Add MultiSourceInformationStrategy

pkg/compiler/lib/src/js_backend/backend.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.
 
 library js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 12 matching lines @@
 import '../constants/values.dart';
 import '../core_types.dart' show CommonElements, ElementEnvironment;
 import '../deferred_load.dart' show DeferredLoadTask;
 import '../dump_info.dart' show DumpInfoTask;
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/resolution_types.dart';
 import '../elements/types.dart';
 import '../enqueue.dart'
     show Enqueuer, EnqueueTask, ResolutionEnqueuer, TreeShakingEnqueuerStrategy;
+import '../io/multi_information.dart' show MultiSourceInformationStrategy;
 import '../io/position_information.dart' show PositionSourceInformationStrategy;
 import '../io/source_information.dart' show SourceInformationStrategy;
 import '../io/start_end_information.dart'
     show StartEndSourceInformationStrategy;
 import '../js/js.dart' as jsAst;
 import '../js/js.dart' show js;
 import '../js/js_source_mapping.dart' show JavaScriptSourceInformationStrategy;
 import '../js/rewrite_async.dart';
 import '../js_emitter/js_emitter.dart' show CodeEmitterTask;
 import '../kernel/task.dart';
@@ skipping 470 matching lines @@
   final BackendImpacts impacts;
 
   /// Common classes used by the backend.
   BackendClasses backendClasses;
 
   /// Backend access to the front-end.
   final JSFrontendAccess frontend;
 
   Tracer tracer;
 
+  static SourceInformationStrategy createSourceInformationStrategy(
+      {bool generateSourceMap: false,
+      bool useMultiSourceInfo: false,
+      bool useNewSourceInfo: false}) {
+    if (!generateSourceMap) return const JavaScriptSourceInformationStrategy();
+    if (useMultiSourceInfo) {
+      if (useNewSourceInfo) {
+        return const MultiSourceInformationStrategy(const [
+          const PositionSourceInformationStrategy(),
+          const StartEndSourceInformationStrategy()
+        ]);
+      } else {
+        return const MultiSourceInformationStrategy(const [
+          const StartEndSourceInformationStrategy(),
+          const PositionSourceInformationStrategy()
+        ]);
+      }
+    } else if (useNewSourceInfo) {
+      return const PositionSourceInformationStrategy();
+    } else {
+      return const StartEndSourceInformationStrategy();
+    }
+  }
+
   JavaScriptBackend(Compiler compiler,
       {bool generateSourceMap: true,
       bool useStartupEmitter: false,
+      bool useMultiSourceInfo: false,
       bool useNewSourceInfo: false,
       bool useKernel: false})
       : rti = new _RuntimeTypes(compiler),
         rtiEncoder = new _RuntimeTypesEncoder(compiler),
         annotations = new Annotations(compiler),
-        this.sourceInformationStrategy = generateSourceMap
-            ? (useNewSourceInfo
-                ? new PositionSourceInformationStrategy()
-                : const StartEndSourceInformationStrategy())
-            : const JavaScriptSourceInformationStrategy(),
+        this.sourceInformationStrategy = createSourceInformationStrategy(
+            generateSourceMap: generateSourceMap,
+            useMultiSourceInfo: useMultiSourceInfo,
+            useNewSourceInfo: useNewSourceInfo),
         impacts = new BackendImpacts(compiler),
         frontend = new JSFrontendAccess(compiler),
         this.compiler = compiler {
     helpers = new BackendHelpers(compiler.elementEnvironment, commonElements);
     emitter =
         new CodeEmitterTask(compiler, generateSourceMap, useStartupEmitter);
     typeVariableHandler = new TypeVariableHandler(compiler);
     customElementsAnalysis = new CustomElementsAnalysis(this);
     lookupMapAnalysis = new LookupMapAnalysis(this, reporter);
     jsInteropAnalysis = new JsInteropAnalysis(this);
@@ skipping 2645 matching lines @@
   }
 
   @override
   FieldEntity get symbolField => helpers.symbolImplementationField;
 
   @override
   InterfaceType get symbolType {
     return _env.getRawType(helpers.symbolImplementationClass);
   }
 }