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// Copyright 2016 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/snapshot/serializer-common.h"
#include "src/codegen/external-reference-table.h"
#include "src/objects/foreign-inl.h"
#include "src/objects/objects-inl.h"
#include "src/objects/slots.h"
#include "third_party/zlib/zlib.h"
namespace v8 {
namespace internal {
ExternalReferenceEncoder::ExternalReferenceEncoder(Isolate* isolate) {
#ifdef DEBUG
api_references_ = isolate->api_external_references();
if (api_references_ != nullptr) {
for (uint32_t i = 0; api_references_[i] != 0; ++i) count_.push_back(0);
}
#endif // DEBUG
map_ = isolate->external_reference_map();
if (map_ != nullptr) return;
map_ = new AddressToIndexHashMap();
isolate->set_external_reference_map(map_);
// Add V8's external references.
ExternalReferenceTable* table = isolate->external_reference_table();
for (uint32_t i = 0; i < ExternalReferenceTable::kSize; ++i) {
Address addr = table->address(i);
// Ignore duplicate references.
// This can happen due to ICF. See http://crbug.com/726896.
if (map_->Get(addr).IsNothing()) map_->Set(addr, Value::Encode(i, false));
DCHECK(map_->Get(addr).IsJust());
}
// Add external references provided by the embedder.
const intptr_t* api_references = isolate->api_external_references();
if (api_references == nullptr) return;
for (uint32_t i = 0; api_references[i] != 0; ++i) {
Address addr = static_cast<Address>(api_references[i]);
// Ignore duplicate references.
// This can happen due to ICF. See http://crbug.com/726896.
if (map_->Get(addr).IsNothing()) map_->Set(addr, Value::Encode(i, true));
DCHECK(map_->Get(addr).IsJust());
}
}
ExternalReferenceEncoder::~ExternalReferenceEncoder() {
#ifdef DEBUG
if (!i::FLAG_external_reference_stats) return;
if (api_references_ == nullptr) return;
for (uint32_t i = 0; api_references_[i] != 0; ++i) {
Address addr = static_cast<Address>(api_references_[i]);
DCHECK(map_->Get(addr).IsJust());
v8::base::OS::Print(
"index=%5d count=%5d %-60s\n", i, count_[i],
ExternalReferenceTable::ResolveSymbol(reinterpret_cast<void*>(addr)));
}
#endif // DEBUG
}
Maybe<ExternalReferenceEncoder::Value> ExternalReferenceEncoder::TryEncode(
Address address) {
Maybe<uint32_t> maybe_index = map_->Get(address);
if (maybe_index.IsNothing()) return Nothing<Value>();
Value result(maybe_index.FromJust());
#ifdef DEBUG
if (result.is_from_api()) count_[result.index()]++;
#endif // DEBUG
return Just<Value>(result);
}
ExternalReferenceEncoder::Value ExternalReferenceEncoder::Encode(
Address address) {
Maybe<uint32_t> maybe_index = map_->Get(address);
if (maybe_index.IsNothing()) {
void* addr = reinterpret_cast<void*>(address);
v8::base::OS::PrintError("Unknown external reference %p.\n", addr);
v8::base::OS::PrintError("%s\n",
ExternalReferenceTable::ResolveSymbol(addr));
v8::base::OS::Abort();
}
Value result(maybe_index.FromJust());
#ifdef DEBUG
if (result.is_from_api()) count_[result.index()]++;
#endif // DEBUG
return result;
}
const char* ExternalReferenceEncoder::NameOfAddress(Isolate* isolate,
Address address) const {
Maybe<uint32_t> maybe_index = map_->Get(address);
if (maybe_index.IsNothing()) return "<unknown>";
Value value(maybe_index.FromJust());
if (value.is_from_api()) return "<from api>";
return isolate->external_reference_table()->name(value.index());
}
void SerializedData::AllocateData(uint32_t size) {
DCHECK(!owns_data_);
data_ = NewArray<byte>(size);
size_ = size;
owns_data_ = true;
}
// static
constexpr uint32_t SerializedData::kMagicNumber;
// The partial snapshot cache is terminated by undefined. We visit the
// partial snapshot...
// - during deserialization to populate it.
// - during normal GC to keep its content alive.
// - not during serialization. The partial serializer adds to it explicitly.
DISABLE_CFI_PERF
void SerializerDeserializer::Iterate(Isolate* isolate, RootVisitor* visitor) {
std::vector<Object>* cache = isolate->partial_snapshot_cache();
for (size_t i = 0;; ++i) {
// Extend the array ready to get a value when deserializing.
if (cache->size() <= i) cache->push_back(Smi::zero());
// During deserialization, the visitor populates the partial snapshot cache
// and eventually terminates the cache with undefined.
visitor->VisitRootPointer(Root::kPartialSnapshotCache, nullptr,
FullObjectSlot(&cache->at(i)));
if (cache->at(i).IsUndefined(isolate)) break;
}
}
bool SerializerDeserializer::CanBeDeferred(HeapObject o) {
// ArrayBuffer instances are serialized by first re-assigning a index
// to the backing store field, then serializing the object, and then
// storing the actual backing store address again (and the same for the
// ArrayBufferExtension). If serialization of the object itself is deferred,
// the real backing store address is written into the snapshot, which cannot
// be processed when deserializing.
return !o.IsString() && !o.IsScript() && !o.IsJSTypedArray() &&
!o.IsJSArrayBuffer();
}
void SerializerDeserializer::RestoreExternalReferenceRedirectors(
const std::vector<AccessorInfo>& accessor_infos) {
// Restore wiped accessor infos.
for (AccessorInfo info : accessor_infos) {
Foreign::cast(info.js_getter())
.set_foreign_address(info.redirected_getter());
}
}
void SerializerDeserializer::RestoreExternalReferenceRedirectors(
const std::vector<CallHandlerInfo>& call_handler_infos) {
for (CallHandlerInfo info : call_handler_infos) {
Foreign::cast(info.js_callback())
.set_foreign_address(info.redirected_callback());
}
}
uint32_t Checksum(Vector<const byte> payload) {
#ifdef MEMORY_SANITIZER
// Computing the checksum includes padding bytes for objects like strings.
// Mark every object as initialized in the code serializer.
MSAN_MEMORY_IS_INITIALIZED(payload.begin(), payload.length());
#endif // MEMORY_SANITIZER
// Priming the adler32 call so it can see what CPU features are available.
adler32(0, NULL, 0);
return static_cast<uint32_t>(adler32(0, payload.begin(), payload.length()));
}
} // namespace internal
} // namespace v8
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