Rename InferCtxtLike to SolverDelegate, use a newtype to define an impl in rustc_next_trait_solver

compiler/rustc_infer/src/infer/mod.rs

@@ -10,7 +10,7 @@ pub use BoundRegionConversionTime::*;
 pub use RegionVariableOrigin::*;
 pub use SubregionOrigin::*;
 
-use crate::infer::relate::{Relate, RelateResult};
+use crate::infer::relate::RelateResult;
 use crate::traits::{self, ObligationCause, ObligationInspector, PredicateObligation, TraitEngine};
 use error_reporting::TypeErrCtxt;
 use free_regions::RegionRelations;
@@ -44,7 +44,7 @@ use rustc_middle::ty::{ConstVid, EffectVid, FloatVid, IntVid, TyVid};
 use rustc_middle::ty::{GenericArg, GenericArgKind, GenericArgs, GenericArgsRef};
 use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::Symbol;
-use rustc_span::{Span, DUMMY_SP};
+use rustc_span::Span;
 use snapshot::undo_log::InferCtxtUndoLogs;
 use std::cell::{Cell, RefCell};
 use std::fmt;
@@ -334,145 +334,6 @@ pub struct InferCtxt<'tcx> {
     pub obligation_inspector: Cell<Option<ObligationInspector<'tcx>>>,
 }
 
-impl<'tcx> ty::InferCtxtLike for InferCtxt<'tcx> {
-    type Interner = TyCtxt<'tcx>;
-
-    fn interner(&self) -> TyCtxt<'tcx> {
-        self.tcx
-    }
-
-    fn universe_of_ty(&self, vid: TyVid) -> Option<ty::UniverseIndex> {
-        // FIXME(BoxyUwU): this is kind of jank and means that printing unresolved
-        // ty infers will give you the universe of the var it resolved to not the universe
-        // it actually had. It also means that if you have a `?0.1` and infer it to `u8` then
-        // try to print out `?0.1` it will just print `?0`.
-        match self.probe_ty_var(vid) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn universe_of_lt(&self, lt: ty::RegionVid) -> Option<ty::UniverseIndex> {
-        match self.inner.borrow_mut().unwrap_region_constraints().probe_value(lt) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn universe_of_ct(&self, ct: ConstVid) -> Option<ty::UniverseIndex> {
-        // Same issue as with `universe_of_ty`
-        match self.probe_const_var(ct) {
-            Err(universe) => Some(universe),
-            Ok(_) => None,
-        }
-    }
-
-    fn root_ty_var(&self, var: TyVid) -> TyVid {
-        self.root_var(var)
-    }
-
-    fn root_const_var(&self, var: ConstVid) -> ConstVid {
-        self.root_const_var(var)
-    }
-
-    fn opportunistic_resolve_ty_var(&self, vid: TyVid) -> Ty<'tcx> {
-        match self.probe_ty_var(vid) {
-            Ok(ty) => ty,
-            Err(_) => Ty::new_var(self.tcx, self.root_var(vid)),
-        }
-    }
-
-    fn opportunistic_resolve_int_var(&self, vid: IntVid) -> Ty<'tcx> {
-        self.opportunistic_resolve_int_var(vid)
-    }
-
-    fn opportunistic_resolve_float_var(&self, vid: FloatVid) -> Ty<'tcx> {
-        self.opportunistic_resolve_float_var(vid)
-    }
-
-    fn opportunistic_resolve_ct_var(&self, vid: ConstVid) -> ty::Const<'tcx> {
-        match self.probe_const_var(vid) {
-            Ok(ct) => ct,
-            Err(_) => ty::Const::new_var(self.tcx, self.root_const_var(vid)),
-        }
-    }
-
-    fn opportunistic_resolve_effect_var(&self, vid: EffectVid) -> ty::Const<'tcx> {
-        match self.probe_effect_var(vid) {
-            Some(ct) => ct,
-            None => {
-                ty::Const::new_infer(self.tcx, InferConst::EffectVar(self.root_effect_var(vid)))
-            }
-        }
-    }
-
-    fn opportunistic_resolve_lt_var(&self, vid: ty::RegionVid) -> ty::Region<'tcx> {
-        self.inner.borrow_mut().unwrap_region_constraints().opportunistic_resolve_var(self.tcx, vid)
-    }
-
-    fn defining_opaque_types(&self) -> &'tcx ty::List<LocalDefId> {
-        self.defining_opaque_types
-    }
-
-    fn next_ty_infer(&self) -> Ty<'tcx> {
-        self.next_ty_var(DUMMY_SP)
-    }
-
-    fn next_const_infer(&self) -> ty::Const<'tcx> {
-        self.next_const_var(DUMMY_SP)
-    }
-
-    fn fresh_args_for_item(&self, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
-        self.fresh_args_for_item(DUMMY_SP, def_id)
-    }
-
-    fn instantiate_binder_with_infer<T: TypeFoldable<Self::Interner> + Copy>(
-        &self,
-        value: ty::Binder<'tcx, T>,
-    ) -> T {
-        self.instantiate_binder_with_fresh_vars(
-            DUMMY_SP,
-            BoundRegionConversionTime::HigherRankedType,
-            value,
-        )
-    }
-
-    fn enter_forall<T: TypeFoldable<TyCtxt<'tcx>> + Copy, U>(
-        &self,
-        value: ty::Binder<'tcx, T>,
-        f: impl FnOnce(T) -> U,
-    ) -> U {
-        self.enter_forall(value, f)
-    }
-
-    fn relate<T: Relate<TyCtxt<'tcx>>>(
-        &self,
-        param_env: ty::ParamEnv<'tcx>,
-        lhs: T,
-        variance: ty::Variance,
-        rhs: T,
-    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
-        self.at(&ObligationCause::dummy(), param_env).relate_no_trace(lhs, variance, rhs)
-    }
-
-    fn eq_structurally_relating_aliases<T: Relate<TyCtxt<'tcx>>>(
-        &self,
-        param_env: ty::ParamEnv<'tcx>,
-        lhs: T,
-        rhs: T,
-    ) -> Result<Vec<Goal<'tcx, ty::Predicate<'tcx>>>, NoSolution> {
-        self.at(&ObligationCause::dummy(), param_env)
-            .eq_structurally_relating_aliases_no_trace(lhs, rhs)
-    }
-
-    fn resolve_vars_if_possible<T>(&self, value: T) -> T
-    where
-        T: TypeFoldable<TyCtxt<'tcx>>,
-    {
-        self.resolve_vars_if_possible(value)
-    }
-}
-
 /// See the `error_reporting` module for more details.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, TypeFoldable, TypeVisitable)]
 pub enum ValuePairs<'tcx> {
@@ -826,6 +687,10 @@ impl<'tcx> InferCtxt<'tcx> {
         self.tcx.dcx()
     }
 
+    pub fn defining_opaque_types(&self) -> &'tcx ty::List<LocalDefId> {
+        self.defining_opaque_types
+    }
+
     pub fn next_trait_solver(&self) -> bool {
         self.next_trait_solver
     }

compiler/rustc_next_trait_solver/src/canonicalizer.rs

@@ -4,10 +4,11 @@ use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::visit::TypeVisitableExt;
 use rustc_type_ir::{
-    self as ty, Canonical, CanonicalTyVarKind, CanonicalVarInfo, CanonicalVarKind, InferCtxtLike,
-    Interner,
+    self as ty, Canonical, CanonicalTyVarKind, CanonicalVarInfo, CanonicalVarKind, Interner,
 };
 
+use crate::delegate::SolverDelegate;
+
 /// Whether we're canonicalizing a query input or the query response.
 ///
 /// When canonicalizing an input we're in the context of the caller
@@ -37,7 +38,7 @@ pub enum CanonicalizeMode {
     },
 }
 
-pub struct Canonicalizer<'a, Infcx: InferCtxtLike<Interner = I>, I: Interner> {
+pub struct Canonicalizer<'a, Infcx: SolverDelegate<Interner = I>, I: Interner> {
     infcx: &'a Infcx,
     canonicalize_mode: CanonicalizeMode,
 
@@ -46,7 +47,7 @@ pub struct Canonicalizer<'a, Infcx: InferCtxtLike<Interner = I>, I: Interner> {
     binder_index: ty::DebruijnIndex,
 }
 
-impl<'a, Infcx: InferCtxtLike<Interner = I>, I: Interner> Canonicalizer<'a, Infcx, I> {
+impl<'a, Infcx: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, Infcx, I> {
     pub fn canonicalize<T: TypeFoldable<I>>(
         infcx: &'a Infcx,
         canonicalize_mode: CanonicalizeMode,
@@ -210,7 +211,7 @@ impl<'a, Infcx: InferCtxtLike<Interner = I>, I: Interner> Canonicalizer<'a, Infc
     }
 }
 
-impl<Infcx: InferCtxtLike<Interner = I>, I: Interner> TypeFolder<I>
+impl<Infcx: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I>
     for Canonicalizer<'_, Infcx, I>
 {
     fn interner(&self) -> I {

compiler/rustc_type_ir/src/infcx.rs → compiler/rustc_next_trait_solver/src/delegate.rs

@@ -1,9 +1,9 @@
-use crate::fold::TypeFoldable;
-use crate::relate::Relate;
-use crate::solve::{Goal, NoSolution};
-use crate::{self as ty, Interner};
+use rustc_type_ir::fold::TypeFoldable;
+use rustc_type_ir::relate::Relate;
+use rustc_type_ir::solve::{Goal, NoSolution};
+use rustc_type_ir::{self as ty, Interner};
 
-pub trait InferCtxtLike: Sized {
+pub trait SolverDelegate: Sized {
     type Interner: Interner;
 
     fn interner(&self) -> Self::Interner;
@@ -72,4 +72,6 @@ pub trait InferCtxtLike: Sized {
     fn resolve_vars_if_possible<T>(&self, value: T) -> T
     where
         T: TypeFoldable<Self::Interner>;
+
+    fn probe<T>(&self, probe: impl FnOnce() -> T) -> T;
 }

compiler/rustc_next_trait_solver/src/lib.rs

@@ -1,3 +1,4 @@
 pub mod canonicalizer;
+pub mod delegate;
 pub mod resolve;
 pub mod solve;

compiler/rustc_next_trait_solver/src/resolve.rs

@@ -1,27 +1,29 @@
 use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::visit::TypeVisitableExt;
-use rustc_type_ir::{self as ty, InferCtxtLike, Interner};
+use rustc_type_ir::{self as ty, Interner};
+
+use crate::delegate::SolverDelegate;
 
 ///////////////////////////////////////////////////////////////////////////
 // EAGER RESOLUTION
 
 /// Resolves ty, region, and const vars to their inferred values or their root vars.
-pub struct EagerResolver<'a, Infcx, I = <Infcx as InferCtxtLike>::Interner>
+pub struct EagerResolver<'a, Infcx, I = <Infcx as SolverDelegate>::Interner>
 where
-    Infcx: InferCtxtLike<Interner = I>,
+    Infcx: SolverDelegate<Interner = I>,
     I: Interner,
 {
     infcx: &'a Infcx,
 }
 
-impl<'a, Infcx: InferCtxtLike> EagerResolver<'a, Infcx> {
+impl<'a, Infcx: SolverDelegate> EagerResolver<'a, Infcx> {
     pub fn new(infcx: &'a Infcx) -> Self {
         EagerResolver { infcx }
     }
 }
 
-impl<Infcx: InferCtxtLike<Interner = I>, I: Interner> TypeFolder<I> for EagerResolver<'_, Infcx> {
+impl<Infcx: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for EagerResolver<'_, Infcx> {
     fn interner(&self) -> I {
         self.infcx.interner()
     }

compiler/rustc_trait_selection/src/solve/alias_relate.rs

@@ -16,11 +16,11 @@
 //! relate them structurally.
 
 use super::EvalCtxt;
-use rustc_infer::infer::InferCtxt;
+use crate::solve::infcx::RustcSolverDelegate;
 use rustc_middle::traits::solve::{Certainty, Goal, QueryResult};
 use rustc_middle::ty;
 
-impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
+impl<'tcx> EvalCtxt<'_, RustcSolverDelegate<'tcx>> {
     #[instrument(level = "trace", skip(self), ret)]
     pub(super) fn compute_alias_relate_goal(
         &mut self,