Disallow extending a malformed type (issue 13940).

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 "lib/invocation_mirror.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 3787 matching lines @@
       // We do not check that the bounds are repeated. We use the original ones.
       // TODO(regis): Should we check?
     }
     cls.set_type_parameters(orig_type_parameters);
   }
   AbstractType& super_type = Type::Handle();
   if (CurrentToken() == Token::kEXTENDS) {
     ConsumeToken();
     const intptr_t type_pos = TokenPos();
     super_type = ParseType(ClassFinalizer::kResolveTypeParameters);
+    if (super_type.IsDynamicType()) {
+      // The string 'dynamic' is not resolved yet at this point, but a malformed
+      // type mapped to dynamic can be encountered here.
+      ErrorMsg(type_pos,
+               "class '%s' may not extend a malformed type",
+               class_name.ToCString());
+    }
     if (super_type.IsTypeParameter()) {
       ErrorMsg(type_pos,
                "class '%s' may not extend type parameter '%s'",
                class_name.ToCString(),
                String::Handle(super_type.UserVisibleName()).ToCString());
     }
     if (CurrentToken() == Token::kWITH) {
       super_type = ParseMixins(pending_classes, super_type);
     }
   } else {
@@ skipping 6805 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart