Use diagnostic items to check for Send, UnwindSafe and RefUnwindSafe traits

Author: roxelo

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -690,12 +690,14 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
         // Blacklist traits for which it would be nonsensical to suggest borrowing.
         // For instance, immutable references are always Copy, so suggesting to
         // borrow would always succeed, but it's probably not what the user wanted.
-        let blacklist: Vec<_> =
-            [LangItem::Copy, LangItem::Clone, LangItem::Unpin, LangItem::Sized, LangItem::Send]
+        let mut blacklist: Vec<_> =
+            [LangItem::Copy, LangItem::Clone, LangItem::Unpin, LangItem::Sized]
                 .iter()
                 .filter_map(|lang_item| self.tcx.lang_items().require(*lang_item).ok())
                 .collect();
 
+        blacklist.push(self.tcx.get_diagnostic_item(sym::send_trait).unwrap());
+
         let span = obligation.cause.span;
         let param_env = obligation.param_env;
         let trait_ref = trait_ref.skip_binder();

compiler/rustc_typeck/src/check/upvar.rs

@@ -663,7 +663,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if self.need_2229_migrations_for_trait(
             min_captures,
             var_hir_id,
-            tcx.lang_items().send_trait(),
+            tcx.get_diagnostic_item(sym::send_trait),
         ) {
             auto_trait_reasons.insert("`Send`");
         }
@@ -679,15 +679,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         if self.need_2229_migrations_for_trait(
             min_captures,
             var_hir_id,
-            tcx.lang_items().unwind_safe_trait(),
+            tcx.get_diagnostic_item(sym::unwind_safe_trait),
         ) {
             auto_trait_reasons.insert("`UnwindSafe`");
         }
 
         if self.need_2229_migrations_for_trait(
             min_captures,
             var_hir_id,
-            tcx.lang_items().ref_unwind_safe_trait(),
+            tcx.get_diagnostic_item(sym::ref_unwind_safe_trait),
         ) {
             auto_trait_reasons.insert("`RefUnwindSafe`");
         }

library/std/src/panic.rs

@@ -133,7 +133,7 @@ pub fn panic_any<M: 'static + Any + Send>(msg: M) -> ! {
 /// [`AssertUnwindSafe`] wrapper struct can be used to force this trait to be
 /// implemented for any closed over variables passed to `catch_unwind`.
 #[stable(feature = "catch_unwind", since = "1.9.0")]
-#[rustc_diagnostic_item = "unwind_safe_trait"]
+#[cfg_attr(not(test), rustc_diagnostic_item = "unwind_safe_trait")]
 #[rustc_on_unimplemented(
     message = "the type `{Self}` may not be safely transferred across an unwind boundary",
     label = "`{Self}` may not be safely transferred across an unwind boundary"
@@ -149,7 +149,7 @@ pub auto trait UnwindSafe {}
 /// This is a "helper marker trait" used to provide impl blocks for the
 /// [`UnwindSafe`] trait, for more information see that documentation.
 #[stable(feature = "catch_unwind", since = "1.9.0")]
-#[rustc_diagnostic_item = "ref_unwind_safe_trait"]
+#[cfg_attr(not(test), rustc_diagnostic_item = "ref_unwind_safe_trait")]
 #[rustc_on_unimplemented(
     message = "the type `{Self}` may contain interior mutability and a reference may not be safely \
                transferrable across a catch_unwind boundary",