Extend compiler API to support multiple outputs.

dart/sdk/lib/_internal/compiler/implementation/compiler.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.
 
 part of dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 185 matching lines @@
   final bool analyzeOnly;
   final bool enableNativeLiveTypeAnalysis;
   final bool rejectDeprecatedFeatures;
   final bool checkDeprecationInSdk;
 
   /**
    * If [:true:], comment tokens are collected in [commentMap] during scanning.
    */
   final bool preserveComments;
 
+  final api.CompilerOutputProvider outputProvider;
+
   bool disableInlining = false;
 
   List<Uri> librariesToAnalyzeWhenRun;
 
   final Tracer tracer;
 
   CompilerTask measuredTask;
   Element _currentElement;
   LibraryElement coreLibrary;
   LibraryElement isolateLibrary;
@@ skipping 108 matching lines @@
             this.enableMinification: false,
             this.enableNativeLiveTypeAnalysis: false,
             bool emitJavaScript: true,
             bool generateSourceMap: true,
             bool disallowUnsafeEval: false,
             this.analyzeAll: false,
             this.analyzeOnly: false,
             this.rejectDeprecatedFeatures: false,
             this.checkDeprecationInSdk: false,
             this.preserveComments: false,
+            outputProvider,
             List<String> strips: const []})
       : libraries = new Map<String, LibraryElement>(),
-        progress = new Stopwatch() {
+        progress = new Stopwatch(),
+        this.outputProvider =
+            (outputProvider == null) ? NullSink.outputProvider : outputProvider
+  {
     progress.start();
     world = new World(this);
 
     closureMapping.ClosureNamer closureNamer;
     if (emitJavaScript) {
       js_backend.JavaScriptBackend jsBackend =
           new js_backend.JavaScriptBackend(this, generateSourceMap,
                                            disallowUnsafeEval);
       closureNamer = jsBackend.namer;
       backend = jsBackend;
@@ skipping 733 matching lines @@
   // TODO(johnniwinther): Use [spannable] and [message] to provide better
   // information on assertion errors.
   if (condition is Function){
     condition = condition();
   }
   if (spannable == null || !condition) {
     throw new SpannableAssertionFailure(spannable, message);
   }
   return true;
 }
+
+/// A sink that drains into /dev/null.
+class NullSink extends Sink<String> {
+  final String name;
+
+  NullSink(this.name);
+
+  add(String value) {}
+
+  void close() {}
+
+  toString() => name;
+
+  /// Convenience method for getting an [api.CompilerOutputProvider].
+  static NullSink outputProvider(String name, String extension) {
+    return new NullSink('$name.$extension');
+  }
+}