Move WF goal to clause

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -330,7 +330,8 @@ fn check_opaque_type_well_formed<'tcx>(
     // Require the hidden type to be well-formed with only the generics of the opaque type.
     // Defining use functions may have more bounds than the opaque type, which is ok, as long as the
     // hidden type is well formed even without those bounds.
-    let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(definition_ty.into()));
+    let predicate =
+        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(definition_ty.into())));
     ocx.register_obligation(Obligation::misc(tcx, definition_span, def_id, param_env, predicate));
 
     // Check that all obligations are satisfied by the implementation's

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1419,9 +1419,11 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 //
                 // See #91068 for an example.
                 self.prove_predicates(
-                    sig.inputs_and_output
+                    sig.inputs_and_output.iter().map(|ty| {
-                        .iter()
+                        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(
-                        .map(|ty| ty::Binder::dummy(ty::PredicateKind::WellFormed(ty.into()))),
+                            ty.into(),
+                        )))
+                    }),
                     term_location.to_locations(),
                     ConstraintCategory::Boring,
                 );
@@ -1850,7 +1852,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 
                 let array_ty = rvalue.ty(body.local_decls(), tcx);
                 self.prove_predicate(
-                    ty::PredicateKind::WellFormed(array_ty.into()),
+                    ty::PredicateKind::Clause(ty::Clause::WellFormed(array_ty.into())),
                     Locations::Single(location),
                     ConstraintCategory::Boring,
                 );

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1527,10 +1527,11 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     ty::Clause::TypeOutlives(_) => {
                         // Do nothing, we deal with regions separately
                     }
-                    ty::Clause::RegionOutlives(_) | ty::Clause::ConstArgHasType(..) => bug!(),
+                    ty::Clause::RegionOutlives(_)
+                    | ty::Clause::ConstArgHasType(..)
+                    | ty::Clause::WellFormed(_) => bug!(),
                 },
-                ty::PredicateKind::WellFormed(_)
+                ty::PredicateKind::AliasRelate(..)
-                | ty::PredicateKind::AliasRelate(..)
                 | ty::PredicateKind::ObjectSafe(_)
                 | ty::PredicateKind::ClosureKind(_, _, _)
                 | ty::PredicateKind::Subtype(_)

compiler/rustc_hir_analysis/src/check/check.rs

@@ -439,7 +439,8 @@ fn check_opaque_meets_bounds<'tcx>(
     // Additionally require the hidden type to be well-formed with only the generics of the opaque type.
     // Defining use functions may have more bounds than the opaque type, which is ok, as long as the
     // hidden type is well formed even without those bounds.
-    let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_ty.into()));
+    let predicate =
+        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(hidden_ty.into())));
     ocx.register_obligation(Obligation::new(tcx, misc_cause, param_env, predicate));
 
     // Check that all obligations are satisfied by the implementation's

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -321,7 +321,9 @@ fn compare_method_predicate_entailment<'tcx>(
             infcx.tcx,
             ObligationCause::dummy(),
             param_env,
-            ty::Binder::dummy(ty::PredicateKind::WellFormed(unnormalized_impl_fty.into())),
+            ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(
+                unnormalized_impl_fty.into(),
+            ))),
         ));
     }
 

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -81,7 +81,7 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
             self.tcx(),
             cause,
             param_env,
-            ty::Binder::dummy(ty::PredicateKind::WellFormed(arg)),
+            ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(arg))),
         ));
     }
 }
@@ -1876,7 +1876,8 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
             // We lower empty bounds like `Vec<dyn Copy>:` as
             // `WellFormed(Vec<dyn Copy>)`, which will later get checked by
             // regular WF checking
-            if let ty::PredicateKind::WellFormed(..) = pred.kind().skip_binder() {
+            if let ty::PredicateKind::Clause(ty::Clause::WellFormed(..)) = pred.kind().skip_binder()
+            {
                 continue;
             }
             // Match the existing behavior.

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -219,7 +219,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
                     } else {
                         let span = bound_pred.bounded_ty.span;
                         let predicate = ty::Binder::bind_with_vars(
-                            ty::PredicateKind::WellFormed(ty.into()),
+                            ty::PredicateKind::Clause(ty::Clause::WellFormed(ty.into())),
                             bound_vars,
                         );
                         predicates.insert((predicate.to_predicate(tcx), span));

compiler/rustc_hir_analysis/src/hir_wf_check.rs

@@ -79,7 +79,7 @@ fn diagnostic_hir_wf_check<'tcx>(
                 self.tcx,
                 cause,
                 self.param_env,
-                ty::PredicateKind::WellFormed(tcx_ty.into()),
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(tcx_ty.into())),
             ));
 
             for error in ocx.select_all_or_error() {

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -542,7 +542,7 @@ fn trait_predicate_kind<'tcx>(
         | ty::PredicateKind::Clause(ty::Clause::Projection(_))
         | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
         | ty::PredicateKind::AliasRelate(..)
-        | ty::PredicateKind::WellFormed(_)
+        | ty::PredicateKind::Clause(ty::Clause::WellFormed(_))
         | ty::PredicateKind::Subtype(_)
         | ty::PredicateKind::Coerce(_)
         | ty::PredicateKind::ObjectSafe(_)

compiler/rustc_hir_analysis/src/outlives/explicit.rs

@@ -55,7 +55,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
                     ty::PredicateKind::Clause(ty::Clause::Trait(..))
                     | ty::PredicateKind::Clause(ty::Clause::Projection(..))
                     | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
-                    | ty::PredicateKind::WellFormed(..)
+                    | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
                     | ty::PredicateKind::AliasRelate(..)
                     | ty::PredicateKind::ObjectSafe(..)
                     | ty::PredicateKind::ClosureKind(..)

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -483,7 +483,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.tcx,
             cause,
             self.param_env,
-            ty::Binder::dummy(ty::PredicateKind::WellFormed(arg)),
+            ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(arg))),
         ));
     }
 
@@ -668,7 +668,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 | ty::PredicateKind::Coerce(..)
                 | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
                 | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
-                | ty::PredicateKind::WellFormed(..)
+                | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
                 | ty::PredicateKind::ObjectSafe(..)
                 | ty::PredicateKind::AliasRelate(..)
                 | ty::PredicateKind::ConstEvaluatable(..)

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -452,7 +452,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             tcx,
             obligation.cause,
             self.param_env,
-            ty::Binder::dummy(ty::PredicateKind::WellFormed(method_ty.into())),
+            ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(method_ty.into()))),
         ));
 
         let callee = MethodCallee { def_id, substs, sig: fn_sig };

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -838,7 +838,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                 | ty::PredicateKind::Coerce(..)
                 | ty::PredicateKind::Clause(ty::Clause::Projection(..))
                 | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
-                | ty::PredicateKind::WellFormed(..)
+                | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
                 | ty::PredicateKind::ObjectSafe(..)
                 | ty::PredicateKind::ClosureKind(..)
                 | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -696,7 +696,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 };
 
                 // Don't point out the span of `WellFormed` predicates.
-                if !matches!(p.kind().skip_binder(), ty::PredicateKind::Clause(_)) {
+                if !matches!(
+                    p.kind().skip_binder(),
+                    ty::PredicateKind::Clause(ty::Clause::Projection(..) | ty::Clause::Trait(..))
+                ) {
                     continue;
                 };
 

compiler/rustc_infer/src/infer/combine.rs

@@ -417,7 +417,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
                 self.tcx(),
                 self.trace.cause.clone(),
                 self.param_env,
-                ty::Binder::dummy(ty::PredicateKind::WellFormed(b_ty.into())),
+                ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(b_ty.into()))),
             ));
         }
 

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

@@ -29,7 +29,7 @@ pub fn explicit_outlives_bounds<'tcx>(
             | ty::PredicateKind::AliasRelate(..)
             | ty::PredicateKind::Coerce(..)
             | ty::PredicateKind::Subtype(..)
-            | ty::PredicateKind::WellFormed(..)
+            | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
             | ty::PredicateKind::ObjectSafe(..)
             | ty::PredicateKind::ClosureKind(..)
             | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))

compiler/rustc_infer/src/traits/util.rs

@@ -227,7 +227,7 @@ impl<'tcx, O: Elaboratable<'tcx>> Elaborator<'tcx, O> {
                 debug!(?data, ?obligations, "super_predicates");
                 self.extend_deduped(obligations);
             }
-            ty::PredicateKind::WellFormed(..) => {
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(..)) => {
                 // Currently, we do not elaborate WF predicates,
                 // although we easily could.
             }

compiler/rustc_lint/src/builtin.rs

@@ -1610,7 +1610,7 @@ impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
                     Clause(Clause::Projection(..)) |
                     AliasRelate(..) |
                     // Ignore bounds that a user can't type
-                    WellFormed(..) |
+                    Clause(Clause::WellFormed(..)) |
                     ObjectSafe(..) |
                     ClosureKind(..) |
                     Subtype(..) |

compiler/rustc_middle/src/ty/flags.rs

@@ -270,7 +270,7 @@ impl FlagComputation {
                 self.add_alias_ty(projection_ty);
                 self.add_term(term);
             }
-            ty::PredicateKind::WellFormed(arg) => {
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                 self.add_substs(slice::from_ref(&arg));
             }
             ty::PredicateKind::ObjectSafe(_def_id) => {}

compiler/rustc_middle/src/ty/mod.rs

@@ -523,7 +523,7 @@ impl<'tcx> Predicate<'tcx> {
             ty::PredicateKind::Clause(ty::Clause::Trait(data)) => {
                 tcx.trait_is_coinductive(data.def_id())
             }
-            ty::PredicateKind::WellFormed(_) => true,
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(_)) => true,
             _ => false,
         }
     }
@@ -536,7 +536,7 @@ impl<'tcx> Predicate<'tcx> {
     #[inline]
     pub fn allow_normalization(self) -> bool {
         match self.kind().skip_binder() {
-            PredicateKind::WellFormed(_) => false,
+            PredicateKind::Clause(Clause::WellFormed(_)) => false,
             PredicateKind::Clause(Clause::Trait(_))
             | PredicateKind::Clause(Clause::RegionOutlives(_))
             | PredicateKind::Clause(Clause::TypeOutlives(_))
@@ -584,6 +584,9 @@ pub enum Clause<'tcx> {
     /// Ensures that a const generic argument to a parameter `const N: u8`
     /// is of type `u8`.
     ConstArgHasType(Const<'tcx>, Ty<'tcx>),
+
+    /// No syntax: `T` well-formed.
+    WellFormed(GenericArg<'tcx>),
 }
 
 impl<'tcx> Binder<'tcx, Clause<'tcx>> {
@@ -610,9 +613,6 @@ pub enum PredicateKind<'tcx> {
     /// Prove a clause
     Clause(Clause<'tcx>),
 
-    /// No syntax: `T` well-formed.
-    WellFormed(GenericArg<'tcx>),
-
     /// Trait must be object-safe.
     ObjectSafe(DefId),
 
@@ -1324,7 +1324,7 @@ impl<'tcx> Predicate<'tcx> {
             | PredicateKind::Subtype(..)
             | PredicateKind::Coerce(..)
             | PredicateKind::Clause(Clause::RegionOutlives(..))
-            | PredicateKind::WellFormed(..)
+            | PredicateKind::Clause(Clause::WellFormed(..))
             | PredicateKind::ObjectSafe(..)
             | PredicateKind::ClosureKind(..)
             | PredicateKind::Clause(Clause::TypeOutlives(..))
@@ -1345,7 +1345,7 @@ impl<'tcx> Predicate<'tcx> {
             | PredicateKind::Subtype(..)
             | PredicateKind::Coerce(..)
             | PredicateKind::Clause(Clause::RegionOutlives(..))
-            | PredicateKind::WellFormed(..)
+            | PredicateKind::Clause(Clause::WellFormed(..))
             | PredicateKind::ObjectSafe(..)
             | PredicateKind::ClosureKind(..)
             | PredicateKind::Clause(Clause::TypeOutlives(..))
@@ -1367,7 +1367,7 @@ impl<'tcx> Predicate<'tcx> {
             | PredicateKind::Subtype(..)
             | PredicateKind::Coerce(..)
             | PredicateKind::Clause(Clause::RegionOutlives(..))
-            | PredicateKind::WellFormed(..)
+            | PredicateKind::Clause(Clause::WellFormed(..))
             | PredicateKind::ObjectSafe(..)
             | PredicateKind::ClosureKind(..)
             | PredicateKind::ConstEvaluatable(..)

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -2877,7 +2877,7 @@ define_print_and_forward_display! {
             ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, ty)) => {
                 p!("the constant `", print(ct), "` has type `", print(ty), "`")
             },
-            ty::PredicateKind::WellFormed(arg) => p!(print(arg), " well-formed"),
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => p!(print(arg), " well-formed"),
             ty::PredicateKind::ObjectSafe(trait_def_id) => {
                 p!("the trait `", print_def_path(trait_def_id, &[]), "` is object-safe")
             }

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -179,6 +179,7 @@ impl<'tcx> fmt::Debug for ty::Clause<'tcx> {
             ty::Clause::RegionOutlives(ref pair) => pair.fmt(f),
             ty::Clause::TypeOutlives(ref pair) => pair.fmt(f),
             ty::Clause::Projection(ref pair) => pair.fmt(f),
+            ty::Clause::WellFormed(ref data) => write!(f, "WellFormed({:?})", data),
         }
     }
 }
@@ -189,7 +190,6 @@ impl<'tcx> fmt::Debug for ty::PredicateKind<'tcx> {
             ty::PredicateKind::Clause(ref a) => a.fmt(f),
             ty::PredicateKind::Subtype(ref pair) => pair.fmt(f),
             ty::PredicateKind::Coerce(ref pair) => pair.fmt(f),
-            ty::PredicateKind::WellFormed(data) => write!(f, "WellFormed({:?})", data),
             ty::PredicateKind::ObjectSafe(trait_def_id) => {
                 write!(f, "ObjectSafe({:?})", trait_def_id)
             }

compiler/rustc_privacy/src/lib.rs

@@ -183,7 +183,7 @@ where
                 ty.visit_with(self)
             }
             ty::PredicateKind::ConstEvaluatable(ct) => ct.visit_with(self),
-            ty::PredicateKind::WellFormed(arg) => arg.visit_with(self),
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => arg.visit_with(self),
 
             ty::PredicateKind::ObjectSafe(_)
             | ty::PredicateKind::ClosureKind(_, _, _)

compiler/rustc_trait_selection/src/solve/eval_ctxt.rs

@@ -319,7 +319,7 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
                 ty::PredicateKind::ObjectSafe(trait_def_id) => {
                     self.compute_object_safe_goal(trait_def_id)
                 }
-                ty::PredicateKind::WellFormed(arg) => {
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                     self.compute_well_formed_goal(Goal { param_env, predicate: arg })
                 }
                 ty::PredicateKind::Ambiguous => {

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -119,7 +119,6 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
                                     )
                                 }
                                 ty::PredicateKind::Clause(_)
-                                | ty::PredicateKind::WellFormed(_)
                                 | ty::PredicateKind::ObjectSafe(_)
                                 | ty::PredicateKind::ClosureKind(_, _, _)
                                 | ty::PredicateKind::ConstEvaluatable(_)

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -826,7 +826,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
                 // we start out with a `ParamEnv` with no inference variables,
                 // and these don't correspond to adding any new bounds to
                 // the `ParamEnv`.
-                ty::PredicateKind::WellFormed(..)
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
                 | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
                 | ty::PredicateKind::AliasRelate(..)
                 | ty::PredicateKind::ObjectSafe(..)

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1048,7 +1048,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         self.report_closure_error(&obligation, closure_def_id, found_kind, kind)
                     }
 
-                    ty::PredicateKind::WellFormed(ty) => {
+                    ty::PredicateKind::Clause(ty::Clause::WellFormed(ty)) => {
                         match self.tcx.sess.opts.unstable_opts.trait_solver {
                             TraitSolver::Classic => {
                                 // WF predicates cannot themselves make
@@ -2415,7 +2415,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 err
             }
 
-            ty::PredicateKind::WellFormed(arg) => {
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                 // Same hacky approach as above to avoid deluging user
                 // with error messages.
                 if arg.references_error()

compiler/rustc_trait_selection/src/traits/fulfill.rs

@@ -354,7 +354,7 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                 ty::PredicateKind::Clause(ty::Clause::RegionOutlives(_))
                 | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(_))
                 | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
-                | ty::PredicateKind::WellFormed(_)
+                | ty::PredicateKind::Clause(ty::Clause::WellFormed(_))
                 | ty::PredicateKind::ObjectSafe(_)
                 | ty::PredicateKind::ClosureKind(..)
                 | ty::PredicateKind::Subtype(_)
@@ -433,7 +433,7 @@ impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx> {
                     }
                 }
 
-                ty::PredicateKind::WellFormed(arg) => {
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                     match wf::obligations(
                         self.selcx.infcx,
                         obligation.param_env,

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -310,7 +310,7 @@ fn predicate_references_self<'tcx>(
 
         ty::PredicateKind::AliasRelate(..) => bug!("`AliasRelate` not allowed as assumption"),
 
-        ty::PredicateKind::WellFormed(..)
+        ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
         | ty::PredicateKind::ObjectSafe(..)
         | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
         | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
@@ -361,7 +361,7 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
         | ty::PredicateKind::Subtype(..)
         | ty::PredicateKind::Coerce(..)
         | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
-        | ty::PredicateKind::WellFormed(..)
+        | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
         | ty::PredicateKind::ObjectSafe(..)
         | ty::PredicateKind::ClosureKind(..)
         | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))

compiler/rustc_trait_selection/src/traits/query/type_op/ascribe_user_type.rs

@@ -67,7 +67,8 @@ fn relate_mir_and_user_ty<'tcx>(
     ocx.eq(&cause, param_env, mir_ty, user_ty)?;
 
     // FIXME(#104764): We should check well-formedness before normalization.
-    let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(user_ty.into()));
+    let predicate =
+        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(user_ty.into())));
     ocx.register_obligation(Obligation::new(ocx.infcx.tcx, cause, param_env, predicate));
     Ok(())
 }
@@ -119,7 +120,9 @@ fn relate_mir_and_user_substs<'tcx>(
         let impl_self_ty = ocx.normalize(&cause, param_env, impl_self_ty);
 
         ocx.eq(&cause, param_env, self_ty, impl_self_ty)?;
-        let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(impl_self_ty.into()));
+        let predicate = ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(
+            impl_self_ty.into(),
+        )));
         ocx.register_obligation(Obligation::new(tcx, cause.clone(), param_env, predicate));
     }
 
@@ -134,7 +137,7 @@ fn relate_mir_and_user_substs<'tcx>(
     // them?  This would only be relevant if some input
     // type were ill-formed but did not appear in `ty`,
     // which...could happen with normalization...
-    let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(ty.into()));
+    let predicate = ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(ty.into())));
     ocx.register_obligation(Obligation::new(tcx, cause, param_env, predicate));
     Ok(())
 }

compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs

@@ -137,7 +137,7 @@ pub fn compute_implied_outlives_bounds_inner<'tcx>(
                 | ty::PredicateKind::TypeWellFormedFromEnv(..) => {}
 
                 // We need to search through *all* WellFormed predicates
-                ty::PredicateKind::WellFormed(arg) => {
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                     wf_args.push(arg);
                 }
 

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -674,7 +674,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     }
                 }
 
-                ty::PredicateKind::WellFormed(arg) => {
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
                     // So, there is a bit going on here. First, `WellFormed` predicates
                     // are coinductive, like trait predicates with auto traits.
                     // This means that we need to detect if we have recursively

compiler/rustc_trait_selection/src/traits/wf.rs

@@ -160,7 +160,7 @@ pub fn predicate_obligations<'tcx>(
             wf.compute(ct.into());
             wf.compute(ty.into());
         }
-        ty::PredicateKind::WellFormed(arg) => {
+        ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => {
             wf.compute(arg);
         }
 
@@ -386,7 +386,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
                         cause,
                         depth,
                         param_env,
-                        ty::Binder::dummy(ty::PredicateKind::WellFormed(arg)),
+                        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(arg))),
                     )
                 }),
         );
@@ -478,7 +478,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
                         cause.clone(),
                         depth,
                         param_env,
-                        ty::Binder::dummy(ty::PredicateKind::WellFormed(arg)),
+                        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(arg))),
                     )
                 }),
         );
@@ -541,7 +541,9 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
                                 cause,
                                 self.recursion_depth,
                                 self.param_env,
-                                ty::Binder::dummy(ty::PredicateKind::WellFormed(ct.into())),
+                                ty::Binder::dummy(ty::PredicateKind::Clause(
+                                    ty::Clause::WellFormed(ct.into()),
+                                )),
                             ));
                         }
                         ty::ConstKind::Expr(_) => {
@@ -784,7 +786,9 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
                         cause,
                         self.recursion_depth,
                         param_env,
-                        ty::Binder::dummy(ty::PredicateKind::WellFormed(ty.into())),
+                        ty::Binder::dummy(ty::PredicateKind::Clause(ty::Clause::WellFormed(
+                            ty.into(),
+                        ))),
                     ));
                 }
             }
@@ -969,7 +973,7 @@ pub(crate) fn required_region_bounds<'tcx>(
                 | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
                 | ty::PredicateKind::Subtype(..)
                 | ty::PredicateKind::Coerce(..)
-                | ty::PredicateKind::WellFormed(..)
+                | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
                 | ty::PredicateKind::ObjectSafe(..)
                 | ty::PredicateKind::ClosureKind(..)
                 | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))

compiler/rustc_traits/src/chalk/lowering.rs

@@ -122,7 +122,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
                         predicate.lower_into(interner),
                     ))
                 }
-                ty::PredicateKind::WellFormed(arg) => match arg.unpack() {
+                ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => match arg.unpack() {
                     ty::GenericArgKind::Type(ty) => chalk_ir::DomainGoal::WellFormed(
                         chalk_ir::WellFormed::Ty(ty.lower_into(interner)),
                     ),
@@ -192,7 +192,7 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi
                     chalk_ir::WhereClause::AliasEq(predicate.lower_into(interner)),
                 ))
             }
-            ty::PredicateKind::WellFormed(arg) => match arg.unpack() {
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(arg)) => match arg.unpack() {
                 GenericArgKind::Type(ty) => match ty.kind() {
                     // FIXME(chalk): In Chalk, a placeholder is WellFormed if it
                     // `FromEnv`. However, when we "lower" Params, we don't update
@@ -672,7 +672,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'
             ty::PredicateKind::Clause(ty::Clause::Projection(predicate)) => {
                 Some(chalk_ir::WhereClause::AliasEq(predicate.lower_into(interner)))
             }
-            ty::PredicateKind::WellFormed(_ty) => None,
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(_ty)) => None,
             ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
             ty::PredicateKind::ObjectSafe(..)
@@ -807,7 +807,7 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<Ru
                 ))
             }
             ty::PredicateKind::Clause(ty::Clause::TypeOutlives(_predicate)) => None,
-            ty::PredicateKind::WellFormed(_ty) => None,
+            ty::PredicateKind::Clause(ty::Clause::WellFormed(_ty)) => None,
             ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
             ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))

compiler/rustc_traits/src/normalize_erasing_regions.rs

@@ -62,7 +62,7 @@ fn not_outlives_predicate(p: ty::Predicate<'_>) -> bool {
         | ty::PredicateKind::Clause(ty::Clause::Projection(..))
         | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
         | ty::PredicateKind::AliasRelate(..)
-        | ty::PredicateKind::WellFormed(..)
+        | ty::PredicateKind::Clause(ty::Clause::WellFormed(..))
         | ty::PredicateKind::ObjectSafe(..)
         | ty::PredicateKind::ClosureKind(..)
         | ty::PredicateKind::Subtype(..)

src/librustdoc/clean/mod.rs

@@ -345,7 +345,7 @@ pub(crate) fn clean_predicate<'tcx>(
         }
         // FIXME(generic_const_exprs): should this do something?
         ty::PredicateKind::ConstEvaluatable(..) => None,
-        ty::PredicateKind::WellFormed(..) => None,
+        ty::PredicateKind::Clause(ty::Clause::WellFormed(..)) => None,
         ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) => None,
 
         ty::PredicateKind::Subtype(..)

src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs

@@ -33,7 +33,7 @@ pub fn is_min_const_fn<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>, msrv: &Msrv)
                     | ty::Clause::Trait(..)
                     | ty::Clause::ConstArgHasType(..),
                 )
-                | ty::PredicateKind::WellFormed(_)
+                | ty::PredicateKind::Clause(ty::Clause::WellFormed(_))
                 | ty::PredicateKind::ConstEvaluatable(..)
                 | ty::PredicateKind::ConstEquate(..)
                 | ty::PredicateKind::TypeWellFormedFromEnv(..) => continue,