[Commonizer] Implement first ReApproximationCirNodeTransformer

^KT-48288

native/commonizer/src/org/jetbrains/kotlin/commonizer/facade.kt

@@ -15,6 +15,8 @@ import org.jetbrains.kotlin.commonizer.mergedtree.CirNode.Companion.indexOfCommo
 import org.jetbrains.kotlin.commonizer.mergedtree.CirRootNode
 import org.jetbrains.kotlin.commonizer.metadata.CirTreeSerializer
 import org.jetbrains.kotlin.commonizer.transformer.InlineTypeAliasCirNodeTransformer
+import org.jetbrains.kotlin.commonizer.transformer.ReApproximationCirNodeTransformer
+import org.jetbrains.kotlin.commonizer.transformer.ReApproximationCirNodeTransformer.SignatureBuildingContextProvider
 import org.jetbrains.kotlin.commonizer.tree.CirTreeRoot
 import org.jetbrains.kotlin.commonizer.tree.defaultCirTreeRootDeserializer
 import org.jetbrains.kotlin.commonizer.tree.mergeCirTree
@@ -63,6 +65,19 @@ internal fun commonizeTarget(
 
         InlineTypeAliasCirNodeTransformer(parameters.storageManager, classifiers).invoke(mergedTree)
 
+        /*
+        ReApproximationCirNodeTransformer(
+            parameters.storageManager, classifiers,
+            SignatureBuildingContextProvider(classifiers, typeAliasInvariant = true, skipArguments = false)
+        ).invoke(mergedTree)
+
+         */
+
+        ReApproximationCirNodeTransformer(
+            parameters.storageManager, classifiers,
+            SignatureBuildingContextProvider(classifiers, typeAliasInvariant = true, skipArguments = true)
+        ).invoke(mergedTree)
+
         mergedTree.accept(CommonizationVisitor(mergedTree), Unit)
 
         return mergedTree

native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/CirTypeSignature.kt

@@ -0,0 +1,213 @@
+/*
+ * Copyright 2010-2021 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.commonizer.mergedtree
+
+import gnu.trove.TIntHashSet
+import org.jetbrains.kotlin.commonizer.cir.*
+import org.jetbrains.kotlin.commonizer.utils.Interner
+import org.jetbrains.kotlin.types.Variance
+
+class CirTypeSignature {
+    private val elements = ArrayList<Any>()
+
+    private var hashCode = 0
+
+    fun add(element: Any) {
+        elements.add(element)
+        hashCode = 31 * hashCode + element.hashCode()
+    }
+
+    override fun hashCode(): Int = hashCode
+
+    override fun equals(other: Any?): Boolean {
+        if (other === this) return true
+        if (other !is CirTypeSignature) return false
+        if (other.hashCode != this.hashCode) return false
+        if (other.elements != this.elements) return false
+        return true
+    }
+
+    override fun toString(): String {
+        return elements.joinToString("")
+    }
+
+    companion object {
+        val interner = Interner<CirTypeSignature>()
+    }
+}
+
+internal fun SignatureBuildingContext(
+    memberContext: CirMemberContext, functionOrPropertyOrConstructor: CirHasTypeParameters,
+    classifierSignatureBuildingContext: ClassifierSignatureBuildingContext = ClassifierSignatureBuildingContext.Default,
+    argumentsSignatureBuildingContext: ArgumentsSignatureBuildingContext = ArgumentsSignatureBuildingContext.Default,
+): SignatureBuildingContext {
+    return DefaultSignatureBuildingContext(
+        memberContext, classifierSignatureBuildingContext, argumentsSignatureBuildingContext, functionOrPropertyOrConstructor
+    )
+}
+
+internal sealed interface SignatureBuildingContext {
+    val memberContext: CirMemberContext
+    val classifierSignatureBuildingContext: ClassifierSignatureBuildingContext
+    val argumentsSignatureBuildingContext: ArgumentsSignatureBuildingContext
+}
+
+internal sealed interface ClassifierSignatureBuildingContext {
+    fun appendSignature(signature: CirTypeSignature, classifierId: CirEntityId)
+
+    object Default : ClassifierSignatureBuildingContext {
+        override fun appendSignature(signature: CirTypeSignature, classifierId: CirEntityId) = signature.add(classifierId)
+    }
+
+    class TypeAliasInvariant(private val commonIdResolver: CirCommonClassifierIdResolver) : ClassifierSignatureBuildingContext {
+        override fun appendSignature(signature: CirTypeSignature, classifierId: CirEntityId) {
+            return signature.add(commonIdResolver.findCommonId(classifierId) ?: classifierId)
+        }
+    }
+}
+
+internal sealed interface ArgumentsSignatureBuildingContext {
+    fun appendSignature(signature: CirTypeSignature, context: SignatureBuildingContext, arguments: List<CirTypeProjection>)
+
+    object Default : ArgumentsSignatureBuildingContext {
+        override fun appendSignature(signature: CirTypeSignature, context: SignatureBuildingContext, arguments: List<CirTypeProjection>) {
+            if (arguments.isEmpty()) return
+            signature.add(TypeSignatureElements.ArgumentsStartToken)
+            arguments.forEachIndexed { index, argument ->
+                when (argument) {
+                    is CirRegularTypeProjection -> {
+                        when (argument.projectionKind) {
+                            Variance.INVARIANT -> Unit
+                            Variance.IN_VARIANCE -> signature.add(TypeSignatureElements.InVariance)
+                            Variance.OUT_VARIANCE -> signature.add(TypeSignatureElements.OutVariance)
+                        }
+                        signature.appendTypeApproximationSignature(context, argument.type)
+                    }
+                    is CirStarTypeProjection -> signature.add(TypeSignatureElements.StarProjection)
+                }
+                if (index != arguments.lastIndex) {
+                    signature.add(TypeSignatureElements.ArgumentsSeparator)
+                }
+            }
+            signature.add(TypeSignatureElements.ArgumentsEndToken)
+        }
+    }
+
+    /**
+     * Won't render any type arguments
+     */
+    object Skip : ArgumentsSignatureBuildingContext {
+        override fun appendSignature(
+            signature: CirTypeSignature, context: SignatureBuildingContext, arguments: List<CirTypeProjection>
+        ) = Unit
+    }
+}
+
+
+private enum class TypeSignatureElements(val stringRepresentation: String) {
+    ArgumentsStartToken("<"),
+    ArgumentsEndToken(">"),
+    ArgumentsSeparator(", "),
+    NullableToken("?"),
+    UpperBoundsStartToken(" : ["),
+    UpperBoundsEndToken("]"),
+    InVariance("in "),
+    OutVariance("out "),
+    StarProjection("*"),
+    FlexibleTypeSeparator("..");
+
+    override fun toString(): String {
+        return stringRepresentation
+    }
+}
+
+
+internal fun buildApproximationSignature(context: SignatureBuildingContext, type: CirType): CirTypeSignature {
+    val signature = CirTypeSignature()
+    signature.appendTypeApproximationSignature(context, type)
+    return CirTypeSignature.interner.intern(signature)
+}
+
+internal fun CirTypeSignature.appendTypeApproximationSignature(context: SignatureBuildingContext, type: CirType) {
+    return when (type) {
+        is CirFlexibleType -> appendFlexibleTypeApproximationSignature(context, type)
+        is CirTypeParameterType -> appendTypeParameterTypeApproximationSignature(context.forTypeParameterTypes(), type)
+        is CirClassOrTypeAliasType -> appendClassOrTypeAliasTypeApproximationSignature(context, type)
+    }
+}
+
+internal fun CirTypeSignature.appendClassOrTypeAliasTypeApproximationSignature(
+    context: SignatureBuildingContext, type: CirClassOrTypeAliasType
+) {
+    context.classifierSignatureBuildingContext.appendSignature(this, type.classifierId)
+    context.argumentsSignatureBuildingContext.appendSignature(this, context, type.arguments)
+    if (type.isMarkedNullable) add(TypeSignatureElements.NullableToken)
+}
+
+private fun CirTypeSignature.appendTypeParameterTypeApproximationSignature(
+    context: TypeParameterTypeSignatureBuildingContext, type: CirTypeParameterType
+) {
+    val typeParameter = context.resolveTypeParameter(type.index)
+    add(typeParameter.name)
+    if (context.isVisitedFirstTime(type.index)) {
+        add(TypeSignatureElements.UpperBoundsStartToken)
+        typeParameter.upperBounds.forEachIndexed { index, upperBound ->
+            appendTypeApproximationSignature(context, upperBound)
+            if (index != typeParameter.upperBounds.lastIndex) add(TypeSignatureElements.ArgumentsSeparator)
+        }
+        add(TypeSignatureElements.UpperBoundsEndToken)
+    }
+    if (type.isMarkedNullable) add(TypeSignatureElements.NullableToken)
+}
+
+private fun CirTypeSignature.appendFlexibleTypeApproximationSignature(
+    context: SignatureBuildingContext, type: CirFlexibleType
+) {
+    appendTypeApproximationSignature(context, type.lowerBound)
+    add(TypeSignatureElements.FlexibleTypeSeparator)
+    appendTypeApproximationSignature(context, type.upperBound)
+}
+
+private fun SignatureBuildingContext.forTypeParameterTypes(): TypeParameterTypeSignatureBuildingContext = when (this) {
+    is DefaultSignatureBuildingContext -> TypeParameterTypeSignatureBuildingContext(
+        memberContext, classifierSignatureBuildingContext, argumentsSignatureBuildingContext, functionOrPropertyOrConstructor
+    )
+    is TypeParameterTypeSignatureBuildingContext -> this
+}
+
+private class DefaultSignatureBuildingContext(
+    override val memberContext: CirMemberContext,
+    override val classifierSignatureBuildingContext: ClassifierSignatureBuildingContext,
+    override val argumentsSignatureBuildingContext: ArgumentsSignatureBuildingContext,
+    val functionOrPropertyOrConstructor: CirHasTypeParameters
+) : SignatureBuildingContext
+
+private class TypeParameterTypeSignatureBuildingContext(
+    override val memberContext: CirMemberContext,
+    override val classifierSignatureBuildingContext: ClassifierSignatureBuildingContext,
+    override val argumentsSignatureBuildingContext: ArgumentsSignatureBuildingContext,
+    private val functionOrPropertyOrConstructor: CirHasTypeParameters
+) : SignatureBuildingContext {
+
+    private val alreadyVisitedParameterTypeIndices = TIntHashSet()
+
+    fun isVisitedFirstTime(typeParameterIndex: Int): Boolean {
+        return alreadyVisitedParameterTypeIndices.add(typeParameterIndex)
+    }
+
+    fun resolveTypeParameter(index: Int): CirTypeParameter {
+        var indexOffset = 0
+        memberContext.classes.forEach { clazz ->
+            val indexInClass = index - indexOffset
+            if (indexInClass >= 0 && indexInClass <= clazz.typeParameters.lastIndex) {
+                return clazz.typeParameters[indexInClass]
+            }
+            indexOffset += clazz.typeParameters.size
+        }
+
+        return functionOrPropertyOrConstructor.typeParameters[index - indexOffset]
+    }
+}

native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/CirTypeSubstitutor.kt

@@ -1,45 +0,0 @@
-/*
- * Copyright 2010-2021 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.commonizer.mergedtree
-
-import org.jetbrains.kotlin.commonizer.cir.CirFunction
-import org.jetbrains.kotlin.commonizer.cir.CirProperty
-import org.jetbrains.kotlin.commonizer.cir.CirType
-import org.jetbrains.kotlin.commonizer.cir.CirValueParameter.Companion.copyInterned
-
-interface CirTypeSubstitutor {
-    fun substitute(targetIndex: Int, type: CirType): CirType
-}
-
-fun CirTypeSubstitutor.substitute(index: Int, property: CirProperty): CirProperty {
-    val newReturnType = substitute(index, property.returnType)
-    return if (newReturnType != property.returnType) property.copy(returnType = newReturnType) else property
-}
-
-fun CirTypeSubstitutor.substitute(index: Int, function: CirFunction): CirFunction {
-    val newExtensionReceiverType = function.extensionReceiver?.type?.let { substitute(index, it) }
-
-    val newExtensionReceiver = if (newExtensionReceiverType != function.extensionReceiver?.type)
-        function.extensionReceiver?.copy(type = checkNotNull(newExtensionReceiverType))
-    else function.extensionReceiver
-
-    val newValueParameters = function.valueParameters.map { valueParameter ->
-        val newReturnType = substitute(index, valueParameter.returnType)
-        if (newReturnType != valueParameter.returnType) valueParameter.copyInterned(returnType = newReturnType) else valueParameter
-    }
-
-    val newReturnType = substitute(index, function.returnType)
-
-    return if (
-        newExtensionReceiver != function.extensionReceiver ||
-        newValueParameters != function.valueParameters ||
-        newReturnType != function.returnType
-    ) function.copy(
-        extensionReceiver = newExtensionReceiver,
-        valueParameters = newValueParameters,
-        returnType = newReturnType
-    ) else function
-}

native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/approximationKeys.kt

@@ -7,38 +7,11 @@
 
 package org.jetbrains.kotlin.commonizer.mergedtree
 
-import gnu.trove.TIntHashSet
 import org.jetbrains.kotlin.commonizer.cir.*
-import org.jetbrains.kotlin.commonizer.utils.Interner
 import org.jetbrains.kotlin.commonizer.utils.appendHashCode
 import org.jetbrains.kotlin.commonizer.utils.hashCode
 import org.jetbrains.kotlin.commonizer.utils.isObjCInteropCallableAnnotation
-import org.jetbrains.kotlin.types.Variance
 
-class CirTypeSignature {
-    private val elements = ArrayList<Any>()
-
-    private var hashCode = 0
-
-    fun add(element: Any) {
-        elements.add(element)
-        hashCode = 31 * hashCode + element.hashCode()
-    }
-
-    override fun hashCode(): Int = hashCode
-
-    override fun equals(other: Any?): Boolean {
-        if (other === this) return true
-        if (other !is CirTypeSignature) return false
-        if (other.hashCode != this.hashCode) return false
-        if (other.elements != this.elements) return false
-        return true
-    }
-
-    override fun toString(): String {
-        return elements.joinToString("")
-    }
-}
 
 typealias ObjCFunctionApproximation = Int
 
@@ -48,14 +21,13 @@ data class PropertyApproximationKey(
 ) {
     companion object {
         internal fun create(
-            context: CirMemberContext,
-            commonClassifierIdResolver: CirCommonClassifierIdResolver,
-            property: CirProperty
+            property: CirProperty,
+            signatureBuildingContext: SignatureBuildingContext
         ): PropertyApproximationKey {
             return PropertyApproximationKey(
                 name = property.name,
                 extensionReceiverParameterType = property.extensionReceiver?.let {
-                    buildApproximationSignature(SignatureBuildingContext.create(context, commonClassifierIdResolver, property), it.type)
+                    buildApproximationSignature(signatureBuildingContext, it.type)
                 }
             )
         }
@@ -71,15 +43,14 @@ data class FunctionApproximationKey(
 
     companion object {
         internal fun create(
-            context: CirMemberContext,
-            commonClassifierIdResolver: CirCommonClassifierIdResolver,
-            function: CirFunction
+            function: CirFunction,
+            signatureBuildingContext: SignatureBuildingContext
         ): FunctionApproximationKey {
             return FunctionApproximationKey(
                 name = function.name,
-                valueParametersTypes = valueParameterTypes(context, commonClassifierIdResolver, function),
+                valueParametersTypes = valueParameterTypes(function, signatureBuildingContext),
                 extensionReceiverParameterType = function.extensionReceiver?.let {
-                    buildApproximationSignature(SignatureBuildingContext.create(context, commonClassifierIdResolver, function), it.type)
+                    buildApproximationSignature(signatureBuildingContext, it.type)
                 },
                 objCFunctionApproximation = objCFunctionApproximation(function)
             )
@@ -102,7 +73,6 @@ data class FunctionApproximationKey(
         .appendHashCode(objCFunctionApproximation)
 }
 
-private val typeSignatureInterner = Interner<CirTypeSignature>()
 
 data class ConstructorApproximationKey(
     val valueParametersTypes: Array<CirTypeSignature>,
@@ -111,10 +81,10 @@ data class ConstructorApproximationKey(
 
     companion object {
         internal fun create(
-            context: CirMemberContext, commonClassifierIdResolver: CirCommonClassifierIdResolver, constructor: CirClassConstructor
+            constructor: CirClassConstructor, signatureBuildingContext: SignatureBuildingContext
         ): ConstructorApproximationKey {
             return ConstructorApproximationKey(
-                valueParametersTypes = valueParameterTypes(context, commonClassifierIdResolver, constructor),
+                valueParametersTypes = valueParameterTypes(constructor, signatureBuildingContext),
                 objCFunctionApproximation = objCFunctionApproximation(constructor)
             )
         }
@@ -140,150 +110,13 @@ private fun <T> objCFunctionApproximation(value: T): ObjCFunctionApproximation
 }
 
 private fun <T> valueParameterTypes(
-    context: CirMemberContext,
-    commonClassifierIdResolver: CirCommonClassifierIdResolver,
-    callable: T
+    callable: T,
+    signatureBuildingContext: SignatureBuildingContext,
 ): Array<CirTypeSignature>
         where T : CirHasTypeParameters, T : CirCallableMemberWithParameters, T : CirMaybeCallableMemberOfClass {
     if (callable.valueParameters.isEmpty()) return emptyArray()
     return Array(callable.valueParameters.size) { index ->
         val parameter = callable.valueParameters[index]
-        buildApproximationSignature(SignatureBuildingContext.create(context, commonClassifierIdResolver, callable), parameter.returnType)
-    }
-}
-
-private enum class TypeSignatureElements(val stringRepresentation: String) {
-    ArgumentsStartToken("<"),
-    ArgumentsEndToken(">"),
-    ArgumentsSeparator(", "),
-    NullableToken("?"),
-    UpperBoundsStartToken(" : ["),
-    UpperBoundsEndToken("]"),
-    InVariance("in "),
-    OutVariance("out "),
-    StarProjection("*"),
-    FlexibleTypeSeparator("..");
-
-    override fun toString(): String {
-        return stringRepresentation
-    }
-}
-
-
-internal fun buildApproximationSignature(context: SignatureBuildingContext, type: CirType): CirTypeSignature {
-    val signature = CirTypeSignature()
-    signature.appendTypeApproximationSignature(context, type)
-    return typeSignatureInterner.intern(signature)
-}
-
-internal fun CirTypeSignature.appendTypeApproximationSignature(context: SignatureBuildingContext, type: CirType) {
-    return when (type) {
-        is CirFlexibleType -> appendFlexibleTypeApproximationSignature(context, type)
-        is CirTypeParameterType -> appendTypeParameterTypeApproximationSignature(context.forTypeParameterTypes(), type)
-        is CirClassOrTypeAliasType -> appendClassOrTypeAliasTypeApproximationSignature(context, type)
-    }
-}
-
-internal fun CirTypeSignature.appendClassOrTypeAliasTypeApproximationSignature(
-    context: SignatureBuildingContext, type: CirClassOrTypeAliasType
-) {
-    add(context.commonClassifierIdResolver.findCommonId(type.classifierId) ?: type.classifierId)
-    if (type.arguments.isNotEmpty()) {
-        add(TypeSignatureElements.ArgumentsStartToken)
-        type.arguments.forEachIndexed { index, argument ->
-            when (argument) {
-                is CirRegularTypeProjection -> {
-                    when (argument.projectionKind) {
-                        Variance.INVARIANT -> Unit
-                        Variance.IN_VARIANCE -> add(TypeSignatureElements.InVariance)
-                        Variance.OUT_VARIANCE -> add(TypeSignatureElements.OutVariance)
-                    }
-                    appendTypeApproximationSignature(context, argument.type)
-                }
-                is CirStarTypeProjection -> add(TypeSignatureElements.StarProjection)
-            }
-            if (index != type.arguments.lastIndex) {
-                add(TypeSignatureElements.ArgumentsSeparator)
-            }
-        }
-        add(TypeSignatureElements.ArgumentsEndToken)
-    }
-    if (type.isMarkedNullable) add(TypeSignatureElements.NullableToken)
-}
-
-private fun CirTypeSignature.appendTypeParameterTypeApproximationSignature(
-    context: TypeParameterTypeSignatureBuildingContext, type: CirTypeParameterType
-) {
-    val typeParameter = context.resolveTypeParameter(type.index)
-    add(typeParameter.name)
-    if (context.isVisitedFirstTime(type.index)) {
-        add(TypeSignatureElements.UpperBoundsStartToken)
-        typeParameter.upperBounds.forEachIndexed { index, upperBound ->
-            appendTypeApproximationSignature(context, upperBound)
-            if (index != typeParameter.upperBounds.lastIndex) add(TypeSignatureElements.ArgumentsSeparator)
-        }
-        add(TypeSignatureElements.UpperBoundsEndToken)
-    }
-    if (type.isMarkedNullable) add(TypeSignatureElements.NullableToken)
-}
-
-private fun CirTypeSignature.appendFlexibleTypeApproximationSignature(
-    context: SignatureBuildingContext, type: CirFlexibleType
-) {
-    appendTypeApproximationSignature(context, type.lowerBound)
-    add(TypeSignatureElements.FlexibleTypeSeparator)
-    appendTypeApproximationSignature(context, type.upperBound)
-}
-
-internal sealed interface SignatureBuildingContext {
-    val commonClassifierIdResolver: CirCommonClassifierIdResolver
-
-    companion object {
-        fun create(
-            memberContext: CirMemberContext,
-            commonClassifierIdResolver: CirCommonClassifierIdResolver,
-            functionOrPropertyOrConstructor: CirHasTypeParameters
-        ): SignatureBuildingContext {
-            return DefaultSignatureBuildingContext(memberContext, commonClassifierIdResolver, functionOrPropertyOrConstructor)
-        }
-    }
-}
-
-private fun SignatureBuildingContext.forTypeParameterTypes(): TypeParameterTypeSignatureBuildingContext = when (this) {
-    is DefaultSignatureBuildingContext -> TypeParameterTypeSignatureBuildingContext(
-        memberContext, commonClassifierIdResolver, functionOrPropertyOrConstructor
-    )
-    is TypeParameterTypeSignatureBuildingContext -> this
-}
-
-private class DefaultSignatureBuildingContext(
-    val memberContext: CirMemberContext,
-    override val commonClassifierIdResolver: CirCommonClassifierIdResolver,
-    val functionOrPropertyOrConstructor: CirHasTypeParameters
-) : SignatureBuildingContext
-
-private class TypeParameterTypeSignatureBuildingContext(
-    private val memberContext: CirMemberContext,
-    override val commonClassifierIdResolver: CirCommonClassifierIdResolver,
-    private val functionOrPropertyOrConstructor: CirHasTypeParameters
-) : SignatureBuildingContext {
-
-    private val alreadyVisitedParameterTypeIndices = TIntHashSet()
-
-    fun isVisitedFirstTime(typeParameterIndex: Int): Boolean {
-        return alreadyVisitedParameterTypeIndices.add(typeParameterIndex)
-    }
-
-    fun resolveTypeParameter(index: Int): CirTypeParameter {
-        var indexOffset = 0
-        memberContext.classes.forEach { clazz ->
-            val indexInClass = index - indexOffset
-            if (indexInClass >= 0 && indexInClass <= clazz.typeParameters.lastIndex) {
-                return clazz.typeParameters[indexInClass]
-            }
-            indexOffset += clazz.typeParameters.size
-        }
-
-        return functionOrPropertyOrConstructor.typeParameters[index - indexOffset]
+        buildApproximationSignature(signatureBuildingContext, parameter.returnType)
     }
 }

native/commonizer/src/org/jetbrains/kotlin/commonizer/transformer/ReApproximationCirNodeTransformer.kt

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2010-2021 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.commonizer.transformer
+
+import org.jetbrains.kotlin.commonizer.cir.CirHasTypeParameters
+import org.jetbrains.kotlin.commonizer.mergedtree.*
+import org.jetbrains.kotlin.commonizer.mergedtree.CirNodeRelationship.ParentNode
+import org.jetbrains.kotlin.commonizer.mergedtree.ClassifierSignatureBuildingContext.TypeAliasInvariant
+import org.jetbrains.kotlin.commonizer.utils.fastForEach
+import org.jetbrains.kotlin.storage.StorageManager
+
+internal class ReApproximationCirNodeTransformer(
+    private val storageManager: StorageManager,
+    private val classifiers: CirKnownClassifiers,
+    private val signatureBuildingContextProvider: SignatureBuildingContextProvider
+) : CirNodeTransformer {
+
+    internal class SignatureBuildingContextProvider(
+        private val classifiers: CirKnownClassifiers,
+        private val typeAliasInvariant: Boolean,
+        private val skipArguments: Boolean
+    ) {
+        operator fun invoke(member: CirMemberContext, functionOrPropertyOrConstructor: CirHasTypeParameters): SignatureBuildingContext {
+            return SignatureBuildingContext(
+                memberContext = member, functionOrPropertyOrConstructor = functionOrPropertyOrConstructor,
+                classifierSignatureBuildingContext = if (typeAliasInvariant) TypeAliasInvariant(classifiers.commonClassifierIdResolver)
+                else ClassifierSignatureBuildingContext.Default,
+                argumentsSignatureBuildingContext = if (skipArguments) ArgumentsSignatureBuildingContext.Skip
+                else ArgumentsSignatureBuildingContext.Default
+            )
+        }
+    }
+
+    override fun invoke(root: CirRootNode) {
+        for (index in 0 until root.targetDeclarations.size) {
+            root.modules.forEach { (_, module) -> this(module, index) }
+        }
+    }
+
+    private operator fun invoke(module: CirModuleNode, index: Int) {
+        module.packages.forEach { (_, pkg) -> this(pkg, index) }
+    }
+
+    private operator fun invoke(pkg: CirPackageNode, index: Int) {
+        pkg.functions.values.toTypedArray().fastForEach { function -> this(pkg, function, index, CirMemberContext.empty) }
+        pkg.properties.values.toTypedArray().fastForEach { property -> this(pkg, property, index, CirMemberContext.empty) }
+        pkg.classes.values.toTypedArray().fastForEach { clazz -> this(clazz, index, CirMemberContext.empty) }
+    }
+
+    private operator fun invoke(clazz: CirClassNode, index: Int, context: CirMemberContext) {
+        val contextWithClass = context.withContextOf(clazz.targetDeclarations[index] ?: return)
+        clazz.functions.values.toTypedArray().fastForEach { function -> this(clazz, function, index, contextWithClass) }
+        clazz.properties.values.toTypedArray().fastForEach { property -> this(clazz, property, index, contextWithClass) }
+        clazz.constructors.values.toTypedArray().fastForEach { constructor -> this(clazz, constructor, index, contextWithClass) }
+        clazz.classes.values.toTypedArray().fastForEach { innerClass -> this(innerClass, index, contextWithClass) }
+    }
+
+    private operator fun invoke(parent: CirNodeWithMembers<*, *>, function: CirFunctionNode, index: Int, context: CirMemberContext) {
+        /* Only perform re-approximation to nodes that are not 'complete' */
+        if (function.targetDeclarations.none { it == null }) return
+        val functionAtIndex = function.targetDeclarations[index] ?: return
+
+        val approximationKey = FunctionApproximationKey.create(functionAtIndex, signatureBuildingContextProvider(context, functionAtIndex))
+        val newNode = parent.functions.getOrPut(approximationKey) {
+            buildFunctionNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
+        }
+
+        newNode.targetDeclarations.setIfAbsent(index, functionAtIndex)
+    }
+
+    private operator fun invoke(parent: CirNodeWithMembers<*, *>, property: CirPropertyNode, index: Int, context: CirMemberContext) {
+        /* Only perform re-approximation to nodes that are not 'complete' */
+        if (property.targetDeclarations.none { it == null }) return
+        val propertyAtIndex = property.targetDeclarations[index] ?: return
+
+        val approximationKey = PropertyApproximationKey.create(propertyAtIndex, signatureBuildingContextProvider(context, propertyAtIndex))
+        val newNode = parent.properties.getOrPut(approximationKey) {
+            buildPropertyNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
+        }
+
+        newNode.targetDeclarations.setIfAbsent(index, propertyAtIndex)
+    }
+
+    private operator fun invoke(
+        parent: CirClassNode, constructor: CirClassConstructorNode, index: Int, context: CirMemberContext
+    ) {
+        /* Only perform re-approximation to nodes that are not 'complete' */
+        if (constructor.targetDeclarations.none { it == null }) return
+        val constructorAtIndex = constructor.targetDeclarations[index] ?: return
+
+        val approximationKey =
+            ConstructorApproximationKey.create(constructorAtIndex, signatureBuildingContextProvider(context, constructorAtIndex))
+
+        val newNode = parent.constructors.getOrPut(approximationKey) {
+            buildClassConstructorNode(storageManager, parent.targetDeclarations.size, classifiers, ParentNode(parent))
+        }
+
+        newNode.targetDeclarations.setIfAbsent(index, constructorAtIndex)
+    }
+}

native/commonizer/src/org/jetbrains/kotlin/commonizer/tree/mergeCirTree.kt

@@ -82,33 +82,36 @@ internal fun CirNodeWithMembers<*, *>.buildFunction(
     context: TargetBuildingContext, function: CirFunction, parent: CirNode<*, *>? = null
 ) {
     val functionNode = functions.getOrPut(
-        FunctionApproximationKey.create(context.memberContext, context.classifiers.commonClassifierIdResolver, function)
+        FunctionApproximationKey.create(function, SignatureBuildingContext(context.memberContext, function))
     ) {
         buildFunctionNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
-    functionNode.targetDeclarations[context.targetIndex] = function
+    /* Multiple type substitutions could in result in the same commonization result */
+    functionNode.targetDeclarations.setIfAbsent(context.targetIndex, function)
 }
 
 internal fun CirNodeWithMembers<*, *>.buildProperty(
     context: TargetBuildingContext, property: CirProperty, parent: CirNode<*, *>? = null
 ) {
     val propertyNode = properties.getOrPut(
-        PropertyApproximationKey.create(context.memberContext, context.classifiers.commonClassifierIdResolver, property)
+        PropertyApproximationKey.create(property, SignatureBuildingContext(context.memberContext, property))
     ) {
         buildPropertyNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
-    propertyNode.targetDeclarations[context.targetIndex] = property
+    /* Multiple type substitutions could in result in the same commonization result */
+    propertyNode.targetDeclarations.setIfAbsent(context.targetIndex, property)
 }
 
 internal fun CirClassNode.buildConstructor(
     context: TargetBuildingContext, constructor: CirClassConstructor, parent: CirNode<*, *>
 ) {
     val constructorNode = constructors.getOrPut(
-        ConstructorApproximationKey.create(context.memberContext, context.classifiers.commonClassifierIdResolver, constructor)
+        ConstructorApproximationKey.create(constructor, SignatureBuildingContext(context.memberContext, constructor))
     ) {
         buildClassConstructorNode(context.storageManager, context.targets, context.classifiers, ParentNode(parent))
     }
-    constructorNode.targetDeclarations[context.targetIndex] = constructor
+    /* Multiple type substitutions could in result in the same commonization result */
+    constructorNode.targetDeclarations.setIfAbsent(context.targetIndex, constructor)
 }
 
 internal fun CirPackageNode.buildTypeAlias(context: TargetBuildingContext, treeTypeAlias: CirTreeTypeAlias) {

native/commonizer/src/org/jetbrains/kotlin/commonizer/utils/commonizedGroup.kt

@@ -32,8 +32,7 @@ class CommonizedGroup<T : Any>(
         elements[index] = value
     }
 
-    internal fun setAllowingOverride(index: Int, value: T?) {
-        elements[index] = value
+    fun setIfAbsent(index: Int, value: T?) {
+        if (this[index] == null) set(index, value)
     }
 }
-

native/commonizer/tests/org/jetbrains/kotlin/commonizer/core/TypeCommonizerTest.kt

@@ -371,7 +371,7 @@ class TypeCommonizerTest : AbstractInlineSourcesCommonizationTest() {
             }
         )
         assertEquals(
-            mockTAType("kotlin/sequences/SequenceBuilder") { mockClassType("kotlin/sequences/SequenceScope") }, commonizer(
+            mockClassType("kotlin/sequences/SequenceScope"), commonizer(
                 listOf(
                     mockTAType("kotlin/sequences/SequenceBuilder") { mockClassType("kotlin/sequences/SequenceScope") },
                     mockTAType("kotlin/sequences/SequenceBuilder") { mockClassType("kotlin/sequences/SequenceScope") },

native/commonizer/tests/org/jetbrains/kotlin/commonizer/hierarchical/ParameterizedTypesCommonizationTest.kt

@@ -110,11 +110,7 @@ class ParameterizedTypesCommonizationTest : AbstractInlineSourcesCommonizationTe
                 typealias TA2<R> = TA1<String, R>
                 typealias TA3 = TA2<Int>
                 
-                /*
-                 Desirable solution below!
-                 Test ensures that no wrong commonization is emitted for now.
-                 */
-                //expect fun x1(x: TA1<String, Int>) 
+                expect fun x1(x: TA1<String, Int>) 
             """.trimIndent()
         )
     }