3 files changed, 143 insertions, 10 deletions

diff --git a/crates/ide/src/expand_macro.rs b/crates/ide/src/expand_macro.rs
index e0d01fa96..3f38e2145 100644
--- a/crates/ide/src/expand_macro.rs
+++ b/crates/ide/src/expand_macro.rs
@@ -3,8 +3,7 @@ use std::iter;
 use hir::Semantics;
 use ide_db::RootDatabase;
 use syntax::{
-    algo::find_node_at_offset, ast, ted, AstNode, NodeOrToken, SyntaxKind, SyntaxKind::*,
-    SyntaxNode, WalkEvent, T,
+    ast, match_ast, ted, AstNode, NodeOrToken, SyntaxKind, SyntaxKind::*, SyntaxNode, WalkEvent, T,
 };
 
 use crate::FilePosition;
@@ -28,16 +27,37 @@ pub struct ExpandedMacro {
 pub(crate) fn expand_macro(db: &RootDatabase, position: FilePosition) -> Option<ExpandedMacro> {
     let sema = Semantics::new(db);
     let file = sema.parse(position.file_id);
-    let mac = find_node_at_offset::<ast::MacroCall>(file.syntax(), position.offset)?;
-    let name = mac.path()?.segment()?.name_ref()?;
 
-    let expanded = expand_macro_recur(&sema, &mac)?;
+    let tok = file.syntax().token_at_offset(position.offset).left_biased()?;
+    let mut expanded = None;
+    let mut name = None;
+    for node in tok.ancestors() {
+        match_ast! {
+            match node {
+                ast::MacroCall(mac) => {
+                    name = Some(mac.path()?.segment()?.name_ref()?.to_string());
+                    expanded = expand_macro_recur(&sema, &mac);
+                    break;
+                },
+                ast::Item(item) => {
+                    // FIXME: add the macro name
+                    // FIXME: make this recursive too
+                    name = Some("?".to_string());
+                    expanded = sema.expand_attr_macro(&item);
+                    if expanded.is_some() {
+                        break;
+                    }
+                },
+                _ => {}
+            }
+        }
+    }
 
     // FIXME:
     // macro expansion may lose all white space information
     // But we hope someday we can use ra_fmt for that
-    let expansion = insert_whitespaces(expanded);
-    Some(ExpandedMacro { name: name.to_string(), expansion })
+    let expansion = insert_whitespaces(expanded?);
+    Some(ExpandedMacro { name: name?, expansion })
 }
 
 fn expand_macro_recur(
diff --git a/crates/ide/src/goto_definition.rs b/crates/ide/src/goto_definition.rs
index b0bfd646e..2d36c34e9 100644
--- a/crates/ide/src/goto_definition.rs
+++ b/crates/ide/src/goto_definition.rs
@@ -1,10 +1,10 @@
 use std::convert::TryInto;
 
 use either::Either;
-use hir::{InFile, Semantics};
+use hir::{AsAssocItem, InFile, ModuleDef, Semantics};
 use ide_db::{
     base_db::{AnchoredPath, FileId, FileLoader},
-    defs::{NameClass, NameRefClass},
+    defs::{Definition, NameClass, NameRefClass},
     RootDatabase,
 };
 use syntax::{
@@ -57,7 +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);
@@ -99,6 +100,34 @@ fn try_lookup_include_path(
     })
 }
 
+/// 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 {
@@ -1262,4 +1291,58 @@ fn main() {
 "#,
         );
     }
+
+    #[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 = !;
+}
+"#,
+        );
+    }
 }
diff --git a/crates/ide/src/syntax_highlighting.rs b/crates/ide/src/syntax_highlighting.rs
index 79c2f4a1e..b03f1c71f 100644
--- a/crates/ide/src/syntax_highlighting.rs
+++ b/crates/ide/src/syntax_highlighting.rs
@@ -192,6 +192,7 @@ fn traverse(
     let mut bindings_shadow_count: FxHashMap<Name, u32> = FxHashMap::default();
 
     let mut current_macro_call: Option<ast::MacroCall> = None;
+    let mut current_attr_macro_call = None;
     let mut current_macro: Option<ast::Macro> = None;
     let mut macro_highlighter = MacroHighlighter::default();
     let mut inside_attribute = false;
@@ -227,6 +228,19 @@ fn traverse(
             }
             _ => (),
         }
+        match event.clone().map(|it| it.into_node().and_then(ast::Item::cast)) {
+            WalkEvent::Enter(Some(item)) => {
+                if sema.is_attr_macro_call(&item) {
+                    current_attr_macro_call = Some(item);
+                }
+            }
+            WalkEvent::Leave(Some(item)) => {
+                if current_attr_macro_call == Some(item) {
+                    current_attr_macro_call = None;
+                }
+            }
+            _ => (),
+        }
 
         match event.clone().map(|it| it.into_node().and_then(ast::Macro::cast)) {
             WalkEvent::Enter(Some(mac)) => {
@@ -286,6 +300,22 @@ fn traverse(
                 }
                 None => token.into(),
             }
+        } else if current_attr_macro_call.is_some() {
+            let token = match element.clone().into_token() {
+                Some(it) => it,
+                _ => continue,
+            };
+            let token = sema.descend_into_macros(token.clone());
+            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()
         };