Save incremental data with KLIB compiler

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

@@ -83,6 +83,8 @@ fun generateKLib(
 
     val psi2IrContext = runAnalysisAndPreparePsi2Ir(depsDescriptors)
 
+    trySaveIncrementalData(psi2IrContext, configuration, files)
+
     val moduleFragment = psi2IrContext.generateModuleFragment(files)
 
     val moduleName = configuration[CommonConfigurationKeys.MODULE_NAME]!!

compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klibIncremental.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.ir.backend.js
+
+import com.intellij.openapi.vfs.VfsUtilCore
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.CommonConfigurationKeys
+import org.jetbrains.kotlin.config.CompilerConfiguration
+import org.jetbrains.kotlin.config.languageVersionSettings
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.js.config.JSConfigurationKeys.INCREMENTAL_RESULTS_CONSUMER
+import org.jetbrains.kotlin.metadata.ProtoBuf
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi2ir.generators.GeneratorContext
+import org.jetbrains.kotlin.resolve.BindingContext
+import org.jetbrains.kotlin.resolve.BindingContextUtils
+import org.jetbrains.kotlin.serialization.js.KotlinJavascriptSerializationUtil
+import org.jetbrains.kotlin.utils.JsMetadataVersion
+
+// todo: think if possible to unify with org.jetbrains.kotlin.js.facade.K2JSTranslator.trySaveIncrementalData
+internal fun trySaveIncrementalData(context: GeneratorContext, config: CompilerConfiguration, files: List<KtFile>) {
+    val incrementalResults = config.get(INCREMENTAL_RESULTS_CONSUMER) ?: return
+
+    val bindingContext = context.bindingContext
+    val moduleDescriptor = context.moduleDescriptor
+
+    val emptyByteArray = emptyArray<Byte>().toByteArray()
+
+    for (file in files) {
+        val memberScope = file.declarations.map { getDescriptorForElement(bindingContext, it) }
+        val packagePart = serializeScope(bindingContext, moduleDescriptor, file.packageFqName, memberScope, config)
+        val ioFile = VfsUtilCore.virtualToIoFile(file.virtualFile)
+        incrementalResults.processPackagePart(ioFile, packagePart.toByteArray(), binaryAst = emptyByteArray, inlineData = emptyByteArray)
+    }
+
+    val settings = config.languageVersionSettings
+    incrementalResults.processHeader(KotlinJavascriptSerializationUtil.serializeHeader(moduleDescriptor, null, settings).toByteArray())
+}
+
+// copied from org.jetbrains.kotlin.js.translate.utils.BindingUtils.getDescriptorForElement
+fun getDescriptorForElement(
+    context: BindingContext,
+    element: PsiElement
+): DeclarationDescriptor = BindingContextUtils.getNotNull(context, BindingContext.DECLARATION_TO_DESCRIPTOR, element)
+
+// copied from org.jetbrains.kotlin.js.facade.K2JSTranslator.serializeScope
+private fun serializeScope(
+    bindingContext: BindingContext,
+    moduleDescriptor: ModuleDescriptor,
+    packageName: FqName,
+    scope: Collection<DeclarationDescriptor>,
+    configuration: CompilerConfiguration
+): ProtoBuf.PackageFragment =
+    KotlinJavascriptSerializationUtil.serializeDescriptors(
+        bindingContext,
+        moduleDescriptor,
+        scope,
+        packageName,
+        configuration.languageVersionSettings,
+        configuration.get(CommonConfigurationKeys.METADATA_VERSION) ?: JsMetadataVersion.INSTANCE
+    )