Enable disabling incremental compilation for tests

compiler/backend/src/org/jetbrains/kotlin/codegen/MultifileClassCodegen.kt

@@ -247,7 +247,7 @@ public class MultifileClassCodegen(
         }
 
         private fun getCompiledPackageFragment(packageFqName: FqName, state: GenerationState): PackageFragmentDescriptor? =
-                if (!IncrementalCompilation.ENABLED) null
+                if (!IncrementalCompilation.isEnabled()) null
                 else state.module.getPackage(packageFqName).fragments.firstOrNull { fragment ->
                     fragment is IncrementalPackageFragmentProvider.IncrementalPackageFragment &&
                     fragment.target == state.targetId

compiler/backend/src/org/jetbrains/kotlin/codegen/PackageCodegen.java

@@ -141,7 +141,7 @@ public class PackageCodegen {
 
     @Nullable
     private PackageFragmentDescriptor getCompiledPackageFragment(@NotNull FqName fqName) {
-        if (!IncrementalCompilation.ENABLED) {
+        if (!IncrementalCompilation.isEnabled()) {
             return null;
         }
 

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -65,7 +65,7 @@ public open class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
         val configuration = CompilerConfiguration()
         configuration.put(CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY, messageSeverityCollector)
 
-        if (IncrementalCompilation.ENABLED) {
+        if (IncrementalCompilation.isEnabled()) {
             val incrementalCompilationComponents = services.get(javaClass<IncrementalCompilationComponents>())
             configuration.put(JVMConfigurationKeys.INCREMENTAL_COMPILATION_COMPONENTS, incrementalCompilationComponents)
         }

compiler/util/src/org/jetbrains/kotlin/config/IncrementalCompilation.java

@@ -16,6 +16,22 @@
 
 package org.jetbrains.kotlin.config;
 
+import org.jetbrains.annotations.TestOnly;
+
 public class IncrementalCompilation {
-    public static final boolean ENABLED = !"false".equals(System.getProperty("kotlin.incremental.compilation"));
-}
+    private static final String INCREMENTAL_COMPILATION_PROPERTY = "kotlin.incremental.compilation";
+
+    public static boolean isEnabled() {
+        return !"false".equals(System.getProperty(INCREMENTAL_COMPILATION_PROPERTY));
+    }
+
+    @TestOnly
+    public static void disableIncrementalCompilation() {
+        System.setProperty(INCREMENTAL_COMPILATION_PROPERTY, "false");
+    }
+
+    @TestOnly
+    public static void enableIncrementalCompilation() {
+        System.setProperty(INCREMENTAL_COMPILATION_PROPERTY, "true");
+    }
+}

jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilder.kt

@@ -134,7 +134,7 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
 
         val dataManager = projectDescriptor.dataManager
 
-        if (IncrementalCompilation.ENABLED &&
+        if (IncrementalCompilation.isEnabled() &&
             chunk.targets.any { dataManager.dataPaths.getKotlinCacheVersion(it).isIncompatible() }
         ) {
             LOG.info("Clearing caches for " + chunk.targets.map { it.presentableName }.join())
@@ -215,7 +215,7 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
             copyJsLibraryFilesIfNeeded(chunk, project)
         }
 
-        if (!IncrementalCompilation.ENABLED) return OK
+        if (!IncrementalCompilation.isEnabled()) return OK
 
         val caches = filesToCompile.keySet().map { incrementalCaches[it]!! }
         val marker = ChangesProcessor(context, chunk, allCompiledFiles, caches)
@@ -293,8 +293,8 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
             return compileToJs(chunk, commonArguments, environment, null, messageCollector, project)
         }
 
-        if (IncrementalCompilation.ENABLED) {
-            for (target in chunk.getTargets()) {
+        if (IncrementalCompilation.isEnabled()) {
+            for (target in chunk.targets) {
                 val cache = incrementalCaches[target]!!
                 val removedAndDirtyFiles = filesToCompile[target] + dirtyFilesHolder.getRemovedFiles(target).map { File(it) }
                 cache.markOutputClassesDirty(removedAndDirtyFiles)
@@ -410,7 +410,7 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
             return sources
         }
 
-        if (!IncrementalCompilation.ENABLED) {
+        if (!IncrementalCompilation.isEnabled()) {
             return
         }
 
@@ -449,7 +449,7 @@ public class KotlinBuilder : ModuleLevelBuilder(BuilderCategory.SOURCE_PROCESSOR
     ): ChangesInfo {
         incrementalCaches.values().forEach { it.saveCacheFormatVersion() }
 
-        if (!IncrementalCompilation.ENABLED) {
+        if (!IncrementalCompilation.isEnabled()) {
             return ChangesInfo.NO_CHANGES
         }
 

jps-plugin/src/org/jetbrains/kotlin/jps/build/KotlinBuilderModuleScriptGenerator.java

@@ -72,7 +72,7 @@ public class KotlinBuilderModuleScriptGenerator {
             File outputDir = getOutputDirSafe(target);
 
             List<File> moduleSources = new ArrayList<File>(
-                    IncrementalCompilation.ENABLED
+                    IncrementalCompilation.isEnabled()
                     ? sourceFiles.get(target)
                     : KotlinSourceFileCollector.getAllKotlinSourceFiles(target));
 

jps-plugin/src/org/jetbrains/kotlin/jps/incremental/CacheFormatVersion.kt

@@ -38,7 +38,7 @@ class CacheFormatVersion(targetDataRoot: File) {
     private val file = File(targetDataRoot, FORMAT_VERSION_FILE_PATH)
 
     fun isIncompatible(): Boolean {
-        assert(IncrementalCompilation.ENABLED) { "Incremental compilation is not enabled" }
+        assert(IncrementalCompilation.isEnabled()) { "Incremental compilation is not enabled" }
         if (!file.exists()) return false
 
         val versionNumber = file.readText().toInt()

jps-plugin/src/org/jetbrains/kotlin/modules/KotlinModuleXmlBuilder.java

@@ -83,7 +83,7 @@ public class KotlinModuleXmlBuilder {
     ) {
         p.println("<!-- Classpath -->");
         for (File file : files) {
-            boolean isOutput = directoriesToFilterOut.contains(file) && !IncrementalCompilation.ENABLED;
+            boolean isOutput = directoriesToFilterOut.contains(file) && !IncrementalCompilation.isEnabled();
             if (isOutput) {
                 // For IDEA's make (incremental compilation) purposes, output directories of the current module and its dependencies
                 // appear on the class path, so we are at risk of seeing the results of the previous build, i.e. if some class was