[Commonizer] Drop no more necessary logic for forward declarations

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/TargetProvider.kt

@@ -18,11 +18,7 @@ interface ModulesProvider {
     open class ModuleInfo(
         val name: String,
         val originalLocation: File,
-        val cInteropAttributes: CInteropModuleAttributes?
+        val isCInterop: Boolean
-    )
-
-    class CInteropModuleAttributes(
-        val exportForwardDeclarations: Collection<String>
     )
 
     /**

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt

@@ -202,10 +202,8 @@ private fun commonizeClass(classId: CirEntityId, classifiers: CirKnownClassifier
 
     return when (val node = classifiers.commonizedNodes.classNode(classId)) {
         null -> {
-            // No node means that the class was not subject for commonization.
+            // No node means that the type alias was not subject for commonization. It is missing in some target(s) => not commonized.
-            // - Either it is missing in certain targets at all => not commonized.
+            false
-            // - Or it is a known forward declaration => consider it as commonized.
-            classifiers.forwardDeclarations.isExportedForwardDeclaration(classId)
         }
         else -> {
             // Common declaration in node is not null -> successfully commonized.

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

@@ -40,7 +40,6 @@ private fun mergeAndCommonize(storageManager: StorageManager, parameters: Common
     // build merged tree:
     val classifiers = CirKnownClassifiers(
         commonizedNodes = CirCommonizedClassifierNodes.default(),
-        forwardDeclarations = CirForwardDeclarations.default(),
         commonDependencies = CirProvidedClassifiers.of(
             CirFictitiousFunctionClassifiers,
             CirProvidedClassifiers.by(parameters.dependencyModulesProvider)

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/konan/NativeDistributionModulesProvider.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.descriptors.commonizer.konan
 
 import org.jetbrains.kotlin.descriptors.commonizer.ModulesProvider
-import org.jetbrains.kotlin.descriptors.commonizer.ModulesProvider.CInteropModuleAttributes
 import org.jetbrains.kotlin.descriptors.commonizer.ModulesProvider.ModuleInfo
 import org.jetbrains.kotlin.konan.library.KONAN_STDLIB_NAME
 import org.jetbrains.kotlin.library.SerializedMetadata
@@ -18,8 +17,8 @@ internal class NativeDistributionModulesProvider(libraries: Collection<NativeLib
         name: String,
         originalLocation: File,
         val dependencies: Set<String>,
-        cInteropAttributes: CInteropModuleAttributes?
+        isCInterop: Boolean
-    ) : ModuleInfo(name, originalLocation, cInteropAttributes)
+    ) : ModuleInfo(name, originalLocation, isCInterop)
 
     private val libraryMap: Map<String, NativeLibrary>
     private val moduleInfoMap: Map<String, NativeModuleInfo>
@@ -35,12 +34,8 @@ internal class NativeDistributionModulesProvider(libraries: Collection<NativeLib
             val location = File(library.library.libraryFile.path)
             val dependencies = manifestData.dependencies.toSet()
 
-            val cInteropAttributes = if (manifestData.isInterop) {
-                CInteropModuleAttributes(manifestData.exportForwardDeclarations)
-            } else null
-
             libraryMap.put(name, library)?.let { error("Duplicated libraries: $name") }
-            moduleInfoMap[name] = NativeModuleInfo(name, location, dependencies, cInteropAttributes)
+            moduleInfoMap[name] = NativeModuleInfo(name, location, dependencies, manifestData.isInterop)
         }
 
         this.libraryMap = libraryMap

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/CirKnownClassifiers.kt

@@ -6,13 +6,10 @@
 package org.jetbrains.kotlin.descriptors.commonizer.mergedtree
 
 import gnu.trove.THashMap
-import gnu.trove.THashSet
 import org.jetbrains.kotlin.descriptors.commonizer.cir.CirEntityId
-import org.jetbrains.kotlin.descriptors.commonizer.utils.isUnderKotlinNativeSyntheticPackages
 
 class CirKnownClassifiers(
     val commonizedNodes: CirCommonizedClassifierNodes,
-    val forwardDeclarations: CirForwardDeclarations,
     val commonDependencies: CirProvidedClassifiers
 )
 
@@ -46,25 +43,3 @@ interface CirCommonizedClassifierNodes {
         }
     }
 }
-
-/** A set of all exported forward declaration classes/objects/structs. */
-interface CirForwardDeclarations {
-    /* Accessors */
-    fun isExportedForwardDeclaration(classId: CirEntityId): Boolean
-
-    /* Mutators */
-    fun addExportedForwardDeclaration(classId: CirEntityId)
-
-    companion object {
-        fun default() = object : CirForwardDeclarations {
-            private val exportedForwardDeclarations = THashSet<CirEntityId>()
-
-            override fun isExportedForwardDeclaration(classId: CirEntityId) = classId in exportedForwardDeclarations
-
-            override fun addExportedForwardDeclaration(classId: CirEntityId) {
-                check(classId.packageName.isUnderKotlinNativeSyntheticPackages)
-                exportedForwardDeclarations += classId
-            }
-        }
-    }
-}

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/CirProvidedClassifiersByModules.kt

@@ -47,7 +47,7 @@ internal class CirProvidedClassifiersByModules private constructor(
             var hasForwardDeclarations = false
 
             modulesProvider.loadModuleInfos().forEach { moduleInfo ->
-                if (moduleInfo.cInteropAttributes != null) {
+                if (moduleInfo.isCInterop) {
                     // this is a C-interop module
                     hasForwardDeclarations = true
                 }

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/mergedtree/CirTreeMerger.kt

@@ -88,9 +88,6 @@ class CirTreeMerger(
     private fun processRoot(): CirTreeMergeResult {
         val rootNode: CirRootNode = buildRootNode(storageManager, leafTargetsSize)
 
-        // remember any exported forward declarations from common fragments of dependee modules
-        parameters.dependencyModulesProvider?.loadModuleInfos()?.forEach(::processCInteropModuleAttributes)
-
         val commonModuleNames = parameters.getCommonModuleNames()
         val missingModuleInfosByTargets = mutableMapOf<LeafCommonizerTarget, Collection<ModuleInfo>>()
 
@@ -138,18 +135,15 @@ class CirTreeMerger(
         commonModuleInfos.forEach { moduleInfo ->
             val metadata = targetProvider.modulesProvider.loadModuleMetadata(moduleInfo.name)
             val module = KlibModuleMetadata.read(SerializedMetadataLibraryProvider(metadata))
-            processModule(context, rootNode, moduleInfo, module)
+            processModule(context, rootNode, module)
         }
     }
 
     private fun processModule(
         context: CirTreeMergingContext,
         rootNode: CirRootNode,
-        moduleInfo: ModuleInfo,
         module: KlibModuleMetadata
     ) {
-        processCInteropModuleAttributes(moduleInfo)
-
         val moduleName: CirName = CirName.create(module.name)
         val moduleNode: CirModuleNode = rootNode.modules.getOrPut(moduleName) {
             buildModuleNode(storageManager, leafTargetsSize)
@@ -345,19 +339,6 @@ class CirTreeMerger(
             typeResolver = context.typeResolver
         )
     }
-
-    private fun processCInteropModuleAttributes(moduleInfo: ModuleInfo) {
-        val cInteropAttributes = moduleInfo.cInteropAttributes ?: return
-        val exportForwardDeclarations = cInteropAttributes.exportForwardDeclarations.takeIf { it.isNotEmpty() } ?: return
-
-        exportForwardDeclarations.forEach { classFqName ->
-            // Class has synthetic package FQ name (cnames/objcnames). Need to transfer it to the main package.
-            val packageName = CirPackageName.create(classFqName.substringBeforeLast('.', missingDelimiterValue = ""))
-            val className = CirName.create(classFqName.substringAfterLast('.'))
-
-            classifiers.forwardDeclarations.addExportedForwardDeclaration(CirEntityId.create(packageName, className))
-        }
-    }
 }
 
 private class ClassesToProcess {

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

@@ -28,7 +28,6 @@ class TypeCommonizerTest : AbstractCommonizerTest<CirType, CirType>() {
         // reset cache
         classifiers = CirKnownClassifiers(
             commonizedNodes = CirCommonizedClassifierNodes.default(),
-            forwardDeclarations = CirForwardDeclarations.default(),
             commonDependencies = object : CirProvidedClassifiers {
                 override fun hasClassifier(classifierId: CirEntityId) = classifierId.packageName.isUnderStandardKotlinPackages
                 override fun classifier(classifierId: CirEntityId) = error("This method should not be called")

native/commonizer/tests/org/jetbrains/kotlin/descriptors/commonizer/utils/mocks.kt

@@ -78,10 +78,6 @@ internal val MOCK_CLASSIFIERS = CirKnownClassifiers(
         override fun addClassNode(classId: CirEntityId, node: CirClassNode) = error("This method should not be called")
         override fun addTypeAliasNode(typeAliasId: CirEntityId, node: CirTypeAliasNode) = error("This method should not be called")
     },
-    forwardDeclarations = object : CirForwardDeclarations {
-        override fun isExportedForwardDeclaration(classId: CirEntityId) = false
-        override fun addExportedForwardDeclaration(classId: CirEntityId) = error("This method should not be called")
-    },
     commonDependencies = CirProvidedClassifiers.EMPTY
 )
 
@@ -97,7 +93,7 @@ internal class MockModulesProvider private constructor(
         return SERIALIZER.serializeModule(module)
     }
 
-    private fun fakeModuleInfo(name: String) = ModuleInfo(name, File("/tmp/commonizer/mocks/$name"), null)
+    private fun fakeModuleInfo(name: String) = ModuleInfo(name, File("/tmp/commonizer/mocks/$name"), false)
 
     companion object {
         @JvmName("createByModuleNames")