[JS IR BE] Support coroutines

* Move FinallyBlockLowering to common part
* Fix catching of dynamic exception
* Fix bridges for suspend functions
* Disable explicit cast to Unit
* Run lowering per module
* Update some test data

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/Ir.kt

@@ -44,7 +44,7 @@ abstract class Symbols<out T : CommonBackendContext>(val context: T, private val
         return initializer()
     }
 
-    val refClass = calc { symbolTable.referenceClass(context.getInternalClass("Ref")) }
+//    val refClass = calc { symbolTable.referenceClass(context.getInternalClass("Ref")) }
 
     //abstract val areEqualByValue: List<IrFunctionSymbol>
 

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

@@ -0,0 +1,318 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.backend.common.lower
+
+import org.jetbrains.kotlin.backend.common.*
+import org.jetbrains.kotlin.backend.common.descriptors.synthesizedName
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.builders.*
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.impl.IrVariableImpl
+import org.jetbrains.kotlin.ir.descriptors.IrTemporaryVariableDescriptorImpl
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.*
+import org.jetbrains.kotlin.ir.symbols.IrReturnTargetSymbol
+import org.jetbrains.kotlin.ir.symbols.IrReturnableBlockSymbol
+import org.jetbrains.kotlin.ir.symbols.impl.IrReturnableBlockSymbolImpl
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.toKotlinType
+import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.isNothing
+import org.jetbrains.kotlin.types.typeUtil.isUnit
+
+class FinallyBlocksLowering(val context: CommonBackendContext, private val throwableType: IrType): FileLoweringPass, IrElementTransformerVoidWithContext() {
+
+    private interface HighLevelJump {
+        fun toIr(context: CommonBackendContext, startOffset: Int, endOffset: Int, value: IrExpression): IrExpression
+    }
+
+    private data class Return(val target: IrReturnTargetSymbol): HighLevelJump {
+        override fun toIr(context: CommonBackendContext, startOffset: Int, endOffset: Int, value: IrExpression)
+                =
+            IrReturnImpl(startOffset, endOffset, context.irBuiltIns.nothingType, target, value)
+    }
+
+    private data class Break(val loop: IrLoop): HighLevelJump {
+        override fun toIr(context: CommonBackendContext, startOffset: Int, endOffset: Int, value: IrExpression)
+                = IrCompositeImpl(
+            startOffset, endOffset, context.irBuiltIns.unitType, null,
+            statements = listOf(
+                value,
+                IrBreakImpl(startOffset, endOffset, context.irBuiltIns.nothingType, loop)
+            )
+        )
+    }
+
+    private data class Continue(val loop: IrLoop): HighLevelJump {
+        override fun toIr(context: CommonBackendContext, startOffset: Int, endOffset: Int, value: IrExpression)
+                = IrCompositeImpl(
+            startOffset, endOffset, context.irBuiltIns.unitType, null,
+            statements = listOf(
+                value,
+                IrContinueImpl(startOffset, endOffset, context.irBuiltIns.nothingType, loop)
+            )
+        )
+    }
+
+    private abstract class Scope
+
+    private class ReturnableScope(val descriptor: CallableDescriptor): Scope()
+
+    private class LoopScope(val loop: IrLoop): Scope()
+
+    private class TryScope(var expression: IrExpression,
+                           val finallyExpression: IrExpression,
+                           val irBuilder: IrBuilderWithScope
+    ): Scope() {
+        val jumps = mutableMapOf<HighLevelJump, IrReturnTargetSymbol>()
+    }
+
+    private val scopeStack = mutableListOf<Scope>()
+
+    private inline fun <S: Scope, R> using(scope: S, block: (S) -> R): R {
+        scopeStack.push(scope)
+        try {
+            return block(scope)
+        } finally {
+            scopeStack.pop()
+        }
+    }
+
+    override fun lower(irFile: IrFile) {
+        irFile.transformChildrenVoid(this)
+    }
+
+    override fun visitFunctionNew(declaration: IrFunction): IrStatement {
+        using(ReturnableScope(declaration.descriptor)) {
+            return super.visitFunctionNew(declaration)
+        }
+    }
+
+    override fun visitContainerExpression(expression: IrContainerExpression): IrExpression {
+        if (expression !is IrReturnableBlockImpl)
+            return super.visitContainerExpression(expression)
+
+        using(ReturnableScope(expression.descriptor)) {
+            return super.visitContainerExpression(expression)
+        }
+    }
+
+    override fun visitLoop(loop: IrLoop): IrExpression {
+        using(LoopScope(loop)) {
+            return super.visitLoop(loop)
+        }
+    }
+
+    override fun visitBreak(jump: IrBreak): IrExpression {
+        val startOffset = jump.startOffset
+        val endOffset = jump.endOffset
+        val irBuilder = context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol, startOffset, endOffset)
+        return performHighLevelJump(
+            targetScopePredicate = { it is LoopScope && it.loop == jump.loop },
+            jump                 = Break(jump.loop),
+            startOffset          = startOffset,
+            endOffset            = endOffset,
+            value                = irBuilder.irGetObject(context.ir.symbols.unit)
+        ) ?: jump
+    }
+
+    override fun visitContinue(jump: IrContinue): IrExpression {
+        val startOffset = jump.startOffset
+        val endOffset = jump.endOffset
+        val irBuilder = context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol, startOffset, endOffset)
+        return performHighLevelJump(
+            targetScopePredicate = { it is LoopScope && it.loop == jump.loop },
+            jump                 = Continue(jump.loop),
+            startOffset          = startOffset,
+            endOffset            = endOffset,
+            value                = irBuilder.irGetObject(context.ir.symbols.unit)
+        ) ?: jump
+    }
+
+    override fun visitReturn(expression: IrReturn): IrExpression {
+        expression.transformChildrenVoid(this)
+
+        return performHighLevelJump(
+            targetScopePredicate = { it is ReturnableScope && it.descriptor == expression.returnTarget },
+            jump                 = Return(expression.returnTargetSymbol),
+            startOffset          = expression.startOffset,
+            endOffset            = expression.endOffset,
+            value                = expression.value
+        ) ?: expression
+    }
+
+    private fun performHighLevelJump(targetScopePredicate: (Scope) -> Boolean,
+                                     jump: HighLevelJump,
+                                     startOffset: Int,
+                                     endOffset: Int,
+                                     value: IrExpression
+    ): IrExpression? {
+        val tryScopes = scopeStack.reversed()
+                .takeWhile { !targetScopePredicate(it) }
+                .filterIsInstance<TryScope>()
+                .toList()
+        if (tryScopes.isEmpty())
+            return null
+        return performHighLevelJump(tryScopes, 0, jump, startOffset, endOffset, value)
+    }
+
+    private val IrReturnTarget.returnType: IrType
+        get() = when (this) {
+            is IrConstructor -> context.irBuiltIns.unitType
+            is IrFunction -> returnType
+            is IrReturnableBlock -> type
+            else -> error("Unknown ReturnTarget: $this")
+        }
+
+    private fun performHighLevelJump(tryScopes: List<TryScope>,
+                                     index: Int,
+                                     jump: HighLevelJump,
+                                     startOffset: Int,
+                                     endOffset: Int,
+                                     value: IrExpression
+    ): IrExpression {
+        if (index == tryScopes.size)
+            return jump.toIr(context, startOffset, endOffset, value)
+
+        val currentTryScope = tryScopes[index]
+        currentTryScope.jumps.getOrPut(jump) {
+            val type = (jump as? Return)?.target?.owner?.returnType ?: value.type
+            val symbol = getIrReturnableBlockSymbol(jump.toString(), type)
+            with(currentTryScope) {
+                irBuilder.run {
+                    val inlinedFinally = irInlineFinally(symbol, type, expression, finallyExpression)
+                    expression = performHighLevelJump(
+                            tryScopes   = tryScopes,
+                            index       = index + 1,
+                            jump        = jump,
+                            startOffset = startOffset,
+                            endOffset   = endOffset,
+                            value       = inlinedFinally)
+                }
+            }
+            symbol
+        }.let {
+            return IrReturnImpl(
+                startOffset = startOffset,
+                endOffset = endOffset,
+                type = context.irBuiltIns.nothingType,
+                returnTargetSymbol = it,
+                value = value
+            )
+        }
+    }
+
+    override fun visitTry(aTry: IrTry): IrExpression {
+        val finallyExpression = aTry.finallyExpression
+                ?: return super.visitTry(aTry)
+
+        val startOffset = aTry.startOffset
+        val endOffset = aTry.endOffset
+        val irBuilder = context.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol, startOffset, endOffset)
+        val transformer = this
+        irBuilder.run {
+            val transformedTry = IrTryImpl(
+                startOffset = startOffset,
+                endOffset = endOffset,
+                type = context.irBuiltIns.unitType
+            )
+            val transformedFinallyExpression = finallyExpression.transform(transformer, null)
+            val parameter = IrTemporaryVariableDescriptorImpl(
+                containingDeclaration = currentScope!!.scope.scopeOwner,
+                name = Name.identifier("t"),
+                outType = throwableType.toKotlinType()
+            )
+            val catchParameter = IrVariableImpl(
+                startOffset, endOffset, IrDeclarationOrigin.CATCH_PARAMETER, parameter,
+                throwableType
+            )
+
+            val syntheticTry = IrTryImpl(
+                startOffset = startOffset,
+                endOffset = endOffset,
+                type = context.irBuiltIns.unitType,
+                tryResult = transformedTry,
+                catches = listOf(
+                    irCatch(catchParameter).apply {
+                        result = irComposite {
+                            +finallyExpression.copy()
+                            +irThrow(irGet(catchParameter))
+                        }
+                    }),
+                finallyExpression = null
+            )
+            using(TryScope(syntheticTry, transformedFinallyExpression, this)) {
+                val fallThroughType = aTry.type
+                val fallThroughSymbol = getIrReturnableBlockSymbol("fallThrough", fallThroughType)
+                val transformedResult = aTry.tryResult.transform(transformer, null)
+                transformedTry.tryResult = irReturn(fallThroughSymbol, transformedResult)
+                for (aCatch in aTry.catches) {
+                    val transformedCatch = aCatch.transform(transformer, null)
+                    transformedCatch.result = irReturn(fallThroughSymbol, transformedCatch.result)
+                    transformedTry.catches.add(transformedCatch)
+                }
+                return irInlineFinally(fallThroughSymbol, fallThroughType, it.expression, it.finallyExpression)
+            }
+        }
+    }
+
+    private fun IrBuilderWithScope.irInlineFinally(symbol: IrReturnableBlockSymbol, type: IrType,
+                                                                                    value: IrExpression,
+                                                                                    finallyExpression: IrExpression
+    ): IrExpression {
+        val returnType = symbol.descriptor.returnType!!
+        return when {
+            returnType.isUnit() || returnType.isNothing() -> irBlock(value, null, type) {
+                +irReturnableBlock(symbol, type) {
+                    +value
+                }
+                +finallyExpression.copy()
+            }
+            else -> irComposite(value, null, type) {
+                val tmp = irTemporary(irReturnableBlock(symbol, type) {
+                    +irReturn(symbol, value)
+                })
+                +finallyExpression.copy()
+                +irGet(tmp)
+            }
+        }
+    }
+
+    private fun getFakeFunctionDescriptor(name: String, returnType: KotlinType) =
+            SimpleFunctionDescriptorImpl.create(
+                currentScope!!.scope.scopeOwner,
+                Annotations.EMPTY,
+                name.synthesizedName,
+                CallableMemberDescriptor.Kind.SYNTHESIZED,
+                SourceElement.NO_SOURCE
+            ).apply {
+                initialize(null, null, emptyList(), emptyList(), returnType,
+                           Modality.ABSTRACT,
+                           Visibilities.PRIVATE
+                )
+            }
+
+    private fun getIrReturnableBlockSymbol(name: String, returnType: IrType): IrReturnableBlockSymbol =
+        IrReturnableBlockSymbolImpl(getFakeFunctionDescriptor(name, returnType.toKotlinType()))
+
+    private inline fun <reified T : IrElement> T.copy() = this.deepCopyWithVariables()
+
+    fun IrBuilderWithScope.irReturn(target: IrReturnTargetSymbol, value: IrExpression) =
+        IrReturnImpl(startOffset, endOffset, context.irBuiltIns.nothingType, target, value)
+
+    inline fun IrBuilderWithScope.irReturnableBlock(symbol: IrReturnableBlockSymbol, type: IrType, body: IrBlockBuilder.() -> Unit) =
+        IrReturnableBlockImpl(
+            startOffset, endOffset, type, symbol, null,
+            IrBlockBuilder(context, scope, startOffset, endOffset, null, type, true)
+                .block(body).statements
+        )
+}

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

@@ -247,6 +247,31 @@ class InnerClassConstructorCallsLowering(val context: BackendContext) : BodyLowe
                 return newCall
             }
 
+            override fun visitFunctionReference(expression: IrFunctionReference): IrExpression {
+                expression.transformChildrenVoid(this)
+
+                val callee = expression.symbol as? IrConstructorSymbol ?: return expression
+                val parent = callee.owner.parent as? IrClass ?: return expression
+                if (!parent.isInner) return expression
+
+                val newCallee = context.descriptorsFactory.getInnerClassConstructorWithOuterThisParameter(callee.owner)
+
+                val newReference = expression.run { IrFunctionReferenceImpl(startOffset, endOffset, type, newCallee, newCallee.descriptor, typeArgumentsCount, origin) }
+
+                newReference.let {
+                    it.dispatchReceiver = expression.dispatchReceiver
+                    it.extensionReceiver = expression.extensionReceiver
+                    for (t in 0 until expression.typeArgumentsCount) {
+                        it.putTypeArgument(t, expression.getTypeArgument(t))
+                    }
+
+                    for (v in 0 until expression.valueArgumentsCount) {
+                        it.putValueArgument(v, expression.getValueArgument(v))
+                    }
+                }
+
+                return newReference
+            }
             // TODO callable references?
         })
     }

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

@@ -88,6 +88,13 @@ inline fun IrGeneratorWithScope.irBlock(
 ) =
     this.irBlock(expression.startOffset, expression.endOffset, origin, resultType, body)
 
+inline fun IrGeneratorWithScope.irComposite(
+    expression: IrExpression, origin: IrStatementOrigin? = null,
+    resultType: IrType? = expression.type,
+    body: IrBlockBuilder.() -> Unit
+) =
+    this.irComposite(expression.startOffset, expression.endOffset, origin, resultType, body)
+
 inline fun IrGeneratorWithScope.irBlockBody(irElement: IrElement, body: IrBlockBodyBuilder.() -> Unit) =
     this.irBlockBody(irElement.startOffset, irElement.endOffset, body)
 

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/utils/kotlinTypeBasedUtils.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.backend.common.utils
 
 import org.jetbrains.kotlin.backend.common.descriptors.isFunctionOrKFunctionType
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.isBuiltinFunctionalTypeOrSubtype
 import org.jetbrains.kotlin.builtins.isFunctionTypeOrSubtype
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.types.IrType
@@ -36,3 +37,5 @@ fun List<IrType>.commonSupertype() = CommonSupertypes.commonSupertype(map(IrType
 fun IrType.isSubtypeOf(superType: IrType) = toKotlinType().isSubtypeOf(superType.toKotlinType())
 
 fun IrType.isSubtypeOfClass(superClass: IrClassSymbol) = DescriptorUtils.isSubtypeOfClass(toKotlinType(), superClass.descriptor)
+
+fun IrType.isBuiltinFunctionalTypeOrSubtype() = toKotlinType().isBuiltinFunctionalTypeOrSubtype

compiler/ir/backend.common/src/org/jetbrains/kotlin/ir/util/IrBackendUtils.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.ir.util
 import org.jetbrains.kotlin.backend.common.atMostOne
 import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.name.Name
 
@@ -31,3 +32,6 @@ fun IrClassSymbol.getPropertyGetter(name: String): IrFunctionSymbol? =
 
 fun IrClassSymbol.getPropertySetter(name: String): IrFunctionSymbol? =
     this.getPropertyDeclaration(name)?.setter?.symbol
+
+fun IrClassSymbol.getPropertyField(name: String): IrFieldSymbol? =
+    this.getPropertyDeclaration(name)?.backingField?.symbol

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

@@ -99,7 +99,6 @@ class JsIntrinsics(
     val jsInstanceOf = binOpBool("jsInstanceOf")
     val jsTypeOf = unOp("jsTypeOf", irBuiltIns.string)
 
-
     // Number conversions:
 
     val jsNumberToByte = getInternalFunction("numberToByte")
@@ -132,6 +131,14 @@ class JsIntrinsics(
     val jsCompareTo = getInternalFunction("compareTo")
     val jsEquals = getInternalFunction("equals")
 
+    // Coroutines
+
+    val jsCoroutineContext = context.symbolTable.referenceSimpleFunction(context.coroutineContextProperty.getter!!)
+
+    val jsGetContinuation = context.run {
+        val f = getInternalFunctions("getContinuation")
+        symbolTable.referenceSimpleFunction(f.single())
+    }
     val jsNumberRangeToNumber = getInternalFunction("numberRangeToNumber")
     val jsNumberRangeToLong = getInternalFunction("numberRangeToLong")
 

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

@@ -13,20 +13,28 @@ import org.jetbrains.kotlin.backend.common.ir.Symbols
 import org.jetbrains.kotlin.backend.js.JsDescriptorsFactory
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.backend.js.lower.inline.ModuleIndex
 import org.jetbrains.kotlin.ir.backend.js.utils.OperatorNames
-import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrFile
+import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
-import org.jetbrains.kotlin.ir.symbols.*
-import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.toKotlinType
+import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.IrEnumEntrySymbol
+import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.types.impl.IrDynamicTypeImpl
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.types.createDynamicType
 
 class JsIrBackendContext(
     val module: ModuleDescriptor,
@@ -48,28 +56,75 @@ class JsIrBackendContext(
     private val internalPackageName = FqName("kotlin.js")
     private val internalPackage = module.getPackage(internalPackageName)
 
+    // TODO: replace it with appropriate package name once we migrate to 1.3 coroutines
+    private val coroutinePackageNameSrting = "kotlin.coroutines.experimental"
+
+    private val INTRINSICS_PACKAGE_NAME = Name.identifier("intrinsics")
+    private val COROUTINE_SUSPENDED_NAME = Name.identifier("COROUTINE_SUSPENDED")
+    private val COROUTINE_CONTEXT_NAME = Name.identifier("coroutineContext")
+    private val COROUTINE_IMPL_NAME = Name.identifier("CoroutineImpl")
+    private val CONTINUATION_NAME = Name.identifier("Continuation")
+
+    // TODO: what is more clear way reference this getter?
+    private val CONTINUATION_CONTEXT_GETTER_NAME = Name.special("<get-context>")
+
+    private val coroutinePackageName = FqName(coroutinePackageNameSrting)
+    private val coroutineIntrinsicsPackageName = coroutinePackageName.child(INTRINSICS_PACKAGE_NAME)
+
+    private val coroutinePackage = module.getPackage(coroutinePackageName)
+    private val coroutineIntrinsicsPackage = module.getPackage(coroutineIntrinsicsPackageName)
+
+    val enumEntryToGetInstanceFunction = mutableMapOf<IrEnumEntrySymbol, IrSimpleFunctionSymbol>()
+
+    val coroutineGetContext: IrFunctionSymbol
+        get() {
+            val continuation = symbolTable.referenceClass(
+                coroutinePackage.memberScope.getContributedClassifier(
+                    CONTINUATION_NAME,
+                    NoLookupLocation.FROM_BACKEND
+                ) as ClassDescriptor
+            )
+            val contextGetter = continuation.owner.declarations.single { it.descriptor.name == CONTINUATION_CONTEXT_GETTER_NAME } as IrFunction
+            return contextGetter.symbol
+        }
+
+    val coroutineContextProperty: PropertyDescriptor
+        get() {
+            val vars = internalPackage.memberScope.getContributedVariables(
+                COROUTINE_CONTEXT_NAME,
+                NoLookupLocation.FROM_BACKEND
+            )
+            return vars.single()
+        }
+
     val intrinsics = JsIntrinsics(module, irBuiltIns, this)
 
     private val operatorMap = referenceOperators()
 
-    data class SecondaryCtorPair(val delegate: IrSimpleFunctionSymbol, val stub: IrSimpleFunctionSymbol)
+    val functions = (0..22).map { symbolTable.referenceClass(builtIns.getFunction(it)) }
 
-    val secondaryConstructorsMap = mutableMapOf<IrConstructorSymbol, SecondaryCtorPair>()
-    val enumEntryToGetInstanceFunction = mutableMapOf<IrEnumEntrySymbol, IrSimpleFunctionSymbol>()
+    val kFunctions by lazy {
+        (0..22).map { symbolTable.referenceClass(reflectionTypes.getKFunction(it)) }
+    }
 
-    fun getOperatorByName(name: Name, type: IrType) = operatorMap[name]?.get(type.toKotlinType())
+    val suspendFunctions = (0..22).map { symbolTable.referenceClass(builtIns.getSuspendFunction(it)) }
+
+    val dynamicType = IrDynamicTypeImpl(createDynamicType(builtIns), emptyList(), Variance.INVARIANT)
 
     val originalModuleIndex = ModuleIndex(irModuleFragment)
 
+    fun getOperatorByName(name: Name, type: KotlinType) = operatorMap[name]?.get(type)
+
     override val ir = object : Ir<CommonBackendContext>(this, irModuleFragment) {
         override val symbols = object : Symbols<CommonBackendContext>(this@JsIrBackendContext, symbolTable.lazyWrapper) {
 
             override fun calc(initializer: () -> IrClassSymbol): IrClassSymbol {
+                val v = lazy { initializer() }
                 return object : IrClassSymbol {
-                    override val owner: IrClass get() = TODO("not implemented")
-                    override val isBound: Boolean get() = TODO("not implemented")
-                    override fun bind(owner: IrClass) = TODO("not implemented")
-                    override val descriptor: ClassDescriptor get() = TODO("not implemented")
+                    override val owner: IrClass get() = v.value.owner
+                    override val isBound: Boolean get() = v.value.isBound
+                    override fun bind(owner: IrClass) = v.value.bind(owner)
+                    override val descriptor: ClassDescriptor get() = v.value.descriptor
                 }
             }
 
@@ -97,10 +152,10 @@ class JsIrBackendContext(
                 get() = TODO("not implemented")
             override val copyRangeTo: Map<ClassDescriptor, IrSimpleFunctionSymbol>
                 get() = TODO("not implemented")
-            override val coroutineImpl: IrClassSymbol
-                get() = TODO("not implemented")
-            override val coroutineSuspendedGetter: IrSimpleFunctionSymbol
-                get() = TODO("not implemented")
+            override val coroutineImpl = symbolTable.referenceClass(getInternalClass(COROUTINE_IMPL_NAME.identifier))
+            override val coroutineSuspendedGetter = symbolTable.referenceSimpleFunction(
+                coroutineIntrinsicsPackage.memberScope.getContributedVariables(COROUTINE_SUSPENDED_NAME, NoLookupLocation.FROM_BACKEND).single().getter!!
+            )
         }
 
         override fun shouldGenerateHandlerParameterForDefaultBodyFun() = true
@@ -132,6 +187,8 @@ class JsIrBackendContext(
 
     override fun getInternalFunctions(name: String) = findFunctions(internalPackage.memberScope, name)
 
+    fun getFunctions(fqName: FqName) = findFunctions(module.getPackage(fqName.parent()).memberScope, fqName.shortName())
+
     override fun log(message: () -> String) {
         /*TODO*/
         print(message())

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

@@ -6,13 +6,18 @@
 package org.jetbrains.kotlin.ir.backend.js
 
 import com.intellij.openapi.project.Project
-import org.jetbrains.kotlin.backend.common.*
+import org.jetbrains.kotlin.backend.common.FileLoweringPass
 import org.jetbrains.kotlin.backend.common.lower.*
+import org.jetbrains.kotlin.backend.common.runOnFilePostfix
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.ir.backend.js.lower.*
-import org.jetbrains.kotlin.ir.backend.js.lower.inline.*
+import org.jetbrains.kotlin.ir.backend.js.lower.coroutines.SuspendFunctionsLowering
+import org.jetbrains.kotlin.ir.backend.js.lower.inline.FunctionInlining
+import org.jetbrains.kotlin.ir.backend.js.lower.inline.RemoveInlineFunctionsWithReifiedTypeParametersLowering
+import org.jetbrains.kotlin.ir.backend.js.lower.inline.ReturnableBlockLowering
+import org.jetbrains.kotlin.ir.backend.js.lower.inline.replaceUnboundSymbols
 import org.jetbrains.kotlin.ir.backend.js.transformers.irToJs.IrModuleToJsTransformer
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
@@ -59,9 +64,7 @@ fun compile(
 
     context.performInlining(moduleFragment)
 
-    context.lower(moduleFragment.files)
-    val transformer = SecondaryCtorLowering.CallsiteRedirectionTransformer(context)
-    moduleFragment.files.forEach { it.accept(transformer, null) }
+    context.lower(moduleFragment)
 
     val program = moduleFragment.accept(IrModuleToJsTransformer(context), null)
 
@@ -80,30 +83,32 @@ private fun JsIrBackendContext.performInlining(moduleFragment: IrModuleFragment)
     }
 }
 
-private fun JsIrBackendContext.lower(files: List<IrFile>) {
-    LateinitLowering(this, true).lower(files)
-    DefaultArgumentStubGenerator(this).runOnFilePostfix(files)
-    DefaultParameterInjector(this).runOnFilePostfix(files)
-    SharedVariablesLowering(this).runOnFilePostfix(files)
-    EnumClassLowering(this).runOnFilePostfix(files)
-    EnumUsageLowering(this).lower(files)
-    ReturnableBlockLowering(this).lower(files)
-    LocalDeclarationsLowering(this).runOnFilePostfix(files)
-    InnerClassesLowering(this).runOnFilePostfix(files)
-    InnerClassConstructorCallsLowering(this).runOnFilePostfix(files)
-    PropertiesLowering().lower(files)
-    InitializersLowering(this, JsLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, false).runOnFilePostfix(files)
-    MultipleCatchesLowering(this).lower(files)
-    BridgesConstruction(this).runOnFilePostfix(files)
-    TypeOperatorLowering(this).lower(files)
-    BlockDecomposerLowering(this).runOnFilePostfix(files)
-    SecondaryCtorLowering(this).runOnFilePostfix(files)
-    CallableReferenceLowering(this).lower(files)
-    IntrinsicifyCallsLowering(this).lower(files)
+private fun JsIrBackendContext.lower(moduleFragment: IrModuleFragment) {
+    moduleFragment.files.forEach(LateinitLowering(this, true)::lower)
+    moduleFragment.files.forEach(DefaultArgumentStubGenerator(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(DefaultParameterInjector(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(SharedVariablesLowering(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(EnumClassLowering(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(EnumUsageLowering(this)::lower)
+    moduleFragment.files.forEach(ReturnableBlockLowering(this)::lower)
+    moduleFragment.files.forEach(LocalDeclarationsLowering(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(InnerClassesLowering(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(InnerClassConstructorCallsLowering(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(SuspendFunctionsLowering(this)::lower)
+    moduleFragment.files.forEach(PropertiesLowering()::lower)
+    moduleFragment.files.forEach(InitializersLowering(this, JsLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, false)::runOnFilePostfix)
+    moduleFragment.files.forEach(MultipleCatchesLowering(this)::lower)
+    moduleFragment.files.forEach(BridgesConstruction(this)::runOnFilePostfix)
+    moduleFragment.files.forEach(TypeOperatorLowering(this)::lower)
+    moduleFragment.files.forEach(BlockDecomposerLowering(this)::runOnFilePostfix)
+    val sctor = SecondaryCtorLowering(this)
+    moduleFragment.files.forEach(sctor.getConstructorProcessorLowering())
+    moduleFragment.files.forEach(sctor.getConstructorRedirectorLowering())
+    val clble = CallableReferenceLowering(this)
+    moduleFragment.files.forEach(clble.getReferenceCollector())
+    moduleFragment.files.forEach(clble.getClosureBuilder())
+    moduleFragment.files.forEach(clble.getReferenceReplacer())
+    moduleFragment.files.forEach(IntrinsicifyCallsLowering(this)::lower)
 }
 
 private fun FileLoweringPass.lower(files: List<IrFile>) = files.forEach { lower(it) }
-private fun DeclarationContainerLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
-private fun BodyLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
-private fun FunctionLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
-private fun ClassLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir.backend.js.ir
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.utils.OperatorNames
 import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.types.toKotlinType
 import org.jetbrains.kotlin.name.Name
 
 class JsIrArithBuilder(val context: JsIrBackendContext) {
@@ -15,15 +16,15 @@ class JsIrArithBuilder(val context: JsIrBackendContext) {
     val symbols = context.ir.symbols
 
     private fun buildBinaryOperator(name: Name, l: IrExpression, r: IrExpression): IrExpression {
-        val symbol = context.getOperatorByName(name, l.type)!!
-        return JsIrBuilder.buildCall(symbol).apply {
+        val symbol = context.getOperatorByName(name, l.type.toKotlinType())
+        return JsIrBuilder.buildCall(symbol!!).apply {
             dispatchReceiver = l
             putValueArgument(0, r)
         }
     }
 
     private fun buildUnaryOperator(name: Name, v: IrExpression): IrExpression {
-        val symbol = context.getOperatorByName(name, v.type)!!
+        val symbol = context.getOperatorByName(name, v.type.toKotlinType())!!
         return JsIrBuilder.buildCall(symbol).apply { dispatchReceiver = v }
     }
 

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

@@ -5,16 +5,31 @@
 
 package org.jetbrains.kotlin.ir.backend.js.ir
 
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationOriginImpl
-import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
-import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
-import org.jetbrains.kotlin.ir.declarations.impl.IrVariableImpl
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.impl.*
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.ir.types.IrSimpleType
 import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.createType
+import org.jetbrains.kotlin.ir.types.getClass
+import org.jetbrains.kotlin.ir.types.impl.IrStarProjectionImpl
+import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.ir.util.createDispatchReceiverParameter
+import org.jetbrains.kotlin.ir.util.endOffset
+import org.jetbrains.kotlin.ir.util.startOffset
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
+import org.jetbrains.kotlin.resolve.OverridingStrategy
+import org.jetbrains.kotlin.resolve.OverridingUtil
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.typeUtil.immediateSupertypes
+import java.lang.reflect.Proxy
 
 object JsIrBuilder {
 
@@ -77,8 +92,8 @@ object JsIrBuilder {
     fun buildFunctionReference(type: IrType, symbol: IrFunctionSymbol) =
         IrFunctionReferenceImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, symbol, symbol.descriptor, 0, null)
 
-    fun buildVar(symbol: IrVariableSymbol, initializer: IrExpression? = null, type: IrType? = null) =
-        IrVariableImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, SYNTHESIZED_DECLARATION, symbol, type ?: symbol.owner.type)
+    fun buildVar(symbol: IrVariableSymbol, initializer: IrExpression? = null, type: IrType) =
+        IrVariableImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, SYNTHESIZED_DECLARATION, symbol, type)
             .apply { this.initializer = initializer }
 
     fun buildBreak(type: IrType, loop: IrLoop) = IrBreakImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, loop)
@@ -107,8 +122,8 @@ object JsIrBuilder {
         return element
     }
 
-    fun buildWhen(type: IrType, branches: List<IrBranch>) =
-        IrWhenImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, SYNTHESIZED_STATEMENT, branches)
+    fun buildWhen(type: IrType, branches: List<IrBranch>, origin: IrStatementOrigin = SYNTHESIZED_STATEMENT) =
+        IrWhenImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, origin, branches)
 
     fun buildTypeOperator(type: IrType, operator: IrTypeOperator, argument: IrExpression, toType: IrType, symbol: IrClassifierSymbol) =
         IrTypeOperatorCallImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, operator, toType, symbol, argument)
@@ -117,4 +132,276 @@ object JsIrBuilder {
     fun buildBoolean(type: IrType, v: Boolean) = IrConstImpl.boolean(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, v)
     fun buildInt(type: IrType, v: Int) = IrConstImpl.int(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, v)
     fun buildString(type: IrType, s: String) = IrConstImpl.string(UNDEFINED_OFFSET, UNDEFINED_OFFSET, type, s)
+    fun buildCatch(ex: IrVariable, block: IrBlockImpl) = IrCatchImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, ex, block)
 }
+
+
+object SetDeclarationsParentVisitor : IrElementVisitor<Unit, IrDeclarationParent> {
+    override fun visitElement(element: IrElement, data: IrDeclarationParent) {
+        if (element !is IrDeclarationParent) {
+            element.acceptChildren(this, data)
+        }
+    }
+
+    override fun visitDeclaration(declaration: IrDeclaration, data: IrDeclarationParent) {
+        declaration.parent = data
+        super.visitDeclaration(declaration, data)
+    }
+}
+
+fun SymbolTable.translateErased(type: KotlinType): IrSimpleType {
+    val descriptor = TypeUtils.getClassDescriptor(type)
+    if (descriptor == null) return translateErased(type.immediateSupertypes().first())
+    val classSymbol = this.referenceClass(descriptor)
+
+    val nullable = type.isMarkedNullable
+    val arguments = type.arguments.map { IrStarProjectionImpl }
+
+    return classSymbol.createType(nullable, arguments)
+}
+
+fun IrDeclarationContainer.addChildren(declarations: List<IrDeclaration>) {
+    declarations.forEach { this.addChild(it) }
+}
+
+fun IrDeclarationContainer.addChild(declaration: IrDeclaration) {
+    this.declarations += declaration
+    declaration.accept(SetDeclarationsParentVisitor, this)
+}
+
+fun IrClass.simpleFunctions(): List<IrSimpleFunction> = this.declarations.flatMap {
+    when (it) {
+        is IrSimpleFunction -> listOf(it)
+        is IrProperty -> listOfNotNull(it.getter as IrSimpleFunction?, it.setter as IrSimpleFunction?)
+        else -> emptyList()
+    }
+}
+
+fun IrClass.setSuperSymbols(superTypes: List<IrType>) {
+    val supers = superTypes.map { it.getClass()!! }
+    assert(this.superDescriptors().toSet() == supers.map { it.descriptor }.toSet())
+    assert(this.superTypes.isEmpty())
+    this.superTypes += superTypes
+
+    val superMembers = supers.flatMap {
+        it.simpleFunctions()
+    }.associateBy { it.descriptor }
+
+    this.simpleFunctions().forEach {
+        assert(it.overriddenSymbols.isEmpty())
+
+        it.descriptor.overriddenDescriptors.mapTo(it.overriddenSymbols) {
+            val superMember = superMembers[it.original] ?: error(it.original)
+            superMember.symbol
+        }
+    }
+}
+
+fun IrSimpleFunction.setOverrides(symbolTable: SymbolTable) {
+    assert(this.overriddenSymbols.isEmpty())
+
+    this.descriptor.overriddenDescriptors.mapTo(this.overriddenSymbols) {
+        symbolTable.referenceSimpleFunction(it.original)
+    }
+}
+
+
+private fun IrClass.superDescriptors() =
+    this.descriptor.typeConstructor.supertypes.map { it.constructor.declarationDescriptor as ClassDescriptor }
+
+fun IrClass.setSuperSymbols(symbolTable: SymbolTable) {
+    assert(this.superTypes.isEmpty())
+    this.descriptor.typeConstructor.supertypes.mapTo(this.superTypes) { symbolTable.translateErased(it) }
+
+    this.simpleFunctions().forEach {
+        it.setOverrides(symbolTable)
+    }
+}
+
+private fun IrElement.innerStartOffset(descriptor: DeclarationDescriptorWithSource): Int =
+    descriptor.startOffset ?: this.startOffset
+
+private fun IrElement.innerEndOffset(descriptor: DeclarationDescriptorWithSource): Int =
+    descriptor.endOffset ?: this.endOffset
+
+fun IrFunction.createParameterDeclarations(symbolTable: SymbolTable) {
+
+    fun ParameterDescriptor.irValueParameter() = IrValueParameterImpl(
+        innerStartOffset(this), innerEndOffset(this),
+        IrDeclarationOrigin.DEFINED,
+        this, symbolTable.translateErased(this.type),
+        (this as? ValueParameterDescriptor)?.varargElementType?.let { symbolTable.translateErased(it) }
+    ).also {
+        it.parent = this@createParameterDeclarations
+    }
+
+    dispatchReceiverParameter = descriptor.dispatchReceiverParameter?.irValueParameter()
+    extensionReceiverParameter = descriptor.extensionReceiverParameter?.irValueParameter()
+
+    assert(valueParameters.isEmpty())
+    descriptor.valueParameters.mapTo(valueParameters) { it.irValueParameter() }
+
+    assert(typeParameters.isEmpty())
+    descriptor.typeParameters.mapTo(typeParameters) {
+        IrTypeParameterImpl(
+            innerStartOffset(it), innerEndOffset(it),
+            IrDeclarationOrigin.DEFINED,
+            it
+        ).also { typeParameter ->
+            typeParameter.parent = this
+            typeParameter.descriptor.upperBounds.mapTo(typeParameter.superTypes, symbolTable::translateErased)
+        }
+    }
+}
+
+private fun createFakeOverride(
+    descriptor: CallableMemberDescriptor,
+    startOffset: Int,
+    endOffset: Int,
+    symbolTable: SymbolTable
+): IrDeclaration {
+
+    fun FunctionDescriptor.createFunction(): IrSimpleFunction = IrFunctionImpl(
+        startOffset, endOffset,
+        IrDeclarationOrigin.FAKE_OVERRIDE, this
+    ).apply {
+        returnType = symbolTable.translateErased(this@createFunction.returnType!!)
+        createParameterDeclarations(symbolTable)
+    }
+
+    return when (descriptor) {
+        is FunctionDescriptor -> descriptor.createFunction()
+        is PropertyDescriptor ->
+            IrPropertyImpl(startOffset, endOffset, IrDeclarationOrigin.FAKE_OVERRIDE, descriptor).apply {
+                // TODO: add field if getter is missing?
+                getter = descriptor.getter?.createFunction() as IrSimpleFunction?
+                setter = descriptor.setter?.createFunction() as IrSimpleFunction?
+            }
+        else -> TODO(descriptor.toString())
+    }
+}
+
+private fun createFakeOverride(
+    descriptor: CallableMemberDescriptor,
+    overriddenDeclarations: List<IrDeclaration>,
+    irClass: IrClass
+): IrDeclaration {
+
+    // TODO: this function doesn't substitute types.
+    fun IrSimpleFunction.copyFake(descriptor: FunctionDescriptor): IrSimpleFunction = IrFunctionImpl(
+        irClass.startOffset, irClass.endOffset, IrDeclarationOrigin.FAKE_OVERRIDE, descriptor
+    ).also {
+        it.returnType = returnType
+        it.parent = irClass
+        it.createDispatchReceiverParameter()
+
+        it.extensionReceiverParameter = this.extensionReceiverParameter?.let {
+            IrValueParameterImpl(
+                it.startOffset,
+                it.endOffset,
+                IrDeclarationOrigin.DEFINED,
+                it.descriptor.extensionReceiverParameter!!,
+                it.type,
+                null
+            )
+        }
+
+        this.valueParameters.mapTo(it.valueParameters) { oldParameter ->
+            IrValueParameterImpl(
+                oldParameter.startOffset,
+                oldParameter.endOffset,
+                IrDeclarationOrigin.DEFINED,
+                it.descriptor.valueParameters[oldParameter.index],
+                oldParameter.type,
+                (oldParameter as? IrValueParameter)?.varargElementType
+            )
+        }
+
+        this.typeParameters.mapTo(it.typeParameters) { oldParameter ->
+            IrTypeParameterImpl(
+                irClass.startOffset,
+                irClass.endOffset,
+                IrDeclarationOrigin.DEFINED,
+                it.descriptor.typeParameters[oldParameter.index]
+            ).apply {
+                superTypes += oldParameter.superTypes
+            }
+        }
+    }
+
+    val copiedDeclaration = overriddenDeclarations.first()
+
+    return when (copiedDeclaration) {
+        is IrSimpleFunction -> copiedDeclaration.copyFake(descriptor as FunctionDescriptor)
+        is IrProperty -> IrPropertyImpl(
+            irClass.startOffset,
+            irClass.endOffset,
+            IrDeclarationOrigin.FAKE_OVERRIDE,
+            descriptor as PropertyDescriptor
+        ).apply {
+            parent = irClass
+            getter = copiedDeclaration.getter?.copyFake(descriptor.getter!!)
+            setter = copiedDeclaration.setter?.copyFake(descriptor.setter!!)
+        }
+        else -> error(copiedDeclaration)
+    }
+}
+
+fun IrClass.setSuperSymbolsAndAddFakeOverrides(superTypes: List<IrType>) {
+    val overriddenSuperMembers = this.declarations.map { it.descriptor }
+        .filterIsInstance<CallableMemberDescriptor>().flatMap { it.overriddenDescriptors.map { it.original } }.toSet()
+
+    val unoverriddenSuperMembers = superTypes.map { it.getClass()!! }.flatMap {
+        it.declarations.filter { it.descriptor !in overriddenSuperMembers }.mapNotNull {
+            when (it) {
+                is IrSimpleFunction -> it.descriptor to it
+                is IrProperty -> it.descriptor to it
+                else -> null
+            }
+        }
+    }.toMap()
+
+    val irClass = this
+
+    val overridingStrategy = object : OverridingStrategy() {
+        override fun addFakeOverride(fakeOverride: CallableMemberDescriptor) {
+            val overriddenDeclarations =
+                fakeOverride.overriddenDescriptors.map { unoverriddenSuperMembers[it]!! }
+
+            assert(overriddenDeclarations.isNotEmpty())
+
+            irClass.declarations.add(createFakeOverride(fakeOverride, overriddenDeclarations, irClass))
+        }
+
+        override fun inheritanceConflict(first: CallableMemberDescriptor, second: CallableMemberDescriptor) {
+            error("inheritance conflict in synthesized class ${irClass.descriptor}:\n  $first\n  $second")
+        }
+
+        override fun overrideConflict(fromSuper: CallableMemberDescriptor, fromCurrent: CallableMemberDescriptor) {
+            error("override conflict in synthesized class ${irClass.descriptor}:\n  $fromSuper\n  $fromCurrent")
+        }
+    }
+
+    unoverriddenSuperMembers.keys.groupBy { it.name }.forEach { (name, members) ->
+        OverridingUtil.generateOverridesInFunctionGroup(
+            name,
+            members,
+            emptyList(),
+            this.descriptor,
+            overridingStrategy
+        )
+    }
+
+    this.setSuperSymbols(superTypes)
+}
+
+inline fun <reified T> stub(name: String): T {
+    return Proxy.newProxyInstance(T::class.java.classLoader, arrayOf(T::class.java)) {
+            _ /* proxy */, method, _ /* methodArgs */ ->
+        if (method.name == "toString" && method.parameterCount == 0) {
+            "${T::class.simpleName} stub for $name"
+        } else {
+            error("${T::class.simpleName}.${method.name} is not supported for $name")
+        }
+    } as T
+}

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

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.ir.backend.js.lower
 
 import org.jetbrains.kotlin.backend.common.DeclarationContainerLoweringPass
+import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
@@ -22,22 +23,10 @@ import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 
-class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationContainerLoweringPass {
-    private lateinit var function: IrFunction
-    private var tmpVarCounter: Int = 0
+class BlockDecomposerLowering(context: JsIrBackendContext) : DeclarationContainerLoweringPass {
 
-    private val statementTransformer = StatementTransformer()
-    private val expressionTransformer = ExpressionTransformer()
-
-    private val constTrue = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, true)
-    private val constFalse = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, false)
-    private val nothingType = context.irBuiltIns.nothingNType
-
-    private val unitType = context.irBuiltIns.unitType
-    private val unitValue = JsIrBuilder.buildGetObjectValue(unitType, context.symbolTable.referenceClass(context.builtIns.unit))
-
-    private val unreachableFunction =
-        JsSymbolBuilder.buildSimpleFunction(context.module, Namer.UNREACHABLE_NAME).initialize(returnType = nothingType)
+    private val decomposerTransformer = BlockDecomposerTransformer(context)
+    private val nothingType = context.irBuiltIns.nothingType
 
     override fun lower(irDeclarationContainer: IrDeclarationContainer) {
         irDeclarationContainer.declarations.transformFlat { declaration ->
@@ -53,9 +42,7 @@ class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationCont
     }
 
     fun lower(irFunction: IrFunction) {
-        function = irFunction
-        tmpVarCounter = 0
-        irFunction.transformChildrenVoid(statementTransformer)
+        irFunction.accept(decomposerTransformer, null)
     }
 
     fun lower(irField: IrField, container: IrDeclarationContainer): List<IrDeclaration> {
@@ -86,6 +73,33 @@ class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationCont
 
         return listOf(irField)
     }
+}
+
+class BlockDecomposerTransformer(context: JsIrBackendContext) : IrElementTransformerVoid() {
+    private lateinit var function: IrFunction
+    private var tmpVarCounter: Int = 0
+
+    private val statementTransformer = StatementTransformer()
+    private val expressionTransformer = ExpressionTransformer()
+
+    private val constTrue = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, true)
+    private val constFalse = JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, false)
+    private val nothingType = context.irBuiltIns.nothingNType
+
+    private val unitType = context.irBuiltIns.unitType
+    private val unitValue = JsIrBuilder.buildGetObjectValue(unitType, context.symbolTable.referenceClass(context.builtIns.unit))
+
+    private val unreachableFunction =
+        JsSymbolBuilder.buildSimpleFunction(context.module, Namer.UNREACHABLE_NAME).initialize(returnType = nothingType)
+    private val booleanNotSymbol = context.irBuiltIns.booleanNotSymbol
+
+    override fun visitFunction(declaration: IrFunction): IrStatement {
+        function = declaration
+        tmpVarCounter = 0
+        return declaration.transform(statementTransformer, null)
+    }
+
+    override fun visitElement(element: IrElement) = element.transform(statementTransformer, null)
 
     private fun processStatements(statements: MutableList<IrStatement>) {
         statements.transformFlat {
@@ -171,7 +185,7 @@ class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationCont
                 val result = IrCompositeImpl(receiverResult.startOffset, expression.endOffset, unitType)
                 val receiverValue = receiverResult.statements.last() as IrExpression
                 val tmp = makeTempVar(receiverResult.type)
-                val irVar = JsIrBuilder.buildVar(tmp, receiverValue)
+                val irVar = JsIrBuilder.buildVar(tmp, receiverValue, receiverResult.type)
                 val setValue = valueResult.statements.last() as IrExpression
                 result.statements += receiverResult.statements.run { subList(0, lastIndex) }
                 result.statements += irVar
@@ -249,7 +263,7 @@ class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationCont
 
                 val newLoopCondition = newCondition.statements.last() as IrExpression
 
-                val breakCond = JsIrBuilder.buildCall(context.irBuiltIns.booleanNotSymbol).apply {
+                val breakCond = JsIrBuilder.buildCall(booleanNotSymbol).apply {
                     putValueArgument(0, newLoopCondition)
                 }
 
@@ -373,7 +387,7 @@ class BlockDecomposerLowering(val context: JsIrBackendContext) : DeclarationCont
             return block
         }
 
-        override fun visitTry(aTry: IrTry) = aTry.also { it.transformChildrenVoid(this); }
+        override fun visitTry(aTry: IrTry) = aTry.also { it.transformChildrenVoid(this) }
     }
 
     private inner class ExpressionTransformer : IrElementTransformerVoid() {

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

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrNull
+import org.jetbrains.kotlin.ir.types.isUnit
 import org.jetbrains.kotlin.ir.types.toKotlinType
 import org.jetbrains.kotlin.ir.util.createParameterDeclarations
 import org.jetbrains.kotlin.ir.util.isInterface
@@ -48,18 +49,21 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 //  Example: for given class hierarchy
 //
 //          class C<T>  {
-//            fun foo(t: T) = ...
+//            fun foo(t: T) = ... // bridge
 //          }
 //
 //          class D : C<Int> {
-//            override fun foo(t: Int) = impl
+//            override fun foo(t: Int) = impl // delegate to
+//          }
+//
+//          class E : D {
+//            <fake override> fun foo(t: Int)  // function
 //          }
 //
 //  it adds method D that delegates generic calls to implementation:
 //
-//          class D : C<Int> {
-//            override fun foo(t: Int) = impl
-//            fun foo(t: Any?) = foo(t as Int)  // Constructed bridge
+//          class E : D {
+//            fun foo(t: Any?) = foo(t as Int) // bridgeDescriptorForIrFunction
 //          }
 //
 class BridgesConstruction(val context: JsIrBackendContext) : ClassLoweringPass {
@@ -125,6 +129,8 @@ class BridgesConstruction(val context: JsIrBackendContext) : ClassLoweringPass {
             bridge.descriptor.returnType, bridge.descriptor.modality, function.visibility
         )
 
+        bridgeDescriptorForIrFunction.isSuspend = bridge.descriptor.isSuspend
+
         // TODO: Support offsets for debug info
         val irFunction = IrFunctionImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, IrDeclarationOrigin.DEFINED, bridgeDescriptorForIrFunction)
         irFunction.createParameterDeclarations()
@@ -136,7 +142,10 @@ class BridgesConstruction(val context: JsIrBackendContext) : ClassLoweringPass {
             irFunction.extensionReceiverParameter?.let {
                 call.extensionReceiver = irCastIfNeeded(irGet(it), delegateTo.extensionReceiverParameter!!.type)
             }
-            irFunction.valueParameters.mapIndexed { i, valueParameter ->
+
+            val toTake = irFunction.valueParameters.size - if (call.descriptor.isSuspend xor irFunction.descriptor.isSuspend) 1 else 0
+
+            irFunction.valueParameters.subList(0, toTake).mapIndexed { i, valueParameter ->
                 call.putValueArgument(i, irCastIfNeeded(irGet(valueParameter), delegateTo.valueParameters[i].type))
             }
             +irReturn(call)
@@ -147,8 +156,9 @@ class BridgesConstruction(val context: JsIrBackendContext) : ClassLoweringPass {
         return irFunction
     }
 
+    // TODO: get rid of Unit check
     private fun IrBlockBodyBuilder.irCastIfNeeded(argument: IrExpression, type: IrType): IrExpression =
-        if (argument.type.classifierOrNull == type.classifierOrNull) argument else irAs(argument, type)
+        if (argument.type.classifierOrNull == type.classifierOrNull || type.isUnit()) argument else irAs(argument, type)
 }
 
 // Handle for common.bridges

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

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
+import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrValueParameterSymbol
 import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
@@ -30,7 +31,7 @@ import org.jetbrains.kotlin.ir.visitors.*
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 
 // TODO: generate $metadata$ property and fill it with corresponding KFunction/KProperty interface
-class CallableReferenceLowering(val context: JsIrBackendContext) : FileLoweringPass {
+class CallableReferenceLowering(val context: JsIrBackendContext) {
 
     private data class CallableReferenceKey(
         val declaration: IrFunction,
@@ -47,12 +48,26 @@ class CallableReferenceLowering(val context: JsIrBackendContext) : FileLoweringP
 
     private val newDeclarations = mutableListOf<IrDeclaration>()
 
-    override fun lower(irFile: IrFile) {
-        irFile.acceptVoid(CallableReferenceCollector())
-        buildClosures()
-        irFile.transformChildrenVoid(CallableReferenceTransformer())
-        irFile.declarations += newDeclarations
-    }
+    fun getReferenceCollector() = object : FileLoweringPass {
+        private val collector = CallableReferenceCollector()
+        override fun lower(irFile: IrFile) = irFile.acceptVoid(collector)
+    }::lower
+
+    fun getClosureBuilder() = object : FileLoweringPass {
+        override fun lower(irFile: IrFile) {
+            newDeclarations.clear()
+            buildClosures(irFile)
+            irFile.declarations += newDeclarations
+        }
+
+    }::lower
+
+    fun getReferenceReplacer() = object : FileLoweringPass {
+        private val replacer = CallableReferenceTransformer()
+        override fun lower(irFile: IrFile) {
+            irFile.transformChildrenVoid(replacer)
+        }
+    }::lower
 
     private fun makeCallableKey(declaration: IrFunction, reference: IrCallableReference) =
         CallableReferenceKey(declaration, reference.dispatchReceiver != null, reference.extensionReceiver != null)
@@ -72,15 +87,30 @@ class CallableReferenceLowering(val context: JsIrBackendContext) : FileLoweringP
         }
     }
 
-    private fun buildClosures() {
+    private fun buildClosures(irFile: IrFile) {
+
+        val declarationsSet = mutableSetOf<IrFunctionSymbol>()
+        irFile.acceptVoid(object : IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) = element.acceptChildrenVoid(this)
+
+            override fun visitFunction(declaration: IrFunction) {
+                super.visitFunction(declaration)
+                declarationsSet += declaration.symbol
+            }
+        })
+
+
         for (v in collectedReferenceMap.values) {
             newDeclarations += v.accept(object : IrElementVisitor<List<IrDeclaration>, Nothing?> {
                 override fun visitElement(element: IrElement, data: Nothing?) = error("Unreachable execution")
                 override fun visitFunctionReference(expression: IrFunctionReference, data: Nothing?) =
-                    lowerKFunctionReference(expression.symbol.owner, expression)
+                    if (expression.symbol in declarationsSet) lowerKFunctionReference(expression.symbol.owner, expression) else emptyList()
 
                 override fun visitPropertyReference(expression: IrPropertyReference, data: Nothing?) =
-                    lowerKPropertyReference(expression.getter!!.owner, expression)
+                    if (expression.getter in declarationsSet) lowerKPropertyReference(
+                        expression.getter!!.owner,
+                        expression
+                    ) else emptyList()
             }, null)
         }
     }

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

@@ -67,21 +67,25 @@ class MultipleCatchesLowering(val context: JsIrBackendContext) : FileLoweringPas
 
                 val commonType = mergeTypes(aTry.catches.map { it.catchParameter.type })
 
-                val pendingExceptionSymbol = JsSymbolBuilder.buildVar(data!!.descriptor, commonType, "\$pending\$", false)
+                val pendingExceptionSymbol = JsSymbolBuilder.buildVar(data!!.descriptor, commonType, "\$p", false)
                 val pendingExceptionDeclaration = JsIrBuilder.buildVar(pendingExceptionSymbol, type = commonType)
                 val pendingException = JsIrBuilder.buildGetValue(pendingExceptionSymbol)
 
                 val branches = mutableListOf<IrBranch>()
 
                 for (catch in aTry.catches) {
-                    assert(!catch.catchParameter.isVar) { "caught exception parameter has to immutable" }
+                    assert(!catch.catchParameter.isVar) { "caught exception parameter has to be immutable" }
                     val type = catch.catchParameter.type
+
                     val typeSymbol = type.classifierOrNull
+                    val castedPendingException = if (type !is IrDynamicType)
+                        buildImplicitCast(pendingException, type, typeSymbol!!)
+                    else pendingException
+
                     val catchBody = catch.result.transform(object : IrElementTransformer<VariableDescriptor> {
                         override fun visitGetValue(expression: IrGetValue, data: VariableDescriptor) =
-                            if (typeSymbol != null && expression.descriptor == data)
-                                // TODO how is it good to generate implicit cast for each access?
-                                buildImplicitCast(pendingException, type, typeSymbol)
+                            if (expression.descriptor == data)
+                                castedPendingException
                             else
                                 expression
                     }, catch.parameter)

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

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.ir.backend.js.lower
 
 import org.jetbrains.kotlin.backend.common.DeclarationContainerLoweringPass
+import org.jetbrains.kotlin.backend.common.runOnFilePostfix
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.descriptors.impl.LazyClassReceiverParameterDescriptor
 import org.jetbrains.kotlin.ir.IrElement
@@ -14,7 +15,6 @@ import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.symbols.JsSymbolBuilder
 import org.jetbrains.kotlin.ir.backend.js.symbols.initialize
-import org.jetbrains.kotlin.ir.backend.js.utils.Namer
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
 import org.jetbrains.kotlin.ir.expressions.*
@@ -24,7 +24,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrReturnImpl
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.symbols.IrFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
-import org.jetbrains.kotlin.ir.symbols.IrValueParameterSymbol
+import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.IrValueParameterSymbolImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.util.defaultType
@@ -33,19 +33,29 @@ import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 
-class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransformerVoid(), DeclarationContainerLoweringPass {
+class SecondaryCtorLowering(val context: JsIrBackendContext) {
 
-    private val oldCtorToNewMap = mutableMapOf<IrConstructorSymbol, JsIrBackendContext.SecondaryCtorPair>()
+    data class ConstructorPair(val delegate: IrSimpleFunctionSymbol, val stub: IrSimpleFunctionSymbol)
 
-    override fun lower(irDeclarationContainer: IrDeclarationContainer) {
-        irDeclarationContainer.declarations.transformFlat {
-            if (it is IrClass) {
-                listOf(it) + lowerClass(it)
-            } else null
+    private val oldCtorToNewMap = mutableMapOf<IrConstructorSymbol, ConstructorPair>()
+
+    fun getConstructorProcessorLowering() = object : DeclarationContainerLoweringPass {
+        override fun lower(irDeclarationContainer: IrDeclarationContainer) {
+            irDeclarationContainer.declarations.transformFlat {
+                if (it is IrClass) {
+                    listOf(it) + lowerClass(it)
+                } else null
+            }
         }
+    }::runOnFilePostfix
 
-        context.secondaryConstructorsMap.putAll(oldCtorToNewMap)
-    }
+    fun getConstructorRedirectorLowering() = object : DeclarationContainerLoweringPass {
+        override fun lower(irDeclarationContainer: IrDeclarationContainer) {
+            for (it in irDeclarationContainer.declarations) {
+                it.accept(CallsiteRedirectionTransformer(), null)
+            }
+        }
+    }::runOnFilePostfix
 
     private fun lowerClass(irClass: IrClass): List<IrSimpleFunction> {
         val className = irClass.name.asString()
@@ -74,12 +84,10 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
                 //   val t = Object.create(Foo.prototype);
                 //   return Foo_init_$Init$(..., t)
                 // }
-
-                val newInitConstructor = createInitConstructor(declaration, constructorName, irClass.defaultType)
+                val newInitConstructor = createInitConstructor(declaration, irClass, constructorName, irClass.defaultType)
                 val newCreateConstructor = createCreateConstructor(declaration, newInitConstructor, constructorName, irClass.defaultType)
 
-                oldCtorToNewMap[declaration.symbol] =
-                        JsIrBackendContext.SecondaryCtorPair(newInitConstructor.symbol, newCreateConstructor.symbol)
+                oldCtorToNewMap[declaration.symbol] = ConstructorPair(newInitConstructor.symbol, newCreateConstructor.symbol)
 
                 oldConstructors += declaration
                 newConstructors += newInitConstructor
@@ -92,7 +100,11 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
         return newConstructors
     }
 
-    private class ThisUsageReplaceTransformer(val function: IrFunctionSymbol, val thisSymbol: IrValueParameterSymbol) :
+    private class ThisUsageReplaceTransformer(
+        val function: IrFunctionSymbol,
+        val newThisSymbol: IrValueSymbol,
+        val oldThisSymbol: IrValueSymbol?
+    ) :
         IrElementTransformerVoid() {
 
         override fun visitReturn(expression: IrReturn): IrExpression = IrReturnImpl(
@@ -100,15 +112,15 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
             expression.endOffset,
             expression.type,
             function,
-            IrGetValueImpl(expression.startOffset, expression.endOffset, thisSymbol.owner.type, thisSymbol)
+            IrGetValueImpl(expression.startOffset, expression.endOffset, newThisSymbol.owner.type, newThisSymbol)
         )
 
         override fun visitGetValue(expression: IrGetValue): IrExpression =
-            if (expression.descriptor.name.isSpecial && expression.descriptor.name.asString() == Namer.THIS_SPECIAL_NAME) IrGetValueImpl(
+            if (expression.symbol == oldThisSymbol) IrGetValueImpl(
                 expression.startOffset,
                 expression.endOffset,
                 expression.type,
-                thisSymbol,
+                newThisSymbol,
                 expression.origin
             ) else {
                 expression
@@ -117,6 +129,7 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
 
     private fun createInitConstructor(
         declaration: IrConstructor,
+        klass: IrClass,
         name: String,
         type: IrType
     ): IrSimpleFunction =
@@ -135,6 +148,7 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
             )
 
             val thisParam = JsIrBuilder.buildValueParameter(thisSymbol, type)
+            val oldThisReceiver = klass.thisReceiver?.symbol
 
             return IrFunctionImpl(
                 declaration.startOffset, declaration.endOffset,
@@ -147,7 +161,7 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
                 typeParameters += declaration.typeParameters
 //                parent = declaration.parent
                 body = JsIrBuilder.buildBlockBody(statements + retStmt).apply {
-                    transformChildrenVoid(ThisUsageReplaceTransformer(it, thisSymbol))
+                    transformChildrenVoid(ThisUsageReplaceTransformer(it, thisSymbol, oldThisReceiver))
                 }
             }
 
@@ -198,23 +212,22 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
         }
 
 
-    class CallsiteRedirectionTransformer(val context: JsIrBackendContext) : IrElementTransformer<IrFunction?> {
+    inner class CallsiteRedirectionTransformer : IrElementTransformer<IrFunction?> {
 
         override fun visitFunction(declaration: IrFunction, data: IrFunction?): IrStatement = super.visitFunction(declaration, declaration)
 
-        override fun visitCall(expression: IrCall, ownerFunc: IrFunction?): IrElement {
-            super.visitCall(expression, ownerFunc)
+        override fun visitCall(expression: IrCall, data: IrFunction?): IrElement {
+            super.visitCall(expression, data)
 
             // TODO: figure out the reason why symbol is not bound
             if (expression.symbol.isBound) {
 
-                val target = expression.symbol.owner as IrFunction
+                val target = expression.symbol.owner
 
                 if (target is IrConstructor) {
                     if (!target.descriptor.isPrimary) {
-                        val ctor = context.secondaryConstructorsMap[target.symbol]
+                        val ctor = oldCtorToNewMap[target.symbol]
                         if (ctor != null) {
-
                             return redirectCall(expression, ctor.stub)
                         }
                     }
@@ -224,8 +237,8 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
             return expression
         }
 
-        override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall, ownerFunc: IrFunction?): IrElement {
-            super.visitDelegatingConstructorCall(expression, ownerFunc)
+        override fun visitDelegatingConstructorCall(expression: IrDelegatingConstructorCall, data: IrFunction?): IrElement {
+            super.visitDelegatingConstructorCall(expression, data)
 
             val target = expression.symbol
             if (target.owner.isPrimary) {
@@ -233,9 +246,9 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
                 return expression
             }
 
-            val fromPrimary = ownerFunc!! is IrConstructor
+            val fromPrimary = data!! is IrConstructor
             // TODO: what is `deserialized` constructor?
-            val ctor = context.secondaryConstructorsMap[target] ?: return expression
+            val ctor = oldCtorToNewMap[target] ?: return expression
             val newCall = redirectCall(expression, ctor.delegate)
 
             val readThis = if (fromPrimary) {
@@ -246,7 +259,7 @@ class SecondaryCtorLowering(val context: JsIrBackendContext) : IrElementTransfor
                     IrValueParameterSymbolImpl(LazyClassReceiverParameterDescriptor(target.descriptor.containingDeclaration))
                 )
             } else {
-                IrGetValueImpl(expression.startOffset, expression.endOffset, expression.type, ownerFunc.valueParameters.last().symbol)
+                IrGetValueImpl(expression.startOffset, expression.endOffset, expression.type, data.valueParameters.last().symbol)
             }
 
             newCall.putValueArgument(expression.valueArgumentsCount, readThis)

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

@@ -0,0 +1,735 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.coroutines
+
+import org.jetbrains.kotlin.backend.common.peek
+import org.jetbrains.kotlin.backend.common.pop
+import org.jetbrains.kotlin.backend.common.push
+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.symbols.JsSymbolBuilder
+import org.jetbrains.kotlin.ir.declarations.IrVariable
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.*
+import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.visitors.*
+
+class SuspendState(type: IrType) {
+    val entryBlock: IrContainerExpression = JsIrBuilder.buildComposite(type)
+    val successors = mutableSetOf<SuspendState>()
+    var id = -1
+}
+
+data class LoopBounds(val headState: SuspendState, val exitState: SuspendState)
+
+data class FinallyTargets(val normal: SuspendState, val fromThrow: SuspendState)
+
+data class TryState(val tryState: SuspendState, val catchState: SuspendState, val finallyState: FinallyTargets?)
+
+class IrDispatchPoint(val target: SuspendState) : IrExpressionBase(UNDEFINED_OFFSET, UNDEFINED_OFFSET, target.entryBlock.type) {
+    override fun <R, D> accept(visitor: IrElementVisitor<R, D>, data: D) = visitor.visitExpression(this, data)
+
+    override fun <D> acceptChildren(visitor: IrElementVisitor<Unit, D>, data: D) {}
+
+    override fun <D> transformChildren(transformer: IrElementTransformer<D>, data: D) {}
+}
+
+
+class DispatchPointTransformer(val action: (SuspendState) -> IrExpression) : IrElementTransformerVoid() {
+    override fun visitExpression(expression: IrExpression): IrExpression {
+        val dispatchPoint = expression as? IrDispatchPoint
+            ?: return super.visitExpression(expression)
+        return action(dispatchPoint.target)
+    }
+}
+
+class StateMachineBuilder(
+    private val suspendableNodes: MutableSet<IrElement>,
+    val context: JsIrBackendContext,
+    val function: IrFunctionSymbol,
+    private val rootLoop: IrLoop,
+    private val exceptionSymbol: IrFieldSymbol,
+    private val exStateSymbol: IrFieldSymbol,
+    private val stateSymbol: IrFieldSymbol,
+    thisSymbol: IrValueParameterSymbol,
+    private val suspendResult: IrVariableSymbol
+) : IrElementVisitorVoid {
+
+    private val loopMap = mutableMapOf<IrLoop, LoopBounds>()
+    private val unit = context.irBuiltIns.unitType
+    private val nothing = context.irBuiltIns.nothingType
+    private val int = context.irBuiltIns.intType
+    private val booleanNotSymbol = context.irBuiltIns.booleanNotSymbol
+    private val eqeqeqSymbol = context.irBuiltIns.eqeqeqSymbol
+
+    private val thisReceiver = JsIrBuilder.buildGetValue(thisSymbol)
+
+    private var hasExceptions = false
+
+    val entryState = SuspendState(unit)
+    val rootExceptionTrap = buildExceptionTrapState()
+    private val globalExceptionSymbol =
+        JsSymbolBuilder.buildTempVar(function, exceptionSymbol.owner.type, "e")
+    lateinit var globalCatch: IrCatch
+
+    fun finalizeStateMachine() {
+        val unitValue = JsIrBuilder.buildGetObjectValue(
+            unit,
+            context.symbolTable.referenceClass(context.builtIns.unit)
+        )
+        globalCatch = buildGlobalCatch()
+        if (currentBlock.statements.lastOrNull() !is IrReturn) {
+            addStatement(JsIrBuilder.buildReturn(function, unitValue, nothing))
+        }
+        if (!hasExceptions) entryState.successors += rootExceptionTrap
+    }
+
+    private fun buildGlobalCatch(): IrCatch {
+
+        val catchVariable =
+            JsIrBuilder.buildVar(globalExceptionSymbol, type = exceptionSymbol.owner.type)
+        val block = JsIrBuilder.buildBlock(unit)
+        if (hasExceptions) {
+            val thenBlock = JsIrBuilder.buildBlock(unit)
+            val elseBlock = JsIrBuilder.buildBlock(unit)
+            val check = JsIrBuilder.buildCall(eqeqeqSymbol).apply {
+                putValueArgument(0, exceptionState())
+                putValueArgument(1, IrDispatchPoint(rootExceptionTrap))
+            }
+            block.statements += JsIrBuilder.buildIfElse(unit, check, thenBlock, elseBlock)
+            thenBlock.statements += JsIrBuilder.buildThrow(
+                nothing,
+                JsIrBuilder.buildGetValue(globalExceptionSymbol)
+            )
+
+            // TODO: exception table
+            elseBlock.statements += JsIrBuilder.buildSetField(
+                stateSymbol,
+                thisReceiver,
+                exceptionState(),
+                unit
+            )
+            elseBlock.statements += JsIrBuilder.buildSetField(
+                exceptionSymbol,
+                thisReceiver,
+                JsIrBuilder.buildGetValue(globalExceptionSymbol),
+                unit
+            )
+        } else {
+            block.statements += JsIrBuilder.buildThrow(
+                nothing,
+                JsIrBuilder.buildGetValue(globalExceptionSymbol)
+            )
+        }
+
+        return JsIrBuilder.buildCatch(catchVariable, block)
+    }
+
+    private var currentState = entryState
+    private var currentBlock = entryState.entryBlock
+
+    private val returnableBlockMap = mutableMapOf<IrReturnableBlockSymbol, Pair<SuspendState, IrVariableSymbol?>>()
+
+    private val catchBlockStack = mutableListOf(rootExceptionTrap)
+
+    private fun buildExceptionTrapState(): SuspendState {
+        val state = SuspendState(unit)
+        state.entryBlock.statements += JsIrBuilder.buildThrow(nothing, pendingException())
+        return state
+    }
+
+    private fun newState() {
+        val newState = SuspendState(unit)
+        doDispatch(newState)
+        updateState(newState)
+    }
+
+    private fun updateState(newState: SuspendState) {
+        currentState = newState
+        currentBlock = newState.entryBlock
+    }
+
+    private fun lastExpression() = currentBlock.statements.lastOrNull() as? IrExpression ?: unitValue
+
+    private fun IrContainerExpression.addStatement(statement: IrStatement) {
+        statements.add(statement)
+    }
+
+    private fun addStatement(statement: IrStatement) = currentBlock.addStatement(statement)
+
+    private fun maybeDoDispatch(target: SuspendState) {
+        val lastStatement = currentBlock.statements.lastOrNull()
+        if (lastStatement !is IrReturn && lastStatement !is IrContinue && lastStatement !is IrThrow) {
+            doDispatch(target)
+        }
+    }
+
+    private fun doDispatch(target: SuspendState, andContinue: Boolean = true) = doDispatchImpl(target, currentBlock, andContinue)
+
+    private fun doDispatchImpl(target: SuspendState, block: IrContainerExpression, andContinue: Boolean) {
+        val irDispatch = IrDispatchPoint(target)
+        currentState.successors.add(target)
+        block.addStatement(JsIrBuilder.buildSetField(stateSymbol, thisReceiver, irDispatch, unit))
+        if (andContinue) doContinue(block)
+    }
+
+    private fun doContinue(block: IrContainerExpression = currentBlock) {
+        block.addStatement(JsIrBuilder.buildContinue(nothing, rootLoop))
+    }
+
+    private fun transformLastExpression(transformer: (IrExpression) -> IrStatement) {
+        val expression = lastExpression()
+        val newStatement = transformer(expression)
+        currentBlock.statements.let { if (it.isNotEmpty()) it[it.lastIndex] = newStatement else it += newStatement }
+    }
+
+    private fun buildDispatchBlock(target: SuspendState) = JsIrBuilder.buildComposite(unit)
+        .also { doDispatchImpl(target, it, true) }
+
+    override fun visitElement(element: IrElement) {
+        if (element in suspendableNodes) {
+            element.acceptChildrenVoid(this)
+        } else {
+            addStatement(element as IrStatement)
+        }
+
+    }
+
+    private fun transformLoop(loop: IrLoop, transformer: (IrLoop, SuspendState /*head*/, SuspendState /*exit*/) -> Unit) {
+
+        if (loop !in suspendableNodes) return addStatement(loop)
+
+        newState()
+
+        val loopHeadState = currentState
+        val loopExitState = SuspendState(unit)
+
+        loopMap[loop] = LoopBounds(loopHeadState, loopExitState)
+
+        transformer(loop, loopHeadState, loopExitState)
+
+        loopMap.remove(loop)
+
+        updateState(loopExitState)
+    }
+
+    override fun visitWhileLoop(loop: IrWhileLoop) = transformLoop(loop) { l, head, exit ->
+        l.condition.acceptVoid(this)
+
+        transformLastExpression {
+            val exitCond = JsIrBuilder.buildCall(booleanNotSymbol).apply { putValueArgument(0, it) }
+            val irBreak = buildDispatchBlock(exit)
+            JsIrBuilder.buildIfElse(unit, exitCond, irBreak)
+        }
+
+        l.body?.acceptVoid(this)
+
+        doDispatch(head)
+    }
+
+    override fun visitDoWhileLoop(loop: IrDoWhileLoop) = transformLoop(loop) { l, head, exit ->
+        l.body?.acceptVoid(this)
+
+        l.condition.acceptVoid(this)
+
+        transformLastExpression {
+            val irContinue = buildDispatchBlock(head)
+            JsIrBuilder.buildIfElse(unit, it, irContinue)
+        }
+
+        doDispatch(exit)
+    }
+
+    private fun processReturnableBlock(expression: IrReturnableBlock) {
+
+        if (expression !in suspendableNodes) return super.visitBlock(expression)
+
+        val exitState = SuspendState(unit)
+        val resultVariable = if (hasResultingValue(expression)) {
+            val symbol = tempVar(expression.type, "RETURNABLE_BLOCK")
+            addStatement(JsIrBuilder.buildVar(symbol, null, expression.type))
+            symbol
+        } else null
+
+        returnableBlockMap[expression.symbol] = Pair(exitState, resultVariable)
+
+        super.visitBlock(expression)
+
+        returnableBlockMap.remove(expression.symbol)
+
+        maybeDoDispatch(exitState)
+
+        updateState(exitState)
+
+        if (resultVariable != null) {
+            addStatement(JsIrBuilder.buildGetValue(resultVariable))
+        }
+    }
+
+    override fun visitBlock(expression: IrBlock) =
+        if (expression is IrReturnableBlock) processReturnableBlock(expression) else super.visitBlock(expression)
+
+    private fun implicitCast(value: IrExpression, toType: IrType) =
+        JsIrBuilder.buildTypeOperator(toType, IrTypeOperator.IMPLICIT_CAST, value, toType, toType.classifierOrFail)
+
+    override fun visitCall(expression: IrCall) {
+        super.visitCall(expression)
+
+        if (expression.descriptor.isSuspend) {
+            val result = lastExpression()
+            val continueState = SuspendState(unit)
+            val dispatch = IrDispatchPoint(continueState)
+
+            currentState.successors += continueState
+
+            transformLastExpression { JsIrBuilder.buildSetField(stateSymbol, thisReceiver, dispatch, unit) }
+
+            addStatement(JsIrBuilder.buildSetVariable(suspendResult, result, unit))
+
+            val irReturn = JsIrBuilder.buildReturn(function, JsIrBuilder.buildGetValue(suspendResult), nothing)
+            val check = JsIrBuilder.buildCall(eqeqeqSymbol).apply {
+                putValueArgument(0, JsIrBuilder.buildGetValue(suspendResult))
+                putValueArgument(1, JsIrBuilder.buildCall(context.ir.symbols.coroutineSuspendedGetter))
+            }
+
+            val suspensionBlock = JsIrBuilder.buildBlock(unit, listOf(irReturn))
+            addStatement(JsIrBuilder.buildIfElse(unit, check, suspensionBlock))
+            doContinue()
+
+            updateState(continueState)
+            addStatement(implicitCast(JsIrBuilder.buildGetValue(suspendResult), expression.type))
+        }
+    }
+
+    override fun visitBreak(jump: IrBreak) {
+        val exitState = loopMap[jump.loop]!!.exitState
+        doDispatch(exitState)
+    }
+
+    override fun visitContinue(jump: IrContinue) {
+        val headState = loopMap[jump.loop]!!.headState
+        doDispatch(headState)
+    }
+
+    private fun wrap(expression: IrExpression, variable: IrVariableSymbol) =
+        JsIrBuilder.buildSetVariable(variable, expression, unit)
+
+    override fun visitWhen(expression: IrWhen) {
+
+        if (expression !in suspendableNodes) return addStatement(expression)
+
+        val exitState = SuspendState(expression.type)
+
+        val varSymbol: IrVariableSymbol?
+        val branches: List<IrBranch>
+
+        if (hasResultingValue(expression)) {
+            varSymbol = tempVar(expression.type, "WHEN_RESULT")
+            addStatement(JsIrBuilder.buildVar(varSymbol, type = expression.type))
+
+            branches = expression.branches.map {
+                val wrapped = wrap(it.result, varSymbol)
+                if (it.result in suspendableNodes) {
+                    suspendableNodes += wrapped
+                }
+                when (it) {
+                    is IrElseBranch -> IrElseBranchImpl(
+                        it.startOffset,
+                        it.endOffset,
+                        it.condition,
+                        wrapped
+                    )
+                    else /* IrBranch */ -> IrBranchImpl(
+                        it.startOffset,
+                        it.endOffset,
+                        it.condition,
+                        wrapped
+                    )
+                }
+            }
+        } else {
+            varSymbol = null
+            branches = expression.branches
+        }
+
+        val rootState = currentState
+        val rootBlock = currentBlock
+
+        for (branch in branches) {
+            if (branch !is IrElseBranch) {
+                branch.condition.acceptVoid(this)
+                val branchBlock = JsIrBuilder.buildComposite(branch.result.type)
+                val elseBlock = JsIrBuilder.buildComposite(expression.type)
+
+                val dispatchState = currentState
+                transformLastExpression {
+                    // TODO: make sure elseBlock is added iff it really needs
+                    JsIrBuilder.buildIfElse(unit, it, branchBlock, elseBlock)
+                }
+
+                currentBlock = branchBlock
+                branch.result.acceptVoid(this)
+
+                if (currentBlock.statements.last() !is IrContinue) {
+                    if (currentState !== rootState) {
+                        doDispatch(exitState)
+                    }
+                }
+
+                currentState = dispatchState
+                currentBlock = elseBlock
+            } else {
+                branch.result.acceptVoid(this)
+                if (currentBlock.statements.last() !is IrContinue) {
+                    if (currentState !== rootState) {
+                        doDispatch(exitState)
+                    }
+                }
+                break
+            }
+        }
+
+        currentState = rootState
+        currentBlock = rootBlock
+        maybeDoDispatch(exitState)
+
+        updateState(exitState)
+        if (varSymbol != null) {
+            addStatement(JsIrBuilder.buildGetValue(varSymbol))
+        }
+    }
+
+    override fun visitSetVariable(expression: IrSetVariable) {
+        if (expression !in suspendableNodes) return addStatement(expression)
+        expression.acceptChildrenVoid(this)
+        transformLastExpression { expression.apply { value = it } }
+    }
+
+    override fun visitVariable(declaration: IrVariable) {
+        if (declaration !in suspendableNodes) return addStatement(declaration)
+        declaration.acceptChildrenVoid(this)
+        transformLastExpression { declaration.apply { initializer = it } }
+    }
+
+    override fun visitGetField(expression: IrGetField) {
+        if (expression !in suspendableNodes) return addStatement(expression)
+        expression.acceptChildrenVoid(this)
+        transformLastExpression { expression.apply { receiver = it } }
+    }
+
+    override fun visitGetClass(expression: IrGetClass) {
+        if (expression !in suspendableNodes) return addStatement(expression)
+        expression.acceptChildrenVoid(this)
+        transformLastExpression { expression.apply { argument = it } }
+    }
+
+    private fun transformArguments(arguments: Array<IrExpression?>): Array<IrExpression?> {
+
+        var suspendableCount = arguments.fold(0) { r, n -> if (n in suspendableNodes) r + 1 else r }
+
+        val newArguments = arrayOfNulls<IrExpression>(arguments.size)
+
+        for ((i, arg) in arguments.withIndex()) {
+            newArguments[i] = if (arg != null && suspendableCount > 0) {
+                if (arg in suspendableNodes) suspendableCount--
+                arg.acceptVoid(this)
+                val tmp = tempVar(arg.type, "ARGUMENT")
+                transformLastExpression { JsIrBuilder.buildVar(tmp, it, it.type) }
+                JsIrBuilder.buildGetValue(tmp)
+            } else arg
+        }
+
+        return newArguments
+    }
+
+    override fun visitMemberAccess(expression: IrMemberAccessExpression) {
+
+        if (expression !in suspendableNodes) {
+            addExceptionEdge()
+            return addStatement(expression)
+        }
+
+        val arguments = arrayOfNulls<IrExpression>(expression.valueArgumentsCount + 2)
+        arguments[0] = expression.dispatchReceiver
+        arguments[1] = expression.extensionReceiver
+
+        for (i in 0 until expression.valueArgumentsCount) {
+            arguments[i + 2] = expression.getValueArgument(i)
+        }
+
+        val newArguments = transformArguments(arguments)
+
+        expression.dispatchReceiver = newArguments[0]
+        expression.extensionReceiver = newArguments[1]
+        for (i in 0 until expression.valueArgumentsCount) {
+            expression.putValueArgument(i, newArguments[i + 2])
+        }
+
+        addExceptionEdge()
+        addStatement(expression)
+    }
+
+    override fun visitSetField(expression: IrSetField) {
+        if (expression !in suspendableNodes) return addStatement(expression)
+
+        val newArguments = transformArguments(arrayOf(expression.receiver, expression.value))
+
+        val receiver = newArguments[0]
+        val value = newArguments[1] as IrExpression
+
+        addStatement(expression.run {
+            IrSetFieldImpl(
+                startOffset,
+                endOffset,
+                symbol,
+                receiver,
+                value,
+                unit,
+                origin,
+                superQualifierSymbol
+            )
+        })
+    }
+
+    // TODO: should it be lowered before?
+    override fun visitStringConcatenation(expression: IrStringConcatenation) {
+        assert(expression in suspendableNodes)
+
+        val arguments = arrayOfNulls<IrExpression>(expression.arguments.size)
+
+        expression.arguments.forEachIndexed { i, a -> arguments[i] = a }
+
+        val newArguments = transformArguments(arguments)
+
+        addStatement(expression.run {
+            IrStringConcatenationImpl(
+                startOffset,
+                endOffset,
+                type,
+                newArguments.map { it!! })
+        })
+    }
+
+    private val unitValue = JsIrBuilder.buildGetObjectValue(
+        unit,
+        context.symbolTable.referenceClass(context.builtIns.unit)
+    )
+
+    override fun visitReturn(expression: IrReturn) {
+        expression.acceptChildrenVoid(this)
+        if (expression.returnTargetSymbol is IrReturnableBlockSymbol) {
+            val (exitState, varSymbol) = returnableBlockMap[expression.returnTargetSymbol]!!
+            if (varSymbol != null) {
+                transformLastExpression { JsIrBuilder.buildSetVariable(varSymbol, it, it.type) }
+            }
+            doDispatch(exitState)
+        } else {
+            transformLastExpression { expression.apply { value = it } }
+        }
+    }
+
+    private fun addExceptionEdge() {
+        hasExceptions = true
+        currentState.successors += catchBlockStack.peek()!!
+    }
+
+    private fun hasResultingValue(expression: IrExpression) = expression.type.run { !isUnit() && !isNothing() }
+
+    override fun visitThrow(expression: IrThrow) {
+        expression.acceptChildrenVoid(this)
+        addExceptionEdge()
+        transformLastExpression { expression.apply { value = it } }
+    }
+
+    override fun visitTry(aTry: IrTry) {
+        val tryState = buildTryState(aTry)
+        val enclosingCatch = catchBlockStack.peek()!!
+
+        catchBlockStack.push(tryState.catchState)
+
+        val finallyStateVarSymbol = tempVar(int, "FINALLY_STATE")
+        val exitState = SuspendState(unit)
+
+        val varSymbol = if (hasResultingValue(aTry)) tempVar(aTry.type, "TRY_RESULT") else null
+
+        if (aTry.finallyExpression != null) {
+            addStatement(
+                JsIrBuilder.buildVar(
+                    finallyStateVarSymbol,
+                    IrDispatchPoint(exitState), int
+                )
+            )
+        }
+        if (varSymbol != null) {
+            addStatement(JsIrBuilder.buildVar(varSymbol, type = aTry.type))
+        }
+
+        // TODO: refact it with exception table, see coroutinesInternal.kt
+        setupExceptionState(tryState.catchState)
+
+        val tryResult = if (varSymbol != null) {
+            JsIrBuilder.buildSetVariable(varSymbol, aTry.tryResult, unit).also {
+                if (it.value in suspendableNodes) suspendableNodes += it
+            }
+        } else aTry.tryResult
+
+        tryResult.acceptVoid(this)
+
+        if (tryState.finallyState != null) {
+            doDispatch(tryState.finallyState.normal)
+        } else {
+            setupExceptionState(enclosingCatch)
+            doDispatch(exitState)
+        }
+
+        addExceptionEdge()
+        catchBlockStack.pop()
+        updateState(tryState.catchState)
+
+        if (tryState.finallyState != null) {
+            setupExceptionState(tryState.finallyState.fromThrow)
+        } else {
+            setupExceptionState(enclosingCatch)
+        }
+
+        val ex = pendingException()
+
+        var rethrowNeeded = true
+
+        for (catch in aTry.catches) {
+            val type = catch.catchParameter.type
+            val initializer = if (type !is IrDynamicType) implicitCast(ex, type) else ex
+            val irVar = catch.catchParameter.also {
+                it.initializer = initializer
+            }
+            val catchResult = if (varSymbol != null) {
+                JsIrBuilder.buildSetVariable(varSymbol, catch.result, unit).also {
+                    if (it.value in suspendableNodes) suspendableNodes += it
+                }
+            } else catch.result
+
+            if (type is IrDynamicType) {
+                rethrowNeeded = false
+
+                addStatement(irVar)
+                catchResult.acceptVoid(this)
+                val exitDispatch = tryState.finallyState?.run { normal } ?: exitState
+                maybeDoDispatch(exitDispatch)
+
+            } else {
+                val check = buildIsCheck(ex, type)
+
+                val branchBlock = JsIrBuilder.buildComposite(catchResult.type)
+
+                val elseBlock = JsIrBuilder.buildComposite(catchResult.type)
+                val irIf = JsIrBuilder.buildIfElse(catchResult.type, check, branchBlock, elseBlock)
+                val ifBlock = currentBlock
+
+                currentBlock = branchBlock
+
+                addStatement(irVar)
+                catchResult.acceptVoid(this)
+                val exitDispatch = tryState.finallyState?.run { normal } ?: exitState
+                maybeDoDispatch(exitDispatch)
+
+                currentBlock = ifBlock
+                addStatement(irIf)
+                currentBlock = elseBlock
+            }
+        }
+
+        if (rethrowNeeded) {
+            addExceptionEdge()
+            addStatement(JsIrBuilder.buildThrow(nothing, ex))
+        }
+
+        if (tryState.finallyState == null) {
+            currentState.successors += enclosingCatch
+        }
+
+        val finallyState = tryState.finallyState
+        if (finallyState != null) {
+            val throwExitState = SuspendState(unit)
+            updateState(finallyState.fromThrow)
+            tryState.tryState.successors += finallyState.fromThrow
+            addStatement(
+                JsIrBuilder.buildSetVariable(
+                    finallyStateVarSymbol,
+                    IrDispatchPoint(throwExitState), int
+                )
+            )
+            doDispatch(finallyState.normal)
+
+            updateState(finallyState.normal)
+            tryState.tryState.successors += finallyState.normal
+            setupExceptionState(enclosingCatch)
+            aTry.finallyExpression?.acceptVoid(this)
+            currentState.successors += listOf(throwExitState, exitState)
+            addStatement(
+                JsIrBuilder.buildSetField(
+                    stateSymbol,
+                    thisReceiver,
+                    JsIrBuilder.buildGetValue(
+                        finallyStateVarSymbol
+                    ),
+                    unit
+                )
+            )
+            doContinue()
+
+            updateState(throwExitState)
+            addStatement(JsIrBuilder.buildThrow(nothing, pendingException()))
+            addExceptionEdge()
+        }
+
+        updateState(exitState)
+        if (varSymbol != null) {
+            addStatement(JsIrBuilder.buildGetValue(varSymbol))
+        }
+    }
+
+    private fun setupExceptionState(target: SuspendState) {
+        addStatement(
+            JsIrBuilder.buildSetField(
+                exStateSymbol, thisReceiver,
+                IrDispatchPoint(target), unit
+            )
+        )
+    }
+
+    private fun exceptionState() = JsIrBuilder.buildGetField(exStateSymbol, thisReceiver)
+    private fun pendingException() = JsIrBuilder.buildGetField(exceptionSymbol, thisReceiver)
+
+    private fun buildTryState(aTry: IrTry) =
+        TryState(
+            currentState,
+            SuspendState(unit),
+            aTry.finallyExpression?.run {
+                FinallyTargets(
+                    SuspendState(
+                        unit
+                    ), SuspendState(unit)
+                )
+            }
+        )
+
+
+    private fun buildIsCheck(value: IrExpression, toType: IrType) =
+        JsIrBuilder.buildTypeOperator(
+            context.irBuiltIns.booleanType,
+            IrTypeOperator.INSTANCEOF,
+            value,
+            toType,
+            toType.classifierOrNull!!
+        )
+
+    private fun tempVar(type: IrType, name: String? = null) =
+        JsSymbolBuilder.buildTempVar(function, type, name)
+}

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

@@ -0,0 +1,943 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.coroutines
+
+import org.jetbrains.kotlin.backend.common.*
+import org.jetbrains.kotlin.backend.common.descriptors.getFunction
+import org.jetbrains.kotlin.backend.common.descriptors.synthesizedName
+import org.jetbrains.kotlin.backend.common.ir.createOverriddenDescriptor
+import org.jetbrains.kotlin.backend.common.lower.SymbolWithIrBuilder
+import org.jetbrains.kotlin.backend.common.lower.copyAsValueParameter
+import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
+import org.jetbrains.kotlin.backend.common.lower.irBlockBody
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.ClassConstructorDescriptorImpl
+import org.jetbrains.kotlin.descriptors.impl.ClassDescriptorImpl
+import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
+import org.jetbrains.kotlin.ir.backend.js.ir.*
+import org.jetbrains.kotlin.ir.builders.*
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.impl.IrClassImpl
+import org.jetbrains.kotlin.ir.declarations.impl.IrConstructorImpl
+import org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl
+import org.jetbrains.kotlin.ir.descriptors.IrTemporaryVariableDescriptorImpl
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.*
+import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.ir.symbols.impl.IrConstructorSymbolImpl
+import org.jetbrains.kotlin.ir.symbols.impl.IrSimpleFunctionSymbolImpl
+import org.jetbrains.kotlin.ir.symbols.impl.IrVariableSymbolImpl
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.classifierOrFail
+import org.jetbrains.kotlin.ir.types.toKotlinType
+import org.jetbrains.kotlin.ir.types.typeWith
+import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.visitors.*
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.storage.LockBasedStorageManager
+import org.jetbrains.kotlin.utils.DFS
+
+internal class SuspendFunctionsLowering(val context: JsIrBackendContext): FileLoweringPass {
+
+    private object STATEMENT_ORIGIN_COROUTINE_IMPL : IrStatementOriginImpl("COROUTINE_IMPL")
+    private object DECLARATION_ORIGIN_COROUTINE_IMPL : IrDeclarationOriginImpl("COROUTINE_IMPL")
+
+    private val builtCoroutines = mutableMapOf<FunctionDescriptor, BuiltCoroutine>()
+    private val suspendLambdas = mutableMapOf<FunctionDescriptor, IrFunctionReference>()
+
+    override fun lower(irFile: IrFile) {
+        markSuspendLambdas(irFile)
+        buildCoroutines(irFile)
+        transformCallableReferencesToSuspendLambdas(irFile)
+    }
+
+    private fun buildCoroutines(irFile: IrFile) {
+        irFile.declarations.transformFlat(::tryTransformSuspendFunction)
+        irFile.acceptVoid(object: IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) {
+                element.acceptChildrenVoid(this)
+            }
+
+            override fun visitClass(declaration: IrClass) {
+                declaration.acceptChildrenVoid(this)
+                declaration.declarations.transformFlat(::tryTransformSuspendFunction)
+            }
+        })
+    }
+
+    private fun tryTransformSuspendFunction(element: IrElement) =
+            if (element is IrFunction && element.descriptor.isSuspend && element.descriptor.modality != Modality.ABSTRACT)
+                transformSuspendFunction(element, suspendLambdas[element.descriptor])
+            else null
+
+    private fun markSuspendLambdas(irElement: IrElement) {
+        irElement.acceptChildrenVoid(object : IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) {
+                element.acceptChildrenVoid(this)
+            }
+
+            override fun visitFunctionReference(expression: IrFunctionReference) {
+                expression.acceptChildrenVoid(this)
+
+                val descriptor = expression.descriptor
+                if (descriptor.isSuspend)
+                    suspendLambdas.put(descriptor, expression)
+            }
+        })
+    }
+
+    private fun transformCallableReferencesToSuspendLambdas(irElement: IrElement) {
+        irElement.transformChildrenVoid(object : IrElementTransformerVoid() {
+
+            override fun visitFunctionReference(expression: IrFunctionReference): IrExpression {
+                expression.transformChildrenVoid(this)
+
+                val descriptor = expression.descriptor
+                if (!descriptor.isSuspend)
+                    return expression
+                val coroutine = builtCoroutines[descriptor]
+                    ?: throw Error("Non-local callable reference to suspend lambda: $descriptor")
+                val constructorParameters = coroutine.coroutineConstructor.valueParameters
+                val expressionArguments = expression.getArguments().map { it.second }
+                assert(constructorParameters.size == expressionArguments.size,
+                       { "Inconsistency between callable reference to suspend lambda and the corresponding coroutine" })
+                val irBuilder = context.createIrBuilder(expression.symbol, expression.startOffset, expression.endOffset)
+                irBuilder.run {
+                    return irCall(coroutine.coroutineConstructor.symbol).apply {
+                        expressionArguments.forEachIndexed { index, argument ->
+                            putValueArgument(index, argument)
+                        }
+                    }
+                }
+            }
+        })
+    }
+
+    private sealed class SuspendFunctionKind {
+        object NO_SUSPEND_CALLS : SuspendFunctionKind()
+        class DELEGATING(val delegatingCall: IrCall) : SuspendFunctionKind()
+        object NEEDS_STATE_MACHINE : SuspendFunctionKind()
+    }
+
+    private fun transformSuspendFunction(irFunction: IrFunction, functionReference: IrFunctionReference?): List<IrDeclaration>? {
+        val suspendFunctionKind = getSuspendFunctionKind(irFunction)
+        return when (suspendFunctionKind) {
+            is SuspendFunctionKind.NO_SUSPEND_CALLS -> {
+                null                                                            // No suspend function calls - just an ordinary function.
+            }
+
+            is SuspendFunctionKind.DELEGATING -> {                              // Calls another suspend function at the end.
+                removeReturnIfSuspendedCallAndSimplifyDelegatingCall(
+                        irFunction, suspendFunctionKind.delegatingCall)
+                null                                                            // No need in state machine.
+            }
+
+            is SuspendFunctionKind.NEEDS_STATE_MACHINE -> {
+                val coroutine = buildCoroutine(irFunction, functionReference)   // Coroutine implementation.
+                if (suspendLambdas.contains(irFunction.descriptor))             // Suspend lambdas are called through factory method <create>,
+                    listOf(coroutine)                                           // thus we can eliminate original body.
+                else
+                    listOf<IrDeclaration>(
+                            coroutine,
+                            irFunction
+                    )
+            }
+        }
+    }
+
+    private fun getSuspendFunctionKind(irFunction: IrFunction): SuspendFunctionKind {
+        if (suspendLambdas.contains(irFunction.descriptor))
+            return SuspendFunctionKind.NEEDS_STATE_MACHINE            // Suspend lambdas always need coroutine implementation.
+
+        val body = irFunction.body
+                ?: return SuspendFunctionKind.NO_SUSPEND_CALLS
+
+        var numberOfSuspendCalls = 0
+        body.acceptVoid(object: IrElementVisitorVoid {
+            override fun visitElement(element: IrElement) {
+                element.acceptChildrenVoid(this)
+            }
+
+            override fun visitCall(expression: IrCall) {
+                expression.acceptChildrenVoid(this)
+
+                if (expression.descriptor.isSuspend)
+                    ++numberOfSuspendCalls
+            }
+        })
+        // It is important to optimize the case where there is only one suspend call and it is the last statement
+        // because we don't need to build a fat coroutine class in that case.
+        // This happens a lot in practise because of suspend functions with default arguments.
+        // TODO: use TailRecursionCallsCollector.
+        val lastStatement = (body as IrBlockBody).statements.lastOrNull()
+        val lastCall = when (lastStatement) {
+            is IrCall -> lastStatement
+            is IrReturn -> {
+                var value: IrElement = lastStatement
+                /*
+                 * Check if matches this pattern:
+                 * block/return {
+                 *     block/return {
+                 *         .. suspendCall()
+                 *     }
+                 * }
+                 */
+                loop@while (true) {
+                    when {
+                        value is IrBlock && value.statements.size == 1 -> value = value.statements.first()
+                        value is IrReturn -> value = value.value
+                        else -> break@loop
+                    }
+                }
+                value as? IrCall
+            }
+            else -> null
+        }
+        val suspendCallAtEnd = lastCall != null && lastCall.descriptor.isSuspend     // Suspend call.
+        return when {
+            numberOfSuspendCalls == 0   -> SuspendFunctionKind.NO_SUSPEND_CALLS
+            numberOfSuspendCalls == 1
+                    && suspendCallAtEnd -> SuspendFunctionKind.DELEGATING(
+                lastCall!!
+            )
+            else                        -> SuspendFunctionKind.NEEDS_STATE_MACHINE
+        }
+    }
+
+    private val symbols = context.ir.symbols
+    private val unit = context.run { symbolTable.referenceClass(builtIns.unit) }
+    private val getContinuationSymbol =
+        context.run {
+            val f = getInternalFunctions("getContinuation")
+            symbolTable.referenceSimpleFunction(f.single())
+        }
+    private val continuationClassSymbol = getContinuationSymbol.owner.returnType.classifierOrFail as IrClassSymbol
+    private val returnIfSuspendedDescriptor = context.getInternalFunctions("returnIfSuspended").single()
+
+    private fun removeReturnIfSuspendedCallAndSimplifyDelegatingCall(irFunction: IrFunction, delegatingCall: IrCall) {
+        val returnValue =
+                if (delegatingCall.descriptor.original == returnIfSuspendedDescriptor)
+                    delegatingCall.getValueArgument(0)!!
+                else delegatingCall
+        context.createIrBuilder(irFunction.symbol).run {
+            val statements = (irFunction.body as IrBlockBody).statements
+            val lastStatement = statements.last()
+            assert (lastStatement == delegatingCall || lastStatement is IrReturn) { "Unexpected statement $lastStatement" }
+            statements[statements.size - 1] = irReturn(returnValue)
+        }
+    }
+
+    private fun buildCoroutine(irFunction: IrFunction, functionReference: IrFunctionReference?): IrClass {
+        val descriptor = irFunction.descriptor
+        val coroutine = CoroutineBuilder(irFunction, functionReference).build()
+        builtCoroutines.put(descriptor, coroutine)
+
+        if (functionReference == null) {
+            // It is not a lambda - replace original function with a call to constructor of the built coroutine.
+            val irBuilder = context.createIrBuilder(irFunction.symbol, irFunction.startOffset, irFunction.endOffset)
+            irFunction.body = irBuilder.irBlockBody(irFunction) {
+                +irReturn(
+                        irCall(coroutine.doResumeFunction.symbol).apply {
+                            dispatchReceiver = irCall(coroutine.coroutineConstructor.symbol).apply {
+                                val functionParameters = irFunction.explicitParameters
+                                functionParameters.forEachIndexed { index, argument ->
+                                    putValueArgument(index, irGet(argument))
+                                }
+                                putValueArgument(functionParameters.size,
+                                        irCall(getContinuationSymbol, getContinuationSymbol.owner.returnType, listOf(irFunction.returnType)))
+                            }
+                            putValueArgument(0, irGetObject(unit)) // value
+                            putValueArgument(1, irNull()) // exception
+                        })
+            }
+        }
+
+        return coroutine.coroutineClass
+    }
+
+    private class BuiltCoroutine(val coroutineClass: IrClass,
+                                 val coroutineConstructor: IrConstructor,
+                                 val doResumeFunction: IrFunction)
+
+    private var coroutineId = 0
+
+    private inner class CoroutineBuilder(val irFunction: IrFunction, val functionReference: IrFunctionReference?) {
+
+        private val functionParameters = irFunction.explicitParameters
+        private val boundFunctionParameters = functionReference?.getArgumentsWithIr()?.map { it.first }
+        private val unboundFunctionParameters = boundFunctionParameters?.let { functionParameters - it }
+
+        private lateinit var suspendResult: IrVariable
+        private lateinit var suspendState: IrVariable
+        private lateinit var dataArgument: IrValueParameter
+        private lateinit var exceptionArgument: IrValueParameter
+        private lateinit var coroutineClassDescriptor: ClassDescriptorImpl
+        private lateinit var coroutineClass: IrClassImpl
+        private lateinit var coroutineClassThis: IrValueParameter
+        private lateinit var argumentToPropertiesMap: Map<ParameterDescriptor, IrField>
+
+        private val coroutineImplSymbol = symbols.coroutineImpl
+        private val coroutineImplConstructorSymbol = coroutineImplSymbol.constructors.single()
+        private val coroutineImplClassDescriptor = coroutineImplSymbol.descriptor
+        private val create1Function = coroutineImplSymbol.owner.simpleFunctions()
+            .single { it.name.asString() == "create" && it.valueParameters.size == 1 }
+
+        private val create1CompletionParameter = create1Function.valueParameters[0]
+
+        private val coroutineImplLabelFieldSymbol = coroutineImplSymbol.getPropertyField("label")!!
+//        private val coroutineImplResultFieldSymbol = coroutineImplSymbol.getPropertyField("pendingResult")!!
+        private val coroutineImplExceptionFieldSymbol = coroutineImplSymbol.getPropertyField("pendingException")!!
+        private val coroutineImplExceptionStateFieldSymbol = coroutineImplSymbol.getPropertyField("exceptionState")!!
+
+        private val coroutineConstructors = mutableListOf<IrConstructor>()
+        private var exceptionTrapId = -1
+
+        fun build(): BuiltCoroutine {
+            val superTypes = mutableListOf<IrType>(coroutineImplSymbol.owner.defaultType)
+            var suspendFunctionClass: IrClass? = null
+            var functionClass: IrClass? = null
+            var suspendFunctionClassTypeArguments: List<IrType>? = null
+            var functionClassTypeArguments: List<IrType>? = null
+            if (unboundFunctionParameters != null) {
+                // Suspend lambda inherits SuspendFunction.
+                val numberOfParameters = unboundFunctionParameters.size
+                suspendFunctionClass = context.suspendFunctions[numberOfParameters].owner
+                val unboundParameterTypes = unboundFunctionParameters.map { it.type }
+                suspendFunctionClassTypeArguments = unboundParameterTypes + irFunction.returnType
+                superTypes += suspendFunctionClass.typeWith(suspendFunctionClassTypeArguments)
+
+                functionClass = context.functions[numberOfParameters + 1].owner
+                val continuationType = continuationClassSymbol.typeWith(irFunction.returnType)
+                functionClassTypeArguments = unboundParameterTypes + continuationType + context.irBuiltIns.anyNType
+                superTypes += functionClass.typeWith(functionClassTypeArguments)
+
+            }
+            coroutineClassDescriptor = ClassDescriptorImpl(
+                    /* containingDeclaration = */ irFunction.descriptor.containingDeclaration,
+                    /* name                  = */ "${irFunction.descriptor.name}\$${coroutineId++}".synthesizedName,
+                    /* modality              = */ Modality.FINAL,
+                    /* kind                  = */ ClassKind.CLASS,
+                    /* superTypes            = */ superTypes.map { it.toKotlinType() },
+                    /* source                = */ SourceElement.NO_SOURCE,
+                    /* isExternal            = */ false,
+                    /* storageManager        = */ LockBasedStorageManager.NO_LOCKS
+            ).also {
+                it.initialize(stub("coroutine class"), stub("coroutine class constructors"), null)
+            }
+            coroutineClass = IrClassImpl(
+                startOffset = irFunction.startOffset,
+                endOffset   = irFunction.endOffset,
+                origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                descriptor  = coroutineClassDescriptor
+            )
+            coroutineClass.parent = irFunction.parent
+            coroutineClass.createParameterDeclarations()
+            coroutineClassThis = coroutineClass.thisReceiver!!
+
+
+            val overriddenMap = mutableMapOf<CallableMemberDescriptor, CallableMemberDescriptor>()
+            val constructors = mutableSetOf<ClassConstructorDescriptor>()
+            val coroutineConstructorBuilder = createConstructorBuilder()
+            constructors.add(coroutineConstructorBuilder.symbol.descriptor)
+            coroutineConstructorBuilder.initialize()
+
+            val doResumeFunction = coroutineImplSymbol.owner.simpleFunctions()
+                    .single { it.name.asString() == "doResume" }
+            val doResumeMethodBuilder = createDoResumeMethodBuilder(doResumeFunction, coroutineClass)
+            doResumeMethodBuilder.initialize()
+            overriddenMap += doResumeFunction.descriptor to doResumeMethodBuilder.symbol.descriptor
+
+            var coroutineFactoryConstructorBuilder: SymbolWithIrBuilder<IrConstructorSymbol, IrConstructor>? = null
+            var createMethodBuilder: SymbolWithIrBuilder<IrSimpleFunctionSymbol, IrSimpleFunction>? = null
+            var invokeMethodBuilder: SymbolWithIrBuilder<IrSimpleFunctionSymbol, IrSimpleFunction>? = null
+            if (functionReference != null) {
+                // Suspend lambda - create factory methods.
+                coroutineFactoryConstructorBuilder = createFactoryConstructorBuilder(boundFunctionParameters!!)
+                constructors.add(coroutineFactoryConstructorBuilder.symbol.descriptor)
+
+                val createFunctionDescriptor = coroutineImplClassDescriptor.unsubstitutedMemberScope
+                        .getContributedFunctions(Name.identifier("create"), NoLookupLocation.FROM_BACKEND)
+                        .atMostOne { it.valueParameters.size == unboundFunctionParameters!!.size + 1 }
+                createMethodBuilder = createCreateMethodBuilder(
+                        unboundArgs                    = unboundFunctionParameters!!,
+                        superFunctionDescriptor        = createFunctionDescriptor,
+                        coroutineConstructor           = coroutineConstructorBuilder.ir,
+                        coroutineClass                 = coroutineClass)
+                createMethodBuilder.initialize()
+                if (createFunctionDescriptor != null)
+                    overriddenMap += createFunctionDescriptor to createMethodBuilder.symbol.descriptor
+
+                val invokeFunctionDescriptor = functionClass!!.descriptor
+                        .getFunction("invoke", functionClassTypeArguments!!.map { it.toKotlinType() })
+                val suspendInvokeFunctionDescriptor = suspendFunctionClass!!.descriptor
+                        .getFunction("invoke", suspendFunctionClassTypeArguments!!.map { it.toKotlinType() })
+                invokeMethodBuilder = createInvokeMethodBuilder(
+                        suspendFunctionInvokeFunctionDescriptor = suspendInvokeFunctionDescriptor,
+                        functionInvokeFunctionDescriptor        = invokeFunctionDescriptor,
+                        createFunction                          = createMethodBuilder.ir,
+                        doResumeFunction                        = doResumeMethodBuilder.ir,
+                        coroutineClass                          = coroutineClass)
+            }
+
+            coroutineClass.addChild(coroutineConstructorBuilder.ir)
+            coroutineConstructors += coroutineConstructorBuilder.ir
+
+            coroutineFactoryConstructorBuilder?.let {
+                it.initialize()
+                coroutineClass.addChild(it.ir)
+                coroutineConstructors += it.ir
+            }
+
+            createMethodBuilder?.let {
+                coroutineClass.addChild(it.ir)
+            }
+
+            invokeMethodBuilder?.let {
+                it.initialize()
+                coroutineClass.addChild(it.ir)
+            }
+
+            coroutineClass.addChild(doResumeMethodBuilder.ir)
+
+            coroutineClass.setSuperSymbolsAndAddFakeOverrides(superTypes)
+
+            setupExceptionState()
+
+            return BuiltCoroutine(
+                coroutineClass = coroutineClass,
+                coroutineConstructor = coroutineFactoryConstructorBuilder?.ir
+                    ?: coroutineConstructorBuilder.ir,
+                doResumeFunction = doResumeMethodBuilder.ir
+            )
+        }
+
+        private fun createConstructorBuilder()
+                = object : SymbolWithIrBuilder<IrConstructorSymbol, IrConstructor>() {
+
+            override fun buildSymbol() = IrConstructorSymbolImpl(
+                    ClassConstructorDescriptorImpl.create(
+                            /* containingDeclaration = */ coroutineClassDescriptor,
+                            /* annotations           = */ Annotations.EMPTY,
+                            /* isPrimary             = */ false,
+                            /* source                = */ SourceElement.NO_SOURCE
+                    )
+            )
+
+            private lateinit var constructorParameters: List<IrValueParameter>
+
+            override fun doInitialize() {
+                val descriptor = symbol.descriptor as ClassConstructorDescriptorImpl
+                constructorParameters = (
+                        functionParameters
+                        + coroutineImplConstructorSymbol.owner.valueParameters[0] // completion.
+                        ).mapIndexed { index, parameter ->
+
+                    val parameterDescriptor = parameter.descriptor.copyAsValueParameter(descriptor, index)
+                    parameter.copy(parameterDescriptor)
+                }
+
+                descriptor.initialize(
+                        constructorParameters.map { it.descriptor as ValueParameterDescriptor },
+                        Visibilities.PUBLIC
+                )
+                descriptor.returnType = coroutineClassDescriptor.defaultType
+            }
+
+            override fun buildIr(): IrConstructor {
+                // Save all arguments to fields.
+                argumentToPropertiesMap = functionParameters.associate {
+                    it.descriptor to addField(it.name, it.type, false)
+                }
+
+                val startOffset = irFunction.startOffset
+                val endOffset = irFunction.endOffset
+                return IrConstructorImpl(
+                    startOffset = startOffset,
+                    endOffset   = endOffset,
+                    origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                    symbol      = symbol).apply {
+
+                    returnType  = coroutineClass.defaultType
+
+                    this.valueParameters += constructorParameters
+
+                    val irBuilder = context.createIrBuilder(symbol, startOffset, endOffset)
+                    body = irBuilder.irBlockBody {
+                        val completionParameter = valueParameters.last()
+                        +IrDelegatingConstructorCallImpl(startOffset, endOffset,
+                                context.irBuiltIns.unitType,
+                                coroutineImplConstructorSymbol, coroutineImplConstructorSymbol.descriptor).apply {
+                            putValueArgument(0, irGet(completionParameter))
+                        }
+                        +IrInstanceInitializerCallImpl(startOffset, endOffset, coroutineClass.symbol, context.irBuiltIns.unitType)
+                        functionParameters.forEachIndexed { index, parameter ->
+                            +irSetField(
+                                    irGet(coroutineClassThis),
+                                    argumentToPropertiesMap[parameter.descriptor]!!,
+                                    irGet(valueParameters[index])
+                            )
+                        }
+                    }
+                }
+            }
+        }
+
+        private fun createFactoryConstructorBuilder(boundParams: List<IrValueParameter>)
+                = object : SymbolWithIrBuilder<IrConstructorSymbol, IrConstructor>() {
+
+            override fun buildSymbol() = IrConstructorSymbolImpl(
+                    ClassConstructorDescriptorImpl.create(
+                            /* containingDeclaration = */ coroutineClassDescriptor,
+                            /* annotations           = */ Annotations.EMPTY,
+                            /* isPrimary             = */ false,
+                            /* source                = */ SourceElement.NO_SOURCE
+                    )
+            )
+
+            lateinit var constructorParameters: List<IrValueParameter>
+
+            override fun doInitialize() {
+                val descriptor = symbol.descriptor as ClassConstructorDescriptorImpl
+                constructorParameters = boundParams.mapIndexed { index, parameter ->
+                    val parameterDescriptor = parameter.descriptor.copyAsValueParameter(descriptor, index)
+                    parameter.copy(parameterDescriptor)
+                }
+                descriptor.initialize(
+                        constructorParameters.map { it.descriptor as ValueParameterDescriptor },
+                        Visibilities.PUBLIC
+                )
+                descriptor.returnType = coroutineClassDescriptor.defaultType
+            }
+
+            override fun buildIr(): IrConstructor {
+                val startOffset = irFunction.startOffset
+                val endOffset = irFunction.endOffset
+                return IrConstructorImpl(
+                    startOffset = startOffset,
+                    endOffset   = endOffset,
+                    origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                    symbol      = symbol).apply {
+
+                    returnType = coroutineClass.defaultType
+
+                    this.valueParameters += constructorParameters
+
+                    val irBuilder = context.createIrBuilder(symbol, startOffset, endOffset)
+                    body = irBuilder.irBlockBody {
+                        +IrDelegatingConstructorCallImpl(startOffset, endOffset, context.irBuiltIns.unitType,
+                                coroutineImplConstructorSymbol, coroutineImplConstructorSymbol.descriptor).apply {
+                            putValueArgument(0, irNull()) // Completion.
+                        }
+                        +IrInstanceInitializerCallImpl(startOffset, endOffset, coroutineClass.symbol,
+                                context.irBuiltIns.unitType)
+                        // Save all arguments to fields.
+                        boundParams.forEachIndexed { index, parameter ->
+                            +irSetField(irGet(coroutineClassThis), argumentToPropertiesMap[parameter.descriptor]!!,
+                                    irGet(valueParameters[index]))
+                        }
+                    }
+                }
+            }
+        }
+
+        private fun createCreateMethodBuilder(unboundArgs: List<IrValueParameter>,
+                                              superFunctionDescriptor: FunctionDescriptor?,
+                                              coroutineConstructor: IrConstructor,
+                                              coroutineClass: IrClass)
+                = object: SymbolWithIrBuilder<IrSimpleFunctionSymbol, IrSimpleFunction>() {
+
+            override fun buildSymbol() = IrSimpleFunctionSymbolImpl(
+                    SimpleFunctionDescriptorImpl.create(
+                            /* containingDeclaration = */ coroutineClassDescriptor,
+                            /* annotations           = */ Annotations.EMPTY,
+                            /* name                  = */ Name.identifier("create"),
+                            /* kind                  = */ CallableMemberDescriptor.Kind.DECLARATION,
+                            /* source                = */ SourceElement.NO_SOURCE
+                    )
+            )
+
+            lateinit var parameters: List<IrValueParameter>
+
+            override fun doInitialize() {
+                val descriptor = symbol.descriptor as SimpleFunctionDescriptorImpl
+                parameters = (
+                        unboundArgs + create1CompletionParameter
+                        ).mapIndexed { index, parameter ->
+                    parameter.copy(parameter.descriptor.copyAsValueParameter(descriptor, index))
+                }
+
+                descriptor.initialize(
+                        /* receiverParameterType        = */ null,
+                        /* dispatchReceiverParameter    = */ coroutineClassDescriptor.thisAsReceiverParameter,
+                        /* typeParameters               = */ emptyList(),
+                        /* unsubstitutedValueParameters = */ parameters.map { it.descriptor as ValueParameterDescriptor },
+                        /* unsubstitutedReturnType      = */ coroutineClassDescriptor.defaultType,
+                        /* modality                     = */ Modality.FINAL,
+                        /* visibility                   = */ Visibilities.PRIVATE).apply {
+                    if (superFunctionDescriptor != null) {
+                        overriddenDescriptors           +=   superFunctionDescriptor.overriddenDescriptors
+                        overriddenDescriptors           +=   superFunctionDescriptor
+                    }
+                }
+            }
+
+            override fun buildIr(): IrSimpleFunction {
+                val startOffset = irFunction.startOffset
+                val endOffset = irFunction.endOffset
+                return IrFunctionImpl(
+                    startOffset = startOffset,
+                    endOffset   = endOffset,
+                    origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                    symbol      = symbol).apply {
+
+                    returnType  = coroutineClass.defaultType
+                    parent = coroutineClass
+
+                    this.valueParameters += parameters
+                    this.createDispatchReceiverParameter()
+
+                    val thisReceiver = this.dispatchReceiverParameter!!
+
+                    val irBuilder = context.createIrBuilder(symbol, startOffset, endOffset)
+                    body = irBuilder.irBlockBody(startOffset, endOffset) {
+                        +irReturn(
+                                irCall(coroutineConstructor).apply {
+                                    var unboundIndex = 0
+                                    val unboundArgsSet = unboundArgs.toSet()
+                                    functionParameters.map {
+                                        if (unboundArgsSet.contains(it))
+                                            irGet(valueParameters[unboundIndex++])
+                                        else
+                                            irGetField(irGet(thisReceiver), argumentToPropertiesMap[it.descriptor]!!)
+                                    }.forEachIndexed { index, argument ->
+                                        putValueArgument(index, argument)
+                                    }
+                                    putValueArgument(functionParameters.size, irGet(valueParameters[unboundIndex]))
+                                    assert(unboundIndex == valueParameters.size - 1,
+                                            { "Not all arguments of <create> are used" })
+                                })
+                    }
+                }
+            }
+        }
+
+        private fun createInvokeMethodBuilder(suspendFunctionInvokeFunctionDescriptor: FunctionDescriptor,
+                                              functionInvokeFunctionDescriptor: FunctionDescriptor,
+                                              createFunction: IrFunction,
+                                              doResumeFunction: IrFunction,
+                                              coroutineClass: IrClass)
+                = object: SymbolWithIrBuilder<IrSimpleFunctionSymbol, IrSimpleFunction>() {
+
+            override fun buildSymbol() = IrSimpleFunctionSymbolImpl(
+                    SimpleFunctionDescriptorImpl.create(
+                            /* containingDeclaration = */ coroutineClassDescriptor,
+                            /* annotations           = */ Annotations.EMPTY,
+                            /* name                  = */ Name.identifier("invoke"),
+                            /* kind                  = */ CallableMemberDescriptor.Kind.DECLARATION,
+                            /* source                = */ SourceElement.NO_SOURCE
+                    )
+            )
+
+            lateinit var parameters: List<IrValueParameter>
+
+            override fun doInitialize() {
+                val descriptor = symbol.descriptor as SimpleFunctionDescriptorImpl
+                parameters = createFunction.valueParameters
+                        // Skip completion - invoke() already has it implicitly as a suspend function.
+                        .take(createFunction.valueParameters.size - 1)
+                        .map { it.copy(it.descriptor.copyAsValueParameter(descriptor, it.index)) }
+
+                descriptor.initialize(
+                        /* receiverParameterType        = */ null,
+                        /* dispatchReceiverParameter    = */ coroutineClassDescriptor.thisAsReceiverParameter,
+                        /* typeParameters               = */ emptyList(),
+                        /* unsubstitutedValueParameters = */ parameters.map { it.descriptor as ValueParameterDescriptor },
+                        /* unsubstitutedReturnType      = */ irFunction.descriptor.returnType,
+                        /* modality                     = */ Modality.FINAL,
+                        /* visibility                   = */ Visibilities.PRIVATE).apply {
+                    overriddenDescriptors               +=   suspendFunctionInvokeFunctionDescriptor
+                    overriddenDescriptors               +=   functionInvokeFunctionDescriptor
+                    isSuspend                           =    true
+                }
+            }
+
+            override fun buildIr(): IrSimpleFunction {
+                val startOffset = irFunction.startOffset
+                val endOffset = irFunction.endOffset
+                return IrFunctionImpl(
+                    startOffset = startOffset,
+                    endOffset   = endOffset,
+                    origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                    symbol      = symbol).apply {
+
+                    returnType  = irFunction.returnType
+                    parent = coroutineClass
+
+                    valueParameters += parameters
+                    this.createDispatchReceiverParameter()
+
+                    val thisReceiver = this.dispatchReceiverParameter!!
+
+                    val irBuilder = context.createIrBuilder(symbol, startOffset, endOffset)
+                    body = irBuilder.irBlockBody(startOffset, endOffset) {
+                        +irReturn(
+                                irCall(doResumeFunction).apply {
+                                    dispatchReceiver = irCall(createFunction).apply {
+                                        dispatchReceiver = irGet(thisReceiver)
+                                        valueParameters.forEachIndexed { index, parameter ->
+                                            putValueArgument(index, irGet(parameter))
+                                        }
+                                        putValueArgument(valueParameters.size,
+                                                irCall(getContinuationSymbol, getContinuationSymbol.owner.returnType, listOf(returnType)))
+                                    }
+                                    putValueArgument(0, irGetObject(symbols.unit))       // value
+                                    putValueArgument(1, irNull())       // exception
+                                }
+                        )
+                    }
+                }
+            }
+        }
+
+        private fun addField(name: Name, type: IrType, isMutable: Boolean): IrField = createField(
+            irFunction.startOffset,
+            irFunction.endOffset,
+            type,
+            name,
+            isMutable,
+            DECLARATION_ORIGIN_COROUTINE_IMPL,
+            coroutineClassDescriptor
+        ).also {
+            coroutineClass.addChild(it)
+        }
+
+        private fun createDoResumeMethodBuilder(doResumeFunction: IrFunction, coroutineClass: IrClass)
+                = object: SymbolWithIrBuilder<IrSimpleFunctionSymbol, IrSimpleFunction>() {
+
+            override fun buildSymbol() = IrSimpleFunctionSymbolImpl(
+                    doResumeFunction.descriptor.createOverriddenDescriptor(coroutineClassDescriptor)
+            )
+
+            override fun doInitialize() { }
+
+            override fun buildIr(): IrSimpleFunction {
+                val originalBody = irFunction.body!!
+                val startOffset = irFunction.startOffset
+                val endOffset = irFunction.endOffset
+                val function = IrFunctionImpl(
+                    startOffset = startOffset,
+                    endOffset   = endOffset,
+                    origin      = DECLARATION_ORIGIN_COROUTINE_IMPL,
+                    symbol      = symbol).apply {
+
+                    returnType  = context.irBuiltIns.anyNType
+                    parent = coroutineClass
+
+                    this.createDispatchReceiverParameter()
+
+                    doResumeFunction.valueParameters.mapIndexedTo(this.valueParameters) { index, it ->
+                        it.copy(descriptor.valueParameters[index])
+                    }
+
+                }
+
+                dataArgument = function.valueParameters[0]
+                exceptionArgument = function.valueParameters[1]
+                suspendResult = JsIrBuilder.buildVar(IrVariableSymbolImpl(
+                    IrTemporaryVariableDescriptorImpl(
+                        containingDeclaration = irFunction.descriptor,
+                        name = "suspendResult".synthesizedName,
+                        outType = context.builtIns.nullableAnyType,
+                        isMutable = true
+                    )
+                ), JsIrBuilder.buildGetValue(dataArgument.symbol), context.irBuiltIns.anyNType)
+                suspendState = JsIrBuilder.buildVar(IrVariableSymbolImpl(
+                    IrTemporaryVariableDescriptorImpl(
+                        containingDeclaration = irFunction.descriptor,
+                        name = "suspendState".synthesizedName,
+                        outType = coroutineImplLabelFieldSymbol.owner.type.toKotlinType(),
+                        isMutable = true
+                    )
+                ), type = coroutineImplLabelFieldSymbol.owner.type)
+
+                val body =
+                    (originalBody as IrBlockBody).run {
+                        IrBlockImpl(
+                            startOffset,
+                            endOffset,
+                            context.irBuiltIns.unitType,
+                            STATEMENT_ORIGIN_COROUTINE_IMPL,
+                            statements
+                        )
+                    }
+
+                buildStateMachine(body, function)
+
+                return function
+            }
+        }
+
+        private fun setupExceptionState() {
+            for (it in coroutineConstructors) {
+                (it.body as? IrBlockBody)?.run {
+                    val receiver = JsIrBuilder.buildGetValue(coroutineClassThis.symbol)
+                    val id = JsIrBuilder.buildInt(context.irBuiltIns.intType, exceptionTrapId)
+                    statements += JsIrBuilder.buildSetField(coroutineImplExceptionStateFieldSymbol, receiver, id, context.irBuiltIns.unitType)
+                }
+            }
+        }
+
+        private fun buildStateMachine(body: IrBlock, function: IrFunction) {
+            val unit = context.irBuiltIns.unitType
+
+            val switch = IrWhenImpl(body.startOffset, body.endOffset, unit,
+                                    COROUTINE_SWITCH
+            )
+            val rootTry = IrTryImpl(body.startOffset, body.endOffset, unit).apply {
+                tryResult = switch
+            }
+            val rootLoop = IrDoWhileLoopImpl(
+                body.startOffset,
+                body.endOffset,
+                unit,
+                COROUTINE_ROOT_LOOP,
+                rootTry,
+                JsIrBuilder.buildBoolean(context.irBuiltIns.booleanType, true)
+            )
+
+            val suspendableNodes = mutableSetOf<IrElement>()
+            val loweredBody =
+                collectSuspendableNodes(body, suspendableNodes, context, function)
+            val thisReceiver = (function.dispatchReceiverParameter as IrValueParameter).symbol
+
+            val stateMachineBuilder = StateMachineBuilder(
+                suspendableNodes,
+                context,
+                function.symbol,
+                rootLoop,
+                coroutineImplExceptionFieldSymbol,
+                coroutineImplExceptionStateFieldSymbol,
+                coroutineImplLabelFieldSymbol,
+                thisReceiver,
+                suspendResult.symbol
+            )
+
+            loweredBody.acceptVoid(stateMachineBuilder)
+
+            stateMachineBuilder.finalizeStateMachine()
+
+            rootTry.catches += stateMachineBuilder.globalCatch
+
+            val visited = mutableSetOf<SuspendState>()
+
+            val sortedStates = DFS.topologicalOrder(listOf(stateMachineBuilder.entryState), { it.successors }, { visited.add(it) })
+            sortedStates.withIndex().forEach { it.value.id = it.index }
+
+            fun buildDispatch(target: SuspendState) = target.run {
+                assert(id >= 0)
+                JsIrBuilder.buildInt(context.irBuiltIns.intType, id)
+            }
+
+            val eqeqeqInt = context.irBuiltIns.eqeqeqSymbol
+
+            for (state in sortedStates) {
+                val condition = JsIrBuilder.buildCall(eqeqeqInt).apply {
+                    putValueArgument(0, JsIrBuilder.buildGetField(coroutineImplLabelFieldSymbol, JsIrBuilder.buildGetValue(thisReceiver)))
+                    putValueArgument(1, JsIrBuilder.buildInt(context.irBuiltIns.intType, state.id))
+                }
+
+                switch.branches += IrBranchImpl(state.entryBlock.startOffset, state.entryBlock.endOffset, condition, state.entryBlock)
+            }
+
+            val irResultDeclaration = suspendResult
+
+            rootLoop.transform(DispatchPointTransformer(::buildDispatch), null)
+
+            exceptionTrapId = stateMachineBuilder.rootExceptionTrap.id
+
+            val functionBody = IrBlockBodyImpl(function.startOffset, function.endOffset, listOf(irResultDeclaration, rootLoop))
+
+            function.body = functionBody
+
+            val liveLocals = computeLivenessAtSuspensionPoints(functionBody).values.flatten().toSet()
+
+            val localToPropertyMap = mutableMapOf<IrValueSymbol, IrFieldSymbol>()
+            var localCounter = 0
+            // TODO: optimize by using the same property for different locals.
+            liveLocals.forEach {
+                if (it != suspendState && it != suspendResult) {
+                    localToPropertyMap.getOrPut(it.symbol) {
+                        addField(Name.identifier("${it.name}${localCounter++}"), it.type, (it as? IrVariable)?.isVar ?: false).symbol
+                    }
+                }
+            }
+            irFunction.explicitParameters.forEach {
+                localToPropertyMap.getOrPut(it.symbol) {
+                    argumentToPropertiesMap.getValue(it.descriptor).symbol
+                }
+            }
+
+            function.transform(
+                LiveLocalsTransformer(
+                    localToPropertyMap,
+                    JsIrBuilder.buildGetValue(
+                        thisReceiver
+                    ),
+                    unit
+                ), null)
+        }
+
+        private fun computeLivenessAtSuspensionPoints(body: IrBody): Map<IrCall, List<IrValueDeclaration>> {
+            // TODO: data flow analysis.
+            // Just save all visible for now.
+            val result = mutableMapOf<IrCall, List<IrValueDeclaration>>()
+            body.acceptChildrenVoid(object : VariablesScopeTracker() {
+                override fun visitCall(expression: IrCall) {
+                    if (!expression.descriptor.isSuspend) return super.visitCall(expression)
+
+                    expression.acceptChildrenVoid(this)
+                    val visibleVariables = mutableListOf<IrValueDeclaration>()
+                    scopeStack.forEach { visibleVariables += it }
+                    result.put(expression, visibleVariables)
+                }
+            })
+
+            return result
+        }
+    }
+
+    private open class VariablesScopeTracker: IrElementVisitorVoid {
+
+        protected val scopeStack = mutableListOf<MutableSet<IrVariable>>(mutableSetOf())
+
+        override fun visitElement(element: IrElement) {
+            element.acceptChildrenVoid(this)
+        }
+
+        override fun visitContainerExpression(expression: IrContainerExpression) {
+            if (!expression.isTransparentScope)
+                scopeStack.push(mutableSetOf())
+            super.visitContainerExpression(expression)
+            if (!expression.isTransparentScope)
+                scopeStack.pop()
+        }
+
+        override fun visitCatch(aCatch: IrCatch) {
+            scopeStack.push(mutableSetOf())
+            super.visitCatch(aCatch)
+            scopeStack.pop()
+        }
+
+        override fun visitVariable(declaration: IrVariable) {
+            super.visitVariable(declaration)
+            scopeStack.peek()!!.add(declaration)
+        }
+    }
+}

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

@@ -0,0 +1,174 @@
+/*
+ * Copyright 2010-2018 JetBrains s.r.o. 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.coroutines
+
+import org.jetbrains.kotlin.backend.common.lower.FinallyBlocksLowering
+import org.jetbrains.kotlin.backend.common.pop
+import org.jetbrains.kotlin.backend.common.push
+import org.jetbrains.kotlin.ir.IrElement
+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.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrVariable
+import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrGetFieldImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrSetFieldImpl
+import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
+import org.jetbrains.kotlin.ir.symbols.IrReturnableBlockSymbol
+import org.jetbrains.kotlin.ir.symbols.IrValueSymbol
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.visitors.*
+
+
+object COROUTINE_ROOT_LOOP : IrStatementOriginImpl("COROUTINE_ROOT_LOOP")
+object COROUTINE_SWITCH : IrStatementOriginImpl("COROUTINE_SWITCH")
+
+open class SuspendableNodesCollector(protected val suspendableNodes: MutableSet<IrElement>) : IrElementVisitorVoid {
+
+    protected var hasSuspendableChildren = false
+
+    override fun visitElement(element: IrElement) {
+        val current = hasSuspendableChildren
+        hasSuspendableChildren = false
+        element.acceptChildrenVoid(this)
+        if (hasSuspendableChildren) {
+            suspendableNodes += element
+        }
+        hasSuspendableChildren = hasSuspendableChildren || current
+    }
+
+    override fun visitCall(expression: IrCall) {
+        super.visitCall(expression)
+        if (expression.descriptor.isSuspend) {
+            suspendableNodes += expression
+            hasSuspendableChildren = true
+        }
+    }
+}
+
+fun collectSuspendableNodes(
+    body: IrBlock,
+    suspendableNodes: MutableSet<IrElement>,
+    context: JsIrBackendContext,
+    function: IrFunction
+): IrBlock {
+
+    // 1st: mark suspendable loops and tries
+    body.acceptVoid(SuspendableNodesCollector(suspendableNodes))
+    // 2nd: mark inner terminators
+    val terminatorsCollector = SuspendedTerminatorsCollector(suspendableNodes)
+    body.acceptVoid(terminatorsCollector)
+
+    if (terminatorsCollector.shouldFinalliesBeLowered) {
+        val finallyLower = FinallyBlocksLowering(context, context.dynamicType)
+
+        function.body = IrBlockBodyImpl(body.startOffset, body.endOffset, body.statements)
+        function.transform(finallyLower, null)
+
+        val newBody = function.body as IrBlockBody
+        function.body = null
+        suspendableNodes.clear()
+        val newBlock = JsIrBuilder.buildBlock(body.type, newBody.statements)
+
+        return collectSuspendableNodes(newBlock, suspendableNodes, context, function)
+    }
+
+    return body
+}
+
+class SuspendedTerminatorsCollector(suspendableNodes: MutableSet<IrElement>) : SuspendableNodesCollector(suspendableNodes) {
+
+    var shouldFinalliesBeLowered = false
+
+    override fun visitBreakContinue(jump: IrBreakContinue) {
+        if (jump.loop in suspendableNodes) {
+            suspendableNodes.add(jump)
+            hasSuspendableChildren = true
+        }
+
+        shouldFinalliesBeLowered = shouldFinalliesBeLowered || tryStack.any { it.finallyExpression != null && it in suspendableNodes }
+    }
+
+    private val tryStack = mutableListOf<IrTry>()
+    private val tryLoopStack = mutableListOf<IrStatement>()
+
+    private fun pushTry(aTry: IrTry) {
+        tryStack.push(aTry)
+        tryLoopStack.push(aTry)
+    }
+
+    private fun popTry() {
+        tryLoopStack.pop()
+        tryStack.pop()
+    }
+
+    private fun pushLoop(loop: IrLoop) {
+        tryLoopStack.push(loop)
+    }
+
+    private fun popLoop() {
+        tryLoopStack.pop()
+    }
+
+    override fun visitLoop(loop: IrLoop) {
+        pushLoop(loop)
+
+        super.visitLoop(loop)
+
+        popLoop()
+    }
+
+    override fun visitTry(aTry: IrTry) {
+        pushTry(aTry)
+
+        super.visitTry(aTry)
+
+        popTry()
+    }
+
+    override fun visitReturn(expression: IrReturn) {
+        shouldFinalliesBeLowered = shouldFinalliesBeLowered || tryStack.any { it.finallyExpression != null && it in suspendableNodes }
+
+        super.visitReturn(expression)
+
+        if (expression.returnTargetSymbol is IrReturnableBlockSymbol) {
+            suspendableNodes.add(expression)
+            hasSuspendableChildren = true
+        }
+    }
+}
+
+
+class LiveLocalsTransformer(
+    private val localMap: Map<IrValueSymbol, IrFieldSymbol>,
+    private val receiver: IrExpression,
+    private val unitType: IrType
+) :
+    IrElementTransformerVoid() {
+    override fun visitGetValue(expression: IrGetValue): IrExpression {
+        val field = localMap[expression.symbol] ?: return expression
+        return expression.run { IrGetFieldImpl(startOffset, endOffset, field, type, receiver, origin) }
+    }
+
+    override fun visitSetVariable(expression: IrSetVariable): IrExpression {
+        expression.transformChildrenVoid(this)
+        val field = localMap[expression.symbol] ?: return expression
+        return expression.run { IrSetFieldImpl(startOffset, endOffset, field, receiver, value, unitType, origin) }
+    }
+
+    override fun visitVariable(declaration: IrVariable): IrStatement {
+        declaration.transformChildrenVoid(this)
+        val field = localMap[declaration.symbol] ?: return declaration
+        val initializer = declaration.initializer
+        return if (initializer != null) {
+            declaration.run { IrSetFieldImpl(startOffset, endOffset, field, receiver, initializer, unitType) }
+        } else {
+            JsIrBuilder.buildComposite(declaration.type)
+        }
+    }
+}

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsExpressionTransformer.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.ir.types.isUnit
 import org.jetbrains.kotlin.js.backend.ast.*
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
+@Suppress("PARAMETER_NAME_CHANGED_ON_OVERRIDE")
 class IrElementToJsExpressionTransformer : BaseIrElementToJsNodeTransformer<JsExpression, JsGenerationContext> {
 
     override fun visitVararg(expression: IrVararg, context: JsGenerationContext): JsExpression {
@@ -158,7 +159,7 @@ class IrElementToJsExpressionTransformer : BaseIrElementToJsNodeTransformer<JsEx
         val arguments = translateCallArguments(expression, context)
 
         if (dispatchReceiver != null &&
-            dispatchReceiver.type.isFunctionTypeOrSubtype() && symbol.owner.name == OperatorNameConventions.INVOKE
+            dispatchReceiver.type.isFunctionTypeOrSubtype() && symbol.descriptor.name == OperatorNameConventions.INVOKE && !symbol.descriptor.isSuspend
         ) {
             return JsInvocation(jsDispatchReceiver!!, arguments)
         }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrElementToJsStatementTransformer.kt

@@ -6,12 +6,14 @@
 package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.ir.backend.js.lower.coroutines.COROUTINE_SWITCH
 import org.jetbrains.kotlin.ir.backend.js.utils.JsGenerationContext
 import org.jetbrains.kotlin.ir.backend.js.utils.constructedClass
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.js.backend.ast.*
 
+@Suppress("PARAMETER_NAME_CHANGED_ON_OVERRIDE")
 class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsStatement, JsGenerationContext> {
 
     override fun visitBlockBody(body: IrBlockBody, context: JsGenerationContext): JsStatement {
@@ -81,9 +83,40 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
     }
 
     override fun visitWhen(expression: IrWhen, context: JsGenerationContext): JsStatement {
+        if (expression.origin == COROUTINE_SWITCH) return toSwitch(expression, context)
         return expression.toJsNode(this, context, ::JsIf) ?: JsEmpty
     }
 
+    private fun toSwitch(expression: IrWhen, context: JsGenerationContext): JsStatement {
+        var expr: IrExpression? = null
+        val cases = expression.branches.map {
+            val body = it.result
+            val id = if (it is IrElseBranch) null else {
+                val call = it.condition as IrCall
+                expr = call.getValueArgument(0) as IrExpression
+                call.getValueArgument(1)
+            }
+            Pair(id, body)
+        }
+
+        val exprTransformer = IrElementToJsExpressionTransformer()
+        val jsExpr = expr!!.accept(exprTransformer, context)
+
+        return JsSwitch(jsExpr, cases.map { (id, body) ->
+
+            val jsId = id?.accept(exprTransformer, context)
+            val jsBody = body.accept(this, context).asBlock()
+            val case: JsSwitchMember
+            if (jsId == null) {
+                case = JsDefault()
+            } else {
+                case = JsCase().also { it.caseExpression = jsId }
+            }
+
+            case.also { it.statements += jsBody.statements }
+        })
+    }
+
     override fun visitWhileLoop(loop: IrWhileLoop, context: JsGenerationContext): JsStatement {
         //TODO what if body null?
         val label = context.getNameForLoop(loop)
@@ -94,7 +127,8 @@ class IrElementToJsStatementTransformer : BaseIrElementToJsNodeTransformer<JsSta
     override fun visitDoWhileLoop(loop: IrDoWhileLoop, context: JsGenerationContext): JsStatement {
         //TODO what if body null?
         val label = context.getNameForLoop(loop)
-        val loopStatement = JsDoWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
+        val loopStatement =
+            JsDoWhile(loop.condition.accept(IrElementToJsExpressionTransformer(), context), loop.body?.accept(this, context))
         return label?.let { JsLabel(it, loopStatement) } ?: loopStatement
     }
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsClassGenerator.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 
 import org.jetbrains.kotlin.backend.common.onlyIf
+import org.jetbrains.kotlin.backend.common.utils.isBuiltinFunctionalTypeOrSubtype
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ClassKind
@@ -20,6 +21,7 @@ import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.IrClassSymbolImpl
 import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.isAny
+import org.jetbrains.kotlin.ir.util.defaultType
 import org.jetbrains.kotlin.ir.util.isInterface
 import org.jetbrains.kotlin.ir.util.isReal
 import org.jetbrains.kotlin.ir.util.resolveFakeOverride
@@ -166,7 +168,7 @@ class JsClassGenerator(private val irClass: IrClass, val context: JsGenerationCo
             irClass.superTypes.mapNotNull {
                 val symbol = it.classifierOrFail
                 // TODO: make sure that there is a test which breaks when isExternal is used here instead of isEffectivelyExternal
-                if (symbol.isInterface && !symbol.isEffectivelyExternal()) JsNameRef(context.getNameForSymbol(symbol)) else null
+                if (symbol.isInterface && !irClass.defaultType.isBuiltinFunctionalTypeOrSubtype() && !symbol.isEffectivelyExternal()) JsNameRef(context.getNameForSymbol(symbol)) else null
             }
         )
     )

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt

@@ -132,6 +132,17 @@ class JsIntrinsicTransformers(backendContext: JsIrBackendContext) {
                 val value = args[2]
                 JsInvocation(JsNameRef(Namer.KPROPERTY_SET, reference), listOf(receiver, value))
             }
+
+            add(intrinsics.jsGetContinuation) { _, context: JsGenerationContext ->
+                context.continuation
+            }
+
+            add(intrinsics.jsCoroutineContext) { _, context: JsGenerationContext ->
+                val contextGetter = backendContext.coroutineGetContext
+                val getterName = context.getNameForSymbol(contextGetter)
+                val continuation = context.continuation
+                JsInvocation(JsNameRef(getterName, continuation))
+            }
         }
     }
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.ir.backend.js.transformers.irToJs
 
+import org.jetbrains.kotlin.backend.common.descriptors.isSuspend
 import org.jetbrains.kotlin.ir.backend.js.utils.JsGenerationContext
 import org.jetbrains.kotlin.ir.backend.js.utils.Namer
 import org.jetbrains.kotlin.ir.declarations.IrFunction
@@ -49,6 +50,9 @@ fun translateFunction(declaration: IrFunction, name: JsName?, context: JsGenerat
 
     declaration.extensionReceiverParameter?.let { function.addParameter(functionContext.getNameForSymbol(it.symbol)) }
     functionParams.forEach { function.addParameter(it) }
+    if (declaration.descriptor.isSuspend) {
+        function.addParameter(context.currentScope.declareName(Namer.CONTINUATION))
+    }
 
     return function
 }
@@ -57,11 +61,15 @@ fun translateCallArguments(expression: IrMemberAccessExpression, context: JsGene
     val transformer = IrElementToJsExpressionTransformer()
     val size = expression.valueArgumentsCount
 
-    return (0 until size).mapTo(ArrayList(size)) {
+    val arguments = (0 until size).mapTo(ArrayList(size)) {
         val argument = expression.getValueArgument(it)
         val result = argument?.accept(transformer, context) ?: JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(1))
         result
     }
+
+    return if (expression.descriptor.isSuspend) {
+        arguments + context.continuation
+    } else arguments
 }
 
 val IrFunction.isStatic: Boolean get() = this.dispatchReceiverParameter == null

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/JsGenerationContext.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.*
@@ -44,4 +45,20 @@ class JsGenerationContext {
 
     fun getNameForSymbol(symbol: IrSymbol): JsName = staticContext.getNameForSymbol(symbol, this)
     fun getNameForLoop(loop: IrLoop): JsName? = staticContext.getNameForLoop(loop, this)
+
+    val continuation
+        get() = if (isCoroutineDoResume()) {
+            JsThisRef()
+        } else {
+            if (currentFunction!!.descriptor.isSuspend) {
+                JsNameRef(currentScope.declareName(Namer.CONTINUATION))
+            } else {
+                getNameForSymbol(currentFunction.valueParameters.last().symbol).makeRef()
+            }
+        }
+
+    private fun isCoroutineDoResume(): Boolean {
+        val overriddenSymbols = (currentFunction as? IrSimpleFunction)?.overriddenSymbols ?: return false
+        return staticContext.doResumeFunctionSymbol in overriddenSymbols
+    }
 }

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/JsStaticContext.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.ir.backend.js.utils
 
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.transformers.irToJs.JsIntrinsicTransformers
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.expressions.IrLoop
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.js.backend.ast.JsClassModel
@@ -24,6 +25,9 @@ class JsStaticContext(
     val intrinsics = JsIntrinsicTransformers(backendContext)
     // TODO: use IrSymbol instead of JsName
     val classModels = mutableMapOf<JsName, JsClassModel>()
+    val coroutineImplDeclaration = backendContext.ir.symbols.coroutineImpl.owner
+    val doResumeFunctionSymbol = coroutineImplDeclaration.declarations
+        .filterIsInstance<IrSimpleFunction>().single { it.name.asString() == "doResume" }.symbol
 
     val initializerBlock = JsGlobalBlock()
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/Namer.kt

@@ -60,6 +60,8 @@ object Namer {
     val DEFINE_INLINE_FUNCTION = "defineInlineFunction"
     val DEFAULT_PARAMETER_IMPLEMENTOR_SUFFIX = "\$default"
 
+    val CONTINUATION = "\$cont"
+
     val JS_ERROR = JsNameRef("Error")
 
     val JS_OBJECT = JsNameRef("Object")

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/SimpleNameGenerator.kt

@@ -60,7 +60,7 @@ class SimpleNameGenerator : NameGenerator {
                     nameDeclarator = context.currentScope::declareFreshName
                 }
                 is PropertyDescriptor -> {
-                    nameBuilder.append(descriptor.name.identifier)
+                    nameBuilder.append(descriptor.name.asString())
                     if (descriptor.visibility == Visibilities.PRIVATE || descriptor.modality != Modality.FINAL) {
                         nameBuilder.append('$')
                         nameBuilder.append(getNameForDescriptor(descriptor.containingDeclaration, context))

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/builders/ExpressionHelpers.kt

@@ -183,8 +183,12 @@ fun IrBuilderWithScope.irGet(type: IrType, receiver: IrExpression, getterSymbol:
         origin = IrStatementOrigin.GET_PROPERTY
     )
 
-fun IrBuilderWithScope.irCall(callee: IrFunctionSymbol, type: IrType): IrCall =
-    IrCallImpl(startOffset, endOffset, type, callee, callee.descriptor)
+fun IrBuilderWithScope.irCall(callee: IrFunctionSymbol, type: IrType, typeArguments: List<IrType> = emptyList()): IrCall =
+    IrCallImpl(startOffset, endOffset, type, callee, callee.descriptor).apply {
+        typeArguments.forEachIndexed { index, irType ->
+            this.putTypeArgument(index, irType)
+        }
+    }
 
 fun IrBuilderWithScope.irCall(callee: IrFunctionSymbol): IrCall =
     IrCallImpl(startOffset, endOffset, callee.owner.returnType, callee, callee.descriptor)
@@ -237,3 +241,14 @@ fun IrBuilderWithScope.irString(value: String) =
 
 fun IrBuilderWithScope.irConcat() =
     IrStringConcatenationImpl(startOffset, endOffset, context.irBuiltIns.stringType)
+
+
+fun IrBuilderWithScope.irSetField(receiver: IrExpression, irField: IrField, value: IrExpression): IrExpression =
+    IrSetFieldImpl(
+        startOffset,
+        endOffset,
+        irField.symbol,
+        receiver = receiver,
+        value = value,
+        type = context.irBuiltIns.unitType
+    )

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/builders/IrBuilder.kt

@@ -19,12 +19,13 @@ package org.jetbrains.kotlin.ir.builders
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
-import org.jetbrains.kotlin.ir.expressions.IrBlock
 import org.jetbrains.kotlin.ir.expressions.IrBlockBody
+import org.jetbrains.kotlin.ir.expressions.IrContainerExpression
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrBlockImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 import java.util.*
@@ -84,12 +85,13 @@ class IrBlockBuilder(
     startOffset: Int,
     endOffset: Int,
     val origin: IrStatementOrigin? = null,
-    var resultType: IrType? = null
-) : IrStatementsBuilder<IrBlock>(context, scope, startOffset, endOffset) {
+    var resultType: IrType? = null,
+    val isTransparent:Boolean = false
+) : IrStatementsBuilder<IrContainerExpression>(context, scope, startOffset, endOffset) {
 
     private val statements = ArrayList<IrStatement>()
 
-    inline fun block(body: IrBlockBuilder.() -> Unit): IrBlock {
+    inline fun block(body: IrBlockBuilder.() -> Unit): IrContainerExpression {
         body()
         return doBuild()
     }
@@ -98,11 +100,11 @@ class IrBlockBuilder(
         statements.add(irStatement)
     }
 
-    override fun doBuild(): IrBlock {
+    override fun doBuild(): IrContainerExpression {
         val resultType = this.resultType
                 ?: statements.lastOrNull().safeAs<IrExpression>()?.type
                 ?: context.irBuiltIns.unitType
-        val irBlock = IrBlockImpl(startOffset, endOffset, resultType, origin)
+        val irBlock = if (isTransparent) IrCompositeImpl(startOffset, endOffset, resultType, origin) else IrBlockImpl(startOffset, endOffset, resultType, origin)
         irBlock.statements.addAll(statements)
         return irBlock
     }
@@ -154,6 +156,20 @@ inline fun IrGeneratorWithScope.irBlock(
         origin, resultType
     ).block(body)
 
+inline fun IrGeneratorWithScope.irComposite(
+    startOffset: Int = UNDEFINED_OFFSET,
+    endOffset: Int = UNDEFINED_OFFSET,
+    origin: IrStatementOrigin? = null,
+    resultType: IrType? = null,
+    body: IrBlockBuilder.() -> Unit
+): IrExpression =
+    IrBlockBuilder(
+        context, scope,
+        startOffset,
+        endOffset,
+        origin, resultType, true
+    ).block(body)
+
 inline fun IrGeneratorWithScope.irBlockBody(
     startOffset: Int = UNDEFINED_OFFSET, endOffset: Int = UNDEFINED_OFFSET,
     body: IrBlockBodyBuilder.() -> Unit

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/irTypes.kt

@@ -8,6 +8,9 @@ package org.jetbrains.kotlin.ir.types
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
+import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.IrClassSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrTypeParameterSymbolImpl
@@ -75,6 +78,17 @@ fun IrType.toKotlinType(): KotlinType {
     }
 }
 
+fun IrType.getClass(): IrClass? =
+    (this.classifierOrNull as? IrClassSymbol)?.owner
+
+fun IrClassSymbol.createType(hasQuestionMark: Boolean, arguments: List<IrTypeArgument>): IrSimpleType =
+    IrSimpleTypeImpl(
+        this,
+        hasQuestionMark,
+        arguments,
+        emptyList()
+    )
+
 private fun makeKotlinType(
     classifier: IrClassifierSymbol,
     arguments: List<IrTypeArgument>,
@@ -95,6 +109,20 @@ fun ClassifierDescriptor.toIrType(hasQuestionMark: Boolean = false): IrType {
     return IrSimpleTypeImpl(defaultType, symbol, hasQuestionMark, listOf(), listOf())
 }
 
+val IrTypeParameter.defaultType: IrType get() = symbol.owner.defaultType
+
+fun IrClassifierSymbol.typeWith(vararg arguments: IrType): IrSimpleType = typeWith(arguments.toList())
+
+fun IrClassifierSymbol.typeWith(arguments: List<IrType>): IrSimpleType =
+    IrSimpleTypeImpl(
+        this,
+        false,
+        arguments.map { makeTypeProjection(it, Variance.INVARIANT) },
+        emptyList()
+    )
+
+fun IrClass.typeWith(arguments: List<IrType>) = this.symbol.typeWith(arguments)
+
 fun KotlinType.toIrType(): IrType? {
     if (isDynamic()) return IrDynamicTypeImpl(this, listOf(), Variance.INVARIANT)
 
@@ -113,6 +141,7 @@ fun KotlinType.toIrType(): IrType? {
     return IrSimpleTypeImpl(this, symbol, isMarkedNullable, arguments, annotations)
 }
 
+// TODO: this function creates unbound symbol which is the great source of problems
 private fun ClassifierDescriptor.getSymbol(): IrClassifierSymbol = when (this) {
     is ClassDescriptor -> IrClassSymbolImpl(this)
     is TypeParameterDescriptor -> IrTypeParameterSymbolImpl(this)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -6,20 +6,30 @@
 package org.jetbrains.kotlin.ir.util
 
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.PropertyDescriptorImpl
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.impl.IrFieldImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrTypeParameterImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrValueParameterSymbol
+import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.toIrType
 import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
+import org.jetbrains.kotlin.types.KotlinType
 
 /**
  * Binds the arguments explicitly represented in the IR to the parameters of the accessed function.
@@ -168,6 +178,21 @@ fun IrFunction.createParameterDeclarations() {
     }
 }
 
+fun IrClass.createParameterDeclarations() {
+    thisReceiver = IrValueParameterImpl(
+        startOffset, endOffset,
+        IrDeclarationOrigin.INSTANCE_RECEIVER,
+        descriptor.thisAsReceiverParameter,
+        this.symbol.typeWith(this.typeParameters.map { it.defaultType }),
+        null
+    ).also { valueParameter ->
+        valueParameter.parent = this
+    }
+
+    assert(typeParameters.isEmpty())
+    assert(descriptor.declaredTypeParameters.isEmpty())
+}
+
 //fun IrClass.createParameterDeclarations() {
 //    descriptor.thisAsReceiverParameter.let {
 //        thisReceiver = IrValueParameterImpl(
@@ -311,6 +336,40 @@ fun IrValueParameter.copy(newDescriptor: ParameterDescriptor): IrValueParameter
     )
 }
 
+fun createField(
+    startOffset: Int,
+    endOffset: Int,
+    type: IrType,
+    name: Name,
+    isMutable: Boolean,
+    origin: IrDeclarationOrigin,
+    owner: ClassDescriptor
+): IrField {
+    val descriptor = PropertyDescriptorImpl.create(
+        /* containingDeclaration = */ owner,
+        /* annotations           = */ Annotations.EMPTY,
+        /* modality              = */ Modality.FINAL,
+        /* visibility            = */ Visibilities.PRIVATE,
+        /* isVar                 = */ isMutable,
+        /* name                  = */ name,
+        /* kind                  = */ CallableMemberDescriptor.Kind.DECLARATION,
+        /* source                = */ SourceElement.NO_SOURCE,
+        /* lateInit              = */ false,
+        /* isConst               = */ false,
+        /* isExpect              = */ false,
+        /* isActual                = */ false,
+        /* isExternal            = */ false,
+        /* isDelegated           = */ false
+    ).apply {
+        initialize(null, null)
+
+        val receiverType: KotlinType? = null
+        setType(type.toKotlinType(), emptyList(), owner.thisAsReceiverParameter, receiverType)
+    }
+
+    return IrFieldImpl(startOffset, endOffset, origin, descriptor, type)
+}
+
 fun IrFunction.createDispatchReceiverParameter() {
     assert(this.dispatchReceiverParameter == null)
 

compiler/testData/codegen/box/boxingOptimization/nullCheck.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/boxingOptimization/safeCallWithElvis.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/boxingOptimization/simple.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/boxingOptimization/simpleUninitializedMerge.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/callableReference/function/innerConstructorFromTopLevelOneStringArg.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 class A {
     inner class Inner(val result: Int)
 }

compiler/testData/codegen/box/callableReference/function/newArray.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 private fun <T> upcast(value: T): T = value
 
 fun box(): String {

compiler/testData/codegen/box/controlStructures/factorialTest.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/coroutines/32defaultParametersInSuspend.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/accessorForSuspend.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/asyncIterator.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/asyncIteratorNullMerge.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/beginWithException.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/beginWithExceptionNoHandleException.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/coercionToUnit.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/controlFlow/doWhileStatement.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/controlFlow/returnFromFinally.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/controlFlow/whileStatement.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/controllerAccessFromInnerLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/coroutineContextInInlinedLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/createCoroutineSafe.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/crossInlineWithCapturedOuterReceiver.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // COMMON_COROUTINES_TEST

compiler/testData/codegen/box/coroutines/defaultParametersInSuspend.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/delegatedSuspendMember.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_COROUTINES
 // COMMON_COROUTINES_TEST

compiler/testData/codegen/box/coroutines/dispatchResume.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/falseUnitCoercion.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/featureIntersection/destructuringInLambdas.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/featureIntersection/safeCallOnTwoReceivers.kt

@@ -6,7 +6,6 @@
 import helpers.*
 import COROUTINES_PACKAGE.*
 import COROUTINES_PACKAGE.intrinsics.*
-import kotlin.test.assertEquals
 
 class A(val w: String) {
     suspend fun String.ext(): String = suspendCoroutineUninterceptedOrReturn {

compiler/testData/codegen/box/coroutines/featureIntersection/safeCallOnTwoReceiversLong.kt

@@ -6,7 +6,6 @@
 import helpers.*
 import COROUTINES_PACKAGE.*
 import COROUTINES_PACKAGE.intrinsics.*
-import kotlin.test.assertEquals
 
 class A(val w: String) {
     suspend fun Long.ext(): String = suspendCoroutineUninterceptedOrReturn {

compiler/testData/codegen/box/coroutines/inlineClasses/bridgeGenerationNonInline.kt

@@ -1,4 +1,4 @@
-// IGNORE_BACKEND: JS_IR, JVM_IR
+// IGNORE_BACKEND: JVM_IR
 // WITH_COROUTINES
 // COMMON_COROUTINES_TEST
 

compiler/testData/codegen/box/coroutines/intLikeVarSpilling/complicatedMerge.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intLikeVarSpilling/noVariableInTable.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intLikeVarSpilling/usedInMethodCall.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intLikeVarSpilling/usedInVarStore.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intrinsicSemantics/coroutineContext.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intrinsicSemantics/coroutineContextReceiver.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/intrinsicSemantics/coroutineContextReceiverNotIntrinsic.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/localFunctions/named/capturedParameters.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/localFunctions/named/capturedVariables.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/localFunctions/named/extension.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/localFunctions/named/nestedLocals.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/localFunctions/named/withArguments.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/multipleInvokeCallsInsideInlineLambda1.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/multipleInvokeCallsInsideInlineLambda2.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/multipleInvokeCallsInsideInlineLambda3.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/noSuspensionPoints.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/overrideDefaultArgument.kt

@@ -3,6 +3,7 @@
 // WITH_RUNTIME
 // WITH_COROUTINES
 // COMMON_COROUTINES_TEST
+// DONT_RUN_GENERATED_CODE: JS_IR
 import helpers.*
 import COROUTINES_PACKAGE.*
 import COROUTINES_PACKAGE.intrinsics.*

compiler/testData/codegen/box/coroutines/stackUnwinding/exception.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/suspendFunctionAsCoroutine/dispatchResume.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/suspendFunctionAsCoroutine/privateFunctions.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/suspendFunctionAsCoroutine/withVariables.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/suspendInTheMiddleOfObjectConstructionWithJumpOut.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/unitTypeReturn/coroutineNonLocalReturn.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/unitTypeReturn/coroutineReturn.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/coroutines/varValueConflictsWithTable.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JVM_IR
 // WITH_RUNTIME
 // WITH_COROUTINES

compiler/testData/codegen/box/deadCodeElimination/emptyVariableRange.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/delegatedProperty/provideDelegate/differentReceivers.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/delegatedProperty/provideDelegate/evaluationOrder.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/delegatedProperty/provideDelegate/generic.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/delegatedProperty/provideDelegate/inClass.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/delegatedProperty/provideDelegate/inlineProvideDelegate.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/delegatedProperty/provideDelegate/propertyMetadata.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.*

compiler/testData/codegen/box/functions/localFunctions/callInlineLocalInLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambda.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambdaInnerUsage1.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/functions/localFunctions/definedWithinLambdaInnerUsage2.kt

@@ -1,5 +1,4 @@
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 
 import kotlin.test.assertEquals

compiler/testData/codegen/box/increment/augmentedAssignmentWithComplexRhs.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 import kotlin.test.*
 

compiler/testData/codegen/box/multiplatform/defaultArguments/constructor.kt

@@ -1,6 +1,5 @@
 // !LANGUAGE: +MultiPlatformProjects
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 // FILE: common.kt
 

compiler/testData/codegen/box/multiplatform/defaultArguments/function.kt

@@ -1,6 +1,5 @@
 // !LANGUAGE: +MultiPlatformProjects
 // IGNORE_BACKEND: JVM_IR
-// IGNORE_BACKEND: JS_IR
 // WITH_RUNTIME
 // FILE: common.kt