[JS BE] implement es6-classes lowering

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt

@@ -228,7 +228,14 @@ private val removeInlineFunctionsWithReifiedTypeParametersLoweringPhase = makeDe
 )
 
 private val throwableSuccessorsLoweringPhase = makeBodyLoweringPhase(
-    ::ThrowableLowering,
+    { context ->
+        context.run {
+            val extendThrowableSymbol =
+                if (es6mode) setPropertiesToThrowableInstanceSymbol else extendThrowableSymbol
+
+            ThrowableLowering(this, extendThrowableSymbol)
+        }
+    },
     name = "ThrowableLowering",
     description = "Link kotlin.Throwable and JavaScript Error together to provide proper interop between language and platform exceptions"
 )
@@ -517,6 +524,19 @@ private val typeOperatorLoweringPhase = makeBodyLoweringPhase(
     )
 )
 
+private val es6AddInternalParametersToConstructorPhase = makeBodyLoweringPhase(
+    ::ES6AddInternalParametersToConstructorPhase,
+    name = "ES6CreateInitFunctionPhase",
+    description = "Add `box` and `resultType` params, create init functions for constructors"
+)
+
+private val es6ConstructorLowering = makeBodyLoweringPhase(
+    ::ES6ConstructorLowering,
+    name = "ES6ConstructorLoweringPhase",
+    description = "Lower constructors",
+    prerequisite = setOf(es6AddInternalParametersToConstructorPhase)
+)
+
 private val secondaryConstructorLoweringPhase = makeDeclarationTransformerPhase(
     ::SecondaryConstructorLowering,
     name = "SecondaryConstructorLoweringPhase",

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsMapping.kt

@@ -21,6 +21,8 @@ class JsMapping : DefaultMapping() {
     val classToSyntheticPrimaryConstructor = newMapping<IrClass, IrConstructor>()
     val privateMemberToCorrespondingStatic = newMapping<IrFunction, IrSimpleFunction>()
 
+    val constructorToInitFunction = newMapping<IrConstructor, IrSimpleFunction>()
+
     val enumEntryToGetInstanceFun = newMapping<IrEnumEntry, IrSimpleFunction>()
     val enumEntryToInstanceField = newMapping<IrEnumEntry, IrField>()
     val enumConstructorToNewConstructor = newMapping<IrConstructor, IrConstructor>()

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6AddInternalParametersToConstructorPhase.kt

@@ -0,0 +1,213 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.backend.js.lower
+
+import org.jetbrains.kotlin.backend.common.BodyLoweringPass
+import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.lower.PrimaryConstructorLowering.*
+import org.jetbrains.kotlin.ir.builders.declarations.addValueParameter
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrDelegatingConstructorCallImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
+import org.jetbrains.kotlin.ir.types.isAny
+import org.jetbrains.kotlin.ir.util.defaultType
+import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.util.statements
+import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
+
+/**
+ * Add ES6_INIT_BOX_PARAMETER for each constructor (except constructors
+ * of inline, external and primitive (string, arrays) classes).
+ * Uses: Inline class's constructor initialize field of outer class before
+ * call `super`, but its impossible in ES6. ES6_INIT_BOX_PARAMETER - object,
+ * that collect these values and pass to super constructor. In the last
+ * constructor of delegation chain ES6_INIT_BOX_PARAMETER will be open
+ * with `Object.assign(this, box)`
+ *
+ * Add ES6_RESULT_TYPE PARAMETER for each secondary ctor (except
+ * constructors of external and primitive (string, arrays) classes).
+ * Uses: Pass information about type of new object to `Reflect.construct()`
+ *
+ * Transform SYNTHETIC_PRIMARY_CONSTRUCTOR:
+ * constructor() {
+ *   //statements
+ * }
+ * ==>
+ * constructor() {
+ *   init(this)
+ * }
+ * init($this$) {
+ *   //statements from ctor
+ * }
+ */
+class ES6AddInternalParametersToConstructorPhase(val context: JsIrBackendContext) : BodyLoweringPass {
+    object ES6_SYNTHETIC_PRIMARY_INIT_FUNCTION : IrDeclarationOriginImpl("ES6_SYNTHETIC_PRIMARY_INIT_FUNCTION")
+    object ES6_INIT_BOX_PARAMETER : IrDeclarationOriginImpl("ES6_INIT_BOX_PARAMETER")
+    object ES6_RESULT_TYPE_PARAMETER : IrDeclarationOriginImpl("ES6_RESULT_TYPE_PARAMETER")
+
+    override fun lower(irBody: IrBody, container: IrDeclaration) {
+        assert(context.es6mode)
+
+        container.transform(CallSiteTransformer(), null)
+
+        if (container !is IrConstructor) return
+
+        if (!container.hasStrictSignature()) container.addInternalValueParameters()
+
+        if (container.origin === SYNTHETIC_PRIMARY_CONSTRUCTOR) {
+            createInitFunction(container)
+            openInitializerBox(container)
+        }
+    }
+
+    private fun IrConstructor.addInternalValueParameters() {
+        addValueParameter("box", context.dynamicType, ES6_INIT_BOX_PARAMETER)
+
+        if (!isPrimary) {
+            addValueParameter("resultType", context.dynamicType, ES6_RESULT_TYPE_PARAMETER)
+        }
+    }
+
+    private fun createInitFunction(constructor: IrConstructor) {
+        val irClass = constructor.parentAsClass
+        val initFunction = buildInitFunction(constructor, irClass)
+        irClass.declarations += initFunction
+
+        context.mapping.constructorToInitFunction[constructor] = initFunction
+
+        initFunction.transformChildren(object : IrElementTransformerVoid() {
+            override fun visitDeclaration(declaration: IrDeclaration): IrStatement {
+                declaration.parent = initFunction
+                return declaration
+            }
+        }, null)
+    }
+
+    private fun openInitializerBox(constructor: IrConstructor) = with(constructor.body as IrBlockBody) {
+        statements.clear()
+        statements += JsIrBuilder.buildCall(context.intrinsics.jsOpenInitializerBox).also {
+            it.putValueArgument(0, JsIrBuilder.buildGetValue(constructor.parentAsClass.thisReceiver!!.symbol))
+            it.putValueArgument(1, JsIrBuilder.buildGetValue(constructor.valueParameters.last().symbol))
+        }
+    }
+
+    private fun buildInitFunction(constructor: IrConstructor, irClass: IrClass): IrSimpleFunction {
+        val functionName = "${irClass.name}_init"
+
+        return JsIrBuilder.buildFunction(
+            functionName,
+            context.irBuiltIns.unitType,
+            irClass,
+            Visibilities.PROTECTED,
+            Modality.FINAL,
+            constructor.isInline,
+            constructor.isExternal,
+            origin = ES6_SYNTHETIC_PRIMARY_INIT_FUNCTION
+        ).apply {
+            addValueParameter("\$this\$", context.dynamicType)
+
+            body = JsIrBuilder.buildBlockBody(constructor.body?.statements ?: emptyList())
+
+            transformChildren(object : IrElementTransformerVoid() {
+                override fun visitGetValue(expression: IrGetValue): IrExpression {
+                    return if (expression.symbol.owner === constructor.parentAsClass.thisReceiver!!) {
+                        with(expression) { IrGetValueImpl(startOffset, endOffset, type, valueParameters.single().symbol) }
+                    } else {
+                        expression
+                    }
+                }
+            }, null)
+        }
+    }
+
+    /**
+     * Pass `null` for ES6_INIT_BOX_PARAMETER and ES6_RESULT_TYPE_PARAMETER
+     */
+    inner class CallSiteTransformer : IrElementTransformerVoid() {
+        override fun visitConstructorCall(expression: IrConstructorCall): IrExpression {
+            val constructor = expression.symbol.owner
+            val parent = constructor.parentAsClass
+
+            if (constructor.hasStrictSignature() || parent.defaultType.isAny()) return expression
+
+            val newArgsCount = if (constructor.isPrimary) 1 else 2
+            return expression.run {
+                IrConstructorCallImpl(
+                    startOffset,
+                    endOffset,
+                    type,
+                    symbol,
+                    typeArgumentsCount,
+                    constructorTypeArgumentsCount,
+                    valueArgumentsCount + newArgsCount
+                ).also {
+                    for (i in 0 until valueArgumentsCount) {
+                        it.putValueArgument(i, getValueArgument(i))
+                    }
+
+                    it.putValueArgument(
+                        valueArgumentsCount,
+                        JsIrBuilder.buildNull(context.dynamicType)
+                    )
+
+                    if (!constructor.isPrimary) {
+                        it.putValueArgument(
+                            valueArgumentsCount + 1,
+                            JsIrBuilder.buildNull(context.dynamicType)
+                        )
+                    }
+                }
+            }
+        }
+
+        override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall): IrExpression {
+            val constructor = expression.symbol.owner
+            val parent = constructor.parentAsClass
+
+            if (constructor.hasStrictSignature() || parent.defaultType.isAny()) return expression
+
+            val newArgsCount = if (constructor.isPrimary) 1 else 2
+
+            return expression.run {
+                IrDelegatingConstructorCallImpl(
+                    startOffset,
+                    endOffset,
+                    type,
+                    symbol,
+                    typeArgumentsCount,
+                    valueArgumentsCount + newArgsCount
+                ).also {
+                    for (i in 0 until valueArgumentsCount) {
+                        it.putValueArgument(i, getValueArgument(i))
+                    }
+
+                    it.putValueArgument(
+                        valueArgumentsCount,
+                        JsIrBuilder.buildNull(context.dynamicType)
+                    )
+
+                    if (!constructor.isPrimary) {
+                        it.putValueArgument(
+                            valueArgumentsCount + 1,
+                            JsIrBuilder.buildNull(context.dynamicType)
+                        )
+                    }
+                }
+            }
+        }
+    }
+
+    private fun IrConstructor.hasStrictSignature(): Boolean {
+        val primitives = with(context.irBuiltIns) { primitiveArrays + stringClass }
+        return with(parentAsClass) { isExternal || isInline || symbol in primitives }
+    }
+}

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ES6ConstructorLowering.kt

@@ -0,0 +1,565 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.backend.js.lower
+
+import org.jetbrains.kotlin.backend.common.BodyLoweringPass
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
+import org.jetbrains.kotlin.ir.backend.js.lower.ES6AddInternalParametersToConstructorPhase.*
+import org.jetbrains.kotlin.ir.backend.js.lower.PrimaryConstructorLowering.*
+import org.jetbrains.kotlin.ir.builders.declarations.addValueParameter
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrVarargImpl
+import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
+import org.jetbrains.kotlin.ir.symbols.IrVariableSymbol
+import org.jetbrains.kotlin.ir.types.isAny
+import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
+
+object ES6_THIS_VARIABLE_ORIGIN : IrDeclarationOriginImpl("ES6_THIS_VARIABLE_ORIGIN")
+
+class ES6ConstructorLowering(val context: JsIrBackendContext) : BodyLoweringPass {
+    override fun lower(irBody: IrBody, container: IrDeclaration) {
+        assert(context.es6mode)
+
+        if (container !is IrConstructor) return
+
+        if (container.hasStrictSignature()) return
+
+        hackEnums(container)
+        hackExceptions(context, container)
+
+        val superCall = getSuperCall(container) ?: return
+        val superCtor = superCall.symbol.owner
+        val helper = LowerCtorHelper(context, container, superCtor)
+
+        if (container.isPrimary) {
+            if (superCtor.isPrimary) primaryToPrimary(helper)
+            else primaryToSecondary(helper)
+        } else {
+            if (superCtor.isPrimary) secondaryToPrimary(helper)
+            else secondaryToSecondary(helper)
+
+            replaceCallToDefaultPrimary(context, container)
+            changeIrConstructorToIrFunction(context, container)
+        }
+    }
+
+    /**
+     * constructor(args, box) {
+     *   var currBox = box || {}
+     *
+     *   //1. Superclass is Any
+     *   Object.assign(this, currBox)
+     *   //body
+     *
+     *   //2. Base class isInline or isExternal or array/string
+     *   super(args)
+     *   Object.assign(this, currBox)
+     *   //body
+     *
+     *   //3. Base class !isInline and !isExternal and !(array/string)
+     *   //fill initialization box
+     *   super(args, currBox)
+     *   //body
+     * }
+     */
+    private fun primaryToPrimary(helper: LowerCtorHelper) = with(helper) {
+        statements.add(0, boxOrEmptyObject)
+
+        if (superCtor.parentAsClass.defaultType.isAny()) {
+            //after superCall
+            statements.add(1, openBoxStatement(thisSymbol, boxSymbol))
+            return
+        }
+
+        if (superCtor.hasStrictSignature()) {
+            //after superCall
+            statements.add(2, openBoxStatement(thisSymbol, boxSymbol))
+        } else {
+            fillInitializerBox(boxSymbol, constructor)
+            putBoxToSuperCall(boxSymbol, constructor)
+        }
+    }
+
+    /**
+     * constructor(args, box) {
+     *   var currBox = box || {}
+     *
+     *   //1. Base class isExternal or array/string
+     *   var $this$ = Base_constructor(.., currBox)
+     *   Object.assign(this, currBox)
+     *   return $this$
+     *
+     *   //2. Base class !isInline and !isExternal and !(array/string)
+     *   //fill initialization box
+     *   var $this$ = Base_constructor(.., currBox, new.target)
+     *   //body
+     *   return $this$
+     * }
+     */
+    private fun primaryToSecondary(helper: LowerCtorHelper) = with(helper) {
+        statements.add(0, boxOrEmptyObject)
+
+        if (superCtor.hasStrictSignature()) {
+            fun createNewSuperCall(): IrCall {
+                val callType = JsIrBuilder.buildCall(context.intrinsics.jsClass, context.dynamicType, listOf(superCtor.returnType))
+                val newTarget = JsIrBuilder.buildCall(context.intrinsics.jsNewTarget)
+                val args = IrVarargImpl(
+                    UNDEFINED_OFFSET, UNDEFINED_OFFSET,
+                    context.dynamicType,
+                    context.dynamicType,
+                    getElements(constructor)
+                )
+
+                return JsIrBuilder.buildCall(context.intrinsics.jsConstruct).apply {
+                    putValueArgument(0, callType)
+                    putValueArgument(1, newTarget)
+                    putValueArgument(2, args)
+
+                    putTypeArgument(0, superCtor.returnType)
+                }
+            }
+
+            val newThis = createThisVariable(createNewSuperCall())
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements.add(2, openBoxStatement(newThis.symbol, boxSymbol))
+            statements += returnThis(constructor, newThis)
+
+            redirectOldThisToNewOne(constructor, newThis)
+        } else {
+            putBoxToSuperCall(boxSymbol, constructor)
+            fillInitializerBox(boxSymbol, constructor)
+
+            val newTarget = JsIrBuilder.buildCall(context.intrinsics.jsNewTarget)
+            val newThis = createThisVariable(createNewSuperCallPrimaryToSecondary(superCall, newTarget))
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements += returnThis(constructor, newThis)
+
+            redirectOldThisToNewOne(constructor, newThis)
+        }
+    }
+
+    /**
+     * Derived_constructor(.., box, resultType) {
+     *   var currBox = box || {}
+     *   var currResultType = resultType || Derived
+     *
+     *   //1. Base class isInline or isExternal or array/string
+     *   var $this$ = construct(Base, currResultType, [..])
+     *   Object.assign(this, currBox)
+     *   //body
+     *   return $this$
+     *
+     *   //2. Base class !isInline and !isExternal and !(array/string)
+     *   //fill initialization box
+     *   var $this$ = construct(Base, currResultType, [.., currBox])
+     *   //body
+     *   return $this$
+     * }
+     */
+    private fun secondaryToPrimary(helper: LowerCtorHelper) = with(helper) {
+        statements.add(0, boxOrEmptyObject)
+        statements.add(1, resultTypeOrDefaultType())
+        val resultTypeSymbol = (statements[1] as IrVariable).symbol
+
+        if (superCtor.hasStrictSignature()) {
+            val newThis = createThisVariable(createNewSuperCallSecondaryToPrimary(constructor, superCtor, resultTypeSymbol))
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements.add(3, openBoxStatement(newThis.symbol, boxSymbol))
+            statements.add(returnThis(constructor, newThis))
+
+            redirectOldThisToNewOne(constructor, newThis)
+        } else {
+            fillInitializerBox(boxSymbol, constructor)
+
+            val newThis = createThisVariable(createNewSuperCallSecondaryToPrimary(constructor, superCtor, resultTypeSymbol, boxSymbol))
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements.add(returnThis(constructor, newThis))
+
+            redirectOldThisToNewOne(constructor, newThis)
+        }
+    }
+
+    /**
+     * Derived_constructor(.., box, resultType) {
+     *   var currBox = box || {}
+     *   var currResultType = resultType || Derived
+     *   //fill initialization box
+     *
+     *   //1. Base class isInline or isExternal or array/string
+     *   var $this$ = Base_constructor(..)
+     *   Object.assign(this, currBox)
+     *   //body
+     *   return $this$
+     *
+     *   //2. Base class !isInline and !isExternal and !(array/string)
+     *   var $this$ = Base_constructor(.., currBox, currResultType)
+     *   //body
+     *   return $this$
+     * }
+     */
+    private fun secondaryToSecondary(helper: LowerCtorHelper) = with(helper) {
+        statements.add(0, boxOrEmptyObject)
+        statements.add(1, resultTypeOrDefaultType())
+        val resultTypeSymbol = (statements[1] as IrVariable).symbol
+
+        putBoxToSuperCall(boxSymbol, constructor)
+        fillInitializerBox(boxSymbol, constructor)
+
+        if (superCtor.hasStrictSignature()) {
+            val newThis = createThisVariable(superCall)
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements.add(3, openBoxStatement(newThis.symbol, boxSymbol))
+            statements += returnThis(constructor, newThis)
+
+            redirectOldThisToNewOne(constructor, newThis)
+        } else {
+            val newThis = createThisVariable(createNewSuperCallSecondaryToSecondary(superCall, boxSymbol, resultTypeSymbol))
+            changeReturnUnitToReturnInstance(newThis)
+
+            statements += returnThis(constructor, newThis)
+
+            redirectOldThisToNewOne(constructor, newThis)
+        }
+    }
+
+    //superCallBuilder
+    private fun createNewSuperCallSecondaryToSecondary(
+        superCall: IrDelegatingConstructorCall,
+        boxSymbol: IrValueSymbol,
+        resultTypeSymbol: IrVariableSymbol
+    ) = superCall.apply {
+        putValueArgument(ES6_INIT_BOX_PARAMETER, JsIrBuilder.buildGetValue(boxSymbol))
+        putValueArgument(ES6_RESULT_TYPE_PARAMETER, JsIrBuilder.buildGetValue(resultTypeSymbol))
+    }
+
+    //superCallBuilder
+    private fun createNewSuperCallPrimaryToSecondary(
+        superCall: IrDelegatingConstructorCall,
+        newTarget: IrCall? = null
+    ) = superCall.apply { putValueArgument(ES6_RESULT_TYPE_PARAMETER, newTarget) }
+
+    private fun IrDelegatingConstructorCall.putValueArgument(origin: IrDeclarationOrigin, value: IrExpression?) {
+        val valueParameters = symbol.owner.valueParameters
+        for (i in valueParameters.indices) {
+            if (valueParameters[i].origin === origin) {
+                putValueArgument(i, value)
+            }
+        }
+    }
+
+    //superCallBuilder
+    private fun createNewSuperCallSecondaryToPrimary(
+        constructor: IrConstructor,
+        superCtor: IrConstructor,
+        resultTypeSymbol: IrVariableSymbol,
+        boxSymbol: IrVariableSymbol? = null
+    ): IrCall {
+        val callType = JsIrBuilder.buildCall(context.intrinsics.jsClass, context.dynamicType, listOf(superCtor.returnType))
+        val resultType = JsIrBuilder.buildGetValue(resultTypeSymbol)
+        val arguments = IrVarargImpl(
+            UNDEFINED_OFFSET, UNDEFINED_OFFSET,
+            context.irBuiltIns.anyNType,
+            context.irBuiltIns.anyNType,
+            getElements(constructor, boxSymbol)
+        )
+
+        if (superCtor.parentAsClass.defaultType.isAny()) {
+            //superType is Any, and we have default primary --> create call to default primary
+            return JsIrBuilder.buildCall(context.intrinsics.jsConstruct, context.irBuiltIns.nothingType).apply {
+                arguments.elements.clear()
+                arguments.addElement(JsIrBuilder.buildGetValue(boxSymbol!!))
+
+                putValueArgument(0, JsIrBuilder.buildCall(context.intrinsics.jsClass, context.dynamicType, listOf(constructor.returnType)))
+                putValueArgument(1, resultType)
+                putValueArgument(2, arguments)
+
+                putTypeArgument(0, constructor.returnType)
+            }
+        }
+
+        return JsIrBuilder.buildCall(context.intrinsics.jsConstruct, context.irBuiltIns.nothingType).apply {
+            putValueArgument(0, callType)
+            putValueArgument(1, resultType)
+            putValueArgument(2, arguments)
+
+            putTypeArgument(0, superCtor.returnType)
+        }
+    }
+
+    /**
+     * Copy arguments from superCall
+     */
+    private fun getElements(constructor: IrConstructor, boxSymbol: IrValueSymbol? = null): List<IrVarargElement> {
+        val result = mutableListOf<IrVarargElement>()
+
+        val superCall = constructor.body!!.statements.filterIsInstance<IrDelegatingConstructorCall>().first()
+        repeat(superCall.valueArgumentsCount) { i ->
+            val arg = superCall.getValueArgument(i) ?: return@repeat
+            if (superCall.symbol.owner.valueParameters[i].origin === ES6_INIT_BOX_PARAMETER) {
+                result += JsIrBuilder.buildGetValue(boxSymbol!!)
+            } else {
+                if (arg.type.getInlinedClass() != null) {
+                    val any = context.irBuiltIns.anyNType
+                    result += JsIrBuilder.buildTypeOperator(any, IrTypeOperator.REINTERPRET_CAST, arg, any)
+                } else {
+                    result += arg
+                }
+            }
+        }
+
+        return result
+    }
+
+    //builder
+    private fun returnThis(constructor: IrConstructor, newThis: IrVariable): IrReturn {
+        return JsIrBuilder.buildReturn(
+            constructor.symbol,
+            JsIrBuilder.buildGetValue(newThis.symbol),
+            context.irBuiltIns.nothingType
+        )
+    }
+
+    /**
+     * Transform statements like `this.x = y` to `box.x = y`
+     */
+    private fun fillInitializerBox(boxSymbol: IrValueSymbol, constructor: IrConstructor) {
+        val statements = (constructor.body as IrBlockBody).statements
+        for (i in statements.indices) {
+            val current = statements[i]
+            if (current is IrSetField) {
+                if ((current.receiver as? IrGetValue)?.symbol?.owner === constructor.parentAsClass.thisReceiver) {
+                    current.receiver = JsIrBuilder.buildGetValue(boxSymbol)
+                }
+            }
+
+            if (statements[i] is IrDelegatingConstructorCall) {
+                break
+            }
+        }
+    }
+
+    //transformer
+    private fun putBoxToSuperCall(boxSymbol: IrValueSymbol, constructor: IrConstructor) {
+        constructor.transformChildren(object : IrElementTransformerVoid() {
+            override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall): IrExpression {
+                return expression.also { it.putValueArgument(ES6_INIT_BOX_PARAMETER, JsIrBuilder.buildGetValue(boxSymbol)) }
+            }
+        }, null)
+    }
+
+    //builder
+    private fun openBoxStatement(thisSymbol: IrValueSymbol, boxSymbol: IrValueSymbol): IrCall {
+        return JsIrBuilder.buildCall(context.intrinsics.jsOpenInitializerBox).also {
+            it.putValueArgument(0, JsIrBuilder.buildGetValue(thisSymbol))
+            it.putValueArgument(1, JsIrBuilder.buildGetValue(boxSymbol))
+        }
+    }
+
+    //util
+    private fun IrConstructor.hasStrictSignature(): Boolean {
+        val primitives = with(context.irBuiltIns) { primitiveArrays + stringClass }
+        return with(parentAsClass) { isExternal || isInline || symbol in primitives }
+    }
+}
+
+//transformer
+private fun replaceCallToDefaultPrimary(context: JsIrBackendContext, constructor: IrConstructor) {
+    val thisSymbol = (((constructor.body as IrBlockBody).statements
+        .find { it is IrVariable && it.origin === ES6_THIS_VARIABLE_ORIGIN }) as IrVariable?)?.symbol ?: return
+
+    (constructor.body as IrBlockBody).statements.transform {
+        if (it is IrDelegatingConstructorCall) {
+            val superCtor = it.symbol.owner
+            val initFunc = context.mapping.constructorToInitFunction[superCtor]!!
+
+            JsIrBuilder.buildCall(initFunc.symbol).apply {
+                putValueArgument(0, JsIrBuilder.buildGetValue(thisSymbol))
+            }
+        } else it
+    }
+}
+
+//transformer
+private fun redirectOldThisToNewOne(constructor: IrConstructor, newThis: IrVariable) {
+    constructor.transformChildren(object : IrElementTransformerVoid() {
+        override fun visitGetValue(expression: IrGetValue): IrExpression {
+            return if (expression.symbol.owner === constructor.parentAsClass.thisReceiver!!) {
+                with(expression) { IrGetValueImpl(startOffset, endOffset, type, newThis.symbol) }
+            } else {
+                expression
+            }
+        }
+    }, null)
+}
+
+/**
+ * Change `return Unit` to `return $this$`
+ */
+private fun LowerCtorHelper.changeReturnUnitToReturnInstance(newThis: IrVariable) {
+    constructor.transformChildren(object : IrElementTransformerVoid() {
+        override fun visitReturn(expression: IrReturn): IrExpression {
+            return JsIrBuilder.buildReturn(
+                constructor.symbol,
+                JsIrBuilder.buildGetValue(newThis.symbol),
+                expression.type
+            )
+        }
+    }, null)
+}
+
+private fun hackEnums(constructor: IrConstructor) {
+    constructor.transformChildren(object : IrElementTransformerVoid() {
+        override fun visitTypeOperator(expression: IrTypeOperatorCall): IrExpression {
+            return (expression.argument as? IrDelegatingConstructorCall) ?: expression
+        }
+    }, null)
+}
+
+/**
+ * Swap call synthetic primary ctor and call extendThrowable
+ */
+private fun hackExceptions(context: JsIrBackendContext, constructor: IrConstructor) {
+    val setPropertiesSymbol = context.setPropertiesToThrowableInstanceSymbol
+
+    val statements = (constructor.body as IrBlockBody).statements
+
+    var callIndex = -1
+    var superCallIndex = -1
+    for (i in statements.indices) {
+        val s = statements[i]
+
+        if (s is IrCall && s.symbol === setPropertiesSymbol) callIndex = i
+        if (s is IrDelegatingConstructorCall && s.symbol.owner.origin === SYNTHETIC_PRIMARY_CONSTRUCTOR) superCallIndex = i
+    }
+
+    if (callIndex != -1 && superCallIndex != -1) {
+        val tmp = statements[callIndex]
+        statements[callIndex] = statements[superCallIndex]
+        statements[superCallIndex] = tmp
+    }
+}
+
+private class LowerCtorHelper(
+    private val context: JsIrBackendContext,
+    val constructor: IrConstructor,
+    val superCtor: IrConstructor
+) {
+    private val boxParameterSymbol = constructor.valueParameters.find { it.origin === ES6_INIT_BOX_PARAMETER }!!.symbol
+    val resultTypeParameterSymbol by lazy {
+        constructor.valueParameters.find { it.origin === ES6_RESULT_TYPE_PARAMETER }!!.symbol
+    }
+
+    val statements = (constructor.body as IrBlockBody).statements
+
+    /**
+     * var currBox = box || {}
+     */
+    val boxOrEmptyObject = boxOrEmptyObject(boxParameterSymbol, constructor)
+    private fun boxOrEmptyObject(boxSymbol: IrValueSymbol, parent: IrConstructor): IrVariable {
+        val emptyObject = JsIrBuilder.buildCall(context.intrinsics.jsEmptyObject)
+        val or = JsIrBuilder.buildCall(context.intrinsics.jsOr, context.dynamicType).apply {
+            putValueArgument(0, JsIrBuilder.buildGetValue(boxSymbol))
+            putValueArgument(1, emptyObject)
+        }
+        return JsIrBuilder.buildVar(context.dynamicType, parent, "currBox", initializer = or)
+    }
+
+    val boxSymbol = boxOrEmptyObject.symbol
+    val thisSymbol = constructor.parentAsClass.thisReceiver!!.symbol
+
+    val superCall: IrDelegatingConstructorCall by lazy { getSuperCall(constructor)!! }
+
+    /**
+     * var $this$ = `newSuperCall`
+     */
+    fun createThisVariable(newSuperCall: IrExpression): IrVariable {
+        val newThis = JsIrBuilder.buildVar(
+            context.dynamicType,
+            constructor,
+            "\$this\$",
+            initializer = newSuperCall
+        ).apply {
+            origin = ES6_THIS_VARIABLE_ORIGIN
+        }
+
+        (constructor.body as IrBlockBody).statements.transform {
+            if (it === superCall) newThis
+            else it
+        }
+
+        return newThis
+    }
+
+    /**
+     * var currResultType = resultType || D
+     */
+    fun resultTypeOrDefaultType(): IrStatement {
+        val defaultType = JsIrBuilder.buildCall(context.intrinsics.es6DefaultType).apply {
+            putTypeArgument(0, constructor.parentAsClass.defaultType)
+        }
+        val or = JsIrBuilder.buildCall(context.intrinsics.jsOr, context.dynamicType).apply {
+            putValueArgument(0, JsIrBuilder.buildGetValue(resultTypeParameterSymbol))
+            putValueArgument(1, defaultType)
+        }
+        return JsIrBuilder.buildVar(context.dynamicType, constructor, "currResultType", initializer = or)
+    }
+}
+
+private fun getSuperCall(constructor: IrConstructor): IrDelegatingConstructorCall? {
+    var result: IrDelegatingConstructorCall? = null
+    (constructor.body as IrBlockBody).acceptChildren(object : IrElementVisitor<Unit, Any?> {
+        override fun visitElement(element: IrElement, data: Any?) { }
+
+        override fun visitBlock(expression: IrBlock, data: Any?) {
+            expression.statements.forEach { it.accept(this, data) }
+        }
+
+        override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall, data: Any?) {
+            result = result ?: expression
+        }
+    }, null)
+    return result
+}
+
+private fun changeIrConstructorToIrFunction(context: JsIrBackendContext, container: IrConstructor) {
+    val newConstructor = JsIrBuilder.buildFunction(
+        "${container.parentAsClass.name}_constructor",
+        container.returnType,
+        container.parent
+    ).apply {
+        container.valueParameters.forEach { param ->
+            addValueParameter(param.name.asString(), param.type, param.origin)
+        }
+
+        val parametersMap = container.valueParameters.zip(valueParameters).toMap()
+        body = container.body
+        transformChildren(object : IrElementTransformerVoid() {
+            override fun visitGetValue(expression: IrGetValue): IrExpression {
+                val newParam = parametersMap[expression.symbol.owner]
+                return if (newParam != null) JsIrBuilder.buildGetValue(newParam.symbol) else expression
+            }
+        }, null)
+    }
+
+    container.parentAsClass.declarations.transform {
+        if (it === container) newConstructor else it
+    }
+
+    context.mapping.secondaryConstructorToDelegate[container] = newConstructor
+}

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/PrimaryConstructorLowering.kt

@@ -38,7 +38,7 @@ class PrimaryConstructorLowering(context: JsCommonBackendContext) : DeclarationT
         return null
     }
 
-    private object SYNTHETIC_PRIMARY_CONSTRUCTOR : IrDeclarationOriginImpl("SYNTHETIC_PRIMARY_CONSTRUCTOR")
+    object SYNTHETIC_PRIMARY_CONSTRUCTOR : IrDeclarationOriginImpl("SYNTHETIC_PRIMARY_CONSTRUCTOR")
 
     private val unitType = context.irBuiltIns.unitType
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/SecondaryCtorLowering.kt

@@ -36,6 +36,7 @@ import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 class SecondaryConstructorLowering(val context: JsIrBackendContext) : DeclarationTransformer {
 
     override fun transformFlat(declaration: IrDeclaration): List<IrDeclaration>? {
+        assert(!context.es6mode)
 
         if (declaration is IrConstructor && !declaration.isPrimary) {
             val irClass = declaration.parentAsClass
@@ -228,7 +229,10 @@ private class CallsiteRedirectionTransformer(private val context: JsIrBackendCon
 
         val target = expression.symbol.owner
         return if (target.isSecondaryConstructorCall) {
-            val factory = context.buildConstructorFactory(target, target.parentAsClass)
+            val factory = with(context) {
+                if (es6mode) mapping.secondaryConstructorToDelegate[target] ?: error("Not found IrFunction for secondary ctor")
+                else buildConstructorFactory(target, target.parentAsClass)
+            }
             replaceSecondaryConstructorWithFactoryFunction(expression, factory.symbol)
         } else expression
     }
@@ -240,8 +244,14 @@ private class CallsiteRedirectionTransformer(private val context: JsIrBackendCon
 
         return if (target.isSecondaryConstructorCall) {
             val klass = target.parentAsClass
-            val delegate = context.buildConstructorDelegate(target, klass)
+            val delegate = with(context) {
+                if (es6mode) mapping.secondaryConstructorToDelegate[target] ?: error("Not found IrFunction for secondary ctor")
+                else buildConstructorDelegate(target, klass)
+            }
             val newCall = replaceSecondaryConstructorWithFactoryFunction(expression, delegate.symbol)
+            if (context.es6mode) {
+                return newCall
+            }
 
             val readThis = expression.run {
                 if (data!! is IrConstructor) {

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ThrowableLowering.kt

@@ -13,18 +13,21 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationParent
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.isNullableString
 import org.jetbrains.kotlin.ir.types.makeNotNull
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 
 
-class ThrowableLowering(val context: JsIrBackendContext) : BodyLoweringPass {
+class ThrowableLowering(
+    val context: JsIrBackendContext,
+    val extendThrowableFunction: IrSimpleFunctionSymbol
+) : BodyLoweringPass {
     private val nothingNType get() = context.irBuiltIns.nothingNType
 
     private val throwableConstructors = context.throwableConstructors
     private val newThrowableFunction = context.newThrowableSymbol
-    private val extendThrowableFunction = context.extendThrowableSymbol
 
     fun nullValue(): IrExpression = IrConstImpl.constNull(UNDEFINED_OFFSET, UNDEFINED_OFFSET, nothingNType)