missing files handling in converter

- silently continue if no files were found to convert

compiler/frontend.android/src/org/jetbrains/jet/lang/resolve/android/AndroidUIXmlParser.kt

@@ -10,19 +10,21 @@ import org.jetbrains.kotlin.psi.JetFile
 
 class AndroidUIXmlParser(val project: Project?, val searchPaths: Collection<File>) {
 
+    inner class NoUIXMLsFound: Exception("No android UI xmls found in ${searchPaths.joinToString(", ")}")
+
     val ids: MutableCollection<AndroidWidget> = ArrayList()
     val kw = KotlinStringWriter()
     val androidImports = arrayListOf("android.app.Activity",
                                      "android.view.View",
                                      "android.widget.*")
 
-    public fun parse(): String {
-        doParse()
-        return produceKotlinSignatures().toString()
+    public fun parseToString(): String? {
+        return doParse()
     }
 
-    public fun parseToPsi(): JetFile {
-        return JetPsiFactory(project).createFile(parse())
+    public fun parseToPsi(): JetFile? {
+        val s = parseToString()
+        return if (s != null) JetPsiFactory(project).createFile(s) else null
     }
 
     private fun isAndroidUIXml(file: File): Boolean {
@@ -48,7 +50,8 @@ class AndroidUIXmlParser(val project: Project?, val searchPaths: Collection<File
         kw.writeEmptyLine()
     }
 
-    private fun doParse() {
+    private fun doParse(): String? {
+        if (searchPaths.empty) return null
         val xmlStreams = searchForUIXml(searchPaths).map { FileInputStream(it) }
         val factory = SAXParserFactory.newInstance()
         factory?.setNamespaceAware(true)
@@ -58,6 +61,7 @@ class AndroidUIXmlParser(val project: Project?, val searchPaths: Collection<File
         for (xmlStream in xmlStreams) {
             parser.parse(xmlStream, handler)
         }
+        return produceKotlinSignatures().toString()
     }
 
     private fun widgetCallback(id: String, className: String) {

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/TopDownAnalyzerFacadeForJVM.java

@@ -121,7 +121,7 @@ public enum TopDownAnalyzerFacadeForJVM {
             @Nullable IncrementalCacheProvider incrementalCacheProvider
     ) {
         List<JetFile> filesToAnalyze = new ArrayList<JetFile>(files);
-        filesToAnalyze.add(searchForAndroidDeclarations(project));
+        searchAndAddAndroidDeclarations(project, filesToAnalyze);
 
         FileBasedDeclarationProviderFactory providerFactory =
                 new FileBasedDeclarationProviderFactory(topDownAnalysisParameters.getStorageManager(), filesToAnalyze);
@@ -177,9 +177,11 @@ public enum TopDownAnalyzerFacadeForJVM {
         return module;
     }
 
-    private static JetFile searchForAndroidDeclarations(Project project) {
+    private static Collection<JetFile> searchAndAddAndroidDeclarations(Project project, Collection<JetFile> files) {
         AndroidUIXmlPathProvider provider = ServiceManager.getService(project, AndroidUIXmlPathProvider.class);
         Collection<File> paths = provider.getPaths();
-        return new AndroidUIXmlParser(project, paths).parseToPsi();
+        JetFile file = new AndroidUIXmlParser(project, paths).parseToPsi();
+        if (file != null) files.add(file);
+        return files;
     }
 }

compiler/tests/org/jetbrains/jet/codegen/AndroidXmlTest.java

@@ -51,7 +51,7 @@ public class AndroidXmlTest extends TestCaseWithTmpdir {
     public void testCompileResult() throws Exception {
         ArrayList<File> paths = new ArrayList<File>();
         paths.add(singleFile);
-        String text = new AndroidUIXmlParser(null, paths).parse();
+        String text = new AndroidUIXmlParser(null, paths).parseToString();
         JetCoreEnvironment jetCoreEnvironment = JetTestUtils.createEnvironmentWithMockJdkAndIdeaAnnotations(getTestRootDisposable(),
                                                                                                             ConfigurationKind.ALL);
         JetFile psiFile = JetTestUtils.createFile(singleFile.getName(), text, jetCoreEnvironment.getProject());
@@ -75,7 +75,7 @@ public class AndroidXmlTest extends TestCaseWithTmpdir {
         paths.add(singleFile);
         AndroidUIXmlParser parser = new AndroidUIXmlParser(null, paths);
 
-        String actual = parser.parse();
+        String actual = parser.parseToString();
         String expected = loadOrCreate(new File(getTestDataPath() + "/converter/singleFile/layout.kt"), actual);
 
         assertEquals(expected, actual);