1 files changed, 696 insertions, 0 deletions

diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
new file mode 100644
index 000000000..c10a6c844
--- /dev/null
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -0,0 +1,696 @@
+//! FIXME: write short doc here
+
+use hir::{db::AstDatabase, Source};
+use ra_syntax::{
+    ast::{self, DocCommentsOwner},
+    match_ast, AstNode, SyntaxNode,
+};
+
+use crate::{
+    db::RootDatabase,
+    display::{ShortLabel, ToNav},
+    expand::descend_into_macros,
+    references::{classify_name_ref, NameKind::*},
+    FilePosition, NavigationTarget, RangeInfo,
+};
+
+pub(crate) fn goto_definition(
+    db: &RootDatabase,
+    position: FilePosition,
+) -> Option<RangeInfo<Vec<NavigationTarget>>> {
+    let file = db.parse_or_expand(position.file_id.into())?;
+    let token = file.token_at_offset(position.offset).filter(|it| !it.kind().is_trivia()).next()?;
+    let token = descend_into_macros(db, position.file_id, token);
+
+    let res = match_ast! {
+        match (token.value.parent()) {
+            ast::NameRef(name_ref) => {
+                let navs = reference_definition(db, token.with_value(&name_ref)).to_vec();
+                RangeInfo::new(name_ref.syntax().text_range(), navs.to_vec())
+            },
+            ast::Name(name) => {
+                let navs = name_definition(db, token.with_value(&name))?;
+                RangeInfo::new(name.syntax().text_range(), navs)
+
+            },
+            _ => return None,
+        }
+    };
+
+    Some(res)
+}
+
+#[derive(Debug)]
+pub(crate) enum ReferenceResult {
+    Exact(NavigationTarget),
+    Approximate(Vec<NavigationTarget>),
+}
+
+impl ReferenceResult {
+    fn to_vec(self) -> Vec<NavigationTarget> {
+        use self::ReferenceResult::*;
+        match self {
+            Exact(target) => vec![target],
+            Approximate(vec) => vec,
+        }
+    }
+}
+
+pub(crate) fn reference_definition(
+    db: &RootDatabase,
+    name_ref: Source<&ast::NameRef>,
+) -> ReferenceResult {
+    use self::ReferenceResult::*;
+
+    let name_kind = classify_name_ref(db, name_ref).map(|d| d.kind);
+    match name_kind {
+        Some(Macro(mac)) => return Exact(mac.to_nav(db)),
+        Some(Field(field)) => return Exact(field.to_nav(db)),
+        Some(AssocItem(assoc)) => return Exact(assoc.to_nav(db)),
+        Some(Def(def)) => match NavigationTarget::from_def(db, def) {
+            Some(nav) => return Exact(nav),
+            None => return Approximate(vec![]),
+        },
+        Some(SelfType(imp)) => {
+            // FIXME: ideally, this should point to the type in the impl, and
+            // not at the whole impl. And goto **type** definition should bring
+            // us to the actual type
+            return Exact(imp.to_nav(db));
+        }
+        Some(Local(local)) => return Exact(local.to_nav(db)),
+        Some(GenericParam(_)) => {
+            // FIXME: go to the generic param def
+        }
+        None => {}
+    };
+
+    // Fallback index based approach:
+    let navs = crate::symbol_index::index_resolve(db, name_ref.value)
+        .into_iter()
+        .map(|s| s.to_nav(db))
+        .collect();
+    Approximate(navs)
+}
+
+pub(crate) fn name_definition(
+    db: &RootDatabase,
+    name: Source<&ast::Name>,
+) -> Option<Vec<NavigationTarget>> {
+    let parent = name.value.syntax().parent()?;
+
+    if let Some(module) = ast::Module::cast(parent.clone()) {
+        if module.has_semi() {
+            let src = name.with_value(module);
+            if let Some(child_module) = hir::Module::from_declaration(db, src) {
+                let nav = child_module.to_nav(db);
+                return Some(vec![nav]);
+            }
+        }
+    }
+
+    if let Some(nav) = named_target(db, name.with_value(&parent)) {
+        return Some(vec![nav]);
+    }
+
+    None
+}
+
+fn named_target(db: &RootDatabase, node: Source<&SyntaxNode>) -> Option<NavigationTarget> {
+    match_ast! {
+        match (node.value) {
+            ast::StructDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::EnumDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::EnumVariant(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::FnDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::TypeAliasDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::ConstDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::StaticDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::TraitDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::RecordFieldDef(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::Module(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    it.short_label(),
+                ))
+            },
+            ast::MacroCall(it) => {
+                Some(NavigationTarget::from_named(
+                    db,
+                    node.with_value(&it),
+                    it.doc_comment_text(),
+                    None,
+                ))
+            },
+            _ => None,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use test_utils::covers;
+
+    use crate::mock_analysis::analysis_and_position;
+
+    fn check_goto(fixture: &str, expected: &str) {
+        let (analysis, pos) = analysis_and_position(fixture);
+
+        let mut navs = analysis.goto_definition(pos).unwrap().unwrap().info;
+        assert_eq!(navs.len(), 1);
+        let nav = navs.pop().unwrap();
+        nav.assert_match(expected);
+    }
+
+    #[test]
+    fn goto_definition_works_in_items() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            enum E { X(Foo<|>) }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 11) [7; 10)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_resolves_correct_name() {
+        check_goto(
+            "
+            //- /lib.rs
+            use a::Foo;
+            mod a;
+            mod b;
+            enum E { X(Foo<|>) }
+            //- /a.rs
+            struct Foo;
+            //- /b.rs
+            struct Foo;
+            ",
+            "Foo STRUCT_DEF FileId(2) [0; 11) [7; 10)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_module_declaration() {
+        check_goto(
+            "
+            //- /lib.rs
+            mod <|>foo;
+            //- /foo.rs
+            // empty
+            ",
+            "foo SOURCE_FILE FileId(2) [0; 10)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            mod <|>foo;
+            //- /foo/mod.rs
+            // empty
+            ",
+            "foo SOURCE_FILE FileId(2) [0; 10)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macros() {
+        covers!(goto_definition_works_for_macros);
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! foo {
+                () => {
+                    {}
+                };
+            }
+
+            fn bar() {
+                <|>foo!();
+            }
+            ",
+            "foo MACRO_CALL FileId(1) [0; 50) [13; 16)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macros_from_other_crates() {
+        covers!(goto_definition_works_for_macros);
+        check_goto(
+            "
+            //- /lib.rs
+            use foo::foo;
+            fn bar() {
+                <|>foo!();
+            }
+
+            //- /foo/lib.rs
+            #[macro_export]
+            macro_rules! foo {
+                () => {
+                    {}
+                };
+            }
+            ",
+            "foo MACRO_CALL FileId(2) [0; 66) [29; 32)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macros_in_use_tree() {
+        check_goto(
+            "
+            //- /lib.rs
+            use foo::foo<|>;
+
+            //- /foo/lib.rs
+            #[macro_export]
+            macro_rules! foo {
+                () => {
+                    {}
+                };
+            }
+            ",
+            "foo MACRO_CALL FileId(2) [0; 66) [29; 32)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macro_defined_fn_with_arg() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! define_fn {
+                ($name:ident) => (fn $name() {})
+            }
+
+            define_fn!(
+                foo
+            )
+
+            fn bar() {
+               <|>foo();
+            }
+            ",
+            "foo FN_DEF FileId(1) [80; 83) [80; 83)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_macro_defined_fn_no_arg() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! define_fn {
+                () => (fn foo() {})
+            }
+
+            define_fn!();
+
+            fn bar() {
+               <|>foo();
+            }
+            ",
+            "foo FN_DEF FileId(1) [39; 42) [39; 42)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_methods() {
+        covers!(goto_definition_works_for_methods);
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                fn frobnicate(&self) {  }
+            }
+
+            fn bar(foo: &Foo) {
+                foo.frobnicate<|>();
+            }
+            ",
+            "frobnicate FN_DEF FileId(1) [27; 52) [30; 40)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_fields() {
+        covers!(goto_definition_works_for_fields);
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo {
+                spam: u32,
+            }
+
+            fn bar(foo: &Foo) {
+                foo.spam<|>;
+            }
+            ",
+            "spam RECORD_FIELD_DEF FileId(1) [17; 26) [17; 21)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_record_fields() {
+        covers!(goto_definition_works_for_record_fields);
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo {
+                spam: u32,
+            }
+
+            fn bar() -> Foo {
+                Foo {
+                    spam<|>: 0,
+                }
+            }
+            ",
+            "spam RECORD_FIELD_DEF FileId(1) [17; 26) [17; 21)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_ufcs_inherent_methods() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                fn frobnicate() {  }
+            }
+
+            fn bar(foo: &Foo) {
+                Foo::frobnicate<|>();
+            }
+            ",
+            "frobnicate FN_DEF FileId(1) [27; 47) [30; 40)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_ufcs_trait_methods_through_traits() {
+        check_goto(
+            "
+            //- /lib.rs
+            trait Foo {
+                fn frobnicate();
+            }
+
+            fn bar() {
+                Foo::frobnicate<|>();
+            }
+            ",
+            "frobnicate FN_DEF FileId(1) [16; 32) [19; 29)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_for_ufcs_trait_methods_through_self() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            trait Trait {
+                fn frobnicate();
+            }
+            impl Trait for Foo {}
+
+            fn bar() {
+                Foo::frobnicate<|>();
+            }
+            ",
+            "frobnicate FN_DEF FileId(1) [30; 46) [33; 43)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_on_self() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                pub fn new() -> Self {
+                    Self<|> {}
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [12; 73)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            impl Foo {
+                pub fn new() -> Self<|> {
+                    Self {}
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [12; 73)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo { A }
+            impl Foo {
+                pub fn new() -> Self<|> {
+                    Foo::A
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [15; 75)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo { A }
+            impl Foo {
+                pub fn thing(a: &Self<|>) {
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [15; 62)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_on_self_in_trait_impl() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            trait Make {
+                fn new() -> Self;
+            }
+            impl Make for Foo {
+                fn new() -> Self {
+                    Self<|> {}
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [49; 115)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo;
+            trait Make {
+                fn new() -> Self;
+            }
+            impl Make for Foo {
+                fn new() -> Self<|> {
+                    Self {}
+                }
+            }
+            ",
+            "impl IMPL_BLOCK FileId(1) [49; 115)",
+        );
+    }
+
+    #[test]
+    fn goto_definition_works_when_used_on_definition_name_itself() {
+        check_goto(
+            "
+            //- /lib.rs
+            struct Foo<|> { value: u32 }
+            ",
+            "Foo STRUCT_DEF FileId(1) [0; 25) [7; 10)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            struct Foo {
+                field<|>: string,
+            }
+            "#,
+            "field RECORD_FIELD_DEF FileId(1) [17; 30) [17; 22)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            fn foo_test<|>() {
+            }
+            ",
+            "foo_test FN_DEF FileId(1) [0; 17) [3; 11)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo<|> {
+                Variant,
+            }
+            ",
+            "Foo ENUM_DEF FileId(1) [0; 25) [5; 8)",
+        );
+
+        check_goto(
+            "
+            //- /lib.rs
+            enum Foo {
+                Variant1,
+                Variant2<|>,
+                Variant3,
+            }
+            ",
+            "Variant2 ENUM_VARIANT FileId(1) [29; 37) [29; 37)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            static inner<|>: &str = "";
+            "#,
+            "inner STATIC_DEF FileId(1) [0; 24) [7; 12)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            const inner<|>: &str = "";
+            "#,
+            "inner CONST_DEF FileId(1) [0; 23) [6; 11)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            type Thing<|> = Option<()>;
+            "#,
+            "Thing TYPE_ALIAS_DEF FileId(1) [0; 24) [5; 10)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            trait Foo<|> {
+            }
+            "#,
+            "Foo TRAIT_DEF FileId(1) [0; 13) [6; 9)",
+        );
+
+        check_goto(
+            r#"
+            //- /lib.rs
+            mod bar<|> {
+            }
+            "#,
+            "bar MODULE FileId(1) [0; 11) [4; 7)",
+        );
+    }
+
+    #[test]
+    fn goto_from_macro() {
+        check_goto(
+            "
+            //- /lib.rs
+            macro_rules! id {
+                ($($tt:tt)*) => { $($tt)* }
+            }
+            fn foo() {}
+            id! {
+                fn bar() {
+                    fo<|>o();
+                }
+            }
+            ",
+            "foo FN_DEF FileId(1) [52; 63) [55; 58)",
+        );
+    }
+}