17 files changed, 243 insertions, 150 deletions

diff --git a/crates/ide/src/call_hierarchy.rs b/crates/ide/src/call_hierarchy.rs
index b848945d7..96021f677 100644
--- a/crates/ide/src/call_hierarchy.rs
+++ b/crates/ide/src/call_hierarchy.rs
@@ -53,10 +53,8 @@ pub(crate) fn incoming_calls(db: &RootDatabase, position: FilePosition) -> Optio
         for (r_range, _) in references {
             let token = file.token_at_offset(r_range.start()).next()?;
             let token = sema.descend_into_macros(token);
-            let syntax = token.parent();
-
             // This target is the containing function
-            if let Some(nav) = syntax.ancestors().find_map(|node| {
+            if let Some(nav) = token.ancestors().find_map(|node| {
                 let fn_ = ast::Fn::cast(node)?;
                 let def = sema.to_def(&fn_)?;
                 def.try_to_nav(sema.db)
@@ -77,12 +75,13 @@ pub(crate) fn outgoing_calls(db: &RootDatabase, position: FilePosition) -> Optio
     let file = file.syntax();
     let token = file.token_at_offset(position.offset).next()?;
     let token = sema.descend_into_macros(token);
-    let syntax = token.parent();
 
     let mut calls = CallLocations::default();
 
-    syntax
-        .descendants()
+    token
+        .parent()
+        .into_iter()
+        .flat_map(|it| it.descendants())
         .filter_map(|node| FnCallNode::with_node_exact(&node))
         .filter_map(|call_node| {
             let name_ref = call_node.name_ref()?;
diff --git a/crates/ide/src/display.rs b/crates/ide/src/display.rs
index bae9e40df..1f7b665c0 100644
--- a/crates/ide/src/display.rs
+++ b/crates/ide/src/display.rs
@@ -5,6 +5,5 @@ pub(crate) mod navigation_target;
 mod short_label;
 
 pub(crate) use navigation_target::{ToNav, TryToNav};
-pub(crate) use short_label::ShortLabel;
 
 pub(crate) use syntax::display::{function_declaration, macro_label};
diff --git a/crates/ide/src/display/navigation_target.rs b/crates/ide/src/display/navigation_target.rs
index 198243466..69c3751a1 100644
--- a/crates/ide/src/display/navigation_target.rs
+++ b/crates/ide/src/display/navigation_target.rs
@@ -3,7 +3,9 @@
 use std::fmt;
 
 use either::Either;
-use hir::{AssocItem, Documentation, FieldSource, HasAttrs, HasSource, InFile, ModuleSource};
+use hir::{
+    AssocItem, Documentation, FieldSource, HasAttrs, HasSource, HirDisplay, InFile, ModuleSource,
+};
 use ide_db::{
     base_db::{FileId, FileRange, SourceDatabase},
     symbol_index::FileSymbolKind,
@@ -98,7 +100,7 @@ impl NavigationTarget {
                 SymbolKind::Module,
             );
             res.docs = module.attrs(db).docs();
-            res.description = src.value.short_label();
+            res.description = Some(module.display(db).to_string());
             return res;
         }
         module.to_nav(db)
@@ -251,8 +253,8 @@ impl ToNavFromAst for hir::Trait {
 
 impl<D> TryToNav for D
 where
-    D: HasSource + ToNavFromAst + Copy + HasAttrs,
-    D::Ast: ast::NameOwner + ShortLabel,
+    D: HasSource + ToNavFromAst + Copy + HasAttrs + HirDisplay,
+    D::Ast: ast::NameOwner,
 {
     fn try_to_nav(&self, db: &RootDatabase) -> Option<NavigationTarget> {
         let src = self.source(db)?;
@@ -262,7 +264,7 @@ where
             D::KIND,
         );
         res.docs = self.docs(db);
-        res.description = src.value.short_label();
+        res.description = Some(self.display(db).to_string());
         Some(res)
     }
 }
@@ -317,7 +319,7 @@ impl TryToNav for hir::Field {
                 let mut res =
                     NavigationTarget::from_named(db, src.with_value(it), SymbolKind::Field);
                 res.docs = self.docs(db);
-                res.description = it.short_label();
+                res.description = Some(self.display(db).to_string());
                 res
             }
             FieldSource::Pos(it) => {
diff --git a/crates/ide/src/doc_links.rs b/crates/ide/src/doc_links.rs
index 7bdd3cca3..461e11060 100644
--- a/crates/ide/src/doc_links.rs
+++ b/crates/ide/src/doc_links.rs
@@ -279,7 +279,7 @@ pub(crate) fn external_docs(
     let token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(token);
 
-    let node = token.parent();
+    let node = token.parent()?;
     let definition = match_ast! {
         match node {
             ast::NameRef(name_ref) => NameRefClass::classify(&sema, &name_ref).map(|d| d.referenced(sema.db)),
diff --git a/crates/ide/src/extend_selection.rs b/crates/ide/src/extend_selection.rs
index b540d04fe..e187243cb 100644
--- a/crates/ide/src/extend_selection.rs
+++ b/crates/ide/src/extend_selection.rs
@@ -88,7 +88,7 @@ fn try_extend_selection(
                     return Some(range);
                 }
             }
-            token.parent()
+            token.parent()?
         }
         NodeOrToken::Node(node) => node,
     };
@@ -142,7 +142,8 @@ fn extend_tokens_from_range(
     let extended = {
         let fst_expanded = sema.descend_into_macros(first_token.clone());
         let lst_expanded = sema.descend_into_macros(last_token.clone());
-        let mut lca = algo::least_common_ancestor(&fst_expanded.parent(), &lst_expanded.parent())?;
+        let mut lca =
+            algo::least_common_ancestor(&fst_expanded.parent()?, &lst_expanded.parent()?)?;
         lca = shallowest_node(&lca);
         if lca.first_token() == Some(fst_expanded) && lca.last_token() == Some(lst_expanded) {
             lca = lca.parent()?;
@@ -151,9 +152,13 @@ fn extend_tokens_from_range(
     };
 
     // Compute parent node range
-    let validate = |token: &SyntaxToken| {
+    let validate = |token: &SyntaxToken| -> bool {
         let expanded = sema.descend_into_macros(token.clone());
-        algo::least_common_ancestor(&extended, &expanded.parent()).as_ref() == Some(&extended)
+        let parent = match expanded.parent() {
+            Some(it) => it,
+            None => return false,
+        };
+        algo::least_common_ancestor(&extended, &parent).as_ref() == Some(&extended)
     };
 
     // Find the first and last text range under expanded parent
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index e8f31e4b1..6986477a5 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -30,7 +30,7 @@ pub(crate) fn goto_definition(
     let file = sema.parse(position.file_id).syntax().clone();
     let original_token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(original_token.clone());
-    let parent = token.parent();
+    let parent = token.parent()?;
     if let Some(comment) = ast::Comment::cast(token) {
         let nav = def_for_doc_comment(&sema, position, &comment)?.try_to_nav(db)?;
         return Some(RangeInfo::new(original_token.text_range(), vec![nav]));
@@ -63,7 +63,7 @@ fn def_for_doc_comment(
     position: FilePosition,
     doc_comment: &ast::Comment,
 ) -> Option<hir::ModuleDef> {
-    let parent = doc_comment.syntax().parent();
+    let parent = doc_comment.syntax().parent()?;
     let (link, ns) = extract_positioned_link_from_comment(position, doc_comment)?;
 
     let def = doc_owner_to_def(sema, parent)?;
diff --git a/crates/ide/src/goto_type_definition.rs b/crates/ide/src/goto_type_definition.rs
index 369a59820..2d38cb112 100644
--- a/crates/ide/src/goto_type_definition.rs
+++ b/crates/ide/src/goto_type_definition.rs
@@ -22,7 +22,7 @@ pub(crate) fn goto_type_definition(
     let token: SyntaxToken = pick_best(file.syntax().token_at_offset(position.offset))?;
     let token: SyntaxToken = sema.descend_into_macros(token);
 
-    let (ty, node) = sema.ancestors_with_macros(token.parent()).find_map(|node| {
+    let (ty, node) = sema.token_ancestors_with_macros(token).find_map(|node| {
         let ty = match_ast! {
             match node {
                 ast::Expr(it) => sema.type_of_expr(&it)?,
diff --git a/crates/ide/src/hover.rs b/crates/ide/src/hover.rs
index ea45086ce..8d45b4875 100644
--- a/crates/ide/src/hover.rs
+++ b/crates/ide/src/hover.rs
@@ -1,7 +1,7 @@
 use either::Either;
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, FieldSource, GenericParam, HasAttrs, HasSource,
-    HirDisplay, Module, ModuleDef, ModuleSource, Semantics,
+    Adt, AsAssocItem, AssocItemContainer, GenericParam, HasAttrs, HasSource, HirDisplay, Module,
+    ModuleDef, Semantics,
 };
 use ide_db::{
     base_db::SourceDatabase,
@@ -14,7 +14,7 @@ use stdx::format_to;
 use syntax::{ast, match_ast, AstNode, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
 
 use crate::{
-    display::{macro_label, ShortLabel, TryToNav},
+    display::{macro_label, TryToNav},
     doc_links::{remove_links, rewrite_links},
     markdown_remove::remove_markdown,
     markup::Markup,
@@ -92,7 +92,7 @@ pub(crate) fn hover(
 
     let mut res = HoverResult::default();
 
-    let node = token.parent();
+    let node = token.parent()?;
     let definition = match_ast! {
         match node {
             // we don't use NameClass::referenced_or_defined here as we do not want to resolve
@@ -335,34 +335,18 @@ fn hover_for_definition(
             let label = macro_label(&it.source(db)?.value);
             from_def_source_labeled(db, it, Some(label), mod_path)
         }
-        Definition::Field(def) => {
-            let src = def.source(db)?.value;
-            if let FieldSource::Named(it) = src {
-                from_def_source_labeled(db, def, it.short_label(), mod_path)
-            } else {
-                None
-            }
-        }
+        Definition::Field(def) => from_hir_fmt(db, def, mod_path),
         Definition::ModuleDef(it) => match it {
-            ModuleDef::Module(it) => from_def_source_labeled(
-                db,
-                it,
-                match it.definition_source(db).value {
-                    ModuleSource::Module(it) => it.short_label(),
-                    ModuleSource::SourceFile(it) => it.short_label(),
-                    ModuleSource::BlockExpr(it) => it.short_label(),
-                },
-                mod_path,
-            ),
-            ModuleDef::Function(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Struct(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Union(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Adt(Adt::Enum(it)) => from_def_source(db, it, mod_path),
-            ModuleDef::Variant(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Const(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Static(it) => from_def_source(db, it, mod_path),
-            ModuleDef::Trait(it) => from_def_source(db, it, mod_path),
-            ModuleDef::TypeAlias(it) => from_def_source(db, it, mod_path),
+            ModuleDef::Module(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Function(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Struct(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Union(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Adt(Adt::Enum(it)) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Variant(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Const(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Static(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::Trait(it) => from_hir_fmt(db, it, mod_path),
+            ModuleDef::TypeAlias(it) => from_hir_fmt(db, it, mod_path),
             ModuleDef::BuiltinType(it) => famous_defs
                 .and_then(|fd| hover_for_builtin(fd, it))
                 .or_else(|| Some(Markup::fenced_block(&it.name()))),
@@ -370,26 +354,25 @@ fn hover_for_definition(
         Definition::Local(it) => hover_for_local(it, db),
         Definition::SelfType(impl_def) => {
             impl_def.target_ty(db).as_adt().and_then(|adt| match adt {
-                Adt::Struct(it) => from_def_source(db, it, mod_path),
-                Adt::Union(it) => from_def_source(db, it, mod_path),
-                Adt::Enum(it) => from_def_source(db, it, mod_path),
+                Adt::Struct(it) => from_hir_fmt(db, it, mod_path),
+                Adt::Union(it) => from_hir_fmt(db, it, mod_path),
+                Adt::Enum(it) => from_hir_fmt(db, it, mod_path),
             })
         }
         Definition::Label(it) => Some(Markup::fenced_block(&it.name(db))),
         Definition::GenericParam(it) => match it {
             GenericParam::TypeParam(it) => Some(Markup::fenced_block(&it.display(db))),
             GenericParam::LifetimeParam(it) => Some(Markup::fenced_block(&it.name(db))),
-            GenericParam::ConstParam(it) => from_def_source(db, it, None),
+            GenericParam::ConstParam(it) => Some(Markup::fenced_block(&it.display(db))),
         },
     };
 
-    fn from_def_source<A, D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
+    fn from_hir_fmt<D>(db: &RootDatabase, def: D, mod_path: Option<String>) -> Option<Markup>
     where
-        D: HasSource<Ast = A> + HasAttrs + Copy,
-        A: ShortLabel,
+        D: HasAttrs + HirDisplay,
     {
-        let short_label = def.source(db)?.value.short_label();
-        from_def_source_labeled(db, def, short_label, mod_path)
+        let label = def.display(db).to_string();
+        from_def_source_labeled(db, def, Some(label), mod_path)
     }
 
     fn from_def_source_labeled<D>(
@@ -438,7 +421,7 @@ fn hover_for_keyword(
     if !token.kind().is_keyword() {
         return None;
     }
-    let famous_defs = FamousDefs(&sema, sema.scope(&token.parent()).krate());
+    let famous_defs = FamousDefs(&sema, sema.scope(&token.parent()?).krate());
     // std exposes {}_keyword modules with docstrings on the root to document keywords
     let keyword_mod = format!("{}_keyword", token.text());
     let doc_owner = find_std_module(&famous_defs, &keyword_mod)?;
@@ -670,7 +653,9 @@ fn main() { let foo_test = fo$0o(); }
                 ```
 
                 ```rust
-                pub fn foo<'a, T: AsRef<str>>(b: &'a T) -> &'a str
+                pub fn foo<'a, T>(b: &'a T) -> &'a str
+                where
+                    T: AsRef<str>,
                 ```
             "#]],
         );
@@ -878,7 +863,7 @@ fn main() { So$0me(12); }
                 ```
 
                 ```rust
-                Some
+                Some(T)
                 ```
             "#]],
         );
@@ -944,7 +929,7 @@ fn main() {
                 ```
 
                 ```rust
-                Some
+                Some(T)
                 ```
 
                 ---
@@ -1441,13 +1426,14 @@ fn bar() { fo$0o(); }
                 ```
             "#]],
         );
+        // Top level `pub(crate)` will be displayed as no visibility.
         check(
-            r#"pub(crate) async unsafe extern "C" fn foo$0() {}"#,
+            r#"mod m { pub(crate) async unsafe extern "C" fn foo$0() {} }"#,
             expect![[r#"
                 *foo*
 
                 ```rust
-                test
+                test::m
                 ```
 
                 ```rust
@@ -1489,11 +1475,18 @@ extern crate st$0d;
 //! abc123
             "#,
             expect![[r#"
-            *std*
-            Standard library for this test
+                *std*
+
+                ```rust
+                extern crate std
+                ```
 
-            Printed?
-            abc123
+                ---
+
+                Standard library for this test
+
+                Printed?
+                abc123
             "#]],
         );
         check(
@@ -1507,11 +1500,18 @@ extern crate std as ab$0c;
 //! abc123
             "#,
             expect![[r#"
-            *abc*
-            Standard library for this test
+                *abc*
+
+                ```rust
+                extern crate std
+                ```
+
+                ---
 
-            Printed?
-            abc123
+                Standard library for this test
+
+                Printed?
+                abc123
             "#]],
         );
     }
@@ -2021,7 +2021,7 @@ enum E {
                 ```
 
                 ```rust
-                V
+                V { field: i32 }
                 ```
 
                 ---
@@ -2417,7 +2417,7 @@ fn main() { let s$0t = S{ f1:Arg(0) }; }
                                     focus_range: 24..25,
                                     name: "S",
                                     kind: Struct,
-                                    description: "struct S",
+                                    description: "struct S<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2463,7 +2463,7 @@ fn main() { let s$0t = S{ f1: S{ f1: Arg(0) } }; }
                                     focus_range: 24..25,
                                     name: "S",
                                     kind: Struct,
-                                    description: "struct S",
+                                    description: "struct S<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2605,7 +2605,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2702,7 +2702,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2715,7 +2715,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 22..25,
                                     name: "Bar",
                                     kind: Trait,
-                                    description: "trait Bar",
+                                    description: "trait Bar<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2819,7 +2819,7 @@ fn foo(ar$0g: &impl Foo + Bar<S>) {}
                                     focus_range: 19..22,
                                     name: "Bar",
                                     kind: Trait,
-                                    description: "trait Bar",
+                                    description: "trait Bar<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2916,7 +2916,7 @@ fn foo(ar$0g: &impl Foo<S>) {}
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -2966,7 +2966,7 @@ fn main() { let s$0t = foo(); }
                                     focus_range: 49..50,
                                     name: "B",
                                     kind: Struct,
-                                    description: "struct B",
+                                    description: "struct B<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3042,7 +3042,7 @@ fn foo(ar$0g: &dyn Foo<S>) {}
                                     focus_range: 6..9,
                                     name: "Foo",
                                     kind: Trait,
-                                    description: "trait Foo",
+                                    description: "trait Foo<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3090,7 +3090,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 6..15,
                                     name: "ImplTrait",
                                     kind: Trait,
-                                    description: "trait ImplTrait",
+                                    description: "trait ImplTrait<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3103,7 +3103,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 50..51,
                                     name: "B",
                                     kind: Struct,
-                                    description: "struct B",
+                                    description: "struct B<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3116,7 +3116,7 @@ fn foo(a$0rg: &impl ImplTrait<B<dyn DynTrait<B<S>>>>) {}
                                     focus_range: 28..36,
                                     name: "DynTrait",
                                     kind: Trait,
-                                    description: "trait DynTrait",
+                                    description: "trait DynTrait<T>",
                                 },
                             },
                             HoverGotoTypeData {
@@ -3582,6 +3582,17 @@ mod foo$0;
 "#,
             expect![[r#"
                 *foo*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                mod foo
+                ```
+
+                ---
+
                 For the horde!
             "#]],
         );
@@ -3606,7 +3617,7 @@ use foo::bar::{self$0};
                 ```
 
                 ```rust
-                pub mod bar
+                mod bar
                 ```
 
                 ---
@@ -3657,4 +3668,43 @@ cosnt _: &str$0 = ""; }"#;
             "#]],
         );
     }
+
+    #[test]
+    fn hover_macro_expanded_function() {
+        check(
+            r#"
+struct S<'a, T>(&'a T);
+trait Clone {}
+macro_rules! foo {
+    () => {
+        fn bar<'t, T: Clone + 't>(s: &mut S<'t, T>, t: u32) -> *mut u32 where
+            't: 't + 't,
+            for<'a> T: Clone + 'a
+        { 0 as _ }
+    };
+}
+
+foo!();
+
+fn main() {
+    bar$0;
+}
+"#,
+            expect![[r#"
+                *bar*
+
+                ```rust
+                test
+                ```
+
+                ```rust
+                fn bar<'t, T>(s: &mut S<'t, T>, t: u32) -> *mut u32
+                where
+                    T: Clone + 't,
+                    't: 't + 't,
+                    for<'a> T: Clone + 'a,
+                ```
+            "#]],
+        )
+    }
 }
diff --git a/crates/ide/src/join_lines.rs b/crates/ide/src/join_lines.rs
index d571ed559..4b25135cd 100644
--- a/crates/ide/src/join_lines.rs
+++ b/crates/ide/src/join_lines.rs
@@ -32,29 +32,35 @@ pub(crate) fn join_lines(file: &SourceFile, range: TextRange) -> TextEdit {
         range
     };
 
-    let node = match file.syntax().covering_element(range) {
-        NodeOrToken::Node(node) => node,
-        NodeOrToken::Token(token) => token.parent(),
-    };
     let mut edit = TextEdit::builder();
-    for token in node.descendants_with_tokens().filter_map(|it| it.into_token()) {
-        let range = match range.intersect(token.text_range()) {
-            Some(range) => range,
-            None => continue,
-        } - token.text_range().start();
-        let text = token.text();
-        for (pos, _) in text[range].bytes().enumerate().filter(|&(_, b)| b == b'\n') {
-            let pos: TextSize = (pos as u32).into();
-            let offset = token.text_range().start() + range.start() + pos;
-            if !edit.invalidates_offset(offset) {
-                remove_newline(&mut edit, &token, offset);
+    match file.syntax().covering_element(range) {
+        NodeOrToken::Node(node) => {
+            for token in node.descendants_with_tokens().filter_map(|it| it.into_token()) {
+                remove_newlines(&mut edit, &token, range)
             }
         }
-    }
-
+        NodeOrToken::Token(token) => remove_newlines(&mut edit, &token, range),
+    };
     edit.finish()
 }
 
+fn remove_newlines(edit: &mut TextEditBuilder, token: &SyntaxToken, range: TextRange) {
+    let intersection = match range.intersect(token.text_range()) {
+        Some(range) => range,
+        None => return,
+    };
+
+    let range = intersection - token.text_range().start();
+    let text = token.text();
+    for (pos, _) in text[range].bytes().enumerate().filter(|&(_, b)| b == b'\n') {
+        let pos: TextSize = (pos as u32).into();
+        let offset = token.text_range().start() + range.start() + pos;
+        if !edit.invalidates_offset(offset) {
+            remove_newline(edit, &token, offset);
+        }
+    }
+}
+
 fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextSize) {
     if token.kind() != WHITESPACE || token.text().bytes().filter(|&b| b == b'\n').count() != 1 {
         let mut string_open_quote = false;
@@ -148,7 +154,7 @@ fn has_comma_after(node: &SyntaxNode) -> bool {
 }
 
 fn join_single_expr_block(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Option<()> {
-    let block_expr = ast::BlockExpr::cast(token.parent())?;
+    let block_expr = ast::BlockExpr::cast(token.parent()?)?;
     if !block_expr.is_standalone() {
         return None;
     }
@@ -170,7 +176,7 @@ fn join_single_expr_block(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Op
 }
 
 fn join_single_use_tree(edit: &mut TextEditBuilder, token: &SyntaxToken) -> Option<()> {
-    let use_tree_list = ast::UseTreeList::cast(token.parent())?;
+    let use_tree_list = ast::UseTreeList::cast(token.parent()?)?;
     let (tree,) = use_tree_list.use_trees().collect_tuple()?;
     edit.replace(use_tree_list.syntax().text_range(), tree.syntax().text().to_string());
     Some(())
diff --git a/crates/ide/src/matching_brace.rs b/crates/ide/src/matching_brace.rs
index 000c412d9..4241a6dac 100644
--- a/crates/ide/src/matching_brace.rs
+++ b/crates/ide/src/matching_brace.rs
@@ -25,7 +25,7 @@ pub(crate) fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<Text
             Some((node, idx))
         })
         .next()?;
-    let parent = brace_token.parent();
+    let parent = brace_token.parent()?;
     if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
         cov_mark::hit!(pipes_not_braces);
         return None;
diff --git a/crates/ide/src/parent_module.rs b/crates/ide/src/parent_module.rs
index 03d71b380..22b0d6ecb 100644
--- a/crates/ide/src/parent_module.rs
+++ b/crates/ide/src/parent_module.rs
@@ -1,6 +1,7 @@
 use hir::Semantics;
 use ide_db::base_db::{CrateId, FileId, FilePosition};
 use ide_db::RootDatabase;
+use itertools::Itertools;
 use syntax::{
     algo::find_node_at_offset,
     ast::{self, AstNode},
@@ -18,8 +19,7 @@ use crate::NavigationTarget;
 // | VS Code | **Rust Analyzer: Locate parent module**
 // |===
 
-/// This returns `Vec` because a module may be included from several places. We
-/// don't handle this case yet though, so the Vec has length at most one.
+/// This returns `Vec` because a module may be included from several places.
 pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<NavigationTarget> {
     let sema = Semantics::new(db);
     let source_file = sema.parse(position.file_id);
@@ -37,27 +37,23 @@ pub(crate) fn parent_module(db: &RootDatabase, position: FilePosition) -> Vec<Na
         }
     }
 
-    let module = match module {
-        Some(module) => sema.to_def(&module),
-        None => sema.to_module_def(position.file_id),
-    };
-    let module = match module {
-        None => return Vec::new(),
-        Some(it) => it,
-    };
-    let nav = NavigationTarget::from_module_to_decl(db, module);
-    vec![nav]
+    match module {
+        Some(module) => sema
+            .to_def(&module)
+            .into_iter()
+            .map(|module| NavigationTarget::from_module_to_decl(db, module))
+            .collect(),
+        None => sema
+            .to_module_defs(position.file_id)
+            .map(|module| NavigationTarget::from_module_to_decl(db, module))
+            .collect(),
+    }
 }
 
 /// Returns `Vec` for the same reason as `parent_module`
 pub(crate) fn crate_for(db: &RootDatabase, file_id: FileId) -> Vec<CrateId> {
     let sema = Semantics::new(db);
-    let module = match sema.to_module_def(file_id) {
-        Some(it) => it,
-        None => return Vec::new(),
-    };
-    let krate = module.krate();
-    vec![krate.into()]
+    sema.to_module_defs(file_id).map(|module| module.krate().into()).unique().collect()
 }
 
 #[cfg(test)]
@@ -67,11 +63,13 @@ mod tests {
     use crate::fixture;
 
     fn check(ra_fixture: &str) {
-        let (analysis, position, expected) = fixture::nav_target_annotation(ra_fixture);
-        let mut navs = analysis.parent_module(position).unwrap();
-        assert_eq!(navs.len(), 1);
-        let nav = navs.pop().unwrap();
-        assert_eq!(expected, FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() });
+        let (analysis, position, expected) = fixture::annotations(ra_fixture);
+        let navs = analysis.parent_module(position).unwrap();
+        let navs = navs
+            .iter()
+            .map(|nav| FileRange { file_id: nav.file_id, range: nav.focus_or_full_range() })
+            .collect::<Vec<_>>();
+        assert_eq!(expected.into_iter().map(|(fr, _)| fr).collect::<Vec<_>>(), navs);
     }
 
     #[test]
@@ -120,15 +118,46 @@ mod foo {
     }
 
     #[test]
-    fn test_resolve_crate_root() {
-        let (analysis, file_id) = fixture::file(
+    fn test_resolve_multi_parent_module() {
+        check(
             r#"
 //- /main.rs
 mod foo;
+  //^^^
+#[path = "foo.rs"]
+mod bar;
+  //^^^
+//- /foo.rs
+$0
+"#,
+        );
+    }
+
+    #[test]
+    fn test_resolve_crate_root() {
+        let (analysis, file_id) = fixture::file(
+            r#"
 //- /foo.rs
 $0
+//- /main.rs
+mod foo;
 "#,
         );
         assert_eq!(analysis.crate_for(file_id).unwrap().len(), 1);
     }
+
+    #[test]
+    fn test_resolve_multi_parent_crate() {
+        let (analysis, file_id) = fixture::file(
+            r#"
+//- /baz.rs
+$0
+//- /foo.rs crate:foo
+mod baz;
+//- /bar.rs crate:bar
+mod baz;
+"#,
+        );
+        assert_eq!(analysis.crate_for(file_id).unwrap().len(), 2);
+    }
 }
diff --git a/crates/ide/src/references.rs b/crates/ide/src/references.rs
index e10a3ccf7..379674530 100644
--- a/crates/ide/src/references.rs
+++ b/crates/ide/src/references.rs
@@ -148,14 +148,15 @@ fn decl_access(def: &Definition, syntax: &SyntaxNode, range: TextRange) -> Optio
 
 fn get_name_of_item_declaration(syntax: &SyntaxNode, position: FilePosition) -> Option<ast::Name> {
     let token = syntax.token_at_offset(position.offset).right_biased()?;
+    let token_parent = token.parent()?;
     let kind = token.kind();
     if kind == T![;] {
-        ast::Struct::cast(token.parent())
+        ast::Struct::cast(token_parent)
             .filter(|struct_| struct_.field_list().is_none())
             .and_then(|struct_| struct_.name())
     } else if kind == T!['{'] {
         match_ast! {
-            match (token.parent()) {
+            match token_parent {
                 ast::RecordFieldList(rfl) => match_ast! {
                     match (rfl.syntax().parent()?) {
                         ast::Variant(it) => it.name(),
@@ -169,7 +170,7 @@ fn get_name_of_item_declaration(syntax: &SyntaxNode, position: FilePosition) ->
             }
         }
     } else if kind == T!['('] {
-        let tfl = ast::TupleFieldList::cast(token.parent())?;
+        let tfl = ast::TupleFieldList::cast(token_parent)?;
         match_ast! {
             match (tfl.syntax().parent()?) {
                 ast::Variant(it) => it.name(),
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 0c7a8fbf8..397e2126b 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -167,8 +167,7 @@ fn find_related_tests(
             let functions = refs.iter().filter_map(|(range, _)| {
                 let token = file.token_at_offset(range.start()).next()?;
                 let token = sema.descend_into_macros(token);
-                let syntax = token.parent();
-                syntax.ancestors().find_map(ast::Fn::cast)
+                token.ancestors().find_map(ast::Fn::cast)
             });
 
             for fn_def in functions {
diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index 9bed329d8..870146d24 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -64,7 +64,7 @@ pub(crate) fn highlight(
             Some(range) => {
                 let node = match source_file.syntax().covering_element(range) {
                     NodeOrToken::Node(it) => it,
-                    NodeOrToken::Token(it) => it.parent(),
+                    NodeOrToken::Token(it) => it.parent().unwrap(),
                 };
                 (node, range)
             }
@@ -167,16 +167,19 @@ fn traverse(
         let element_to_highlight = if current_macro_call.is_some() && element.kind() != COMMENT {
             // Inside a macro -- expand it first
             let token = match element.clone().into_token() {
-                Some(it) if it.parent().kind() == TOKEN_TREE => it,
+                Some(it) if it.parent().map_or(false, |it| it.kind() == TOKEN_TREE) => it,
                 _ => continue,
             };
             let token = sema.descend_into_macros(token.clone());
-            let parent = token.parent();
-
-            // We only care Name and Name_ref
-            match (token.kind(), parent.kind()) {
-                (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
-                _ => token.into(),
+            match token.parent() {
+                Some(parent) => {
+                    // We only care Name and Name_ref
+                    match (token.kind(), parent.kind()) {
+                        (IDENT, NAME) | (IDENT, NAME_REF) => parent.into(),
+                        _ => token.into(),
+                    }
+                }
+                None => token.into(),
             }
         } else {
             element.clone()
diff --git a/crates/ide/src/syntax_highlighting/format.rs b/crates/ide/src/syntax_highlighting/format.rs
index 8c67a0863..e503abc93 100644
--- a/crates/ide/src/syntax_highlighting/format.rs
+++ b/crates/ide/src/syntax_highlighting/format.rs
@@ -28,7 +28,7 @@ pub(super) fn highlight_format_string(
 }
 
 fn is_format_string(string: &ast::String) -> Option<()> {
-    let parent = string.syntax().parent();
+    let parent = string.syntax().parent()?;
 
     let name = parent.parent().and_then(ast::MacroCall::cast)?.path()?.segment()?.name_ref()?;
     if !matches!(name.text(), "format_args" | "format_args_nl") {
diff --git a/crates/ide/src/syntax_tree.rs b/crates/ide/src/syntax_tree.rs
index f979ba434..8979de528 100644
--- a/crates/ide/src/syntax_tree.rs
+++ b/crates/ide/src/syntax_tree.rs
@@ -27,7 +27,7 @@ pub(crate) fn syntax_tree(
                 if let Some(tree) = syntax_tree_for_string(&token, text_range) {
                     return tree;
                 }
-                token.parent()
+                token.parent().unwrap()
             }
         };
 
diff --git a/crates/ide/src/typing.rs b/crates/ide/src/typing.rs
index a718faf63..e10b7d98e 100644
--- a/crates/ide/src/typing.rs
+++ b/crates/ide/src/typing.rs
@@ -108,7 +108,7 @@ fn on_dot_typed(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
     };
     let current_indent_len = TextSize::of(current_indent);
 
-    let parent = whitespace.syntax().parent();
+    let parent = whitespace.syntax().parent()?;
     // Make sure dot is a part of call chain
     if !matches!(parent.kind(), FIELD_EXPR | METHOD_CALL_EXPR) {
         return None;