Heap profiler: for objects of class "Object", try to lookup name

src/profile-generator.cc

Index: src/profile-generator.cc
diff --git a/src/profile-generator.cc b/src/profile-generator.cc
index 07426f293992dab657bcdd02101b1fe265142d73..db9f8928de7f6c508f7cdb690f0b8df04d62effa 100644
--- a/src/profile-generator.cc
+++ b/src/profile-generator.cc
@@ -1663,7 +1663,7 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
   } else if (object->IsJSGlobalObject()) {
     const char* tag = objects_tags_.GetTag(object);
     const char* name = collection_->names()->GetName(
-        GetConstructorNameForHeapProfile(JSObject::cast(object)));
+        GetConstructorName(JSObject::cast(object)));
     if (tag != NULL) {
       name = collection_->names()->GetFormatted("%s / %s", name, tag);
     }
@@ -1691,8 +1691,7 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
     return AddEntry(object,
                     HeapEntry::kObject,
                     collection_->names()->GetName(
-                        GetConstructorNameForHeapProfile(
-                            JSObject::cast(object))),
+                        GetConstructorName(JSObject::cast(object))),
                     children_count,
                     retainers_count);
   } else if (object->IsString()) {
@@ -2101,6 +2100,31 @@ void V8HeapExplorer::ExtractInternalReferences(JSObject* js_obj,
 }
 
 
+String* V8HeapExplorer::GetConstructorName(JSObject* object) {
+  if (object->IsJSFunction()) return HEAP->closure_symbol();
+  String* constructor_name = object->constructor_name();
+  if (constructor_name == HEAP->Object_symbol()) {
+    // Look up an immediate "constructor" property, if it is a function,
+    // return its name. This is for instances of binding objects, which
+    // have prototype constructor type "Object".
+    Object* constructor_prop = NULL;
+    LookupResult result;
+    object->LocalLookupRealNamedProperty(HEAP->constructor_symbol(), &result);
+    if (result.IsProperty()) {
+      constructor_prop = result.GetLazyValue();
+    }
+    if (constructor_prop->IsJSFunction()) {
+      Object* maybe_name = JSFunction::cast(constructor_prop)->shared()->name();
+      if (maybe_name->IsString()) {
+        String* name = String::cast(maybe_name);
+        if (name->length() > 0) return name;
+      }
+    }
+  }
+  return object->constructor_name();
+}
+
+
 HeapEntry* V8HeapExplorer::GetEntry(Object* obj) {
   if (!obj->IsHeapObject()) return NULL;
   return filler_->FindOrAddEntry(obj, this);
@@ -3250,10 +3274,4 @@ void HeapSnapshotJSONSerializer::SortHashMap(
   sorted_entries->Sort(SortUsingEntryValue);
 }
 
-
-String* GetConstructorNameForHeapProfile(JSObject* object) {
-  if (object->IsJSFunction()) return HEAP->closure_symbol();
-  return object->constructor_name();
-}
-
 } }  // namespace v8::internal