Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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; |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 16 | map_ = new base::HashMap(base::HashMap::PointersMatch); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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); |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 20 | if (!root->IsHeapObject()) continue; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 21 | // Omit root entries that can be written after initialization. They must |
| 22 | // not be referenced through the root list in the snapshot. |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 23 | if (isolate->heap()->RootCanBeTreatedAsConstant(root_index)) { |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 24 | HeapObject* heap_object = HeapObject::cast(root); |
Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 25 | base::HashMap::Entry* entry = LookupEntry(map_, heap_object, false); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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 | } |
Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 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)); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 37 | } |
| 38 | } |
| 39 | isolate->set_root_index_map(map_); |
| 40 | } |
| 41 | |
| 42 | } // namespace internal |
| 43 | } // namespace v8 |