1 // Copyright 2015 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "src/address-map.h" 6 #include "src/heap/heap.h" 7 #include "src/isolate.h" 8 #include "src/objects-inl.h" 9 10 namespace v8 { 11 namespace internal { 12 13 RootIndexMap::RootIndexMap(Isolate* isolate) { 14 map_ = isolate->root_index_map(); 15 if (map_ != NULL) return; 16 map_ = new base::HashMap(base::HashMap::PointersMatch); 17 for (uint32_t i = 0; i < Heap::kStrongRootListLength; i++) { 18 Heap::RootListIndex root_index = static_cast<Heap::RootListIndex>(i); 19 Object* root = isolate->heap()->root(root_index); 20 if (!root->IsHeapObject()) continue; 21 // Omit root entries that can be written after initialization. They must 22 // not be referenced through the root list in the snapshot. 23 if (isolate->heap()->RootCanBeTreatedAsConstant(root_index)) { 24 HeapObject* heap_object = HeapObject::cast(root); 25 base::HashMap::Entry* entry = LookupEntry(map_, heap_object, false); 26 if (entry != NULL) { 27 // Some are initialized to a previous value in the root list. 28 DCHECK_LT(GetValue(entry), i); 29 } else { 30 SetValue(LookupEntry(map_, heap_object, true), i); 31 } 32 } else { 33 // Immortal immovable root objects are constant and allocated on the first 34 // page of old space. Non-constant roots cannot be immortal immovable. The 35 // root index map contains all immortal immmovable root objects. 36 CHECK(!Heap::RootIsImmortalImmovable(root_index)); 37 } 38 } 39 isolate->set_root_index_map(map_); 40 } 41 42 } // namespace internal 43 } // namespace v8 44
