Add `Go to Type Definition` hover action.

8 files changed, 956 insertions, 35 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 1a9f6cc76..c22eb451b 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -26,8 +26,8 @@ use hir_ty::{
     autoderef,
     display::{HirDisplayError, HirFormatter},
     expr::ExprValidator,
-    method_resolution, ApplicationTy, Canonical, InEnvironment, Substs, TraitEnvironment, Ty,
-    TyDefId, TypeCtor,
+    method_resolution, ApplicationTy, Canonical, GenericPredicate, InEnvironment, OpaqueTyId,
+    Substs, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
 };
 use ra_db::{CrateId, CrateName, Edition, FileId};
 use ra_prof::profile;
@@ -1380,6 +1380,87 @@ impl Type {
             ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
         }
     }
+
+    /// Returns a flattened list of all the ADTs and Traits mentioned in the type
+    pub fn flattened_type_items(&self, db: &dyn HirDatabase) -> Vec<AdtOrTrait> {
+        fn push_new_item(item: AdtOrTrait, acc: &mut Vec<AdtOrTrait>) {
+            if !acc.contains(&item) {
+                acc.push(item);
+            }
+        }
+
+        fn push_bounds(
+            db: &dyn HirDatabase,
+            predicates: &[GenericPredicate],
+            acc: &mut Vec<AdtOrTrait>,
+        ) {
+            for p in predicates.iter() {
+                match p {
+                    GenericPredicate::Implemented(trait_ref) => {
+                        push_new_item(Trait::from(trait_ref.trait_).into(), acc);
+                        walk_types(db, &trait_ref.substs, acc);
+                    }
+                    GenericPredicate::Projection(_) => {}
+                    GenericPredicate::Error => (),
+                }
+            }
+        }
+
+        fn walk_types<T: TypeWalk>(db: &dyn HirDatabase, tw: &T, acc: &mut Vec<AdtOrTrait>) {
+            tw.walk(&mut |ty| walk_type(db, ty, acc));
+        }
+
+        fn walk_type(db: &dyn HirDatabase, ty: &Ty, acc: &mut Vec<AdtOrTrait>) {
+            match ty.strip_references() {
+                Ty::Apply(ApplicationTy { ctor, parameters, .. }) => {
+                    match ctor {
+                        TypeCtor::Adt(adt_id) => push_new_item(Adt::from(*adt_id).into(), acc),
+                        _ => (),
+                    }
+                    // adt params, tuples, etc...
+                    walk_types(db, parameters, acc);
+                }
+                Ty::Dyn(predicates) => {
+                    push_bounds(db, predicates, acc);
+                }
+                Ty::Placeholder(id) => {
+                    let generic_params = db.generic_params(id.parent);
+                    let param_data = &generic_params.types[id.local_id];
+                    match param_data.provenance {
+                        hir_def::generics::TypeParamProvenance::ArgumentImplTrait => {
+                            let predicates: Vec<_> = db
+                                .generic_predicates_for_param(*id)
+                                .into_iter()
+                                .map(|pred| pred.value.clone())
+                                .collect();
+                            push_bounds(db, &predicates, acc);
+                        }
+                        _ => (),
+                    }
+                }
+                Ty::Opaque(opaque_ty) => {
+                    let bounds = match opaque_ty.opaque_ty_id {
+                        OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
+                            let datas = db
+                                .return_type_impl_traits(func)
+                                .expect("impl trait id without data");
+                            let data = (*datas)
+                                .as_ref()
+                                .map(|rpit| rpit.impl_traits[idx as usize].bounds.clone());
+                            data.clone().subst(&opaque_ty.parameters)
+                        }
+                    };
+                    push_bounds(db, &bounds.value, acc);
+                    walk_types(db, &opaque_ty.parameters, acc);
+                }
+                _ => (),
+            }
+        }
+
+        let mut res: Vec<AdtOrTrait> = Vec::new(); // not a Set to preserve the order
+        walk_type(db, &self.ty.value, &mut res);
+        res
+    }
 }
 
 impl HirDisplay for Type {
@@ -1488,3 +1569,26 @@ pub trait HasVisibility {
         vis.is_visible_from(db.upcast(), module.id)
     }
 }
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum AdtOrTrait {
+    Adt(Adt),
+    Trait(Trait),
+}
+impl_froms!(AdtOrTrait: Adt, Trait);
+
+impl AdtOrTrait {
+    pub fn module(self, db: &dyn HirDatabase) -> Module {
+        match self {
+            AdtOrTrait::Adt(adt) => adt.module(db),
+            AdtOrTrait::Trait(trait_) => trait_.module(db),
+        }
+    }
+
+    pub fn name(self, db: &dyn HirDatabase) -> Name {
+        match self {
+            AdtOrTrait::Adt(adt) => adt.name(db),
+            AdtOrTrait::Trait(trait_) => trait_.name(db),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3364a822f..eded039e4 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -51,10 +51,10 @@ mod has_source;
 
 pub use crate::{
     code_model::{
-        Adt, AsAssocItem, AssocItem, AssocItemContainer, AttrDef, Const, Crate, CrateDependency,
-        DefWithBody, Docs, Enum, EnumVariant, Field, FieldSource, Function, GenericDef, HasAttrs,
-        HasVisibility, ImplDef, Local, MacroDef, Module, ModuleDef, ScopeDef, Static, Struct,
-        Trait, Type, TypeAlias, TypeParam, Union, VariantDef, Visibility,
+        Adt, AdtOrTrait, AsAssocItem, AssocItem, AssocItemContainer, AttrDef, Const, Crate,
+        CrateDependency, DefWithBody, Docs, Enum, EnumVariant, Field, FieldSource, Function,
+        GenericDef, HasAttrs, HasVisibility, ImplDef, Local, MacroDef, Module, ModuleDef, ScopeDef,
+        Static, Struct, Trait, Type, TypeAlias, TypeParam, Union, VariantDef, Visibility,
     },
     has_source::HasSource,
     semantics::{original_range, PathResolution, Semantics, SemanticsScope},
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 2b9372b4b..9d4d6aaa4 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -1052,10 +1052,10 @@ pub enum OpaqueTyId {
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub struct ReturnTypeImplTraits {
-    pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
+    pub impl_traits: Vec<ReturnTypeImplTrait>,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
-pub(crate) struct ReturnTypeImplTrait {
-    pub(crate) bounds: Binders<Vec<GenericPredicate>>,
+pub struct ReturnTypeImplTrait {
+    pub bounds: Binders<Vec<GenericPredicate>>,
 }
diff --git a/crates/ra_ide/src/display/navigation_target.rs b/crates/ra_ide/src/display/navigation_target.rs
index c7bb1e69f..325b247bb 100644
--- a/crates/ra_ide/src/display/navigation_target.rs
+++ b/crates/ra_ide/src/display/navigation_target.rs
@@ -321,6 +321,15 @@ impl ToNav for hir::Adt {
     }
 }
 
+impl ToNav for hir::AdtOrTrait {
+    fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
+        match self {
+            hir::AdtOrTrait::Adt(adt) => adt.to_nav(db),
+            hir::AdtOrTrait::Trait(trait_) => trait_.to_nav(db),
+        }
+    }
+}
+
 impl ToNav for hir::AssocItem {
     fn to_nav(&self, db: &RootDatabase) -> NavigationTarget {
         match self {
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index ad78b7671..c434e5c8b 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -1,8 +1,8 @@
 use std::iter::once;
 
 use hir::{
-    Adt, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource, HirDisplay,
-    ModuleDef, ModuleSource, Semantics,
+    Adt, AdtOrTrait, AsAssocItem, AssocItemContainer, Documentation, FieldSource, HasSource,
+    HirDisplay, Module, ModuleDef, ModuleSource, Semantics,
 };
 use itertools::Itertools;
 use ra_db::SourceDatabase;
@@ -24,19 +24,21 @@ pub struct HoverConfig {
     pub implementations: bool,
     pub run: bool,
     pub debug: bool,
+    pub goto_type_def: bool,
 }
 
 impl Default for HoverConfig {
     fn default() -> Self {
-        Self { implementations: true, run: true, debug: true }
+        Self { implementations: true, run: true, debug: true, goto_type_def: true }
     }
 }
 
 impl HoverConfig {
-    pub const NO_ACTIONS: Self = Self { implementations: false, run: false, debug: false };
+    pub const NO_ACTIONS: Self =
+        Self { implementations: false, run: false, debug: false, goto_type_def: false };
 
     pub fn any(&self) -> bool {
-        self.implementations || self.runnable()
+        self.implementations || self.runnable() || self.goto_type_def
     }
 
     pub fn none(&self) -> bool {
@@ -52,6 +54,13 @@ impl HoverConfig {
 pub enum HoverAction {
     Runnable(Runnable),
     Implementaion(FilePosition),
+    GoToType(Vec<HoverGotoTypeData>),
+}
+
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct HoverGotoTypeData {
+    pub mod_path: String,
+    pub nav: NavigationTarget,
 }
 
 /// Contains the results when hovering over an item
@@ -138,6 +147,10 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
                 res.push_action(action);
             }
 
+            if let Some(action) = goto_type_action(db, name_kind) {
+                res.push_action(action);
+            }
+
             return Some(RangeInfo::new(range, res));
         }
     }
@@ -218,6 +231,24 @@ fn runnable_action(
     }
 }
 
+fn goto_type_action(db: &RootDatabase, def: Definition) -> Option<HoverAction> {
+    match def {
+        Definition::Local(it) => {
+            let ty = it.ty(db);
+            let v = ty.flattened_type_items(db);
+            let targets = v.into_iter()
+                .map(|it| HoverGotoTypeData {
+                    mod_path: adt_or_trait_mod_path(db, &it),
+                    nav: it.to_nav(db),
+                })
+                .collect_vec();
+
+            Some(HoverAction::GoToType(targets))
+        }
+        _ => None,
+    }
+}
+
 fn hover_text(
     docs: Option<String>,
     desc: Option<String>,
@@ -248,25 +279,30 @@ fn definition_owner_name(db: &RootDatabase, def: &Definition) -> Option<String>
     .map(|name| name.to_string())
 }
 
-fn determine_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
-    let mod_path = def.module(db).map(|module| {
-        once(db.crate_graph()[module.krate().into()].display_name.as_ref().map(ToString::to_string))
-            .chain(
-                module
-                    .path_to_root(db)
-                    .into_iter()
-                    .rev()
-                    .map(|it| it.name(db).map(|name| name.to_string())),
-            )
-            .chain(once(definition_owner_name(db, def)))
-            .flatten()
-            .join("::")
-    });
-    mod_path
+fn determine_mod_path(db: &RootDatabase, module: Module, name: Option<String>) -> String {
+    once(db.crate_graph()[module.krate().into()].display_name.as_ref().map(ToString::to_string))
+        .chain(
+            module
+                .path_to_root(db)
+                .into_iter()
+                .rev()
+                .map(|it| it.name(db).map(|name| name.to_string())),
+        )
+        .chain(once(name))
+        .flatten()
+        .join("::")
+}
+
+fn adt_or_trait_mod_path(db: &RootDatabase, item: &AdtOrTrait) -> String {
+    determine_mod_path(db, item.module(db), Some(item.name(db).to_string()))
+}
+
+fn definition_mod_path(db: &RootDatabase, def: &Definition) -> Option<String> {
+    def.module(db).map(|module| determine_mod_path(db, module, definition_owner_name(db, def)))
 }
 
 fn hover_text_from_name_kind(db: &RootDatabase, def: Definition) -> Option<String> {
-    let mod_path = determine_mod_path(db, &def);
+    let mod_path = definition_mod_path(db, &def);
     return match def {
         Definition::Macro(it) => {
             let src = it.source(db);
@@ -1310,4 +1346,737 @@ fn func(foo: i32) { if true { <|>foo; }; }
             ]
             "###);
     }
+
+    #[test]
+    fn test_hover_struct_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            struct S{ f1: u32 }
+
+            fn main() {
+                let s<|>t = S{ f1:0 };
+            }
+            ",
+            &["S"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..19,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    7..8,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_goto_type_actions() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            struct Arg(u32);
+            struct S<T>{ f1: T }
+
+            fn main() {
+                let s<|>t = S{ f1:Arg(0) };
+            }
+            ",
+            &["S<Arg>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 17..37,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    24..25,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "Arg",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..16,
+                                name: "Arg",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    7..10,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct Arg",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_generic_struct_has_flattened_goto_type_actions() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            struct Arg(u32);
+            struct S<T>{ f1: T }
+
+            fn main() {
+                let s<|>t = S{ f1: S{ f1: Arg(0) } };
+            }
+            ",
+            &["S<S<Arg>>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 17..37,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    24..25,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "Arg",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..16,
+                                name: "Arg",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    7..10,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct Arg",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_tuple_has_goto_type_actions() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            struct A(u32);
+            struct B(u32);
+            mod M {
+                pub struct C(u32);
+            }
+
+            fn main() {
+                let s<|>t = (A(1), B(2), M::C(3) );
+            }
+            ",
+            &["(A, B, C)"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "A",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..14,
+                                name: "A",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    7..8,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct A",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "B",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 15..29,
+                                name: "B",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    22..23,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct B",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "M::C",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 42..60,
+                                name: "C",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    53..54,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "pub struct C",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+               "###);
+    }
+
+    #[test]
+    fn test_hover_return_impl_trait_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            trait Foo {}
+
+            fn foo() -> impl Foo {}
+
+            fn main() {
+                let s<|>t = foo();
+            }
+            ",
+            &["impl Foo"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..12,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_generic_return_impl_trait_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            trait Foo<T> {}
+            struct S;
+
+            fn foo() -> impl Foo<S> {}
+
+            fn main() {
+                let s<|>t = foo();
+            }
+            ",
+            &["impl Foo<S>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..15,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 16..25,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    23..24,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_arg_impl_trait_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait Foo {}
+            fn foo(ar<|>g: &impl Foo) {}
+            ",
+            &["&impl Foo"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..12,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_arg_generic_impl_trait_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait Foo<T> {}
+            struct S {}
+            fn foo(ar<|>g: &impl Foo<S>) {}
+            ",
+            &["&impl Foo<S>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..15,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 16..27,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    23..24,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_dyn_return_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /main.rs
+            trait Foo {}
+            struct S;
+            impl Foo for S {}
+
+            struct B<T>{}
+
+            fn foo() -> B<dyn Foo> {}
+
+            fn main() {
+                let s<|>t = foo();
+            }
+            ",
+            &["B<dyn Foo>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "B",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 41..54,
+                                name: "B",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    48..49,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct B",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..12,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_dyn_arg_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait Foo {}
+            fn foo(ar<|>g: &dyn Foo) {}
+            ",
+            &["&dyn Foo"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..12,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_generic_dyn_arg_has_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait Foo<T> {}
+            struct S {}
+            fn foo(ar<|>g: &dyn Foo<S>) {}
+            ",
+            &["&dyn Foo<S>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "Foo",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..15,
+                                name: "Foo",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..9,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait Foo",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 16..27,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    23..24,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
+
+    #[test]
+    fn test_hover_arg_goto_type_action() {
+        let (_, actions) = check_hover_result(
+            "
+            //- /lib.rs
+            trait ImplTrait<T> {}
+            trait DynTrait<T> {}
+            struct B<T> {}
+            struct S {}
+        
+            fn foo(a<|>rg: &impl ImplTrait<B<dyn DynTrait<S>>>) {}
+            ",
+            &["&impl ImplTrait<B<dyn DynTrait<S>>>"],
+        );
+        assert_debug_snapshot!(actions,
+            @r###"
+            [
+                GoToType(
+                    [
+                        HoverGotoTypeData {
+                            mod_path: "ImplTrait",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 0..21,
+                                name: "ImplTrait",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    6..15,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait ImplTrait",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "S",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 58..69,
+                                name: "S",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    65..66,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct S",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "DynTrait",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 22..42,
+                                name: "DynTrait",
+                                kind: TRAIT_DEF,
+                                focus_range: Some(
+                                    28..36,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "trait DynTrait",
+                                ),
+                                docs: None,
+                            },
+                        },
+                        HoverGotoTypeData {
+                            mod_path: "B",
+                            nav: NavigationTarget {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                full_range: 43..57,
+                                name: "B",
+                                kind: STRUCT_DEF,
+                                focus_range: Some(
+                                    50..51,
+                                ),
+                                container_name: None,
+                                description: Some(
+                                    "struct B",
+                                ),
+                                docs: None,
+                            },
+                        },
+                    ],
+                ),
+            ]
+            "###);
+    }
 }
diff --git a/crates/ra_ide/src/lib.rs b/crates/ra_ide/src/lib.rs
index 51dc1f041..be9ab62c0 100644
--- a/crates/ra_ide/src/lib.rs
+++ b/crates/ra_ide/src/lib.rs
@@ -66,7 +66,7 @@ pub use crate::{
     display::{file_structure, FunctionSignature, NavigationTarget, StructureNode},
     expand_macro::ExpandedMacro,
     folding_ranges::{Fold, FoldKind},
-    hover::{HoverAction, HoverConfig, HoverResult},
+    hover::{HoverAction, HoverConfig, HoverGotoTypeData, HoverResult},
     inlay_hints::{InlayHint, InlayHintsConfig, InlayKind},
     references::{Declaration, Reference, ReferenceAccess, ReferenceKind, ReferenceSearchResult},
     runnables::{Runnable, RunnableKind, TestId},
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 0df7427cb..aa2c4ae15 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -296,6 +296,7 @@ impl Config {
             set(value, "/hoverActions/implementations", &mut self.hover.implementations);
             set(value, "/hoverActions/run", &mut self.hover.run);
             set(value, "/hoverActions/debug", &mut self.hover.debug);
+            set(value, "/hoverActions/gotoTypeDef", &mut self.hover.goto_type_def);
         } else {
             self.hover = HoverConfig::NO_ACTIONS;
         }
diff --git a/crates/rust-analyzer/src/main_loop/handlers.rs b/crates/rust-analyzer/src/main_loop/handlers.rs
index f3868bf17..2d7e649d2 100644
--- a/crates/rust-analyzer/src/main_loop/handlers.rs
+++ b/crates/rust-analyzer/src/main_loop/handlers.rs
@@ -18,8 +18,8 @@ use lsp_types::{
     TextDocumentIdentifier, Url, WorkspaceEdit,
 };
 use ra_ide::{
-    FileId, FilePosition, FileRange, HoverAction, Query, RangeInfo, Runnable, RunnableKind,
-    SearchScope, TextEdit,
+    FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, NavigationTarget, Query,
+    RangeInfo, Runnable, RunnableKind, SearchScope, TextEdit,
 };
 use ra_prof::profile;
 use ra_project_model::TargetKind;
@@ -1150,6 +1150,23 @@ fn debug_single_command(runnable: &lsp_ext::Runnable) -> Command {
     }
 }
 
+fn goto_location_command(snap: &GlobalStateSnapshot, nav: &NavigationTarget) -> Option<Command> {
+    let value = if snap.config.client_caps.location_link {
+        let link = to_proto::location_link(snap, None, nav.clone()).ok()?;
+        to_value(link).ok()?
+    } else {
+        let range = FileRange { file_id: nav.file_id(), range: nav.range() };
+        let location = to_proto::location(snap, range).ok()?;
+        to_value(location).ok()?
+    };
+
+    Some(Command {
+        title: nav.name().to_string(),
+        command: "rust-analyzer.gotoLocation".into(),
+        arguments: Some(vec![value]),
+    })
+}
+
 fn to_command_link(command: Command, tooltip: String) -> lsp_ext::CommandLink {
     lsp_ext::CommandLink { tooltip: Some(tooltip), command }
 }
@@ -1180,7 +1197,7 @@ fn show_impl_command_link(
     None
 }
 
-fn to_runnable_action(
+fn runnable_action_links(
     snap: &GlobalStateSnapshot,
     file_id: FileId,
     runnable: Runnable,
@@ -1208,6 +1225,26 @@ fn to_runnable_action(
     })
 }
 
+fn goto_type_action_links(
+    snap: &GlobalStateSnapshot,
+    nav_targets: &[HoverGotoTypeData],
+) -> Option<lsp_ext::CommandLinkGroup> {
+    if !snap.config.hover.goto_type_def || nav_targets.is_empty() {
+        return None;
+    }
+
+    Some(lsp_ext::CommandLinkGroup {
+        title: Some("Go to ".into()),
+        commands: nav_targets
+            .iter()
+            .filter_map(|it| {
+                goto_location_command(snap, &it.nav)
+                    .map(|cmd| to_command_link(cmd, it.mod_path.clone()))
+            })
+            .collect(),
+    })
+}
+
 fn prepare_hover_actions(
     snap: &GlobalStateSnapshot,
     file_id: FileId,
@@ -1221,7 +1258,8 @@ fn prepare_hover_actions(
         .iter()
         .filter_map(|it| match it {
             HoverAction::Implementaion(position) => show_impl_command_link(snap, position),
-            HoverAction::Runnable(r) => to_runnable_action(snap, file_id, r.clone()),
+            HoverAction::Runnable(r) => runnable_action_links(snap, file_id, r.clone()),
+            HoverAction::GoToType(targets) => goto_type_action_links(snap, targets),
         })
         .collect()
 }