Issue 3968. Support for redirecting factory constructors

compiler/java/com/google/dart/compiler/resolver/Resolver.java

 // 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.
 
 package com.google.dart.compiler.resolver;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import com.google.dart.compiler.DartCompilationPhase;
@@ skipping 636 matching lines @@
       DartBlock body = functionNode.getBody();
       boolean isInterface = false;
       if (ElementKind.of(member.getEnclosingElement()).equals(ElementKind.CLASS)
           && ((ClassElement) member.getEnclosingElement()).isInterface()) {
         isInterface =true;
       }
       if (body == null
           && !Elements.isNonFactoryConstructor(member)
           && !member.getModifiers().isAbstract()
           && !member.getModifiers().isExternal()
+          && node.getRedirectedTypeName() == null
           && !isInterface) {
         onError(functionNode, ResolverErrorCode.METHOD_MUST_HAVE_BODY);
       }
       resolve(functionNode.getBody());
 
       if (Elements.isNonFactoryConstructor(member)
           && !(body instanceof DartNativeBlock)) {
         resolveInitializers(node, initializedFields);
       }
 
+      // resolve redirecting factory constructor
+      {
+        DartTypeNode rcTypeName = node.getRedirectedTypeName();
+        if (rcTypeName != null) {
+          InterfaceType rcType = (InterfaceType) resolveType(rcTypeName, true, true,
+              TypeErrorCode.NO_SUCH_TYPE, ResolverErrorCode.WRONG_NUMBER_OF_TYPE_ARGUMENTS);
+          switch (TypeKind.of(rcType)) {
+            case INTERFACE:
+              Element element = recordType(rcTypeName, rcType);
+              DartIdentifier rcName = node.getRedirectedConstructorName();
+              if (rcName != null) {
+                element = ((ClassElement) element).lookupConstructor(rcName.getName());
+                switch (ElementKind.of(element)) {
+                  case CONSTRUCTOR:
+                    recordElement(rcName, element);
+                    if (member.getModifiers().isConstant() && !element.getModifiers().isConstant()) {
+                      onError(rcName,
+                          ResolverErrorCode.REDIRECTION_CONSTRUCTOR_TARGET_MUST_BE_CONST);
+                    }
+                    break;
+                }
+              }
+              break;
+          }
+        }
+      }
+
       context = previousContext;
       innermostFunction = currentMethod = null;
       enclosingElement = previousEnclosingElement;
       return member;
     }
 
     @Override
     public Element visitField(DartField node) {
       DartExpression expression = node.getValue();
       Modifiers modifiers = node.getModifiers();
@@ skipping 1593 matching lines @@
           ClassElement currentClass = (ClassElement) constructor.getEnclosingElement();
           if (nextClass == currentClass) {
             return (ConstructorNodeElement) nextConstructorElement;
           }
         }
       }
     }
     return null;
   }
 }