DDC: mostly incremental compilation, fixes #223

lib/src/options.dart

 // Copyright (c) 2014, 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.
 
 /// Set of flags and options passed to the compiler
 library dev_compiler.src.options;
 
 import 'dart:io';
 
 import 'package:args/args.dart';
@@ skipping 127 matching lines @@
   /// package (if we can infer where that is located).
   final String runtimeDir;
 
   /// The files to compile.
   final List<String> inputs;
 
   /// The base directory for [inputs]. Module imports will be generated relative
   /// to this directory.
   final String inputBaseDir;
 
+  /// True to save compiler messages to a file.
+  /// Useful for incremental compilation and tests.
+  final bool saveMessages;
+
   CompilerOptions(
       {this.strongOptions: const StrongModeOptions(),
       this.sourceOptions: const SourceResolverOptions(),
       this.codegenOptions: const CodegenOptions(),
       this.runnerOptions: const RunnerOptions(),
       this.checkSdk: false,
       this.dumpInfo: false,
       this.dumpInfoFile,
       this.useColors: true,
       this.help: false,
       this.logLevel: Level.SEVERE,
       this.serverMode: false,
       this.enableHashing: false,
       this.widget: true,
       this.host: 'localhost',
       this.port: 8080,
       this.runtimeDir,
-      this.inputs,
-      this.inputBaseDir});
+      this.inputs: const [],
+      this.inputBaseDir,
+      this.saveMessages: false});
 }
 
 /// Parses options from the command-line
 CompilerOptions parseOptions(List<String> argv, {bool forceOutDir: false}) {
   ArgResults args = argParser.parse(argv);
   bool showUsage = args['help'];
 
   var serverMode = args['server'];
   var enableHashing = args['hashing'];
   if (enableHashing == null) {
     enableHashing = serverMode;
   }
   // TODO(jmesserly): shouldn't level always default to warning?
   var logLevel = serverMode ? Level.WARNING : Level.SEVERE;
   var levelName = args['log'];
   if (levelName != null) {
     levelName = levelName.toUpperCase();
     logLevel = Level.LEVELS
         .firstWhere((l) => l.name == levelName, orElse: () => logLevel);
   }
   var useColors = stdioType(stdout) == StdioType.TERMINAL;
   var sdkPath = args['dart-sdk'];
   if (sdkPath == null && !args['mock-sdk']) {
     sdkPath = getSdkDir(argv).path;
   }
   var runtimeDir = args['runtime-dir'];
   if (runtimeDir == null) {
-    runtimeDir = _computeRuntimeDir();
+    runtimeDir = _computedRuntimeDir;
   }
   var outputDir = args['out'];
   if (outputDir == null && (serverMode || forceOutDir)) {
     outputDir = Directory.systemTemp.createTempSync("dev_compiler_out_").path;
   }
   var dumpInfo = args['dump-info'];
   if (dumpInfo == null) dumpInfo = serverMode;
 
   var v8Binary = args['v8-binary'];
   if (v8Binary == null) v8Binary = 'iojs';
@@ skipping 36 matching lines @@
       dumpInfoFile: args['dump-info-file'],
       useColors: useColors,
       help: showUsage,
       logLevel: logLevel,
       serverMode: serverMode,
       enableHashing: enableHashing,
       widget: args['widget'],
       host: args['host'],
       port: int.parse(args['port']),
       runtimeDir: runtimeDir,
+      saveMessages: args['save-messages'],
       inputs: args.rest);
 }
 
 final ArgParser argParser = StrongModeOptions.addArguments(new ArgParser()
   ..addFlag('sdk-check',
       abbr: 's', help: 'Typecheck sdk libs', defaultsTo: false)
   ..addFlag('mock-sdk',
       abbr: 'm', help: 'Use a mock Dart SDK', defaultsTo: false)
 
   // input/output options
@@ skipping 47 matching lines @@
       help: 'Compile code with static errors', defaultsTo: false)
   ..addOption('log', abbr: 'l', help: 'Logging level (defaults to severe)')
   ..addFlag('dump-info',
       abbr: 'i', help: 'Dump summary information', defaultsTo: null)
   ..addOption('v8-binary',
       help: 'V8-based binary to run JavaScript output with (iojs, node, d8)',
       defaultsTo: 'iojs')
   ..addOption('dump-info-file',
       abbr: 'f',
       help: 'Dump info json file (requires dump-info)',
-      defaultsTo: null));
+      defaultsTo: null)
+  ..addFlag('save-messages', help: 'Save compiler messages to a text file'));
 
 /// Tries to find the `lib/runtime/` directory of the dev_compiler package. This
 /// works when running devc from it's sources or from a snapshot that is
 /// activated via `pub global activate`.
-String _computeRuntimeDir() {
+final String _computedRuntimeDir = () {
+  // TODO(jmesserly): if we're in the test runner we can't get our runtime path.
+  if (Platform.script.scheme == 'data') return null;
+
   var scriptPath = path.fromUri(Platform.script);
   var file = path.basename(scriptPath);
   var dir = path.dirname(scriptPath);
   var lastdir = path.basename(dir);
   dir = path.dirname(dir);
 
   // Both the source devc.dart and the snapshot generated by pub global activate
   // are under a bin folder.
   if (lastdir != 'bin') return null;
 
@@ skipping 26 matching lines @@
     // We should be under "/path/to/pub-cache/global_packages/dev_compiler".
     // The pub-cache directory is two levels up, but we verify that the layout
     // looks correct.
     if (path.basename(dir) != 'dev_compiler') return null;
     dir = path.dirname(dir);
     if (path.basename(dir) != 'global_packages') return null;
     dir = path.dirname(dir);
     return path.join(dir, cacheDir, 'lib', 'runtime');
   }
   return null;
-}
+}();
+
+/// The timestamp of the compiler itself. Used to invalidate output if the
+/// compiler itself changes.

[Leaf, 2015/09/04 21:46:31]

At some point, we should probably include a version string in the generated code
so that we could invalidate even if we can't find the compiler sources.  Maybe a
TODO?

+final DateTime compilerLastModified = () {
+  if (_computedRuntimeDir == null) return null;
+
+  DateTime lastModify = null;
+  var compilerLib = new Directory(path.join(_computedRuntimeDir, '..'));
+  for (var file in compilerLib.listSync(recursive: true)) {
+    if (file is File && file.path.endsWith('.dart')) {
+      var modify = file.lastModifiedSync();
+      if (lastModify == null || modify.isAfter(lastModify)) lastModify = modify;
+    }
+  }
+  return lastModify;
+}();