14 files changed, 169 insertions, 87 deletions

diff --git a/crates/ra_assists/src/doc_tests/generated.rs b/crates/ra_assists/src/doc_tests/generated.rs
index 64444ee3a..24392836c 100644
--- a/crates/ra_assists/src/doc_tests/generated.rs
+++ b/crates/ra_assists/src/doc_tests/generated.rs
@@ -180,7 +180,7 @@ trait Trait<T> {
 }
 
 impl Trait<u32> for () {
-    fn foo(&self) -> u32 { unimplemented!() }
+    fn foo(&self) -> u32 { todo!() }
 
 }
 "#####,
diff --git a/crates/ra_assists/src/handlers/add_missing_impl_members.rs b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
index 722f207e2..2d6d44980 100644
--- a/crates/ra_assists/src/handlers/add_missing_impl_members.rs
+++ b/crates/ra_assists/src/handlers/add_missing_impl_members.rs
@@ -40,7 +40,7 @@ enum AddMissingImplMembersMode {
 // }
 //
 // impl Trait<u32> for () {
-//     fn foo(&self) -> u32 { unimplemented!() }
+//     fn foo(&self) -> u32 { todo!() }
 //
 // }
 // ```
@@ -165,7 +165,7 @@ fn add_missing_impl_members_inner(
 
 fn add_body(fn_def: ast::FnDef) -> ast::FnDef {
     if fn_def.body().is_none() {
-        fn_def.with_body(make::block_from_expr(make::expr_unimplemented()))
+        fn_def.with_body(make::block_from_expr(make::expr_todo()))
     } else {
         fn_def
     }
@@ -215,8 +215,8 @@ impl Foo for S {
     fn bar(&self) {}
     <|>type Output;
     const CONST: usize = 42;
-    fn foo(&self) { unimplemented!() }
-    fn baz(&self) { unimplemented!() }
+    fn foo(&self) { todo!() }
+    fn baz(&self) { todo!() }
 
 }",
         );
@@ -250,7 +250,7 @@ struct S;
 
 impl Foo for S {
     fn bar(&self) {}
-    <|>fn foo(&self) { unimplemented!() }
+    <|>fn foo(&self) { todo!() }
 
 }",
         );
@@ -268,7 +268,7 @@ impl Foo for S { <|> }",
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) { unimplemented!() }
+    <|>fn foo(&self) { todo!() }
 }",
         );
     }
@@ -285,7 +285,7 @@ impl Foo<u32> for S { <|> }",
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
 impl Foo<u32> for S {
-    <|>fn foo(&self, t: u32) -> &u32 { unimplemented!() }
+    <|>fn foo(&self, t: u32) -> &u32 { todo!() }
 }",
         );
     }
@@ -302,7 +302,7 @@ impl<U> Foo<U> for S { <|> }",
 trait Foo<T> { fn foo(&self, t: T) -> &T; }
 struct S;
 impl<U> Foo<U> for S {
-    <|>fn foo(&self, t: U) -> &U { unimplemented!() }
+    <|>fn foo(&self, t: U) -> &U { todo!() }
 }",
         );
     }
@@ -319,7 +319,7 @@ impl Foo for S {}<|>",
 trait Foo { fn foo(&self); }
 struct S;
 impl Foo for S {
-    <|>fn foo(&self) { unimplemented!() }
+    <|>fn foo(&self) { todo!() }
 }",
         )
     }
@@ -342,7 +342,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar) { unimplemented!() }
+    <|>fn foo(&self, bar: foo::Bar) { todo!() }
 }",
         );
     }
@@ -365,7 +365,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) { unimplemented!() }
+    <|>fn foo(&self, bar: foo::Bar<u32>) { todo!() }
 }",
         );
     }
@@ -388,7 +388,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo<u32> for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>) { unimplemented!() }
+    <|>fn foo(&self, bar: foo::Bar<u32>) { todo!() }
 }",
         );
     }
@@ -414,7 +414,7 @@ mod foo {
 struct Param;
 struct S;
 impl foo::Foo<Param> for S {
-    <|>fn foo(&self, bar: Param) { unimplemented!() }
+    <|>fn foo(&self, bar: Param) { todo!() }
 }",
         );
     }
@@ -439,7 +439,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<u32>::Assoc) { unimplemented!() }
+    <|>fn foo(&self, bar: foo::Bar<u32>::Assoc) { todo!() }
 }",
         );
     }
@@ -464,7 +464,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: foo::Bar<foo::Baz>) { unimplemented!() }
+    <|>fn foo(&self, bar: foo::Bar<foo::Baz>) { todo!() }
 }",
         );
     }
@@ -487,7 +487,7 @@ mod foo {
 }
 struct S;
 impl foo::Foo for S {
-    <|>fn foo(&self, bar: dyn Fn(u32) -> i32) { unimplemented!() }
+    <|>fn foo(&self, bar: dyn Fn(u32) -> i32) { todo!() }
 }",
         );
     }
@@ -544,7 +544,7 @@ trait Foo {
 struct S;
 impl Foo for S {
     <|>type Output;
-    fn foo(&self) { unimplemented!() }
+    fn foo(&self) { todo!() }
 }"#,
         )
     }
diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index be4b0accb..7c0d93691 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -4,7 +4,6 @@ use std::sync::Arc;
 
 use either::Either;
 use hir_expand::{
-    hygiene::Hygiene,
     name::{AsName, Name},
     InFile,
 };
@@ -13,7 +12,7 @@ use ra_prof::profile;
 use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner, VisibilityOwner};
 
 use crate::{
-    attr::Attrs, db::DefDatabase, src::HasChildSource, src::HasSource, trace::Trace,
+    body::CfgExpander, db::DefDatabase, src::HasChildSource, src::HasSource, trace::Trace,
     type_ref::TypeRef, visibility::RawVisibility, EnumId, HasModule, LocalEnumVariantId,
     LocalStructFieldId, Lookup, ModuleId, StructId, UnionId, VariantId,
 };
@@ -125,8 +124,9 @@ fn lower_enum(
 
 impl VariantData {
     fn new(db: &dyn DefDatabase, flavor: InFile<ast::StructKind>, module_id: ModuleId) -> Self {
+        let mut expander = CfgExpander::new(db, flavor.file_id, module_id.krate);
         let mut trace = Trace::new_for_arena();
-        match lower_struct(db, &mut trace, &flavor, module_id) {
+        match lower_struct(db, &mut expander, &mut trace, &flavor) {
             StructKind::Tuple => VariantData::Tuple(trace.into_arena()),
             StructKind::Record => VariantData::Record(trace.into_arena()),
             StructKind::Unit => VariantData::Unit,
@@ -178,8 +178,9 @@ impl HasChildSource for VariantId {
                 it.lookup(db).container.module(db),
             ),
         };
+        let mut expander = CfgExpander::new(db, src.file_id, module_id.krate);
         let mut trace = Trace::new_for_map();
-        lower_struct(db, &mut trace, &src, module_id);
+        lower_struct(db, &mut expander, &mut trace, &src);
         src.with_value(trace.into_map())
     }
 }
@@ -193,16 +194,15 @@ pub enum StructKind {
 
 fn lower_struct(
     db: &dyn DefDatabase,
+    expander: &mut CfgExpander,
     trace: &mut Trace<StructFieldData, Either<ast::TupleFieldDef, ast::RecordFieldDef>>,
     ast: &InFile<ast::StructKind>,
-    module_id: ModuleId,
 ) -> StructKind {
-    let crate_graph = db.crate_graph();
     match &ast.value {
         ast::StructKind::Tuple(fl) => {
             for (i, fd) in fl.fields().enumerate() {
-                let attrs = Attrs::new(&fd, &Hygiene::new(db.upcast(), ast.file_id));
-                if !attrs.is_cfg_enabled(&crate_graph[module_id.krate].cfg_options) {
+                let attrs = expander.parse_attrs(&fd);
+                if !expander.is_cfg_enabled(&attrs) {
                     continue;
                 }
 
@@ -219,8 +219,8 @@ fn lower_struct(
         }
         ast::StructKind::Record(fl) => {
             for fd in fl.fields() {
-                let attrs = Attrs::new(&fd, &Hygiene::new(db.upcast(), ast.file_id));
-                if !attrs.is_cfg_enabled(&crate_graph[module_id.krate].cfg_options) {
+                let attrs = expander.parse_attrs(&fd);
+                if !expander.is_cfg_enabled(&attrs) {
                     continue;
                 }
 
diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 7b0c506b1..2f2e3e5ba 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -93,6 +93,7 @@ impl Attrs {
     }
 
     pub(crate) fn is_cfg_enabled(&self, cfg_options: &CfgOptions) -> bool {
+        // FIXME: handle cfg_attr :-)
         self.by_key("cfg").tt_values().all(|tt| cfg_options.is_cfg_enabled(tt) != Some(false))
     }
 }
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index e09996c6f..7fac6ce66 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -14,6 +14,7 @@ use ra_syntax::{ast, AstNode, AstPtr};
 use rustc_hash::FxHashMap;
 
 use crate::{
+    attr::Attrs,
     db::DefDatabase,
     expr::{Expr, ExprId, Pat, PatId},
     item_scope::BuiltinShadowMode,
@@ -23,26 +24,62 @@ use crate::{
     src::HasSource,
     AsMacroCall, DefWithBodyId, HasModule, Lookup, ModuleId,
 };
+use ra_cfg::CfgOptions;
+use ra_db::CrateId;
+
+/// A subser of Exander that only deals with cfg attributes. We only need it to
+/// avoid cyclic queries in crate def map during enum processing.
+pub(crate) struct CfgExpander {
+    cfg_options: CfgOptions,
+    hygiene: Hygiene,
+}
 
 pub(crate) struct Expander {
+    cfg_expander: CfgExpander,
     crate_def_map: Arc<CrateDefMap>,
     current_file_id: HirFileId,
-    hygiene: Hygiene,
     ast_id_map: Arc<AstIdMap>,
     module: ModuleId,
     recursive_limit: usize,
 }
 
+impl CfgExpander {
+    pub(crate) fn new(
+        db: &dyn DefDatabase,
+        current_file_id: HirFileId,
+        krate: CrateId,
+    ) -> CfgExpander {
+        let hygiene = Hygiene::new(db.upcast(), current_file_id);
+        let cfg_options = db.crate_graph()[krate].cfg_options.clone();
+        CfgExpander { cfg_options, hygiene }
+    }
+
+    pub(crate) fn parse_attrs(&self, owner: &dyn ast::AttrsOwner) -> Attrs {
+        Attrs::new(owner, &self.hygiene)
+    }
+
+    pub(crate) fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
+        attrs.is_cfg_enabled(&self.cfg_options)
+    }
+}
+
 impl Expander {
     pub(crate) fn new(
         db: &dyn DefDatabase,
         current_file_id: HirFileId,
         module: ModuleId,
     ) -> Expander {
+        let cfg_expander = CfgExpander::new(db, current_file_id, module.krate);
         let crate_def_map = db.crate_def_map(module.krate);
-        let hygiene = Hygiene::new(db.upcast(), current_file_id);
         let ast_id_map = db.ast_id_map(current_file_id);
-        Expander { crate_def_map, current_file_id, hygiene, ast_id_map, module, recursive_limit: 0 }
+        Expander {
+            cfg_expander,
+            crate_def_map,
+            current_file_id,
+            ast_id_map,
+            module,
+            recursive_limit: 0,
+        }
     }
 
     pub(crate) fn enter_expand<T: ast::AstNode>(
@@ -75,7 +112,7 @@ impl Expander {
                         ast_id_map: mem::take(&mut self.ast_id_map),
                         bomb: DropBomb::new("expansion mark dropped"),
                     };
-                    self.hygiene = Hygiene::new(db.upcast(), file_id);
+                    self.cfg_expander.hygiene = Hygiene::new(db.upcast(), file_id);
                     self.current_file_id = file_id;
                     self.ast_id_map = db.ast_id_map(file_id);
                     self.recursive_limit += 1;
@@ -91,7 +128,7 @@ impl Expander {
     }
 
     pub(crate) fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) {
-        self.hygiene = Hygiene::new(db.upcast(), mark.file_id);
+        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);
         self.recursive_limit -= 1;
@@ -102,8 +139,16 @@ impl Expander {
         InFile { file_id: self.current_file_id, value }
     }
 
+    pub(crate) fn parse_attrs(&self, owner: &dyn ast::AttrsOwner) -> Attrs {
+        self.cfg_expander.parse_attrs(owner)
+    }
+
+    pub(crate) fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
+        self.cfg_expander.is_cfg_enabled(attrs)
+    }
+
     fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
-        Path::from_src(path, &self.hygiene)
+        Path::from_src(path, &self.cfg_expander.hygiene)
     }
 
     fn resolve_path_as_macro(&self, db: &dyn DefDatabase, path: &ModPath) -> Option<MacroDefId> {
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 9d6ee095e..c1d7eb826 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -2,9 +2,7 @@
 //! representation.
 
 use either::Either;
-
 use hir_expand::{
-    hygiene::Hygiene,
     name::{name, AsName, Name},
     MacroDefId, MacroDefKind,
 };
@@ -18,10 +16,8 @@ use ra_syntax::{
 };
 use test_utils::tested_by;
 
-use super::{ExprSource, PatSource};
 use crate::{
     adt::StructKind,
-    attr::Attrs,
     body::{Body, BodySourceMap, Expander, PatPtr, SyntheticSyntax},
     builtin_type::{BuiltinFloat, BuiltinInt},
     db::DefDatabase,
@@ -33,10 +29,12 @@ use crate::{
     path::GenericArgs,
     path::Path,
     type_ref::{Mutability, TypeRef},
-    AdtId, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, HasModule, Intern,
-    ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
+    AdtId, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern, ModuleDefId,
+    StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
 };
 
+use super::{ExprSource, PatSource};
+
 pub(super) fn lower(
     db: &dyn DefDatabase,
     def: DefWithBodyId,
@@ -300,7 +298,6 @@ impl ExprCollector<'_> {
                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
             }
             ast::Expr::RecordLit(e) => {
-                let crate_graph = self.db.crate_graph();
                 let path = e.path().and_then(|path| self.expander.parse_path(path));
                 let mut field_ptrs = Vec::new();
                 let record_lit = if let Some(nfl) = e.record_field_list() {
@@ -308,13 +305,8 @@ impl ExprCollector<'_> {
                         .fields()
                         .inspect(|field| field_ptrs.push(AstPtr::new(field)))
                         .filter_map(|field| {
-                            let module_id = ContainerId::DefWithBodyId(self.def).module(self.db);
-                            let attrs = Attrs::new(
-                                &field,
-                                &Hygiene::new(self.db.upcast(), self.expander.current_file_id),
-                            );
-
-                            if !attrs.is_cfg_enabled(&crate_graph[module_id.krate].cfg_options) {
+                            let attrs = self.expander.parse_attrs(&field);
+                            if !self.expander.is_cfg_enabled(&attrs) {
                                 return None;
                             }
 
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index b8fbf0ed4..56a20c5bd 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -20,7 +20,7 @@ use crate::{
     type_ref::{Mutability, TypeBound, TypeRef},
     visibility::RawVisibility,
     AssocContainerId, AssocItemId, ConstId, ConstLoc, Expander, FunctionId, FunctionLoc, HasModule,
-    ImplId, Intern, Lookup, ModuleId, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
+    ImplId, Intern, Lookup, StaticId, TraitId, TypeAliasId, TypeAliasLoc,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -218,10 +218,17 @@ impl ImplData {
         let mut items = Vec::new();
 
         if let Some(item_list) = src.value.item_list() {
-            items.extend(collect_impl_items(db, item_list.impl_items(), src.file_id, id));
+            let mut expander = Expander::new(db, impl_loc.ast_id.file_id, module_id);
+            items.extend(collect_impl_items(
+                db,
+                &mut expander,
+                item_list.impl_items(),
+                src.file_id,
+                id,
+            ));
             items.extend(collect_impl_items_in_macros(
                 db,
-                module_id,
+                &mut expander,
                 &src.with_value(item_list),
                 id,
             ));
@@ -268,18 +275,17 @@ impl ConstData {
 
 fn collect_impl_items_in_macros(
     db: &dyn DefDatabase,
-    module_id: ModuleId,
+    expander: &mut Expander,
     impl_def: &InFile<ast::ItemList>,
     id: ImplId,
 ) -> Vec<AssocItemId> {
-    let mut expander = Expander::new(db, impl_def.file_id, module_id);
     let mut res = Vec::new();
 
     // We set a limit to protect against infinite recursion
     let limit = 100;
 
     for m in impl_def.value.syntax().children().filter_map(ast::MacroCall::cast) {
-        res.extend(collect_impl_items_in_macro(db, &mut expander, m, id, limit))
+        res.extend(collect_impl_items_in_macro(db, expander, m, id, limit))
     }
 
     res
@@ -300,6 +306,7 @@ fn collect_impl_items_in_macro(
         let items: InFile<ast::MacroItems> = expander.to_source(items);
         let mut res = collect_impl_items(
             db,
+            expander,
             items.value.items().filter_map(|it| ImplItem::cast(it.syntax().clone())),
             items.file_id,
             id,
@@ -319,32 +326,26 @@ fn collect_impl_items_in_macro(
 
 fn collect_impl_items(
     db: &dyn DefDatabase,
+    expander: &mut Expander,
     impl_items: impl Iterator<Item = ImplItem>,
     file_id: crate::HirFileId,
     id: ImplId,
 ) -> Vec<AssocItemId> {
     let items = db.ast_id_map(file_id);
-    let crate_graph = db.crate_graph();
-    let module_id = id.lookup(db).container.module(db);
 
     impl_items
         .filter_map(|item_node| match item_node {
             ast::ImplItem::FnDef(it) => {
+                let attrs = expander.parse_attrs(&it);
+                if !expander.is_cfg_enabled(&attrs) {
+                    return None;
+                }
                 let def = FunctionLoc {
                     container: AssocContainerId::ImplId(id),
                     ast_id: AstId::new(file_id, items.ast_id(&it)),
                 }
                 .intern(db);
-
-                if !db
-                    .function_data(def)
-                    .attrs
-                    .is_cfg_enabled(&crate_graph[module_id.krate].cfg_options)
-                {
-                    None
-                } else {
-                    Some(def.into())
-                }
+                Some(def.into())
             }
             ast::ImplItem::ConstDef(it) => {
                 let def = ConstLoc {
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index 8fe3f8617..98c74fe25 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -462,6 +462,14 @@ impl DefCollector<'_> {
                 Some(ModuleDefId::AdtId(AdtId::EnumId(e))) => {
                     tested_by!(glob_enum);
                     // glob import from enum => just import all the variants
+
+                    // XXX: urgh, so this works by accident! Here, we look at
+                    // the enum data, and, in theory, this might require us to
+                    // look back at the crate_def_map, creating a cycle. For
+                    // example, `enum E { crate::some_macro!(); }`. Luckely, the
+                    // only kind of macro that is allowed inside enum is a
+                    // `cfg_macro`, and we don't need to run name resolution for
+                    // it, but this is sheer luck!
                     let enum_data = self.db.enum_data(e);
                     let resolutions = enum_data
                         .variants
@@ -977,11 +985,7 @@ impl ModCollector<'_, '_> {
     }
 
     fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
-        // FIXME: handle cfg_attr :-)
-        attrs
-            .by_key("cfg")
-            .tt_values()
-            .all(|tt| self.def_collector.cfg_options.is_cfg_enabled(tt) != Some(false))
+        attrs.is_cfg_enabled(self.def_collector.cfg_options)
     }
 }
 
diff --git a/crates/ra_hir_def/src/nameres/tests/incremental.rs b/crates/ra_hir_def/src/nameres/tests/incremental.rs
index 496fc6b08..87165ac33 100644
--- a/crates/ra_hir_def/src/nameres/tests/incremental.rs
+++ b/crates/ra_hir_def/src/nameres/tests/incremental.rs
@@ -32,6 +32,9 @@ fn typing_inside_a_function_should_not_invalidate_def_map() {
 
         use crate::foo::bar::Baz;
 
+        enum E { A, B }
+        use E::*;
+
         fn foo() -> i32 {
             1 + 1
         }
@@ -46,6 +49,9 @@ fn typing_inside_a_function_should_not_invalidate_def_map() {
 
         use crate::foo::bar::Baz;
 
+        enum E { A, B }
+        use E::*;
+
         fn foo() -> i32 { 92 }
         ",
     );
diff --git a/crates/ra_syntax/src/ast/make.rs b/crates/ra_syntax/src/ast/make.rs
index f39559e9e..0f4a50be4 100644
--- a/crates/ra_syntax/src/ast/make.rs
+++ b/crates/ra_syntax/src/ast/make.rs
@@ -100,6 +100,9 @@ pub fn expr_empty_block() -> ast::Expr {
 pub fn expr_unimplemented() -> ast::Expr {
     expr_from_text("unimplemented!()")
 }
+pub fn expr_todo() -> ast::Expr {
+    expr_from_text("todo!()")
+}
 pub fn expr_path(path: ast::Path) -> ast::Expr {
     expr_from_text(&path.to_string())
 }
diff --git a/docs/user/assists.md b/docs/user/assists.md
index 754131f6f..cc42169d8 100644
--- a/docs/user/assists.md
+++ b/docs/user/assists.md
@@ -175,7 +175,7 @@ trait Trait<T> {
 }
 
 impl Trait<u32> for () {
-    fn foo(&self) -> u32 { unimplemented!() }
+    fn foo(&self) -> u32 { todo!() }
 
 }
 ```
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 21c1c9f23..35a05131c 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -66,23 +66,44 @@ export class Config {
         return vscode.workspace.getConfiguration(this.rootSection);
     }
 
-    get serverPath() { return this.cfg.get<null | string>("serverPath")!; }
-    get channel() { return this.cfg.get<UpdatesChannel>("updates.channel")!; }
-    get askBeforeDownload() { return this.cfg.get<boolean>("updates.askBeforeDownload")!; }
-    get traceExtension() { return this.cfg.get<boolean>("trace.extension")!; }
+    /**
+     * Beware that postfix `!` operator erases both `null` and `undefined`.
+     * This is why the following doesn't work as expected:
+     *
+     * ```ts
+     * const nullableNum = vscode
+     *  .workspace
+     *  .getConfiguration
+     *  .getConfiguration("rust-analyer")
+     *  .get<number | null>(path)!;
+     *
+     * // What happens is that type of `nullableNum` is `number` but not `null | number`:
+     * const fullFledgedNum: number = nullableNum;
+     * ```
+     * So this getter handles this quirk by not requiring the caller to use postfix `!`
+     */
+    private get<T>(path: string): T {
+        return this.cfg.get<T>(path)!;
+    }
+
+    get serverPath() { return this.get<null | string>("serverPath"); }
+    get channel() { return this.get<UpdatesChannel>("updates.channel"); }
+    get askBeforeDownload() { return this.get<boolean>("updates.askBeforeDownload"); }
+    get traceExtension() { return this.get<boolean>("trace.extension"); }
+
 
     get inlayHints() {
         return {
-            typeHints: this.cfg.get<boolean>("inlayHints.typeHints")!,
-            parameterHints: this.cfg.get<boolean>("inlayHints.parameterHints")!,
-            chainingHints: this.cfg.get<boolean>("inlayHints.chainingHints")!,
-            maxLength: this.cfg.get<null | number>("inlayHints.maxLength")!,
+            typeHints: this.get<boolean>("inlayHints.typeHints"),
+            parameterHints: this.get<boolean>("inlayHints.parameterHints"),
+            chainingHints: this.get<boolean>("inlayHints.chainingHints"),
+            maxLength: this.get<null | number>("inlayHints.maxLength"),
         };
     }
 
     get checkOnSave() {
         return {
-            command: this.cfg.get<string>("checkOnSave.command")!,
+            command: this.get<string>("checkOnSave.command"),
         };
     }
 }
diff --git a/editors/code/src/inlay_hints.ts b/editors/code/src/inlay_hints.ts
index 6a8bd942e..da74f03d2 100644
--- a/editors/code/src/inlay_hints.ts
+++ b/editors/code/src/inlay_hints.ts
@@ -229,13 +229,13 @@ interface InlaysDecorations {
 }
 
 interface RustSourceFile {
-    /*
-    * Source of the token to cancel in-flight inlay hints request if any.
-    */
+    /**
+     * Source of the token to cancel in-flight inlay hints request if any.
+     */
     inlaysRequest: null | vscode.CancellationTokenSource;
     /**
-    * Last applied decorations.
-    */
+     * Last applied decorations.
+     */
     cachedDecorations: null | InlaysDecorations;
 
     document: RustDocument;
diff --git a/xtask/tests/tidy-tests/main.rs b/xtask/tests/tidy-tests/main.rs
index 80911a68e..4f525fcd0 100644
--- a/xtask/tests/tidy-tests/main.rs
+++ b/xtask/tests/tidy-tests/main.rs
@@ -20,7 +20,16 @@ fn rust_files_are_tidy() {
 }
 
 fn check_todo(path: &Path, text: &str) {
-    if path.ends_with("tests/cli.rs") {
+    let whitelist = &[
+        // This file itself is whitelisted since this test itself contains matches.
+        "tests/cli.rs",
+        // Some of our assists generate `todo!()` so those files are whitelisted.
+        "doc_tests/generated.rs",
+        "handlers/add_missing_impl_members.rs",
+        // To support generating `todo!()` in assists, we have `expr_todo()` in ast::make.
+        "ast/make.rs",
+    ];
+    if whitelist.iter().any(|p| path.ends_with(p)) {
         return;
     }
     if text.contains("TODO") || text.contains("TOOD") || text.contains("todo!") {