Merge #6299

6299: Diagnose items that are #[cfg]d out r=jonas-schievink a=jonas-schievink

This emits a hint-level diagnostic with `Unnecessary` tag to "gray out" any items whose `#[cfg]` attributes remove the item before name resolution.

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 13 insertions, 0 deletions

diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index c8cd04264..bff8edb62 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -913,6 +913,7 @@ impl ModCollector<'_, '_> {
         for &item in items {
             let attrs = self.item_tree.attrs(item.into());
             if !self.is_cfg_enabled(attrs) {
+                self.emit_unconfigured_diagnostic(item);
                 continue;
             }
             let module =
@@ -1323,6 +1324,18 @@ impl ModCollector<'_, '_> {
     fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
         attrs.is_cfg_enabled(self.def_collector.cfg_options)
     }
+
+    fn emit_unconfigured_diagnostic(&mut self, item: ModItem) {
+        let ast_id = item.ast_id(self.item_tree);
+        let id_map = self.def_collector.db.ast_id_map(self.file_id);
+        let syntax_ptr = id_map.get(ast_id).syntax_node_ptr();
+
+        let ast_node = InFile::new(self.file_id, syntax_ptr);
+        self.def_collector
+            .def_map
+            .diagnostics
+            .push(DefDiagnostic::unconfigured_code(self.module_id, ast_node));
+    }
 }
 
 fn is_macro_rules(path: &ModPath) -> bool {