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// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/image_snapshot.h"
#include "platform/assert.h"
#include "vm/compiler/backend/code_statistics.h"
#include "vm/dwarf.h"
#include "vm/hash.h"
#include "vm/hash_map.h"
#include "vm/heap/heap.h"
#include "vm/json_writer.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/program_visitor.h"
#include "vm/stub_code.h"
#include "vm/timeline.h"
#include "vm/type_testing_stubs.h"
namespace dart {
#if defined(DART_PRECOMPILER)
DEFINE_FLAG(bool,
print_instruction_stats,
false,
"Print instruction statistics");
DEFINE_FLAG(charp,
print_instructions_sizes_to,
NULL,
"Print sizes of all instruction objects to the given file");
#endif
DEFINE_FLAG(bool,
trace_reused_instructions,
false,
"Print code that lacks reusable instructions");
intptr_t ObjectOffsetTrait::Hashcode(Key key) {
RawObject* obj = key;
ASSERT(!obj->IsSmi());
uword body = RawObject::ToAddr(obj) + sizeof(RawObject);
uword end = RawObject::ToAddr(obj) + obj->Size();
uint32_t hash = obj->GetClassId();
// Don't include the header. Objects in the image are pre-marked, but objects
// in the current isolate are not.
for (uword cursor = body; cursor < end; cursor += sizeof(uint32_t)) {
hash = CombineHashes(hash, *reinterpret_cast<uint32_t*>(cursor));
}
return FinalizeHash(hash, 30);
}
bool ObjectOffsetTrait::IsKeyEqual(Pair pair, Key key) {
RawObject* a = pair.object;
RawObject* b = key;
ASSERT(!a->IsSmi());
ASSERT(!b->IsSmi());
if (a->GetClassId() != b->GetClassId()) {
return false;
}
intptr_t heap_size = a->Size();
if (b->Size() != heap_size) {
return false;
}
// Don't include the header. Objects in the image are pre-marked, but objects
// in the current isolate are not.
uword body_a = RawObject::ToAddr(a) + sizeof(RawObject);
uword body_b = RawObject::ToAddr(b) + sizeof(RawObject);
uword body_size = heap_size - sizeof(RawObject);
return 0 == memcmp(reinterpret_cast<const void*>(body_a),
reinterpret_cast<const void*>(body_b), body_size);
}
ImageWriter::ImageWriter(Heap* heap,
const void* shared_objects,
const void* shared_instructions,
const void* reused_instructions)
: heap_(heap),
next_data_offset_(0),
next_text_offset_(0),
objects_(),
instructions_() {
ResetOffsets();
SetupShared(&shared_objects_, shared_objects);
SetupShared(&shared_instructions_, shared_instructions);
SetupShared(&reuse_instructions_, reused_instructions);
}
void ImageWriter::SetupShared(ObjectOffsetMap* map, const void* shared_image) {
if (shared_image == NULL) {
return;
}
Image image(shared_image);
uword obj_addr = reinterpret_cast<uword>(image.object_start());
uword end_addr = obj_addr + image.object_size();
while (obj_addr < end_addr) {
int32_t offset = obj_addr - reinterpret_cast<uword>(shared_image);
RawObject* raw_obj = RawObject::FromAddr(obj_addr);
ObjectOffsetPair pair;
pair.object = raw_obj;
pair.offset = offset;
map->Insert(pair);
obj_addr += raw_obj->Size();
}
ASSERT(obj_addr == end_addr);
}
int32_t ImageWriter::GetTextOffsetFor(RawInstructions* instructions,
RawCode* code) {
intptr_t offset = heap_->GetObjectId(instructions);
if (offset != 0) {
return offset;
}
if (!reuse_instructions_.IsEmpty()) {
ObjectOffsetPair* pair = reuse_instructions_.Lookup(instructions);
if (pair == NULL) {
// Code should have been removed by DropCodeWithoutReusableInstructions.
FATAL("Expected instructions to reuse\n");
}
return pair->offset;
}
ObjectOffsetPair* pair = shared_instructions_.Lookup(instructions);
if (pair != NULL) {
// Negative offsets tell the reader the offset is w/r/t the shared
// instructions image instead of the app-specific instructions image.
// Compare ImageReader::GetInstructionsAt.
return -pair->offset;
}
intptr_t heap_size = instructions->Size();
offset = next_text_offset_;
heap_->SetObjectId(instructions, offset);
next_text_offset_ += heap_size;
instructions_.Add(InstructionsData(instructions, code, offset));
return offset;
}
bool ImageWriter::GetSharedDataOffsetFor(RawObject* raw_object,
uint32_t* offset) {
ObjectOffsetPair* pair = shared_objects_.Lookup(raw_object);
if (pair == NULL) {
return false;
}
*offset = pair->offset;
return true;
}
uint32_t ImageWriter::GetDataOffsetFor(RawObject* raw_object) {
intptr_t heap_size = raw_object->Size();
intptr_t offset = next_data_offset_;
next_data_offset_ += heap_size;
objects_.Add(ObjectData(raw_object));
return offset;
}
#if defined(DART_PRECOMPILER)
void ImageWriter::DumpInstructionStats() {
CombinedCodeStatistics instruction_stats;
for (intptr_t i = 0; i < instructions_.length(); i++) {
auto& data = instructions_[i];
CodeStatistics* stats = data.insns_->stats();
if (stats != nullptr) {
stats->AppendTo(&instruction_stats);
}
}
instruction_stats.DumpStatistics();
}
void ImageWriter::DumpInstructionsSizes() {
auto thread = Thread::Current();
auto zone = thread->zone();
auto& cls = Class::Handle(zone);
auto& lib = Library::Handle(zone);
auto& owner = Object::Handle(zone);
auto& url = String::Handle(zone);
auto& name = String::Handle(zone);
JSONWriter js;
js.OpenArray();
for (intptr_t i = 0; i < instructions_.length(); i++) {
auto& data = instructions_[i];
if (data.code_->IsNull()) {
// TODO(34650): Type testing stubs are added to the serializer without
// their Code.
continue;
}
owner = data.code_->owner();
js.OpenObject();
if (owner.IsFunction()) {
cls = Function::Cast(owner).Owner();
name = cls.ScrubbedName();
lib = cls.library();
url = lib.url();
js.PrintPropertyStr("l", url);
js.PrintPropertyStr("c", name);
}
js.PrintProperty("n", data.code_->QualifiedName());
js.PrintProperty("s", data.insns_->Size());
js.CloseObject();
}
js.CloseArray();
auto file_open = Dart::file_open_callback();
auto file_write = Dart::file_write_callback();
auto file_close = Dart::file_close_callback();
if ((file_open == nullptr) || (file_write == nullptr) ||
(file_close == nullptr)) {
return;
}
auto file = file_open(FLAG_print_instructions_sizes_to, /*write=*/true);
if (file == nullptr) {
OS::PrintErr("Failed to open file %s\n", FLAG_print_instructions_sizes_to);
return;
}
char* output = nullptr;
intptr_t output_length = 0;
js.Steal(&output, &output_length);
file_write(output, output_length, file);
free(output);
file_close(file);
}
void ImageWriter::DumpStatistics() {
if (FLAG_print_instruction_stats) {
DumpInstructionStats();
}
if (FLAG_print_instructions_sizes_to != nullptr) {
DumpInstructionsSizes();
}
}
#endif
void ImageWriter::Write(WriteStream* clustered_stream, bool vm) {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Heap* heap = thread->isolate()->heap();
NOT_IN_PRODUCT(TimelineDurationScope tds(thread, Timeline::GetIsolateStream(),
"WriteInstructions"));
// Handlify collected raw pointers as building the names below
// will allocate on the Dart heap.
for (intptr_t i = 0; i < instructions_.length(); i++) {
InstructionsData& data = instructions_[i];
data.insns_ = &Instructions::Handle(zone, data.raw_insns_);
ASSERT(data.raw_code_ != NULL);
data.code_ = &Code::Handle(zone, data.raw_code_);
// Reset object id as an isolate snapshot after a VM snapshot will not use
// the VM snapshot's text image.
heap->SetObjectId(data.insns_->raw(), 0);
}
for (intptr_t i = 0; i < objects_.length(); i++) {
ObjectData& data = objects_[i];
data.obj_ = &Object::Handle(zone, data.raw_obj_);
}
// Append the direct-mapped RO data objects after the clustered snapshot.
offset_space_ = vm ? V8SnapshotProfileWriter::kVmData
: V8SnapshotProfileWriter::kIsolateData;
WriteROData(clustered_stream);
offset_space_ = vm ? V8SnapshotProfileWriter::kVmText
: V8SnapshotProfileWriter::kIsolateText;
WriteText(clustered_stream, vm);
}
void ImageWriter::WriteROData(WriteStream* stream) {
stream->Align(OS::kMaxPreferredCodeAlignment);
// Heap page starts here.
intptr_t section_start = stream->Position();
stream->WriteWord(next_data_offset_); // Data length.
COMPILE_ASSERT(OS::kMaxPreferredCodeAlignment >= kObjectAlignment);
stream->Align(OS::kMaxPreferredCodeAlignment);
ASSERT(stream->Position() - section_start == Image::kHeaderSize);
// Heap page objects start here.
for (intptr_t i = 0; i < objects_.length(); i++) {
const Object& obj = *objects_[i].obj_;
AutoTraceImage(obj, section_start, stream);
NoSafepointScope no_safepoint;
uword start = reinterpret_cast<uword>(obj.raw()) - kHeapObjectTag;
uword end = start + obj.raw()->Size();
// Write object header with the mark and VM heap bits set.
uword marked_tags = obj.raw()->ptr()->tags_;
marked_tags = RawObject::VMHeapObjectTag::update(true, marked_tags);
marked_tags = RawObject::OldBit::update(true, marked_tags);
marked_tags = RawObject::OldAndNotMarkedBit::update(false, marked_tags);
marked_tags = RawObject::OldAndNotRememberedBit::update(true, marked_tags);
marked_tags = RawObject::NewBit::update(false, marked_tags);
#if defined(HASH_IN_OBJECT_HEADER)
marked_tags |= static_cast<uword>(obj.raw()->ptr()->hash_) << 32;
#endif
stream->WriteWord(marked_tags);
start += sizeof(uword);
for (uword* cursor = reinterpret_cast<uword*>(start);
cursor < reinterpret_cast<uword*>(end); cursor++) {
stream->WriteWord(*cursor);
}
}
}
AssemblyImageWriter::AssemblyImageWriter(Thread* thread,
Dart_StreamingWriteCallback callback,
void* callback_data,
const void* shared_objects,
const void* shared_instructions)
: ImageWriter(thread->heap(), shared_objects, shared_instructions, NULL),
assembly_stream_(512 * KB, callback, callback_data),
dwarf_(NULL) {
#if defined(DART_PRECOMPILER)
Zone* zone = Thread::Current()->zone();
dwarf_ = new (zone) Dwarf(zone, &assembly_stream_);
#endif
}
void AssemblyImageWriter::Finalize() {
#ifdef DART_PRECOMPILER
dwarf_->Write();
#endif
}
static void EnsureIdentifier(char* label) {
for (char c = *label; c != '\0'; c = *++label) {
if (((c >= 'a') && (c <= 'z')) || ((c >= 'A') && (c <= 'Z')) ||
((c >= '0') && (c <= '9'))) {
continue;
}
*label = '_';
}
}
void AssemblyImageWriter::WriteText(WriteStream* clustered_stream, bool vm) {
Zone* zone = Thread::Current()->zone();
const char* instructions_symbol =
vm ? "_kDartVmSnapshotInstructions" : "_kDartIsolateSnapshotInstructions";
assembly_stream_.Print(".text\n");
assembly_stream_.Print(".globl %s\n", instructions_symbol);
// Start snapshot at page boundary.
ASSERT(VirtualMemory::PageSize() >= OS::kMaxPreferredCodeAlignment);
assembly_stream_.Print(".balign %" Pd ", 0\n", VirtualMemory::PageSize());
assembly_stream_.Print("%s:\n", instructions_symbol);
// This head also provides the gap to make the instructions snapshot
// look like a HeapPage.
intptr_t instructions_length = next_text_offset_;
WriteWordLiteralText(instructions_length);
intptr_t header_words = Image::kHeaderSize / sizeof(uword);
for (intptr_t i = 1; i < header_words; i++) {
WriteWordLiteralText(0);
}
FrameUnwindPrologue();
Object& owner = Object::Handle(zone);
String& str = String::Handle(zone);
ObjectStore* object_store = Isolate::Current()->object_store();
TypeTestingStubFinder tts;
intptr_t offset = Image::kHeaderSize;
for (intptr_t i = 0; i < instructions_.length(); i++) {
const Instructions& insns = *instructions_[i].insns_;
const Code& code = *instructions_[i].code_;
if (profile_writer_ != nullptr) {
ASSERT(offset_space_ != V8SnapshotProfileWriter::kSnapshot);
profile_writer_->SetObjectTypeAndName({offset_space_, offset},
"Instructions",
/*name=*/nullptr);
profile_writer_->AttributeBytesTo({offset_space_, offset},
insns.raw()->Size());
}
offset += insns.raw()->Size();
ASSERT(insns.raw()->Size() % sizeof(uint64_t) == 0);
// 1. Write from the header to the entry point.
{
NoSafepointScope no_safepoint;
uword beginning = reinterpret_cast<uword>(insns.raw_ptr());
uword entry = beginning + Instructions::HeaderSize();
// Write Instructions with the mark and VM heap bits set.
uword marked_tags = insns.raw_ptr()->tags_;
marked_tags = RawObject::VMHeapObjectTag::update(true, marked_tags);
marked_tags = RawObject::OldBit::update(true, marked_tags);
marked_tags = RawObject::OldAndNotMarkedBit::update(false, marked_tags);
marked_tags =
RawObject::OldAndNotRememberedBit::update(true, marked_tags);
marked_tags = RawObject::NewBit::update(false, marked_tags);
#if defined(HASH_IN_OBJECT_HEADER)
// Can't use GetObjectTagsAndHash because the update methods discard the
// high bits.
marked_tags |= static_cast<uword>(insns.raw_ptr()->hash_) << 32;
#endif
WriteWordLiteralText(marked_tags);
beginning += sizeof(uword);
WriteByteSequence(beginning, entry);
}
// 2. Write a label at the entry point.
// Linux's perf uses these labels.
if (code.IsNull()) {
const char* name = tts.StubNameFromAddresss(insns.EntryPoint());
assembly_stream_.Print("Precompiled_%s:\n", name);
} else {
owner = code.owner();
if (owner.IsNull()) {
const char* name = StubCode::NameOfStub(insns.EntryPoint());
if (name == nullptr &&
code.raw() == object_store->build_method_extractor_code()) {
name = "BuildMethodExtractor";
}
if (name != NULL) {
assembly_stream_.Print("Precompiled_Stub_%s:\n", name);
} else {
const char* name = tts.StubNameFromAddresss(insns.EntryPoint());
assembly_stream_.Print("Precompiled__%s:\n", name);
}
} else if (owner.IsClass()) {
str = Class::Cast(owner).Name();
const char* name = str.ToCString();
EnsureIdentifier(const_cast<char*>(name));
assembly_stream_.Print("Precompiled_AllocationStub_%s_%" Pd ":\n", name,
i);
} else if (owner.IsFunction()) {
const char* name = Function::Cast(owner).ToQualifiedCString();
EnsureIdentifier(const_cast<char*>(name));
assembly_stream_.Print("Precompiled_%s_%" Pd ":\n", name, i);
} else {
UNREACHABLE();
}
}
#ifdef DART_PRECOMPILER
// Create a label for use by DWARF.
if (!code.IsNull()) {
const intptr_t dwarf_index = dwarf_->AddCode(code);
assembly_stream_.Print(".Lcode%" Pd ":\n", dwarf_index);
}
#endif
{
// 3. Write from the entry point to the end.
NoSafepointScope no_safepoint;
uword beginning = reinterpret_cast<uword>(insns.raw()) - kHeapObjectTag;
uword entry = beginning + Instructions::HeaderSize();
uword payload_size = insns.Size();
payload_size = Utils::RoundUp(payload_size, OS::PreferredCodeAlignment());
uword end = entry + payload_size;
ASSERT(Utils::IsAligned(beginning, sizeof(uword)));
ASSERT(Utils::IsAligned(entry, sizeof(uword)));
ASSERT(Utils::IsAligned(end, sizeof(uword)));
WriteByteSequence(entry, end);
}
}
FrameUnwindEpilogue();
#if defined(TARGET_OS_LINUX) || defined(TARGET_OS_ANDROID) || \
defined(TARGET_OS_FUCHSIA)
assembly_stream_.Print(".section .rodata\n");
#elif defined(TARGET_OS_MACOS) || defined(TARGET_OS_MACOS_IOS)
assembly_stream_.Print(".const\n");
#else
UNIMPLEMENTED();
#endif
const char* data_symbol =
vm ? "_kDartVmSnapshotData" : "_kDartIsolateSnapshotData";
assembly_stream_.Print(".globl %s\n", data_symbol);
assembly_stream_.Print(".balign %" Pd ", 0\n",
OS::kMaxPreferredCodeAlignment);
assembly_stream_.Print("%s:\n", data_symbol);
uword buffer = reinterpret_cast<uword>(clustered_stream->buffer());
intptr_t length = clustered_stream->bytes_written();
WriteByteSequence(buffer, buffer + length);
}
void AssemblyImageWriter::FrameUnwindPrologue() {
// Creates DWARF's .debug_frame
// CFI = Call frame information
// CFA = Canonical frame address
assembly_stream_.Print(".cfi_startproc\n");
#if defined(TARGET_ARCH_X64)
assembly_stream_.Print(".cfi_def_cfa rbp, 0\n"); // CFA is fp+0
assembly_stream_.Print(".cfi_offset rbp, 0\n"); // saved fp is *(CFA+0)
assembly_stream_.Print(".cfi_offset rip, 8\n"); // saved pc is *(CFA+8)
// saved sp is CFA+16
// Should be ".cfi_value_offset rsp, 16", but requires gcc newer than late
// 2016 and not supported by Android's libunwind.
// DW_CFA_expression 0x10
// uleb128 register (rsp) 7 (DWARF register number)
// uleb128 size of operation 2
// DW_OP_plus_uconst 0x23
// uleb128 addend 16
assembly_stream_.Print(".cfi_escape 0x10, 31, 2, 0x23, 16\n");
#elif defined(TARGET_ARCH_ARM64)
COMPILE_ASSERT(FP == R29);
COMPILE_ASSERT(LR == R30);
assembly_stream_.Print(".cfi_def_cfa x29, 0\n"); // CFA is fp+0
assembly_stream_.Print(".cfi_offset x29, 0\n"); // saved fp is *(CFA+0)
assembly_stream_.Print(".cfi_offset x30, 8\n"); // saved pc is *(CFA+8)
// saved sp is CFA+16
// Should be ".cfi_value_offset sp, 16", but requires gcc newer than late
// 2016 and not supported by Android's libunwind.
// DW_CFA_expression 0x10
// uleb128 register (x31) 31
// uleb128 size of operation 2
// DW_OP_plus_uconst 0x23
// uleb128 addend 16
assembly_stream_.Print(".cfi_escape 0x10, 31, 2, 0x23, 16\n");
#elif defined(TARGET_ARCH_ARM)
#if defined(TARGET_OS_MACOS) || defined(TARGET_OS_MACOS_IOS)
COMPILE_ASSERT(FP == R7);
assembly_stream_.Print(".cfi_def_cfa r7, 0\n"); // CFA is fp+j0
assembly_stream_.Print(".cfi_offset r7, 0\n"); // saved fp is *(CFA+0)
#else
COMPILE_ASSERT(FP == R11);
assembly_stream_.Print(".cfi_def_cfa r11, 0\n"); // CFA is fp+0
assembly_stream_.Print(".cfi_offset r11, 0\n"); // saved fp is *(CFA+0)
#endif
assembly_stream_.Print(".cfi_offset lr, 4\n"); // saved pc is *(CFA+4)
// saved sp is CFA+8
// Should be ".cfi_value_offset sp, 8", but requires gcc newer than late
// 2016 and not supported by Android's libunwind.
// DW_CFA_expression 0x10
// uleb128 register (sp) 13
// uleb128 size of operation 2
// DW_OP_plus_uconst 0x23
// uleb128 addend 8
assembly_stream_.Print(".cfi_escape 0x10, 13, 2, 0x23, 8\n");
// libunwind on ARM may use .ARM.exidx instead of .debug_frame
#if !defined(TARGET_OS_MACOS) && !defined(TARGET_OS_MACOS_IOS)
COMPILE_ASSERT(FP == R11);
assembly_stream_.Print(".fnstart\n");
assembly_stream_.Print(".save {r11, lr}\n");
assembly_stream_.Print(".setfp r11, sp, #0\n");
#endif
#endif
}
void AssemblyImageWriter::FrameUnwindEpilogue() {
#if defined(TARGET_ARCH_ARM)
#if !defined(TARGET_OS_MACOS) && !defined(TARGET_OS_MACOS_IOS)
assembly_stream_.Print(".fnend\n");
#endif
#endif
assembly_stream_.Print(".cfi_endproc\n");
}
void AssemblyImageWriter::WriteByteSequence(uword start, uword end) {
for (uword* cursor = reinterpret_cast<uword*>(start);
cursor < reinterpret_cast<uword*>(end); cursor++) {
WriteWordLiteralText(*cursor);
}
}
BlobImageWriter::BlobImageWriter(Thread* thread,
uint8_t** instructions_blob_buffer,
ReAlloc alloc,
intptr_t initial_size,
const void* shared_objects,
const void* shared_instructions,
const void* reused_instructions)
: ImageWriter(thread->heap(),
shared_objects,
shared_instructions,
reused_instructions),
instructions_blob_stream_(instructions_blob_buffer, alloc, initial_size) {
}
void BlobImageWriter::WriteText(WriteStream* clustered_stream, bool vm) {
// This header provides the gap to make the instructions snapshot look like a
// HeapPage.
intptr_t instructions_length = next_text_offset_;
instructions_blob_stream_.WriteWord(instructions_length);
intptr_t header_words = Image::kHeaderSize / sizeof(uword);
for (intptr_t i = 1; i < header_words; i++) {
instructions_blob_stream_.WriteWord(0);
}
NoSafepointScope no_safepoint;
for (intptr_t i = 0; i < instructions_.length(); i++) {
const Instructions& insns = *instructions_[i].insns_;
AutoTraceImage(insns, 0, &this->instructions_blob_stream_);
uword beginning = reinterpret_cast<uword>(insns.raw_ptr());
uword entry = beginning + Instructions::HeaderSize();
uword payload_size = insns.Size();
payload_size = Utils::RoundUp(payload_size, OS::PreferredCodeAlignment());
uword end = entry + payload_size;
ASSERT(Utils::IsAligned(beginning, sizeof(uword)));
ASSERT(Utils::IsAligned(entry, sizeof(uword)));
// Write Instructions with the mark and VM heap bits set.
uword marked_tags = insns.raw_ptr()->tags_;
marked_tags = RawObject::VMHeapObjectTag::update(true, marked_tags);
marked_tags = RawObject::OldBit::update(true, marked_tags);
marked_tags = RawObject::OldAndNotMarkedBit::update(false, marked_tags);
marked_tags = RawObject::OldAndNotRememberedBit::update(true, marked_tags);
marked_tags = RawObject::NewBit::update(false, marked_tags);
#if defined(HASH_IN_OBJECT_HEADER)
// Can't use GetObjectTagsAndHash because the update methods discard the
// high bits.
marked_tags |= static_cast<uword>(insns.raw_ptr()->hash_) << 32;
#endif
instructions_blob_stream_.WriteWord(marked_tags);
beginning += sizeof(uword);
for (uword* cursor = reinterpret_cast<uword*>(beginning);
cursor < reinterpret_cast<uword*>(end); cursor++) {
instructions_blob_stream_.WriteWord(*cursor);
}
}
}
ImageReader::ImageReader(const uint8_t* data_image,
const uint8_t* instructions_image,
const uint8_t* shared_data_image,
const uint8_t* shared_instructions_image)
: data_image_(data_image),
instructions_image_(instructions_image),
shared_data_image_(shared_data_image),
shared_instructions_image_(shared_instructions_image) {
ASSERT(data_image != NULL);
ASSERT(instructions_image != NULL);
}
RawApiError* ImageReader::VerifyAlignment() const {
if (!Utils::IsAligned(data_image_, kObjectAlignment) ||
!Utils::IsAligned(shared_data_image_, kObjectAlignment) ||
!Utils::IsAligned(instructions_image_, OS::PreferredCodeAlignment()) ||
!Utils::IsAligned(shared_instructions_image_,
OS::PreferredCodeAlignment())) {
return ApiError::New(
String::Handle(String::New("Snapshot is misaligned", Heap::kOld)),
Heap::kOld);
}
return ApiError::null();
}
RawInstructions* ImageReader::GetInstructionsAt(int32_t offset) const {
ASSERT(Utils::IsAligned(offset, OS::PreferredCodeAlignment()));
RawObject* result;
if (offset < 0) {
result = RawObject::FromAddr(
reinterpret_cast<uword>(shared_instructions_image_) - offset);
} else {
result = RawObject::FromAddr(reinterpret_cast<uword>(instructions_image_) +
offset);
}
ASSERT(result->IsInstructions());
ASSERT(result->IsMarked());
return Instructions::RawCast(result);
}
RawObject* ImageReader::GetObjectAt(uint32_t offset) const {
ASSERT(Utils::IsAligned(offset, kObjectAlignment));
RawObject* result =
RawObject::FromAddr(reinterpret_cast<uword>(data_image_) + offset);
ASSERT(result->IsMarked());
return result;
}
RawObject* ImageReader::GetSharedObjectAt(uint32_t offset) const {
ASSERT(Utils::IsAligned(offset, kObjectAlignment));
RawObject* result =
RawObject::FromAddr(reinterpret_cast<uword>(shared_data_image_) + offset);
ASSERT(result->IsMarked());
return result;
}
void DropCodeWithoutReusableInstructions(const void* reused_instructions) {
class DropCodeVisitor : public FunctionVisitor, public ClassVisitor {
public:
explicit DropCodeVisitor(const void* reused_instructions)
: code_(Code::Handle()), instructions_(Instructions::Handle()) {
ImageWriter::SetupShared(&reused_instructions_, reused_instructions);
if (FLAG_trace_reused_instructions) {
OS::PrintErr("%" Pd " reusable instructions\n",
reused_instructions_.Size());
}
}
void Visit(const Class& cls) {
code_ = cls.allocation_stub();
if (!code_.IsNull() && !IsAvailable(code_)) {
if (FLAG_trace_reused_instructions) {
OS::PrintErr("No reusable instructions for %s\n", cls.ToCString());
}
cls.DisableAllocationStub();
}
}
void Visit(const Function& func) {
if (func.HasCode()) {
code_ = func.CurrentCode();
if (!IsAvailable(code_)) {
if (FLAG_trace_reused_instructions) {
OS::PrintErr("No reusable instructions for %s\n", func.ToCString());
}
func.ClearCode();
func.ClearICDataArray();
return;
}
}
code_ = func.unoptimized_code();
if (!code_.IsNull() && !IsAvailable(code_)) {
if (FLAG_trace_reused_instructions) {
OS::PrintErr("No reusable instructions for %s\n", func.ToCString());
}
func.ClearCode();
func.ClearICDataArray();
return;
}
}
private:
bool IsAvailable(const Code& code) {
ObjectOffsetPair* pair = reused_instructions_.Lookup(code.instructions());
return pair != NULL;
}
ObjectOffsetMap reused_instructions_;
Code& code_;
Instructions& instructions_;
DISALLOW_COPY_AND_ASSIGN(DropCodeVisitor);
};
DropCodeVisitor visitor(reused_instructions);
ProgramVisitor::VisitClasses(&visitor);
ProgramVisitor::VisitFunctions(&visitor);
}
} // namespace dart