Recover when failing to normalize closure signature.

[rust.git] / compiler / rustc_middle / src / ty / instance.rs

diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index e8dd179eac19831c92d0bb09296bb1d8852e525f..0e10fe25c10cb3c5de5e7a9626a7ca138a786672 100644 (file)
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -496,12 +496,12 @@ pub fn resolve_closure(
         def_id: DefId,
         substs: ty::SubstsRef<'tcx>,
         requested_kind: ty::ClosureKind,
-    ) -> Instance<'tcx> {
+    ) -> Option<Instance<'tcx>> {
         let actual_kind = substs.as_closure().kind();
 
         match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
             Ok(true) => Instance::fn_once_adapter_instance(tcx, def_id, substs),
-            _ => Instance::new(def_id, substs),
+            _ => Some(Instance::new(def_id, substs)),
         }
     }
 
@@ -515,7 +515,7 @@ pub fn fn_once_adapter_instance(
         tcx: TyCtxt<'tcx>,
         closure_did: DefId,
         substs: ty::SubstsRef<'tcx>,
-    ) -> Instance<'tcx> {
+    ) -> Option<Instance<'tcx>> {
         debug!("fn_once_adapter_shim({:?}, {:?})", closure_did, substs);
         let fn_once = tcx.require_lang_item(LangItem::FnOnce, None);
         let call_once = tcx
@@ -531,12 +531,13 @@ pub fn fn_once_adapter_instance(
         let self_ty = tcx.mk_closure(closure_did, substs);
 
         let sig = substs.as_closure().sig();
-        let sig = tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), sig);
+        let sig =
+            tcx.try_normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), sig).ok()?;
         assert_eq!(sig.inputs().len(), 1);
         let substs = tcx.mk_substs_trait(self_ty, &[sig.inputs()[0].into()]);
 
         debug!("fn_once_adapter_shim: self_ty={:?} sig={:?}", self_ty, sig);
-        Instance { def, substs }
+        Some(Instance { def, substs })
     }
 
     /// Depending on the kind of `InstanceDef`, the MIR body associated with an