Deeply normalize when processing registered region obligations

7 files changed, 43 insertions, 1 deletions

diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
index 995ed1e3b57..5ec45212bc7 100644
--- a/compiler/rustc_trait_selection/src/lib.rs
+++ b/compiler/rustc_trait_selection/src/lib.rs
@@ -39,6 +39,7 @@ extern crate smallvec;
 
 pub mod errors;
 pub mod infer;
+pub mod regions;
 pub mod solve;
 pub mod traits;
 
diff --git a/compiler/rustc_trait_selection/src/regions.rs b/compiler/rustc_trait_selection/src/regions.rs
new file mode 100644
index 00000000000..3c53da32d0a
--- /dev/null
+++ b/compiler/rustc_trait_selection/src/regions.rs
@@ -0,0 +1,37 @@
+use rustc_infer::infer::outlives::env::OutlivesEnvironment;
+use rustc_infer::infer::{InferCtxt, RegionResolutionError};
+use rustc_middle::traits::ObligationCause;
+
+pub trait InferCtxtRegionExt<'tcx> {
+    /// Resolve regions, using the deep normalizer to normalize any type-outlives
+    /// obligations in the process. This is in `rustc_trait_selection` because
+    /// we need to normalize.
+    ///
+    /// Prefer this method over `resolve_regions_with_normalize`, unless you are
+    /// doing something specific for normalization.
+    fn resolve_regions(
+        &self,
+        outlives_env: &OutlivesEnvironment<'tcx>,
+    ) -> Vec<RegionResolutionError<'tcx>>;
+}
+
+impl<'tcx> InferCtxtRegionExt<'tcx> for InferCtxt<'tcx> {
+    fn resolve_regions(
+        &self,
+        outlives_env: &OutlivesEnvironment<'tcx>,
+    ) -> Vec<RegionResolutionError<'tcx>> {
+        self.resolve_regions(outlives_env, |ty| {
+            let ty = self.resolve_vars_if_possible(ty);
+
+            if self.next_trait_solver() {
+                crate::solve::deeply_normalize(
+                    self.at(&ObligationCause::dummy(), outlives_env.param_env),
+                    ty,
+                )
+                .map_err(|_| ty)
+            } else {
+                Ok(ty)
+            }
+        })
+    }
+}
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index c4344758574..87b68a8bd2d 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -179,7 +179,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
         }
 
         let outlives_env = OutlivesEnvironment::new(full_env);
-        infcx.process_registered_region_obligations(&outlives_env);
+        let _ = infcx.process_registered_region_obligations::<!>(&outlives_env, |ty| Ok(ty));
 
         let region_data =
             infcx.inner.borrow_mut().unwrap_region_constraints().region_constraint_data().clone();
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index ecbb92ca5b9..c49185a52c7 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -6,6 +6,7 @@
 
 use crate::infer::outlives::env::OutlivesEnvironment;
 use crate::infer::InferOk;
+use crate::regions::InferCtxtRegionExt;
 use crate::solve::inspect::{InspectGoal, ProofTreeInferCtxtExt, ProofTreeVisitor};
 use crate::solve::{deeply_normalize_for_diagnostics, inspect};
 use crate::traits::engine::TraitEngineExt;
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 013a50f9fa1..caf950037fd 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -3,6 +3,7 @@ use std::fmt::Debug;
 
 use super::FulfillmentContext;
 use super::TraitEngine;
+use crate::regions::InferCtxtRegionExt;
 use crate::solve::FulfillmentCtxt as NextFulfillmentCtxt;
 use crate::traits::error_reporting::TypeErrCtxtExt;
 use crate::traits::NormalizeExt;
diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs
index 0cd376fcbbd..93f9c2333f0 100644
--- a/compiler/rustc_trait_selection/src/traits/misc.rs
+++ b/compiler/rustc_trait_selection/src/traits/misc.rs
@@ -1,5 +1,6 @@
 //! Miscellaneous type-system utilities that are too small to deserve their own modules.
 
+use crate::regions::InferCtxtRegionExt;
 use crate::traits::{self, ObligationCause, ObligationCtxt};
 
 use hir::LangItem;
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 080ad7bd549..a7f6021d57a 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -25,6 +25,7 @@ pub mod wf;
 
 use crate::infer::outlives::env::OutlivesEnvironment;
 use crate::infer::{InferCtxt, TyCtxtInferExt};
+use crate::regions::InferCtxtRegionExt;
 use crate::traits::error_reporting::TypeErrCtxtExt as _;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_errors::ErrorGuaranteed;