1 files changed, 41 insertions, 14 deletions

diff --git a/compiler/rustc_infer/src/infer/combine.rs b/compiler/rustc_infer/src/infer/combine.rs
index b5427f639..cf895ed0d 100644
--- a/compiler/rustc_infer/src/infer/combine.rs
+++ b/compiler/rustc_infer/src/infer/combine.rs
@@ -37,7 +37,7 @@ use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
 use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, InferConst, ToPredicate, Ty, TyCtxt, TypeVisitable};
+use rustc_middle::ty::{self, InferConst, Ty, TyCtxt, TypeVisitable};
 use rustc_middle::ty::{IntType, UintType};
 use rustc_span::{Span, DUMMY_SP};
 
@@ -347,10 +347,10 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
 
         if needs_wf {
             self.obligations.push(Obligation::new(
+                self.tcx(),
                 self.trace.cause.clone(),
                 self.param_env,
-                ty::Binder::dummy(ty::PredicateKind::WellFormed(b_ty.into()))
-                    .to_predicate(self.infcx.tcx),
+                ty::Binder::dummy(ty::PredicateKind::WellFormed(b_ty.into())),
             ));
         }
 
@@ -444,9 +444,19 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
             ty::PredicateKind::ConstEquate(b, a)
         };
         self.obligations.push(Obligation::new(
+            self.tcx(),
             self.trace.cause.clone(),
             self.param_env,
-            ty::Binder::dummy(predicate).to_predicate(self.tcx()),
+            ty::Binder::dummy(predicate),
+        ));
+    }
+
+    pub fn mark_ambiguous(&mut self) {
+        self.obligations.push(Obligation::new(
+            self.tcx(),
+            self.trace.cause.clone(),
+            self.param_env,
+            ty::Binder::dummy(ty::PredicateKind::Ambiguous),
         ));
     }
 }
@@ -520,6 +530,11 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.infcx.tcx
     }
+
+    fn intercrate(&self) -> bool {
+        self.infcx.intercrate
+    }
+
     fn param_env(&self) -> ty::ParamEnv<'tcx> {
         self.param_env
     }
@@ -532,6 +547,10 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
         true
     }
 
+    fn mark_ambiguous(&mut self) {
+        span_bug!(self.cause.span, "opaque types are handled in `tys`");
+    }
+
     fn binders<T>(
         &mut self,
         a: ty::Binder<'tcx, T>,
@@ -563,6 +582,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                 &opt_variances,
                 a_subst,
                 b_subst,
+                true,
             )
         }
     }
@@ -655,6 +675,10 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                 // relatable.
                 Ok(t)
             }
+            ty::Opaque(def_id, substs) => {
+                let s = self.relate(substs, substs)?;
+                Ok(if s == substs { t } else { self.infcx.tcx.mk_opaque(def_id, s) })
+            }
             _ => relate::super_relate_tys(self, t, t),
         }?;
 
@@ -729,7 +753,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                                 origin: var_value.origin,
                                 val: ConstVariableValue::Unknown { universe: self.for_universe },
                             });
-                            Ok(self.tcx().mk_const_var(new_var_id, c.ty()))
+                            Ok(self.tcx().mk_const(new_var_id, c.ty()))
                         }
                     }
                 }
@@ -741,10 +765,7 @@ impl<'tcx> TypeRelation<'tcx> for Generalizer<'_, 'tcx> {
                     substs,
                     substs,
                 )?;
-                Ok(self.tcx().mk_const(ty::ConstS {
-                    ty: c.ty(),
-                    kind: ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs }),
-                }))
+                Ok(self.tcx().mk_const(ty::UnevaluatedConst { def, substs }, c.ty()))
             }
             _ => relate::super_relate_consts(self, c, c),
         }
@@ -797,6 +818,11 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         self.infcx.tcx
     }
 
+    fn intercrate(&self) -> bool {
+        assert!(!self.infcx.intercrate);
+        false
+    }
+
     fn param_env(&self) -> ty::ParamEnv<'tcx> {
         self.param_env
     }
@@ -809,6 +835,10 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
         true
     }
 
+    fn mark_ambiguous(&mut self) {
+        bug!()
+    }
+
     fn relate_with_variance<T: Relate<'tcx>>(
         &mut self,
         _variance: ty::Variance,
@@ -942,7 +972,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                                         },
                                     },
                                 );
-                            Ok(self.tcx().mk_const_var(new_var_id, c.ty()))
+                            Ok(self.tcx().mk_const(new_var_id, c.ty()))
                         }
                     }
                 }
@@ -955,10 +985,7 @@ impl<'tcx> TypeRelation<'tcx> for ConstInferUnifier<'_, 'tcx> {
                     substs,
                 )?;
 
-                Ok(self.tcx().mk_const(ty::ConstS {
-                    ty: c.ty(),
-                    kind: ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, substs }),
-                }))
+                Ok(self.tcx().mk_const(ty::UnevaluatedConst { def, substs }, c.ty()))
             }
             _ => relate::super_relate_consts(self, c, c),
         }