Add lang item for AsyncFnKindHelper::Upvars

compiler/rustc_hir/src/lang_items.rs

@@ -228,10 +228,11 @@ language_item_table! {
     AsyncFn,                 sym::async_fn,            async_fn_trait,             Target::Trait,          GenericRequirement::Exact(1);
     AsyncFnMut,              sym::async_fn_mut,        async_fn_mut_trait,         Target::Trait,          GenericRequirement::Exact(1);
     AsyncFnOnce,             sym::async_fn_once,       async_fn_once_trait,        Target::Trait,          GenericRequirement::Exact(1);
-    AsyncFnOnceOutput,       sym::async_fn_once_output,async_fn_once_output,       Target::AssocTy,        GenericRequirement::Exact(1);
+    AsyncFnOnceOutput,       sym::async_fn_once_output, async_fn_once_output,       Target::AssocTy,        GenericRequirement::Exact(1);
     CallOnceFuture,          sym::call_once_future,    call_once_future,           Target::AssocTy,        GenericRequirement::Exact(1);
     CallRefFuture,           sym::call_ref_future,     call_ref_future,            Target::AssocTy,        GenericRequirement::Exact(2);
-    AsyncFnKindHelper,       sym::async_fn_kind_helper,async_fn_kind_helper,       Target::Trait,          GenericRequirement::Exact(1);
+    AsyncFnKindHelper,       sym::async_fn_kind_helper, async_fn_kind_helper,      Target::Trait,          GenericRequirement::Exact(1);
+    AsyncFnKindUpvars,       sym::async_fn_kind_upvars, async_fn_kind_upvars,      Target::AssocTy,          GenericRequirement::Exact(5);
 
     FnOnceOutput,            sym::fn_once_output,      fn_once_output,             Target::AssocTy,        GenericRequirement::None;
 

compiler/rustc_span/src/symbol.rs

@@ -438,6 +438,7 @@ symbols! {
         async_fn,
         async_fn_in_trait,
         async_fn_kind_helper,
+        async_fn_kind_upvars,
         async_fn_mut,
         async_fn_once,
         async_fn_once_output,

compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs

@@ -9,7 +9,6 @@ use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::bug;
 use rustc_middle::traits::solve::Goal;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable, Upcast};
-use rustc_span::sym;
 
 use crate::solve::EvalCtxt;
 
@@ -582,13 +581,7 @@ fn coroutine_closure_to_ambiguous_coroutine<'tcx>(
     args: ty::CoroutineClosureArgs<'tcx>,
     sig: ty::CoroutineClosureSignature<'tcx>,
 ) -> Ty<'tcx> {
-    let async_fn_kind_trait_def_id = tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
+    let upvars_projection_def_id = tcx.require_lang_item(LangItem::AsyncFnKindUpvars, None);
-    let upvars_projection_def_id = tcx
-        .associated_items(async_fn_kind_trait_def_id)
-        .filter_by_name_unhygienic(sym::Upvars)
-        .next()
-        .unwrap()
-        .def_id;
     let tupled_upvars_ty = Ty::new_projection(
         tcx,
         upvars_projection_def_id,

compiler/rustc_trait_selection/src/traits/project.rs

@@ -1680,14 +1680,8 @@ fn confirm_closure_candidate<'cx, 'tcx>(
                         args.coroutine_captures_by_ref_ty(),
                     )
                 } else {
-                    let async_fn_kind_trait_def_id =
+                    let upvars_projection_def_id =
-                        tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
+                        tcx.require_lang_item(LangItem::AsyncFnKindUpvars, None);
-                    let upvars_projection_def_id = tcx
-                        .associated_items(async_fn_kind_trait_def_id)
-                        .filter_by_name_unhygienic(sym::Upvars)
-                        .next()
-                        .unwrap()
-                        .def_id;
                     let tupled_upvars_ty = Ty::new_projection(
                         tcx,
                         upvars_projection_def_id,
@@ -1816,14 +1810,8 @@ fn confirm_async_closure_candidate<'cx, 'tcx>(
                             args.coroutine_captures_by_ref_ty(),
                         )
                     } else {
-                        let async_fn_kind_trait_def_id =
+                        let upvars_projection_def_id =
-                            tcx.require_lang_item(LangItem::AsyncFnKindHelper, None);
+                            tcx.require_lang_item(LangItem::AsyncFnKindUpvars, None);
-                        let upvars_projection_def_id = tcx
-                            .associated_items(async_fn_kind_trait_def_id)
-                            .filter_by_name_unhygienic(sym::Upvars)
-                            .next()
-                            .unwrap()
-                            .def_id;
                         // When we don't know the closure kind (and therefore also the closure's upvars,
                         // which are computed at the same time), we must delay the computation of the
                         // generator's upvars. We do this using the `AsyncFnKindHelper`, which as a trait

library/core/src/ops/async_function.rs

@@ -146,6 +146,7 @@ mod internal_implementation_detail {
         // `for<'env> fn() -> (&'env T, ...)`. This allows us to represent the binder
         // of the closure's self-capture, and these upvar types will be instantiated with
         // the `'closure_env` region provided to the associated type.
+        #[cfg_attr(not(bootstrap), lang = "async_fn_kind_upvars")]
         type Upvars<'closure_env, Inputs, Upvars, BorrowedUpvarsAsFnPtr>;
     }
 }