Merging upstream version 1.75.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

14 files changed, 291 insertions, 194 deletions

diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index 23d2c0c4e..27d2bdead 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -37,6 +37,8 @@ pub(super) trait GoalKind<'tcx>:
 
     fn trait_ref(self, tcx: TyCtxt<'tcx>) -> ty::TraitRef<'tcx>;
 
+    fn polarity(self) -> ty::ImplPolarity;
+
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self;
 
     fn trait_def_id(self, tcx: TyCtxt<'tcx>) -> DefId;
@@ -191,18 +193,26 @@ pub(super) trait GoalKind<'tcx>:
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
-    /// A generator (that comes from an `async` desugaring) is known to implement
-    /// `Future<Output = O>`, where `O` is given by the generator's return type
+    /// A coroutine (that comes from an `async` desugaring) is known to implement
+    /// `Future<Output = O>`, where `O` is given by the coroutine's return type
     /// that was computed during type-checking.
     fn consider_builtin_future_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
 
-    /// A generator (that doesn't come from an `async` desugaring) is known to
-    /// implement `Generator<R, Yield = Y, Return = O>`, given the resume, yield,
-    /// and return types of the generator computed during type-checking.
-    fn consider_builtin_generator_candidate(
+    /// A coroutine (that comes from a `gen` desugaring) is known to implement
+    /// `Iterator<Item = O>`, where `O` is given by the generator's yield type
+    /// that was computed during type-checking.
+    fn consider_builtin_iterator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx>;
+
+    /// A coroutine (that doesn't come from an `async` or `gen` desugaring) is known to
+    /// implement `Coroutine<R, Yield = Y, Return = O>`, given the resume, yield,
+    /// and return types of the coroutine computed during type-checking.
+    fn consider_builtin_coroutine_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx>;
@@ -410,7 +420,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::FnPtr(_)
             | ty::Dynamic(_, _, _)
             | ty::Closure(_, _)
-            | ty::Generator(_, _, _)
+            | ty::Coroutine(_, _, _)
             | ty::Never
             | ty::Tuple(_) => {
                 let simp =
@@ -467,9 +477,9 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             ty::Alias(_, _) | ty::Placeholder(..) | ty::Error(_) => (),
 
             // FIXME: These should ideally not exist as a self type. It would be nice for
-            // the builtin auto trait impls of generators to instead directly recurse
+            // the builtin auto trait impls of coroutines to instead directly recurse
             // into the witness.
-            ty::GeneratorWitness(..) => (),
+            ty::CoroutineWitness(..) => (),
 
             // These variants should not exist as a self type.
             ty::Infer(ty::TyVar(_) | ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_))
@@ -552,8 +562,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             G::consider_builtin_pointee_candidate(self, goal)
         } else if lang_items.future_trait() == Some(trait_def_id) {
             G::consider_builtin_future_candidate(self, goal)
-        } else if lang_items.gen_trait() == Some(trait_def_id) {
-            G::consider_builtin_generator_candidate(self, goal)
+        } else if lang_items.iterator_trait() == Some(trait_def_id) {
+            G::consider_builtin_iterator_candidate(self, goal)
+        } else if lang_items.coroutine_trait() == Some(trait_def_id) {
+            G::consider_builtin_coroutine_candidate(self, goal)
         } else if lang_items.discriminant_kind_trait() == Some(trait_def_id) {
             G::consider_builtin_discriminant_kind_candidate(self, goal)
         } else if lang_items.destruct_trait() == Some(trait_def_id) {
@@ -620,8 +632,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::FnPtr(_)
             | ty::Dynamic(..)
             | ty::Closure(..)
-            | ty::Generator(..)
-            | ty::GeneratorWitness(..)
+            | ty::Coroutine(..)
+            | ty::CoroutineWitness(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Param(_)
@@ -776,8 +788,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::FnPtr(_)
             | ty::Alias(..)
             | ty::Closure(..)
-            | ty::Generator(..)
-            | ty::GeneratorWitness(..)
+            | ty::Coroutine(..)
+            | ty::CoroutineWitness(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Param(_)
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
index 16f288045..839968b25 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
@@ -12,7 +12,7 @@ use crate::solve::EvalCtxt;
 
 // Calculates the constituent types of a type for `auto trait` purposes.
 //
-// For types with an "existential" binder, i.e. generator witnesses, we also
+// For types with an "existential" binder, i.e. coroutine witnesses, we also
 // instantiate the binder with placeholders eagerly.
 #[instrument(level = "debug", skip(ecx), ret)]
 pub(in crate::solve) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
@@ -57,14 +57,14 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
 
         ty::Closure(_, ref args) => Ok(vec![args.as_closure().tupled_upvars_ty()]),
 
-        ty::Generator(_, ref args, _) => {
-            let generator_args = args.as_generator();
-            Ok(vec![generator_args.tupled_upvars_ty(), generator_args.witness()])
+        ty::Coroutine(_, ref args, _) => {
+            let coroutine_args = args.as_coroutine();
+            Ok(vec![coroutine_args.tupled_upvars_ty(), coroutine_args.witness()])
         }
 
-        ty::GeneratorWitness(def_id, args) => Ok(ecx
+        ty::CoroutineWitness(def_id, args) => Ok(ecx
             .tcx()
-            .generator_hidden_types(def_id)
+            .coroutine_hidden_types(def_id)
             .map(|bty| {
                 ecx.instantiate_binder_with_placeholders(replace_erased_lifetimes_with_bound_vars(
                     tcx,
@@ -124,8 +124,8 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
         | ty::RawPtr(..)
         | ty::Char
         | ty::Ref(..)
-        | ty::Generator(..)
-        | ty::GeneratorWitness(..)
+        | ty::Coroutine(..)
+        | ty::CoroutineWitness(..)
         | ty::Array(..)
         | ty::Closure(..)
         | ty::Never
@@ -177,7 +177,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
         ty::Dynamic(..)
         | ty::Str
         | ty::Slice(_)
-        | ty::Generator(_, _, Movability::Static)
+        | ty::Coroutine(_, _, Movability::Static)
         | ty::Foreign(..)
         | ty::Ref(_, _, Mutability::Mut)
         | ty::Adt(_, _)
@@ -194,18 +194,18 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
 
         ty::Closure(_, args) => Ok(vec![args.as_closure().tupled_upvars_ty()]),
 
-        ty::Generator(_, args, Movability::Movable) => {
-            if ecx.tcx().features().generator_clone {
-                let generator = args.as_generator();
-                Ok(vec![generator.tupled_upvars_ty(), generator.witness()])
+        ty::Coroutine(_, args, Movability::Movable) => {
+            if ecx.tcx().features().coroutine_clone {
+                let coroutine = args.as_coroutine();
+                Ok(vec![coroutine.tupled_upvars_ty(), coroutine.witness()])
             } else {
                 Err(NoSolution)
             }
         }
 
-        ty::GeneratorWitness(def_id, args) => Ok(ecx
+        ty::CoroutineWitness(def_id, args) => Ok(ecx
             .tcx()
-            .generator_hidden_types(def_id)
+            .coroutine_hidden_types(def_id)
             .map(|bty| {
                 ecx.instantiate_binder_with_placeholders(replace_erased_lifetimes_with_bound_vars(
                     ecx.tcx(),
@@ -278,8 +278,8 @@ pub(in crate::solve) fn extract_tupled_inputs_and_output_from_callable<'tcx>(
         | ty::RawPtr(_)
         | ty::Ref(_, _, _)
         | ty::Dynamic(_, _, _)
-        | ty::Generator(_, _, _)
-        | ty::GeneratorWitness(..)
+        | ty::Coroutine(_, _, _)
+        | ty::CoroutineWitness(..)
         | ty::Never
         | ty::Tuple(_)
         | ty::Alias(_, _)
diff --git a/compiler/rustc_trait_selection/src/solve/canonicalize.rs b/compiler/rustc_trait_selection/src/solve/canonicalize.rs
index aa92b924e..377ae1b4e 100644
--- a/compiler/rustc_trait_selection/src/solve/canonicalize.rs
+++ b/compiler/rustc_trait_selection/src/solve/canonicalize.rs
@@ -224,12 +224,20 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'_, 'tcx> {
         let kind = match *r {
             ty::ReLateBound(..) => return r,
 
-            ty::ReStatic => match self.canonicalize_mode {
+            // We may encounter `ReStatic` in item signatures or the hidden type
+            // of an opaque. `ReErased` should only be encountered in the hidden
+            // type of an opaque for regions that are ignored for the purposes of
+            // captures.
+            //
+            // FIXME: We should investigate the perf implications of not uniquifying
+            // `ReErased`. We may be able to short-circuit registering region
+            // obligations if we encounter a `ReErased` on one side, for example.
+            ty::ReStatic | ty::ReErased => match self.canonicalize_mode {
                 CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                 CanonicalizeMode::Response { .. } => return r,
             },
 
-            ty::ReErased | ty::ReFree(_) | ty::ReEarlyBound(_) => match self.canonicalize_mode {
+            ty::ReFree(_) | ty::ReEarlyBound(_) => match self.canonicalize_mode {
                 CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                 CanonicalizeMode::Response { .. } => bug!("unexpected region in response: {r:?}"),
             },
@@ -329,8 +337,8 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'_, 'tcx> {
             | ty::FnPtr(_)
             | ty::Dynamic(_, _, _)
             | ty::Closure(_, _)
-            | ty::Generator(_, _, _)
-            | ty::GeneratorWitness(..)
+            | ty::Coroutine(_, _, _)
+            | ty::CoroutineWitness(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Alias(_, _)
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
index 066129d8e..70235b710 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
@@ -119,25 +119,11 @@ impl NestedGoals<'_> {
 
 #[derive(PartialEq, Eq, Debug, Hash, HashStable, Clone, Copy)]
 pub enum GenerateProofTree {
-    Yes(UseGlobalCache),
+    Yes,
     IfEnabled,
     Never,
 }
 
-#[derive(PartialEq, Eq, Debug, Hash, HashStable, Clone, Copy)]
-pub enum UseGlobalCache {
-    Yes,
-    No,
-}
-impl UseGlobalCache {
-    pub fn from_bool(use_cache: bool) -> Self {
-        match use_cache {
-            true => UseGlobalCache::Yes,
-            false => UseGlobalCache::No,
-        }
-    }
-}
-
 pub trait InferCtxtEvalExt<'tcx> {
     /// Evaluates a goal from **outside** of the trait solver.
     ///
diff --git a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
index 15c8d9e5b..69bfdd468 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
@@ -17,7 +17,7 @@ use rustc_middle::traits::solve::{Certainty, Goal};
 use rustc_middle::ty;
 
 use crate::solve::inspect::ProofTreeBuilder;
-use crate::solve::{GenerateProofTree, InferCtxtEvalExt, UseGlobalCache};
+use crate::solve::{GenerateProofTree, InferCtxtEvalExt};
 
 pub struct InspectGoal<'a, 'tcx> {
     infcx: &'a InferCtxt<'tcx>,
@@ -82,8 +82,7 @@ impl<'a, 'tcx> InspectCandidate<'a, 'tcx> {
                 }
 
                 for &goal in &instantiated_goals {
-                    let (_, proof_tree) =
-                        infcx.evaluate_root_goal(goal, GenerateProofTree::Yes(UseGlobalCache::No));
+                    let (_, proof_tree) = infcx.evaluate_root_goal(goal, GenerateProofTree::Yes);
                     let proof_tree = proof_tree.unwrap();
                     visitor.visit_goal(&InspectGoal::new(
                         infcx,
@@ -169,11 +168,11 @@ impl<'a, 'tcx> InspectGoal<'a, 'tcx> {
         let mut candidates = vec![];
         let last_eval_step = match self.evaluation.evaluation.kind {
             inspect::CanonicalGoalEvaluationKind::Overflow
-            | inspect::CanonicalGoalEvaluationKind::CacheHit(_) => {
+            | inspect::CanonicalGoalEvaluationKind::CycleInStack => {
                 warn!("unexpected root evaluation: {:?}", self.evaluation);
                 return vec![];
             }
-            inspect::CanonicalGoalEvaluationKind::Uncached { ref revisions } => {
+            inspect::CanonicalGoalEvaluationKind::Evaluation { ref revisions } => {
                 if let Some(last) = revisions.last() {
                     last
                 } else {
@@ -227,8 +226,7 @@ impl<'tcx> ProofTreeInferCtxtExt<'tcx> for InferCtxt<'tcx> {
         goal: Goal<'tcx, ty::Predicate<'tcx>>,
         visitor: &mut V,
     ) -> ControlFlow<V::BreakTy> {
-        let (_, proof_tree) =
-            self.evaluate_root_goal(goal, GenerateProofTree::Yes(UseGlobalCache::No));
+        let (_, proof_tree) = self.evaluate_root_goal(goal, GenerateProofTree::Yes);
         let proof_tree = proof_tree.unwrap();
         visitor.visit_goal(&InspectGoal::new(self, 0, &proof_tree))
     }
diff --git a/compiler/rustc_trait_selection/src/solve/inspect/build.rs b/compiler/rustc_trait_selection/src/solve/inspect/build.rs
index 2eba98b02..088455b38 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect/build.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect/build.rs
@@ -3,6 +3,8 @@
 //! This code is *a bit* of a mess and can hopefully be
 //! mostly ignored. For a general overview of how it works,
 //! see the comment on [ProofTreeBuilder].
+use std::mem;
+
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::traits::solve::{
     CanonicalInput, Certainty, Goal, IsNormalizesToHack, QueryInput, QueryResult,
@@ -10,7 +12,6 @@ use rustc_middle::traits::solve::{
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::config::DumpSolverProofTree;
 
-use crate::solve::eval_ctxt::UseGlobalCache;
 use crate::solve::{self, inspect, EvalCtxt, GenerateProofTree};
 
 /// The core data structure when building proof trees.
@@ -34,12 +35,7 @@ use crate::solve::{self, inspect, EvalCtxt, GenerateProofTree};
 /// is called to recursively convert the whole structure to a
 /// finished proof tree.
 pub(in crate::solve) struct ProofTreeBuilder<'tcx> {
-    state: Option<Box<BuilderData<'tcx>>>,
-}
-
-struct BuilderData<'tcx> {
-    tree: DebugSolver<'tcx>,
-    use_global_cache: UseGlobalCache,
+    state: Option<Box<DebugSolver<'tcx>>>,
 }
 
 /// The current state of the proof tree builder, at most places
@@ -118,36 +114,46 @@ pub(in crate::solve) enum WipGoalEvaluationKind<'tcx> {
     Nested { is_normalizes_to_hack: IsNormalizesToHack },
 }
 
-#[derive(Eq, PartialEq, Debug)]
-pub(in crate::solve) enum WipCanonicalGoalEvaluationKind {
+#[derive(Eq, PartialEq)]
+pub(in crate::solve) enum WipCanonicalGoalEvaluationKind<'tcx> {
     Overflow,
-    CacheHit(inspect::CacheHit),
+    CycleInStack,
+    Interned { revisions: &'tcx [inspect::GoalEvaluationStep<'tcx>] },
+}
+
+impl std::fmt::Debug for WipCanonicalGoalEvaluationKind<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Overflow => write!(f, "Overflow"),
+            Self::CycleInStack => write!(f, "CycleInStack"),
+            Self::Interned { revisions: _ } => f.debug_struct("Interned").finish_non_exhaustive(),
+        }
+    }
 }
 
 #[derive(Eq, PartialEq, Debug)]
 struct WipCanonicalGoalEvaluation<'tcx> {
     goal: CanonicalInput<'tcx>,
-    kind: Option<WipCanonicalGoalEvaluationKind>,
+    kind: Option<WipCanonicalGoalEvaluationKind<'tcx>>,
+    /// Only used for uncached goals. After we finished evaluating
+    /// the goal, this is interned and moved into `kind`.
     revisions: Vec<WipGoalEvaluationStep<'tcx>>,
     result: Option<QueryResult<'tcx>>,
 }
 
 impl<'tcx> WipCanonicalGoalEvaluation<'tcx> {
     fn finalize(self) -> inspect::CanonicalGoalEvaluation<'tcx> {
-        let kind = match self.kind {
-            Some(WipCanonicalGoalEvaluationKind::Overflow) => {
+        assert!(self.revisions.is_empty());
+        let kind = match self.kind.unwrap() {
+            WipCanonicalGoalEvaluationKind::Overflow => {
                 inspect::CanonicalGoalEvaluationKind::Overflow
             }
-            Some(WipCanonicalGoalEvaluationKind::CacheHit(hit)) => {
-                inspect::CanonicalGoalEvaluationKind::CacheHit(hit)
+            WipCanonicalGoalEvaluationKind::CycleInStack => {
+                inspect::CanonicalGoalEvaluationKind::CycleInStack
+            }
+            WipCanonicalGoalEvaluationKind::Interned { revisions } => {
+                inspect::CanonicalGoalEvaluationKind::Evaluation { revisions }
             }
-            None => inspect::CanonicalGoalEvaluationKind::Uncached {
-                revisions: self
-                    .revisions
-                    .into_iter()
-                    .map(WipGoalEvaluationStep::finalize)
-                    .collect(),
-            },
         };
 
         inspect::CanonicalGoalEvaluation { goal: self.goal, kind, result: self.result.unwrap() }
@@ -226,33 +232,20 @@ impl<'tcx> WipProbeStep<'tcx> {
 }
 
 impl<'tcx> ProofTreeBuilder<'tcx> {
-    fn new(
-        state: impl Into<DebugSolver<'tcx>>,
-        use_global_cache: UseGlobalCache,
-    ) -> ProofTreeBuilder<'tcx> {
-        ProofTreeBuilder {
-            state: Some(Box::new(BuilderData { tree: state.into(), use_global_cache })),
-        }
+    fn new(state: impl Into<DebugSolver<'tcx>>) -> ProofTreeBuilder<'tcx> {
+        ProofTreeBuilder { state: Some(Box::new(state.into())) }
     }
 
     fn nested<T: Into<DebugSolver<'tcx>>>(&self, state: impl FnOnce() -> T) -> Self {
-        match &self.state {
-            Some(prev_state) => Self {
-                state: Some(Box::new(BuilderData {
-                    tree: state().into(),
-                    use_global_cache: prev_state.use_global_cache,
-                })),
-            },
-            None => Self { state: None },
-        }
+        ProofTreeBuilder { state: self.state.as_ref().map(|_| Box::new(state().into())) }
     }
 
     fn as_mut(&mut self) -> Option<&mut DebugSolver<'tcx>> {
-        self.state.as_mut().map(|boxed| &mut boxed.tree)
+        self.state.as_deref_mut()
     }
 
     pub fn finalize(self) -> Option<inspect::GoalEvaluation<'tcx>> {
-        match self.state?.tree {
+        match *self.state? {
             DebugSolver::GoalEvaluation(wip_goal_evaluation) => {
                 Some(wip_goal_evaluation.finalize())
             }
@@ -260,13 +253,6 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
         }
     }
 
-    pub fn use_global_cache(&self) -> bool {
-        self.state
-            .as_ref()
-            .map(|state| matches!(state.use_global_cache, UseGlobalCache::Yes))
-            .unwrap_or(true)
-    }
-
     pub fn new_maybe_root(
         tcx: TyCtxt<'tcx>,
         generate_proof_tree: GenerateProofTree,
@@ -276,10 +262,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
             GenerateProofTree::IfEnabled => {
                 let opts = &tcx.sess.opts.unstable_opts;
                 match opts.dump_solver_proof_tree {
-                    DumpSolverProofTree::Always => {
-                        let use_cache = opts.dump_solver_proof_tree_use_cache.unwrap_or(true);
-                        ProofTreeBuilder::new_root(UseGlobalCache::from_bool(use_cache))
-                    }
+                    DumpSolverProofTree::Always => ProofTreeBuilder::new_root(),
                     // `OnError` is handled by reevaluating goals in error
                     // reporting with `GenerateProofTree::Yes`.
                     DumpSolverProofTree::OnError | DumpSolverProofTree::Never => {
@@ -287,12 +270,12 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
                     }
                 }
             }
-            GenerateProofTree::Yes(use_cache) => ProofTreeBuilder::new_root(use_cache),
+            GenerateProofTree::Yes => ProofTreeBuilder::new_root(),
         }
     }
 
-    pub fn new_root(use_global_cache: UseGlobalCache) -> ProofTreeBuilder<'tcx> {
-        ProofTreeBuilder::new(DebugSolver::Root, use_global_cache)
+    pub fn new_root() -> ProofTreeBuilder<'tcx> {
+        ProofTreeBuilder::new(DebugSolver::Root)
     }
 
     pub fn new_noop() -> ProofTreeBuilder<'tcx> {
@@ -336,9 +319,27 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
         })
     }
 
+    pub fn finalize_evaluation(
+        &mut self,
+        tcx: TyCtxt<'tcx>,
+    ) -> Option<&'tcx [inspect::GoalEvaluationStep<'tcx>]> {
+        self.as_mut().map(|this| match this {
+            DebugSolver::CanonicalGoalEvaluation(evaluation) => {
+                let revisions = mem::take(&mut evaluation.revisions)
+                    .into_iter()
+                    .map(WipGoalEvaluationStep::finalize);
+                let revisions = &*tcx.arena.alloc_from_iter(revisions);
+                let kind = WipCanonicalGoalEvaluationKind::Interned { revisions };
+                assert_eq!(evaluation.kind.replace(kind), None);
+                revisions
+            }
+            _ => unreachable!(),
+        })
+    }
+
     pub fn canonical_goal_evaluation(&mut self, canonical_goal_evaluation: ProofTreeBuilder<'tcx>) {
         if let Some(this) = self.as_mut() {
-            match (this, canonical_goal_evaluation.state.unwrap().tree) {
+            match (this, *canonical_goal_evaluation.state.unwrap()) {
                 (
                     DebugSolver::GoalEvaluation(goal_evaluation),
                     DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluation),
@@ -348,7 +349,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
         }
     }
 
-    pub fn goal_evaluation_kind(&mut self, kind: WipCanonicalGoalEvaluationKind) {
+    pub fn goal_evaluation_kind(&mut self, kind: WipCanonicalGoalEvaluationKind<'tcx>) {
         if let Some(this) = self.as_mut() {
             match this {
                 DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluation) => {
@@ -372,7 +373,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
     }
     pub fn goal_evaluation(&mut self, goal_evaluation: ProofTreeBuilder<'tcx>) {
         if let Some(this) = self.as_mut() {
-            match (this, goal_evaluation.state.unwrap().tree) {
+            match (this, *goal_evaluation.state.unwrap()) {
                 (
                     DebugSolver::AddedGoalsEvaluation(WipAddedGoalsEvaluation {
                         evaluations, ..
@@ -396,7 +397,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
     }
     pub fn goal_evaluation_step(&mut self, goal_evaluation_step: ProofTreeBuilder<'tcx>) {
         if let Some(this) = self.as_mut() {
-            match (this, goal_evaluation_step.state.unwrap().tree) {
+            match (this, *goal_evaluation_step.state.unwrap()) {
                 (
                     DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluations),
                     DebugSolver::GoalEvaluationStep(goal_evaluation_step),
@@ -444,7 +445,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
 
     pub fn finish_probe(&mut self, probe: ProofTreeBuilder<'tcx>) {
         if let Some(this) = self.as_mut() {
-            match (this, probe.state.unwrap().tree) {
+            match (this, *probe.state.unwrap()) {
                 (
                     DebugSolver::Probe(WipProbe { steps, .. })
                     | DebugSolver::GoalEvaluationStep(WipGoalEvaluationStep {
@@ -486,7 +487,7 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
 
     pub fn added_goals_evaluation(&mut self, added_goals_evaluation: ProofTreeBuilder<'tcx>) {
         if let Some(this) = self.as_mut() {
-            match (this, added_goals_evaluation.state.unwrap().tree) {
+            match (this, *added_goals_evaluation.state.unwrap()) {
                 (
                     DebugSolver::GoalEvaluationStep(WipGoalEvaluationStep {
                         evaluation: WipProbe { steps, .. },
diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs
index 77a3b5e12..dba5369fa 100644
--- a/compiler/rustc_trait_selection/src/solve/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/mod.rs
@@ -32,18 +32,13 @@ mod assembly;
 mod canonicalize;
 mod eval_ctxt;
 mod fulfill;
-mod inherent_projection;
 pub mod inspect;
 mod normalize;
-mod opaques;
 mod project_goals;
 mod search_graph;
 mod trait_goals;
-mod weak_types;
 
-pub use eval_ctxt::{
-    EvalCtxt, GenerateProofTree, InferCtxtEvalExt, InferCtxtSelectExt, UseGlobalCache,
-};
+pub use eval_ctxt::{EvalCtxt, GenerateProofTree, InferCtxtEvalExt, InferCtxtSelectExt};
 pub use fulfill::FulfillmentCtxt;
 pub(crate) use normalize::{deeply_normalize, deeply_normalize_with_skipped_universes};
 
diff --git a/compiler/rustc_trait_selection/src/solve/normalize.rs b/compiler/rustc_trait_selection/src/solve/normalize.rs
index 872f0c879..b0a348985 100644
--- a/compiler/rustc_trait_selection/src/solve/normalize.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalize.rs
@@ -129,7 +129,7 @@ impl<'tcx> NormalizationFolder<'_, 'tcx> {
             self.at.cause.clone(),
             self.at.param_env,
             ty::ProjectionPredicate {
-                projection_ty: tcx.mk_alias_ty(uv.def, uv.args),
+                projection_ty: AliasTy::new(tcx, uv.def, uv.args),
                 term: new_infer_ct.into(),
             },
         );
diff --git a/compiler/rustc_trait_selection/src/solve/inherent_projection.rs b/compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs
index 28fe59b7f..28fe59b7f 100644
--- a/compiler/rustc_trait_selection/src/solve/inherent_projection.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals/inherent_projection.rs
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs
index 0f9d36342..240141065 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals/mod.rs
@@ -18,6 +18,10 @@ use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_middle::ty::{ToPredicate, TypeVisitableExt};
 use rustc_span::{sym, ErrorGuaranteed, DUMMY_SP};
 
+mod inherent_projection;
+mod opaques;
+mod weak_types;
+
 impl<'tcx> EvalCtxt<'_, 'tcx> {
     #[instrument(level = "debug", skip(self), ret)]
     pub(super) fn compute_projection_goal(
@@ -97,6 +101,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
         self.projection_ty.trait_ref(tcx)
     }
 
+    fn polarity(self) -> ty::ImplPolarity {
+        ty::ImplPolarity::Positive
+    }
+
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self {
         self.with_self_ty(tcx, self_ty)
     }
@@ -346,14 +354,16 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
             ty::TraitRef::from_lang_item(tcx, LangItem::Sized, DUMMY_SP, [output])
         });
 
-        let pred = ty::Clause::from_projection_clause(
-            tcx,
-            tupled_inputs_and_output.map_bound(|(inputs, output)| ty::ProjectionPredicate {
-                projection_ty: tcx
-                    .mk_alias_ty(goal.predicate.def_id(), [goal.predicate.self_ty(), inputs]),
+        let pred = tupled_inputs_and_output
+            .map_bound(|(inputs, output)| ty::ProjectionPredicate {
+                projection_ty: ty::AliasTy::new(
+                    tcx,
+                    goal.predicate.def_id(),
+                    [goal.predicate.self_ty(), inputs],
+                ),
                 term: output.into(),
-            }),
-        );
+            })
+            .to_predicate(tcx);
 
         // A built-in `Fn` impl only holds if the output is sized.
         // (FIXME: technically we only need to check this if the type is a fn ptr...)
@@ -386,8 +396,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
                 | ty::FnPtr(..)
                 | ty::Closure(..)
                 | ty::Infer(ty::IntVar(..) | ty::FloatVar(..))
-                | ty::Generator(..)
-                | ty::GeneratorWitness(..)
+                | ty::Coroutine(..)
+                | ty::CoroutineWitness(..)
                 | ty::Never
                 | ty::Foreign(..) => tcx.types.unit,
 
@@ -453,70 +463,103 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx> {
         let self_ty = goal.predicate.self_ty();
-        let ty::Generator(def_id, args, _) = *self_ty.kind() else {
+        let ty::Coroutine(def_id, args, _) = *self_ty.kind() else {
             return Err(NoSolution);
         };
 
-        // Generators are not futures unless they come from `async` desugaring
+        // Coroutines are not futures unless they come from `async` desugaring
         let tcx = ecx.tcx();
-        if !tcx.generator_is_async(def_id) {
+        if !tcx.coroutine_is_async(def_id) {
             return Err(NoSolution);
         }
 
-        let term = args.as_generator().return_ty().into();
+        let term = args.as_coroutine().return_ty().into();
 
         Self::consider_implied_clause(
             ecx,
             goal,
             ty::ProjectionPredicate {
-                projection_ty: ecx.tcx().mk_alias_ty(goal.predicate.def_id(), [self_ty]),
+                projection_ty: ty::AliasTy::new(ecx.tcx(), goal.predicate.def_id(), [self_ty]),
                 term,
             }
             .to_predicate(tcx),
             // Technically, we need to check that the future type is Sized,
+            // but that's already proven by the coroutine being WF.
+            [],
+        )
+    }
+
+    fn consider_builtin_iterator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        let self_ty = goal.predicate.self_ty();
+        let ty::Coroutine(def_id, args, _) = *self_ty.kind() else {
+            return Err(NoSolution);
+        };
+
+        // Coroutines are not Iterators unless they come from `gen` desugaring
+        let tcx = ecx.tcx();
+        if !tcx.coroutine_is_gen(def_id) {
+            return Err(NoSolution);
+        }
+
+        let term = args.as_coroutine().yield_ty().into();
+
+        Self::consider_implied_clause(
+            ecx,
+            goal,
+            ty::ProjectionPredicate {
+                projection_ty: ty::AliasTy::new(ecx.tcx(), goal.predicate.def_id(), [self_ty]),
+                term,
+            }
+            .to_predicate(tcx),
+            // Technically, we need to check that the iterator type is Sized,
             // but that's already proven by the generator being WF.
             [],
         )
     }
 
-    fn consider_builtin_generator_candidate(
+    fn consider_builtin_coroutine_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx> {
         let self_ty = goal.predicate.self_ty();
-        let ty::Generator(def_id, args, _) = *self_ty.kind() else {
+        let ty::Coroutine(def_id, args, _) = *self_ty.kind() else {
             return Err(NoSolution);
         };
 
-        // `async`-desugared generators do not implement the generator trait
+        // `async`-desugared coroutines do not implement the coroutine trait
         let tcx = ecx.tcx();
-        if tcx.generator_is_async(def_id) {
+        if !tcx.is_general_coroutine(def_id) {
             return Err(NoSolution);
         }
 
-        let generator = args.as_generator();
+        let coroutine = args.as_coroutine();
 
         let name = tcx.associated_item(goal.predicate.def_id()).name;
         let term = if name == sym::Return {
-            generator.return_ty().into()
+            coroutine.return_ty().into()
         } else if name == sym::Yield {
-            generator.yield_ty().into()
+            coroutine.yield_ty().into()
         } else {
-            bug!("unexpected associated item `<{self_ty} as Generator>::{name}`")
+            bug!("unexpected associated item `<{self_ty} as Coroutine>::{name}`")
         };
 
         Self::consider_implied_clause(
             ecx,
             goal,
             ty::ProjectionPredicate {
-                projection_ty: ecx
-                    .tcx()
-                    .mk_alias_ty(goal.predicate.def_id(), [self_ty, generator.resume_ty()]),
+                projection_ty: ty::AliasTy::new(
+                    ecx.tcx(),
+                    goal.predicate.def_id(),
+                    [self_ty, coroutine.resume_ty()],
+                ),
                 term,
             }
             .to_predicate(tcx),
-            // Technically, we need to check that the future type is Sized,
-            // but that's already proven by the generator being WF.
+            // Technically, we need to check that the coroutine type is Sized,
+            // but that's already proven by the coroutine being WF.
             [],
         )
     }
@@ -553,8 +596,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
             | ty::FnPtr(..)
             | ty::Closure(..)
             | ty::Infer(ty::IntVar(..) | ty::FloatVar(..))
-            | ty::Generator(..)
-            | ty::GeneratorWitness(..)
+            | ty::Coroutine(..)
+            | ty::CoroutineWitness(..)
             | ty::Never
             | ty::Foreign(..)
             | ty::Adt(_, _)
diff --git a/compiler/rustc_trait_selection/src/solve/opaques.rs b/compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs
index f08adc020..ebd129f32 100644
--- a/compiler/rustc_trait_selection/src/solve/opaques.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals/opaques.rs
@@ -7,7 +7,7 @@ use rustc_middle::traits::Reveal;
 use rustc_middle::ty;
 use rustc_middle::ty::util::NotUniqueParam;
 
-use super::{EvalCtxt, SolverMode};
+use crate::solve::{EvalCtxt, SolverMode};
 
 impl<'tcx> EvalCtxt<'_, 'tcx> {
     pub(super) fn normalize_opaque_type(
diff --git a/compiler/rustc_trait_selection/src/solve/weak_types.rs b/compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs
index 54de32cf6..54de32cf6 100644
--- a/compiler/rustc_trait_selection/src/solve/weak_types.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals/weak_types.rs
diff --git a/compiler/rustc_trait_selection/src/solve/search_graph/mod.rs b/compiler/rustc_trait_selection/src/solve/search_graph.rs
index 33513f6bd..7ffa1d7d3 100644
--- a/compiler/rustc_trait_selection/src/solve/search_graph/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/search_graph.rs
@@ -6,7 +6,6 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_index::Idx;
 use rustc_index::IndexVec;
 use rustc_middle::dep_graph::dep_kinds;
-use rustc_middle::traits::solve::inspect::CacheHit;
 use rustc_middle::traits::solve::CacheData;
 use rustc_middle::traits::solve::{CanonicalInput, Certainty, EvaluationCache, QueryResult};
 use rustc_middle::ty::TyCtxt;
@@ -191,8 +190,8 @@ impl<'tcx> SearchGraph<'tcx> {
         };
 
         // Try to fetch the goal from the global cache.
-        if inspect.use_global_cache() {
-            if let Some(CacheData { result, reached_depth, encountered_overflow }) =
+        'global: {
+            let Some(CacheData { result, proof_tree, reached_depth, encountered_overflow }) =
                 self.global_cache(tcx).get(
                     tcx,
                     input,
@@ -201,13 +200,26 @@ impl<'tcx> SearchGraph<'tcx> {
                     },
                     available_depth,
                 )
-            {
-                inspect.goal_evaluation_kind(inspect::WipCanonicalGoalEvaluationKind::CacheHit(
-                    CacheHit::Global,
-                ));
-                self.on_cache_hit(reached_depth, encountered_overflow);
-                return result;
+            else {
+                break 'global;
+            };
+
+            // If we're building a proof tree and the current cache entry does not
+            // contain a proof tree, we do not use the entry but instead recompute
+            // the goal. We simply overwrite the existing entry once we're done,
+            // caching the proof tree.
+            if !inspect.is_noop() {
+                if let Some(revisions) = proof_tree {
+                    inspect.goal_evaluation_kind(
+                        inspect::WipCanonicalGoalEvaluationKind::Interned { revisions },
+                    );
+                } else {
+                    break 'global;
+                }
             }
+
+            self.on_cache_hit(reached_depth, encountered_overflow);
+            return result;
         }
 
         // Check whether we're in a cycle.
@@ -238,9 +250,7 @@ impl<'tcx> SearchGraph<'tcx> {
             // Finally we can return either the provisional response for that goal if we have a
             // coinductive cycle or an ambiguous result if the cycle is inductive.
             Entry::Occupied(entry) => {
-                inspect.goal_evaluation_kind(inspect::WipCanonicalGoalEvaluationKind::CacheHit(
-                    CacheHit::Provisional,
-                ));
+                inspect.goal_evaluation_kind(inspect::WipCanonicalGoalEvaluationKind::CycleInStack);
 
                 let stack_depth = *entry.get();
                 debug!("encountered cycle with depth {stack_depth:?}");
@@ -329,6 +339,8 @@ impl<'tcx> SearchGraph<'tcx> {
                 (current_entry, result)
             });
 
+        let proof_tree = inspect.finalize_evaluation(tcx);
+
         // We're now done with this goal. In case this goal is involved in a larger cycle
         // do not remove it from the provisional cache and update its provisional result.
         // We only add the root of cycles to the global cache.
@@ -346,7 +358,9 @@ impl<'tcx> SearchGraph<'tcx> {
             // more details.
             let reached_depth = final_entry.reached_depth.as_usize() - self.stack.len();
             self.global_cache(tcx).insert(
+                tcx,
                 input,
+                proof_tree,
                 reached_depth,
                 final_entry.encountered_overflow,
                 final_entry.cycle_participants,
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 8055c63b9..a0e2ad6e2 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -22,6 +22,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         self.trait_ref
     }
 
+    fn polarity(self) -> ty::ImplPolarity {
+        self.polarity
+    }
+
     fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self {
         self.with_self_ty(tcx, self_ty)
     }
@@ -136,12 +140,13 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         // `assemble_candidates_after_normalizing_self_ty`, and we'd
         // just be registering an identical candidate here.
         //
-        // Returning `Err(NoSolution)` here is ok in `SolverMode::Coherence`
-        // since we'll always be registering an ambiguous candidate in
+        // We always return `Err(NoSolution)` here in `SolverMode::Coherence`
+        // since we'll always register an ambiguous candidate in
         // `assemble_candidates_after_normalizing_self_ty` due to normalizing
         // the TAIT.
         if let ty::Alias(ty::Opaque, opaque_ty) = goal.predicate.self_ty().kind() {
             if matches!(goal.param_env.reveal(), Reveal::All)
+                || matches!(ecx.solver_mode(), SolverMode::Coherence)
                 || opaque_ty
                     .def_id
                     .as_local()
@@ -237,14 +242,25 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx> {
-        if goal.predicate.polarity != ty::ImplPolarity::Positive {
-            return Err(NoSolution);
-        }
-
-        if let ty::FnPtr(..) = goal.predicate.self_ty().kind() {
-            ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
-        } else {
-            Err(NoSolution)
+        let self_ty = goal.predicate.self_ty();
+        match goal.predicate.polarity {
+            ty::ImplPolarity::Positive => {
+                if self_ty.is_fn_ptr() {
+                    ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+                } else {
+                    Err(NoSolution)
+                }
+            }
+            ty::ImplPolarity::Negative => {
+                // If a type is rigid and not a fn ptr, then we know for certain
+                // that it does *not* implement `FnPtr`.
+                if !self_ty.is_fn_ptr() && self_ty.is_known_rigid() {
+                    ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+                } else {
+                    Err(NoSolution)
+                }
+            }
+            ty::ImplPolarity::Reservation => bug!(),
         }
     }
 
@@ -318,23 +334,47 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
             return Err(NoSolution);
         }
 
-        let ty::Generator(def_id, _, _) = *goal.predicate.self_ty().kind() else {
+        let ty::Coroutine(def_id, _, _) = *goal.predicate.self_ty().kind() else {
             return Err(NoSolution);
         };
 
-        // Generators are not futures unless they come from `async` desugaring
+        // Coroutines are not futures unless they come from `async` desugaring
         let tcx = ecx.tcx();
-        if !tcx.generator_is_async(def_id) {
+        if !tcx.coroutine_is_async(def_id) {
             return Err(NoSolution);
         }
 
-        // Async generator unconditionally implement `Future`
+        // Async coroutine unconditionally implement `Future`
         // Technically, we need to check that the future output type is Sized,
-        // but that's already proven by the generator being WF.
+        // but that's already proven by the coroutine being WF.
+        ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
+    }
+
+    fn consider_builtin_iterator_candidate(
+        ecx: &mut EvalCtxt<'_, 'tcx>,
+        goal: Goal<'tcx, Self>,
+    ) -> QueryResult<'tcx> {
+        if goal.predicate.polarity != ty::ImplPolarity::Positive {
+            return Err(NoSolution);
+        }
+
+        let ty::Coroutine(def_id, _, _) = *goal.predicate.self_ty().kind() else {
+            return Err(NoSolution);
+        };
+
+        // Coroutines are not iterators unless they come from `gen` desugaring
+        let tcx = ecx.tcx();
+        if !tcx.coroutine_is_gen(def_id) {
+            return Err(NoSolution);
+        }
+
+        // Gen coroutines unconditionally implement `Iterator`
+        // Technically, we need to check that the iterator output type is Sized,
+        // but that's already proven by the coroutines being WF.
         ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
     }
 
-    fn consider_builtin_generator_candidate(
+    fn consider_builtin_coroutine_candidate(
         ecx: &mut EvalCtxt<'_, 'tcx>,
         goal: Goal<'tcx, Self>,
     ) -> QueryResult<'tcx> {
@@ -343,24 +383,24 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         }
 
         let self_ty = goal.predicate.self_ty();
-        let ty::Generator(def_id, args, _) = *self_ty.kind() else {
+        let ty::Coroutine(def_id, args, _) = *self_ty.kind() else {
             return Err(NoSolution);
         };
 
-        // `async`-desugared generators do not implement the generator trait
+        // `async`-desugared coroutines do not implement the coroutine trait
         let tcx = ecx.tcx();
-        if tcx.generator_is_async(def_id) {
+        if !tcx.is_general_coroutine(def_id) {
             return Err(NoSolution);
         }
 
-        let generator = args.as_generator();
+        let coroutine = args.as_coroutine();
         Self::consider_implied_clause(
             ecx,
             goal,
-            ty::TraitRef::new(tcx, goal.predicate.def_id(), [self_ty, generator.resume_ty()])
+            ty::TraitRef::new(tcx, goal.predicate.def_id(), [self_ty, coroutine.resume_ty()])
                 .to_predicate(tcx),
-            // Technically, we need to check that the generator types are Sized,
-            // but that's already proven by the generator being WF.
+            // Technically, we need to check that the coroutine types are Sized,
+            // but that's already proven by the coroutine being WF.
             [],
         )
     }
@@ -843,10 +883,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
 
             ty::Infer(_) | ty::Bound(_, _) => bug!("unexpected type `{self_ty}`"),
 
-            // Generators have one special built-in candidate, `Unpin`, which
+            // Coroutines have one special built-in candidate, `Unpin`, which
             // takes precedence over the structural auto trait candidate being
             // assembled.
-            ty::Generator(_, _, movability)
+            ty::Coroutine(_, _, movability)
                 if Some(goal.predicate.def_id()) == self.tcx().lang_items().unpin_trait() =>
             {
                 match movability {
@@ -878,8 +918,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             | ty::FnDef(_, _)
             | ty::FnPtr(_)
             | ty::Closure(_, _)
-            | ty::Generator(_, _, _)
-            | ty::GeneratorWitness(..)
+            | ty::Coroutine(_, _, _)
+            | ty::CoroutineWitness(..)
             | ty::Never
             | ty::Tuple(_)
             | ty::Adt(_, _)