Fix false positives in unmounted_routes lint due to 'launch'.

codegen/src/lints/mod.rs

@@ -180,10 +180,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for RocketLint {
             }
         }
 
-        if let Some((recvr, _)) = rocket_method_call("launch", cx, expr) {
+        // This captures a corner case where neither `manage` nor `mount` is
-            let instance = recvr.and_then(|r| instance_for(self, r));
+        // called on an instance.
-            self.instances.entry(instance)
+        if let Some((Some(recvr_expr), _)) = rocket_method_call("launch", cx, expr) {
-                .or_insert_with(|| InstanceInfo::default());
+            if let Some(instance) = instance_for(self, recvr_expr) {
+                self.instances.entry(Some(instance))
+                    .or_insert_with(|| InstanceInfo::default());
+            }
         }
     }
 

codegen/tests/compile-fail/simple_unmounted.rs

@@ -0,0 +1,14 @@
+#![feature(plugin)]
+#![plugin(rocket_codegen)]
+#![allow(dead_code)]
+#![deny(unmounted_route)]
+
+extern crate rocket;
+
+#[get("/")]
+fn index() {  }
+//~^ ERROR is not mounted
+
+fn main() {
+    rocket::ignite().launch();
+}

codegen/tests/run-pass/refactored_rocket_no_lint_errors.rs

@@ -0,0 +1,28 @@
+#![feature(plugin)]
+#![plugin(rocket_codegen)]
+#![allow(dead_code, unused_variables)]
+#![deny(unmounted_routes, unmanaged_state)]
+
+extern crate rocket;
+
+use rocket::{Rocket, State};
+
+#[get("/")]
+fn index(state: State<u32>) {  }
+
+fn rocket() -> Rocket {
+    rocket::ignite()
+        .mount("/", routes![index])
+        .manage(100u32)
+}
+
+fn main() {
+    if false {
+        rocket().launch();
+    }
+
+    let instance = rocket();
+    if false {
+        instance.launch();
+    }
+}