Fix caches closing/flushing when IC builds non-incrementally

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

@@ -26,20 +26,26 @@ internal class IncrementalCachesManager (
 ) {
     private val incrementalCacheDir = File(cacheDirectory, "increCache.${targetId.name}")
     private val lookupCacheDir = File(cacheDirectory, "lookups")
-    private var incrementalCacheOpen = false
-    private var lookupCacheOpen = false
+    private var incrementalCacheField: GradleIncrementalCacheImpl? = null
+    private var lookupCacheField: LookupStorage? = null
 
-    val incrementalCache: GradleIncrementalCacheImpl by lazy {
-        val cache = GradleIncrementalCacheImpl(targetDataRoot = incrementalCacheDir.apply { mkdirs() }, targetOutputDir = outputDir, target = targetId)
-        incrementalCacheOpen = true
-        cache
-    }
+    val incrementalCache: GradleIncrementalCacheImpl
+        get() {
+            if (incrementalCacheField == null) {
+                incrementalCacheField = GradleIncrementalCacheImpl(targetDataRoot = incrementalCacheDir.apply { mkdirs() }, targetOutputDir = outputDir, target = targetId)
+            }
 
-    val lookupCache: LookupStorage by lazy {
-        val cache = LookupStorage(lookupCacheDir.apply { mkdirs() })
-        lookupCacheOpen = true
-        cache
-    }
+            return incrementalCacheField!!
+        }
+
+    val lookupCache: LookupStorage
+        get() {
+            if (lookupCacheField == null) {
+                lookupCacheField = LookupStorage(lookupCacheDir.apply { mkdirs() })
+            }
+
+            return lookupCacheField!!
+        }
 
     fun clean() {
         close(flush = false)
@@ -47,20 +53,20 @@ internal class IncrementalCachesManager (
     }
 
     fun close(flush: Boolean = false) {
-        if (incrementalCacheOpen) {
+        incrementalCacheField?.let {
             if (flush) {
-                incrementalCache.flush(false)
+                it.flush(false)
             }
-            incrementalCache.close()
-            incrementalCacheOpen = false
+            it.close()
+            incrementalCacheField = null
         }
 
-        if (lookupCacheOpen) {
+        lookupCacheField?.let {
             if (flush) {
-                lookupCache.flush(false)
+                it.flush(false)
             }
-            lookupCache.close()
-            lookupCacheOpen = false
+            it.close()
+            lookupCacheField = null
         }
     }
 }

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

@@ -132,7 +132,7 @@ internal class IncrementalJvmCompilerRunner(
         return try {
             val javaFilesProcessor = ChangedJavaFilesProcessor()
             val changedFiles = getChangedFiles(caches)
-            val compilationMode = calculateSourcesToCompile(javaFilesProcessor, caches, changedFiles, args.classpathAsList)
+            val compilationMode = calculateSourcesToCompile(javaFilesProcessor, caches, changedFiles, args)
             compileIncrementally(args, caches, javaFilesProcessor, allKotlinSources, targetId, compilationMode, messageCollector)
         }
         catch (e: PersistentEnumeratorBase.CorruptedException) {
@@ -161,12 +161,13 @@ internal class IncrementalJvmCompilerRunner(
             javaFilesProcessor: ChangedJavaFilesProcessor,
             caches: IncrementalCachesManager,
             changedFiles: ChangedFiles,
-            classpath: Iterable<File>
+            args: K2JVMCompilerArguments
     ): CompilationMode {
         fun rebuild(reason: ()->String): CompilationMode {
             reporter.report {"Non-incremental compilation will be performed: ${reason()}"}
             caches.clean()
             dirtySourcesSinceLastTimeFile.delete()
+            args.destinationAsFile.deleteRecursively()
             return CompilationMode.Rebuild
         }
 
@@ -178,7 +179,7 @@ internal class IncrementalJvmCompilerRunner(
         val modifiedClassFiles = changedFiles.modified.filter(File::isClassFile)
         if (modifiedClassFiles.any()) return rebuild {"Modified class files: ${reporter.pathsAsString(modifiedClassFiles)}"}
 
-        val classpathSet = classpath.toHashSet()
+        val classpathSet = args.classpathAsList.toHashSet()
         val modifiedClasspathEntries = changedFiles.modified.filter {it in classpathSet}
         val lastBuildInfo = BuildInfo.read(lastBuildInfoFile)
         reporter.report { "Last Kotlin Build info -- $lastBuildInfo" }