diff --git a/compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirJvmKotlinMangler.kt b/compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirJvmKotlinMangler.kt
index dc4621b2a2d..41a13752d7b 100644
--- a/compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirJvmKotlinMangler.kt
+++ b/compiler/fir/fir2ir/jvm-backend/src/org/jetbrains/kotlin/fir/backend/jvm/FirJvmKotlinMangler.kt
@@ -14,18 +14,15 @@ import org.jetbrains.kotlin.fir.signaturer.FirMangler
 @NoMutableState
 class FirJvmKotlinMangler(private val session: FirSession) : AbstractKotlinMangler<FirDeclaration>(), FirMangler {
 
-    override val FirDeclaration.mangleString: String
-        get() = getMangleComputer(MangleMode.FULL).computeMangle(this)
+    override fun FirDeclaration.mangleString(): String = getMangleComputer(MangleMode.FULL).computeMangle(this)
 
-    override val FirDeclaration.signatureString: String
-        get() = getMangleComputer(MangleMode.SIGNATURE).computeMangle(this)
+    override fun FirDeclaration.signatureString(): String = getMangleComputer(MangleMode.SIGNATURE).computeMangle(this)
 
-    override val FirDeclaration.fqnString: String
-        get() = getMangleComputer(MangleMode.FQNAME).computeMangle(this)
+    override fun FirDeclaration.fqnString(): String = getMangleComputer(MangleMode.FQNAME).computeMangle(this)
 
-    override fun FirDeclaration.isExported(): Boolean = true
+    override fun FirDeclaration.isExported(compatibleMode: Boolean): Boolean = true
 
-    override fun getExportChecker(): KotlinExportChecker<FirDeclaration> {
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<FirDeclaration>  {
         return object : KotlinExportChecker<FirDeclaration> {
             override fun check(declaration: FirDeclaration, type: SpecialDeclarationType): Boolean = true
 
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
index 9268d445fba..9cf26a799f1 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
@@ -40,17 +40,17 @@ class FirBasedSignatureComposer(private val mangler: FirMangler) : Fir2IrSignatu
         }
 
         override fun visitConstructor(constructor: FirConstructor, data: Any?) {
-            hashId = mangler.run { constructor.signatureMangle }
+            hashId = mangler.run { constructor.signatureMangle() }
             setExpected(constructor.isExpect)
         }
 
         override fun visitSimpleFunction(simpleFunction: FirSimpleFunction, data: Any?) {
-            hashId = mangler.run { simpleFunction.signatureMangle }
+            hashId = mangler.run { simpleFunction.signatureMangle() }
             setExpected(simpleFunction.isExpect)
         }
 
         override fun visitProperty(property: FirProperty, data: Any?) {
-            hashId = mangler.run { property.signatureMangle }
+            hashId = mangler.run { property.signatureMangle() }
             setExpected(property.isExpect)
         }
 
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/IrUtils.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/IrUtils.kt
index 314ffde0583..ebfd4418bb8 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/IrUtils.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/ir/IrUtils.kt
@@ -457,11 +457,11 @@ val IrFunction.allParametersCount: Int
 // TODO: merge it with FakeOverrideBuilder.
 private class FakeOverrideBuilderForLowerings : FakeOverrideBuilderStrategy() {
 
-    override fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction) {
+    override fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction, compatibilityMode: Boolean) {
         declaration.acquireSymbol(IrSimpleFunctionSymbolImpl())
     }
 
-    override fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty) {
+    override fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty, compatibilityMode: Boolean) {
         val propertySymbol = IrPropertySymbolImpl()
         declaration.getter?.let { it.correspondingPropertySymbol = propertySymbol }
         declaration.setter?.let { it.correspondingPropertySymbol = propertySymbol }
@@ -470,18 +470,18 @@ private class FakeOverrideBuilderForLowerings : FakeOverrideBuilderStrategy() {
 
         declaration.getter?.let {
             it.correspondingPropertySymbol = declaration.symbol
-            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override getter: $it"))
+            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override getter: $it"), compatibilityMode)
         }
         declaration.setter?.let {
             it.correspondingPropertySymbol = declaration.symbol
-            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override setter: $it"))
+            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override setter: $it"), compatibilityMode)
         }
     }
 }
 
 fun IrClass.addFakeOverrides(irBuiltIns: IrBuiltIns, implementedMembers: List<IrOverridableMember> = emptyList()) {
     IrOverridingUtil(irBuiltIns, FakeOverrideBuilderForLowerings())
-        .buildFakeOverridesForClassUsingOverriddenSymbols(this, implementedMembers)
+        .buildFakeOverridesForClassUsingOverriddenSymbols(this, implementedMembers, compatibilityMode = false)
         .forEach { addChild(it) }
 }
 
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameTables.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameTables.kt
index 60725596408..1cff43ee56e 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameTables.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/NameTables.kt
@@ -34,7 +34,7 @@ import kotlin.math.abs
 private fun <T> mapToKey(declaration: T): String {
     return with(JsManglerIr) {
         if (declaration is IrDeclaration) {
-            declaration.hashedMangle.toString()
+            declaration.hashedMangle().toString()
         } else if (declaration is String) {
             declaration.hashMangle.toString()
         } else {
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt
index 7bdbc2f5a66..88f580c6eb3 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt
@@ -27,16 +27,16 @@ abstract class FakeOverrideBuilderStrategy {
     open fun fakeOverrideMember(superType: IrType, member: IrOverridableMember, clazz: IrClass): IrOverridableMember =
         buildFakeOverrideMember(superType, member, clazz)
 
-    fun linkFakeOverride(fakeOverride: IrOverridableMember) {
+    fun linkFakeOverride(fakeOverride: IrOverridableMember, compatibilityMode: Boolean) {
         when (fakeOverride) {
-            is IrFakeOverrideFunction -> linkFunctionFakeOverride(fakeOverride)
-            is IrFakeOverrideProperty -> linkPropertyFakeOverride(fakeOverride)
+            is IrFakeOverrideFunction -> linkFunctionFakeOverride(fakeOverride, compatibilityMode)
+            is IrFakeOverrideProperty -> linkPropertyFakeOverride(fakeOverride, compatibilityMode)
             else -> error("Unexpected fake override: $fakeOverride")
         }
     }
 
-    protected abstract fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction)
-    protected abstract fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty)
+    protected abstract fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction, compatibilityMode: Boolean)
+    protected abstract fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty, compatibilityMode: Boolean)
 }
 
 private fun IrOverridableMember.isPrivateToThisModule(thisClass: IrClass, memberClass: IrClass): Boolean {
@@ -133,7 +133,7 @@ class IrOverridingUtil(
             }
         }
 
-    fun buildFakeOverridesForClass(clazz: IrClass) {
+    fun buildFakeOverridesForClass(clazz: IrClass, oldSignatures: Boolean) {
         val superTypes = clazz.superTypes
 
         @Suppress("UNCHECKED_CAST")
@@ -158,14 +158,15 @@ class IrOverridingUtil(
             generateOverridesInFunctionGroup(
                 group.value,
                 fromCurrent.filter { it.name == group.key },
-                clazz
+                clazz, oldSignatures
             )
         }
     }
 
     fun buildFakeOverridesForClassUsingOverriddenSymbols(
         clazz: IrClass,
-        implementedMembers: List<IrOverridableMember> = emptyList()
+        implementedMembers: List<IrOverridableMember> = emptyList(),
+        compatibilityMode: Boolean
     ): List<IrOverridableMember> {
         val overriddenMembers = (clazz.declarations.filterIsInstance<IrOverridableMember>() + implementedMembers)
             .flatMap { member -> member.overriddenSymbols.map { it.owner } }
@@ -189,7 +190,7 @@ class IrOverridingUtil(
         val unoverriddenSuperMembersGroupedByName = unoverriddenSuperMembers.groupBy { it.name }
         val fakeOverrides = mutableListOf<IrOverridableMember>()
         for (group in unoverriddenSuperMembersGroupedByName.values) {
-            createAndBindFakeOverrides(clazz, group, fakeOverrides)
+            createAndBindFakeOverrides(clazz, group, fakeOverrides, compatibilityMode)
         }
         return fakeOverrides
     }
@@ -207,7 +208,8 @@ class IrOverridingUtil(
     private fun generateOverridesInFunctionGroup(
         membersFromSupertypes: List<IrOverridableMember>,
         membersFromCurrent: List<IrOverridableMember>,
-        current: IrClass
+        current: IrClass,
+        compatibilityMode: Boolean
     ) {
         val notOverridden = membersFromSupertypes.toMutableSet()
 
@@ -217,7 +219,7 @@ class IrOverridingUtil(
         }
 
         val addedFakeOverrides = mutableListOf<IrOverridableMember>()
-        createAndBindFakeOverrides(current, notOverridden, addedFakeOverrides)
+        createAndBindFakeOverrides(current, notOverridden, addedFakeOverrides, compatibilityMode)
         current.declarations.addAll(addedFakeOverrides)
     }
 
@@ -259,7 +261,8 @@ class IrOverridingUtil(
     private fun createAndBindFakeOverrides(
         current: IrClass,
         notOverridden: Collection<IrOverridableMember>,
-        addedFakeOverrides: MutableList<IrOverridableMember>
+        addedFakeOverrides: MutableList<IrOverridableMember>,
+        compatibilityMode: Boolean
     ) {
         val fromSuper = notOverridden.toMutableSet()
         while (fromSuper.isNotEmpty()) {
@@ -268,7 +271,7 @@ class IrOverridingUtil(
                 notOverriddenFromSuper,
                 fromSuper
             )
-            createAndBindFakeOverride(overridables, current, addedFakeOverrides)
+            createAndBindFakeOverride(overridables, current, addedFakeOverrides, compatibilityMode)
         }
     }
 
@@ -381,7 +384,8 @@ class IrOverridingUtil(
     private fun createAndBindFakeOverride(
         overridables: Collection<IrOverridableMember>,
         current: IrClass,
-        addedFakeOverrides: MutableList<IrOverridableMember>
+        addedFakeOverrides: MutableList<IrOverridableMember>,
+        compatibilityMode: Boolean
     ) {
         val effectiveOverridden = filterVisibleFakeOverrides(overridables)
 
@@ -416,7 +420,7 @@ class IrOverridingUtil(
         ) { "Overridden symbols should be set for " + CallableMemberDescriptor.Kind.FAKE_OVERRIDE }
 
         addedFakeOverrides.add(fakeOverride)
-        fakeOverrideBuilder.linkFakeOverride(fakeOverride)
+        fakeOverrideBuilder.linkFakeOverride(fakeOverride, compatibilityMode)
     }
 
     private fun isVisibilityMoreSpecific(
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/KotlinMangler.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/KotlinMangler.kt
index 4ef072d5062..245f9d7caec 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/KotlinMangler.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/KotlinMangler.kt
@@ -14,14 +14,16 @@ interface KotlinMangler<D : Any> {
 
     val String.hashMangle: Long
 
-    fun D.isExported(): Boolean
-    val D.mangleString: String
-    val D.signatureString: String
-    val D.fqnString: String
+    fun D.isExported(compatibleMode: Boolean): Boolean
+    fun D.mangleString(): String
+    fun D.signatureString(): String
+    fun D.fqnString(): String
 
-    val D.hashedMangle: Long get() = mangleString.hashMangle
-    val D.signatureMangle: Long get() = signatureString.hashMangle
-    val D.fqnMangle: Long get() = fqnString.hashMangle
+    fun D.hashedMangle(): Long = mangleString().hashMangle
+    fun D.signatureMangle(): Long = signatureString().hashMangle
+    fun D.fqnMangle(): Long = fqnString().hashMangle
+
+    fun D.isPlatformSpecificExport(): Boolean = false
 
     val manglerName: String
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrideChecker.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrideChecker.kt
index a96546e90bc..51fe1825882 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrideChecker.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrideChecker.kt
@@ -5,7 +5,10 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
 import org.jetbrains.kotlin.descriptors.findClassAcrossModuleDependencies
 import org.jetbrains.kotlin.ir.IrElement
-import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
+import org.jetbrains.kotlin.ir.declarations.IrOverridableMember
+import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
@@ -41,7 +44,7 @@ class FakeOverrideChecker(
             .filterNot { it.visibility == DescriptorVisibilities.PRIVATE || it.visibility == DescriptorVisibilities.INVISIBLE_FAKE }
 
         val descriptorSignatures = descriptorFakeOverrides
-            .map { with(descriptorMangler) { it.signatureString }}
+            .map { with(descriptorMangler) { it.signatureString() } }
             .sorted()
 
         val irFakeOverrides = clazz.declarations
@@ -53,7 +56,7 @@ class FakeOverrideChecker(
         }
 
         val irSignatures = irFakeOverrides
-            .map { with(irMangler) { it.signatureString }}
+            .map { with(irMangler) { it.signatureString() } }
             .sorted()
 
         // We can't have equality here because dependency libraries could have
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrides.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrides.kt
index 744f5d7eeab..e8df97c6a98 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrides.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrides.kt
@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.backend.common.overrides
 
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.DeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.GlobalDeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
@@ -31,6 +32,7 @@ import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.KotlinMangler
 import org.jetbrains.kotlin.ir.util.SymbolTable
+import org.jetbrains.kotlin.ir.util.fileOrNull
 import org.jetbrains.kotlin.ir.util.parentAsClass
 
 class FakeOverrideGlobalDeclarationTable(
@@ -77,13 +79,15 @@ class FakeOverrideBuilder(
     // TODO: The declaration table is needed for the signaturer.
     private val fakeOverrideDeclarationTable = FakeOverrideDeclarationTable(mangler)
 
-    private val fakeOverrideClassQueue = mutableListOf<IrClass>()
-    fun enqueueClass(clazz: IrClass, signature: IdSignature) {
+//    private class CompatibilityMode(val oldSignatures: Boolean)
+
+    private val fakeOverrideCandidates = mutableMapOf<IrClass, CompatibilityMode>()
+    fun enqueueClass(clazz: IrClass, signature: IdSignature, compatibilityMode: CompatibilityMode) {
         fakeOverrideDeclarationTable.assumeDeclarationSignature(clazz, signature)
-        fakeOverrideClassQueue.add(clazz)
+        fakeOverrideCandidates[clazz] = compatibilityMode
     }
 
-    private fun buildFakeOverrideChainsForClass(clazz: IrClass) {
+    private fun buildFakeOverrideChainsForClass(clazz: IrClass, compatibilityMode: CompatibilityMode) {
         if (haveFakeOverrides.contains(clazz)) return
         if (!platformSpecificClassFilter.needToConstructFakeOverrides(clazz)) return
 
@@ -93,20 +97,25 @@ class FakeOverrideBuilder(
             it.getClass() ?: error("Unexpected super type: $it")
         }
 
-        superClasses.forEach {
-            buildFakeOverrideChainsForClass(it)
-            haveFakeOverrides.add(it)
+        superClasses.forEach { superClass ->
+            val mode = fakeOverrideCandidates[superClass] ?: compatibilityMode
+            buildFakeOverrideChainsForClass(superClass, mode)
+            haveFakeOverrides.add(superClass)
         }
 
-        irOverridingUtil.buildFakeOverridesForClass(clazz)
+        fakeOverrideDeclarationTable.run {
+            inFile(clazz.fileOrNull) {
+                irOverridingUtil.buildFakeOverridesForClass(clazz, compatibilityMode.oldSignatures)
+            }
+        }
     }
 
-    override fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction) {
-        val signature = composeSignature(declaration)
+    override fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction, compatibilityMode: Boolean) {
+        val signature = composeSignature(declaration, compatibilityMode)
         declareFunctionFakeOverride(declaration, signature)
     }
 
-    override fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty) {
+    override fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty, compatibilityMode: Boolean) {
         // To compute a signature for a property with type parameters,
         // we must have its accessor's correspondingProperty pointing to the property's symbol.
         // See IrMangleComputer.mangleTypeParameterReference() for details.
@@ -123,21 +132,21 @@ class FakeOverrideBuilder(
             it.correspondingPropertySymbol = tempSymbol
         }
 
-        val signature = composeSignature(declaration)
+        val signature = composeSignature(declaration, compatibilityMode)
         declarePropertyFakeOverride(declaration, signature)
 
         declaration.getter?.let {
             it.correspondingPropertySymbol = declaration.symbol
-            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override getter: $it"))
+            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override getter: $it"), compatibilityMode)
         }
         declaration.setter?.let {
             it.correspondingPropertySymbol = declaration.symbol
-            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override setter: $it"))
+            linkFunctionFakeOverride(it as? IrFakeOverrideFunction ?: error("Unexpected fake override setter: $it"), compatibilityMode)
         }
     }
 
-    private fun composeSignature(declaration: IrDeclaration) =
-        fakeOverrideDeclarationTable.signaturer.composeSignatureForDeclaration(declaration)
+    private fun composeSignature(declaration: IrDeclaration, compatibleMode: Boolean) =
+        fakeOverrideDeclarationTable.signaturer.composeSignatureForDeclaration(declaration, compatibleMode)
 
     private fun declareFunctionFakeOverride(declaration: IrFakeOverrideFunction, signature: IdSignature) {
         val parent = declaration.parentAsClass
@@ -159,16 +168,18 @@ class FakeOverrideBuilder(
         }
     }
 
-    private fun provideFakeOverrides(klass: IrClass) {
-        buildFakeOverrideChainsForClass(klass)
+    private fun provideFakeOverrides(klass: IrClass, compatibleMode: CompatibilityMode) {
+        buildFakeOverrideChainsForClass(klass, compatibleMode)
         irOverridingUtil.clear()
         haveFakeOverrides.add(klass)
     }
 
     fun provideFakeOverrides() {
-        while (fakeOverrideClassQueue.isNotEmpty()) {
-            val klass = fakeOverrideClassQueue.removeLast()
-            provideFakeOverrides(klass)
+        val entries = fakeOverrideCandidates.entries
+        while (entries.isNotEmpty()) {
+            val candidate = entries.last()
+            entries.remove(candidate)
+            provideFakeOverrides(candidate.key, candidate.value)
         }
     }
 }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/BasicIrModuleDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/BasicIrModuleDeserializer.kt
index bb85d2b7d67..f42921a5002 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/BasicIrModuleDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/BasicIrModuleDeserializer.kt
@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinAbiVersion
 import org.jetbrains.kotlin.protobuf.CodedInputStream
 import org.jetbrains.kotlin.protobuf.ExtensionRegistryLite
 
@@ -25,9 +26,10 @@ abstract class BasicIrModuleDeserializer(
     moduleDescriptor: ModuleDescriptor,
     override val klib: IrLibrary,
     override val strategy: DeserializationStrategy,
-    private val containsErrorCode: Boolean = false,
+    libraryAbiVersion: KotlinAbiVersion,
+    private val containsErrorCode: Boolean = false
 ) :
-    IrModuleDeserializer(moduleDescriptor) {
+    IrModuleDeserializer(moduleDescriptor, libraryAbiVersion) {
 
     private val fileToDeserializerMap = mutableMapOf<IrFile, IrFileDeserializer>()
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DeclarationTable.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DeclarationTable.kt
index 8ad6297765f..d80ffdd9027 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DeclarationTable.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DeclarationTable.kt
@@ -6,14 +6,19 @@
 package org.jetbrains.kotlin.backend.common.serialization
 
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
+import org.jetbrains.kotlin.descriptors.ClassKind
+import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
+import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.backend.common.serialization.signature.PublicIdSignatureComputer
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrSymbolOwner
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
-import org.jetbrains.kotlin.ir.util.IdSignature
-import org.jetbrains.kotlin.ir.util.KotlinMangler
-import org.jetbrains.kotlin.ir.util.render
+import org.jetbrains.kotlin.ir.expressions.IrFunctionExpression
+import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
+import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
 
 
 interface IdSignatureClashTracker {
@@ -43,13 +48,13 @@ abstract class GlobalDeclarationTable(
         }
     }
 
-    open fun computeSignatureByDeclaration(declaration: IrDeclaration): IdSignature {
+    open fun computeSignatureByDeclaration(declaration: IrDeclaration, compatibleMode: Boolean): IdSignature {
         return table.getOrPut(declaration) {
-            publicIdSignatureComputer.composePublicIdSignature(declaration).also { clashTracker.commit(declaration, it) }
+            publicIdSignatureComputer.composePublicIdSignature(declaration, compatibleMode).also { clashTracker.commit(declaration, it) }
         }
     }
 
-    fun isExportedDeclaration(declaration: IrDeclaration): Boolean = with(mangler) { declaration.isExported() }
+    fun isExportedDeclaration(declaration: IrDeclaration, compatibleMode: Boolean): Boolean = with(mangler) { declaration.isExported(compatibleMode) }
 }
 
 open class DeclarationTable(globalTable: GlobalDeclarationTable) {
@@ -62,24 +67,34 @@ open class DeclarationTable(globalTable: GlobalDeclarationTable) {
         signaturer.inFile(file?.symbol, block)
     }
 
-    fun isExportedDeclaration(declaration: IrDeclaration) = globalDeclarationTable.isExportedDeclaration(declaration)
+
+    private fun IrDeclaration.isLocalDeclaration(compatibleMode: Boolean): Boolean {
+        return !isExportedDeclaration(this, compatibleMode)
+    }
+
+    fun isExportedDeclaration(declaration: IrDeclaration, compatibleMode: Boolean) =
+        globalDeclarationTable.isExportedDeclaration(declaration, compatibleMode)
 
     protected open fun tryComputeBackendSpecificSignature(declaration: IrDeclaration): IdSignature? = null
 
-    private fun computeSignatureByDeclaration(declaration: IrDeclaration): IdSignature {
-        tryComputeBackendSpecificSignature(declaration)?.let { return it }
-        return if (declaration.isLocalDeclaration()) {
-            table.getOrPut(declaration) { signaturer.composeFileLocalIdSignature(declaration) }
-        } else globalDeclarationTable.computeSignatureByDeclaration(declaration)
+    private fun allocateIndexedSignature(declaration: IrDeclaration, compatibleMode: Boolean): IdSignature {
+        return table.getOrPut(declaration) { signaturer.composeFileLocalIdSignature(declaration, compatibleMode) }
     }
 
-    fun privateDeclarationSignature(declaration: IrDeclaration, builder: () -> IdSignature): IdSignature {
-        assert(declaration.isLocalDeclaration())
+    private fun computeSignatureByDeclaration(declaration: IrDeclaration, compatibleMode: Boolean): IdSignature {
+        tryComputeBackendSpecificSignature(declaration)?.let { return it }
+        return if (declaration.isLocalDeclaration(compatibleMode)) {
+            allocateIndexedSignature(declaration, compatibleMode)
+        } else globalDeclarationTable.computeSignatureByDeclaration(declaration, compatibleMode)
+    }
+
+    fun privateDeclarationSignature(declaration: IrDeclaration, compatibleMode: Boolean, builder: () -> IdSignature): IdSignature {
+        assert(declaration.isLocalDeclaration(compatibleMode))
         return table.getOrPut(declaration) { builder() }
     }
 
-    fun signatureByDeclaration(declaration: IrDeclaration): IdSignature {
-        return computeSignatureByDeclaration(declaration)
+    fun signatureByDeclaration(declaration: IrDeclaration, compatibleMode: Boolean): IdSignature {
+        return computeSignatureByDeclaration(declaration, compatibleMode)
     }
 
     fun assumeDeclarationSignature(declaration: IrDeclaration, signature: IdSignature) {
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DescriptorByIdSignatureFinder.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DescriptorByIdSignatureFinder.kt
index bde4ece0255..7ccaeb565f5 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DescriptorByIdSignatureFinder.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/DescriptorByIdSignatureFinder.kt
@@ -140,7 +140,7 @@ class DescriptorByIdSignatureFinder(
                 // We don't compute id for typealiases and classes.
                 candidate is ClassDescriptor || candidate is TypeAliasDescriptor
             } else {
-                val candidateHash = with(mangler) { candidate.signatureMangle }
+                val candidateHash = with(mangler) { candidate.signatureMangle() }
                 candidateHash == id
             }
         }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt
index a8580747e5c..1382dcc10d9 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IncrementalCompilationSupport.kt
@@ -17,6 +17,7 @@ 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.KotlinAbiVersion
 import org.jetbrains.kotlin.library.SerializedIrFile
 import org.jetbrains.kotlin.library.impl.*
 
@@ -79,7 +80,7 @@ class CurrentModuleWithICDeserializer(
     private val irBuiltIns: IrBuiltIns,
     icData: List<SerializedIrFile>,
     icReaderFactory: (IrLibrary) -> IrModuleDeserializer) :
-    IrModuleDeserializer(delegate.moduleDescriptor) {
+    IrModuleDeserializer(delegate.moduleDescriptor, KotlinAbiVersion.CURRENT) {
 
     private val dirtyDeclarations = mutableMapOf<IdSignature, IrSymbol>()
     private val icKlib = ICKotlinLibrary(icData)
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrDeclarationDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrDeclarationDeserializer.kt
index 69a9dd646a5..f0f91101ec9 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrDeclarationDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrDeclarationDeserializer.kt
@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.descriptors.InlineClassRepresentation
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrVariableImpl
+import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.expressions.IrBlockBody
 import org.jetbrains.kotlin.ir.expressions.IrBody
@@ -24,6 +25,7 @@ import org.jetbrains.kotlin.ir.expressions.IrStatementOriginImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrErrorExpressionImpl
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.symbols.impl.IrPublicSymbolBase
+import org.jetbrains.kotlin.ir.symbols.impl.IrTypeParameterPublicSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrTypeParameterSymbolImpl
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.*
@@ -32,6 +34,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.protobuf.CodedInputStream
 import org.jetbrains.kotlin.protobuf.ExtensionRegistryLite
 import org.jetbrains.kotlin.types.Variance
+import kotlin.collections.set
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrAnonymousInit as ProtoAnonymousInit
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrClass as ProtoClass
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrConstructor as ProtoConstructor
@@ -73,6 +76,7 @@ class IrDeclarationDeserializer(
     private val skipMutableState: Boolean = false,
     additionalStatementOriginIndex: Map<String, IrStatementOrigin> = emptyMap(),
     allowErrorStatementOrigins: Boolean = false,
+    private val compatibilityMode: CompatibilityMode
 ) {
 
     val bodyDeserializer = IrBodyDeserializer(builtIns, allowErrorNodes, irFactory, fileReader, this, statementOriginIndex + additionalStatementOriginIndex, allowErrorStatementOrigins)
@@ -334,7 +338,7 @@ class IrDeclarationDeserializer(
                         else -> computeMissingInlineClassRepresentationForCompatibility(this)
                     }
 
-                    fakeOverrideBuilder.enqueueClass(this, signature)
+                    fakeOverrideBuilder.enqueueClass(this, signature, compatibilityMode)
                 }
             }
         }
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
index 3dd0dc4eb87..ba96257bbb2 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt
@@ -71,9 +71,7 @@ class FileDeserializationState(
 
     val symbolDeserializer =
         IrSymbolDeserializer(
-            linker.symbolTable,
-            fileReader,
-            file.symbol,
+            linker.symbolTable, fileReader, file.symbol,
             fileProto.actualList,
             ::addIdSignature,
             linker::handleExpectActualMapping,
@@ -102,6 +100,7 @@ class FileDeserializationState(
         symbolDeserializer,
         linker.fakeOverrideBuilder.platformSpecificClassFilter,
         linker.fakeOverrideBuilder,
+        compatibilityMode = moduleDeserializer.compatibilityMode
     )
 
     val fileDeserializer = IrFileDeserializer(file, fileReader, fileProto, symbolDeserializer, declarationDeserializer)
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileSerializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileSerializer.kt
index c5a687e44c4..550a60b8969 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileSerializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileSerializer.kt
@@ -120,6 +120,7 @@ open class IrFileSerializer(
     val messageLogger: IrMessageLogger,
     private val declarationTable: DeclarationTable,
     private val expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
+    private val compatibilityMode: CompatibilityMode,
     private val bodiesOnlyForInlines: Boolean = false,
     private val skipExpects: Boolean = false,
     // required for JS IC caches
@@ -312,7 +313,7 @@ open class IrFileSerializer(
     }
 
     private fun protoIdSignature(declaration: IrDeclaration): Int {
-        val idSig = declarationTable.signatureByDeclaration(declaration)
+        val idSig = declarationTable.signatureByDeclaration(declaration, compatibilityMode.oldSignatures)
         return protoIdSignature(idSig)
     }
 
@@ -1470,7 +1471,7 @@ open class IrFileSerializer(
 
         for (declaration in declarations) {
             val byteArray = serializeDeclaration(declaration).toByteArray()
-            val idSig = declarationTable.signatureByDeclaration(declaration)
+            val idSig = declarationTable.signatureByDeclaration(declaration, compatibleMode = false)
 
             // TODO: keep order similar
             // ^ TODO what does that mean?
@@ -1521,8 +1522,8 @@ open class IrFileSerializer(
             }
 
             val byteArray = serializeDeclaration(it).toByteArray()
-            val idSig = declarationTable.signatureByDeclaration(it)
-            require(idSig === idSig.topLevelSignature()) { "IdSig: $idSig\ntopLevel: ${idSig.topLevelSignature()}" }
+            val idSig = declarationTable.signatureByDeclaration(it, compatibilityMode.oldSignatures)
+            require(idSig == idSig.topLevelSignature()) { "IdSig: $idSig\ntopLevel: ${idSig.topLevelSignature()}" }
             require(!idSig.isPackageSignature()) { "IsSig: $idSig\nDeclaration: ${it.render()}" }
 
             // TODO: keep order similar
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
index 1cbd18ff6bc..b5e8d29cb86 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleDeserializer.kt
@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinAbiVersion
 
 internal fun IrSymbol.kind(): BinarySymbolData.SymbolKind {
     return when (this) {
@@ -28,11 +29,35 @@ internal fun IrSymbol.kind(): BinarySymbolData.SymbolKind {
     }
 }
 
-abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor) {
+class CompatibilityMode(val abiVersion: KotlinAbiVersion) {
+
+    init {
+        assert(abiVersion.isCompatible())
+    }
+
+    val oldSignatures: Boolean
+        get() {
+            if (abiVersion.minor == LAST_PRIVATE_SIG_ABI_VERSION.minor) {
+                return abiVersion.patch <= LAST_PRIVATE_SIG_ABI_VERSION.patch
+            }
+            return abiVersion.minor < LAST_PRIVATE_SIG_ABI_VERSION.minor
+        }
+
+    companion object {
+        val LAST_PRIVATE_SIG_ABI_VERSION = KotlinAbiVersion(1, 5, 0)
+
+        val WITH_PRIVATE_SIG = CompatibilityMode(LAST_PRIVATE_SIG_ABI_VERSION)
+        val WITH_COMMON_SIG = CompatibilityMode(KotlinAbiVersion.CURRENT)
+
+        val CURRENT = WITH_COMMON_SIG
+    }
+}
+
+abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor, val libraryAbiVersion: KotlinAbiVersion) {
     abstract operator fun contains(idSig: IdSignature): Boolean
     abstract fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol
 
-    open fun referenceSimpleFunctionByLocalSignature(file: IrFile, idSignature: IdSignature) : IrSimpleFunctionSymbol =
+    open fun referenceSimpleFunctionByLocalSignature(file: IrFile, idSignature: IdSignature): IrSimpleFunctionSymbol =
         error("Unsupported operation")
 
     open fun referencePropertyByLocalSignature(file: IrFile, idSignature: IdSignature): IrPropertySymbol =
@@ -53,7 +78,9 @@ abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor) {
 
     open fun init(delegate: IrModuleDeserializer) {}
 
-    open fun addModuleReachableTopLevel(idSig: IdSignature) { error("Unsupported Operation (sig: $idSig") }
+    open fun addModuleReachableTopLevel(idSig: IdSignature) {
+        error("Unsupported Operation (sig: $idSig")
+    }
 
     open fun deserializeReachableDeclarations() { error("Unsupported Operation") }
 
@@ -64,14 +91,16 @@ abstract class IrModuleDeserializer(val moduleDescriptor: ModuleDescriptor) {
     open val strategy: DeserializationStrategy = DeserializationStrategy.ONLY_DECLARATION_HEADERS
 
     open val isCurrent = false
+
+    val compatibilityMode: CompatibilityMode get() = CompatibilityMode(libraryAbiVersion)
 }
 
 // Used to resolve built in symbols like `kotlin.ir.internal.*` or `kotlin.FunctionN`
 class IrModuleDeserializerWithBuiltIns(
     builtIns: IrBuiltIns,
     private val functionFactory: IrAbstractFunctionFactory,
-    private val delegate: IrModuleDeserializer
-) : IrModuleDeserializer(delegate.moduleDescriptor) {
+    private val delegate: IrModuleDeserializer,
+) : IrModuleDeserializer(delegate.moduleDescriptor, delegate.libraryAbiVersion) {
 
     init {
         // TODO: figure out how it should work for K/N
@@ -205,7 +234,7 @@ class IrModuleDeserializerWithBuiltIns(
 open class CurrentModuleDeserializer(
     override val moduleFragment: IrModuleFragment,
     override val moduleDependencies: Collection<IrModuleDeserializer>
-) : IrModuleDeserializer(moduleFragment.descriptor) {
+) : IrModuleDeserializer(moduleFragment.descriptor, KotlinAbiVersion.CURRENT) {
     override fun contains(idSig: IdSignature): Boolean = false // TODO:
 
     override fun deserializeIrSymbol(idSig: IdSignature, symbolKind: BinarySymbolData.SymbolKind): IrSymbol {
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
index 2e6657240a4..ce91796e418 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrModuleSerializer.kt
@@ -12,7 +12,7 @@ import org.jetbrains.kotlin.ir.util.IrMessageLogger
 import org.jetbrains.kotlin.library.SerializedIrFile
 import org.jetbrains.kotlin.library.SerializedIrModule
 
-abstract class IrModuleSerializer<F : IrFileSerializer>(protected val messageLogger: IrMessageLogger) {
+abstract class IrModuleSerializer<F : IrFileSerializer>(protected val messageLogger: IrMessageLogger, protected val compatibilityMode: CompatibilityMode) {
     abstract fun createSerializerForFile(file: IrFile): F
 
     /**
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
index 7336e0a06fd..849a45574e1 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/KotlinIrLinker.kt
@@ -22,11 +22,6 @@ import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.IrMessageLogger
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.file
-import org.jetbrains.kotlin.library.IrLibrary
-import org.jetbrains.kotlin.ir.util.IdSignature
-import org.jetbrains.kotlin.ir.util.IrMessageLogger
-import org.jetbrains.kotlin.ir.util.SymbolTable
-import org.jetbrains.kotlin.ir.util.file
 import org.jetbrains.kotlin.library.KotlinLibrary
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
@@ -90,7 +85,7 @@ abstract class KotlinIrLinker(
 
     protected abstract fun createModuleDeserializer(
         moduleDescriptor: ModuleDescriptor,
-        klib: IrLibrary?,
+        klib: KotlinLibrary?,
         strategy: DeserializationStrategy,
     ): IrModuleDeserializer
 
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/AbstractKotlinMangler.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/AbstractKotlinMangler.kt
index b919e211ee9..ddaffc89962 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/AbstractKotlinMangler.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/AbstractKotlinMangler.kt
@@ -11,6 +11,6 @@ import org.jetbrains.kotlin.ir.util.KotlinMangler
 abstract class AbstractKotlinMangler<D : Any> : KotlinMangler<D> {
     override val String.hashMangle get() = cityHash64()
 
-    abstract fun getExportChecker(): KotlinExportChecker<D>
+    abstract fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<D>
     abstract fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<D>
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/descriptor/DescriptorBasedKotlinManglerImpl.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/descriptor/DescriptorBasedKotlinManglerImpl.kt
index 2573a7cc2c1..5a4dbfba20d 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/descriptor/DescriptorBasedKotlinManglerImpl.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/descriptor/DescriptorBasedKotlinManglerImpl.kt
@@ -9,11 +9,11 @@ import org.jetbrains.kotlin.backend.common.serialization.mangle.*
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
-import org.jetbrains.kotlin.ir.declarations.IrAnonymousInitializer
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.declarations.IrEnumEntry
 import org.jetbrains.kotlin.ir.declarations.IrField
 import org.jetbrains.kotlin.ir.util.KotlinMangler
+import org.jetbrains.kotlin.types.KotlinType
 
 abstract class DescriptorBasedKotlinManglerImpl : AbstractKotlinMangler<DeclarationDescriptor>(), KotlinMangler.DescriptorMangler {
     private fun withMode(mode: MangleMode, descriptor: DeclarationDescriptor): String =
@@ -21,23 +21,15 @@ abstract class DescriptorBasedKotlinManglerImpl : AbstractKotlinMangler<Declarat
 
     override fun ClassDescriptor.mangleEnumEntryString(): String = withMode(MangleMode.FQNAME, this)
 
-    override fun ClassDescriptor.isExportEnumEntry(): Boolean =
-        getExportChecker().check(this, SpecialDeclarationType.ENUM_ENTRY)
+    override fun PropertyDescriptor.mangleFieldString(): String = mangleString()
 
-    override fun PropertyDescriptor.isExportField(): Boolean = false
+    override fun DeclarationDescriptor.mangleString(): String = withMode(MangleMode.FULL, this)
 
-    override fun PropertyDescriptor.mangleFieldString(): String = error("Fields supposed to be non-exporting")
+    override fun DeclarationDescriptor.signatureString(): String = withMode(MangleMode.SIGNATURE, this)
 
-    override val DeclarationDescriptor.mangleString: String
-        get() = withMode(MangleMode.FULL, this)
+    override fun DeclarationDescriptor.fqnString(): String = withMode(MangleMode.FQNAME, this)
 
-    override val DeclarationDescriptor.signatureString: String
-        get() = withMode(MangleMode.SIGNATURE, this)
-
-    override val DeclarationDescriptor.fqnString: String
-        get() = withMode(MangleMode.FQNAME, this)
-
-    override fun DeclarationDescriptor.isExported(): Boolean = getExportChecker().check(this, SpecialDeclarationType.REGULAR)
+    override fun DeclarationDescriptor.isExported(compatibleMode: Boolean): Boolean = getExportChecker(compatibleMode).check(this, SpecialDeclarationType.REGULAR)
 }
 
 class Ir2DescriptorManglerAdapter(private val delegate: DescriptorBasedKotlinManglerImpl) : AbstractKotlinMangler<IrDeclaration>(),
@@ -45,31 +37,26 @@ class Ir2DescriptorManglerAdapter(private val delegate: DescriptorBasedKotlinMan
     override val manglerName: String
         get() = delegate.manglerName
 
-    override fun IrDeclaration.isExported(): Boolean {
+    override fun IrDeclaration.isExported(compatibleMode: Boolean): Boolean {
+        return delegate.run { descriptor.isExported(compatibleMode) }
+    }
+
+    override fun IrDeclaration.mangleString(): String {
         return when (this) {
-            is IrAnonymousInitializer -> false
-            is IrEnumEntry -> delegate.run { descriptor.isExportEnumEntry() }
-            is IrField -> delegate.run { descriptor.isExportField() }
-            else -> delegate.run { descriptor.isExported() }
+            is IrEnumEntry -> delegate.run { descriptor.mangleEnumEntryString() }
+            is IrField -> delegate.run { descriptor.mangleFieldString() }
+            else -> delegate.run { descriptor.mangleString() }
         }
     }
 
-    override val IrDeclaration.mangleString: String
-        get() {
-            return when (this) {
-                is IrEnumEntry -> delegate.run { descriptor.mangleEnumEntryString() }
-                is IrField -> delegate.run { descriptor.mangleFieldString() }
-                else -> delegate.run { descriptor.mangleString }
-            }
-        }
+    override fun IrDeclaration.signatureString(): String = delegate.run { descriptor.signatureString() }
 
-    override val IrDeclaration.signatureString: String
-        get() = delegate.run { descriptor.signatureString }
+    override fun IrDeclaration.fqnString(): String = delegate.run { descriptor.fqnString() }
 
-    override val IrDeclaration.fqnString: String
-        get() = delegate.run { descriptor.fqnString }
+    override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<IrDeclaration> =
+        error("Should not have been reached")
 
-    override fun getExportChecker() = error("Should not have been reached")
-
-    override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<IrDeclaration> = error("Should not have been reached")
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<IrDeclaration> {
+        error("Should not be called")
+    }
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrBasedKotlinManglerImpl.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrBasedKotlinManglerImpl.kt
index 3c31d54100e..973eebd2c93 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrBasedKotlinManglerImpl.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrBasedKotlinManglerImpl.kt
@@ -12,14 +12,13 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 import org.jetbrains.kotlin.ir.util.KotlinMangler
 
 abstract class IrBasedKotlinManglerImpl : AbstractKotlinMangler<IrDeclaration>(), KotlinMangler.IrMangler {
-    override val IrDeclaration.mangleString: String
-        get() = getMangleComputer(MangleMode.FULL).computeMangle(this)
 
-    override val IrDeclaration.signatureString: String
-        get() = getMangleComputer(MangleMode.SIGNATURE).computeMangle(this)
+    override fun IrDeclaration.mangleString(): String = getMangleComputer(MangleMode.FULL).computeMangle(this)
 
-    override val IrDeclaration.fqnString: String
-        get() = getMangleComputer(MangleMode.FQNAME).computeMangle(this)
+    override fun IrDeclaration.signatureString(): String = getMangleComputer(MangleMode.SIGNATURE).computeMangle(this)
 
-    override fun IrDeclaration.isExported(): Boolean = getExportChecker().check(this, SpecialDeclarationType.REGULAR)
+    override fun IrDeclaration.fqnString(): String = getMangleComputer(MangleMode.FQNAME).computeMangle(this)
+
+    override fun IrDeclaration.isExported(compatibleMode: Boolean): Boolean =
+        getExportChecker(compatibleMode).check(this, SpecialDeclarationType.REGULAR)
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrExportCheckerVisitor.kt b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrExportCheckerVisitor.kt
index 8d77c1eb0e7..ae2cc2cc716 100644
--- a/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrExportCheckerVisitor.kt
+++ b/compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/mangle/ir/IrExportCheckerVisitor.kt
@@ -23,15 +23,23 @@ import org.jetbrains.kotlin.name.SpecialNames
 abstract class IrExportCheckerVisitor(private val compatibleMode: Boolean) : KotlinExportChecker<IrDeclaration> {
 
     private val compatibleChecker = CompatibleChecker()
-    private val newChecker = NewChecker()
+    private val checker = Checker()
 
+    /**
+     * @return true if [declaration] is exportable from klib point of view.
+     * Depending on [compatibleMode] option the same declaration could have FileLocal or Common signature.
+     */
     override fun check(declaration: IrDeclaration, type: SpecialDeclarationType): Boolean {
-        return declaration.accept(if (compatibleMode) compatibleChecker else newChecker, null)
+        return declaration.accept(if (compatibleMode) compatibleChecker else checker, null)
     }
 
     abstract override fun IrDeclaration.isPlatformSpecificExported(): Boolean
 
-    private class NewChecker : IrElementVisitor<Boolean, Nothing?> {
+    /**
+     * Corresponding to export policy of klib ABI >= 1.6.0.
+     * In that case any non-local declaration (including type parameter and field) is exportable and could be navigated between modules
+     */
+    private class Checker : IrElementVisitor<Boolean, Nothing?> {
         override fun visitElement(element: IrElement, data: Nothing?): Boolean {
             error("Should bot reach here ${element.render()}")
         }
@@ -68,6 +76,14 @@ abstract class IrExportCheckerVisitor(private val compatibleMode: Boolean) : Kot
         override fun visitErrorDeclaration(declaration: IrErrorDeclaration, data: Nothing?): Boolean = false
     }
 
+    /**
+     * Was using for klib ABI version <= 1.5.0. In that case declaration which has itself or in their hierarchy private or local parent
+     * is considered non-exportable.
+     *
+     * Also type parameters and fields are not exportable.
+     *
+     * Is used to link libraries with ABI level <= 1.5.0
+     */
     private inner class CompatibleChecker : IrElementVisitor<Boolean, Nothing?> {
         private fun IrDeclaration.isExported(annotations: List<IrConstructorCall>, visibility: DescriptorVisibility?): Boolean {
             val speciallyExported = annotations.hasAnnotation(publishedApiAnnotation) || isPlatformSpecificExported()
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
index 990b3ea1ebd..14b240de686 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
@@ -105,7 +105,8 @@ fun generateKLib(
     irFactory: IrFactory,
     outputKlibPath: String,
     nopack: Boolean,
-    jsOutputName: String?,
+    abiVersion: KotlinAbiVersion = KotlinAbiVersion.CURRENT,
+    jsOutputName: String?
 ) {
     val incrementalDataProvider = configuration.get(JSConfigurationKeys.INCREMENTAL_DATA_PROVIDER)
     val errorPolicy = configuration.get(JSConfigurationKeys.ERROR_TOLERANCE_POLICY) ?: ErrorTolerancePolicy.DEFAULT
@@ -196,6 +197,7 @@ fun generateKLib(
         nopack,
         perFile = false,
         hasErrors,
+        abiVersion,
         jsOutputName
     )
 }
@@ -495,15 +497,19 @@ fun serializeModuleIntoKlib(
     nopack: Boolean,
     perFile: Boolean,
     containsErrorCode: Boolean = false,
+    abiVersion: KotlinAbiVersion,
     jsOutputName: String?,
 ) {
     assert(files.size == moduleFragment.files.size)
 
+    val compatibilityMode = CompatibilityMode(abiVersion)
+
     val serializedIr =
         JsIrModuleSerializer(
             messageLogger,
             moduleFragment.irBuiltins,
-            expectDescriptorToSymbol = expectDescriptorToSymbol,
+            expectDescriptorToSymbol,
+            compatibilityMode,
             skipExpects = !configuration.expectActualLinker
         ).serializedIrModule(moduleFragment)
 
@@ -559,7 +565,7 @@ fun serializeModuleIntoKlib(
     val fullSerializedIr = SerializedIrModule(compiledKotlinFiles.map { it.irData })
 
     val versions = KotlinLibraryVersioning(
-        abiVersion = KotlinAbiVersion.CURRENT,
+        abiVersion = compatibilityMode.abiVersion,
         libraryVersion = null,
         compilerVersion = KotlinCompilerVersion.VERSION,
         metadataVersion = KlibMetadataVersion.INSTANCE.toString(),
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
index e6dd420495f..f70b792ca87 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
@@ -10,7 +10,6 @@ import org.jetbrains.kotlin.backend.common.serialization.IdSignatureClashTracker
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
 import org.jetbrains.kotlin.backend.common.serialization.signature.PublicIdSignatureComputer
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrFileSerializer.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrFileSerializer.kt
index 84a81912402..158bcb0683e 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrFileSerializer.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrFileSerializer.kt
@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir
 
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.DeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.IrFileSerializer
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
@@ -19,6 +20,7 @@ class JsIrFileSerializer(
     messageLogger: IrMessageLogger,
     declarationTable: DeclarationTable,
     expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
+    compatibilityMode: CompatibilityMode,
     skipExpects: Boolean,
     bodiesOnlyForInlines: Boolean = false,
     icMode: Boolean = false,
@@ -26,6 +28,7 @@ class JsIrFileSerializer(
     messageLogger,
     declarationTable,
     expectDescriptorToSymbol,
+    compatibilityMode,
     bodiesOnlyForInlines = bodiesOnlyForInlines,
     skipExpects = skipExpects,
     skipMutableState = icMode,
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrLinker.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrLinker.kt
index 48478bc63b3..18058b945a9 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrLinker.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrLinker.kt
@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.ir.util.ReferenceSymbolTable
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.TypeTranslator
 import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinAbiVersion
 import org.jetbrains.kotlin.library.KotlinLibrary
 import org.jetbrains.kotlin.library.containsErrorCode
 
@@ -37,17 +38,19 @@ class JsIrLinker(
     private val IrLibrary.libContainsErrorCode: Boolean
         get() = this is KotlinLibrary && this.containsErrorCode
 
-    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer =
-        JsModuleDeserializer(moduleDescriptor, klib ?: error("Expecting kotlin library"), strategy, klib.libContainsErrorCode)
+    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: KotlinLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer = klib?.let { lib ->
+        JsModuleDeserializer(moduleDescriptor, lib, strategy, lib.versions.abiVersion ?: KotlinAbiVersion.CURRENT, lib.libContainsErrorCode)
+    } ?: error("Expecting kotlin library")
 
-    private inner class JsModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, strategy: DeserializationStrategy, allowErrorCode: Boolean) :
-        BasicIrModuleDeserializer(this, moduleDescriptor, klib, strategy, allowErrorCode)
+
+    private inner class JsModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, strategy: DeserializationStrategy, libraryAbiVersion: KotlinAbiVersion, allowErrorCode: Boolean) :
+        BasicIrModuleDeserializer(this, moduleDescriptor, klib, strategy, libraryAbiVersion, allowErrorCode)
 
     override fun createCurrentModuleDeserializer(moduleFragment: IrModuleFragment, dependencies: Collection<IrModuleDeserializer>): IrModuleDeserializer {
         val currentModuleDeserializer = super.createCurrentModuleDeserializer(moduleFragment, dependencies)
         icData?.let {
             return CurrentModuleWithICDeserializer(currentModuleDeserializer, symbolTable, builtIns, it.icData) { lib ->
-                JsModuleDeserializer(currentModuleDeserializer.moduleDescriptor, lib, currentModuleDeserializer.strategy, it.containsErrorCode)
+                JsModuleDeserializer(currentModuleDeserializer.moduleDescriptor, lib, currentModuleDeserializer.strategy, KotlinAbiVersion.CURRENT, it.containsErrorCode)
             }
         }
         return currentModuleDeserializer
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrModuleSerializer.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrModuleSerializer.kt
index 84399737dc0..83a76551c6b 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrModuleSerializer.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsIrModuleSerializer.kt
@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir
 
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.DeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.IrModuleSerializer
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
@@ -19,11 +20,12 @@ class JsIrModuleSerializer(
     messageLogger: IrMessageLogger,
     irBuiltIns: IrBuiltIns,
     private val expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
+    compatibilityMode: CompatibilityMode,
     val skipExpects: Boolean
-) : IrModuleSerializer<JsIrFileSerializer>(messageLogger) {
+) : IrModuleSerializer<JsIrFileSerializer>(messageLogger, compatibilityMode) {
 
     private val globalDeclarationTable = JsGlobalDeclarationTable(irBuiltIns)
 
     override fun createSerializerForFile(file: IrFile): JsIrFileSerializer =
-        JsIrFileSerializer(messageLogger, DeclarationTable(globalDeclarationTable), expectDescriptorToSymbol, skipExpects = skipExpects)
+        JsIrFileSerializer(messageLogger, DeclarationTable(globalDeclarationTable), expectDescriptorToSymbol, skipExpects = skipExpects, compatibilityMode = compatibilityMode)
 }
\ No newline at end of file
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsMangler.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsMangler.kt
index 0738cb64448..0d3065b2e85 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsMangler.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsMangler.kt
@@ -19,11 +19,7 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclaration
 
 abstract class AbstractJsManglerIr : IrBasedKotlinManglerImpl() {
 
-    companion object {
-        private val exportChecker = JsIrExportChecker()
-    }
-
-    private class JsIrExportChecker : IrExportCheckerVisitor() {
+    private class JsIrExportChecker(compatibleMode: Boolean) : IrExportCheckerVisitor(compatibleMode) {
         override fun IrDeclaration.isPlatformSpecificExported() = false
     }
 
@@ -31,7 +27,7 @@ abstract class AbstractJsManglerIr : IrBasedKotlinManglerImpl() {
         override fun copy(newMode: MangleMode): IrMangleComputer = JsIrManglerComputer(builder, newMode)
     }
 
-    override fun getExportChecker(): KotlinExportChecker<IrDeclaration> = exportChecker
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<IrDeclaration> = JsIrExportChecker(compatibleMode)
 
     override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<IrDeclaration> {
         return JsIrManglerComputer(StringBuilder(256), mode)
@@ -54,7 +50,7 @@ abstract class AbstractJsDescriptorMangler : DescriptorBasedKotlinManglerImpl()
         override fun copy(newMode: MangleMode): DescriptorMangleComputer = JsDescriptorManglerComputer(builder, newMode)
     }
 
-    override fun getExportChecker(): KotlinExportChecker<DeclarationDescriptor> = exportChecker
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<DeclarationDescriptor> = exportChecker
 
     override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<DeclarationDescriptor> {
         return JsDescriptorManglerComputer(StringBuilder(256), mode)
diff --git a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt
index 5922cebcdb0..26b7219872f 100644
--- a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt
+++ b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmIrLinker.kt
@@ -21,12 +21,13 @@ import org.jetbrains.kotlin.ir.descriptors.IrAbstractFunctionFactory
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.symbols.IrFieldSymbol
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
-import org.jetbrains.kotlin.ir.symbols.isPublicApi
 import org.jetbrains.kotlin.ir.util.DeclarationStubGenerator
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.IrMessageLogger
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinAbiVersion
+import org.jetbrains.kotlin.library.KotlinLibrary
 import org.jetbrains.kotlin.load.java.descriptors.JavaCallableMemberDescriptor
 import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor
 import org.jetbrains.kotlin.load.java.lazy.descriptors.LazyJavaPackageFragment
@@ -52,17 +53,17 @@ class JvmIrLinker(
         moduleDescriptor.name.asString().startsWith("<dependencies of ")
 
     // TODO: implement special Java deserializer
-    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer {
+    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: KotlinLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer {
         if (klib != null) {
             assert(moduleDescriptor.getCapability(KlibModuleOrigin.CAPABILITY) != null)
-            return JvmModuleDeserializer(moduleDescriptor, klib, strategy)
+            return JvmModuleDeserializer(moduleDescriptor, klib, klib.versions.abiVersion ?: KotlinAbiVersion.CURRENT, strategy)
         }
 
         return MetadataJVMModuleDeserializer(moduleDescriptor, emptyList())
     }
 
-    private inner class JvmModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, strategy: DeserializationStrategy) :
-        BasicIrModuleDeserializer(this, moduleDescriptor, klib, strategy)
+    private inner class JvmModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary, libraryAbiVersion: KotlinAbiVersion, strategy: DeserializationStrategy) :
+        BasicIrModuleDeserializer(this, moduleDescriptor, klib, strategy, libraryAbiVersion)
 
     private fun DeclarationDescriptor.isJavaDescriptor(): Boolean {
         if (this is PackageFragmentDescriptor) {
@@ -122,7 +123,7 @@ class JvmIrLinker(
     }
 
     private inner class MetadataJVMModuleDeserializer(moduleDescriptor: ModuleDescriptor, dependencies: List<IrModuleDeserializer>) :
-        IrModuleDeserializer(moduleDescriptor) {
+        IrModuleDeserializer(moduleDescriptor, KotlinAbiVersion.CURRENT) {
 
         // TODO: implement proper check whether `idSig` belongs to this module
         override fun contains(idSig: IdSignature): Boolean = true
diff --git a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmMangler.kt b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmMangler.kt
index b9fbb71dd68..ed43e10f7da 100644
--- a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmMangler.kt
+++ b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/ir/backend/jvm/serialization/JvmMangler.kt
@@ -28,11 +28,7 @@ import org.jetbrains.kotlin.load.java.lazy.descriptors.isJavaField
 
 abstract class AbstractJvmManglerIr : IrBasedKotlinManglerImpl() {
 
-    companion object {
-        private val exportChecker = JvmIrExportChecker()
-    }
-
-    private class JvmIrExportChecker : IrExportCheckerVisitor() {
+    private class JvmIrExportChecker(compatibleMode: Boolean) : IrExportCheckerVisitor(compatibleMode) {
         override fun IrDeclaration.isPlatformSpecificExported() = false
     }
 
@@ -44,7 +40,7 @@ abstract class AbstractJvmManglerIr : IrBasedKotlinManglerImpl() {
             irFunction.isFromJava()
     }
 
-    override fun getExportChecker(): KotlinExportChecker<IrDeclaration> = exportChecker
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<IrDeclaration> = JvmIrExportChecker(compatibleMode)
 
     override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<IrDeclaration> {
         return JvmIrManglerComputer(StringBuilder(256), mode)
@@ -71,8 +67,7 @@ abstract class AbstractJvmDescriptorMangler(private val mainDetector: MainFuncti
         override fun addReturnTypeSpecialCase(functionDescriptor: FunctionDescriptor): Boolean =
             functionDescriptor is JavaMethodDescriptor
 
-        override fun copy(newMode: MangleMode): DescriptorMangleComputer =
-            JvmDescriptorManglerComputer(builder, mainDetector, newMode)
+        override fun copy(newMode: MangleMode): DescriptorMangleComputer = JvmDescriptorManglerComputer(builder, mainDetector, newMode)
 
         private fun isMainFunction(descriptor: FunctionDescriptor): Boolean = mainDetector?.isMain(descriptor) ?: false
 
@@ -89,10 +84,14 @@ abstract class AbstractJvmDescriptorMangler(private val mainDetector: MainFuncti
             return if (isJavaField) MangleConstant.JAVA_FIELD_SUFFIX else null
         }
 
-        override fun visitModuleDeclaration(descriptor: ModuleDescriptor, data: Nothing?) {} // SKIP in case of synthetic properties
+        override fun visitModuleDeclaration(descriptor: ModuleDescriptor, data: Nothing?) {
+            // In general, having module descriptor as `containingDeclaration` for regular declaration is considered an error (in JS/Native)
+            // because there should be `PackageFragmentDescriptor` in between
+            // but on JVM there is `SyntheticJavaPropertyDescriptor` whose parent is a module. So let just skip it.
+        }
     }
 
-    override fun getExportChecker(): KotlinExportChecker<DeclarationDescriptor> = exportChecker
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<DeclarationDescriptor> = exportChecker
 
     override fun getMangleComputer(mode: MangleMode): KotlinMangleComputer<DeclarationDescriptor> {
         return JvmDescriptorManglerComputer(StringBuilder(256), mainDetector, mode)
diff --git a/compiler/tests-common/tests/org/jetbrains/kotlin/ir/AbstractKlibTextTestCase.kt b/compiler/tests-common/tests/org/jetbrains/kotlin/ir/AbstractKlibTextTestCase.kt
index dd92a497702..e181406372b 100644
--- a/compiler/tests-common/tests/org/jetbrains/kotlin/ir/AbstractKlibTextTestCase.kt
+++ b/compiler/tests-common/tests/org/jetbrains/kotlin/ir/AbstractKlibTextTestCase.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
 import junit.framework.TestCase
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.DeserializationStrategy
 import org.jetbrains.kotlin.backend.common.serialization.KlibIrVersion
 import org.jetbrains.kotlin.backend.common.serialization.metadata.KlibMetadataIncrementalSerializer
@@ -134,7 +135,7 @@ abstract class AbstractKlibTextTestCase : CodegenTestCase() {
     protected fun serializeModule(irModuleFragment: IrModuleFragment, bindingContext: BindingContext, stdlib: KotlinLibrary, containsErrorCode: Boolean, expectActualSymbols: MutableMap<DeclarationDescriptor, IrSymbol>, skipExpect: Boolean): String {
         val ktFiles = myFiles.psiFiles
         val serializedIr =
-            JsIrModuleSerializer(IrMessageLogger.None, irModuleFragment.irBuiltins, expectActualSymbols, skipExpect).serializedIrModule(
+            JsIrModuleSerializer(IrMessageLogger.None, irModuleFragment.irBuiltins, expectActualSymbols, CompatibilityMode.CURRENT, skipExpect).serializedIrModule(
                 irModuleFragment
             )
 
diff --git a/js/js.tests/test/org/jetbrains/kotlin/benchmarks/GenerateIrRuntime.kt b/js/js.tests/test/org/jetbrains/kotlin/benchmarks/GenerateIrRuntime.kt
index 23183586a9e..61fa56b008d 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/benchmarks/GenerateIrRuntime.kt
+++ b/js/js.tests/test/org/jetbrains/kotlin/benchmarks/GenerateIrRuntime.kt
@@ -14,6 +14,7 @@ import com.intellij.psi.PsiManager
 import org.jetbrains.kotlin.analyzer.AnalysisResult
 import org.jetbrains.kotlin.backend.common.phaser.PhaseConfig
 import org.jetbrains.kotlin.backend.common.phaser.invokeToplevel
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.KlibIrVersion
 import org.jetbrains.kotlin.backend.common.serialization.metadata.KlibMetadataVersion
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureDescriptor
@@ -492,6 +493,7 @@ class GenerateIrRuntime {
             emptyList(),
             true,
             perFile,
+            abiVersion = KotlinAbiVersion.CURRENT,
             jsOutputName = null
         )
 
@@ -506,7 +508,7 @@ class GenerateIrRuntime {
 
 
     private fun doSerializeIrModule(module: IrModuleFragment): SerializedIrModule {
-        val serializedIr = JsIrModuleSerializer(IrMessageLogger.None, module.irBuiltins, mutableMapOf(), true).serializedIrModule(module)
+        val serializedIr = JsIrModuleSerializer(IrMessageLogger.None, module.irBuiltins, mutableMapOf(), CompatibilityMode.CURRENT, true).serializedIrModule(module)
         return serializedIr
     }
 
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
index 8fe7819005a..dfc92e72011 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
@@ -5,6 +5,7 @@ import org.jetbrains.kotlin.backend.common.IrValidator
 import org.jetbrains.kotlin.backend.common.IrValidatorConfig
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.phaser.*
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.metadata.KlibMetadataMonolithicSerializer
 import org.jetbrains.kotlin.backend.konan.MemoryModel
 import org.jetbrains.kotlin.backend.konan.llvm.*
@@ -155,7 +156,7 @@ internal val serializerPhase = konanUnitPhase(
 
             serializedIr = irModule?.let { ir ->
                 KonanIrModuleSerializer(
-                    messageLogger, ir.irBuiltins, expectDescriptorToSymbol, skipExpects = !expectActualLinker
+                    messageLogger, ir.irBuiltins, expectDescriptorToSymbol, skipExpects = !expectActualLinker, compatibilityMode = CompatibilityMode.CURRENT
                 ).serializedIrModule(ir)
             }
 
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BinaryInterface.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BinaryInterface.kt
index af85951e56e..c0ab278b06e 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BinaryInterface.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/BinaryInterface.kt
@@ -34,9 +34,9 @@ import org.jetbrains.kotlin.name.Name
 object KonanBinaryInterface {
     private val mangler = object : AbstractKonanIrMangler(true) {}
 
-    private val exportChecker = mangler.getExportChecker()
+    private val exportChecker = mangler.getExportChecker(compatibleMode = true)
 
-    val IrFunction.functionName: String get() = mangler.run { signatureString }
+    val IrFunction.functionName: String get() = mangler.run { signatureString() }
 
     val IrFunction.symbolName: String get() = funSymbolNameImpl()
     val IrField.symbolName: String get() =
@@ -65,7 +65,7 @@ object KonanBinaryInterface {
             return name // no wrapping currently required
         }
 
-        return withPrefix(MangleConstant.FUN_PREFIX, mangler.run { mangleString })
+        return withPrefix(MangleConstant.FUN_PREFIX, mangler.run { mangleString() })
     }
 
     private fun IrField.fieldSymbolNameImpl(): String {
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrFileSerializer.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrFileSerializer.kt
index 52d1371d352..439cf4da51e 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrFileSerializer.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrFileSerializer.kt
@@ -1,5 +1,6 @@
 package org.jetbrains.kotlin.backend.konan.serialization
 
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
 import org.jetbrains.kotlin.backend.common.serialization.DeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.IrFileSerializer
 import org.jetbrains.kotlin.backend.konan.RuntimeNames
@@ -16,8 +17,9 @@ class KonanIrFileSerializer(
     declarationTable: DeclarationTable,
     expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
     skipExpects: Boolean,
-    bodiesOnlyForInlines: Boolean = false
-): IrFileSerializer(messageLogger, declarationTable, expectDescriptorToSymbol, skipExpects = skipExpects, bodiesOnlyForInlines = bodiesOnlyForInlines) {
+    bodiesOnlyForInlines: Boolean = false,
+    compatibilityMode: CompatibilityMode
+): IrFileSerializer(messageLogger, declarationTable, expectDescriptorToSymbol, compatibilityMode, bodiesOnlyForInlines, skipExpects) {
 
     override fun backendSpecificExplicitRoot(node: IrAnnotationContainer): Boolean {
         val fqn = when (node) {
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrModuleSerializer.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrModuleSerializer.kt
index da413a51569..6171c8719d6 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrModuleSerializer.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrModuleSerializer.kt
@@ -1,6 +1,7 @@
 package org.jetbrains.kotlin.backend.konan.serialization
 
-import org.jetbrains.kotlin.backend.common.serialization.*
+import org.jetbrains.kotlin.backend.common.serialization.CompatibilityMode
+import org.jetbrains.kotlin.backend.common.serialization.IrModuleSerializer
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
 import org.jetbrains.kotlin.backend.konan.ir.interop.IrProviderForCEnumAndCStructStubs
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
@@ -13,8 +14,9 @@ class KonanIrModuleSerializer(
     messageLogger: IrMessageLogger,
     irBuiltIns: IrBuiltIns,
     private val expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
-    val skipExpects: Boolean
-) : IrModuleSerializer<KonanIrFileSerializer>(messageLogger) {
+    val skipExpects: Boolean,
+    compatibilityMode: CompatibilityMode
+) : IrModuleSerializer<KonanIrFileSerializer>(messageLogger, compatibilityMode) {
 
     private val globalDeclarationTable = KonanGlobalDeclarationTable(irBuiltIns)
 
@@ -28,5 +30,5 @@ class KonanIrModuleSerializer(
             file.fileEntry.name != IrProviderForCEnumAndCStructStubs.cTypeDefinitionsFileName
 
     override fun createSerializerForFile(file: IrFile): KonanIrFileSerializer =
-            KonanIrFileSerializer(messageLogger, KonanDeclarationTable(globalDeclarationTable), expectDescriptorToSymbol, skipExpects = skipExpects)
+            KonanIrFileSerializer(messageLogger, KonanDeclarationTable(globalDeclarationTable), expectDescriptorToSymbol, skipExpects = skipExpects, compatibilityMode = compatibilityMode)
 }
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrlinker.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrlinker.kt
index 2a02eebc4d0..23470525ecf 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrlinker.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrlinker.kt
@@ -41,7 +41,7 @@ import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
-import org.jetbrains.kotlin.library.IrLibrary
+import org.jetbrains.kotlin.library.KotlinAbiVersion
 import org.jetbrains.kotlin.library.KotlinLibrary
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
@@ -93,16 +93,16 @@ internal class KonanIrLinker(
     private val forwardDeclarationDeserializer = forwardModuleDescriptor?.let { KonanForwardDeclarationModuleDeserializer(it) }
     override val fakeOverrideBuilder = FakeOverrideBuilder(this, symbolTable, KonanManglerIr, builtIns, KonanFakeOverrideClassFilter)
 
-    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: IrLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer {
+    override fun createModuleDeserializer(moduleDescriptor: ModuleDescriptor, klib: KotlinLibrary?, strategy: DeserializationStrategy): IrModuleDeserializer {
         if (moduleDescriptor === forwardModuleDescriptor) {
             return forwardDeclarationDeserializer ?: error("forward declaration deserializer expected")
         }
 
-        if (klib is KotlinLibrary && klib.isInteropLibrary()) {
+        if (klib != null && klib.isInteropLibrary()) {
             // See https://youtrack.jetbrains.com/issue/KT-43517.
             // Disabling this flag forces linker to generate IR.
             val isCached = false //cachedLibraries.isLibraryCached(klib)
-            return KonanInteropModuleDeserializer(moduleDescriptor, isCached)
+            return KonanInteropModuleDeserializer(moduleDescriptor, klib, isCached)
         }
 
         return KonanModuleDeserializer(moduleDescriptor, klib ?: error("Expecting kotlin library"), strategy)
@@ -110,16 +110,17 @@ internal class KonanIrLinker(
 
     private inner class KonanModuleDeserializer(
             moduleDescriptor: ModuleDescriptor,
-            klib: IrLibrary,
+            klib: KotlinLibrary,
             strategy: DeserializationStrategy
-    ): BasicIrModuleDeserializer(this@KonanIrLinker, moduleDescriptor, klib, strategy){
+    ): BasicIrModuleDeserializer(this@KonanIrLinker, moduleDescriptor, klib, strategy, klib.versions.abiVersion ?: KotlinAbiVersion.CURRENT) {
         override val moduleFragment: IrModuleFragment = KonanIrModuleFragmentImpl(moduleDescriptor, builtIns, emptyList())
     }
 
     private inner class KonanInteropModuleDeserializer(
             moduleDescriptor: ModuleDescriptor,
+            klib: KotlinLibrary,
             private val isLibraryCached: Boolean
-    ) : IrModuleDeserializer(moduleDescriptor) {
+    ) : IrModuleDeserializer(moduleDescriptor, klib.versions.abiVersion ?: KotlinAbiVersion.CURRENT) {
         init {
             assert(moduleDescriptor.kotlinLibrary.isInteropLibrary())
         }
@@ -170,7 +171,7 @@ internal class KonanIrLinker(
         override val moduleDependencies: Collection<IrModuleDeserializer> = listOfNotNull(forwardDeclarationDeserializer)
     }
 
-    private inner class KonanForwardDeclarationModuleDeserializer(moduleDescriptor: ModuleDescriptor) : IrModuleDeserializer(moduleDescriptor) {
+    private inner class KonanForwardDeclarationModuleDeserializer(moduleDescriptor: ModuleDescriptor) : IrModuleDeserializer(moduleDescriptor, KotlinAbiVersion.CURRENT) {
         init {
             assert(moduleDescriptor.isForwardDeclarationModule)
         }
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanMangler.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanMangler.kt
index 0169c9c5415..0fb5d0fe486 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanMangler.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanMangler.kt
@@ -1,5 +1,6 @@
 package org.jetbrains.kotlin.backend.konan.serialization
 
+import org.jetbrains.kotlin.backend.common.serialization.mangle.KotlinExportChecker
 import org.jetbrains.kotlin.backend.common.serialization.mangle.MangleMode
 import org.jetbrains.kotlin.backend.common.serialization.mangle.descriptor.DescriptorBasedKotlinManglerImpl
 import org.jetbrains.kotlin.backend.common.serialization.mangle.descriptor.DescriptorExportCheckerVisitor
@@ -12,40 +13,42 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.util.hasAnnotation
+import org.jetbrains.kotlin.types.KotlinType
 
 abstract class AbstractKonanIrMangler(private val withReturnType: Boolean) : IrBasedKotlinManglerImpl() {
-    override fun getExportChecker(): IrExportCheckerVisitor = KonanIrExportChecker()
+    override fun getExportChecker(compatibleMode: Boolean): IrExportCheckerVisitor = KonanIrExportChecker(compatibleMode)
 
-    override fun getMangleComputer(mode: MangleMode): IrMangleComputer =
-            KonanIrManglerComputer(StringBuilder(256), mode, withReturnType)
+    override fun getMangleComputer(mode: MangleMode): IrMangleComputer = KonanIrManglerComputer(StringBuilder(256), mode, withReturnType)
 
-    private class KonanIrExportChecker : IrExportCheckerVisitor() {
-        override fun IrDeclaration.isPlatformSpecificExported(): Boolean {
-            if (this is IrSimpleFunction) if (isFakeOverride) return false
+    override fun IrDeclaration.isPlatformSpecificExport(): Boolean {
+        if (this is IrSimpleFunction) if (isFakeOverride) return false
 
-            // TODO: revise
-            if (annotations.hasAnnotation(RuntimeNames.symbolNameAnnotation)) {
-                // Treat any `@SymbolName` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(KonanFqNames.gcUnsafeCall)) {
+        // TODO: revise
+        if (annotations.hasAnnotation(RuntimeNames.symbolNameAnnotation)) {
+            // Treat any `@SymbolName` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(KonanFqNames.gcUnsafeCall)) {
                 // Treat any `@GCUnsafeCall` declaration as exported.
                 return true
             }
             if (annotations.hasAnnotation(RuntimeNames.exportForCppRuntime)) {
-                // Treat any `@ExportForCppRuntime` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(RuntimeNames.cnameAnnotation)) {
-                // Treat `@CName` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(RuntimeNames.exportForCompilerAnnotation)) {
-                return true
-            }
-
-            return false
+            // Treat any `@ExportForCppRuntime` declaration as exported.
+            return true
         }
+        if (annotations.hasAnnotation(RuntimeNames.cnameAnnotation)) {
+            // Treat `@CName` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(RuntimeNames.exportForCompilerAnnotation)) {
+            return true
+        }
+
+        return false
+    }
+
+    private inner class KonanIrExportChecker(compatibleMode: Boolean) : IrExportCheckerVisitor(compatibleMode) {
+        override fun IrDeclaration.isPlatformSpecificExported(): Boolean = isPlatformSpecificExport()
     }
 
     private class KonanIrManglerComputer(builder: StringBuilder, mode: MangleMode, private val withReturnType: Boolean) : IrMangleComputer(builder, mode) {
@@ -88,39 +91,40 @@ abstract class AbstractKonanIrMangler(private val withReturnType: Boolean) : IrB
 object KonanManglerIr : AbstractKonanIrMangler(false)
 
 abstract class AbstractKonanDescriptorMangler : DescriptorBasedKotlinManglerImpl() {
-    override fun getExportChecker(): DescriptorExportCheckerVisitor = KonanDescriptorExportChecker()
+    override fun getExportChecker(compatibleMode: Boolean): KotlinExportChecker<DeclarationDescriptor> = KonanDescriptorExportChecker()
 
-    override fun getMangleComputer(mode: MangleMode): DescriptorMangleComputer =
-            KonanDescriptorMangleComputer(StringBuilder(256), mode)
+    override fun getMangleComputer(mode: MangleMode): DescriptorMangleComputer = KonanDescriptorMangleComputer(StringBuilder(256), mode)
 
-    private class KonanDescriptorExportChecker : DescriptorExportCheckerVisitor() {
-        override fun DeclarationDescriptor.isPlatformSpecificExported(): Boolean {
-            if (this is SimpleFunctionDescriptor) {
-                if (kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) return false
-            }
-            // TODO: revise
-            if (annotations.hasAnnotation(RuntimeNames.symbolNameAnnotation)) {
-                // Treat any `@SymbolName` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(KonanFqNames.gcUnsafeCall)) {
-                // Treat any `@GCUnsafeCall` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(RuntimeNames.exportForCppRuntime)) {
-                // Treat any `@ExportForCppRuntime` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(RuntimeNames.cnameAnnotation)) {
-                // Treat `@CName` declaration as exported.
-                return true
-            }
-            if (annotations.hasAnnotation(RuntimeNames.exportForCompilerAnnotation)) {
-                return true
-            }
+    private inner class KonanDescriptorExportChecker : DescriptorExportCheckerVisitor() {
+        override fun DeclarationDescriptor.isPlatformSpecificExported(): Boolean = isPlatformSpecificExport()
+    }
 
-            return false
+    override fun DeclarationDescriptor.isPlatformSpecificExport(): Boolean {
+        if (this is SimpleFunctionDescriptor) {
+            if (kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) return false
         }
+        // TODO: revise
+        if (annotations.hasAnnotation(RuntimeNames.symbolNameAnnotation)) {
+            // Treat any `@SymbolName` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(KonanFqNames.gcUnsafeCall)) {
+            // Treat any `@GCUnsafeCall` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(RuntimeNames.exportForCppRuntime)) {
+            // Treat any `@ExportForCppRuntime` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(RuntimeNames.cnameAnnotation)) {
+            // Treat `@CName` declaration as exported.
+            return true
+        }
+        if (annotations.hasAnnotation(RuntimeNames.exportForCompilerAnnotation)) {
+            return true
+        }
+
+        return false
     }
 
     private class KonanDescriptorMangleComputer(builder: StringBuilder, mode: MangleMode) : DescriptorMangleComputer(builder, mode) {