stabilise cfg_attr

src/libsyntax/config.rs

@@ -94,11 +94,6 @@ impl<'a> StripUnconfigured<'a> {
             return vec![attr];
         }
 
-        let gate_cfg_attr_multi = if let Some(ref features) = self.features {
-            !features.cfg_attr_multi
-        } else {
-            false
-        };
         let cfg_attr_span = attr.span;
 
         let (cfg_predicate, expanded_attrs) = match attr.parse(self.sess, |parser| {
@@ -130,21 +125,8 @@ impl<'a> StripUnconfigured<'a> {
         // Check feature gate and lint on zero attributes in source. Even if the feature is gated,
         // we still compute as if it wasn't, since the emitted error will stop compilation further
         // along the compilation.
-        match (expanded_attrs.len(), gate_cfg_attr_multi) {
-            (0, false) => {
-                // FIXME: Emit unused attribute lint here.
-            },
-            (1, _) => {},
-            (_, true) => {
-                emit_feature_err(
-                    self.sess,
-                    "cfg_attr_multi",
-                    cfg_attr_span,
-                    GateIssue::Language,
-                    "cfg_attr with zero or more than one attributes is experimental",
-                );
-            },
-            (_, false) => {}
+        if expanded_attrs.len() == 0 {
+            // FIXME: Emit unused attribute lint here.
         }
 
         if attr::cfg_matches(&cfg_predicate, self.sess, self.features) {