use deeply_normalize for assumed_wf_types

compiler/rustc_trait_selection/src/traits/engine.rs

@@ -4,6 +4,7 @@ use std::fmt::Debug;
 use super::TraitEngine;
 use super::{ChalkFulfillmentContext, FulfillmentContext};
 use crate::solve::FulfillmentCtxt as NextFulfillmentCtxt;
+use crate::traits::error_reporting::TypeErrCtxtExt;
 use crate::traits::NormalizeExt;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::ErrorGuaranteed;
@@ -24,7 +25,6 @@ use rustc_middle::ty::ToPredicate;
 use rustc_middle::ty::TypeFoldable;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_session::config::TraitSolver;
-use rustc_span::Span;
 
 pub trait TraitEngineExt<'tcx> {
     fn new(infcx: &InferCtxt<'tcx>) -> Box<Self>;
@@ -198,17 +198,24 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         }
     }
 
+    pub fn assumed_wf_types_and_report_errors(
+        &self,
+        param_env: ty::ParamEnv<'tcx>,
+        def_id: LocalDefId,
+    ) -> Result<FxIndexSet<Ty<'tcx>>, ErrorGuaranteed> {
+        self.assumed_wf_types(param_env, def_id)
+            .map_err(|errors| self.infcx.err_ctxt().report_fulfillment_errors(&errors))
+    }
+
     pub fn assumed_wf_types(
         &self,
         param_env: ty::ParamEnv<'tcx>,
-        span: Span,
         def_id: LocalDefId,
-    ) -> FxIndexSet<Ty<'tcx>> {
+    ) -> Result<FxIndexSet<Ty<'tcx>>, Vec<FulfillmentError<'tcx>>> {
         let tcx = self.infcx.tcx;
-        let assumed_wf_types = tcx.assumed_wf_types(def_id);
         let mut implied_bounds = FxIndexSet::default();
-        let cause = ObligationCause::misc(span, def_id);
-        for ty in assumed_wf_types {
+        let mut errors = Vec::new();
+        for &(ty, span) in tcx.assumed_wf_types(def_id) {
             // FIXME(@lcnr): rustc currently does not check wf for types
             // pre-normalization, meaning that implied bounds are sometimes
             // incorrect. See #100910 for more details.
@@ -221,10 +228,15 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
             // sound and then uncomment this line again.
 
             // implied_bounds.insert(ty);
-            let normalized = self.normalize(&cause, param_env, ty);
-            implied_bounds.insert(normalized);
+            let cause = ObligationCause::misc(span, def_id);
+            match self.infcx.at(&cause, param_env).deeply_normalize(ty) {
+                // Insert well-formed types, ignoring duplicates.
+                Ok(normalized) => drop(implied_bounds.insert(normalized)),
+                Err(normalization_errors) => errors.extend(normalization_errors),
+            };
         }
-        implied_bounds
+
+        if errors.is_empty() { Ok(implied_bounds) } else { Err(errors) }
     }
 
     pub fn make_canonicalized_query_response<T>(