Add interfaces for a new compiler API.

pkg/compiler/lib/src/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 774 matching lines @@
   final bool fatalWarnings;
 
   /// If `true`, some values are cached for reuse in incremental compilation.
   /// Incremental compilation is basically calling [run] more than once.
   final bool hasIncrementalSupport;
 
   /// If `true` native extension syntax is supported by the frontend.
   final bool allowNativeExtensions;
 
   /// Output provider from user of Compiler API.
-  api.CompilerOutputProvider userOutputProvider;
+  api.CompilerOutput userOutputProvider;
 
   /// Generate output even when there are compile-time errors.
   final bool generateCodeWithCompileTimeErrors;
 
   /// The compiler is run from the build bot.
   final bool testMode;
 
   bool disableInlining = false;
 
   List<Uri> librariesToAnalyzeWhenRun;
@@ skipping 248 matching lines @@
             this.dumpInfo: false,
             this.showPackageWarnings: false,
             this.useContentSecurityPolicy: false,
             this.suppressWarnings: false,
             this.fatalWarnings: false,
             bool hasIncrementalSupport: false,
             this.enableExperimentalMirrors: false,
             this.allowNativeExtensions: false,
             this.generateCodeWithCompileTimeErrors: false,
             this.testMode: false,
-            api.CompilerOutputProvider outputProvider,
+            api.CompilerOutput outputProvider,
             List<String> strips: const []})
       : this.disableTypeInferenceFlag =
           disableTypeInferenceFlag || !emitJavaScript,
         this.analyzeOnly =
             analyzeOnly || analyzeSignaturesOnly || analyzeAllFlag,
         this.analyzeSignaturesOnly = analyzeSignaturesOnly,
         this.analyzeAllFlag = analyzeAllFlag,
         this.hasIncrementalSupport = hasIncrementalSupport,
         cacheStrategy = new CacheStrategy(hasIncrementalSupport),
-        this.userOutputProvider = (outputProvider == null)
-            ? NullSink.outputProvider
-            : outputProvider {
+        this.userOutputProvider = outputProvider == null
+            ? const NullCompilerOutput() : outputProvider {
     if (hasIncrementalSupport) {
       // TODO(ahe): This is too much. Any method from platform and package
       // libraries can be inlined.
       disableInlining = true;
     }
     world = new World(this);
     // TODO(johnniwinther): Initialize core types in [initializeCoreClasses] and
     // make its field final.
     _coreTypes = new _CompilerCoreTypes(this);
     types = new Types(this);
@@ skipping 1076 matching lines @@
 
   EventSink<String> outputProvider(String name, String extension) {
     if (compilationFailed) {
       if (!generateCodeWithCompileTimeErrors || testMode) {
         // Disable output in test mode: The build bot currently uses the time
         // stamp of the generated file to determine whether the output is
         // up-to-date.
         return new NullSink('$name.$extension');
       }
     }
-    return userOutputProvider(name, extension);
+    return userOutputProvider.createEventSink(name, extension);
   }
 }
 
 class CompilerTask {
   final Compiler compiler;
   final Stopwatch watch;
   UserTag profilerTag;
 
   CompilerTask(Compiler compiler)
       : this.compiler = compiler,
@@ skipping 113 matching lines @@
   }
   return true;
 }
 
 /// Returns `true` when [s] is private if used as an identifier.
 bool isPrivateName(String s) => !s.isEmpty && s.codeUnitAt(0) == $_;
 
 /// Returns `true` when [s] is public if used as an identifier.
 bool isPublicName(String s) => !isPrivateName(s);
 
-/// A sink that drains into /dev/null.
-class NullSink implements EventSink<String> {
-  final String name;
-
-  NullSink(this.name);
-
-  add(String value) {}
-
-  void addError(Object error, [StackTrace stackTrace]) {}
-
-  void close() {}
-
-  toString() => name;
-
-  /// Convenience method for getting an [api.CompilerOutputProvider].
-  static NullSink outputProvider(String name, String extension) {
-    return new NullSink('$name.$extension');
-  }
-}
-
 /// Information about suppressed warnings and hints for a given library.
 class SuppressionInfo {
   int warnings = 0;
   int hints = 0;
 }
 
 class GenericTask extends CompilerTask {
   final String name;
 
   GenericTask(this.name, Compiler compiler)
@@ skipping 180 matching lines @@
   InterfaceType streamType([DartType elementType]) {
     InterfaceType type = streamClass.computeType(compiler);
     if (elementType == null) {
       return streamClass.rawType;
     }
     return type.createInstantiation([elementType]);
   }
 }
 
 typedef void InternalErrorFunction(Spannable location, String message);