Allows turning on checked mode on a per-isolate basis

runtime/vm/ast.cc

 // Copyright (c) 2011, 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/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/resolver.h"
@@ skipping 497 matching lines @@
     return NULL;
   }
   return new StoreLocalNode(token_pos(), &local(), rhs);
 }
 
 
 AstNode* LoadStaticFieldNode::MakeAssignmentNode(AstNode* rhs) {
   if (field().is_final()) {
     return NULL;
   }
-  if (FLAG_enable_type_checks) {
+  if (Isolate::Current()->TypeChecksEnabled()) {
     rhs = new AssignableNode(
         field().token_pos(),
         rhs,
         AbstractType::ZoneHandle(field().type()),
         String::ZoneHandle(field().name()));
   }
   return new StoreStaticFieldNode(token_pos(), field(), rhs);
 }
 
 
@@ skipping 38 matching lines @@
       // order to trigger the throw at runtime.
       return new StaticSetterNode(token_pos(), NULL, cls(), field_name(), rhs);
     }
 #if defined(DEBUG)
     const String& getter_name = String::Handle(Field::GetterName(field_name()));
     const Function& getter =
         Function::Handle(cls().LookupStaticFunction(getter_name));
     ASSERT(!getter.IsNull() &&
            (getter.kind() == RawFunction::kImplicitStaticFinalGetter));
 #endif
-    if (FLAG_enable_type_checks) {
+    if (Isolate::Current()->TypeChecksEnabled()) {
       rhs = new AssignableNode(
           field.token_pos(),
           rhs,
           AbstractType::ZoneHandle(field.type()),
           String::ZoneHandle(field.name()));
     }
     return new StoreStaticFieldNode(token_pos(), field, rhs);
   }
   // Didn't find a static setter or a static field.
   // If this static getter is in an instance function where
@@ skipping 52 matching lines @@
   if (result.IsError() || result.IsNull()) {
     // TODO(turnidge): We could get better error messages by returning
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   return &Instance::ZoneHandle(Instance::Cast(result).raw());
 }
 
 }  // namespace dart