Rollup of 7 pull requests

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -225,7 +225,7 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
     /// `align_offset(ptr, target_align)` needs special handling in const eval, because the pointer
     /// may not have an address.
     ///
-    /// If `ptr` does have a known address, then we return `CONTINUE` and the function call should
+    /// If `ptr` does have a known address, then we return `Continue(())` and the function call should
     /// proceed as normal.
     ///
     /// If `ptr` doesn't have an address, but its underlying allocation's alignment is at most
@@ -273,18 +273,18 @@ impl<'mir, 'tcx: 'mir> CompileTimeEvalContext<'mir, 'tcx> {
                         ret,
                         StackPopUnwind::NotAllowed,
                     )?;
-                    Ok(ControlFlow::BREAK)
+                    Ok(ControlFlow::Break(()))
                 } else {
                     // Not alignable in const, return `usize::MAX`.
                     let usize_max = Scalar::from_machine_usize(self.machine_usize_max(), self);
                     self.write_scalar(usize_max, dest)?;
                     self.return_to_block(ret)?;
-                    Ok(ControlFlow::BREAK)
+                    Ok(ControlFlow::Break(()))
                 }
             }
             Err(_addr) => {
                 // The pointer has an address, continue with function call.
-                Ok(ControlFlow::CONTINUE)
+                Ok(ControlFlow::Continue(()))
             }
         }
     }

compiler/rustc_const_eval/src/interpret/util.rs

@@ -26,7 +26,7 @@ where
 
         fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
             if !ty.needs_subst() {
-                return ControlFlow::CONTINUE;
+                return ControlFlow::Continue(());
             }
 
             match *ty.kind() {
@@ -48,7 +48,7 @@ where
                             return subst.visit_with(self);
                         }
                     }
-                    ControlFlow::CONTINUE
+                    ControlFlow::Continue(())
                 }
                 _ => ty.super_visit_with(self),
             }

compiler/rustc_const_eval/src/lib.rs

@@ -6,7 +6,6 @@ Rust MIR: a lowered representation of Rust.
 
 #![feature(assert_matches)]
 #![feature(box_patterns)]
-#![feature(control_flow_enum)]
 #![feature(decl_macro)]
 #![feature(exact_size_is_empty)]
 #![feature(let_chains)]

compiler/rustc_data_structures/src/graph/iterate/mod.rs

@@ -317,12 +317,12 @@ where
         _node: G::Node,
         _prior_status: Option<NodeStatus>,
     ) -> ControlFlow<Self::BreakVal> {
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     /// Called after all nodes reachable from this one have been examined.
     fn node_settled(&mut self, _node: G::Node) -> ControlFlow<Self::BreakVal> {
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     /// Behave as if no edges exist from `source` to `target`.
@@ -346,8 +346,8 @@ where
         prior_status: Option<NodeStatus>,
     ) -> ControlFlow<Self::BreakVal> {
         match prior_status {
-            Some(NodeStatus::Visited) => ControlFlow::BREAK,
-            _ => ControlFlow::CONTINUE,
+            Some(NodeStatus::Visited) => ControlFlow::Break(()),
+            _ => ControlFlow::Continue(()),
         }
     }
 }

compiler/rustc_data_structures/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(associated_type_bounds)]
 #![feature(auto_traits)]
 #![feature(cell_leak)]
-#![feature(control_flow_enum)]
 #![feature(extend_one)]
 #![feature(hash_raw_entry)]
 #![feature(hasher_prefixfree_extras)]

compiler/rustc_hir/src/lang_items.rs

@@ -291,6 +291,7 @@ language_item_table! {
     IdentityFuture,          sym::identity_future,     identity_future_fn,         Target::Fn,             GenericRequirement::None;
     GetContext,              sym::get_context,         get_context_fn,             Target::Fn,             GenericRequirement::None;
 
+    Context,                 sym::Context,             context,                    Target::Struct,         GenericRequirement::None;
     FuturePoll,              sym::poll,                future_poll_fn,             Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
 
     FromFrom,                sym::from,                from_fn,                    Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;

compiler/rustc_hir_analysis/src/check/check.rs

@@ -267,7 +267,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
         fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
             debug!(?t, "root_visit_ty");
             if t == self.opaque_identity_ty {
-                ControlFlow::CONTINUE
+                ControlFlow::Continue(())
             } else {
                 t.visit_with(&mut ConstrainOpaqueTypeRegionVisitor {
                     tcx: self.tcx,
@@ -282,7 +282,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
                 if self.references_parent_regions {
                     ControlFlow::Break(t)
                 } else {
-                    ControlFlow::CONTINUE
+                    ControlFlow::Continue(())
                 }
             }
         }
@@ -1439,7 +1439,7 @@ fn opaque_type_cycle_error(tcx: TyCtxt<'_>, def_id: LocalDefId, span: Span) -> E
                         match *t.kind() {
                             ty::Alias(ty::Opaque, ty::AliasTy { def_id: def, .. }) => {
                                 self.0.push(def);
-                                ControlFlow::CONTINUE
+                                ControlFlow::Continue(())
                             }
                             _ => t.super_visit_with(self),
                         }

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1428,7 +1428,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
                 }
 
                 fn visit_region(&mut self, _: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
-                    ControlFlow::BREAK
+                    ControlFlow::Break(())
                 }
 
                 fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -416,13 +416,13 @@ fn fast_reject_auto_impl<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId, self_ty:
             if t != self.self_ty_root {
                 for impl_def_id in tcx.non_blanket_impls_for_ty(self.trait_def_id, t) {
                     match tcx.impl_polarity(impl_def_id) {
-                        ImplPolarity::Negative => return ControlFlow::BREAK,
+                        ImplPolarity::Negative => return ControlFlow::Break(()),
                         ImplPolarity::Reservation => {}
                         // FIXME(@lcnr): That's probably not good enough, idk
                         //
                         // We might just want to take the rustdoc code and somehow avoid
                         // explicit impls for `Self`.
-                        ImplPolarity::Positive => return ControlFlow::CONTINUE,
+                        ImplPolarity::Positive => return ControlFlow::Continue(()),
                     }
                 }
             }
@@ -440,7 +440,7 @@ fn fast_reject_auto_impl<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId, self_ty:
                         }
                     }
 
-                    ControlFlow::CONTINUE
+                    ControlFlow::Continue(())
                 }
                 _ => t.super_visit_with(self),
             }

compiler/rustc_hir_analysis/src/constrained_generic_params.rs

@@ -61,7 +61,7 @@ impl<'tcx> TypeVisitor<'tcx> for ParameterCollector {
         match *t.kind() {
             ty::Alias(ty::Projection, ..) if !self.include_nonconstraining => {
                 // projections are not injective
-                return ControlFlow::CONTINUE;
+                return ControlFlow::Continue(());
             }
             ty::Param(data) => {
                 self.parameters.push(Parameter::from(data));
@@ -76,7 +76,7 @@ impl<'tcx> TypeVisitor<'tcx> for ParameterCollector {
         if let ty::ReEarlyBound(data) = *r {
             self.parameters.push(Parameter::from(data));
         }
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     fn visit_const(&mut self, c: ty::Const<'tcx>) -> ControlFlow<Self::BreakTy> {

compiler/rustc_hir_analysis/src/variance/mod.rs

@@ -92,7 +92,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
                         a.visit_with(self)?;
                     }
                 }
-                ControlFlow::CONTINUE
+                ControlFlow::Continue(())
             } else {
                 substs.visit_with(self)
             }

compiler/rustc_hir_typeck/src/closure.rs

@@ -236,7 +236,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                         if t == self.expected_ty {
-                            ControlFlow::BREAK
+                            ControlFlow::Break(())
                         } else {
                             t.super_visit_with(self)
                         }

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs

@@ -543,7 +543,7 @@ impl<'tcx> TypeVisitor<'tcx> for TraitObjectVisitor {
                 if let Some(def_id) = preds.principal_def_id() {
                     self.0.insert(def_id);
                 }
-                ControlFlow::CONTINUE
+                ControlFlow::Continue(())
             }
             _ => t.super_visit_with(self),
         }

compiler/rustc_infer/src/infer/nll_relate/mod.rs

@@ -849,7 +849,7 @@ impl<'me, 'tcx> TypeVisitor<'tcx> for ScopeInstantiator<'me, 'tcx> {
         t.super_visit_with(self);
         self.target_index.shift_out(1);
 
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
@@ -863,7 +863,7 @@ impl<'me, 'tcx> TypeVisitor<'tcx> for ScopeInstantiator<'me, 'tcx> {
             _ => {}
         }
 
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 }
 

compiler/rustc_infer/src/infer/opaque_types.rs

@@ -440,24 +440,24 @@ where
         t: &ty::Binder<'tcx, T>,
     ) -> ControlFlow<Self::BreakTy> {
         t.super_visit_with(self);
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 
     fn visit_region(&mut self, r: ty::Region<'tcx>) -> ControlFlow<Self::BreakTy> {
         match *r {
             // ignore bound regions, keep visiting
-            ty::ReLateBound(_, _) => ControlFlow::CONTINUE,
+            ty::ReLateBound(_, _) => ControlFlow::Continue(()),
             _ => {
                 (self.op)(r);
-                ControlFlow::CONTINUE
+                ControlFlow::Continue(())
             }
         }
     }
 
     fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
         // We're only interested in types involving regions
         if !ty.flags().intersects(ty::TypeFlags::HAS_FREE_REGIONS) {
-            return ControlFlow::CONTINUE;
+            return ControlFlow::Continue(());
         }
 
         match ty.kind() {
@@ -507,7 +507,7 @@ where
             }
         }
 
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 }
 

compiler/rustc_infer/src/infer/resolve.rs

@@ -147,7 +147,7 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for UnresolvedTypeOrConstFinder<'a, 'tcx> {
         } else if !t.has_non_region_infer() {
             // All const/type variables in inference types must already be resolved,
             // no need to visit the contents.
-            ControlFlow::CONTINUE
+            ControlFlow::Continue(())
         } else {
             // Otherwise, keep visiting.
             t.super_visit_with(self)
@@ -178,7 +178,7 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for UnresolvedTypeOrConstFinder<'a, 'tcx> {
         } else if !ct.has_non_region_infer() {
             // All const/type variables in inference types must already be resolved,
             // no need to visit the contents.
-            ControlFlow::CONTINUE
+            ControlFlow::Continue(())
         } else {
             // Otherwise, keep visiting.
             ct.super_visit_with(self)

compiler/rustc_lint/src/types.rs

@@ -1147,7 +1147,7 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
 
             fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
                 if !ty.has_opaque_types() {
-                    return ControlFlow::CONTINUE;
+                    return ControlFlow::Continue(());
                 }
 
                 if let ty::Alias(ty::Opaque, ..) = ty.kind() {

compiler/rustc_macros/src/type_visitable.rs

@@ -26,7 +26,7 @@ pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2:
                 __visitor: &mut __V
             ) -> ::std::ops::ControlFlow<__V::BreakTy> {
                 match *self { #body_visit }
-                ::std::ops::ControlFlow::CONTINUE
+                ::std::ops::ControlFlow::Continue(())
             }
         },
     )

compiler/rustc_middle/src/macros.rs

@@ -93,7 +93,7 @@ macro_rules! TrivialTypeTraversalImpls {
                     _: &mut F)
                     -> ::std::ops::ControlFlow<F::BreakTy>
                 {
-                    ::std::ops::ControlFlow::CONTINUE
+                    ::std::ops::ControlFlow::Continue(())
                 }
             }
         )+
@@ -219,7 +219,7 @@ macro_rules! EnumTypeTraversalImpl {
                         $($crate::ty::visit::TypeVisitable::visit_with(
                             $variant_arg, $visitor
                         )?;)*
-                        ::std::ops::ControlFlow::CONTINUE
+                        ::std::ops::ControlFlow::Continue(())
                     }
                     $($output)*
                 )
@@ -237,7 +237,7 @@ macro_rules! EnumTypeTraversalImpl {
                         $($crate::ty::visit::TypeVisitable::visit_with(
                             $variant_arg, $visitor
                         )?;)*
-                        ::std::ops::ControlFlow::CONTINUE
+                        ::std::ops::ControlFlow::Continue(())
                     }
                     $($output)*
                 )
@@ -251,7 +251,7 @@ macro_rules! EnumTypeTraversalImpl {
             @VisitVariants($this, $visitor)
                 input($($input)*)
                 output(
-                    $variant => { ::std::ops::ControlFlow::CONTINUE }
+                    $variant => { ::std::ops::ControlFlow::Continue(()) }
                     $($output)*
                 )
         )

compiler/rustc_middle/src/mir/type_visitable.rs

@@ -4,6 +4,6 @@ use super::*;
 
 impl<'tcx, R: Idx, C: Idx> TypeVisitable<'tcx> for BitMatrix<R, C> {
     fn visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> ControlFlow<V::BreakTy> {
-        ControlFlow::CONTINUE
+        ControlFlow::Continue(())
     }
 }

compiler/rustc_middle/src/ty/context.rs

@@ -1952,6 +1952,15 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_ty(GeneratorWitness(types))
     }
 
+    /// Creates a `&mut Context<'_>` [`Ty`] with erased lifetimes.
+    pub fn mk_task_context(self) -> Ty<'tcx> {
+        let context_did = self.require_lang_item(LangItem::Context, None);
+        let context_adt_ref = self.adt_def(context_did);
+        let context_substs = self.intern_substs(&[self.lifetimes.re_erased.into()]);
+        let context_ty = self.mk_adt(context_adt_ref, context_substs);
+        self.mk_mut_ref(self.lifetimes.re_erased, context_ty)
+    }
+
     #[inline]
     pub fn mk_ty_var(self, v: TyVid) -> Ty<'tcx> {
         self.mk_ty_infer(TyVar(v))