Remove GeneratorWitness and rename GeneratorWitnessMIR.

compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs

@@ -426,7 +426,6 @@ fn push_debuginfo_type_name<'tcx>(
         | ty::Placeholder(..)
         | ty::Alias(..)
         | ty::Bound(..)
-        | ty::GeneratorWitnessMIR(..)
         | ty::GeneratorWitness(..) => {
             bug!(
                 "debuginfo: Trying to create type name for \

compiler/rustc_const_eval/src/const_eval/valtrees.rs

@@ -152,7 +152,7 @@ pub(crate) fn const_to_valtree_inner<'tcx>(
         // FIXME(oli-obk): we can probably encode closures just like structs
         | ty::Closure(..)
         | ty::Generator(..)
-        | ty::GeneratorWitness(..) |ty::GeneratorWitnessMIR(..)=> Err(ValTreeCreationError::NonSupportedType),
+        | ty::GeneratorWitness(..) => Err(ValTreeCreationError::NonSupportedType),
     }
 }
 
@@ -280,7 +280,6 @@ pub fn valtree_to_const_value<'tcx>(
         | ty::Closure(..)
         | ty::Generator(..)
         | ty::GeneratorWitness(..)
-        | ty::GeneratorWitnessMIR(..)
         | ty::FnPtr(_)
         | ty::RawPtr(_)
         | ty::Str

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -963,7 +963,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                 | ty::Ref(..)
                 | ty::Generator(..)
                 | ty::GeneratorWitness(..)
-                | ty::GeneratorWitnessMIR(..)
                 | ty::Array(..)
                 | ty::Closure(..)
                 | ty::Never

compiler/rustc_const_eval/src/interpret/intrinsics.rs

@@ -100,8 +100,7 @@ pub(crate) fn eval_nullary_intrinsic<'tcx>(
             | ty::Dynamic(_, _, _)
             | ty::Closure(_, _)
             | ty::Generator(_, _, _)
-            | ty::GeneratorWitness(_)
-            | ty::GeneratorWitnessMIR(_, _)
+            | ty::GeneratorWitness(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Error(_) => ConstValue::from_target_usize(0u64, &tcx),

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -583,7 +583,6 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
             | ty::Bound(..)
             | ty::Param(..)
             | ty::Alias(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::GeneratorWitness(..) => bug!("Encountered invalid type {:?}", ty),
         }
     }

compiler/rustc_const_eval/src/util/type_name.rs

@@ -64,8 +64,7 @@ impl<'tcx> Printer<'tcx> for AbsolutePathPrinter<'tcx> {
 
             ty::Alias(ty::Weak, _) => bug!("type_name: unexpected weak projection"),
             ty::Alias(ty::Inherent, _) => bug!("type_name: unexpected inherent projection"),
-            ty::GeneratorWitness(_) => bug!("type_name: unexpected `GeneratorWitness`"),
-            ty::GeneratorWitnessMIR(..) => bug!("type_name: unexpected `GeneratorWitnessMIR`"),
+            ty::GeneratorWitness(..) => bug!("type_name: unexpected `GeneratorWitness`"),
         }
     }
 

compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs

@@ -157,7 +157,6 @@ impl<'tcx> InherentCollect<'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Bound(..)
             | ty::Placeholder(_)
             | ty::Infer(_) => {

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -245,7 +245,6 @@ fn do_orphan_check_impl<'tcx>(
             ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Bound(..)
             | ty::Placeholder(..)
             | ty::Infer(..) => {

compiler/rustc_hir_analysis/src/variance/constraints.rs

@@ -314,11 +314,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
                 // types, where we use Error as the Self type
             }
 
-            ty::Placeholder(..)
-            | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
-            | ty::Bound(..)
-            | ty::Infer(..) => {
+            ty::Placeholder(..) | ty::GeneratorWitness(..) | ty::Bound(..) | ty::Infer(..) => {
                 bug!("unexpected type encountered in variance inference: {}", ty);
             }
         }

compiler/rustc_hir_typeck/src/cast.rs

@@ -129,7 +129,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             | ty::Float(_)
             | ty::Array(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::RawPtr(_)
             | ty::Ref(..)
             | ty::FnDef(..)

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -535,7 +535,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 self.tcx,
                 self.tcx.typeck_root_def_id(expr_def_id.to_def_id()),
             );
-            let witness = Ty::new_generator_witness_mir(self.tcx, expr_def_id.to_def_id(), args);
+            let witness = Ty::new_generator_witness(self.tcx, expr_def_id.to_def_id(), args);
 
             // Unify `interior` with `witness` and collect all the resulting obligations.
             let span = self.tcx.hir().body(body_id).value.span;

compiler/rustc_infer/src/infer/canonical/canonicalizer.rs

@@ -459,7 +459,6 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'cx, 'tcx> {
             ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Bool
             | ty::Char
             | ty::Int(..)

compiler/rustc_infer/src/infer/equate.rs

@@ -119,26 +119,6 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> {
                         .obligations,
                 );
             }
-            // Optimization of GeneratorWitness relation since we know that all
-            // free regions are replaced with bound regions during construction.
-            // This greatly speeds up equating of GeneratorWitness.
-            (&ty::GeneratorWitness(a_types), &ty::GeneratorWitness(b_types)) => {
-                let a_types = infcx.tcx.anonymize_bound_vars(a_types);
-                let b_types = infcx.tcx.anonymize_bound_vars(b_types);
-                if a_types.bound_vars() == b_types.bound_vars() {
-                    let (a_types, b_types) = infcx.instantiate_binder_with_placeholders(
-                        a_types.map_bound(|a_types| (a_types, b_types.skip_binder())),
-                    );
-                    for (a, b) in std::iter::zip(a_types, b_types) {
-                        self.relate(a, b)?;
-                    }
-                } else {
-                    return Err(ty::error::TypeError::Sorts(ty::relate::expected_found(
-                        self, a, b,
-                    )));
-                }
-            }
-
             _ => {
                 self.fields.infcx.super_combine_tys(self, a, b)?;
             }

compiler/rustc_infer/src/infer/outlives/components.rs

@@ -112,7 +112,7 @@ fn compute_components<'tcx>(
             }
 
             // All regions are bound inside a witness
-            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => (),
+            ty::GeneratorWitness(..) => (),
 
             // OutlivesTypeParameterEnv -- the actual checking that `X:'a`
             // is implied by the environment is done in regionck.

compiler/rustc_infer/src/infer/sub.rs

@@ -147,25 +147,6 @@ impl<'tcx> TypeRelation<'tcx> for Sub<'_, '_, 'tcx> {
                 );
                 Ok(a)
             }
-            // Optimization of GeneratorWitness relation since we know that all
-            // free regions are replaced with bound regions during construction.
-            // This greatly speeds up subtyping of GeneratorWitness.
-            (&ty::GeneratorWitness(a_types), &ty::GeneratorWitness(b_types)) => {
-                let a_types = infcx.tcx.anonymize_bound_vars(a_types);
-                let b_types = infcx.tcx.anonymize_bound_vars(b_types);
-                if a_types.bound_vars() == b_types.bound_vars() {
-                    let (a_types, b_types) = infcx.instantiate_binder_with_placeholders(
-                        a_types.map_bound(|a_types| (a_types, b_types.skip_binder())),
-                    );
-                    for (a, b) in std::iter::zip(a_types, b_types) {
-                        self.relate(a, b)?;
-                    }
-                    Ok(a)
-                } else {
-                    Err(ty::error::TypeError::Sorts(ty::relate::expected_found(self, a, b)))
-                }
-            }
-
             _ => {
                 self.fields.infcx.super_combine_tys(self, a, b)?;
                 Ok(a)

compiler/rustc_lint/src/types.rs

@@ -1271,7 +1271,6 @@ impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Placeholder(..)
             | ty::FnDef(..) => bug!("unexpected type in foreign function: {:?}", ty),
         }

compiler/rustc_middle/src/ty/context.rs

@@ -1384,7 +1384,6 @@ impl<'tcx> TyCtxt<'tcx> {
                     Placeholder,
                     Generator,
                     GeneratorWitness,
-                    GeneratorWitnessMIR,
                     Dynamic,
                     Closure,
                     Tuple,

compiler/rustc_middle/src/ty/error.rs

@@ -242,8 +242,7 @@ impl<'tcx> Ty<'tcx> {
             ty::Dynamic(..) => "trait object".into(),
             ty::Closure(..) => "closure".into(),
             ty::Generator(def_id, ..) => tcx.generator_kind(def_id).unwrap().descr().into(),
-            ty::GeneratorWitness(..) |
-            ty::GeneratorWitnessMIR(..) => "generator witness".into(),
+            ty::GeneratorWitness(..) => "generator witness".into(),
             ty::Infer(ty::TyVar(_)) => "inferred type".into(),
             ty::Infer(ty::IntVar(_)) => "integer".into(),
             ty::Infer(ty::FloatVar(_)) => "floating-point number".into(),
@@ -295,7 +294,7 @@ impl<'tcx> Ty<'tcx> {
             ty::Dynamic(..) => "trait object".into(),
             ty::Closure(..) => "closure".into(),
             ty::Generator(def_id, ..) => tcx.generator_kind(def_id).unwrap().descr().into(),
-            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => "generator witness".into(),
+            ty::GeneratorWitness(..) => "generator witness".into(),
             ty::Tuple(..) => "tuple".into(),
             ty::Placeholder(..) => "higher-ranked type".into(),
             ty::Bound(..) => "bound type variable".into(),

compiler/rustc_middle/src/ty/fast_reject.rs

@@ -29,8 +29,7 @@ pub enum SimplifiedType {
     Trait(DefId),
     Closure(DefId),
     Generator(DefId),
-    GeneratorWitness(usize),
-    GeneratorWitnessMIR(DefId),
+    GeneratorWitness(DefId),
     Function(usize),
     Placeholder,
 }
@@ -130,10 +129,7 @@ pub fn simplify_type<'tcx>(
         ty::Ref(_, _, mutbl) => Some(SimplifiedType::Ref(mutbl)),
         ty::FnDef(def_id, _) | ty::Closure(def_id, _) => Some(SimplifiedType::Closure(def_id)),
         ty::Generator(def_id, _, _) => Some(SimplifiedType::Generator(def_id)),
-        ty::GeneratorWitness(tys) => {
-            Some(SimplifiedType::GeneratorWitness(tys.skip_binder().len()))
-        }
-        ty::GeneratorWitnessMIR(def_id, _) => Some(SimplifiedType::GeneratorWitnessMIR(def_id)),
+        ty::GeneratorWitness(def_id, _) => Some(SimplifiedType::GeneratorWitness(def_id)),
         ty::Never => Some(SimplifiedType::Never),
         ty::Tuple(tys) => Some(SimplifiedType::Tuple(tys.len())),
         ty::FnPtr(f) => Some(SimplifiedType::Function(f.skip_binder().inputs().len())),
@@ -169,7 +165,7 @@ impl SimplifiedType {
             | SimplifiedType::Trait(d)
             | SimplifiedType::Closure(d)
             | SimplifiedType::Generator(d)
-            | SimplifiedType::GeneratorWitnessMIR(d) => Some(d),
+            | SimplifiedType::GeneratorWitness(d) => Some(d),
             _ => None,
         }
     }
@@ -240,7 +236,6 @@ impl DeepRejectCtxt {
             | ty::Closure(..)
             | ty::Generator(..)
             | ty::GeneratorWitness(..)
-            | ty::GeneratorWitnessMIR(..)
             | ty::Placeholder(..)
             | ty::Bound(..)
             | ty::Infer(_) => bug!("unexpected impl_ty: {impl_ty}"),
@@ -342,7 +337,7 @@ impl DeepRejectCtxt {
 
             ty::Error(_) => true,
 
-            ty::GeneratorWitness(..) | ty::GeneratorWitnessMIR(..) => {
+            ty::GeneratorWitness(..) => {
                 bug!("unexpected obligation type: {:?}", obligation_ty)
             }
         }

compiler/rustc_middle/src/ty/flags.rs

@@ -127,11 +127,7 @@ impl FlagComputation {
                 self.add_ty(args.tupled_upvars_ty());
             }
 
-            &ty::GeneratorWitness(ts) => {
-                self.bound_computation(ts, |flags, ts| flags.add_tys(ts));
-            }
-
-            ty::GeneratorWitnessMIR(_, args) => {
+            ty::GeneratorWitness(_, args) => {
                 let should_remove_further_specializable =
                     !self.flags.contains(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
                 self.add_args(args);

compiler/rustc_middle/src/ty/layout.rs

@@ -810,7 +810,6 @@ where
                 | ty::Never
                 | ty::FnDef(..)
                 | ty::GeneratorWitness(..)
-                | ty::GeneratorWitnessMIR(..)
                 | ty::Foreign(..)
                 | ty::Dynamic(_, _, ty::Dyn) => {
                     bug!("TyAndLayout::field({:?}): not applicable", this)

compiler/rustc_middle/src/ty/opaque_types.rs

@@ -157,9 +157,9 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ReverseMapper<'tcx> {
                 Ty::new_generator(self.tcx, def_id, args, movability)
             }
 
-            ty::GeneratorWitnessMIR(def_id, args) => {
+            ty::GeneratorWitness(def_id, args) => {
                 let args = self.fold_closure_args(def_id, args);
-                Ty::new_generator_witness_mir(self.tcx, def_id, args)
+                Ty::new_generator_witness(self.tcx, def_id, args)
             }
 
             ty::Param(param) => {

compiler/rustc_middle/src/ty/print/mod.rs

@@ -271,7 +271,7 @@ fn characteristic_def_id_of_type_cached<'a>(
         ty::FnDef(def_id, _)
         | ty::Closure(def_id, _)
         | ty::Generator(def_id, _, _)
-        | ty::GeneratorWitnessMIR(def_id, _)
+        | ty::GeneratorWitness(def_id, _)
         | ty::Foreign(def_id) => Some(def_id),
 
         ty::Bool
@@ -286,7 +286,6 @@ fn characteristic_def_id_of_type_cached<'a>(
         | ty::Infer(_)
         | ty::Bound(..)
         | ty::Error(_)
-        | ty::GeneratorWitness(..)
         | ty::Never
         | ty::Float(_) => None,
     }

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -838,10 +838,7 @@ pub trait PrettyPrinter<'tcx>:
 
                 p!("}}")
             }
-            ty::GeneratorWitness(types) => {
-                p!(in_binder(&types));
-            }
-            ty::GeneratorWitnessMIR(did, args) => {
+            ty::GeneratorWitness(did, args) => {
                 p!(write("{{"));
                 if !self.tcx().sess.verbose() {
                     p!("generator witness");

compiler/rustc_middle/src/ty/relate.rs

@@ -453,24 +453,14 @@ pub fn structurally_relate_tys<'tcx, R: TypeRelation<'tcx>>(
             Ok(Ty::new_generator(tcx, a_id, args, movability))
         }
 
-        (&ty::GeneratorWitness(a_types), &ty::GeneratorWitness(b_types)) => {
-            // Wrap our types with a temporary GeneratorWitness struct
-            // inside the binder so we can related them
-            let a_types = a_types.map_bound(GeneratorWitness);
-            let b_types = b_types.map_bound(GeneratorWitness);
-            // Then remove the GeneratorWitness for the result
-            let types = relation.relate(a_types, b_types)?.map_bound(|witness| witness.0);
-            Ok(Ty::new_generator_witness(tcx, types))
-        }
-
-        (&ty::GeneratorWitnessMIR(a_id, a_args), &ty::GeneratorWitnessMIR(b_id, b_args))
+        (&ty::GeneratorWitness(a_id, a_args), &ty::GeneratorWitness(b_id, b_args))
             if a_id == b_id =>
         {
             // All GeneratorWitness types with the same id represent
             // the (anonymous) type of the same generator expression. So
             // all of their regions should be equated.
             let args = relation.relate(a_args, b_args)?;
-            Ok(Ty::new_generator_witness_mir(tcx, a_id, args))
+            Ok(Ty::new_generator_witness(tcx, a_id, args))
         }
 
         (&ty::Closure(a_id, a_args), &ty::Closure(b_id, b_args)) if a_id == b_id => {

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -657,9 +657,8 @@ impl<'tcx> TypeSuperFoldable<TyCtxt<'tcx>> for Ty<'tcx> {
             ty::Generator(did, args, movability) => {
                 ty::Generator(did, args.try_fold_with(folder)?, movability)
             }
-            ty::GeneratorWitness(types) => ty::GeneratorWitness(types.try_fold_with(folder)?),
-            ty::GeneratorWitnessMIR(did, args) => {
-                ty::GeneratorWitnessMIR(did, args.try_fold_with(folder)?)
+            ty::GeneratorWitness(did, args) => {
+                ty::GeneratorWitness(did, args.try_fold_with(folder)?)
             }
             ty::Closure(did, args) => ty::Closure(did, args.try_fold_with(folder)?),
             ty::Alias(kind, data) => ty::Alias(kind, data.try_fold_with(folder)?),
@@ -708,8 +707,7 @@ impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for Ty<'tcx> {
                 ty.visit_with(visitor)
             }
             ty::Generator(_did, ref args, _) => args.visit_with(visitor),
-            ty::GeneratorWitness(ref types) => types.visit_with(visitor),
-            ty::GeneratorWitnessMIR(_did, ref args) => args.visit_with(visitor),
+            ty::GeneratorWitness(_did, ref args) => args.visit_with(visitor),
             ty::Closure(_did, ref args) => args.visit_with(visitor),
             ty::Alias(_, ref data) => data.visit_with(visitor),