Report error on missing factory class

runtime/vm/parser.cc

 // 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.
 
 #include "vm/parser.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/compiler_stats.h"
@@ skipping 2910 matching lines @@
     }
   }
 
   ExpectToken(Token::kLBRACE);
   ClassDesc members(interface, interface_name, true, interface_pos);
   while (CurrentToken() != Token::kRBRACE) {
     ParseClassMemberDefinition(&members);
   }
   ExpectToken(Token::kRBRACE);
 
+  if (members.has_constructor() && !interface.HasFactoryClass()) {
+    ErrorMsg(interfacename_pos,
+             "interface '%s' with constructor must declare a factory class",
+             interface_name.ToCString());
+  }
+
   Array& array = Array::Handle();
   array = Array::MakeArray(members.fields());
   interface.SetFields(array);
 
   // Creating a new array for functions marks the interface as parsed.
   array = Array::MakeArray(members.functions());
   interface.SetFunctions(array);
   ASSERT(interface.is_interface());
 
   pending_classes.Add(interface, Heap::kOld);
@@ skipping 5311 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart