Update parser to not check that all final fields are initialized for external constructors.

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 1661 matching lines @@
     if (initialized_field->raw() == field->raw()) {
       ErrorMsg(init_pos,
                "duplicate initialization for field %s",
                String::Handle(field->name()).ToCString());
     }
   }
   initialized_fields->Add(field);
 }
 
 
+void Parser::CheckNoInitializersInExternal() {
+  if (CurrentToken() == Token::kCOLON) {
+    ErrorMsg("initializer lists invalid for 'external' constructors");
+  }
+}
+
+
 void Parser::ParseInitializers(const Class& cls,
                                LocalVariable* receiver,
                                GrowableArray<Field*>* initialized_fields) {
   TRACE_PARSER("ParseInitializers");
   bool super_init_seen = false;
   if (CurrentToken() == Token::kCOLON) {
     if ((LookaheadToken(1) == Token::kTHIS) &&
         ((LookaheadToken(2) == Token::kLPAREN) ||
         ((LookaheadToken(2) == Token::kPERIOD) &&
             (LookaheadToken(4) == Token::kLPAREN)))) {
@@ skipping 215 matching lines @@
         p->set_invisible(true);
         AstNode* value = new LoadLocalNode(param.name_pos, p);
         AstNode* initializer = new StoreInstanceFieldNode(
             param.name_pos, instance, field, value);
         current_block_->statements->Add(initializer);
       }
     }
   }
 
   // Now parse the explicit initializer list or constructor redirection.
-  ParseInitializers(cls, receiver, &initialized_fields);
+  if (!func.is_external()) {
+    ParseInitializers(cls, receiver, &initialized_fields);
+  } else {
+    // 'external' constructors should have no initializers.
+    CheckNoInitializersInExternal();
+  }
 
   SequenceNode* init_statements = CloseBlock();
   if (init_statements->length() > 0) {
     // Generate guard around the initializer code.
     LocalVariable* phase_param = LookupPhaseParameter();
     AstNode* phase_value = new LoadLocalNode(TokenPos(), phase_param);
     AstNode* phase_check = new BinaryOpNode(
         TokenPos(), Token::kBIT_AND, phase_value,
         new LiteralNode(TokenPos(),
                         Smi::ZoneHandle(Smi::New(Function::kCtorPhaseInit))));
@@ skipping 7154 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart