Merge pull request swiftlang#26504 from slavapestov/final-req-test

SILGen: Add test to ensure we don't have a vtable entry for synthesized members of a final class

Author: slavapestov

test/SILGen/synthesized_conformance_class.swift

@@ -63,6 +63,34 @@ extension Nonfinal: Encodable where T: Encodable {}
 // CHECK-LABEL: // Nonfinal<A>.encode(to:)
 // CHECK-NEXT: sil hidden [ossa] @$s29synthesized_conformance_class8NonfinalCAASERzlE6encode2toys7Encoder_p_tKF : $@convention(method) <T where T : Encodable> (@in_guaranteed Encoder, @guaranteed Nonfinal<T>) -> @error Error {
 
+final class FinalHashableClass : Hashable {
+  static func ==(lhs: FinalHashableClass, rhs: FinalHashableClass) -> Bool {
+    return false
+  }
+
+  func hash(into: inout Hasher) {}
+}
+
+// CHECK-LABEL: sil hidden [ossa] @$s29synthesized_conformance_class4doItySiAA18FinalHashableClassCF : $@convention(thin) (@guaranteed FinalHashableClass) -> Int {
+// CHECK: bb0(%0 : @guaranteed $FinalHashableClass):
+// CHECK:   [[FN:%.*]] = function_ref @$s29synthesized_conformance_class18FinalHashableClassC9hashValueSivg : $@convention(method) (@guaranteed FinalHashableClass) -> Int
+// CHECK-NEXT: [[RESULT:%.*]] = apply [[FN]](%0) : $@convention(method) (@guaranteed FinalHashableClass) -> Int
+// CHECK-NEXT: return [[RESULT]] : $Int
+
+func doIt(_ c: FinalHashableClass) -> Int {
+  return c.hashValue
+}
+
+// VTable for FinalHashableClass
+//
+// Note: we should not be emitting a vtable entry for the synthesized
+// FinalHashableClass.hashValue getter!
+
+// CHECK: sil_vtable FinalHashableClass {
+// CHECK-NEXT: #FinalHashableClass.init!allocator.1: (FinalHashableClass.Type) -> () -> FinalHashableClass : @$s29synthesized_conformance_class18FinalHashableClassCACycfC
+// CHECK-NEXT: #FinalHashableClass.deinit!deallocator.1: @$s29synthesized_conformance_class18FinalHashableClassCfD
+// CHECK-NEXT: }
+
 // Witness tables for Final
 
 // CHECK-LABEL: sil_witness_table hidden <T where T : Encodable> Final<T>: Encodable module synthesized_conformance_class {