Consider a crate staged if it has stable or unstable in its root

src/librustc/metadata/creader.rs

@@ -350,16 +350,8 @@ impl<'a> CrateReader<'a> {
     fn is_staged_api(&self, data: &[u8]) -> bool {
         let attrs = decoder::get_crate_attributes(data);
         for attr in &attrs {
-            if attr.name() == "feature" {
-                if let Some(metas) = attr.meta_item_list() {
-                    for meta in metas {
-                        if let ast::MetaWord(ref name) = meta.node {
-                            if &name[..] == "staged_api" {
-                                return true
-                            }
-                        }
-                    }
-                }
+            if attr.name() == "stable" || attr.name() == "unstable" {
+                return true
             }
         }
         false

src/librustc/middle/stability.rs

@@ -85,7 +85,7 @@ impl<'a, 'tcx: 'a> Annotator<'a, 'tcx> {
                    item_sp: Span, kind: AnnotationKind, visit_children: F)
         where F: FnOnce(&mut Annotator)
     {
-        if self.index.staged_api[&LOCAL_CRATE] {
+        if self.index.staged_api[&LOCAL_CRATE] && self.tcx.sess.features.borrow().staged_api {
             debug!("annotate(id = {:?}, attrs = {:?})", id, attrs);
             if let Some(mut stab) = attr::find_stability(self.tcx.sess.diagnostic(),
                                                          attrs, item_sp) {
@@ -279,9 +279,17 @@ impl<'tcx> Index<'tcx> {
                            |v| intravisit::walk_crate(v, krate));
     }
 
-    pub fn new(sess: &Session) -> Index<'tcx> {
+    pub fn new(krate: &Crate) -> Index<'tcx> {
+        let mut is_staged_api = false;
+        for attr in &krate.attrs {
+            if attr.name() == "stable" || attr.name() == "unstable" {
+                is_staged_api = true;
+                break
+            }
+        }
+
         let mut staged_api = FnvHashMap();
-        staged_api.insert(LOCAL_CRATE, sess.features.borrow().staged_api);
+        staged_api.insert(LOCAL_CRATE, is_staged_api);
         Index {
             staged_api: staged_api,
             map: DefIdMap(),

src/librustc_driver/driver.rs

@@ -738,7 +738,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
                                freevars,
                                region_map,
                                lang_items,
-                               stability::Index::new(sess),
+                               stability::Index::new(krate),
                                |tcx| {
                                    // passes are timed inside typeck
                                    typeck::check_crate(tcx, trait_map);

src/librustc_driver/test.rs

@@ -136,7 +136,7 @@ fn test_env<F>(source_string: &str,
                                freevars,
                                region_map,
                                lang_items,
-                               stability::Index::new(&sess),
+                               stability::Index::new(krate),
                                |tcx| {
                                    let infcx = infer::new_infer_ctxt(tcx, &tcx.tables, None, false);
                                    body(Env { infcx: &infcx });