Make IrScript a statement container first, update JS support

The IrScript is now the IrStatementContainer with significant
statements order, and the code is adapted accordingly

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

@@ -17,9 +17,12 @@
 package org.jetbrains.kotlin.backend.common
 
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrBody
+import org.jetbrains.kotlin.ir.expressions.IrStatementContainer
 import org.jetbrains.kotlin.ir.util.transformFlat
+import org.jetbrains.kotlin.ir.util.transformSubsetFlat
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
@@ -111,11 +114,6 @@ private class DeclarationContainerLoweringVisitor(
         declaration.acceptChildrenVoid(this)
         loweringPass.lower(declaration)
     }
-
-    override fun visitScript(declaration: IrScript) {
-        declaration.acceptChildrenVoid(this)
-        loweringPass.lower(declaration)
-    }
 }
 
 fun BodyLoweringPass.runOnFilePostfix(
@@ -160,11 +158,8 @@ private class BodyLoweringVisitor(
     }
 
     override fun visitScript(declaration: IrScript, data: IrDeclaration?) {
-        ArrayList(declaration.declarations).forEach { it.accept(this, declaration) }
-        if (withLocalDeclarations) {
-            declaration.statements.forEach { it.accept(this, null) }
-        }
         declaration.thisReceiver.accept(this, declaration)
+        ArrayList(declaration.statements).forEach { it.accept(this, declaration) }
     }
 }
 
@@ -214,22 +209,26 @@ interface DeclarationTransformer : FileLoweringPass {
 
             val visitor = this
 
+            fun IrDeclaration.replaceInContainer(container: MutableList<in IrDeclaration>, result: List<IrDeclaration>): Boolean {
+                var index = container.indexOf(this)
+                if (index == -1) {
+                    index = container.indexOf(declaration)
+                } else {
+                    container.removeAt(index)
+                    --index
+                }
+                return container.addAll(index + 1, result)
+            }
+
             fun IrDeclaration.transform() {
 
                 acceptVoid(visitor)
 
                 val result = transformer.transformFlatRestricted(this)
                 if (result != null) {
-                    (parent as? IrDeclarationContainer)?.let {
-                        var index = it.declarations.indexOf(this)
-                        if (index == -1) {
-                            index = it.declarations.indexOf(declaration)
-                        } else {
-                            it.declarations.removeAt(index)
-                            --index
-                        }
-
-                        it.declarations.addAll(index + 1, result)
+                    when (val parentCopy = parent) {
+                        is IrDeclarationContainer -> replaceInContainer(parentCopy.declarations, result)
+                        is IrStatementContainer -> replaceInContainer(parentCopy.statements, result)
                     }
                 }
             }
@@ -248,12 +247,12 @@ interface DeclarationTransformer : FileLoweringPass {
         }
 
         override fun visitScript(declaration: IrScript) {
-            ArrayList(declaration.declarations).forEach { it.accept(this, null) }
-            declaration.declarations.transformFlat(transformer::transformFlatRestricted)
-
-            if (transformer.withLocalDeclarations) {
-                declaration.statements.forEach { it.accept(this, null) }
+            ArrayList(declaration.statements).forEach {
+                if (transformer.withLocalDeclarations || it is IrDeclaration) {
+                    it.accept(this, null)
+                }
             }
+            declaration.statements.transformSubsetFlat(transformer::transformFlatRestricted)
 
             declaration.thisReceiver.accept(this, null)
         }

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

@@ -7,10 +7,12 @@ package org.jetbrains.kotlin.backend.common.lower
 
 import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.ir.addChild
+import org.jetbrains.kotlin.backend.common.ir.setDeclarationsParent
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrBody
+import org.jetbrains.kotlin.ir.expressions.IrStatementContainer
 import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
@@ -22,8 +24,12 @@ open class LocalClassPopupLowering(val context: BackendContext) : BodyLoweringPa
         runOnFilePostfix(irFile, withLocalDeclarations = true, allowDeclarationModification = true)
     }
 
+    private data class ExtractedLocalClass(
+        val local: IrClass, val newContainer: IrDeclarationParent, val extractedUnder: IrStatement?
+    )
+
     override fun lower(irBody: IrBody, container: IrDeclaration) {
-        val extractedLocalClasses = arrayListOf<Pair<IrClass, IrDeclarationContainer>>()
+        val extractedLocalClasses = arrayListOf<ExtractedLocalClass>()
 
         irBody.transform(object : IrElementTransformerVoidWithContext() {
 
@@ -32,22 +38,46 @@ open class LocalClassPopupLowering(val context: BackendContext) : BodyLoweringPa
                     if (allScopes.size > 1) allScopes[allScopes.lastIndex - 1] else createScope(container as IrSymbolOwner)
                 if (!shouldPopUp(declaration, currentScope)) return declaration
 
-                val newContainer = run {
-                    var currentParent = declaration.parent
-                    while (currentParent is IrDeclaration && currentParent !is IrClass && currentParent !is IrScript) {
-                        currentParent = currentParent.parent
+                var extractedUnder: IrStatement? = declaration
+                var newContainer = declaration.parent
+                while (newContainer is IrDeclaration && newContainer !is IrClass && newContainer !is IrScript) {
+                    extractedUnder = newContainer
+                    newContainer = newContainer.parent
+                }
+                when (newContainer) {
+                    is IrStatementContainer -> {
+                        // TODO: check if it is the correct behavior
+                        if (extractedUnder == declaration) {
+                            extractedUnder = (newContainer.statements.indexOf(extractedUnder) + 1)
+                                .takeIf { it > 0 && it < newContainer.statements.size }
+                                ?.let { newContainer.statements[it] }
+                        }
+                        extractedLocalClasses.add(ExtractedLocalClass(declaration, newContainer, extractedUnder))
                     }
-
-                    currentParent as IrDeclarationContainer // IrClass or IrScript or IrPackageFragment
+                    is IrDeclarationContainer -> extractedLocalClasses.add(ExtractedLocalClass(declaration, newContainer, extractedUnder))
+                    else -> error("Inexpected container type $newContainer")
                 }
 
-                extractedLocalClasses.add(declaration to newContainer)
                 return IrCompositeImpl(declaration.startOffset, declaration.endOffset, context.irBuiltIns.unitType)
             }
         }, null)
 
-        for ((local, newContainer) in extractedLocalClasses) {
-            newContainer.addChild(local)
+        for ((local, newContainer, extractedUnder) in extractedLocalClasses) {
+            when (newContainer) {
+                is IrStatementContainer -> {
+                    val insertIndex = extractedUnder?.let { newContainer.statements.indexOf(it) } ?: -1
+                    if (insertIndex >= 0) {
+                        newContainer.statements.add(insertIndex, local)
+                    } else {
+                        newContainer.statements.add(local)
+                    }
+                    local.setDeclarationsParent(newContainer)
+                }
+                is IrDeclarationContainer -> {
+                    newContainer.addChild(local)
+                }
+                else -> error("Inexpected container type $newContainer")
+            }
 
             local.acceptVoid(object : IrElementVisitorVoid {
                 override fun visitElement(element: IrElement) {

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

@@ -19,9 +19,9 @@ package org.jetbrains.kotlin.backend.common.lower
 import org.jetbrains.kotlin.backend.common.BackendContext
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.ValueParameterDescriptorImpl
-import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.*
@@ -162,6 +162,12 @@ open class IrBuildingTransformer(private val context: BackendContext) : IrElemen
             return super.visitEnumEntry(declaration)
         }
     }
+
+    override fun visitScript(declaration: IrScript): IrStatement {
+        withBuilder(declaration.symbol) {
+            return super.visitScript(declaration)
+        }
+    }
 }
 
 fun IrConstructor.callsSuper(irBuiltIns: IrBuiltIns): Boolean {

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

@@ -117,10 +117,6 @@ class BlockDecomposerTransformer(
         function = declaration
 
         with(declaration) {
-            val transformedDeclarations = declarations.map { it.transform(statementTransformer, null) as IrDeclaration }
-            declarations.clear()
-            declarations.addAll(transformedDeclarations)
-
             val transformedStatements = mutableListOf<IrStatement>()
             statements.forEach {
                 val transformer = if (it === statements.last()) expressionTransformer else statementTransformer

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

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrReturnImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrSetFieldImpl
 import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.util.patchDeclarationParents
 import org.jetbrains.kotlin.ir.util.transformFlat
 import org.jetbrains.kotlin.name.Name
 
@@ -35,7 +36,7 @@ class CreateScriptFunctionsPhase(val context: CommonBackendContext) : FileLoweri
     private fun lower(irScript: IrScript): List<IrDeclaration> {
         val (startOffset, endOffset) = getFunctionBodyOffsets(irScript)
 
-        val initializeStatements = irScript.declarations
+        val initializeStatements = irScript.statements
             .filterIsInstance<IrProperty>()
             .mapNotNull { it.backingField }
             .filter { it.initializer != null }
@@ -55,14 +56,16 @@ class CreateScriptFunctionsPhase(val context: CommonBackendContext) : FileLoweri
             it.body = it.factory.createBlockBody(
                 startOffset,
                 endOffset,
-                irScript.statements.prepareForEvaluateScriptFunction(it)
+                irScript.statements.filter { it !is IrDeclaration }.prepareForEvaluateScriptFunction(it)
             )
         }
 
         with(irScript) {
-            declarations += initializeScriptFunction
-            declarations += evaluateScriptFunction
-            statements.clear()
+            statements.removeIf { it !is IrDeclaration }
+            statements += initializeScriptFunction
+            initializeScriptFunction.patchDeclarationParents(this)
+            statements += evaluateScriptFunction
+            evaluateScriptFunction.patchDeclarationParents(this)
             statements += createCall(initializeScriptFunction)
             statements += createCall(evaluateScriptFunction)
         }

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

@@ -152,7 +152,7 @@ class ScriptRemoveReceiverLowering(val context: CommonBackendContext) : FileLowe
 
         script.transformChildrenVoid(transformer)
 
-        script.declarations.forEach {
+        script.statements.forEach {
             when (it) {
                 is IrSimpleFunction -> it.dispatchReceiverParameter = null
                 is IrProperty -> {

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

@@ -29,8 +29,19 @@ class StaticMembersLowering(val context: JsIrBackendContext) : DeclarationTransf
                 if (declaration.isExported(context)) {
                     context.additionalExportedDeclarations.add(declaration)
                 }
+                var extractedUnder = declaration
+                var newContainer = declaration.parent
+                while (newContainer is IrDeclaration && newContainer != irClass.file) {
+                    extractedUnder = newContainer
+                    newContainer = newContainer.parent
+                }
+                val insertBefore = irClass.file.declarations.indexOf(extractedUnder)
+                if (insertBefore >= 0) {
+                    irClass.file.declarations.add(insertBefore, declaration)
+                } else {
+                    irClass.file.declarations += declaration
+                }
                 declaration.parent = irClass.file
-                irClass.file.declarations += declaration
                 return listOf()
             }
         }

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

@@ -52,8 +52,11 @@ class IrDeclarationToJsTransformer : BaseIrElementToJsNodeTransformer<JsStatemen
 
     override fun visitScript(irScript: IrScript, context: JsGenerationContext): JsStatement {
         return JsGlobalBlock().apply {
-            statements += irScript.declarations.map { it.accept(this@IrDeclarationToJsTransformer, context) }
-            statements += irScript.statements.map { it.accept(IrElementToJsStatementTransformer(), context) }
+            irScript.statements.forEach {
+                statements +=
+                    if (it is IrDeclaration) it.accept(this@IrDeclarationToJsTransformer, context)
+                    else it.accept(IrElementToJsStatementTransformer(), context)
+            }
         }
     }
 }

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

@@ -186,10 +186,12 @@ class NameTables(
             for (declaration in p.declarations) {
                 generateNamesForTopLevelDecl(declaration)
                 if (declaration is IrScript) {
-                    for (memberDecl in declaration.declarations) {
-                        generateNamesForTopLevelDecl(memberDecl)
-                        if (memberDecl is IrClass) {
-                            classDeclaration += memberDecl
+                    for (memberDecl in declaration.statements) {
+                        if (memberDecl is IrDeclaration) {
+                            generateNamesForTopLevelDecl(memberDecl)
+                            if (memberDecl is IrClass) {
+                                classDeclaration += memberDecl
+                            }
                         }
                     }
                 }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/FunctionGenerator.kt

@@ -100,7 +100,7 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
 
     fun generatePropertyAccessor(
         descriptor: PropertyAccessorDescriptor,
-        ktProperty: KtProperty,
+        ktProperty: KtVariableDeclaration,
         ktAccessor: KtPropertyAccessor?
     ): IrSimpleFunction =
         declareSimpleFunctionInner(
@@ -121,9 +121,9 @@ class FunctionGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
 
     fun generateDefaultAccessorForPrimaryConstructorParameter(
         descriptor: PropertyAccessorDescriptor,
-        ktParameter: KtParameter
+        ktElement: KtElement
     ): IrSimpleFunction =
-        declareSimpleFunctionInner(descriptor, ktParameter, IrDeclarationOrigin.DEFAULT_PROPERTY_ACCESSOR).buildWithScope { irAccessor ->
+        declareSimpleFunctionInner(descriptor, ktElement, IrDeclarationOrigin.DEFAULT_PROPERTY_ACCESSOR).buildWithScope { irAccessor ->
             declarationGenerator.generateScopedTypeParameterDeclarations(irAccessor, descriptor.typeParameters)
             irAccessor.returnType = descriptor.returnType!!.toIrType()
             FunctionGenerator(declarationGenerator).generateSyntheticFunctionParameterDeclarations(irAccessor)

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/PropertyGenerator.kt

@@ -16,10 +16,11 @@
 
 package org.jetbrains.kotlin.psi2ir.generators
 
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
-import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
-import org.jetbrains.kotlin.descriptors.DescriptorVisibility
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.descriptors.impl.PropertyGetterDescriptorImpl
 import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
 import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
@@ -41,38 +42,74 @@ class PropertyGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
             generateSimpleProperty(ktProperty, propertyDescriptor)
     }
 
+    fun generateDestructuringDeclarationEntryAsPropertyDeclaration(ktEntry: KtDestructuringDeclarationEntry, entryInitializer: IrExpression): IrProperty {
+        val propertyDescriptor = getPropertyDescriptor(ktEntry)
+        return context.symbolTable.declareProperty(
+            ktEntry.startOffsetSkippingComments, ktEntry.endOffset,
+            IrDeclarationOrigin.DEFINED,
+            propertyDescriptor,
+            isDelegated = false
+        ).buildWithScope { irProperty ->
+            irProperty.backingField = generatePropertyBackingField(ktEntry, propertyDescriptor) { null }
+
+            irProperty.getter = generateGetterIfRequired(ktEntry, propertyDescriptor)
+            irProperty.setter = generateSetterIfRequired(ktEntry, propertyDescriptor)
+
+            irProperty.linkCorrespondingPropertySymbol()
+        }
+    }
+
     fun generatePropertyForPrimaryConstructorParameter(ktParameter: KtParameter, irValueParameter: IrValueParameter): IrDeclaration {
         val propertyDescriptor = getOrFail(BindingContext.PRIMARY_CONSTRUCTOR_PARAMETER, ktParameter)
+        return generateSyntheticProperty(ktParameter, propertyDescriptor, irValueParameter)
+    }
 
+    fun generateSyntheticProperty(
+        ktDeclarationContainer: KtElement, propertyDescriptor: PropertyDescriptor,
+        irValueParameter: IrValueParameter?, generateSyntheticAccessors: Boolean = false
+    ): IrProperty {
         val irPropertyType = propertyDescriptor.type.toIrType()
         return context.symbolTable.declareProperty(
-            ktParameter.startOffsetSkippingComments, ktParameter.endOffset,
+            ktDeclarationContainer.startOffsetSkippingComments, ktDeclarationContainer.endOffset,
             IrDeclarationOrigin.DEFINED,
             propertyDescriptor,
             isDelegated = false
         ).also { irProperty ->
             irProperty.backingField =
-                generatePropertyBackingField(ktParameter, propertyDescriptor) {
-                    context.irFactory.createExpressionBody(
-                        IrGetValueImpl(
-                            ktParameter.startOffsetSkippingComments, ktParameter.endOffset,
-                            irPropertyType,
-                            irValueParameter.symbol,
-                            IrStatementOrigin.INITIALIZE_PROPERTY_FROM_PARAMETER
+                generatePropertyBackingField(ktDeclarationContainer, propertyDescriptor) {
+                    if (irValueParameter == null) null
+                    else {
+                        context.irFactory.createExpressionBody(
+                            IrGetValueImpl(
+                                ktDeclarationContainer.startOffsetSkippingComments, ktDeclarationContainer.endOffset,
+                                irPropertyType,
+                                irValueParameter.symbol,
+                                IrStatementOrigin.INITIALIZE_PROPERTY_FROM_PARAMETER
+                            )
                         )
-                    )
+                    }
                 }
 
             val getter = propertyDescriptor.getter
-                ?: throw AssertionError("Property declared in primary constructor has no getter: $propertyDescriptor")
+                ?: if (generateSyntheticAccessors)
+                    // TODO: check if this is the correct way to generate synthetic accessor
+                    PropertyGetterDescriptorImpl(
+                        propertyDescriptor,
+                        Annotations.EMPTY, Modality.FINAL, DescriptorVisibilities.PUBLIC, false, false, false,
+                        CallableMemberDescriptor.Kind.SYNTHESIZED, null, propertyDescriptor.source
+                    ).apply {
+                        initialize(propertyDescriptor.type)
+                    }
+                else throw AssertionError("Property declared in primary constructor has no getter: $propertyDescriptor")
             irProperty.getter =
-                FunctionGenerator(declarationGenerator).generateDefaultAccessorForPrimaryConstructorParameter(getter, ktParameter)
+                FunctionGenerator(declarationGenerator).generateDefaultAccessorForPrimaryConstructorParameter(getter, ktDeclarationContainer)
 
             if (propertyDescriptor.isVar) {
                 val setter = propertyDescriptor.setter
+                    // TODO: implement setter descriptor generation, if needed
                     ?: throw AssertionError("Property declared in primary constructor has no setter: $propertyDescriptor")
                 irProperty.setter =
-                    FunctionGenerator(declarationGenerator).generateDefaultAccessorForPrimaryConstructorParameter(setter, ktParameter)
+                    FunctionGenerator(declarationGenerator).generateDefaultAccessorForPrimaryConstructorParameter(setter, ktDeclarationContainer)
             }
 
             irProperty.linkCorrespondingPropertySymbol()
@@ -105,7 +142,7 @@ class PropertyGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
     private fun PropertyDescriptor.actuallyHasBackingField(bindingContext: BindingContext) =
         hasBackingField(bindingContext) || context.extensions.isPropertyWithPlatformField(this)
 
-    private fun generateSimpleProperty(ktProperty: KtProperty, propertyDescriptor: PropertyDescriptor): IrProperty =
+    private fun generateSimpleProperty(ktProperty: KtVariableDeclaration, propertyDescriptor: PropertyDescriptor): IrProperty =
         context.symbolTable.declareProperty(
             ktProperty.startOffsetSkippingComments, ktProperty.endOffset,
             IrDeclarationOrigin.DEFINED,
@@ -154,18 +191,18 @@ class PropertyGenerator(declarationGenerator: DeclarationGenerator) : Declaratio
         }
     }
 
-    private fun generateGetterIfRequired(ktProperty: KtProperty, property: PropertyDescriptor): IrSimpleFunction? {
+    private fun generateGetterIfRequired(ktProperty: KtVariableDeclaration, property: PropertyDescriptor): IrSimpleFunction? {
         val getter = property.getter ?: return null
-        return FunctionGenerator(declarationGenerator).generatePropertyAccessor(getter, ktProperty, ktProperty.getter)
+        return FunctionGenerator(declarationGenerator).generatePropertyAccessor(getter, ktProperty, (ktProperty as? KtProperty)?.getter)
     }
 
-    private fun generateSetterIfRequired(ktProperty: KtProperty, property: PropertyDescriptor): IrSimpleFunction? {
+    private fun generateSetterIfRequired(ktProperty: KtVariableDeclaration, property: PropertyDescriptor): IrSimpleFunction? {
         if (!property.isVar) return null
         val setter = property.setter ?: return null
-        return FunctionGenerator(declarationGenerator).generatePropertyAccessor(setter, ktProperty, ktProperty.setter)
+        return FunctionGenerator(declarationGenerator).generatePropertyAccessor(setter, ktProperty, (ktProperty as? KtProperty)?.setter)
     }
 
-    private fun getPropertyDescriptor(ktProperty: KtProperty): PropertyDescriptor {
+    private fun getPropertyDescriptor(ktProperty: KtVariableDeclaration): PropertyDescriptor {
         val variableDescriptor = getOrFail(BindingContext.VARIABLE, ktProperty)
         return variableDescriptor as? PropertyDescriptor ?: TODO("not a property: $variableDescriptor")
     }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ScriptGenerator.kt

@@ -5,14 +5,36 @@
 
 package org.jetbrains.kotlin.psi2ir.generators
 
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.ParameterDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.ScriptDescriptor
-import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.assertCast
+import org.jetbrains.kotlin.ir.builders.declarations.IrFunctionBuilder
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.lazy.IrLazyFunction
+import org.jetbrains.kotlin.ir.descriptors.WrappedFunctionDescriptorWithContainerSource
+import org.jetbrains.kotlin.ir.descriptors.WrappedSimpleFunctionDescriptor
+import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
+import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
+import org.jetbrains.kotlin.ir.expressions.impl.IrSetFieldImpl
+import org.jetbrains.kotlin.ir.symbols.impl.IrSimpleFunctionSymbolImpl
+import org.jetbrains.kotlin.ir.util.varargElementType
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.KtDestructuringDeclaration
 import org.jetbrains.kotlin.psi.KtScript
 import org.jetbrains.kotlin.psi.KtScriptInitializer
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.pureEndOffset
 import org.jetbrains.kotlin.psi.psiUtil.pureStartOffset
+import org.jetbrains.kotlin.psi.psiUtil.startOffsetSkippingComments
+import org.jetbrains.kotlin.psi2ir.deparenthesize
+import org.jetbrains.kotlin.psi2ir.intermediate.createTemporaryVariableInBlock
+import org.jetbrains.kotlin.psi2ir.intermediate.setExplicitReceiverValue
 import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.calls.util.isSingleUnderscore
 
 class ScriptGenerator(declarationGenerator: DeclarationGenerator) : DeclarationGeneratorExtension(declarationGenerator) {
     fun generateScriptDeclaration(ktScript: KtScript): IrDeclaration? {
@@ -29,20 +51,102 @@ class ScriptGenerator(declarationGenerator: DeclarationGenerator) : DeclarationG
             val startOffset = ktScript.pureStartOffset
             val endOffset = ktScript.pureEndOffset
 
-            irScript.thisReceiver = context.symbolTable.declareValueParameter(
-                startOffset, endOffset,
-                IrDeclarationOrigin.INSTANCE_RECEIVER,
-                descriptor.thisAsReceiverParameter,
-                descriptor.thisAsReceiverParameter.type.toIrType()
-            ).also { it.parent = irScript }
+            fun makeReceiver(descriptor: ClassDescriptor): IrValueParameter {
+                val receiverParameterDescriptor = descriptor.thisAsReceiverParameter
+                return context.symbolTable.declareValueParameter(
+                    startOffset, endOffset,
+                    IrDeclarationOrigin.INSTANCE_RECEIVER,
+                    receiverParameterDescriptor,
+                    receiverParameterDescriptor.type.toIrType()
+                ).also { it.parent = irScript }
+            }
+
+            irScript.thisReceiver = makeReceiver(descriptor)
 
             for (d in ktScript.declarations) {
-                if (d is KtScriptInitializer) irScript.statements += BodyGenerator(
-                    irScript.symbol,
-                    context
-                ).generateExpressionBody(d.body!!).expression
-                else irScript.declarations += declarationGenerator.generateMemberDeclaration(d)!!
+                when (d) {
+                    is KtScriptInitializer -> {
+                        irScript.statements += BodyGenerator(
+                            irScript.symbol,
+                            context
+                        ).generateExpressionBody(d.body!!).expression
+                    }
+                    is KtDestructuringDeclaration -> {
+                        // copied with modifications from StatementGenerator.visitDestructuringDeclaration
+                        // TODO: consider code deduplication
+                        val bodyGenerator = BodyGenerator(irScript.symbol, context)
+                        val statementGenerator = bodyGenerator.createStatementGenerator()
+                        val irBlock = IrCompositeImpl(
+                            d.startOffsetSkippingComments, d.endOffset,
+                            context.irBuiltIns.unitType, IrStatementOrigin.DESTRUCTURING_DECLARATION
+                        )
+                        val ktInitializer = d.initializer!!
+                        val initializerExpr = ktInitializer.deparenthesize().accept(statementGenerator, null).assertCast<IrExpression>()
+                        val containerValue =
+                            statementGenerator.scope.createTemporaryVariableInBlock(context, initializerExpr, irBlock, "container")
+
+                        val callGenerator = CallGenerator(statementGenerator)
+
+                        for ((index, ktEntry) in d.entries.withIndex()) {
+                            val componentResolvedCall = getOrFail(BindingContext.COMPONENT_RESOLVED_CALL, ktEntry)
+
+                            val componentSubstitutedCall = statementGenerator.pregenerateCall(componentResolvedCall)
+                            componentSubstitutedCall.setExplicitReceiverValue(containerValue)
+
+                            val componentVariable = getOrFail(BindingContext.VARIABLE, ktEntry)
+
+                            // componentN for '_' SHOULD NOT be evaluated
+                            if (componentVariable.name.isSpecial || ktEntry.isSingleUnderscore) continue
+
+                            val irComponentCall = callGenerator.generateCall(
+                                ktEntry.startOffsetSkippingComments, ktEntry.endOffset, componentSubstitutedCall,
+                                IrStatementOrigin.COMPONENT_N.withIndex(index + 1)
+                            )
+
+                            val irComponentProperty =
+                                PropertyGenerator(declarationGenerator).generateDestructuringDeclarationEntryAsPropertyDeclaration(
+                                    ktEntry, irComponentCall
+                                )
+                            val irComponentBackingField = irComponentProperty.backingField!!
+
+                            irScript.statements += irComponentProperty
+
+                            val irComponentInitializer = IrSetFieldImpl(
+                                ktEntry.startOffsetSkippingComments, ktEntry.endOffset,
+                                irComponentBackingField.symbol,
+                                context.irBuiltIns.unitType,
+                                origin = null, superQualifierSymbol = null
+                            ).apply {
+                                value = irComponentCall
+                                receiver = IrGetValueImpl(
+                                    ktEntry.startOffsetSkippingComments, ktEntry.endOffset, irScript.thisReceiver.symbol
+                                )
+                            }
+                            irBlock.statements.add(irComponentInitializer)
+                        }
+                        irScript.statements += irBlock
+                    }
+                    else -> irScript.statements += declarationGenerator.generateMemberDeclaration(d)!!
+                }
+            }
+
+            descriptor.resultValue?.let { resultDescriptor ->
+                // TODO: initializer
+                // TODO: do not keet direct link
+                val resultProperty =
+                    PropertyGenerator(declarationGenerator)
+                        .generateSyntheticProperty(ktScript, resultDescriptor, null, generateSyntheticAccessors = true)
+                resultProperty.origin = IrDeclarationOrigin.SCRIPT_RESULT_PROPERTY
+                irScript.statements += resultProperty
             }
         }
     }
+
+    private fun ParameterDescriptor.toIrValueParameter(startOffset: Int, endOffset: Int, origin: IrDeclarationOrigin) =
+        context.symbolTable.declareValueParameter(
+            startOffset, endOffset, origin,
+            this,
+            type.toIrType(),
+            varargElementType?.toIrType()
+        )
 }

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrScript.kt

@@ -5,14 +5,14 @@
 
 package org.jetbrains.kotlin.ir.declarations
 
-import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.expressions.IrStatementContainer
 import org.jetbrains.kotlin.ir.symbols.IrScriptSymbol
 
 //TODO: make IrScript as IrPackageFragment, because script is used as a file, not as a class
 //NOTE: declarations and statements stored separately
 abstract class IrScript :
-    IrDeclarationBase(), IrSymbolDeclaration<IrScriptSymbol>, IrDeclarationContainer, IrDeclarationWithName, IrDeclarationParent {
-    abstract val statements: MutableList<IrStatement>
+    IrDeclarationBase(), IrSymbolDeclaration<IrScriptSymbol>, IrDeclarationWithName,
+    IrDeclarationParent, IrStatementContainer {
 
     // NOTE: is the result of the FE conversion, because there script interpreted as a class and has receiver
     abstract var thisReceiver: IrValueParameter

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrScriptImpl.kt

@@ -18,7 +18,7 @@ import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.utils.SmartList
 
-private val SCRIPT_ORIGIN = object : IrDeclarationOriginImpl("FIELD_FOR_OBJECT_INSTANCE") {}
+private val SCRIPT_ORIGIN = object : IrDeclarationOriginImpl("SCRIPT") {}
 
 class IrScriptImpl(
     override val symbol: IrScriptSymbol,
@@ -38,7 +38,6 @@ class IrScriptImpl(
 
     override var annotations: List<IrConstructorCall> = SmartList()
 
-    override val declarations: MutableList<IrDeclaration> = mutableListOf()
     override val statements: MutableList<IrStatement> = mutableListOf()
 
     override lateinit var thisReceiver: IrValueParameter
@@ -59,13 +58,11 @@ class IrScriptImpl(
     }
 
     override fun <D> acceptChildren(visitor: IrElementVisitor<Unit, D>, data: D) {
-        declarations.forEach { it.accept(visitor, data) }
         statements.forEach { it.accept(visitor, data) }
         thisReceiver.accept(visitor, data)
     }
 
     override fun <D> transformChildren(transformer: IrElementTransformer<D>, data: D) {
-        declarations.transformInPlace(transformer, data)
         statements.transformInPlace(transformer, data)
         thisReceiver = thisReceiver.transform(transformer, data)
     }

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

@@ -117,10 +117,9 @@ open class DeepCopyIrTreeWithSymbols(
             //TODO: something may go wrong, because expected using symbolRemapper
             IrScriptSymbolImpl(declaration.descriptor as ScriptDescriptor),
             declaration.name
-        ).also {
-            it.thisReceiver = declaration.thisReceiver.transform()
-            declaration.transformDeclarationsTo(it)
-            it.statements.addAll(declaration.statements.map { it.transform() })
+        ).also { scriptCopy ->
+            scriptCopy.thisReceiver = declaration.thisReceiver.transform()
+            declaration.statements.mapTo(scriptCopy.statements) { it.transform() }
         }
     }
 

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

@@ -51,6 +51,7 @@ private tailrec fun erase(type: IrType): IrClass? {
 
     return when (classifier) {
         is IrClassSymbol -> classifier.owner
+        is IrScriptSymbol -> null // TODO: check if correct
         is IrTypeParameterSymbol -> erase(classifier.owner.superTypes.first())
         else -> error(classifier)
     }

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

@@ -46,19 +46,42 @@ inline fun <T> MutableList<T>.transformFlat(transformation: (T) -> List<T>?) {
     while (i < size) {
         val item = get(i)
 
-        val transformed = transformation(item)
+        i = replaceInPlace(transformation(item), i)
+    }
+}
 
-        when (transformed?.size) {
-            null -> i++
-            0 -> removeAt(i)
-            1 -> set(i++, transformed.first())
-            else -> {
-                addAll(i, transformed)
-                i += transformed.size
-                removeAt(i)
-            }
+/**
+ * Transforms a subset of a mutable list in place.
+ * Each element `it` that has a type S is replaced with a result of `transformation(it)`,
+ * `null` means "keep existing element" (to avoid creating excessive singleton lists).
+ */
+inline fun <T, reified S : T> MutableList<T>.transformSubsetFlat(transformation: (S) -> List<S>?) {
+    var i = 0
+    while (i < size) {
+        val item = get(i)
+
+        if (item !is S) {
+            i++
+            continue
+        }
+
+        i = replaceInPlace(transformation(item), i)
+    }
+}
+
+@PublishedApi internal fun <T> MutableList<T>.replaceInPlace(transformed: List<T>?, atIndex: Int): Int {
+    var i = atIndex
+    when (transformed?.size) {
+        null -> i++
+        0 -> removeAt(i)
+        1 -> set(i++, transformed.first())
+        else -> {
+            addAll(i, transformed)
+            i += transformed.size
+            removeAt(i)
         }
     }
+    return i
 }
 
 /**

libraries/scripting/js-test/test/org/jetbrains/kotlin/scripting/repl/js/test/ReplTest.kt

@@ -143,7 +143,10 @@ abstract class AbstractReplTestRunner : TestCase() {
                 var t = 2 * 2
                 class A(val value: Int = 5) {
                     fun bar(): Int {
-                        var q = 4
+                        class B(val value: Int = 4) {
+                            fun baz(): Int = value
+                        }
+                        var q = B().baz()
                         var w = 1
                         return q + w
                     }
@@ -221,9 +224,11 @@ abstract class AbstractReplTestRunner : TestCase() {
                 if (compileResult !is ReplCompileResult.CompiledClasses) return compileResult.toString()
 
                 val evalResult = tester.evaluate(compileResult)
-                if (evalResult !is ReplEvalResult.ValueResult) return evalResult.toString()
-
-                result = evalResult.value
+                when (evalResult) {
+                    is ReplEvalResult.Error.Runtime -> return evalResult.cause.toString()
+                    !is ReplEvalResult.ValueResult -> return evalResult.toString()
+                    else -> result = evalResult.value
+                }
             }
         }
         return result