Add FLAG_trace_maps

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 3618 matching lines @@
   i::Handle<i::AccessorInfo> info = MakeAccessorInfo(
       name, getter, setter, data, settings, attributes, signature);
   if (info.is_null()) return false;
   bool fast = Utils::OpenHandle(obj)->HasFastProperties();
   i::Handle<i::Object> result;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
       isolate, result,
       i::JSObject::SetAccessor(Utils::OpenHandle(obj), info),
       false);
   if (result->IsUndefined()) return false;
-  if (fast) i::JSObject::MigrateSlowToFast(Utils::OpenHandle(obj), 0);
+  if (fast) {
+    i::JSObject::MigrateSlowToFast(Utils::OpenHandle(obj), 0, "APISetAccessor");
+  }
   return true;
 }
 
 
 bool Object::SetAccessor(Handle<String> name,
                          AccessorGetterCallback getter,
                          AccessorSetterCallback setter,
                          v8::Handle<Value> data,
                          AccessControl settings,
                          PropertyAttribute attributes) {
@@ skipping 165 matching lines @@
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ON_BAILOUT(isolate, "v8::Object::TurnOnAccessCheck()", return);
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   i::Handle<i::JSObject> obj = Utils::OpenHandle(this);
 
   // When turning on access checks for a global object deoptimize all functions
   // as optimized code does not always handle access checks.
   i::Deoptimizer::DeoptimizeGlobalObject(*obj);
 
-  i::Handle<i::Map> new_map = i::Map::Copy(i::Handle<i::Map>(obj->map()));
+  i::Handle<i::Map> new_map =
+      i::Map::Copy(i::Handle<i::Map>(obj->map()), "APITurnOnAccessCheck");
   new_map->set_is_access_check_needed(true);
   i::JSObject::MigrateToMap(obj, new_map);
 }
 
 
 Local<v8::Object> v8::Object::Clone() {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ON_BAILOUT(isolate, "v8::Object::Clone()", return Local<Object>());
   ENTER_V8(isolate);
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
@@ skipping 3948 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal