[dart2js] if --output-type=dart make output file out.dart and print correct info message.

lib/compiler/implementation/dart2js.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #library('dart2js');
 
 #import('dart:io');
 #import('dart:uri');
 #import('dart:utf');
 
@@ skipping 60 matching lines @@
   bool showWarnings = true;
   bool verbose = false;
   Uri libraryRoot = cwd;
   Uri out = cwd.resolve('out.js');
   Uri sourceMapOut = cwd.resolve('out.js.map');
   Uri packageRoot = null;
   List<String> options = new List<String>();
   bool explicitOut = false;
   bool wantHelp = false;
   bool enableColors = false;
+  String outputLanguage = 'JavaScript';
 
   passThrough(String argument) => options.add(argument);
 
   setLibraryRoot(String argument) {
     libraryRoot = cwd.resolve(extractPath(argument));
   }
 
   setPackageRoot(String argument) {
     packageRoot = cwd.resolve(extractPath(argument));
   }
 
   setOutput(String argument) {
     explicitOut = true;
     out = cwd.resolve(nativeToUriPath(extractParameter(argument)));
     sourceMapOut = new Uri.fromString('$out.map');
   }
 
+  setOutputType(String argument) {
+    if (argument == '--output-type=dart') {
+      outputLanguage = 'Dart';
+      if (!explicitOut) {
+        out = cwd.resolve('out.dart');
+        sourceMapOut = cwd.resolve('out.dart.map');
+      }
+    }
+    passThrough(argument);
+  }
+
   handleShortOptions(String argument) {
     var shortOptions = argument.substring(1).splitChars();
     for (var shortOption in shortOptions) {
       switch (shortOption) {
         case 'v':
           verbose = true;
           break;
         case 'h':
         case '?':
           wantHelp = true;
           break;
         case 'c':
           passThrough('--enable-checked-mode');
           break;
         default:
           throw 'Internal error: "$shortOption" did not match';
       }
     }
   }
 
   List<String> arguments = <String>[];
   List<OptionHandler> handlers = <OptionHandler>[
     new OptionHandler('-[chv?]+', handleShortOptions),
     new OptionHandler('--throw-on-error', (_) => throwOnError = true),
     new OptionHandler('--suppress-warnings', (_) => showWarnings = false),
-    new OptionHandler('--output-type=dart|--output-type=js', passThrough),
+    new OptionHandler('--output-type=dart|--output-type=js', setOutputType),
     new OptionHandler('--verbose', (_) => verbose = true),
     new OptionHandler('--library-root=.+', setLibraryRoot),
     new OptionHandler('--out=.+|-o.+', setOutput),
     new OptionHandler('--allow-mock-compilation', passThrough),
     new OptionHandler('--minify', passThrough),
     new OptionHandler('--force-cut-declaration-types', passThrough),
     // TODO(ahe): Remove the --no-colors option.
     new OptionHandler('--disable-diagnostic-colors', (_) => enableColors = false),
     new OptionHandler('--enable-diagnostic-colors', (_) => enableColors = true),
     new OptionHandler('--enable[_-]checked[_-]mode|--checked',
@@ skipping 113 matching lines @@
   // directly. In effect, we don't support truly asynchronous API.
   String code = api.compile(uri, libraryRoot, packageRoot, provider, handler,
                             options).value;
   if (code === null) {
     fail('Error: Compilation failed.');
   }
   String sourceMapFileName =
       sourceMapOut.path.substring(sourceMapOut.path.lastIndexOf('/') + 1);
   code = '$code\n//@ sourceMappingURL=${sourceMapFileName}';
   writeString(out, code);
-  int jsBytesWritten = code.length;
-  info('compiled $dartBytesRead bytes Dart -> $jsBytesWritten bytes JS '
-       'in ${relativize(cwd, out, isWindows)}');
+  int bytesWritten = code.length;
+  info('compiled $dartBytesRead bytes Dart -> $bytesWritten bytes '
+       '$outputLanguage in ${relativize(cwd, out, isWindows)}');
   if (!explicitOut) {
     String input = uriPathToNative(arguments[0]);
     String output = relativize(cwd, out, isWindows);
-    print('Dart file $input compiled to JavaScript: $output');
+    print('Dart file $input compiled to $outputLanguage: $output');
   }
 }
 
 class AbortLeg {
   final message;
   AbortLeg(this.message);
   toString() => 'Aborted due to --throw-on-error: $message';
 }
 
 void writeString(Uri uri, String text) {
@@ skipping 114 matching lines @@
     } catch (ignored) {
       print('Internal error: error while printing exception');
     }
     try {
       print(trace);
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   }
 }