Uplift TypeRelation and Relate

Cargo.lock

@@ -4005,6 +4005,7 @@ dependencies = [
  "rustc_index",
  "rustc_macros",
  "rustc_middle",
+ "rustc_next_trait_solver",
  "rustc_span",
  "rustc_target",
  "smallvec",
@@ -4314,6 +4315,7 @@ dependencies = [
  "rustc_serialize",
  "rustc_type_ir",
  "rustc_type_ir_macros",
+ "tracing",
 ]
 
 [[package]]

compiler/rustc_borrowck/src/constraints/mod.rs

@@ -1,7 +1,7 @@
 use rustc_data_structures::graph::scc::Sccs;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::mir::ConstraintCategory;
-use rustc_middle::ty::{RegionVid, VarianceDiagInfo};
+use rustc_middle::ty::{RegionVid, TyCtxt, VarianceDiagInfo};
 use rustc_span::Span;
 use std::fmt;
 use std::ops::Index;

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -1,14 +1,14 @@
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::ErrorGuaranteed;
-use rustc_infer::infer::NllRegionVariableOrigin;
-use rustc_infer::infer::{ObligationEmittingRelation, StructurallyRelateAliases};
+use rustc_infer::infer::relate::{ObligationEmittingRelation, StructurallyRelateAliases};
+use rustc_infer::infer::relate::{Relate, RelateResult, TypeRelation};
+use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_infer::traits::{Obligation, PredicateObligations};
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::span_bug;
 use rustc_middle::traits::query::NoSolution;
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::fold::FnMutDelegate;
-use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
@@ -314,7 +314,7 @@ impl<'me, 'bccx, 'tcx> NllTypeRelating<'me, 'bccx, 'tcx> {
     }
 }
 
-impl<'bccx, 'tcx> TypeRelation<'tcx> for NllTypeRelating<'_, 'bccx, 'tcx> {
+impl<'bccx, 'tcx> TypeRelation<InferCtxt<'tcx>> for NllTypeRelating<'_, 'bccx, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.type_checker.infcx.tcx
     }
@@ -324,7 +324,7 @@ impl<'bccx, 'tcx> TypeRelation<'tcx> for NllTypeRelating<'_, 'bccx, 'tcx> {
     }
 
     #[instrument(skip(self, info), level = "trace", ret)]
-    fn relate_with_variance<T: Relate<'tcx>>(
+    fn relate_with_variance<T: Relate<InferCtxt<'tcx>>>(
         &mut self,
         variance: ty::Variance,
         info: ty::VarianceDiagInfo<TyCtxt<'tcx>>,
@@ -445,7 +445,7 @@ impl<'bccx, 'tcx> TypeRelation<'tcx> for NllTypeRelating<'_, 'bccx, 'tcx> {
         b: ty::Binder<'tcx, T>,
     ) -> RelateResult<'tcx, ty::Binder<'tcx, T>>
     where
-        T: Relate<'tcx>,
+        T: Relate<InferCtxt<'tcx>>,
     {
         // We want that
         //

compiler/rustc_hir_typeck/src/coercion.rs

@@ -41,6 +41,7 @@ use rustc_errors::{codes::*, struct_span_code_err, Applicability, Diag};
 use rustc_hir as hir;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir_analysis::hir_ty_lowering::HirTyLowerer;
+use rustc_infer::infer::relate::RelateResult;
 use rustc_infer::infer::{Coercion, DefineOpaqueTypes, InferOk, InferResult};
 use rustc_infer::traits::{IfExpressionCause, MatchExpressionArmCause};
 use rustc_infer::traits::{Obligation, PredicateObligation};
@@ -51,7 +52,6 @@ use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability, PointerCoercion,
 };
 use rustc_middle::ty::error::TypeError;
-use rustc_middle::ty::relate::RelateResult;
 use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, GenericArgsRef, Ty, TyCtxt};
 use rustc_session::parse::feature_err;

compiler/rustc_infer/Cargo.toml

@@ -16,6 +16,7 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
+rustc_next_trait_solver = { path = "../rustc_next_trait_solver" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }

compiler/rustc_infer/src/infer/at.rs

@@ -27,8 +27,8 @@
 
 use super::*;
 
+use crate::infer::relate::{Relate, StructurallyRelateAliases, TypeRelation};
 use rustc_middle::bug;
-use rustc_middle::ty::relate::{Relate, TypeRelation};
 use rustc_middle::ty::{Const, ImplSubject};
 
 /// Whether we should define opaque types or just treat them opaquely.
@@ -90,7 +90,7 @@ impl<'tcx> InferCtxt<'tcx> {
     }
 }
 
-pub trait ToTrace<'tcx>: Relate<'tcx> + Copy {
+pub trait ToTrace<'tcx>: Relate<InferCtxt<'tcx>> + Copy {
     fn to_trace(
         cause: &ObligationCause<'tcx>,
         a_is_expected: bool,

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

@@ -58,6 +58,7 @@ use crate::traits::{
     PredicateObligation,
 };
 
+use crate::infer::relate::{self, RelateResult, TypeRelation};
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_errors::{
     codes::*, pluralize, struct_span_code_err, Applicability, Diag, DiagCtxt, DiagStyledString,
@@ -73,7 +74,6 @@ use rustc_middle::bug;
 use rustc_middle::dep_graph::DepContext;
 use rustc_middle::ty::error::TypeErrorToStringExt;
 use rustc_middle::ty::print::{with_forced_trimmed_paths, PrintError, PrintTraitRefExt as _};
-use rustc_middle::ty::relate::{self, RelateResult, TypeRelation};
 use rustc_middle::ty::Upcast;
 use rustc_middle::ty::{
     self, error::TypeError, IsSuggestable, List, Region, Ty, TyCtxt, TypeFoldable,
@@ -2687,15 +2687,15 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
     /// with the other type. A TyVar inference type is compatible with any type, and an IntVar or
     /// FloatVar inference type are compatible with themselves or their concrete types (Int and
     /// Float types, respectively). When comparing two ADTs, these rules apply recursively.
-    pub fn same_type_modulo_infer<T: relate::Relate<'tcx>>(&self, a: T, b: T) -> bool {
+    pub fn same_type_modulo_infer<T: relate::Relate<InferCtxt<'tcx>>>(&self, a: T, b: T) -> bool {
         let (a, b) = self.resolve_vars_if_possible((a, b));
         SameTypeModuloInfer(self).relate(a, b).is_ok()
     }
 }
 
 struct SameTypeModuloInfer<'a, 'tcx>(&'a InferCtxt<'tcx>);
 
-impl<'tcx> TypeRelation<'tcx> for SameTypeModuloInfer<'_, 'tcx> {
+impl<'tcx> TypeRelation<InferCtxt<'tcx>> for SameTypeModuloInfer<'_, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.0.tcx
     }
@@ -2704,7 +2704,7 @@ impl<'tcx> TypeRelation<'tcx> for SameTypeModuloInfer<'_, 'tcx> {
         "SameTypeModuloInfer"
     }
 
-    fn relate_with_variance<T: relate::Relate<'tcx>>(
+    fn relate_with_variance<T: relate::Relate<InferCtxt<'tcx>>>(
         &mut self,
         _variance: ty::Variance,
         _info: ty::VarianceDiagInfo<TyCtxt<'tcx>>,
@@ -2755,7 +2755,7 @@ impl<'tcx> TypeRelation<'tcx> for SameTypeModuloInfer<'_, 'tcx> {
         b: ty::Binder<'tcx, T>,
     ) -> relate::RelateResult<'tcx, ty::Binder<'tcx, T>>
     where
-        T: relate::Relate<'tcx>,
+        T: relate::Relate<InferCtxt<'tcx>>,
     {
         Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?))
     }

compiler/rustc_infer/src/infer/mod.rs

@@ -1,16 +1,14 @@
 pub use at::DefineOpaqueTypes;
 pub use freshen::TypeFreshener;
 pub use lexical_region_resolve::RegionResolutionError;
-pub use relate::combine::CombineFields;
-pub use relate::combine::ObligationEmittingRelation;
-pub use relate::StructurallyRelateAliases;
 pub use rustc_macros::{TypeFoldable, TypeVisitable};
 pub use rustc_middle::ty::IntVarValue;
 pub use BoundRegionConversionTime::*;
 pub use RegionVariableOrigin::*;
 pub use SubregionOrigin::*;
 pub use ValuePairs::*;
 
+use crate::infer::relate::{CombineFields, RelateResult};
 use crate::traits::{
     self, ObligationCause, ObligationInspector, PredicateObligations, TraitEngine, TraitEngineExt,
 };
@@ -39,7 +37,6 @@ use rustc_middle::traits::select;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::fold::BoundVarReplacerDelegate;
 use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
-use rustc_middle::ty::relate::RelateResult;
 use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, GenericParamDefKind, InferConst, InferTy, Ty, TyCtxt};
 use rustc_middle::ty::{ConstVid, EffectVid, FloatVid, IntVid, TyVid};
@@ -62,7 +59,7 @@ pub mod opaque_types;
 pub mod outlives;
 mod projection;
 pub mod region_constraints;
-mod relate;
+pub mod relate;
 pub mod resolve;
 pub(crate) mod snapshot;
 pub mod type_variable;

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

@@ -1,15 +1,13 @@
 use std::collections::hash_map::Entry;
 
 use rustc_data_structures::fx::FxHashMap;
+use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::TypeVisitableExt;
-use rustc_middle::ty::{
-    self,
-    error::TypeError,
-    relate::{self, Relate, RelateResult, TypeRelation},
-    Ty, TyCtxt,
-};
+use rustc_middle::ty::{self, Ty, TyCtxt};
 
 use crate::infer::region_constraints::VerifyIfEq;
+use crate::infer::relate::{self as relate, Relate, RelateResult, TypeRelation};
+use crate::infer::InferCtxt;
 
 /// Given a "verify-if-eq" type test like:
 ///
@@ -135,7 +133,7 @@ impl<'tcx> MatchAgainstHigherRankedOutlives<'tcx> {
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for MatchAgainstHigherRankedOutlives<'tcx> {
+impl<'tcx> TypeRelation<InferCtxt<'tcx>> for MatchAgainstHigherRankedOutlives<'tcx> {
     fn tag(&self) -> &'static str {
         "MatchAgainstHigherRankedOutlives"
     }
@@ -145,7 +143,7 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstHigherRankedOutlives<'tcx> {
     }
 
     #[instrument(level = "trace", skip(self))]
-    fn relate_with_variance<T: Relate<'tcx>>(
+    fn relate_with_variance<T: Relate<InferCtxt<'tcx>>>(
         &mut self,
         variance: ty::Variance,
         _: ty::VarianceDiagInfo<TyCtxt<'tcx>>,
@@ -208,7 +206,7 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstHigherRankedOutlives<'tcx> {
         value: ty::Binder<'tcx, T>,
     ) -> RelateResult<'tcx, ty::Binder<'tcx, T>>
     where
-        T: Relate<'tcx>,
+        T: Relate<InferCtxt<'tcx>>,
     {
         self.pattern_depth.shift_in(1);
         let result = Ok(pattern.rebind(self.relate(pattern.skip_binder(), value.skip_binder())?));

compiler/rustc_infer/src/infer/region_constraints/leak_check.rs

@@ -1,11 +1,11 @@
 use super::*;
+use crate::infer::relate::RelateResult;
 use crate::infer::snapshot::CombinedSnapshot;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::graph::{scc::Sccs, vec_graph::VecGraph};
 use rustc_index::Idx;
 use rustc_middle::span_bug;
 use rustc_middle::ty::error::TypeError;
-use rustc_middle::ty::relate::RelateResult;
 
 impl<'tcx> RegionConstraintCollector<'_, 'tcx> {
     /// Searches new universes created during `snapshot`, looking for

compiler/rustc_middle/src/ty/_match.rs → compiler/rustc_infer/src/infer/relate/_match.rs

@@ -1,8 +1,11 @@
-use crate::ty::error::TypeError;
-use crate::ty::relate::{self, Relate, RelateResult, TypeRelation};
-use crate::ty::{self, InferConst, Ty, TyCtxt};
+use rustc_middle::ty::error::{ExpectedFound, TypeError};
+use rustc_middle::ty::{self, InferConst, Ty, TyCtxt};
 use tracing::{debug, instrument};
 
+use super::{structurally_relate_tys, Relate, RelateResult, TypeRelation};
+use crate::infer::relate;
+use crate::infer::InferCtxt;
+
 /// A type "A" *matches* "B" if the fresh types in B could be
 /// instantiated with values so as to make it equal to A. Matching is
 /// intended to be used only on freshened types, and it basically
@@ -29,7 +32,7 @@ impl<'tcx> MatchAgainstFreshVars<'tcx> {
     }
 }
 
-impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
+impl<'tcx> TypeRelation<InferCtxt<'tcx>> for MatchAgainstFreshVars<'tcx> {
     fn tag(&self) -> &'static str {
         "MatchAgainstFreshVars"
     }
@@ -38,7 +41,7 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
         self.tcx
     }
 
-    fn relate_with_variance<T: Relate<'tcx>>(
+    fn relate_with_variance<T: Relate<InferCtxt<'tcx>>>(
         &mut self,
         _: ty::Variance,
         _: ty::VarianceDiagInfo<TyCtxt<'tcx>>,
@@ -72,12 +75,12 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
             ) => Ok(a),
 
             (&ty::Infer(_), _) | (_, &ty::Infer(_)) => {
-                Err(TypeError::Sorts(relate::expected_found(a, b)))
+                Err(TypeError::Sorts(ExpectedFound::new(true, a, b)))
             }
 
             (&ty::Error(guar), _) | (_, &ty::Error(guar)) => Ok(Ty::new_error(self.tcx(), guar)),
 
-            _ => relate::structurally_relate_tys(self, a, b),
+            _ => structurally_relate_tys(self, a, b),
         }
     }
 
@@ -97,7 +100,7 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
             }
 
             (ty::ConstKind::Infer(_), _) | (_, ty::ConstKind::Infer(_)) => {
-                return Err(TypeError::ConstMismatch(relate::expected_found(a, b)));
+                return Err(TypeError::ConstMismatch(ExpectedFound::new(true, a, b)));
             }
 
             _ => {}
@@ -112,7 +115,7 @@ impl<'tcx> TypeRelation<'tcx> for MatchAgainstFreshVars<'tcx> {
         b: ty::Binder<'tcx, T>,
     ) -> RelateResult<'tcx, ty::Binder<'tcx, T>>
     where
-        T: Relate<'tcx>,
+        T: Relate<InferCtxt<'tcx>>,
     {
         Ok(a.rebind(self.relate(a.skip_binder(), b.skip_binder())?))
     }

compiler/rustc_infer/src/infer/relate/combine.rs

@@ -22,13 +22,14 @@ use super::glb::Glb;
 use super::lub::Lub;
 use super::type_relating::TypeRelating;
 use super::StructurallyRelateAliases;
+use super::{RelateResult, TypeRelation};
+use crate::infer::relate;
 use crate::infer::{DefineOpaqueTypes, InferCtxt, InferOk, TypeTrace};
 use crate::traits::{Obligation, PredicateObligations};
 use rustc_middle::bug;
 use rustc_middle::infer::unify_key::EffectVarValue;
 use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::relate::{RelateResult, TypeRelation};
 use rustc_middle::ty::{self, InferConst, Ty, TyCtxt, TypeVisitableExt, Upcast};
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::Span;
@@ -124,7 +125,7 @@ impl<'tcx> InferCtxt<'tcx> {
             (_, ty::Alias(..)) | (ty::Alias(..), _) if self.next_trait_solver() => {
                 match relation.structurally_relate_aliases() {
                     StructurallyRelateAliases::Yes => {
-                        ty::relate::structurally_relate_tys(relation, a, b)
+                        relate::structurally_relate_tys(relation, a, b)
                     }
                     StructurallyRelateAliases::No => {
                         relation.register_type_relate_obligation(a, b);
@@ -135,7 +136,7 @@ impl<'tcx> InferCtxt<'tcx> {
 
             // All other cases of inference are errors
             (&ty::Infer(_), _) | (_, &ty::Infer(_)) => {
-                Err(TypeError::Sorts(ty::relate::expected_found(a, b)))
+                Err(TypeError::Sorts(ExpectedFound::new(true, a, b)))
             }
 
             // During coherence, opaque types should be treated as *possibly*
@@ -147,7 +148,7 @@ impl<'tcx> InferCtxt<'tcx> {
                 Ok(a)
             }
 
-            _ => ty::relate::structurally_relate_tys(relation, a, b),
+            _ => relate::structurally_relate_tys(relation, a, b),
         }
     }
 
@@ -243,11 +244,11 @@ impl<'tcx> InferCtxt<'tcx> {
                         Ok(b)
                     }
                     StructurallyRelateAliases::Yes => {
-                        ty::relate::structurally_relate_consts(relation, a, b)
+                        relate::structurally_relate_consts(relation, a, b)
                     }
                 }
             }
-            _ => ty::relate::structurally_relate_consts(relation, a, b),
+            _ => relate::structurally_relate_consts(relation, a, b),
         }
     }
 
@@ -333,7 +334,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
     }
 }
 
-pub trait ObligationEmittingRelation<'tcx>: TypeRelation<'tcx> {
+pub trait ObligationEmittingRelation<'tcx>: TypeRelation<InferCtxt<'tcx>> {
     fn span(&self) -> Span;
 
     fn param_env(&self) -> ty::ParamEnv<'tcx>;