Bug fixes and clean-up

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 221 matching lines @@
  * [InternalAnalysisContext].
  */
 abstract class ExtendedAnalysisContext implements InternalAnalysisContext {
   List<AnalysisTarget> get explicitTargets;
   List<AnalysisTarget> get priorityTargets;
   void set typeProvider(TypeProvider typeProvider);
   CacheEntry getCacheEntry(AnalysisTarget target);
 }
 
 /**
+ * An exception indicating that an attempt was made to perform a task on a
+ * target while gathering the inputs to perform the same task for the same
+ * target.
+ */
+class InfiniteTaskLoopException extends AnalysisException {
+  /**
+   * Initialize a newly created exception to represent an attempt to perform
+   * the task for the target represented by the given [item].
+   */
+  InfiniteTaskLoopException(WorkItem item) : super(
+          'Infinite loop while performing task ${item.descriptor.name} for ${item.target}');
+}
+
+/**
  * 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;
 
   /**
@@ skipping 108 matching lines @@
         }
       }
       builder.currentValue = inputEntry.getValue(inputResult);
       if (!builder.moveNext()) {
         inputs = builder.inputValue;
         builder = null;
       }
     }
     return null;
   }
+
+  @override
+  String toString() => 'Run $descriptor on $target';
 }
 
 /**
  * A description of the work to be done to compute a desired analysis result.
  * The class implements a lazy depth-first traversal of the work item's input.
  */
 class WorkOrder implements Iterator<WorkItem> {
   /**
    * The task manager used to build work items.
    */
@@ skipping 56 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;
   }
 }
-
-/**
- * An exception indicating that an attempt was made to perform a task on a
- * target while gathering the inputs to perform the same task for the same
- * target.
- */
-class InfiniteTaskLoopException extends AnalysisException {
-  /**
-   * Initialize a newly created exception to represent an attempt to perform
-   * the task for the target represented by the given [item].
-   */
-  InfiniteTaskLoopException(WorkItem item) : super('Infinite loop while performing task ${item.descriptor.name} for ${item.target}');
-}