store some DefIds in the struct

Author: ada4a

clippy_lints/src/future_not_send.rs

@@ -10,8 +10,8 @@ use rustc_middle::ty::print::PrintTraitRefExt;
 use rustc_middle::ty::{
     self, AliasTy, Binder, ClauseKind, PredicateKind, Ty, TyCtxt, TypeVisitable, TypeVisitableExt, TypeVisitor,
 };
-use rustc_session::declare_lint_pass;
-use rustc_span::def_id::LocalDefId;
+use rustc_session::impl_lint_pass;
+use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::{Span, sym};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::traits::{self, FulfillmentError, ObligationCtxt};
@@ -59,7 +59,21 @@ declare_clippy_lint! {
     "public Futures must be Send"
 }
 
-declare_lint_pass!(FutureNotSend => [FUTURE_NOT_SEND]);
+impl_lint_pass!(FutureNotSend => [FUTURE_NOT_SEND]);
+
+pub(crate) struct FutureNotSend {
+    future_trait: Option<DefId>,
+    send_trait: Option<DefId>,
+}
+
+impl FutureNotSend {
+    pub(crate) fn new(tcx: TyCtxt<'_>) -> Self {
+        Self {
+            future_trait: tcx.lang_items().future_trait(),
+            send_trait: tcx.get_diagnostic_item(sym::Send),
+        }
+    }
+}
 
 impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
     fn check_fn(
@@ -76,8 +90,8 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
         }
         let ret_ty = return_ty(cx, cx.tcx.local_def_id_to_hir_id(fn_def_id).expect_owner());
         if let ty::Alias(ty::Opaque, AliasTy { def_id, args, .. }) = *ret_ty.kind()
-            && let Some(future_trait) = cx.tcx.lang_items().future_trait()
-            && let Some(send_trait) = cx.tcx.get_diagnostic_item(sym::Send)
+            && let Some(future_trait) = self.future_trait
+            && let Some(send_trait) = self.send_trait
         {
             let preds = cx.tcx.explicit_item_self_bounds(def_id);
             let is_future = preds.iter_instantiated_copied(cx.tcx, args).any(|(p, _)| {

clippy_lints/src/lib.rs

@@ -645,7 +645,7 @@ pub fn register_lint_passes(store: &mut rustc_lint::LintStore, conf: &'static Co
     store.register_late_pass(|_| Box::<redundant_pub_crate::RedundantPubCrate>::default());
     store.register_late_pass(|_| Box::<dereference::Dereferencing<'_>>::default());
     store.register_late_pass(|_| Box::new(option_if_let_else::OptionIfLetElse));
-    store.register_late_pass(|_| Box::new(future_not_send::FutureNotSend));
+    store.register_late_pass(|tcx| Box::new(future_not_send::FutureNotSend::new(tcx)));
     store.register_late_pass(move |_| Box::new(large_futures::LargeFuture::new(conf)));
     store.register_late_pass(|_| Box::new(if_let_mutex::IfLetMutex));
     store.register_late_pass(|_| Box::new(if_not_else::IfNotElse));