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

runtime/vm/dart.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/dart.h"
 
 #include "vm/become.h"
 #include "vm/clustered_snapshot.h"
 #include "vm/code_observers.h"
 #include "vm/cpu.h"
@@ skipping 655 matching lines @@
 #else
   buffer.AddString("release");
 #endif
 
   if (Snapshot::IncludesCode(kind)) {
     // Checked mode affects deopt ids.
     const bool asserts =
         (isolate != NULL) ? isolate->asserts() : FLAG_enable_asserts;
     const bool type_checks =
         (isolate != NULL) ? isolate->type_checks() : FLAG_enable_type_checks;
+    const bool field_guards =
+        (isolate != NULL) ? isolate->use_field_guards() : FLAG_use_field_guards;
     buffer.AddString(asserts ? " asserts" : " no-asserts");
     buffer.AddString(type_checks ? " type-checks" : " no-type-checks");
+    buffer.AddString(field_guards ? "field-guards" : "no-field-guards");
 
 // Generated code must match the host architecture and ABI.
 #if defined(TARGET_ARCH_ARM)
 #if defined(TARGET_ABI_IOS)
     buffer.AddString(" arm-ios");
 #elif defined(TARGET_ABI_EABI)
     buffer.AddString(" arm-eabi");
 #else
 #error Unknown ABI
 #endif
@@ skipping 75 matching lines @@
   return predefined_handles_->handles_.IsValidScopedHandle(address);
 }
 
 
 bool Dart::IsReadOnlyApiHandle(Dart_Handle handle) {
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->api_handles_.IsValidHandle(handle);
 }
 
 }  // namespace dart