Deeply normalize signature in new solver

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -9,8 +9,8 @@ use rustc_infer::infer::{
 };
 use rustc_infer::traits::ObligationCause;
 use rustc_infer::traits::query::{
-    CanonicalTypeOpAscribeUserTypeGoal, CanonicalTypeOpNormalizeGoal,
-    CanonicalTypeOpProvePredicateGoal,
+    CanonicalTypeOpAscribeUserTypeGoal, CanonicalTypeOpDeeplyNormalizeGoal,
+    CanonicalTypeOpNormalizeGoal, CanonicalTypeOpProvePredicateGoal,
 };
 use rustc_middle::ty::error::TypeError;
 use rustc_middle::ty::{
@@ -109,6 +109,14 @@ impl<'tcx, T: Copy + fmt::Display + TypeFoldable<TyCtxt<'tcx>> + 'tcx> ToUnivers
     }
 }
 
+impl<'tcx, T: Copy + fmt::Display + TypeFoldable<TyCtxt<'tcx>> + 'tcx> ToUniverseInfo<'tcx>
+    for CanonicalTypeOpDeeplyNormalizeGoal<'tcx, T>
+{
+    fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
+        UniverseInfo::TypeOp(Rc::new(DeeplyNormalizeQuery { canonical_query: self, base_universe }))
+    }
+}
+
 impl<'tcx> ToUniverseInfo<'tcx> for CanonicalTypeOpAscribeUserTypeGoal<'tcx> {
     fn to_universe_info(self, base_universe: ty::UniverseIndex) -> UniverseInfo<'tcx> {
         UniverseInfo::TypeOp(Rc::new(AscribeUserTypeQuery { canonical_query: self, base_universe }))
@@ -285,6 +293,53 @@ where
     }
 }
 
+struct DeeplyNormalizeQuery<'tcx, T> {
+    canonical_query: CanonicalTypeOpDeeplyNormalizeGoal<'tcx, T>,
+    base_universe: ty::UniverseIndex,
+}
+
+impl<'tcx, T> TypeOpInfo<'tcx> for DeeplyNormalizeQuery<'tcx, T>
+where
+    T: Copy + fmt::Display + TypeFoldable<TyCtxt<'tcx>> + 'tcx,
+{
+    fn fallback_error(&self, tcx: TyCtxt<'tcx>, span: Span) -> Diag<'tcx> {
+        tcx.dcx().create_err(HigherRankedLifetimeError {
+            cause: Some(HigherRankedErrorCause::CouldNotNormalize {
+                value: self.canonical_query.canonical.value.value.value.to_string(),
+            }),
+            span,
+        })
+    }
+
+    fn base_universe(&self) -> ty::UniverseIndex {
+        self.base_universe
+    }
+
+    fn nice_error<'infcx>(
+        &self,
+        mbcx: &mut MirBorrowckCtxt<'_, 'infcx, 'tcx>,
+        cause: ObligationCause<'tcx>,
+        placeholder_region: ty::Region<'tcx>,
+        error_region: Option<ty::Region<'tcx>>,
+    ) -> Option<Diag<'infcx>> {
+        let (infcx, key, _) =
+            mbcx.infcx.tcx.infer_ctxt().build_with_canonical(cause.span, &self.canonical_query);
+        let ocx = ObligationCtxt::new(&infcx);
+
+        let (param_env, value) = key.into_parts();
+        let _ = ocx.deeply_normalize(&cause, param_env, value.value);
+
+        let diag = try_extract_error_from_fulfill_cx(
+            &ocx,
+            mbcx.mir_def_id(),
+            placeholder_region,
+            error_region,
+        )?
+        .with_dcx(mbcx.dcx());
+        Some(diag)
+    }
+}
+
 struct AscribeUserTypeQuery<'tcx> {
     canonical_query: CanonicalTypeOpAscribeUserTypeGoal<'tcx>,
     base_universe: ty::UniverseIndex,

compiler/rustc_borrowck/src/type_check/canonical.rs

@@ -149,6 +149,18 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         self.normalize_with_category(value, location, ConstraintCategory::Boring)
     }
 
+    pub(super) fn deeply_normalize<T>(&mut self, value: T, location: impl NormalizeLocation) -> T
+    where
+        T: type_op::normalize::Normalizable<'tcx> + fmt::Display + Copy + 'tcx,
+    {
+        let result: Result<_, ErrorGuaranteed> = self.fully_perform_op(
+            location.to_locations(),
+            ConstraintCategory::Boring,
+            self.infcx.param_env.and(type_op::normalize::DeeplyNormalize { value }),
+        );
+        result.unwrap_or(value)
+    }
+
     #[instrument(skip(self), level = "debug")]
     pub(super) fn normalize_with_category<T>(
         &mut self,

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -300,9 +300,8 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
         // Add implied bounds from impl header.
         if matches!(tcx.def_kind(defining_ty_def_id), DefKind::AssocFn | DefKind::AssocConst) {
             for &(ty, _) in tcx.assumed_wf_types(tcx.local_parent(defining_ty_def_id)) {
-                let result: Result<_, ErrorGuaranteed> = param_env
-                    .and(DeeplyNormalize { value: ty })
-                    .fully_perform(self.infcx, span);
+                let result: Result<_, ErrorGuaranteed> =
+                    param_env.and(DeeplyNormalize { value: ty }).fully_perform(self.infcx, span);
                 let Ok(TypeOpOutput { output: norm_ty, constraints: c, .. }) = result else {
                     continue;
                 };

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1116,7 +1116,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                     ConstraintCategory::Boring,
                 );
 
-                let sig = self.normalize(unnormalized_sig, term_location);
+                let sig = self.deeply_normalize(unnormalized_sig, term_location);
                 // HACK(#114936): `WF(sig)` does not imply `WF(normalized(sig))`
                 // with built-in `Fn` implementations, since the impl may not be
                 // well-formed itself.