blob: 61292bf562dad03ce63d59c65c8eb14e77520d90 [file] [log] [blame]
// Copyright 2015 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/address-map.h"
#include "src/heap/heap.h"
#include "src/isolate.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
RootIndexMap::RootIndexMap(Isolate* isolate) {
map_ = isolate->root_index_map();
if (map_ != NULL) return;
map_ = new base::HashMap(base::HashMap::PointersMatch);
for (uint32_t i = 0; i < Heap::kStrongRootListLength; i++) {
Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(i);
Object* root = isolate->heap()->root(root_index);
if (!root->IsHeapObject()) continue;
// Omit root entries that can be written after initialization. They must
// not be referenced through the root list in the snapshot.
if (isolate->heap()->RootCanBeTreatedAsConstant(root_index)) {
HeapObject* heap_object = HeapObject::cast(root);
base::HashMap::Entry* entry = LookupEntry(map_, heap_object, false);
if (entry != NULL) {
// Some are initialized to a previous value in the root list.
DCHECK_LT(GetValue(entry), i);
} else {
SetValue(LookupEntry(map_, heap_object, true), i);
} else {
// Immortal immovable root objects are constant and allocated on the first
// page of old space. Non-constant roots cannot be immortal immovable. The
// root index map contains all immortal immmovable root objects.
} // namespace internal
} // namespace v8