Simplify

crates/hir/src/lib.rs

@@ -1793,10 +1793,7 @@ impl MacroDef {
     }
 
     pub fn is_builtin_derive(&self) -> bool {
-        match self.id.kind {
-            MacroDefKind::BuiltInAttr(exp, _) => exp.is_derive(),
-            _ => false,
-        }
+        matches!(self.id.kind, MacroDefKind::BuiltInAttr(exp, _) if exp.is_derive())
     }
 
     pub fn is_attr(&self) -> bool {
@@ -2433,24 +2430,7 @@ impl Impl {
 
     pub fn is_builtin_derive(self, db: &dyn HirDatabase) -> Option<InFile<ast::Attr>> {
         let src = self.source(db)?;
-        let item = src.file_id.is_builtin_derive(db.upcast())?;
-        let hygenic = hir_expand::hygiene::Hygiene::new(db.upcast(), item.file_id);
-
-        // FIXME: handle `cfg_attr`
-        let attr = item
-            .value
-            .attrs()
-            .filter_map(|it| {
-                let path = ModPath::from_src(db.upcast(), it.path()?, &hygenic)?;
-                if path.as_ident()?.to_smol_str() == "derive" {
-                    Some(it)
-                } else {
-                    None
-                }
-            })
-            .last()?;
-
-        Some(item.with_value(attr))
+        src.file_id.is_builtin_derive(db.upcast())
     }
 }
 

crates/hir_expand/src/lib.rs

@@ -262,16 +262,16 @@ impl HirFileId {
     }
 
     /// Indicate it is macro file generated for builtin derive
-    pub fn is_builtin_derive(&self, db: &dyn db::AstDatabase) -> Option<InFile<ast::Item>> {
+    pub fn is_builtin_derive(&self, db: &dyn db::AstDatabase) -> Option<InFile<ast::Attr>> {
         match self.0 {
             HirFileIdRepr::FileId(_) => None,
             HirFileIdRepr::MacroFile(macro_file) => {
                 let loc: MacroCallLoc = db.lookup_intern_macro_call(macro_file.macro_call_id);
-                let item = match loc.def.kind {
+                let attr = match loc.def.kind {
                     MacroDefKind::BuiltInDerive(..) => loc.kind.to_node(db),
                     _ => return None,
                 };
-                Some(item.with_value(ast::Item::cast(item.value.clone())?))
+                Some(attr.with_value(ast::Attr::cast(attr.value.clone())?))
             }
         }
     }
@@ -383,10 +383,20 @@ impl MacroCallKind {
             MacroCallKind::FnLike { ast_id, .. } => {
                 ast_id.with_value(ast_id.to_node(db).syntax().clone())
             }
-            MacroCallKind::Derive { ast_id, .. } => {
-                ast_id.with_value(ast_id.to_node(db).syntax().clone())
+            MacroCallKind::Derive { ast_id, derive_attr_index, .. } => {
+                // FIXME: handle `cfg_attr`
+                ast_id.with_value(ast_id.to_node(db)).map(|it| {
+                    it.doc_comments_and_attrs()
+                        .nth(*derive_attr_index as usize)
+                        .and_then(|it| match it {
+                            Either::Left(attr) => Some(attr.syntax().clone()),
+                            Either::Right(_) => None,
+                        })
+                        .unwrap_or_else(|| it.syntax().clone())
+                })
             }
             MacroCallKind::Attr { ast_id, is_derive: true, invoc_attr_index, .. } => {
+                // FIXME: handle `cfg_attr`
                 ast_id.with_value(ast_id.to_node(db)).map(|it| {
                     it.doc_comments_and_attrs()
                         .nth(*invoc_attr_index as usize)

crates/ide_completion/src/tests/attribute.rs

@@ -735,6 +735,26 @@ mod derive {
         )
     }
 
+    #[test]
+    fn derive_no_attrs() {
+        check_derive(
+            r#"
+//- proc_macros: identity
+//- minicore: derive
+#[derive($0)] struct Test;
+"#,
+            expect![[r#""#]],
+        );
+        check_derive(
+            r#"
+//- proc_macros: identity
+//- minicore: derive
+#[derive(i$0)] struct Test;
+"#,
+            expect![[r#""#]],
+        );
+    }
+
     #[test]
     fn derive_flyimport() {
         check_derive(