test/IRGen/partial_apply_forwarder.sil

// RUN: %target-swift-frontend -primary-file %s -emit-ir | %FileCheck %s -DINT=i%target-ptrsize
sil_stage canonical

import Builtin

public protocol P {}
public class C : P {}
public class D<T : P> {}
class E {}

public protocol Observable {
  associatedtype Result
  func subscribe<T: Observer>(o: T) -> ()
}

public protocol Observer {
  associatedtype Result
}

sil hidden @witness_method : $@convention(thin) <S where S : Observable><O where O : Observer, S.Result == O.Result> (@in S) -> @owned @callee_owned (@in O) -> () {
bb0(%0 : $*S):
  %1 = witness_method $S, #Observable.subscribe!1 : $@convention(witness_method: Observable) <τ_0_0 where τ_0_0 : Observable><τ_1_0 where τ_1_0 : Observer, τ_0_0.Result == τ_1_0.Result> (@in τ_1_0, @in_guaranteed τ_0_0) -> ()
  %2 = partial_apply %1<S, O>(%0) : $@convention(witness_method: Observable) <τ_0_0 where τ_0_0 : Observable><τ_1_0 where τ_1_0 : Observer, τ_0_0.Result == τ_1_0.Result> (@in τ_1_0, @in_guaranteed τ_0_0) -> ()
  return %2 : $@callee_owned (@in O) -> ()
}

// CHECK-LABEL: define internal swiftcc %T23partial_apply_forwarder1DCyAA1CCG* @"$s23unspecialized_uncurriedTA"(%swift.refcounted*
// CHECK: [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder1CCMa"([[INT]] 0)
// CHECK: [[TYPE:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK: [[CAST:%.*]] = bitcast %swift.refcounted* %0 to %T23partial_apply_forwarder1EC*
// CHECK: [[CALL:%.*]] = call swiftcc %T23partial_apply_forwarder1DC* @unspecialized_uncurried(%swift.type* [[TYPE]], i8** getelementptr inbounds ([1 x i8*], [1 x i8*]* @"$s23partial_apply_forwarder1CCAA1PAAWP", i32 0, i32 0), %T23partial_apply_forwarder1EC* swiftself [[CAST]])

sil hidden @specialized_curried : $@convention(thin) (@owned E) -> @owned @callee_owned () -> @owned D<C> {
bb0(%0 : $E):
  %1 = function_ref @unspecialized_uncurried : $@convention(method) <τ_0_0 where τ_0_0 : P> (@guaranteed E) -> @owned D<τ_0_0>
  %2 = partial_apply %1<C>(%0) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@guaranteed E) -> @owned D<τ_0_0>
  return %2 : $@callee_owned () -> @owned D<C>
}

sil hidden_external @unspecialized_uncurried : $@convention(method) <τ_0_0 where τ_0_0 : P> (@guaranteed E) -> @owned D<τ_0_0>


// CHECK-LABEL: define internal swiftcc void @"$s7takingPTA"(%swift.refcounted*
// CHECK: [[CONTEXT:%.*]] = alloca %swift.refcounted*
// CHECK: [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder1CCMa"([[INT]] 0)
// CHECK: [[TYPE:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK: store %swift.refcounted* %0, %swift.refcounted** [[CONTEXT]]
// CHECK: [[CAST:%.*]] = bitcast %swift.refcounted** [[CONTEXT]] to %swift.opaque*
// CHECK:  call swiftcc void @takingP(%swift.type* [[TYPE]], i8**{{.*}}$s23partial_apply_forwarder1CCAA1PAAWP{{.*}}, %swift.opaque* {{.*}} swiftself [[CAST]]
// CHECK:  ret
sil hidden_external @takingP : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> ()

sil hidden @reabstract_context : $@convention(thin) (@owned C) -> () {
bb0(%0 : $C):
  %6 = alloc_stack $C
  store %0 to %6 : $*C
  %8 = function_ref @takingP : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> ()
  %9 = partial_apply %8<C>(%6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> ()
  dealloc_stack %6 : $*C
  strong_release %9 : $@callee_owned() -> ()
  %10 = tuple ()
  return %10 : $()
}

public protocol Q {
  associatedtype Update
}

public struct BaseProducer<T> : Q {
  public typealias Update = T
}

public class WeakBox<T> {}

public struct EmptyType {}

sil hidden_external @takingQ : $@convention(thin) <τ_0_0 where  τ_0_0 : Q> (@owned WeakBox<τ_0_0>) -> ()
sil hidden_external @takingQAndEmpty : $@convention(thin) <τ_0_0 where  τ_0_0 : Q> (@owned WeakBox<τ_0_0>, EmptyType) -> ()
sil hidden_external @takingEmptyAndQ : $@convention(thin) <τ_0_0 where  τ_0_0 : Q> (EmptyType, @owned WeakBox<τ_0_0>) -> ()

// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc { i8*, %swift.refcounted* } @bind_polymorphic_param_from_context(%swift.opaque* noalias nocapture, %swift.type* %"\CF\84_0_1")
// CHECK: entry:
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder12BaseProducerVMa"([[INT]] 255, %swift.type* %"\CF\84_0_1")
// CHECK:   [[BPTYPE:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder7WeakBoxCMa"([[INT]] 0, %swift.type* [[BPTYPE]])
// CHECK:   [[WEAKBOXTYPE:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   [[OBJ:%.*]] = call noalias %swift.refcounted* @swift_allocObject(%swift.type* [[WEAKBOXTYPE]]
// CHECK:   [[WB:%.*]] = bitcast %swift.refcounted* [[OBJ]] to %T23partial_apply_forwarder7WeakBoxC*
// CHECK:   [[REF:%.*]] = bitcast %T23partial_apply_forwarder7WeakBoxC* [[WB]] to %swift.refcounted*
// CHECK:   [[CLOSURE:%.*]] = insertvalue { i8*, %swift.refcounted* } { i8* bitcast (void (%swift.refcounted*)* @"$s7takingQTA" to i8*), %swift.refcounted* undef }, %swift.refcounted* [[REF]], 1
// CHECK:   ret { i8*, %swift.refcounted* } [[CLOSURE]]

// CHECK-LABEL: define internal swiftcc void @"$s7takingQTA"(%swift.refcounted* swiftself)
// CHECK: entry:
// CHECK:   [[WB:%.*]] = bitcast %swift.refcounted* %0 to %T23partial_apply_forwarder7WeakBoxC*
// CHECK:   [[TYADDR:%.*]] = getelementptr inbounds %T23partial_apply_forwarder7WeakBoxC, %T23partial_apply_forwarder7WeakBoxC* %1, i32 0, i32 0, i32 0
// CHECK:   [[TY:%.*]] = load %swift.type*, %swift.type** [[TYADDR]]
// CHECK:   [[GENPARAMSADDR:%.*]] = bitcast %swift.type* [[TY]] to %swift.type**
// CHECK:   [[PARAMTYADDR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[GENPARAMSADDR]], {{(i64 10|i32 13)}}
// CHECK:   %"BaseProducer<\CF\84_0_1>" = load %swift.type*, %swift.type** [[PARAMTYADDR]]
// CHECK:   [[WITNESS:%.*]] = call i8** @swift_getWitnessTable(
// CHECK:   [[OBJ:%.*]] = bitcast %swift.refcounted* %0 to %T23partial_apply_forwarder7WeakBoxC.1*
// CHECK:   tail call swiftcc void @takingQ(%T23partial_apply_forwarder7WeakBoxC.1* [[OBJ]], i8** [[WITNESS]])
// CHECK: }

sil public @bind_polymorphic_param_from_context : $@convention(thin) <τ_0_1>(@in τ_0_1) -> @owned @callee_owned () -> () {
bb0(%0 : $*τ_0_1):
  %1 = alloc_ref $WeakBox<BaseProducer<τ_0_1>>
  %8 = function_ref @takingQ : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>) -> ()
  %9 = partial_apply %8<BaseProducer<τ_0_1>>(%1) : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>) -> ()
  return %9 : $@callee_owned () -> ()
}

// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc { i8*, %swift.refcounted* } @bind_polymorphic_param_from_context_2(%swift.opaque* noalias nocapture, %swift.type* %"\CF\84_0_1")
// CHECK:   [[OBJ:%.*]] = call {{.*}} @swift_allocObject
// CHECK:   [[WB:%.*]] = bitcast %swift.refcounted* [[OBJ]]
// CHECK:   [[REF:%.*]] = bitcast {{.*}}* [[WB]] to %swift.refcounted*
// CHECK:   [[CLOSURE:%.*]] = insertvalue { i8*, %swift.refcounted* } { i8* bitcast (void (%swift.refcounted*)* @"$s15takingQAndEmptyTA" to i8*), %swift.refcounted* undef }, %swift.refcounted* [[REF]], 1
// CHECK: }
sil public @bind_polymorphic_param_from_context_2 : $@convention(thin) <τ_0_1>(@in τ_0_1, EmptyType) -> @owned @callee_owned () -> () {
bb0(%0 : $*τ_0_1, %2: $EmptyType):
  %1 = alloc_ref $WeakBox<BaseProducer<τ_0_1>>
  %8 = function_ref @takingQAndEmpty : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>, EmptyType) -> ()
  %9 = partial_apply %8<BaseProducer<τ_0_1>>(%1, %2) : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>, EmptyType) -> ()
  return %9 : $@callee_owned () -> ()
}

// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc { i8*, %swift.refcounted* } @bind_polymorphic_param_from_context_3(%swift.opaque* noalias nocapture, %swift.type* %"\CF\84_0_1")
// CHECK:   [[OBJ:%.*]] = call {{.*}} @swift_allocObject
// CHECK:   [[WB:%.*]] = bitcast %swift.refcounted* [[OBJ]]
// CHECK:   [[REF:%.*]] = bitcast {{.*}}* [[WB]] to %swift.refcounted*
// CHECK:   [[CLOSURE:%.*]] = insertvalue { i8*, %swift.refcounted* } { i8* bitcast (void (%swift.refcounted*)* @"$s15takingEmptyAndQTA" to i8*), %swift.refcounted* undef }, %swift.refcounted* [[REF]], 1
// CHECK: }

sil public @bind_polymorphic_param_from_context_3 : $@convention(thin) <τ_0_1>(@in τ_0_1, EmptyType) -> @owned @callee_owned () -> () {
bb0(%0 : $*τ_0_1, %2: $EmptyType):
  %1 = alloc_ref $WeakBox<BaseProducer<τ_0_1>>
  %8 = function_ref @takingEmptyAndQ : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (EmptyType, @owned WeakBox<τ_0_0>) -> ()
  %9 = partial_apply %8<BaseProducer<τ_0_1>>(%2, %1) : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (EmptyType, @owned WeakBox<τ_0_0>) -> ()
  return %9 : $@callee_owned () -> ()
}

// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc void @bind_polymorphic_param_from_forwarder_parameter(%swift.opaque* noalias nocapture, %swift.type* %"\CF\84_0_1")
// CHECK: entry:
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder12BaseProducerVMa"([[INT]] 255, %swift.type* %"\CF\84_0_1")
// CHECK:   [[BPTY:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder7WeakBoxCMa"([[INT]] 0, %swift.type* [[BPTY]]
// CHECK:   [[WBTY:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   call noalias %swift.refcounted* @swift_allocObject(%swift.type* [[WBTY]]
// CHECK:   ret void

// CHECK-LABEL: define internal swiftcc void @"$s7takingQTA.1"(%T23partial_apply_forwarder7WeakBoxC*, %swift.refcounted* swiftself)
// CHECK: entry:
// CHECK:   [[TYADDR:%.*]] = getelementptr inbounds %T23partial_apply_forwarder7WeakBoxC, %T23partial_apply_forwarder7WeakBoxC* %0
// CHECK:   [[TY:%.*]] = load %swift.type*, %swift.type** [[TYADDR]]
// CHECK:   [[CAST:%.*]] = bitcast %T23partial_apply_forwarder7WeakBoxC* %0 to %T23partial_apply_forwarder7WeakBoxC.1*
// CHECK:   [[TYPARAMSADDR:%.*]] = bitcast %swift.type* [[TY]] to %swift.type**
// CHECK:   [[TYPARAM:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[TYPARAMSADDR]], {{(i64 10|i32 13)}}
// CHECK:   %"BaseProducer<\CF\84_0_1>" = load %swift.type*, %swift.type** [[TYPARAM]]
// CHECK:   [[WITNESS:%.*]] = call i8** @swift_getWitnessTable
// CHECK:   tail call swiftcc void @takingQ(%T23partial_apply_forwarder7WeakBoxC.1* [[CAST]], i8** [[WITNESS]])
// CHECK:   ret void

sil public @bind_polymorphic_param_from_forwarder_parameter : $@convention(thin) <τ_0_1>(@in τ_0_1) -> () {
bb0(%0 : $*τ_0_1):
  %1 = alloc_ref $WeakBox<BaseProducer<τ_0_1>>
  %8 = function_ref @takingQ : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>) -> ()
  %9 = partial_apply %8<BaseProducer<τ_0_1>>() : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (@owned WeakBox<τ_0_0>) -> ()
  %10 = tuple ()
  return %10 : $()
}

struct S {
  var x : Builtin.Int64
}

sil hidden_external @takingQAndS : $@convention(thin) <τ_0_0 where  τ_0_0 : Q> (S, @owned WeakBox<τ_0_0>) -> ()

// CHECK-LABEL: define{{( dllexport)?}}{{( protected)?}} swiftcc { i8*, %swift.refcounted* } @bind_polymorphic_param_from_context_with_layout(%swift.opaque* noalias nocapture, i64, %swift.type* %"\CF\84_0_1")
// CHECK: entry:
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder12BaseProducerVMa"([[INT]] 255, %swift.type* %"\CF\84_0_1")
// CHECK:   [[BPTY:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   [[TMP:%.*]] = call swiftcc %swift.metadata_response @"$s23partial_apply_forwarder7WeakBoxCMa"([[INT]] 0, %swift.type* [[BPTY]]
// CHECK:   [[WBTY:%.*]] = extractvalue %swift.metadata_response [[TMP]], 0
// CHECK:   [[WBREF:%.*]] = call noalias %swift.refcounted* @swift_allocObject(%swift.type* [[WBTY]]
// CHECK:   [[WB:%.*]] = bitcast %swift.refcounted* [[WBREF]] to %T23partial_apply_forwarder7WeakBoxC*
// CHECK:   [[CONTEXT0:%.*]] = call noalias %swift.refcounted* @swift_allocObject
// CHECK:   [[CONTEXT:%.*]] = bitcast %swift.refcounted* [[CONTEXT0]] to <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>*
// CHECK:   [[SADDR:%.*]] = getelementptr inbounds <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>, <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>* [[CONTEXT]], i32 0, i32 {{(1|2)}}
// CHECK:   [[XADDR:%.*]] = getelementptr inbounds %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder1SV* [[SADDR]], i32 0, i32 0
// CHECK:   store i64 %1, i64* [[XADDR]]
// CHECK:   [[WBADDR:%.*]] = getelementptr inbounds <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>, <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>* [[CONTEXT]], i32 0, i32 {{(2|3)}}
// CHECK:   store %T23partial_apply_forwarder7WeakBoxC* [[WB]], %T23partial_apply_forwarder7WeakBoxC** [[WBADDR]]
// CHECK:   [[CLOSURE:%.*]] = insertvalue { i8*, %swift.refcounted* } { i8* bitcast (void (%swift.refcounted*)* @"$s11takingQAndSTA" to i8*), %swift.refcounted* undef }, %swift.refcounted* [[CONTEXT0]], 1
// CHECK:   ret { i8*, %swift.refcounted* } [[CLOSURE]]

// CHECK-LABEL: define internal swiftcc void @"$s11takingQAndSTA"(%swift.refcounted* swiftself)
// CHECK: entry:
// CHECK:   [[CONTEXT:%.*]] = bitcast %swift.refcounted* %0 to <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>*
// CHECK:   [[SADDR:%.*]] = getelementptr inbounds <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>, <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>* [[CONTEXT]], i32 0, i32 {{(1|2)}}
// CHECK:   [[XADDR:%.*]] = getelementptr inbounds %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder1SV* [[SADDR]], i32 0, i32 0
// CHECK:   [[X:%.*]] = load i64, i64* [[XADDR]]
// CHECK:   [[WBADDR:%.*]] = getelementptr inbounds <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>, <{ %swift.refcounted,{{.*}} %T23partial_apply_forwarder1SV, %T23partial_apply_forwarder7WeakBoxC* }>* [[CONTEXT]], i32 0, i32 {{(2|3)}}
// CHECK:   [[WB:%.*]] = load %T23partial_apply_forwarder7WeakBoxC*, %T23partial_apply_forwarder7WeakBoxC** [[WBADDR]]
// CHECK:   [[WBREF:%.*]] = bitcast %T23partial_apply_forwarder7WeakBoxC* [[WB]] to %swift.refcounted*
// CHECK:   call %swift.refcounted* @swift_retain(%swift.refcounted* returned [[WBREF]])
// CHECK:   [[TYADDR:%.*]] = getelementptr inbounds %T23partial_apply_forwarder7WeakBoxC, %T23partial_apply_forwarder7WeakBoxC* [[WB]], i32 0, i32 0, i32 0
// CHECK:   [[TY:%.*]] = load %swift.type*, %swift.type** [[TYADDR]] 
// CHECK:   %.asUnsubstituted = bitcast %T23partial_apply_forwarder7WeakBoxC* [[WB]] to %T23partial_apply_forwarder7WeakBoxC.1*
// CHECK:   call void @swift_release(%swift.refcounted* %0)
// CHECK:   [[GENPARAMSADDR:%.*]] = bitcast %swift.type* [[TY]] to %swift.type**
// CHECK:   [[GENPARAMADDR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[GENPARAMSADDR]], {{(i64 10|i32 13)}}
// CHECK:   %"BaseProducer<\CF\84_0_1>" = load %swift.type*, %swift.type** [[GENPARAMADDR]]
// CHECK:   [[WITNESS:%.*]] = call i8** @swift_getWitnessTable
// CHECK:   tail call swiftcc void @takingQAndS(i64 [[X]], %T23partial_apply_forwarder7WeakBoxC.1* %.asUnsubstituted, i8** [[WITNESS]])

sil public @bind_polymorphic_param_from_context_with_layout : $@convention(thin) <τ_0_1>(@in τ_0_1, S) -> @owned @callee_owned () -> () {
bb0(%0 : $*τ_0_1, %1: $S):
  %2 = alloc_ref $WeakBox<BaseProducer<τ_0_1>>
  %8 = function_ref @takingQAndS : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (S, @owned WeakBox<τ_0_0>) -> ()
  %9 = partial_apply %8<BaseProducer<τ_0_1>>(%1, %2) : $@convention(thin) <τ_0_0 where τ_0_0 : Q> (S, @owned WeakBox<τ_0_0>) -> ()
  return %9 : $@callee_owned () -> ()
}

public class Empty<T> {}

sil private @inner_closure : $@convention(thin) <T> (Empty<T>) -> @owned Empty<T> {
bb0(%0 : $Empty<T>):
  return %0 : $Empty<T>
}

sil hidden @returns_closure : $@convention(thin) <T> (Empty<T>) -> (@owned Empty<T>, @callee_guaranteed @owned (Empty<T>) -> @owned Empty<T>) {
bb0(%0 : $Empty<T>):
  %1 = function_ref @inner_closure : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> @owned Empty<τ_0_0>
  %2 = partial_apply [callee_guaranteed] %1<T>() : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> @owned Empty<τ_0_0>
  %5 = tuple (%0 : $Empty<T>, %2 : $@callee_guaranteed (Empty<T>) -> @owned Empty<T>)
  return %5 : $(Empty<T>, @callee_guaranteed (Empty<T>) -> @owned Empty<T>)
}

sil hidden @specializes_closure_returning_closure : $@convention(thin) () -> @callee_guaranteed (Empty<S>) -> (@owned Empty<S>, @owned @callee_guaranteed (Empty<S>) -> @owned Empty<S>) {
bb0:
  %0 = function_ref @returns_closure : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> (@owned Empty<τ_0_0>, @owned @callee_guaranteed (Empty<τ_0_0>) -> @owned Empty<τ_0_0>)
  %1 = partial_apply [callee_guaranteed] %0<S>() : $@convention(thin) <τ_0_0> (Empty<τ_0_0>) -> (@owned Empty<τ_0_0>, @owned @callee_guaranteed (Empty<τ_0_0>) -> @owned Empty<τ_0_0>)
  return %1 : $@callee_guaranteed (Empty<S>) -> (@owned Empty<S>, @owned @callee_guaranteed (Empty<S>) -> @owned Empty<S>)
}

// CHECK-LABEL: define hidden swiftcc { i8*, %swift.refcounted* } @specializes_closure_returning_closure() #0 {
// CHECK: entry:
// CHECK: ret { i8*, %swift.refcounted* } { i8* bitcast ({ %{{.*}}Empty{{.*}}*, i8*, %swift.refcounted* } (%{{.*}}Empty{{.*}}*, %swift.refcounted*)* @"{{.*}}returns_closure{{.*}}" to i8*), %swift.refcounted* null }

sil_vtable WeakBox {}
sil_vtable C {}
sil_vtable D {}
sil_vtable E {}
sil_vtable Empty {}
sil_witness_table C: P module main {}