Disable IC when IC cache is missing

Check task build directory for any files

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

@@ -454,6 +454,9 @@ abstract class BaseGradleIT {
                 System.getProperty("maven.repo.local")?.let {
                     add("-Dmaven.repo.local=$it") // TODO: proper escaping
                 }
+                if (options.withBuildCache) {
+                    add("--build-cache")
+                }
                 addAll(options.freeCommandLineArgs)
             }
 

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

@@ -95,8 +95,6 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKo
             logger.kotlinDebug { "Set $this.incremental=$value" }
         }
 
-    abstract protected fun createCompilerArgs(): T
-
     @get:Internal
     internal val pluginOptions = CompilerPluginOptions()
 
@@ -238,6 +236,11 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments>() : AbstractKo
         compilerArgs.pluginClasspaths = pluginClasspath.toTypedArray()
         compilerArgs.pluginOptions = pluginOptions.arguments.toTypedArray()
     }
+
+    protected fun hasFilesInTaskBuildDirectory(): Boolean {
+        val taskBuildDir = taskBuildDirectory
+        return taskBuildDir.walk().any { it != taskBuildDir && it.isFile }
+    }
 }
 
 @CacheableTask
@@ -341,11 +344,15 @@ open class KotlinCompile : AbstractKotlinCompile<K2JVMCompilerArguments>(), Kotl
         val reporter = GradleICReporter(project.rootProject.projectDir)
 
         val environment = when {
-            !incremental -> GradleCompilerEnvironment(computedCompilerClasspath, messageCollector, outputItemCollector, args)
+            !incremental ->
+                GradleCompilerEnvironment(computedCompilerClasspath, messageCollector, outputItemCollector, args)
             else -> {
                 logger.info(USING_INCREMENTAL_COMPILATION_MESSAGE)
                 val friendTask = friendTaskName?.let { project.tasks.findByName(it) as? KotlinCompile }
-                GradleIncrementalCompilerEnvironment(computedCompilerClasspath, changedFiles, reporter, taskBuildDirectory,
+                GradleIncrementalCompilerEnvironment(
+                        computedCompilerClasspath,
+                        if (hasFilesInTaskBuildDirectory()) changedFiles else ChangedFiles.Unknown(),
+                        reporter, taskBuildDirectory,
                         messageCollector, outputItemCollector, args, kaptAnnotationsFileUpdater,
                         artifactDifferenceRegistryProvider,
                         artifactFile = artifactFile,
@@ -508,7 +515,9 @@ open class Kotlin2JsCompile() : AbstractKotlinCompile<K2JSCompilerArguments>(),
             incremental -> {
                 logger.warn(USING_EXPERIMENTAL_JS_INCREMENTAL_COMPILATION_MESSAGE)
                 GradleIncrementalCompilerEnvironment(
-                        computedCompilerClasspath, changedFiles, reporter, taskBuildDirectory,
+                        computedCompilerClasspath,
+                        if (hasFilesInTaskBuildDirectory()) changedFiles else ChangedFiles.Unknown(),
+                        reporter, taskBuildDirectory,
                         messageCollector, outputItemCollector, args)
             }
             else -> {