Uplift OpaqueTypeKey too, use it in response

compiler/rustc_middle/src/ty/mod.rs

@@ -94,6 +94,7 @@ pub use self::context::{
 };
 pub use self::instance::{Instance, InstanceDef, ReifyReason, ShortInstance, UnusedGenericParams};
 pub use self::list::{List, ListWithCachedTypeInfo};
+pub use self::opaque_types::OpaqueTypeKey;
 pub use self::parameterized::ParameterizedOverTcx;
 pub use self::pattern::{Pattern, PatternKind};
 pub use self::predicate::{
@@ -758,45 +759,6 @@ impl<'a, 'tcx> IntoIterator for &'a InstantiatedPredicates<'tcx> {
     }
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
-#[derive(TypeFoldable, TypeVisitable)]
-pub struct OpaqueTypeKey<'tcx> {
-    pub def_id: LocalDefId,
-    pub args: GenericArgsRef<'tcx>,
-}
-
-impl<'tcx> OpaqueTypeKey<'tcx> {
-    pub fn iter_captured_args(
-        self,
-        tcx: TyCtxt<'tcx>,
-    ) -> impl Iterator<Item = (usize, GenericArg<'tcx>)> {
-        std::iter::zip(self.args, tcx.variances_of(self.def_id)).enumerate().filter_map(
-            |(i, (arg, v))| match (arg.unpack(), v) {
-                (_, ty::Invariant) => Some((i, arg)),
-                (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => None,
-                _ => bug!("unexpected opaque type arg variance"),
-            },
-        )
-    }
-
-    pub fn fold_captured_lifetime_args(
-        self,
-        tcx: TyCtxt<'tcx>,
-        mut f: impl FnMut(Region<'tcx>) -> Region<'tcx>,
-    ) -> Self {
-        let Self { def_id, args } = self;
-        let args = std::iter::zip(args, tcx.variances_of(def_id)).map(|(arg, v)| {
-            match (arg.unpack(), v) {
-                (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => arg,
-                (ty::GenericArgKind::Lifetime(lt), _) => f(lt).into(),
-                _ => arg,
-            }
-        });
-        let args = tcx.mk_args_from_iter(args);
-        Self { def_id, args }
-    }
-}
-
 #[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)]
 pub struct OpaqueHiddenType<'tcx> {
     /// The span of this particular definition of the opaque type. So

compiler/rustc_middle/src/ty/opaque_types.rs

@@ -7,6 +7,8 @@ use rustc_span::def_id::DefId;
 use rustc_span::Span;
 use tracing::{debug, instrument, trace};
 
+pub type OpaqueTypeKey<'tcx> = rustc_type_ir::OpaqueTypeKey<TyCtxt<'tcx>>;
+
 /// Converts generic params of a TypeFoldable from one
 /// item's generics to another. Usually from a function's generics
 /// list to the opaque type's own generics.

compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs

@@ -14,7 +14,6 @@ use crate::solve::{
     inspect, response_no_constraints_raw, CanonicalResponse, QueryResult, Response,
 };
 use rustc_data_structures::fx::FxHashSet;
-use rustc_hir::def_id::LocalDefId;
 use rustc_index::IndexVec;
 use rustc_infer::infer::canonical::query_response::make_query_region_constraints;
 use rustc_infer::infer::canonical::{CanonicalExt, QueryRegionConstraints};
@@ -224,7 +223,6 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
                 .filter(|(a, _)| {
                     self.predefined_opaques_in_body.opaque_types.iter().all(|(pa, _)| pa != a)
                 })
-                .map(|(key, value)| (key.def_id, key.args, value))
                 .collect(),
             normalization_nested_goals,
         }
@@ -393,14 +391,10 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
         }
     }
 
-    fn register_new_opaque_types(
-        &mut self,
-        opaque_types: &[(LocalDefId, ty::GenericArgsRef<'tcx>, Ty<'tcx>)],
-    ) {
-        for &(def_id, args, ty) in opaque_types {
+    fn register_new_opaque_types(&mut self, opaque_types: &[(ty::OpaqueTypeKey<'tcx>, Ty<'tcx>)]) {
+        for &(key, ty) in opaque_types {
             let hidden_ty = ty::OpaqueHiddenType { ty, span: DUMMY_SP };
-            self.infcx
-                .inject_new_hidden_type_unchecked(ty::OpaqueTypeKey { def_id, args }, hidden_ty);
+            self.infcx.inject_new_hidden_type_unchecked(key, hidden_ty);
         }
     }
 }

compiler/rustc_type_ir/src/interner.rs

@@ -29,7 +29,7 @@ pub trait Interner:
     + IrPrint<ty::FnSig<Self>>
 {
     type DefId: Copy + Debug + Hash + Eq + TypeFoldable<Self>;
-    type LocalDefId: Copy + Debug + Hash + Eq + TypeFoldable<Self>;
+    type LocalDefId: Copy + Debug + Hash + Eq + Into<Self::DefId> + TypeFoldable<Self>;
     type AdtDef: AdtDef<Self>;
 
     type GenericArgs: GenericArgs<Self>;
@@ -104,7 +104,11 @@ pub trait Interner:
     type GenericsOf: GenericsOf<Self>;
     fn generics_of(self, def_id: Self::DefId) -> Self::GenericsOf;
 
-    type VariancesOf: Copy + Debug + Deref<Target = [ty::Variance]>;
+    type VariancesOf: Copy
+        + Debug
+        + Deref<Target = [ty::Variance]>
+        // FIXME: This is terrible!
+        + IntoIterator<Item: Deref<Target = ty::Variance>>;
     fn variances_of(self, def_id: Self::DefId) -> Self::VariancesOf;
 
     // FIXME: Remove after uplifting `EarlyBinder`

compiler/rustc_type_ir/src/lib.rs

@@ -47,6 +47,7 @@ mod flags;
 mod generic_arg;
 mod infcx;
 mod interner;
+mod opaque_ty;
 mod predicate;
 mod predicate_kind;
 mod region_kind;
@@ -63,6 +64,7 @@ pub use flags::*;
 pub use generic_arg::*;
 pub use infcx::InferCtxtLike;
 pub use interner::*;
+pub use opaque_ty::*;
 pub use predicate::*;
 pub use predicate_kind::*;
 pub use region_kind::*;

compiler/rustc_type_ir/src/opaque_ty.rs

@@ -0,0 +1,51 @@
+use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
+use rustc_type_ir_macros::{TypeFoldable_Generic, TypeVisitable_Generic};
+
+use crate::inherent::*;
+use crate::{self as ty, Interner};
+
+#[derive(derivative::Derivative)]
+#[derivative(
+    Clone(bound = ""),
+    Hash(bound = ""),
+    PartialEq(bound = ""),
+    Eq(bound = ""),
+    Debug(bound = ""),
+    Copy(bound = "")
+)]
+#[derive(TypeVisitable_Generic, TypeFoldable_Generic)]
+#[cfg_attr(feature = "nightly", derive(TyEncodable, TyDecodable, HashStable_NoContext))]
+pub struct OpaqueTypeKey<I: Interner> {
+    pub def_id: I::LocalDefId,
+    pub args: I::GenericArgs,
+}
+
+impl<I: Interner> OpaqueTypeKey<I> {
+    pub fn iter_captured_args(self, tcx: I) -> impl Iterator<Item = (usize, I::GenericArg)> {
+        let variances = tcx.variances_of(self.def_id.into());
+        std::iter::zip(self.args, variances.into_iter()).enumerate().filter_map(|(i, (arg, v))| {
+            match (arg.kind(), *v) {
+                (_, ty::Invariant) => Some((i, arg)),
+                (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => None,
+                _ => panic!("unexpected opaque type arg variance"),
+            }
+        })
+    }
+
+    pub fn fold_captured_lifetime_args(
+        self,
+        tcx: I,
+        mut f: impl FnMut(I::Region) -> I::Region,
+    ) -> Self {
+        let Self { def_id, args } = self;
+        let variances = tcx.variances_of(def_id.into());
+        let args =
+            std::iter::zip(args, variances.into_iter()).map(|(arg, v)| match (arg.kind(), *v) {
+                (ty::GenericArgKind::Lifetime(_), ty::Bivariant) => arg,
+                (ty::GenericArgKind::Lifetime(lt), _) => f(lt).into(),
+                _ => arg,
+            });
+        let args = tcx.mk_args_from_iter(args);
+        Self { def_id, args }
+    }
+}

compiler/rustc_type_ir/src/solve.rs

@@ -268,7 +268,7 @@ pub struct Response<I: Interner> {
 #[cfg_attr(feature = "nightly", derive(HashStable_NoContext))]
 pub struct ExternalConstraintsData<I: Interner> {
     pub region_constraints: Vec<ty::OutlivesPredicate<I, I::GenericArg>>,
-    pub opaque_types: Vec<(I::LocalDefId, I::GenericArgs, I::Ty)>,
+    pub opaque_types: Vec<(ty::OpaqueTypeKey<I>, I::Ty)>,
     pub normalization_nested_goals: NestedNormalizationGoals<I>,
 }