blob: 46d70459c0cfa173d1d0934d16be895b6f11c29d [file] [log] [blame]
// 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/code-serializer.h"
#include "src/codegen/macro-assembler.h"
#include "src/debug/debug.h"
#include "src/heap/heap-inl.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/objects/objects-inl.h"
#include "src/objects/slots.h"
#include "src/objects/visitors.h"
#include "src/snapshot/object-deserializer.h"
#include "src/snapshot/snapshot.h"
#include "src/utils/version.h"
namespace v8 {
namespace internal {
ScriptData::ScriptData(const byte* data, int length)
: owns_data_(false), rejected_(false), data_(data), length_(length) {
if (!IsAligned(reinterpret_cast<intptr_t>(data), kPointerAlignment)) {
byte* copy = NewArray<byte>(length);
DCHECK(IsAligned(reinterpret_cast<intptr_t>(copy), kPointerAlignment));
CopyBytes(copy, data, length);
data_ = copy;
AcquireDataOwnership();
}
}
CodeSerializer::CodeSerializer(Isolate* isolate, uint32_t source_hash)
: Serializer(isolate), source_hash_(source_hash) {
allocator()->UseCustomChunkSize(FLAG_serialization_chunk_size);
}
// static
ScriptCompiler::CachedData* CodeSerializer::Serialize(
Handle<SharedFunctionInfo> info) {
Isolate* isolate = info->GetIsolate();
TRACE_EVENT_CALL_STATS_SCOPED(isolate, "v8", "V8.Execute");
HistogramTimerScope histogram_timer(isolate->counters()->compile_serialize());
RuntimeCallTimerScope runtimeTimer(isolate,
RuntimeCallCounterId::kCompileSerialize);
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.CompileSerialize");
base::ElapsedTimer timer;
if (FLAG_profile_deserialization) timer.Start();
Handle<Script> script(Script::cast(info->script()), isolate);
if (FLAG_trace_serializer) {
PrintF("[Serializing from");
script->name().ShortPrint();
PrintF("]\n");
}
// TODO(7110): Enable serialization of Asm modules once the AsmWasmData is
// context independent.
if (script->ContainsAsmModule()) return nullptr;
// Serialize code object.
Handle<String> source(String::cast(script->source()), isolate);
CodeSerializer cs(isolate, SerializedCodeData::SourceHash(
source, script->origin_options()));
DisallowHeapAllocation no_gc;
cs.reference_map()->AddAttachedReference(
reinterpret_cast<void*>(source->ptr()));
ScriptData* script_data = cs.SerializeSharedFunctionInfo(info);
if (FLAG_profile_deserialization) {
double ms = timer.Elapsed().InMillisecondsF();
int length = script_data->length();
PrintF("[Serializing to %d bytes took %0.3f ms]\n", length, ms);
}
ScriptCompiler::CachedData* result =
new ScriptCompiler::CachedData(script_data->data(), script_data->length(),
ScriptCompiler::CachedData::BufferOwned);
script_data->ReleaseDataOwnership();
delete script_data;
return result;
}
ScriptData* CodeSerializer::SerializeSharedFunctionInfo(
Handle<SharedFunctionInfo> info) {
DisallowHeapAllocation no_gc;
VisitRootPointer(Root::kHandleScope, nullptr,
FullObjectSlot(info.location()));
SerializeDeferredObjects();
Pad();
SerializedCodeData data(sink_.data(), this);
return data.GetScriptData();
}
bool CodeSerializer::SerializeReadOnlyObject(HeapObject obj) {
PagedSpace* read_only_space = isolate()->heap()->read_only_space();
if (!read_only_space->Contains(obj)) return false;
// For objects in RO_SPACE, never serialize the object, but instead create a
// back reference that encodes the page number as the chunk_index and the
// offset within the page as the chunk_offset.
Address address = obj.address();
Page* page = Page::FromAddress(address);
uint32_t chunk_index = 0;
for (Page* p : *read_only_space) {
if (p == page) break;
++chunk_index;
}
uint32_t chunk_offset = static_cast<uint32_t>(page->Offset(address));
SerializerReference back_reference =
SerializerReference::BackReference(RO_SPACE, chunk_index, chunk_offset);
reference_map()->Add(reinterpret_cast<void*>(obj.ptr()), back_reference);
CHECK(SerializeBackReference(obj));
return true;
}
void CodeSerializer::SerializeObject(HeapObject obj) {
if (SerializeHotObject(obj)) return;
if (SerializeRoot(obj)) return;
if (SerializeBackReference(obj)) return;
if (SerializeReadOnlyObject(obj)) return;
CHECK(!obj.IsCode());
ReadOnlyRoots roots(isolate());
if (ElideObject(obj)) {
return SerializeObject(roots.undefined_value());
}
if (obj.IsScript()) {
Script script_obj = Script::cast(obj);
DCHECK_NE(script_obj.compilation_type(), Script::COMPILATION_TYPE_EVAL);
// We want to differentiate between undefined and uninitialized_symbol for
// context_data for now. It is hack to allow debugging for scripts that are
// included as a part of custom snapshot. (see debug::Script::IsEmbedded())
Object context_data = script_obj.context_data();
if (context_data != roots.undefined_value() &&
context_data != roots.uninitialized_symbol()) {
script_obj.set_context_data(roots.undefined_value());
}
// We don't want to serialize host options to avoid serializing unnecessary
// object graph.
FixedArray host_options = script_obj.host_defined_options();
script_obj.set_host_defined_options(roots.empty_fixed_array());
SerializeGeneric(obj);
script_obj.set_host_defined_options(host_options);
script_obj.set_context_data(context_data);
return;
}
if (obj.IsSharedFunctionInfo()) {
SharedFunctionInfo sfi = SharedFunctionInfo::cast(obj);
// TODO(7110): Enable serializing of Asm modules once the AsmWasmData
// is context independent.
DCHECK(!sfi.IsApiFunction() && !sfi.HasAsmWasmData());
DebugInfo debug_info;
BytecodeArray debug_bytecode_array;
if (sfi.HasDebugInfo()) {
// Clear debug info.
debug_info = sfi.GetDebugInfo();
if (debug_info.HasInstrumentedBytecodeArray()) {
debug_bytecode_array = debug_info.DebugBytecodeArray();
sfi.SetDebugBytecodeArray(debug_info.OriginalBytecodeArray());
}
sfi.set_script_or_debug_info(debug_info.script());
}
DCHECK(!sfi.HasDebugInfo());
SerializeGeneric(obj);
// Restore debug info
if (!debug_info.is_null()) {
sfi.set_script_or_debug_info(debug_info);
if (!debug_bytecode_array.is_null()) {
sfi.SetDebugBytecodeArray(debug_bytecode_array);
}
}
return;
}
// NOTE(mmarchini): If we try to serialize an InterpreterData our process
// will crash since it stores a code object. Instead, we serialize the
// bytecode array stored within the InterpreterData, which is the important
// information. On deserialization we'll create our code objects again, if
// --interpreted-frames-native-stack is on. See v8:9122 for more context
#ifndef V8_TARGET_ARCH_ARM
if (V8_UNLIKELY(FLAG_interpreted_frames_native_stack) &&
obj.IsInterpreterData()) {
obj = InterpreterData::cast(obj).bytecode_array();
}
#endif // V8_TARGET_ARCH_ARM
if (obj.IsBytecodeArray()) {
// Clear the stack frame cache if present
BytecodeArray::cast(obj).ClearFrameCacheFromSourcePositionTable();
}
// Past this point we should not see any (context-specific) maps anymore.
CHECK(!obj.IsMap());
// There should be no references to the global object embedded.
CHECK(!obj.IsJSGlobalProxy() && !obj.IsJSGlobalObject());
// Embedded FixedArrays that need rehashing must support rehashing.
CHECK_IMPLIES(obj.NeedsRehashing(), obj.CanBeRehashed());
// We expect no instantiated function objects or contexts.
CHECK(!obj.IsJSFunction() && !obj.IsContext());
SerializeGeneric(obj);
}
void CodeSerializer::SerializeGeneric(HeapObject heap_object) {
// Object has not yet been serialized. Serialize it here.
ObjectSerializer serializer(this, heap_object, &sink_);
serializer.Serialize();
}
#ifndef V8_TARGET_ARCH_ARM
// NOTE(mmarchini): when FLAG_interpreted_frames_native_stack is on, we want to
// create duplicates of InterpreterEntryTrampoline for the deserialized
// functions, otherwise we'll call the builtin IET for those functions (which
// is not what a user of this flag wants).
void CreateInterpreterDataForDeserializedCode(Isolate* isolate,
Handle<SharedFunctionInfo> sfi,
bool log_code_creation) {
Script script = Script::cast(sfi->script());
Handle<Script> script_handle(script, isolate);
String name = ReadOnlyRoots(isolate).empty_string();
if (script.name().IsString()) name = String::cast(script.name());
Handle<String> name_handle(name, isolate);
SharedFunctionInfo::ScriptIterator iter(isolate, script);
for (SharedFunctionInfo info = iter.Next(); !info.is_null();
info = iter.Next()) {
if (!info.HasBytecodeArray()) continue;
Handle<Code> code = isolate->factory()->CopyCode(Handle<Code>::cast(
isolate->factory()->interpreter_entry_trampoline_for_profiling()));
Handle<InterpreterData> interpreter_data =
Handle<InterpreterData>::cast(isolate->factory()->NewStruct(
INTERPRETER_DATA_TYPE, AllocationType::kOld));
interpreter_data->set_bytecode_array(info.GetBytecodeArray());
interpreter_data->set_interpreter_trampoline(*code);
info.set_interpreter_data(*interpreter_data);
if (!log_code_creation) continue;
Handle<AbstractCode> abstract_code = Handle<AbstractCode>::cast(code);
int line_num = script.GetLineNumber(info.StartPosition()) + 1;
int column_num = script.GetColumnNumber(info.StartPosition()) + 1;
PROFILE(isolate,
CodeCreateEvent(CodeEventListener::INTERPRETED_FUNCTION_TAG,
*abstract_code, info, *name_handle, line_num,
column_num));
}
}
#endif // V8_TARGET_ARCH_ARM
MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize(
Isolate* isolate, ScriptData* cached_data, Handle<String> source,
ScriptOriginOptions origin_options) {
base::ElapsedTimer timer;
if (FLAG_profile_deserialization || FLAG_log_function_events) timer.Start();
HandleScope scope(isolate);
SerializedCodeData::SanityCheckResult sanity_check_result =
SerializedCodeData::CHECK_SUCCESS;
const SerializedCodeData scd = SerializedCodeData::FromCachedData(
isolate, cached_data,
SerializedCodeData::SourceHash(source, origin_options),
&sanity_check_result);
if (sanity_check_result != SerializedCodeData::CHECK_SUCCESS) {
if (FLAG_profile_deserialization) PrintF("[Cached code failed check]\n");
DCHECK(cached_data->rejected());
isolate->counters()->code_cache_reject_reason()->AddSample(
sanity_check_result);
return MaybeHandle<SharedFunctionInfo>();
}
// Deserialize.
MaybeHandle<SharedFunctionInfo> maybe_result =
ObjectDeserializer::DeserializeSharedFunctionInfo(isolate, &scd, source);
Handle<SharedFunctionInfo> result;
if (!maybe_result.ToHandle(&result)) {
// Deserializing may fail if the reservations cannot be fulfilled.
if (FLAG_profile_deserialization) PrintF("[Deserializing failed]\n");
return MaybeHandle<SharedFunctionInfo>();
}
if (FLAG_profile_deserialization) {
double ms = timer.Elapsed().InMillisecondsF();
int length = cached_data->length();
PrintF("[Deserializing from %d bytes took %0.3f ms]\n", length, ms);
}
bool log_code_creation =
isolate->logger()->is_listening_to_code_events() ||
isolate->is_profiling() ||
isolate->code_event_dispatcher()->IsListeningToCodeEvents();
#ifndef V8_TARGET_ARCH_ARM
if (V8_UNLIKELY(FLAG_interpreted_frames_native_stack))
CreateInterpreterDataForDeserializedCode(isolate, result,
log_code_creation);
#endif // V8_TARGET_ARCH_ARM
if (log_code_creation || FLAG_log_function_events) {
String name = ReadOnlyRoots(isolate).empty_string();
Script script = Script::cast(result->script());
Handle<Script> script_handle(script, isolate);
if (script.name().IsString()) name = String::cast(script.name());
Handle<String> name_handle(name, isolate);
if (FLAG_log_function_events) {
LOG(isolate, FunctionEvent("deserialize", script.id(),
timer.Elapsed().InMillisecondsF(),
result->StartPosition(), result->EndPosition(),
*name_handle));
}
if (log_code_creation) {
Script::InitLineEnds(Handle<Script>(script, isolate));
DisallowHeapAllocation no_gc;
SharedFunctionInfo::ScriptIterator iter(isolate, script);
for (i::SharedFunctionInfo info = iter.Next(); !info.is_null();
info = iter.Next()) {
if (info.is_compiled()) {
int line_num = script.GetLineNumber(info.StartPosition()) + 1;
int column_num = script.GetColumnNumber(info.StartPosition()) + 1;
PROFILE(isolate, CodeCreateEvent(CodeEventListener::SCRIPT_TAG,
info.abstract_code(), info,
*name_handle, line_num, column_num));
}
}
}
}
if (isolate->NeedsSourcePositionsForProfiling()) {
Handle<Script> script(Script::cast(result->script()), isolate);
Script::InitLineEnds(script);
}
return scope.CloseAndEscape(result);
}
SerializedCodeData::SerializedCodeData(const std::vector<byte>* payload,
const CodeSerializer* cs) {
DisallowHeapAllocation no_gc;
std::vector<Reservation> reservations = cs->EncodeReservations();
// Calculate sizes.
uint32_t reservation_size =
static_cast<uint32_t>(reservations.size()) * kUInt32Size;
uint32_t num_stub_keys = 0; // TODO(jgruber): Remove.
uint32_t stub_keys_size = num_stub_keys * kUInt32Size;
uint32_t payload_offset = kHeaderSize + reservation_size + stub_keys_size;
uint32_t padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
uint32_t size =
padded_payload_offset + static_cast<uint32_t>(payload->size());
DCHECK(IsAligned(size, kPointerAlignment));
// Allocate backing store and create result data.
AllocateData(size);
// Zero out pre-payload data. Part of that is only used for padding.
memset(data_, 0, padded_payload_offset);
// Set header values.
SetMagicNumber();
SetHeaderValue(kVersionHashOffset, Version::Hash());
SetHeaderValue(kSourceHashOffset, cs->source_hash());
SetHeaderValue(kFlagHashOffset, FlagList::Hash());
SetHeaderValue(kNumReservationsOffset,
static_cast<uint32_t>(reservations.size()));
SetHeaderValue(kPayloadLengthOffset, static_cast<uint32_t>(payload->size()));
// Zero out any padding in the header.
memset(data_ + kUnalignedHeaderSize, 0, kHeaderSize - kUnalignedHeaderSize);
// Copy reservation chunk sizes.
CopyBytes(data_ + kHeaderSize,
reinterpret_cast<const byte*>(reservations.data()),
reservation_size);
// Copy serialized data.
CopyBytes(data_ + padded_payload_offset, payload->data(),
static_cast<size_t>(payload->size()));
Checksum checksum(ChecksummedContent());
SetHeaderValue(kChecksumPartAOffset, checksum.a());
SetHeaderValue(kChecksumPartBOffset, checksum.b());
}
SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
Isolate* isolate, uint32_t expected_source_hash) const {
if (this->size_ < kHeaderSize) return INVALID_HEADER;
uint32_t magic_number = GetMagicNumber();
if (magic_number != kMagicNumber) return MAGIC_NUMBER_MISMATCH;
uint32_t version_hash = GetHeaderValue(kVersionHashOffset);
uint32_t source_hash = GetHeaderValue(kSourceHashOffset);
uint32_t flags_hash = GetHeaderValue(kFlagHashOffset);
uint32_t payload_length = GetHeaderValue(kPayloadLengthOffset);
uint32_t c1 = GetHeaderValue(kChecksumPartAOffset);
uint32_t c2 = GetHeaderValue(kChecksumPartBOffset);
if (version_hash != Version::Hash()) return VERSION_MISMATCH;
if (source_hash != expected_source_hash) return SOURCE_MISMATCH;
if (flags_hash != FlagList::Hash()) return FLAGS_MISMATCH;
uint32_t max_payload_length =
this->size_ -
POINTER_SIZE_ALIGN(kHeaderSize +
GetHeaderValue(kNumReservationsOffset) * kInt32Size);
if (payload_length > max_payload_length) return LENGTH_MISMATCH;
if (!Checksum(ChecksummedContent()).Check(c1, c2)) return CHECKSUM_MISMATCH;
return CHECK_SUCCESS;
}
uint32_t SerializedCodeData::SourceHash(Handle<String> source,
ScriptOriginOptions origin_options) {
const uint32_t source_length = source->length();
static constexpr uint32_t kModuleFlagMask = (1 << 31);
const uint32_t is_module = origin_options.IsModule() ? kModuleFlagMask : 0;
DCHECK_EQ(0, source_length & kModuleFlagMask);
return source_length | is_module;
}
// Return ScriptData object and relinquish ownership over it to the caller.
ScriptData* SerializedCodeData::GetScriptData() {
DCHECK(owns_data_);
ScriptData* result = new ScriptData(data_, size_);
result->AcquireDataOwnership();
owns_data_ = false;
data_ = nullptr;
return result;
}
std::vector<SerializedData::Reservation> SerializedCodeData::Reservations()
const {
uint32_t size = GetHeaderValue(kNumReservationsOffset);
std::vector<Reservation> reservations(size);
memcpy(reservations.data(), data_ + kHeaderSize,
size * sizeof(SerializedData::Reservation));
return reservations;
}
Vector<const byte> SerializedCodeData::Payload() const {
int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size;
int payload_offset = kHeaderSize + reservations_size;
int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset);
const byte* payload = data_ + padded_payload_offset;
DCHECK(IsAligned(reinterpret_cast<intptr_t>(payload), kPointerAlignment));
int length = GetHeaderValue(kPayloadLengthOffset);
DCHECK_EQ(data_ + size_, payload + length);
return Vector<const byte>(payload, length);
}
SerializedCodeData::SerializedCodeData(ScriptData* data)
: SerializedData(const_cast<byte*>(data->data()), data->length()) {}
SerializedCodeData SerializedCodeData::FromCachedData(
Isolate* isolate, ScriptData* cached_data, uint32_t expected_source_hash,
SanityCheckResult* rejection_result) {
DisallowHeapAllocation no_gc;
SerializedCodeData scd(cached_data);
*rejection_result = scd.SanityCheck(isolate, expected_source_hash);
if (*rejection_result != CHECK_SUCCESS) {
cached_data->Reject();
return SerializedCodeData(nullptr, 0);
}
return scd;
}
} // namespace internal
} // namespace v8