Prepare to enable in-object properties in subclasses on a case by case basis.

src/heap/objects-visiting.cc

 // Copyright 2011 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/heap/objects-visiting.h"
 
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/objects-visiting-inl.h"
 
 namespace v8 {
@@ skipping 61 matching lines @@
 
     case CELL_TYPE:
       return kVisitCell;
 
     case PROPERTY_CELL_TYPE:
       return kVisitPropertyCell;
 
     case WEAK_CELL_TYPE:
       return kVisitWeakCell;
 
-    case JS_SET_TYPE:
-      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
-                                 JSSet::kSize, has_unboxed_fields);
-
-    case JS_MAP_TYPE:
-      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
-                                 JSMap::kSize, has_unboxed_fields);
-
     case JS_WEAK_MAP_TYPE:
     case JS_WEAK_SET_TYPE:
       return kVisitJSWeakCollection;
 
     case JS_REGEXP_TYPE:
       return kVisitJSRegExp;
 
     case SHARED_FUNCTION_INFO_TYPE:
       return kVisitSharedFunctionInfo;
 
-    case JS_PROXY_TYPE:
-      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
-                                 JSProxy::kSize, has_unboxed_fields);
-
-    case JS_FUNCTION_PROXY_TYPE:
-      return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
-                                 JSFunctionProxy::kSize, has_unboxed_fields);
-
-    case FOREIGN_TYPE:
-      return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric,
-                                 Foreign::kSize, has_unboxed_fields);
-
     case SYMBOL_TYPE:
       return kVisitSymbol;
 
-    case FILLER_TYPE:
-      return kVisitDataObjectGeneric;
-
     case JS_ARRAY_BUFFER_TYPE:
       return kVisitJSArrayBuffer;
 
     case JS_TYPED_ARRAY_TYPE:
       return kVisitJSTypedArray;
 
     case JS_DATA_VIEW_TYPE:
       return kVisitJSDataView;
 
     case JS_OBJECT_TYPE:
     case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
     case JS_GENERATOR_OBJECT_TYPE:
     case JS_MODULE_TYPE:
     case JS_VALUE_TYPE:
     case JS_DATE_TYPE:
     case JS_ARRAY_TYPE:
     case JS_GLOBAL_PROXY_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case JS_MESSAGE_OBJECT_TYPE:
     case JS_SET_ITERATOR_TYPE:
     case JS_MAP_ITERATOR_TYPE:
     case JS_ITERATOR_RESULT_TYPE:
       return GetVisitorIdForSize(kVisitJSObject, kVisitJSObjectGeneric,
                                  instance_size, has_unboxed_fields);
 
     case JS_FUNCTION_TYPE:
       return kVisitJSFunction;
 
+    case FILLER_TYPE:
+      if (instance_size == kPointerSize) return kVisitDataObjectGeneric;
+    // Fall through.
+    case FOREIGN_TYPE:
     case HEAP_NUMBER_TYPE:
     case MUTABLE_HEAP_NUMBER_TYPE:
     case SIMD128_VALUE_TYPE:
       return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric,
                                  instance_size, has_unboxed_fields);
 
     case FIXED_UINT8_ARRAY_TYPE:
     case FIXED_INT8_ARRAY_TYPE:
     case FIXED_UINT16_ARRAY_TYPE:
     case FIXED_INT16_ARRAY_TYPE:
     case FIXED_UINT32_ARRAY_TYPE:
     case FIXED_INT32_ARRAY_TYPE:
     case FIXED_FLOAT32_ARRAY_TYPE:
     case FIXED_UINT8_CLAMPED_ARRAY_TYPE:
       return kVisitFixedTypedArray;
 
     case FIXED_FLOAT64_ARRAY_TYPE:
       return kVisitFixedFloat64Array;
 
 #define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE:
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
       if (instance_type == ALLOCATION_SITE_TYPE) {
         return kVisitAllocationSite;
       }
-
+    // Fall through.

[Michael Starzinger, 2015/11/17 09:35:40]

IMHO this fall-through case just makes the code unnecessary hard to read and
refactor. I think it is fine to have a separate call to GetVisitorIdForSize()
for this block of instance types and move the block back up to the other
JS_FOO_TYPE objects.

[Igor Sheludko, 2015/11/17 09:54:03]

Done.

+    case JS_SET_TYPE:
+    case JS_MAP_TYPE:
+    case JS_PROXY_TYPE:
+    case JS_FUNCTION_PROXY_TYPE:
       return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric,
                                  instance_size, has_unboxed_fields);
 
     default:
       UNREACHABLE();
       return kVisitorIdCount;
   }
 }
 
 
@@ skipping 175 matching lines @@
 };
 
 
 template Object* VisitWeakList<Context>(Heap* heap, Object* list,
                                         WeakObjectRetainer* retainer);
 
 template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list,
                                                WeakObjectRetainer* retainer);
 }  // namespace internal
 }  // namespace v8