directly no_mangle annotated stuff, they can't do anything about it
+            (!recursing && attrs.by_key("no_mangle").exists())
+                || attrs.by_key("allow").tt_values().any(|tt| {
+                    let allows = tt.to_string();
+                    allows.contains(allow_name)
+                        || allows.contains(allow::BAD_STYLE)
+                        || allows.contains(allow::NONSTANDARD_STYLE)
+                })
+        };
+        is_allowed(id)
+            // go upwards one step or give up
+            || match id {
+                AttrDefId::ModuleId(m) => m.containing_module(self.db.upcast()).map(|v| v.into()),
+                AttrDefId::FunctionId(f) => Some(f.lookup(self.db.upcast()).container.into()),
+                AttrDefId::StaticId(sid) => Some(sid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::ConstId(cid) => Some(cid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::TraitId(tid) => Some(tid.lookup(self.db.upcast()).container.into()),
+                AttrDefId::ImplId(iid) => Some(iid.lookup(self.db.upcast()).container.into()),
+                // These warnings should not explore macro definitions at all
+                AttrDefId::MacroDefId(_) => None,
+                // Will never occur under an enum/struct/union/type alias
+                AttrDefId::AdtId(_) => None,
+                AttrDefId::FieldId(_) => None,
+                AttrDefId::EnumVariantId(_) => None,
+                AttrDefId::TypeAliasId(_) => None,
+                AttrDefId::GenericParamId(_) => None,
+            }
+            .map(|mid| self.allowed(mid, allow_name, true))
+            .unwrap_or(false)
    }
    fn validate_func(&mut self, func: FunctionId) {
@@ -109,7 +140,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
        }
        // Check whether non-snake case identifiers are allowed for this function.
-        if self.allowed(func.into(), allow::NON_SNAKE_CASE) {
+        if self.allowed(func.into(), allow::NON_SNAKE_CASE, false) {
            return;
        }
@@ -328,8 +359,9 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
    fn validate_struct(&mut self, struct_id: StructId) {
        let data = self.db.struct_data(struct_id);
-        let non_camel_case_allowed = self.allowed(struct_id.into(), allow::NON_CAMEL_CASE_TYPES);
+        let non_camel_case_allowed =
-        let non_snake_case_allowed = self.allowed(struct_id.into(), allow::NON_SNAKE_CASE);
+            self.allowed(struct_id.into(), allow::NON_CAMEL_CASE_TYPES, false);
+        let non_snake_case_allowed = self.allowed(struct_id.into(), allow::NON_SNAKE_CASE, false);
        // Check the structure name.
        let struct_name = data.name.to_string();
@@ -461,7 +493,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
        let data = self.db.enum_data(enum_id);
        // Check whether non-camel case names are allowed for this enum.
-        if self.allowed(enum_id.into(), allow::NON_CAMEL_CASE_TYPES) {
+        if self.allowed(enum_id.into(), allow::NON_CAMEL_CASE_TYPES, false) {
            return;
        }
@@ -584,7 +616,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
    fn validate_const(&mut self, const_id: ConstId) {
        let data = self.db.const_data(const_id);
-        if self.allowed(const_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+        if self.allowed(const_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
            return;
        }
@@ -632,7 +664,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
            return;
        }
-        if self.allowed(static_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+        if self.allowed(static_id.into(), allow::NON_UPPER_CASE_GLOBAL, false) {
            return;
        }
@@ -867,23 +899,116 @@ fn main() {
    fn allow_attributes() {
        check_diagnostics(
            r#"
-            #[allow(non_snake_case)]
+#[allow(non_snake_case)]
-    fn NonSnakeCaseName(SOME_VAR: u8) -> u8{
+fn NonSnakeCaseName(SOME_VAR: u8) -> u8{
-        let OtherVar = SOME_VAR + 1;
+    // cov_flags generated output from elsewhere in this file
-        OtherVar
+    extern "C" {
+        #[no_mangle]
+        static lower_case: u8;
    }
-    #[allow(non_snake_case, non_camel_case_types)]
+    let OtherVar = SOME_VAR + 1;
-    pub struct some_type {
+    OtherVar
-        SOME_FIELD: u8,
+}
-        SomeField: u16,
+#[allow(nonstandard_style)]
+mod CheckNonstandardStyle {
+    fn HiImABadFnName() {}
+}
+#[allow(bad_style)]
+mod CheckBadStyle {
+    fn HiImABadFnName() {}
+}
+mod F {
+    #![allow(non_snake_case)]
+    fn CheckItWorksWithModAttr(BAD_NAME_HI: u8) {}
+}
+#[allow(non_snake_case, non_camel_case_types)]
+pub struct some_type {
+    SOME_FIELD: u8,
+    SomeField: u16,
+}
+#[allow(non_upper_case_globals)]
+pub const some_const: u8 = 10;
+#[allow(non_upper_case_globals)]
+pub static SomeStatic: u8 = 10;
+    "#,
+        );
    }
-    #[allow(non_upper_case_globals)]
+    #[test]
-    pub const some_const: u8 = 10;
+    fn allow_attributes_crate_attr() {
+        check_diagnostics(
+            r#"
+#![allow(non_snake_case)]
-    #[allow(non_upper_case_globals)]
+mod F {
-    pub static SomeStatic: u8 = 10;
+    fn CheckItWorksWithCrateAttr(BAD_NAME_HI: u8) {}
+}
+    "#,
+        );
+    }
+    #[test]
+    #[ignore]
+    fn bug_trait_inside_fn() {
+        // FIXME:
+        // This is broken, and in fact, should not even be looked at by this
+        // lint in the first place. There's weird stuff going on in the
+        // collection phase.
+        // It's currently being brought in by:
+        // * validate_func on `a` recursing into modules
+        // * then it finds the trait and then the function while iterating
+        //   through modules
+        // * then validate_func is called on Dirty
+        // * ... which then proceeds to look at some unknown module taking no
+        //   attrs from either the impl or the fn a, and then finally to the root
+        //   module
+        //
+        // It should find the attribute on the trait, but it *doesn't even see
+        // the trait* as far as I can tell.
+        check_diagnostics(
+            r#"
+trait T { fn a(); }
+struct U {}
+impl T for U {
+    fn a() {
+        // this comes out of bitflags, mostly
+        #[allow(non_snake_case)]
+        trait __BitFlags {
+            const HiImAlsoBad: u8 = 2;
+            #[inline]
+            fn Dirty(&self) -> bool {
+                false
+            }
+        }
+    }
+}
+    "#,
+        );
+    }
+    #[test]
+    #[ignore]
+    fn bug_traits_arent_checked() {
+        // FIXME: Traits and functions in traits aren't currently checked by
+        // r-a, even though rustc will complain about them.
+        check_diagnostics(
+            r#"
+trait BAD_TRAIT {
+    // ^^^^^^^^^ Trait `BAD_TRAIT` should have CamelCase name, e.g. `BadTrait`
+    fn BAD_FUNCTION();
+    // ^^^^^^^^^^^^ Function `BAD_FUNCTION` should have snake_case name, e.g. `bad_function`
+    fn BadFunction();
+    // ^^^^^^^^^^^^ Function `BadFunction` should have snake_case name, e.g. `bad_function`
+}
    "#,
        );
    }
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index e7c9dabc2..4fb7d9cf2 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -9,6 +9,7 @@ use std::{
 use chalk_ir::BoundVar;
 use hir_def::{
+    body,
    db::DefDatabase,
    find_path,
    generics::TypeParamProvenance,
@@ -18,7 +19,7 @@ use hir_def::{
    visibility::Visibility,
    AssocContainerId, Lookup, ModuleId, TraitId,
 };
-use hir_expand::name::Name;
+use hir_expand::{hygiene::Hygiene, name::Name};
 use crate::{
    const_from_placeholder_idx, db::HirDatabase, from_assoc_type_id, from_foreign_def_id,
@@ -997,6 +998,18 @@ impl HirDisplay for TypeRef {
                write!(f, "dyn ")?;
                f.write_joined(bounds, " + ")?;
            }
+            TypeRef::Macro(macro_call) => {
+                let macro_call = macro_call.to_node(f.db.upcast());
+                let ctx = body::LowerCtx::with_hygiene(&Hygiene::new_unhygienic());
+                match macro_call.path() {
+                    Some(path) => match Path::from_src(path, &ctx) {
+                        Some(path) => path.hir_fmt(f)?,
+                        None => write!(f, "{{macro}}")?,
+                    },
+                    None => write!(f, "{{macro}}")?,
+                }
+                write!(f, "!(..)")?;
+            }
            TypeRef::Error => write!(f, "{{error}}")?,
        }
        Ok(())
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 113234fa4..0505fa4ae 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -56,6 +56,7 @@ pub use mapping::{
    to_foreign_def_id, to_placeholder_idx,
 };
 pub use traits::TraitEnvironment;
+pub use utils::all_super_traits;
 pub use walk::TypeWalk;
 pub use chalk_ir::{
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index a035686bc..7fd46becd 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -5,12 +5,14 @@
 //!  - Building the type for an item: This happens through the `type_for_def` query.
 //!
 //! This usually involves resolving names, collecting generic arguments etc.
+use std::cell::{Cell, RefCell};
 use std::{iter, sync::Arc};
 use base_db::CrateId;
 use chalk_ir::{cast::Cast, fold::Shift, interner::HasInterner, Mutability, Safety};
 use hir_def::{
    adt::StructKind,
+    body::{Expander, LowerCtx},
    builtin_type::BuiltinType,
    generics::{TypeParamProvenance, WherePredicate, WherePredicateTypeTarget},
    path::{GenericArg, Path, PathSegment, PathSegments},
@@ -20,10 +22,11 @@ use hir_def::{
    GenericDefId, HasModule, ImplId, LocalFieldId, Lookup, StaticId, StructId, TraitId,
    TypeAliasId, TypeParamId, UnionId, VariantId,
 };
-use hir_expand::name::Name;
+use hir_expand::{name::Name, ExpandResult};
 use la_arena::ArenaMap;
 use smallvec::SmallVec;
 use stdx::impl_from;
+use syntax::ast;
 use crate::{
    db::HirDatabase,
@@ -50,7 +53,7 @@ pub struct TyLoweringContext<'a> {
    /// possible currently, so this should be fine for now.
    pub type_param_mode: TypeParamLoweringMode,
    pub impl_trait_mode: ImplTraitLoweringMode,
-    impl_trait_counter: std::cell::Cell<u16>,
+    impl_trait_counter: Cell<u16>,
    /// When turning `impl Trait` into opaque types, we have to collect the
    /// bounds at the same time to get the IDs correct (without becoming too
    /// complicated). I don't like using interior mutability (as for the
@@ -59,16 +62,17 @@ pub struct TyLoweringContext<'a> {
    /// we're grouping the mutable data (the counter and this field) together
    /// with the immutable context (the references to the DB and resolver).
    /// Splitting this up would be a possible fix.
-    opaque_type_data: std::cell::RefCell<Vec<ReturnTypeImplTrait>>,
+    opaque_type_data: RefCell<Vec<ReturnTypeImplTrait>>,
+    expander: RefCell<Option<Expander>>,
 }
 impl<'a> TyLoweringContext<'a> {
    pub fn new(db: &'a dyn HirDatabase, resolver: &'a Resolver) -> Self {
-        let impl_trait_counter = std::cell::Cell::new(0);
+        let impl_trait_counter = Cell::new(0);
        let impl_trait_mode = ImplTraitLoweringMode::Disallowed;
        let type_param_mode = TypeParamLoweringMode::Placeholder;
        let in_binders = DebruijnIndex::INNERMOST;
-        let opaque_type_data = std::cell::RefCell::new(Vec::new());
+        let opaque_type_data = RefCell::new(Vec::new());
        Self {
            db,
            resolver,
@@ -77,6 +81,7 @@ impl<'a> TyLoweringContext<'a> {
            impl_trait_counter,
            type_param_mode,
            opaque_type_data,
+            expander: RefCell::new(None),
        }
    }
@@ -86,15 +91,18 @@ impl<'a> TyLoweringContext<'a> {
        f: impl FnOnce(&TyLoweringContext) -> T,
    ) -> T {
        let opaque_ty_data_vec = self.opaque_type_data.replace(Vec::new());
+        let expander = self.expander.replace(None);
        let new_ctx = Self {
            in_binders: debruijn,
-            impl_trait_counter: std::cell::Cell::new(self.impl_trait_counter.get()),
+            impl_trait_counter: Cell::new(self.impl_trait_counter.get()),
-            opaque_type_data: std::cell::RefCell::new(opaque_ty_data_vec),
+            opaque_type_data: RefCell::new(opaque_ty_data_vec),
+            expander: RefCell::new(expander),
            ..*self
        };
        let result = f(&new_ctx);
        self.impl_trait_counter.set(new_ctx.impl_trait_counter.get());
        self.opaque_type_data.replace(new_ctx.opaque_type_data.into_inner());
+        self.expander.replace(new_ctx.expander.into_inner());
        result
    }
@@ -287,6 +295,53 @@ impl<'a> TyLoweringContext<'a> {
                    }
                }
            }
+            TypeRef::Macro(macro_call) => {
+                let (expander, recursion_start) = {
+                    let mut expander = self.expander.borrow_mut();
+                    if expander.is_some() {
+                        (Some(expander), false)
+                    } else {
+                        if let Some(module_id) = self.resolver.module() {
+                            *expander = Some(Expander::new(
+                                self.db.upcast(),
+                                macro_call.file_id,
+                                module_id,
+                            ));
+                            (Some(expander), true)
+                        } else {
+                            (None, false)
+                        }
+                    }
+                };
+                let ty = if let Some(mut expander) = expander {
+                    let expander_mut = expander.as_mut().unwrap();
+                    let macro_call = macro_call.to_node(self.db.upcast());
+                    match expander_mut.enter_expand::<ast::Type>(self.db.upcast(), macro_call) {
+                        Ok(ExpandResult { value: Some((mark, expanded)), .. }) => {
+                            let ctx =
+                                LowerCtx::new(self.db.upcast(), expander_mut.current_file_id());
+                            let type_ref = TypeRef::from_ast(&ctx, expanded);
+                            drop(expander);
+                            let ty = self.lower_ty(&type_ref);
+                            self.expander
+                                .borrow_mut()
+                                .as_mut()
+                                .unwrap()
+                                .exit(self.db.upcast(), mark);
+                            Some(ty)
+                        }
+                        _ => None,
+                    }
+                } else {
+                    None
+                };
+                if recursion_start {
+                    *self.expander.borrow_mut() = None;
+                }
+                ty.unwrap_or_else(|| TyKind::Error.intern(&Interner))
+            }
            TypeRef::Error => TyKind::Error.intern(&Interner),
        };
        (ty, res)
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 3693e3284..48bbcfd9f 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -246,29 +246,39 @@ pub struct InherentImpls {
 impl InherentImpls {
    pub(crate) fn inherent_impls_in_crate_query(db: &dyn HirDatabase, krate: CrateId) -> Arc<Self> {
-        let mut map: FxHashMap<_, Vec<_>> = FxHashMap::default();
+        let mut impls = Self { map: FxHashMap::default() };
        let crate_def_map = db.crate_def_map(krate);
-        for (_module_id, module_data) in crate_def_map.modules() {
+        collect_def_map(db, &crate_def_map, &mut impls);
-            for impl_id in module_data.scope.impls() {
-                let data = db.impl_data(impl_id);
+        return Arc::new(impls);
-                if data.target_trait.is_some() {
-                    continue;
+        fn collect_def_map(db: &dyn HirDatabase, def_map: &DefMap, impls: &mut InherentImpls) {
+            for (_module_id, module_data) in def_map.modules() {
+                for impl_id in module_data.scope.impls() {
+                    let data = db.impl_data(impl_id);
+                    if data.target_trait.is_some() {
+                        continue;
+                    }
+                    let self_ty = db.impl_self_ty(impl_id);
+                    let fp = TyFingerprint::for_inherent_impl(self_ty.skip_binders());
+                    if let Some(fp) = fp {
+                        impls.map.entry(fp).or_default().push(impl_id);
+                    }
+                    // `fp` should only be `None` in error cases (either erroneous code or incomplete name resolution)
                }
-                let self_ty = db.impl_self_ty(impl_id);
+                // To better support custom derives, collect impls in all unnamed const items.
-                let fp = TyFingerprint::for_inherent_impl(self_ty.skip_binders());
+                // const _: () = { ... };
-                if let Some(fp) = fp {
+                for konst in module_data.scope.unnamed_consts() {
-                    map.entry(fp).or_default().push(impl_id);
+                    let body = db.body(konst.into());
+                    for (_, block_def_map) in body.blocks(db.upcast()) {
+                        collect_def_map(db, &block_def_map, impls);
+                    }
                }
-                // `fp` should only be `None` in error cases (either erroneous code or incomplete name resolution)
            }
        }
-        // NOTE: We're not collecting inherent impls from unnamed consts here, we intentionally only
-        // support trait impls there.
-        Arc::new(Self { map })
    }
    pub fn for_self_ty(&self, self_ty: &Ty) -> &[ImplId] {
diff --git a/crates/hir_ty/src/tests/macros.rs b/crates/hir_ty/src/tests/macros.rs
index b8e373ed8..6588aa46c 100644
--- a/crates/hir_ty/src/tests/macros.rs
+++ b/crates/hir_ty/src/tests/macros.rs
@@ -1074,3 +1074,202 @@ fn macro_in_arm() {
        "#]],
    );
 }
+#[test]
+fn macro_in_type_alias_position() {
+    check_infer(
+        r#"
+        macro_rules! U32 {
+            () => { u32 };
+        }
+        trait Foo {
+            type Ty;
+        }
+        impl<T> Foo for T {
+            type Ty = U32!();
+        }
+        type TayTo = U32!();
+        fn testy() {
+            let a: <() as Foo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            147..196 '{     ...yTo; }': ()
+            157..158 'a': u32
+            185..186 'b': u32
+        "#]],
+    );
+}
+#[test]
+fn nested_macro_in_type_alias_position() {
+    check_infer(
+        r#"
+        macro_rules! U32Inner2 {
+            () => { u32 };
+        }
+        macro_rules! U32Inner1 {
+            () => { U32Inner2!() };
+        }
+        macro_rules! U32 {
+            () => { U32Inner1!() };
+        }
+        trait Foo {
+            type Ty;
+        }
+        impl<T> Foo for T {
+            type Ty = U32!();
+        }
+        type TayTo = U32!();
+        fn testy() {
+            let a: <() as Foo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            259..308 '{     ...yTo; }': ()
+            269..270 'a': u32
+            297..298 'b': u32
+        "#]],
+    );
+}
+#[test]
+fn macros_in_type_alias_position_generics() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+        macro_rules! U32 {
+            () => { u32 };
+        }
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+        trait Moo {
+            type Ty;
+        }
+        impl<T> Moo for T {
+            type Ty = Bar!();
+        }
+        type TayTo = Bar!();
+        fn main() {
+            let a: <() as Moo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            228..277 '{     ...yTo; }': ()
+            238..239 'a': Foo<u32, u32>
+            266..267 'b': Foo<u32, u32>
+        "#]],
+    );
+}
+#[test]
+fn macros_in_type_position() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+        macro_rules! U32 {
+            () => { u32 };
+        }
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+        fn main() {
+            let a: Bar!();
+        }
+        "#,
+        expect![[r#"
+            133..155 '{     ...!(); }': ()
+            143..144 'a': Foo<u32, u32>
+        "#]],
+    );
+}
+#[test]
+fn macros_in_type_generics() {
+    check_infer(
+        r#"
+        struct Foo<A, B>(A, B);
+        macro_rules! U32 {
+            () => { u32 };
+        }
+        macro_rules! Bar {
+            () => { Foo<U32!(), U32!()> };
+        }
+        trait Moo {
+            type Ty;
+        }
+        impl<T> Moo for T {
+            type Ty = Foo<Bar!(), Bar!()>;
+        }
+        type TayTo = Foo<Bar!(), U32!()>;
+        fn main() {
+            let a: <() as Moo>::Ty;
+            let b: TayTo;
+        }
+        "#,
+        expect![[r#"
+            254..303 '{     ...yTo; }': ()
+            264..265 'a': Foo<Foo<u32, u32>, Foo<u32, u32>>
+            292..293 'b': Foo<Foo<u32, u32>, u32>
+        "#]],
+    );
+}
+#[test]
+fn infinitely_recursive_macro_type() {
+    check_infer(
+        r#"
+        struct Bar<T, X>(T, X);
+        macro_rules! Foo {
+            () => { Foo!() }
+        }
+        macro_rules! U32 {
+            () => { u32 }
+        }
+        type A = Foo!();
+        type B = Bar<Foo!(), U32!()>;
+        fn main() {
+            let a: A;
+            let b: B;
+        }
+        "#,
+        expect![[r#"
+            166..197 '{     ...: B; }': ()
+            176..177 'a': {unknown}
+            190..191 'b': Bar<{unknown}, u32>
+        "#]],
+    );
+}
diff --git a/crates/hir_ty/src/tests/method_resolution.rs b/crates/hir_ty/src/tests/method_resolution.rs
index 4b2c82b41..a4c132bc5 100644
--- a/crates/hir_ty/src/tests/method_resolution.rs
+++ b/crates/hir_ty/src/tests/method_resolution.rs
@@ -1294,7 +1294,7 @@ mod b {
 }
 #[test]
-fn impl_in_unnamed_const() {
+fn trait_impl_in_unnamed_const() {
    check_types(
        r#"
 struct S;
@@ -1314,3 +1314,38 @@ fn f() {
    "#,
    );
 }
+#[test]
+fn inherent_impl_in_unnamed_const() {
+    check_types(
+        r#"
+struct S;
+const _: () = {
+    impl S {
+        fn method(&self) -> u16 { 0 }
+        pub(super) fn super_method(&self) -> u16 { 0 }
+        pub(crate) fn crate_method(&self) -> u16 { 0 }
+        pub fn pub_method(&self) -> u16 { 0 }
+    }
+};
+fn f() {
+    S.method();
+  //^^^^^^^^^^ u16
+    S.super_method();
+  //^^^^^^^^^^^^^^^^ u16
+    S.crate_method();
+  //^^^^^^^^^^^^^^^^ u16
+    S.pub_method();
+  //^^^^^^^^^^^^^^ u16
+}
+    "#,
+    );
+}
diff --git a/crates/hir_ty/src/tests/simple.rs b/crates/hir_ty/src/tests/simple.rs
index 84c5c05fd..5948d0bc2 100644
--- a/crates/hir_ty/src/tests/simple.rs
+++ b/crates/hir_ty/src/tests/simple.rs
@@ -1765,6 +1765,24 @@ fn main() {
 }
 #[test]
+fn shadowing_primitive_with_inner_items() {
+    check_types(
+        r#"
+struct i32;
+struct Foo;
+impl i32 { fn foo(&self) -> Foo { Foo } }
+fn main() {
+    fn inner() {}
+    let x: i32 = i32;
+    x.foo();
+        //^ Foo
+}"#,
+    );
+}
+#[test]
 fn not_shadowing_primitive_by_module() {
    check_types(
        r#"
diff --git a/crates/hir_ty/src/utils.rs b/crates/hir_ty/src/utils.rs
index 5f6cb052a..2f04ee57a 100644
--- a/crates/hir_ty/src/utils.rs
+++ b/crates/hir_ty/src/utils.rs
@@ -78,7 +78,7 @@ fn direct_super_trait_refs(db: &dyn HirDatabase, trait_ref: &TraitRef) -> Vec<Tr
 /// Returns an iterator over the whole super trait hierarchy (including the
 /// trait itself).
-pub(super) fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
+pub fn all_super_traits(db: &dyn DefDatabase, trait_: TraitId) -> Vec<TraitId> {
    // we need to take care a bit here to avoid infinite loops in case of cycles
    // (i.e. if we have `trait A: B; trait B: A;`)
    let mut result = vec![trait_];
diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 4f0b4a62e..1c911a8b2 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -84,6 +84,7 @@ pub struct DiagnosticsConfig {
 pub(crate) fn diagnostics(
    db: &RootDatabase,
    config: &DiagnosticsConfig,
+    resolve: bool,
    file_id: FileId,
 ) -> Vec<Diagnostic> {
    let _p = profile::span("diagnostics");
@@ -107,25 +108,25 @@ pub(crate) fn diagnostics(
    let res = RefCell::new(res);
    let sink_builder = DiagnosticSinkBuilder::new()
        .on::<hir::diagnostics::UnresolvedModule, _>(|d| {
-            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::MissingFields, _>(|d| {
-            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::MissingOkOrSomeInTailExpr, _>(|d| {
-            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::NoSuchField, _>(|d| {
-            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::RemoveThisSemicolon, _>(|d| {
-            res.borrow_mut().push(diagnostic_with_fix(d, &sema));
+            res.borrow_mut().push(diagnostic_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::IncorrectCase, _>(|d| {
-            res.borrow_mut().push(warning_with_fix(d, &sema));
+            res.borrow_mut().push(warning_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::ReplaceFilterMapNextWithFindMap, _>(|d| {
-            res.borrow_mut().push(warning_with_fix(d, &sema));
+            res.borrow_mut().push(warning_with_fix(d, &sema, resolve));
        })
        .on::<hir::diagnostics::InactiveCode, _>(|d| {
            // If there's inactive code somewhere in a macro, don't propagate to the call-site.
@@ -152,7 +153,7 @@ pub(crate) fn diagnostics(
            // Override severity and mark as unused.
            res.borrow_mut().push(
                Diagnostic::hint(range, d.message())
-                    .with_fix(d.fix(&sema))
+                    .with_fix(d.fix(&sema, resolve))
                    .with_code(Some(d.code())),
            );
        })
@@ -208,15 +209,23 @@ pub(crate) fn diagnostics(
    res.into_inner()
 }
-fn diagnostic_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
+fn diagnostic_with_fix<D: DiagnosticWithFix>(
+    d: &D,
+    sema: &Semantics<RootDatabase>,
+    resolve: bool,
+) -> Diagnostic {
    Diagnostic::error(sema.diagnostics_display_range(d.display_source()).range, d.message())
-        .with_fix(d.fix(&sema))
+        .with_fix(d.fix(&sema, resolve))
        .with_code(Some(d.code()))
 }
-fn warning_with_fix<D: DiagnosticWithFix>(d: &D, sema: &Semantics<RootDatabase>) -> Diagnostic {
+fn warning_with_fix<D: DiagnosticWithFix>(
+    d: &D,
+    sema: &Semantics<RootDatabase>,
+    resolve: bool,
+) -> Diagnostic {
    Diagnostic::hint(sema.diagnostics_display_range(d.display_source()).range, d.message())
-        .with_fix(d.fix(&sema))
+        .with_fix(d.fix(&sema, resolve))
        .with_code(Some(d.code()))
 }
@@ -271,13 +280,19 @@ fn text_edit_for_remove_unnecessary_braces_with_self_in_use_statement(
 }
 fn fix(id: &'static str, label: &str, source_change: SourceChange, target: TextRange) -> Assist {
+    let mut res = unresolved_fix(id, label, target);
+    res.source_change = Some(source_change);
+    res
+}
+fn unresolved_fix(id: &'static str, label: &str, target: TextRange) -> Assist {
    assert!(!id.contains(' '));
    Assist {
        id: AssistId(id, AssistKind::QuickFix),
        label: Label::new(label),
        group: None,
        target,
-        source_change: Some(source_change),
+        source_change: None,
    }
 }
@@ -299,7 +314,7 @@ mod tests {
        let (analysis, file_position) = fixture::position(ra_fixture_before);
        let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), file_position.file_id)
+            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
            .unwrap()
            .pop()
            .unwrap();
@@ -328,7 +343,7 @@ mod tests {
    fn check_no_fix(ra_fixture: &str) {
        let (analysis, file_position) = fixture::position(ra_fixture);
        let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), file_position.file_id)
+            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
            .unwrap()
            .pop()
            .unwrap();
@@ -342,7 +357,7 @@ mod tests {
        let diagnostics = files
            .into_iter()
            .flat_map(|file_id| {
-                analysis.diagnostics(&DiagnosticsConfig::default(), file_id).unwrap()
+                analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap()
            })
            .collect::<Vec<_>>();
        assert_eq!(diagnostics.len(), 0, "unexpected diagnostics:\n{:#?}", diagnostics);
@@ -350,7 +365,8 @@ mod tests {
    fn check_expect(ra_fixture: &str, expect: Expect) {
        let (analysis, file_id) = fixture::file(ra_fixture);
-        let diagnostics = analysis.diagnostics(&DiagnosticsConfig::default(), file_id).unwrap();
+        let diagnostics =
+            analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap();
        expect.assert_debug_eq(&diagnostics)
    }
@@ -709,7 +725,7 @@ fn test_fn() {
            expect![[r#"
                [
                    Diagnostic {
-                        message: "unresolved macro call",
+                        message: "unresolved macro `foo::bar!`",
                        range: 5..8,
                        severity: Error,
                        fix: None,
@@ -895,10 +911,11 @@ struct Foo {
        let (analysis, file_id) = fixture::file(r#"mod foo;"#);
-        let diagnostics = analysis.diagnostics(&config, file_id).unwrap();
+        let diagnostics = analysis.diagnostics(&config, true, file_id).unwrap();
        assert!(diagnostics.is_empty());
-        let diagnostics = analysis.diagnostics(&DiagnosticsConfig::default(), file_id).unwrap();
+        let diagnostics =
+            analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap();
        assert!(!diagnostics.is_empty());
    }
@@ -1004,8 +1021,9 @@ impl TestStruct {
        let expected = r#"fn foo() {}"#;
        let (analysis, file_position) = fixture::position(input);
-        let diagnostics =
+        let diagnostics = analysis
-            analysis.diagnostics(&DiagnosticsConfig::default(), file_position.file_id).unwrap();
+            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
+            .unwrap();
        assert_eq!(diagnostics.len(), 1);
        check_fix(input, expected);
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index 69cf5288c..7be8b3459 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -20,17 +20,26 @@ use syntax::{
 };
 use text_edit::TextEdit;
-use crate::{diagnostics::fix, references::rename::rename_with_semantics, Assist, FilePosition};
+use crate::{
+    diagnostics::{fix, unresolved_fix},
+    references::rename::rename_with_semantics,
+    Assist, FilePosition,
+};
 /// A [Diagnostic] that potentially has a fix available.
 ///
 /// [Diagnostic]: hir::diagnostics::Diagnostic
 pub(crate) trait DiagnosticWithFix: Diagnostic {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist>;
+    /// `resolve` determines if the diagnostic should fill in the `edit` field
+    /// of the assist.
+    ///
+    /// If `resolve` is false, the edit will be computed later, on demand, and
+    /// can be omitted.
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist>;
 }
 impl DiagnosticWithFix for UnresolvedModule {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        let unresolved_module = self.decl.to_node(&root);
        Some(fix(
@@ -50,7 +59,7 @@ impl DiagnosticWithFix for UnresolvedModule {
 }
 impl DiagnosticWithFix for NoSuchField {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        missing_record_expr_field_fix(
            &sema,
@@ -61,7 +70,7 @@ impl DiagnosticWithFix for NoSuchField {
 }
 impl DiagnosticWithFix for MissingFields {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        // Note that although we could add a diagnostics to
        // fill the missing tuple field, e.g :
        // `struct A(usize);`
@@ -97,7 +106,7 @@ impl DiagnosticWithFix for MissingFields {
 }
 impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        let tail_expr = self.expr.to_node(&root);
        let tail_expr_range = tail_expr.syntax().text_range();
@@ -110,7 +119,7 @@ impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
 }
 impl DiagnosticWithFix for RemoveThisSemicolon {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        let semicolon = self
@@ -130,7 +139,7 @@ impl DiagnosticWithFix for RemoveThisSemicolon {
 }
 impl DiagnosticWithFix for IncorrectCase {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        let name_node = self.ident.to_node(&root);
@@ -138,16 +147,19 @@ impl DiagnosticWithFix for IncorrectCase {
        let frange = name_node.original_file_range(sema.db);
        let file_position = FilePosition { file_id: frange.file_id, offset: frange.range.start() };
-        let rename_changes =
-            rename_with_semantics(sema, file_position, &self.suggested_text).ok()?;
        let label = format!("Rename to {}", self.suggested_text);
-        Some(fix("change_case", &label, rename_changes, frange.range))
+        let mut res = unresolved_fix("change_case", &label, frange.range);
+        if resolve {
+            let source_change = rename_with_semantics(sema, file_position, &self.suggested_text);
+            res.source_change = Some(source_change.ok().unwrap_or_default());
+        }
+        Some(res)
    }
 }
 impl DiagnosticWithFix for ReplaceFilterMapNextWithFindMap {
-    fn fix(&self, sema: &Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        let root = sema.db.parse_or_expand(self.file)?;
        let next_expr = self.next_expr.to_node(&root);
        let next_call = ast::MethodCallExpr::cast(next_expr.syntax().clone())?;
diff --git a/crates/ide/src/diagnostics/unlinked_file.rs b/crates/ide/src/diagnostics/unlinked_file.rs
index 5482b7287..7d39f4fbe 100644
--- a/crates/ide/src/diagnostics/unlinked_file.rs
+++ b/crates/ide/src/diagnostics/unlinked_file.rs
@@ -50,7 +50,7 @@ impl Diagnostic for UnlinkedFile {
 }
 impl DiagnosticWithFix for UnlinkedFile {
-    fn fix(&self, sema: &hir::Semantics<RootDatabase>) -> Option<Assist> {
+    fn fix(&self, sema: &hir::Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
        // If there's an existing module that could add a `mod` item to include the unlinked file,
        // suggest that as a fix.
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index d057d5402..a04333e63 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -110,6 +110,13 @@ mod tests {
        assert_eq!(expected, FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() });
    }
+    fn check_unresolved(ra_fixture: &str) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let navs = analysis.goto_definition(position).unwrap().expect("no definition found").info;
+        assert!(navs.is_empty(), "didn't expect this to resolve anywhere: {:?}", navs)
+    }
    #[test]
    fn goto_def_for_extern_crate() {
        check(
@@ -927,17 +934,12 @@ fn f() -> impl Iterator<Item$0 = u8> {}
    }
    #[test]
-    #[should_panic = "unresolved reference"]
    fn unknown_assoc_ty() {
-        check(
+        check_unresolved(
            r#"
-trait Iterator {
+trait Iterator { type Item; }
-    type Item;
-       //^^^^
-}
 fn f() -> impl Iterator<Invalid$0 = u8> {}
-            "#,
+"#,
        )
    }
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 0615b26d3..99e45633e 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -82,7 +82,7 @@ pub use crate::{
    references::{rename::RenameError, ReferenceSearchResult},
    runnables::{Runnable, RunnableKind, TestId},
    syntax_highlighting::{
-        tags::{Highlight, HlMod, HlMods, HlPunct, HlTag},
+        tags::{Highlight, HlMod, HlMods, HlOperator, HlPunct, HlTag},
        HlRange,
    },
 };
@@ -244,6 +244,12 @@ impl Analysis {
        self.with_db(|db| db.parse(file_id).tree())
    }
+    /// Returns true if this file belongs to an immutable library.
+    pub fn is_library_file(&self, file_id: FileId) -> Cancelable<bool> {
+        use ide_db::base_db::SourceDatabaseExt;
+        self.with_db(|db| db.source_root(db.file_source_root(file_id)).is_library)
+    }
    /// Gets the file's `LineIndex`: data structure to convert between absolute
    /// offsets and line/column representation.
    pub fn file_line_index(&self, file_id: FileId) -> Cancelable<Arc<LineIndex>> {
@@ -526,9 +532,39 @@ impl Analysis {
    pub fn diagnostics(
        &self,
        config: &DiagnosticsConfig,
+        resolve: bool,
        file_id: FileId,
    ) -> Cancelable<Vec<Diagnostic>> {
-        self.with_db(|db| diagnostics::diagnostics(db, config, file_id))
+        self.with_db(|db| diagnostics::diagnostics(db, config, resolve, file_id))
+    }
+    /// Convenience function to return assists + quick fixes for diagnostics
+    pub fn assists_with_fixes(
+        &self,
+        assist_config: &AssistConfig,
+        diagnostics_config: &DiagnosticsConfig,
+        resolve: bool,
+        frange: FileRange,
+    ) -> Cancelable<Vec<Assist>> {
+        let include_fixes = match &assist_config.allowed {
+            Some(it) => it.iter().any(|&it| it == AssistKind::None || it == AssistKind::QuickFix),
+            None => true,
+        };
+        self.with_db(|db| {
+            let mut res = Assist::get(db, assist_config, resolve, frange);
+            ssr::add_ssr_assist(db, &mut res, resolve, frange);
+            if include_fixes {
+                res.extend(
+                    diagnostics::diagnostics(db, diagnostics_config, resolve, frange.file_id)
+                        .into_iter()
+                        .filter_map(|it| it.fix)
+                        .filter(|it| it.target.intersect(frange.range).is_some()),
+                );
+            }
+            res
+        })
    }
    /// Returns the edit required to rename reference at the position to the new
diff --git a/crates/ide/src/move_item.rs b/crates/ide/src/move_item.rs
index 8d37f4f92..246f10a0a 100644
--- a/crates/ide/src/move_item.rs
+++ b/crates/ide/src/move_item.rs
@@ -1,4 +1,4 @@
-use std::iter::once;
+use std::{iter::once, mem};
 use hir::Semantics;
 use ide_db::{base_db::FileRange, RootDatabase};
@@ -102,7 +102,7 @@ fn move_in_direction(
            ast::GenericArgList(it) => swap_sibling_in_list(node, it.generic_args(), range, direction),
            ast::VariantList(it) => swap_sibling_in_list(node, it.variants(), range, direction),
            ast::TypeBoundList(it) => swap_sibling_in_list(node, it.bounds(), range, direction),
-            _ => Some(replace_nodes(node, &match direction {
+            _ => Some(replace_nodes(range, node, &match direction {
                Direction::Up => node.prev_sibling(),
                Direction::Down => node.next_sibling(),
            }?))
@@ -125,7 +125,7 @@ fn swap_sibling_in_list<A: AstNode + Clone, I: Iterator<Item = A>>(
        .next();
    if let Some((l, r)) = list_lookup {
-        Some(replace_nodes(l.syntax(), r.syntax()))
+        Some(replace_nodes(range, l.syntax(), r.syntax()))
    } else {
        // Cursor is beyond any movable list item (for example, on curly brace in enum).
        // It's not necessary, that parent of list is movable (arg list's parent is not, for example),
@@ -134,11 +134,38 @@ fn swap_sibling_in_list<A: AstNode + Clone, I: Iterator<Item = A>>(
    }
 }
-fn replace_nodes(first: &SyntaxNode, second: &SyntaxNode) -> TextEdit {
+fn replace_nodes<'a>(
+    range: TextRange,
+    mut first: &'a SyntaxNode,
+    mut second: &'a SyntaxNode,
+) -> TextEdit {
+    let cursor_offset = if range.is_empty() {
+        // FIXME: `applySnippetTextEdits` does not support non-empty selection ranges
+        if first.text_range().contains_range(range) {
+            Some(range.start() - first.text_range().start())
+        } else if second.text_range().contains_range(range) {
+            mem::swap(&mut first, &mut second);
+            Some(range.start() - first.text_range().start())
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+    let first_with_cursor = match cursor_offset {
+        Some(offset) => {
+            let mut item_text = first.text().to_string();
+            item_text.insert_str(offset.into(), "$0");
+            item_text
+        }
+        None => first.text().to_string(),