From bea1a8c4227f5bb9aa6453dab4bb7166c0466895 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Steven=20Sch=C3=A4fer?= <stevenschaefer@google.com>
Date: Mon, 8 Feb 2021 16:50:46 +0100
Subject: [PATCH] JVM IR: Use Object.clone in Enum.values

---
 .../kotlin/backend/jvm/lower/EnumClassLowering.kt | 15 +++++++++------
 .../codegen/bytecodeText/enum/enumCheckcasts.kt   |  5 -----
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/EnumClassLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/EnumClassLowering.kt
index 1fc66f8c086..558fab8a96f 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/EnumClassLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/EnumClassLowering.kt
@@ -32,10 +32,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrSetValueImpl
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrValueParameterSymbol
 import org.jetbrains.kotlin.ir.types.typeWith
-import org.jetbrains.kotlin.ir.util.defaultType
-import org.jetbrains.kotlin.ir.util.isEnumClass
-import org.jetbrains.kotlin.ir.util.isEnumEntry
-import org.jetbrains.kotlin.ir.util.patchDeclarationParents
+import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.name.Name
@@ -156,8 +153,14 @@ private class EnumClassLowering(val context: JvmBackendContext) : ClassLoweringP
                 declaration.body = context.createJvmIrBuilder(declaration.symbol).run {
                     irExprBody(
                         when (body.kind) {
-                            IrSyntheticBodyKind.ENUM_VALUES ->
-                                irArray(valuesField.type) { addSpread(irGetField(null, valuesField)) }
+                            IrSyntheticBodyKind.ENUM_VALUES -> {
+                                val cloneFun = context.irBuiltIns.arrayClass.functions.single {
+                                    it.owner.name.asString() == "clone"
+                                }
+                                irCall(cloneFun, declaration.returnType).apply {
+                                    dispatchReceiver = irGetField(null, valuesField)
+                                }
+                            }
 
                             IrSyntheticBodyKind.ENUM_VALUEOF ->
                                 irCall(backendContext.ir.symbols.enumValueOfFunction).apply {
diff --git a/compiler/testData/codegen/bytecodeText/enum/enumCheckcasts.kt b/compiler/testData/codegen/bytecodeText/enum/enumCheckcasts.kt
index 6cbc5a8a212..f0a119e862e 100644
--- a/compiler/testData/codegen/bytecodeText/enum/enumCheckcasts.kt
+++ b/compiler/testData/codegen/bytecodeText/enum/enumCheckcasts.kt
@@ -3,10 +3,5 @@ enum class Foo {
     open fun result() = "Fail"
 }
 
-// JVM_TEMPLATES:
 // There are two CHECKCASTs, one in Foo.valueOf and one in Foo.values
 // 2 CHECKCAST
-
-// JVM_IR_TEMPLATES:
-// There should be only one CHECKCAST in Foo.valueOf
-// 1 CHECKCAST
\ No newline at end of file