1 files changed, 135 insertions, 6 deletions

diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index a04333e63..2d36c34e9 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -1,10 +1,15 @@
+use std::convert::TryInto;
+
 use either::Either;
-use hir::{InFile, Semantics};
+use hir::{AsAssocItem, InFile, ModuleDef, Semantics};
 use ide_db::{
-    defs::{NameClass, NameRefClass},
+    base_db::{AnchoredPath, FileId, FileLoader},
+    defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
 };
-use syntax::{ast, match_ast, AstNode, AstToken, SyntaxKind::*, SyntaxToken, TokenAtOffset, T};
+use syntax::{
+    ast, match_ast, AstNode, AstToken, SyntaxKind::*, SyntaxToken, TextRange, TokenAtOffset, T,
+};
 
 use crate::{
     display::TryToNav,
@@ -32,7 +37,7 @@ pub(crate) fn goto_definition(
     let original_token = pick_best(file.token_at_offset(position.offset))?;
     let token = sema.descend_into_macros(original_token.clone());
     let parent = token.parent()?;
-    if let Some(_) = ast::Comment::cast(token) {
+    if let Some(_) = ast::Comment::cast(token.clone()) {
         let (attributes, def) = doc_attributes(&sema, &parent)?;
 
         let (docs, doc_mapping) = attributes.docs_with_rangemap(db)?;
@@ -45,7 +50,6 @@ pub(crate) fn goto_definition(
         let nav = resolve_doc_path_for_def(db, def, &link, ns)?.try_to_nav(db)?;
         return Some(RangeInfo::new(original_token.text_range(), vec![nav]));
     }
-
     let nav = match_ast! {
         match parent {
             ast::NameRef(name_ref) => {
@@ -53,7 +57,8 @@ pub(crate) fn goto_definition(
             },
             ast::Name(name) => {
                 let def = NameClass::classify(&sema, &name)?.referenced_or_defined(sema.db);
-                def.try_to_nav(sema.db)
+                try_find_trait_item_definition(&sema.db, &def)
+                    .or_else(|| def.try_to_nav(sema.db))
             },
             ast::Lifetime(lt) => if let Some(name_class) = NameClass::classify_lifetime(&sema, &lt) {
                 let def = name_class.referenced_or_defined(sema.db);
@@ -61,6 +66,7 @@ pub(crate) fn goto_definition(
             } else {
                 reference_definition(&sema, Either::Left(&lt))
             },
+            ast::TokenTree(tt) => try_lookup_include_path(sema.db, tt, token, position.file_id),
             _ => return None,
         }
     };
@@ -68,6 +74,60 @@ pub(crate) fn goto_definition(
     Some(RangeInfo::new(original_token.text_range(), nav.into_iter().collect()))
 }
 
+fn try_lookup_include_path(
+    db: &RootDatabase,
+    tt: ast::TokenTree,
+    token: SyntaxToken,
+    file_id: FileId,
+) -> Option<NavigationTarget> {
+    let path = ast::String::cast(token)?.value()?.into_owned();
+    let macro_call = tt.syntax().parent().and_then(ast::MacroCall::cast)?;
+    let name = macro_call.path()?.segment()?.name_ref()?;
+    if !matches!(&*name.text(), "include" | "include_str" | "include_bytes") {
+        return None;
+    }
+    let file_id = db.resolve_path(AnchoredPath { anchor: file_id, path: &path })?;
+    let size = db.file_text(file_id).len().try_into().ok()?;
+    Some(NavigationTarget {
+        file_id,
+        full_range: TextRange::new(0.into(), size),
+        name: path.into(),
+        focus_range: None,
+        kind: None,
+        container_name: None,
+        description: None,
+        docs: None,
+    })
+}
+
+/// finds the trait definition of an impl'd item
+/// e.g.
+/// ```rust
+/// trait A { fn a(); }
+/// struct S;
+/// impl A for S { fn a(); } // <-- on this function, will get the location of a() in the trait
+/// ```
+fn try_find_trait_item_definition(db: &RootDatabase, def: &Definition) -> Option<NavigationTarget> {
+    let name = def.name(db)?;
+    let assoc = match def {
+        Definition::ModuleDef(ModuleDef::Function(f)) => f.as_assoc_item(db),
+        Definition::ModuleDef(ModuleDef::Const(c)) => c.as_assoc_item(db),
+        Definition::ModuleDef(ModuleDef::TypeAlias(ty)) => ty.as_assoc_item(db),
+        _ => None,
+    }?;
+
+    let imp = match assoc.container(db) {
+        hir::AssocItemContainer::Impl(imp) => imp,
+        _ => return None,
+    };
+
+    let trait_ = imp.trait_(db)?;
+    trait_
+        .items(db)
+        .iter()
+        .find_map(|itm| (itm.name(db)? == name).then(|| itm.try_to_nav(db)).flatten())
+}
+
 fn pick_best(tokens: TokenAtOffset<SyntaxToken>) -> Option<SyntaxToken> {
     return tokens.max_by_key(priority);
     fn priority(n: &SyntaxToken) -> usize {
@@ -1216,4 +1276,73 @@ fn f(e: Enum) {
 "#,
         );
     }
+
+    #[test]
+    fn goto_include() {
+        check(
+            r#"
+//- /main.rs
+fn main() {
+    let str = include_str!("foo.txt$0");
+}
+//- /foo.txt
+// empty
+//^ file
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_of_trait_impl_fn() {
+        check(
+            r#"
+trait Twait {
+    fn a();
+    // ^
+}
+
+struct Stwuct;
+
+impl Twait for Stwuct {
+    fn a$0();
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_of_trait_impl_const() {
+        check(
+            r#"
+trait Twait {
+    const NOMS: bool;
+       // ^^^^
+}
+
+struct Stwuct;
+
+impl Twait for Stwuct {
+    const NOMS$0: bool = true;
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn goto_def_of_trait_impl_type_alias() {
+        check(
+            r#"
+trait Twait {
+    type IsBad;
+      // ^^^^^
+}
+
+struct Stwuct;
+
+impl Twait for Stwuct {
+    type IsBad$0 = !;
+}
+"#,
+        );
+    }
 }