sdk/lib/_internal/compiler/implementation/dart2js.dart - sdk.git - Git at Google

 // 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:async';
 import 'dart:collection' show Queue, LinkedHashMap;
 import 'dart:io';
 import 'dart:uri';
 import 'dart:utf';

 import '../compiler.dart' as api;
 import 'source_file.dart';
 import 'source_file_provider.dart';
 import 'filenames.dart';
 import 'util/uri_extras.dart';
 import '../../libraries.dart';

 const String LIBRARY_ROOT = '../../../../..';
 const String OUTPUT_LANGUAGE_DART = 'Dart';

 typedef void HandleOption(String option);

 class OptionHandler {
   String pattern;
   HandleOption handle;

   OptionHandler(this.pattern, this.handle);
 }

 /**
  * Extract the parameter of an option.
  *
  * For example, in ['--out=fisk.js'] and ['-ohest.js'], the parameters
  * are ['fisk.js'] and ['hest.js'], respectively.
  */
 String extractParameter(String argument) {
   // m[0] is the entire match (which will be equal to argument). m[1]
   // is something like "-o" or "--out=", and m[2] is the parameter.
   Match m = new RegExp('^(-[a-z]|--.+=)(.*)').firstMatch(argument);
   if (m == null) helpAndFail('Error: Unknown option "$argument".');
   return m[2];
 }

 String extractPath(String argument) {
   String path = nativeToUriPath(extractParameter(argument));
   return path.endsWith("/") ? path : "$path/";
 }

 void parseCommandLine(List<OptionHandler> handlers, List<String> argv) {
   // TODO(ahe): Use ../../args/args.dart for parsing options instead.
   var patterns = <String>[];
   for (OptionHandler handler in handlers) {
     patterns.add(handler.pattern);
   }
   var pattern = new RegExp('^(${patterns.join(")\$|(")})\$');
   OUTER: for (String argument in argv) {
     Match match = pattern.firstMatch(argument);
     assert(match.groupCount == handlers.length);
     for (int i = 0; i < handlers.length; i++) {
       if (match[i + 1] != null) {
         handlers[i].handle(argument);
         continue OUTER;
       }
     }
     throw 'Internal error: "$argument" did not match';
   }
 }

 void compile(List<String> argv) {
   bool isWindows = (Platform.operatingSystem == 'windows');
   Uri cwd = getCurrentDirectory();
   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;
   String outputLanguage = 'JavaScript';
   bool stripArgumentSet = false;
   bool analyzeOnly = false;
   SourceFileProvider inputProvider = new SourceFileProvider();
   FormattingDiagnosticHandler diagnosticHandler =
       new FormattingDiagnosticHandler(inputProvider);

   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 = Uri.parse('$out.map');
   }

   setOutputType(String argument) {
     if (argument == '--output-type=dart') {
       outputLanguage = OUTPUT_LANGUAGE_DART;
       if (!explicitOut) {
         out = cwd.resolve('out.dart');
         sourceMapOut = cwd.resolve('out.dart.map');
       }
     }
     passThrough(argument);
   }

   String getDepsOutput(Map<String, SourceFile> sourceFiles) {
     var filenames = new List.from(sourceFiles.keys);
     filenames.sort();
     return filenames.join("\n");
   }

   setStrip(String argument) {
     stripArgumentSet = true;
     passThrough(argument);
   }

   setAnalyzeOnly(String argument) {
     analyzeOnly = true;
     passThrough(argument);
   }

   setCategories(String argument) {
     List<String> categories = extractParameter(argument).split(',');
     Set<String> allowedCategories =
         LIBRARIES.values.map((x) => x.category).toSet();
     allowedCategories.remove('Shared');
     allowedCategories.remove('Internal');
     List<String> allowedCategoriesList =
         new List<String>.from(allowedCategories);
     allowedCategoriesList.sort();
     if (categories.contains('all')) {
       categories = allowedCategoriesList;
     } else {
       String allowedCategoriesString = allowedCategoriesList.join(', ');
       for (String category in categories) {
         if (!allowedCategories.contains(category)) {
           fail('Error: unsupported library category "$category", '
                'supported categories are: $allowedCategoriesString');
         }
       }
     }
     return passThrough('--categories=${categories.join(",")}');
   }

   // TODO(8522): Remove this method once option is restored.
   complainAboutDisallowUnsafeEval(String argument) {
     fail('Error: $argument is currently not supported, '
          'see http://dartbug.com/8522');
   }

   handleShortOptions(String argument) {
     var shortOptions = argument.substring(1).split("");
     for (var shortOption in shortOptions) {
       switch (shortOption) {
         case 'v':
           diagnosticHandler.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',
                       (_) => diagnosticHandler.throwOnError = true),
     new OptionHandler('--suppress-warnings',
                       (_) => diagnosticHandler.showWarnings = false),
     new OptionHandler('--output-type=dart|--output-type=js', setOutputType),
     new OptionHandler('--verbose', (_) => diagnosticHandler.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-strip=.*', setStrip),
     // TODO(ahe): Remove the --no-colors option.
     new OptionHandler('--disable-diagnostic-colors',
                       (_) => diagnosticHandler.enableColors = false),
     new OptionHandler('--enable-diagnostic-colors',
                       (_) => diagnosticHandler.enableColors = true),
     new OptionHandler('--enable[_-]checked[_-]mode|--checked',
                       (_) => passThrough('--enable-checked-mode')),
     new OptionHandler('--enable-concrete-type-inference',
                       (_) => passThrough('--enable-concrete-type-inference')),
     new OptionHandler(r'--help|/\?|/h', (_) => wantHelp = true),
     new OptionHandler('--package-root=.+|-p.+', setPackageRoot),
     new OptionHandler('--disallow-unsafe-eval',
                       complainAboutDisallowUnsafeEval),
     new OptionHandler('--analyze-all', passThrough),
     new OptionHandler('--analyze-only', setAnalyzeOnly),
     new OptionHandler('--disable-native-live-type-analysis', passThrough),
     new OptionHandler('--reject-deprecated-language-features', passThrough),
     new OptionHandler('--report-sdk-use-of-deprecated-language-features',
                       passThrough),
     new OptionHandler('--categories=.*', setCategories),

     // The following two options must come last.
     new OptionHandler('-.*', (String argument) {
       helpAndFail('Error: Unknown option "$argument".');
     }),
     new OptionHandler('.*', (String argument) {
       arguments.add(nativeToUriPath(argument));
     })
   ];

   parseCommandLine(handlers, argv);
   if (wantHelp) helpAndExit(diagnosticHandler.verbose);

   if (outputLanguage != OUTPUT_LANGUAGE_DART && stripArgumentSet) {
     helpAndFail('Error: --force-strip may only be used with '
         '--output-type=dart');
   }
   if (arguments.isEmpty) {
     helpAndFail('Error: No Dart file specified.');
   }
   if (arguments.length > 1) {
     var extra = arguments.getRange(1, arguments.length - 1);
     helpAndFail('Error: Extra arguments: ${extra.join(" ")}');
   }

   void handler(Uri uri, int begin, int end, String message,
                api.Diagnostic kind) {
     diagnosticHandler.diagnosticHandler(uri, begin, end, message, kind);
   }

   Uri uri = cwd.resolve(arguments[0]);
   if (packageRoot == null) {
     packageRoot = uri.resolve('./packages/');
   }

   diagnosticHandler.info('package root is $packageRoot');

   int charactersWritten = 0;

   compilationDone(String code) {
     if (analyzeOnly) return;
     if (code == null) {
       fail('Error: Compilation failed.');
     }
     writeString(Uri.parse('$out.deps'),
                 getDepsOutput(inputProvider.sourceFiles));
     diagnosticHandler.info(
          'compiled ${inputProvider.dartCharactersRead} characters Dart '
          '-> $charactersWritten characters $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 $outputLanguage: $output');
     }
   }

   StreamSink<String> outputProvider(String name, String extension) {
     Uri uri;
     String sourceMapFileName;
     bool isPrimaryOutput = false;
     if (name == '') {
       if (extension == 'js' || extension == 'dart') {
         isPrimaryOutput = true;
         uri = out;
         sourceMapFileName =
             sourceMapOut.path.substring(sourceMapOut.path.lastIndexOf('/') + 1);
       } else if (extension == 'js.map' || extension == 'dart.map') {
         uri = sourceMapOut;
       } else {
         fail('Error: Unknown extension: $extension');
       }
     } else {
       uri = out.resolve('$name.$extension');
     }

     if (uri.scheme != 'file') {
       fail('Error: Unhandled scheme ${uri.scheme} in $uri.');
     }
     var outputStream = new File(uriPathToNative(uri.path)).openOutputStream();

     CountingSink sink;

     onDone() {
       if (sourceMapFileName != null) {
         String sourceMapTag = '//@ sourceMappingURL=$sourceMapFileName\n';
         sink.count += sourceMapTag.length;
         outputStream.writeString(sourceMapTag);
       }
       outputStream.close();
       if (isPrimaryOutput) {
         charactersWritten += sink.count;
       }
     }

     var controller = new StreamController<String>();
     controller.stream.listen(outputStream.writeString, onDone: onDone);
     sink = new CountingSink(controller);
     return sink;
   }

   api.compile(uri, libraryRoot, packageRoot,
               inputProvider.readStringFromUri, handler,
               options, outputProvider)
       .then(compilationDone);
 }

 // TODO(ahe): Get rid of this class if http://dartbug.com/8118 is fixed.
 class CountingSink implements StreamSink<String> {
   final StreamSink<String> sink;
   int count = 0;

   CountingSink(this.sink);

   add(String value) {
     sink.add(value);
     count += value.length;
   }

   signalError(AsyncError error) => sink.signalError(error);

   close() => sink.close();
 }

 class AbortLeg {
   final message;
   AbortLeg(this.message);
   toString() => 'Aborted due to --throw-on-error: $message';
 }

 void writeString(Uri uri, String text) {
   if (uri.scheme != 'file') {
     fail('Error: Unhandled scheme ${uri.scheme}.');
   }
   var file = new File(uriPathToNative(uri.path)).openSync(FileMode.WRITE);
   file.writeStringSync(text);
   file.closeSync();
 }

 void fail(String message) {
   print(message);
   exit(1);
 }

 void compilerMain(Options options) {
   var root = uriPathToNative("/$LIBRARY_ROOT");
   List<String> argv = ['--library-root=${options.script}$root'];
   argv.addAll(options.arguments);
   compile(argv);
 }

 void help() {
   // This message should be no longer than 20 lines. The default
   // terminal size normally 80x24. Two lines are used for the prompts
   // before and after running the compiler. Another two lines may be
   // used to print an error message.
   print('''
 Usage: dart2js [options] dartfile

 Compiles Dart to JavaScript.

 Common options:
   -o<file> Generate the output into <file>.
   -c       Insert runtime type checks and enable assertions (checked mode).
   -h       Display this message (add -v for information about all options).''');
 }

 void verboseHelp() {
   print('''
 Usage: dart2js [options] dartfile

 Compiles Dart to JavaScript.

 Supported options:
   -o<file>, --out=<file>
     Generate the output into <file>.

   -c, --enable-checked-mode, --checked
     Insert runtime type checks and enable assertions (checked mode).

   -h, /h, /?, --help
     Display this message (add -v for information about all options).

   -v, --verbose
     Display verbose information.

   -p<path>, --package-root=<path>
     Where to find packages, that is, "package:..." imports.

   --analyze-all
     Analyze all code.  Without this option, the compiler only analyzes
     code that is reachable from [main].  This option is useful for
     finding errors in libraries, but using it can result in bigger and
     slower output.

   --analyze-only
     Analyze but do not generate code.

   --minify
     Generate minified output.

   --suppress-warnings
     Do not display any warnings.

   --enable-diagnostic-colors
     Add colors to diagnostic messages.

 The following options are only used for compiler development and may
 be removed in a future version:

   --output-type=dart
     Output Dart code instead of JavaScript.

   --throw-on-error
     Throw an exception if a compile-time error is detected.

   --library-root=<directory>
     Where to find the Dart platform libraries.

   --allow-mock-compilation
     Do not generate a call to main if either of the following
     libraries are used: dart:dom, dart:html dart:io.

   --enable-concrete-type-inference
     Enable experimental concrete type inference.

   --disable-native-live-type-analysis
     Disable the optimization that removes unused native types from dart:html
     and related libraries.

 '''
 /* TODO(8522): Restore this comment once option is restored.
 '''
   --disallow-unsafe-eval
     Disable dynamic generation of code in the generated output. This is
     necessary to satisfy CSP restrictions (see http://www.w3.org/TR/CSP/).
     This flag is not continuously tested. Please report breakages and we
     will fix them as soon as possible.

 '''
 */
 '''
   --reject-deprecated-language-features
     Reject deprecated language features.  Without this option, the
     compiler will accept language features that are no longer valid
     according to The Dart Programming Language Specification, version
     0.12, M1.

   --report-sdk-use-of-deprecated-language-features
     Report use of deprecated features in Dart platform libraries.
     Without this option, the compiler will silently accept use of
     deprecated language features from these libraries.  The option
     --reject-deprecated-language-features controls if these usages are
     reported as errors or warnings.

   --categories=<categories>

     A comma separated list of allowed library categories.  The default
     is "Client".  Possible categories can be seen by providing an
     unsupported category, for example, --categories=help.  To enable
     all categories, use --categories=all.

 '''.trim());
 }

 void helpAndExit(bool verbose) {
   if (verbose) {
     verboseHelp();
   } else {
     help();
   }
   exit(0);
 }

 void helpAndFail(String message) {
   help();
   print('');
   fail(message);
 }

 void main() {
   try {
     compilerMain(new Options());
   } catch (exception, trace) {
     try {
       print('Internal error: $exception');
     } 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.
     }
   }
 }
	// 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:async';
	import 'dart:collection' show Queue, LinkedHashMap;
	import 'dart:io';
	import 'dart:uri';
	import 'dart:utf';

	import '../compiler.dart' as api;
	import 'source_file.dart';
	import 'source_file_provider.dart';
	import 'filenames.dart';
	import 'util/uri_extras.dart';
	import '../../libraries.dart';

	const String LIBRARY_ROOT = '../../../../..';
	const String OUTPUT_LANGUAGE_DART = 'Dart';

	typedef void HandleOption(String option);

	class OptionHandler {
	String pattern;
	HandleOption handle;

	OptionHandler(this.pattern, this.handle);
	}

	/**
	* Extract the parameter of an option.
	*
	* For example, in ['--out=fisk.js'] and ['-ohest.js'], the parameters
	* are ['fisk.js'] and ['hest.js'], respectively.
	*/
	String extractParameter(String argument) {
	// m[0] is the entire match (which will be equal to argument). m[1]
	// is something like "-o" or "--out=", and m[2] is the parameter.
	Match m = new RegExp('^(-[a-z]\|--.+=)(.*)').firstMatch(argument);
	if (m == null) helpAndFail('Error: Unknown option "$argument".');
	return m[2];
	}

	String extractPath(String argument) {
	String path = nativeToUriPath(extractParameter(argument));
	return path.endsWith("/") ? path : "$path/";
	}

	void parseCommandLine(List<OptionHandler> handlers, List<String> argv) {
	// TODO(ahe): Use ../../args/args.dart for parsing options instead.
	var patterns = <String>[];
	for (OptionHandler handler in handlers) {
	patterns.add(handler.pattern);
	}
	var pattern = new RegExp('^(${patterns.join(")\$\|(")})\$');
	OUTER: for (String argument in argv) {
	Match match = pattern.firstMatch(argument);
	assert(match.groupCount == handlers.length);
	for (int i = 0; i < handlers.length; i++) {
	if (match[i + 1] != null) {
	handlers[i].handle(argument);
	continue OUTER;
	}
	}
	throw 'Internal error: "$argument" did not match';
	}
	}

	void compile(List<String> argv) {
	bool isWindows = (Platform.operatingSystem == 'windows');
	Uri cwd = getCurrentDirectory();
	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;
	String outputLanguage = 'JavaScript';
	bool stripArgumentSet = false;
	bool analyzeOnly = false;
	SourceFileProvider inputProvider = new SourceFileProvider();
	FormattingDiagnosticHandler diagnosticHandler =
	new FormattingDiagnosticHandler(inputProvider);

	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 = Uri.parse('$out.map');
	}

	setOutputType(String argument) {
	if (argument == '--output-type=dart') {
	outputLanguage = OUTPUT_LANGUAGE_DART;
	if (!explicitOut) {
	out = cwd.resolve('out.dart');
	sourceMapOut = cwd.resolve('out.dart.map');
	}
	}
	passThrough(argument);
	}

	String getDepsOutput(Map<String, SourceFile> sourceFiles) {
	var filenames = new List.from(sourceFiles.keys);
	filenames.sort();
	return filenames.join("\n");
	}

	setStrip(String argument) {
	stripArgumentSet = true;
	passThrough(argument);
	}

	setAnalyzeOnly(String argument) {
	analyzeOnly = true;
	passThrough(argument);
	}

	setCategories(String argument) {
	List<String> categories = extractParameter(argument).split(',');
	Set<String> allowedCategories =
	LIBRARIES.values.map((x) => x.category).toSet();
	allowedCategories.remove('Shared');
	allowedCategories.remove('Internal');
	List<String> allowedCategoriesList =
	new List<String>.from(allowedCategories);
	allowedCategoriesList.sort();
	if (categories.contains('all')) {
	categories = allowedCategoriesList;
	} else {
	String allowedCategoriesString = allowedCategoriesList.join(', ');
	for (String category in categories) {
	if (!allowedCategories.contains(category)) {
	fail('Error: unsupported library category "$category", '
	'supported categories are: $allowedCategoriesString');
	}
	}
	}
	return passThrough('--categories=${categories.join(",")}');
	}

	// TODO(8522): Remove this method once option is restored.
	complainAboutDisallowUnsafeEval(String argument) {
	fail('Error: $argument is currently not supported, '
	'see http://dartbug.com/8522');
	}

	handleShortOptions(String argument) {
	var shortOptions = argument.substring(1).split("");
	for (var shortOption in shortOptions) {
	switch (shortOption) {
	case 'v':
	diagnosticHandler.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',
	(_) => diagnosticHandler.throwOnError = true),
	new OptionHandler('--suppress-warnings',
	(_) => diagnosticHandler.showWarnings = false),
	new OptionHandler('--output-type=dart\|--output-type=js', setOutputType),
	new OptionHandler('--verbose', (_) => diagnosticHandler.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-strip=.*', setStrip),
	// TODO(ahe): Remove the --no-colors option.
	new OptionHandler('--disable-diagnostic-colors',
	(_) => diagnosticHandler.enableColors = false),
	new OptionHandler('--enable-diagnostic-colors',
	(_) => diagnosticHandler.enableColors = true),
	new OptionHandler('--enable[_-]checked[_-]mode\|--checked',
	(_) => passThrough('--enable-checked-mode')),
	new OptionHandler('--enable-concrete-type-inference',
	(_) => passThrough('--enable-concrete-type-inference')),
	new OptionHandler(r'--help\|/\?\|/h', (_) => wantHelp = true),
	new OptionHandler('--package-root=.+\|-p.+', setPackageRoot),
	new OptionHandler('--disallow-unsafe-eval',
	complainAboutDisallowUnsafeEval),
	new OptionHandler('--analyze-all', passThrough),
	new OptionHandler('--analyze-only', setAnalyzeOnly),
	new OptionHandler('--disable-native-live-type-analysis', passThrough),
	new OptionHandler('--reject-deprecated-language-features', passThrough),
	new OptionHandler('--report-sdk-use-of-deprecated-language-features',
	passThrough),
	new OptionHandler('--categories=.*', setCategories),

	// The following two options must come last.
	new OptionHandler('-.*', (String argument) {
	helpAndFail('Error: Unknown option "$argument".');
	}),
	new OptionHandler('.*', (String argument) {
	arguments.add(nativeToUriPath(argument));
	})
	];

	parseCommandLine(handlers, argv);
	if (wantHelp) helpAndExit(diagnosticHandler.verbose);

	if (outputLanguage != OUTPUT_LANGUAGE_DART && stripArgumentSet) {
	helpAndFail('Error: --force-strip may only be used with '
	'--output-type=dart');
	}
	if (arguments.isEmpty) {
	helpAndFail('Error: No Dart file specified.');
	}
	if (arguments.length > 1) {
	var extra = arguments.getRange(1, arguments.length - 1);
	helpAndFail('Error: Extra arguments: ${extra.join(" ")}');
	}

	void handler(Uri uri, int begin, int end, String message,
	api.Diagnostic kind) {
	diagnosticHandler.diagnosticHandler(uri, begin, end, message, kind);
	}

	Uri uri = cwd.resolve(arguments[0]);
	if (packageRoot == null) {
	packageRoot = uri.resolve('./packages/');
	}

	diagnosticHandler.info('package root is $packageRoot');

	int charactersWritten = 0;

	compilationDone(String code) {
	if (analyzeOnly) return;
	if (code == null) {
	fail('Error: Compilation failed.');
	}
	writeString(Uri.parse('$out.deps'),
	getDepsOutput(inputProvider.sourceFiles));
	diagnosticHandler.info(
	'compiled ${inputProvider.dartCharactersRead} characters Dart '
	'-> $charactersWritten characters $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 $outputLanguage: $output');
	}
	}

	StreamSink<String> outputProvider(String name, String extension) {
	Uri uri;
	String sourceMapFileName;
	bool isPrimaryOutput = false;
	if (name == '') {
	if (extension == 'js' \|\| extension == 'dart') {
	isPrimaryOutput = true;
	uri = out;
	sourceMapFileName =
	sourceMapOut.path.substring(sourceMapOut.path.lastIndexOf('/') + 1);
	} else if (extension == 'js.map' \|\| extension == 'dart.map') {
	uri = sourceMapOut;
	} else {
	fail('Error: Unknown extension: $extension');
	}
	} else {
	uri = out.resolve('$name.$extension');
	}

	if (uri.scheme != 'file') {
	fail('Error: Unhandled scheme ${uri.scheme} in $uri.');
	}
	var outputStream = new File(uriPathToNative(uri.path)).openOutputStream();

	CountingSink sink;

	onDone() {
	if (sourceMapFileName != null) {
	String sourceMapTag = '//@ sourceMappingURL=$sourceMapFileName\n';
	sink.count += sourceMapTag.length;
	outputStream.writeString(sourceMapTag);
	}
	outputStream.close();
	if (isPrimaryOutput) {
	charactersWritten += sink.count;
	}
	}

	var controller = new StreamController<String>();
	controller.stream.listen(outputStream.writeString, onDone: onDone);
	sink = new CountingSink(controller);
	return sink;
	}

	api.compile(uri, libraryRoot, packageRoot,
	inputProvider.readStringFromUri, handler,
	options, outputProvider)
	.then(compilationDone);
	}

	// TODO(ahe): Get rid of this class if http://dartbug.com/8118 is fixed.
	class CountingSink implements StreamSink<String> {
	final StreamSink<String> sink;
	int count = 0;

	CountingSink(this.sink);

	add(String value) {
	sink.add(value);
	count += value.length;
	}

	signalError(AsyncError error) => sink.signalError(error);

	close() => sink.close();
	}

	class AbortLeg {
	final message;
	AbortLeg(this.message);
	toString() => 'Aborted due to --throw-on-error: $message';
	}

	void writeString(Uri uri, String text) {
	if (uri.scheme != 'file') {
	fail('Error: Unhandled scheme ${uri.scheme}.');
	}
	var file = new File(uriPathToNative(uri.path)).openSync(FileMode.WRITE);
	file.writeStringSync(text);
	file.closeSync();
	}

	void fail(String message) {
	print(message);
	exit(1);
	}

	void compilerMain(Options options) {
	var root = uriPathToNative("/$LIBRARY_ROOT");
	List<String> argv = ['--library-root=${options.script}$root'];
	argv.addAll(options.arguments);
	compile(argv);
	}

	void help() {
	// This message should be no longer than 20 lines. The default
	// terminal size normally 80x24. Two lines are used for the prompts
	// before and after running the compiler. Another two lines may be
	// used to print an error message.
	print('''
	Usage: dart2js [options] dartfile

	Compiles Dart to JavaScript.

	Common options:
	-o<file> Generate the output into <file>.
	-c Insert runtime type checks and enable assertions (checked mode).
	-h Display this message (add -v for information about all options).''');
	}

	void verboseHelp() {
	print('''
	Usage: dart2js [options] dartfile

	Compiles Dart to JavaScript.

	Supported options:
	-o<file>, --out=<file>
	Generate the output into <file>.

	-c, --enable-checked-mode, --checked
	Insert runtime type checks and enable assertions (checked mode).

	-h, /h, /?, --help
	Display this message (add -v for information about all options).

	-v, --verbose
	Display verbose information.

	-p<path>, --package-root=<path>
	Where to find packages, that is, "package:..." imports.

	--analyze-all
	Analyze all code. Without this option, the compiler only analyzes
	code that is reachable from [main]. This option is useful for
	finding errors in libraries, but using it can result in bigger and
	slower output.

	--analyze-only
	Analyze but do not generate code.

	--minify
	Generate minified output.

	--suppress-warnings
	Do not display any warnings.

	--enable-diagnostic-colors
	Add colors to diagnostic messages.

	The following options are only used for compiler development and may
	be removed in a future version:

	--output-type=dart
	Output Dart code instead of JavaScript.

	--throw-on-error
	Throw an exception if a compile-time error is detected.

	--library-root=<directory>
	Where to find the Dart platform libraries.

	--allow-mock-compilation
	Do not generate a call to main if either of the following
	libraries are used: dart:dom, dart:html dart:io.

	--enable-concrete-type-inference
	Enable experimental concrete type inference.

	--disable-native-live-type-analysis
	Disable the optimization that removes unused native types from dart:html
	and related libraries.

	'''
	/* TODO(8522): Restore this comment once option is restored.
	'''
	--disallow-unsafe-eval
	Disable dynamic generation of code in the generated output. This is
	necessary to satisfy CSP restrictions (see http://www.w3.org/TR/CSP/).
	This flag is not continuously tested. Please report breakages and we
	will fix them as soon as possible.

	'''
	*/
	'''
	--reject-deprecated-language-features
	Reject deprecated language features. Without this option, the
	compiler will accept language features that are no longer valid
	according to The Dart Programming Language Specification, version
	0.12, M1.

	--report-sdk-use-of-deprecated-language-features
	Report use of deprecated features in Dart platform libraries.
	Without this option, the compiler will silently accept use of
	deprecated language features from these libraries. The option
	--reject-deprecated-language-features controls if these usages are
	reported as errors or warnings.

	--categories=<categories>

	A comma separated list of allowed library categories. The default
	is "Client". Possible categories can be seen by providing an
	unsupported category, for example, --categories=help. To enable
	all categories, use --categories=all.

	'''.trim());
	}

	void helpAndExit(bool verbose) {
	if (verbose) {
	verboseHelp();
	} else {
	help();
	}
	exit(0);
	}

	void helpAndFail(String message) {
	help();
	print('');
	fail(message);
	}

	void main() {
	try {
	compilerMain(new Options());
	} catch (exception, trace) {
	try {
	print('Internal error: $exception');
	} 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.
	}
	}
	}