Initial re-write of analysis context for the new task model

pkg/analyzer/lib/src/task/driver.dart

 // Copyright (c) 2015, 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 analyzer.src.task.driver;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/src/context/cache.dart';
@@ skipping 10 matching lines @@
  */
 class AnalysisDriver {
   /**
    * The task manager used to figure out how to compute analysis results.
    */
   final TaskManager taskManager;
 
   /**
    * The context in which analysis is to be performed.
    */
-  final ExtendedAnalysisContext context;
+  final InternalAnalysisContext context;
 
   /**
    * The work order that was previously computed but that has not yet been
    * completed.
    */
   WorkOrder currentWorkOrder;
 
   /**
    * The controller that is notified when a task is started.
    */
@@ skipping 74 matching lines @@
    */
   WorkOrder createWorkOrderForResult(
       AnalysisTarget target, ResultDescriptor result) {
     CacheEntry entry = context.getCacheEntry(target);
     CacheState state = entry.getState(result);
     if (state == CacheState.VALID ||
         state == CacheState.ERROR ||
         state == CacheState.IN_PROCESS) {
       return null;
     }
-    return new WorkOrder(taskManager,
-        new WorkItem(context, target, taskManager.findTask(target, result)));
+    try {
+      return new WorkOrder(taskManager,
+          new WorkItem(context, target, taskManager.findTask(target, result)));
+    } catch (exception, stackTrace) {
+      throw new AnalysisException(
+          'Could not create work order (target = $target; result = $result)',
+          new CaughtException(exception, stackTrace));
+    }
   }
 
   /**
    * Create a work order that will produce the required analysis results for
    * the given [target]. If [isPriority] is true, then the target is a priority
    * target. Return the work order that was created, or `null` if there is no
    * further work that needs to be done for the given target.
    */
   WorkOrder createWorkOrderForTarget(AnalysisTarget target, bool isPriority) {
     for (ResultDescriptor result in taskManager.generalResults) {
@@ skipping 115 matching lines @@
 }
 
 /**
  * A description of a single anaysis task that can be performed to advance
  * analysis.
  */
 class WorkItem {
   /**
    * The context in which the task will be performed.
    */
-  final ExtendedAnalysisContext context;
+  final InternalAnalysisContext context;
 
   /**
    * The target for which a task is to be performed.
    */
   final AnalysisTarget target;
 
   /**
    * A description of the task to be performed.
    */
   final TaskDescriptor descriptor;
@@ skipping 179 matching lines @@
     TaskDescriptor descriptor = currentItem.descriptor;
     AnalysisTarget target = currentItem.target;
     for (WorkItem item in pendingItems) {
       if (item.descriptor == descriptor && item.target == target) {
         return true;
       }
     }
     return false;
   }
 }