[eclipse-archived/xtext-core#1835] better treatment of unsupported Java versions in Xtext

Signed-off-by: Christian Dietrich <christian.dietrich@itemis.de>

Author: cdietrich

xtext-gradle-builder/src/main/java/org/xtext/gradle/builder/XtextGradleBuilder.xtend

@@ -12,7 +12,6 @@ import java.net.URLClassLoader
 import java.util.List
 import java.util.Set
 import java.util.concurrent.ConcurrentHashMap
-import org.eclipse.emf.common.notify.Notifier
 import org.eclipse.emf.common.util.URI
 import org.eclipse.xtext.ISetup
 import org.eclipse.xtext.build.BuildRequest
@@ -52,7 +51,7 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 	val sharedInjector = Guice.createInjector
 	val incrementalbuilder = sharedInjector.getInstance(IncrementalBuilder)
 	val debugInfoInstaller = sharedInjector.getInstance(DebugInfoInstaller)
-
+	
 	new(Set<String> setupNames, String encoding) throws Exception {
 		System.setProperty("org.eclipse.emf.common.util.ReferenceClearingQueue", "false")
 		for (setupName : setupNames) {
@@ -67,12 +66,12 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 		val containerHandle = gradleRequest.containerHandle
 		val validator = new GradleValidatonCallback(gradleRequest.logger)
 		val response = new GradleBuildResponse
-
+		
 		indexChangedClasspathEntries(gradleRequest)
-
+		
 		val request = new BuildRequest => [
 			baseDir = createFolderURI(gradleRequest.projectDir)
-			if(needsCleanBuild(gradleRequest)) {
+			if (needsCleanBuild(gradleRequest)) {
 				dirtyFiles = gradleRequest.allFiles.map[URI.createFileURI(absolutePath)].toList
 				state = new IndexState
 			} else {
@@ -84,28 +83,28 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 			}
 
 			afterValidate = validator
-			afterGenerateFile = [source, target|response.generatedFiles.add(new File(target.toFileString))]
-
+			afterGenerateFile = [source, target| response.generatedFiles.add(new File(target.toFileString))]
+			
 			preparResourceSet(containerHandle, state.resourceDescriptions, gradleRequest)
 		]
-
+		
 		val result = doBuild(request, gradleRequest)
-
-		if(!validator.isErrorFree) {
+		
+		if (!validator.isErrorFree) {
 			throw new GradleException("Xtext validation failed, see build log for details.")
 		}
-
+		
 		val resultingIndex = result.indexState
 		index.setContainer(containerHandle, resultingIndex.resourceDescriptions)
 		generatedMappings.put(containerHandle, resultingIndex.fileMappings)
 		return response
 	}
-
+	
 	private def indexChangedClasspathEntries(GradleBuildRequest gradleRequest) {
 		val registry = IResourceServiceProvider.Registry.INSTANCE
-		gradleRequest.dirtyClasspathEntries.filter[exists].forEach [ dirtyClasspathEntry |
+		gradleRequest.dirtyClasspathEntries.filter[exists].forEach[dirtyClasspathEntry|
 			val hash = hash(dirtyClasspathEntry)
-			if(dependencyHashes.get(dirtyClasspathEntry) != hash) {
+			if (dependencyHashes.get(dirtyClasspathEntry) != hash) {
 				val containerHandle = dirtyClasspathEntry.path
 				val request = new BuildRequest => [
 					indexOnly = true
@@ -114,128 +113,136 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 					 * Only mark files as dirty that have changed in the jar,
 					 * detect the deleted ones and reuse the existing index chunk for unchanged ones.
 					 */
-					dirtyFiles += new PathTraverser().findAllResourceUris(dirtyClasspathEntry.path) [ uri |
+					dirtyFiles += new PathTraverser().findAllResourceUris(dirtyClasspathEntry.path) [uri|
 						registry.getResourceServiceProvider(uri) !== null
 					]
-
-					afterValidate = [false] // workaround for indexOnly not working in Xtext 2.9.0
+					
+					afterValidate = [false] //workaround for indexOnly not working in Xtext 2.9.0
+					
 					val indexChunk = new ResourceDescriptionsData(emptyList)
 					val fileMappings = new Source2GeneratedMapping
 					state = new IndexState(indexChunk, fileMappings)
 					preparResourceSet(containerHandle, indexChunk, gradleRequest)
 				]
-
+				
 				val result = doBuild(request, gradleRequest)
 				val resultingIndex = result.indexState
 				index.setContainer(containerHandle, resultingIndex.resourceDescriptions)
 				dependencyHashes.put(dirtyClasspathEntry, hash)
 			}
 		]
 	}
-
+	
 	private def HashCode hash(File file) {
 		val hasher = Hashing.md5.newHasher
 		hash(file, hasher)
 		hasher.hash
 	}
-
+	
 	private def void hash(File file, Hasher hasher) {
-		if(file.isDirectory) {
+		if (file.isDirectory) {
 			file.listFiles.forEach[hash(hasher)]
 		} else {
 			Files.asByteSource(file).copyTo(Funnels.asOutputStream(hasher))
 		}
 	}
-
+	
 	private def preparResourceSet(BuildRequest it, String containerHandle, ResourceDescriptionsData indexChunk, GradleBuildRequest gradleRequest) {
 		resourceSet = sharedInjector.getInstance(XtextResourceSet) => [
 			classpathURIContext = gradleRequest.jvmTypesLoader
 			attachProjectConfig(gradleRequest)
 			attachGeneratorConfig(gradleRequest)
 			attachOutputConfig(gradleRequest)
 			attachPreferences(gradleRequest)
-			attachJavaConfig(gradleRequest)
 			attachProjectDescription(containerHandle, gradleRequest.allClasspathEntries.map[path].toList, it)
 			val contextualIndex = index.createShallowCopyWith(it)
 			contextualIndex.setContainer(containerHandle, indexChunk)
 		]
 	}
-
+	
 	private def doBuild(BuildRequest request, GradleBuildRequest gradleRequest) {
 		try {
 			val registry = IResourceServiceProvider.Registry.INSTANCE
-			if(needsCleanBuild(gradleRequest)) {
+			if (needsCleanBuild(gradleRequest)) {
 				doClean(gradleRequest)
 			}
-			incrementalbuilder.build(request, [uri|registry.getResourceServiceProvider(uri)])
+			incrementalbuilder.build(request, [uri| registry.getResourceServiceProvider(uri)])
 		} finally {
 			cleanup(gradleRequest, request)
 		}
 	}
-
+	
 	private def doClean(GradleBuildRequest request) {
-		request.generatorConfigsByLanguage.values.map[outputConfigs].flatten.filter[cleanAutomatically].map[target].forEach [
-			deleteRecursive
-		]
+		request.generatorConfigsByLanguage.values
+			.map[outputConfigs].flatten
+			.filter[cleanAutomatically]
+			.map[target]
+			.forEach[
+				deleteRecursive
+			]
 	}
-
+	
 	private def void deleteRecursive(File file) {
-		if(file.isDirectory) {
+		if (file.isDirectory) {
 			file.listFiles.forEach[deleteRecursive]
 		}
 		file.delete
 	}
-
+	
 	private def boolean needsCleanBuild(GradleBuildRequest request) {
 		!request.incremental || !request.dirtyClasspathEntries.isEmpty || index.getContainer(request.containerHandle) === null
 	}
-
+	
 	private def getJvmTypesLoader(GradleBuildRequest gradleRequest) {
-		val parent = if(gradleRequest.bootstrapClasspath === null || gradleRequest.bootstrapClasspath.empty) {
-				ClassLoader.systemClassLoader
-			} else {
-				new AlternateJdkLoader(gradleRequest.bootstrapClasspath)
-			}
+		val parent = if (gradleRequest.bootstrapClasspath === null || gradleRequest.bootstrapClasspath.empty) {
+			ClassLoader.systemClassLoader
+		} else {
+			new AlternateJdkLoader(gradleRequest.bootstrapClasspath)
+		}
 		new URLClassLoader(gradleRequest.allClasspathEntries.map[toURI.toURL], parent)
 	}
-
+	
 	private def cleanup(GradleBuildRequest gradleRequest, BuildRequest request) {
 		val resourceSet = request.resourceSet
 		val jvmTypesLoader = resourceSet.classpathURIContext
-		if(jvmTypesLoader instanceof Closeable) {
+		if (jvmTypesLoader instanceof Closeable) {
 			try {
 				jvmTypesLoader.close
-			} catch(Exception e) {
+			} catch (Exception e) {
 				gradleRequest.logger.debug("Couldn't close jvm types classloader", e)
 			}
 		}
 		resourceSet.resources.clear
 		resourceSet.eAdapters.clear
 	}
-
+	
 	private def attachProjectConfig(XtextResourceSet resourceSet, GradleBuildRequest gradleRequest) {
 		ProjectConfigAdapter.install(resourceSet, new GradleProjectConfig(gradleRequest))
 	}
-
+	
 	private def attachProjectDescription(String containerHandle, List<String> dependencies, XtextResourceSet resourceSet) {
 		new ProjectDescription => [
 			name = containerHandle
 			it.dependencies = dependencies
 			attachToEmfObject(resourceSet)
 		]
 	}
-
+	
 	private def attachGeneratorConfig(XtextResourceSet resourceSet, GradleBuildRequest gradleRequest) {
 		new GeneratorConfigProvider.GeneratorConfigAdapter => [
 			attachToEmfObject(resourceSet)
 			language2GeneratorConfig.putAll(
-				gradleRequest.generatorConfigsByLanguage.mapValues [ gradleConfig |
+				gradleRequest.generatorConfigsByLanguage.mapValues[gradleConfig|
+					val javaVersion = JavaVersion.fromQualifier(gradleConfig.javaSourceLevel.toString)
+					if (javaVersion === null) {
+						gradleRequest.logger.warn("Xtext does not support Java " + gradleConfig.javaSourceLevel.toString + ", falling back to " + JavaVersion.JAVA8.label)
+					}
 					new GeneratorConfig => [
 						generateSyntheticSuppressWarnings = gradleConfig.isGenerateSyntheticSuppressWarnings
 						generateGeneratedAnnotation = gradleConfig.isGenerateGeneratedAnnotation
-						includeDateInGeneratedAnnotation = gradleConfig.isIncludeDateInGeneratedAnnotation
+						includeDateInGeneratedAnnotation = 	gradleConfig.isIncludeDateInGeneratedAnnotation
 						generatedAnnotationComment = gradleConfig.generatedAnnotationComment
-						javaSourceVersion = JavaVersion.fromQualifier(gradleConfig.javaSourceLevel.toString)
+						javaSourceVersion = javaVersion ?: JavaVersion.JAVA8
 					]
 				]
 			)
@@ -244,13 +251,10 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 
 	private def attachOutputConfig(XtextResourceSet resourceSet, GradleBuildRequest gradleRequest) {
 		resourceSet.eAdapters += new OutputConfigurationAdapter(
-			gradleRequest.generatorConfigsByLanguage.mapValues [
-				outputConfigs.map [ gradleOutputConfig |
+			gradleRequest.generatorConfigsByLanguage.mapValues[
+				outputConfigs.map[gradleOutputConfig|
 					new OutputConfiguration(gradleOutputConfig.outletName) => [
 						outputDirectory = gradleOutputConfig.target.absolutePath
-						cleanUpDerivedResources = gradleOutputConfig.cleanAutomatically
-						canClearOutputDirectory = gradleOutputConfig.cleanAutomatically
-						overrideExistingResources = gradleOutputConfig.cleanAutomatically
 					]
 				].toSet
 			]
@@ -265,24 +269,11 @@ class XtextGradleBuilder implements IncrementalXtextBuilder {
 			}
 		]
 	}
-
-	private def attachJavaConfig(XtextResourceSet resourceSet, GradleBuildRequest gradleRequest) {
-		try {
-			val configClass = Class.forName("org.eclipse.xtext.java.resource.JavaConfig")
-			val javaConfig = configClass.newInstance
-			val javaVersion = JavaVersion.fromQualifier(gradleRequest.generatorConfigsByLanguage.values.head.javaSourceLevel.toString)
-			configClass.getMethod("attachToEmfObject", Notifier).invoke(javaConfig, resourceSet)
-			configClass.getMethod("setJavaSourceLevel", JavaVersion).invoke(javaConfig, javaVersion)
-			configClass.getMethod("setJavaTargetLevel", JavaVersion).invoke(javaConfig, javaVersion)
-		} catch(ClassNotFoundException ignore) {
-			// this only exists in Xtext 2.11 and upwards
-		}
-	}
-
+	
 	override void installDebugInfo(GradleInstallDebugInfoRequest gradleRequest) {
 		val request = new InstallDebugInfoRequest => [
 			classesDir = gradleRequest.classesDir
-			sourceInstallerByFileExtension = gradleRequest.sourceInstallerByFileExtension.mapValues [ gradleConfig |
+			sourceInstallerByFileExtension = gradleRequest.sourceInstallerByFileExtension.mapValues[gradleConfig|
 				new SourceInstallerConfig => [
 					sourceInstaller = SourceInstaller.valueOf(gradleConfig.sourceInstaller.name)
 					hideSyntheticVariables = gradleConfig.isHideSyntheticVariables