diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor1.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor1.kt
index ba6ac834cb1..d0885def5ac 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor1.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor1.kt
@@ -5,14 +5,15 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.builder
 
-import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.descriptors.commonizer.Target
 import org.jetbrains.kotlin.descriptors.commonizer.builder.CommonizedMemberScope.Companion.plusAssign
 import org.jetbrains.kotlin.descriptors.commonizer.builder.CommonizedPackageFragmentProvider.Companion.plusAssign
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.dimension
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.utils.addIfNotNull
 
@@ -51,7 +52,8 @@ internal class DeclarationsBuilderVisitor1(
 
     override fun visitModuleNode(node: CirModuleNode, data: List<DeclarationDescriptor?>): List<ModuleDescriptorImpl?> {
         // build module descriptors:
-        val moduleDescriptorsGroup = CommonizedGroup<ModuleDescriptorImpl>(node.dimension)
+        val moduleDescriptorsGroup =
+            CommonizedGroup<ModuleDescriptorImpl>(node.dimension)
         node.buildDescriptors(components, moduleDescriptorsGroup)
         val moduleDescriptors = moduleDescriptorsGroup.toList()
 
@@ -74,7 +76,8 @@ internal class DeclarationsBuilderVisitor1(
         val containingDeclarations = data.asListContaining<ModuleDescriptorImpl>()
 
         // build package fragments:
-        val packageFragmentsGroup = CommonizedGroup<CommonizedPackageFragmentDescriptor>(node.dimension)
+        val packageFragmentsGroup =
+            CommonizedGroup<CommonizedPackageFragmentDescriptor>(node.dimension)
         node.buildDescriptors(components, packageFragmentsGroup, containingDeclarations)
         val packageFragments = packageFragmentsGroup.toList()
 
@@ -102,7 +105,10 @@ internal class DeclarationsBuilderVisitor1(
         error("This method should not be called in ${this::class.java}")
 
     override fun visitClassNode(node: CirClassNode, data: List<DeclarationDescriptor?>): List<DeclarationDescriptor?> {
-        val classesGroup = CommonizedGroup<ClassifierDescriptorWithTypeParameters>(node.dimension)
+        val classesGroup =
+            CommonizedGroup<ClassifierDescriptorWithTypeParameters>(
+                node.dimension
+            )
         node.buildDescriptors(components, classesGroup, data)
         val classes = classesGroup.toList().asListContaining<CommonizedClassDescriptor>()
 
@@ -124,7 +130,10 @@ internal class DeclarationsBuilderVisitor1(
         error("This method should not be called in ${this::class.java}")
 
     override fun visitTypeAliasNode(node: CirTypeAliasNode, data: List<DeclarationDescriptor?>): List<DeclarationDescriptor?> {
-        val typeAliasesGroup = CommonizedGroup<ClassifierDescriptorWithTypeParameters>(node.dimension)
+        val typeAliasesGroup =
+            CommonizedGroup<ClassifierDescriptorWithTypeParameters>(
+                node.dimension
+            )
         node.buildDescriptors(components, typeAliasesGroup, data)
         val typeAliases = typeAliasesGroup.toList()
 
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor2.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor2.kt
index acf8751ac52..0a94c5d5243 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor2.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/DeclarationsBuilderVisitor2.kt
@@ -6,12 +6,12 @@
 package org.jetbrains.kotlin.descriptors.commonizer.builder
 
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.builder.CommonizedMemberScope.Companion.plusAssign
+import org.jetbrains.kotlin.descriptors.commonizer.builder.DeclarationsBuilderVisitor1.Companion.asListContaining
 import org.jetbrains.kotlin.descriptors.commonizer.builder.DeclarationsBuilderVisitor1.Companion.noContainingDeclarations
 import org.jetbrains.kotlin.descriptors.commonizer.builder.DeclarationsBuilderVisitor1.Companion.noReturningDeclarations
-import org.jetbrains.kotlin.descriptors.commonizer.builder.DeclarationsBuilderVisitor1.Companion.asListContaining
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 
 /** Builds and initializes the new tree of common descriptors */
@@ -65,14 +65,16 @@ internal class DeclarationsBuilderVisitor2(
     }
 
     override fun visitPropertyNode(node: CirPropertyNode, data: List<DeclarationDescriptor?>): List<PropertyDescriptor?> {
-        val propertyDescriptorsGroup = CommonizedGroup<PropertyDescriptor>(node.dimension)
+        val propertyDescriptorsGroup =
+            CommonizedGroup<PropertyDescriptor>(node.dimension)
         node.buildDescriptors(components, propertyDescriptorsGroup, data)
 
         return propertyDescriptorsGroup.toList()
     }
 
     override fun visitFunctionNode(node: CirFunctionNode, data: List<DeclarationDescriptor?>): List<DeclarationDescriptor?> {
-        val functionDescriptorsGroup = CommonizedGroup<SimpleFunctionDescriptor>(node.dimension)
+        val functionDescriptorsGroup =
+            CommonizedGroup<SimpleFunctionDescriptor>(node.dimension)
         node.buildDescriptors(components, functionDescriptorsGroup, data)
 
         return functionDescriptorsGroup.toList()
@@ -114,7 +116,8 @@ internal class DeclarationsBuilderVisitor2(
     override fun visitClassConstructorNode(node: CirClassConstructorNode, data: List<DeclarationDescriptor?>): List<DeclarationDescriptor?> {
         val containingDeclarations = data.asListContaining<CommonizedClassDescriptor>()
 
-        val constructorsGroup = CommonizedGroup<ClassConstructorDescriptor>(node.dimension)
+        val constructorsGroup =
+            CommonizedGroup<ClassConstructorDescriptor>(node.dimension)
         node.buildDescriptors(components, constructorsGroup, containingDeclarations)
 
         return constructorsGroup.toList()
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/utils.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/builderUtils.kt
similarity index 97%
rename from konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/utils.kt
rename to konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/builderUtils.kt
index b1b1a968a73..06036dccb93 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/utils.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/builderUtils.kt
@@ -7,10 +7,10 @@ package org.jetbrains.kotlin.descriptors.commonizer.builder
 
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
-import org.jetbrains.kotlin.descriptors.commonizer.isUnderStandardKotlinPackages
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirSimpleTypeKind.Companion.areCompatible
-import org.jetbrains.kotlin.descriptors.commonizer.resolveClassOrTypeAliasByFqName
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isUnderStandardKotlinPackages
+import org.jetbrains.kotlin.descriptors.commonizer.utils.resolveClassOrTypeAliasByFqName
 import org.jetbrains.kotlin.descriptors.impl.ValueParameterDescriptorImpl
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.FqName
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/classDescriptors.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/classDescriptors.kt
index 7fb470c933e..9d457dd0f9a 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/classDescriptors.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/classDescriptors.kt
@@ -5,10 +5,12 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.builder
 
-import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
+import org.jetbrains.kotlin.descriptors.ClassConstructorDescriptor
+import org.jetbrains.kotlin.descriptors.ClassKind
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.name.FqName
 
 internal fun CirClassNode.buildDescriptors(
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/context.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/context.kt
index 115e1bee2d9..3ce2933ce1c 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/context.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/context.kt
@@ -7,14 +7,14 @@ package org.jetbrains.kotlin.descriptors.commonizer.builder
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.Target
-import org.jetbrains.kotlin.descriptors.commonizer.createKotlinNativeForwardDeclarationsModule
-import org.jetbrains.kotlin.descriptors.commonizer.isUnderKotlinNativeSyntheticPackages
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.dimension
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
+import org.jetbrains.kotlin.descriptors.commonizer.utils.createKotlinNativeForwardDeclarationsModule
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isUnderKotlinNativeSyntheticPackages
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.FqName
@@ -29,13 +29,23 @@ class DeclarationsBuilderCache(dimension: Int) {
         check(dimension > 0)
     }
 
-    private val modules = CommonizedGroup<List<ModuleDescriptorImpl>>(dimension)
-    private val packageFragments = CommonizedGroupMap<Pair<Name, FqName>, CommonizedPackageFragmentDescriptor>(dimension)
-    private val classes = CommonizedGroupMap<FqName, CommonizedClassDescriptor>(dimension)
-    private val typeAliases = CommonizedGroupMap<FqName, CommonizedTypeAliasDescriptor>(dimension)
+    private val modules =
+        CommonizedGroup<List<ModuleDescriptorImpl>>(dimension)
+    private val packageFragments =
+        CommonizedGroupMap<Pair<Name, FqName>, CommonizedPackageFragmentDescriptor>(
+            dimension
+        )
+    private val classes =
+        CommonizedGroupMap<FqName, CommonizedClassDescriptor>(dimension)
+    private val typeAliases =
+        CommonizedGroupMap<FqName, CommonizedTypeAliasDescriptor>(
+            dimension
+        )
 
-    private val forwardDeclarationsModules = CommonizedGroup<ModuleDescriptorImpl>(dimension)
-    private val allModulesWithDependencies = CommonizedGroup<List<ModuleDescriptor>>(dimension)
+    private val forwardDeclarationsModules =
+        CommonizedGroup<ModuleDescriptorImpl>(dimension)
+    private val allModulesWithDependencies =
+        CommonizedGroup<List<ModuleDescriptor>>(dimension)
 
     fun getCachedPackageFragments(moduleName: Name, packageFqName: FqName): List<CommonizedPackageFragmentDescriptor?> =
         packageFragments.getOrFail(moduleName to packageFqName)
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/functionDescriptors.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/functionDescriptors.kt
index 5e178a33139..92ea699028b 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/functionDescriptors.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/functionDescriptors.kt
@@ -9,10 +9,10 @@ import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.SourceElement
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirFunction
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirFunctionNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
 
 internal fun CirFunctionNode.buildDescriptors(
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/moduleDescriptors.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/moduleDescriptors.kt
index b9f7ad4b80b..f2cada42d57 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/moduleDescriptors.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/moduleDescriptors.kt
@@ -5,10 +5,10 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.builder
 
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirModule
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirModuleNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 
 internal fun CirModuleNode.buildDescriptors(
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/packageFragments.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/packageFragments.kt
index dfde683bc50..625aab9257d 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/packageFragments.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/packageFragments.kt
@@ -6,10 +6,10 @@
 package org.jetbrains.kotlin.descriptors.commonizer.builder
 
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirPackage
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirPackageNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.descriptors.impl.PackageFragmentDescriptorImpl
 import org.jetbrains.kotlin.name.FqName
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/propertyDescriptors.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/propertyDescriptors.kt
index 99e803700a5..1777bdfcd48 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/propertyDescriptors.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/propertyDescriptors.kt
@@ -9,10 +9,10 @@ import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.SourceElement
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirProperty
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirPropertyNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.impl.FieldDescriptorImpl
 import org.jetbrains.kotlin.descriptors.impl.PropertyDescriptorImpl
 import org.jetbrains.kotlin.resolve.DescriptorFactory
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/typeAliasDescriptors.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/typeAliasDescriptors.kt
index 4eb6b066075..acdb349a06d 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/typeAliasDescriptors.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/typeAliasDescriptors.kt
@@ -7,11 +7,11 @@ package org.jetbrains.kotlin.descriptors.commonizer.builder
 
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirClass
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirTypeAlias
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirTypeAliasNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.indexOfCommon
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
 import org.jetbrains.kotlin.name.FqName
 
 internal fun CirTypeAliasNode.buildDescriptors(
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cli.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cli.kt
index 04c60858cea..b6415d27d09 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cli.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cli.kt
@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.config.LanguageVersionSettingsImpl
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.commonizer.ModuleForCommonization.DeserializedModule
 import org.jetbrains.kotlin.descriptors.commonizer.ModuleForCommonization.SyntheticModule
+import org.jetbrains.kotlin.descriptors.commonizer.utils.createKotlinNativeForwardDeclarationsModule
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.ir.util.UniqId
 import org.jetbrains.kotlin.konan.library.*
@@ -153,10 +154,11 @@ private fun loadModules(repository: File, targets: List<KonanTarget>): Map<Input
             DeserializedModule(rawModule, data, File(library.libraryFile.path))
         }
 
-        val rawForwardDeclarationsModule = createKotlinNativeForwardDeclarationsModule(
-            storageManager = storageManager,
-            builtIns = rawStdlibModule.builtIns
-        )
+        val rawForwardDeclarationsModule =
+            createKotlinNativeForwardDeclarationsModule(
+                storageManager = storageManager,
+                builtIns = rawStdlibModule.builtIns
+            )
 
         val onlyDeserializedModules = listOf(rawStdlibModule) + otherModules.map { it.module }
         val allModules = onlyDeserializedModules + rawForwardDeclarationsModule
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
index 66d8819aadf..d2919a9c8e1 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/CommonizationVisitor.kt
@@ -5,8 +5,8 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.core
 
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 
 internal class CommonizationVisitor(
     private val root: CirRootNode
@@ -89,7 +89,8 @@ internal class CommonizationVisitor(
             }
 
             // find out common (and commonized) supertypes
-            val supertypesMap = CommonizedGroupMap<String, CirType>(node.target.size)
+            val supertypesMap =
+                CommonizedGroupMap<String, CirType>(node.target.size)
             node.target.forEachIndexed { index, clazz ->
                 for (supertype in clazz!!.supertypes) {
                     supertypesMap[supertype.fqNameWithTypeParameters][index] = supertype
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt
index cdc94092e49..c5471c8c361 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt
@@ -5,8 +5,8 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.core
 
-import org.jetbrains.kotlin.descriptors.commonizer.isUnderStandardKotlinPackages
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isUnderStandardKotlinPackages
 import org.jetbrains.kotlin.types.AbstractStrictEqualityTypeChecker
 
 interface TypeCommonizer : Commonizer<CirType, CirType> {
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/ValueParameterCommonizer.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/ValueParameterCommonizer.kt
index f6d0347c59b..1eea32eeb67 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/ValueParameterCommonizer.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/ValueParameterCommonizer.kt
@@ -5,11 +5,11 @@
 
 package org.jetbrains.kotlin.descriptors.commonizer.core
 
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirCommonValueParameter
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirValueParameter
-import org.jetbrains.kotlin.descriptors.commonizer.isNull
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirClassifiersCache
+import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirCommonValueParameter
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirType
+import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirValueParameter
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isNull
 import org.jetbrains.kotlin.name.Name
 
 interface ValueParameterCommonizer : Commonizer<CirValueParameter, CirValueParameter> {
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/classifiers.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/classifiers.kt
index 758e12cd7ba..9549b79bbcb 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/classifiers.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/classifiers.kt
@@ -6,11 +6,11 @@
 package org.jetbrains.kotlin.descriptors.commonizer.mergedtree
 
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
-import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.*
+import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirClassNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode.ClassifiersCacheImpl
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildClassNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildTypeAliasNode
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.storage.NullableLazyValue
 import org.jetbrains.kotlin.storage.StorageManager
@@ -23,10 +23,20 @@ internal fun mergeClasses(
 ): CirClassNode {
     val node = buildClassNode(storageManager, cacheRW, containingDeclarationCommon, classes)
 
-    val constructorsMap = CommonizedGroupMap<ConstructorApproximationKey, ClassConstructorDescriptor>(classes.size)
-    val propertiesMap = CommonizedGroupMap<PropertyApproximationKey, PropertyDescriptor>(classes.size)
-    val functionsMap = CommonizedGroupMap<FunctionApproximationKey, SimpleFunctionDescriptor>(classes.size)
-    val classesMap = CommonizedGroupMap<Name, ClassDescriptor>(classes.size)
+    val constructorsMap =
+        CommonizedGroupMap<ConstructorApproximationKey, ClassConstructorDescriptor>(
+            classes.size
+        )
+    val propertiesMap =
+        CommonizedGroupMap<PropertyApproximationKey, PropertyDescriptor>(
+            classes.size
+        )
+    val functionsMap =
+        CommonizedGroupMap<FunctionApproximationKey, SimpleFunctionDescriptor>(
+            classes.size
+        )
+    val classesMap =
+        CommonizedGroupMap<Name, ClassDescriptor>(classes.size)
 
     classes.forEachIndexed { index, clazz ->
         clazz?.constructors?.forEach { constructorsMap[ConstructorApproximationKey(it)][index] = it }
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/CirType.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/CirType.kt
index 84709438904..55dd2e3ad38 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/CirType.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/CirType.kt
@@ -9,11 +9,11 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.declarationDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.fqName
-import org.jetbrains.kotlin.descriptors.commonizer.fqNameWithTypeParameters
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirSimpleTypeKind.CLASS
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirSimpleTypeKind.TYPE_ALIAS
+import org.jetbrains.kotlin.descriptors.commonizer.utils.declarationDescriptor
+import org.jetbrains.kotlin.descriptors.commonizer.utils.fqName
+import org.jetbrains.kotlin.descriptors.commonizer.utils.fqNameWithTypeParameters
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.types.*
 import kotlin.LazyThreadSafetyMode.PUBLICATION
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/nodeBuilders.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/nodeBuilders.kt
index 035c2a38b31..eec1969d590 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/nodeBuilders.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/ir/nodeBuilders.kt
@@ -6,11 +6,12 @@
 package org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir
 
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.commonizer.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroup
+import org.jetbrains.kotlin.descriptors.commonizer.InputTarget
+import org.jetbrains.kotlin.descriptors.commonizer.OutputTarget
 import org.jetbrains.kotlin.descriptors.commonizer.core.*
-import org.jetbrains.kotlin.descriptors.commonizer.firstNonNull
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode.ClassifiersCacheImpl
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroup
+import org.jetbrains.kotlin.descriptors.commonizer.utils.firstNonNull
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/memberScopes.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/memberScopes.kt
index 1b7b2e3078d..28d26d1e5c0 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/memberScopes.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/memberScopes.kt
@@ -7,9 +7,9 @@ package org.jetbrains.kotlin.descriptors.commonizer.mergedtree
 
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.commonizer.core.Commonizer
-import org.jetbrains.kotlin.descriptors.commonizer.fqNameWithTypeParameters
-import org.jetbrains.kotlin.descriptors.commonizer.isBlacklistedDarwinFunction
-import org.jetbrains.kotlin.descriptors.commonizer.isKniBridgeFunction
+import org.jetbrains.kotlin.descriptors.commonizer.utils.fqNameWithTypeParameters
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isBlacklistedDarwinFunction
+import org.jetbrains.kotlin.descriptors.commonizer.utils.isKniBridgeFunction
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/modules.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/modules.kt
index 38d2b8fe361..7912311e046 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/modules.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/modules.kt
@@ -7,13 +7,10 @@ package org.jetbrains.kotlin.descriptors.commonizer.mergedtree
 
 import org.jetbrains.kotlin.backend.common.serialization.metadata.impl.ExportedForwardDeclarationsPackageFragmentDescriptor
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.*
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
-import org.jetbrains.kotlin.descriptors.commonizer.firstNonNull
-import org.jetbrains.kotlin.descriptors.commonizer.isUnderKotlinNativeSyntheticPackages
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirModuleNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildModuleNode
+import org.jetbrains.kotlin.descriptors.commonizer.utils.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.resolve.scopes.ChainedMemberScope
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
@@ -27,7 +24,8 @@ internal fun mergeModules(
 ): CirModuleNode {
     val node = buildModuleNode(storageManager, modules)
 
-    val packageMemberScopesMap = CommonizedGroupMap<FqName, MemberScope>(modules.size)
+    val packageMemberScopesMap =
+        CommonizedGroupMap<FqName, MemberScope>(modules.size)
 
     modules.forEachIndexed { index, module ->
         module?.collectNonEmptyPackageMemberScopes { packageFqName, memberScope ->
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/packages.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/packages.kt
index c5a39eec033..d2578ad6f88 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/packages.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/packages.kt
@@ -9,10 +9,10 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirPackageNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildPackageNode
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
@@ -27,10 +27,19 @@ internal fun mergePackages(
 ): CirPackageNode {
     val node = buildPackageNode(storageManager, moduleName, packageFqName, packageMemberScopes)
 
-    val propertiesMap = CommonizedGroupMap<PropertyApproximationKey, PropertyDescriptor>(packageMemberScopes.size)
-    val functionsMap = CommonizedGroupMap<FunctionApproximationKey, SimpleFunctionDescriptor>(packageMemberScopes.size)
-    val classesMap = CommonizedGroupMap<Name, ClassDescriptor>(packageMemberScopes.size)
-    val typeAliasesMap = CommonizedGroupMap<Name, TypeAliasDescriptor>(packageMemberScopes.size)
+    val propertiesMap =
+        CommonizedGroupMap<PropertyApproximationKey, PropertyDescriptor>(
+            packageMemberScopes.size
+        )
+    val functionsMap =
+        CommonizedGroupMap<FunctionApproximationKey, SimpleFunctionDescriptor>(
+            packageMemberScopes.size
+        )
+    val classesMap =
+        CommonizedGroupMap<Name, ClassDescriptor>(packageMemberScopes.size)
+    val typeAliasesMap = CommonizedGroupMap<Name, TypeAliasDescriptor>(
+        packageMemberScopes.size
+    )
 
     packageMemberScopes.forEachIndexed { index, memberScope ->
         memberScope?.collectMembers(
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/root.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/root.kt
index d8a3c90930c..a3c4f16b30d 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/root.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/root.kt
@@ -6,10 +6,10 @@
 package org.jetbrains.kotlin.descriptors.commonizer.mergedtree
 
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.InputTarget
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildRootNode
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.storage.StorageManager
 
@@ -19,7 +19,8 @@ internal fun mergeRoots(
 ): CirRootNode {
     val node = buildRootNode(storageManager, modulesByTargets.map { it.first })
 
-    val modulesMap = CommonizedGroupMap<Name, ModuleDescriptor>(modulesByTargets.size)
+    val modulesMap =
+        CommonizedGroupMap<Name, ModuleDescriptor>(modulesByTargets.size)
 
     modulesByTargets.forEachIndexed { index, (_, modules) ->
         for (module in modules) {
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils.kt
deleted file mode 100644
index 43aea744363..00000000000
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils.kt
+++ /dev/null
@@ -1,149 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.descriptors.commonizer
-
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
-import org.jetbrains.kotlin.incremental.components.LookupLocation
-import org.jetbrains.kotlin.konan.library.KonanFactories.DefaultDeserializedDescriptorFactory
-import org.jetbrains.kotlin.konan.library.KonanFactories.createDefaultKonanResolvedModuleDescriptorsFactory
-import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
-import org.jetbrains.kotlin.serialization.konan.impl.ForwardDeclarationsFqNames
-import org.jetbrains.kotlin.serialization.konan.impl.KlibResolvedModuleDescriptorsFactoryImpl
-import org.jetbrains.kotlin.storage.StorageManager
-import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.TypeUtils.getTypeParameterDescriptorOrNull
-import org.jetbrains.kotlin.types.Variance
-import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
-import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
-
-internal fun <T> Sequence<T>.toList(expectedCapacity: Int): List<T> {
-    val result = ArrayList<T>(expectedCapacity)
-    toCollection(result)
-    return result
-}
-
-internal inline fun <reified T> Iterable<T?>.firstNonNull() = firstIsInstance<T>()
-
-internal inline val KotlinType.declarationDescriptor: ClassifierDescriptor
-    get() = (constructor.declarationDescriptor ?: error("No declaration descriptor found for $constructor"))
-
-internal inline val KotlinType.fqName: FqName
-    get() = declarationDescriptor.fqNameSafe
-
-internal val KotlinType.fqNameWithTypeParameters: String
-    get() = buildString { buildFqNameWithTypeParameters(this@fqNameWithTypeParameters, HashSet()) }
-
-private fun StringBuilder.buildFqNameWithTypeParameters(type: KotlinType, exploredTypeParameters: MutableSet<KotlinType>) {
-    append(type.fqName)
-
-    val typeParameterDescriptor = getTypeParameterDescriptorOrNull(type)
-    if (typeParameterDescriptor != null) {
-        // N.B this is type parameter type
-
-        if (exploredTypeParameters.add(type.makeNotNullable())) { // print upper bounds once the first time when type parameter type is met
-            append(":[")
-            typeParameterDescriptor.upperBounds.forEachIndexed { index, upperBound ->
-                if (index > 0)
-                    append(",")
-                buildFqNameWithTypeParameters(upperBound, exploredTypeParameters)
-            }
-            append("]")
-        }
-    } else {
-        // N.B. this is classifier type
-
-        val arguments = type.arguments
-        if (arguments.isNotEmpty()) {
-            append("<")
-            arguments.forEachIndexed { index, argument ->
-                if (index > 0)
-                    append(",")
-
-                if (argument.isStarProjection)
-                    append("*")
-                else {
-                    val variance = argument.projectionKind
-                    if (variance != Variance.INVARIANT)
-                        append(variance).append(" ")
-                    buildFqNameWithTypeParameters(argument.type, exploredTypeParameters)
-                }
-            }
-            append(">")
-        }
-    }
-
-    if (type.isMarkedNullable)
-        append("?")
-}
-
-internal fun Any?.isNull(): Boolean = this == null
-
-private val STANDARD_KOTLIN_PACKAGE_PREFIXES = listOf(
-    KotlinBuiltIns.BUILT_INS_PACKAGE_NAME.asString(),
-    "kotlinx"
-)
-
-private val KOTLIN_NATIVE_SYNTHETIC_PACKAGES_PREFIXES = ForwardDeclarationsFqNames.syntheticPackages
-    .map { fqName ->
-        check(!fqName.isRoot)
-        fqName.asString()
-    }
-
-private const val DARWIN_PACKAGE_PREFIX = "platform.darwin"
-
-internal val FqName.isUnderStandardKotlinPackages: Boolean
-    get() = hasAnyPrefix(STANDARD_KOTLIN_PACKAGE_PREFIXES)
-
-internal val FqName.isUnderKotlinNativeSyntheticPackages: Boolean
-    get() = hasAnyPrefix(KOTLIN_NATIVE_SYNTHETIC_PACKAGES_PREFIXES)
-
-internal val FqName.isUnderDarwinPackage: Boolean
-    get() = asString().hasPrefix(DARWIN_PACKAGE_PREFIX)
-
-private fun FqName.hasAnyPrefix(prefixes: List<String>): Boolean =
-    asString().let { fqName -> prefixes.any(fqName::hasPrefix) }
-
-private fun String.hasPrefix(prefix: String): Boolean {
-    val lengthDifference = length - prefix.length
-    return when {
-        lengthDifference == 0 -> this == prefix
-        lengthDifference > 0 -> this[prefix.length] == '.' && this.startsWith(prefix)
-        else -> false
-    }
-}
-
-internal val ModuleDescriptor.packageFragmentProvider
-    get() = (this as ModuleDescriptorImpl).packageFragmentProviderForModuleContentWithoutDependencies
-
-internal fun createKotlinNativeForwardDeclarationsModule(
-    storageManager: StorageManager,
-    builtIns: KotlinBuiltIns
-): ModuleDescriptorImpl =
-    (createDefaultKonanResolvedModuleDescriptorsFactory(DefaultDeserializedDescriptorFactory) as KlibResolvedModuleDescriptorsFactoryImpl)
-        .createForwardDeclarationsModule(
-            builtIns = builtIns,
-            storageManager = storageManager
-        )
-
-// similar to org.jetbrains.kotlin.descriptors.DescriptorUtilKt#resolveClassByFqName, but resolves also type aliases
-internal fun ModuleDescriptor.resolveClassOrTypeAliasByFqName(
-    fqName: FqName,
-    lookupLocation: LookupLocation
-): ClassifierDescriptorWithTypeParameters? {
-    if (fqName.isRoot) return null
-
-    (getPackage(fqName.parent()).memberScope.getContributedClassifier(
-        fqName.shortName(),
-        lookupLocation
-    ) as? ClassifierDescriptorWithTypeParameters)?.let { return it }
-
-    return (resolveClassOrTypeAliasByFqName(fqName.parent(), lookupLocation) as? ClassDescriptor)
-        ?.unsubstitutedInnerClassesScope
-        ?.getContributedClassifier(fqName.shortName(), lookupLocation) as? ClassifierDescriptorWithTypeParameters
-}
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/blacklist.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/blacklist.kt
similarity index 96%
rename from konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/blacklist.kt
rename to konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/blacklist.kt
index 44438bba1c8..fb5fc485d8c 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/blacklist.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/blacklist.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.descriptors.commonizer
+package org.jetbrains.kotlin.descriptors.commonizer.utils
 
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/commonizedGroup.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/commonizedGroup.kt
similarity index 92%
rename from konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/commonizedGroup.kt
rename to konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/commonizedGroup.kt
index 895a45be97b..ab6ae3a22c8 100644
--- a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/commonizedGroup.kt
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/commonizedGroup.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.descriptors.commonizer
+package org.jetbrains.kotlin.descriptors.commonizer.utils
 
 /** Fixed-size ordered collection with no extra space that represents a commonized group of same-rank elements */
 internal class CommonizedGroup<T : Any>(
@@ -41,7 +41,11 @@ internal class CommonizedGroup<T : Any>(
 internal class CommonizedGroupMap<K, V : Any>(val size: Int) : Iterable<Map.Entry<K, CommonizedGroup<V>>> {
     private val wrapped: MutableMap<K, CommonizedGroup<V>> = HashMap()
 
-    operator fun get(key: K): CommonizedGroup<V> = wrapped.getOrPut(key) { CommonizedGroup(size) }
+    operator fun get(key: K): CommonizedGroup<V> = wrapped.getOrPut(key) {
+        CommonizedGroup(
+            size
+        )
+    }
     fun getOrNull(key: K): CommonizedGroup<V>? = wrapped[key]
 
     override fun iterator(): Iterator<Map.Entry<K, CommonizedGroup<V>>> = wrapped.iterator()
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/fqName.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/fqName.kt
new file mode 100644
index 00000000000..e32da0e9177
--- /dev/null
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/fqName.kt
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.utils
+
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.serialization.konan.impl.ForwardDeclarationsFqNames
+
+private val STANDARD_KOTLIN_PACKAGE_PREFIXES = listOf(
+    KotlinBuiltIns.BUILT_INS_PACKAGE_NAME.asString(),
+    "kotlinx"
+)
+
+private val KOTLIN_NATIVE_SYNTHETIC_PACKAGES_PREFIXES = ForwardDeclarationsFqNames.syntheticPackages
+    .map { fqName ->
+        check(!fqName.isRoot)
+        fqName.asString()
+    }
+
+private const val DARWIN_PACKAGE_PREFIX = "platform.darwin"
+
+internal val FqName.isUnderStandardKotlinPackages: Boolean
+    get() = hasAnyPrefix(STANDARD_KOTLIN_PACKAGE_PREFIXES)
+
+internal val FqName.isUnderKotlinNativeSyntheticPackages: Boolean
+    get() = hasAnyPrefix(KOTLIN_NATIVE_SYNTHETIC_PACKAGES_PREFIXES)
+
+internal val FqName.isUnderDarwinPackage: Boolean
+    get() = asString().hasPrefix(DARWIN_PACKAGE_PREFIX)
+
+private fun FqName.hasAnyPrefix(prefixes: List<String>): Boolean =
+    asString().let { fqName -> prefixes.any(fqName::hasPrefix) }
+
+private fun String.hasPrefix(prefix: String): Boolean {
+    val lengthDifference = length - prefix.length
+    return when {
+        lengthDifference == 0 -> this == prefix
+        lengthDifference > 0 -> this[prefix.length] == '.' && this.startsWith(prefix)
+        else -> false
+    }
+}
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/misc.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/misc.kt
new file mode 100644
index 00000000000..84cb2bdbf9c
--- /dev/null
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/misc.kt
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.utils
+
+import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstance
+
+internal fun <T> Sequence<T>.toList(expectedCapacity: Int): List<T> {
+    val result = ArrayList<T>(expectedCapacity)
+    toCollection(result)
+    return result
+}
+
+internal inline fun <reified T> Iterable<T?>.firstNonNull() = firstIsInstance<T>()
+
+internal fun Any?.isNull(): Boolean = this == null
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/moduleDescriptor.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/moduleDescriptor.kt
new file mode 100644
index 00000000000..7a79dacd712
--- /dev/null
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/moduleDescriptor.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.utils
+
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
+import org.jetbrains.kotlin.incremental.components.LookupLocation
+import org.jetbrains.kotlin.konan.library.KonanFactories.DefaultDeserializedDescriptorFactory
+import org.jetbrains.kotlin.konan.library.KonanFactories.createDefaultKonanResolvedModuleDescriptorsFactory
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.serialization.konan.impl.KlibResolvedModuleDescriptorsFactoryImpl
+import org.jetbrains.kotlin.storage.StorageManager
+
+internal val ModuleDescriptor.packageFragmentProvider
+    get() = (this as ModuleDescriptorImpl).packageFragmentProviderForModuleContentWithoutDependencies
+
+internal fun createKotlinNativeForwardDeclarationsModule(
+    storageManager: StorageManager,
+    builtIns: KotlinBuiltIns
+): ModuleDescriptorImpl =
+    (createDefaultKonanResolvedModuleDescriptorsFactory(DefaultDeserializedDescriptorFactory) as KlibResolvedModuleDescriptorsFactoryImpl)
+        .createForwardDeclarationsModule(
+            builtIns = builtIns,
+            storageManager = storageManager
+        )
+
+// similar to org.jetbrains.kotlin.descriptors.DescriptorUtilKt#resolveClassByFqName, but resolves also type aliases
+internal fun ModuleDescriptor.resolveClassOrTypeAliasByFqName(
+    fqName: FqName,
+    lookupLocation: LookupLocation
+): ClassifierDescriptorWithTypeParameters? {
+    if (fqName.isRoot) return null
+
+    (getPackage(fqName.parent()).memberScope.getContributedClassifier(
+        fqName.shortName(),
+        lookupLocation
+    ) as? ClassifierDescriptorWithTypeParameters)?.let { return it }
+
+    return (resolveClassOrTypeAliasByFqName(fqName.parent(), lookupLocation) as? ClassDescriptor)
+        ?.unsubstitutedInnerClassesScope
+        ?.getContributedClassifier(fqName.shortName(), lookupLocation) as? ClassifierDescriptorWithTypeParameters
+}
diff --git a/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/type.kt b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/type.kt
new file mode 100644
index 00000000000..5c83760b915
--- /dev/null
+++ b/konan/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/utils/type.kt
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.descriptors.commonizer.utils
+
+import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
+
+internal inline val KotlinType.declarationDescriptor: ClassifierDescriptor
+    get() = (constructor.declarationDescriptor ?: error("No declaration descriptor found for $constructor"))
+
+internal inline val KotlinType.fqName: FqName
+    get() = declarationDescriptor.fqNameSafe
+
+internal val KotlinType.fqNameWithTypeParameters: String
+    get() = buildString { buildFqNameWithTypeParameters(this@fqNameWithTypeParameters, HashSet()) }
+
+private fun StringBuilder.buildFqNameWithTypeParameters(type: KotlinType, exploredTypeParameters: MutableSet<KotlinType>) {
+    append(type.fqName)
+
+    val typeParameterDescriptor = TypeUtils.getTypeParameterDescriptorOrNull(type)
+    if (typeParameterDescriptor != null) {
+        // N.B this is type parameter type
+
+        if (exploredTypeParameters.add(type.makeNotNullable())) { // print upper bounds once the first time when type parameter type is met
+            append(":[")
+            typeParameterDescriptor.upperBounds.forEachIndexed { index, upperBound ->
+                if (index > 0)
+                    append(",")
+                buildFqNameWithTypeParameters(upperBound, exploredTypeParameters)
+            }
+            append("]")
+        }
+    } else {
+        // N.B. this is classifier type
+
+        val arguments = type.arguments
+        if (arguments.isNotEmpty()) {
+            append("<")
+            arguments.forEachIndexed { index, argument ->
+                if (index > 0)
+                    append(",")
+
+                if (argument.isStarProjection)
+                    append("*")
+                else {
+                    val variance = argument.projectionKind
+                    if (variance != Variance.INVARIANT)
+                        append(variance).append(" ")
+                    buildFqNameWithTypeParameters(argument.type, exploredTypeParameters)
+                }
+            }
+            append(">")
+        }
+    }
+
+    if (type.isMarkedNullable)
+        append("?")
+}
diff --git a/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/core/DefaultTypeCommonizerTest.kt b/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/core/DefaultTypeCommonizerTest.kt
index 315b6d8578a..18bad84cd7f 100644
--- a/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/core/DefaultTypeCommonizerTest.kt
+++ b/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/core/DefaultTypeCommonizerTest.kt
@@ -7,11 +7,11 @@ package org.jetbrains.kotlin.descriptors.commonizer.core
 
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
-import org.jetbrains.kotlin.descriptors.commonizer.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirRootNode.ClassifiersCacheImpl
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.CirType
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildClassNode
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.ir.buildTypeAliasNode
+import org.jetbrains.kotlin.descriptors.commonizer.utils.CommonizedGroupMap
 import org.jetbrains.kotlin.descriptors.commonizer.utils.mockClassType
 import org.jetbrains.kotlin.descriptors.commonizer.utils.mockTAType
 import org.jetbrains.kotlin.name.FqName
@@ -369,8 +369,10 @@ class DefaultTypeCommonizerTest : AbstractCommonizerTest<CirType, CirType>() {
     private fun prepareCache(variants: Array<out KotlinType>) {
         check(variants.isNotEmpty())
 
-        val classesMap = CommonizedGroupMap<FqName, ClassDescriptor>(variants.size)
-        val typeAliasesMap = CommonizedGroupMap<FqName, TypeAliasDescriptor>(variants.size)
+        val classesMap =
+            CommonizedGroupMap<FqName, ClassDescriptor>(variants.size)
+        val typeAliasesMap =
+            CommonizedGroupMap<FqName, TypeAliasDescriptor>(variants.size)
 
         fun recurse(type: KotlinType, index: Int) {
             @Suppress("MoveVariableDeclarationIntoWhen")
diff --git a/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/utils/ComparingDeclarationsVisitor.kt b/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/utils/ComparingDeclarationsVisitor.kt
index 186ee3a182e..cf3e98153a8 100644
--- a/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/utils/ComparingDeclarationsVisitor.kt
+++ b/konan/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/utils/ComparingDeclarationsVisitor.kt
@@ -7,9 +7,6 @@ package org.jetbrains.kotlin.descriptors.commonizer.utils
 
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
-import org.jetbrains.kotlin.descriptors.commonizer.fqName
-import org.jetbrains.kotlin.descriptors.commonizer.fqNameWithTypeParameters
-import org.jetbrains.kotlin.descriptors.commonizer.isNull
 import org.jetbrains.kotlin.descriptors.commonizer.mergedtree.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe