// Copyright 2012 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/execution/isolate.h"
#include <stdlib.h>
#include <atomic>
#include <cstdint>
#include <fstream>
#include <memory>
#include <sstream>
#include <string>
#include <unordered_map>
#include <utility>
#include "include/v8-template.h"
#include "src/api/api-inl.h"
#include "src/ast/ast-value-factory.h"
#include "src/ast/scopes.h"
#include "src/base/hashmap.h"
#include "src/base/logging.h"
#include "src/base/platform/mutex.h"
#include "src/base/platform/platform.h"
#include "src/base/sys-info.h"
#include "src/base/utils/random-number-generator.h"
#include "src/baseline/baseline-batch-compiler.h"
#include "src/bigint/bigint.h"
#include "src/builtins/builtins-promise.h"
#include "src/builtins/constants-table-builder.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/compilation-cache.h"
#include "src/codegen/flush-instruction-cache.h"
#include "src/common/assert-scope.h"
#include "src/common/ptr-compr-inl.h"
#include "src/compiler-dispatcher/lazy-compile-dispatcher.h"
#include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
#include "src/date/date.h"
#include "src/debug/debug-frames.h"
#if V8_ENABLE_WEBASSEMBLY
#include "src/debug/debug-wasm-objects.h"
#endif // V8_ENABLE_WEBASSEMBLY
#include "src/debug/debug.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/deoptimizer/materialized-object-store.h"
#include "src/diagnostics/basic-block-profiler.h"
#include "src/diagnostics/compilation-statistics.h"
#include "src/execution/frames-inl.h"
#include "src/execution/frames.h"
#include "src/execution/isolate-inl.h"
#include "src/execution/local-isolate.h"
#include "src/execution/messages.h"
#include "src/execution/microtask-queue.h"
#include "src/execution/protectors-inl.h"
#include "src/execution/runtime-profiler.h"
#include "src/execution/simulator.h"
#include "src/execution/v8threads.h"
#include "src/execution/vm-state-inl.h"
#include "src/handles/global-handles-inl.h"
#include "src/handles/persistent-handles.h"
#include "src/heap/heap-inl.h"
#include "src/heap/heap.h"
#include "src/heap/local-heap.h"
#include "src/heap/parked-scope.h"
#include "src/heap/read-only-heap.h"
#include "src/heap/safepoint.h"
#include "src/ic/stub-cache.h"
#include "src/init/bootstrapper.h"
#include "src/init/setup-isolate.h"
#include "src/init/v8.h"
#include "src/interpreter/interpreter.h"
#include "src/libsampler/sampler.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/logging/metrics.h"
#include "src/logging/runtime-call-stats-scope.h"
#include "src/numbers/hash-seed-inl.h"
#include "src/objects/backing-store.h"
#include "src/objects/call-site-info-inl.h"
#include "src/objects/elements.h"
#include "src/objects/feedback-vector.h"
#include "src/objects/hash-table-inl.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/objects/js-array-inl.h"
#include "src/objects/js-generator-inl.h"
#include "src/objects/js-weak-refs-inl.h"
#include "src/objects/managed-inl.h"
#include "src/objects/module-inl.h"
#include "src/objects/promise-inl.h"
#include "src/objects/prototype.h"
#include "src/objects/slots.h"
#include "src/objects/smi.h"
#include "src/objects/source-text-module-inl.h"
#include "src/objects/visitors.h"
#include "src/profiler/heap-profiler.h"
#include "src/profiler/tracing-cpu-profiler.h"
#include "src/regexp/regexp-stack.h"
#include "src/snapshot/embedded/embedded-data.h"
#include "src/snapshot/embedded/embedded-file-writer-interface.h"
#include "src/snapshot/read-only-deserializer.h"
#include "src/snapshot/shared-heap-deserializer.h"
#include "src/snapshot/startup-deserializer.h"
#include "src/strings/string-builder-inl.h"
#include "src/strings/string-stream.h"
#include "src/tasks/cancelable-task.h"
#include "src/tracing/tracing-category-observer.h"
#include "src/utils/address-map.h"
#include "src/utils/ostreams.h"
#include "src/utils/version.h"
#include "src/zone/accounting-allocator.h"
#include "src/zone/type-stats.h"
#ifdef V8_INTL_SUPPORT
#include "src/objects/intl-objects.h"
#include "unicode/locid.h"
#include "unicode/uobject.h"
#endif // V8_INTL_SUPPORT
#if V8_ENABLE_WEBASSEMBLY
#include "src/trap-handler/trap-handler.h"
#include "src/wasm/wasm-code-manager.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects.h"
#endif // V8_ENABLE_WEBASSEMBLY
#if defined(V8_OS_WIN64)
#include "src/diagnostics/unwinding-info-win64.h"
#endif // V8_OS_WIN64
#ifdef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
#include "src/base/platform/wrappers.h"
#include "src/heap/conservative-stack-visitor.h"
#endif
#if USE_SIMULATOR
#include "src/execution/simulator-base.h"
#endif
extern "C" const uint8_t* v8_Default_embedded_blob_code_;
extern "C" uint32_t v8_Default_embedded_blob_code_size_;
extern "C" const uint8_t* v8_Default_embedded_blob_data_;
extern "C" uint32_t v8_Default_embedded_blob_data_size_;
namespace v8 {
namespace internal {
#ifdef DEBUG
#define TRACE_ISOLATE(tag) \
do { \
if (FLAG_trace_isolates) { \
PrintF("Isolate %p (id %d)" #tag "\n", reinterpret_cast<void*>(this), \
id()); \
} \
} while (false)
#else
#define TRACE_ISOLATE(tag)
#endif
const uint8_t* DefaultEmbeddedBlobCode() {
return v8_Default_embedded_blob_code_;
}
uint32_t DefaultEmbeddedBlobCodeSize() {
return v8_Default_embedded_blob_code_size_;
}
const uint8_t* DefaultEmbeddedBlobData() {
return v8_Default_embedded_blob_data_;
}
uint32_t DefaultEmbeddedBlobDataSize() {
return v8_Default_embedded_blob_data_size_;
}
namespace {
// These variables provide access to the current embedded blob without requiring
// an isolate instance. This is needed e.g. by Code::InstructionStart, which may
// not have access to an isolate but still needs to access the embedded blob.
// The variables are initialized by each isolate in Init(). Writes and reads are
// relaxed since we can guarantee that the current thread has initialized these
// variables before accessing them. Different threads may race, but this is fine
// since they all attempt to set the same values of the blob pointer and size.
std::atomic<const uint8_t*> current_embedded_blob_code_(nullptr);
std::atomic<uint32_t> current_embedded_blob_code_size_(0);
std::atomic<const uint8_t*> current_embedded_blob_data_(nullptr);
std::atomic<uint32_t> current_embedded_blob_data_size_(0);
// The various workflows around embedded snapshots are fairly complex. We need
// to support plain old snapshot builds, nosnap builds, and the requirements of
// subtly different serialization tests. There's two related knobs to twiddle:
//
// - The default embedded blob may be overridden by setting the sticky embedded
// blob. This is set automatically whenever we create a new embedded blob.
//
// - Lifecycle management can be either manual or set to refcounting.
//
// A few situations to demonstrate their use:
//
// - A plain old snapshot build neither overrides the default blob nor
// refcounts.
//
// - mksnapshot sets the sticky blob and manually frees the embedded
// blob once done.
//
// - Most serializer tests do the same.
//
// - Nosnapshot builds set the sticky blob and enable refcounting.
// This mutex protects access to the following variables:
// - sticky_embedded_blob_code_
// - sticky_embedded_blob_code_size_
// - sticky_embedded_blob_data_
// - sticky_embedded_blob_data_size_
// - enable_embedded_blob_refcounting_
// - current_embedded_blob_refs_
base::LazyMutex current_embedded_blob_refcount_mutex_ = LAZY_MUTEX_INITIALIZER;
const uint8_t* sticky_embedded_blob_code_ = nullptr;
uint32_t sticky_embedded_blob_code_size_ = 0;
const uint8_t* sticky_embedded_blob_data_ = nullptr;
uint32_t sticky_embedded_blob_data_size_ = 0;
bool enable_embedded_blob_refcounting_ = true;
int current_embedded_blob_refs_ = 0;
const uint8_t* StickyEmbeddedBlobCode() { return sticky_embedded_blob_code_; }
uint32_t StickyEmbeddedBlobCodeSize() {
return sticky_embedded_blob_code_size_;
}
const uint8_t* StickyEmbeddedBlobData() { return sticky_embedded_blob_data_; }
uint32_t StickyEmbeddedBlobDataSize() {
return sticky_embedded_blob_data_size_;
}
void SetStickyEmbeddedBlob(const uint8_t* code, uint32_t code_size,
const uint8_t* data, uint32_t data_size) {
sticky_embedded_blob_code_ = code;
sticky_embedded_blob_code_size_ = code_size;
sticky_embedded_blob_data_ = data;
sticky_embedded_blob_data_size_ = data_size;
}
} // namespace
void DisableEmbeddedBlobRefcounting() {
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
enable_embedded_blob_refcounting_ = false;
}
void FreeCurrentEmbeddedBlob() {
CHECK(!enable_embedded_blob_refcounting_);
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
if (StickyEmbeddedBlobCode() == nullptr) return;
CHECK_EQ(StickyEmbeddedBlobCode(), Isolate::CurrentEmbeddedBlobCode());
CHECK_EQ(StickyEmbeddedBlobData(), Isolate::CurrentEmbeddedBlobData());
OffHeapInstructionStream::FreeOffHeapOffHeapInstructionStream(
const_cast<uint8_t*>(Isolate::CurrentEmbeddedBlobCode()),
Isolate::CurrentEmbeddedBlobCodeSize(),
const_cast<uint8_t*>(Isolate::CurrentEmbeddedBlobData()),
Isolate::CurrentEmbeddedBlobDataSize());
current_embedded_blob_code_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_code_size_.store(0, std::memory_order_relaxed);
current_embedded_blob_data_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_data_size_.store(0, std::memory_order_relaxed);
sticky_embedded_blob_code_ = nullptr;
sticky_embedded_blob_code_size_ = 0;
sticky_embedded_blob_data_ = nullptr;
sticky_embedded_blob_data_size_ = 0;
}
// static
bool Isolate::CurrentEmbeddedBlobIsBinaryEmbedded() {
// In some situations, we must be able to rely on the embedded blob being
// immortal immovable. This is the case if the blob is binary-embedded.
// See blob lifecycle controls above for descriptions of when the current
// embedded blob may change (e.g. in tests or mksnapshot). If the blob is
// binary-embedded, it is immortal immovable.
const uint8_t* code =
current_embedded_blob_code_.load(std::memory_order::memory_order_relaxed);
if (code == nullptr) return false;
return code == DefaultEmbeddedBlobCode();
}
void Isolate::SetEmbeddedBlob(const uint8_t* code, uint32_t code_size,
const uint8_t* data, uint32_t data_size) {
CHECK_NOT_NULL(code);
CHECK_NOT_NULL(data);
embedded_blob_code_ = code;
embedded_blob_code_size_ = code_size;
embedded_blob_data_ = data;
embedded_blob_data_size_ = data_size;
current_embedded_blob_code_.store(code, std::memory_order_relaxed);
current_embedded_blob_code_size_.store(code_size, std::memory_order_relaxed);
current_embedded_blob_data_.store(data, std::memory_order_relaxed);
current_embedded_blob_data_size_.store(data_size, std::memory_order_relaxed);
#ifdef DEBUG
// Verify that the contents of the embedded blob are unchanged from
// serialization-time, just to ensure the compiler isn't messing with us.
EmbeddedData d = EmbeddedData::FromBlob();
if (d.EmbeddedBlobDataHash() != d.CreateEmbeddedBlobDataHash()) {
FATAL(
"Embedded blob data section checksum verification failed. This "
"indicates that the embedded blob has been modified since compilation "
"time.");
}
if (FLAG_text_is_readable) {
if (d.EmbeddedBlobCodeHash() != d.CreateEmbeddedBlobCodeHash()) {
FATAL(
"Embedded blob code section checksum verification failed. This "
"indicates that the embedded blob has been modified since "
"compilation time. A common cause is a debugging breakpoint set "
"within builtin code.");
}
}
#endif // DEBUG
}
void Isolate::ClearEmbeddedBlob() {
CHECK(enable_embedded_blob_refcounting_);
CHECK_EQ(embedded_blob_code_, CurrentEmbeddedBlobCode());
CHECK_EQ(embedded_blob_code_, StickyEmbeddedBlobCode());
CHECK_EQ(embedded_blob_data_, CurrentEmbeddedBlobData());
CHECK_EQ(embedded_blob_data_, StickyEmbeddedBlobData());
embedded_blob_code_ = nullptr;
embedded_blob_code_size_ = 0;
embedded_blob_data_ = nullptr;
embedded_blob_data_size_ = 0;
current_embedded_blob_code_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_code_size_.store(0, std::memory_order_relaxed);
current_embedded_blob_data_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_data_size_.store(0, std::memory_order_relaxed);
sticky_embedded_blob_code_ = nullptr;
sticky_embedded_blob_code_size_ = 0;
sticky_embedded_blob_data_ = nullptr;
sticky_embedded_blob_data_size_ = 0;
}
const uint8_t* Isolate::embedded_blob_code() const {
return embedded_blob_code_;
}
uint32_t Isolate::embedded_blob_code_size() const {
return embedded_blob_code_size_;
}
const uint8_t* Isolate::embedded_blob_data() const {
return embedded_blob_data_;
}
uint32_t Isolate::embedded_blob_data_size() const {
return embedded_blob_data_size_;
}
// static
const uint8_t* Isolate::CurrentEmbeddedBlobCode() {
return current_embedded_blob_code_.load(
std::memory_order::memory_order_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobCodeSize() {
return current_embedded_blob_code_size_.load(
std::memory_order::memory_order_relaxed);
}
// static
const uint8_t* Isolate::CurrentEmbeddedBlobData() {
return current_embedded_blob_data_.load(
std::memory_order::memory_order_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobDataSize() {
return current_embedded_blob_data_size_.load(
std::memory_order::memory_order_relaxed);
}
// static
base::AddressRegion Isolate::GetShortBuiltinsCallRegion() {
// Update calculations below if the assert fails.
STATIC_ASSERT(kMaxPCRelativeCodeRangeInMB <= 4096);
if (kMaxPCRelativeCodeRangeInMB == 0) {
// Return empty region if pc-relative calls/jumps are not supported.
return base::AddressRegion(kNullAddress, 0);
}
constexpr size_t max_size = std::numeric_limits<size_t>::max();
if (uint64_t{kMaxPCRelativeCodeRangeInMB} * MB > max_size) {
// The whole addressable space is reachable with pc-relative calls/jumps.
return base::AddressRegion(kNullAddress, max_size);
}
constexpr size_t radius = kMaxPCRelativeCodeRangeInMB * MB;
DCHECK_LT(CurrentEmbeddedBlobCodeSize(), radius);
Address embedded_blob_code_start =
reinterpret_cast<Address>(CurrentEmbeddedBlobCode());
if (embedded_blob_code_start == kNullAddress) {
// Return empty region if there's no embedded blob.
return base::AddressRegion(kNullAddress, 0);
}
Address embedded_blob_code_end =
embedded_blob_code_start + CurrentEmbeddedBlobCodeSize();
Address region_start =
(embedded_blob_code_end > radius) ? (embedded_blob_code_end - radius) : 0;
Address region_end = embedded_blob_code_start + radius;
if (region_end < embedded_blob_code_start) {
region_end = static_cast<Address>(-1);
}
return base::AddressRegion(region_start, region_end - region_start);
}
size_t Isolate::HashIsolateForEmbeddedBlob() {
DCHECK(builtins_.is_initialized());
DCHECK(Builtins::AllBuiltinsAreIsolateIndependent());
DisallowGarbageCollection no_gc;
static constexpr size_t kSeed = 0;
size_t hash = kSeed;
// Hash data sections of builtin code objects.
for (Builtin builtin = Builtins::kFirst; builtin <= Builtins::kLast;
++builtin) {
Code code = FromCodeT(builtins()->code(builtin));
DCHECK(Internals::HasHeapObjectTag(code.ptr()));
uint8_t* const code_ptr =
reinterpret_cast<uint8_t*>(code.ptr() - kHeapObjectTag);
// These static asserts ensure we don't miss relevant fields. We don't hash
// pointer compression base, instruction/metadata size value and flags since
// they change when creating the off-heap trampolines. Other data fields
// must remain the same.
#ifdef V8_EXTERNAL_CODE_SPACE
STATIC_ASSERT(Code::kMainCageBaseUpper32BitsOffset == Code::kDataStart);
STATIC_ASSERT(Code::kInstructionSizeOffset ==
Code::kMainCageBaseUpper32BitsOffsetEnd + 1);
#else
STATIC_ASSERT(Code::kInstructionSizeOffset == Code::kDataStart);
#endif // V8_EXTERNAL_CODE_SPACE
STATIC_ASSERT(Code::kMetadataSizeOffset ==
Code::kInstructionSizeOffsetEnd + 1);
STATIC_ASSERT(Code::kFlagsOffset == Code::kMetadataSizeOffsetEnd + 1);
STATIC_ASSERT(Code::kBuiltinIndexOffset == Code::kFlagsOffsetEnd + 1);
static constexpr int kStartOffset = Code::kBuiltinIndexOffset;
for (int j = kStartOffset; j < Code::kUnalignedHeaderSize; j++) {
hash = base::hash_combine(hash, size_t{code_ptr[j]});
}
}
// The builtins constants table is also tightly tied to embedded builtins.
hash = base::hash_combine(
hash, static_cast<size_t>(heap_.builtins_constants_table().length()));
return hash;
}
base::Thread::LocalStorageKey Isolate::isolate_key_;
base::Thread::LocalStorageKey Isolate::per_isolate_thread_data_key_;
std::atomic<bool> Isolate::isolate_key_created_{false};
namespace {
// A global counter for all generated Isolates, might overflow.
std::atomic<int> isolate_counter{0};
} // namespace
Isolate::PerIsolateThreadData*
Isolate::FindOrAllocatePerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::Current();
PerIsolateThreadData* per_thread = nullptr;
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
if (per_thread == nullptr) {
if (FLAG_adjust_os_scheduling_parameters) {
base::OS::AdjustSchedulingParams();
}
per_thread = new PerIsolateThreadData(this, thread_id);
thread_data_table_.Insert(per_thread);
}
DCHECK(thread_data_table_.Lookup(thread_id) == per_thread);
}
return per_thread;
}
void Isolate::DiscardPerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::TryGetCurrent();
if (thread_id.IsValid()) {
DCHECK_NE(thread_manager_->mutex_owner_.load(std::memory_order_relaxed),
thread_id);
base::MutexGuard lock_guard(&thread_data_table_mutex_);
PerIsolateThreadData* per_thread = thread_data_table_.Lookup(thread_id);
if (per_thread) {
DCHECK(!per_thread->thread_state_);
thread_data_table_.Remove(per_thread);
}
}
}
Isolate::PerIsolateThreadData* Isolate::FindPerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::Current();
return FindPerThreadDataForThread(thread_id);
}
Isolate::PerIsolateThreadData* Isolate::FindPerThreadDataForThread(
ThreadId thread_id) {
PerIsolateThreadData* per_thread = nullptr;
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
}
return per_thread;
}
void Isolate::InitializeOncePerProcess() {
isolate_key_ = base::Thread::CreateThreadLocalKey();
bool expected = false;
CHECK(isolate_key_created_.compare_exchange_strong(
expected, true, std::memory_order_relaxed));
per_isolate_thread_data_key_ = base::Thread::CreateThreadLocalKey();
}
void Isolate::DisposeOncePerProcess() {
bool expected = true;
CHECK(isolate_key_created_.compare_exchange_strong(
expected, false, std::memory_order_relaxed));
}
Address Isolate::get_address_from_id(IsolateAddressId id) {
return isolate_addresses_[id];
}
char* Isolate::Iterate(RootVisitor* v, char* thread_storage) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(thread_storage);
Iterate(v, thread);
return thread_storage + sizeof(ThreadLocalTop);
}
void Isolate::IterateThread(ThreadVisitor* v, char* t) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(t);
v->VisitThread(this, thread);
}
void Isolate::Iterate(RootVisitor* v, ThreadLocalTop* thread) {
// Visit the roots from the top for a given thread.
v->VisitRootPointer(Root::kStackRoots, nullptr,
FullObjectSlot(&thread->pending_exception_));
v->VisitRootPointer(Root::kStackRoots, nullptr,
FullObjectSlot(&thread->pending_message_));
v->VisitRootPointer(Root::kStackRoots, nullptr,
FullObjectSlot(&thread->context_));
v->VisitRootPointer(Root::kStackRoots, nullptr,
FullObjectSlot(&thread->scheduled_exception_));
for (v8::TryCatch* block = thread->try_catch_handler_; block != nullptr;
block = block->next_) {
// TODO(3770): Make TryCatch::exception_ an Address (and message_obj_ too).
v->VisitRootPointer(
Root::kStackRoots, nullptr,
FullObjectSlot(reinterpret_cast<Address>(&(block->exception_))));
v->VisitRootPointer(
Root::kStackRoots, nullptr,
FullObjectSlot(reinterpret_cast<Address>(&(block->message_obj_))));
}
#ifdef V8_ENABLE_CONSERVATIVE_STACK_SCANNING
ConservativeStackVisitor stack_visitor(this, v);
thread_local_top()->stack_.IteratePointers(&stack_visitor);
#endif
// Iterate over pointers on native execution stack.
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmCodeRefScope wasm_code_ref_scope;
if (FLAG_experimental_wasm_stack_switching) {
wasm::StackMemory* current = wasm_stacks_;
DCHECK_NOT_NULL(current);
do {
if (current->IsActive()) {
// The active stack's jump buffer does not match the current state, use
// the thread info below instead.
current = current->next();
continue;
}
for (StackFrameIterator it(this, current); !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
current = current->next();
} while (current != wasm_stacks_);
}
#endif // V8_ENABLE_WEBASSEMBLY
for (StackFrameIterator it(this, thread); !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
}
void Isolate::Iterate(RootVisitor* v) {
ThreadLocalTop* current_t = thread_local_top();
Iterate(v, current_t);
}
void Isolate::RegisterTryCatchHandler(v8::TryCatch* that) {
thread_local_top()->try_catch_handler_ = that;
}
void Isolate::UnregisterTryCatchHandler(v8::TryCatch* that) {
DCHECK(thread_local_top()->try_catch_handler_ == that);
thread_local_top()->try_catch_handler_ = that->next_;
}
Handle<String> Isolate::StackTraceString() {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
HeapStringAllocator allocator;
StringStream::ClearMentionedObjectCache(this);
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator);
Handle<String> stack_trace = accumulator.ToString(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
return stack_trace;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToStdOut();
return factory()->empty_string();
} else {
base::OS::Abort();
}
}
void Isolate::PushStackTraceAndDie(void* ptr1, void* ptr2, void* ptr3,
void* ptr4) {
StackTraceFailureMessage message(this,
StackTraceFailureMessage::kIncludeStackTrace,
ptr1, ptr2, ptr3, ptr4);
message.Print();
base::OS::Abort();
}
void Isolate::PushParamsAndDie(void* ptr1, void* ptr2, void* ptr3, void* ptr4,
void* ptr5, void* ptr6) {
StackTraceFailureMessage message(
this, StackTraceFailureMessage::kDontIncludeStackTrace, ptr1, ptr2, ptr3,
ptr4, ptr5, ptr6);
message.Print();
base::OS::Abort();
}
void StackTraceFailureMessage::Print() volatile {
// Print the details of this failure message object, including its own address
// to force stack allocation.
base::OS::PrintError(
"Stacktrace:\n ptr1=%p\n ptr2=%p\n ptr3=%p\n ptr4=%p\n "
"ptr5=%p\n ptr6=%p\n failure_message_object=%p\n%s",
ptr1_, ptr2_, ptr3_, ptr4_, ptr5_, ptr6_, this, &js_stack_trace_[0]);
}
StackTraceFailureMessage::StackTraceFailureMessage(
Isolate* isolate, StackTraceFailureMessage::StackTraceMode mode, void* ptr1,
void* ptr2, void* ptr3, void* ptr4, void* ptr5, void* ptr6) {
isolate_ = isolate;
ptr1_ = ptr1;
ptr2_ = ptr2;
ptr3_ = ptr3;
ptr4_ = ptr4;
ptr5_ = ptr5;
ptr6_ = ptr6;
// Write a stracktrace into the {js_stack_trace_} buffer.
const size_t buffer_length = arraysize(js_stack_trace_);
memset(&js_stack_trace_, 0, buffer_length);
memset(&code_objects_, 0, sizeof(code_objects_));
if (mode == kIncludeStackTrace) {
FixedStringAllocator fixed(&js_stack_trace_[0], buffer_length - 1);
StringStream accumulator(&fixed, StringStream::kPrintObjectConcise);
isolate->PrintStack(&accumulator, Isolate::kPrintStackVerbose);
// Keeping a reference to the last code objects to increase likelyhood that
// they get included in the minidump.
const size_t code_objects_length = arraysize(code_objects_);
size_t i = 0;
StackFrameIterator it(isolate);
for (; !it.done() && i < code_objects_length; it.Advance()) {
code_objects_[i++] =
reinterpret_cast<void*>(it.frame()->unchecked_code().ptr());
}
}
}
bool NoExtension(const v8::FunctionCallbackInfo<v8::Value>&) { return false; }
namespace {
class CallSiteBuilder {
public:
CallSiteBuilder(Isolate* isolate, FrameSkipMode mode, int limit,
Handle<Object> caller)
: isolate_(isolate),
mode_(mode),
limit_(limit),
caller_(caller),
skip_next_frame_(mode != SKIP_NONE) {
DCHECK_IMPLIES(mode_ == SKIP_UNTIL_SEEN, caller_->IsJSFunction());
// Modern web applications are usually built with multiple layers of
// framework and library code, and stack depth tends to be more than
// a dozen frames, so we over-allocate a bit here to avoid growing
// the elements array in the common case.
elements_ = isolate->factory()->NewFixedArray(std::min(64, limit));
}
bool Visit(FrameSummary const& summary) {
if (Full()) return false;
#if V8_ENABLE_WEBASSEMBLY
if (summary.IsWasm()) {
AppendWasmFrame(summary.AsWasm());
return true;
}
#endif // V8_ENABLE_WEBASSEMBLY
AppendJavaScriptFrame(summary.AsJavaScript());
return true;
}
void AppendAsyncFrame(Handle<JSGeneratorObject> generator_object) {
Handle<JSFunction> function(generator_object->function(), isolate_);
if (!IsVisibleInStackTrace(function)) return;
int flags = CallSiteInfo::kIsAsync;
if (IsStrictFrame(function)) flags |= CallSiteInfo::kIsStrict;
Handle<Object> receiver(generator_object->receiver(), isolate_);
Handle<BytecodeArray> code(function->shared().GetBytecodeArray(isolate_),
isolate_);
// The stored bytecode offset is relative to a different base than what
// is used in the source position table, hence the subtraction.
int offset = Smi::ToInt(generator_object->input_or_debug_pos()) -
(BytecodeArray::kHeaderSize - kHeapObjectTag);
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
if (V8_UNLIKELY(FLAG_detailed_error_stack_trace)) {
parameters = isolate_->factory()->CopyFixedArrayUpTo(
handle(generator_object->parameters_and_registers(), isolate_),
function->shared()
.internal_formal_parameter_count_without_receiver());
}
AppendFrame(receiver, function, code, offset, flags, parameters);
}
void AppendPromiseCombinatorFrame(Handle<JSFunction> element_function,
Handle<JSFunction> combinator) {
if (!IsVisibleInStackTrace(combinator)) return;
int flags =
CallSiteInfo::kIsAsync | CallSiteInfo::kIsSourcePositionComputed;
Handle<Object> receiver(combinator->native_context().promise_function(),
isolate_);
// TODO(v8:11880): avoid roundtrips between cdc and code.
Handle<Code> code(FromCodeT(combinator->code()), isolate_);
// TODO(mmarchini) save Promises list from the Promise combinator
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
// We store the offset of the promise into the element function's
// hash field for element callbacks.
int promise_index =
Smi::ToInt(Smi::cast(element_function->GetIdentityHash())) - 1;
AppendFrame(receiver, combinator, code, promise_index, flags, parameters);
}
void AppendJavaScriptFrame(
FrameSummary::JavaScriptFrameSummary const& summary) {
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(summary.function())) return;
int flags = 0;
Handle<JSFunction> function = summary.function();
if (IsStrictFrame(function)) flags |= CallSiteInfo::kIsStrict;
if (summary.is_constructor()) flags |= CallSiteInfo::kIsConstructor;
AppendFrame(summary.receiver(), function, summary.abstract_code(),
summary.code_offset(), flags, summary.parameters());
}
#if V8_ENABLE_WEBASSEMBLY
void AppendWasmFrame(FrameSummary::WasmFrameSummary const& summary) {
if (summary.code()->kind() != wasm::WasmCode::kWasmFunction) return;
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = CallSiteInfo::kIsWasm;
if (instance->module_object().is_asm_js()) {
flags |= CallSiteInfo::kIsAsmJsWasm;
if (summary.at_to_number_conversion()) {
flags |= CallSiteInfo::kIsAsmJsAtNumberConversion;
}
}
auto code = Managed<wasm::GlobalWasmCodeRef>::Allocate(
isolate_, 0, summary.code(),
instance->module_object().shared_native_module());
AppendFrame(instance,
handle(Smi::FromInt(summary.function_index()), isolate_), code,
summary.code_offset(), flags,
isolate_->factory()->empty_fixed_array());
}
#endif // V8_ENABLE_WEBASSEMBLY
bool Full() { return index_ >= limit_; }
Handle<FixedArray> Build() {
return FixedArray::ShrinkOrEmpty(isolate_, elements_, index_);
}
private:
// Poison stack frames below the first strict mode frame.
// The stack trace API should not expose receivers and function
// objects on frames deeper than the top-most one with a strict mode
// function.
bool IsStrictFrame(Handle<JSFunction> function) {
if (!encountered_strict_function_) {
encountered_strict_function_ =
is_strict(function->shared().language_mode());
}
return encountered_strict_function_;
}
// Determines whether the given stack frame should be displayed in a stack
// trace.
bool IsVisibleInStackTrace(Handle<JSFunction> function) {
return ShouldIncludeFrame(function) && IsNotHidden(function);
}
// This mechanism excludes a number of uninteresting frames from the stack
// trace. This can be be the first frame (which will be a builtin-exit frame
// for the error constructor builtin) or every frame until encountering a
// user-specified function.
bool ShouldIncludeFrame(Handle<JSFunction> function) {
switch (mode_) {
case SKIP_NONE:
return true;
case SKIP_FIRST:
if (!skip_next_frame_) return true;
skip_next_frame_ = false;
return false;
case SKIP_UNTIL_SEEN:
if (skip_next_frame_ && (*function == *caller_)) {
skip_next_frame_ = false;
return false;
}
return !skip_next_frame_;
}
UNREACHABLE();
}
bool IsNotHidden(Handle<JSFunction> function) {
// TODO(szuend): Remove this check once the flag is enabled
// by default.
if (!FLAG_experimental_stack_trace_frames &&
function->shared().IsApiFunction()) {
return false;
}
// Functions defined not in user scripts are not visible unless directly
// exposed, in which case the native flag is set.
// The --builtins-in-stack-traces command line flag allows including
// internal call sites in the stack trace for debugging purposes.
if (!FLAG_builtins_in_stack_traces &&
!function->shared().IsUserJavaScript()) {
return function->shared().native() || function->shared().IsApiFunction();
}
return true;
}
void AppendFrame(Handle<Object> receiver_or_instance, Handle<Object> function,
Handle<HeapObject> code, int offset, int flags,
Handle<FixedArray> parameters) {
if (receiver_or_instance->IsTheHole(isolate_)) {
// TODO(jgruber): Fix all cases in which frames give us a hole value
// (e.g. the receiver in RegExp constructor frames).
receiver_or_instance = isolate_->factory()->undefined_value();
}
auto info = isolate_->factory()->NewCallSiteInfo(
receiver_or_instance, function, code, offset, flags, parameters);
elements_ = FixedArray::SetAndGrow(isolate_, elements_, index_++, info);
}
Isolate* isolate_;
const FrameSkipMode mode_;
int index_ = 0;
const int limit_;
const Handle<Object> caller_;
bool skip_next_frame_;
bool encountered_strict_function_ = false;
Handle<FixedArray> elements_;
};
bool GetStackTraceLimit(Isolate* isolate, int* result) {
if (FLAG_correctness_fuzzer_suppressions) return false;
Handle<JSObject> error = isolate->error_function();
Handle<String> key = isolate->factory()->stackTraceLimit_string();
Handle<Object> stack_trace_limit = JSReceiver::GetDataProperty(error, key);
if (!stack_trace_limit->IsNumber()) return false;
// Ensure that limit is not negative.
*result = std::max(FastD2IChecked(stack_trace_limit->Number()), 0);
if (*result != FLAG_stack_trace_limit) {
isolate->CountUsage(v8::Isolate::kErrorStackTraceLimit);
}
return true;
}
bool IsBuiltinFunction(Isolate* isolate, HeapObject object, Builtin builtin) {
if (!object.IsJSFunction()) return false;
JSFunction const function = JSFunction::cast(object);
return function.code() == isolate->builtins()->code(builtin);
}
void CaptureAsyncStackTrace(Isolate* isolate, Handle<JSPromise> promise,
CallSiteBuilder* builder) {
while (!builder->Full()) {
// Check that the {promise} is not settled.
if (promise->status() != Promise::kPending) return;
// Check that we have exactly one PromiseReaction on the {promise}.
if (!promise->reactions().IsPromiseReaction()) return;
Handle<PromiseReaction> reaction(
PromiseReaction::cast(promise->reactions()), isolate);
if (!reaction->next().IsSmi()) return;
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kAsyncFunctionAwaitResolveClosure) ||
IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kAsyncGeneratorAwaitResolveClosure) ||
IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kAsyncGeneratorYieldResolveClosure)) {
// Now peek into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Handle<Context> context(
JSFunction::cast(reaction->fulfill_handler()).context(), isolate);
Handle<JSGeneratorObject> generator_object(
JSGeneratorObject::cast(context->extension()), isolate);
CHECK(generator_object->is_suspended());
// Append async frame corresponding to the {generator_object}.
builder->AppendAsyncFrame(generator_object);
// Try to continue from here.
if (generator_object->IsJSAsyncFunctionObject()) {
Handle<JSAsyncFunctionObject> async_function_object =
Handle<JSAsyncFunctionObject>::cast(generator_object);
promise = handle(async_function_object->promise(), isolate);
} else {
Handle<JSAsyncGeneratorObject> async_generator_object =
Handle<JSAsyncGeneratorObject>::cast(generator_object);
if (async_generator_object->queue().IsUndefined(isolate)) return;
Handle<AsyncGeneratorRequest> async_generator_request(
AsyncGeneratorRequest::cast(async_generator_object->queue()),
isolate);
promise = handle(JSPromise::cast(async_generator_request->promise()),
isolate);
}
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kPromiseAllResolveElementClosure)) {
Handle<JSFunction> function(JSFunction::cast(reaction->fulfill_handler()),
isolate);
Handle<Context> context(function->context(), isolate);
Handle<JSFunction> combinator(context->native_context().promise_all(),
isolate);
builder->AppendPromiseCombinatorFrame(function, combinator);
// Now peak into the Promise.all() resolve element context to
// find the promise capability that's being resolved when all
// the concurrent promises resolve.
int const index =
PromiseBuiltins::kPromiseAllResolveElementCapabilitySlot;
Handle<PromiseCapability> capability(
PromiseCapability::cast(context->get(index)), isolate);
if (!capability->promise().IsJSPromise()) return;
promise = handle(JSPromise::cast(capability->promise()), isolate);
} else if (IsBuiltinFunction(isolate, reaction->reject_handler(),
Builtin::kPromiseAnyRejectElementClosure)) {
Handle<JSFunction> function(JSFunction::cast(reaction->reject_handler()),
isolate);
Handle<Context> context(function->context(), isolate);
Handle<JSFunction> combinator(context->native_context().promise_any(),
isolate);
builder->AppendPromiseCombinatorFrame(function, combinator);
// Now peak into the Promise.any() reject element context to
// find the promise capability that's being resolved when any of
// the concurrent promises resolve.
int const index = PromiseBuiltins::kPromiseAnyRejectElementCapabilitySlot;
Handle<PromiseCapability> capability(
PromiseCapability::cast(context->get(index)), isolate);
if (!capability->promise().IsJSPromise()) return;
promise = handle(JSPromise::cast(capability->promise()), isolate);
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kPromiseCapabilityDefaultResolve)) {
Handle<JSFunction> function(JSFunction::cast(reaction->fulfill_handler()),
isolate);
Handle<Context> context(function->context(), isolate);
promise =
handle(JSPromise::cast(context->get(PromiseBuiltins::kPromiseSlot)),
isolate);
} else {
// We have some generic promise chain here, so try to
// continue with the chained promise on the reaction
// (only works for native promise chains).
Handle<HeapObject> promise_or_capability(
reaction->promise_or_capability(), isolate);
if (promise_or_capability->IsJSPromise()) {
promise = Handle<JSPromise>::cast(promise_or_capability);
} else if (promise_or_capability->IsPromiseCapability()) {
Handle<PromiseCapability> capability =
Handle<PromiseCapability>::cast(promise_or_capability);
if (!capability->promise().IsJSPromise()) return;
promise = handle(JSPromise::cast(capability->promise()), isolate);
} else {
// Otherwise the {promise_or_capability} must be undefined here.
CHECK(promise_or_capability->IsUndefined(isolate));
return;
}
}
}
}
void CaptureAsyncStackTrace(Isolate* isolate, CallSiteBuilder* builder) {
Handle<Object> current_microtask = isolate->factory()->current_microtask();
if (current_microtask->IsPromiseReactionJobTask()) {
Handle<PromiseReactionJobTask> promise_reaction_job_task =
Handle<PromiseReactionJobTask>::cast(current_microtask);
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
if (IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtin::kAsyncFunctionAwaitResolveClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtin::kAsyncGeneratorAwaitResolveClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtin::kAsyncGeneratorYieldResolveClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtin::kAsyncFunctionAwaitRejectClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtin::kAsyncGeneratorAwaitRejectClosure)) {
// Now peek into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Handle<Context> context(
JSFunction::cast(promise_reaction_job_task->handler()).context(),
isolate);
Handle<JSGeneratorObject> generator_object(
JSGeneratorObject::cast(context->extension()), isolate);
if (generator_object->is_executing()) {
if (generator_object->IsJSAsyncFunctionObject()) {
Handle<JSAsyncFunctionObject> async_function_object =
Handle<JSAsyncFunctionObject>::cast(generator_object);
Handle<JSPromise> promise(async_function_object->promise(), isolate);
CaptureAsyncStackTrace(isolate, promise, builder);
} else {
Handle<JSAsyncGeneratorObject> async_generator_object =
Handle<JSAsyncGeneratorObject>::cast(generator_object);
Handle<Object> queue(async_generator_object->queue(), isolate);
if (!queue->IsUndefined(isolate)) {
Handle<AsyncGeneratorRequest> async_generator_request =
Handle<AsyncGeneratorRequest>::cast(queue);
Handle<JSPromise> promise(
JSPromise::cast(async_generator_request->promise()), isolate);
CaptureAsyncStackTrace(isolate, promise, builder);
}
}
}
} else {
// The {promise_reaction_job_task} doesn't belong to an await (or
// yield inside an async generator), but we might still be able to
// find an async frame if we follow along the chain of promises on
// the {promise_reaction_job_task}.
Handle<HeapObject> promise_or_capability(
promise_reaction_job_task->promise_or_capability(), isolate);
if (promise_or_capability->IsJSPromise()) {
Handle<JSPromise> promise =
Handle<JSPromise>::cast(promise_or_capability);
CaptureAsyncStackTrace(isolate, promise, builder);
}
}
}
}
template <typename Visitor>
void VisitStack(Isolate* isolate, Visitor* visitor,
StackTrace::StackTraceOptions options = StackTrace::kDetailed) {
DisallowJavascriptExecution no_js(isolate);
for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
switch (frame->type()) {
case StackFrame::BUILTIN_EXIT:
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION:
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BASELINE:
case StackFrame::BUILTIN:
#if V8_ENABLE_WEBASSEMBLY
case StackFrame::WASM:
#endif // V8_ENABLE_WEBASSEMBLY
{
// A standard frame may include many summarized frames (due to
// inlining).
std::vector<FrameSummary> summaries;
CommonFrame::cast(frame)->Summarize(&summaries);
for (auto rit = summaries.rbegin(); rit != summaries.rend(); ++rit) {
FrameSummary& summary = *rit;
// Skip frames from other origins when asked to do so.
if (!(options & StackTrace::kExposeFramesAcrossSecurityOrigins) &&
!summary.native_context()->HasSameSecurityTokenAs(
isolate->context())) {
continue;
}
if (!visitor->Visit(summary)) return;
}
break;
}
default:
break;
}
}
}
Handle<FixedArray> CaptureSimpleStackTrace(Isolate* isolate, int limit,
FrameSkipMode mode,
Handle<Object> caller) {
TRACE_EVENT_BEGIN1(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__,
"maxFrameCount", limit);
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmCodeRefScope code_ref_scope;
#endif // V8_ENABLE_WEBASSEMBLY
CallSiteBuilder builder(isolate, mode, limit, caller);
VisitStack(isolate, &builder);
// If --async-stack-traces are enabled and the "current microtask" is a
// PromiseReactionJobTask, we try to enrich the stack trace with async
// frames.
if (FLAG_async_stack_traces) {
CaptureAsyncStackTrace(isolate, &builder);
}
Handle<FixedArray> stack_trace = builder.Build();
TRACE_EVENT_END1(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__,
"frameCount", stack_trace->length());
return stack_trace;
}
} // namespace
MaybeHandle<JSObject> Isolate::CaptureAndSetErrorStack(
Handle<JSObject> error_object, FrameSkipMode mode, Handle<Object> caller) {
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__);
Handle<Object> error_stack = factory()->undefined_value();
// Capture the "simple stack trace" for the error.stack property,
// which can be disabled by setting Error.stackTraceLimit to a non
// number value or simply deleting the property. If the inspector
// is active, and requests more stack frames than the JavaScript
// program itself, we collect up to the maximum.
int stack_trace_limit = 0;
if (GetStackTraceLimit(this, &stack_trace_limit)) {
int limit = stack_trace_limit;
if (capture_stack_trace_for_uncaught_exceptions_ &&
!(stack_trace_for_uncaught_exceptions_options_ &
StackTrace::kExposeFramesAcrossSecurityOrigins)) {
// Collect up to the maximum of what the JavaScript program and
// the inspector want. There's a special case here where the API
// can ask the stack traces to also include cross-origin frames,
// in which case we collect a separate trace below. Note that
// the inspector doesn't use this option, so we could as well
// just deprecate this in the future.
if (limit < stack_trace_for_uncaught_exceptions_frame_limit_) {
limit = stack_trace_for_uncaught_exceptions_frame_limit_;
}
}
error_stack = CaptureSimpleStackTrace(this, limit, mode, caller);
}
// Next is the inspector part: Depending on whether we got a "simple
// stack trace" above and whether that's usable (meaning the API
// didn't request to include cross-origin frames), we remember the
// cap for the stack trace (either a positive limit indicating that
// the Error.stackTraceLimit value was below what was requested via
// the API, or a negative limit to indicate the opposite), or we
// collect a "detailed stack trace" eagerly and stash that away.
if (capture_stack_trace_for_uncaught_exceptions_) {
Handle<Object> limit_or_stack_frame_infos;
if (error_stack->IsUndefined(this) ||
(stack_trace_for_uncaught_exceptions_options_ &
StackTrace::kExposeFramesAcrossSecurityOrigins)) {
limit_or_stack_frame_infos = CaptureDetailedStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
} else {
int limit =
stack_trace_limit > stack_trace_for_uncaught_exceptions_frame_limit_
? -stack_trace_for_uncaught_exceptions_frame_limit_
: stack_trace_limit;
limit_or_stack_frame_infos = handle(Smi::FromInt(limit), this);
}
error_stack =
factory()->NewErrorStackData(error_stack, limit_or_stack_frame_infos);
}
RETURN_ON_EXCEPTION(
this,
JSObject::SetProperty(this, error_object, factory()->error_stack_symbol(),
error_stack, StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError)),
JSObject);
return error_object;
}
Handle<FixedArray> Isolate::GetDetailedStackTrace(
Handle<JSReceiver> error_object) {
Handle<Object> error_stack = JSReceiver::GetDataProperty(
error_object, factory()->error_stack_symbol());
if (!error_stack->IsErrorStackData()) {
return Handle<FixedArray>();
}
Handle<ErrorStackData> error_stack_data =
Handle<ErrorStackData>::cast(error_stack);
ErrorStackData::EnsureStackFrameInfos(this, error_stack_data);
if (!error_stack_data->limit_or_stack_frame_infos().IsFixedArray()) {
return Handle<FixedArray>();
}
return handle(
FixedArray::cast(error_stack_data->limit_or_stack_frame_infos()), this);
}
Handle<FixedArray> Isolate::GetSimpleStackTrace(
Handle<JSReceiver> error_object) {
Handle<Object> error_stack = JSReceiver::GetDataProperty(
error_object, factory()->error_stack_symbol());
if (error_stack->IsFixedArray()) {
return Handle<FixedArray>::cast(error_stack);
}
if (!error_stack->IsErrorStackData()) {
return factory()->empty_fixed_array();
}
Handle<ErrorStackData> error_stack_data =
Handle<ErrorStackData>::cast(error_stack);
if (!error_stack_data->HasCallSiteInfos()) {
return factory()->empty_fixed_array();
}
return handle(error_stack_data->call_site_infos(), this);
}
Address Isolate::GetAbstractPC(int* line, int* column) {
JavaScriptFrameIterator it(this);
if (it.done()) {
*line = -1;
*column = -1;
return kNullAddress;
}
JavaScriptFrame* frame = it.frame();
DCHECK(!frame->is_builtin());
Handle<SharedFunctionInfo> shared = handle(frame->function().shared(), this);
SharedFunctionInfo::EnsureSourcePositionsAvailable(this, shared);
int position = frame->position();
Object maybe_script = frame->function().shared().script();
if (maybe_script.IsScript()) {
Handle<Script> script(Script::cast(maybe_script), this);
Script::PositionInfo info;
Script::GetPositionInfo(script, position, &info, Script::WITH_OFFSET);
*line = info.line + 1;
*column = info.column + 1;
} else {
*line = position;
*column = -1;
}
if (frame->is_unoptimized()) {
UnoptimizedFrame* iframe = static_cast<UnoptimizedFrame*>(frame);
Address bytecode_start =
iframe->GetBytecodeArray().GetFirstBytecodeAddress();
return bytecode_start + iframe->GetBytecodeOffset();
}
return frame->pc();
}
namespace {
class StackFrameBuilder {
public:
StackFrameBuilder(Isolate* isolate, int limit)
: isolate_(isolate),
frames_(isolate_->factory()->empty_fixed_array()),
index_(0),
limit_(limit) {}
bool Visit(FrameSummary& summary) {
// Check if we have enough capacity left.
if (index_ >= limit_) return false;
// Skip frames that aren't subject to debugging.
if (!summary.is_subject_to_debugging()) return true;
Handle<StackFrameInfo> frame = summary.CreateStackFrameInfo();
frames_ = FixedArray::SetAndGrow(isolate_, frames_, index_++, frame);
return true;
}
Handle<FixedArray> Build() {
return FixedArray::ShrinkOrEmpty(isolate_, frames_, index_);
}
private:
Isolate* isolate_;
Handle<FixedArray> frames_;
int index_;
int limit_;
};
} // namespace
Handle<FixedArray> Isolate::CaptureDetailedStackTrace(
int limit, StackTrace::StackTraceOptions options) {
TRACE_EVENT_BEGIN1(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__,
"maxFrameCount", limit);
StackFrameBuilder builder(this, limit);
VisitStack(this, &builder, options);
Handle<FixedArray> stack_trace = builder.Build();
TRACE_EVENT_END1(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__,
"frameCount", stack_trace->length());
return stack_trace;
}
namespace {
class CurrentScriptNameStackVisitor {
public:
explicit CurrentScriptNameStackVisitor(Isolate* isolate)
: isolate_(isolate) {}
bool Visit(FrameSummary& summary) {
// Skip frames that aren't subject to debugging. Keep this in sync with
// StackFrameBuilder::Visit so both visitors visit the same frames.
if (!summary.is_subject_to_debugging()) return true;
// Frames that are subject to debugging always have a valid script object.
Handle<Script> script = Handle<Script>::cast(summary.script());
Handle<Object> name_or_url_obj =
handle(script->GetNameOrSourceURL(), isolate_);
if (!name_or_url_obj->IsString()) return true;
Handle<String> name_or_url = Handle<String>::cast(name_or_url_obj);
if (!name_or_url->length()) return true;
name_or_url_ = name_or_url;
return false;
}
Handle<String> CurrentScriptNameOrSourceURL() const { return name_or_url_; }
private:
Isolate* const isolate_;
Handle<String> name_or_url_;
};
} // namespace
Handle<String> Isolate::CurrentScriptNameOrSourceURL() {
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), __func__);
CurrentScriptNameStackVisitor visitor(this);
VisitStack(this, &visitor);
return visitor.CurrentScriptNameOrSourceURL();
}
void Isolate::PrintStack(FILE* out, PrintStackMode mode) {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
StringStream::ClearMentionedObjectCache(this);
HeapStringAllocator allocator;
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator, mode);
accumulator.OutputToFile(out);
InitializeLoggingAndCounters();
accumulator.Log(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToFile(out);
}
}
static void PrintFrames(Isolate* isolate, StringStream* accumulator,
StackFrame::PrintMode mode) {
StackFrameIterator it(isolate);
for (int i = 0; !it.done(); it.Advance()) {
it.frame()->Print(accumulator, mode, i++);
}
}
void Isolate::PrintStack(StringStream* accumulator, PrintStackMode mode) {
HandleScope scope(this);
DCHECK(accumulator->IsMentionedObjectCacheClear(this));
// Avoid printing anything if there are no frames.
if (c_entry_fp(thread_local_top()) == 0) return;
accumulator->Add(
"\n==== JS stack trace =========================================\n\n");
PrintFrames(this, accumulator, StackFrame::OVERVIEW);
if (mode == kPrintStackVerbose) {
accumulator->Add(
"\n==== Details ================================================\n\n");
PrintFrames(this, accumulator, StackFrame::DETAILS);
accumulator->PrintMentionedObjectCache(this);
}
accumulator->Add("=====================\n\n");
}
void Isolate::SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback) {
thread_local_top()->failed_access_check_callback_ = callback;
}
void Isolate::ReportFailedAccessCheck(Handle<JSObject> receiver) {
if (!thread_local_top()->failed_access_check_callback_) {
return ScheduleThrow(*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
DCHECK(receiver->IsAccessCheckNeeded());
DCHECK(!context().is_null());
// Get the data object from access check info.
HandleScope scope(this);
Handle<Object> data;
{
DisallowGarbageCollection no_gc;
AccessCheckInfo access_check_info = AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) {
no_gc.Release();
return ScheduleThrow(
*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
data = handle(access_check_info.data(), this);
}
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
thread_local_top()->failed_access_check_callback_(
v8::Utils::ToLocal(receiver), v8::ACCESS_HAS, v8::Utils::ToLocal(data));
}
bool Isolate::MayAccess(Handle<Context> accessing_context,
Handle<JSObject> receiver) {
DCHECK(receiver->IsJSGlobalProxy() || receiver->IsAccessCheckNeeded());
// Check for compatibility between the security tokens in the
// current lexical context and the accessed object.
// During bootstrapping, callback functions are not enabled yet.
if (bootstrapper()->IsActive()) return true;
{
DisallowGarbageCollection no_gc;
if (receiver->IsJSGlobalProxy()) {
Object receiver_context = JSGlobalProxy::cast(*receiver).native_context();
if (!receiver_context.IsContext()) return false;
// Get the native context of current top context.
// avoid using Isolate::native_context() because it uses Handle.
Context native_context =
accessing_context->global_object().native_context();
if (receiver_context == native_context) return true;
if (Context::cast(receiver_context).security_token() ==
native_context.security_token())
return true;
}
}
HandleScope scope(this);
Handle<Object> data;
v8::AccessCheckCallback callback = nullptr;
{
DisallowGarbageCollection no_gc;
AccessCheckInfo access_check_info = AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) return false;
Object fun_obj = access_check_info.callback();
callback = v8::ToCData<v8::AccessCheckCallback>(fun_obj);
data = handle(access_check_info.data(), this);
}
LOG(this, ApiSecurityCheck());
{
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
return callback(v8::Utils::ToLocal(accessing_context),
v8::Utils::ToLocal(receiver), v8::Utils::ToLocal(data));
}
}
Object Isolate::StackOverflow() {
// Whoever calls this method should not have overflown the stack limit by too
// much. Otherwise we risk actually running out of stack space.
// We allow for up to 8kB overflow, because we typically allow up to 4KB
// overflow per frame in generated code, but might call through more smaller
// frames until we reach this method.
// If this DCHECK fails, one of the frames on the stack should be augmented by
// an additional stack check.
#if defined(V8_USE_ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER)
// Allow for a bit more overflow in sanitizer builds, because C++ frames take
// significantly more space there.
DCHECK_GE(GetCurrentStackPosition(), stack_guard()->real_climit() - 32 * KB);
#else
DCHECK_GE(GetCurrentStackPosition(), stack_guard()->real_climit() - 8 * KB);
#endif
if (FLAG_correctness_fuzzer_suppressions) {
FATAL("Aborting on stack overflow");
}
DisallowJavascriptExecution no_js(this);
HandleScope scope(this);
Handle<JSFunction> fun = range_error_function();
Handle<Object> msg = factory()->NewStringFromAsciiChecked(
MessageFormatter::TemplateString(MessageTemplate::kStackOverflow));
Handle<Object> options = factory()->undefined_value();
Handle<Object> no_caller;
Handle<JSObject> exception;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
this, exception,
ErrorUtils::Construct(this, fun, fun, msg, options, SKIP_NONE, no_caller,
ErrorUtils::StackTraceCollection::kEnabled));
JSObject::AddProperty(this, exception, factory()->wasm_uncatchable_symbol(),
factory()->true_value(), NONE);
Throw(*exception);
#ifdef VERIFY_HEAP
if (FLAG_verify_heap && FLAG_stress_compaction) {
heap()->CollectAllGarbage(Heap::kNoGCFlags,
GarbageCollectionReason::kTesting);
}
#endif // VERIFY_HEAP
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::ThrowAt(Handle<JSObject> exception, MessageLocation* location) {
Handle<Name> key_start_pos = factory()->error_start_pos_symbol();
Object::SetProperty(this, exception, key_start_pos,
handle(Smi::FromInt(location->start_pos()), this),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
Handle<Name> key_end_pos = factory()->error_end_pos_symbol();
Object::SetProperty(this, exception, key_end_pos,
handle(Smi::FromInt(location->end_pos()), this),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
Handle<Name> key_script = factory()->error_script_symbol();
Object::SetProperty(this, exception, key_script, location->script(),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
return ThrowInternal(*exception, location);
}
Object Isolate::TerminateExecution() {
return Throw(ReadOnlyRoots(this).termination_exception());
}
void Isolate::CancelTerminateExecution() {
if (try_catch_handler()) {
try_catch_handler()->has_terminated_ = false;
}
if (has_pending_exception() &&
pending_exception() == ReadOnlyRoots(this).termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
if (has_scheduled_exception() &&
scheduled_exception() == ReadOnlyRoots(this).termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_scheduled_exception();
}
}
void Isolate::RequestInterrupt(InterruptCallback callback, void* data) {
ExecutionAccess access(this);
api_interrupts_queue_.push(InterruptEntry(callback, data));
stack_guard()->RequestApiInterrupt();
}
void Isolate::InvokeApiInterruptCallbacks() {
RCS_SCOPE(this, RuntimeCallCounterId::kInvokeApiInterruptCallbacks);
// Note: callback below should be called outside of execution access lock.
while (true) {
InterruptEntry entry;
{
ExecutionAccess access(this);
if (api_interrupts_queue_.empty()) return;
entry = api_interrupts_queue_.front();
api_interrupts_queue_.pop();
}
VMState<EXTERNAL> state(this);
HandleScope handle_scope(this);
entry.first(reinterpret_cast<v8::Isolate*>(this), entry.second);
}
}
namespace {
void ReportBootstrappingException(Handle<Object> exception,
MessageLocation* location) {
base::OS::PrintError("Exception thrown during bootstrapping\n");
if (location == nullptr || location->script().is_null()) return;
// We are bootstrapping and caught an error where the location is set
// and we have a script for the location.
// In this case we could have an extension (or an internal error
// somewhere) and we print out the line number at which the error occurred
// to the console for easier debugging.
int line_number =
location->script()->GetLineNumber(location->start_pos()) + 1;
if (exception->IsString() && location->script()->name().IsString()) {
base::OS::PrintError(
"Extension or internal compilation error: %s in %s at line %d.\n",
String::cast(*exception).ToCString().get(),
String::cast(location->script()->name()).ToCString().get(),
line_number);
} else if (location->script()->name().IsString()) {
base::OS::PrintError(
"Extension or internal compilation error in %s at line %d.\n",
String::cast(location->script()->name()).ToCString().get(),
line_number);
} else if (exception->IsString()) {
base::OS::PrintError("Extension or internal compilation error: %s.\n",
String::cast(*exception).ToCString().get());
} else {
base::OS::PrintError("Extension or internal compilation error.\n");
}
#ifdef OBJECT_PRINT
// Since comments and empty lines have been stripped from the source of
// builtins, print the actual source here so that line numbers match.
if (location->script()->source().IsString()) {
Handle<String> src(String::cast(location->script()->source()),
location->script()->GetIsolate());
PrintF("Failing script:");
int len = src->length();
if (len == 0) {
PrintF(" <not available>\n");
} else {
PrintF("\n");
line_number = 1;
PrintF("%5d: ", line_number);
for (int i = 0; i < len; i++) {
uint16_t character = src->Get(i);
PrintF("%c", character);
if (character == '\n' && i < len - 2) {
PrintF("%5d: ", ++line_number);
}
}
PrintF("\n");
}
}
#endif
}
} // anonymous namespace
Handle<JSMessageObject> Isolate::CreateMessageOrAbort(
Handle<Object> exception, MessageLocation* location) {
Handle<JSMessageObject> message_obj = CreateMessage(exception, location);
// If the abort-on-uncaught-exception flag is specified, and if the
// embedder didn't specify a custom uncaught exception callback,
// or if the custom callback determined that V8 should abort, then
// abort.
if (FLAG_abort_on_uncaught_exception) {
CatchType prediction = PredictExceptionCatcher();
if ((prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) &&
(!abort_on_uncaught_exception_callback_ ||
abort_on_uncaught_exception_callback_(
reinterpret_cast<v8::Isolate*>(this)))) {
// Prevent endless recursion.
FLAG_abort_on_uncaught_exception = false;
// This flag is intended for use by JavaScript developers, so
// print a user-friendly stack trace (not an internal one).
PrintF(stderr, "%s\n\nFROM\n",
MessageHandler::GetLocalizedMessage(this, message_obj).get());
std::ostringstream stack_trace_stream;
PrintCurrentStackTrace(stack_trace_stream);
PrintF(stderr, "%s", stack_trace_stream.str().c_str());
base::OS::Abort();
}
}
return message_obj;
}
Object Isolate::ThrowInternal(Object raw_exception, MessageLocation* location) {
DCHECK(!has_pending_exception());
IF_WASM(DCHECK_IMPLIES, trap_handler::IsTrapHandlerEnabled(),
!trap_handler::IsThreadInWasm());
HandleScope scope(this);
Handle<Object> exception(raw_exception, this);
if (FLAG_print_all_exceptions) {
PrintF("=========================================================\n");
PrintF("Exception thrown:\n");
if (location) {
Handle<Script> script = location->script();
Handle<Object> name(script->GetNameOrSourceURL(), this);
PrintF("at ");
if (name->IsString() && String::cast(*name).length() > 0)
String::cast(*name).PrintOn(stdout);
else
PrintF("<anonymous>");
// Script::GetLineNumber and Script::GetColumnNumber can allocate on the heap to
// initialize the line_ends array, so be careful when calling them.
#ifdef DEBUG
if (AllowGarbageCollection::IsAllowed()) {
#else
if ((false)) {
#endif
PrintF(", %d:%d - %d:%d\n",
Script::GetLineNumber(script, location->start_pos()) + 1,
Script::GetColumnNumber(script, location->start_pos()),
Script::GetLineNumber(script, location->end_pos()) + 1,
Script::GetColumnNumber(script, location->end_pos()));
// Make sure to update the raw exception pointer in case it moved.
raw_exception = *exception;
} else {
PrintF(", line %d\n", script->GetLineNumber(location->start_pos()) + 1);
}
}
raw_exception.Print();
PrintF("Stack Trace:\n");
PrintStack(stdout);
PrintF("=========================================================\n");
}
// Determine whether a message needs to be created for the given exception
// depending on the following criteria:
// 1) External v8::TryCatch missing: Always create a message because any
// JavaScript handler for a finally-block might re-throw to top-level.
// 2) External v8::TryCatch exists: Only create a message if the handler
// captures messages or is verbose (which reports despite the catch).
// 3) ReThrow from v8::TryCatch: The message from a previous throw still
// exists and we preserve it instead of creating a new message.
bool requires_message = try_catch_handler() == nullptr ||
try_catch_handler()->is_verbose_ ||
try_catch_handler()->capture_message_;
bool rethrowing_message = thread_local_top()->rethrowing_message_;
thread_local_top()->rethrowing_message_ = false;
// Notify debugger of exception.
if (is_catchable_by_javascript(raw_exception)) {
base::Optional<Object> maybe_exception = debug()->OnThrow(exception);
if (maybe_exception.has_value()) {
return *maybe_exception;
}
}
// Generate the message if required.
if (requires_message && !rethrowing_message) {
MessageLocation computed_location;
// If no location was specified we try to use a computed one instead.
if (location == nullptr && ComputeLocation(&computed_location)) {
location = &computed_location;
}
if (bootstrapper()->IsActive()) {
// It's not safe to try to make message objects or collect stack traces
// while the bootstrapper is active since the infrastructure may not have
// been properly initialized.
ReportBootstrappingException(exception, location);
} else {
Handle<Object> message_obj = CreateMessageOrAbort(exception, location);
set_pending_message(*message_obj);
}
}
// Set the exception being thrown.
set_pending_exception(*exception);
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::ReThrow(Object exception) {
DCHECK(!has_pending_exception());
// Set the exception being re-thrown.
set_pending_exception(exception);
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::ReThrow(Object exception, Object message) {
DCHECK(!has_pending_exception());
DCHECK(!has_pending_message());
set_pending_message(message);
return ReThrow(exception);
}
namespace {
#if V8_ENABLE_WEBASSEMBLY
// This scope will set the thread-in-wasm flag after the execution of all
// destructors. The thread-in-wasm flag is only set when the scope gets enabled.
class SetThreadInWasmFlagScope {
public:
SetThreadInWasmFlagScope() {
DCHECK_IMPLIES(trap_handler::IsTrapHandlerEnabled(),
!trap_handler::IsThreadInWasm());
}
~SetThreadInWasmFlagScope() {
if (enabled_) trap_handler::SetThreadInWasm();
}
void Enable() { enabled_ = true; }
private:
bool enabled_ = false;
};
#endif // V8_ENABLE_WEBASSEMBLY
} // namespace
Object Isolate::UnwindAndFindHandler() {
#if V8_ENABLE_WEBASSEMBLY
// Create the {SetThreadInWasmFlagScope} first in this function so that its
// destructor gets called after all the other destructors. It is important
// that the destructor sets the thread-in-wasm flag after all other
// destructors. The other destructors may cause exceptions, e.g. ASan on
// Windows, which would invalidate the thread-in-wasm flag when the wasm trap
// handler handles such non-wasm exceptions.
SetThreadInWasmFlagScope set_thread_in_wasm_flag_scope;
#endif // V8_ENABLE_WEBASSEMBLY
Object exception = pending_exception();
auto FoundHandler = [&](Context context, Address instruction_start,
intptr_t handler_offset,
Address constant_pool_address, Address handler_sp,
Address handler_fp, int num_frames_above_handler) {
// Store information to be consumed by the CEntry.
thread_local_top()->pending_handler_context_ = context;
thread_local_top()->pending_handler_entrypoint_ =
instruction_start + handler_offset;
thread_local_top()->pending_handler_constant_pool_ = constant_pool_address;
thread_local_top()->pending_handler_fp_ = handler_fp;
thread_local_top()->pending_handler_sp_ = handler_sp;
thread_local_top()->num_frames_above_pending_handler_ =
num_frames_above_handler;
// Return and clear pending exception. The contract is that:
// (1) the pending exception is stored in one place (no duplication), and
// (2) within generated-code land, that one place is the return register.
// If/when we unwind back into C++ (returning to the JSEntry stub,
// or to Execution::CallWasm), the returned exception will be sent
// back to isolate->set_pending_exception(...).
clear_pending_exception();
return exception;
};
// Special handling of termination exceptions, uncatchable by JavaScript and
// Wasm code, we unwind the handlers until the top ENTRY handler is found.
bool catchable_by_js = is_catchable_by_javascript(exception);
int visited_frames = 0;
// Compute handler and stack unwinding information by performing a full walk
// over the stack and dispatching according to the frame type.
for (StackFrameIterator iter(this);; iter.Advance(), visited_frames++) {
// Handler must exist.
DCHECK(!iter.done());
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
// For JSEntry frames we always have a handler.
StackHandler* handler = frame->top_handler();
// Restore the next handler.
thread_local_top()->handler_ = handler->next_address();
// Gather information from the handler.
Code code = frame->LookupCode();
HandlerTable table(code);
return FoundHandler(Context(), code.InstructionStart(this, frame->pc()),
table.LookupReturn(0), code.constant_pool(),
handler->address() + StackHandlerConstants::kSize,
0, visited_frames);
}
#if V8_ENABLE_WEBASSEMBLY
case StackFrame::C_WASM_ENTRY: {
StackHandler* handler = frame->top_handler();
thread_local_top()->handler_ = handler->next_address();
Code code = frame->LookupCode();
HandlerTable table(code);
Address instruction_start = code.InstructionStart(this, frame->pc());
int return_offset = static_cast<int>(frame->pc() - instruction_start);
int handler_offset = table.LookupReturn(return_offset);
DCHECK_NE(-1, handler_offset);
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
code.stack_slots() * kSystemPointerSize;
return FoundHandler(Context(), instruction_start, handler_offset,
code.constant_pool(), return_sp, frame->fp(),
visited_frames);
}
case StackFrame::WASM: {
if (!is_catchable_by_wasm(exception)) break;
// For WebAssembly frames we perform a lookup in the handler table.
// This code ref scope is here to avoid a check failure when looking up
// the code. It's not actually necessary to keep the code alive as it's
// currently being executed.
wasm::WasmCodeRefScope code_ref_scope;
WasmFrame* wasm_frame = static_cast<WasmFrame*>(frame);
wasm::WasmCode* wasm_code =
wasm::GetWasmCodeManager()->LookupCode(frame->pc());
int offset = wasm_frame->LookupExceptionHandlerInTable();
if (offset < 0) break;
wasm::GetWasmEngine()->SampleCatchEvent(this);
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
wasm_code->stack_slots() * kSystemPointerSize;
// This is going to be handled by WebAssembly, so we need to set the TLS
// flag. The {SetThreadInWasmFlagScope} will set the flag after all
// destructors have been executed.
set_thread_in_wasm_flag_scope.Enable();
return FoundHandler(Context(), wasm_code->instruction_start(), offset,
wasm_code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
case StackFrame::WASM_COMPILE_LAZY: {
// Can only fail directly on invocation. This happens if an invalid
// function was validated lazily.
DCHECK(FLAG_wasm_lazy_validation);
break;
}
#endif // V8_ENABLE_WEBASSEMBLY
case StackFrame::OPTIMIZED: {
// For optimized frames we perform a lookup in the handler table.
if (!catchable_by_js) break;
OptimizedFrame* js_frame = static_cast<OptimizedFrame*>(frame);
Code code = frame->LookupCode();
int offset = js_frame->LookupExceptionHandlerInTable(nullptr, nullptr);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures
// that argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
code.stack_slots() * kSystemPointerSize;
// TODO(bmeurer): Turbofanned BUILTIN frames appear as OPTIMIZED,
// but do not have a code kind of TURBOFAN.
if (CodeKindCanDeoptimize(code.kind()) &&
code.marked_for_deoptimization()) {
// If the target code is lazy deoptimized, we jump to the original
// return address, but we make a note that we are throwing, so
// that the deoptimizer can do the right thing.
offset = static_cast<int>(frame->pc() - code.entry());
set_deoptimizer_lazy_throw(true);
}
return FoundHandler(Context(), code.InstructionStart(this, frame->pc()),
offset, code.constant_pool(), return_sp,
frame->fp(), visited_frames);
}
case StackFrame::STUB: {
// Some stubs are able to handle exceptions.
if (!catchable_by_js) break;
StubFrame* stub_frame = static_cast<StubFrame*>(frame);
#if defined(DEBUG) && V8_ENABLE_WEBASSEMBLY
wasm::WasmCodeRefScope code_ref_scope;
DCHECK_NULL(wasm::GetWasmCodeManager()->LookupCode(frame->pc()));
#endif // defined(DEBUG) && V8_ENABLE_WEBASSEMBLY
Code code = stub_frame->LookupCode();
if (!code.IsCode() || code.kind() != CodeKind::BUILTIN ||
!code.has_handler_table() || !code.is_turbofanned()) {
break;
}
int offset = stub_frame->LookupExceptionHandlerInTable();
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures
// that argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
code.stack_slots() * kSystemPointerSize;
return FoundHandler(Context(), code.InstructionStart(this, frame->pc()),
offset, code.constant_pool(), return_sp,
frame->fp(), visited_frames);
}
case StackFrame::INTERPRETED:
case StackFrame::BASELINE: {
// For interpreted frame we perform a range lookup in the handler table.
if (!catchable_by_js) break;
UnoptimizedFrame* js_frame = UnoptimizedFrame::cast(frame);
int register_slots = UnoptimizedFrameConstants::RegisterStackSlotCount(
js_frame->GetBytecodeArray().register_count());
int context_reg = 0; // Will contain register index holding context.
int offset =
js_frame->LookupExceptionHandlerInTable(&context_reg, nullptr);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
// Note: This is only needed for interpreted frames that have been
// materialized by the deoptimizer. If there is a handler frame
// in between then {frame->sp()} would already be correct.
Address return_sp = frame->fp() -
InterpreterFrameConstants::kFixedFrameSizeFromFp -
register_slots * kSystemPointerSize;
// Patch the bytecode offset in the interpreted frame to reflect the
// position of the exception handler. The special builtin below will
// take care of continuing to dispatch at that position. Also restore
// the correct context for the handler from the interpreter register.
Context context =
Context::cast(js_frame->ReadInterpreterRegister(context_reg));
DCHECK(context.IsContext());
if (frame->is_baseline()) {
BaselineFrame* sp_frame = BaselineFrame::cast(js_frame);
Code code = sp_frame->LookupCode();
intptr_t pc_offset = sp_frame->GetPCForBytecodeOffset(offset);
// Patch the context register directly on the frame, so that we don't
// need to have a context read + write in the baseline code.
sp_frame->PatchContext(context);
return FoundHandler(
Context(), code.InstructionStart(this, sp_frame->sp()), pc_offset,
code.constant_pool(), return_sp, sp_frame->fp(), visited_frames);
} else {
InterpretedFrame::cast(js_frame)->PatchBytecodeOffset(
static_cast<int>(offset));
Code code =
FromCodeT(builtins()->code(Builtin::kInterpreterEnterAtBytecode));
// We subtract a frame from visited_frames because otherwise the
// shadow stack will drop the underlying interpreter entry trampoline
// in which the handler runs.
//
// An interpreted frame cannot be the first frame we look at
// because at a minimum, an exit frame into C++ has to separate
// it and the context in which this C++ code runs.
CHECK_GE(visited_frames, 1);
return FoundHandler(context, code.InstructionStart(), 0,
code.constant_pool(), return_sp, frame->fp(),
visited_frames - 1);
}
}
case StackFrame::BUILTIN:
// For builtin frames we are guaranteed not to find a handler.
if (catchable_by_js) {
CHECK_EQ(-1, BuiltinFrame::cast(frame)->LookupExceptionHandlerInTable(
nullptr, nullptr));
}
break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
// Builtin continuation frames with catch can handle exceptions.
if (!catchable_by_js) break;
JavaScriptBuiltinContinuationWithCatchFrame* js_frame =
JavaScriptBuiltinContinuationWithCatchFrame::cast(frame);
js_frame->SetException(exception);
// Reconstruct the stack pointer from the frame pointer.
Address return_sp = js_frame->fp() - js_frame->GetSPToFPDelta();
Code code = js_frame->LookupCode();
return FoundHandler(Context(), code.InstructionStart(), 0,
code.constant_pool(), return_sp, frame->fp(),
visited_frames);
}
default:
// All other types can not handle exception.
break;
}
if (frame->is_optimized()) {
// Remove per-frame stored materialized objects.
bool removed = materialized_object_store_->Remove(frame->fp());
USE(removed);
// If there were any materialized objects, the code should be
// marked for deopt.
DCHECK_IMPLIES(removed, frame->LookupCode().marked_for_deoptimization());
}
}
UNREACHABLE();
}
namespace {
HandlerTable::CatchPrediction PredictException(JavaScriptFrame* frame) {
HandlerTable::CatchPrediction prediction;
if (frame->is_optimized()) {
if (frame->LookupExceptionHandlerInTable(nullptr, nullptr) > 0) {
// This optimized frame will catch. It's handler table does not include
// exception prediction, and we need to use the corresponding handler
// tables on the unoptimized code objects.
std::vector<FrameSummary> summaries;
frame->Summarize(&summaries);
for (size_t i = summaries.size(); i != 0; i--) {
const FrameSummary& summary = summaries[i - 1];
Handle<AbstractCode> code = summary.AsJavaScript().abstract_code();
if (code->IsCode() && code->kind() == CodeKind::BUILTIN) {
prediction = code->GetCode().GetBuiltinCatchPrediction();
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
// Must have been constructed from a bytecode array.
CHECK_EQ(CodeKind::INTERPRETED_FUNCTION, code->kind());
int code_offset = summary.code_offset();
HandlerTable table(code->GetBytecodeArray());
int index = table.LookupRange(code_offset, nullptr, &prediction);
if (index <= 0) continue;
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
}
} else if (frame->LookupExceptionHandlerInTable(nullptr, &prediction) > 0) {
return prediction;
}
return HandlerTable::UNCAUGHT;
}
Isolate::CatchType ToCatchType(HandlerTable::CatchPrediction prediction) {
switch (prediction) {
case HandlerTable::UNCAUGHT:
return Isolate::NOT_CAUGHT;
case HandlerTable::CAUGHT:
return Isolate::CAUGHT_BY_JAVASCRIPT;
case HandlerTable::PROMISE:
return Isolate::CAUGHT_BY_PROMISE;
case HandlerTable::UNCAUGHT_ASYNC_AWAIT:
case HandlerTable::ASYNC_AWAIT:
return Isolate::CAUGHT_BY_ASYNC_AWAIT;
default:
UNREACHABLE();
}
}
} // anonymous namespace
Isolate::CatchType Isolate::PredictExceptionCatcher() {
Address external_handler = thread_local_top()->try_catch_handler_address();
if (TopExceptionHandlerType(Object()) ==
ExceptionHandlerType::kExternalTryCatch) {
return CAUGHT_BY_EXTERNAL;
}
// Search for an exception handler by performing a full walk over the stack.
for (StackFrameIterator iter(this); !iter.done(); iter.Advance()) {
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
Address entry_handler = frame->top_handler()->next_address();
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
if (external_handler != kNullAddress &&
!try_catch_handler()->is_verbose_) {
if (entry_handler == kNullAddress ||
entry_handler > external_handler) {
return CAUGHT_BY_EXTERNAL;
}
}
} break;
// For JavaScript frames we perform a lookup in the handler table.
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BASELINE:
case StackFrame::BUILTIN: {
JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
Isolate::CatchType prediction = ToCatchType(PredictException(js_frame));
if (prediction == NOT_CAUGHT) break;
return prediction;
}
case StackFrame::STUB: {
Handle<Code> code(frame->LookupCode(), this);
if (!code->IsCode() || code->kind() != CodeKind::BUILTIN ||
!code->has_handler_table() || !code->is_turbofanned()) {
break;
}
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
Handle<Code> code(frame->LookupCode(), this);
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
default:
// All other types can not handle exception.
break;
}
}
// Handler not found.
return NOT_CAUGHT;
}
Object Isolate::ThrowIllegalOperation() {
if (FLAG_stack_trace_on_illegal) PrintStack(stdout);
return Throw(ReadOnlyRoots(heap()).illegal_access_string());
}
void Isolate::ScheduleThrow(Object exception) {
// When scheduling a throw we first throw the exception to get the
// error reporting if it is uncaught before rescheduling it.
Throw(exception);
PropagatePendingExceptionToExternalTryCatch(
TopExceptionHandlerType(pending_exception()));
if (has_pending_exception()) {
set_scheduled_exception(pending_exception());
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
}
void Isolate::RestorePendingMessageFromTryCatch(v8::TryCatch* handler) {
DCHECK(handler == try_catch_handler());
DCHECK(handler->HasCaught());
DCHECK(handler->rethrow_);
DCHECK(handler->capture_message_);
Object message(reinterpret_cast<Address>(handler->message_obj_));
DCHECK(message.IsJSMessageObject() || message.IsTheHole(this));
set_pending_message(message);
}
void Isolate::CancelScheduledExceptionFromTryCatch(v8::TryCatch* handler) {
DCHECK(has_scheduled_exception());
if (reinterpret_cast<void*>(scheduled_exception().ptr()) ==
handler->exception_) {
DCHECK_NE(scheduled_exception(),
ReadOnlyRoots(heap()).termination_exception());
clear_scheduled_exception();
} else {
DCHECK_EQ(scheduled_exception(),
ReadOnlyRoots(heap()).termination_exception());
// Clear termination once we returned from all V8 frames.
if (thread_local_top()->CallDepthIsZero()) {
thread_local_top()->external_caught_exception_ = false;
clear_scheduled_exception();
}
}
if (reinterpret_cast<void*>(thread_local_top()->pending_message_.ptr()) ==
handler->message_obj_) {
clear_pending_message();
}
}
Object Isolate::PromoteScheduledException() {
Object thrown = scheduled_exception();
clear_scheduled_exception();
// Re-throw the exception to avoid getting repeated error reporting.
return ReThrow(thrown);
}
void Isolate::PrintCurrentStackTrace(std::ostream& out) {
Handle<FixedArray> frames = CaptureSimpleStackTrace(
this, FixedArray::kMaxLength, SKIP_NONE, factory()->undefined_value());
IncrementalStringBuilder builder(this);
for (int i = 0; i < frames->length(); ++i) {
Handle<CallSiteInfo> frame(CallSiteInfo::cast(frames->get(i)), this);
SerializeCallSiteInfo(this, frame, &builder);
}
Handle<String> stack_trace = builder.Finish().ToHandleChecked();
stack_trace->PrintOn(out);
}
bool Isolate::ComputeLocation(MessageLocation* target) {
StackTraceFrameIterator it(this);
if (it.done()) return false;
// Compute the location from the function and the relocation info of the
// baseline code. For optimized code this will use the deoptimization
// information to get canonical location information.
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmCodeRefScope code_ref_scope;
#endif // V8_ENABLE_WEBASSEMBLY
FrameSummary summary = it.GetTopValidFrame();
Handle<SharedFunctionInfo> shared;
Handle<Object> script = summary.script();
if (!script->IsScript() || Script::cast(*script).source().IsUndefined(this)) {
return false;
}
if (summary.IsJavaScript()) {
shared = handle(summary.AsJavaScript().function()->shared(), this);
}
if (summary.AreSourcePositionsAvailable()) {
int pos = summary.SourcePosition();
*target =
MessageLocation(Handle<Script>::cast(script), pos, pos + 1, shared);
} else {
*target = MessageLocation(Handle<Script>::cast(script), shared,
summary.code_offset());
}
return true;
}
bool Isolate::ComputeLocationFromException(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSObject()) return false;
Handle<Name> start_pos_symbol = factory()->error_start_pos_symbol();
Handle<Object> start_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), start_pos_symbol);
if (!start_pos->IsSmi()) return false;
int start_pos_value = Handle<Smi>::cast(start_pos)->value();
Handle<Name> end_pos_symbol = factory()->error_end_pos_symbol();
Handle<Object> end_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), end_pos_symbol);
if (!end_pos->IsSmi()) return false;
int end_pos_value = Handle<Smi>::cast(end_pos)->value();
Handle<Name> script_symbol = factory()->error_script_symbol();
Handle<Object> script = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), script_symbol);
if (!script->IsScript()) return false;
Handle<Script> cast_script(Script::cast(*script), this);
*target = MessageLocation(cast_script, start_pos_value, end_pos_value);
return true;
}
bool Isolate::ComputeLocationFromSimpleStackTrace(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSReceiver()) {
return false;
}
Handle<FixedArray> call_site_infos =
GetSimpleStackTrace(Handle<JSReceiver>::cast(exception));
for (int i = 0; i < call_site_infos->length(); ++i) {
Handle<CallSiteInfo> call_site_info(
CallSiteInfo::cast(call_site_infos->get(i)), this);
if (CallSiteInfo::ComputeLocation(call_site_info, target)) {
return true;
}
}
return false;
}
bool Isolate::ComputeLocationFromDetailedStackTrace(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSReceiver()) return false;
Handle<FixedArray> stack_frame_infos =
GetDetailedStackTrace(Handle<JSReceiver>::cast(exception));
if (stack_frame_infos.is_null() || stack_frame_infos->length() == 0) {
return false;
}
Handle<StackFrameInfo> info(StackFrameInfo::cast(stack_frame_infos->get(0)),
this);
const int pos = StackFrameInfo::GetSourcePosition(info);
*target = MessageLocation(handle(info->script(), this), pos, pos + 1);
return true;
}
Handle<JSMessageObject> Isolate::CreateMessage(Handle<Object> exception,
MessageLocation* location) {
Handle<FixedArray> stack_trace_object;
if (capture_stack_trace_for_uncaught_exceptions_) {
if (exception->IsJSError()) {
// We fetch the stack trace that corresponds to this error object.
// If the lookup fails, the exception is probably not a valid Error
// object. In that case, we fall through and capture the stack trace
// at this throw site.
stack_trace_object =
GetDetailedStackTrace(Handle<JSObject>::cast(exception));
}
if (stack_trace_object.is_null()) {
// Not an error object, we capture stack and location at throw site.
stack_trace_object = CaptureDetailedStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
}
}
MessageLocation computed_location;
if (location == nullptr &&
(ComputeLocationFromException(&computed_location, exception) ||
ComputeLocationFromSimpleStackTrace(&computed_location, exception) ||
ComputeLocation(&computed_location))) {
location = &computed_location;
}
return MessageHandler::MakeMessageObject(
this, MessageTemplate::kUncaughtException, location, exception,
stack_trace_object);
}
Handle<JSMessageObject> Isolate::CreateMessageFromException(
Handle<Object> exception) {
Handle<FixedArray> stack_trace_object;
if (exception->IsJSError()) {
stack_trace_object =
GetDetailedStackTrace(Handle<JSObject>::cast(exception));
}
MessageLocation* location = nullptr;
MessageLocation computed_location;
if (ComputeLocationFromException(&computed_location, exception) ||
ComputeLocationFromDetailedStackTrace(&computed_location, exception)) {
location = &computed_location;
}
return MessageHandler::MakeMessageObject(
this, MessageTemplate::kPlaceholderOnly, location, exception,
stack_trace_object);
}
Isolate::ExceptionHandlerType Isolate::TopExceptionHandlerType(
Object exception) {
DCHECK_NE(ReadOnlyRoots(heap()).the_hole_value(), exception);
Address js_handler = Isolate::handler(thread_local_top());
Address external_handler = thread_local_top()->try_catch_handler_address();
// A handler cannot be on top if it doesn't exist. For uncatchable exceptions,
// the JavaScript handler cannot be on top.
if (js_handler == kNullAddress || !is_catchable_by_javascript(exception)) {
if (external_handler == kNullAddress) {
return ExceptionHandlerType::kNone;
}
return ExceptionHandlerType::kExternalTryCatch;
}
if (external_handler == kNullAddress) {
return ExceptionHandlerType::kJavaScriptHandler;
}
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
//
// Note, that finally clauses would re-throw an exception unless it's aborted
// by jumps in control flow (like return, break, etc.) and we'll have another
// chance to set proper v8::TryCatch later.
DCHECK_NE(kNullAddress, external_handler);
DCHECK_NE(kNullAddress, js_handler);
if (external_handler < js_handler) {
return ExceptionHandlerType::kExternalTryCatch;
}
return ExceptionHandlerType::kJavaScriptHandler;
}
std::vector<MemoryRange>* Isolate::GetCodePages() const {
return code_pages_.load(std::memory_order_acquire);
}
void Isolate::SetCodePages(std::vector<MemoryRange>* new_code_pages) {
code_pages_.store(new_code_pages, std::memory_order_release);
}
void Isolate::ReportPendingMessages() {
DCHECK(AllowExceptions::IsAllowed(this));
// The embedder might run script in response to an exception.
AllowJavascriptExecutionDebugOnly allow_script(this);
Object exception_obj = pending_exception();
ExceptionHandlerType top_handler = TopExceptionHandlerType(exception_obj);
// Try to propagate the exception to an external v8::TryCatch handler. If
// propagation was unsuccessful, then we will get another chance at reporting
// the pending message if the exception is re-thrown.
bool has_been_propagated =
PropagatePendingExceptionToExternalTryCatch(top_handler);
if (!has_been_propagated) return;
// Clear the pending message object early to avoid endless recursion.
Object message_obj = pending_message();
clear_pending_message();
// For uncatchable exceptions we do nothing. If needed, the exception and the
// message have already been propagated to v8::TryCatch.
if (!is_catchable_by_javascript(exception_obj)) return;
// Determine whether the message needs to be reported to all message handlers
// depending on whether the topmost external v8::TryCatch is verbose. We know
// there's no JavaScript handler on top; if there was, we would've returned
// early.
DCHECK_NE(ExceptionHandlerType::kJavaScriptHandler, top_handler);
bool should_report_exception;
if (top_handler == ExceptionHandlerType::kExternalTryCatch) {
should_report_exception = try_catch_handler()->is_verbose_;
} else {
should_report_exception = true;
}
// Actually report the pending message to all message handlers.
if (!message_obj.IsTheHole(this) && should_report_exception) {
HandleScope scope(this);
Handle<JSMessageObject> message(JSMessageObject::cast(message_obj), this);
Handle<Object> exception(exception_obj, this);
Handle<Script> script(message->script(), this);
// Clear the exception and restore it afterwards, otherwise
// CollectSourcePositions will abort.
clear_pending_exception();
JSMessageObject::EnsureSourcePositionsAvailable(this, message);
set_pending_exception(*exception);
int start_pos = message->GetStartPosition();
int end_pos = message->GetEndPosition();
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message);
}
}
bool Isolate::OptionalRescheduleException(bool clear_exception) {
DCHECK(has_pending_exception());
PropagatePendingExceptionToExternalTryCatch(
TopExceptionHandlerType(pending_exception()));
bool is_termination_exception =
pending_exception() == ReadOnlyRoots(this).termination_exception();
if (is_termination_exception) {
if (clear_exception) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
} else if (thread_local_top()->external_caught_exception_) {
// If the exception is externally caught, clear it if there are no
// JavaScript frames on the way to the C++ frame that has the
// external handler.
DCHECK_NE(thread_local_top()->try_catch_handler_address(), kNullAddress);
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
JavaScriptFrameIterator it(this);
if (it.done() || (it.frame()->sp() > external_handler_address)) {
clear_exception = true;
}
}
// Clear the exception if needed.
if (clear_exception) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
// Reschedule the exception.
set_scheduled_exception(pending_exception());
clear_pending_exception();
return true;
}
void Isolate::PushPromise(Handle<JSObject> promise) {
ThreadLocalTop* tltop = thread_local_top();
PromiseOnStack* prev = tltop->promise_on_stack_;
Handle<JSObject> global_promise = global_handles()->Create(*promise);
tltop->promise_on_stack_ = new PromiseOnStack(global_promise, prev);
}
void Isolate::PopPromise() {
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return;
PromiseOnStack* prev = tltop->promise_on_stack_->prev();
Handle<Object> global_promise = tltop->promise_on_stack_->promise();
delete tltop->promise_on_stack_;
tltop->promise_on_stack_ = prev;
global_handles()->Destroy(global_promise.location());
}
namespace {
bool PromiseIsRejectHandler(Isolate* isolate, Handle<JSReceiver> handler) {
// Recurse to the forwarding Promise (e.g. return false) due to
// - await reaction forwarding to the throwaway Promise, which has
// a dependency edge to the outer Promise.
// - PromiseIdResolveHandler forwarding to the output of .then
// - Promise.all/Promise.race forwarding to a throwaway Promise, which
// has a dependency edge to the generated outer Promise.
// Otherwise, this is a real reject handler for the Promise.
Handle<Symbol> key = isolate->factory()->promise_forwarding_handler_symbol();
Handle<Object> forwarding_handler = JSReceiver::GetDataProperty(handler, key);
return forwarding_handler->IsUndefined(isolate);
}
bool PromiseHasUserDefinedRejectHandlerInternal(Isolate* isolate,
Handle<JSPromise> promise) {
Handle<Object> current(promise->reactions(), isolate);
while (!current->IsSmi()) {
Handle<PromiseReaction> reaction = Handle<PromiseReaction>::cast(current);
Handle<HeapObject> promise_or_capability(reaction->promise_or_capability(),
isolate);
if (!promise_or_capability->IsUndefined(isolate)) {
if (!promise_or_capability->IsJSPromise()) {
promise_or_capability = handle(
Handle<PromiseCapability>::cast(promise_or_capability)->promise(),
isolate);
}
promise = Handle<JSPromise>::cast(promise_or_capability);
if (!reaction->reject_handler().IsUndefined(isolate)) {
Handle<JSReceiver> reject_handler(
JSReceiver::cast(reaction->reject_handler()), isolate);
if (PromiseIsRejectHandler(isolate, reject_handler)) return true;
}
if (isolate->PromiseHasUserDefinedRejectHandler(promise)) return true;
}
current = handle(reaction->next(), isolate);
}
return false;
}
} // namespace
bool Isolate::PromiseHasUserDefinedRejectHandler(Handle<JSPromise> promise) {
Handle<Symbol> key = factory()->promise_handled_by_symbol();
std::stack<Handle<JSPromise>> promises;
// First descend into the outermost promise and collect the stack of
// Promises for reverse processing.
while (true) {
// If this promise was marked as being handled by a catch block
// in an async function, then it has a user-defined reject handler.
if (promise->handled_hint()) return true;
if (promise->status() == Promise::kPending) {
promises.push(promise);
}
Handle<Object> outer_promise_obj = JSObject::GetDataProperty(promise, key);
if (!outer_promise_obj->IsJSPromise()) break;
promise = Handle<JSPromise>::cast(outer_promise_obj);
}
while (!promises.empty()) {
promise = promises.top();
if (PromiseHasUserDefinedRejectHandlerInternal(this, promise)) return true;
promises.pop();
}
return false;
}
Handle<Object> Isolate::GetPromiseOnStackOnThrow() {
Handle<Object> undefined = factory()->undefined_value();
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return undefined;
// Find the top-most try-catch or try-finally handler.
CatchType prediction = PredictExceptionCatcher();
if (prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) {
return undefined;
}
Handle<Object> retval = undefined;
PromiseOnStack* promise_on_stack = tltop->promise_on_stack_;
for (StackFrameIterator it(this); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
HandlerTable::CatchPrediction catch_prediction;
if (frame->is_java_script()) {
catch_prediction = PredictException(JavaScriptFrame::cast(frame));
} else if (frame->type() == StackFrame::STUB) {
Code code = frame->LookupCode();
if (!code.IsCode() || code.kind() != CodeKind::BUILTIN ||
!code.has_handler_table() || !code.is_turbofanned()) {
continue;
}
catch_prediction = code.GetBuiltinCatchPrediction();
} else {
continue;
}
switch (catch_prediction) {
case HandlerTable::UNCAUGHT:
continue;
case HandlerTable::CAUGHT:
if (retval->IsJSPromise()) {
// Caught the result of an inner async/await invocation.
// Mark the inner promise as caught in the "synchronous case" so
// that Debug::OnException will see. In the synchronous case,
// namely in the code in an async function before the first
// await, the function which has this exception event has not yet
// returned, so the generated Promise has not yet been marked
// by AsyncFunctionAwaitCaught with promiseHandledHintSymbol.
Handle<JSPromise>::cast(retval)->set_handled_hint(true);
}
return retval;
case HandlerTable::PROMISE:
return promise_on_stack
? Handle<Object>::cast(promise_on_stack->promise())
: undefined;
case HandlerTable::UNCAUGHT_ASYNC_AWAIT:
case HandlerTable::ASYNC_AWAIT: {
// If in the initial portion of async/await, continue the loop to pop up
// successive async/await stack frames until an asynchronous one with
// dependents is found, or a non-async stack frame is encountered, in
// order to handle the synchronous async/await catch prediction case:
// assume that async function calls are awaited.
if (!promise_on_stack) return retval;
retval = promise_on_stack->promise();
if (retval->IsJSPromise()) {
if (PromiseHasUserDefinedRejectHandler(
Handle<JSPromise>::cast(retval))) {
return retval;
}
}
promise_on_stack = promise_on_stack->prev();
continue;
}
}
}
return retval;
}
void Isolate::SetCaptureStackTraceForUncaughtExceptions(
bool capture, int frame_limit, StackTrace::StackTraceOptions options) {
capture_stack_trace_for_uncaught_exceptions_ = capture;
stack_trace_for_uncaught_exceptions_frame_limit_ = frame_limit;
stack_trace_for_uncaught_exceptions_options_ = options;
}
bool Isolate::get_capture_stack_trace_for_uncaught_exceptions() const {
return capture_stack_trace_for_uncaught_exceptions_;
}
void Isolate::SetAbortOnUncaughtExceptionCallback(
v8::Isolate::AbortOnUncaughtExceptionCallback callback) {
abort_on_uncaught_exception_callback_ = callback;
}
void Isolate::InstallConditionalFeatures(Handle<Context> context) {
Handle<JSGlobalObject> global = handle(context->global_object(), this);
Handle<String> sab_name = factory()->SharedArrayBuffer_string();
if (IsSharedArrayBufferConstructorEnabled(context)) {
if (!JSObject::HasRealNamedProperty(global, sab_name).FromMaybe(true)) {
JSObject::AddProperty(this, global, factory()->SharedArrayBuffer_string(),
shared_array_buffer_fun(), DONT_ENUM);
}
}
}
bool Isolate::IsSharedArrayBufferConstructorEnabled(Handle<Context> context) {
if (!FLAG_harmony_sharedarraybuffer) return false;
if (!FLAG_enable_sharedarraybuffer_per_context) return true;
if (sharedarraybuffer_constructor_enabled_callback()) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
return sharedarraybuffer_constructor_enabled_callback()(api_context);
}
return false;
}
bool Isolate::IsWasmSimdEnabled(Handle<Context> context) {
#if V8_ENABLE_WEBASSEMBLY
if (wasm_simd_enabled_callback()) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
return wasm_simd_enabled_callback()(api_context);
}
return FLAG_experimental_wasm_simd;
#else
return false;
#endif // V8_ENABLE_WEBASSEMBLY
}
bool Isolate::AreWasmExceptionsEnabled(Handle<Context> context) {
#if V8_ENABLE_WEBASSEMBLY
if (wasm_exceptions_enabled_callback()) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
return wasm_exceptions_enabled_callback()(api_context);
}
return FLAG_experimental_wasm_eh;
#else
return false;
#endif // V8_ENABLE_WEBASSEMBLY
}
bool Isolate::IsWasmDynamicTieringEnabled() {
#if V8_ENABLE_WEBASSEMBLY
if (FLAG_wasm_dynamic_tiering) return true;
if (wasm_dynamic_tiering_enabled_callback()) {
HandleScope handle_scope(this);
v8::Local<v8::Context> api_context =
v8::Utils::ToLocal(handle(context(), this));
return wasm_dynamic_tiering_enabled_callback()(api_context);
}
#endif // V8_ENABLE_WEBASSEMBLY
return false;
}
Handle<Context> Isolate::GetIncumbentContext() {
JavaScriptFrameIterator it(this);
// 1st candidate: most-recently-entered author function's context
// if it's newer than the last Context::BackupIncumbentScope entry.
//
// NOTE: This code assumes that the stack grows downward.
Address top_backup_incumbent =
top_backup_incumbent_scope()
? top_backup_incumbent_scope()->JSStackComparableAddressPrivate()
: 0;
if (!it.done() &&
(!top_backup_incumbent || it.frame()->sp() < top_backup_incumbent)) {
Context context = Context::cast(it.frame()->context());
return Handle<Context>(context.native_context(), this);
}
// 2nd candidate: the last Context::Scope's incumbent context if any.
if (top_backup_incumbent_scope()) {
return Utils::OpenHandle(
*top_backup_incumbent_scope()->backup_incumbent_context_);
}
// Last candidate: the entered context or microtask context.
// Given that there is no other author function is running, there must be
// no cross-context function running, then the incumbent realm must match
// the entry realm.
v8::Local<v8::Context> entered_context =
reinterpret_cast<v8::Isolate*>(this)->GetEnteredOrMicrotaskContext();
return Utils::OpenHandle(*entered_context);
}
char* Isolate::ArchiveThread(char* to) {
MemCopy(to, reinterpret_cast<char*>(thread_local_top()),
sizeof(ThreadLocalTop));
return to + sizeof(ThreadLocalTop);
}
char* Isolate::RestoreThread(char* from) {
MemCopy(reinterpret_cast<char*>(thread_local_top()), from,
sizeof(ThreadLocalTop));
DCHECK(context().is_null() || context().IsContext());
return from + sizeof(ThreadLocalTop);
}
void Isolate::ReleaseSharedPtrs() {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
while (managed_ptr_destructors_head_) {
ManagedPtrDestructor* l = managed_ptr_destructors_head_;
ManagedPtrDestructor* n = nullptr;
managed_ptr_destructors_head_ = nullptr;
for (; l != nullptr; l = n) {
l->destructor_(l->shared_ptr_ptr_);
n = l->next_;
delete l;
}
}
}
bool Isolate::IsBuiltinTableHandleLocation(Address* handle_location) {
FullObjectSlot location(handle_location);
FullObjectSlot first_root(builtin_table());
FullObjectSlot last_root(first_root + Builtins::kBuiltinCount);
if (location >= last_root) return false;
if (location < first_root) return false;
return true;
}
void Isolate::RegisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
DCHECK_NULL(destructor->prev_);
DCHECK_NULL(destructor->next_);
if (managed_ptr_destructors_head_) {
managed_ptr_destructors_head_->prev_ = destructor;
}
destructor->next_ = managed_ptr_destructors_head_;
managed_ptr_destructors_head_ = destructor;
}
void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
if (destructor->prev_) {
destructor->prev_->next_ = destructor->next_;
} else {
DCHECK_EQ(destructor, managed_ptr_destructors_head_);
managed_ptr_destructors_head_ = destructor->next_;
}
if (destructor->next_) destructor->next_->prev_ = destructor->prev_;
destructor->prev_ = nullptr;
destructor->next_ = nullptr;
}
#if V8_ENABLE_WEBASSEMBLY
void Isolate::AddSharedWasmMemory(Handle<WasmMemoryObject> memory_object) {
HandleScope scope(this);
Handle<WeakArrayList> shared_wasm_memories =
factory()->shared_wasm_memories();
shared_wasm_memories = WeakArrayList::AddToEnd(
this, shared_wasm_memories, MaybeObjectHandle::Weak(memory_object));
heap()->set_shared_wasm_memories(*shared_wasm_memories);
}
#endif // V8_ENABLE_WEBASSEMBLY
Isolate::PerIsolateThreadData::~PerIsolateThreadData() {
#if defined(USE_SIMULATOR)
delete simulator_;
#endif
}
Isolate::PerIsolateThreadData* Isolate::ThreadDataTable::Lookup(
ThreadId thread_id) {
auto t = table_.find(thread_id);
if (t == table_.end()) return nullptr;
return t->second;
}
void Isolate::ThreadDataTable::Insert(Isolate::PerIsolateThreadData* data) {
bool inserted = table_.insert(std::make_pair(data->thread_id_, data)).second;
CHECK(inserted);
}
void Isolate::ThreadDataTable::Remove(PerIsolateThreadData* data) {
table_.erase(data->thread_id_);
delete data;
}
void Isolate::ThreadDataTable::RemoveAllThreads() {
for (auto& x : table_) {
delete x.second;
}
table_.clear();
}
class TracingAccountingAllocator : public AccountingAllocator {
public:
explicit TracingAccountingAllocator(Isolate* isolate) : isolate_(isolate) {}
~TracingAccountingAllocator() = default;
protected:
void TraceAllocateSegmentImpl(v8::internal::Segment* segment) override {
base::MutexGuard lock(&mutex_);
UpdateMemoryTrafficAndReportMemoryUsage(segment->total_size());
}
void TraceZoneCreationImpl(const Zone* zone) override {
base::MutexGuard lock(&mutex_);
active_zones_.insert(zone);
nesting_depth_++;
}
void TraceZoneDestructionImpl(const Zone* zone) override {
base::MutexGuard lock(&mutex_);
#ifdef V8_ENABLE_PRECISE_ZONE_STATS
if (FLAG_trace_zone_type_stats) {
type_stats_.MergeWith(zone->type_stats());
}
#endif
UpdateMemoryTrafficAndReportMemoryUsage(zone->segment_bytes_allocated());
active_zones_.erase(zone);
nesting_depth_--;
#ifdef V8_ENABLE_PRECISE_ZONE_STATS
if (FLAG_trace_zone_type_stats && active_zones_.empty()) {
type_stats_.Dump();
}
#endif
}
private:
void UpdateMemoryTrafficAndReportMemoryUsage(size_t memory_traffic_delta) {
if (!FLAG_trace_zone_stats &&
!(TracingFlags::zone_stats.load(std::memory_order_relaxed) &
v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
// Don't print anything if the zone tracing was enabled only because of
// FLAG_trace_zone_type_stats.
return;
}
memory_traffic_since_last_report_ += memory_traffic_delta;
if (memory_traffic_since_last_report_ < FLAG_zone_stats_tolerance) return;
memory_traffic_since_last_report_ = 0;
Dump(buffer_, true);
{
std::string trace_str = buffer_.str();
if (FLAG_trace_zone_stats) {
PrintF(
"{"
"\"type\": \"v8-zone-trace\", "
"\"stats\": %s"
"}\n",
trace_str.c_str());
}
if (V8_UNLIKELY(
TracingFlags::zone_stats.load(std::memory_order_relaxed) &
v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING)) {
TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("v8.zone_stats"),
"V8.Zone_Stats", TRACE_EVENT_SCOPE_THREAD, "stats",
TRACE_STR_COPY(trace_str.c_str()));
}
}
// Clear the buffer.
buffer_.str(std::string());
}
void Dump(std::ostringstream& out, bool dump_details) {
// Note: Neither isolate nor zones are locked, so be careful with accesses
// as the allocator is potentially used on a concurrent thread.
double time = isolate_->time_millis_since_init();
out << "{"
<< "\"isolate\": \"" << reinterpret_cast<void*>(isolate_) << "\", "
<< "\"time\": " << time << ", ";
size_t total_segment_bytes_allocated = 0;
size_t total_zone_allocation_size = 0;
size_t total_zone_freed_size = 0;
if (dump_details) {
// Print detailed zone stats if memory usage changes direction.
out << "\"zones\": [";
bool first = true;
for (const Zone* zone : active_zones_) {
size_t zone_segment_bytes_allocated = zone->segment_bytes_allocated();
size_t zone_allocation_size = zone->allocation_size_for_tracing();
size_t freed_size = zone->freed_size_for_tracing();
if (first) {
first = false;
} else {
out << ", ";
}
out << "{"
<< "\"name\": \"" << zone->name() << "\", "
<< "\"allocated\": " << zone_segment_bytes_allocated << ", "
<< "\"used\": " << zone_allocation_size << ", "
<< "\"freed\": " << freed_size << "}";
total_segment_bytes_allocated += zone_segment_bytes_allocated;
total_zone_allocation_size += zone_allocation_size;
total_zone_freed_size += freed_size;
}
out << "], ";
} else {
// Just calculate total allocated/used memory values.
for (const Zone* zone : active_zones_) {
total_segment_bytes_allocated += zone->segment_bytes_allocated();
total_zone_allocation_size += zone->allocation_size_for_tracing();
total_zone_freed_size += zone->freed_size_for_tracing();
}
}
out << "\"allocated\": " << total_segment_bytes_allocated << ", "
<< "\"used\": " << total_zone_allocation_size << ", "
<< "\"freed\": " << total_zone_freed_size << "}";
}
Isolate* const isolate_;
std::atomic<size_t> nesting_depth_{0};
base::Mutex mutex_;
std::unordered_set<const Zone*> active_zones_;
#ifdef V8_ENABLE_PRECISE_ZONE_STATS
TypeStats type_stats_;
#endif
std::ostringstream buffer_;
// This value is increased on both allocations and deallocations.
size_t memory_traffic_since_last_report_ = 0;
};
#ifdef DEBUG
std::atomic<size_t> Isolate::non_disposed_isolates_;
#endif // DEBUG
// static
Isolate* Isolate::New() { return Isolate::Allocate(false); }
// static
Isolate* Isolate::NewShared(const v8::Isolate::CreateParams& params) {
DCHECK(ReadOnlyHeap::IsReadOnlySpaceShared());
Isolate* isolate = Isolate::Allocate(true);
v8::Isolate::Initialize(reinterpret_cast<v8::Isolate*>(isolate), params);
return isolate;
}
// static
Isolate* Isolate::Allocate(bool is_shared) {
// v8::V8::Initialize() must be called before creating any isolates.
DCHECK_NOT_NULL(V8::GetCurrentPlatform());
// IsolateAllocator allocates the memory for the Isolate object according to
// the given allocation mode.
std::unique_ptr<IsolateAllocator> isolate_allocator =
std::make_unique<IsolateAllocator>();
// Construct Isolate object in the allocated memory.
void* isolate_ptr = isolate_allocator->isolate_memory();
Isolate* isolate =
new (isolate_ptr) Isolate(std::move(isolate_allocator), is_shared);
#ifdef V8_COMPRESS_POINTERS_IN_ISOLATE_CAGE
DCHECK(IsAligned(isolate->isolate_root(), kPtrComprCageBaseAlignment));
DCHECK_EQ(isolate->isolate_root(), isolate->cage_base());
#endif
#ifdef DEBUG
non_disposed_isolates_++;
#endif // DEBUG
return isolate;
}
// static
void Isolate::Delete(Isolate* isolate) {
DCHECK_NOT_NULL(isolate);
// v8::V8::Dispose() must only be called after deleting all isolates.
DCHECK_NOT_NULL(V8::GetCurrentPlatform());
// Temporarily set this isolate as current so that various parts of
// the isolate can access it in their destructors without having a
// direct pointer. We don't use Enter/Exit here to avoid
// initializing the thread data.
PerIsolateThreadData* saved_data = isolate->CurrentPerIsolateThreadData();
DCHECK_EQ(true, isolate_key_created_.load(std::memory_order_relaxed));
Isolate* saved_isolate = reinterpret_cast<Isolate*>(
base::Thread::GetThreadLocal(isolate->isolate_key_));
SetIsolateThreadLocals(isolate, nullptr);
isolate->set_thread_id(ThreadId::Current());
isolate->Deinit();
#ifdef DEBUG
non_disposed_isolates_--;
#endif // DEBUG
// Take ownership of the IsolateAllocator to ensure the Isolate memory will
// be available during Isolate descructor call.
std::unique_ptr<IsolateAllocator> isolate_allocator =
std::move(isolate->isolate_allocator_);
isolate->~Isolate();
// Now free the memory owned by the allocator.
isolate_allocator.reset();
// Restore the previous current isolate.
SetIsolateThreadLocals(saved_isolate, saved_data);
}
void Isolate::SetUpFromReadOnlyArtifacts(
std::shared_ptr<ReadOnlyArtifacts> artifacts, ReadOnlyHeap* ro_heap) {
if (ReadOnlyHeap::IsReadOnlySpaceShared()) {
DCHECK_NOT_NULL(artifacts);
artifacts_ = artifacts;
} else {
DCHECK_NULL(artifacts);
}
DCHECK_NOT_NULL(ro_heap);
DCHECK_IMPLIES(read_only_heap_ != nullptr, read_only_heap_ == ro_heap);
read_only_heap_ = ro_heap;
heap_.SetUpFromReadOnlyHeap(read_only_heap_);
}
v8::PageAllocator* Isolate::page_allocator() const {
return isolate_allocator_->page_allocator();
}
Isolate::Isolate(std::unique_ptr<i::IsolateAllocator> isolate_allocator,
bool is_shared)
: isolate_data_(this, isolate_allocator->GetPtrComprCageBase()),
is_shared_(is_shared),
isolate_allocator_(std::move(isolate_allocator)),
id_(isolate_counter.fetch_add(1, std::memory_order_relaxed)),
allocator_(new TracingAccountingAllocator(this)),
builtins_(this),
#if defined(DEBUG) || defined(VERIFY_HEAP)
num_active_deserializers_(0),
#endif
rail_mode_(PERFORMANCE_ANIMATION),
code_event_dispatcher_(new CodeEventDispatcher()),
detailed_source_positions_for_profiling_(FLAG_detailed_line_info),
persistent_handles_list_(new PersistentHandlesList()),
jitless_(FLAG_jitless),
#if V8_SFI_HAS_UNIQUE_ID
next_unique_sfi_id_(0),
#endif
next_module_async_evaluating_ordinal_(
SourceTextModule::kFirstAsyncEvaluatingOrdinal),
cancelable_task_manager_(new CancelableTaskManager()) {
TRACE_ISOLATE(constructor);
CheckIsolateLayout();
// ThreadManager is initialized early to support locking an isolate
// before it is entered.
thread_manager_ = new ThreadManager(this);
handle_scope_data_.Initialize();
// When pointer compression is on with a per-Isolate cage, allocation in the
// shared Isolate can point into the per-Isolate RO heap as the offsets are
// constant across Isolates.
//
// When pointer compression is on with a shared cage or when pointer
// compression is off, a shared RO heap is required. Otherwise a shared
// allocation requested by a client Isolate could point into the client
// Isolate's RO space (e.g. an RO map) whose pages gets unmapped when it is
// disposed.
CHECK_IMPLIES(is_shared_, COMPRESS_POINTERS_IN_ISOLATE_CAGE_BOOL ||
V8_SHARED_RO_HEAP_BOOL);
#define ISOLATE_INIT_EXECUTE(type, name, initial_value) \
name##_ = (initial_value);
ISOLATE_INIT_LIST(ISOLATE_INIT_EXECUTE)
#undef ISOLATE_INIT_EXECUTE
#define ISOLATE_INIT_ARRAY_EXECUTE(type, name, length) \
memset(name##_, 0, sizeof(type) * length);
ISOLATE_INIT_ARRAY_LIST(ISOLATE_INIT_ARRAY_EXECUTE)
#undef ISOLATE_INIT_ARRAY_EXECUTE
InitializeLoggingAndCounters();
debug_ = new Debug(this);
InitializeDefaultEmbeddedBlob();
MicrotaskQueue::SetUpDefaultMicrotaskQueue(this);
if (is_shared_) {
global_safepoint_ = std::make_unique<GlobalSafepoint>(this);
}
}
void Isolate::CheckIsolateLayout() {
CHECK_EQ(OFFSET_OF(Isolate, isolate_data_), 0);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.embedder_data_)),
Internals::kIsolateEmbedderDataOffset);
CHECK_EQ(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.fast_c_call_caller_fp_)),
Internals::kIsolateFastCCallCallerFpOffset);
CHECK_EQ(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.fast_c_call_caller_pc_)),
Internals::kIsolateFastCCallCallerPcOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.cage_base_)),
Internals::kIsolateCageBaseOffset);
CHECK_EQ(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.long_task_stats_counter_)),
Internals::kIsolateLongTaskStatsCounterOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.stack_guard_)),
Internals::kIsolateStackGuardOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, isolate_data_.roots_table_)),
Internals::kIsolateRootsOffset);
STATIC_ASSERT(Internals::kStackGuardSize == sizeof(StackGuard));
STATIC_ASSERT(Internals::kBuiltinTier0TableSize ==
Builtins::kBuiltinTier0Count * kSystemPointerSize);
STATIC_ASSERT(Internals::kBuiltinTier0EntryTableSize ==
Builtins::kBuiltinTier0Count * kSystemPointerSize);
#ifdef V8_SANDBOXED_EXTERNAL_POINTERS
CHECK_EQ(static_cast<int>(OFFSET_OF(ExternalPointerTable, buffer_)),
Internals::kExternalPointerTableBufferOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(ExternalPointerTable, capacity_)),
Internals::kExternalPointerTableCapacityOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(ExternalPointerTable, freelist_head_)),
Internals::kExternalPointerTableFreelistHeadOffset);
#endif
}
void Isolate::ClearSerializerData() {
delete external_reference_map_;
external_reference_map_ = nullptr;
}
bool Isolate::LogObjectRelocation() {
return FLAG_verify_predictable || logger()->is_logging() || is_profiling() ||
heap()->isolate()->logger()->is_listening_to_code_events() ||
(heap_profiler() != nullptr &&
heap_profiler()->is_tracking_object_moves()) ||
heap()->has_heap_object_allocation_tracker();
}
void Isolate::Deinit() {
TRACE_ISOLATE(deinit);
DisallowHeapAllocation no_allocation;
tracing_cpu_profiler_.reset();
if (FLAG_stress_sampling_allocation_profiler > 0) {
heap_profiler()->StopSamplingHeapProfiler();
}
metrics_recorder_->NotifyIsolateDisposal();
recorder_context_id_map_.clear();
#if defined(V8_OS_WIN64)
if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
heap()->memory_allocator() && RequiresCodeRange() &&
heap()->code_range()->AtomicDecrementUnwindInfoUseCount() == 1) {
const base::AddressRegion& code_region = heap()->code_region();
void* start = reinterpret_cast<void*>(code_region.begin());
win64_unwindinfo::UnregisterNonABICompliantCodeRange(start);
}
#endif // V8_OS_WIN64
FutexEmulation::IsolateDeinit(this);
debug()->Unload();
#if V8_ENABLE_WEBASSEMBLY
wasm::GetWasmEngine()->DeleteCompileJobsOnIsolate(this);
BackingStore::RemoveSharedWasmMemoryObjects(this);
#endif // V8_ENABLE_WEBASSEMBLY
if (concurrent_recompilation_enabled()) {
optimizing_compile_dispatcher_->Stop();
delete optimizing_compile_dispatcher_;
optimizing_compile_dispatcher_ = nullptr;
}
// All client isolates should already be detached.
if (is_shared()) global_safepoint()->AssertNoClients();
if (FLAG_print_deopt_stress) {
PrintF(stdout, "=== Stress deopt counter: %u\n", stress_deopt_count_);
}
// We must stop the logger before we tear down other components.
sampler::Sampler* sampler = logger_->sampler();
if (sampler && sampler->IsActive()) sampler->Stop();
FreeThreadResources();
logger_->StopProfilerThread();
// We start with the heap tear down so that releasing managed objects does
// not cause a GC.
heap_.StartTearDown();
// This stops cancelable tasks (i.e. concurrent marking tasks).
// Stop concurrent tasks before destroying resources since they might still
// use those.
{
IgnoreLocalGCRequests ignore_gc_requests(heap());
ParkedScope parked_scope(main_thread_local_heap());
cancelable_task_manager()->CancelAndWait();
}
// Cancel all baseline compiler tasks.
delete baseline_batch_compiler_;
baseline_batch_compiler_ = nullptr;
if (lazy_compile_dispatcher_) {
lazy_compile_dispatcher_->AbortAll();
lazy_compile_dispatcher_.reset();
}
// At this point there are no more background threads left in this isolate.
heap_.safepoint()->AssertMainThreadIsOnlyThread();
{
// This isolate might have to park for a shared GC initiated by another
// client isolate before it can actually detach from the shared isolate.
AllowGarbageCollection allow_shared_gc;
DetachFromSharedIsolate();
}
ReleaseSharedPtrs();
builtins_.TearDown();
bootstrapper_->TearDown();
if (runtime_profiler_ != nullptr) {
delete runtime_profiler_;
runtime_profiler_ = nullptr;
}
delete heap_profiler_;
heap_profiler_ = nullptr;
string_table_.reset();
#if USE_SIMULATOR
delete simulator_data_;
simulator_data_ = nullptr;
#endif
// After all concurrent tasks are stopped, we know for sure that stats aren't
// updated anymore.
DumpAndResetStats();
heap_.TearDown();
main_thread_local_isolate_.reset();
FILE* logfile = logger_->TearDownAndGetLogFile();
if (logfile != nullptr) base::Fclose(logfile);
#if V8_ENABLE_WEBASSEMBLY
wasm::GetWasmEngine()->RemoveIsolate(this);
#endif // V8_ENABLE_WEBASSEMBLY
TearDownEmbeddedBlob();
delete interpreter_;
interpreter_ = nullptr;
delete ast_string_constants_;
ast_string_constants_ = nullptr;
code_event_dispatcher_.reset();
delete root_index_map_;
root_index_map_ = nullptr;
delete compiler_zone_;
compiler_zone_ = nullptr;
compiler_cache_ = nullptr;
SetCodePages(nullptr);
ClearSerializerData();
#ifdef V8_SANDBOXED_EXTERNAL_POINTERS
external_pointer_table().TearDown();
#endif // V8_SANDBOXED_EXTERNAL_POINTERS
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
thread_data_table_.RemoveAllThreads();
}
}
void Isolate::SetIsolateThreadLocals(Isolate* isolate,
PerIsolateThreadData* data) {
base::Thread::SetThreadLocal(isolate_key_, isolate);
base::Thread::SetThreadLocal(per_isolate_thread_data_key_, data);
}
Isolate::~Isolate() {
TRACE_ISOLATE(destructor);
// The entry stack must be empty when we get here.
DCHECK(entry_stack_ == nullptr || entry_stack_->previous_item == nullptr);
delete entry_stack_;
entry_stack_ = nullptr;
delete date_cache_;
date_cache_ = nullptr;
delete regexp_stack_;
regexp_stack_ = nullptr;
delete descriptor_lookup_cache_;
descriptor_lookup_cache_ = nullptr;
delete load_stub_cache_;
load_stub_cache_ = nullptr;
delete store_stub_cache_;
store_stub_cache_ = nullptr;
delete materialized_object_store_;
materialized_object_store_ = nullptr;
delete logger_;
logger_ = nullptr;
delete handle_scope_implementer_;
handle_scope_implementer_ = nullptr;
delete code_tracer();
set_code_tracer(nullptr);
delete compilation_cache_;
compilation_cache_ = nullptr;
delete bootstrapper_;
bootstrapper_ = nullptr;
delete inner_pointer_to_code_cache_;
inner_pointer_to_code_cache_ = nullptr;
delete thread_manager_;
thread_manager_ = nullptr;
bigint_processor_->Destroy();
delete global_handles_;
global_handles_ = nullptr;
delete eternal_handles_;
eternal_handles_ = nullptr;
delete string_stream_debug_object_cache_;
string_stream_debug_object_cache_ = nullptr;
delete random_number_generator_;
random_number_generator_ = nullptr;
delete fuzzer_rng_;
fuzzer_rng_ = nullptr;
delete debug_;
debug_ = nullptr;
delete cancelable_task_manager_;
cancelable_task_manager_ = nullptr;
delete allocator_;
allocator_ = nullptr;
// Assert that |default_microtask_queue_| is the last MicrotaskQueue instance.
DCHECK_IMPLIES(default_microtask_queue_,
default_microtask_queue_ == default_microtask_queue_->next());
delete default_microtask_queue_;
default_microtask_queue_ = nullptr;
// The ReadOnlyHeap should not be destroyed when sharing without pointer
// compression as the object itself is shared.
if (read_only_heap_->IsOwnedByIsolate()) {
delete read_only_heap_;
read_only_heap_ = nullptr;
}
}
void Isolate::InitializeThreadLocal() {
thread_local_top()->Initialize(this);
clear_pending_exception();
clear_pending_message();
clear_scheduled_exception();
}
void Isolate::SetTerminationOnExternalTryCatch() {
if (try_catch_handler() == nullptr) return;
try_catch_handler()->can_continue_ = false;
try_catch_handler()->has_terminated_ = true;
try_catch_handler()->exception_ =
reinterpret_cast<void*>(ReadOnlyRoots(heap()).null_value().ptr());
}
bool Isolate::PropagatePendingExceptionToExternalTryCatch(
ExceptionHandlerType top_handler) {
Object exception = pending_exception();
if (top_handler == ExceptionHandlerType::kJavaScriptHandler) {
thread_local_top()->external_caught_exception_ = false;
return false;
}
if (top_handler == ExceptionHandlerType::kNone) {
thread_local_top()->external_caught_exception_ = false;
return true;
}
DCHECK_EQ(ExceptionHandlerType::kExternalTryCatch, top_handler);
thread_local_top()->external_caught_exception_ = true;
if (!is_catchable_by_javascript(exception)) {
SetTerminationOnExternalTryCatch();
} else {
v8::TryCatch* handler = try_catch_handler();
DCHECK(pending_message().IsJSMessageObject() ||
pending_message().IsTheHole(this));
handler->can_continue_ = true;
handler->has_terminated_ = false;
handler->exception_ = reinterpret_cast<void*>(exception.ptr());
// Propagate to the external try-catch only if we got an actual message.
if (!has_pending_message()) return true;
handler->message_obj_ = reinterpret_cast<void*>(pending_message().ptr());
}
return true;
}
bool Isolate::InitializeCounters() {
if (async_counters_) return false;
async_counters_ = std::make_shared<Counters>(this);
return true;
}
void Isolate::InitializeLoggingAndCounters() {
if (logger_ == nullptr) {
logger_ = new Logger(this);
}
InitializeCounters();
}
namespace {
void CreateOffHeapTrampolines(Isolate* isolate) {
DCHECK_NOT_NULL(isolate->embedded_blob_code());
DCHECK_NE(0, isolate->embedded_blob_code_size());
DCHECK_NOT_NULL(isolate->embedded_blob_data());
DCHECK_NE(0, isolate->embedded_blob_data_size());
HandleScope scope(isolate);
Builtins* builtins = isolate->builtins();
EmbeddedData d = EmbeddedData::FromBlob(isolate);
STATIC_ASSERT(Builtins::kAllBuiltinsAreIsolateIndependent);
for (Builtin builtin = Builtins::kFirst; builtin <= Builtins::kLast;
++builtin) {
Address instruction_start = d.InstructionStartOfBuiltin(builtin);
// TODO(v8:11880): avoid roundtrips between cdc and code.
Handle<Code> trampoline = isolate->factory()->NewOffHeapTrampolineFor(
FromCodeT(builtins->code_handle(builtin), isolate), instruction_start);
// From this point onwards, the old builtin code object is unreachable and
// will be collected by the next GC.
builtins->set_code(builtin, ToCodeT(*trampoline));
}
}
#ifdef DEBUG
bool IsolateIsCompatibleWithEmbeddedBlob(Isolate* isolate) {
EmbeddedData d = EmbeddedData::FromBlob(isolate);
return (d.IsolateHash() == isolate->HashIsolateForEmbeddedBlob());
}
#endif // DEBUG
} // namespace
void Isolate::InitializeDefaultEmbeddedBlob() {
const uint8_t* code = DefaultEmbeddedBlobCode();
uint32_t code_size = DefaultEmbeddedBlobCodeSize();
const uint8_t* data = DefaultEmbeddedBlobData();
uint32_t data_size = DefaultEmbeddedBlobDataSize();
if (StickyEmbeddedBlobCode() != nullptr) {
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
// Check again now that we hold the lock.
if (StickyEmbeddedBlobCode() != nullptr) {
code = StickyEmbeddedBlobCode();
code_size = StickyEmbeddedBlobCodeSize();
data = StickyEmbeddedBlobData();
data_size = StickyEmbeddedBlobDataSize();
current_embedded_blob_refs_++;
}
}
if (code == nullptr) {
CHECK_EQ(0, code_size);
} else {
SetEmbeddedBlob(code, code_size, data, data_size);
}
}
void Isolate::CreateAndSetEmbeddedBlob() {
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
PrepareBuiltinSourcePositionMap();
PrepareBuiltinLabelInfoMap();
// If a sticky blob has been set, we reuse it.
if (StickyEmbeddedBlobCode() != nullptr) {
CHECK_EQ(embedded_blob_code(), StickyEmbeddedBlobCode());
CHECK_EQ(embedded_blob_data(), StickyEmbeddedBlobData());
CHECK_EQ(CurrentEmbeddedBlobCode(), StickyEmbeddedBlobCode());
CHECK_EQ(CurrentEmbeddedBlobData(), StickyEmbeddedBlobData());
} else {
// Create and set a new embedded blob.
uint8_t* code;
uint32_t code_size;
uint8_t* data;
uint32_t data_size;
OffHeapInstructionStream::CreateOffHeapOffHeapInstructionStream(
this, &code, &code_size, &data, &data_size);
CHECK_EQ(0, current_embedded_blob_refs_);
const uint8_t* const_code = const_cast<const uint8_t*>(code);
const uint8_t* const_data = const_cast<const uint8_t*>(data);
SetEmbeddedBlob(const_code, code_size, const_data, data_size);
current_embedded_blob_refs_++;
SetStickyEmbeddedBlob(code, code_size, data, data_size);
}
MaybeRemapEmbeddedBuiltinsIntoCodeRange();
CreateOffHeapTrampolines(this);
}
void Isolate::MaybeRemapEmbeddedBuiltinsIntoCodeRange() {
if (!is_short_builtin_calls_enabled() || !RequiresCodeRange()) {
return;
}
if (V8_ENABLE_NEAR_CODE_RANGE_BOOL &&
GetShortBuiltinsCallRegion().contains(heap_.code_region())) {
// The embedded builtins are within the pc-relative reach from the code
// range, so there's no need to remap embedded builtins.
return;
}
CHECK_NOT_NULL(embedded_blob_code_);
CHECK_NE(embedded_blob_code_size_, 0);
DCHECK_NOT_NULL(heap_.code_range_);
embedded_blob_code_ = heap_.code_range_->RemapEmbeddedBuiltins(
this, embedded_blob_code_, embedded_blob_code_size_);
CHECK_NOT_NULL(embedded_blob_code_);
// The un-embedded code blob is already a part of the registered code range
// so it's not necessary to register it again.
}
void Isolate::TearDownEmbeddedBlob() {
// Nothing to do in case the blob is embedded into the binary or unset.
if (StickyEmbeddedBlobCode() == nullptr) return;
if (!is_short_builtin_calls_enabled()) {
CHECK_EQ(embedded_blob_code(), StickyEmbeddedBlobCode());
CHECK_EQ(embedded_blob_data(), StickyEmbeddedBlobData());
}
CHECK_EQ(CurrentEmbeddedBlobCode(), StickyEmbeddedBlobCode());
CHECK_EQ(CurrentEmbeddedBlobData(), StickyEmbeddedBlobData());
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
current_embedded_blob_refs_--;
if (current_embedded_blob_refs_ == 0 && enable_embedded_blob_refcounting_) {
// We own the embedded blob and are the last holder. Free it.
OffHeapInstructionStream::FreeOffHeapOffHeapInstructionStream(
const_cast<uint8_t*>(CurrentEmbeddedBlobCode()),
embedded_blob_code_size(),
const_cast<uint8_t*>(CurrentEmbeddedBlobData()),
embedded_blob_data_size());
ClearEmbeddedBlob();
}
}
bool Isolate::InitWithoutSnapshot() {
return Init(nullptr, nullptr, nullptr, false);
}
bool Isolate::InitWithSnapshot(SnapshotData* startup_snapshot_data,
SnapshotData* read_only_snapshot_data,
SnapshotData* shared_heap_snapshot_data,
bool can_rehash) {
DCHECK_NOT_NULL(startup_snapshot_data);
DCHECK_NOT_NULL(read_only_snapshot_data);
DCHECK_NOT_NULL(shared_heap_snapshot_data);
return Init(startup_snapshot_data, read_only_snapshot_data,
shared_heap_snapshot_data, can_rehash);
}
static std::string AddressToString(uintptr_t address) {
std::stringstream stream_address;
stream_address << "0x" << std::hex << address;
return stream_address.str();
}
void Isolate::AddCrashKeysForIsolateAndHeapPointers() {
DCHECK_NOT_NULL(add_crash_key_callback_);
const uintptr_t isolate_address = reinterpret_cast<uintptr_t>(this);
add_crash_key_callback_(v8::CrashKeyId::kIsolateAddress,
AddressToString(isolate_address));
const uintptr_t ro_space_firstpage_address =
heap()->read_only_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kReadonlySpaceFirstPageAddress,
AddressToString(ro_space_firstpage_address));
const uintptr_t map_space_firstpage_address =
heap()->map_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kMapSpaceFirstPageAddress,
AddressToString(map_space_firstpage_address));
const uintptr_t code_space_firstpage_address =
heap()->code_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kCodeSpaceFirstPageAddress,
AddressToString(code_space_firstpage_address));
}
void Isolate::InitializeCodeRanges() {
DCHECK_NULL(GetCodePages());
MemoryRange embedded_range{
reinterpret_cast<const void*>(embedded_blob_code()),
embedded_blob_code_size()};
code_pages_buffer1_.push_back(embedded_range);
SetCodePages(&code_pages_buffer1_);
}
namespace {
// This global counter contains number of stack loads/stores per optimized/wasm
// function.
using MapOfLoadsAndStoresPerFunction =
std::map<std::string /* function_name */,
std::pair<uint64_t /* loads */, uint64_t /* stores */>>;
MapOfLoadsAndStoresPerFunction* stack_access_count_map = nullptr;
class BigIntPlatform : public bigint::Platform {
public:
explicit BigIntPlatform(Isolate* isolate) : isolate_(isolate) {}
~BigIntPlatform() override = default;
bool InterruptRequested() override {
StackLimitCheck interrupt_check(isolate_);
return (interrupt_check.InterruptRequested() &&
isolate_->stack_guard()->HasTerminationRequest());
}
private:
Isolate* isolate_;
};
} // namespace
VirtualMemoryCage* Isolate::GetPtrComprCodeCageForTesting() {
return V8_EXTERNAL_CODE_SPACE_BOOL ? heap_.code_range() : GetPtrComprCage();
}
bool Isolate::Init(SnapshotData* startup_snapshot_data,
SnapshotData* read_only_snapshot_data,
SnapshotData* shared_heap_snapshot_data, bool can_rehash) {
TRACE_ISOLATE(init);
const bool create_heap_objects = (read_only_snapshot_data == nullptr);
// We either have all or none.
DCHECK_EQ(create_heap_objects, startup_snapshot_data == nullptr);
DCHECK_EQ(create_heap_objects, shared_heap_snapshot_data == nullptr);
base::ElapsedTimer timer;
if (create_heap_objects && FLAG_profile_deserialization) timer.Start();
time_millis_at_init_ = heap_.MonotonicallyIncreasingTimeInMs();
stress_deopt_count_ = FLAG_deopt_every_n_times;
force_slow_path_ = FLAG_force_slow_path;
has_fatal_error_ = false;
// The initialization process does not handle memory exhaustion.
AlwaysAllocateScope always_allocate(heap());
#define ASSIGN_ELEMENT(CamelName, hacker_name) \
isolate_addresses_[IsolateAddressId::k##CamelName##Address] = \
reinterpret_cast<Address>(hacker_name##_address());
FOR_EACH_ISOLATE_ADDRESS_NAME(ASSIGN_ELEMENT)
#undef ASSIGN_ELEMENT
// We need to initialize code_pages_ before any on-heap code is allocated to
// make sure we record all code allocations.
InitializeCodeRanges();
compilation_cache_ = new CompilationCache(this);
descriptor_lookup_cache_ = new DescriptorLookupCache();
inner_pointer_to_code_cache_ = new InnerPointerToCodeCache(this);
global_handles_ = new GlobalHandles(this);
eternal_handles_ = new EternalHandles();
bootstrapper_ = new Bootstrapper(this);
handle_scope_implementer_ = new HandleScopeImplementer(this);
load_stub_cache_ = new StubCache(this);
store_stub_cache_ = new StubCache(this);
materialized_object_store_ = new MaterializedObjectStore(this);
regexp_stack_ = new RegExpStack();
date_cache_ = new DateCache();
heap_profiler_ = new HeapProfiler(heap());
interpreter_ = new interpreter::Interpreter(this);
bigint_processor_ = bigint::Processor::New(new BigIntPlatform(this));
if (FLAG_lazy_compile_dispatcher) {
lazy_compile_dispatcher_ = std::make_unique<LazyCompileDispatcher>(
this, V8::GetCurrentPlatform(), FLAG_stack_size);
}
baseline_batch_compiler_ = new baseline::BaselineBatchCompiler(this);
#if USE_SIMULATOR
simulator_data_ = new SimulatorData;
#endif
// Enable logging before setting up the heap
logger_->SetUp(this);
metrics_recorder_ = std::make_shared<metrics::Recorder>();
{
// Ensure that the thread has a valid stack guard. The v8::Locker object
// will ensure this too, but we don't have to use lockers if we are only
// using one thread.
ExecutionAccess lock(this);
stack_guard()->InitThread(lock);
}
// Create LocalIsolate/LocalHeap for the main thread and set state to Running.
main_thread_local_isolate_.reset(new LocalIsolate(this, ThreadKind::kMain));
{
IgnoreLocalGCRequests ignore_gc_requests(heap());
main_thread_local_heap()->Unpark();
}
// Lock clients_mutex_ in order to prevent shared GCs from other clients
// during deserialization.
base::Optional<base::MutexGuard> clients_guard;
if (shared_isolate_) {
clients_guard.emplace(&shared_isolate_->global_safepoint()->clients_mutex_);
}
// The main thread LocalHeap needs to be set up when attaching to the shared
// isolate. Otherwise a global safepoint would find an isolate without
// LocalHeaps and not wait until this thread is ready for a GC.
AttachToSharedIsolate();
// SetUp the object heap.
DCHECK(!heap_.HasBeenSetUp());
heap_.SetUp(main_thread_local_heap());
ReadOnlyHeap::SetUp(this, read_only_snapshot_data, can_rehash);
heap_.SetUpSpaces(&isolate_data_.new_allocation_info_,
&isolate_data_.old_allocation_info_);
if (OwnsStringTable()) {
string_table_ = std::make_shared<StringTable>(this);
} else {
// Only refer to shared string table after attaching to the shared isolate.
DCHECK_NOT_NULL(shared_isolate());
string_table_ = shared_isolate()->string_table_;
}
if (V8_SHORT_BUILTIN_CALLS_BOOL && FLAG_short_builtin_calls) {
// Check if the system has more than 4GB of physical memory by comparing the
// old space size with respective threshold value.
//
// Additionally, enable if there is already a process-wide CodeRange that
// has re-embedded builtins.
is_short_builtin_calls_enabled_ = (heap_.MaxOldGenerationSize() >=
kShortBuiltinCallsOldSpaceSizeThreshold);
if (COMPRESS_POINTERS_IN_SHARED_CAGE_BOOL) {
std::shared_ptr<CodeRange> code_range =
CodeRange::GetProcessWideCodeRange();
if (code_range && code_range->embedded_blob_code_copy() != nullptr) {
is_short_builtin_calls_enabled_ = true;
}
}
if (V8_ENABLE_NEAR_CODE_RANGE_BOOL) {
// The short builtin calls could still be enabled if allocated code range
// is close enough to embedded builtins so that the latter could be
// reached using pc-relative (short) calls/jumps.
is_short_builtin_calls_enabled_ |=
GetShortBuiltinsCallRegion().contains(heap_.code_region());
}
}
#ifdef V8_EXTERNAL_CODE_SPACE
if (heap_.code_range()) {
code_cage_base_ = GetPtrComprCageBaseAddress(heap_.code_range()->base());
} else {
code_cage_base_ = cage_base();
}
#endif // V8_EXTERNAL_CODE_SPACE
isolate_data_.external_reference_table()->Init(this);
#ifdef V8_SANDBOXED_EXTERNAL_POINTERS
external_pointer_table().Init(this);
#endif // V8_SANDBOXED_EXTERNAL_POINTERS
#if V8_ENABLE_WEBASSEMBLY
wasm::GetWasmEngine()->AddIsolate(this);
#endif // V8_ENABLE_WEBASSEMBLY
if (setup_delegate_ == nullptr) {
setup_delegate_ = new SetupIsolateDelegate(create_heap_objects);
}
if (!FLAG_inline_new) heap_.DisableInlineAllocation();
if (!setup_delegate_->SetupHeap(&heap_)) {
V8::FatalProcessOutOfMemory(this, "heap object creation");
}
if (create_heap_objects) {
// Terminate the startup and shared heap object caches so we can iterate.
startup_object_cache_.push_back(ReadOnlyRoots(this).undefined_value());
shared_heap_object_cache_.push_back(ReadOnlyRoots(this).undefined_value());
}
InitializeThreadLocal();
// Profiler has to be created after ThreadLocal is initialized
// because it makes use of interrupts.
tracing_cpu_profiler_.reset(new TracingCpuProfilerImpl(this));
bootstrapper_->Initialize(create_heap_objects);
if (create_heap_objects) {
builtins_constants_table_builder_ = new BuiltinsConstantsTableBuilder(this);
setup_delegate_->SetupBuiltins(this);
#ifndef V8_TARGET_ARCH_ARM
// Store the interpreter entry trampoline on the root list. It is used as a
// template for further copies that may later be created to help profile
// interpreted code.
// We currently cannot do this on arm due to RELATIVE_CODE_TARGETs
// assuming that all possible Code targets may be addressed with an int24
// offset, effectively limiting code space size to 32MB. We can guarantee
// this at mksnapshot-time, but not at runtime.
// See also: https://crbug.com/v8/8713.
heap_.SetInterpreterEntryTrampolineForProfiling(
FromCodeT(builtins()->code(Builtin::kInterpreterEntryTrampoline)));
#endif
builtins_constants_table_builder_->Finalize();
delete builtins_constants_table_builder_;
builtins_constants_table_builder_ = nullptr;
CreateAndSetEmbeddedBlob();
} else {
setup_delegate_->SetupBuiltins(this);
MaybeRemapEmbeddedBuiltinsIntoCodeRange();
}
// Initialize custom memcopy and memmove functions (must happen after
// embedded blob setup).
init_memcopy_functions();
if (FLAG_log_internal_timer_events) {
set_event_logger(Logger::DefaultEventLoggerSentinel);
}
if (FLAG_trace_turbo || FLAG_trace_turbo_graph || FLAG_turbo_profiling) {
PrintF("Concurrent recompilation has been disabled for tracing.\n");
} else if (OptimizingCompileDispatcher::Enabled()) {
optimizing_compile_dispatcher_ = new OptimizingCompileDispatcher(this);
}
// Initialize runtime profiler before deserialization, because collections may
// occur, clearing/updating ICs.
runtime_profiler_ = new RuntimeProfiler(this);
// If we are deserializing, read the state into the now-empty heap.
{
CodePageCollectionMemoryModificationScope modification_scope(heap());
if (create_heap_objects) {
heap_.read_only_space()->ClearStringPaddingIfNeeded();
read_only_heap_->OnCreateHeapObjectsComplete(this);
} else {
SharedHeapDeserializer shared_heap_deserializer(
this, shared_heap_snapshot_data, can_rehash);
shared_heap_deserializer.DeserializeIntoIsolate();
StartupDeserializer startup_deserializer(this, startup_snapshot_data,
can_rehash);
startup_deserializer.DeserializeIntoIsolate();
}
load_stub_cache_->Initialize();
store_stub_cache_->Initialize();
interpreter_->Initialize();
heap_.NotifyDeserializationComplete();
}
#ifdef VERIFY_HEAP
if (FLAG_verify_heap) {
heap_.VerifyReadOnlyHeap();
}
#endif
delete setup_delegate_;
setup_delegate_ = nullptr;
Builtins::InitializeIsolateDataTables(this);
Builtins::EmitCodeCreateEvents(this);
#ifdef DEBUG
// Verify that the current heap state (usually deserialized from the snapshot)
// is compatible with the embedded blob. If this DCHECK fails, we've likely
// loaded a snapshot generated by a different V8 version or build-time
// configuration.
if (!IsolateIsCompatibleWithEmbeddedBlob(this)) {
FATAL(
"The Isolate is incompatible with the embedded blob. This is usually "
"caused by incorrect usage of mksnapshot. When generating custom "
"snapshots, embedders must ensure they pass the same flags as during "
"the V8 build process (e.g.: --turbo-instruction-scheduling).");
}
#endif // DEBUG
#ifndef V8_TARGET_ARCH_ARM
// The IET for profiling should always be a full on-heap Code object.
DCHECK(!Code::cast(heap_.interpreter_entry_trampoline_for_profiling())
.is_off_heap_trampoline());
#endif // V8_TARGET_ARCH_ARM
if (FLAG_print_builtin_code) builtins()->PrintBuiltinCode();
if (FLAG_print_builtin_size) builtins()->PrintBuiltinSize();
// Finish initialization of ThreadLocal after deserialization is done.
clear_pending_exception();
clear_pending_message();
clear_scheduled_exception();
// Quiet the heap NaN if needed on target platform.
if (!create_heap_objects)
Assembler::QuietNaN(ReadOnlyRoots(this).nan_value());
if (FLAG_trace_turbo) {
// Create an empty file.
std::ofstream(GetTurboCfgFileName(this).c_str(), std::ios_base::trunc);
}
{
HandleScope scope(this);
ast_string_constants_ = new AstStringConstants(this, HashSeed(this));
}
initialized_from_snapshot_ = !create_heap_objects;
if (FLAG_stress_sampling_allocation_profiler > 0) {
uint64_t sample_interval = FLAG_stress_sampling_allocation_profiler;
int stack_depth = 128;
v8::HeapProfiler::SamplingFlags sampling_flags =
v8::HeapProfiler::SamplingFlags::kSamplingForceGC;
heap_profiler()->StartSamplingHeapProfiler(sample_interval, stack_depth,
sampling_flags);
}
#if defined(V8_OS_WIN64)
if (win64_unwindinfo::CanRegisterUnwindInfoForNonABICompliantCodeRange() &&
heap()->code_range()->AtomicIncrementUnwindInfoUseCount() == 0) {
const base::AddressRegion& code_region = heap()->code_region();
void* start = reinterpret_cast<void*>(code_region.begin());
size_t size_in_bytes = code_region.size();
win64_unwindinfo::RegisterNonABICompliantCodeRange(start, size_in_bytes);
}
#endif // V8_OS_WIN64
if (create_heap_objects && FLAG_profile_deserialization) {
double ms = timer.Elapsed().InMillisecondsF();
PrintF("[Initializing isolate from scratch took %0.3f ms]\n", ms);
}
#ifdef V8_ENABLE_WEBASSEMBLY
if (FLAG_experimental_wasm_stack_switching) {
std::unique_ptr<wasm::StackMemory> stack(
wasm::StackMemory::GetCurrentStackView(this));
this->wasm_stacks() = stack.get();
if (FLAG_trace_wasm_stack_switching) {
PrintF("Set up native stack object (limit: %p, base: %p)\n",
stack->jslimit(), reinterpret_cast<void*>(stack->base()));
}
HandleScope scope(this);
Handle<WasmContinuationObject> continuation =
WasmContinuationObject::New(this, std::move(stack));
heap()
->roots_table()
.slot(RootIndex::kActiveContinuation)
.store(*continuation);
}
#endif
initialized_ = true;
return true;
}
void Isolate::Enter() {
Isolate* current_isolate = nullptr;
PerIsolateThreadData* current_data = CurrentPerIsolateThreadData();
if (current_data != nullptr) {
current_isolate = current_data->isolate_;
DCHECK_NOT_NULL(current_isolate);
if (current_isolate == this) {
DCHECK(Current() == this);
DCHECK_NOT_NULL(entry_stack_);
DCHECK(entry_stack_->previous_thread_data == nullptr ||
entry_stack_->previous_thread_data->thread_id() ==
ThreadId::Current());
// Same thread re-enters the isolate, no need to re-init anything.
entry_stack_->entry_count++;
return;
}
}
PerIsolateThreadData* data = FindOrAllocatePerThreadDataForThisThread();
DCHECK_NOT_NULL(data);
DCHECK(data->isolate_ == this);
EntryStackItem* item =
new EntryStackItem(current_data, current_isolate, entry_stack_);
entry_stack_ = item;
SetIsolateThreadLocals(this, data);
// In case it's the first time some thread enters the isolate.
set_thread_id(data->thread_id());
}
void Isolate::Exit() {
DCHECK_NOT_NULL(entry_stack_);
DCHECK(entry_stack_->previous_thread_data == nullptr ||
entry_stack_->previous_thread_data->thread_id() ==
ThreadId::Current());
if (--entry_stack_->entry_count > 0) return;
DCHECK_NOT_NULL(CurrentPerIsolateThreadData());
DCHECK(CurrentPerIsolateThreadData()->isolate_ == this);
// Pop the stack.
EntryStackItem* item = entry_stack_;
entry_stack_ = item->previous_item;
PerIsolateThreadData* previous_thread_data = item->previous_thread_data;
Isolate* previous_isolate = item->previous_isolate;
delete item;
// Reinit the current thread for the isolate it was running before this one.
SetIsolateThreadLocals(previous_isolate, previous_thread_data);
}
std::unique_ptr<PersistentHandles> Isolate::NewPersistentHandles() {
return std::make_unique<PersistentHandles>(this);
}
void Isolate::DumpAndResetStats() {
if (FLAG_trace_turbo_stack_accesses) {
StdoutStream os;
uint64_t total_loads = 0;
uint64_t total_stores = 0;
os << "=== Stack access counters === " << std::endl;
if (!stack_access_count_map) {
os << "No stack accesses in optimized/wasm functions found.";
} else {
DCHECK_NOT_NULL(stack_access_count_map);
os << "Number of optimized/wasm stack-access functions: "
<< stack_access_count_map->size() << std::endl;
for (auto it = stack_access_count_map->cbegin();
it != stack_access_count_map->cend(); it++) {
std::string function_name((*it).first);
std::pair<uint64_t, uint64_t> per_func_count = (*it).second;
os << "Name: " << function_name << ", Loads: " << per_func_count.first
<< ", Stores: " << per_func_count.second << std::endl;
total_loads += per_func_count.first;
total_stores += per_func_count.second;
}
os << "Total Loads: " << total_loads << ", Total Stores: " << total_stores
<< std::endl;
stack_access_count_map = nullptr;
}
}
if (turbo_statistics() != nullptr) {
DCHECK(FLAG_turbo_stats || FLAG_turbo_stats_nvp);
StdoutStream os;
if (FLAG_turbo_stats) {
AsPrintableStatistics ps = {*turbo_statistics(), false};
os << ps << std::endl;
}
if (FLAG_turbo_stats_nvp) {
AsPrintableStatistics ps = {*turbo_statistics(), true};
os << ps << std::endl;
}
delete turbo_statistics_;
turbo_statistics_ = nullptr;
}
#if V8_ENABLE_WEBASSEMBLY
// TODO(7424): There is no public API for the {WasmEngine} yet. So for now we
// just dump and reset the engines statistics together with the Isolate.
if (FLAG_turbo_stats_wasm) {
wasm::GetWasmEngine()->DumpAndResetTurboStatistics();
}
#endif // V8_ENABLE_WEBASSEMBLY
#if V8_RUNTIME_CALL_STATS
if (V8_UNLIKELY(TracingFlags::runtime_stats.load(std::memory_order_relaxed) ==
v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE)) {
counters()->worker_thread_runtime_call_stats()->AddToMainTable(
counters()->runtime_call_stats());
counters()->runtime_call_stats()->Print();
counters()->runtime_call_stats()->Reset();
}
#endif // V8_RUNTIME_CALL_STATS
if (BasicBlockProfiler::Get()->HasData(this)) {
StdoutStream out;
BasicBlockProfiler::Get()->Print(out, this);
BasicBlockProfiler::Get()->ResetCounts(this);
}
}
void Isolate::AbortConcurrentOptimization(BlockingBehavior behavior) {
if (concurrent_recompilation_enabled()) {
DisallowGarbageCollection no_recursive_gc;
optimizing_compile_dispatcher()->Flush(behavior);
}
}
CompilationStatistics* Isolate::GetTurboStatistics() {
if (turbo_statistics() == nullptr)
set_turbo_statistics(new CompilationStatistics());
return turbo_statistics();
}
CodeTracer* Isolate::GetCodeTracer() {
if (code_tracer() == nullptr) set_code_tracer(new CodeTracer(id()));
return code_tracer();
}
bool Isolate::use_optimizer() {
return FLAG_opt && !serializer_enabled_ && CpuFeatures::SupportsOptimizer() &&
!is_precise_count_code_coverage();
}
void Isolate::IncreaseTotalRegexpCodeGenerated(Handle<HeapObject> code) {
PtrComprCageBase cage_base(this);
DCHECK(code->IsCode(cage_base) || code->IsByteArray(cage_base));
total_regexp_code_generated_ += code->Size(cage_base);
}
bool Isolate::NeedsDetailedOptimizedCodeLineInfo() const {
return NeedsSourcePositionsForProfiling() ||
detailed_source_positions_for_profiling();
}
bool Isolate::NeedsSourcePositionsForProfiling() const {
return
// Static conditions.
FLAG_trace_deopt || FLAG_trace_turbo || FLAG_trace_turbo_graph ||
FLAG_turbo_profiling || FLAG_perf_prof || FLAG_log_maps || FLAG_log_ic ||
// Dynamic conditions; changing any of these conditions triggers source
// position collection for the entire heap
// (CollectSourcePositionsForAllBytecodeArrays).
is_profiling() || debug_->is_active() || logger_->is_logging();
}
void Isolate::SetFeedbackVectorsForProfilingTools(Object value) {
DCHECK(value.IsUndefined(this) || value.IsArrayList());
heap()->set_feedback_vectors_for_profiling_tools(value);
}
void Isolate::MaybeInitializeVectorListFromHeap() {
if (!heap()->feedback_vectors_for_profiling_tools().IsUndefined(this)) {
// Already initialized, return early.
DCHECK(heap()->feedback_vectors_for_profiling_tools().IsArrayList());
return;
}
// Collect existing feedback vectors.
std::vector<Handle<FeedbackVector>> vectors;
{
HeapObjectIterator heap_iterator(heap());
for (HeapObject current_obj = heap_iterator.Next(); !current_obj.is_null();
current_obj = heap_iterator.Next()) {
if (!current_obj.IsFeedbackVector()) continue;
FeedbackVector vector = FeedbackVector::cast(current_obj);
SharedFunctionInfo shared = vector.shared_function_info();
// No need to preserve the feedback vector for non-user-visible functions.
if (!shared.IsSubjectToDebugging()) continue;
vectors.emplace_back(vector, this);
}
}
// Add collected feedback vectors to the root list lest we lose them to GC.
Handle<ArrayList> list =
ArrayList::New(this, static_cast<int>(vectors.size()));
for (const auto& vector : vectors) list = ArrayList::Add(this, list, vector);
SetFeedbackVectorsForProfilingTools(*list);
}
void Isolate::set_date_cache(DateCache* date_cache) {
if (date_cache != date_cache_) {
delete date_cache_;
}
date_cache_ = date_cache;
}
Isolate::KnownPrototype Isolate::IsArrayOrObjectOrStringPrototype(
Object object) {
Object context = heap()->native_contexts_list();
while (!context.IsUndefined(this)) {
Context current_context = Context::cast(context);
if (current_context.initial_object_prototype() == object) {
return KnownPrototype::kObject;
} else if (current_context.initial_array_prototype() == object) {
return KnownPrototype::kArray;
} else if (current_context.initial_string_prototype() == object) {
return KnownPrototype::kString;
}
context = current_context.next_context_link();
}
return KnownPrototype::kNone;
}
bool Isolate::IsInAnyContext(Object object, uint32_t index) {
DisallowGarbageCollection no_gc;
Object context = heap()->native_contexts_list();
while (!context.IsUndefined(this)) {
Context current_context = Context::cast(context);
if (current_context.get(index) == object) {
return true;
}
context = current_context.next_context_link();
}
return false;
}
void Isolate::UpdateNoElementsProtectorOnSetElement(Handle<JSObject> object) {
DisallowGarbageCollection no_gc;
if (!object->map().is_prototype_map()) return;
if (!Protectors::IsNoElementsIntact(this)) return;
KnownPrototype obj_type = IsArrayOrObjectOrStringPrototype(*object);
if (obj_type == KnownPrototype::kNone) return;
if (obj_type == KnownPrototype::kObject) {
this->CountUsage(v8::Isolate::kObjectPrototypeHasElements);
} else if (obj_type == KnownPrototype::kArray) {
this->CountUsage(v8::Isolate::kArrayPrototypeHasElements);
}
Protectors::InvalidateNoElements(this);
}
static base::RandomNumberGenerator* ensure_rng_exists(
base::RandomNumberGenerator** rng, int seed) {
if (*rng == nullptr) {
if (seed != 0) {
*rng = new base::RandomNumberGenerator(seed);
} else {
*rng = new base::RandomNumberGenerator();
}
}
return *rng;
}
base::RandomNumberGenerator* Isolate::random_number_generator() {
// TODO(bmeurer) Initialized lazily because it depends on flags; can
// be fixed once the default isolate cleanup is done.
return ensure_rng_exists(&random_number_generator_, FLAG_random_seed);
}
base::RandomNumberGenerator* Isolate::fuzzer_rng() {
if (fuzzer_rng_ == nullptr) {
int64_t seed = FLAG_fuzzer_random_seed;
if (seed == 0) {
seed = random_number_generator()->initial_seed();
}
fuzzer_rng_ = new base::RandomNumberGenerator(seed);
}
return fuzzer_rng_;
}
int Isolate::GenerateIdentityHash(uint32_t mask) {
int hash;
int attempts = 0;
do {
hash = random_number_generator()->NextInt() & mask;
} while (hash == 0 && attempts++ < 30);
return hash != 0 ? hash : 1;
}
Code Isolate::FindCodeObject(Address a) {
return heap()->GcSafeFindCodeForInnerPointer(a);
}
#ifdef DEBUG
#define ISOLATE_FIELD_OFFSET(type, name, ignored) \
const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
#undef ISOLATE_FIELD_OFFSET
#endif
Handle<Symbol> Isolate::SymbolFor(RootIndex dictionary_index,
Handle<String> name, bool private_symbol) {
Handle<String> key = factory()->InternalizeString(name);
Handle<NameDictionary> dictionary =
Handle<NameDictionary>::cast(root_handle(dictionary_index));
InternalIndex entry = dictionary->FindEntry(this, key);
Handle<Symbol> symbol;
if (entry.is_not_found()) {
symbol =
private_symbol ? factory()->NewPrivateSymbol() : factory()->NewSymbol();
symbol->set_description(*key);
dictionary = NameDictionary::Add(this, dictionary, key, symbol,
PropertyDetails::Empty(), &entry);
switch (dictionary_index) {
case RootIndex::kPublicSymbolTable:
symbol->set_is_in_public_symbol_table(true);
heap()->set_public_symbol_table(*dictionary);
break;
case RootIndex::kApiSymbolTable:
heap()->set_api_symbol_table(*dictionary);
break;
case RootIndex::kApiPrivateSymbolTable:
heap()->set_api_private_symbol_table(*dictionary);
break;
default:
UNREACHABLE();
}
} else {
symbol = Handle<Symbol>(Symbol::cast(dictionary->ValueAt(entry)), this);
}
return symbol;
}
void Isolate::AddBeforeCallEnteredCallback(BeforeCallEnteredCallback callback) {
auto pos = std::find(before_call_entered_callbacks_.begin(),
before_call_entered_callbacks_.end(), callback);
if (pos != before_call_entered_callbacks_.end()) return;
before_call_entered_callbacks_.push_back(callback);
}
void Isolate::RemoveBeforeCallEnteredCallback(
BeforeCallEnteredCallback callback) {
auto pos = std::find(before_call_entered_callbacks_.begin(),
before_call_entered_callbacks_.end(), callback);
if (pos == before_call_entered_callbacks_.end()) return;
before_call_entered_callbacks_.erase(pos);
}
void Isolate::AddCallCompletedCallback(CallCompletedCallback callback) {
auto pos = std::find(call_completed_callbacks_.begin(),
call_completed_callbacks_.end(), callback);
if (pos != call_completed_callbacks_.end()) return;
call_completed_callbacks_.push_back(callback);
}
void Isolate::RemoveCallCompletedCallback(CallCompletedCallback callback) {
auto pos = std::find(call_completed_callbacks_.begin(),
call_completed_callbacks_.end(), callback);
if (pos == call_completed_callbacks_.end()) return;
call_completed_callbacks_.erase(pos);
}
void Isolate::FireCallCompletedCallbackInternal(
MicrotaskQueue* microtask_queue) {
DCHECK(thread_local_top()->CallDepthIsZero());
bool perform_checkpoint =
microtask_queue &&
microtask_queue->microtasks_policy() == v8::MicrotasksPolicy::kAuto;
v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this);
if (perform_checkpoint) microtask_queue->PerformCheckpoint(isolate);
if (call_completed_callbacks_.empty()) return;
// Fire callbacks. Increase call depth to prevent recursive callbacks.
v8::Isolate::SuppressMicrotaskExecutionScope suppress(isolate);
std::vector<CallCompletedCallback> callbacks(call_completed_callbacks_);
for (auto& callback : callbacks) {
callback(reinterpret_cast<v8::Isolate*>(this));
}
}
void Isolate::UpdatePromiseHookProtector() {
if (Protectors::IsPromiseHookIntact(this)) {
HandleScope scope(this);
Protectors::InvalidatePromiseHook(this);
}
}
void Isolate::PromiseHookStateUpdated() {
promise_hook_flags_ =
(promise_hook_flags_ & PromiseHookFields::HasContextPromiseHook::kMask) |
PromiseHookFields::HasIsolatePromiseHook::encode(promise_hook_) |
PromiseHookFields::HasAsyncEventDelegate::encode(async_event_delegate_) |
PromiseHookFields::IsDebugActive::encode(debug()->is_active());
if (promise_hook_flags_ != 0) {
UpdatePromiseHookProtector();
}
}
namespace {
MaybeHandle<JSPromise> NewRejectedPromise(Isolate* isolate,
v8::Local<v8::Context> api_context,
Handle<Object> exception) {
v8::Local<v8::Promise::Resolver> resolver;
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
isolate, resolver, v8::Promise::Resolver::New(api_context),
MaybeHandle<JSPromise>());
RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
isolate, resolver->Reject(api_context, v8::Utils::ToLocal(exception)),
MaybeHandle<JSPromise>());
v8::Local<v8::Promise> promise = resolver->GetPromise();
return v8::Utils::OpenHandle(*promise);
}
} // namespace
MaybeHandle<JSPromise> Isolate::RunHostImportModuleDynamicallyCallback(
Handle<Script> referrer, Handle<Object> specifier,
MaybeHandle<Object> maybe_import_assertions_argument) {
v8::Local<v8::Context> api_context =
v8::Utils::ToLocal(Handle<Context>::cast(native_context()));
if (host_import_module_dynamically_with_import_assertions_callback_ ==
nullptr &&
host_import_module_dynamically_callback_ == nullptr) {
Handle<Object> exception =
factory()->NewError(error_function(), MessageTemplate::kUnsupported);
return NewRejectedPromise(this, api_context, exception);
}
Handle<String> specifier_str;
MaybeHandle<String> maybe_specifier = Object::ToString(this, specifier);
if (!maybe_specifier.ToHandle(&specifier_str)) {
Handle<Object> exception(pending_exception(), this);
clear_pending_exception();
return NewRejectedPromise(this, api_context, exception);
}
DCHECK(!has_pending_exception());
v8::Local<v8::Promise> promise;
Handle<FixedArray> import_assertions_array;
if (!GetImportAssertionsFromArgument(maybe_import_assertions_argument)
.ToHandle(&import_assertions_array)) {
Handle<Object> exception(pending_exception(), this);
clear_pending_exception();
return NewRejectedPromise(this, api_context, exception);
}
if (host_import_module_dynamically_callback_) {
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
this, promise,
host_import_module_dynamically_callback_(
api_context,
v8::Utils::ToLocal(handle(referrer->host_defined_options(), this)),
v8::Utils::ToLocal(handle(referrer->name(), this)),
v8::Utils::ToLocal(specifier_str),
ToApiHandle<v8::FixedArray>(import_assertions_array)),
MaybeHandle<JSPromise>());
} else {
// TODO(cbruni, v8:12302): Avoid creating tempory ScriptOrModule objects.
auto script_or_module = i::Handle<i::ScriptOrModule>::cast(
this->factory()->NewStruct(i::SCRIPT_OR_MODULE_TYPE));
script_or_module->set_resource_name(referrer->name());
script_or_module->set_host_defined_options(
referrer->host_defined_options());
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
this, promise,
host_import_module_dynamically_with_import_assertions_callback_(
api_context, v8::Utils::ToLocal(script_or_module),
v8::Utils::ToLocal(specifier_str),
ToApiHandle<v8::FixedArray>(import_assertions_array)),
MaybeHandle<JSPromise>());
}
return v8::Utils::OpenHandle(*promise);
}
MaybeHandle<FixedArray> Isolate::GetImportAssertionsFromArgument(
MaybeHandle<Object> maybe_import_assertions_argument) {
Handle<FixedArray> import_assertions_array = factory()->empty_fixed_array();
Handle<Object> import_assertions_argument;
if (!maybe_import_assertions_argument.ToHandle(&import_assertions_argument) ||
import_assertions_argument->IsUndefined()) {
return import_assertions_array;
}
// The parser shouldn't have allowed the second argument to import() if
// the flag wasn't enabled.
DCHECK(FLAG_harmony_import_assertions);
if (!import_assertions_argument->IsJSReceiver()) {
this->Throw(
*factory()->NewTypeError(MessageTemplate::kNonObjectImportArgument));
return MaybeHandle<FixedArray>();
}
Handle<JSReceiver> import_assertions_argument_receiver =
Handle<JSReceiver>::cast(import_assertions_argument);
Handle<Name> key = factory()->assert_string();
Handle<Object> import_assertions_object;
if (!JSReceiver::GetProperty(this, import_assertions_argument_receiver, key)
.ToHandle(&import_assertions_object)) {
// This can happen if the property has a getter function that throws
// an error.
return MaybeHandle<FixedArray>();
}
// If there is no 'assert' option in the options bag, it's not an error. Just
// do the import() as if no assertions were provided.
if (import_assertions_object->IsUndefined()) return import_assertions_array;
if (!import_assertions_object->IsJSReceiver()) {
this->Throw(
*factory()->NewTypeError(MessageTemplate::kNonObjectAssertOption));
return MaybeHandle<FixedArray>();
}
Handle<JSReceiver> import_assertions_object_receiver =
Handle<JSReceiver>::cast(import_assertions_object);
Handle<FixedArray> assertion_keys;
if (!KeyAccumulator::GetKeys(import_assertions_object_receiver,
KeyCollectionMode::kOwnOnly, ENUMERABLE_STRINGS,
GetKeysConversion::kConvertToString)
.ToHandle(&assertion_keys)) {
// This happens if the assertions object is a Proxy whose ownKeys() or
// getOwnPropertyDescriptor() trap throws.
return MaybeHandle<FixedArray>();
}
// The assertions will be passed to the host in the form: [key1,
// value1, key2, value2, ...].
constexpr size_t kAssertionEntrySizeForDynamicImport = 2;
import_assertions_array = factory()->NewFixedArray(static_cast<int>(
assertion_keys->length() * kAssertionEntrySizeForDynamicImport));
for (int i = 0; i < assertion_keys->length(); i++) {
Handle<String> assertion_key(String::cast(assertion_keys->get(i)), this);
Handle<Object> assertion_value;
if (!JSReceiver::GetProperty(this, import_assertions_object_receiver,
assertion_key)
.ToHandle(&assertion_value)) {
// This can happen if the property has a getter function that throws
// an error.
return MaybeHandle<FixedArray>();
}
if (!assertion_value->IsString()) {
this->Throw(*factory()->NewTypeError(
MessageTemplate::kNonStringImportAssertionValue));
return MaybeHandle<FixedArray>();
}
import_assertions_array->set((i * kAssertionEntrySizeForDynamicImport),
*assertion_key);
import_assertions_array->set((i * kAssertionEntrySizeForDynamicImport) + 1,
*assertion_value);
}
return import_assertions_array;
}
void Isolate::ClearKeptObjects() { heap()->ClearKeptObjects(); }
void Isolate::SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyCallback callback) {
DCHECK_NULL(host_import_module_dynamically_with_import_assertions_callback_);
host_import_module_dynamically_callback_ = callback;
}
void Isolate::SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyWithImportAssertionsCallback callback) {
DCHECK_NULL(host_import_module_dynamically_callback_);
host_import_module_dynamically_with_import_assertions_callback_ = callback;
}
MaybeHandle<JSObject> Isolate::RunHostInitializeImportMetaObjectCallback(
Handle<SourceTextModule> module) {
CHECK(module->import_meta(kAcquireLoad).IsTheHole(this));
Handle<JSObject> import_meta = factory()->NewJSObjectWithNullProto();
if (host_initialize_import_meta_object_callback_ != nullptr) {
v8::Local<v8::Context> api_context =
v8::Utils::ToLocal(Handle<Context>(native_context()));
host_initialize_import_meta_object_callback_(
api_context, Utils::ToLocal(Handle<Module>::cast(module)),
v8::Local<v8::Object>::Cast(v8::Utils::ToLocal(import_meta)));
if (has_scheduled_exception()) {
PromoteScheduledException();
return {};
}
}
return import_meta;
}
void Isolate::SetHostInitializeImportMetaObjectCallback(
HostInitializeImportMetaObjectCallback callback) {
host_initialize_import_meta_object_callback_ = callback;
}
MaybeHandle<Object> Isolate::RunPrepareStackTraceCallback(
Handle<Context> context, Handle<JSObject> error, Handle<JSArray> sites) {
v8::Local<v8::Context> api_context = Utils::ToLocal(context);
v8::Local<v8::Value> stack;
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
this, stack,
prepare_stack_trace_callback_(api_context, Utils::ToLocal(error),
Utils::ToLocal(sites)),
MaybeHandle<Object>());
return Utils::OpenHandle(*stack);
}
int Isolate::LookupOrAddExternallyCompiledFilename(const char* filename) {
if (embedded_file_writer_ != nullptr) {
return embedded_file_writer_->LookupOrAddExternallyCompiledFilename(
filename);
}
return 0;
}
const char* Isolate::GetExternallyCompiledFilename(int index) const {
if (embedded_file_writer_ != nullptr) {
return embedded_file_writer_->GetExternallyCompiledFilename(index);
}
return "";
}
int Isolate::GetExternallyCompiledFilenameCount() const {
if (embedded_file_writer_ != nullptr) {
return embedded_file_writer_->GetExternallyCompiledFilenameCount();
}
return 0;
}
void Isolate::PrepareBuiltinSourcePositionMap() {
if (embedded_file_writer_ != nullptr) {
return embedded_file_writer_->PrepareBuiltinSourcePositionMap(
this->builtins());
}
}
void Isolate::PrepareBuiltinLabelInfoMap() {
if (embedded_file_writer_ != nullptr) {
embedded_file_writer_->PrepareBuiltinLabelInfoMap(
heap()->construct_stub_create_deopt_pc_offset().value(),
heap()->construct_stub_invoke_deopt_pc_offset().value());
}
}
#if defined(V8_OS_WIN64)
void Isolate::SetBuiltinUnwindData(
Builtin builtin,
const win64_unwindinfo::BuiltinUnwindInfo& unwinding_info) {
if (embedded_file_writer_ != nullptr) {
embedded_file_writer_->SetBuiltinUnwindData(builtin, unwinding_info);
}
}
#endif // V8_OS_WIN64
void Isolate::SetPrepareStackTraceCallback(PrepareStackTraceCallback callback) {
prepare_stack_trace_callback_ = callback;
}
bool Isolate::HasPrepareStackTraceCallback() const {
return prepare_stack_trace_callback_ != nullptr;
}
void Isolate::SetAddCrashKeyCallback(AddCrashKeyCallback callback) {
add_crash_key_callback_ = callback;
// Log the initial set of data.
AddCrashKeysForIsolateAndHeapPointers();
}
void Isolate::SetAtomicsWaitCallback(v8::Isolate::AtomicsWaitCallback callback,
void* data) {
atomics_wait_callback_ = callback;
atomics_wait_callback_data_ = data;
}
void Isolate::RunAtomicsWaitCallback(v8::Isolate::AtomicsWaitEvent event,
Handle<JSArrayBuffer> array_buffer,
size_t offset_in_bytes, int64_t value,
double timeout_in_ms,
AtomicsWaitWakeHandle* stop_handle) {
DCHECK(array_buffer->is_shared());
if (atomics_wait_callback_ == nullptr) return;
HandleScope handle_scope(this);
atomics_wait_callback_(
event, v8::Utils::ToLocalShared(array_buffer), offset_in_bytes, value,
timeout_in_ms,
reinterpret_cast<v8::Isolate::AtomicsWaitWakeHandle*>(stop_handle),
atomics_wait_callback_data_);
}
void Isolate::SetPromiseHook(PromiseHook hook) {
promise_hook_ = hook;
PromiseHookStateUpdated();
}
void Isolate::RunAllPromiseHooks(PromiseHookType type,
Handle<JSPromise> promise,
Handle<Object> parent) {
if (HasContextPromiseHooks()) {
native_context()->RunPromiseHook(type, promise, parent);
}
if (HasIsolatePromiseHooks() || HasAsyncEventDelegate()) {
RunPromiseHook(type, promise, parent);
}
}
void Isolate::RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
Handle<Object> parent) {
if (!HasIsolatePromiseHooks()) return;
DCHECK(promise_hook_ != nullptr);
promise_hook_(type, v8::Utils::PromiseToLocal(promise),
v8::Utils::ToLocal(parent));
}
void Isolate::OnAsyncFunctionSuspended(Handle<JSPromise> promise,
Handle<JSPromise> parent) {
DCHECK_EQ(0, promise->async_task_id());
RunPromiseHook(PromiseHookType::kInit, promise, parent);
if (HasAsyncEventDelegate()) {
DCHECK_NE(nullptr, async_event_delegate_);
promise->set_async_task_id(++async_task_count_);
async_event_delegate_->AsyncEventOccurred(debug::kDebugAwait,
promise->async_task_id(), false);
}
if (debug()->is_active()) {
// We are about to suspend execution of the current async function,
// so pop the outer promise from the isolate's promise stack.
PopPromise();
}
}
void Isolate::OnPromiseThen(Handle<JSPromise> promise) {
if (!HasAsyncEventDelegate()) return;
Maybe<debug::DebugAsyncActionType> action_type =
Nothing<debug::DebugAsyncActionType>();
for (JavaScriptFrameIterator it(this); !it.done(); it.Advance()) {
std::vector<Handle<SharedFunctionInfo>> infos;
it.frame()->GetFunctions(&infos);
for (auto it = infos.rbegin(); it != infos.rend(); ++it) {
Handle<SharedFunctionInfo> info = *it;
if (info->HasBuiltinId()) {
// We should not report PromiseThen and PromiseCatch which is called
// indirectly, e.g. Promise.all calls Promise.then internally.
switch (info->builtin_id()) {
case Builtin::kPromisePrototypeCatch:
action_type = Just(debug::kDebugPromiseCatch);
continue;
case Builtin::kPromisePrototypeFinally:
action_type = Just(debug::kDebugPromiseFinally);
continue;
case Builtin::kPromisePrototypeThen:
action_type = Just(debug::kDebugPromiseThen);
continue;
default:
return;
}
}
if (info->IsUserJavaScript() && action_type.IsJust()) {
DCHECK_EQ(0, promise->async_task_id());
promise->set_async_task_id(++async_task_count_);
async_event_delegate_->AsyncEventOccurred(action_type.FromJust(),
promise->async_task_id(),
debug()->IsBlackboxed(info));
}
return;
}
}
}
void Isolate::OnPromiseBefore(Handle<JSPromise> promise) {
RunPromiseHook(PromiseHookType::kBefore, promise,
factory()->undefined_value());
if (HasAsyncEventDelegate()) {
if (promise->async_task_id()) {
async_event_delegate_->AsyncEventOccurred(
debug::kDebugWillHandle, promise->async_task_id(), false);
}
}
if (debug()->is_active()) PushPromise(promise);
}
void Isolate::OnPromiseAfter(Handle<JSPromise> promise) {
RunPromiseHook(PromiseHookType::kAfter, promise,
factory()->undefined_value());
if (HasAsyncEventDelegate()) {
if (promise->async_task_id()) {
async_event_delegate_->AsyncEventOccurred(
debug::kDebugDidHandle, promise->async_task_id(), false);
}
}
if (debug()->is_active()) PopPromise();
}
void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
promise_reject_callback_ = callback;
}
void Isolate::ReportPromiseReject(Handle<JSPromise> promise,
Handle<Object> value,
v8::PromiseRejectEvent event) {
if (promise_reject_callback_ == nullptr) return;
promise_reject_callback_(v8::PromiseRejectMessage(
v8::Utils::PromiseToLocal(promise), event, v8::Utils::ToLocal(value)));
}
void Isolate::SetUseCounterCallback(v8::Isolate::UseCounterCallback callback) {
DCHECK(!use_counter_callback_);
use_counter_callback_ = callback;
}
void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature) {
// The counter callback
// - may cause the embedder to call into V8, which is not generally possible
// during GC.
// - requires a current native context, which may not always exist.
// TODO(jgruber): Consider either removing the native context requirement in
// blink, or passing it to the callback explicitly.
if (heap_.gc_state() == Heap::NOT_IN_GC && !context().is_null()) {
DCHECK(context().IsContext());
DCHECK(context().native_context().IsNativeContext());
if (use_counter_callback_) {
HandleScope handle_scope(this);
use_counter_callback_(reinterpret_cast<v8::Isolate*>(this), feature);
}
} else {
heap_.IncrementDeferredCount(feature);
}
}
void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature, int count) {
for (int i = 0; i < count; ++i) {
CountUsage(feature);
}
}
int Isolate::GetNextScriptId() { return heap()->NextScriptId(); }
// static
std::string Isolate::GetTurboCfgFileName(Isolate* isolate) {
if (FLAG_trace_turbo_cfg_file == nullptr) {
std::ostringstream os;
os << "turbo-" << base::OS::GetCurrentProcessId() << "-";
if (isolate != nullptr) {
os << isolate->id();
} else {
os << "any";
}
os << ".cfg";
return os.str();
} else {
return FLAG_trace_turbo_cfg_file;
}
}
// Heap::detached_contexts tracks detached contexts as pairs
// (number of GC since the context was detached, the context).
void Isolate::AddDetachedContext(Handle<Context> context) {
HandleScope scope(this);
Handle<WeakArrayList> detached_contexts = factory()->detached_contexts();
detached_contexts = WeakArrayList::AddToEnd(
this, detached_contexts, MaybeObjectHandle(Smi::zero(), this),
MaybeObjectHandle::Weak(context));
heap()->set_detached_contexts(*detached_contexts);
}
void Isolate::CheckDetachedContextsAfterGC() {
HandleScope scope(this);
Handle<WeakArrayList> detached_contexts = factory()->detached_contexts();
int length = detached_contexts->length();
if (length == 0) return;
int new_length = 0;
for (int i = 0; i < length; i += 2) {
int mark_sweeps = detached_contexts->Get(i).ToSmi().value();
MaybeObject context = detached_contexts->Get(i + 1);
DCHECK(context->IsWeakOrCleared());
if (!context->IsCleared()) {
detached_contexts->Set(
new_length, MaybeObject::FromSmi(Smi::FromInt(mark_sweeps + 1)));
detached_contexts->Set(new_length + 1, context);
new_length += 2;
}
}
detached_contexts->set_length(new_length);
while (new_length < length) {
detached_contexts->Set(new_length, MaybeObject::FromSmi(Smi::zero()));
++new_length;
}
if (FLAG_trace_detached_contexts) {
PrintF("%d detached contexts are collected out of %d\n",
length - new_length, length);
for (int i = 0; i < new_length; i += 2) {
int mark_sweeps = detached_contexts->Get(i).ToSmi().value();
MaybeObject context = detached_contexts->Get(i + 1);
DCHECK(context->IsWeakOrCleared());
if (mark_sweeps > 3) {
PrintF("detached context %p\n survived %d GCs (leak?)\n",
reinterpret_cast<void*>(context.ptr()), mark_sweeps);
}
}
}
}
void Isolate::DetachGlobal(Handle<Context> env) {
counters()->errors_thrown_per_context()->AddSample(
env->native_context().GetErrorsThrown());
ReadOnlyRoots roots(this);
Handle<JSGlobalProxy> global_proxy(env->global_proxy(), this);
global_proxy->set_native_context(roots.null_value());
// NOTE: Turbofan's JSNativeContextSpecialization depends on DetachGlobal
// causing a map change.
JSObject::ForceSetPrototype(this, global_proxy, factory()->null_value());
global_proxy->map().set_constructor_or_back_pointer(roots.null_value(),
kRelaxedStore);
if (FLAG_track_detached_contexts) AddDetachedContext(env);
DCHECK(global_proxy->IsDetached());
env->native_context().set_microtask_queue(this, nullptr);
}
double Isolate::LoadStartTimeMs() {
base::MutexGuard guard(&rail_mutex_);
return load_start_time_ms_;
}
void Isolate::UpdateLoadStartTime() {
base::MutexGuard guard(&rail_mutex_);
load_start_time_ms_ = heap()->MonotonicallyIncreasingTimeInMs();
}
void Isolate::SetRAILMode(RAILMode rail_mode) {
RAILMode old_rail_mode = rail_mode_.load();
if (old_rail_mode != PERFORMANCE_LOAD && rail_mode == PERFORMANCE_LOAD) {
base::MutexGuard guard(&rail_mutex_);
load_start_time_ms_ = heap()->MonotonicallyIncreasingTimeInMs();
}
rail_mode_.store(rail_mode);
if (old_rail_mode == PERFORMANCE_LOAD && rail_mode != PERFORMANCE_LOAD) {
heap()->incremental_marking()->incremental_marking_job()->ScheduleTask(
heap());
}
if (FLAG_trace_rail) {
PrintIsolate(this, "RAIL mode: %s\n", RAILModeName(rail_mode));
}
}
void Isolate::IsolateInBackgroundNotification() {
is_isolate_in_background_ = true;
heap()->ActivateMemoryReducerIfNeeded();
}
void Isolate::IsolateInForegroundNotification() {
is_isolate_in_background_ = false;
}
void Isolate::PrintWithTimestamp(const char* format, ...) {
base::OS::Print("[%d:%p] %8.0f ms: ", base::OS::GetCurrentProcessId(),
static_cast<void*>(this), time_millis_since_init());
va_list arguments;
va_start(arguments, format);
base::OS::VPrint(format, arguments);
va_end(arguments);
}
void Isolate::SetIdle(bool is_idle) {
StateTag state = current_vm_state();
if (js_entry_sp() != kNullAddress) return;
DCHECK(state == EXTERNAL || state == IDLE);
if (is_idle) {
set_current_vm_state(IDLE);
} else if (state == IDLE) {
set_current_vm_state(EXTERNAL);
}
}
void Isolate::CollectSourcePositionsForAllBytecodeArrays() {
if (!initialized_) return;
HandleScope scope(this);
std::vector<Handle<SharedFunctionInfo>> sfis;
{
HeapObjectIterator iterator(heap());
for (HeapObject obj = iterator.Next(); !obj.is_null();
obj = iterator.Next()) {
if (!obj.IsSharedFunctionInfo()) continue;
SharedFunctionInfo sfi = SharedFunctionInfo::cast(obj);
if (!sfi.CanCollectSourcePosition(this)) continue;
sfis.push_back(Handle<SharedFunctionInfo>(sfi, this));
}
}
for (auto sfi : sfis) {
SharedFunctionInfo::EnsureSourcePositionsAvailable(this, sfi);
}
}
#ifdef V8_INTL_SUPPORT
namespace {
std::string GetStringFromLocales(Isolate* isolate, Handle<Object> locales) {
if (locales->IsUndefined(isolate)) return "";
return std::string(String::cast(*locales).ToCString().get());
}
bool StringEqualsLocales(Isolate* isolate, const std::string& str,
Handle<Object> locales) {
if (locales->IsUndefined(isolate)) return str == "";
return Handle<String>::cast(locales)->IsEqualTo(
base::VectorOf(str.c_str(), str.length()));
}
} // namespace
const std::string& Isolate::DefaultLocale() {
if (default_locale_.empty()) {
icu::Locale default_locale;
// Translate ICU's fallback locale to a well-known locale.
if (strcmp(default_locale.getName(), "en_US_POSIX") == 0 ||
strcmp(default_locale.getName(), "c") == 0) {
set_default_locale("en-US");
} else {
// Set the locale
set_default_locale(default_locale.isBogus()
? "und"
: Intl::ToLanguageTag(default_locale).FromJust());
}
DCHECK(!default_locale_.empty());
}
return default_locale_;
}
void Isolate::ResetDefaultLocale() {
default_locale_.clear();
clear_cached_icu_objects();
// We inline fast paths assuming certain locales. Since this path is rarely
// taken, we deoptimize everything to keep things simple.
Deoptimizer::DeoptimizeAll(this);
}
icu::UMemory* Isolate::get_cached_icu_object(ICUObjectCacheType cache_type,
Handle<Object> locales) {
const ICUObjectCacheEntry& entry =
icu_object_cache_[static_cast<int>(cache_type)];
return StringEqualsLocales(this, entry.locales, locales) ? entry.obj.get()
: nullptr;
}
void Isolate::set_icu_object_in_cache(ICUObjectCacheType cache_type,
Handle<Object> locales,
std::shared_ptr<icu::UMemory> obj) {
icu_object_cache_[static_cast<int>(cache_type)] = {
GetStringFromLocales(this, locales), std::move(obj)};
}
void Isolate::clear_cached_icu_object(ICUObjectCacheType cache_type) {
icu_object_cache_[static_cast<int>(cache_type)] = ICUObjectCacheEntry{};
}
void Isolate::clear_cached_icu_objects() {
for (int i = 0; i < kICUObjectCacheTypeCount; i++) {
clear_cached_icu_object(static_cast<ICUObjectCacheType>(i));
}
}
#endif // V8_INTL_SUPPORT
bool StackLimitCheck::JsHasOverflowed(uintptr_t gap) const {
StackGuard* stack_guard = isolate_->stack_guard();
#ifdef USE_SIMULATOR
// The simulator uses a separate JS stack.
Address jssp_address = Simulator::current(isolate_)->get_sp();
uintptr_t jssp = static_cast<uintptr_t>(jssp_address);
if (jssp - gap < stack_guard->real_jslimit()) return true;
#endif // USE_SIMULATOR
return GetCurrentStackPosition() - gap < stack_guard->real_climit();
}
SaveContext::SaveContext(Isolate* isolate) : isolate_(isolate) {
if (!isolate->context().is_null()) {
context_ = Handle<Context>(isolate->context(), isolate);
}
c_entry_fp_ = isolate->c_entry_fp(isolate->thread_local_top());
}
SaveContext::~SaveContext() {
isolate_->set_context(context_.is_null() ? Context() : *context_);
}
bool SaveContext::IsBelowFrame(CommonFrame* frame) {
return (c_entry_fp_ == 0) || (c_entry_fp_ > frame->sp());
}
SaveAndSwitchContext::SaveAndSwitchContext(Isolate* isolate,
Context new_context)
: SaveContext(isolate) {
isolate->set_context(new_context);
}
#ifdef DEBUG
AssertNoContextChange::AssertNoContextChange(Isolate* isolate)
: isolate_(isolate), context_(isolate->context(), isolate) {}
namespace {
bool Overlapping(const MemoryRange& a, const MemoryRange& b) {
uintptr_t a1 = reinterpret_cast<uintptr_t>(a.start);
uintptr_t a2 = a1 + a.length_in_bytes;
uintptr_t b1 = reinterpret_cast<uintptr_t>(b.start);
uintptr_t b2 = b1 + b.length_in_bytes;
// Either b1 or b2 are in the [a1, a2) range.
return (a1 <= b1 && b1 < a2) || (a1 <= b2 && b2 < a2);
}
} // anonymous namespace
#endif // DEBUG
void Isolate::AddCodeMemoryRange(MemoryRange range) {
base::MutexGuard guard(&code_pages_mutex_);
std::vector<MemoryRange>* old_code_pages = GetCodePages();
DCHECK_NOT_NULL(old_code_pages);
#ifdef DEBUG
auto overlapping = [range](const MemoryRange& a) {
return Overlapping(range, a);
};
DCHECK_EQ(old_code_pages->end(),
std::find_if(old_code_pages->begin(), old_code_pages->end(),
overlapping));
#endif
std::vector<MemoryRange>* new_code_pages;
if (old_code_pages == &code_pages_buffer1_) {
new_code_pages = &code_pages_buffer2_;
} else {
new_code_pages = &code_pages_buffer1_;
}
// Copy all existing data from the old vector to the new vector and insert the
// new page.
new_code_pages->clear();
new_code_pages->reserve(old_code_pages->size() + 1);
std::merge(old_code_pages->begin(), old_code_pages->end(), &range, &range + 1,
std::back_inserter(*new_code_pages),
[](const MemoryRange& a, const MemoryRange& b) {
return a.start < b.start;
});
// Atomically switch out the pointer
SetCodePages(new_code_pages);
}
// |chunk| is either a Page or an executable LargePage.
void Isolate::AddCodeMemoryChunk(MemoryChunk* chunk) {
// We only keep track of individual code pages/allocations if we are on arm32,
// because on x64 and arm64 we have a code range which makes this unnecessary.
#if !defined(V8_TARGET_ARCH_ARM)
return;
#else
void* new_page_start = reinterpret_cast<void*>(chunk->area_start());
size_t new_page_size = chunk->area_size();
MemoryRange new_range{new_page_start, new_page_size};
AddCodeMemoryRange(new_range);
#endif // !defined(V8_TARGET_ARCH_ARM)
}
void Isolate::AddCodeRange(Address begin, size_t length_in_bytes) {
AddCodeMemoryRange(
MemoryRange{reinterpret_cast<void*>(begin), length_in_bytes});
}
bool Isolate::RequiresCodeRange() const {
return kPlatformRequiresCodeRange && !jitless_;
}
v8::metrics::Recorder::ContextId Isolate::GetOrRegisterRecorderContextId(
Handle<NativeContext> context) {
if (serializer_enabled_) return v8::metrics::Recorder::ContextId::Empty();
i::Object id = context->recorder_context_id();
if (id.IsNullOrUndefined()) {
CHECK_LT(last_recorder_context_id_, i::Smi::kMaxValue);
context->set_recorder_context_id(
i::Smi::FromIntptr(++last_recorder_context_id_));
v8::HandleScope handle_scope(reinterpret_cast<v8::Isolate*>(this));
auto result = recorder_context_id_map_.emplace(
std::piecewise_construct,
std::forward_as_tuple(last_recorder_context_id_),
std::forward_as_tuple(reinterpret_cast<v8::Isolate*>(this),
ToApiHandle<v8::Context>(context)));
result.first->second.SetWeak(
reinterpret_cast<void*>(last_recorder_context_id_),
RemoveContextIdCallback, v8::WeakCallbackType::kParameter);
return v8::metrics::Recorder::ContextId(last_recorder_context_id_);
} else {
DCHECK(id.IsSmi());
return v8::metrics::Recorder::ContextId(
static_cast<uintptr_t>(i::Smi::ToInt(id)));
}
}
MaybeLocal<v8::Context> Isolate::GetContextFromRecorderContextId(
v8::metrics::Recorder::ContextId id) {
auto result = recorder_context_id_map_.find(id.id_);
if (result == recorder_context_id_map_.end() || result->second.IsEmpty())
return MaybeLocal<v8::Context>();
return result->second.Get(reinterpret_cast<v8::Isolate*>(this));
}
void Isolate::UpdateLongTaskStats() {
if (last_long_task_stats_counter_ != isolate_data_.long_task_stats_counter_) {
last_long_task_stats_counter_ = isolate_data_.long_task_stats_counter_;
long_task_stats_ = v8::metrics::LongTaskStats{};
}
}
v8::metrics::LongTaskStats* Isolate::GetCurrentLongTaskStats() {
UpdateLongTaskStats();
return &long_task_stats_;
}
void Isolate::RemoveContextIdCallback(const v8::WeakCallbackInfo<void>& data) {
Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate());
uintptr_t context_id = reinterpret_cast<uintptr_t>(data.GetParameter());
isolate->recorder_context_id_map_.erase(context_id);
}
LocalHeap* Isolate::main_thread_local_heap() {
return main_thread_local_isolate()->heap();
}
LocalHeap* Isolate::CurrentLocalHeap() {
LocalHeap* local_heap = LocalHeap::Current();
return local_heap ? local_heap : main_thread_local_heap();
}
// |chunk| is either a Page or an executable LargePage.
void Isolate::RemoveCodeMemoryChunk(MemoryChunk* chunk) {
// We only keep track of individual code pages/allocations if we are on arm32,
// because on x64 and arm64 we have a code range which makes this unnecessary.
#if !defined(V8_TARGET_ARCH_ARM)
return;
#else
void* removed_page_start = reinterpret_cast<void*>(chunk->area_start());
std::vector<MemoryRange>* old_code_pages = GetCodePages();
DCHECK_NOT_NULL(old_code_pages);
std::vector<MemoryRange>* new_code_pages;
if (old_code_pages == &code_pages_buffer1_) {
new_code_pages = &code_pages_buffer2_;
} else {
new_code_pages = &code_pages_buffer1_;
}
// Copy all existing data from the old vector to the new vector except the
// removed page.
new_code_pages->clear();
new_code_pages->reserve(old_code_pages->size() - 1);
std::remove_copy_if(old_code_pages->begin(), old_code_pages->end(),
std::back_inserter(*new_code_pages),
[removed_page_start](const MemoryRange& range) {
return range.start == removed_page_start;
});
DCHECK_EQ(old_code_pages->size(), new_code_pages->size() + 1);
// Atomically switch out the pointer
SetCodePages(new_code_pages);
#endif // !defined(V8_TARGET_ARCH_ARM)
}
#undef TRACE_ISOLATE
// static
Address Isolate::load_from_stack_count_address(const char* function_name) {
DCHECK_NOT_NULL(function_name);
if (!stack_access_count_map) {
stack_access_count_map = new MapOfLoadsAndStoresPerFunction{};
}
auto& map = *stack_access_count_map;
std::string name(function_name);
// It is safe to return the address of std::map values.
// Only iterators and references to the erased elements are invalidated.
return reinterpret_cast<Address>(&map[name].first);
}
// static
Address Isolate::store_to_stack_count_address(const char* function_name) {
DCHECK_NOT_NULL(function_name);
if (!stack_access_count_map) {
stack_access_count_map = new MapOfLoadsAndStoresPerFunction{};
}
auto& map = *stack_access_count_map;
std::string name(function_name);
// It is safe to return the address of std::map values.
// Only iterators and references to the erased elements are invalidated.
return reinterpret_cast<Address>(&map[name].second);
}
void Isolate::AttachToSharedIsolate() {
DCHECK(!attached_to_shared_isolate_);
if (shared_isolate_) {
DCHECK(shared_isolate_->is_shared());
shared_isolate_->global_safepoint()->AppendClient(this);
}
#if DEBUG
attached_to_shared_isolate_ = true;
#endif // DEBUG
}
void Isolate::DetachFromSharedIsolate() {
DCHECK(attached_to_shared_isolate_);
if (shared_isolate_) {
shared_isolate_->global_safepoint()->RemoveClient(this);
shared_isolate_ = nullptr;
}
#if DEBUG
attached_to_shared_isolate_ = false;
#endif // DEBUG
}
} // namespace internal
} // namespace v8