Add build rules for dart2js.

dart/utils/compiler/build_helper.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.
+
+#import('dart:io');
+#import('dart:uri');
+
+main() {
+  List<String> arguments = new Options().arguments;
+  Uri uri = new Uri(scheme: 'file', path: '${arguments[0]}/');
+  String dartVmLocation = uri.resolve(arguments[1]).path;
+  String productionLauncherLocation = uri.resolve(arguments[2]).path;
+  String developerLauncherLocation = uri.resolve(arguments[3]).path;
+  String productionLaunch = '#!$dartVmLocation\n';
+  String developerLaunch = '#!$dartVmLocation --enable_checked_mode\n';
+  String launcherScript = """

[ngeoffray, 2012/03/17 16:00:56]

Maybe move this variable into its own method: buildLauncherScript(uri) { }

[ahe, 2012/03/17 16:16:46]

Next CL.

+
+#import('dart:io');
+
+#import('${uri.resolve('../../frog/file_system_vm.dart').path}', prefix: 'fs');
+#import('${uri.resolve('../../frog/lang.dart').path}', prefix: 'lang');
+#import('${uri.resolve('../../frog/leg/frog_leg.dart').path}', prefix: 'leg');
+
+void main() {
+  lang.legCompile = leg.compile;
+  try {
+
+    List<String> argv = (new Options()).arguments;
+
+    // Infer --out if there is none defined.
+    var outFileDefined = false;
+    for (var arg in argv) {
+      if (arg.startsWith('--out=')) outFileDefined = true;
+    }
+
+    if (!outFileDefined) {
+      argv.insertRange(0, 1, '--out=' + argv[argv.length-1] + '.js');
+    }
+
+    // TODO(dgrove) we're simulating node by placing the arguments to frogc
+    // starting at index 2.
+    argv.insertRange(0, 4, null);
+
+    argv[2] = '--leg';
+    argv[3] = '--libdir=${uri.resolve('../../frog/lib').path}';
+
+    // TODO(dgrove) Until we have a way of getting the executable's path, we'll
+    // run from '.'
+    var homedir = (new File('.')).fullPathSync();
+
+    if (!lang.compile(homedir, argv, new fs.VMFileSystem())) {
+      print('Compilation failed');
+      exit(1);
+    }
+  } catch (var exception, var trace) {
+    try {
+      print('Internal error: \$exception');
+    } catch (var ignored) {
+      print('Internal error: error while printing exception');
+    }
+    try {
+      print(trace);
+    } finally {

[ngeoffray, 2012/03/17 16:00:56]

Please add a comment that 253 is recognized by test.dart to be a crash.

[ahe, 2012/03/17 16:16:46]

Next CL.

+      exit(253);
+    }
+  }
+}
+""";
+  var f = new File(productionLauncherLocation);
+  var stream = f.openSync(FileMode.WRITE);
+  stream.writeStringSync(productionLaunch);
+  stream.writeStringSync(launcherScript);
+  stream.closeSync();
+  f = new File(developerLauncherLocation);
+  stream = f.openSync(FileMode.WRITE);
+  stream.writeStringSync(developerLaunch);
+  stream.writeStringSync(launcherScript);
+  stream.closeSync();
+  // TODO(ahe): Make scripts executable.

[ngeoffray, 2012/03/17 16:00:56]

Why not doing it now? Are we missing the API?

[ahe, 2012/03/17 16:16:46]

I think there is API for running "chmod +x", but I'll deal with this later; I'm
doing this in steps.

[ahe, 2012/03/17 16:21:37]

Adding a little more insight into my thinking: running "chmod +x" will not work
on Windows, but I'm hooking this up to the build system now. So I'm being
conservative to avoid breaking Windows builds.

+  // TODO(ahe): Also make .bat files for Windows.
+}