- Add the ability to protect VirtualMemory.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
@@ skipping 762 matching lines @@
   type = Type::NewNonParameterizedType(cls);
   object_store->set_void_type(type);
 
   // The class 'Dynamic' is registered in the class dictionary because its name
   // is a built-in identifier, rather than a reserved keyword. Its name is not
   // heap allocated, because the class resides in the VM isolate.
   // The corresponding type, the "unknown type", is stored in the object store.
   cls = dynamic_class_;
   type = Type::NewNonParameterizedType(cls);
   object_store->set_dynamic_type(type);
-  core_lib.AddClass(cls);
 
   // Allocate pre-initialized values.
   Bool& bool_value = Bool::Handle();
   bool_value = Bool::New(true);
   object_store->set_true_value(bool_value);
   bool_value = Bool::New(false);
   object_store->set_false_value(bool_value);
 
   // Setup some default native field classes which can be extended for
   // specifying native fields in dart classes.
@@ skipping 5250 matching lines @@
   isolate->object_store()->set_core_library(core_lib);
   const String& core_impl_lib_url =
       String::Handle(Symbols::New("dart:coreimpl"));
   const Library& core_impl_lib =
       Library::Handle(Library::NewLibraryHelper(core_impl_lib_url, false));
   isolate->object_store()->set_core_impl_library(core_impl_lib);
   core_impl_lib.Register();
   core_lib.AddImport(core_impl_lib);
   core_impl_lib.AddImport(core_lib);
   isolate->object_store()->set_root_library(Library::Handle());
+
+  // Hook up predefined classes without setting their library pointers.

[siva, 2012/07/27 01:55:00]

The comment on top seems more meaningful i.e.

// The class 'Dynamic' is registered in the class dictionary because it's name
is a built-in identifier, rather than a reserved keyword. It's name is not heap
allocated, because the class resides in the VM isolate. This class is registered
into the dictionary without setting the corresponding library pointer in the
class as it is in the VM isolate which is read only.

[Ivan Posva, 2012/07/27 18:02:56]

Added a better comment. The name should actually be setup for the shared classes
once we can properly use strings from the VM isolate.

+  const Class& cls = Class::Handle(Object::dynamic_class());
+  core_lib.AddObject(cls, String::Handle(cls.Name()));
 }
 
 
 void Library::InitMathLibrary(Isolate* isolate) {
   const String& url = String::Handle(Symbols::New("dart:math"));
   const Library& lib = Library::Handle(Library::New(url));
   lib.Register();
   const Library& core_impl_lib = Library::Handle(Library::CoreImplLibrary());
   lib.AddImport(core_impl_lib);
   isolate->object_store()->set_math_library(lib);
@@ skipping 4782 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart