test/SILOptimizer/devirt_generic_witness_method_ownership.sil

// RUN: %target-sil-opt -enable-sil-verify-all %s -devirtualizer | %FileCheck %s

sil_stage canonical

import Builtin
import Swift
import SwiftShims

public protocol Decodable {
  init(json: [String : Any])
}

public class Item : Decodable {
  required public init(json: [String : Any])
  deinit
}

public class ItemSubclass : Item {
  deinit
  required public init(json: [String : Any])
}

sil [ossa] @witness_method_impl : $@convention(witness_method: Decodable) (@owned Dictionary<String, Any>, @thick Item.Type) -> @out Item {
bb0(%0 : $*Item, %1 : @owned $Dictionary<String, Any>, %2 : $@thick Item.Type):
  %3 = class_method %2 : $@thick Item.Type, #Item.init!allocator.1 : (Item.Type) -> ([String : Any]) -> Item, $@convention(method) (@owned Dictionary<String, Any>, @thick Item.Type) -> @owned Item
  %4 = apply %3(%1, %2) : $@convention(method) (@owned Dictionary<String, Any>, @thick Item.Type) -> @owned Item
  store %4 to [init] %0 : $*Item
  %6 = tuple ()
  return %6 : $()
}

// Check that it is possible to devirtualize a partial_appy of a generic witness_method.
// Since it is a derived class that invokes an implementation from a base class,
// make sure that the resulting closure is properly converted into a required type.

// CHECK-LABEL: sil [ossa] @test_generic_witness_method_partial_apply_devirt : $@convention(thin) (@thick ItemSubclass.Type) -> @owned @callee_owned (@owned Dictionary<String, Any>) -> @out ItemSubclass
// CHECK: %[[UPCASTED_ARG:[0-9]+]] = upcast %0 : $@thick ItemSubclass.Type to $@thick Item.Type
// CHECK: %[[FUNCTION_REF:[0-9]+]] = function_ref @witness_method_impl
// CHECK: %[[PA:[0-9]+]] = partial_apply %[[FUNCTION_REF]](%[[UPCASTED_ARG]]) : $@convention(witness_method: Decodable) (@owned Dictionary<String, Any>, @thick Item.Type) -> @out Item
// CHECK: %[[RETURN_VALUE:[0-9]+]] = convert_function %[[PA]] : $@callee_owned (@owned Dictionary<String, Any>) -> @out Item to $@callee_owned (@owned Dictionary<String, Any>) -> @out ItemSubclass
// CHECK: return %[[RETURN_VALUE]] : $@callee_owned (@owned Dictionary<String, Any>) -> @out ItemSubclass

sil [ossa]@test_generic_witness_method_partial_apply_devirt : $@convention(thin) (@thick ItemSubclass.Type) -> @owned @callee_owned (@owned Dictionary<String, Any>) -> @out ItemSubclass {
bb0(%0 : $@thick ItemSubclass.Type):
  %1 = witness_method $ItemSubclass, #Decodable.init!allocator.1 : <Self where Self : Decodable> (Self.Type) -> ([String : Any]) -> Self : $@convention(witness_method: Decodable) <τ_0_0 where τ_0_0 : Decodable> (@owned Dictionary<String, Any>, @thick τ_0_0.Type) -> @out τ_0_0
  %2 = partial_apply %1<ItemSubclass>(%0) : $@convention(witness_method: Decodable) <τ_0_0 where τ_0_0 : Decodable> (@owned Dictionary<String, Any>, @thick τ_0_0.Type) -> @out τ_0_0
  return %2 : $@callee_owned (@owned Dictionary<String, Any>) -> @out ItemSubclass
}

sil_witness_table [serialized] Item: Decodable module main {
  method #Decodable.init!allocator.1: <Self where Self : Decodable> (Self.Type) -> ([String : Any]) -> Self : @witness_method_impl
}