plugin mode still needs to work

Author: oli-obk

src/lib.rs

@@ -2,6 +2,7 @@
 #![feature(plugin_registrar)]
 #![feature(rustc_private)]
 #![allow(unknown_lints)]
+#![feature(borrow_state)]
 
 extern crate rustc_plugin;
 use rustc_plugin::Registry;
@@ -12,7 +13,7 @@ pub use clippy_lints::*;
 
 #[plugin_registrar]
 pub fn plugin_registrar(reg: &mut Registry) {
-    if reg.sess.lint_store.borrow().get_lint_groups().iter().any(|&(s, _, _)| s == "clippy") {
+    if reg.sess.lint_store.borrow_state() == std::cell::BorrowState::Unused && reg.sess.lint_store.borrow().get_lint_groups().iter().any(|&(s, _, _)| s == "clippy") {
         reg.sess.struct_warn("running cargo clippy on a crate that also imports the clippy plugin").emit();
     } else {
         register_plugins(reg);