Rollup merge of #125255 - compiler-errors:eval-ctxt-generic, r=lcnr

Make `EvalCtxt` generic over `InferCtxtLike`

...but don't change any of the impls, yet! These can get uplifted as we add more methods to `InferCtxtLike`/`Interner` :3

This is built on top of #125230.

r? lcnr

19 files changed, 212 insertions, 174 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 69681930be6..d75f250275b 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -233,6 +233,10 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
     fn parent(self, def_id: Self::DefId) -> Self::DefId {
         self.parent(def_id)
     }
+
+    fn recursion_limit(self) -> usize {
+        self.recursion_limit().0
+    }
 }
 
 impl<'tcx> rustc_type_ir::inherent::Abi<TyCtxt<'tcx>> for abi::Abi {
diff --git a/compiler/rustc_middle/src/ty/predicate.rs b/compiler/rustc_middle/src/ty/predicate.rs
index 644fca7c5fe..be91249a25f 100644
--- a/compiler/rustc_middle/src/ty/predicate.rs
+++ b/compiler/rustc_middle/src/ty/predicate.rs
@@ -37,7 +37,11 @@ pub struct Predicate<'tcx>(
     pub(super) Interned<'tcx, WithCachedTypeInfo<ty::Binder<'tcx, PredicateKind<'tcx>>>>,
 );
 
-impl<'tcx> rustc_type_ir::inherent::Predicate<TyCtxt<'tcx>> for Predicate<'tcx> {}
+impl<'tcx> rustc_type_ir::inherent::Predicate<TyCtxt<'tcx>> for Predicate<'tcx> {
+    fn is_coinductive(self, interner: TyCtxt<'tcx>) -> bool {
+        self.is_coinductive(interner)
+    }
+}
 
 impl<'tcx> rustc_type_ir::visit::Flags for Predicate<'tcx> {
     fn flags(&self) -> TypeFlags {
diff --git a/compiler/rustc_trait_selection/src/solve/alias_relate.rs b/compiler/rustc_trait_selection/src/solve/alias_relate.rs
index 65cc0a45857..43e61de955a 100644
--- a/compiler/rustc_trait_selection/src/solve/alias_relate.rs
+++ b/compiler/rustc_trait_selection/src/solve/alias_relate.rs
@@ -16,10 +16,11 @@
 //! relate them structurally.
 
 use super::EvalCtxt;
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::solve::{Certainty, Goal, QueryResult};
 use rustc_middle::ty;
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn compute_alias_relate_goal(
         &mut self,
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
index b1dd6ae6611..11524410692 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs
@@ -1,8 +1,7 @@
 //! Code shared by trait and projection goals for candidate assembly.
 
-use crate::solve::GoalSource;
-use crate::solve::{EvalCtxt, SolverMode};
 use rustc_hir::def_id::DefId;
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_middle::bug;
 use rustc_middle::traits::solve::inspect::ProbeKind;
@@ -17,6 +16,9 @@ use rustc_middle::ty::{TypeVisitableExt, Upcast};
 use rustc_span::{ErrorGuaranteed, DUMMY_SP};
 use std::fmt::Debug;
 
+use crate::solve::GoalSource;
+use crate::solve::{EvalCtxt, SolverMode};
+
 pub(super) mod structural_traits;
 
 /// A candidate is a possible way to prove a goal.
@@ -46,18 +48,18 @@ pub(super) trait GoalKind<'tcx>:
     /// work, then produce a response (typically by executing
     /// [`EvalCtxt::evaluate_added_goals_and_make_canonical_response`]).
     fn probe_and_match_goal_against_assumption(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
-        then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>,
+        then: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> QueryResult<'tcx>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// Consider a clause, which consists of a "assumption" and some "requirements",
     /// to satisfy a goal. If the requirements hold, then attempt to satisfy our
     /// goal by equating it with the assumption.
     fn probe_and_consider_implied_clause(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         parent_source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
@@ -75,7 +77,7 @@ pub(super) trait GoalKind<'tcx>:
     /// additionally checking all of the supertraits and object bounds to hold,
     /// since they're not implied by the well-formedness of the object type.
     fn probe_and_consider_object_bound_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
@@ -99,7 +101,7 @@ pub(super) trait GoalKind<'tcx>:
     }
 
     fn consider_impl_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         impl_def_id: DefId,
     ) -> Result<Candidate<'tcx>, NoSolution>;
@@ -111,7 +113,7 @@ pub(super) trait GoalKind<'tcx>:
     /// Trait goals always hold while projection goals never do. This is a bit arbitrary
     /// but prevents incorrect normalization while hiding any trait errors.
     fn consider_error_guaranteed_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         guar: ErrorGuaranteed,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -120,13 +122,13 @@ pub(super) trait GoalKind<'tcx>:
     /// These components are given by built-in rules from
     /// [`structural_traits::instantiate_constituent_tys_for_auto_trait`].
     fn consider_auto_trait_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// A trait alias holds if the RHS traits and `where` clauses hold.
     fn consider_trait_alias_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -135,7 +137,7 @@ pub(super) trait GoalKind<'tcx>:
     /// These components are given by built-in rules from
     /// [`structural_traits::instantiate_constituent_tys_for_sized_trait`].
     fn consider_builtin_sized_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -144,27 +146,27 @@ pub(super) trait GoalKind<'tcx>:
     /// These components are given by built-in rules from
     /// [`structural_traits::instantiate_constituent_tys_for_copy_clone_trait`].
     fn consider_builtin_copy_clone_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// A type is `PointerLike` if we can compute its layout, and that layout
     /// matches the layout of `usize`.
     fn consider_builtin_pointer_like_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// A type is a `FnPtr` if it is of `FnPtr` type.
     fn consider_builtin_fn_ptr_trait_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// A callable type (a closure, fn def, or fn ptr) is known to implement the `Fn<A>`
     /// family of traits where `A` is given by the signature of the type.
     fn consider_builtin_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution>;
@@ -172,7 +174,7 @@ pub(super) trait GoalKind<'tcx>:
     /// An async closure is known to implement the `AsyncFn<A>` family of traits
     /// where `A` is given by the signature of the type.
     fn consider_builtin_async_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution>;
@@ -181,13 +183,13 @@ pub(super) trait GoalKind<'tcx>:
     /// is used internally to delay computation for async closures until after
     /// upvar analysis is performed in HIR typeck.
     fn consider_builtin_async_fn_kind_helper_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// `Tuple` is implemented if the `Self` type is a tuple.
     fn consider_builtin_tuple_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -197,7 +199,7 @@ pub(super) trait GoalKind<'tcx>:
     /// the built-in types. For structs, the metadata type is given by the struct
     /// tail.
     fn consider_builtin_pointee_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -205,7 +207,7 @@ pub(super) trait GoalKind<'tcx>:
     /// `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>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -213,19 +215,19 @@ pub(super) trait GoalKind<'tcx>:
     /// `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>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     /// A coroutine (that comes from a `gen` desugaring) is known to implement
     /// `FusedIterator`
     fn consider_builtin_fused_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     fn consider_builtin_async_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -233,27 +235,27 @@ pub(super) trait GoalKind<'tcx>:
     /// 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>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     fn consider_builtin_discriminant_kind_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     fn consider_builtin_async_destruct_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     fn consider_builtin_destruct_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
     fn consider_builtin_transmute_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution>;
 
@@ -265,12 +267,12 @@ pub(super) trait GoalKind<'tcx>:
     /// otherwise recompute this for codegen. This is a bit of a mess but the
     /// easiest way to maintain the existing behavior for now.
     fn consider_structural_builtin_unsize_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<Candidate<'tcx>>;
 }
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     pub(super) fn assemble_and_evaluate_candidates<G: GoalKind<'tcx>>(
         &mut self,
         goal: Goal<'tcx, G>,
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 cf826596392..930ae5af811 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
@@ -3,6 +3,7 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::LangItem;
 use rustc_hir::{def_id::DefId, Movability, Mutability};
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_macros::{TypeFoldable, TypeVisitable};
 use rustc_middle::bug;
@@ -18,7 +19,7 @@ use crate::solve::EvalCtxt;
 // instantiate the binder with placeholders eagerly.
 #[instrument(level = "trace", skip(ecx), ret)]
 pub(in crate::solve) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
-    ecx: &EvalCtxt<'_, 'tcx>,
+    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
     ty: Ty<'tcx>,
 ) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution> {
     let tcx = ecx.tcx();
@@ -97,7 +98,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_auto_trait<'tcx>(
 
 #[instrument(level = "trace", skip(ecx), ret)]
 pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
-    ecx: &EvalCtxt<'_, 'tcx>,
+    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
     ty: Ty<'tcx>,
 ) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution> {
     match *ty.kind() {
@@ -161,7 +162,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
 
 #[instrument(level = "trace", skip(ecx), ret)]
 pub(in crate::solve) fn instantiate_constituent_tys_for_copy_clone_trait<'tcx>(
-    ecx: &EvalCtxt<'_, 'tcx>,
+    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
     ty: Ty<'tcx>,
 ) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution> {
     match *ty.kind() {
@@ -663,7 +664,7 @@ fn coroutine_closure_to_ambiguous_coroutine<'tcx>(
 // normalize eagerly here. See https://github.com/lcnr/solver-woes/issues/9
 // for more details.
 pub(in crate::solve) fn predicates_for_object_candidate<'tcx>(
-    ecx: &EvalCtxt<'_, 'tcx>,
+    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
     param_env: ty::ParamEnv<'tcx>,
     trait_ref: ty::TraitRef<'tcx>,
     object_bound: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
@@ -716,7 +717,7 @@ pub(in crate::solve) fn predicates_for_object_candidate<'tcx>(
 }
 
 struct ReplaceProjectionWith<'a, 'tcx> {
-    ecx: &'a EvalCtxt<'a, 'tcx>,
+    ecx: &'a EvalCtxt<'a, InferCtxt<'tcx>>,
     param_env: ty::ParamEnv<'tcx>,
     mapping: FxHashMap<DefId, ty::PolyProjectionPredicate<'tcx>>,
     nested: Vec<Goal<'tcx, ty::Predicate<'tcx>>>,
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
index 52deb22098f..a642d0c40fc 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs
@@ -52,7 +52,7 @@ impl<'tcx, T> ResponseT<'tcx> for inspect::State<TyCtxt<'tcx>, T> {
     }
 }
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     /// Canonicalizes the goal remembering the original values
     /// for each bound variable.
     pub(super) fn canonicalize_goal<T: TypeFoldable<TyCtxt<'tcx>>>(
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
index 70308d4359d..7e1d7d73e0b 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
@@ -4,7 +4,6 @@ use std::ops::ControlFlow;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::at::ToTrace;
-use rustc_infer::infer::canonical::CanonicalVarValues;
 use rustc_infer::infer::{
     BoundRegionConversionTime, DefineOpaqueTypes, InferCtxt, InferOk, TyCtxtInferExt,
 };
@@ -13,10 +12,8 @@ use rustc_infer::traits::solve::{MaybeCause, NestedNormalizationGoals};
 use rustc_infer::traits::ObligationCause;
 use rustc_macros::{extension, HashStable, HashStable_NoContext, TyDecodable, TyEncodable};
 use rustc_middle::bug;
-use rustc_middle::infer::canonical::CanonicalVarInfos;
 use rustc_middle::traits::solve::{
-    inspect, CanonicalInput, CanonicalResponse, Certainty, PredefinedOpaques,
-    PredefinedOpaquesData, QueryResult,
+    inspect, CanonicalInput, CanonicalResponse, Certainty, PredefinedOpaquesData, QueryResult,
 };
 use rustc_middle::traits::specialization_graph;
 use rustc_middle::ty::{
@@ -25,7 +22,7 @@ use rustc_middle::ty::{
 };
 use rustc_session::config::DumpSolverProofTree;
 use rustc_span::DUMMY_SP;
-use rustc_type_ir::{self as ir, Interner};
+use rustc_type_ir::{self as ir, CanonicalVarValues, Interner};
 use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Generic};
 
 use crate::traits::coherence;
@@ -41,7 +38,11 @@ pub(super) mod canonical;
 mod probe;
 mod select;
 
-pub struct EvalCtxt<'a, 'tcx> {
+pub struct EvalCtxt<
+    'a,
+    Infcx: InferCtxtLike<Interner = I>,
+    I: Interner = <Infcx as InferCtxtLike>::Interner,
+> {
     /// The inference context that backs (mostly) inference and placeholder terms
     /// instantiated while solving goals.
     ///
@@ -57,11 +58,11 @@ pub struct EvalCtxt<'a, 'tcx> {
     /// If some `InferCtxt` method is missing, please first think defensively about
     /// the method's compatibility with this solver, or if an existing one does
     /// the job already.
-    infcx: &'a InferCtxt<'tcx>,
+    infcx: &'a Infcx,
 
     /// The variable info for the `var_values`, only used to make an ambiguous response
     /// with no constraints.
-    variables: CanonicalVarInfos<'tcx>,
+    variables: I::CanonicalVars,
     /// Whether we're currently computing a `NormalizesTo` goal. Unlike other goals,
     /// `NormalizesTo` goals act like functions with the expected term always being
     /// fully unconstrained. This would weaken inference however, as the nested goals
@@ -70,9 +71,9 @@ pub struct EvalCtxt<'a, 'tcx> {
     /// when then adds these to its own context. The caller is always an `AliasRelate`
     /// goal so this never leaks out of the solver.
     is_normalizes_to_goal: bool,
-    pub(super) var_values: CanonicalVarValues<'tcx>,
+    pub(super) var_values: CanonicalVarValues<I>,
 
-    predefined_opaques_in_body: PredefinedOpaques<'tcx>,
+    predefined_opaques_in_body: I::PredefinedOpaques,
 
     /// The highest universe index nameable by the caller.
     ///
@@ -85,9 +86,9 @@ pub struct EvalCtxt<'a, 'tcx> {
     /// new placeholders to the caller.
     pub(super) max_input_universe: ty::UniverseIndex,
 
-    pub(super) search_graph: &'a mut SearchGraph<'tcx>,
+    pub(super) search_graph: &'a mut SearchGraph<I>,
 
-    nested_goals: NestedGoals<TyCtxt<'tcx>>,
+    nested_goals: NestedGoals<I>,
 
     // Has this `EvalCtxt` errored out with `NoSolution` in `try_evaluate_added_goals`?
     //
@@ -97,7 +98,7 @@ pub struct EvalCtxt<'a, 'tcx> {
     // evaluation code.
     tainted: Result<(), NoSolution>,
 
-    pub(super) inspect: ProofTreeBuilder<TyCtxt<'tcx>>,
+    pub(super) inspect: ProofTreeBuilder<I>,
 }
 
 #[derive(derivative::Derivative)]
@@ -157,7 +158,7 @@ impl<'tcx> InferCtxt<'tcx> {
     }
 }
 
-impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
+impl<'a, 'tcx> EvalCtxt<'a, InferCtxt<'tcx>> {
     pub(super) fn solver_mode(&self) -> SolverMode {
         self.search_graph.solver_mode()
     }
@@ -172,7 +173,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
     pub(super) fn enter_root<R>(
         infcx: &InferCtxt<'tcx>,
         generate_proof_tree: GenerateProofTree,
-        f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> R,
+        f: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> R,
     ) -> (R, Option<inspect::GoalEvaluation<TyCtxt<'tcx>>>) {
         let mode = if infcx.intercrate { SolverMode::Coherence } else { SolverMode::Normal };
         let mut search_graph = search_graph::SearchGraph::new(mode);
@@ -225,10 +226,10 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
     /// and registering opaques from the canonicalized input.
     fn enter_canonical<R>(
         tcx: TyCtxt<'tcx>,
-        search_graph: &'a mut search_graph::SearchGraph<'tcx>,
+        search_graph: &'a mut search_graph::SearchGraph<TyCtxt<'tcx>>,
         canonical_input: CanonicalInput<'tcx>,
         canonical_goal_evaluation: &mut ProofTreeBuilder<TyCtxt<'tcx>>,
-        f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>, Goal<'tcx, ty::Predicate<'tcx>>) -> R,
+        f: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>, Goal<'tcx, ty::Predicate<'tcx>>) -> R,
     ) -> R {
         let intercrate = match search_graph.solver_mode() {
             SolverMode::Normal => false,
@@ -287,7 +288,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
     #[instrument(level = "debug", skip(tcx, search_graph, goal_evaluation), ret)]
     fn evaluate_canonical_goal(
         tcx: TyCtxt<'tcx>,
-        search_graph: &'a mut search_graph::SearchGraph<'tcx>,
+        search_graph: &'a mut search_graph::SearchGraph<TyCtxt<'tcx>>,
         canonical_input: CanonicalInput<'tcx>,
         goal_evaluation: &mut ProofTreeBuilder<TyCtxt<'tcx>>,
     ) -> QueryResult<'tcx> {
@@ -600,7 +601,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
     }
 }
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     pub(super) fn tcx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/probe.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/probe.rs
index 9edc489754c..1748c9be927 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/probe.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/probe.rs
@@ -1,6 +1,7 @@
 use crate::solve::assembly::Candidate;
 
 use super::EvalCtxt;
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::BuiltinImplSource;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::traits::solve::{inspect, CandidateSource, QueryResult};
@@ -8,7 +9,7 @@ use rustc_middle::ty::TyCtxt;
 use std::marker::PhantomData;
 
 pub(in crate::solve) struct ProbeCtxt<'me, 'a, 'tcx, F, T> {
-    ecx: &'me mut EvalCtxt<'a, 'tcx>,
+    ecx: &'me mut EvalCtxt<'a, InferCtxt<'tcx>>,
     probe_kind: F,
     _result: PhantomData<T>,
 }
@@ -17,7 +18,10 @@ impl<'tcx, F, T> ProbeCtxt<'_, '_, 'tcx, F, T>
 where
     F: FnOnce(&T) -> inspect::ProbeKind<TyCtxt<'tcx>>,
 {
-    pub(in crate::solve) fn enter(self, f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> T) -> T {
+    pub(in crate::solve) fn enter(
+        self,
+        f: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> T,
+    ) -> T {
         let ProbeCtxt { ecx: outer_ecx, probe_kind, _result } = self;
 
         let infcx = outer_ecx.infcx;
@@ -60,13 +64,13 @@ where
     #[instrument(level = "debug", skip_all, fields(source = ?self.source))]
     pub(in crate::solve) fn enter(
         self,
-        f: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>,
+        f: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> QueryResult<'tcx>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         self.cx.enter(|ecx| f(ecx)).map(|result| Candidate { source: self.source, result })
     }
 }
 
-impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
+impl<'a, 'tcx> EvalCtxt<'a, InferCtxt<'tcx>> {
     /// `probe_kind` is only called when proof tree building is enabled so it can be
     /// as expensive as necessary to output the desired information.
     pub(in crate::solve) fn probe<F, T>(&mut self, probe_kind: F) -> ProbeCtxt<'_, 'a, 'tcx, F, T>
diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs
index b085d009d75..60722d3618f 100644
--- a/compiler/rustc_trait_selection/src/solve/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/mod.rs
@@ -15,6 +15,7 @@
 //! about it on zulip.
 use rustc_hir::def_id::DefId;
 use rustc_infer::infer::canonical::{Canonical, CanonicalVarValues};
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_macros::extension;
 use rustc_middle::bug;
@@ -82,7 +83,7 @@ impl<'tcx> Canonical<'tcx, Response<TyCtxt<'tcx>>> {
     }
 }
 
-impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
+impl<'a, 'tcx> EvalCtxt<'a, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self))]
     fn compute_type_outlives_goal(
         &mut self,
@@ -201,7 +202,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
     }
 }
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self, goals))]
     fn add_goals(
         &mut self,
diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/anon_const.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/anon_const.rs
index 94e078f5615..c9621e705e5 100644
--- a/compiler/rustc_trait_selection/src/solve/normalizes_to/anon_const.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/anon_const.rs
@@ -1,8 +1,9 @@
 use crate::solve::EvalCtxt;
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::solve::{Certainty, Goal, QueryResult};
 use rustc_middle::ty;
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn normalize_anon_const(
         &mut self,
diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/inherent.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/inherent.rs
index 353bdb9caff..2146a2c2f08 100644
--- a/compiler/rustc_trait_selection/src/solve/normalizes_to/inherent.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/inherent.rs
@@ -4,12 +4,13 @@
 //! 1. instantiate generic parameters,
 //! 2. equate the self type, and
 //! 3. instantiate and register where clauses.
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::solve::{Certainty, Goal, GoalSource, QueryResult};
 use rustc_middle::ty;
 
 use crate::solve::EvalCtxt;
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     pub(super) fn normalize_inherent_associated_type(
         &mut self,
         goal: Goal<'tcx, ty::NormalizesTo<'tcx>>,
diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs
index 8c492b62c1a..7ef8373663b 100644
--- a/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs
@@ -5,6 +5,7 @@ use super::assembly::{self, structural_traits, Candidate};
 use super::{EvalCtxt, GoalSource};
 use rustc_hir::def_id::DefId;
 use rustc_hir::LangItem;
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::solve::inspect::ProbeKind;
 use rustc_infer::traits::solve::MaybeCause;
@@ -24,7 +25,7 @@ mod inherent;
 mod opaque_types;
 mod weak_types;
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn compute_normalizes_to_goal(
         &mut self,
@@ -98,11 +99,11 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn probe_and_match_goal_against_assumption(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
-        then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>,
+        then: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> QueryResult<'tcx>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if let Some(projection_pred) = assumption.as_projection_clause() {
             if projection_pred.projection_def_id() == goal.predicate.def_id() {
@@ -137,7 +138,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_impl_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, NormalizesTo<'tcx>>,
         impl_def_id: DefId,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -199,7 +200,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
                 return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
             };
 
-            let error_response = |ecx: &mut EvalCtxt<'_, 'tcx>, reason| {
+            let error_response = |ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>, reason| {
                 let guar = tcx.dcx().span_delayed_bug(tcx.def_span(assoc_def.item.def_id), reason);
                 let error_term = match assoc_def.item.kind {
                     ty::AssocKind::Const => ty::Const::new_error(
@@ -279,14 +280,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     /// Fail to normalize if the predicate contains an error, alternatively, we could normalize to `ty::Error`
     /// and succeed. Can experiment with this to figure out what results in better error messages.
     fn consider_error_guaranteed_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         _guar: ErrorGuaranteed,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         Err(NoSolution)
     }
 
     fn consider_auto_trait_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         ecx.tcx().dcx().span_delayed_bug(
@@ -297,42 +298,42 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_trait_alias_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("trait aliases do not have associated types: {:?}", goal);
     }
 
     fn consider_builtin_sized_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`Sized` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_copy_clone_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`Copy`/`Clone` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_pointer_like_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`PointerLike` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_fn_ptr_trait_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`FnPtr` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         goal_kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -375,7 +376,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_async_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         goal_kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -460,7 +461,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_async_fn_kind_helper_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let [
@@ -507,14 +508,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_tuple_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`Tuple` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_pointee_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let tcx = ecx.tcx();
@@ -596,7 +597,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_future_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -628,7 +629,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -660,14 +661,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_fused_iterator_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`FusedIterator` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_async_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -703,7 +704,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_coroutine_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -748,14 +749,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_structural_builtin_unsize_candidates(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<Candidate<'tcx>> {
         bug!("`Unsize` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_discriminant_kind_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -807,7 +808,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_async_destruct_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -860,14 +861,14 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 
     fn consider_builtin_destruct_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`Destruct` does not have an associated type: {:?}", goal);
     }
 
     fn consider_builtin_transmute_candidate(
-        _ecx: &mut EvalCtxt<'_, 'tcx>,
+        _ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         bug!("`BikeshedIntrinsicFrom` does not have an associated type: {:?}", goal)
@@ -880,7 +881,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
 /// diverge.
 #[instrument(level = "trace", skip(ecx, param_env), ret)]
 fn fetch_eligible_assoc_item_def<'tcx>(
-    ecx: &EvalCtxt<'_, 'tcx>,
+    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
     param_env: ty::ParamEnv<'tcx>,
     goal_trait_ref: ty::TraitRef<'tcx>,
     trait_assoc_def_id: DefId,
diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/opaque_types.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/opaque_types.rs
index 9fdb280cdc6..3b83d347276 100644
--- a/compiler/rustc_trait_selection/src/solve/normalizes_to/opaque_types.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/opaque_types.rs
@@ -1,6 +1,7 @@
 //! Computes a normalizes-to (projection) goal for opaque types. This goal
 //! behaves differently depending on the param-env's reveal mode and whether
 //! the opaque is in a defining scope.
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::traits::solve::{Certainty, Goal, QueryResult};
 use rustc_middle::traits::Reveal;
@@ -9,7 +10,7 @@ use rustc_middle::ty::util::NotUniqueParam;
 
 use crate::solve::{EvalCtxt, SolverMode};
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     pub(super) fn normalize_opaque_type(
         &mut self,
         goal: Goal<'tcx, ty::NormalizesTo<'tcx>>,
diff --git a/compiler/rustc_trait_selection/src/solve/normalizes_to/weak_types.rs b/compiler/rustc_trait_selection/src/solve/normalizes_to/weak_types.rs
index 13af5068b6c..109a9e9671f 100644
--- a/compiler/rustc_trait_selection/src/solve/normalizes_to/weak_types.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalizes_to/weak_types.rs
@@ -3,12 +3,13 @@
 //!
 //! Since a weak alias is never ambiguous, this just computes the `type_of` of
 //! the alias and registers the where-clauses of the type alias.
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::solve::{Certainty, Goal, GoalSource, QueryResult};
 use rustc_middle::ty;
 
 use crate::solve::EvalCtxt;
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     pub(super) fn normalize_weak_type(
         &mut self,
         goal: Goal<'tcx, ty::NormalizesTo<'tcx>>,
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index 0f1be1072a8..8fa78e49dc6 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -1,10 +1,11 @@
 use crate::solve::GoalSource;
 
 use super::EvalCtxt;
+use rustc_infer::infer::InferCtxt;
 use rustc_middle::traits::solve::{Certainty, Goal, QueryResult};
 use rustc_middle::ty::{self, ProjectionPredicate};
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn compute_projection_goal(
         &mut self,
diff --git a/compiler/rustc_trait_selection/src/solve/search_graph.rs b/compiler/rustc_trait_selection/src/solve/search_graph.rs
index 0164d44667c..5a5df439a78 100644
--- a/compiler/rustc_trait_selection/src/solve/search_graph.rs
+++ b/compiler/rustc_trait_selection/src/solve/search_graph.rs
@@ -1,18 +1,21 @@
-use crate::solve::FIXPOINT_STEP_LIMIT;
+use std::mem;
 
-use super::inspect;
-use super::inspect::ProofTreeBuilder;
-use super::SolverMode;
-use rustc_data_structures::fx::FxHashMap;
-use rustc_data_structures::fx::FxHashSet;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_index::Idx;
 use rustc_index::IndexVec;
 use rustc_middle::dep_graph::dep_kinds;
 use rustc_middle::traits::solve::CacheData;
-use rustc_middle::traits::solve::{CanonicalInput, Certainty, EvaluationCache, QueryResult};
+use rustc_middle::traits::solve::EvaluationCache;
 use rustc_middle::ty::TyCtxt;
+use rustc_next_trait_solver::solve::{CanonicalInput, Certainty, QueryResult};
 use rustc_session::Limit;
-use std::mem;
+use rustc_type_ir::inherent::*;
+use rustc_type_ir::Interner;
+
+use super::inspect;
+use super::inspect::ProofTreeBuilder;
+use super::SolverMode;
+use crate::solve::FIXPOINT_STEP_LIMIT;
 
 rustc_index::newtype_index! {
     #[orderable]
@@ -30,9 +33,10 @@ bitflags::bitflags! {
     }
 }
 
-#[derive(Debug)]
-struct StackEntry<'tcx> {
-    input: CanonicalInput<'tcx>,
+#[derive(derivative::Derivative)]
+#[derivative(Debug(bound = ""))]
+struct StackEntry<I: Interner> {
+    input: CanonicalInput<I>,
 
     available_depth: Limit,
 
@@ -53,11 +57,11 @@ struct StackEntry<'tcx> {
     has_been_used: HasBeenUsed,
     /// Starts out as `None` and gets set when rerunning this
     /// goal in case we encounter a cycle.
-    provisional_result: Option<QueryResult<'tcx>>,
+    provisional_result: Option<QueryResult<I>>,
 }
 
 /// The provisional result for a goal which is not on the stack.
-struct DetachedEntry<'tcx> {
+struct DetachedEntry<I: Interner> {
     /// The head of the smallest non-trivial cycle involving this entry.
     ///
     /// Given the following rules, when proving `A` the head for
@@ -68,7 +72,7 @@ struct DetachedEntry<'tcx> {
     /// C :- A + B + C
     /// ```
     head: StackDepth,
-    result: QueryResult<'tcx>,
+    result: QueryResult<I>,
 }
 
 /// Stores the stack depth of a currently evaluated goal *and* already
@@ -83,14 +87,15 @@ struct DetachedEntry<'tcx> {
 ///
 /// The provisional cache can theoretically result in changes to the observable behavior,
 /// see tests/ui/traits/next-solver/cycles/provisional-cache-impacts-behavior.rs.
-#[derive(Default)]
-struct ProvisionalCacheEntry<'tcx> {
+#[derive(derivative::Derivative)]
+#[derivative(Default(bound = ""))]
+struct ProvisionalCacheEntry<I: Interner> {
     stack_depth: Option<StackDepth>,
-    with_inductive_stack: Option<DetachedEntry<'tcx>>,
-    with_coinductive_stack: Option<DetachedEntry<'tcx>>,
+    with_inductive_stack: Option<DetachedEntry<I>>,
+    with_coinductive_stack: Option<DetachedEntry<I>>,
 }
 
-impl<'tcx> ProvisionalCacheEntry<'tcx> {
+impl<I: Interner> ProvisionalCacheEntry<I> {
     fn is_empty(&self) -> bool {
         self.stack_depth.is_none()
             && self.with_inductive_stack.is_none()
@@ -98,13 +103,13 @@ impl<'tcx> ProvisionalCacheEntry<'tcx> {
     }
 }
 
-pub(super) struct SearchGraph<'tcx> {
+pub(super) struct SearchGraph<I: Interner> {
     mode: SolverMode,
     /// The stack of goals currently being computed.
     ///
     /// An element is *deeper* in the stack if its index is *lower*.
-    stack: IndexVec<StackDepth, StackEntry<'tcx>>,
-    provisional_cache: FxHashMap<CanonicalInput<'tcx>, ProvisionalCacheEntry<'tcx>>,
+    stack: IndexVec<StackDepth, StackEntry<I>>,
+    provisional_cache: FxHashMap<CanonicalInput<I>, ProvisionalCacheEntry<I>>,
     /// We put only the root goal of a coinductive cycle into the global cache.
     ///
     /// If we were to use that result when later trying to prove another cycle
@@ -112,11 +117,11 @@ pub(super) struct SearchGraph<'tcx> {
     ///
     /// See tests/ui/next-solver/coinduction/incompleteness-unstable-result.rs for
     /// an example of where this is needed.
-    cycle_participants: FxHashSet<CanonicalInput<'tcx>>,
+    cycle_participants: FxHashSet<CanonicalInput<I>>,
 }
 
-impl<'tcx> SearchGraph<'tcx> {
-    pub(super) fn new(mode: SolverMode) -> SearchGraph<'tcx> {
+impl<I: Interner> SearchGraph<I> {
+    pub(super) fn new(mode: SolverMode) -> SearchGraph<I> {
         Self {
             mode,
             stack: Default::default(),
@@ -144,7 +149,7 @@ impl<'tcx> SearchGraph<'tcx> {
     ///
     /// Directly popping from the stack instead of using this method
     /// would cause us to not track overflow and recursion depth correctly.
-    fn pop_stack(&mut self) -> StackEntry<'tcx> {
+    fn pop_stack(&mut self) -> StackEntry<I> {
         let elem = self.stack.pop().unwrap();
         if let Some(last) = self.stack.raw.last_mut() {
             last.reached_depth = last.reached_depth.max(elem.reached_depth);
@@ -153,17 +158,6 @@ impl<'tcx> SearchGraph<'tcx> {
         elem
     }
 
-    /// The trait solver behavior is different for coherence
-    /// so we use a separate cache. Alternatively we could use
-    /// a single cache and share it between coherence and ordinary
-    /// trait solving.
-    pub(super) fn global_cache(&self, tcx: TyCtxt<'tcx>) -> &'tcx EvaluationCache<'tcx> {
-        match self.mode {
-            SolverMode::Normal => &tcx.new_solver_evaluation_cache,
-            SolverMode::Coherence => &tcx.new_solver_coherence_evaluation_cache,
-        }
-    }
-
     pub(super) fn is_empty(&self) -> bool {
         if self.stack.is_empty() {
             debug_assert!(self.provisional_cache.is_empty());
@@ -181,8 +175,8 @@ impl<'tcx> SearchGraph<'tcx> {
     /// the remaining depth of all nested goals to prevent hangs
     /// in case there is exponential blowup.
     fn allowed_depth_for_nested(
-        tcx: TyCtxt<'tcx>,
-        stack: &IndexVec<StackDepth, StackEntry<'tcx>>,
+        tcx: I,
+        stack: &IndexVec<StackDepth, StackEntry<I>>,
     ) -> Option<Limit> {
         if let Some(last) = stack.raw.last() {
             if last.available_depth.0 == 0 {
@@ -195,13 +189,13 @@ impl<'tcx> SearchGraph<'tcx> {
                 Limit(last.available_depth.0 - 1)
             })
         } else {
-            Some(tcx.recursion_limit())
+            Some(Limit(tcx.recursion_limit()))
         }
     }
 
     fn stack_coinductive_from(
-        tcx: TyCtxt<'tcx>,
-        stack: &IndexVec<StackDepth, StackEntry<'tcx>>,
+        tcx: I,
+        stack: &IndexVec<StackDepth, StackEntry<I>>,
         head: StackDepth,
     ) -> bool {
         stack.raw[head.index()..]
@@ -220,8 +214,8 @@ impl<'tcx> SearchGraph<'tcx> {
     // we reach a fixpoint and all other cycle participants to make sure that
     // their result does not get moved to the global cache.
     fn tag_cycle_participants(
-        stack: &mut IndexVec<StackDepth, StackEntry<'tcx>>,
-        cycle_participants: &mut FxHashSet<CanonicalInput<'tcx>>,
+        stack: &mut IndexVec<StackDepth, StackEntry<I>>,
+        cycle_participants: &mut FxHashSet<CanonicalInput<I>>,
         usage_kind: HasBeenUsed,
         head: StackDepth,
     ) {
@@ -234,7 +228,7 @@ impl<'tcx> SearchGraph<'tcx> {
     }
 
     fn clear_dependent_provisional_results(
-        provisional_cache: &mut FxHashMap<CanonicalInput<'tcx>, ProvisionalCacheEntry<'tcx>>,
+        provisional_cache: &mut FxHashMap<CanonicalInput<I>, ProvisionalCacheEntry<I>>,
         head: StackDepth,
     ) {
         #[allow(rustc::potential_query_instability)]
@@ -244,6 +238,19 @@ impl<'tcx> SearchGraph<'tcx> {
             !entry.is_empty()
         });
     }
+}
+
+impl<'tcx> SearchGraph<TyCtxt<'tcx>> {
+    /// The trait solver behavior is different for coherence
+    /// so we use a separate cache. Alternatively we could use
+    /// a single cache and share it between coherence and ordinary
+    /// trait solving.
+    pub(super) fn global_cache(&self, tcx: TyCtxt<'tcx>) -> &'tcx EvaluationCache<'tcx> {
+        match self.mode {
+            SolverMode::Normal => &tcx.new_solver_evaluation_cache,
+            SolverMode::Coherence => &tcx.new_solver_coherence_evaluation_cache,
+        }
+    }
 
     /// Probably the most involved method of the whole solver.
     ///
@@ -252,10 +259,13 @@ impl<'tcx> SearchGraph<'tcx> {
     pub(super) fn with_new_goal(
         &mut self,
         tcx: TyCtxt<'tcx>,
-        input: CanonicalInput<'tcx>,
+        input: CanonicalInput<TyCtxt<'tcx>>,
         inspect: &mut ProofTreeBuilder<TyCtxt<'tcx>>,
-        mut prove_goal: impl FnMut(&mut Self, &mut ProofTreeBuilder<TyCtxt<'tcx>>) -> QueryResult<'tcx>,
-    ) -> QueryResult<'tcx> {
+        mut prove_goal: impl FnMut(
+            &mut Self,
+            &mut ProofTreeBuilder<TyCtxt<'tcx>>,
+        ) -> QueryResult<TyCtxt<'tcx>>,
+    ) -> QueryResult<TyCtxt<'tcx>> {
         // Check for overflow.
         let Some(available_depth) = Self::allowed_depth_for_nested(tcx, &self.stack) else {
             if let Some(last) = self.stack.raw.last_mut() {
@@ -489,9 +499,9 @@ impl<'tcx> SearchGraph<'tcx> {
 
     fn response_no_constraints(
         tcx: TyCtxt<'tcx>,
-        goal: CanonicalInput<'tcx>,
+        goal: CanonicalInput<TyCtxt<'tcx>>,
         certainty: Certainty,
-    ) -> QueryResult<'tcx> {
+    ) -> QueryResult<TyCtxt<'tcx>> {
         Ok(super::response_no_constraints_raw(tcx, goal.max_universe, goal.variables, certainty))
     }
 }
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index 9139c75d399..e59eef22f41 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -8,6 +8,7 @@ use super::{EvalCtxt, GoalSource, SolverMode};
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{LangItem, Movability};
+use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::solve::MaybeCause;
 use rustc_middle::bug;
@@ -37,7 +38,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_impl_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, TraitPredicate<'tcx>>,
         impl_def_id: DefId,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -93,7 +94,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_error_guaranteed_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         _guar: ErrorGuaranteed,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         // FIXME: don't need to enter a probe here.
@@ -102,11 +103,11 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn probe_and_match_goal_against_assumption(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         source: CandidateSource<'tcx>,
         goal: Goal<'tcx, Self>,
         assumption: ty::Clause<'tcx>,
-        then: impl FnOnce(&mut EvalCtxt<'_, 'tcx>) -> QueryResult<'tcx>,
+        then: impl FnOnce(&mut EvalCtxt<'_, InferCtxt<'tcx>>) -> QueryResult<'tcx>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if let Some(trait_clause) = assumption.as_trait_clause() {
             if trait_clause.def_id() == goal.predicate.def_id()
@@ -130,7 +131,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_auto_trait_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -173,7 +174,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_trait_alias_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -196,7 +197,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_sized_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -211,7 +212,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_copy_clone_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -226,7 +227,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_pointer_like_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -256,7 +257,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_fn_ptr_trait_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let self_ty = goal.predicate.self_ty();
@@ -287,7 +288,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         goal_kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -328,7 +329,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_async_fn_trait_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
         goal_kind: ty::ClosureKind,
     ) -> Result<Candidate<'tcx>, NoSolution> {
@@ -379,7 +380,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_async_fn_kind_helper_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         let [closure_fn_kind_ty, goal_kind_ty] = **goal.predicate.trait_ref.args else {
@@ -406,7 +407,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     /// impl Tuple for (T1, .., Tn) {}
     /// ```
     fn consider_builtin_tuple_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -422,7 +423,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_pointee_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -434,7 +435,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_future_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -460,7 +461,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -486,7 +487,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_fused_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -510,7 +511,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_async_iterator_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -536,7 +537,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_coroutine_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -568,7 +569,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_discriminant_kind_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -581,7 +582,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_async_destruct_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -594,7 +595,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_destruct_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -610,7 +611,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 
     fn consider_builtin_transmute_candidate(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -651,7 +652,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     /// impl<'a, T: Trait + 'a> Unsize<dyn Trait + 'a> for T {}
     /// ```
     fn consider_structural_builtin_unsize_candidates(
-        ecx: &mut EvalCtxt<'_, 'tcx>,
+        ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
         goal: Goal<'tcx, Self>,
     ) -> Vec<Candidate<'tcx>> {
         if goal.predicate.polarity != ty::PredicatePolarity::Positive {
@@ -722,7 +723,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
     }
 }
 
-impl<'tcx> EvalCtxt<'_, 'tcx> {
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
     /// Trait upcasting allows for coercions between trait objects:
     /// ```ignore (builtin impl example)
     /// trait Super {}
@@ -846,7 +847,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         // having any inference side-effects. We process obligations because
         // unification may initially succeed due to deferred projection equality.
         let projection_may_match =
-            |ecx: &mut EvalCtxt<'_, 'tcx>,
+            |ecx: &mut EvalCtxt<'_, InferCtxt<'tcx>>,
              source_projection: ty::PolyExistentialProjection<'tcx>,
              target_projection: ty::PolyExistentialProjection<'tcx>| {
                 source_projection.item_def_id() == target_projection.item_def_id()
@@ -1152,7 +1153,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         source: CandidateSource<'tcx>,
         goal: Goal<'tcx, TraitPredicate<'tcx>>,
         constituent_tys: impl Fn(
-            &EvalCtxt<'_, 'tcx>,
+            &EvalCtxt<'_, InferCtxt<'tcx>>,
             Ty<'tcx>,
         ) -> Result<Vec<ty::Binder<'tcx, Ty<'tcx>>>, NoSolution>,
     ) -> Result<Candidate<'tcx>, NoSolution> {
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index 5289dfd932f..19c76fb165a 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -96,6 +96,7 @@ pub trait GenericArgs<I: Interner<GenericArgs = Self>>:
 pub trait Predicate<I: Interner<Predicate = Self>>:
     Copy + Debug + Hash + Eq + TypeSuperVisitable<I> + TypeSuperFoldable<I> + Flags
 {
+    fn is_coinductive(self, interner: I) -> bool;
 }
 
 /// Common capabilities of placeholder kinds
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index 9acf7c04dd6..0b51d2e75f4 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -124,6 +124,8 @@ pub trait Interner:
     ) -> Self::GenericArgs;
 
     fn parent(self, def_id: Self::DefId) -> Self::DefId;
+
+    fn recursion_limit(self) -> usize;
 }
 
 /// Imagine you have a function `F: FnOnce(&[T]) -> R`, plus an iterator `iter`