| // 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/code-stubs.h" |
| #include "src/log.h" |
| #include "src/macro-assembler.h" |
| #include "src/profiler/cpu-profiler.h" |
| #include "src/snapshot/deserializer.h" |
| #include "src/version.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| ScriptData* CodeSerializer::Serialize(Isolate* isolate, |
| Handle<SharedFunctionInfo> info, |
| Handle<String> source) { |
| base::ElapsedTimer timer; |
| if (FLAG_profile_deserialization) timer.Start(); |
| if (FLAG_trace_serializer) { |
| PrintF("[Serializing from"); |
| Object* script = info->script(); |
| if (script->IsScript()) Script::cast(script)->name()->ShortPrint(); |
| PrintF("]\n"); |
| } |
| |
| // Serialize code object. |
| SnapshotByteSink sink(info->code()->CodeSize() * 2); |
| CodeSerializer cs(isolate, &sink, *source); |
| DisallowHeapAllocation no_gc; |
| Object** location = Handle<Object>::cast(info).location(); |
| cs.VisitPointer(location); |
| cs.SerializeDeferredObjects(); |
| cs.Pad(); |
| |
| SerializedCodeData data(sink.data(), cs); |
| ScriptData* script_data = data.GetScriptData(); |
| |
| 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); |
| } |
| |
| return script_data; |
| } |
| |
| void CodeSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code, |
| WhereToPoint where_to_point, int skip) { |
| int root_index = root_index_map_.Lookup(obj); |
| if (root_index != RootIndexMap::kInvalidRootIndex) { |
| PutRoot(root_index, obj, how_to_code, where_to_point, skip); |
| return; |
| } |
| |
| if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return; |
| |
| FlushSkip(skip); |
| |
| if (obj->IsCode()) { |
| Code* code_object = Code::cast(obj); |
| switch (code_object->kind()) { |
| case Code::OPTIMIZED_FUNCTION: // No optimized code compiled yet. |
| case Code::HANDLER: // No handlers patched in yet. |
| case Code::REGEXP: // No regexp literals initialized yet. |
| case Code::NUMBER_OF_KINDS: // Pseudo enum value. |
| case Code::BYTECODE_HANDLER: // No direct references to handlers. |
| CHECK(false); |
| case Code::BUILTIN: |
| SerializeBuiltin(code_object->builtin_index(), how_to_code, |
| where_to_point); |
| return; |
| case Code::STUB: |
| SerializeCodeStub(code_object->stub_key(), how_to_code, where_to_point); |
| return; |
| #define IC_KIND_CASE(KIND) case Code::KIND: |
| IC_KIND_LIST(IC_KIND_CASE) |
| #undef IC_KIND_CASE |
| SerializeIC(code_object, how_to_code, where_to_point); |
| return; |
| case Code::FUNCTION: |
| DCHECK(code_object->has_reloc_info_for_serialization()); |
| SerializeGeneric(code_object, how_to_code, where_to_point); |
| return; |
| case Code::WASM_FUNCTION: |
| case Code::WASM_TO_JS_FUNCTION: |
| case Code::JS_TO_WASM_FUNCTION: |
| UNREACHABLE(); |
| } |
| UNREACHABLE(); |
| } |
| |
| // 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()); |
| // There should be no hash table embedded. They would require rehashing. |
| CHECK(!obj->IsHashTable()); |
| // We expect no instantiated function objects or contexts. |
| CHECK(!obj->IsJSFunction() && !obj->IsContext()); |
| |
| SerializeGeneric(obj, how_to_code, where_to_point); |
| } |
| |
| void CodeSerializer::SerializeGeneric(HeapObject* heap_object, |
| HowToCode how_to_code, |
| WhereToPoint where_to_point) { |
| // Object has not yet been serialized. Serialize it here. |
| ObjectSerializer serializer(this, heap_object, sink_, how_to_code, |
| where_to_point); |
| serializer.Serialize(); |
| } |
| |
| void CodeSerializer::SerializeBuiltin(int builtin_index, HowToCode how_to_code, |
| WhereToPoint where_to_point) { |
| DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) || |
| (how_to_code == kPlain && where_to_point == kInnerPointer) || |
| (how_to_code == kFromCode && where_to_point == kInnerPointer)); |
| DCHECK_LT(builtin_index, Builtins::builtin_count); |
| DCHECK_LE(0, builtin_index); |
| |
| if (FLAG_trace_serializer) { |
| PrintF(" Encoding builtin: %s\n", |
| isolate()->builtins()->name(builtin_index)); |
| } |
| |
| sink_->Put(kBuiltin + how_to_code + where_to_point, "Builtin"); |
| sink_->PutInt(builtin_index, "builtin_index"); |
| } |
| |
| void CodeSerializer::SerializeCodeStub(uint32_t stub_key, HowToCode how_to_code, |
| WhereToPoint where_to_point) { |
| DCHECK((how_to_code == kPlain && where_to_point == kStartOfObject) || |
| (how_to_code == kPlain && where_to_point == kInnerPointer) || |
| (how_to_code == kFromCode && where_to_point == kInnerPointer)); |
| DCHECK(CodeStub::MajorKeyFromKey(stub_key) != CodeStub::NoCache); |
| DCHECK(!CodeStub::GetCode(isolate(), stub_key).is_null()); |
| |
| int index = AddCodeStubKey(stub_key) + kCodeStubsBaseIndex; |
| |
| if (FLAG_trace_serializer) { |
| PrintF(" Encoding code stub %s as %d\n", |
| CodeStub::MajorName(CodeStub::MajorKeyFromKey(stub_key)), index); |
| } |
| |
| sink_->Put(kAttachedReference + how_to_code + where_to_point, "CodeStub"); |
| sink_->PutInt(index, "CodeStub key"); |
| } |
| |
| void CodeSerializer::SerializeIC(Code* ic, HowToCode how_to_code, |
| WhereToPoint where_to_point) { |
| // The IC may be implemented as a stub. |
| uint32_t stub_key = ic->stub_key(); |
| if (stub_key != CodeStub::NoCacheKey()) { |
| if (FLAG_trace_serializer) { |
| PrintF(" %s is a code stub\n", Code::Kind2String(ic->kind())); |
| } |
| SerializeCodeStub(stub_key, how_to_code, where_to_point); |
| return; |
| } |
| // The IC may be implemented as builtin. Only real builtins have an |
| // actual builtin_index value attached (otherwise it's just garbage). |
| // Compare to make sure we are really dealing with a builtin. |
| int builtin_index = ic->builtin_index(); |
| if (builtin_index < Builtins::builtin_count) { |
| Builtins::Name name = static_cast<Builtins::Name>(builtin_index); |
| Code* builtin = isolate()->builtins()->builtin(name); |
| if (builtin == ic) { |
| if (FLAG_trace_serializer) { |
| PrintF(" %s is a builtin\n", Code::Kind2String(ic->kind())); |
| } |
| DCHECK(ic->kind() == Code::KEYED_LOAD_IC || |
| ic->kind() == Code::KEYED_STORE_IC); |
| SerializeBuiltin(builtin_index, how_to_code, where_to_point); |
| return; |
| } |
| } |
| // The IC may also just be a piece of code kept in the non_monomorphic_cache. |
| // In that case, just serialize as a normal code object. |
| if (FLAG_trace_serializer) { |
| PrintF(" %s has no special handling\n", Code::Kind2String(ic->kind())); |
| } |
| DCHECK(ic->kind() == Code::LOAD_IC || ic->kind() == Code::STORE_IC); |
| SerializeGeneric(ic, how_to_code, where_to_point); |
| } |
| |
| int CodeSerializer::AddCodeStubKey(uint32_t stub_key) { |
| // TODO(yangguo) Maybe we need a hash table for a faster lookup than O(n^2). |
| int index = 0; |
| while (index < stub_keys_.length()) { |
| if (stub_keys_[index] == stub_key) return index; |
| index++; |
| } |
| stub_keys_.Add(stub_key); |
| return index; |
| } |
| |
| MaybeHandle<SharedFunctionInfo> CodeSerializer::Deserialize( |
| Isolate* isolate, ScriptData* cached_data, Handle<String> source) { |
| base::ElapsedTimer timer; |
| if (FLAG_profile_deserialization) timer.Start(); |
| |
| HandleScope scope(isolate); |
| |
| base::SmartPointer<SerializedCodeData> scd( |
| SerializedCodeData::FromCachedData(isolate, cached_data, *source)); |
| if (scd.is_empty()) { |
| if (FLAG_profile_deserialization) PrintF("[Cached code failed check]\n"); |
| DCHECK(cached_data->rejected()); |
| return MaybeHandle<SharedFunctionInfo>(); |
| } |
| |
| // Prepare and register list of attached objects. |
| Vector<const uint32_t> code_stub_keys = scd->CodeStubKeys(); |
| Vector<Handle<Object> > attached_objects = Vector<Handle<Object> >::New( |
| code_stub_keys.length() + kCodeStubsBaseIndex); |
| attached_objects[kSourceObjectIndex] = source; |
| for (int i = 0; i < code_stub_keys.length(); i++) { |
| attached_objects[i + kCodeStubsBaseIndex] = |
| CodeStub::GetCode(isolate, code_stub_keys[i]).ToHandleChecked(); |
| } |
| |
| Deserializer deserializer(scd.get()); |
| deserializer.SetAttachedObjects(attached_objects); |
| |
| // Deserialize. |
| Handle<SharedFunctionInfo> result; |
| if (!deserializer.DeserializeCode(isolate).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); |
| } |
| result->set_deserialized(true); |
| |
| if (isolate->logger()->is_logging_code_events() || |
| isolate->cpu_profiler()->is_profiling()) { |
| String* name = isolate->heap()->empty_string(); |
| if (result->script()->IsScript()) { |
| Script* script = Script::cast(result->script()); |
| if (script->name()->IsString()) name = String::cast(script->name()); |
| } |
| isolate->logger()->CodeCreateEvent( |
| Logger::SCRIPT_TAG, result->abstract_code(), *result, NULL, name); |
| } |
| return scope.CloseAndEscape(result); |
| } |
| |
| class Checksum { |
| public: |
| explicit 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.start(), payload.length()); |
| #endif // MEMORY_SANITIZER |
| // Fletcher's checksum. Modified to reduce 64-bit sums to 32-bit. |
| uintptr_t a = 1; |
| uintptr_t b = 0; |
| const uintptr_t* cur = reinterpret_cast<const uintptr_t*>(payload.start()); |
| DCHECK(IsAligned(payload.length(), kIntptrSize)); |
| const uintptr_t* end = cur + payload.length() / kIntptrSize; |
| while (cur < end) { |
| // Unsigned overflow expected and intended. |
| a += *cur++; |
| b += a; |
| } |
| #if V8_HOST_ARCH_64_BIT |
| a ^= a >> 32; |
| b ^= b >> 32; |
| #endif // V8_HOST_ARCH_64_BIT |
| a_ = static_cast<uint32_t>(a); |
| b_ = static_cast<uint32_t>(b); |
| } |
| |
| bool Check(uint32_t a, uint32_t b) const { return a == a_ && b == b_; } |
| |
| uint32_t a() const { return a_; } |
| uint32_t b() const { return b_; } |
| |
| private: |
| uint32_t a_; |
| uint32_t b_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Checksum); |
| }; |
| |
| SerializedCodeData::SerializedCodeData(const List<byte>& payload, |
| const CodeSerializer& cs) { |
| DisallowHeapAllocation no_gc; |
| const List<uint32_t>* stub_keys = cs.stub_keys(); |
| |
| List<Reservation> reservations; |
| cs.EncodeReservations(&reservations); |
| |
| // Calculate sizes. |
| int reservation_size = reservations.length() * kInt32Size; |
| int num_stub_keys = stub_keys->length(); |
| int stub_keys_size = stub_keys->length() * kInt32Size; |
| int payload_offset = kHeaderSize + reservation_size + stub_keys_size; |
| int padded_payload_offset = POINTER_SIZE_ALIGN(payload_offset); |
| int size = padded_payload_offset + payload.length(); |
| |
| // Allocate backing store and create result data. |
| AllocateData(size); |
| |
| // Set header values. |
| SetMagicNumber(cs.isolate()); |
| SetHeaderValue(kVersionHashOffset, Version::Hash()); |
| SetHeaderValue(kSourceHashOffset, SourceHash(cs.source())); |
| SetHeaderValue(kCpuFeaturesOffset, |
| static_cast<uint32_t>(CpuFeatures::SupportedFeatures())); |
| SetHeaderValue(kFlagHashOffset, FlagList::Hash()); |
| SetHeaderValue(kNumReservationsOffset, reservations.length()); |
| SetHeaderValue(kNumCodeStubKeysOffset, num_stub_keys); |
| SetHeaderValue(kPayloadLengthOffset, payload.length()); |
| |
| Checksum checksum(payload.ToConstVector()); |
| SetHeaderValue(kChecksum1Offset, checksum.a()); |
| SetHeaderValue(kChecksum2Offset, checksum.b()); |
| |
| // Copy reservation chunk sizes. |
| CopyBytes(data_ + kHeaderSize, reinterpret_cast<byte*>(reservations.begin()), |
| reservation_size); |
| |
| // Copy code stub keys. |
| CopyBytes(data_ + kHeaderSize + reservation_size, |
| reinterpret_cast<byte*>(stub_keys->begin()), stub_keys_size); |
| |
| memset(data_ + payload_offset, 0, padded_payload_offset - payload_offset); |
| |
| // Copy serialized data. |
| CopyBytes(data_ + padded_payload_offset, payload.begin(), |
| static_cast<size_t>(payload.length())); |
| } |
| |
| SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck( |
| Isolate* isolate, String* source) const { |
| uint32_t magic_number = GetMagicNumber(); |
| if (magic_number != ComputeMagicNumber(isolate)) return MAGIC_NUMBER_MISMATCH; |
| uint32_t version_hash = GetHeaderValue(kVersionHashOffset); |
| uint32_t source_hash = GetHeaderValue(kSourceHashOffset); |
| uint32_t cpu_features = GetHeaderValue(kCpuFeaturesOffset); |
| uint32_t flags_hash = GetHeaderValue(kFlagHashOffset); |
| uint32_t c1 = GetHeaderValue(kChecksum1Offset); |
| uint32_t c2 = GetHeaderValue(kChecksum2Offset); |
| if (version_hash != Version::Hash()) return VERSION_MISMATCH; |
| if (source_hash != SourceHash(source)) return SOURCE_MISMATCH; |
| if (cpu_features != static_cast<uint32_t>(CpuFeatures::SupportedFeatures())) { |
| return CPU_FEATURES_MISMATCH; |
| } |
| if (flags_hash != FlagList::Hash()) return FLAGS_MISMATCH; |
| if (!Checksum(Payload()).Check(c1, c2)) return CHECKSUM_MISMATCH; |
| return CHECK_SUCCESS; |
| } |
| |
| uint32_t SerializedCodeData::SourceHash(String* source) const { |
| return source->length(); |
| } |
| |
| // 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_ = NULL; |
| return result; |
| } |
| |
| Vector<const SerializedData::Reservation> SerializedCodeData::Reservations() |
| const { |
| return Vector<const Reservation>( |
| reinterpret_cast<const Reservation*>(data_ + kHeaderSize), |
| GetHeaderValue(kNumReservationsOffset)); |
| } |
| |
| Vector<const byte> SerializedCodeData::Payload() const { |
| int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size; |
| int code_stubs_size = GetHeaderValue(kNumCodeStubKeysOffset) * kInt32Size; |
| int payload_offset = kHeaderSize + reservations_size + code_stubs_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); |
| } |
| |
| Vector<const uint32_t> SerializedCodeData::CodeStubKeys() const { |
| int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size; |
| const byte* start = data_ + kHeaderSize + reservations_size; |
| return Vector<const uint32_t>(reinterpret_cast<const uint32_t*>(start), |
| GetHeaderValue(kNumCodeStubKeysOffset)); |
| } |
| |
| SerializedCodeData::SerializedCodeData(ScriptData* data) |
| : SerializedData(const_cast<byte*>(data->data()), data->length()) {} |
| |
| SerializedCodeData* SerializedCodeData::FromCachedData(Isolate* isolate, |
| ScriptData* cached_data, |
| String* source) { |
| DisallowHeapAllocation no_gc; |
| SerializedCodeData* scd = new SerializedCodeData(cached_data); |
| SanityCheckResult r = scd->SanityCheck(isolate, source); |
| if (r == CHECK_SUCCESS) return scd; |
| cached_data->Reject(); |
| source->GetIsolate()->counters()->code_cache_reject_reason()->AddSample(r); |
| delete scd; |
| return NULL; |
| } |
| |
| } // namespace internal |
| } // namespace v8 |