VM: Support calling through getters in InstanceMirror.delegate. Implement without accessing private…

runtime/lib/mirrors_impl.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.
 
 // VM-specific implementation of the dart:mirrors library.
 
 import "dart:collection";
 
 final emptyList = new UnmodifiableListView([]);
 final emptyMap = new _UnmodifiableMapView({});
@@ skipping 245 matching lines @@
 
   InstanceMirror setField(Symbol memberName, Object value) {
     this._invokeSetter(_reflectee, _n(memberName), value);
     return reflect(value);
   }
 }
 
 class _LocalInstanceMirror extends _LocalObjectMirror
     implements InstanceMirror {
   // TODO(ahe): This is a hack, see delegate below.
   static Function _invokeOnClosure;

[Florian Schneider, 2013/12/13 12:26:24]

With your cleanup I think this member can go away as well.

[rmacnak, 2013/12/13 18:16:48]

Yes, done.

 
   _LocalInstanceMirror(reflectee) : super(reflectee);
 
   ClassMirror _type;
   ClassMirror get type {
     if (_type == null) {
       // Note it not safe to use reflectee.runtimeType because runtimeType may
       // be overridden.
       _type = reflectType(_computeType(reflectee));
     }
     return _type;
   }
 
   // LocalInstanceMirrors always reflect local instances
   bool hasReflectee = true;
 
   get reflectee => _reflectee;
 
   delegate(Invocation invocation) {
-    if (_invokeOnClosure == null) {
-      // TODO(ahe): This is a total hack.  We're using the mirror
-      // system to access a private field in a different library.  For
-      // some reason, that works.  On the other hand, calling a
-      // private method does not work.
-      ClassMirror invocationImplClass = reflect(invocation).type;
-      Symbol fieldName = MirrorSystem.getSymbol('_invokeOnClosure',
-                                                invocationImplClass.owner);
-      _invokeOnClosure = invocationImplClass.getField(fieldName).reflectee;
+    if (invocation.isMethod) {
+      return this.invoke(invocation.memberName,
+                         invocation.positionalArguments,
+                         invocation.namedArguments).reflectee;
     }
-    return _invokeOnClosure(reflectee, invocation);
+    if (invocation.isGetter) {
+      return this.getField(invocation.memberName).reflectee;
+    }
+    if (invocation.isSetter) {
+      var unwrapped = _n(invocation.memberName);
+      var withoutEqual = _s(unwrapped.substring(0, unwrapped.length - 1));
+      var arg = invocation.positionalArguments[0];
+      this.setField(withoutEqual, arg).reflectee;
+      return arg;
+    }
+    throw "UNREACHABLE";
   }
 
   String toString() => 'InstanceMirror on ${Error.safeToString(_reflectee)}';
 
   bool operator ==(other) {
     return other is _LocalInstanceMirror &&
            identical(_reflectee, other._reflectee);
   }
 
   int get hashCode {
@@ skipping 1156 matching lines @@
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);
       _instanitationCache[key] = typeMirror;
       if (typeMirror is ClassMirror && !typeMirror._isGeneric) {
         _declarationCache[key] = typeMirror;
       }
     }
     return typeMirror;
   }
 }