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

runtime/vm/isolate.h

 // 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.
 
 #ifndef RUNTIME_VM_ISOLATE_H_
 #define RUNTIME_VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/atomic.h"
@@ skipping 620 matching lines @@
   // Isolate-specific flag handling.
   static void FlagsInitialize(Dart_IsolateFlags* api_flags);
   void FlagsCopyTo(Dart_IsolateFlags* api_flags) const;
   void FlagsCopyFrom(const Dart_IsolateFlags& api_flags);
 
 #if defined(PRODUCT)
   bool type_checks() const { return FLAG_enable_type_checks; }
   bool asserts() const { return FLAG_enable_asserts; }
   bool error_on_bad_type() const { return FLAG_error_on_bad_type; }
   bool error_on_bad_override() const { return FLAG_error_on_bad_override; }
+  bool use_field_guards() const { return FLAG_use_field_guards; }
 #else   // defined(PRODUCT)
   bool type_checks() const { return type_checks_; }
   bool asserts() const { return asserts_; }
   bool error_on_bad_type() const { return error_on_bad_type_; }
   bool error_on_bad_override() const { return error_on_bad_override_; }
+  bool use_field_guards() const { return use_field_guards_; }
 #endif  // defined(PRODUCT)
 
   static void KillAllIsolates(LibMsgId msg_id);
   static void KillIfExists(Isolate* isolate, LibMsgId msg_id);
 
   static void DisableIsolateCreation();
   static void EnableIsolateCreation();
   static bool IsolateCreationEnabled();
 
   void StopBackgroundCompiler();
@@ skipping 109 matching lines @@
   DeoptContext* deopt_context_;
 
   bool is_service_isolate_;
 
 // Isolate-specific flags.
 #if !defined(PRODUCT)
   bool type_checks_;
   bool asserts_;
   bool error_on_bad_type_;
   bool error_on_bad_override_;
+  bool use_field_guards_;
 #endif  // !defined(PRODUCT)
 
   // Timestamps of last operation via service.
   int64_t last_allocationprofile_accumulator_reset_timestamp_;
   int64_t last_allocationprofile_gc_timestamp_;
 
   // Ring buffer of objects assigned an id.
   ObjectIdRing* object_id_ring_;
 
   VMTagCounters vm_tag_counters_;
@@ skipping 229 matching lines @@
   intptr_t* spawn_count_;
 
   Dart_IsolateFlags isolate_flags_;
   bool paused_;
   bool errors_are_fatal_;
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_ISOLATE_H_