[KLIB] Create an abstract class for module deserializer

- Introduce Ir-based Functional interface factory
 - Switch from LazyIr to pure
 - Use kotlin library to access raw bytes
 - Link dirty files against IC cache and dependencies instead of LazyIr
 - Move `DescriptorByIdSignatureFinder` from K/N to common
 - Support inline-bodies only MODE

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrGenerationExtension.kt

@@ -10,8 +10,11 @@ import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.extensions.ProjectExtensionDescriptor
 import org.jetbrains.kotlin.ir.builders.IrGeneratorContext
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
+import org.jetbrains.kotlin.ir.util.IrExtensionGenerator
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.TypeTranslator
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -26,7 +29,7 @@ class IrPluginContext(
     val symbols: BuiltinSymbolsBase = BuiltinSymbolsBase(irBuiltIns.builtIns, symbolTable)
 ) : IrGeneratorContext()
 
-interface IrGenerationExtension {
+interface IrGenerationExtension : IrExtensionGenerator {
     companion object :
         ProjectExtensionDescriptor<IrGenerationExtension>("org.jetbrains.kotlin.irGenerationExtension", IrGenerationExtension::class.java)
 

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

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.ir.backend.js.utils.NameTables
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.declarations.StageController
 import org.jetbrains.kotlin.ir.declarations.stageController
+import org.jetbrains.kotlin.ir.util.DeclarationStubGenerator
 import org.jetbrains.kotlin.ir.util.ExternalDependenciesGenerator
 import org.jetbrains.kotlin.ir.util.generateTypicalIrProviderList
 import org.jetbrains.kotlin.ir.util.patchDeclarationParents
@@ -58,11 +59,8 @@ fun compile(
     val context = JsIrBackendContext(moduleDescriptor, irBuiltIns, symbolTable, moduleFragment, exportedDeclarations, configuration)
 
     // Load declarations referenced during `context` initialization
-    dependencyModules.forEach {
+    val irProviders = listOf(deserializer)
-        val irProviders = generateTypicalIrProviderList(it.descriptor, irBuiltIns, symbolTable, deserializer)
+    ExternalDependenciesGenerator(symbolTable, irProviders, configuration.languageVersionSettings).generateUnboundSymbolsAsDependencies()
-        ExternalDependenciesGenerator(symbolTable, irProviders, configuration.languageVersionSettings)
-            .generateUnboundSymbolsAsDependencies()
-    }
 
     val allModules = when (mainModule) {
         is MainModule.SourceFiles -> dependencyModules + listOf(moduleFragment)
@@ -71,16 +69,12 @@ fun compile(
 
     val irFiles = allModules.flatMap { it.files }
 
+    deserializer.postProcess()
+
     moduleFragment.files.clear()
     moduleFragment.files += irFiles
 
-    val irProvidersWithoutDeserializer = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable)
+    symbolTable.lazyWrapper.stubGenerator = DeclarationStubGenerator(moduleDescriptor, symbolTable, irBuiltIns.languageVersionSettings)
-    // Create stubs
-    ExternalDependenciesGenerator(symbolTable, irProvidersWithoutDeserializer, configuration.languageVersionSettings)
-        .generateUnboundSymbolsAsDependencies()
-    moduleFragment.patchDeclarationParents()
-
-    deserializer.finalizeExpectActualLinker()
 
     moveBodilessDeclarationsToSeparatePlace(context, moduleFragment)
 

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendFacade.kt

@@ -13,8 +13,11 @@ import org.jetbrains.kotlin.backend.jvm.codegen.ClassCodegen
 import org.jetbrains.kotlin.backend.jvm.lower.MultifileFacadeFileEntry
 import org.jetbrains.kotlin.backend.jvm.serialization.JvmIdSignatureDescriptor
 import org.jetbrains.kotlin.codegen.state.GenerationState
-import org.jetbrains.kotlin.idea.MainFunctionDetector
+import org.jetbrains.kotlin.descriptors.konan.DeserializedKlibModuleOrigin
 import org.jetbrains.kotlin.descriptors.konan.KlibModuleOrigin
+import org.jetbrains.kotlin.descriptors.konan.klibModuleOrigin
+import org.jetbrains.kotlin.descriptors.konan.kotlinLibrary
+import org.jetbrains.kotlin.idea.MainFunctionDetector
 import org.jetbrains.kotlin.ir.backend.jvm.serialization.EmptyLoggingContext
 import org.jetbrains.kotlin.ir.backend.jvm.serialization.JvmIrLinker
 import org.jetbrains.kotlin.ir.backend.jvm.serialization.JvmManglerDesc
@@ -33,8 +36,9 @@ object JvmBackendFacade {
         val signaturer = JvmIdSignatureDescriptor(mangler)
         val psi2ir = Psi2IrTranslator(state.languageVersionSettings, signaturer = signaturer)
         val psi2irContext = psi2ir.createGeneratorContext(state.module, state.bindingContext, extensions = extensions)
+        val pluginExtensions = IrGenerationExtension.getInstances(state.project)
 
-        for (extension in IrGenerationExtension.getInstances(state.project)) {
+        for (extension in pluginExtensions) {
             psi2ir.addPostprocessingStep { module ->
                 extension.generate(
                     module,
@@ -53,22 +57,22 @@ object JvmBackendFacade {
         val stubGenerator = DeclarationStubGenerator(
             psi2irContext.moduleDescriptor, psi2irContext.symbolTable, psi2irContext.irBuiltIns.languageVersionSettings, extensions
         )
-        val deserializer = JvmIrLinker(
+        val irLinker = JvmIrLinker(psi2irContext.moduleDescriptor, EmptyLoggingContext, psi2irContext.irBuiltIns, psi2irContext.symbolTable, stubGenerator, mangler)
-            EmptyLoggingContext, psi2irContext.irBuiltIns, psi2irContext.symbolTable
+        val dependencies = psi2irContext.moduleDescriptor.allDependencyModules.map {
-        )
+            val kotlinLibrary = (it.getCapability(KlibModuleOrigin.CAPABILITY) as? DeserializedKlibModuleOrigin)?.library
-        psi2irContext.moduleDescriptor.allDependencyModules.filter { it.getCapability(KlibModuleOrigin.CAPABILITY) != null }.forEach {
+            irLinker.deserializeIrModuleHeader(it, kotlinLibrary)
-            deserializer.deserializeIrModuleHeader(it)
         }
-        val irProviders = listOf(deserializer, stubGenerator)
+        val irProviders = listOf(irLinker)
+
         stubGenerator.setIrProviders(irProviders)
 
-        val irModuleFragment = psi2ir.generateModuleFragment(
+        val irModuleFragment = psi2ir.generateModuleFragment(psi2irContext, files, irProviders, expectDescriptorToSymbol = null, pluginExtensions)
-            psi2irContext, files,
+        irLinker.postProcess()
-            irProviders = irProviders,
+
-            expectDescriptorToSymbol = null
+        stubGenerator.unboundSymbolGeneration = true
-        )
+
         // We need to compile all files we reference in Klibs
-        irModuleFragment.files.addAll(deserializer.getAllIrFiles())
+        irModuleFragment.files.addAll(dependencies.flatMap { it.files })
 
         doGenerateFilesInternal(
             state, irModuleFragment, psi2irContext.symbolTable, psi2irContext.sourceManager, phaseConfig, irProviders, extensions

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

@@ -56,7 +56,7 @@ fun compileWasm(
     val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
     ExternalDependenciesGenerator(symbolTable, irProviders, configuration.languageVersionSettings).generateUnboundSymbolsAsDependencies()
     moduleFragment.patchDeclarationParents()
-    deserializer.finalizeExpectActualLinker()
+    deserializer.postProcess()
 
     wasmPhases.invokeToplevel(phaseConfig, context, moduleFragment)
 

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/Psi2IrTranslator.kt

@@ -43,6 +43,7 @@ class Psi2IrTranslator(
         postprocessingSteps.add(step)
     }
 
+    // NOTE: used only for test purpose
     fun generateModule(
         moduleDescriptor: ModuleDescriptor,
         ktFiles: Collection<KtFile>,
@@ -68,7 +69,8 @@ class Psi2IrTranslator(
         context: GeneratorContext,
         ktFiles: Collection<KtFile>,
         irProviders: List<IrProvider>,
-        expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>? = null
+        expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>? = null,
+        pluginExtensions: Collection<IrExtensionGenerator> = emptyList()
     ): IrModuleFragment {
         val moduleGenerator = ModuleGenerator(context)
         val irModule = moduleGenerator.generateModuleFragmentWithoutDependencies(ktFiles)
@@ -76,8 +78,14 @@ class Psi2IrTranslator(
         irModule.patchDeclarationParents()
         expectDescriptorToSymbol?.let { referenceExpectsForUsedActuals(it, context.symbolTable, irModule) }
         postprocess(context, irModule)
-        // do not generate unbound symbols before postprocessing,
+
-        // since plugins must work with non-lazy IR
+        irProviders.filterIsInstance<IrDeserializer>().forEach { it.init(irModule, pluginExtensions) }
+
+        moduleGenerator.generateUnboundSymbolsAsDependencies(irProviders)
+
+        postprocessingSteps.forEach { it.invoke(irModule) }
+
+        // TODO: remove it once plugin API improved
         moduleGenerator.generateUnboundSymbolsAsDependencies(irProviders)
 
         return irModule
@@ -87,8 +95,6 @@ class Psi2IrTranslator(
         insertImplicitCasts(irElement, context)
         generateAnnotationsForDeclarations(context, irElement)
 
-        postprocessingSteps.forEach { it(irElement) }
-
         irElement.patchDeclarationParents()
     }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrFunctionFactory.kt

@@ -0,0 +1,457 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.ir.descriptors
+
+import org.jetbrains.kotlin.builtins.KOTLIN_REFLECT_FQ_NAME
+import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.impl.*
+import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.IrPropertySymbol
+import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
+import org.jetbrains.kotlin.ir.symbols.impl.IrValueParameterSymbolImpl
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.impl.*
+import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.Variance
+
+abstract class IrAbstractFunctionFactory {
+
+    abstract fun functionClassDescriptor(arity: Int): FunctionClassDescriptor
+    abstract fun kFunctionClassDescriptor(arity: Int): FunctionClassDescriptor
+    abstract fun suspendFunctionClassDescriptor(arity: Int): FunctionClassDescriptor
+    abstract fun kSuspendFunctionClassDescriptor(arity: Int): FunctionClassDescriptor
+
+    abstract fun functionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass
+    abstract fun kFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass
+    abstract fun suspendFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass
+    abstract fun kSuspendFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass
+
+    fun functionN(n: Int) = functionN(n) { callback ->
+        val descriptor = functionClassDescriptor(n)
+        declareClass(offset, offset, classOrigin, descriptor) { symbol ->
+            callback(symbol)
+        }
+    }
+
+    fun kFunctionN(n: Int): IrClass {
+        return kFunctionN(n) { callback ->
+            val descriptor = kFunctionClassDescriptor(n)
+            declareClass(offset, offset, classOrigin, descriptor) { symbol ->
+                callback(symbol)
+            }
+        }
+    }
+
+    fun suspendFunctionN(n: Int): IrClass = suspendFunctionN(n) { callback ->
+        val descriptor = suspendFunctionClassDescriptor(n)
+        declareClass(offset, offset, classOrigin, descriptor) { symbol ->
+            callback(symbol)
+        }
+    }
+
+    fun kSuspendFunctionN(n: Int): IrClass = kSuspendFunctionN(n) { callback ->
+        val descriptor = kSuspendFunctionClassDescriptor(n)
+        declareClass(offset, offset, classOrigin, descriptor) { symbol ->
+            callback(symbol)
+        }
+    }
+
+    companion object {
+        val classOrigin = object : IrDeclarationOriginImpl("FUNCTION_INTERFACE_CLASS") {}
+        val memberOrigin = object : IrDeclarationOriginImpl("FUNCTION_INTERFACE_MEMBER") {}
+        const val offset = SYNTHETIC_OFFSET
+    }
+}
+
+class IrFunctionFactory(private val irBuiltIns: IrBuiltIns, private val symbolTable: SymbolTable) : IrAbstractFunctionFactory() {
+
+    // TODO: Lazieness
+
+    private val functionNMap = mutableMapOf<Int, IrClass>()
+    private val kFunctionNMap = mutableMapOf<Int, IrClass>()
+    private val suspendFunctionNMap = mutableMapOf<Int, IrClass>()
+    private val kSuspendFunctionNMap = mutableMapOf<Int, IrClass>()
+
+    override fun functionClassDescriptor(arity: Int): FunctionClassDescriptor =
+        irBuiltIns.builtIns.getFunction(arity) as FunctionClassDescriptor
+
+    override fun functionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass {
+        return functionNMap.getOrPut(arity) {
+            symbolTable.declarator { symbol ->
+                val descriptor = symbol.descriptor as FunctionClassDescriptor
+                val descriptorFactory = FunctionDescriptorFactory.RealDescriptorFactory(descriptor, symbolTable)
+                createFunctionClass(symbol, false, false, arity, irBuiltIns.functionClass, kotlinPackageFragment, descriptorFactory)
+            }
+        }
+    }
+
+    override fun suspendFunctionClassDescriptor(arity: Int): FunctionClassDescriptor =
+        irBuiltIns.builtIns.getSuspendFunction(arity) as FunctionClassDescriptor
+
+    override fun suspendFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass {
+        return suspendFunctionNMap.getOrPut(arity) {
+            symbolTable.declarator { symbol ->
+                val descriptor = symbol.descriptor as FunctionClassDescriptor
+                val descriptorFactory = FunctionDescriptorFactory.RealDescriptorFactory(descriptor, symbolTable)
+                createFunctionClass(symbol, false, true, arity, irBuiltIns.functionClass, kotlinCoroutinesPackageFragment, descriptorFactory)
+            }
+        }
+    }
+
+    override fun kFunctionClassDescriptor(arity: Int): FunctionClassDescriptor {
+        val kFunctionFqn = reflectFunctionClassFqn(reflectionFunctionClassName(false, arity))
+        return irBuiltIns.builtIns.getBuiltInClassByFqName(kFunctionFqn) as FunctionClassDescriptor
+    }
+
+    override fun kFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass {
+        return kFunctionNMap.getOrPut(arity) {
+            symbolTable.declarator { symbol ->
+                val descriptor = symbol.descriptor as FunctionClassDescriptor
+                val descriptorFactory = FunctionDescriptorFactory.RealDescriptorFactory(descriptor, symbolTable)
+                createFunctionClass(symbol, true, false, arity, irBuiltIns.kFunctionClass, kotlinReflectPackageFragment, descriptorFactory)
+            }
+        }
+    }
+
+    override fun kSuspendFunctionClassDescriptor(arity: Int): FunctionClassDescriptor {
+        val kFunctionFqn = reflectFunctionClassFqn(reflectionFunctionClassName(true, arity))
+        return irBuiltIns.builtIns.getBuiltInClassByFqName(kFunctionFqn) as FunctionClassDescriptor
+    }
+
+    override fun kSuspendFunctionN(arity: Int, declarator: SymbolTable.((IrClassSymbol) -> IrClass) -> IrClass): IrClass {
+        return kSuspendFunctionNMap.getOrPut(arity) {
+            symbolTable.declarator { symbol ->
+                val descriptor = symbol.descriptor as FunctionClassDescriptor
+                val descriptorFactory = FunctionDescriptorFactory.RealDescriptorFactory(descriptor, symbolTable)
+                createFunctionClass(symbol, true, true, arity, irBuiltIns.kFunctionClass, kotlinReflectPackageFragment, descriptorFactory)
+            }
+        }
+    }
+
+    companion object {
+        private fun reflectFunctionClassFqn(shortName: Name): FqName = KOTLIN_REFLECT_FQ_NAME.child(shortName)
+        private fun reflectionFunctionClassName(isSuspend: Boolean, arity: Int): Name =
+            Name.identifier("K${if (isSuspend) "Suspend" else ""}Function$arity")
+
+        private fun functionClassName(isK: Boolean, isSuspend: Boolean, arity: Int): String =
+            "${if (isK) "K" else ""}${if (isSuspend) "Suspend" else ""}Function$arity"
+    }
+
+    private sealed class FunctionDescriptorFactory(protected val symbolTable: SymbolTable) {
+        abstract fun memberDescriptor(name: String, factory: (IrSimpleFunctionSymbol) -> IrSimpleFunction): IrSimpleFunctionSymbol
+        abstract fun FunctionDescriptor.valueParameterDescriptor(index: Int): ValueParameterDescriptor
+        abstract fun typeParameterDescriptor(index: Int, factory: (IrTypeParameterSymbol) -> IrTypeParameter): IrTypeParameterSymbol
+        abstract fun classReceiverParameterDescriptor(): ReceiverParameterDescriptor
+        abstract fun FunctionDescriptor.memberReceiverParameterDescriptor(): ReceiverParameterDescriptor
+
+        class RealDescriptorFactory(private val classDescriptor: FunctionClassDescriptor, symbolTable: SymbolTable) :
+            FunctionDescriptorFactory(symbolTable) {
+            override fun memberDescriptor(name: String, factory: (IrSimpleFunctionSymbol) -> IrSimpleFunction): IrSimpleFunctionSymbol {
+                val descriptor = classDescriptor.unsubstitutedMemberScope.run {
+                    if (name[0] == '<') {
+                        val propertyName = name.drop(5).dropLast(1)
+                        val property = getContributedVariables(Name.identifier(propertyName), NoLookupLocation.FROM_BACKEND).single()
+                        property.accessors.first { it.name.asString() == name }
+                    } else {
+                        getContributedFunctions(Name.identifier(name), NoLookupLocation.FROM_BACKEND).first()
+                    }
+                }
+                return symbolTable.declareSimpleFunction(offset, offset, memberOrigin, descriptor, factory).symbol
+            }
+
+            override fun FunctionDescriptor.valueParameterDescriptor(index: Int): ValueParameterDescriptor {
+                assert(containingDeclaration === classDescriptor)
+                return valueParameters[index]
+            }
+
+            override fun typeParameterDescriptor(index: Int, factory: (IrTypeParameterSymbol) -> IrTypeParameter): IrTypeParameterSymbol {
+                val descriptor = classDescriptor.declaredTypeParameters[index]
+                return symbolTable.declareGlobalTypeParameter(offset, offset, classOrigin, descriptor, factory).symbol
+            }
+
+            override fun classReceiverParameterDescriptor(): ReceiverParameterDescriptor {
+                return classDescriptor.thisAsReceiverParameter
+            }
+
+            override fun FunctionDescriptor.memberReceiverParameterDescriptor(): ReceiverParameterDescriptor {
+                assert(containingDeclaration === classDescriptor)
+                return dispatchReceiverParameter ?: error("Expected dispatch receiver at $this")
+            }
+        }
+    }
+
+    private fun IrTypeParametersContainer.createTypeParameters(n: Int, descriptorFactory: FunctionDescriptorFactory): IrTypeParameter {
+
+        var index = 0
+
+        val typeParametersArray = ArrayList<IrTypeParameter>(n + 1)
+
+        for (i in 1 until (n + 1)) {
+            val pName = Name.identifier("P$i")
+
+            val pSymbol = descriptorFactory.typeParameterDescriptor(index) {
+                IrTypeParameterImpl(offset, offset, classOrigin, it, pName, index++, false, Variance.IN_VARIANCE)
+            }
+            val pDeclaration = pSymbol.owner
+
+            pDeclaration.superTypes += irBuiltIns.anyNType
+            pDeclaration.parent = this
+            typeParametersArray.add(pDeclaration)
+        }
+
+        val rSymbol = descriptorFactory.typeParameterDescriptor(index) {
+            IrTypeParameterImpl(offset, offset, classOrigin, it, Name.identifier("R"), index, false, Variance.OUT_VARIANCE)
+        }
+        val rDeclaration = rSymbol.owner
+
+        rDeclaration.superTypes += irBuiltIns.anyNType
+        rDeclaration.parent = this
+        typeParametersArray.add(rDeclaration)
+
+        typeParameters = typeParametersArray
+
+        return rDeclaration
+    }
+
+    private val kotlinPackageFragment: IrPackageFragment by lazy {
+        irBuiltIns.builtIns.getFunction(0).let {
+            symbolTable.declareExternalPackageFragment(it.containingDeclaration as PackageFragmentDescriptor)
+        }
+    }
+    private val kotlinCoroutinesPackageFragment: IrPackageFragment by lazy {
+        irBuiltIns.builtIns.getSuspendFunction(0).let {
+            symbolTable.declareExternalPackageFragment(it.containingDeclaration as PackageFragmentDescriptor)
+        }
+    }
+
+    private val kotlinReflectPackageFragment: IrPackageFragment by lazy {
+        irBuiltIns.kPropertyClass.descriptor.let {
+            symbolTable.declareExternalPackageFragment(it.containingDeclaration as PackageFragmentDescriptor)
+        }
+    }
+
+    private fun IrClass.createThisReceiver(descriptorFactory: FunctionDescriptorFactory): IrValueParameter {
+        val vDescriptor = descriptorFactory.classReceiverParameterDescriptor()
+        val vSymbol = IrValueParameterSymbolImpl(vDescriptor)
+        val type = with(IrSimpleTypeBuilder()) {
+            classifier = symbol
+            arguments = typeParameters.run {
+                val builder = IrSimpleTypeBuilder()
+                mapTo(ArrayList(size)) {
+                    builder.classifier = it.symbol
+                    buildTypeProjection()
+                }
+            }
+            buildSimpleType()
+        }
+        val vDeclaration = IrValueParameterImpl(
+            offset, offset, classOrigin, vSymbol, Name.special("<this>"), -1, type, null,
+            isCrossinline = false,
+            isNoinline = false
+        )
+
+        if (vDescriptor is WrappedReceiverParameterDescriptor) vDescriptor.bind(vDeclaration)
+
+        return vDeclaration
+    }
+
+    private fun FunctionClassDescriptor.createFunctionClass(): IrClass {
+        val s = symbolTable.referenceClass(this)
+        if (s.isBound) return s.owner
+        return symbolTable.declareClass(offset, offset, classOrigin, this, modality) {
+            val factory = FunctionDescriptorFactory.RealDescriptorFactory(this, symbolTable)
+            when (functionKind) {
+                FunctionClassDescriptor.Kind.Function ->
+                    createFunctionClass(it, false, false, arity, irBuiltIns.functionClass, kotlinPackageFragment, factory)
+                FunctionClassDescriptor.Kind.SuspendFunction ->
+                    createFunctionClass(it, false, true, arity, irBuiltIns.functionClass, kotlinCoroutinesPackageFragment, factory)
+                FunctionClassDescriptor.Kind.KFunction ->
+                    createFunctionClass(it, true, false, arity, irBuiltIns.kFunctionClass, kotlinReflectPackageFragment, factory)
+                FunctionClassDescriptor.Kind.KSuspendFunction ->
+                    createFunctionClass(it, true, true, arity, irBuiltIns.kFunctionClass, kotlinReflectPackageFragment, factory)
+            }
+        }
+    }
+
+    private fun IrClass.createMembers(isK: Boolean, isSuspend: Boolean, arity: Int, name: String, descriptorFactory: FunctionDescriptorFactory) {
+        if (!isK) {
+            val invokeSymbol = descriptorFactory.memberDescriptor("invoke") {
+                val returnType = with(IrSimpleTypeBuilder()) {
+                    classifier = typeParameters.last().symbol
+                    buildSimpleType()
+                }
+
+                IrFunctionImpl(offset, offset, memberOrigin, it, Name.identifier("invoke"), Visibilities.PUBLIC, Modality.ABSTRACT,
+                    returnType,
+                    isInline = false,
+                    isExternal = false,
+                    isTailrec = false,
+                    isSuspend = isSuspend,
+                    isOperator = true,
+                    isExpect = false,
+                    isFakeOverride = false
+                )
+            }
+
+            val fDeclaration = invokeSymbol.owner
+
+            fDeclaration.dispatchReceiverParameter = createThisReceiver(descriptorFactory).also { it.parent = fDeclaration }
+
+            val typeBuilder = IrSimpleTypeBuilder()
+            for (i in 1 until typeParameters.size) {
+                val vTypeParam = typeParameters[i - 1]
+                val vDescriptor = with(descriptorFactory) { invokeSymbol.descriptor.valueParameterDescriptor(i - 1) }
+                val vSymbol = IrValueParameterSymbolImpl(vDescriptor)
+                val vType = with(typeBuilder) {
+                    classifier = vTypeParam.symbol
+                    buildSimpleType()
+                }
+                val vDeclaration = IrValueParameterImpl(
+                    offset, offset, memberOrigin, vSymbol, Name.identifier("p$i"), i - 1, vType, null,
+                    isCrossinline = false,
+                    isNoinline = false
+                )
+                vDeclaration.parent = fDeclaration
+                if (vDescriptor is WrappedValueParameterDescriptor) vDescriptor.bind(vDeclaration)
+                fDeclaration.valueParameters += vDeclaration
+            }
+
+            fDeclaration.parent = this
+            declarations += fDeclaration
+        }
+
+        addFakeOverrides()
+    }
+
+    private fun toIrType(wrapped: KotlinType): IrType {
+        val kotlinType = wrapped.unwrap()
+        return with(IrSimpleTypeBuilder()) {
+            classifier =
+                symbolTable.referenceClassifier(kotlinType.constructor.declarationDescriptor ?: error("No classifier for type $kotlinType"))
+            hasQuestionMark = kotlinType.isMarkedNullable
+            arguments = kotlinType.arguments.map {
+                if (it.isStarProjection) IrStarProjectionImpl
+                else makeTypeProjection(toIrType(it.type), it.projectionKind)
+            }
+            buildSimpleType()
+        }
+    }
+
+    private fun IrFunction.createValueParameter(descriptor: ParameterDescriptor): IrValueParameter {
+        val symbol = IrValueParameterSymbolImpl(descriptor)
+        val varargType = if (descriptor is ValueParameterDescriptor) descriptor.varargElementType else null
+        return IrValueParameterImpl(
+            offset,
+            offset,
+            memberOrigin,
+            symbol,
+            toIrType(descriptor.type),
+            varargType?.let { toIrType(it) }).also {
+            it.parent = this
+        }
+    }
+
+    private fun IrClass.addFakeOverrides() {
+
+        val fakeOverrideDescriptors = descriptor.unsubstitutedMemberScope.getContributedDescriptors(DescriptorKindFilter.CALLABLES)
+            .filterIsInstance<CallableMemberDescriptor>().filter { it.kind === CallableMemberDescriptor.Kind.FAKE_OVERRIDE }
+
+        fun createFakeOverrideFunction(descriptor: FunctionDescriptor, property: IrPropertySymbol?): IrSimpleFunction {
+            val returnType = descriptor.returnType?.let { toIrType(it) } ?: error("No return type for $descriptor")
+            val newFunction = symbolTable.declareSimpleFunction(offset, offset, memberOrigin, descriptor) {
+                descriptor.run {
+                    IrFunctionImpl(
+                        offset, offset, memberOrigin, it, name, visibility, modality, returnType,
+                        isInline, isExternal, isTailrec, isSuspend, isOperator, isExpect, true
+                    )
+                }
+            }
+
+            newFunction.parent = this
+            newFunction.overriddenSymbols = descriptor.overriddenDescriptors.map { symbolTable.referenceSimpleFunction(it.original) }
+            newFunction.dispatchReceiverParameter = descriptor.dispatchReceiverParameter?.let { newFunction.createValueParameter(it) }
+            newFunction.extensionReceiverParameter = descriptor.extensionReceiverParameter?.let { newFunction.createValueParameter(it) }
+            newFunction.valueParameters = descriptor.valueParameters.map { newFunction.createValueParameter(it) }
+            newFunction.correspondingPropertySymbol = property
+
+            return newFunction
+        }
+
+        fun createFakeOverrideProperty(descriptor: PropertyDescriptor): IrProperty {
+            return symbolTable.declareProperty(offset, offset, memberOrigin, descriptor) {
+                IrPropertyImpl(offset, offset, memberOrigin, it, descriptor.name).apply {
+                    parent = this@addFakeOverrides
+                    getter = descriptor.getter?.let { g -> createFakeOverrideFunction(g, symbol) }
+                    setter = descriptor.setter?.let { s -> createFakeOverrideFunction(s, symbol) }
+                }
+            }
+        }
+
+
+        fun createFakeOverride(descriptor: CallableMemberDescriptor): IrDeclaration {
+            return when (descriptor) {
+                is FunctionDescriptor -> createFakeOverrideFunction(descriptor, null)
+                is PropertyDescriptor -> createFakeOverrideProperty(descriptor)
+                else -> error("Unexpected member $descriptor")
+            }
+        }
+
+        declarations += fakeOverrideDescriptors.map { createFakeOverride(it) }
+    }
+
+    private fun createFunctionClass(
+        symbol: IrClassSymbol,
+        isK: Boolean,
+        isSuspend: Boolean,
+        n: Int,
+        baseClass: IrClassSymbol,
+        packageFragment: IrPackageFragment,
+        descriptorFactory: FunctionDescriptorFactory
+    ): IrClass {
+        val name = functionClassName(isK, isSuspend, n)
+        val klass = IrClassImpl(
+            offset, offset, classOrigin, symbol, Name.identifier(name), ClassKind.INTERFACE, Visibilities.PUBLIC, Modality.ABSTRACT,
+            isCompanion = false,
+            isInner = false,
+            isData = false,
+            isExternal = false,
+            isInline = false,
+            isExpect = false,
+            isFun = false
+        )
+
+        val r = klass.createTypeParameters(n, descriptorFactory)
+
+        klass.thisReceiver = klass.createThisReceiver(descriptorFactory).also { it.parent = klass }
+
+        klass.superTypes = listOf(with(IrSimpleTypeBuilder()) {
+            classifier = baseClass
+            arguments = listOf(
+                with(IrSimpleTypeBuilder()) {
+                    classifier = r.symbol
+                    buildTypeProjection()
+                },
+            )
+            buildSimpleType()
+        })
+
+        klass.createMembers(isK, isSuspend, n, klass.name.identifier, descriptorFactory)
+
+        klass.parent = packageFragment
+        packageFragment.declarations += klass
+
+        return klass
+    }
+}

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

@@ -52,8 +52,6 @@ class ExternalDependenciesGenerator(
                 assert(symbol.isBound) { "$symbol unbound even after deserialization attempt" }
             }
         } while (unbound.isNotEmpty())
-
-        irProviders.forEach { (it as? IrDeserializer)?.declareForwardDeclarations() }
     }
 }
 

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

@@ -46,8 +46,12 @@ interface LazyIrProvider : IrProvider {
     override fun getDeclaration(symbol: IrSymbol): IrLazyDeclarationBase?
 }
 
+interface IrExtensionGenerator {
+    fun declare(symbol: IrSymbol): IrDeclaration? = null
+}
+
 interface IrDeserializer : IrProvider {
-    fun declareForwardDeclarations()
+    fun init(moduleFragment: IrModuleFragment?, extensions: Collection<IrExtensionGenerator>) {}
 }
 
 interface ReferenceSymbolTable {
@@ -846,6 +850,25 @@ open class SymbolTable(val signaturer: IdSignatureComposer) : ReferenceSymbolTab
         }
         return result
     }
+
+    private inline fun <D : DeclarationDescriptor, IR : IrSymbolOwner, S : IrBindableSymbol<D, IR>> FlatSymbolTable<D, IR, S>.forEachPublicSymbolImpl(
+        block: (IrSymbol) -> Unit
+    ) {
+        idSigToSymbol.forEach { (_, sym) ->
+            assert(sym.isPublicApi)
+            block(sym)
+        }
+    }
+
+    fun forEachPublicSymbol(block: (IrSymbol) -> Unit) {
+        classSymbolTable.forEachPublicSymbolImpl { block(it) }
+        constructorSymbolTable.forEachPublicSymbolImpl { block(it) }
+        simpleFunctionSymbolTable.forEachPublicSymbolImpl { block(it) }
+        propertySymbolTable.forEachPublicSymbolImpl { block(it) }
+        enumEntrySymbolTable.forEachPublicSymbolImpl { block(it) }
+        typeAliasSymbolTable.forEachPublicSymbolImpl { block(it) }
+        fieldSymbolTable.forEachPublicSymbolImpl { block(it) }
+    }
 }
 
 inline fun <T, D : DeclarationDescriptor> SymbolTable.withScope(owner: D, block: SymbolTable.(D) -> T): T {

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DescriptorByIdSignatureFinder.kt

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.common.serialization
+
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.ir.util.KotlinMangler
+
+class DescriptorByIdSignatureFinder(private val moduleDescriptor: ModuleDescriptor, private val mangler: KotlinMangler.DescriptorMangler) {
+    fun findDescriptorBySignature(signature: IdSignature): DeclarationDescriptor? = when (signature) {
+        is IdSignature.AccessorSignature -> findDescriptorForAccessorSignature(signature)
+        is IdSignature.PublicSignature -> findDescriptorForPublicSignature(signature)
+        else -> error("only PublicSignature or AccessorSignature should reach this point, got $signature")
+    }
+
+    private fun findDescriptorForAccessorSignature(signature: IdSignature.AccessorSignature): DeclarationDescriptor? {
+        val propertyDescriptor = findDescriptorBySignature(signature.propertySignature) as? PropertyDescriptor
+            ?: return null
+        return propertyDescriptor.accessors.singleOrNull {
+            it.name == signature.accessorSignature.declarationFqn.shortName()
+        }
+    }
+
+    private fun findDescriptorForPublicSignature(signature: IdSignature.PublicSignature): DeclarationDescriptor? {
+        val packageDescriptor = moduleDescriptor.getPackage(signature.packageFqName())
+        val pathSegments = signature.declarationFqn.pathSegments()
+        val toplevelDescriptors = packageDescriptor.memberScope.getContributedDescriptors { name -> name == pathSegments.first() }
+            .filter { it.name == pathSegments.first() }
+        val candidates = pathSegments.drop(1).fold(toplevelDescriptors) { acc, current ->
+            acc.flatMap { container ->
+                val classDescriptor = container as? ClassDescriptor
+                    ?: return@flatMap emptyList<DeclarationDescriptor>()
+                val nextStepCandidates = classDescriptor.constructors +
+                        classDescriptor.unsubstitutedMemberScope.getContributedDescriptors { name -> name == current } +
+                        // Static scope is required only for Enum.values() and Enum.valueOf().
+                        classDescriptor.staticScope.getContributedDescriptors { name -> name == current }
+                nextStepCandidates.filter { it.name == current }
+            }
+        }
+
+        return when (candidates.size) {
+            1 -> candidates.first()
+            else -> {
+                findDescriptorByHash(candidates, signature.id)
+                    ?: error("No descriptor found for $signature")
+            }
+        }
+    }
+
+    private fun findDescriptorByHash(candidates: List<DeclarationDescriptor>, id: Long?): DeclarationDescriptor? =
+        candidates.firstOrNull { candidate ->
+            if (id == null) {
+                // We don't compute id for typealiases and classes.
+                candidate is ClassDescriptor || candidate is TypeAliasDescriptor
+            } else {
+                val candidateHash = with(mangler) { candidate.signatureMangle }
+                candidateHash == id
+            }
+        }
+}

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt

@@ -0,0 +1,137 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.common.serialization
+
+import org.jetbrains.kotlin.backend.common.serialization.encodings.BinarySymbolData
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.DeserializedDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyAccessorDescriptor
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
+import org.jetbrains.kotlin.ir.declarations.IrSymbolOwner
+import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
+import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.SerializedIrFile
+import org.jetbrains.kotlin.library.impl.*
+
+
+class ICKotlinLibrary(private val icData: List<SerializedIrFile>) : IrLibrary {
+    override val dataFlowGraph: ByteArray? = null
+
+    private inline fun <K, R : IrTableReader<K>> Array<R?>.itemBytes(fileIndex: Int, key: K, factory: () -> R): ByteArray {
+        val reader = this[fileIndex] ?: factory().also { this[fileIndex] = it }
+
+        return reader.tableItemBytes(key)
+    }
+
+    private inline fun <R : IrArrayReader> Array<R?>.itemBytes(fileIndex: Int, index: Int, factory: () -> R): ByteArray {
+        val reader = this[fileIndex] ?: factory().also { this[fileIndex] = it }
+
+        return reader.tableItemBytes(index)
+    }
+
+    private val indexedDeclarations = arrayOfNulls<DeclarationIrTableMemoryReader>(icData.size)
+    private val indexedTypes = arrayOfNulls<IrArrayMemoryReader>(icData.size)
+    private val indexedSignatures = arrayOfNulls<IrArrayMemoryReader>(icData.size)
+    private val indexedStrings = arrayOfNulls<IrArrayMemoryReader>(icData.size)
+    private val indexedBodies = arrayOfNulls<IrArrayMemoryReader>(icData.size)
+
+    override fun irDeclaration(index: Int, fileIndex: Int): ByteArray =
+        indexedDeclarations.itemBytes(fileIndex, DeclarationId(index)) {
+            DeclarationIrTableMemoryReader(icData[fileIndex].declarations)
+        }
+
+    override fun type(index: Int, fileIndex: Int): ByteArray =
+        indexedTypes.itemBytes(fileIndex, index) {
+            IrArrayMemoryReader(icData[fileIndex].types)
+        }
+
+    override fun signature(index: Int, fileIndex: Int): ByteArray =
+        indexedSignatures.itemBytes(fileIndex, index) {
+            IrArrayMemoryReader(icData[fileIndex].signatures)
+        }
+
+    override fun string(index: Int, fileIndex: Int): ByteArray =
+        indexedStrings.itemBytes(fileIndex, index) {
+            IrArrayMemoryReader(icData[fileIndex].strings)
+        }
+
+    override fun body(index: Int, fileIndex: Int): ByteArray =
+        indexedBodies.itemBytes(fileIndex, index) {
+            IrArrayMemoryReader(icData[fileIndex].bodies)
+        }
+
+    override fun file(index: Int): ByteArray = icData[index].fileData
+
+    override fun fileCount(): Int = icData.size
+}
+
+class CurrentModuleWithICDeserializer(
+    private val delegate: IrModuleDeserializer,
+    private val symbolTable: SymbolTable,
+    private val irBuiltIns: IrBuiltIns,
+    icData: List<SerializedIrFile>,
+    icReaderFactory: (IrLibrary) -> IrModuleDeserializer) :
+    IrModuleDeserializer(delegate.moduleDescriptor) {
+
+    private val dirtyDeclarations = mutableMapOf<IdSignature, IrSymbol>()
+    private val icKlib = ICKotlinLibrary(icData)
+
+    private val icDeserializer: IrModuleDeserializer = icReaderFactory(icKlib)
+
+    override fun contains(idSig: IdSignature): Boolean {
+        return idSig in dirtyDeclarations || idSig.topLevelSignature() in icDeserializer || idSig in delegate
+    }
+
+    override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+        dirtyDeclarations[idSig]?.let { return it }
+
+        if (idSig.topLevelSignature() in icDeserializer) return icDeserializer.deserializeIrSymbol(idSig, symbolKind)
+
+        return delegate.deserializeIrSymbol(idSig, symbolKind)
+    }
+
+    override fun addModuleReachableTopLevel(idSig: IdSignature) {
+        assert(idSig in icDeserializer)
+        icDeserializer.addModuleReachableTopLevel(idSig)
+    }
+
+    override fun deserializeReachableDeclarations() {
+        icDeserializer.deserializeReachableDeclarations()
+    }
+
+    override fun postProcess() {
+        icDeserializer.postProcess()
+    }
+
+    private fun DeclarationDescriptor.isDirtyDescriptor(): Boolean {
+        if (this is PropertyAccessorDescriptor) return correspondingProperty.isDirtyDescriptor()
+        return this !is DeserializedDescriptor
+    }
+
+    override fun init() {
+        val knownBuiltIns = irBuiltIns.knownBuiltins.map { (it as IrSymbolOwner).symbol }.toSet()
+        symbolTable.forEachPublicSymbol {
+            if (it.descriptor.isDirtyDescriptor()) { // public && non-deserialized should be dirty symbol
+                if (it !in knownBuiltIns) {
+                    dirtyDeclarations[it.signature] = it
+                }
+            }
+        }
+
+        icDeserializer.init(this)
+    }
+
+    override val klib: IrLibrary
+        get() = icDeserializer.klib
+
+    override val moduleFragment: IrModuleFragment
+        get() = delegate.moduleFragment
+    override val moduleDependencies: Collection<IrModuleDeserializer>
+        get() = delegate.moduleDependencies
+}

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFakeOverrideUtils.kt

@@ -1,76 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.backend.common.serialization
-
-import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.symbols.IrBindableSymbol
-import org.jetbrains.kotlin.ir.util.isReal
-import org.jetbrains.kotlin.ir.util.original
-
-// We may get several real supers here (e.g. see the code snippet from KT-33034).
-// TODO: Consider reworking the resolution algorithm to get a determined super declaration.
-private fun <S: IrBindableSymbol<*, D>, D: IrOverridableDeclaration<S>> D.getRealSupers(): Set<D> {
-    if (this.isReal) {
-        return setOf(this)
-    }
-
-    val visited = mutableSetOf<D>()
-    val realSupers = mutableSetOf<D>()
-
-    fun findRealSupers(declaration: D) {
-        if (declaration in visited) return
-        visited += declaration
-        if (declaration.isReal) {
-            realSupers += declaration
-        } else {
-            declaration.overriddenSymbols.forEach { findRealSupers(it.owner) }
-        }
-    }
-
-    findRealSupers(this)
-
-    if (realSupers.size > 1) {
-        visited.clear()
-
-        fun excludeOverridden(declaration: D) {
-            if (declaration in visited) return
-            visited += declaration
-            declaration.overriddenSymbols.forEach {
-                realSupers.remove(it.owner)
-                excludeOverridden(it.owner)
-            }
-        }
-
-        realSupers.toList().forEach { excludeOverridden(it) }
-    }
-
-    return realSupers
-}
-
-/**
- * Implementation of given method.
- *
- * TODO: this method is actually a part of resolve and probably duplicates another one
- */
-fun IrSimpleFunction.resolveFakeOverride(allowAbstract: Boolean = false): IrSimpleFunction {
-    val realSupers = getRealSupers()
-
-    return if (allowAbstract) {
-        realSupers.first()
-    } else {
-        realSupers.single { it.modality != Modality.ABSTRACT }
-    }
-}
-
-val IrSimpleFunction.target: IrSimpleFunction
-    get() = (if (modality == Modality.ABSTRACT) this else resolveFakeOverride()).original
-
-val IrFunction.target: IrFunction get() = when (this) {
-    is IrSimpleFunction -> this.target
-    is IrConstructor -> this
-    else -> error(this)
-}

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt

@@ -104,7 +104,7 @@ import org.jetbrains.kotlin.backend.common.serialization.proto.PublicIdSignature
 import org.jetbrains.kotlin.backend.common.serialization.proto.AccessorIdSignature as ProtoAccessorIdSignature
 import org.jetbrains.kotlin.backend.common.serialization.proto.FileLocalIdSignature as ProtoFileLocalIdSignature
 
-abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBuiltIns, val symbolTable: SymbolTable) {
+abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBuiltIns, val symbolTable: SymbolTable, protected var deserializeBodies: Boolean) {
 
     abstract fun deserializeIrSymbolToDeclare(code: Long): Pair<IrSymbol, IdSignature>
     abstract fun deserializeIrSymbol(code: Long): IrSymbol
@@ -118,6 +118,9 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     abstract fun referenceIrSymbol(symbol: IrSymbol, signature: IdSignature)
 
     private val parentsStack = mutableListOf<IrDeclarationParent>()
+    private val delegatedSymbolMap = mutableMapOf<IrSymbol, IrSymbol>()
+
+    abstract val deserializeInlineFunctions: Boolean
 
     fun deserializeFqName(fqn: List<Int>): FqName {
         return fqn.run {
@@ -125,6 +128,13 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         }
     }
 
+    private fun deserializeIrSymbolAndRemap(code: Long): IrSymbol {
+        // TODO: could be simplified
+        return deserializeIrSymbol(code).let {
+            delegatedSymbolMap[it] ?: it
+        }
+    }
+
     private fun deserializeName(index: Int): Name {
         val name = deserializeString(index)
         return Name.guessByFirstCharacter(name)
@@ -145,7 +155,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     }
 
     private fun deserializeSimpleType(proto: ProtoSimpleType): IrSimpleType {
-        val symbol = deserializeIrSymbol(proto.classifier) as? IrClassifierSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.classifier) as? IrClassifierSymbol
             ?: error("could not convert sym to ClassifierSymbol")
         logger.log { "deserializeSimpleType: symbol=$symbol" }
 
@@ -167,7 +177,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
 
     private fun deserializeTypeAbbreviation(proto: ProtoTypeAbbreviation): IrTypeAbbreviation =
         IrTypeAbbreviationImpl(
-            deserializeIrSymbol(proto.typeAlias).let {
+            deserializeIrSymbolAndRemap(proto.typeAlias).let {
                 it as? IrTypeAliasSymbol
                     ?: error("IrTypeAliasSymbol expected: $it")
             },
@@ -344,14 +354,14 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         end: Int,
         type: IrType
     ): IrClassReference {
-        val symbol = deserializeIrSymbol(proto.classSymbol) as IrClassifierSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.classSymbol) as IrClassifierSymbol
         val classType = deserializeIrType(proto.classType)
         /** TODO: [createClassifierSymbolForClassReference] is internal function */
         return IrClassReferenceImpl(start, end, type, symbol, classType)
     }
 
     private fun deserializeConstructorCall(proto: ProtoConstructorCall, start: Int, end: Int, type: IrType): IrConstructorCall {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrConstructorSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrConstructorSymbol
         return IrConstructorCallImpl(
             start, end, type,
             symbol, typeArgumentsCount = proto.memberAccess.typeArgumentCount,
@@ -363,10 +373,10 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     }
 
     private fun deserializeCall(proto: ProtoCall, start: Int, end: Int, type: IrType): IrCall {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrFunctionSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrFunctionSymbol
 
         val superSymbol = if (proto.hasSuper()) {
-            deserializeIrSymbol(proto.`super`) as IrClassSymbol
+            deserializeIrSymbolAndRemap(proto.`super`) as IrClassSymbol
         } else null
 
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
@@ -400,7 +410,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         start: Int,
         end: Int
     ): IrDelegatingConstructorCall {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrConstructorSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrConstructorSymbol
         val call = IrDelegatingConstructorCallImpl(
             start,
             end,
@@ -421,7 +431,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         end: Int,
         type: IrType
     ): IrEnumConstructorCall {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrConstructorSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrConstructorSymbol
         val call = IrEnumConstructorCallImpl(
             start,
             end,
@@ -451,10 +461,10 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         start: Int, end: Int, type: IrType
     ): IrFunctionReference {
 
-        val symbol = deserializeIrSymbol(proto.symbol) as IrFunctionSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrFunctionSymbol
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
         val reflectionTarget =
-            if (proto.hasReflectionTargetSymbol()) deserializeIrSymbol(proto.reflectionTargetSymbol) as IrFunctionSymbol else null
+            if (proto.hasReflectionTargetSymbol()) deserializeIrSymbolAndRemap(proto.reflectionTargetSymbol) as IrFunctionSymbol else null
         val callable = IrFunctionReferenceImpl(
             start,
             end,
@@ -477,11 +487,11 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
 
     private fun deserializeGetField(proto: ProtoGetField, start: Int, end: Int, type: IrType): IrGetField {
         val access = proto.fieldAccess
-        val symbol = deserializeIrSymbol(access.symbol) as IrFieldSymbol
+        val symbol = deserializeIrSymbolAndRemap(access.symbol) as IrFieldSymbol
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
 
         val superQualifier = if (access.hasSuper()) {
-            deserializeIrSymbol(access.symbol) as IrClassSymbol
+            deserializeIrSymbolAndRemap(access.symbol) as IrClassSymbol
         } else null
         val receiver = if (access.hasReceiver()) {
             deserializeExpression(access.receiver)
@@ -491,7 +501,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     }
 
     private fun deserializeGetValue(proto: ProtoGetValue, start: Int, end: Int, type: IrType): IrGetValue {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrValueSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrValueSymbol
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
         // TODO: origin!
         return IrGetValueImpl(start, end, type, symbol, origin)
@@ -503,7 +513,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         end: Int,
         type: IrType
     ): IrGetEnumValue {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrEnumEntrySymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrEnumEntrySymbol
         return IrGetEnumValueImpl(start, end, type, symbol)
     }
 
@@ -513,7 +523,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         end: Int,
         type: IrType
     ): IrGetObjectValue {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrClassSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrClassSymbol
         return IrGetObjectValueImpl(start, end, type, symbol)
     }
 
@@ -522,7 +532,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         start: Int,
         end: Int
     ): IrInstanceInitializerCall {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrClassSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrClassSymbol
         return IrInstanceInitializerCallImpl(start, end, symbol, builtIns.unitType)
     }
 
@@ -533,10 +543,10 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         type: IrType
     ): IrLocalDelegatedPropertyReference {
 
-        val delegate = deserializeIrSymbol(proto.delegate) as IrVariableSymbol
+        val delegate = deserializeIrSymbolAndRemap(proto.delegate) as IrVariableSymbol
-        val getter = deserializeIrSymbol(proto.getter) as IrSimpleFunctionSymbol
+        val getter = deserializeIrSymbolAndRemap(proto.getter) as IrSimpleFunctionSymbol
-        val setter = if (proto.hasSetter()) deserializeIrSymbol(proto.setter) as IrSimpleFunctionSymbol else null
+        val setter = if (proto.hasSetter()) deserializeIrSymbolAndRemap(proto.setter) as IrSimpleFunctionSymbol else null
-        val symbol = deserializeIrSymbol(proto.symbol) as IrLocalDelegatedPropertySymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrLocalDelegatedPropertySymbol
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
 
         return IrLocalDelegatedPropertyReferenceImpl(
@@ -551,11 +561,11 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
 
     private fun deserializePropertyReference(proto: ProtoPropertyReference, start: Int, end: Int, type: IrType): IrPropertyReference {
 
-        val symbol = deserializeIrSymbol(proto.symbol) as IrPropertySymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrPropertySymbol
 
-        val field = if (proto.hasField()) deserializeIrSymbol(proto.field) as IrFieldSymbol else null
+        val field = if (proto.hasField()) deserializeIrSymbolAndRemap(proto.field) as IrFieldSymbol else null
-        val getter = if (proto.hasGetter()) deserializeIrSymbol(proto.getter) as IrSimpleFunctionSymbol else null
+        val getter = if (proto.hasGetter()) deserializeIrSymbolAndRemap(proto.getter) as IrSimpleFunctionSymbol else null
-        val setter = if (proto.hasSetter()) deserializeIrSymbol(proto.setter) as IrSimpleFunctionSymbol else null
+        val setter = if (proto.hasSetter()) deserializeIrSymbolAndRemap(proto.setter) as IrSimpleFunctionSymbol else null
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
 
         val callable = IrPropertyReferenceImpl(
@@ -572,16 +582,16 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     }
 
     private fun deserializeReturn(proto: ProtoReturn, start: Int, end: Int, type: IrType): IrReturn {
-        val symbol = deserializeIrSymbol(proto.returnTarget) as IrReturnTargetSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.returnTarget) as IrReturnTargetSymbol
         val value = deserializeExpression(proto.value)
         return IrReturnImpl(start, end, builtIns.nothingType, symbol, value)
     }
 
     private fun deserializeSetField(proto: ProtoSetField, start: Int, end: Int): IrSetField {
         val access = proto.fieldAccess
-        val symbol = deserializeIrSymbol(access.symbol) as IrFieldSymbol
+        val symbol = deserializeIrSymbolAndRemap(access.symbol) as IrFieldSymbol
         val superQualifier = if (access.hasSuper()) {
-            deserializeIrSymbol(access.symbol) as IrClassSymbol
+            deserializeIrSymbolAndRemap(access.symbol) as IrClassSymbol
         } else null
         val receiver = if (access.hasReceiver()) {
             deserializeExpression(access.receiver)
@@ -593,7 +603,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     }
 
     private fun deserializeSetVariable(proto: ProtoSetVariable, start: Int, end: Int): IrSetVariable {
-        val symbol = deserializeIrSymbol(proto.symbol) as IrVariableSymbol
+        val symbol = deserializeIrSymbolAndRemap(proto.symbol) as IrVariableSymbol
         val value = deserializeExpression(proto.value)
         val origin = if (proto.hasOriginName()) deserializeIrStatementOrigin(proto.originName) else null
         return IrSetVariableImpl(start, end, builtIns.unitType, symbol, value, origin)
@@ -902,6 +912,16 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         }
     }
 
+    private fun recordDelegatedSymbol(symbol: IrSymbol) {
+        if (symbol is IrDelegatingSymbol<*, *, *>) {
+            delegatedSymbolMap[symbol] = symbol.delegate
+        }
+    }
+
+    private fun eraseDelegatedSymbol(symbol: IrSymbol) {
+        delegatedSymbolMap.remove(symbol)
+    }
+
     private inline fun <T : IrDeclarationParent> T.usingParent(block: T.() -> Unit): T =
         this.apply { usingParent(this) { block(it) } }
 
@@ -911,6 +931,8 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
     ): T where T : IrDeclaration, T : IrSymbolOwner {
         val (s, uid) = deserializeIrSymbolToDeclare(proto.symbol)
         val coordinates = BinaryCoordinates.decode(proto.coordinates)
+        try {
+            recordDelegatedSymbol(s)
             val result = block(
                 s,
                 uid,
@@ -920,6 +942,9 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
             result.annotations += deserializeAnnotations(proto.annotationList)
             result.parent = parentsStack.peek()!!
             return result
+        } finally {
+            eraseDelegatedSymbol(s)
+        }
     }
 
     private fun deserializeIrTypeParameter(proto: ProtoTypeParameter, index: Int, isGlobal: Boolean): IrTypeParameter {
@@ -1067,12 +1092,23 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
         return result
     }
 
+    private inline fun <T : IrFunction> T.withInlineGuard(block: T.() -> Unit) {
+        val oldInline = deserializeBodies
+        try {
+            deserializeBodies = oldInline || (deserializeInlineFunctions && this is IrSimpleFunction && isInline)
+            block()
+        } finally {
+            deserializeBodies = oldInline
+        }
+    }
+
     private inline fun <T : IrFunction> withDeserializedIrFunctionBase(
         proto: ProtoFunctionBase,
         block: (IrFunctionSymbol, IdSignature, Int, Int, IrDeclarationOrigin, Long) -> T
     ) = withDeserializedIrDeclarationBase(proto.base) { symbol, idSig, startOffset, endOffset, origin, fcode ->
         symbolTable.withScope(symbol.descriptor) {
             block(symbol as IrFunctionSymbol, idSig, startOffset, endOffset, origin, fcode).usingParent {
+                withInlineGuard {
                     typeParameters = deserializeTypeParameters(proto.typeParameterList, false)
                     valueParameters = deserializeValueParameters(proto.valueParameterList)
 
@@ -1089,6 +1125,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
                 }
             }
         }
+    }
 
     private fun deserializeIrFunction(proto: ProtoFunction): IrSimpleFunction {
         return withDeserializedIrFunctionBase(proto.base) { symbol, idSig, startOffset, endOffset, origin, fcode ->
@@ -1111,7 +1148,7 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
                     flags.isFakeOverride
                 )
             }.apply {
-                overriddenSymbols = proto.overriddenList.map { deserializeIrSymbol(it) as IrSimpleFunctionSymbol }
+                overriddenSymbols = proto.overriddenList.map { deserializeIrSymbolAndRemap(it) as IrSimpleFunctionSymbol }
 
                 (descriptor as? WrappedSimpleFunctionDescriptor)?.bind(this)
             }
@@ -1329,5 +1366,3 @@ abstract class IrFileDeserializer(val logger: LoggingContext, val builtIns: IrBu
             deserializeDeclaration(proto)
         }
 }
-
-val irrelevantOrigin = object : IrDeclarationOriginImpl("irrelevant") {}

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt

@@ -0,0 +1,276 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.common.serialization
+
+import org.jetbrains.kotlin.backend.common.serialization.encodings.BinarySymbolData
+import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.descriptors.IrAbstractFunctionFactory
+import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.descriptors.WrappedDeclarationDescriptor
+import org.jetbrains.kotlin.ir.symbols.*
+import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.ir.util.IrExtensionGenerator
+import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.name.Name
+
+internal fun IrSymbol.kind(): BinarySymbolData.SymbolKind {
+    return when (this) {
+        is IrClassSymbol -> BinarySymbolData.SymbolKind.CLASS_SYMBOL
+        is IrConstructorSymbol -> BinarySymbolData.SymbolKind.CONSTRUCTOR_SYMBOL
+        is IrSimpleFunctionSymbol -> BinarySymbolData.SymbolKind.FUNCTION_SYMBOL
+        is IrPropertySymbol -> BinarySymbolData.SymbolKind.PROPERTY_SYMBOL
+        is IrEnumEntrySymbol -> BinarySymbolData.SymbolKind.ENUM_ENTRY_SYMBOL
+        is IrTypeAliasSymbol -> BinarySymbolData.SymbolKind.TYPEALIAS_SYMBOL
+        else -> error("Unexpected symbol kind $this")
+    }
+}
+
+abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor) {
+    abstract operator fun contains(idSig: IdSignature): Boolean
+    abstract fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol
+
+    open fun declareIrSymbol(symbol: IrSymbol) {
+        assert(symbol.isPublicApi)
+        assert(symbol.descriptor !is WrappedDeclarationDescriptor<*>)
+        deserializeIrSymbol(symbol.signature, symbol.kind())
+    }
+
+    open val klib: IrLibrary get() = error("Unsupported operation")
+
+    open fun init() = init(this)
+
+    open fun init(delegate: IrModuleDeserializer) {}
+
+    open fun addModuleReachableTopLevel(idSig: IdSignature) { error("Unsupported Operation (sig: $idSig") }
+
+    open fun deserializeReachableDeclarations() { error("Unsupported Operation") }
+
+    open fun postProcess() {}
+
+    abstract val moduleFragment: IrModuleFragment
+
+    abstract val moduleDependencies: Collection<IrModuleDeserializer>
+
+    open val strategy: DeserializationStrategy = DeserializationStrategy.ONLY_DECLARATION_HEADERS
+}
+
+// Used to resolve built in symbols like `kotlin.ir.internal.*` or `kotlin.FunctionN`
+class IrModuleDeserializerWithBuiltIns(
+    private val builtIns: IrBuiltIns,
+    private val functionFactory: IrAbstractFunctionFactory,
+    private val delegate: IrModuleDeserializer
+) : IrModuleDeserializer(delegate.moduleDescriptor) {
+
+    init {
+        // TODO: figure out how it should work for K/N
+//        assert(builtIns.builtIns.builtInsModule === delegate.moduleDescriptor)
+    }
+
+    private val irBuiltInsMap = builtIns.knownBuiltins.map {
+        val symbol = (it as IrSymbolOwner).symbol
+        symbol.signature to symbol
+    }.toMap()
+
+    private fun checkIsFunctionInterface(idSig: IdSignature): Boolean {
+        val publicSig = idSig.asPublic() ?: return false
+
+        if (publicSig.packageFqn !in functionalPackages) return false
+
+        val declarationFqn = publicSig.declarationFqn
+
+        if (declarationFqn.isRoot) return false
+
+        val fqnParts = declarationFqn.pathSegments()
+
+        val className = fqnParts.first()
+
+        return functionPattern.matcher(className.asString()).find()
+    }
+
+    override operator fun contains(idSig: IdSignature): Boolean {
+        if (idSig in irBuiltInsMap) return true
+
+        return checkIsFunctionInterface(idSig) || idSig in delegate
+    }
+
+    override fun deserializeReachableDeclarations() {
+        delegate.deserializeReachableDeclarations()
+    }
+
+    private fun computeFunctionDescriptor(className: Name): FunctionClassDescriptor {
+        val nameString = className.asString()
+        val isK = nameString[0] == 'K'
+        val isSuspend = (if (isK) nameString[1] else nameString[0]) == 'S'
+        val arity = nameString.run { substring(indexOfFirst { it.isDigit() }).toInt(10) }
+        return functionFactory.run {
+            when {
+                isK && isSuspend -> kSuspendFunctionClassDescriptor(arity)
+                isK -> kFunctionClassDescriptor(arity)
+                isSuspend -> suspendFunctionClassDescriptor(arity)
+                else -> functionClassDescriptor(arity)
+            }
+        }
+    }
+
+    private fun resolveFunctionalInterface(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+        val publicSig = idSig.asPublic() ?: error("$idSig has to be public")
+
+        val fqnParts = publicSig.declarationFqn.pathSegments()
+        val className = fqnParts.firstOrNull() ?: error("Expected class name for $idSig")
+
+        val functionDescriptor = computeFunctionDescriptor(className)
+        val topLevelSignature = IdSignature.PublicSignature(publicSig.packageFqn, FqName(className.asString()), null, publicSig.mask)
+
+        val functionClass = when (functionDescriptor.functionKind) {
+            FunctionClassDescriptor.Kind.KSuspendFunction -> functionFactory.kSuspendFunctionN(functionDescriptor.arity) { callback ->
+                declareClassFromLinker(functionDescriptor, topLevelSignature) { callback(it) }
+            }
+            FunctionClassDescriptor.Kind.KFunction -> functionFactory.kFunctionN(functionDescriptor.arity) { callback ->
+                declareClassFromLinker(functionDescriptor, topLevelSignature) { callback(it) }
+            }
+            FunctionClassDescriptor.Kind.SuspendFunction -> functionFactory.suspendFunctionN(functionDescriptor.arity) { callback ->
+                declareClassFromLinker(functionDescriptor, topLevelSignature) { callback(it) }
+            }
+            FunctionClassDescriptor.Kind.Function -> functionFactory.functionN(functionDescriptor.arity) { callback ->
+                declareClassFromLinker(functionDescriptor, topLevelSignature) { callback(it) }
+            }
+        }
+
+        return when (fqnParts.size) {
+            1 -> functionClass.symbol.also { assert(symbolKind == BinarySymbolData.SymbolKind.CLASS_SYMBOL) }
+            2 -> {
+                val memberName = fqnParts[1]!!
+                functionClass.declarations.single { it is IrDeclarationWithName && it.name == memberName }.let {
+                    (it as IrSymbolOwner).symbol
+                }
+            }
+            3 -> {
+                assert(idSig is IdSignature.AccessorSignature)
+                assert(symbolKind == BinarySymbolData.SymbolKind.FUNCTION_SYMBOL)
+                val propertyName = fqnParts[1]!!
+                val accessorName = fqnParts[2]!!
+                functionClass.declarations.filterIsInstance<IrProperty>().single { it.name == propertyName }.let { p ->
+                    p.getter?.let { g -> if (g.name == accessorName) return g.symbol }
+                    p.setter?.let { s -> if (s.name == accessorName) return s.symbol }
+                    error("No accessor found for signature $idSig")
+                }
+            }
+            else -> error("No member found for signature $idSig")
+        }
+    }
+
+    override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+        irBuiltInsMap[idSig]?.let { return it }
+
+        if (checkIsFunctionInterface(idSig)) return resolveFunctionalInterface(idSig, symbolKind)
+
+        return delegate.deserializeIrSymbol(idSig, symbolKind)
+    }
+
+    override fun postProcess() {
+        delegate.postProcess()
+    }
+
+    override fun init() {
+        delegate.init(this)
+    }
+
+    override val klib: IrLibrary
+        get() = delegate.klib
+
+    override val strategy: DeserializationStrategy
+        get() = delegate.strategy
+
+    override fun addModuleReachableTopLevel(idSig: IdSignature) {
+        delegate.addModuleReachableTopLevel(idSig)
+    }
+
+    override val moduleFragment: IrModuleFragment get() = delegate.moduleFragment
+    override val moduleDependencies: Collection<IrModuleDeserializer> get() = delegate.moduleDependencies
+}
+
+open class CurrentModuleDeserializer(
+    override val moduleFragment: IrModuleFragment,
+    override val moduleDependencies: Collection<IrModuleDeserializer>,
+    private val symbolTable: SymbolTable,
+    private val extensions: Collection<IrExtensionGenerator>
+) : IrModuleDeserializer(moduleFragment.descriptor) {
+    override fun contains(idSig: IdSignature): Boolean = false // TODO:
+
+    override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+        error("Unreachable execution: there could not be back-links")
+    }
+
+    override fun declareIrSymbol(symbol: IrSymbol) {
+        declareIrSymbolImpl(symbol)
+    }
+
+    private fun referenceParentDescriptor(descriptor: DeclarationDescriptor): IrSymbol {
+        return when (descriptor) {
+            is ClassDescriptor -> symbolTable.referenceClass(descriptor)
+            is PropertyDescriptor -> symbolTable.referenceProperty(descriptor)
+            is PackageFragmentDescriptor -> moduleFragment.files.single { it.symbol.descriptor === descriptor }.symbol
+            else -> error("Unexpected declaration parent $descriptor")
+        }
+    }
+
+    private fun declareIrDeclaration(symbol: IrSymbol): IrDeclaration {
+        for (extension in extensions) {
+            extension.declare(symbol)?.let { return it }
+        }
+
+        return declareIrDeclarationDefault(symbol)
+    }
+
+    private fun declareIrDeclarationDefault(symbol: IrSymbol): IrDeclaration {
+        return when (symbol) {
+            is IrClassSymbol -> symbolTable.declareClass(offset, offset, IrDeclarationOrigin.DEFINED, symbol.descriptor)
+            is IrConstructorSymbol -> symbolTable.declareConstructor(offset, offset, IrDeclarationOrigin.DEFINED, symbol.descriptor)
+            is IrSimpleFunctionSymbol -> symbolTable.declareSimpleFunction(offset, offset, IrDeclarationOrigin.DEFINED, symbol.descriptor)
+            is IrPropertySymbol -> symbolTable.declareProperty(offset, offset, IrDeclarationOrigin.DEFINED, symbol.descriptor)
+            is IrTypeAliasSymbol -> TODO("Implement type alias $symbol")
+            is IrEnumEntrySymbol -> symbolTable.declareEnumEntry(offset, offset, IrDeclarationOrigin.DEFINED, symbol.descriptor)
+            else -> error("Unexpected symbol $symbol")
+        }
+    }
+
+    private fun declareIrSymbolImpl(symbol: IrSymbol): IrSymbolOwner {
+        if (symbol.isBound) return symbol.owner
+        val descriptor = symbol.descriptor
+
+        assert(descriptor !is WrappedDeclarationDescriptor<*>)
+
+        val accessor = descriptor as? PropertyAccessorDescriptor
+
+        val parent = descriptor.containingDeclaration ?: error("Expect non-root declaration $descriptor")
+        val parentDeclaration = declareIrSymbolImpl(referenceParentDescriptor(parent)) as IrDeclarationContainer
+
+        val declaredDeclaration = declareIrDeclaration(symbol).also {
+            it.parent = parentDeclaration
+            if (accessor != null) {
+                val property = accessor.correspondingProperty
+                val irProperty = declareIrSymbolImpl(referenceParentDescriptor(property)) as IrProperty
+                val irAccessor = it as IrSimpleFunction
+                irAccessor.correspondingPropertySymbol = irProperty.symbol
+                if (accessor === property.getter) irProperty.getter = irAccessor
+                if (accessor === property.setter) irProperty.setter = irAccessor
+            } else {
+                parentDeclaration.declarations.add(it)
+            }
+        }
+
+        return declaredDeclaration as IrSymbolOwner
+    }
+
+    companion object {
+        private const val offset = UNDEFINED_OFFSET
+    }
+}

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt

@@ -7,13 +7,12 @@ package org.jetbrains.kotlin.backend.common.serialization
 
 import org.jetbrains.kotlin.backend.common.LoggingContext
 import org.jetbrains.kotlin.backend.common.serialization.encodings.BinarySymbolData
-import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.impl.EmptyPackageFragmentDescriptor
 import org.jetbrains.kotlin.ir.IrElement
-import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.IrFile
-import org.jetbrains.kotlin.ir.declarations.impl.IrClassImpl
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
 import org.jetbrains.kotlin.ir.descriptors.*
@@ -26,139 +25,224 @@ import org.jetbrains.kotlin.ir.symbols.impl.*
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.impl.IrErrorTypeImpl
 import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinLibrary
+import org.jetbrains.kotlin.protobuf.CodedInputStream
 import org.jetbrains.kotlin.protobuf.ExtensionRegistryLite.newInstance
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
-import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.types.Variance
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclaration as ProtoDeclaration
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrFile as ProtoFile
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrType as ProtoType
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrStatement as ProtoStatement
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrExpression as ProtoExpression
-import org.jetbrains.kotlin.backend.common.serialization.proto.IrConstructorCall as ProtoConstructorCall
 import org.jetbrains.kotlin.backend.common.serialization.proto.Actual as ProtoActual
 import org.jetbrains.kotlin.backend.common.serialization.proto.IdSignature as ProtoIdSignature
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrConstructorCall as ProtoConstructorCall
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrDeclaration as ProtoDeclaration
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrExpression as ProtoExpression
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrFile as ProtoFile
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrStatement as ProtoStatement
+import org.jetbrains.kotlin.backend.common.serialization.proto.IrType as ProtoType
 
 abstract class KotlinIrLinker(
+    private val currentModule: ModuleDescriptor?,
     val logger: LoggingContext,
     val builtIns: IrBuiltIns,
     val symbolTable: SymbolTable,
-    private val exportedDependencies: List<ModuleDescriptor>,
+    private val exportedDependencies: List<ModuleDescriptor>
-    private val forwardModuleDescriptor: ModuleDescriptor?
 ) : IrDeserializer {
 
+    // Kotlin-MPP related data. Consider some refactoring
     private val expectUniqIdToActualUniqId = mutableMapOf<IdSignature, IdSignature>()
     private val topLevelActualUniqItToDeserializer = mutableMapOf<IdSignature, IrModuleDeserializer>()
     private val expectSymbols = mutableMapOf<IdSignature, IrSymbol>()
     private val actualSymbols = mutableMapOf<IdSignature, IrSymbol>()
 
-    sealed class DeserializationState<T> {
+    private val modulesWithReachableTopLevels = mutableSetOf<IrModuleDeserializer>()
-        val deserializedSymbols = mutableMapOf<IdSignature, IrSymbol>()
 
-        operator fun contains(key: IdSignature) = key in deserializedSymbols
+    protected val deserializersForModules = mutableMapOf<ModuleDescriptor, IrModuleDeserializer>()
-        operator fun get(key: IdSignature): IrSymbol = deserializedSymbols[key] ?: error("No deserialized symbol found for $key")
 
-        abstract fun addIdSignature(key: IdSignature)
+    abstract inner class BasicIrModuleDeserializer(moduleDescriptor: ModuleDescriptor, override val klib: IrLibrary, override val strategy: DeserializationStrategy) :
-        abstract fun processPendingDeclarations(processor: (T) -> Unit)
+        IrModuleDeserializer(moduleDescriptor) {
 
-        class ModuleDeserializationState(val module: IrModuleDeserializer) :
+        private val fileToDeserializerMap = mutableMapOf<IrFile, IrDeserializerForFile>()
-            DeserializationState<IrModuleDeserializer.IrDeserializerForFile>() {
-            private val filesWithPendingTopLevels = mutableSetOf<IrModuleDeserializer.IrDeserializerForFile>()
 
-            fun enqueueFile(fileDeserializer: IrModuleDeserializer.IrDeserializerForFile) {
+        private inner class ModuleDeserializationState {
+            private val filesWithPendingTopLevels = mutableSetOf<IrDeserializerForFile>()
+
+            fun enqueueFile(fileDeserializer: IrDeserializerForFile) {
                 filesWithPendingTopLevels.add(fileDeserializer)
-                module.enqueueModule()
+                enqueueModule()
             }
 
-            override fun addIdSignature(key: IdSignature) {
+            fun addIdSignature(key: IdSignature) {
-                val fileDeserializer = module.moduleReversedFileIndex[key] ?: error("No file found for key $key")
+                val fileDeserializer = moduleReversedFileIndex[key] ?: error("No file found for key $key")
                 fileDeserializer.fileLocalDeserializationState.addIdSignature(key)
 
                 enqueueFile(fileDeserializer)
             }
 
-            override fun processPendingDeclarations(processor: (IrModuleDeserializer.IrDeserializerForFile) -> Unit) {
+            fun processPendingDeclarations() {
                 while (filesWithPendingTopLevels.isNotEmpty()) {
                     val pendingDeserializer = filesWithPendingTopLevels.first()
 
-                    processor(pendingDeserializer)
+                    pendingDeserializer.deserializeFileImplicitDataIfFirstUse()
+                    pendingDeserializer.deserializeAllFileReachableTopLevel()
 
                     filesWithPendingTopLevels.remove(pendingDeserializer)
                 }
             }
         }
 
-        class SimpleDeserializationState(private val checker: (IdSignature) -> Boolean) : DeserializationState<IdSignature>() {
+        private val moduleDeserializationState = ModuleDeserializationState()
+        private val moduleReversedFileIndex = mutableMapOf<IdSignature, IrDeserializerForFile>()
+        override val moduleDependencies by lazy {
+            moduleDescriptor.allDependencyModules.filter { it != moduleDescriptor }.map { resolveModuleDeserializer(it) }
+        }
+
+        override fun init(delegate: IrModuleDeserializer) {
+            val fileCount = klib.fileCount()
+
+            val files = ArrayList<IrFile>(fileCount)
+
+            for (i in 0 until fileCount) {
+                val fileStream = klib.file(i).codedInputStream
+                files.add(deserializeIrFile(ProtoFile.parseFrom(fileStream, newInstance()), i, delegate))
+            }
+
+            moduleFragment.files.addAll(files)
+
+            fileToDeserializerMap.values.forEach { it.deserializeExpectActualMapping() }
+        }
+
+        // TODO: fix to topLevel checker
+        override fun contains(idSig: IdSignature): Boolean = idSig in moduleReversedFileIndex
+
+        override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+            assert(idSig.isPublic)
+
+            val topLevelSignature = idSig.topLevelSignature()
+            val fileDeserializer = moduleReversedFileIndex[topLevelSignature]
+                ?: error("No file for $topLevelSignature (@ $idSig) in module $moduleDescriptor")
+
+            val fileDeserializationState = fileDeserializer.fileLocalDeserializationState
+
+            fileDeserializationState.addIdSignature(topLevelSignature)
+            moduleDeserializationState.enqueueFile(fileDeserializer)
+
+            return fileDeserializationState.deserializedSymbols.getOrPut(idSig) {
+//                val descriptor = resolveSpecialSignature(idSig)
+                val symbol = referenceDeserializedSymbol(symbolKind, idSig)
+
+                handleExpectActualMapping(idSig, symbol)
+            }
+        }
+
+        override fun postProcess() {}
+
+        override val moduleFragment: IrModuleFragment = IrModuleFragmentImpl(moduleDescriptor, builtIns, emptyList())
+
+        private fun deserializeIrFile(fileProto: ProtoFile, fileIndex: Int, moduleDeserializer: IrModuleDeserializer): IrFile {
+
+            val fileName = fileProto.fileEntry.name
+
+            val fileEntry = NaiveSourceBasedFileEntryImpl(fileName, fileProto.fileEntry.lineStartOffsetsList.toIntArray())
+
+            val fileDeserializer =
+                IrDeserializerForFile(fileProto.annotationList, fileProto.actualsList, fileIndex, !strategy.needBodies, strategy.inlineBodies, moduleDeserializer).apply {
+
+                    // Explicitly exported declarations (e.g. top-level initializers) must be deserialized before all other declarations.
+                    // Thus we schedule their deserialization in deserializer's constructor.
+                    fileProto.explicitlyExportedToCompilerList.forEach {
+                        val symbolData = parseSymbolData(it)
+                        val sig = deserializeIdSignature(symbolData.signatureId)
+                        assert(!sig.isPackageSignature())
+                        fileLocalDeserializationState.addIdSignature(sig.topLevelSignature())
+                    }
+                }
+
+            val fqName = fileDeserializer.deserializeFqName(fileProto.fqNameList)
+
+            val packageFragmentDescriptor = EmptyPackageFragmentDescriptor(moduleDescriptor, fqName)
+
+            val symbol = IrFileSymbolImpl(packageFragmentDescriptor)
+            val file = IrFileImpl(fileEntry, symbol, fqName)
+
+            fileDeserializer.file = file
+            fileToDeserializerMap[file] = fileDeserializer
+
+            val fileSignatureIndex = fileProto.declarationIdList.map { fileDeserializer.deserializeIdSignature(it) to it }
+
+            fileSignatureIndex.forEach {
+                moduleReversedFileIndex.getOrPut(it.first) { fileDeserializer }
+            }
+
+            fileDeserializer.reversedSignatureIndex = fileSignatureIndex.toMap()
+
+            if (strategy.theWholeWorld) {
+                for (id in fileSignatureIndex) {
+                    moduleDeserializationState.addIdSignature(id.first)
+                }
+                moduleDeserializationState.enqueueFile(fileDeserializer)
+            } else if (strategy.explicitlyExported) {
+                moduleDeserializationState.enqueueFile(fileDeserializer)
+            }
+
+            return file
+        }
+
+        override fun deserializeReachableDeclarations() {
+            moduleDeserializationState.processPendingDeclarations()
+        }
+
+        private fun enqueueModule() {
+            modulesWithReachableTopLevels.add(this)
+        }
+
+        override fun addModuleReachableTopLevel(idSig: IdSignature) {
+            moduleDeserializationState.addIdSignature(idSig)
+        }
+    }
+
+    inner class IrDeserializerForFile(
+        private var annotations: List<ProtoConstructorCall>?,
+        private val actuals: List<ProtoActual>,
+        private val fileIndex: Int,
+        onlyHeaders: Boolean,
+        inlineBodies: Boolean,
+        private val moduleDeserializer: IrModuleDeserializer
+    ) : IrFileDeserializer(logger, builtIns, symbolTable, !onlyHeaders) {
+
+        private var fileLoops = mutableMapOf<Int, IrLoopBase>()
+
+        lateinit var file: IrFile
+
+        private val irTypeCache = mutableMapOf<Int, IrType>()
+
+        override val deserializeInlineFunctions: Boolean = inlineBodies
+
+        var reversedSignatureIndex = emptyMap<IdSignature, Int>()
+
+        inner class FileDeserializationState {
             private val reachableTopLevels = LinkedHashSet<IdSignature>()
+            val deserializedSymbols = mutableMapOf<IdSignature, IrSymbol>()
 
-            private fun shouldBeProcessed(idSig: IdSignature): Boolean = checker(idSig)
+            fun addIdSignature(key: IdSignature) {
-
-            override fun addIdSignature(key: IdSignature) {
                 reachableTopLevels.add(key)
             }
 
-            override fun processPendingDeclarations(processor: (IdSignature) -> Unit) {
+            fun processPendingDeclarations() {
                 while (reachableTopLevels.isNotEmpty()) {
                     val reachableKey = reachableTopLevels.first()
 
-                    if (shouldBeProcessed(reachableKey)) {
                     val existedSymbol = deserializedSymbols[reachableKey]
                     if (existedSymbol == null || !existedSymbol.isBound) {
-                            processor(reachableKey)
+                        val declaration = deserializeDeclaration(reachableKey)
-                        }
+                        file.declarations.add(declaration)
                     }
 
                     reachableTopLevels.remove(reachableKey)
                 }
             }
         }
-    }
 
-    protected val globalDeserializationState = DeserializationState.SimpleDeserializationState { true }
+        val fileLocalDeserializationState = FileDeserializationState()
-    private val modulesWithReachableTopLevels = mutableSetOf<IrModuleDeserializer>()
-
-    //TODO: This is Native specific. Eliminate me.
-    private val forwardDeclarations = mutableSetOf<IrSymbol>()
-
-    protected val deserializersForModules = mutableMapOf<ModuleDescriptor, IrModuleDeserializer>()
-
-    abstract inner class IrModuleDeserializer(
-        private val moduleDescriptor: ModuleDescriptor,
-        private val strategy: DeserializationStrategy) {
-
-        val fileToDeserializerMap = mutableMapOf<IrFile, IrDeserializerForFile>()
-
-        private val moduleDeserializationState = DeserializationState.ModuleDeserializationState(this)
-        val moduleReversedFileIndex = mutableMapOf<IdSignature, IrDeserializerForFile>()
-        private val moduleDependencies by lazy {
-            moduleDescriptor.allDependencyModules.filter { it != moduleDescriptor }.mapNotNull { resolveModuleDeserializer(it) }
-        }
-
-        protected open fun containsIdSignature(idSig: IdSignature): Boolean = idSig in moduleReversedFileIndex
-
-        // This is a heavy initializer
-        val module = deserializeIrModuleHeader()
-
-        inner class IrDeserializerForFile(
-            private var annotations: List<ProtoConstructorCall>?,
-            private val actuals: List<ProtoActual>,
-            private val fileIndex: Int,
-            onlyHeaders: Boolean
-        ) : IrFileDeserializer(logger, builtIns, symbolTable) {
-
-            private var fileLoops = mutableMapOf<Int, IrLoopBase>()
-
-            lateinit var file: IrFile
-
-            private val deserializeBodies: Boolean = !onlyHeaders
-
-            private val irTypeCache = mutableMapOf<Int, IrType>()
-
-            var reversedSignatureIndex = emptyMap<IdSignature, Int>()
-
-            val fileLocalDeserializationState = DeserializationState.SimpleDeserializationState {
-                moduleDeserializationState.deserializedSymbols[it]?.isBound != true
-            }
 
         fun deserializeDeclaration(idSig: IdSignature): IrDeclaration {
             return deserializeDeclaration(loadTopLevelDeclarationProto(idSig), file)
@@ -185,176 +269,77 @@ abstract class KotlinIrLinker(
             return reversedSignatureIndex[idSig] ?: error("Not found Idx for $idSig")
         }
 
+        private fun readDeclaration(index: Int): CodedInputStream =
+            moduleDeserializer.klib.irDeclaration(index, fileIndex).codedInputStream
+
         private fun loadTopLevelDeclarationProto(idSig: IdSignature): ProtoDeclaration {
             val idSigIndex = resolveSignatureIndex(idSig)
-                val stream = reader(moduleDescriptor, fileIndex, idSigIndex).codedInputStream
+            return ProtoDeclaration.parseFrom(readDeclaration(idSigIndex), newInstance())
-                return ProtoDeclaration.parseFrom(stream, newInstance())
         }
 
+        private fun readType(index: Int): CodedInputStream =
+            moduleDeserializer.klib.type(index, fileIndex).codedInputStream
+
         private fun loadTypeProto(index: Int): ProtoType {
-                val stream = readType(moduleDescriptor, fileIndex, index).codedInputStream
+            return ProtoType.parseFrom(readType(index), newInstance())
-                return ProtoType.parseFrom(stream, newInstance())
         }
 
+        private fun readSignature(index: Int): CodedInputStream =
+            moduleDeserializer.klib.signature(index, fileIndex).codedInputStream
+
         private fun loadSignatureProto(index: Int): ProtoIdSignature {
-                val stream = readSignature(moduleDescriptor, fileIndex, index).codedInputStream
+            return ProtoIdSignature.parseFrom(readSignature(index), newInstance())
-                return ProtoIdSignature.parseFrom(stream, newInstance())
         }
 
+        private fun readBody(index: Int): CodedInputStream =
+            moduleDeserializer.klib.body(index, fileIndex).codedInputStream
+
         private fun loadStatementBodyProto(index: Int): ProtoStatement {
-                val stream = readBody(moduleDescriptor, fileIndex, index).codedInputStream
+            return ProtoStatement.parseFrom(readBody(index), newInstance())
-                return ProtoStatement.parseFrom(stream, newInstance())
         }
 
         private fun loadExpressionBodyProto(index: Int): ProtoExpression {
-                val stream = readBody(moduleDescriptor, fileIndex, index).codedInputStream
+            return ProtoExpression.parseFrom(readBody(index), newInstance())
-                return ProtoExpression.parseFrom(stream, newInstance())
         }
 
         private fun loadStringProto(index: Int): String {
-                return String(readString(moduleDescriptor, fileIndex, index))
+            return String(moduleDeserializer.klib.string(index, fileIndex))
-            }
-            // TODO: this function allows passing descriptor for all kinds of symbols.
-            //  It is incorrect.
-            private fun referenceDeserializedSymbol(
-                symbolKind: BinarySymbolData.SymbolKind,
-                idSignature: IdSignature,
-                descriptor: DeclarationDescriptor?
-            ): IrSymbol {
-                fun checkDescriptorIsNull(symbolKind: BinarySymbolData.SymbolKind) {
-                    assert(descriptor == null) { "Symbol with kind $symbolKind should not have non-wrapped descriptor" }
-                }
-
-                return symbolTable.run {
-                    when (symbolKind) {
-                        BinarySymbolData.SymbolKind.ANONYMOUS_INIT_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            IrAnonymousInitializerSymbolImpl(WrappedClassDescriptor())
-                                .also { require(idSignature.isLocal) }
-                        }
-                        // TODO: FunctionInterfaces
-                        BinarySymbolData.SymbolKind.CLASS_SYMBOL -> referenceClassFromLinker(
-                            descriptor as? ClassDescriptor ?: WrappedClassDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.CONSTRUCTOR_SYMBOL -> referenceConstructorFromLinker(
-                            descriptor as? ClassConstructorDescriptor ?: WrappedClassConstructorDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.TYPE_PARAMETER_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            referenceTypeParameterFromLinker(WrappedTypeParameterDescriptor(), idSignature)
-                        }
-                        BinarySymbolData.SymbolKind.ENUM_ENTRY_SYMBOL -> referenceEnumEntryFromLinker(
-                            descriptor as? ClassDescriptor ?: WrappedEnumEntryDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.STANDALONE_FIELD_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            referenceFieldFromLinker(WrappedFieldDescriptor(), idSignature)
-                        }
-                        BinarySymbolData.SymbolKind.FIELD_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            referenceFieldFromLinker(WrappedPropertyDescriptor(), idSignature)
-                        }
-                        //TODO: FunctionInterfaces
-                        BinarySymbolData.SymbolKind.FUNCTION_SYMBOL -> referenceSimpleFunctionFromLinker(
-                            descriptor as? FunctionDescriptor ?: WrappedSimpleFunctionDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.TYPEALIAS_SYMBOL -> referenceTypeAliasFromLinker(
-                            descriptor as? TypeAliasDescriptor ?: WrappedTypeAliasDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.PROPERTY_SYMBOL -> referencePropertyFromLinker(
-                            descriptor as? PropertyDescriptor ?: WrappedPropertyDescriptor(), idSignature
-                        )
-                        BinarySymbolData.SymbolKind.VARIABLE_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            IrVariableSymbolImpl(WrappedVariableDescriptor())
-                        }
-                        BinarySymbolData.SymbolKind.VALUE_PARAMETER_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            IrValueParameterSymbolImpl(WrappedValueParameterDescriptor())
-                        }
-                        BinarySymbolData.SymbolKind.RECEIVER_PARAMETER_SYMBOL -> IrValueParameterSymbolImpl(
-                            descriptor as? ReceiverParameterDescriptor ?: WrappedReceiverParameterDescriptor()
-                        )
-                        BinarySymbolData.SymbolKind.LOCAL_DELEGATED_PROPERTY_SYMBOL -> {
-                            checkDescriptorIsNull(symbolKind)
-                            IrLocalDelegatedPropertySymbolImpl(WrappedVariableDescriptorWithAccessor())
-                        }
-                        else -> error("Unexpected classifier symbol kind: $symbolKind")
-                    }
-                }
-            }
-
-            private fun isGlobalIdSignature(isSignature: IdSignature): Boolean {
-                return isSignature in globalDeserializationState || isSpecialSignature(isSignature)
         }
 
         private fun getModuleForTopLevelId(idSignature: IdSignature): IrModuleDeserializer? {
-                if (containsIdSignature(idSignature)) return this@IrModuleDeserializer
+            if (idSignature in moduleDeserializer) return moduleDeserializer
-                return moduleDependencies.firstOrNull { it.containsIdSignature(idSignature) }
+            return moduleDeserializer.moduleDependencies.firstOrNull { idSignature in it }
         }
 
-            private fun getStateForID(isSignature: IdSignature): DeserializationState<*> {
+        private fun findModuleDeserializer(idSig: IdSignature): IrModuleDeserializer {
-                if (isSignature.isLocal) return fileLocalDeserializationState
+            assert(idSig.isPublic)
-                if (isGlobalIdSignature(isSignature)) return globalDeserializationState
-                return getModuleForTopLevelId(isSignature)?.moduleDeserializationState ?: handleNoModuleDeserializerFound(isSignature)
-            }
 
-            private fun findDeserializationState(idSignature: IdSignature): DeserializationState<*> {
+            val topLevelSig = idSig.topLevelSignature()
-                if (idSignature.hasTopLevel) {
+            if (topLevelSig in moduleDeserializer) return moduleDeserializer
-                    val topLevelSignature = idSignature.topLevelSignature()
+            return moduleDeserializer.moduleDependencies.firstOrNull { topLevelSig in it } ?: handleNoModuleDeserializerFound(idSig)
-
-                    val topLevelDeserializationState = getStateForID(topLevelSignature)
-
-                    if (topLevelSignature !in topLevelDeserializationState) {
-                        topLevelDeserializationState.addIdSignature(topLevelSignature)
-                    }
-
-                    // If topLevel declaration is module-public and current declaration iы not (e.g. value parameter)
-                    // they should be processed via different tables
-                    if (idSignature.isLocal) return fileLocalDeserializationState
-
-                    return topLevelDeserializationState
-                }
-
-                assert(idSignature.isLocal)
-                return fileLocalDeserializationState
         }
 
         private fun referenceIrSymbolData(symbol: IrSymbol, signature: IdSignature) {
-                val deserializationState = findDeserializationState(signature)
+            assert(signature.isLocal)
-                deserializationState.deserializedSymbols.putIfAbsent(signature, symbol)
+            fileLocalDeserializationState.deserializedSymbols.putIfAbsent(signature, symbol)
+        }
+
+        private fun deserializeIrLocalSymbolData(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+            assert(idSig.isLocal)
+
+            if (idSig.hasTopLevel) {
+                fileLocalDeserializationState.addIdSignature(idSig.topLevelSignature())
+            }
+
+            return fileLocalDeserializationState.deserializedSymbols.getOrPut(idSig) {
+                referenceDeserializedSymbol(symbolKind, idSig)
+            }
         }
 
         private fun deserializeIrSymbolData(idSignature: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
-                val deserializationState = findDeserializationState(idSignature)
+            if (idSignature.isLocal) return deserializeIrLocalSymbolData(idSignature, symbolKind)
 
-                val symbol = deserializationState.deserializedSymbols.getOrPut(idSignature) {
+            return findModuleDeserializer(idSignature).deserializeIrSymbol(idSignature, symbolKind)
-                    val descriptor = resolveSpecialSignature(idSignature)
-
-                    // TODO: move this logic out there
-                    postProcessPlatformSpecificDeclaration(idSignature, descriptor) {
-                        val fdState = getStateForID(it)
-                        assert(it.isPublic && it.topLevelSignature() == it)
-                        if (it !in fdState) fdState.addIdSignature(it)
-                    }
-
-                    val symbol = referenceDeserializedSymbol(symbolKind, idSignature, descriptor).let {
-                        if (expectUniqIdToActualUniqId[idSignature] != null) wrapInDelegatedSymbol(it) else it
-                    }
-
-                    if (idSignature in expectUniqIdToActualUniqId.keys) expectSymbols[idSignature] = symbol
-                    if (idSignature in expectUniqIdToActualUniqId.values) actualSymbols[idSignature] = symbol
-
-                    symbol
-                }
-                if (symbol.descriptor is ClassDescriptor &&
-                    symbol.descriptor !is WrappedDeclarationDescriptor<*> &&
-                    symbol.descriptor.module.isForwardDeclarationModule
-                ) {
-                    forwardDeclarations.add(symbol)
-                }
-
-                return symbol
         }
 
         override fun deserializeIrSymbolToDeclare(code: Long): Pair<IrSymbol, IdSignature> {
@@ -400,12 +385,12 @@ abstract class KotlinIrLinker(
         }
 
         override fun deserializeStatementBody(index: Int): IrElement {
-                if (deserializeBodies) {
+            return if (deserializeBodies) {
                 val bodyData = loadStatementBodyProto(index)
-                    return deserializeStatement(bodyData)
+                deserializeStatement(bodyData)
             } else {
                 val errorType = IrErrorTypeImpl(null, emptyList(), Variance.INVARIANT)
-                    return IrBlockBodyImpl(-1, -1, listOf(IrErrorExpressionImpl(-1, -1, errorType, "Statement body is not deserialized yet")))
+                IrBlockBodyImpl(-1, -1, listOf(IrErrorExpressionImpl(-1, -1, errorType, "Statement body is not deserialized yet")))
             }
         }
 
@@ -421,241 +406,106 @@ abstract class KotlinIrLinker(
         }
 
         fun deserializeAllFileReachableTopLevel() {
-                fileLocalDeserializationState.processPendingDeclarations {
+            fileLocalDeserializationState.processPendingDeclarations()
-                    val declaration = deserializeDeclaration(it)
-                    file.declarations.add(declaration)
-                }
-            }
-        }
-
-        private fun deserializeIrFile(fileProto: ProtoFile, fileIndex: Int): IrFile {
-
-            val fileName = fileProto.fileEntry.name
-
-            val fileEntry = NaiveSourceBasedFileEntryImpl(fileName, fileProto.fileEntry.lineStartOffsetsList.toIntArray())
-
-            val fileDeserializer =
-                IrDeserializerForFile(fileProto.annotationList, fileProto.actualsList, fileIndex, !strategy.needBodies).apply {
-
-                    // Explicitly exported declarations (e.g. top-level initializers) must be deserialized before all other declarations.
-                    // Thus we schedule their deserialization in deserializer's constructor.
-                    fileProto.explicitlyExportedToCompilerList.forEach {
-                        val symbolData = parseSymbolData(it)
-                        val sig = deserializeIdSignature(symbolData.signatureId)
-                        assert(!sig.isPackageSignature())
-                        fileLocalDeserializationState.addIdSignature(sig.topLevelSignature())
         }
     }
 
-            val fqName = fileDeserializer.deserializeFqName(fileProto.fqNameList)
+    private val ByteArray.codedInputStream: CodedInputStream
-
-            val packageFragmentDescriptor = EmptyPackageFragmentDescriptor(moduleDescriptor, fqName)
-
-            val symbol = IrFileSymbolImpl(packageFragmentDescriptor)
-            val file = IrFileImpl(fileEntry, symbol, fqName)
-
-            fileDeserializer.file = file
-            fileToDeserializerMap[file] = fileDeserializer
-
-            val fileSignatureIndex = fileProto.declarationIdList.map { fileDeserializer.deserializeIdSignature(it) to it }
-
-            fileSignatureIndex.forEach {
-                moduleReversedFileIndex.getOrPut(it.first) { fileDeserializer }
-            }
-
-            fileDeserializer.reversedSignatureIndex = fileSignatureIndex.toMap()
-
-            if (strategy.theWholeWorld) {
-                for (id in fileSignatureIndex) {
-                    moduleDeserializationState.addIdSignature(id.first)
-                }
-                moduleDeserializationState.enqueueFile(fileDeserializer)
-            } else if (strategy.explicitlyExported) {
-                moduleDeserializationState.enqueueFile(fileDeserializer)
-            }
-
-            return file
-        }
-
-        private fun deserializeIrModuleHeader(): IrModuleFragment {
-            val fileCount = readFileCount(moduleDescriptor)
-
-            val files = ArrayList<IrFile>(fileCount)
-
-            for (i in 0 until fileCount) {
-                files.add(deserializeIrFile(ProtoFile.parseFrom(readFile(moduleDescriptor, i), newInstance()), i))
-            }
-
-            return IrModuleFragmentImpl(moduleDescriptor, builtIns, files)
-        }
-
-        fun deserializeAllModuleReachableTopLevels() {
-            moduleDeserializationState.processPendingDeclarations { fileDeserializer ->
-                fileDeserializer.deserializeFileImplicitDataIfFirstUse()
-                fileDeserializer.deserializeAllFileReachableTopLevel()
-            }
-        }
-
-        fun enqueueModule() {
-            modulesWithReachableTopLevels.add(this)
-        }
-
-        fun addModuleReachableTopLevel(idSig: IdSignature) {
-            moduleDeserializationState.addIdSignature(idSig)
-        }
-    }
-
-    private fun loadKnownBuiltinSymbols() {
-        val globalDeserializedSymbols = globalDeserializationState.deserializedSymbols
-        builtIns.knownBuiltins.forEach {
-            val symbol = (it as IrSymbolOwner).symbol
-            val signature = symbol.signature
-            globalDeserializedSymbols[signature] = symbol
-        }
-    }
-
-    init {
-        loadKnownBuiltinSymbols()
-    }
-
-    private val ByteArray.codedInputStream: org.jetbrains.kotlin.protobuf.CodedInputStream
         get() {
-            val codedInputStream = org.jetbrains.kotlin.protobuf.CodedInputStream.newInstance(this)
+            val codedInputStream = CodedInputStream.newInstance(this)
             codedInputStream.setRecursionLimit(65535) // The default 64 is blatantly not enough for IR.
             return codedInputStream
         }
 
-    protected abstract fun reader(moduleDescriptor: ModuleDescriptor, fileIndex: Int, idSigIndex: Int): ByteArray
+    protected open fun handleNoModuleDeserializerFound(idSignature: IdSignature): IrModuleDeserializer {
-    protected abstract fun readType(moduleDescriptor: ModuleDescriptor, fileIndex: Int, typeIndex: Int): ByteArray
-    protected abstract fun readSignature(moduleDescriptor: ModuleDescriptor, fileIndex: Int, signatureIndex: Int): ByteArray
-    protected abstract fun readString(moduleDescriptor: ModuleDescriptor, fileIndex: Int, stringIndex: Int): ByteArray
-    protected abstract fun readBody(moduleDescriptor: ModuleDescriptor, fileIndex: Int, bodyIndex: Int): ByteArray
-    protected abstract fun readFile(moduleDescriptor: ModuleDescriptor, fileIndex: Int): ByteArray
-    protected abstract fun readFileCount(moduleDescriptor: ModuleDescriptor): Int
-
-    protected open fun handleNoModuleDeserializerFound(idSignature: IdSignature): DeserializationState<*> {
         error("Deserializer for declaration $idSignature is not found")
     }
 
-    protected open fun resolveModuleDeserializer(moduleDescriptor: ModuleDescriptor): IrModuleDeserializer? {
+    protected open fun resolveModuleDeserializer(moduleDescriptor: ModuleDescriptor): IrModuleDeserializer {
-        return deserializersForModules[moduleDescriptor] ?: error("No module deserializer found for $moduleDescriptor")
+        return deserializersForModules[moduleDescriptor] ?:
+        error("No module deserializer found for $moduleDescriptor")
     }
 
     protected abstract fun createModuleDeserializer(
         moduleDescriptor: ModuleDescriptor,
+        klib: IrLibrary?,
         strategy: DeserializationStrategy,
     ): IrModuleDeserializer
 
-    // TODO: the following code worths some refactoring in the nearest future
+    protected abstract val functionalInteraceFactory: IrAbstractFunctionFactory
 
-    private fun isSpecialSignature(idSig: IdSignature): Boolean {
+    protected abstract fun isBuiltInModule(moduleDescriptor: ModuleDescriptor): Boolean
-        return isSpecialPlatformSignature(idSig) || isSpecialFunctionDescriptor(idSig)
+
-    }
+    // TODO: the following code worth some refactoring in the nearest future
-    private fun resolveSpecialSignature(idSig: IdSignature): DeclarationDescriptor? {
+
-        return resolvePlatformDescriptor(idSig) ?: resolveFunctionDescriptor(idSig)
+    private fun handleExpectActualMapping(idSig: IdSignature, rawSymbol: IrSymbol): IrSymbol {
+        val referencingSymbol = if (idSig in expectUniqIdToActualUniqId.keys) {
+            assert(idSig.run { IdSignature.Flags.IS_EXPECT.test() })
+            wrapInDelegatedSymbol(rawSymbol).also { expectSymbols[idSig] = it }
+        } else rawSymbol
+
+        if (idSig in expectUniqIdToActualUniqId.values) {
+            actualSymbols[idSig] = rawSymbol
         }
 
-    protected open fun resolvePlatformDescriptor(idSig: IdSignature): DeclarationDescriptor? = null
+        return referencingSymbol
-    protected open fun isSpecialPlatformSignature(idSig: IdSignature): Boolean = false
-
-    protected open fun postProcessPlatformSpecificDeclaration(idSig: IdSignature, descriptor: DeclarationDescriptor?, block: (IdSignature) -> Unit) {
-
     }
 
-    private fun isSpecialFunctionDescriptor(idSig: IdSignature): Boolean {
+    private fun referenceDeserializedSymbol(symbolKind: BinarySymbolData.SymbolKind, idSig: IdSignature): IrSymbol = symbolTable.run {
-
+        when (symbolKind) {
-        val publicSig = idSig.asPublic() ?: return false
+            BinarySymbolData.SymbolKind.ANONYMOUS_INIT_SYMBOL -> IrAnonymousInitializerSymbolImpl(WrappedClassDescriptor())
-
+            BinarySymbolData.SymbolKind.CLASS_SYMBOL -> referenceClassFromLinker(WrappedClassDescriptor(), idSig)
-        if (publicSig.packageFqn !in functionalPackages) return false
+            BinarySymbolData.SymbolKind.CONSTRUCTOR_SYMBOL -> referenceConstructorFromLinker(WrappedClassConstructorDescriptor(), idSig)
-
+            BinarySymbolData.SymbolKind.TYPE_PARAMETER_SYMBOL -> referenceTypeParameterFromLinker(WrappedTypeParameterDescriptor(), idSig)
-        val declarationFqn = publicSig.declarationFqn
+            BinarySymbolData.SymbolKind.ENUM_ENTRY_SYMBOL -> referenceEnumEntryFromLinker(WrappedEnumEntryDescriptor(), idSig)
-
+            BinarySymbolData.SymbolKind.STANDALONE_FIELD_SYMBOL -> referenceFieldFromLinker(WrappedFieldDescriptor(), idSig)
-        if (declarationFqn.isRoot) return false
+            BinarySymbolData.SymbolKind.FIELD_SYMBOL -> referenceFieldFromLinker(WrappedPropertyDescriptor(), idSig)
-
+            BinarySymbolData.SymbolKind.FUNCTION_SYMBOL -> referenceSimpleFunctionFromLinker(WrappedSimpleFunctionDescriptor(), idSig)
-        val fqnParts = declarationFqn.pathSegments()
+            BinarySymbolData.SymbolKind.TYPEALIAS_SYMBOL -> referenceTypeAliasFromLinker(WrappedTypeAliasDescriptor(), idSig)
-
+            BinarySymbolData.SymbolKind.PROPERTY_SYMBOL -> referencePropertyFromLinker(WrappedPropertyDescriptor(), idSig)
-        val className = fqnParts.first()
+            BinarySymbolData.SymbolKind.VARIABLE_SYMBOL -> IrVariableSymbolImpl(WrappedVariableDescriptor())
-
+            BinarySymbolData.SymbolKind.VALUE_PARAMETER_SYMBOL -> IrValueParameterSymbolImpl(WrappedValueParameterDescriptor())
-        return functionPattern.matcher(className.asString()).find()
+            BinarySymbolData.SymbolKind.RECEIVER_PARAMETER_SYMBOL -> IrValueParameterSymbolImpl(WrappedReceiverParameterDescriptor())
-    }
+            BinarySymbolData.SymbolKind.LOCAL_DELEGATED_PROPERTY_SYMBOL ->
-
+                IrLocalDelegatedPropertySymbolImpl(WrappedVariableDescriptorWithAccessor())
-    private fun resolveFunctionDescriptor(idSig: IdSignature): DeclarationDescriptor? {
+            else -> error("Unexpected classifier symbol kind: $symbolKind for signature $idSig")
-        if (isSpecialFunctionDescriptor(idSig)) {
-            val publicSig = idSig.asPublic() ?: error("$idSig has to be public")
-
-            val fqnParts = publicSig.declarationFqn.pathSegments()
-            val className = fqnParts.first()
-            val classDescriptor = builtIns.builtIns.getBuiltInClassByFqName(publicSig.packageFqn.child(className))
-
-            fun findMemberDescriptor(): DeclarationDescriptor {
-                val memberName = fqnParts[1]!!
-                val memberDescriptors = classDescriptor.unsubstitutedMemberScope.getContributedDescriptors(DescriptorKindFilter.CALLABLES).filter { d -> d.name == memberName }
-
-                return memberDescriptors.single()
-            }
-            return when (fqnParts.size) {
-                1 -> classDescriptor
-                2 -> findMemberDescriptor()
-                3 -> {
-                    assert(idSig is IdSignature.AccessorSignature)
-                    val propertyDescriptor = findMemberDescriptor() as PropertyDescriptor
-                    val accessorName = fqnParts[2]
-                    propertyDescriptor.accessors.single { it.name == accessorName }
-                }
-                else -> error("No member found for signature $idSig")
         }
     }
 
-        return null
-    }
-
-    /**
-     * Check that descriptor shouldn't be processed by some backend-specific logic.
-     * For example, it is the case for Native interop libraries where there is no IR in libraries.
-     */
-    protected open fun IdSignature.shouldBeDeserialized(): Boolean = true
-
     private fun deserializeAllReachableTopLevels() {
-        do {
+        while (modulesWithReachableTopLevels.isNotEmpty()) {
             val moduleDeserializer = modulesWithReachableTopLevels.first()
             modulesWithReachableTopLevels.remove(moduleDeserializer)
 
-            moduleDeserializer.deserializeAllModuleReachableTopLevels()
+            moduleDeserializer.deserializeReachableDeclarations()
-        } while (modulesWithReachableTopLevels.isNotEmpty())
+        }
     }
 
     private fun findDeserializedDeclarationForSymbol(symbol: IrSymbol): DeclarationDescriptor? {
-        require(symbol.isPublicApi)
+        assert(symbol.isPublicApi || symbol.descriptor.module === currentModule || platformSpecificSymbol(symbol))
-
-        val signature = symbol.signature
-
-        // This is Native specific. Try to eliminate.
-        if (!signature.shouldBeDeserialized()) return null
 
         val descriptor = symbol.descriptor
 
-        /*
+        val moduleDeserializer = resolveModuleDeserializer(descriptor.module)
-            Wrapped descriptors come from inside IrLinker. If a symbol with such a descriptor ends up here, this means we
-            have already looked for it in IrLinker and failed.
-         */
-        if (descriptor is WrappedDeclarationDescriptor<*>) return null
 
-        if (descriptor is FunctionClassDescriptor || (descriptor.containingDeclaration is FunctionClassDescriptor)) {
+//        moduleDeserializer.deserializeIrSymbol(signature, symbol.kind())
-            return null
+        moduleDeserializer.declareIrSymbol(symbol)
-        }
-
-        val topLevelSignature = signature.topLevelSignature()
-        val moduleDeserializer = resolveModuleDeserializer(descriptor.module) ?: return null
-
-        moduleDeserializer.addModuleReachableTopLevel(topLevelSignature)
 
         deserializeAllReachableTopLevels()
         return descriptor
     }
 
+    protected open fun platformSpecificSymbol(symbol: IrSymbol): Boolean = false
+
     override fun getDeclaration(symbol: IrSymbol): IrDeclaration? {
 
-        if (!symbol.isPublicApi) return null
+        if (!symbol.isPublicApi) {
+            val descriptor = symbol.descriptor
+            if (descriptor is WrappedDeclarationDescriptor<*>) return null
+            if (!platformSpecificSymbol(symbol)) {
+                if (descriptor.module !== currentModule) return null
+            }
+        }
 
         if (!symbol.isBound) {
             findDeserializedDeclarationForSymbol(symbol) ?: return null
@@ -672,54 +522,31 @@ abstract class KotlinIrLinker(
         return symbol.owner as IrDeclaration
     }
 
-    // TODO: This is Native specific. Eliminate me.
+    protected open fun createCurrentModuleDeserializer(moduleFragment: IrModuleFragment, dependencies: Collection<IrModuleDeserializer>, extensions: Collection<IrExtensionGenerator>): IrModuleDeserializer =
-    override fun declareForwardDeclarations() {
+        CurrentModuleDeserializer(moduleFragment, dependencies, symbolTable, extensions)
-        if (forwardModuleDescriptor == null) return
 
-        val packageFragments = forwardDeclarations.map { it.descriptor.findPackage() }.distinct()
+    override fun init(moduleFragment: IrModuleFragment?, extensions: Collection<IrExtensionGenerator>) {
-
+        if (moduleFragment != null) {
-        // We don't bother making a real IR module here, as we have no need in it any later.
+            val currentModuleDependencies = moduleFragment.descriptor.allDependencyModules.map {
-        // All we need is just to declare forward declarations in the symbol table
+                deserializersForModules[it] ?: error("No deserializer found for $it")
-        // In case you need a full fledged module, turn the forEach into a map and collect
-        // produced files into an IrModuleFragment.
-
-        packageFragments.forEach { packageFragment ->
-            val symbol = IrFileSymbolImpl(packageFragment)
-            val file = IrFileImpl(NaiveSourceBasedFileEntryImpl("forward declarations pseudo-file"), symbol)
-            val symbols = forwardDeclarations
-                .filter { !it.isBound }
-                .filter { it.descriptor.findPackage() == packageFragment }
-            val declarations = symbols.map {
-
-                val classDescriptor = it.descriptor as ClassDescriptor
-                val declaration = symbolTable.declareClass(
-                    UNDEFINED_OFFSET, UNDEFINED_OFFSET, irrelevantOrigin,
-                    classDescriptor,
-                    classDescriptor.modality
-                ) { symbol: IrClassSymbol -> IrClassImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET, irrelevantOrigin, symbol) }
-                    .also {
-                        it.parent = file
             }
-                declaration
+            val currentModuleDeserializer = createCurrentModuleDeserializer(moduleFragment, currentModuleDependencies, extensions)
-
+            deserializersForModules[moduleFragment.descriptor] =
-            }
+                maybeWrapWithBuiltInAndInit(moduleFragment.descriptor, currentModuleDeserializer)
-            file.declarations.addAll(declarations)
         }
+        deserializersForModules.values.forEach { it.init() }
     }
 
-    fun initializeExpectActualLinker() {
+    fun postProcess() {
-        deserializersForModules.values.forEach {
+        deserializersForModules.values.forEach { it.postProcess() }
-            it.fileToDeserializerMap.values.forEach {
+        finalizeExpectActualLinker()
-                it.deserializeExpectActualMapping()
-            }
-        }
     }
 
     // The issue here is that an expect can not trigger its actual deserialization by reachability
     // because the expect can not see the actual higher in the module dependency dag.
     // So we force deserialization of actuals for all deserialized expect symbols here.
-    fun finalizeExpectActualLinker() {
+    private fun finalizeExpectActualLinker() {
-        expectUniqIdToActualUniqId.filter{ topLevelActualUniqItToDeserializer[it.value] != null}.forEach {
+        expectUniqIdToActualUniqId.filter { topLevelActualUniqItToDeserializer[it.value] != null }.forEach {
             val expectSymbol = expectSymbols[it.key]
             val actualSymbol = actualSymbols[it.value]
             if (expectSymbol != null && (actualSymbol == null || !actualSymbol.isBound)) {
@@ -752,16 +579,24 @@ abstract class KotlinIrLinker(
 
     fun deserializeIrModuleHeader(
         moduleDescriptor: ModuleDescriptor,
+        kotlinLibrary: KotlinLibrary?,
         deserializationStrategy: DeserializationStrategy = DeserializationStrategy.ONLY_REFERENCED
     ): IrModuleFragment {
         val deserializerForModule = deserializersForModules.getOrPut(moduleDescriptor) {
-            createModuleDeserializer(moduleDescriptor, deserializationStrategy)
+            maybeWrapWithBuiltInAndInit(moduleDescriptor, createModuleDeserializer(moduleDescriptor, kotlinLibrary, deserializationStrategy))
         }
         // The IrModule and its IrFiles have been created during module initialization.
-        return deserializerForModule.module
+        return deserializerForModule.moduleFragment
     }
 
-    fun deserializeIrModuleHeader(moduleDescriptor: ModuleDescriptor): IrModuleFragment? {
+    private fun maybeWrapWithBuiltInAndInit(
+        moduleDescriptor: ModuleDescriptor,
+        moduleDeserializer: IrModuleDeserializer
+    ): IrModuleDeserializer =
+        if (isBuiltInModule(moduleDescriptor)) IrModuleDeserializerWithBuiltIns(builtIns, functionalInteraceFactory, moduleDeserializer)
+        else moduleDeserializer
+
+    fun deserializeIrModuleHeader(moduleDescriptor: ModuleDescriptor, kotlinLibrary: KotlinLibrary?): IrModuleFragment {
         // TODO: consider skip deserializing explicitly exported declarations for libraries.
         // Now it's not valid because of all dependencies that must be computed.
         val deserializationStrategy =
@@ -770,23 +605,23 @@ abstract class KotlinIrLinker(
             } else {
                 DeserializationStrategy.EXPLICITLY_EXPORTED
             }
-        return deserializeIrModuleHeader(moduleDescriptor, deserializationStrategy)
+        return deserializeIrModuleHeader(moduleDescriptor, kotlinLibrary, deserializationStrategy)
     }
 
-    fun deserializeFullModule(moduleDescriptor: ModuleDescriptor): IrModuleFragment =
+    fun deserializeFullModule(moduleDescriptor: ModuleDescriptor, kotlinLibrary: KotlinLibrary?): IrModuleFragment =
-        deserializeIrModuleHeader(moduleDescriptor, DeserializationStrategy.ALL)
+        deserializeIrModuleHeader(moduleDescriptor, kotlinLibrary, DeserializationStrategy.ALL)
 
-    fun deserializeOnlyHeaderModule(moduleDescriptor: ModuleDescriptor): IrModuleFragment =
+    fun deserializeOnlyHeaderModule(moduleDescriptor: ModuleDescriptor, kotlinLibrary: KotlinLibrary?): IrModuleFragment =
-        deserializeIrModuleHeader(moduleDescriptor, DeserializationStrategy.ONLY_DECLARATION_HEADERS)
+        deserializeIrModuleHeader(moduleDescriptor, kotlinLibrary, DeserializationStrategy.ONLY_DECLARATION_HEADERS)
 
-    fun getAllIrFiles(): List<IrFile> {
+    fun deserializeHeadersWithInlineBodies(moduleDescriptor: ModuleDescriptor, kotlinLibrary: KotlinLibrary?): IrModuleFragment =
-        return deserializersForModules.values.flatMap { it.module.files }
+        deserializeIrModuleHeader(moduleDescriptor, kotlinLibrary, DeserializationStrategy.WITH_INLINE_BODIES)
-    }
 }
 
-enum class DeserializationStrategy(val needBodies: Boolean, val explicitlyExported: Boolean, val theWholeWorld: Boolean) {
+enum class DeserializationStrategy(val needBodies: Boolean, val explicitlyExported: Boolean, val theWholeWorld: Boolean, val inlineBodies: Boolean) {
-    ONLY_REFERENCED(true, false, false),
+    ONLY_REFERENCED(true, false, false, true),
-    ALL(true, true, true),
+    ALL(true, true, true, true),
-    EXPLICITLY_EXPORTED(true, true, false),
+    EXPLICITLY_EXPORTED(true, true, false, true),
-    ONLY_DECLARATION_HEADERS(false, false, false)
+    ONLY_DECLARATION_HEADERS(false, false, false, false),
+    WITH_INLINE_BODIES(false, false, false, true)
 }

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

@@ -102,6 +102,7 @@ fun generateKLib(
     val incrementalDataProvider = configuration.get(JSConfigurationKeys.INCREMENTAL_DATA_PROVIDER)
 
     val icData: List<KotlinFileSerializedData>
+    val serializedIrFiles: List<SerializedIrFile>?
 
     if (incrementalDataProvider != null) {
         val nonCompiledSources = files.map { VfsUtilCore.virtualToIoFile(it.virtualFile) to it }.toMap()
@@ -124,8 +125,10 @@ fun generateKLib(
         }
 
         icData = storage
+        serializedIrFiles = storage.map { it.irData }
     } else {
         icData = emptyList()
+        serializedIrFiles = null
     }
 
     val depsDescriptors =
@@ -135,8 +138,13 @@ fun generateKLib(
 
     val expectDescriptorToSymbol = mutableMapOf<DeclarationDescriptor, IrSymbol>()
 
-    val moduleFragment = psi2IrContext.generateModuleFragmentWithPlugins(project, files,
+    val irLinker = JsIrLinker(psi2IrContext.moduleDescriptor, emptyLoggingContext, psi2IrContext.irBuiltIns, psi2IrContext.symbolTable, serializedIrFiles)
-        deserializer = null, expectDescriptorToSymbol = expectDescriptorToSymbol)
+
+    val deserializedModuleFragments = sortDependencies(allDependencies.getFullList(), depsDescriptors.descriptors).map {
+        irLinker.deserializeOnlyHeaderModule(depsDescriptors.getModuleDescriptor(it), it)
+    }
+
+    val moduleFragment = psi2IrContext.generateModuleFragmentWithPlugins(project, files, irLinker, expectDescriptorToSymbol)
 
     moduleFragment.acceptVoid(ManglerChecker(JsManglerIr, Ir2DescriptorManglerAdapter(JsManglerDesc)))
 
@@ -193,22 +201,20 @@ fun loadIr(
             val irBuiltIns = psi2IrContext.irBuiltIns
             val symbolTable = psi2IrContext.symbolTable
 
-            val deserializer = JsIrLinker(emptyLoggingContext, irBuiltIns, symbolTable)
+            val irLinker = JsIrLinker(psi2IrContext.moduleDescriptor, emptyLoggingContext, irBuiltIns, symbolTable, null)
 
             val deserializedModuleFragments = sortDependencies(allDependencies.getFullList(), depsDescriptors.descriptors).map {
-                deserializer.deserializeIrModuleHeader(depsDescriptors.getModuleDescriptor(it))!!
+                irLinker.deserializeIrModuleHeader(depsDescriptors.getModuleDescriptor(it), it)
             }
 
-            deserializer.initializeExpectActualLinker()
+            val moduleFragment = psi2IrContext.generateModuleFragmentWithPlugins(project, mainModule.files, irLinker)
-
-            val moduleFragment = psi2IrContext.generateModuleFragmentWithPlugins(project, mainModule.files, deserializer)
 
             // TODO: not sure whether this check should be enabled by default. Add configuration key for it.
             val mangleChecker = ManglerChecker(JsManglerIr, Ir2DescriptorManglerAdapter(JsManglerDesc))
             moduleFragment.acceptVoid(mangleChecker)
             irBuiltIns.knownBuiltins.forEach { it.acceptVoid(mangleChecker) }
 
-            return IrModuleInfo(moduleFragment, deserializedModuleFragments, irBuiltIns, symbolTable, deserializer)
+            return IrModuleInfo(moduleFragment, deserializedModuleFragments, irBuiltIns, symbolTable, irLinker)
         }
         is MainModule.Klib -> {
             val moduleDescriptor = depsDescriptors.getModuleDescriptor(mainModule.lib)
@@ -224,7 +230,7 @@ fun loadIr(
             typeTranslator.constantValueGenerator = constantValueGenerator
             constantValueGenerator.typeTranslator = typeTranslator
             val irBuiltIns = IrBuiltIns(moduleDescriptor.builtIns, typeTranslator, signaturer, symbolTable)
-            val deserializer = JsIrLinker(emptyLoggingContext, irBuiltIns, symbolTable)
+            val irLinker = JsIrLinker(null, emptyLoggingContext, irBuiltIns, symbolTable, null)
 
             val deserializedModuleFragments = sortDependencies(allDependencies.getFullList(), depsDescriptors.descriptors).map {
                 val strategy =
@@ -233,16 +239,16 @@ fun loadIr(
                     else
                         DeserializationStrategy.EXPLICITLY_EXPORTED
 
-                deserializer.deserializeIrModuleHeader(depsDescriptors.getModuleDescriptor(it), strategy)
+                irLinker.deserializeIrModuleHeader(depsDescriptors.getModuleDescriptor(it), it, strategy)
             }
-            deserializer.initializeExpectActualLinker()
+
             val moduleFragment = deserializedModuleFragments.last()
 
-            val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
+            irLinker.init(null, emptyList())
-            ExternalDependenciesGenerator(symbolTable, irProviders, configuration.languageVersionSettings)
+            ExternalDependenciesGenerator(symbolTable, listOf(irLinker), configuration.languageVersionSettings).generateUnboundSymbolsAsDependencies()
-                .generateUnboundSymbolsAsDependencies()
+            irLinker.postProcess()
 
-            return IrModuleInfo(moduleFragment, deserializedModuleFragments, irBuiltIns, symbolTable, deserializer)
+            return IrModuleInfo(moduleFragment, deserializedModuleFragments, irBuiltIns, symbolTable, irLinker)
         }
     }
 }
@@ -266,14 +272,15 @@ private fun runAnalysisAndPreparePsi2Ir(depsDescriptors: ModulesStructure): Gene
 fun GeneratorContext.generateModuleFragmentWithPlugins(
     project: Project,
     files: List<KtFile>,
-    deserializer: IrDeserializer? = null,
+    irLinker: IrDeserializer,
     expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>? = null
 ): IrModuleFragment {
-    val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
     val signaturer = IdSignatureDescriptor(JsManglerDesc)
     val psi2Ir = Psi2IrTranslator(languageVersionSettings, configuration, signaturer)
 
-    for (extension in IrGenerationExtension.getInstances(project)) {
+    val extensions = IrGenerationExtension.getInstances(project)
+
+    for (extension in extensions) {
         psi2Ir.addPostprocessingStep { module ->
             extension.generate(
                 module,
@@ -289,26 +296,9 @@ fun GeneratorContext.generateModuleFragmentWithPlugins(
         }
     }
 
-    val moduleFragment =
+    return psi2Ir.generateModuleFragment(this, files, listOf(irLinker), expectDescriptorToSymbol, extensions)
-        psi2Ir.generateModuleFragment(
-            this,
-            files,
-            irProviders,
-            expectDescriptorToSymbol
-        )
-    return moduleFragment
 }
 
-fun GeneratorContext.generateModuleFragment(files: List<KtFile>, deserializer: IrDeserializer? = null, expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>? = null): IrModuleFragment {
-    val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer)
-    val mangler = JsManglerDesc
-    val signaturer = IdSignatureDescriptor(mangler)
-    return Psi2IrTranslator(
-        languageVersionSettings, configuration, signaturer
-    ).generateModuleFragment(this, files, irProviders, expectDescriptorToSymbol)
-}
-
-
 private fun createBuiltIns(storageManager: StorageManager) = object : KotlinBuiltIns(storageManager) {}
 internal val JsFactories = KlibMetadataFactories(::createBuiltIns, DynamicTypeDeserializer)
 

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

@@ -6,40 +6,45 @@
 package org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir
 
 import org.jetbrains.kotlin.backend.common.LoggingContext
+import org.jetbrains.kotlin.backend.common.serialization.CurrentModuleWithICDeserializer
 import org.jetbrains.kotlin.backend.common.serialization.DeserializationStrategy
+import org.jetbrains.kotlin.backend.common.serialization.IrModuleDeserializer
 import org.jetbrains.kotlin.backend.common.serialization.KotlinIrLinker
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.konan.kotlinLibrary
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
+import org.jetbrains.kotlin.ir.descriptors.IrAbstractFunctionFactory
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.descriptors.IrFunctionFactory
+import org.jetbrains.kotlin.ir.util.IrExtensionGenerator
 import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.SerializedIrFile
 
-class JsIrLinker(logger: LoggingContext, builtIns: IrBuiltIns, symbolTable: SymbolTable) :
+class JsIrLinker(currentModule: ModuleDescriptor?, logger: LoggingContext, builtIns: IrBuiltIns, symbolTable: SymbolTable, private val icData: List<SerializedIrFile>? = null) :
-    KotlinIrLinker(logger, builtIns, symbolTable, emptyList(), null) {
+    KotlinIrLinker(currentModule, logger, builtIns, symbolTable, emptyList()) {
 
-    override fun reader(moduleDescriptor: ModuleDescriptor, fileIndex: Int, idSigIndex: Int) =
+    override val functionalInteraceFactory: IrAbstractFunctionFactory = IrFunctionFactory(builtIns, symbolTable)
-        moduleDescriptor.kotlinLibrary.irDeclaration(idSigIndex, fileIndex)
 
-    override fun readType(moduleDescriptor: ModuleDescriptor, fileIndex: Int, typeIndex: Int) =
+    override fun isBuiltInModule(moduleDescriptor: ModuleDescriptor): Boolean =
-        moduleDescriptor.kotlinLibrary.type(typeIndex, fileIndex)
+        moduleDescriptor === moduleDescriptor.builtIns.builtInsModule
 
-    override fun readSignature(moduleDescriptor: ModuleDescriptor, fileIndex: Int, signatureIndex: Int) =
+    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer =
-        moduleDescriptor.kotlinLibrary.signature(signatureIndex, fileIndex)
+        JsModuleDeserializer(moduleDescriptor, klib ?: error("Expecting kotlin library"), strategy)
 
-    override fun readString(moduleDescriptor: ModuleDescriptor, fileIndex: Int, stringIndex: Int) =
+    private inner class JsModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, strategy: DeserializationStrategy) :
-        moduleDescriptor.kotlinLibrary.string(stringIndex, fileIndex)
+        KotlinIrLinker.BasicIrModuleDeserializer(moduleDescriptor, klib, strategy)
 
-    override fun readBody(moduleDescriptor: ModuleDescriptor, fileIndex: Int, bodyIndex: Int) =
+    override fun createCurrentModuleDeserializer(
-        moduleDescriptor.kotlinLibrary.body(bodyIndex, fileIndex)
+        moduleFragment: IrModuleFragment,
-
+        dependencies: Collection<IrModuleDeserializer>,
-    override fun readFile(moduleDescriptor: ModuleDescriptor, fileIndex: Int) =
+        extensions: Collection<IrExtensionGenerator>
-        moduleDescriptor.kotlinLibrary.file(fileIndex)
+    ): IrModuleDeserializer {
-
+        val currentModuleDeserializer = super.createCurrentModuleDeserializer(moduleFragment, dependencies, extensions)
-    override fun readFileCount(moduleDescriptor: ModuleDescriptor) =
+        icData?.let {
-        moduleDescriptor.kotlinLibrary.fileCount()
+            return CurrentModuleWithICDeserializer(currentModuleDeserializer, symbolTable, builtIns, it) { lib ->
-
+                JsModuleDeserializer(currentModuleDeserializer.moduleDescriptor, lib, currentModuleDeserializer.strategy)
-    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, strategy: DeserializationStrategy): IrModuleDeserializer =
+            }
-        JsModuleDeserializer(moduleDescriptor, strategy)
+        }
-
+        return currentModuleDeserializer
-    private inner class JsModuleDeserializer(moduleDescriptor: ModuleDescriptor, strategy: DeserializationStrategy) :
+    }
-        KotlinIrLinker.IrModuleDeserializer(moduleDescriptor, strategy)
 }

compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt

@@ -6,51 +6,146 @@
 package org.jetbrains.kotlin.ir.backend.jvm.serialization
 
 import org.jetbrains.kotlin.backend.common.LoggingContext
-import org.jetbrains.kotlin.backend.common.serialization.DeserializationStrategy
+import org.jetbrains.kotlin.backend.common.serialization.*
-import org.jetbrains.kotlin.backend.common.serialization.KotlinIrLinker
+import org.jetbrains.kotlin.backend.common.serialization.encodings.BinarySymbolData
-import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.konan.kotlinLibrary
+import org.jetbrains.kotlin.descriptors.konan.KlibModuleOrigin
-import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.declarations.IrField
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
+import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
+import org.jetbrains.kotlin.ir.descriptors.*
+import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
+import org.jetbrains.kotlin.ir.util.DeclarationStubGenerator
 import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.ir.util.IrExtensionGenerator
 import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.load.java.descriptors.*
+import org.jetbrains.kotlin.load.java.lazy.descriptors.LazyJavaPackageFragment
+import org.jetbrains.kotlin.name.Name
 
-class JvmIrLinker(logger: LoggingContext, builtIns: IrBuiltIns, symbolTable: SymbolTable) :
+class JvmIrLinker(currentModule: ModuleDescriptor?, logger: LoggingContext, builtIns: IrBuiltIns, symbolTable: SymbolTable, private val stubGenerator: DeclarationStubGenerator, private val manglerDesc: JvmManglerDesc) :
-    KotlinIrLinker(logger, builtIns, symbolTable, emptyList(), null) {
+    KotlinIrLinker(currentModule, logger, builtIns, symbolTable, emptyList()) {
 
-    override fun handleNoModuleDeserializerFound(idSignature: IdSignature): DeserializationState<*> {
+    override val functionalInteraceFactory: IrAbstractFunctionFactory = IrFunctionFactory(builtIns, symbolTable)
-        // TODO: Implement special java-module deserializer instead of this hack
-        return globalDeserializationState // !!!!!! Wrong, as external references will all have UniqId.NONE
-    }
 
-    override fun reader(moduleDescriptor: ModuleDescriptor, fileIndex: Int, idSigIndex: Int) =
+    private val javaName = Name.identifier("java")
-        moduleDescriptor.kotlinLibrary.irDeclaration(idSigIndex, fileIndex)
 
-    override fun readType(moduleDescriptor: ModuleDescriptor, fileIndex: Int, typeIndex: Int) =
+    override fun isBuiltInModule(moduleDescriptor: ModuleDescriptor): Boolean =
-        moduleDescriptor.kotlinLibrary.type(typeIndex, fileIndex)
+        moduleDescriptor.name.asString() == "<built-ins module>"
-
-    override fun readSignature(moduleDescriptor: ModuleDescriptor, fileIndex: Int, signatureIndex: Int) =
-        moduleDescriptor.kotlinLibrary.signature(signatureIndex, fileIndex)
-
-    override fun readString(moduleDescriptor: ModuleDescriptor, fileIndex: Int, stringIndex: Int) =
-        moduleDescriptor.kotlinLibrary.string(stringIndex, fileIndex)
-
-    override fun readBody(moduleDescriptor: ModuleDescriptor, fileIndex: Int, bodyIndex: Int) =
-        moduleDescriptor.kotlinLibrary.body(bodyIndex, fileIndex)
-
-    override fun readFile(moduleDescriptor: ModuleDescriptor, fileIndex: Int) =
-        moduleDescriptor.kotlinLibrary.file(fileIndex)
-
-    override fun readFileCount(moduleDescriptor: ModuleDescriptor) =
-        moduleDescriptor.kotlinLibrary.fileCount()
-
-    override fun resolveModuleDeserializer(moduleDescriptor: ModuleDescriptor): IrModuleDeserializer? {
-        return deserializersForModules[moduleDescriptor]
-    }
 
     // TODO: implement special Java deserializer
-    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, strategy: DeserializationStrategy): IrModuleDeserializer =
+    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer {
-        JvmModuleDeserializer(moduleDescriptor, strategy)
+        if (klib != null) {
+            assert(moduleDescriptor.getCapability(KlibModuleOrigin.CAPABILITY) != null)
+            return JvmModuleDeserializer(moduleDescriptor, klib, strategy)
+        }
 
-    private inner class JvmModuleDeserializer(moduleDescriptor: ModuleDescriptor, strategy: DeserializationStrategy) :
+        return MetadataJVMModuleDeserializer(moduleDescriptor, emptyList())
-        KotlinIrLinker.IrModuleDeserializer(moduleDescriptor, strategy)
+    }
+
+    private inner class JvmModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, strategy: DeserializationStrategy) :
+        KotlinIrLinker.BasicIrModuleDeserializer(moduleDescriptor, klib, strategy)
+
+    private fun DeclarationDescriptor.isJavaDescriptor(): Boolean {
+        if (this is PackageFragmentDescriptor) {
+            return this is LazyJavaPackageFragment || fqName.startsWith(javaName)
+        }
+
+        return this is JavaClassDescriptor || this is JavaCallableMemberDescriptor || (containingDeclaration?.isJavaDescriptor() == true)
+    }
+
+    private fun DeclarationDescriptor.isCleanDescriptor(): Boolean {
+        if (this is PropertyAccessorDescriptor) return correspondingProperty.isCleanDescriptor()
+        return this is DeserializedDescriptor
+    }
+
+    override fun platformSpecificSymbol(symbol: IrSymbol): Boolean {
+        return symbol.descriptor.isJavaDescriptor()
+    }
+
+    private fun declareJavaFieldStub(symbol: IrFieldSymbol): IrField {
+        return with(stubGenerator) {
+            val old = stubGenerator.unboundSymbolGeneration
+            try {
+                stubGenerator.unboundSymbolGeneration = true
+                generateFieldStub(symbol.descriptor)
+            } finally {
+                stubGenerator.unboundSymbolGeneration = old
+            }
+        }
+    }
+
+
+    override fun createCurrentModuleDeserializer(moduleFragment: IrModuleFragment, dependencies: Collection<IrModuleDeserializer>, extensions: Collection<IrExtensionGenerator>): IrModuleDeserializer =
+        JvmCurrentModuleDeserializer(moduleFragment, dependencies, extensions)
+
+    private inner class JvmCurrentModuleDeserializer(moduleFragment: IrModuleFragment, dependencies: Collection<IrModuleDeserializer>, extensions: Collection<IrExtensionGenerator>) :
+        CurrentModuleDeserializer(moduleFragment, dependencies, symbolTable, extensions) {
+        override fun declareIrSymbol(symbol: IrSymbol) {
+            val descriptor = symbol.descriptor
+
+            if (descriptor.isJavaDescriptor()) {
+                // Wrap java declaration with lazy ir
+                if (symbol is IrFieldSymbol) {
+                    declareJavaFieldStub(symbol)
+                } else {
+                    stubGenerator.generateMemberStub(descriptor)
+                }
+                return
+            }
+
+            if (descriptor.isCleanDescriptor()) {
+                stubGenerator.generateMemberStub(descriptor)
+                return
+            }
+
+            super.declareIrSymbol(symbol)
+        }
+    }
+
+    private inner class MetadataJVMModuleDeserializer(moduleDescriptor: ModuleDescriptor, dependencies: List<IrModuleDeserializer>) :
+        IrModuleDeserializer(moduleDescriptor) {
+
+        // TODO: implement proper check whether `idSig` belongs to this module
+        override fun contains(idSig: IdSignature): Boolean = true
+
+        private val descriptorFinder = DescriptorByIdSignatureFinder(moduleDescriptor, manglerDesc)
+
+        private fun resolveDescriptor(idSig: IdSignature): DeclarationDescriptor {
+            return descriptorFinder.findDescriptorBySignature(idSig) ?: error("No descriptor found for $idSig")
+        }
+
+        override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
+            val descriptor = resolveDescriptor(idSig)
+
+            val declaration = stubGenerator.run {
+                when (symbolKind) {
+                    BinarySymbolData.SymbolKind.CLASS_SYMBOL -> generateClassStub(descriptor as ClassDescriptor)
+                    BinarySymbolData.SymbolKind.PROPERTY_SYMBOL -> generatePropertyStub(descriptor as PropertyDescriptor)
+                    BinarySymbolData.SymbolKind.FUNCTION_SYMBOL -> generateFunctionStub(descriptor as FunctionDescriptor)
+                    BinarySymbolData.SymbolKind.CONSTRUCTOR_SYMBOL -> generateConstructorStub(descriptor as ClassConstructorDescriptor)
+                    BinarySymbolData.SymbolKind.ENUM_ENTRY_SYMBOL -> generateEnumEntryStub(descriptor as ClassDescriptor)
+                    BinarySymbolData.SymbolKind.TYPEALIAS_SYMBOL -> generateTypeAliasStub(descriptor as TypeAliasDescriptor)
+                    else -> error("Unexpected type $symbolKind for sig $idSig")
+                }
+            }
+
+            return declaration.symbol
+        }
+
+        override fun declareIrSymbol(symbol: IrSymbol) {
+            assert(symbol.isPublicApi || symbol.descriptor.isJavaDescriptor())
+            if (symbol is IrFieldSymbol) {
+                declareJavaFieldStub(symbol)
+            } else {
+                stubGenerator.generateMemberStub(symbol.descriptor)
+            }
+        }
+
+        override val moduleFragment: IrModuleFragment = IrModuleFragmentImpl(moduleDescriptor, builtIns, emptyList())
+        override val moduleDependencies: Collection<IrModuleDeserializer> = dependencies
+
+    }
 }

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/repl/js/JsCoreScriptingCompiler.kt

@@ -18,7 +18,6 @@ import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.generateJsCode
-import org.jetbrains.kotlin.ir.backend.js.generateModuleFragment
 import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerDesc
 import org.jetbrains.kotlin.ir.backend.js.utils.NameTables
 import org.jetbrains.kotlin.ir.util.ExternalDependenciesGenerator
@@ -58,14 +57,15 @@ class JsCoreScriptingCompiler(
             if (messageCollector.hasErrors()) return ReplCompileResult.Error("Error while analysis")
         }
 
+        val files = listOf(snippetKtFile)
         val module = analysisResult.moduleDescriptor
         val bindingContext = analysisResult.bindingContext
         val mangler = JsManglerDesc
         val signaturer = IdSignatureDescriptor(mangler)
         val psi2ir = Psi2IrTranslator(environment.configuration.languageVersionSettings, signaturer = signaturer)
         val psi2irContext = psi2ir.createGeneratorContext(module, bindingContext, symbolTable)
-
+        val providers = generateTypicalIrProviderList(module, psi2irContext.irBuiltIns, psi2irContext.symbolTable)
-        val irModuleFragment = psi2irContext.generateModuleFragment(listOf(snippetKtFile))
+        val irModuleFragment = psi2ir.generateModuleFragment(psi2irContext, files, providers, null) // TODO: deserializer
 
         val context = JsIrBackendContext(
             irModuleFragment.descriptor,

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/repl/js/JsScriptDependencyCompiler.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.descriptors.PackageFragmentProvider
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
+import org.jetbrains.kotlin.descriptors.konan.kotlinLibrary
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.backend.js.emptyLoggingContext
 import org.jetbrains.kotlin.ir.backend.js.generateJsCode
@@ -49,10 +50,10 @@ class JsScriptDependencyCompiler(
 
         val signaturer = IdSignatureDescriptor(JsManglerDesc)
         val irBuiltIns = IrBuiltIns(builtIns, typeTranslator, signaturer, symbolTable)
-        val jsLinker = JsIrLinker(emptyLoggingContext, irBuiltIns, symbolTable)
+        val jsLinker = JsIrLinker(null, emptyLoggingContext, irBuiltIns, symbolTable, null)
 
         val moduleFragment = IrModuleFragmentImpl(moduleDescriptor, irBuiltIns)
-        val irDependencies = dependencies.map { jsLinker.deserializeFullModule(it) }
+        val irDependencies = dependencies.map { jsLinker.deserializeFullModule(it, it.kotlinLibrary) }
         val irProviders = generateTypicalIrProviderList(moduleDescriptor, irBuiltIns, symbolTable, deserializer = jsLinker)
 
         ExternalDependenciesGenerator(symbolTable, irProviders, configuration.languageVersionSettings)