IR KT-50039 don't initialize outer 'this' in delegating constructor

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -22317,6 +22317,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @Test
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @Test
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/InnerClassesLowering.kt

@@ -68,8 +68,11 @@ class InnerClassesLowering(val context: BackendContext, private val innerClasses
             if (blockBody !is IrBlockBody) throw AssertionError("Unexpected constructor body: ${irConstructor.body}")
 
             loweredConstructor.body = context.irFactory.createBlockBody(blockBody.startOffset, blockBody.endOffset) {
-                context.createIrBuilder(irConstructor.symbol, irConstructor.startOffset, irConstructor.endOffset).apply {
-                    statements.add(0, irSetField(irGet(irClass.thisReceiver!!), parentThisField, irGet(outerThisParameter)))
+
+                if (irConstructor.shouldInitializeOuterThis()) {
+                    context.createIrBuilder(irConstructor.symbol, irConstructor.startOffset, irConstructor.endOffset).apply {
+                        statements.add(0, irSetField(irGet(irClass.thisReceiver!!), parentThisField, irGet(outerThisParameter)))
+                    }
                 }
 
                 statements.addAll(blockBody.statements)
@@ -90,6 +93,15 @@ class InnerClassesLowering(val context: BackendContext, private val innerClasses
         return loweredConstructor
     }
 
+    private fun IrConstructor.shouldInitializeOuterThis(): Boolean {
+        val irBlockBody = body as? IrBlockBody ?: return false
+        // Constructors are either delegating to a constructor of super class (and initializing an instance of this class),
+        // or delegating to a constructor of this class.
+        // Don't initialize outer 'this' in constructor delegating to this,
+        // otherwise final 'this$0' field will be initialized twice (in delegating constructor and in original constructor),
+        // which is legal, but causes a performance regression on JVM (KT-50039).
+        return irBlockBody.statements.any { it is IrInstanceInitializerCall }
+    }
 }
 
 private fun InnerClassesSupport.primaryConstructorParameterMap(originalConstructor: IrConstructor): Map<IrValueParameter, IrValueParameter> {

compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerDefaultArgument.kt

@@ -10,3 +10,8 @@ class A {
 }
 
 fun box() = A().box()
+
+// CHECK_BYTECODE_TEXT
+// 1 PUTFIELD A\$Inner\.this\$0 : LA;
+//  ^ A$Inner.this$0 SHOULD be written in primary constructor of A$Inner,
+//    and SHOULD NOT be written in corresponding default arguments stub.

compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt

@@ -0,0 +1,17 @@
+class Outer(val outer: String) {
+    open inner class Inner(val inner: String) {
+        constructor() : this("K")
+
+        fun test() = outer + inner
+    }
+
+    fun obj(): Inner =
+        object : Inner() {}
+}
+
+fun box() = Outer("O").obj().test()
+
+// CHECK_BYTECODE_TEXT
+// 1 PUTFIELD Outer\$Inner\.this\$0 : LOuter;
+//  ^ Outer$Inner.this$0 SHOULD be written in primary constructor of Outer$Inner,
+//    and SHOULD NOT be written in delegating constructor.

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -21945,6 +21945,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @Test
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @Test
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -22317,6 +22317,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @Test
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @Test
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -18360,6 +18360,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsLocalCaptureInSuperCall.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java

@@ -17507,6 +17507,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @Test
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @Test
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java

@@ -17471,6 +17471,12 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @Test
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @Test
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -14807,6 +14807,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
             }
 
+            @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+            public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+            }
+
             @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
             public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {
                 runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsLocalCaptureInSuperCall.kt");

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeExtBlackBoxTestGenerated.java

@@ -18390,6 +18390,12 @@ public class NativeExtBlackBoxTestGenerated extends AbstractNativeBlackBoxTest {
                     runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerOfLocalWithCapture.kt");
                 }
 
+                @Test
+                @TestMetadata("objectExtendsInnerWithDelegatingConstructor.kt")
+                public void testObjectExtendsInnerWithDelegatingConstructor() throws Exception {
+                    runTest("compiler/testData/codegen/box/innerNested/superConstructorCall/objectExtendsInnerWithDelegatingConstructor.kt");
+                }
+
                 @Test
                 @TestMetadata("objectExtendsLocalCaptureInSuperCall.kt")
                 public void testObjectExtendsLocalCaptureInSuperCall() throws Exception {