VM: Allow configuring use_field_guards on the per-isolate basis and include it into snapshot featur…

runtime/vm/isolate.cc

 // Copyright (c) 2013, 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/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 708 matching lines @@
   return kOK;
 }
 
 
 void Isolate::FlagsInitialize(Dart_IsolateFlags* api_flags) {
   api_flags->version = DART_FLAGS_CURRENT_VERSION;
   api_flags->enable_type_checks = FLAG_enable_type_checks;
   api_flags->enable_asserts = FLAG_enable_asserts;
   api_flags->enable_error_on_bad_type = FLAG_error_on_bad_type;
   api_flags->enable_error_on_bad_override = FLAG_error_on_bad_override;
+  api_flags->use_field_guards = FLAG_use_field_guards;
 }
 
 
 void Isolate::FlagsCopyTo(Dart_IsolateFlags* api_flags) const {
   api_flags->version = DART_FLAGS_CURRENT_VERSION;
   api_flags->enable_type_checks = type_checks();
   api_flags->enable_asserts = asserts();
   api_flags->enable_error_on_bad_type = error_on_bad_type();
   api_flags->enable_error_on_bad_override = error_on_bad_override();
+  api_flags->use_field_guards = use_field_guards();
 }
 
 
 #if !defined(PRODUCT)
 void Isolate::FlagsCopyFrom(const Dart_IsolateFlags& api_flags) {
   type_checks_ = api_flags.enable_type_checks;
   asserts_ = api_flags.enable_asserts;
   error_on_bad_type_ = api_flags.enable_error_on_bad_type;
   error_on_bad_override_ = api_flags.enable_error_on_bad_override;
+  use_field_guards_ = api_flags.use_field_guards;
   // Leave others at defaults.
 }
 #endif  // !defined(PRODUCT)
 
 
 #if defined(DEBUG)
 // static
 void BaseIsolate::AssertCurrent(BaseIsolate* isolate) {
   ASSERT(isolate == Isolate::Current());
 }
@@ skipping 2193 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart