1 // Copyright 2016 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/snapshot/serializer-common.h"
6 
7 #include "src/external-reference-table.h"
8 #include "src/ic/stub-cache.h"
9 #include "src/list-inl.h"
10 
11 namespace v8 {
12 namespace internal {
13 
ExternalReferenceEncoder(Isolate * isolate)14 ExternalReferenceEncoder::ExternalReferenceEncoder(Isolate* isolate) {
15   map_ = isolate->external_reference_map();
16 #ifdef DEBUG
17   table_ = ExternalReferenceTable::instance(isolate);
18 #endif  // DEBUG
19   if (map_ != nullptr) return;
20   map_ = new AddressToIndexHashMap();
21   ExternalReferenceTable* table = ExternalReferenceTable::instance(isolate);
22   for (uint32_t i = 0; i < table->size(); ++i) {
23     Address addr = table->address(i);
24     DCHECK(map_->Get(addr).IsNothing() ||
25            strncmp(table->name(i), "Redirect to ", 12) == 0);
26     map_->Set(addr, i);
27     DCHECK(map_->Get(addr).IsJust());
28   }
29   isolate->set_external_reference_map(map_);
30 }
31 
Encode(Address address) const32 uint32_t ExternalReferenceEncoder::Encode(Address address) const {
33   Maybe<uint32_t> maybe_index = map_->Get(address);
34   if (maybe_index.IsNothing()) {
35     void* addr = address;
36     v8::base::OS::PrintError("Unknown external reference %p.\n", addr);
37     v8::base::OS::PrintError("%s", ExternalReferenceTable::ResolveSymbol(addr));
38     v8::base::OS::Abort();
39   }
40 #ifdef DEBUG
41   table_->increment_count(maybe_index.FromJust());
42 #endif  // DEBUG
43   return maybe_index.FromJust();
44 }
45 
NameOfAddress(Isolate * isolate,Address address) const46 const char* ExternalReferenceEncoder::NameOfAddress(Isolate* isolate,
47                                                     Address address) const {
48   Maybe<uint32_t> maybe_index = map_->Get(address);
49   if (maybe_index.IsNothing()) return "<unknown>";
50   return ExternalReferenceTable::instance(isolate)->name(
51       maybe_index.FromJust());
52 }
53 
AllocateData(int size)54 void SerializedData::AllocateData(int size) {
55   DCHECK(!owns_data_);
56   data_ = NewArray<byte>(size);
57   size_ = size;
58   owns_data_ = true;
59   DCHECK(IsAligned(reinterpret_cast<intptr_t>(data_), kPointerAlignment));
60 }
61 
62 // The partial snapshot cache is terminated by undefined. We visit the
63 // partial snapshot...
64 //  - during deserialization to populate it.
65 //  - during normal GC to keep its content alive.
66 //  - not during serialization. The partial serializer adds to it explicitly.
67 DISABLE_CFI_PERF
Iterate(Isolate * isolate,ObjectVisitor * visitor)68 void SerializerDeserializer::Iterate(Isolate* isolate, ObjectVisitor* visitor) {
69   List<Object*>* cache = isolate->partial_snapshot_cache();
70   for (int i = 0;; ++i) {
71     // Extend the array ready to get a value when deserializing.
72     if (cache->length() <= i) cache->Add(Smi::kZero);
73     // During deserialization, the visitor populates the partial snapshot cache
74     // and eventually terminates the cache with undefined.
75     visitor->VisitPointer(&cache->at(i));
76     if (cache->at(i)->IsUndefined(isolate)) break;
77   }
78 }
79 
CanBeDeferred(HeapObject * o)80 bool SerializerDeserializer::CanBeDeferred(HeapObject* o) {
81   return !o->IsString() && !o->IsScript();
82 }
83 
84 }  // namespace internal
85 }  // namespace v8
86