Correctly handle the --arch argument to dart test scripts.

tools/testing/dart/test_runner.dart

 // Copyright (c) 2011, 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("test_runner");
 
 #import("status_file_parser.dart");
 #import("test_progress.dart");
 #import("test_suite.dart");
 
@@ skipping 193 matching lines @@
     _testStderr = new List<String>();
     _stdoutStream.dataHandler = _readOutput(_stdoutStream, _testStdout);
     _stderrStream.dataHandler = _readOutput(_stderrStream, _testStderr);
     _timer = new Timer(_timeoutHandler(testCase),
                        testCase.timeout * 1000,
                        false);
     _process.stdin.write(_createArgumentsLine(testCase.arguments).charCodes());
   }
 
   String _createArgumentsLine(List<String> arguments) {
-    var buffer = new StringBuffer();
-    for (var i = 0; i < arguments.length; i++) {
-      buffer.add("${arguments[i]} ");
-    }
-    buffer.add("\n");
-    return buffer.toString();
+    return Strings.join(arguments, ' ') + '\n';
   }
 
   int _reportResult(String output) {
     var test = _currentTest;
     _currentTest = null;
 
     // output = '>>> TEST {PASS, FAIL, OK, CRASH, FAIL, TIMEOUT}'
     var outcome = output.split(" ")[2];
     var exitCode = 0;
     if (outcome == "CRASH") exitCode = -10;
@@ skipping 59 matching lines @@
     _process.exitHandler = _exitHandler;
     _process.start();
   }
 }
 
 
 class ProcessQueue {
   int _numProcesses = 0;
   int _activeTestListers = 0;
   int _maxProcesses;
+  bool _verbose;
   Function _enqueueMoreWork;
   Queue<TestCase> _tests;
   ProgressIndicator _progress;
   // For dartc batch processing we keep a list of batch processes.
   List<DartcBatchRunnerProcess> _batchProcesses;
 
   ProcessQueue(int this._maxProcesses,
                String progress,
+               bool this._verbose,
                Date start_time,
                Function this._enqueueMoreWork)
       : _tests = new Queue<TestCase>(),
         _progress = new ProgressIndicator.fromName(progress, start_time),
         _batchProcesses = new List<DartcBatchRunnerProcess>() {
-    _maxProcesses = _maxProcesses;
     if (!_enqueueMoreWork(this)) _progress.allDone();
   }
 
   void addTestSuite(TestSuite testSuite) {
     _activeTestListers++;
     testSuite.forEachTest(_runTest, _testListerDone);
   }
 
   void _testListerDone() {
     _activeTestListers--;
@@ skipping 31 matching lines @@
   }
 
   DartcBatchRunnerProcess _getDartcBatchRunnerProcess() {
     for (int i = 0; i < _batchProcesses.length; i++) {
       var runner = _batchProcesses[i];
       if (!runner.active) return runner;
     }
     throw new Exception('Unable to find inactive batch runner.');
   }
 
+  void _printTestCase(TestCase testCase) {
+    var path = testCase.executablePath;
+    var args = Strings.join(testCase.arguments, ' ');
+    print('# $path $args');
+  }
+
   void _tryRunTest() {
     _checkDone();
     if (_numProcesses < _maxProcesses && !_tests.isEmpty()) {
       TestCase test = _tests.removeFirst();
+      if (_verbose) _printTestCase(test);
       _progress.start(test);
       Function oldCallback = test.completedHandler;
       Function wrapper = (TestCase test_arg) {
         _numProcesses--;
         _progress.done(test_arg);
         _tryRunTest();
         oldCallback(test_arg);
       };
       test.completedHandler = wrapper;
       if (test.executablePath.contains('compiler')) {
         _ensureDartcBatchRunnersStarted(test.executablePath);
         _getDartcBatchRunnerProcess().startTest(test);
       } else {
         new RunningProcess(test).start();
       }
       _numProcesses++;
     }
   }
 }