runtime/tools/dartfuzz/dartfuzz_test.dart - sdk - Git at Google

 // Copyright (c) 2018, 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:convert';
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:math';

 import 'package:args/args.dart';

 import 'dartfuzz.dart';

 const debug = false;
 const sigkill = 9;
 const timeout = 60; // in seconds

 // Exit code of running a test.
 enum ResultCode { success, timeout, error }

 /// Result of running a test.
 class TestResult {
   const TestResult(this.code, this.output);
   final ResultCode code;
   final String output;
 }

 /// Command runner.
 TestResult runCommand(List<String> cmd, Map<String, String> env) {
   ProcessResult res = Process.runSync(
       'timeout', ['-s', '$sigkill', '$timeout'] + cmd,
       environment: env);
   if (debug) {
     print('\nrunning $cmd yields:\n'
         '${res.exitCode}\n${res.stdout}\n${res.stderr}\n');
   }
   if (res.exitCode == -sigkill) {
     return new TestResult(ResultCode.timeout, res.stdout);
   } else if (res.exitCode != 0) {
     return new TestResult(ResultCode.error, res.stderr);
   }
   return new TestResult(ResultCode.success, res.stdout);
 }

 /// Abstraction for running one test in a particular mode.
 abstract class TestRunner {
   TestResult run();
   String description;

   // Factory.
   static TestRunner getTestRunner(String mode, String top, String tmp,
       Map<String, String> env, Random rand) {
     String prefix = mode.substring(0, 3).toUpperCase();
     String tag = getTag(mode);
     // Prepare extra flags.
     List<String> extraFlags = [];
     if (mode.startsWith('kbc-int')) {
       prefix += '-INT';
       extraFlags += [
         '--enable-interpreter',
         '--compilation-counter-threshold=-1'
       ];
     } else if (mode.startsWith('kbc-mix')) {
       prefix += '-MIX';
       extraFlags += ['--enable-interpreter'];
     } else if (mode.startsWith('kbc-cmp')) {
       prefix += '-CMP';
       extraFlags += ['--use-bytecode-compiler'];
     }
     // Every once in a while, stress test JIT.
     if (mode.startsWith('jit') && rand.nextInt(4) == 0) {
       final r = rand.nextInt(7);
       if (r == 0) {
         prefix += '-NOFIELDGUARDS';
         extraFlags += ['--use_field_guards=false'];
       } else if (r == 1) {
         prefix += '-NOINTRINSIFY';
         extraFlags += ['--intrinsify=false'];
       } else if (r == 2) {
         prefix += '-COMPACTEVERY';
         extraFlags += ['--gc_every=1000', '--use_compactor=true'];
       } else if (r == 3) {
         prefix += '-MARKSWEEPEVERY';
         extraFlags += ['--gc_every=1000', '--use_compactor=false'];
       } else if (r == 4) {
         prefix += '-DEPOPTEVERY';
         extraFlags += ['--deoptimize_every=100'];
       } else if (r == 5) {
         prefix += '-STACKTRACEEVERY';
         extraFlags += ['--stacktrace_every=100'];
       } else if (r == 6) {
         prefix += '-OPTCOUNTER';
         extraFlags += ['--optimization_counter_threshold=1'];
       }
     }
     // Every once in a while, disable VFP on arm32.
     if (mode.contains('arm32') && rand.nextInt(4) == 0) {
       prefix += '-noVFP';
       extraFlags += ['--no-use-vfp'];
     }
     // Every once in a while, use -O3 compiler.
     if (!mode.startsWith('djs') && rand.nextInt(4) == 0) {
       prefix += '-O3';
       extraFlags += ['--optimization_level=3'];
     }
     // Construct runner.
     if (mode.startsWith('jit')) {
       return new TestRunnerJIT(prefix, tag, top, tmp, env, extraFlags);
     } else if (mode.startsWith('aot')) {
       return new TestRunnerAOT(prefix, tag, top, tmp, env, extraFlags);
     } else if (mode.startsWith('kbc')) {
       return new TestRunnerKBC(prefix, tag, top, tmp, env, extraFlags);
     } else if (mode.startsWith('djs')) {
       return new TestRunnerDJS(prefix, tag, top, tmp, env);
     }
     throw ('unknown runner in mode: $mode');
   }

   // Convert mode to tag.
   static String getTag(String mode) {
     if (mode.endsWith('debug-ia32')) return 'DebugIA32';
     if (mode.endsWith('debug-x64')) return 'DebugX64';
     if (mode.endsWith('debug-arm32')) return 'DebugSIMARM';
     if (mode.endsWith('debug-arm64')) return 'DebugSIMARM64';
     if (mode.endsWith('debug-dbc')) return 'DebugSIMDBC';
     if (mode.endsWith('debug-dbc64')) return 'DebugSIMDBC64';
     if (mode.endsWith('ia32')) return 'ReleaseIA32';
     if (mode.endsWith('x64')) return 'ReleaseX64';
     if (mode.endsWith('arm32')) return 'ReleaseSIMARM';
     if (mode.endsWith('arm64')) return 'ReleaseSIMARM64';
     if (mode.endsWith('dbc')) return 'ReleaseSIMDBC';
     if (mode.endsWith('dbc64')) return 'ReleaseSIMDBC64';
     throw ('unknown tag in mode: $mode');
   }
 }

 /// Concrete test runner of Dart JIT.
 class TestRunnerJIT implements TestRunner {
   TestRunnerJIT(String prefix, String tag, String top, String tmp, this.env,
       List<String> extraFlags) {
     description = '$prefix-$tag';
     dart = '$top/out/$tag/dart';
     fileName = '$tmp/fuzz.dart';
     cmd = [dart, "--deterministic"] + extraFlags + [fileName];
   }

   TestResult run() {
     return runCommand(cmd, env);
   }

   String description;
   String dart;
   String fileName;
   Map<String, String> env;
   List<String> cmd;
 }

 /// Concrete test runner of Dart AOT.
 class TestRunnerAOT implements TestRunner {
   TestRunnerAOT(String prefix, String tag, String top, String tmp,
       Map<String, String> e, List<String> extraFlags) {
     description = '$prefix-$tag';
     precompiler = '$top/pkg/vm/tool/precompiler2';
     dart = '$top/pkg/vm/tool/dart_precompiled_runtime2';
     fileName = '$tmp/fuzz.dart';
     snapshot = '$tmp/snapshot';
     env = Map<String, String>.from(e);
     env['DART_CONFIGURATION'] = tag;
     env['OPTIONS'] = extraFlags.join(' ');
   }

   TestResult run() {
     TestResult result = runCommand([precompiler, fileName, snapshot], env);
     if (result.code != ResultCode.success) {
       return result;
     }
     return runCommand([dart, snapshot], env);
   }

   String description;
   String precompiler;
   String dart;
   String fileName;
   String snapshot;
   Map<String, String> env;
 }

 /// Concrete test runner of bytecode.
 class TestRunnerKBC implements TestRunner {
   TestRunnerKBC(String prefix, String tag, String top, String tmp, this.env,
       List<String> extraFlags) {
     description = '$prefix-$tag';
     generate = '$top/pkg/vm/tool/gen_kernel';
     platform = '--platform=$top/out/$tag/vm_platform_strong.dill';
     dill = '$tmp/out.dill';
     dart = '$top/out/$tag/dart';
     fileName = '$tmp/fuzz.dart';
     cmd = [dart] + extraFlags + [dill];
   }

   TestResult run() {
     TestResult result = runCommand(
         [generate, '--gen-bytecode', platform, '-o', dill, fileName], env);
     if (result.code != ResultCode.success) {
       return result;
     }
     return runCommand(cmd, env);
   }

   String description;
   String generate;
   String platform;
   String dill;
   String dart;
   String fileName;
   Map<String, String> env;
   List<String> cmd;
 }

 /// Concrete test runner of Dart2JS.
 class TestRunnerDJS implements TestRunner {
   TestRunnerDJS(String prefix, String tag, String top, String tmp, this.env) {
     description = '$prefix-$tag';
     dart2js = '$top/sdk/bin/dart2js';
     fileName = '$tmp/fuzz.dart';
     js = '$tmp/out.js';
   }

   TestResult run() {
     TestResult result = runCommand([dart2js, fileName, '-o', js], env);
     if (result.code != ResultCode.success) {
       return result;
     }
     return runCommand(['nodejs', js], env);
   }

   String description;
   String dart2js;
   String fileName;
   String js;
   Map<String, String> env;
 }

 /// Class to run fuzz testing.
 class DartFuzzTest {
   DartFuzzTest(this.env, this.repeat, this.time, this.trueDivergence,
       this.showStats, this.top, this.mode1, this.mode2);

   int run() {
     setup();

     print('\n${isolate}: start');
     if (showStats) {
       showStatistics();
     }

     for (int i = 0; i < repeat; i++) {
       numTests++;
       seed = rand.nextInt(1 << 32);
       generateTest();
       runTest();
       if (showStats) {
         showStatistics();
       }
       // Timeout?
       if (timeIsUp()) {
         break;
       }
     }

     print('\n${isolate}: done');
     showStatistics();
     print('');

     cleanup();
     return numDivergences;
   }

   void setup() {
     rand = new Random();
     tmpDir = Directory.systemTemp.createTempSync('dart_fuzz');
     fileName = '${tmpDir.path}/fuzz.dart';
     runner1 = TestRunner.getTestRunner(mode1, top, tmpDir.path, env, rand);
     runner2 = TestRunner.getTestRunner(mode2, top, tmpDir.path, env, rand);
     isolate = 'Isolate (${tmpDir.path}) '
         '${runner1.description} - ${runner2.description}';

     start_time = new DateTime.now().millisecondsSinceEpoch;
     current_time = start_time;
     report_time = start_time;
     end_time = start_time + max(0, time - timeout) * 1000;

     numTests = 0;
     numSuccess = 0;
     numNotRun = 0;
     numTimeOut = 0;
     numDivergences = 0;
   }

   bool timeIsUp() {
     if (time > 0) {
       current_time = new DateTime.now().millisecondsSinceEpoch;
       if (current_time > end_time) {
         return true;
       }
       // Report every 10 minutes.
       if ((current_time - report_time) > (10 * 60 * 1000)) {
         print(
             '\n${isolate}: busy @${numTests} ${current_time - start_time} seconds....');
         report_time = current_time;
       }
     }
     return false;
   }

   void cleanup() {
     tmpDir.delete(recursive: true);
   }

   void showStatistics() {
     stdout.write('\rTests: $numTests Success: $numSuccess Not-Run: '
         '$numNotRun: Time-Out: $numTimeOut Divergences: $numDivergences');
   }

   void generateTest() {
     final file = new File(fileName).openSync(mode: FileMode.write);
     new DartFuzz(seed, file).run();
     file.closeSync();
   }

   void runTest() {
     TestResult result1 = runner1.run();
     TestResult result2 = runner2.run();
     checkDivergence(result1, result2);
   }

   void checkDivergence(TestResult result1, TestResult result2) {
     if (result1.code == result2.code) {
       // No divergence in result code.
       switch (result1.code) {
         case ResultCode.success:
           // Both were successful, inspect output.
           if (result1.output == result2.output) {
             numSuccess++;
           } else {
             reportDivergence(result1, result2, true);
           }
           break;
         case ResultCode.timeout:
           // Both had a time out.
           numTimeOut++;
           break;
         case ResultCode.error:
           // Both had an error.
           numNotRun++;
           break;
       }
     } else {
       // Divergence in result code.
       if (trueDivergence) {
         // When only true divergences are requested, any divergence
         // with at least one time out is treated as a regular time out.
         if (result1.code == ResultCode.timeout ||
             result2.code == ResultCode.timeout) {
           numTimeOut++;
           return;
         }
       }
       reportDivergence(result1, result2, false);
     }
   }

   void reportDivergence(
       TestResult result1, TestResult result2, bool outputDivergence) {
     numDivergences++;
     print(
         '\n${isolate}: !DIVERGENCE! $version:$seed (output=${outputDivergence})');
     if (outputDivergence) {
       // Only report the actual output divergence details when requested,
       // since this output may be lengthy and should be reproducable anyway.
       if (showStats) {
         print('\nout1:\n${result1.output}\nout2:\n${result2.output}\n');
       }
     } else {
       // For any other divergence, always report what went wrong.
       if (result1.code != ResultCode.success) {
         print('\nfail1:\n${result1.output}\n');
       }
       if (result2.code != ResultCode.success) {
         print('\nfail2:\n${result2.output}\n');
       }
     }
   }

   // Context.
   final Map<String, String> env;
   final int repeat;
   final int time;
   final bool trueDivergence;
   final bool showStats;
   final String top;
   final String mode1;
   final String mode2;

   // Test.
   Random rand;
   Directory tmpDir;
   String fileName;
   TestRunner runner1;
   TestRunner runner2;
   String isolate;
   int seed;

   // Timing
   int start_time;
   int current_time;
   int report_time;
   int end_time;

   // Stats.
   int numTests;
   int numSuccess;
   int numNotRun;
   int numTimeOut;
   int numDivergences;
 }

 /// Class to start fuzz testing session.
 class DartFuzzTestSession {
   DartFuzzTestSession(this.isolates, this.repeat, this.time,
       this.trueDivergence, this.showStats, String tp, this.mode1, this.mode2)
       : top = getTop(tp) {}

   start() async {
     print('\n**\n**** Dart Fuzz Testing Session\n**\n');
     print('Fuzz Version    : ${version}');
     print('Isolates        : ${isolates}');
     print('Tests           : ${repeat}');
     if (time > 0) {
       print('Time            : ${time} seconds');
     } else {
       print('Time            : unlimited');
     }
     print('True Divergence : ${trueDivergence}');
     print('Show Stats      : ${showStats}');
     print('Dart Dev        : ${top}');
     // Fork.
     List<ReceivePort> ports = new List();
     for (int i = 0; i < isolates; i++) {
       ReceivePort r = new ReceivePort();
       ports.add(r);
       port = r.sendPort;
       await Isolate.spawn(run, this);
     }
     // Join.
     int divergences = 0;
     for (int i = 0; i < isolates; i++) {
       var d = await ports[i].first;
       divergences += d;
     }
     if (divergences == 0) {
       print('\nsuccess\n');
     } else {
       print('\nfailure ($divergences divergences)\n');
       exitCode = 1;
     }
   }

   static run(DartFuzzTestSession session) {
     int divergences = 0;
     try {
       final m1 = getMode(session.mode1, null);
       final m2 = getMode(session.mode2, m1);
       final fuzz = new DartFuzzTest(
           Platform.environment,
           session.repeat,
           session.time,
           session.trueDivergence,
           session.showStats,
           session.top,
           m1,
           m2);
       divergences = fuzz.run();
     } catch (e) {
       print('Isolate: $e');
     }
     session.port.send(divergences);
   }

   // Picks a top directory (command line, environment, or current).
   static String getTop(String top) {
     if (top == null || top == '') {
       top = Platform.environment['DART_TOP'];
     }
     if (top == null || top == '') {
       top = Directory.current.path;
     }
     return top;
   }

   // Picks a mode (command line or random).
   static String getMode(String mode, String other) {
     // Random when not set.
     if (mode == null || mode == '') {
       // Pick a mode at random (cluster), different from other.
       Random rand = new Random();
       do {
         mode = clusterModes[rand.nextInt(clusterModes.length)];
       } while (mode == other);
     }
     // Verify mode.
     if (modes.contains(mode)) {
       return mode;
     }
     throw ('unknown mode: $mode');
   }

   // Context.
   final int isolates;
   final int repeat;
   final int time;
   final bool trueDivergence;
   final bool showStats;
   final String top;
   final String mode1;
   final String mode2;

   // Passes each port to isolate.
   SendPort port;

   // Modes used on cluster runs.
   static const List<String> clusterModes = [
     'jit-debug-ia32',
     'jit-debug-x64',
     'jit-debug-arm32',
     'jit-debug-arm64',
     'jit-debug-dbc',
     'jit-debug-dbc64',
     'jit-ia32',
     'jit-x64',
     'jit-arm32',
     'jit-arm64',
     'jit-dbc',
     'jit-dbc64',
     'aot-debug-x64',
     'aot-x64',
     'kbc-int-debug-x64',
     'kbc-cmp-debug-x64',
     'kbc-mix-debug-x64',
     'kbc-int-x64',
     'kbc-cmp-x64',
     'kbc-mix-x64',
   ];

   // Modes not used on cluster runs because they have outstanding issues.
   static const List<String> nonClusterModes = [
     // Times out often:
     'aot-debug-arm32',
     'aot-debug-arm64',
     'aot-arm32',
     'aot-arm64',
     // Too many divergences (due to arithmetic):
     'js-x64',
   ];

   // All modes.
   static List<String> modes = clusterModes + nonClusterModes;
 }

 /// Main driver for a fuzz testing session.
 main(List<String> arguments) {
   // Set up argument parser.
   final parser = new ArgParser()
     ..addOption('isolates', help: 'number of isolates to use', defaultsTo: '1')
     ..addOption('repeat', help: 'number of tests to run', defaultsTo: '1000')
     ..addOption('time', help: 'time limit in seconds', defaultsTo: '0')
     ..addFlag('true-divergence',
         negatable: true, help: 'only report true divergences', defaultsTo: true)
     ..addFlag('show-stats',
         negatable: true, help: 'show session statistics', defaultsTo: true)
     ..addOption('dart-top', help: 'explicit value for \$DART_TOP')
     ..addOption('mode1', help: 'execution mode 1')
     ..addOption('mode2', help: 'execution mode 2')
     // Undocumented options for cluster runs.
     ..addOption('shards',
         help: 'number of shards used in cluster run', defaultsTo: '1')
     ..addOption('shard', help: 'shard id in cluster run', defaultsTo: '1')
     ..addOption('output_directory',
         help: 'path to output (ignored)', defaultsTo: null);

   // Starts fuzz testing session.
   try {
     final results = parser.parse(arguments);
     final shards = int.parse(results['shards']);
     final shard = int.parse(results['shard']);
     if (shards > 1) {
       print('\nSHARD $shard OF $shards');
     }
     new DartFuzzTestSession(
             int.parse(results['isolates']),
             int.parse(results['repeat']),
             int.parse(results['time']),
             results['true-divergence'],
             results['show-stats'],
             results['dart-top'],
             results['mode1'],
             results['mode2'])
         .start();
   } catch (e) {
     print('Usage: dart dartfuzz_test.dart [OPTIONS]\n${parser.usage}\n$e');
     exitCode = 255;
   }
 }
	// Copyright (c) 2018, 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:convert';
	import 'dart:io';
	import 'dart:isolate';
	import 'dart:math';

	import 'package:args/args.dart';

	import 'dartfuzz.dart';

	const debug = false;
	const sigkill = 9;
	const timeout = 60; // in seconds

	// Exit code of running a test.
	enum ResultCode { success, timeout, error }

	/// Result of running a test.
	class TestResult {
	const TestResult(this.code, this.output);
	final ResultCode code;
	final String output;
	}

	/// Command runner.
	TestResult runCommand(List<String> cmd, Map<String, String> env) {
	ProcessResult res = Process.runSync(
	'timeout', ['-s', '$sigkill', '$timeout'] + cmd,
	environment: env);
	if (debug) {
	print('\nrunning $cmd yields:\n'
	'${res.exitCode}\n${res.stdout}\n${res.stderr}\n');
	}
	if (res.exitCode == -sigkill) {
	return new TestResult(ResultCode.timeout, res.stdout);
	} else if (res.exitCode != 0) {
	return new TestResult(ResultCode.error, res.stderr);
	}
	return new TestResult(ResultCode.success, res.stdout);
	}

	/// Abstraction for running one test in a particular mode.
	abstract class TestRunner {
	TestResult run();
	String description;

	// Factory.
	static TestRunner getTestRunner(String mode, String top, String tmp,
	Map<String, String> env, Random rand) {
	String prefix = mode.substring(0, 3).toUpperCase();
	String tag = getTag(mode);
	// Prepare extra flags.
	List<String> extraFlags = [];
	if (mode.startsWith('kbc-int')) {
	prefix += '-INT';
	extraFlags += [
	'--enable-interpreter',
	'--compilation-counter-threshold=-1'
	];
	} else if (mode.startsWith('kbc-mix')) {
	prefix += '-MIX';
	extraFlags += ['--enable-interpreter'];
	} else if (mode.startsWith('kbc-cmp')) {
	prefix += '-CMP';
	extraFlags += ['--use-bytecode-compiler'];
	}
	// Every once in a while, stress test JIT.
	if (mode.startsWith('jit') && rand.nextInt(4) == 0) {
	final r = rand.nextInt(7);
	if (r == 0) {
	prefix += '-NOFIELDGUARDS';
	extraFlags += ['--use_field_guards=false'];
	} else if (r == 1) {
	prefix += '-NOINTRINSIFY';
	extraFlags += ['--intrinsify=false'];
	} else if (r == 2) {
	prefix += '-COMPACTEVERY';
	extraFlags += ['--gc_every=1000', '--use_compactor=true'];
	} else if (r == 3) {
	prefix += '-MARKSWEEPEVERY';
	extraFlags += ['--gc_every=1000', '--use_compactor=false'];
	} else if (r == 4) {
	prefix += '-DEPOPTEVERY';
	extraFlags += ['--deoptimize_every=100'];
	} else if (r == 5) {
	prefix += '-STACKTRACEEVERY';
	extraFlags += ['--stacktrace_every=100'];
	} else if (r == 6) {
	prefix += '-OPTCOUNTER';
	extraFlags += ['--optimization_counter_threshold=1'];
	}
	}
	// Every once in a while, disable VFP on arm32.
	if (mode.contains('arm32') && rand.nextInt(4) == 0) {
	prefix += '-noVFP';
	extraFlags += ['--no-use-vfp'];
	}
	// Every once in a while, use -O3 compiler.
	if (!mode.startsWith('djs') && rand.nextInt(4) == 0) {
	prefix += '-O3';
	extraFlags += ['--optimization_level=3'];
	}
	// Construct runner.
	if (mode.startsWith('jit')) {
	return new TestRunnerJIT(prefix, tag, top, tmp, env, extraFlags);
	} else if (mode.startsWith('aot')) {
	return new TestRunnerAOT(prefix, tag, top, tmp, env, extraFlags);
	} else if (mode.startsWith('kbc')) {
	return new TestRunnerKBC(prefix, tag, top, tmp, env, extraFlags);
	} else if (mode.startsWith('djs')) {
	return new TestRunnerDJS(prefix, tag, top, tmp, env);
	}
	throw ('unknown runner in mode: $mode');
	}

	// Convert mode to tag.
	static String getTag(String mode) {
	if (mode.endsWith('debug-ia32')) return 'DebugIA32';
	if (mode.endsWith('debug-x64')) return 'DebugX64';
	if (mode.endsWith('debug-arm32')) return 'DebugSIMARM';
	if (mode.endsWith('debug-arm64')) return 'DebugSIMARM64';
	if (mode.endsWith('debug-dbc')) return 'DebugSIMDBC';
	if (mode.endsWith('debug-dbc64')) return 'DebugSIMDBC64';
	if (mode.endsWith('ia32')) return 'ReleaseIA32';
	if (mode.endsWith('x64')) return 'ReleaseX64';
	if (mode.endsWith('arm32')) return 'ReleaseSIMARM';
	if (mode.endsWith('arm64')) return 'ReleaseSIMARM64';
	if (mode.endsWith('dbc')) return 'ReleaseSIMDBC';
	if (mode.endsWith('dbc64')) return 'ReleaseSIMDBC64';
	throw ('unknown tag in mode: $mode');
	}
	}

	/// Concrete test runner of Dart JIT.
	class TestRunnerJIT implements TestRunner {
	TestRunnerJIT(String prefix, String tag, String top, String tmp, this.env,
	List<String> extraFlags) {
	description = '$prefix-$tag';
	dart = '$top/out/$tag/dart';
	fileName = '$tmp/fuzz.dart';
	cmd = [dart, "--deterministic"] + extraFlags + [fileName];
	}

	TestResult run() {
	return runCommand(cmd, env);
	}

	String description;
	String dart;
	String fileName;
	Map<String, String> env;
	List<String> cmd;
	}

	/// Concrete test runner of Dart AOT.
	class TestRunnerAOT implements TestRunner {
	TestRunnerAOT(String prefix, String tag, String top, String tmp,
	Map<String, String> e, List<String> extraFlags) {
	description = '$prefix-$tag';
	precompiler = '$top/pkg/vm/tool/precompiler2';
	dart = '$top/pkg/vm/tool/dart_precompiled_runtime2';
	fileName = '$tmp/fuzz.dart';
	snapshot = '$tmp/snapshot';
	env = Map<String, String>.from(e);
	env['DART_CONFIGURATION'] = tag;
	env['OPTIONS'] = extraFlags.join(' ');
	}

	TestResult run() {
	TestResult result = runCommand([precompiler, fileName, snapshot], env);
	if (result.code != ResultCode.success) {
	return result;
	}
	return runCommand([dart, snapshot], env);
	}

	String description;
	String precompiler;
	String dart;
	String fileName;
	String snapshot;
	Map<String, String> env;
	}

	/// Concrete test runner of bytecode.
	class TestRunnerKBC implements TestRunner {
	TestRunnerKBC(String prefix, String tag, String top, String tmp, this.env,
	List<String> extraFlags) {
	description = '$prefix-$tag';
	generate = '$top/pkg/vm/tool/gen_kernel';
	platform = '--platform=$top/out/$tag/vm_platform_strong.dill';
	dill = '$tmp/out.dill';
	dart = '$top/out/$tag/dart';
	fileName = '$tmp/fuzz.dart';
	cmd = [dart] + extraFlags + [dill];
	}

	TestResult run() {
	TestResult result = runCommand(
	[generate, '--gen-bytecode', platform, '-o', dill, fileName], env);
	if (result.code != ResultCode.success) {
	return result;
	}
	return runCommand(cmd, env);
	}

	String description;
	String generate;
	String platform;
	String dill;
	String dart;
	String fileName;
	Map<String, String> env;
	List<String> cmd;
	}

	/// Concrete test runner of Dart2JS.
	class TestRunnerDJS implements TestRunner {
	TestRunnerDJS(String prefix, String tag, String top, String tmp, this.env) {
	description = '$prefix-$tag';
	dart2js = '$top/sdk/bin/dart2js';
	fileName = '$tmp/fuzz.dart';
	js = '$tmp/out.js';
	}

	TestResult run() {
	TestResult result = runCommand([dart2js, fileName, '-o', js], env);
	if (result.code != ResultCode.success) {
	return result;
	}
	return runCommand(['nodejs', js], env);
	}

	String description;
	String dart2js;
	String fileName;
	String js;
	Map<String, String> env;
	}

	/// Class to run fuzz testing.
	class DartFuzzTest {
	DartFuzzTest(this.env, this.repeat, this.time, this.trueDivergence,
	this.showStats, this.top, this.mode1, this.mode2);

	int run() {
	setup();

	print('\n${isolate}: start');
	if (showStats) {
	showStatistics();
	}

	for (int i = 0; i < repeat; i++) {
	numTests++;
	seed = rand.nextInt(1 << 32);
	generateTest();
	runTest();
	if (showStats) {
	showStatistics();
	}
	// Timeout?
	if (timeIsUp()) {
	break;
	}
	}

	print('\n${isolate}: done');
	showStatistics();
	print('');

	cleanup();
	return numDivergences;
	}

	void setup() {
	rand = new Random();
	tmpDir = Directory.systemTemp.createTempSync('dart_fuzz');
	fileName = '${tmpDir.path}/fuzz.dart';
	runner1 = TestRunner.getTestRunner(mode1, top, tmpDir.path, env, rand);
	runner2 = TestRunner.getTestRunner(mode2, top, tmpDir.path, env, rand);
	isolate = 'Isolate (${tmpDir.path}) '
	'${runner1.description} - ${runner2.description}';

	start_time = new DateTime.now().millisecondsSinceEpoch;
	current_time = start_time;
	report_time = start_time;
	end_time = start_time + max(0, time - timeout) * 1000;

	numTests = 0;
	numSuccess = 0;
	numNotRun = 0;
	numTimeOut = 0;
	numDivergences = 0;
	}

	bool timeIsUp() {
	if (time > 0) {
	current_time = new DateTime.now().millisecondsSinceEpoch;
	if (current_time > end_time) {
	return true;
	}
	// Report every 10 minutes.
	if ((current_time - report_time) > (10 * 60 * 1000)) {
	print(
	'\n${isolate}: busy @${numTests} ${current_time - start_time} seconds....');
	report_time = current_time;
	}
	}
	return false;
	}

	void cleanup() {
	tmpDir.delete(recursive: true);
	}

	void showStatistics() {
	stdout.write('\rTests: $numTests Success: $numSuccess Not-Run: '
	'$numNotRun: Time-Out: $numTimeOut Divergences: $numDivergences');
	}

	void generateTest() {
	final file = new File(fileName).openSync(mode: FileMode.write);
	new DartFuzz(seed, file).run();
	file.closeSync();
	}

	void runTest() {
	TestResult result1 = runner1.run();
	TestResult result2 = runner2.run();
	checkDivergence(result1, result2);
	}

	void checkDivergence(TestResult result1, TestResult result2) {
	if (result1.code == result2.code) {
	// No divergence in result code.
	switch (result1.code) {
	case ResultCode.success:
	// Both were successful, inspect output.
	if (result1.output == result2.output) {
	numSuccess++;
	} else {
	reportDivergence(result1, result2, true);
	}
	break;
	case ResultCode.timeout:
	// Both had a time out.
	numTimeOut++;
	break;
	case ResultCode.error:
	// Both had an error.
	numNotRun++;
	break;
	}
	} else {
	// Divergence in result code.
	if (trueDivergence) {
	// When only true divergences are requested, any divergence
	// with at least one time out is treated as a regular time out.
	if (result1.code == ResultCode.timeout \|\|
	result2.code == ResultCode.timeout) {
	numTimeOut++;
	return;
	}
	}
	reportDivergence(result1, result2, false);
	}
	}

	void reportDivergence(
	TestResult result1, TestResult result2, bool outputDivergence) {
	numDivergences++;
	print(
	'\n${isolate}: !DIVERGENCE! $version:$seed (output=${outputDivergence})');
	if (outputDivergence) {
	// Only report the actual output divergence details when requested,
	// since this output may be lengthy and should be reproducable anyway.
	if (showStats) {
	print('\nout1:\n${result1.output}\nout2:\n${result2.output}\n');
	}
	} else {
	// For any other divergence, always report what went wrong.
	if (result1.code != ResultCode.success) {
	print('\nfail1:\n${result1.output}\n');
	}
	if (result2.code != ResultCode.success) {
	print('\nfail2:\n${result2.output}\n');
	}
	}
	}

	// Context.
	final Map<String, String> env;
	final int repeat;
	final int time;
	final bool trueDivergence;
	final bool showStats;
	final String top;
	final String mode1;
	final String mode2;

	// Test.
	Random rand;
	Directory tmpDir;
	String fileName;
	TestRunner runner1;
	TestRunner runner2;
	String isolate;
	int seed;

	// Timing
	int start_time;
	int current_time;
	int report_time;
	int end_time;

	// Stats.
	int numTests;
	int numSuccess;
	int numNotRun;
	int numTimeOut;
	int numDivergences;
	}

	/// Class to start fuzz testing session.
	class DartFuzzTestSession {
	DartFuzzTestSession(this.isolates, this.repeat, this.time,
	this.trueDivergence, this.showStats, String tp, this.mode1, this.mode2)
	: top = getTop(tp) {}

	start() async {
	print('\n\n Dart Fuzz Testing Session\n\n');
	print('Fuzz Version : ${version}');
	print('Isolates : ${isolates}');
	print('Tests : ${repeat}');
	if (time > 0) {
	print('Time : ${time} seconds');
	} else {
	print('Time : unlimited');
	}
	print('True Divergence : ${trueDivergence}');
	print('Show Stats : ${showStats}');
	print('Dart Dev : ${top}');
	// Fork.
	List<ReceivePort> ports = new List();
	for (int i = 0; i < isolates; i++) {
	ReceivePort r = new ReceivePort();
	ports.add(r);
	port = r.sendPort;
	await Isolate.spawn(run, this);
	}
	// Join.
	int divergences = 0;
	for (int i = 0; i < isolates; i++) {
	var d = await ports[i].first;
	divergences += d;
	}
	if (divergences == 0) {
	print('\nsuccess\n');
	} else {
	print('\nfailure ($divergences divergences)\n');
	exitCode = 1;
	}
	}

	static run(DartFuzzTestSession session) {
	int divergences = 0;
	try {
	final m1 = getMode(session.mode1, null);
	final m2 = getMode(session.mode2, m1);
	final fuzz = new DartFuzzTest(
	Platform.environment,
	session.repeat,
	session.time,
	session.trueDivergence,
	session.showStats,
	session.top,
	m1,
	m2);
	divergences = fuzz.run();
	} catch (e) {
	print('Isolate: $e');
	}
	session.port.send(divergences);
	}

	// Picks a top directory (command line, environment, or current).
	static String getTop(String top) {
	if (top == null \|\| top == '') {
	top = Platform.environment['DART_TOP'];
	}
	if (top == null \|\| top == '') {
	top = Directory.current.path;
	}
	return top;
	}

	// Picks a mode (command line or random).
	static String getMode(String mode, String other) {
	// Random when not set.
	if (mode == null \|\| mode == '') {
	// Pick a mode at random (cluster), different from other.
	Random rand = new Random();
	do {
	mode = clusterModes[rand.nextInt(clusterModes.length)];
	} while (mode == other);
	}
	// Verify mode.
	if (modes.contains(mode)) {
	return mode;
	}
	throw ('unknown mode: $mode');
	}

	// Context.
	final int isolates;
	final int repeat;
	final int time;
	final bool trueDivergence;
	final bool showStats;
	final String top;
	final String mode1;
	final String mode2;

	// Passes each port to isolate.
	SendPort port;

	// Modes used on cluster runs.
	static const List<String> clusterModes = [
	'jit-debug-ia32',
	'jit-debug-x64',
	'jit-debug-arm32',
	'jit-debug-arm64',
	'jit-debug-dbc',
	'jit-debug-dbc64',
	'jit-ia32',
	'jit-x64',
	'jit-arm32',
	'jit-arm64',
	'jit-dbc',
	'jit-dbc64',
	'aot-debug-x64',
	'aot-x64',
	'kbc-int-debug-x64',
	'kbc-cmp-debug-x64',
	'kbc-mix-debug-x64',
	'kbc-int-x64',
	'kbc-cmp-x64',
	'kbc-mix-x64',
	];

	// Modes not used on cluster runs because they have outstanding issues.
	static const List<String> nonClusterModes = [
	// Times out often:
	'aot-debug-arm32',
	'aot-debug-arm64',
	'aot-arm32',
	'aot-arm64',
	// Too many divergences (due to arithmetic):
	'js-x64',
	];

	// All modes.
	static List<String> modes = clusterModes + nonClusterModes;
	}

	/// Main driver for a fuzz testing session.
	main(List<String> arguments) {
	// Set up argument parser.
	final parser = new ArgParser()
	..addOption('isolates', help: 'number of isolates to use', defaultsTo: '1')
	..addOption('repeat', help: 'number of tests to run', defaultsTo: '1000')
	..addOption('time', help: 'time limit in seconds', defaultsTo: '0')
	..addFlag('true-divergence',
	negatable: true, help: 'only report true divergences', defaultsTo: true)
	..addFlag('show-stats',
	negatable: true, help: 'show session statistics', defaultsTo: true)
	..addOption('dart-top', help: 'explicit value for \$DART_TOP')
	..addOption('mode1', help: 'execution mode 1')
	..addOption('mode2', help: 'execution mode 2')
	// Undocumented options for cluster runs.
	..addOption('shards',
	help: 'number of shards used in cluster run', defaultsTo: '1')
	..addOption('shard', help: 'shard id in cluster run', defaultsTo: '1')
	..addOption('output_directory',
	help: 'path to output (ignored)', defaultsTo: null);

	// Starts fuzz testing session.
	try {
	final results = parser.parse(arguments);
	final shards = int.parse(results['shards']);
	final shard = int.parse(results['shard']);
	if (shards > 1) {
	print('\nSHARD $shard OF $shards');
	}
	new DartFuzzTestSession(
	int.parse(results['isolates']),
	int.parse(results['repeat']),
	int.parse(results['time']),
	results['true-divergence'],
	results['show-stats'],
	results['dart-top'],
	results['mode1'],
	results['mode2'])
	.start();
	} catch (e) {
	print('Usage: dart dartfuzz_test.dart [OPTIONS]\n${parser.usage}\n$e');
	exitCode = 255;
	}
	}