Rollup merge of #70319 - lcnr:issue63695, r=eddyb

correctly normalize constants

closes #70317

implements https://github.com/rust-lang/rust/issues/70125#issuecomment-602133708

r? eddyb cc @varkor

2 files changed, 13 insertions, 2 deletions

diff --git a/src/librustc/ty/query/keys.rs b/src/librustc/ty/query/keys.rs
index 6073d3a545f..6be1f04efca 100644
--- a/src/librustc/ty/query/keys.rs
+++ b/src/librustc/ty/query/keys.rs
@@ -5,7 +5,7 @@ use crate::mir;
 use crate::traits;
 use crate::ty::fast_reject::SimplifiedType;
 use crate::ty::query::caches::DefaultCacheSelector;
-use crate::ty::subst::SubstsRef;
+use crate::ty::subst::{GenericArg, SubstsRef};
 use crate::ty::{self, Ty, TyCtxt};
 use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
 use rustc_span::symbol::Symbol;
@@ -194,6 +194,17 @@ impl<'tcx> Key for ty::PolyTraitRef<'tcx> {
     }
 }
 
+impl<'tcx> Key for GenericArg<'tcx> {
+    type CacheSelector = DefaultCacheSelector;
+
+    fn query_crate(&self) -> CrateNum {
+        LOCAL_CRATE
+    }
+    fn default_span(&self, _: TyCtxt<'_>) -> Span {
+        DUMMY_SP
+    }
+}
+
 impl<'tcx> Key for &'tcx ty::Const<'tcx> {
     type CacheSelector = DefaultCacheSelector;
 
diff --git a/src/librustc/ty/query/mod.rs b/src/librustc/ty/query/mod.rs
index b45b3b3f539..c75e0d95e8f 100644
--- a/src/librustc/ty/query/mod.rs
+++ b/src/librustc/ty/query/mod.rs
@@ -31,7 +31,7 @@ use crate::traits::specialization_graph;
 use crate::traits::Clauses;
 use crate::traits::{self, Vtable};
 use crate::ty::steal::Steal;
-use crate::ty::subst::SubstsRef;
+use crate::ty::subst::{GenericArg, SubstsRef};
 use crate::ty::util::AlwaysRequiresDrop;
 use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, TyCtxt};
 use crate::util::common::ErrorReported;