Stop creating duplicate enum members when the element model has already been built

pkg/analyzer/lib/src/task/dart.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.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 1211 matching lines @@
   TaskDescriptor get descriptor => DESCRIPTOR;
 
   @override
   void internalPerform() {
     //
     // Prepare inputs.
     //
     TypeProvider typeProvider = getRequiredInput(TYPE_PROVIDER_INPUT);
     CompilationUnit unit = getRequiredInput(UNIT_INPUT);
     //
+    // Build the enum members if they have not already been created.
+    //
+    EnumDeclaration findFirstEnum() {
+      for (CompilationUnitMember member in unit.declarations) {
+        if (member is EnumDeclaration) {
+          return member;
+        }
+      }
+      return null;
+    }
+    EnumDeclaration firstEnum = findFirstEnum();

[scheglov, 2016/01/26 21:51:04]

This could be done with less code.
    EnumDeclaration firstEnum = unit.declarations
        .firstWhere((member) => member is EnumDeclaration, orElse: () => null);

[Brian Wilkerson, 2016/01/26 21:59:42]

I discovered firstWhere, but didn't notice the orElse. Unless you care a lot, I
think I'll just leave it at this point; it doesn't get rid of as much code as I
would have liked.

+    if (firstEnum != null && firstEnum.element.accessors.isEmpty) {
+      EnumMemberBuilder builder = new EnumMemberBuilder(typeProvider);
+      unit.accept(builder);
+    }
+    //
     // Record outputs.
     //
-    EnumMemberBuilder builder = new EnumMemberBuilder(typeProvider);
-    unit.accept(builder);
     outputs[CREATED_RESOLVED_UNIT2] = true;
     outputs[RESOLVED_UNIT2] = unit;
   }
 
   /**
    * Return a map from the names of the inputs of this kind of task to the task
    * input descriptors describing those inputs for a task with the
    * given [target].
    */
   static Map<String, TaskInput> buildInputs(AnalysisTarget target) {
@@ skipping 4202 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }