Implement multiproject IC in Gradle

#KT-13528 fixed

build-common/src/org/jetbrains/kotlin/incremental/buildUtil.kt

@@ -175,8 +175,8 @@ fun<Target> OutputItemsCollectorImpl.generatedFiles(
 }
 
 data class DirtyData(
-        val dirtyLookupSymbols: Iterable<LookupSymbol>,
+        val dirtyLookupSymbols: Collection<LookupSymbol> = emptyList(),
-        val dirtyClassesFqNames: Iterable<FqName>
+        val dirtyClassesFqNames: Collection<FqName> = emptyList()
 )
 
 fun <Target> CompilationResult.getDirtyData(
@@ -261,7 +261,7 @@ private fun File.isJavaFile() = extension.equals(JavaFileType.INSTANCE.defaultEx
 private fun findSrcDirRoot(file: File, roots: Iterable<File>): File? =
         roots.firstOrNull { FileUtil.isAncestor(it, file, false) }
 
-private fun <Target> withSubtypes(
+fun <Target> withSubtypes(
         typeFqName: FqName,
         caches: Iterable<IncrementalCacheImpl<Target>>
 ): Set<FqName> {

libraries/tools/kotlin-gradle-plugin-core/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/ArtifactDifferenceRegistry.kt

@@ -0,0 +1,12 @@
+package org.jetbrains.kotlin.gradle.tasks
+
+import org.jetbrains.kotlin.incremental.DirtyData
+import java.io.File
+
+interface ArtifactDifferenceRegistry {
+    operator fun get(artifact: File): Iterable<ArtifactDifference>?
+    fun add(artifact: File, difference: ArtifactDifference)
+    fun remove(artifact: File)
+}
+
+class ArtifactDifference(val buildTS: Long, val dirtyData: DirtyData)

libraries/tools/kotlin-gradle-plugin-core/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/BuildInfo.kt

@@ -0,0 +1,23 @@
+package org.jetbrains.kotlin.gradle.tasks
+
+import java.io.*
+
+internal data class BuildInfo(val startTS: Long) : Serializable {
+    companion object {
+        fun read(file: File): BuildInfo? =
+                try {
+                    ObjectInputStream(FileInputStream(file)).use {
+                        it.readObject() as BuildInfo
+                    }
+                }
+                catch (e: Exception) {
+                    null
+                }
+
+        fun write(buildInfo: BuildInfo, file: File) {
+            ObjectOutputStream(FileOutputStream(file)).use {
+                it.writeObject(buildInfo)
+            }
+        }
+    }
+}

libraries/tools/kotlin-gradle-plugin-core/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/ChangesEither.kt

@@ -0,0 +1,8 @@
+package org.jetbrains.kotlin.gradle.tasks
+
+import org.jetbrains.kotlin.incremental.LookupSymbol
+
+internal sealed class ChangesEither {
+    internal class Known(val lookupSymbols: Set<LookupSymbol>) : ChangesEither()
+    internal class Unknown : ChangesEither()
+}

libraries/tools/kotlin-gradle-plugin-core/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/Tasks.kt

@@ -3,6 +3,7 @@ package org.jetbrains.kotlin.gradle.tasks
 import org.apache.commons.io.FilenameUtils
 import org.codehaus.groovy.runtime.MethodClosure
 import org.gradle.api.GradleException
+import org.gradle.api.Project
 import org.gradle.api.file.SourceDirectorySet
 import org.gradle.api.logging.Logger
 import org.gradle.api.logging.Logging
@@ -42,6 +43,7 @@ import org.jetbrains.kotlin.config.Services
 import org.jetbrains.kotlin.incremental.*
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.modules.TargetId
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.progress.CompilationCanceledStatus
 import org.jetbrains.kotlin.utils.LibraryUtils
 import java.io.File
@@ -52,6 +54,7 @@ const val ANNOTATIONS_PLUGIN_NAME = "org.jetbrains.kotlin.kapt"
 const val KOTLIN_BUILD_DIR_NAME = "kotlin"
 const val CACHES_DIR_NAME = "caches"
 const val DIRTY_SOURCES_FILE_NAME = "dirty-sources.txt"
+const val LAST_BUILD_INFO_FILE_NAME = "last-build.bin"
 const val USING_EXPERIMENTAL_INCREMENTAL_MESSAGE = "Using experimental kotlin incremental compilation"
 
 abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractCompile() {
@@ -154,6 +157,7 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
     private val taskBuildDirectory: File by lazy { File(File(project.buildDir, KOTLIN_BUILD_DIR_NAME), name) }
     private val cacheDirectory: File by lazy { File(taskBuildDirectory, CACHES_DIR_NAME) }
     private val dirtySourcesSinceLastTimeFile: File by lazy { File(taskBuildDirectory, DIRTY_SOURCES_FILE_NAME) }
+    private val lastBuildInfoFile: File by lazy { File(taskBuildDirectory, LAST_BUILD_INFO_FILE_NAME) }
     private val cacheVersions by lazy {
         listOf(normalCacheVersion(taskBuildDirectory),
                experimentalCacheVersion(taskBuildDirectory),
@@ -172,6 +176,7 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
 
     val kaptOptions = KaptOptions()
     val pluginOptions = CompilerPluginOptions()
+    var artifactDifferenceRegistry: ArtifactDifferenceRegistry? = null
 
     override fun populateTargetSpecificArgs(args: K2JVMCompilerArguments) {
         logger.kotlinDebug("args.freeArgs = ${args.freeArgs}")
@@ -232,15 +237,11 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
     }
 
     override fun callCompiler(args: K2JVMCompilerArguments, sources: List<File>, isIncrementalRequested: Boolean, modified: List<File>, removed: List<File>) {
+        val rootProjectDir = project.rootProject.projectDir
 
-        fun projectRelativePath(f: File) = f.toRelativeString(project.projectDir)
+        fun projectRelativePath(f: File) = f.toRelativeString(rootProjectDir)
-
+        fun filesToString(files: Iterable<File>) =
-        if (incremental) {
+                "[" + files.map(::projectRelativePath).sorted().joinToString(separator = ", \n") + "]"
-            // TODO: consider other ways to pass incremental flag to compiler/builder
-            System.setProperty("kotlin.incremental.compilation", "true")
-            // TODO: experimental should be removed as soon as it becomes standard
-            System.setProperty("kotlin.incremental.compilation.experimental", "true")
-        }
 
         val targetType = "java-production"
         val moduleName = args.moduleName
@@ -252,6 +253,8 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
         var currentRemoved = removed.filter { it.isKotlinFile() }
         val allGeneratedFiles = hashSetOf<GeneratedFile<TargetId>>()
         val logAction = { logStr: String -> logger.kotlinInfo(logStr) }
+        val lastBuildInfo = BuildInfo.read(lastBuildInfoFile)
+        logger.kotlinDebug { "Last Kotlin Build info for task $path -- $lastBuildInfo" }
 
         fun getOrCreateIncrementalCache(target: TargetId): GradleIncrementalCacheImpl {
             val cacheDir = File(cacheDirectory, "increCache.${target.name}")
@@ -261,68 +264,117 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
 
         fun getIncrementalCache(it: TargetId) = caches.getOrPut(it, { getOrCreateIncrementalCache(it) })
 
-        fun PsiClass.findLookupSymbols(): Iterable<LookupSymbol> {
+        fun PsiClass.addLookupSymbols(symbols: MutableSet<LookupSymbol>) {
             val fqn = qualifiedName.orEmpty()
-            return listOf(LookupSymbol(name.orEmpty(), if (fqn == name) "" else fqn.removeSuffix("." + name!!))) +
+
-                    methods.map { LookupSymbol(it.name, fqn) } +
+            symbols.add(LookupSymbol(name.orEmpty(), if (fqn == name) "" else fqn.removeSuffix("." + name!!)))
-                    fields.map { LookupSymbol(it.name.orEmpty(), fqn) } +
+            methods.forEach { symbols.add(LookupSymbol(it.name, fqn)) }
-                    innerClasses.flatMap { it.findLookupSymbols() }
+            fields.forEach { symbols.add(LookupSymbol(it.name.orEmpty(), fqn)) }
+            innerClasses.forEach { it.addLookupSymbols(symbols) }
         }
 
-        fun dirtyLookupSymbolsFromModifiedJavaFiles(): List<LookupSymbol> {
+        val dirtyJavaLookupSymbols: Lazy<Collection<LookupSymbol>> = lazy {
+            val symbols = HashSet<LookupSymbol>()
             val modifiedJavaFiles = modified.filter { it.isJavaFile() }
-            return (if (modifiedJavaFiles.any()) {
+            if (modifiedJavaFiles.isEmpty()) return@lazy symbols
-                val rootDisposable = Disposer.newDisposable()
+
-                val configuration = CompilerConfiguration()
+            val rootDisposable = Disposer.newDisposable()
-                val environment = KotlinCoreEnvironment.createForProduction(rootDisposable, configuration, EnvironmentConfigFiles.JVM_CONFIG_FILES)
+            val configuration = CompilerConfiguration()
-                val project = environment.project
+            val environment = KotlinCoreEnvironment.createForProduction(rootDisposable, configuration, EnvironmentConfigFiles.JVM_CONFIG_FILES)
-                val psiFileFactory = PsiFileFactory.getInstance(project) as PsiFileFactoryImpl
+            val project = environment.project
-                modifiedJavaFiles.flatMap {
+            val psiFileFactory = PsiFileFactory.getInstance(project) as PsiFileFactoryImpl
-                    val javaFile = psiFileFactory.createFileFromText(it.nameWithoutExtension, Language.findLanguageByID("JAVA")!!, it.readText())
+
-                    if (javaFile is PsiJavaFile)
+            modifiedJavaFiles.forEach {
-                        javaFile.classes.flatMap { it.findLookupSymbols() }
+                val javaFile = psiFileFactory.createFileFromText(it.nameWithoutExtension, Language.findLanguageByID("JAVA")!!, it.readText())
-                    else listOf()
+                if (javaFile is PsiJavaFile) {
+                    javaFile.classes.forEach { it.addLookupSymbols(symbols) }
                 }
-            } else listOf())
+            }
+            symbols
         }
 
-        fun dirtyKotlinSourcesFromGradle(): MutableSet<File> {
+        fun getClasspathChanges(modifiedClasspath: List<File>): DirtyData? {
-            // TODO: handle classpath changes similarly - compare with cashed version (likely a big change, may be costly, some heuristics could be considered)
+            if (modifiedClasspath.isEmpty()) {
-            val modifiedKotlinFiles = modified.filter { it.isKotlinFile() }.toMutableSet()
+                logger.kotlinDebug { "No classpath changes" }
-            val lookupSymbols = dirtyLookupSymbolsFromModifiedJavaFiles()
+                return DirtyData()
-                    // TODO: add dirty lookups from modified kotlin files to reduce number of steps needed
+            }
-
+            if (artifactDifferenceRegistry == null) {
-            if (lookupSymbols.any()) {
+                logger.kotlinDebug { "No artifact history provider" }
-                val kotlinModifiedFilesSet = modifiedKotlinFiles.toHashSet()
+                return null
-                val dirtyFilesFromLookups = mapLookupSymbolsToFiles(lookupStorage, lookupSymbols, logAction, ::projectRelativePath, excludes = kotlinModifiedFilesSet)
-                modifiedKotlinFiles.addAll(dirtyFilesFromLookups)
             }
 
-            return modifiedKotlinFiles
+            val lastBuildTS = lastBuildInfo?.startTS
+            if (lastBuildTS == null) {
+                logger.kotlinDebug { "Could not determine last build timestamp" }
+                return null
+            }
+
+            val symbols = HashSet<LookupSymbol>()
+            val fqNames = HashSet<FqName>()
+            for (file in modifiedClasspath) {
+                val diffs = artifactDifferenceRegistry!![file]
+                if (diffs == null) {
+                    logger.kotlinDebug { "Could not get changes for file: $file" }
+                    return null
+                }
+
+                val (beforeLastBuild, afterLastBuild) = diffs.partition { it.buildTS < lastBuildTS }
+                if (beforeLastBuild.isEmpty()) {
+                    logger.kotlinDebug { "No known build preceding timestamp $lastBuildTS for file $file" }
+                    return null
+                }
+
+                afterLastBuild.forEach {
+                    symbols.addAll(it.dirtyData.dirtyLookupSymbols)
+                    fqNames.addAll(it.dirtyData.dirtyClassesFqNames)
+                }
+            }
+
+            return DirtyData(symbols, fqNames)
         }
 
-        fun isClassPathChanged(): Boolean =
-                modified.any { classpath.contains(it) }
-
         fun calculateSourcesToCompile(): Pair<Set<File>, Boolean> {
-            if (!incremental
+            fun rebuild(reason: String): Pair<Set<File>, Boolean> {
-                || !isIncrementalRequested
+                logger.kotlinInfo("Non-incremental compilation will be performed: $reason")
-                // TODO: more precise will be not to rebuild unconditionally on classpath changes, but retrieve lookup info and try to find out which sources are affected by cp changes
-                || isClassPathChanged()
-                // so far considering it not incremental TODO: store java files in the cache and extract removed symbols from it here
-                || removed.any { it.isJavaFile() || it.hasClassFileExtension() }
-                || modified.any { it.hasClassFileExtension() }
-            ) {
-                logger.kotlinInfo(if (!isIncrementalRequested) "clean caches on rebuild" else "classpath changed, rebuilding all kotlin files")
                 targets.forEach { getIncrementalCache(it).clean() }
                 lookupStorage.clean()
                 dirtySourcesSinceLastTimeFile.delete()
                 return Pair(sources.toSet(), false)
             }
 
-            val dirtyFiles = dirtyKotlinSourcesFromGradle()
+            if (!incremental) return rebuild("incremental compilation is not enabled")
+            if (!isIncrementalRequested) return rebuild("inputs' changes are unknown (first or clean build)")
+
+            // TODO: store java files in the cache and extract removed symbols from it here
+            val illegalRemovedFiles = removed.filter { it.isJavaFile() || it.hasClassFileExtension() }
+            if (illegalRemovedFiles.any()) return rebuild("unsupported removed files: ${filesToString(illegalRemovedFiles)}")
+
+            val illegalModifiedFiles = modified.filter(File::hasClassFileExtension)
+            if (illegalModifiedFiles.any()) return rebuild("unsupported modified files: ${filesToString(illegalModifiedFiles)}")
+
+            val modifiedClasspathEntries = modified.filter { it in classpath }
+            val classpathChanges = getClasspathChanges(modifiedClasspathEntries)
+                    ?: return rebuild("could not get changes from modified classpath entries: ${filesToString(modifiedClasspathEntries)}")
+
+            val dirtyFiles = modified.filter { it.isKotlinFile() }.toMutableSet()
+            val lookupSymbols = HashSet<LookupSymbol>()
+            lookupSymbols.addAll(dirtyJavaLookupSymbols.value)
+            lookupSymbols.addAll(classpathChanges.dirtyLookupSymbols)
+
+            if (lookupSymbols.any()) {
+                val dirtyFilesFromLookups = mapLookupSymbolsToFiles(lookupStorage, lookupSymbols, logAction, ::projectRelativePath)
+                dirtyFiles.addAll(dirtyFilesFromLookups)
+            }
+
+            val allCaches = targets.map(::getIncrementalCache)
+            val dirtyClassesFqNames = classpathChanges.dirtyClassesFqNames.flatMap { withSubtypes(it, allCaches) }
+            if (dirtyClassesFqNames.any()) {
+                val dirtyFilesFromFqNames = mapClassesFqNamesToFiles(allCaches, dirtyClassesFqNames, logAction, ::projectRelativePath)
+                dirtyFiles.addAll(dirtyFilesFromFqNames)
+            }
+
             if (dirtySourcesSinceLastTimeFile.exists()) {
-                val files = dirtySourcesSinceLastTimeFile.readLines().map(::File).filter { it.exists() }
+                val files = dirtySourcesSinceLastTimeFile.readLines().map(::File).filter(File::exists)
                 if (files.isNotEmpty()) {
                     logger.kotlinDebug { "Source files added since last compilation: $files" }
                 }
@@ -334,9 +386,8 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
         }
 
         fun cleanupOnError() {
-            val filesToDelete = allGeneratedFiles.map { it.outputFile }
+            logger.kotlinInfo("deleting $destinationDir on error")
-            logger.kotlinInfo("deleting output on error: ${filesToDelete.joinToString()}")
+            destinationDir.deleteRecursively()
-            filesToDelete.forEach { it.delete() }
         }
 
         fun processCompilerExitCode(exitCode: ExitCode) {
@@ -379,6 +430,13 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
             kaptAnnotationsFileUpdater = null
         }
 
+        val artifactFile = project.tryGetSingleArtifact()
+        logger.kotlinDebug { "Artifact to register difference for task $path: $artifactFile" }
+        val currentBuildInfo = BuildInfo(startTS = System.currentTimeMillis())
+        BuildInfo.write(currentBuildInfo, lastBuildInfoFile)
+        val buildDirtyLookupSymbols = HashSet<LookupSymbol>()
+        val buildDirtyFqNames = HashSet<FqName>()
+
         var exitCode = ExitCode.OK
         while (sourcesToCompile.any() || currentRemoved.any()) {
             val removedAndModified = (sourcesToCompile + currentRemoved).toList()
@@ -419,18 +477,38 @@ open class KotlinCompile() : AbstractKotlinCompile<K2JVMCompilerArguments>() {
 
             lookupStorage.update(lookupTracker, sourcesToCompile, currentRemoved)
 
-            if (!isIncrementalDecided) break
+            if (!isIncrementalDecided) {
+                artifactFile?.let { artifactDifferenceRegistry?.remove(it) }
+                break
+            }
 
             val (dirtyLookupSymbols, dirtyClassFqNames) = compilationResult.getDirtyData(caches.values, logAction)
             sourcesToCompile = mapLookupSymbolsToFiles(lookupStorage, dirtyLookupSymbols, logAction, ::projectRelativePath, excludes = sourcesToCompile) +
                                mapClassesFqNamesToFiles(caches.values, dirtyClassFqNames, logAction, ::projectRelativePath, excludes = sourcesToCompile)
 
+            buildDirtyLookupSymbols.addAll(dirtyLookupSymbols)
+            buildDirtyFqNames.addAll(dirtyClassFqNames)
+
             if (currentRemoved.any()) {
                 anyClassesCompiled = true
                 currentRemoved = listOf()
             }
         }
 
+        if (exitCode == ExitCode.OK) {
+            buildDirtyLookupSymbols.addAll(dirtyJavaLookupSymbols.value)
+        }
+        if (artifactFile != null && artifactDifferenceRegistry != null) {
+            val dirtyData = DirtyData(buildDirtyLookupSymbols, buildDirtyFqNames)
+            val artifactDifference = ArtifactDifference(currentBuildInfo.startTS, dirtyData)
+            artifactDifferenceRegistry!!.add(artifactFile, artifactDifference)
+            logger.kotlinDebug {
+                val dirtySymbolsSorted = buildDirtyLookupSymbols.map { it.scope + "#" + it.name }.sorted()
+                "Added artifact difference for $artifactFile (ts: ${currentBuildInfo.startTS}): " +
+                        "[\n\t${dirtySymbolsSorted.joinToString(",\n\t")}]"
+            }
+        }
+
         anyClassesCompiled = anyClassesCompiled || allGeneratedFiles.isNotEmpty()
         processCompilerExitCode(exitCode)
     }
@@ -719,6 +797,22 @@ class GradleMessageCollector(val logger: Logger, val outputCollector: OutputItem
     }
 }
 
+fun Project.tryGetSingleArtifact(): File? {
+    val log = logger
+    log.kotlinDebug { "Trying to determine single artifact for project $path" }
+
+    val archives = configurations.findByName("archives")
+    if (archives == null) {
+        log.kotlinDebug { "Could not find 'archives' configuration for project $path" }
+        return null
+    }
+
+    val artifacts = archives.artifacts.files.files
+    log.kotlinDebug { "All artifacts for project $path: [${artifacts.joinToString()}]" }
+
+    return if (artifacts.size == 1) artifacts.first() else null
+}
+
 internal fun Logger.kotlinInfo(message: String) {
     this.info("[KOTLIN] $message")
 }

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinGradleBuildServices.kt

@@ -26,6 +26,9 @@ import org.jetbrains.kotlin.com.intellij.openapi.util.io.ZipFileCache
 import org.jetbrains.kotlin.com.intellij.openapi.vfs.impl.ZipHandler
 import org.jetbrains.kotlin.com.intellij.openapi.vfs.impl.jar.CoreJarFileSystem
 import org.jetbrains.kotlin.gradle.tasks.AbstractKotlinCompile
+import org.jetbrains.kotlin.gradle.tasks.ArtifactDifferenceRegistry
+import org.jetbrains.kotlin.gradle.tasks.incremental.BuildCacheStorage
+import java.io.File
 
 private fun comparableVersionStr(version: String) =
         "(\\d+)\\.(\\d+).*"
@@ -37,31 +40,44 @@ private fun comparableVersionStr(version: String) =
                 ?.let { if (it.all { (it?.value?.length ?: 0).let { it > 0 && it < 4 }}) it else null }
                 ?.joinToString(".", transform = { it!!.value.padStart(3, '0') })
 
-class KotlinGradleBuildServices private constructor(): BuildAdapter() {
+class KotlinGradleBuildServices private constructor(gradle: Gradle): BuildAdapter() {
     companion object {
+        private val CLASS_NAME = KotlinGradleBuildServices::class.java.simpleName
         const val FORCE_SYSTEM_GC_MESSAGE = "Forcing System.gc()"
-        const val INIT_MESSAGE = "Initialized KotlinGradleBuildServices"
+        val INIT_MESSAGE = "Initialized $CLASS_NAME"
-        const val DISPOSE_MESSAGE = "Disposed KotlinGradleBuildServices"
+        val DISPOSE_MESSAGE = "Disposed $CLASS_NAME"
-        private var initialized = false
+        val ALREADY_INITIALIZED_MESSAGE = "$CLASS_NAME is already initialized"
+        @field:Volatile
+        private var instance: KotlinGradleBuildServices? = null
 
         @JvmStatic
         @Synchronized
-        fun init(gradle: Gradle) {
+        fun getInstance(gradle: Gradle): KotlinGradleBuildServices {
-            if (initialized) return
-
-            val listener = KotlinGradleBuildServices()
-            gradle.addBuildListener(listener)
-            initialized = true
             val log = Logging.getLogger(KotlinGradleBuildServices::class.java)
+
+            if (instance != null) {
+                log.kotlinDebug(ALREADY_INITIALIZED_MESSAGE)
+                return instance!!
+            }
+
+            val services = KotlinGradleBuildServices(gradle)
+            gradle.addBuildListener(services)
+            instance = services
             log.kotlinDebug(INIT_MESSAGE)
 
-            listener.buildStarted()
+            services.buildStarted()
+            return services
         }
     }
 
     private val log = Logging.getLogger(this.javaClass)
     private val cleanup = CompilerServicesCleanup()
     private var startMemory: Long? = null
+    private val workingDir = File(gradle.rootProject.buildDir, "kotlin-build").apply { mkdirs() }
+    private val buildCacheStorage = BuildCacheStorage(workingDir)
+
+    internal val artifactDifferenceRegistry: ArtifactDifferenceRegistry
+            get() = buildCacheStorage.artifactDifferenceRegistry
 
     // There is function with the same name in BuildAdapter,
     // but it is called before any plugin can attach build listener
@@ -93,8 +109,11 @@ class KotlinGradleBuildServices private constructor(): BuildAdapter() {
             }
         }
 
+        buildCacheStorage.flush(memoryCachesOnly = false)
+        buildCacheStorage.close()
+
         gradle.removeListener(this)
-        initialized = false
+        instance = null
         log.kotlinDebug(DISPOSE_MESSAGE)
     }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPlugin.kt

@@ -25,10 +25,8 @@ import org.jetbrains.kotlin.gradle.internal.Kapt2GradleSubplugin
 import org.jetbrains.kotlin.gradle.internal.Kapt2KotlinGradleSubplugin
 import org.jetbrains.kotlin.gradle.internal.initKapt
 import org.jetbrains.kotlin.gradle.plugin.android.AndroidGradleWrapper
-import org.jetbrains.kotlin.gradle.tasks.Kotlin2JsCompile
+import org.jetbrains.kotlin.gradle.tasks.*
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.tasks.incremental.configureMultiProjectIncrementalCompilation
-import org.jetbrains.kotlin.gradle.tasks.KotlinTasksProvider
-import org.jetbrains.kotlin.gradle.tasks.SyncOutputTask
 import java.io.File
 import java.net.URL
 import java.util.*
@@ -98,18 +96,14 @@ class Kotlin2JvmSourceSetProcessor(
         sourceSet: SourceSet,
         tasksProvider: KotlinTasksProvider,
         kotlinSourceSetProvider: KotlinSourceSetProvider,
-        private val kotlinPluginVersion: String
+        private val kotlinPluginVersion: String,
+        private val artifactDifferenceRegistry: ArtifactDifferenceRegistry
 ) : KotlinSourceSetProcessor<KotlinCompile>(
         project, javaBasePlugin, sourceSet, tasksProvider, kotlinSourceSetProvider,
         dslExtensionName = KOTLIN_DSL_NAME,
         compileTaskNameSuffix = "kotlin",
         taskDescription = "Compiles the $sourceSet.kotlin."
 ) {
-
-    private companion object {
-        private var cachedKotlinAnnotationProcessingDep: String? = null
-    }
-
     override val defaultKotlinDestinationDir: File
         get() = File(project.buildDir, "kotlin-classes/$sourceSetName")
 
@@ -147,6 +141,7 @@ class Kotlin2JvmSourceSetProcessor(
                 kotlinAfterJavaTask?.let { it.source(kotlinSourceSet.kotlin) }
                 configureJavaTask(kotlinTask, javaTask, logger)
                 createSyncOutputTask(project, kotlinTask, javaTask, kotlinAfterJavaTask, sourceSetName)
+                configureMultiProjectIncrementalCompilation(project, kotlinTask, javaTask, kotlinAfterJavaTask, artifactDifferenceRegistry)
             }
         }
     }
@@ -222,10 +217,11 @@ abstract class AbstractKotlinPlugin(val tasksProvider: KotlinTasksProvider, val
 open class KotlinPlugin(
         tasksProvider: KotlinTasksProvider,
         kotlinSourceSetProvider: KotlinSourceSetProvider,
-        kotlinPluginVersion: String
+        kotlinPluginVersion: String,
+        private val artifactDifferenceRegistry: ArtifactDifferenceRegistry
 ) : AbstractKotlinPlugin(tasksProvider, kotlinSourceSetProvider, kotlinPluginVersion) {
     override fun buildSourceSetProcessor(project: Project, javaBasePlugin: JavaBasePlugin, sourceSet: SourceSet, kotlinPluginVersion: String) =
-            Kotlin2JvmSourceSetProcessor(project, javaBasePlugin, sourceSet, tasksProvider, kotlinSourceSetProvider, kotlinPluginVersion)
+            Kotlin2JvmSourceSetProcessor(project, javaBasePlugin, sourceSet, tasksProvider, kotlinSourceSetProvider, kotlinPluginVersion, artifactDifferenceRegistry)
 
     override fun apply(project: Project) {
         project.createKaptExtension()

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinPluginWrapper.kt

@@ -19,28 +19,28 @@ abstract class KotlinBasePluginWrapper(protected val fileResolver: FileResolver)
     override fun apply(project: Project) {
         // TODO: consider only set if if daemon or parallel compilation are enabled, though this way it should be safe too
         System.setProperty(org.jetbrains.kotlin.cli.common.KOTLIN_COMPILER_ENVIRONMENT_KEEPALIVE_PROPERTY, "true")
+        val kotlinGradleBuildServices = KotlinGradleBuildServices.getInstance(project.gradle)
 
-        val plugin = getPlugin()
+        val plugin = getPlugin(kotlinGradleBuildServices)
         plugin.apply(project)
-
-        KotlinGradleBuildServices.init(project.gradle)
     }
 
-    protected abstract fun getPlugin(): Plugin<Project>
+    protected abstract fun getPlugin(kotlinGradleBuildServices: KotlinGradleBuildServices): Plugin<Project>
 }
 
 open class KotlinPluginWrapper @Inject constructor(fileResolver: FileResolver): KotlinBasePluginWrapper(fileResolver) {
-    override fun getPlugin() =
+    override fun getPlugin(kotlinGradleBuildServices: KotlinGradleBuildServices) =
-            KotlinPlugin(KotlinTasksProvider(), KotlinSourceSetProviderImpl(fileResolver), kotlinPluginVersion)
+            KotlinPlugin(KotlinTasksProvider(), KotlinSourceSetProviderImpl(fileResolver), kotlinPluginVersion,
+                    kotlinGradleBuildServices.artifactDifferenceRegistry)
 }
 
 open class KotlinAndroidPluginWrapper @Inject constructor(fileResolver: FileResolver): KotlinBasePluginWrapper(fileResolver) {
-    override fun getPlugin() =
+    override fun getPlugin(kotlinGradleBuildServices: KotlinGradleBuildServices) =
             KotlinAndroidPlugin(AndroidTasksProvider(), KotlinSourceSetProviderImpl(fileResolver), kotlinPluginVersion)
 }
 
 open class Kotlin2JsPluginWrapper @Inject constructor(fileResolver: FileResolver): KotlinBasePluginWrapper(fileResolver) {
-    override fun getPlugin() =
+    override fun getPlugin(kotlinGradleBuildServices: KotlinGradleBuildServices) =
             Kotlin2JsPlugin(KotlinTasksProvider(), KotlinSourceSetProviderImpl(fileResolver), kotlinPluginVersion)
 }
 

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/incremental/ArtifactDifferenceRegistryImpl.kt

@@ -0,0 +1,102 @@
+package org.jetbrains.kotlin.gradle.tasks.incremental
+
+import org.jetbrains.kotlin.com.intellij.util.io.DataExternalizer
+import org.jetbrains.kotlin.gradle.tasks.ArtifactDifference
+import org.jetbrains.kotlin.gradle.tasks.ArtifactDifferenceRegistry
+import org.jetbrains.kotlin.incremental.DirtyData
+import org.jetbrains.kotlin.incremental.LookupSymbol
+import org.jetbrains.kotlin.incremental.storage.BasicStringMap
+import org.jetbrains.kotlin.name.FqName
+import java.io.DataInput
+import java.io.DataOutput
+import java.io.File
+import java.util.*
+
+internal class ArtifactDifferenceRegistryImpl(
+        storageFile: File
+) : ArtifactDifferenceRegistry, BasicStringMap<Collection<ArtifactDifference>>(
+        storageFile,
+        ArtifactDifferenceCollectionExternalizer
+) {
+    companion object {
+        private val MAX_BUILDS_PER_ARTIFACT = 10
+    }
+
+    override fun get(artifact: File): Iterable<ArtifactDifference>? =
+            storage[artifact.canonicalPath]
+
+    override fun add(artifact: File, difference: ArtifactDifference) {
+        val key = artifact.canonicalPath
+        val oldVal = storage[key] ?: emptyList()
+        val newVal = ArrayList(oldVal)
+        newVal.add(difference)
+        newVal.sortBy { it.buildTS }
+        storage[key] = newVal.takeLast(MAX_BUILDS_PER_ARTIFACT)
+    }
+
+    override fun remove(artifact: File) {
+        storage.remove(artifact.canonicalPath)
+    }
+
+    override fun dumpValue(value: Collection<ArtifactDifference>): String =
+            value.sortedBy { it.buildTS }.joinToString(separator = ",\n\t") { diff ->
+                "{ " +
+                        "timestamp: ${diff.buildTS}, " +
+                        "lookup symbols: [${diff.dirtyData.dirtyLookupSymbols.dumpLookupSymbols()}], "  +
+                        "fq names: [${diff.dirtyData.dirtyClassesFqNames.dumpFqNames()}]"
+                "}"
+            }
+}
+
+private fun <T> Collection<T>.takeLast(n: Int): Collection<T> =
+        drop(Math.max(size - n, 0))
+
+private fun Collection<LookupSymbol>.dumpLookupSymbols(): String =
+        map { "${it.scope}#${it.name}" }.sorted().joinToString()
+
+private fun Collection<FqName>.dumpFqNames(): String =
+        map(FqName::asString).sorted().joinToString()
+
+private object ArtifactDifferenceCollectionExternalizer : DataExternalizer<Collection<ArtifactDifference>> {
+    override fun read(input: DataInput): Collection<ArtifactDifference> =
+            input.readCollectionTo(ArrayList()) {
+                val buildTS = readLong()
+                val dirtyLookupSymbols = readCollectionTo(HashSet()) {
+                    val scope = readUTF()
+                    val name = readUTF()
+                    LookupSymbol(name, scope)
+                }
+                val dirtyFqNames = readCollectionTo(HashSet()) {
+                    FqName(readUTF())
+                }
+                ArtifactDifference(buildTS, DirtyData(dirtyLookupSymbols, dirtyFqNames))
+            }
+
+    override fun save(output: DataOutput, value: Collection<ArtifactDifference>) {
+        output.writeCollection(value) { diff ->
+            writeLong(diff.buildTS)
+            writeCollection(diff.dirtyData.dirtyLookupSymbols) {
+                writeUTF(it.scope)
+                writeUTF(it.name)
+            }
+            writeCollection(diff.dirtyData.dirtyClassesFqNames) {
+                writeUTF(it.asString())
+            }
+        }
+    }
+}
+
+private inline fun <T> DataInput.readCollectionTo(col: MutableCollection<T>, readT: DataInput.()->T): Collection<T> {
+    val size = readInt()
+
+    repeat(size) {
+        col.add(readT())
+    }
+
+    return col
+}
+
+private inline fun <T> DataOutput.writeCollection(col: Collection<T>, writeT: DataOutput.(T)->Unit) {
+    writeInt(col.size)
+    col.forEach { writeT(it) }
+}

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/incremental/BuildCacheStorage.kt

@@ -0,0 +1,59 @@
+package org.jetbrains.kotlin.gradle.tasks.incremental
+
+import org.gradle.api.logging.Logging
+import org.jetbrains.kotlin.gradle.plugin.kotlinDebug
+import org.jetbrains.kotlin.gradle.tasks.ArtifactDifferenceRegistry
+import org.jetbrains.kotlin.incremental.CacheVersion
+import org.jetbrains.kotlin.incremental.storage.BasicMapsOwner
+import java.io.File
+
+/**
+ * "Global" cache holder. Should be created once per root project.
+ */
+internal class BuildCacheStorage(workingDir: File) : BasicMapsOwner() {
+    companion object {
+        private val OWN_VERSION = 0
+        private val ARTIFACT_DIFFERENCE = "artifact-difference"
+    }
+
+    private val log = Logging.getLogger(this.javaClass)
+    private val cachesDir: File = File(workingDir, "caches").apply { mkdirs() }
+    private val versionFile = File(cachesDir, "version.txt")
+    private val version = CacheVersion(
+            OWN_VERSION,
+            versionFile,
+            whenVersionChanged = CacheVersion.Action.REBUILD_ALL_KOTLIN,
+            whenTurnedOff = CacheVersion.Action.REBUILD_ALL_KOTLIN,
+            whenTurnedOn = CacheVersion.Action.REBUILD_ALL_KOTLIN,
+            // assume it's always enabled for simplicity (if IC is not enabled, just don't write to cache)
+            isEnabled = { true })
+
+    internal val artifactDifferenceRegistry: ArtifactDifferenceRegistry
+
+    private val String.storageFile: File
+        get() = File(cachesDir, this + "." + CACHE_EXTENSION)
+
+    init {
+        if (version.checkVersion() != CacheVersion.Action.DO_NOTHING) {
+            log.kotlinDebug { "Cache version is not up-to-date. Removing $cachesDir" }
+            cachesDir.deleteRecursively()
+            cachesDir.mkdirs()
+        }
+
+        artifactDifferenceRegistry = registerMap(ArtifactDifferenceRegistryImpl(ARTIFACT_DIFFERENCE.storageFile))
+    }
+
+    override fun clean() {
+        super.clean()
+        versionFile.delete()
+    }
+
+    override fun close() {
+        super.close()
+        version.saveIfNeeded()
+    }
+
+    override fun flush(memoryCachesOnly: Boolean) {
+        super.flush(memoryCachesOnly)
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/tasks/incremental/multiProjectIncrementalCompilationUtil.kt

@@ -0,0 +1,51 @@
+package org.jetbrains.kotlin.gradle.tasks.incremental
+
+import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.api.tasks.compile.AbstractCompile
+import org.gradle.api.tasks.compile.JavaCompile
+import org.jetbrains.kotlin.com.intellij.openapi.util.io.FileUtil
+import org.jetbrains.kotlin.gradle.plugin.kotlinDebug
+import org.jetbrains.kotlin.gradle.tasks.ArtifactDifferenceRegistry
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.tasks.tryGetSingleArtifact
+import java.io.File
+
+fun configureMultiProjectIncrementalCompilation(
+        project: Project,
+        kotlinTask: KotlinCompile,
+        javaTask: JavaCompile,
+        kotlinAfterJavaTask: KotlinCompile?,
+        artifactDifferenceRegistry: ArtifactDifferenceRegistry
+) {
+    val log = kotlinTask.logger
+    log.kotlinDebug { "Configuring multi-project incremental compilation for project ${project.path}" }
+
+    fun cannotPerformMultiProjectIC(artifact: File, reason: String) {
+        log.kotlinDebug {
+            "Multi-project kotlin incremental compilation cannot be performed for project ${project.path}: $reason"
+        }
+        artifactDifferenceRegistry.remove(artifact)
+    }
+
+    fun isUnknownTaskOutputtingToJavaDestination(task: Task): Boolean {
+        return task !is JavaCompile &&
+                task !is KotlinCompile &&
+                task is AbstractCompile &&
+                FileUtil.isAncestor(javaTask.destinationDir, task.destinationDir, /* strict = */ false)
+    }
+
+    val artifact = project.tryGetSingleArtifact() ?: return
+    if (!kotlinTask.incremental) {
+        return cannotPerformMultiProjectIC(artifact, reason = "incremental compilation is not enabled")
+    }
+
+    val illegalTask = project.tasks.find(::isUnknownTaskOutputtingToJavaDestination)
+    if (illegalTask != null) {
+        return cannotPerformMultiProjectIC(artifact,
+                reason = "unknown task outputs to java destination dir ${illegalTask.path} $(${illegalTask.javaClass})")
+    }
+
+    val kotlinCompile = kotlinAfterJavaTask ?: kotlinTask
+    kotlinCompile.artifactDifferenceRegistry = artifactDifferenceRegistry
+}

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/AbstractKotlinAndroidGradleTests.kt

@@ -92,7 +92,7 @@ fun getSomething() = 10
 
         project.build("build", options = options) {
             assertSuccessful()
-            assertCompiledKotlinSources(listOf("src/main/kotlin/foo/KotlinActivity1.kt", "src/main/kotlin/foo/getSomething.kt"))
+            assertCompiledKotlinSources(listOf("app/src/main/kotlin/foo/KotlinActivity1.kt", "app/src/main/kotlin/foo/getSomething.kt"))
             assertCompiledJavaSources(listOf("app/src/main/java/foo/JavaActivity.java"), weakTesting = true)
         }
     }
@@ -165,7 +165,7 @@ fun getSomething() = 10
 
         project.build(":app:assembleDebug", options = options) {
             assertSuccessful()
-            assertCompiledKotlinSources(project.relativizeToSubproject("app",
+            assertCompiledKotlinSources(project.relativize(
                     androidModuleKt,
                     baseApplicationKt,
                     useBuildConfigJavaKt,

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/BaseGradleIT.kt

@@ -95,11 +95,6 @@ abstract class BaseGradleIT {
         fun relativize(vararg files: File): List<String> =
                 files.map { it.relativeTo(projectDir).path }
 
-        fun relativizeToSubproject(subproject: String, vararg files: File): List<String> {
-            val subprojectSir = File(projectDir, subproject)
-            return files.map { it.relativeTo(subprojectSir).path }
-        }
-
         fun performModifications() {
             for (file in projectDir.walk()) {
                 if (!file.isFile) continue

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/IncrementalCompilationMultiProjectIT.kt

@@ -0,0 +1,188 @@
+package org.jetbrains.kotlin.gradle
+
+import org.jetbrains.kotlin.gradle.util.allKotlinFiles
+import org.jetbrains.kotlin.gradle.util.getFileByName
+import org.jetbrains.kotlin.gradle.util.getFilesByNames
+import org.jetbrains.kotlin.gradle.util.modify
+import org.junit.Test
+import java.io.File
+
+class IncrementalCompilationMultiProjectIT : BaseGradleIT() {
+    companion object {
+        private val GRADLE_VERSION = "2.10"
+    }
+
+    override fun defaultBuildOptions(): BuildOptions =
+            super.defaultBuildOptions().copy(withDaemon = true, incremental = true)
+
+
+    @Test
+    fun testMoveFunctionFromLib() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        val barUseABKt = project.projectDir.getFileByName("barUseAB.kt")
+        val barInApp = File(project.projectDir, "app/src/main/java/bar").apply { mkdirs() }
+        barUseABKt.copyTo(File(barInApp, barUseABKt.name))
+        barUseABKt.delete()
+
+        project.build("build") {
+            assertSuccessful()
+            val affectedSources = project.projectDir.getFilesByNames("fooCallUseAB.kt", "barUseAB.kt")
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    @Test
+    fun testAddNewMethodToLib() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        val aKt = project.projectDir.getFileByName("A.kt")
+        aKt.writeText("""
+package bar
+
+open class A {
+    fun a() {}
+    fun newA() {}
+}
+""")
+
+        project.build("build") {
+            assertSuccessful()
+            val affectedSources = project.projectDir.getFilesByNames("A.kt", "B.kt", "AA.kt", "BB.kt")
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    @Test
+    fun testLibClassBecameFinal() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        val bKt = project.projectDir.getFileByName("B.kt")
+        bKt.modify { it.replace("open class", "class") }
+
+        project.build("build") {
+            assertFailed()
+            val affectedSources = project.projectDir.getFilesByNames(
+                    "B.kt", "barUseAB.kt", "barUseB.kt",
+                    "BB.kt", "fooCallUseAB.kt", "fooUseB.kt")
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    @Test
+    fun testModifyJavaInLib() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        val javaClassJava = project.projectDir.getFileByName("JavaClass.java")
+        javaClassJava.modify { it.replace("String getString", "Object getString") }
+
+        project.build("build") {
+            assertSuccessful()
+            val affectedSources = project.projectDir.getFilesByNames("JavaClassChild.kt", "useJavaClass.kt")
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    @Test
+    fun testCleanBuildLib() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        project.build(":lib:clean", ":lib:build") {
+            assertSuccessful()
+            val affectedSources = File(project.projectDir, "lib").allKotlinFiles()
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+
+        project.build("build") {
+            assertSuccessful()
+            val affectedSources = File(project.projectDir, "app").allKotlinFiles()
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    @Test
+    fun testCompileErrorInLib() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        val bKt = project.projectDir.getFileByName("B.kt")
+        bKt.delete()
+
+        project.build("build") {
+            assertFailed()
+        }
+
+        project.projectDir.getFileByName("barUseB.kt").delete()
+        project.projectDir.getFileByName("barUseAB.kt").delete()
+
+        project.build("build") {
+            assertFailed()
+            val affectedSources = project.projectDir.allKotlinFiles()
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+
+    // checks that multi-project ic is disabled when there is a task that outputs to javaDestination dir
+    // that is not JavaCompile or KotlinCompile
+    @Test
+    fun testCompileLibWithGroovy() {
+        val project = Project("incrementalMultiproject", GRADLE_VERSION)
+        project.setupWorkingDir()
+        val lib = File(project.projectDir, "lib")
+        val libBuildGradle = File(lib, "build.gradle")
+        libBuildGradle.modify {
+            """
+            apply plugin: 'groovy'
+            apply plugin: 'kotlin'
+
+            dependencies {
+                compile 'org.codehaus.groovy:groovy-all:2.4.7'
+            }
+            """.trimIndent()
+        }
+
+        val libGroovySrcBar = File(lib, "src/main/groovy/bar").apply { mkdirs() }
+        val groovyClass = File(libGroovySrcBar, "GroovyClass.groovy")
+        groovyClass.writeText("""
+            package bar
+
+            class GroovyClass {}
+        """)
+
+        project.build("build") {
+            assertSuccessful()
+        }
+
+        project.projectDir.getFileByName("barUseB.kt").delete()
+        project.build("build") {
+            assertSuccessful()
+            val affectedSources = File(project.projectDir, "app").allKotlinFiles()
+            val relativePaths = project.relativize(affectedSources)
+            assertCompiledKotlinSources(relativePaths, weakTesting = false)
+        }
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/util/fileUtil.kt

@@ -5,6 +5,9 @@ import java.io.File
 fun File.getFileByName(name: String): File =
         findFileByName(name) ?: throw AssertionError("Could not find file with name '$name' in $this")
 
+fun File.getFilesByNames(vararg names: String): List<File> =
+        names.map { getFileByName(it) }
+
 fun File.findFileByName(name: String): File? =
         walk().filter { it.isFile && it.name.equals(name, ignoreCase = true) }.firstOrNull()
 

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/build.gradle

@@ -0,0 +1,5 @@
+apply plugin: 'kotlin'
+
+dependencies {
+    compile project(':lib')
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/AA.kt

@@ -0,0 +1,7 @@
+package foo
+
+import bar.*
+
+class AA : A() {
+    fun aa() {}
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/BB.kt

@@ -0,0 +1,7 @@
+package foo
+
+import bar.*
+
+class BB : B() {
+    fun bb() {}
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/FooDummy.kt

@@ -0,0 +1,3 @@
+package foo
+
+class FooDummy

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/JavaClassChild.kt

@@ -0,0 +1,5 @@
+package foo
+
+import bar.*
+
+class JavaClassChild : JavaClass() {}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/fooCallUseAB.kt

@@ -0,0 +1,8 @@
+package foo
+
+import bar.*
+
+fun callUseAB() {
+    val b = B()
+    useAB(b)
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/fooUseA.kt

@@ -0,0 +1,7 @@
+package foo
+
+import bar.*
+
+private fun fooUseA(a: A) {
+    a.a()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/fooUseAA.kt

@@ -0,0 +1,5 @@
+package foo
+
+private fun fooUseAA(aa: AA) {
+    aa.aa()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/fooUseB.kt

@@ -0,0 +1,7 @@
+package foo
+
+import bar.*
+
+private fun fooUseB(b: B) {
+    b.b()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/fooUseBB.kt

@@ -0,0 +1,5 @@
+package foo
+
+private fun fooUseBB(bb: BB) {
+    bb.bb()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/app/src/main/java/foo/useJavaClass.kt

@@ -0,0 +1,7 @@
+package foo
+
+import bar.*
+
+fun useJavaClass(jc: JavaClass) {
+    jc.getString()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/build.gradle

@@ -0,0 +1,16 @@
+buildscript {
+    ext.kotlin_version = '0.1-SNAPSHOT'
+    repositories {
+        maven { url 'file://' + pathToKotlinPlugin }
+    }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+    }
+}
+
+allprojects {
+    // for test with groovy
+    repositories {
+        mavenCentral()
+    }
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/build.gradle

@@ -0,0 +1 @@
+apply plugin: 'kotlin'

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/A.kt

@@ -0,0 +1,5 @@
+package bar
+
+open class A {
+    fun a() {}
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/B.kt

@@ -0,0 +1,5 @@
+package bar
+
+open class B : A() {
+    fun b() {}
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/BarDummy.kt

@@ -0,0 +1,3 @@
+package bar
+
+class BarDummy

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/JavaClass.java

@@ -0,0 +1,5 @@
+package bar;
+
+public class JavaClass {
+    public String getString() { return "Hello, World!"; }
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/barUseA.kt

@@ -0,0 +1,5 @@
+package bar
+
+private fun barUseA(a: A) {
+    a.a()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/barUseAB.kt

@@ -0,0 +1,5 @@
+package bar
+
+fun useAB(b: B) {
+    b.b()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/lib/src/main/java/bar/barUseB.kt

@@ -0,0 +1,5 @@
+package bar
+
+private fun barUseB(b: B) {
+    b.b()
+}

libraries/tools/kotlin-gradle-plugin/src/test/resources/testProject/incrementalMultiproject/settings.gradle

@@ -0,0 +1 @@
+include ':app', ':lib'