// 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 <algorithm>
#include <atomic>
#include <cinttypes>
#include <cstdint>
#include <cstdio>
#include <fstream>
#include <limits>
#include <memory>
#include <optional>
#include <span>
#include <sstream>
#include <string>
#include <unordered_map>
#include <utility>
#include "include/v8-callbacks.h"
#include "include/v8-function.h"
#include "include/v8-template.h"
#include "src/api/api-arguments-inl.h"
#include "src/api/api-inl.h"
#include "src/ast/ast-value-factory.h"
#include "src/ast/scopes.h"
#include "src/base/fpu.h"
#include "src/base/iterator.h"
#include "src/base/logging.h"
#include "src/base/platform/mutex.h"
#include "src/base/platform/platform.h"
#include "src/base/platform/wrappers.h"
#include "src/base/strong-alias.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/builtins.h"
#include "src/builtins/constants-table-builder.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/compilation-cache.h"
#include "src/common/assert-scope.h"
#include "src/common/globals.h"
#include "src/common/ptr-compr-inl.h"
#include "src/common/thread-local-storage.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"
#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/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/simulator.h"
#include "src/execution/tiering-manager.h"
#include "src/execution/v8threads.h"
#include "src/execution/vm-state-inl.h"
#include "src/flags/flags.h"
#include "src/handles/global-handles-inl.h"
#include "src/handles/persistent-handles.h"
#include "src/heap/heap-inl.h"
#include "src/heap/heap-verifier.h"
#include "src/heap/local-heap-inl.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/bytecode-array-iterator.h"
#include "src/interpreter/bytecodes.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/abstract-code-inl.h"
#include "src/objects/backing-store.h"
#include "src/objects/call-site-info-inl.h"
#include "src/objects/feedback-vector.h"
#include "src/objects/hash-table-inl.h"
#include "src/objects/heap-object-set-map-inl.h"
#include "src/objects/instance-type-inl.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/objects/js-array-inl.h"
#include "src/objects/js-function.h"
#include "src/objects/js-generator-inl.h"
#include "src/objects/js-struct.h"
#include "src/objects/js-weak-refs-inl.h"
#include "src/objects/managed-inl.h"
#include "src/objects/module-inl.h"
#include "src/objects/object-conversions-inl.h"
#include "src/objects/objects.h"
#include "src/objects/promise-inl.h"
#include "src/objects/property-descriptor.h"
#include "src/objects/slots.h"
#include "src/objects/smi.h"
#include "src/objects/source-text-module-inl.h"
#include "src/objects/string-set-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/roots/roots.h"
#include "src/roots/static-roots.h"
#include "src/sandbox/js-dispatch-table-inl.h"
#include "src/snapshot/embedded/embedded-data-inl.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/snapshot.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"
#if defined(V8_USE_PERFETTO)
#include "src/tracing/perfetto-logger.h"
#endif // defined(V8_USE_PERFETTO)
#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_MAGLEV
#include "src/maglev/maglev-concurrent-dispatcher.h"
#endif // V8_ENABLE_MAGLEV
#if V8_ENABLE_WEBASSEMBLY
#include "src/builtins/builtins-inl.h"
#include "src/debug/debug-wasm-objects.h"
#include "src/trap-handler/trap-handler.h"
#include "src/wasm/stacks.h"
#include "src/wasm/wasm-code-manager.h"
#include "src/wasm/wasm-code-pointer-table-inl.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects-inl.h"
#if V8_ENABLE_DRUMBRAKE
#include "src/wasm/interpreter/wasm-interpreter.h"
#endif // V8_ENABLE_DRUMBRAKE
#endif // V8_ENABLE_WEBASSEMBLY
#if defined(V8_ENABLE_ETW_STACK_WALKING)
#include "src/diagnostics/etw-jit-win.h"
#endif // V8_ENABLE_ETW_STACK_WALKING
#if defined(V8_OS_WIN64)
#include "src/diagnostics/unwinding-info-win64.h"
#endif // V8_OS_WIN64
#if defined(V8_OS_DARWIN)
#include <sys/sysctl.h>
#include <sys/types.h>
#include <unistd.h>
#endif // V8_OS_DARWIN
#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 (v8_flags.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
// InstructionStream::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);
#ifdef DEBUG
bool IsDebuggerAttached() {
#ifdef V8_OS_LINUX
FILE* fp = fopen("/proc/self/status", "r");
if (!fp) return false;
char line[128];
bool attached = false;
while (fgets(line, sizeof(line), fp)) {
if (strncmp(line, "TracerPid:", 10) == 0) {
int pid = atoi(line + 10);
if (pid != 0) {
attached = true;
}
break;
}
}
fclose(fp);
return attached;
#elif defined(V8_OS_DARWIN)
int mib[4];
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = getpid();
struct kinfo_proc info;
size_t size = sizeof(info);
info.kp_proc.p_flag = 0;
if (sysctl(mib, 4, &info, &size, NULL, 0) == -1) {
return false;
}
return ((info.kp_proc.p_flag & P_TRACED) != 0);
#else
return false;
#endif
}
#endif // DEBUG
// 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_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 (v8_flags.text_is_readable) {
if (d.EmbeddedBlobCodeHash() != d.CreateEmbeddedBlobCodeHash()) {
if (IsDebuggerAttached()) {
PrintF(
"Warning: Embedded blob code section checksum verification failed, "
"but debugger is attached. Skipping.\n");
} else {
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_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobCodeSize() {
return current_embedded_blob_code_size_.load(std::memory_order_relaxed);
}
// static
const uint8_t* Isolate::CurrentEmbeddedBlobData() {
return current_embedded_blob_data_.load(std::memory_order_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobDataSize() {
return current_embedded_blob_data_size_.load(std::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 static entries of the roots table.
hash = base::hash_combine(hash, V8_STATIC_ROOTS_BOOL);
#if V8_STATIC_ROOTS_BOOL
hash = base::hash_combine(hash,
static_cast<int>(RootIndex::kReadOnlyRootsCount));
RootIndex i = RootIndex::kFirstReadOnlyRoot;
for (auto ptr : StaticReadOnlyRootsPointerTable) {
hash = base::hash_combine(ptr, hash);
++i;
}
#endif // V8_STATIC_ROOTS_BOOL
// Hash data sections of builtin code objects.
for (Builtin builtin = Builtins::kFirst; builtin <= Builtins::kLast;
++builtin) {
#if V8_ENABLE_GEARBOX
if (Builtins::IsGearboxPlaceholder(builtin)) {
// When v8 enables gearbox for builtins, there are 3 builtin objects for a
// builtin, one is generic variant, another one is ISX variant, and final
// one is a placeholder, it will be set as either generic or ISX variant
// at runtime. Therefore v8 will modify the contents of the placeholder
// code object when it is being launched, so we didn't take it into the
// hash calculation, otherwise it will cause hash check failed.
continue;
}
#endif
Tagged<Code> code = builtins()->code(builtin);
DCHECK(Internals::HasHeapObjectTag(code.ptr()));
uint8_t* const code_ptr = reinterpret_cast<uint8_t*>(code.address());
// These static asserts ensure we don't miss relevant fields. We don't hash
// instruction_start, but other data fields must remain the same.
static_assert(Code::kEndOfStrongFieldsOffset ==
Code::kInstructionStartOffset);
#ifndef V8_ENABLE_SANDBOX
static_assert(Code::kInstructionStartOffsetEnd + 1 +
kJSDispatchHandleSize ==
Code::kFlagsOffset);
#endif
static_assert(Code::kFlagsOffsetEnd + 1 == Code::kInstructionSizeOffset);
static_assert(Code::kInstructionSizeOffsetEnd + 1 ==
Code::kMetadataSizeOffset);
static_assert(Code::kMetadataSizeOffsetEnd + 1 ==
Code::kInlinedBytecodeSizeOffset);
static_assert(Code::kInlinedBytecodeSizeOffsetEnd + 1 ==
Code::kOsrOffsetOffset);
static_assert(Code::kOsrOffsetOffsetEnd + 1 ==
Code::kHandlerTableOffsetOffset);
static_assert(Code::kHandlerTableOffsetOffsetEnd + 1 ==
Code::kUnwindingInfoOffsetOffset);
static_assert(Code::kUnwindingInfoOffsetOffsetEnd + 1 ==
Code::kConstantPoolOffsetOffset);
static_assert(Code::kConstantPoolOffsetOffsetEnd + 1 ==
Code::kCodeCommentsOffsetOffset);
static_assert(Code::kCodeCommentsOffsetOffsetEnd + 1 ==
Code::kJumpTableInfoOffsetOffset);
static_assert(Code::kJumpTableInfoOffsetOffsetEnd + 1 ==
Code::kParameterCountOffset);
static_assert(Code::kParameterCountOffsetEnd + 1 == Code::kBuiltinIdOffset);
static_assert(Code::kBuiltinIdOffsetEnd + 1 == Code::kUnalignedSize);
// Hash Code::flags field ignoring the Code::IsDisabledBuiltinField bit.
// This bit is set for certain builtins during RO heap deserialization
// and thus might differ from the default state.
uint32_t flags = code->flags(kRelaxedLoad);
flags &= ~Code::IsDisabledBuiltinField::kMask;
hash = base::hash_combine(hash, flags);
// Proceed past the flags field.
static constexpr int kStartOffset = Code::kInstructionSizeOffset;
for (int j = kStartOffset; j < Code::kUnalignedSize; 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, heap_.builtins_constants_table()->ulength().value());
return hash;
}
thread_local Isolate::PerIsolateThreadData* g_current_per_isolate_thread_data_
V8_CONSTINIT = nullptr;
thread_local Isolate* g_current_isolate_ V8_CONSTINIT = nullptr;
V8_TLS_DEFINE_GETTER(Isolate::TryGetCurrent, Isolate*, g_current_isolate_)
// static
void Isolate::SetCurrent(Isolate* isolate) { g_current_isolate_ = isolate; }
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 (v8_flags.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() { Heap::InitializeOncePerProcess(); }
char* Isolate::Iterate(RootVisitor* v, char* thread_storage) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(thread_storage);
Iterate(v, thread);
// Normally, ThreadLocalTop::topmost_script_having_context_ is visited weakly
// but in order to simplify handling of frozen threads we just clear it.
// Otherwise, we'd need to traverse the thread_storage again just to find this
// one field.
thread->topmost_script_having_context_ = {};
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->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->last_entered_context_));
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_))));
}
v->VisitRootPointer(
Root::kStackRoots, nullptr,
FullObjectSlot(continuation_preserved_embedder_data_address()));
#if V8_ENABLE_WEBASSEMBLY
v->VisitRootPointer(Root::kStackRoots, nullptr,
FullObjectSlot(&isolate_data()->active_suspender_));
// Iterate over pointers on native execution stack.
wasm::WasmCodeRefScope wasm_code_ref_scope;
// The vector contains at least the active Wasm/JS stack:
DCHECK_GE(wasm_stacks_.size(), 1);
for (const std::unique_ptr<wasm::StackMemory>& stack : wasm_stacks_) {
stack->Iterate(v, this, thread);
}
#else
StackFrameIterator it(this, thread);
for (; !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
#endif
}
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_EQ(thread_local_top()->try_catch_handler_, that);
thread_local_top()->try_catch_handler_ = that->next_;
SimulatorStack::UnregisterJSStackComparableAddress(this);
}
void Isolate::MarkTryCatchInternal(v8::TryCatch* that) {
that->SetIsInternal(true);
}
bool Isolate::IsInternalTryCatch(v8::TryCatch* that) {
return that->IsInternal();
}
DirectHandle<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);
DirectHandle<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();
}
}
[[noreturn]] void Isolate::PushStackTraceAndDie(const char* reason, void* ptr1,
void* ptr2, void* ptr3,
void* ptr4, void* ptr5,
void* ptr6) {
static std::atomic<bool> recursive{false};
if (recursive.exchange(true)) IMMEDIATE_CRASH();
// Constructing the stack trace requires allocations and handles and is
// therefore only supported on the main thread.
CHECK(LocalHeap::Current()->is_main_thread());
StackTraceFailureMessage message(this,
StackTraceFailureMessage::kIncludeStackTrace,
{ptr1, ptr2, ptr3, ptr4, ptr5, ptr6});
message.Print();
// Print an error message similar to hitting V8_Fatal under
// `v8::base::ControlledCrashesAreHarmless()`, for fuzzers / Clusterfuzz but
// also humans investigating externally reported crashes.
v8::base::OS::PrintError(
"\n\n#\n# Safely terminating process due to hitting "
"Isolate::PushStackTraceAndDie\n#\n");
// Give the embedder a chance to handle the fatal error.
FatalErrorCallback callback = exception_behavior();
if (callback) {
callback("Isolate::PushStackTraceAndDie", reason);
}
base::OS::Abort();
}
[[noreturn]] void Isolate::PushParamsAndDie(const char* reason, 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();
// Print an error message similar to hitting V8_Fatal under
// `v8::base::ControlledCrashesAreHarmless()`, for fuzzers / Clusterfuzz but
// also humans investigating externally reported crashes.
v8::base::OS::PrintError(
"\n\n#\n# Safely terminating process due to hitting "
"Isolate::PushParamsAndDie\n#\n");
// Give the embedder a chance to handle the fatal error.
FatalErrorCallback callback = exception_behavior();
if (callback) {
callback("Isolate::PushParamsAndDie", reason);
}
base::OS::Abort();
}
void Isolate::PushStackTraceAndContinue(void* ptr1, void* ptr2, void* ptr3,
void* ptr4, void* ptr5, void* ptr6) {
StackTraceFailureMessage message(this,
StackTraceFailureMessage::kIncludeStackTrace,
{ptr1, ptr2, ptr3, ptr4, ptr5, ptr6});
message.Print();
V8::GetCurrentPlatform()->DumpWithoutCrashing();
}
void Isolate::PushParamsAndContinue(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();
V8::GetCurrentPlatform()->DumpWithoutCrashing();
}
void StackTraceFailureMessage::Print() volatile {
// Print the details of this failure message object, including its own address
// to force stack allocation.
static_assert(arraysize(ptrs_) >= 6);
base::OS::PrintError(
"Stacktrace:\n ptr0=%p\n ptr1=%p\n ptr2=%p\n ptr3=%p\n "
"ptr4=%p\n ptr5=%p\n failure_message_object=%p\n%s",
reinterpret_cast<void*>(ptrs_[0]), reinterpret_cast<void*>(ptrs_[1]),
reinterpret_cast<void*>(ptrs_[2]), reinterpret_cast<void*>(ptrs_[3]),
reinterpret_cast<void*>(ptrs_[4]), reinterpret_cast<void*>(ptrs_[5]),
this, &js_stack_trace_[0]);
}
StackTraceFailureMessage::StackTraceFailureMessage(
Isolate* isolate, StackTraceFailureMessage::StackTraceMode mode,
const Address* ptrs, size_t ptrs_count)
: isolate_(isolate) {
size_t ptrs_size = std::min(arraysize(ptrs_), ptrs_count);
std::copy(ptrs, ptrs + ptrs_size, &ptrs_[0]);
if (mode == kIncludeStackTrace) {
// Write a stracktrace into the {js_stack_trace_} buffer.
const size_t buffer_length = arraysize(js_stack_trace_);
FixedStringAllocator fixed(&js_stack_trace_[0], buffer_length - 1);
StringStream accumulator(&fixed, StringStream::kPrintObjectConcise);
isolate_->PrintStack(&accumulator, Isolate::kPrintStackVerbose,
AllowAllocation{false});
// Keeping a reference to the last code objects to increase likelihood 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++] = it.frame()->unchecked_code().ptr();
}
}
}
bool NoExtension(const v8::FunctionCallbackInfo<v8::Value>&) { return false; }
namespace {
bool IsBuiltinFunction(Isolate* isolate, Tagged<HeapObject> object,
Builtin builtin) {
if (!IsJSFunction(object)) return false;
Tagged<JSFunction> const function = Cast<JSFunction>(object);
// Currently we have to use full pointer comparison here as builtin Code
// objects are still inside the sandbox while runtime-generated Code objects
// are in trusted space.
static_assert(!kAllCodeObjectsLiveInTrustedSpace);
return function->code(isolate).SafeEquals(isolate->builtins()->code(builtin));
}
// Check if the function is one of the known async function or
// async generator fulfill handlers.
bool IsBuiltinAsyncFulfillHandler(Isolate* isolate, Tagged<HeapObject> object) {
return IsBuiltinFunction(isolate, object,
Builtin::kAsyncFunctionAwaitResolveClosure) ||
IsBuiltinFunction(isolate, object,
Builtin::kAsyncGeneratorAwaitResolveClosure) ||
IsBuiltinFunction(
isolate, object,
Builtin::kAsyncGeneratorYieldWithAwaitResolveClosure);
}
// Check if the function is one of the known async function or
// async generator fulfill handlers.
bool IsBuiltinAsyncRejectHandler(Isolate* isolate, Tagged<HeapObject> object) {
return IsBuiltinFunction(isolate, object,
Builtin::kAsyncFunctionAwaitRejectClosure) ||
IsBuiltinFunction(isolate, object,
Builtin::kAsyncGeneratorAwaitRejectClosure);
}
// Check if the function is one of the known builtin rejection handlers that
// rethrows the exception instead of catching it.
bool IsBuiltinForwardingRejectHandler(Isolate* isolate,
Tagged<HeapObject> object) {
if (IsBuiltinFunction(isolate, object, Builtin::kPromiseCatchFinally) ||
IsBuiltinFunction(isolate, object,
Builtin::kAsyncFromSyncIteratorCloseSyncAndRethrow)) {
return true;
}
#if V8_ENABLE_WEBASSEMBLY
if (IsBuiltinFunction(isolate, object, Builtin::kWasmReject)) {
return true;
}
#endif
return false;
}
MaybeHandle<JSGeneratorObject> TryGetAsyncGenerator(
Isolate* isolate, DirectHandle<PromiseReaction> reaction) {
DisallowGarbageCollection no_gc;
Tagged<HeapObject> fulfill_handler = reaction->fulfill_handler();
if (IsJSGeneratorObject(fulfill_handler)) {
return handle(Cast<JSGeneratorObject>(fulfill_handler), isolate);
}
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
if (IsBuiltinAsyncFulfillHandler(isolate, fulfill_handler)) {
// Now peek into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Tagged<Context> context = Cast<JSFunction>(fulfill_handler)->context();
Handle<JSGeneratorObject> generator_object(
Cast<JSGeneratorObject>(context->extension()), isolate);
return generator_object;
}
return MaybeHandle<JSGeneratorObject>();
}
#if V8_ENABLE_WEBASSEMBLY
MaybeDirectHandle<WasmSuspenderObject> TryGetWasmSuspender(
Isolate* isolate, Tagged<HeapObject> handler) {
// Check if the {handler} is WasmResume.
if (IsBuiltinFunction(isolate, handler, Builtin::kWasmResume)) {
// Now peek into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Tagged<SharedFunctionInfo> shared = Cast<JSFunction>(handler)->shared();
if (shared->HasWasmResumeData()) {
return direct_handle(
TrustedCast<WasmSuspenderObject>(
shared->wasm_resume_data()->trusted_suspender(isolate)),
isolate);
}
}
return MaybeDirectHandle<WasmSuspenderObject>();
}
#endif // V8_ENABLE_WEBASSEMBLY
int GetGeneratorBytecodeOffset(
DirectHandle<JSGeneratorObject> generator_object) {
// The stored bytecode offset is relative to a different base than what
// is used in the source position table, hence the subtraction.
return Smi::ToInt(generator_object->input_or_debug_pos()) -
(BytecodeArray::kHeaderSize - kHeapObjectTag);
}
class CallSiteBuilder {
public:
CallSiteBuilder(Isolate* isolate, FrameSkipMode mode, uint32_t limit,
Handle<Object> caller)
: isolate_(isolate),
mode_(mode),
limit_(limit),
caller_(caller),
skip_next_frame_(mode != SKIP_NONE) {
DCHECK_IMPLIES(mode_ == SKIP_UNTIL_SEEN, IsJSFunction(*caller_));
// 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(CallSiteInfo::Fields::kCount *
std::min(64u, limit_));
}
void SetPrevFrameAsConstructCall() {
if (skipped_prev_frame_) return;
DCHECK_GT(index_, 0);
int base_index = (index_ - 1) * CallSiteInfo::Fields::kCount;
int flags =
Smi::ToInt(elements_->get(base_index + CallSiteInfo::Fields::kFlags));
#if V8_ENABLE_WEBASSEMBLY
if (flags & CallSiteInfo::kIsWasm) return;
#endif
elements_->set(base_index + CallSiteInfo::Fields::kFlags,
Smi::FromInt(flags | CallSiteInfo::kIsConstructor));
}
bool Visit(FrameSummary const& summary) {
if (Full()) return false;
#if V8_ENABLE_WEBASSEMBLY
#if V8_ENABLE_DRUMBRAKE
if (summary.IsWasmInterpreted()) {
AppendWasmInterpretedFrame(summary.AsWasmInterpreted());
return true;
// FrameSummary::IsWasm() should be renamed FrameSummary::IsWasmCompiled
// to be more precise, but we'll leave it as it is to try to reduce merge
// churn.
} else {
#endif // V8_ENABLE_DRUMBRAKE
if (summary.IsWasm()) {
AppendWasmFrame(summary.AsWasm());
return true;
}
#if V8_ENABLE_DRUMBRAKE
}
#endif // V8_ENABLE_DRUMBRAKE
if (summary.IsWasmInlined()) {
AppendWasmInlinedFrame(summary.AsWasmInlined());
return true;
}
if (summary.IsBuiltin()) {
AppendBuiltinFrame(summary.AsBuiltin());
return true;
}
#endif // V8_ENABLE_WEBASSEMBLY
AppendJavaScriptFrame(summary.AsJavaScript());
return true;
}
void AppendAsyncFrame(DirectHandle<JSGeneratorObject> generator_object) {
DirectHandle<JSFunction> function(generator_object->function(), isolate_);
if (!IsVisibleInStackTrace(function)) {
skipped_prev_frame_ = true;
return;
}
int flags = CallSiteInfo::kIsAsync;
if (IsStrictFrame(function)) flags |= CallSiteInfo::kIsStrict;
DirectHandle<JSAny> receiver(generator_object->receiver(), isolate_);
DirectHandle<BytecodeArray> code(
function->shared()->GetBytecodeArray(isolate_), isolate_);
int offset = GetGeneratorBytecodeOffset(generator_object);
AppendFrame(receiver, function, code, offset, flags);
}
void AppendPromiseCombinatorFrame(DirectHandle<JSFunction> element_function,
DirectHandle<JSFunction> combinator) {
if (!IsVisibleInStackTrace(combinator)) {
skipped_prev_frame_ = true;
return;
}
int flags =
CallSiteInfo::kIsAsync | CallSiteInfo::kIsSourcePositionComputed;
DirectHandle<JSFunction> receiver(
combinator->native_context()->promise_function(), isolate_);
DirectHandle<Code> code(combinator->code(isolate_), isolate_);
// TODO(mmarchini) save Promises list from the Promise combinator
// We store the offset of the promise into the element function's
// hash field for element callbacks.
int promise_index =
Smi::ToInt(Cast<JSReceiver>(element_function)->GetIdentityHash()) - 1;
AppendFrame(receiver, combinator, code, promise_index, flags);
}
void AppendJavaScriptFrame(
FrameSummary::JavaScriptFrameSummary const& summary) {
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(summary.function())) {
skipped_prev_frame_ = true;
return;
}
int flags = 0;
DirectHandle<JSFunction> function = summary.function();
if (IsStrictFrame(function)) flags |= CallSiteInfo::kIsStrict;
if (summary.is_constructor()) flags |= CallSiteInfo::kIsConstructor;
AppendFrame(Cast<UnionOf<JSAny, Hole>>(summary.receiver()), function,
handle(summary.abstract_code()->ToUnionType(), isolate_),
summary.code_offset(), flags);
}
#if V8_ENABLE_WEBASSEMBLY
void AppendWasmFrame(FrameSummary::WasmFrameSummary const& summary) {
if (summary.code()->kind() != wasm::WasmCode::kWasmFunction) return;
DirectHandle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = CallSiteInfo::kIsWasm;
DirectHandle<Undefined> code = isolate_->factory()->undefined_value();
AppendFrame(instance,
direct_handle(Smi::FromInt(summary.function_index()), isolate_),
code, summary.code_offset(), flags);
}
#if V8_ENABLE_DRUMBRAKE
void AppendWasmInterpretedFrame(
FrameSummary::WasmInterpretedFrameSummary const& summary) {
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = CallSiteInfo::kIsWasm | CallSiteInfo::kIsWasmInterpretedFrame;
// We don't have any code object in the interpreter, so we pass 'undefined'.
auto code = isolate_->factory()->undefined_value();
AppendFrame(instance,
handle(Smi::FromInt(summary.function_index()), isolate_), code,
summary.byte_offset(), flags);
}
#endif // V8_ENABLE_DRUMBRAKE
void AppendWasmInlinedFrame(
FrameSummary::WasmInlinedFrameSummary const& summary) {
DirectHandle<Undefined> code = isolate_->factory()->undefined_value();
int flags = CallSiteInfo::kIsWasm;
AppendFrame(summary.wasm_instance(),
direct_handle(Smi::FromInt(summary.function_index()), isolate_),
code, summary.code_offset(), flags);
}
void AppendBuiltinFrame(FrameSummary::BuiltinFrameSummary const& summary) {
Builtin builtin = summary.builtin();
DirectHandle<Code> code = isolate_->builtins()->code_handle(builtin);
DirectHandle<Smi> function(Smi::FromInt(static_cast<int>(builtin)),
isolate_);
int flags = CallSiteInfo::kIsBuiltin;
AppendFrame(Cast<UnionOf<JSAny, Hole>>(summary.receiver()), function, code,
summary.code_offset(), flags);
}
#endif // V8_ENABLE_WEBASSEMBLY
bool Full() { return index_ >= limit_; }
Handle<FixedArray> Build() {
return FixedArray::RightTrimOrEmpty(isolate_, elements_,
CallSiteInfo::Fields::kCount * 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(DirectHandle<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(DirectHandle<JSFunction> function) {
return ShouldIncludeFrame(function) && IsNotHidden(function) &&
function->native_context()->HasSameSecurityTokenAs(
isolate_->raw_native_context());
}
// 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(DirectHandle<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(DirectHandle<JSFunction> function) {
// TODO(szuend): Remove this check once the flag is enabled
// by default.
if (!v8_flags.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 (!v8_flags.builtins_in_stack_traces &&
!function->shared()->IsUserJavaScript()) {
return function->shared()->native() ||
function->shared()->IsApiFunction();
}
return true;
}
public:
// Store a deferred entry for a baseline frame.
// Stores the Code + raw PC offset; bytecode offset resolution
// happens lazily in ExpandDeferredFrames().
bool AppendDeferredFrame(JavaScriptFrame* frame, int deferred_flag) {
if (Full()) return false;
DirectHandle<JSFunction> function(frame->function(), isolate_);
if (!IsVisibleInStackTrace(function)) {
skipped_prev_frame_ = true;
return true;
}
int flags = deferred_flag;
if (IsStrictFrame(function)) flags |= CallSiteInfo::kIsStrict;
if (frame->IsConstructor()) flags |= CallSiteInfo::kIsConstructor;
Tagged<Code> code = frame->LookupCode();
int pc_offset = static_cast<int>(frame->pc() - code->instruction_start());
AppendFrame(Cast<UnionOf<JSAny, Hole>>(handle(frame->receiver(), isolate_)),
function, handle(code, isolate_), pc_offset, flags);
return true;
}
void AppendFrame(DirectHandle<UnionOf<JSAny, Hole>> receiver_or_instance,
DirectHandle<UnionOf<Smi, JSFunction>> function,
DirectHandle<Union<Code, BytecodeArray, Undefined>> code_obj,
int offset, int flags) {
#ifdef V8_ENABLE_TDZ_HOLE
DCHECK(!IsTheHole(*receiver_or_instance));
#endif
if (IsTdzHole(*receiver_or_instance)) {
// 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();
}
int base_index = index_ * CallSiteInfo::Fields::kCount;
// Set the last field first and grow the array if needed.
static_assert(CallSiteInfo::Fields::kFlags ==
CallSiteInfo::Fields::kCount - 1);
elements_ = FixedArray::SetAndGrow(
isolate_, elements_, base_index + CallSiteInfo::Fields::kFlags,
Smi::FromInt(flags));
elements_->set(base_index + CallSiteInfo::Fields::kReceiver,
*receiver_or_instance);
elements_->set(base_index + CallSiteInfo::Fields::kFunction, *function);
if (DirectHandle<Code> code; TryCast(code_obj, &code)) {
elements_->set(base_index + CallSiteInfo::Fields::kCode, code->wrapper());
} else if (DirectHandle<BytecodeArray> bytecode;
TryCast(code_obj, &bytecode)) {
elements_->set(base_index + CallSiteInfo::Fields::kCode,
bytecode->wrapper());
} else {
elements_->set(base_index + CallSiteInfo::Fields::kCode,
*isolate_->factory()->undefined_value());
}
elements_->set(base_index + CallSiteInfo::Fields::kOffset,
Smi::FromInt(offset));
index_++;
skipped_prev_frame_ = false;
}
Isolate* isolate_;
const FrameSkipMode mode_;
uint32_t index_ = 0;
const uint32_t limit_;
const Handle<Object> caller_;
bool skip_next_frame_;
bool skipped_prev_frame_ = false;
bool encountered_strict_function_ = false;
Handle<FixedArray> elements_;
};
void CaptureAsyncStackTrace(Isolate* isolate, DirectHandle<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 (!IsPromiseReaction(promise->reactions())) return;
DirectHandle<PromiseReaction> reaction(
Cast<PromiseReaction>(promise->reactions()), isolate);
if (!IsSmi(reaction->next())) return;
Handle<JSGeneratorObject> generator_object;
if (TryGetAsyncGenerator(isolate, reaction).ToHandle(&generator_object)) {
CHECK(generator_object->is_suspended());
// Append async frame corresponding to the {generator_object}.
builder->AppendAsyncFrame(generator_object);
// Try to continue from here.
if (IsJSAsyncFunctionObject(*generator_object)) {
auto async_function_object =
Cast<JSAsyncFunctionObject>(generator_object);
promise = direct_handle(async_function_object->promise(), isolate);
} else {
auto async_generator_object =
Cast<JSAsyncGeneratorObject>(generator_object);
if (IsUndefined(async_generator_object->queue())) return;
DirectHandle<AsyncGeneratorRequest> async_generator_request(
Cast<AsyncGeneratorRequest>(async_generator_object->queue()),
isolate);
promise = direct_handle(
Cast<JSPromise>(async_generator_request->promise()), isolate);
}
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kPromiseAllResolveElementClosure)) {
DirectHandle<JSFunction> function(
Cast<JSFunction>(reaction->fulfill_handler()), isolate);
DirectHandle<Context> context(function->context(), isolate);
DirectHandle<JSFunction> combinator(
context->native_context()->promise_all(), isolate);
builder->AppendPromiseCombinatorFrame(function, combinator);
if (IsNativeContext(*context)) {
// NativeContext is used as a marker that the closure was already
// called. We can't access the reject element context any more.
return;
}
// Now peek 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;
DirectHandle<PromiseCapability> capability(
Cast<PromiseCapability>(context->GetNoCell(index)), isolate);
if (!IsJSPromise(capability->promise())) return;
promise = direct_handle(Cast<JSPromise>(capability->promise()), isolate);
} else if (IsBuiltinFunction(
isolate, reaction->fulfill_handler(),
Builtin::kPromiseAllSettledResolveElementClosure)) {
DirectHandle<JSFunction> function(
Cast<JSFunction>(reaction->fulfill_handler()), isolate);
DirectHandle<Context> context(function->context(), isolate);
DirectHandle<JSFunction> combinator(
context->native_context()->promise_all_settled(), isolate);
builder->AppendPromiseCombinatorFrame(function, combinator);
if (IsNativeContext(*context)) {
// NativeContext is used as a marker that the closure was already
// called. We can't access the reject element context any more.
return;
}
// Now peek into the Promise.allSettled() resolve element context to
// find the promise capability that's being resolved when all
// the concurrent promises resolve.
int const index =
PromiseBuiltins::kPromiseAllResolveElementCapabilitySlot;
DirectHandle<PromiseCapability> capability(
Cast<PromiseCapability>(context->GetNoCell(index)), isolate);
if (!IsJSPromise(capability->promise())) return;
promise = direct_handle(Cast<JSPromise>(capability->promise()), isolate);
} else if (IsBuiltinFunction(isolate, reaction->reject_handler(),
Builtin::kPromiseAnyRejectElementClosure)) {
DirectHandle<JSFunction> function(
Cast<JSFunction>(reaction->reject_handler()), isolate);
DirectHandle<Context> context(function->context(), isolate);
DirectHandle<JSFunction> combinator(
context->native_context()->promise_any(), isolate);
builder->AppendPromiseCombinatorFrame(function, combinator);
if (IsNativeContext(*context)) {
// NativeContext is used as a marker that the closure was already
// called. We can't access the reject element context any more.
return;
}
// Now peek 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;
DirectHandle<PromiseCapability> capability(
Cast<PromiseCapability>(context->GetNoCell(index)), isolate);
if (!IsJSPromise(capability->promise())) return;
promise = direct_handle(Cast<JSPromise>(capability->promise()), isolate);
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtin::kPromiseCapabilityDefaultResolve)) {
DirectHandle<JSFunction> function(
Cast<JSFunction>(reaction->fulfill_handler()), isolate);
DirectHandle<Context> context(function->context(), isolate);
Tagged<Object> promise_or_undefined =
context->GetNoCell(PromiseBuiltins::kPromiseIfNotResolvedSlot);
if (!TryCast(direct_handle(promise_or_undefined, isolate), &promise)) {
DCHECK(IsUndefined(promise_or_undefined));
return;
}
#if V8_ENABLE_WEBASSEMBLY
} else if (DirectHandle<WasmSuspenderObject> suspender;
TryGetWasmSuspender(isolate, reaction->fulfill_handler())
.ToHandle(&suspender)) {
DCHECK_NOT_NULL(suspender->stack());
for (StackFrameIterator it(isolate, suspender->stack()); !it.done();
it.Advance()) {
StackFrame* frame = it.frame();
if (frame->is_wasm()) {
FrameSummaries summaries = CommonFrame::cast(frame)->Summarize();
for (auto& summary : base::Reversed(summaries.frames)) {
if (!summary.native_context()->HasSameSecurityTokenAs(
isolate->raw_native_context())) {
continue;
}
if (!builder->Visit(summary)) return;
}
}
}
Tagged<Object> promise_obj = suspender->promise();
if (IsJSPromise(promise_obj)) {
promise = direct_handle(Cast<JSPromise>(promise_obj), isolate);
} else {
return;
}
#endif // V8_ENABLE_WEBASSEMBLY
} 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 (IsJSPromise(*promise_or_capability)) {
promise = Cast<JSPromise>(promise_or_capability);
} else if (IsPromiseCapability(*promise_or_capability)) {
auto capability = Cast<PromiseCapability>(promise_or_capability);
if (!IsJSPromise(capability->promise())) return;
promise =
direct_handle(Cast<JSPromise>(capability->promise()), isolate);
} else {
// Otherwise the {promise_or_capability} must be undefined here.
CHECK(IsUndefined(*promise_or_capability));
return;
}
}
}
}
MaybeDirectHandle<JSPromise> TryGetCurrentTaskPromise(Isolate* isolate) {
DisallowGarbageCollection no_gc;
Handle<Object> current_microtask = isolate->factory()->current_microtask();
if (IsPromiseReactionJobTask(*current_microtask)) {
auto promise_reaction_job_task =
Cast<PromiseReactionJobTask>(current_microtask);
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
Tagged<JSGeneratorObject> generator_object;
if (IsJSGeneratorObject(promise_reaction_job_task->handler())) {
generator_object =
Cast<JSGeneratorObject>(promise_reaction_job_task->handler());
} else if (IsBuiltinAsyncFulfillHandler(
isolate, promise_reaction_job_task->handler()) ||
IsBuiltinAsyncRejectHandler(
isolate, promise_reaction_job_task->handler())) {
// Now peek into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Tagged<Context> context =
Cast<JSFunction>(promise_reaction_job_task->handler())->context();
generator_object = Cast<JSGeneratorObject>(context->extension());
}
if (!generator_object.is_null()) {
if (generator_object->is_executing()) {
if (IsJSAsyncFunctionObject(generator_object)) {
auto async_function_object =
Cast<JSAsyncFunctionObject>(generator_object);
DirectHandle<JSPromise> promise(async_function_object->promise(),
isolate);
return promise;
} else {
auto async_generator_object =
Cast<JSAsyncGeneratorObject>(generator_object);
Tagged<Object> queue = async_generator_object->queue();
if (!IsUndefined(queue)) {
auto async_generator_request = Cast<AsyncGeneratorRequest>(queue);
DirectHandle<JSPromise> promise(
Cast<JSPromise>(async_generator_request->promise()), isolate);
return promise;
}
}
}
} else {
#if V8_ENABLE_WEBASSEMBLY
DirectHandle<WasmSuspenderObject> suspender;
if (TryGetWasmSuspender(isolate, promise_reaction_job_task->handler())
.ToHandle(&suspender)) {
// The {promise_reaction_job_task} belongs to a suspended Wasm stack
return direct_handle(Cast<JSPromise>(suspender->promise()), isolate);
}
#endif // V8_ENABLE_WEBASSEMBLY
// The {promise_reaction_job_task} doesn't belong to an await (or
// yield inside an async generator) or a suspended Wasm stack,
// 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}.
DirectHandle<HeapObject> promise_or_capability(
promise_reaction_job_task->promise_or_capability(), isolate);
if (IsJSPromise(*promise_or_capability)) {
DirectHandle<JSPromise> promise =
Cast<JSPromise>(promise_or_capability);
return promise;
}
}
} else if (IsPromiseResolveThenableJobTask(*current_microtask)) {
auto promise_resolve_thenable_job_task =
Cast<PromiseResolveThenableJobTask>(current_microtask);
DirectHandle<JSPromise> promise(
promise_resolve_thenable_job_task->promise_to_resolve(), isolate);
return promise;
} else if (IsAsyncResumeTask(*current_microtask)) {
auto async_resume_task = Cast<AsyncResumeTask>(current_microtask);
Tagged<JSGeneratorObject> generator_object = async_resume_task->generator();
if (generator_object->is_executing()) {
int kind = async_resume_task->kind();
if (kind == AsyncResumeTask::kAsyncFunctionAwait) {
DCHECK(IsJSAsyncFunctionObject(generator_object));
auto async_function_object =
Cast<JSAsyncFunctionObject>(generator_object);
DirectHandle<JSPromise> promise(async_function_object->promise(),
isolate);
return promise;
} else {
DCHECK_EQ(kind, AsyncResumeTask::kYield);
DCHECK(IsJSAsyncGeneratorObject(generator_object));
auto async_generator_object =
Cast<JSAsyncGeneratorObject>(generator_object);
Tagged<Object> queue = async_generator_object->queue();
// The queue may legitimately be empty here. The kYield dispatch calls
// AsyncGeneratorResolve (which pops the yield request) followed by
// AsyncGeneratorResumeNext, which may immediately resume the generator
// with a subsequent queued throw/return. That resumed execution pops
// its own request via AsyncGeneratorReject/Resolve before RejectPromise
// triggers this stack capture. V8 has no separate ~draining-queue~
// state (spec sec-asyncgeneratorstart), so is_executing() remains true
// throughout; the empty queue is the tell that we're in that phase.
if (IsUndefined(queue)) return MaybeDirectHandle<JSPromise>();
auto async_generator_request = Cast<AsyncGeneratorRequest>(queue);
DirectHandle<JSPromise> promise(
Cast<JSPromise>(async_generator_request->promise()), isolate);
return promise;
}
}
}
return MaybeDirectHandle<JSPromise>();
}
void CaptureAsyncStackTrace(Isolate* isolate, CallSiteBuilder* builder) {
DirectHandle<JSPromise> promise;
if (TryGetCurrentTaskPromise(isolate).ToHandle(&promise)) {
CaptureAsyncStackTrace(isolate, promise, builder);
}
}
// Summarize a single frame and pass each logical frame to the visitor.
template <typename Visitor>
void VisitStack(Isolate* isolate, Visitor* visitor,
StackTrace::StackTraceOptions options = StackTrace::kDetailed,
AllowAllocation allow_allocation = AllowAllocation{true}) {
DisallowJavascriptExecution no_js(isolate);
for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
switch (frame->type()) {
case StackFrame::BASELINE:
case StackFrame::API_CALLBACK_EXIT:
case StackFrame::API_CONSTRUCT_EXIT:
case StackFrame::BUILTIN_EXIT:
case StackFrame::JAVASCRIPT_BUILTIN_CONTINUATION:
case StackFrame::JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
case StackFrame::TURBOFAN_JS:
case StackFrame::MAGLEV:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN:
#if V8_ENABLE_WEBASSEMBLY
case StackFrame::STUB:
case StackFrame::WASM:
case StackFrame::WASM_SEGMENT_START:
#if V8_ENABLE_DRUMBRAKE
case StackFrame::WASM_INTERPRETER_ENTRY:
#endif // V8_ENABLE_DRUMBRAKE
#endif // V8_ENABLE_WEBASSEMBLY
{
// A standard frame may include many summarized frames (due to
// inlining).
FrameSummaries summaries =
CommonFrame::cast(frame)->Summarize(allow_allocation);
for (auto& summary : base::Reversed(summaries.frames)) {
// Skip frames from other origins when asked to do so.
if (!(options & StackTrace::kExposeFramesAcrossSecurityOrigins) &&
!summary.native_context()->HasSameSecurityTokenAs(
isolate->raw_native_context())) {
continue;
}
if (!visitor->Visit(summary)) return;
}
break;
}
default:
break;
}
}
}
// Specialized stack walk for CallSiteBuilder, handling deferred baseline
// frames and the construct-call flag on the previous frame.
void VisitStack_ForCallSiteBuilder(Isolate* isolate, CallSiteBuilder* visitor) {
DisallowJavascriptExecution no_js(isolate);
// Track whether the last physical frame produced any visited summarized
// frames. Used to correctly attribute construct-call flags.
bool skipped_last_frame = true;
for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
switch (frame->type()) {
case StackFrame::BASELINE:
// Baseline frames are captured as deferred entries so they can be
// expanded later without blocking the stack capture path.
if (!visitor->AppendDeferredFrame(
JavaScriptFrame::cast(frame),
CallSiteInfo::kIsDeferredBaselineFrame)) {
return;
}
skipped_last_frame = true;
break;
case StackFrame::API_CALLBACK_EXIT:
case StackFrame::API_CONSTRUCT_EXIT:
case StackFrame::BUILTIN_EXIT:
case StackFrame::JAVASCRIPT_BUILTIN_CONTINUATION:
case StackFrame::JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
case StackFrame::TURBOFAN_JS:
case StackFrame::MAGLEV:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN:
#if V8_ENABLE_WEBASSEMBLY
case StackFrame::STUB:
case StackFrame::WASM:
case StackFrame::WASM_SEGMENT_START:
#if V8_ENABLE_DRUMBRAKE
case StackFrame::WASM_INTERPRETER_ENTRY:
#endif // V8_ENABLE_DRUMBRAKE
#endif // V8_ENABLE_WEBASSEMBLY
{
// A standard frame may include many summarized frames (due to
// inlining).
FrameSummaries summaries = CommonFrame::cast(frame)->Summarize();
if (summaries.top_frame_is_construct_call && !skipped_last_frame) {
visitor->SetPrevFrameAsConstructCall();
}
skipped_last_frame = true;
for (auto& summary : base::Reversed(summaries.frames)) {
// CaptureSimpleStackTrace uses kDetailed, which does not expose
// frames across security origins.
if (!summary.native_context()->HasSameSecurityTokenAs(
isolate->raw_native_context())) {
continue;
}
if (!visitor->Visit(summary)) return;
skipped_last_frame = false;
}
break;
}
default:
break;
}
}
}
Handle<FixedArray> CaptureSimpleStackTrace(Isolate* isolate, int limit,
FrameSkipMode mode,
Handle<Object> caller) {
TRACE_EVENT_BEGIN(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__), "maxFrameCount", limit);
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmCodeRefScope code_ref_scope;
#endif // V8_ENABLE_WEBASSEMBLY
CallSiteBuilder builder(isolate, mode, static_cast<uint32_t>(limit), caller);
VisitStack_ForCallSiteBuilder(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 (v8_flags.async_stack_traces) {
CaptureAsyncStackTrace(isolate, &builder);
}
Handle<FixedArray> stack_trace = builder.Build();
TRACE_EVENT_END(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), "frameCount",
stack_trace->ulength().value());
return stack_trace;
}
DirectHandle<StackTraceInfo> GetDetailedStackTraceFromCallSiteInfos(
Isolate* isolate, DirectHandle<FixedArray> raw_data_for_call_site_infos,
uint32_t limit) {
Handle<FixedArray> expanded = CallSiteInfo::ExpandDeferredFrames(
isolate, handle(*raw_data_for_call_site_infos, isolate));
raw_data_for_call_site_infos = expanded;
uint32_t call_site_infos_len =
raw_data_for_call_site_infos->ulength().value() /
CallSiteInfo::Fields::kCount;
auto frames =
isolate->factory()->NewFixedArray(std::min(limit, call_site_infos_len));
uint32_t index = 0;
for (uint32_t i = 0; i < call_site_infos_len && index < limit; ++i) {
DirectHandle<CallSiteInfo> call_site_info =
CallSiteInfo::ConstructFromRawData(isolate,
raw_data_for_call_site_infos, i);
if (call_site_info->IsAsync()) {
break;
}
DirectHandle<Script> script;
if (!CallSiteInfo::GetScript(isolate, call_site_info).ToHandle(&script) ||
!script->IsSubjectToDebugging()) {
continue;
}
DirectHandle<StackFrameInfo> stack_frame_info =
isolate->factory()->NewStackFrameInfo(
script, CallSiteInfo::GetSourcePosition(call_site_info),
CallSiteInfo::GetFunctionDebugName(call_site_info),
IsConstructor(*call_site_info));
frames->set(index++, *stack_frame_info);
}
frames = FixedArray::RightTrimOrEmpty(isolate, frames, index);
return isolate->factory()->NewStackTraceInfo(frames);
}
} // namespace
MaybeDirectHandle<JSObject> Isolate::CaptureAndSetErrorStack(
DirectHandle<JSObject> error_object, FrameSkipMode mode,
Handle<Object> caller) {
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
Handle<UnionOf<Undefined, FixedArray>> call_site_infos_or_formatted_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_;
}
}
call_site_infos_or_formatted_stack =
CaptureSimpleStackTrace(this, limit, mode, caller);
}
DirectHandle<Object> error_stack = call_site_infos_or_formatted_stack;
// 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_) {
DirectHandle<StackTraceInfo> stack_trace;
if (IsUndefined(*call_site_infos_or_formatted_stack) ||
(stack_trace_for_uncaught_exceptions_options_ &
StackTrace::kExposeFramesAcrossSecurityOrigins)) {
stack_trace = CaptureDetailedStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
} else {
auto raw_data_for_call_site_infos =
Cast<FixedArray>(call_site_infos_or_formatted_stack);
DCHECK_GE(stack_trace_for_uncaught_exceptions_frame_limit_, 0);
stack_trace = GetDetailedStackTraceFromCallSiteInfos(
this, raw_data_for_call_site_infos,
static_cast<uint32_t>(
stack_trace_for_uncaught_exceptions_frame_limit_));
DCHECK_GE(stack_trace_limit, 0);
// Compare in frames rather than raw slots to avoid overflowing for
// large Error.stackTraceLimit values.
uint32_t frame_count = raw_data_for_call_site_infos->ulength().value() /
CallSiteInfo::Fields::kCount;
if (static_cast<uint32_t>(stack_trace_limit) < frame_count) {
call_site_infos_or_formatted_stack = FixedArray::RightTrimOrEmpty(
this, raw_data_for_call_site_infos,
static_cast<uint32_t>(stack_trace_limit) *
CallSiteInfo::Fields::kCount);
}
// Notify the debugger.
OnStackTraceCaptured(stack_trace);
}
error_stack = factory()->NewErrorStackData(
call_site_infos_or_formatted_stack, stack_trace);
}
RETURN_ON_EXCEPTION(
this,
Object::SetProperty(this, error_object, factory()->error_stack_symbol(),
error_stack, StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError)));
return error_object;
}
Handle<StackTraceInfo> Isolate::GetDetailedStackTrace(
DirectHandle<JSReceiver> maybe_error_object) {
ErrorUtils::StackPropertyLookupResult lookup =
ErrorUtils::GetErrorStackProperty(this, maybe_error_object);
if (!IsErrorStackData(*lookup.error_stack)) return {};
return handle(Cast<ErrorStackData>(lookup.error_stack)->stack_trace(), this);
}
Handle<FixedArray> Isolate::GetSimpleStackTrace(
DirectHandle<JSReceiver> maybe_error_object) {
ErrorUtils::StackPropertyLookupResult lookup =
ErrorUtils::GetErrorStackProperty(this, maybe_error_object);
Handle<FixedArray> raw_data;
if (IsFixedArray(*lookup.error_stack)) {
raw_data = Cast<FixedArray>(lookup.error_stack);
} else if (IsErrorStackData(*lookup.error_stack)) {
auto error_stack_data = Cast<ErrorStackData>(lookup.error_stack);
if (!error_stack_data->HasRawDataForCallSiteInfos()) {
return factory()->empty_fixed_array();
}
raw_data = handle(error_stack_data->raw_data_for_call_site_infos(), this);
} else {
return factory()->empty_fixed_array();
}
raw_data = CallSiteInfo::ExpandDeferredFrames(this, raw_data);
int frame_count = raw_data->ulength().value() / CallSiteInfo::Fields::kCount;
Handle<FixedArray> call_site_infos = factory()->NewFixedArray(frame_count);
for (int i = 0; i < frame_count; ++i) {
DirectHandle<CallSiteInfo> call_site_info =
CallSiteInfo::ConstructFromRawData(this, raw_data, i);
call_site_infos->set(i, *call_site_info);
}
return call_site_infos;
}
Address Isolate::GetAbstractPC(int* line, int* column) {
JavaScriptStackFrameIterator it(this);
if (it.done()) {
*line = -1;
*column = -1;
return kNullAddress;
}
JavaScriptFrame* frame = it.frame();
DCHECK(!frame->is_builtin());
DirectHandle<SharedFunctionInfo> shared(frame->function()->shared(), this);
SharedFunctionInfo::EnsureSourcePositionsAvailable(this, shared);
int position = frame->position();
Tagged<Object> maybe_script = frame->function()->shared()->script();
if (IsScript(maybe_script)) {
DirectHandle<Script> script(Cast<Script>(maybe_script), this);
Script::PositionInfo info;
Script::GetPositionInfo(script, position, &info);
*line = info.line + 1;
*column = info.column + 1;
} else {
*line = position;
*column = -1;
}
if (frame->is_unoptimized()) {
UnoptimizedJSFrame* iframe = static_cast<UnoptimizedJSFrame*>(frame);
Address bytecode_start =
iframe->GetBytecodeArray()->GetFirstBytecodeAddress();
return bytecode_start + iframe->GetBytecodeOffset();
}
return frame->pc();
}
Address Isolate::GetAbstractPCNoGC(int* line, int* column,
DisallowGarbageCollection& no_gc) {
JavaScriptStackFrameIterator it(this);
if (it.done()) {
*line = -1;
*column = -1;
return kNullAddress;
}
JavaScriptFrame* frame = it.frame();
DCHECK(!frame->is_builtin());
int position = frame->position();
Tagged<Object> maybe_script = frame->function()->shared()->script();
if (Tagged<Script> script; TryCast(maybe_script, &script)) {
Script::PositionInfo info;
script->GetPositionInfo(position, &info);
*line = info.line + 1;
*column = info.column + 1;
} else {
*line = position;
*column = -1;
}
if (frame->is_unoptimized()) {
UnoptimizedJSFrame* iframe = static_cast<UnoptimizedJSFrame*>(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;
DirectHandle<StackFrameInfo> frame = summary.CreateStackFrameInfo();
frames_ = FixedArray::SetAndGrow(isolate_, frames_, index_++, frame);
return true;
}
Handle<FixedArray> Build() {
return FixedArray::RightTrimOrEmpty(isolate_, frames_, index_);
}
private:
Isolate* isolate_;
Handle<FixedArray> frames_;
uint32_t index_;
uint32_t limit_;
};
} // namespace
DirectHandle<StackTraceInfo> Isolate::CaptureDetailedStackTrace(
int limit, StackTrace::StackTraceOptions options) {
TRACE_EVENT_BEGIN(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__), "maxFrameCount", limit);
StackFrameBuilder builder(this, static_cast<uint32_t>(limit));
VisitStack(this, &builder, options);
auto frames = builder.Build();
TRACE_EVENT_END(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"), "frameCount",
frames->ulength().value());
auto stack_trace = factory()->NewStackTraceInfo(frames);
OnStackTraceCaptured(stack_trace);
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.
auto script = Cast<Script>(summary.script());
Handle<Object> name_or_url_obj(script->GetNameOrSourceURL(), isolate_);
if (!IsString(*name_or_url_obj)) return true;
auto name_or_url = Cast<String>(name_or_url_obj);
if (!name_or_url->length()) return true;
name_or_url_ = name_or_url;
return false;
}
DirectHandle<String> CurrentScriptNameOrSourceURL() const {
return name_or_url_;
}
private:
Isolate* const isolate_;
Handle<String> name_or_url_;
};
class CurrentScriptIdStackVisitor {
public:
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. A
// valid script object should have a valid id.
auto script = Cast<Script>(summary.script());
script_id_ = script->id();
DCHECK_LT(0, script_id_);
return false;
}
int CurrentScriptId() const { return script_id_; }
private:
int script_id_ = v8::Message::kNoScriptIdInfo;
};
class CurrentScriptIdsAndContextsStackVisitor {
public:
CurrentScriptIdsAndContextsStackVisitor(
Isolate* isolate, std::span<StackTrace::ScriptIdAndContext> frame_data)
: isolate_(isolate), frame_data_(frame_data) {
DCHECK_LT(0, frame_data.size());
}
bool Visit(FrameSummary& summary) {
if (!summary.is_subject_to_debugging()) return true;
// Frames that are subject to debugging always have a valid script object. A
// valid script object should have a valid id.
auto script_handle = Cast<Script>(summary.script());
int script_id = GetRootScriptId(*script_handle);
Handle<NativeContext> context =
handle(summary.native_context()->native_context(), isolate_);
if (context.is_null() || script_id <= 0) return true;
frame_data_[cur_frame_].context = Utils::ToLocal(context).As<v8::Context>();
frame_data_[cur_frame_].id = script_id;
cur_frame_ += 1;
return cur_frame_ < frame_data_.size();
}
size_t FrameCount() const { return cur_frame_; }
private:
int GetRootScriptId(Tagged<Script> script) {
Tagged<Script> cur = script;
while (cur->has_eval_from_shared()) {
Tagged<Object> maybe_sfi = cur->eval_from_shared();
if (!IsSharedFunctionInfo(maybe_sfi)) break;
Tagged<Object> maybe_script =
Cast<SharedFunctionInfo>(maybe_sfi)->script();
if (!IsScript(maybe_script)) break;
cur = Cast<Script>(maybe_script);
}
return cur->id();
}
Isolate* const isolate_;
std::span<StackTrace::ScriptIdAndContext> frame_data_;
size_t cur_frame_ = 0;
};
class CurrentScriptDataStackVisitor {
public:
CurrentScriptDataStackVisitor(Isolate* isolate,
std::span<StackTrace::ScriptData> frame_data)
: isolate_(isolate), frame_data_(frame_data) {
DCHECK_LT(0, frame_data.size());
}
bool Visit(FrameSummary& summary) {
if (!summary.IsJavaScript()) return true;
if (!summary.is_subject_to_debugging()) return true;
auto script_handle = Cast<Script>(summary.script());
int script_id = GetRootScriptId(*script_handle);
DirectHandle<NativeContext> context =
handle(summary.native_context()->native_context(), isolate_);
if (context.is_null() || script_id <= 0) return true;
frame_data_[cur_frame_].function =
Utils::ToLocal(summary.AsJavaScript().function());
frame_data_[cur_frame_].context = Utils::ToLocal(context).As<v8::Context>();
frame_data_[cur_frame_].id = script_id;
cur_frame_ += 1;
return cur_frame_ < frame_data_.size();
}
size_t FrameCount() const { return cur_frame_; }
private:
int GetRootScriptId(Tagged<Script> script) {
Tagged<Script> cur = script;
while (cur->has_eval_from_shared()) {
Tagged<Object> maybe_sfi = cur->eval_from_shared();
if (!IsSharedFunctionInfo(maybe_sfi)) break;
Tagged<Object> maybe_script =
Cast<SharedFunctionInfo>(maybe_sfi)->script();
if (!IsScript(maybe_script)) break;
cur = Cast<Script>(maybe_script);
}
return cur->id();
}
Isolate* const isolate_;
std::span<StackTrace::ScriptData> frame_data_;
size_t cur_frame_ = 0;
};
class CurrentScriptStackVisitor {
public:
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.
current_script_ = Cast<Script>(summary.script());
return false;
}
MaybeDirectHandle<Script> CurrentScript() const { return current_script_; }
private:
MaybeHandle<Script> current_script_;
};
} // namespace
DirectHandle<String> Isolate::CurrentScriptNameOrSourceURL() {
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
CurrentScriptNameStackVisitor visitor(this);
VisitStack(this, &visitor);
return visitor.CurrentScriptNameOrSourceURL();
}
int Isolate::CurrentScriptId() {
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
CurrentScriptIdStackVisitor visitor;
VisitStack(this, &visitor);
return visitor.CurrentScriptId();
}
size_t Isolate::CurrentScriptIdsAndContexts(
std::span<StackTrace::ScriptIdAndContext> frame_data) {
if (frame_data.size() == 0) {
return 0;
}
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
CurrentScriptIdsAndContextsStackVisitor visitor(this, frame_data);
VisitStack(this, &visitor);
return visitor.FrameCount();
}
size_t Isolate::CurrentScriptData(
std::span<StackTrace::ScriptData> frame_data) {
if (frame_data.size() == 0) return 0;
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
CurrentScriptDataStackVisitor visitor(this, frame_data);
// CurrentScriptData should only expose frames from the same origin.
VisitStack(this, &visitor, StackTrace::kDetailed, AllowAllocation{false});
return visitor.FrameCount();
}
MaybeDirectHandle<Script> Isolate::CurrentReferrerScript() {
TRACE_EVENT(TRACE_DISABLED_BY_DEFAULT("v8.stack_trace"),
perfetto::StaticString(__func__));
CurrentScriptStackVisitor visitor{};
VisitStack(this, &visitor);
DirectHandle<Script> script;
if (!visitor.CurrentScript().ToHandle(&script)) {
return MaybeDirectHandle<Script>();
}
return direct_handle(script->GetEvalOrigin(), this);
}
bool Isolate::GetStackTraceLimit(Isolate* isolate, int* result) {
if (v8_flags.correctness_fuzzer_suppressions) return false;
DirectHandle<JSObject> error = isolate->error_function();
DirectHandle<String> key = isolate->factory()->stackTraceLimit_string();
DirectHandle<Object> stack_trace_limit =
JSReceiver::GetDataProperty(isolate, error, key);
if (!IsNumber(*stack_trace_limit)) return false;
// Ensure that limit is not negative.
*result = std::max(
FastD2IChecked(Object::NumberValue(Cast<Number>(*stack_trace_limit))), 0);
if (*result != v8_flags.stack_trace_limit) {
isolate->CountUsage(v8::Isolate::kErrorStackTraceLimit);
}
return true;
}
void Isolate::PrintStack(FILE* out, PrintStackMode mode,
AllowAllocation allow_allocation) {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
StringStream::ClearMentionedObjectCache(this);
HeapStringAllocator allocator;
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator, mode, allow_allocation);
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,
AllowAllocation allow_allocation = AllowAllocation{
true}) {
StackFrameIterator it(isolate);
for (int i = 0; !it.done(); it.Advance()) {
it.frame()->Print(accumulator, mode, i++, allow_allocation);
}
}
void Isolate::PrintStack(StringStream* accumulator, PrintStackMode mode,
AllowAllocation allow_allocation) {
HandleScope scope(this);
DCHECK(accumulator->IsMentionedObjectCacheClear(this));
// Avoid printing anything if there are no frames.
if (c_entry_fp(thread_local_top()) == kNullAddress &&
isolate_data()->fast_c_call_caller_fp() == kNullAddress) {
return;
}
accumulator->Add(
"\n==== JS stack trace =========================================\n\n");
PrintFrames(this, accumulator, StackFrame::OVERVIEW, allow_allocation);
if (mode == kPrintStackVerbose) {
accumulator->Add(
"\n==== Details ================================================\n\n");
PrintFrames(this, accumulator, StackFrame::DETAILS, allow_allocation);
accumulator->PrintMentionedObjectCache(this);
}
accumulator->Add("=====================\n\n");
}
namespace {
class MinimalStackPrinter {
public:
static constexpr const char* kUnknownName = "<none>";
static constexpr const char* kRepeatMarker = "=";
static constexpr const char* kEndMarker = "$";
explicit MinimalStackPrinter(size_t max_length) : max_length_(max_length) {}
bool Visit(FrameSummary& summary) {
if (summary.IsJavaScript()) {
const FrameSummary::JavaScriptFrameSummary& js_summary =
summary.AsJavaScript();
Tagged<String> name = js_summary.function()->shared()->Name();
if (name->length() == 0) {
out_ << kUnknownName;
} else {
Append(name);
}
Handle<Object> script = js_summary.script();
PrintScript(script);
Tagged<Script> s;
if (js_summary.AreSourcePositionsAvailable() &&
TryCast<Script>(*script, &s)) {
int pos = js_summary.SourcePosition();
int line = s->GetLineNumber(pos) + 1;
int column = s->GetColumnNumber(pos) + 1;
out_ << ":" << line << ":" << column;
}
out_ << "\n";
#if V8_ENABLE_WEBASSEMBLY
} else if (summary.IsWasm()) {
const FrameSummary::WasmFrameSummary& wasm_summary = summary.AsWasm();
PrintWasmFrame(wasm_summary.function_index(), wasm_summary.script(),
wasm_summary.SourcePosition());
} else if (summary.IsWasmInlined()) {
const FrameSummary::WasmInlinedFrameSummary& wasm_inlined_summary =
summary.AsWasmInlined();
PrintWasmFrame(wasm_inlined_summary.function_index(),
wasm_inlined_summary.script(),
wasm_inlined_summary.SourcePosition());
#endif // V8_ENABLE_WEBASSEMBLY
}
// Stop iterating when we emitted too many characters.
return HasMoreSpace();
}
void PrintWasmFrame(int function_index, Handle<Object> script,
int source_position) {
out_ << "wasm[" << function_index << "]";
PrintScript(script);
out_ << ":" << source_position;
out_ << "\n";
}
void PrintScript(Handle<Object> script) {
if (IsScript(*script)) {
Tagged<Object> name_or_url = Cast<Script>(script)->GetNameOrSourceURL();
if (IsString(name_or_url)) {
std::string current_name = Cast<String>(name_or_url)->ToStdString();
if (current_name == prev_script_name_) {
out_ << " in " << kRepeatMarker;
} else {
out_ << " in ";
out_ << current_name;
prev_script_name_ = std::move(current_name);
}
}
}
}
void Append(Tagged<String> value) { out_ << value->ToStdString(); }
std::string Build() {
out_ << kEndMarker << "\n";
return out_.str();
}
bool HasMoreSpace() {
size_t current = out_.tellp();
return current < max_length_;
}
private:
std::stringstream out_;
const size_t max_length_;
std::string prev_script_name_;
};
} // namespace
std::string Isolate::BuildMinimalStack(size_t max_length) {
DCHECK_EQ(thread_id(), ThreadId::Current());
DisallowGarbageCollection no_gc;
HandleScope scope(this);
static constexpr v8::StackTrace::StackTraceOptions stackTraceOptions =
static_cast<v8::StackTrace::StackTraceOptions>(
v8::StackTrace::kDetailed |
v8::StackTrace::kExposeFramesAcrossSecurityOrigins);
MinimalStackPrinter printer(max_length);
VisitStack(this, &printer, stackTraceOptions, AllowAllocation{false});
return printer.Build();
}
void Isolate::PrintMinimalStack(FILE* out) {
std::string stack = BuildMinimalStack();
std::fputs(stack.c_str(), out);
}
void Isolate::ReportStackAsCrashKey() {
if (!HasCrashKeyStringCallbacks()) {
return;
}
constexpr size_t kMaximumStackLengthBytes = 1024;
std::string stack = BuildMinimalStack(kMaximumStackLengthBytes);
AddCrashKeyString("v8-oom-stack", CrashKeySize::Size1024, stack);
}
void Isolate::SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback) {
thread_local_top()->failed_access_check_callback_ = callback;
}
MaybeDirectHandle<Object> Isolate::ReportFailedAccessCheck(
DirectHandle<JSObject> receiver) {
if (!thread_local_top()->failed_access_check_callback_) {
THROW_NEW_ERROR(this, NewTypeError(MessageTemplate::kNoAccess));
}
DCHECK(IsAccessCheckNeeded(*receiver));
DCHECK(!context().is_null());
// Get the data object from access check info.
HandleScope scope(this);
DirectHandle<Object> data;
{
DisallowGarbageCollection no_gc;
Tagged<AccessCheckInfo> access_check_info =
AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) {
no_gc.Release();
THROW_NEW_ERROR(this, NewTypeError(MessageTemplate::kNoAccess));
}
data = direct_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));
}
RETURN_VALUE_IF_EXCEPTION(this, {});
// Throw exception even the callback forgot to do so.
THROW_NEW_ERROR(this, NewTypeError(MessageTemplate::kNoAccess));
}
bool Isolate::MayAccess(DirectHandle<NativeContext> accessing_context,
DirectHandle<JSObject> receiver) {
DCHECK(IsJSGlobalProxy(*receiver) || IsAccessCheckNeeded(*receiver));
// 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 (IsJSGlobalProxy(*receiver)) {
std::optional<Tagged<NativeContext>> receiver_context =
Cast<JSGlobalProxy>(*receiver)->GetCreationContext();
if (!receiver_context) return false;
if ((*receiver_context)->HasSameSecurityTokenAs(*accessing_context)) {
return true;
}
}
}
HandleScope scope(this);
DirectHandle<Object> data;
v8::AccessCheckCallback callback = nullptr;
{
DisallowGarbageCollection no_gc;
Tagged<AccessCheckInfo> access_check_info =
AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) return false;
Tagged<Object> fun_obj = access_check_info->callback();
callback = v8::ToCData<v8::AccessCheckCallback, kApiAccessCheckCallbackTag>(
this, fun_obj);
data = direct_handle(access_check_info->data(), this);
}
{
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
return callback(v8::Utils::ToLocal(accessing_context),
v8::Utils::ToLocal(receiver), v8::Utils::ToLocal(data));
}
}
Tagged<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() - 64 * KB);
#elif (defined(V8_TARGET_ARCH_RISCV64) || defined(V8_TARGET_ARCH_RISCV32)) && \
defined(USE_SIMULATOR)
// Allow for more overflow on riscv simulator, because C++ frames take more
// there.
DCHECK_GE(GetCurrentStackPosition(), stack_guard()->real_climit() - 12 * KB);
#elif defined(ENABLE_SLOW_DCHECKS) && V8_HAS_ATTRIBUTE_TRIVIAL_ABI
// In this configuration, direct handles are not trivially copyable. This
// prevents some C++ compiler optimizations and uses more stack space.
DCHECK_GE(GetCurrentStackPosition(), stack_guard()->real_climit() - 10 * KB);
#else
DCHECK_GE(GetCurrentStackPosition(), stack_guard()->real_climit() - 8 * KB);
#endif
if (v8_flags.correctness_fuzzer_suppressions) {
FATAL("Aborting on stack overflow");
}
#if USE_SIMULATOR
// Adjust the stack limit back to the real limit in case it was temporarily
// modified to reflect an overflow in the C stack (see
// AdjustStackLimitForSimulator).
stack_guard()->ResetStackLimitForSimulator();
#endif
DisallowJavascriptExecution no_js(this);
HandleScope scope(this);
DirectHandle<JSFunction> fun = range_error_function();
DirectHandle<Object> msg = factory()->NewStringFromAsciiChecked(
MessageFormatter::TemplateString(MessageTemplate::kStackOverflow));
DirectHandle<Object> options = factory()->undefined_value();
DirectHandle<Object> no_caller;
DirectHandle<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, nullptr, true);
#ifdef VERIFY_HEAP
if (v8_flags.verify_heap && v8_flags.stress_compaction) {
heap()->CollectAllGarbage(GCFlag::kNoFlags,
GarbageCollectionReason::kTesting);
}
#endif // VERIFY_HEAP
return ReadOnlyRoots(heap()).exception();
}
Tagged<Object> Isolate::ThrowAt(DirectHandle<JSObject> exception,
MessageLocation* location) {
DirectHandle<Name> key_start_pos = factory()->error_start_pos_symbol();
Object::SetProperty(this, exception, key_start_pos,
direct_handle(Smi::FromInt(location->start_pos()), this),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
DirectHandle<Name> key_end_pos = factory()->error_end_pos_symbol();
Object::SetProperty(this, exception, key_end_pos,
direct_handle(Smi::FromInt(location->end_pos()), this),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
DirectHandle<Name> key_script = factory()->error_script_symbol();
Object::SetProperty(this, exception, key_script, location->script(),
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError))
.Check();
return Throw(*exception, location);
}
Tagged<Object> Isolate::TerminateExecution() {
return Throw(ReadOnlyRoots(this).termination_exception());
}
void Isolate::CancelTerminateExecution() {
if (!is_execution_terminating()) return;
clear_internal_exception();
if (try_catch_handler()) try_catch_handler()->ResetInternal();
}
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);
struct ApiInterruptScope {
explicit ApiInterruptScope(Isolate* isolate) : isolate_(isolate) {
DCHECK_LE(0, isolate_->api_interrupt_depth_);
DCHECK_LT(isolate_->api_interrupt_depth_,
std::numeric_limits<int>::max());
isolate_->api_interrupt_depth_++;
}
~ApiInterruptScope() {
DCHECK_LT(0, isolate_->api_interrupt_depth_);
isolate_->api_interrupt_depth_--;
}
Isolate* const isolate_;
} scope{this};
// 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);
// API interrupt callbacks are forbidden from executing JavaScript on the
// interrupted Isolate (see v8::Isolate::RequestInterrupt contract in
// v8-isolate.h: "Registered |callback| must not reenter interrupted
// Isolate.").
#ifdef V8_DISALLOW_JS_IN_API_INTERRUPTS_IS_CHECKED
DisallowJavascriptExecution no_js(this);
#endif // V8_DISALLOW_JS_IN_API_INTERRUPTS_IS_CHECKED
entry.first(reinterpret_cast<v8::Isolate*>(this), entry.second);
}
}
void Isolate::RequestInvalidateNoProfilingProtector() {
// This request might be triggered from arbitrary thread but protector
// invalidation must happen on the main thread, so use Api interrupt
// to achieve that.
RequestInterrupt(
[](v8::Isolate* isolate, void*) {
Isolate* i_isolate = reinterpret_cast<Isolate*>(isolate);
if (Protectors::IsNoProfilingIntact(i_isolate)) {
Protectors::InvalidateNoProfiling(i_isolate);
}
},
nullptr);
}
namespace {
void ReportBootstrappingException(DirectHandle<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 (IsString(*exception) && IsString(location->script()->name())) {
base::OS::PrintError(
"Extension or internal compilation error: %s in %s at line %d.\n",
Cast<String>(*exception)->ToCString().get(),
Cast<String>(location->script()->name())->ToCString().get(),
line_number);
} else if (IsString(location->script()->name())) {
base::OS::PrintError(
"Extension or internal compilation error in %s at line %d.\n",
Cast<String>(location->script()->name())->ToCString().get(),
line_number);
} else if (IsString(*exception)) {
base::OS::PrintError("Extension or internal compilation error: %s.\n",
Cast<String>(*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 (IsString(location->script()->source())) {
DirectHandle<String> src(Cast<String>(location->script()->source()),
Isolate::Current());
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
DirectHandle<JSMessageObject> Isolate::CreateMessageOrAbort(
DirectHandle<Object> exception, MessageLocation* location) {
DirectHandle<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.
// Cache the flag on a static so that we can modify the value looked up below
// in the presence of read-only flags.
static bool abort_on_uncaught_exception =
v8_flags.abort_on_uncaught_exception;
if (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.
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;
}
Tagged<Object> Isolate::Throw(Tagged<Object> raw_exception,
MessageLocation* location,
bool is_stack_overflow) {
if (has_exception()) {
// A termination exception may have been thrown while preparing
// {raw_exception}, e.g. by the near heap limit callback
// (crbug.com/409487530).
// In this case ignore the current error and propagate the termination
// exception instead. Any other kind of exception is unexpected.
DCHECK(IsTerminationException(exception()));
return ReadOnlyRoots(heap()).exception();
}
DCHECK_IMPLIES(IsHole(raw_exception),
raw_exception == ReadOnlyRoots{this}.termination_exception());
CHECK(IsOnCentralStack());
HandleScope scope(this);
DirectHandle<Object> exception(raw_exception, this);
if (v8_flags.print_all_exceptions) {
PrintF("=========================================================\n");
PrintF("Exception thrown:\n");
if (location) {
DirectHandle<Script> script = location->script();
DirectHandle<Object> name(script->GetNameOrSourceURL(), this);
PrintF("at ");
if (IsString(*name) && Cast<String>(*name)->length() > 0) {
Cast<String>(*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
Script::PositionInfo start_pos;
Script::PositionInfo end_pos;
Script::GetPositionInfo(script, location->start_pos(), &start_pos);
Script::GetPositionInfo(script, location->end_pos(), &end_pos);
PrintF(", %d:%d - %d:%d\n", start_pos.line + 1, start_pos.column + 1,
end_pos.line + 1, end_pos.column + 1);
} else {
PrintF(", line %d\n", script->GetLineNumber(location->start_pos()) + 1);
}
}
Print(*exception);
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()->IsVerbose() ||
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(*exception)) {
DirectHandle<Object> message(pending_message(), this);
std::optional<Tagged<Object>> maybe_exception =
debug()->OnThrow(exception, is_stack_overflow);
if (maybe_exception.has_value()) {
return *maybe_exception;
}
// Restore the message in case it was clobbered by debugger.
set_pending_message(*message);
}
// 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 {
DirectHandle<Object> message_obj =
CreateMessageOrAbort(exception, location);
set_pending_message(*message_obj);
}
}
// Set the exception being thrown.
set_exception(*exception);
PropagateExceptionToExternalTryCatch(TopExceptionHandlerType(*exception));
if (v8_flags.experimental_report_exceptions_from_callbacks &&
exception_propagation_callback_ && !rethrowing_message &&
!preprocessing_exception_) {
// Don't preprocess exceptions that might happen inside
// |exception_propagation_callback_|.
preprocessing_exception_ = true;
NotifyExceptionPropagationCallback();
preprocessing_exception_ = false;
}
return ReadOnlyRoots(heap()).exception();
}
Tagged<Object> Isolate::ReThrow(Tagged<Object> exception) {
DCHECK(!has_exception());
// Set the exception being re-thrown.
set_exception(exception);
return ReadOnlyRoots(heap()).exception();
}
Tagged<Object> Isolate::ReThrow(Tagged<Object> exception,
Tagged<Object> message) {
DCHECK(!has_exception());
DCHECK(!has_pending_message());
set_pending_message(message);
return ReThrow(exception);
}
Tagged<Object> Isolate::UnwindAndFindHandler() {
// TODO(v8:12676): Fix gcmole failures in this function.
DisableGCMole no_gcmole;
DisallowGarbageCollection no_gc;
// The topmost_script_having_context value becomes outdated after frames
// unwinding.
clear_topmost_script_having_context();
Tagged<Object> exception = this->exception();
auto FoundHandler = [&](StackFrameIterator& iter, Tagged<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;
#if V8_ENABLE_WEBASSEMBLY
// If the exception was caught in a different stack, process all
// intermediate stack switches.
// This cannot be done during unwinding because the stack switching state
// must stay consistent with the thread local top (see crbug.com/406053619).
wasm::StackMemory* active_stack = isolate_data_.active_stack();
if (active_stack != nullptr) {
wasm::StackMemory* parent = nullptr;
Tagged<WasmSuspenderObject> suspender =
isolate_data()->active_suspender();
while (active_stack != iter.wasm_stack()) {
parent = active_stack->jmpbuf()->parent;
SBXCHECK_EQ(parent->jmpbuf()->state, wasm::JumpBuffer::Inactive);
if (v8_flags.trace_wasm_stack_switching) {
PrintF("Switch from stack %d to %d (throw)\n", active_stack->id(),
parent->id());
}
SwitchStacks<wasm::JumpBuffer::Retired, wasm::JumpBuffer::Inactive>(
active_stack, parent, kNullAddress, kNullAddress, kNullAddress);
if (suspender->has_parent() && parent == suspender->parent()->stack()) {
// Exception escapes the current suspender, unwind to the parent.
// Clear the external stack pointer to avoid a UAF.
suspender->set_stack(this, nullptr);
suspender = suspender->parent();
}
RetireWasmStack(active_stack);
active_stack = parent;
}
if (parent) {
// We switched at least once, update the active continuation.
isolate_data_.set_active_stack(active_stack);
isolate_data()->set_active_suspender(suspender);
}
}
// The unwinder is running on the central stack. If the target frame is in a
// secondary stack, update the central stack flags and the stack limit.
Address stack_address =
handler_sp != kNullAddress ? handler_sp : handler_fp;
if (!IsOnCentralStack(stack_address)) {
thread_local_top()->is_on_central_stack_flag_ = false;
iter.wasm_stack()->ShrinkTo(stack_address);
uintptr_t limit =
reinterpret_cast<uintptr_t>(iter.wasm_stack()->jslimit());
stack_guard()->SetStackLimitForStackSwitching(limit);
iter.wasm_stack()->clear_stack_switch_info();
#if V8_OS_WIN
base::Stack::SetCurrentThreadStackBounds(iter.wasm_stack()->limit(),
iter.wasm_stack()->base());
#endif
}
#endif
// Return and clear exception. The contract is that:
// (1) the 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_exception(...).
clear_internal_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);
if (!catchable_by_js && !context().is_null()) {
// Because the array join stack will not pop the elements when throwing the
// uncatchable terminate exception, we need to clear the array join stack to
// avoid leaving the stack in an invalid state.
// See also CycleProtectedArrayJoin.
raw_native_context()->set_array_join_stack(
ReadOnlyRoots(this).undefined_value());
}
// Compute handler and stack unwinding information by performing a full walk
// over the stack and dispatching according to the frame type.
bool ignore_next_frame = false;
for (StackFrameIterator iter(this, thread_local_top());; iter.Advance()) {
if (ignore_next_frame) {
ignore_next_frame = false;
// Since we are skipping the next frame, we must manually perform the
// unwinding cleanup for it here, as the 'continue' will bypass the
// cleanup at the end of the loop body.
if (iter.frame()->is_optimized_js()) {
materialized_object_store_->Remove(iter.frame()->fp());
}
continue;
}
int visited_frames = iter.frame()->iteration_depth();
#if V8_ENABLE_WEBASSEMBLY
if (iter.frame()->type() == StackFrame::WASM_JSPI) {
if (catchable_by_js && iter.frame()->LookupCode()->builtin_id() !=
Builtin::kJSToWasmStressSwitchStacksAsm) {
Tagged<Code> code =
builtins()->code(Builtin::kWasmReturnPromiseOnSuspendAsm);
HandlerTable table(code);
Address instruction_start =
code->InstructionStart(this, iter.frame()->pc());
int handler_offset = table.LookupReturn(0);
return FoundHandler(iter, {}, instruction_start, handler_offset,
kNullAddress, iter.frame()->sp(),
iter.frame()->fp(), visited_frames);
} else {
// Just walk across the stack switch here. We only process it once we
// have reached the handler.
continue;
}
}
#endif
// Handler must exist.
DCHECK(!iter.done());
StackFrame* frame = iter.frame();
// The debugger implements the "restart frame" feature by throwing a
// terminate exception. Check and if we need to restart `frame`,
// jump into the `RestartFrameTrampoline` builtin instead of
// a catch handler.
// Optimized frames take a detour via the deoptimizer before also jumping
// to the `RestartFrameTrampoline` builtin.
if (debug()->ShouldRestartFrame(frame->id())) {
CancelTerminateExecution();
CHECK(!catchable_by_js);
CHECK(frame->is_javascript());
if (frame->is_optimized_js()) {
Tagged<Code> code = frame->LookupCode();
// The debugger triggers lazy deopt for the "to-be-restarted" frame
// immediately when the CDP event arrives while paused.
CHECK(code->marked_for_deoptimization());
set_deoptimizer_lazy_throw(true);
// Jump directly to the optimized frames return, to immediately fall
// into the deoptimizer.
const int offset =
static_cast<int>(frame->pc() - code->instruction_start());
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
// Note: Needed by the deoptimizer to rematerialize frames.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
code->stack_slots() * kSystemPointerSize;
return FoundHandler(iter, {}, code->instruction_start(), offset,
code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
debug()->clear_restart_frame();
Tagged<Code> code = *BUILTIN_CODE(this, RestartFrameTrampoline);
return FoundHandler(iter, {}, code->instruction_start(), 0,
code->constant_pool(), kNullAddress, frame->fp(),
visited_frames);
}
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.
Tagged<Code> code = frame->LookupCode();
HandlerTable table(code);
return FoundHandler(iter, {}, 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: {
#if V8_ENABLE_DRUMBRAKE
if (v8_flags.wasm_jitless) {
StackHandler* handler = frame->top_handler();
thread_local_top()->handler_ = handler->next_address();
Tagged<Code> code =
frame->LookupCode(); // WasmInterpreterCWasmEntry.
HandlerTable table(code);
Address instruction_start = code->InstructionStart(this, frame->pc());
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
Address return_sp = *reinterpret_cast<Address*>(
frame->fp() + WasmInterpreterCWasmEntryConstants::kSPFPOffset);
const int handler_offset = table.LookupReturn(0);
return FoundHandler(iter, {}, instruction_start, handler_offset,
code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
#endif // V8_ENABLE_DRUMBRAKE
StackHandler* handler = frame->top_handler();
thread_local_top()->handler_ = handler->next_address();
Tagged<Code> code = frame->LookupCode();
HandlerTable table(code);
Address instruction_start = code->instruction_start();
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(iter, {}, instruction_start, handler_offset,
code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
#if V8_ENABLE_DRUMBRAKE
case StackFrame::WASM_INTERPRETER_ENTRY: {
} break;
#endif // V8_ENABLE_DRUMBRAKE
case StackFrame::WASM:
case StackFrame::WASM_SEGMENT_START: {
if (!is_catchable_by_wasm(exception)) break;
WasmFrame* wasm_frame = static_cast<WasmFrame*>(frame);
wasm::WasmCode* wasm_code =
wasm::GetWasmCodeManager()->LookupCode(this, frame->pc());
int offset = wasm_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.
// The stack slot count needs to be adjusted for Liftoff frames. It has
// two components: the fixed frame slots, and the maximum number of
// registers pushed on top of the frame in out-of-line code. We know
// that we are not currently in an OOL call, because OOL calls don't
// have exception handlers. So we subtract the OOL spill count from the
// total stack slot count to compute the actual frame size:
int stack_slots = wasm_code->stack_slots() - wasm_code->ool_spills();
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
stack_slots * kSystemPointerSize;
#if V8_ENABLE_DRUMBRAKE
// Transitioning from JS To Wasm.
if (v8_flags.wasm_enable_exec_time_histograms &&
v8_flags.slow_histograms && !v8_flags.wasm_jitless) {
// Start measuring the time spent running Wasm for jitted Wasm.
wasm_execution_timer()->Start();
}
#endif // V8_ENABLE_DRUMBRAKE
return FoundHandler(iter, {}, wasm_code->instruction_start(), offset,
wasm_code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
case StackFrame::WASM_LIFTOFF_SETUP: {
// The WasmLiftoffFrameSetup builtin doesn't throw, and doesn't call
// out to user code that could throw.
UNREACHABLE();
}
#endif // V8_ENABLE_WEBASSEMBLY
case StackFrame::MAGLEV:
case StackFrame::TURBOFAN_JS: {
// For optimized frames we perform a lookup in the handler table.
if (!catchable_by_js) break;
OptimizedJSFrame* opt_frame = static_cast<OptimizedJSFrame*>(frame);
int offset = opt_frame->LookupExceptionHandlerInTable(nullptr, nullptr);
if (offset < 0) break;
// The code might be an optimized code or a turbofanned builtin.
Tagged<Code> code = frame->LookupCode();
// 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 TURBOFAN_JS,
// but do not have a code kind of TURBOFAN_JS.
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->instruction_start());
set_deoptimizer_lazy_throw(true);
}
return FoundHandler(iter, {}, 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 V8_ENABLE_WEBASSEMBLY
DCHECK_NULL(wasm::GetWasmCodeManager()->LookupCode(this, frame->pc()));
#endif // V8_ENABLE_WEBASSEMBLY
// The code might be a dynamically generated stub or a turbofanned
// embedded builtin.
Tagged<Code> code = stub_frame->LookupCode();
if (!code->is_turbofanned() || !code->has_handler_table()) {
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(iter, {}, 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;
UnoptimizedJSFrame* js_frame = UnoptimizedJSFrame::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.
Tagged<Context> context =
Cast<Context>(js_frame->ReadInterpreterRegister(context_reg));
DCHECK(IsContext(context));
if (frame->is_baseline()) {
BaselineFrame* sp_frame = BaselineFrame::cast(js_frame);
Tagged<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(iter, {}, code->instruction_start(), pc_offset,
code->constant_pool(), return_sp, sp_frame->fp(),
visited_frames);
} else {
InterpretedFrame::cast(js_frame)->PatchBytecodeOffset(
static_cast<int>(offset));
Tagged<Code> code = *BUILTIN_CODE(this, InterpreterEnterAtBytecode);
#ifndef V8_ENABLE_RISCV_SHADOW_STACK
// 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(iter, context, code->instruction_start(), 0,
code->constant_pool(), return_sp, frame->fp(),
visited_frames - 1);
#else
return FoundHandler(iter, context, code->instruction_start(), 0,
code->constant_pool(), return_sp, frame->fp(),
visited_frames);
#endif
}
}
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::INTERNAL: {
auto code = frame->GcSafeLookupCode();
if (code->builtin_id() ==
Builtin::kDeoptimizationEntry_LazyAfterFastCall) {
// Deoptimization Entry builtin does the exception handling for the
// fast API if the fast API caller was marked for deoptimization.
// Therefore, even though `frame->fp()` says that we are coming from
// the Deoptimization Entry builtin, we have to do the stack unwinding
// as if we come from the fast call. The return address of the fast
// call is still stored in the isolate, so we can just load it from
// there.
Address fast_call_pc = isolate_data()->fast_c_call_caller_pc();
std::optional<Tagged<GcSafeCode>> result =
inner_pointer_to_code_cache()->GetCacheEntry(fast_call_pc)->code;
CHECK(!result->is_null());
Tagged<GcSafeCode> caller_code = result.value();
int caller_offset =
caller_code->GetOffsetFromInstructionStart(this, fast_call_pc);
// Check if there is actually an exception handler registered at the
// return address of the fast call. If so, then we tell the
// deoptimizer of the exception and just return the Deoptimization
// Entry. Otherwise we iterate the stack further to find a handler.
HandlerTable table(TrustedCast<Code>(caller_code));
int handler_offset = table.LookupReturn(caller_offset);
if (handler_offset < 0) {
// No handler was registered for the fast call. The stack iteration
// would therefore continue with the next frame, which is the frame
// of the caller of the fast API call. We checked that frame already
// here, so there is no need to check it again. Additionally, the
// `pc` of the next frame is off by a call instruction, because for
// a normal deopt, the return address on the stack would point to
// the deopt exit of the call, but to reach the current code
// location, the deopt exit has already been called, to the address
// after the deopt exit is on the stack as the return address.
ignore_next_frame = true;
break;
}
// 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.
int offset =
static_cast<int>(frame->pc() - code->instruction_start());
set_deoptimizer_lazy_throw(true);
return FoundHandler(
iter, {}, code->InstructionStart(this, frame->pc()), offset,
code->constant_pool(), frame->sp(), frame->fp(), visited_frames);
}
break;
}
case StackFrame::JAVASCRIPT_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();
Tagged<Code> code = js_frame->LookupCode();
return FoundHandler(iter, {}, code->instruction_start(), 0,
code->constant_pool(), return_sp, frame->fp(),
visited_frames);
}
default:
// All other types can not handle exception.
break;
}
if (frame->is_optimized_js()) {
// 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 internal
namespace {
class StackFrameSummaryIterator {
public:
explicit StackFrameSummaryIterator(Isolate* isolate)
: stack_iterator_(isolate), summaries_(), index_(0) {
InitSummaries();
}
void Advance() {
if (index_ == 0) {
summaries_.frames.clear();
stack_iterator_.Advance();
InitSummaries();
} else {
index_--;
}
}
bool done() const { return stack_iterator_.done(); }
StackFrame* frame() const { return stack_iterator_.frame(); }
bool has_frame_summary() const { return index_ < summaries_.size(); }
const FrameSummary& frame_summary() const {
DCHECK(has_frame_summary());
return summaries_.frames[index_];
}
Isolate* isolate() const { return stack_iterator_.isolate(); }
private:
void InitSummaries() {
while (!done() && frame()->is_javascript()) {
summaries_ = JavaScriptFrame::cast(frame())->Summarize();
if (summaries_.size() == 0) {
// We may have encountered a Builtin::kWasmMethodWrapper. Skip it.
stack_iterator_.Advance();
continue;
}
DCHECK_GT(summaries_.size(), 0);
index_ = summaries_.size() - 1;
break;
}
}
StackFrameIterator stack_iterator_;
FrameSummaries summaries_;
int index_;
};
HandlerTable::CatchPrediction CatchPredictionFor(Builtin builtin_id) {
switch (builtin_id) {
#define CASE(Name) \
case Builtin::k##Name: \
return HandlerTable::PROMISE;
BUILTIN_PROMISE_REJECTION_PREDICTION_LIST(CASE)
#undef CASE
default:
return HandlerTable::UNCAUGHT;
}
}
HandlerTable::CatchPrediction PredictExceptionFromBytecode(
Tagged<BytecodeArray> bytecode, int code_offset) {
HandlerTable table(bytecode);
int handler_index = table.LookupHandlerIndexForRange(code_offset);
if (handler_index < 0) return HandlerTable::UNCAUGHT;
return table.GetRangePrediction(static_cast<uint32_t>(handler_index));
}
HandlerTable::CatchPrediction PredictException(const FrameSummary& summary,
Isolate* isolate) {
if (!summary.IsJavaScript()) {
// This can happen when WASM is inlined by TurboFan. For now we ignore
// frames that are not JavaScript.
// TODO(https://crbug.com/349588762): We should also check Wasm code
// for exception handling.
return HandlerTable::UNCAUGHT;
}
DirectHandle<AbstractCode> code = summary.AsJavaScript().abstract_code();
if (code->kind() == CodeKind::BUILTIN) {
return CatchPredictionFor(code->GetCode()->builtin_id());
}
// Must have been constructed from a bytecode array.
CHECK_EQ(CodeKind::INTERPRETED_FUNCTION, code->kind());
return PredictExceptionFromBytecode(code->GetBytecodeArray(),
summary.code_offset());
}
HandlerTable::CatchPrediction PredictExceptionFromGenerator(
DirectHandle<JSGeneratorObject> generator, Isolate* isolate) {
return PredictExceptionFromBytecode(
generator->function()->shared()->GetBytecodeArray(isolate),
GetGeneratorBytecodeOffset(generator));
}
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();
}
}
Isolate::CatchType PredictExceptionCatchAtFrame(
const StackFrameSummaryIterator& iterator) {
const StackFrame* frame = iterator.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
Address external_handler =
iterator.isolate()->thread_local_top()->try_catch_handler_address();
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 &&
!iterator.isolate()->try_catch_handler()->IsVerbose() &&
!Isolate::IsInternalTryCatch(
iterator.isolate()->try_catch_handler())) {
if (entry_handler == kNullAddress || entry_handler > external_handler) {
return Isolate::CAUGHT_BY_EXTERNAL;
}
}
} break;
// For JavaScript frames we perform a lookup in the handler table.
case StackFrame::INTERPRETED:
case StackFrame::BASELINE:
case StackFrame::TURBOFAN_JS:
case StackFrame::MAGLEV:
case StackFrame::BUILTIN: {
DCHECK(iterator.has_frame_summary());
return ToCatchType(
PredictException(iterator.frame_summary(), iterator.isolate()));
}
case StackFrame::STUB: {
Tagged<Code> code = frame->LookupCode();
if (code->kind() != CodeKind::BUILTIN || !code->has_handler_table() ||
!code->is_turbofanned()) {
break;
}
return ToCatchType(CatchPredictionFor(code->builtin_id()));
}
case StackFrame::JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
Tagged<Code> code = frame->LookupCode();
return ToCatchType(CatchPredictionFor(code->builtin_id()));
}
default:
// All other types can not handle exception.
break;
}
return Isolate::NOT_CAUGHT;
}
} // anonymous namespace
Isolate::CatchType Isolate::PredictExceptionCatcher() {
if (TopExceptionHandlerType(Tagged<Object>()) ==
ExceptionHandlerType::kExternalTryCatch) {
if (!try_catch_handler()->IsInternal()) {
return CAUGHT_BY_EXTERNAL;
}
}
// Search for an exception handler by performing a full walk over the stack.
for (StackFrameSummaryIterator iter(this); !iter.done(); iter.Advance()) {
Isolate::CatchType prediction = PredictExceptionCatchAtFrame(iter);
if (prediction != NOT_CAUGHT) return prediction;
}
// Handler not found.
return NOT_CAUGHT;
}
Tagged<Object> Isolate::ThrowIllegalOperation() {
if (v8_flags.stack_trace_on_illegal) PrintStack(stdout);
return Throw(ReadOnlyRoots(heap()).illegal_access_string());
}
void Isolate::PrintCurrentStackTrace(
std::ostream& out,
PrintCurrentStackTraceFilterCallback should_include_frame_callback) {
Handle<FixedArray> frames =
CaptureSimpleStackTrace(this, static_cast<int>(FixedArray::kMaxLength),
SKIP_NONE, factory()->undefined_value());
frames = CallSiteInfo::ExpandDeferredFrames(this, frames);
IncrementalStringBuilder builder(this);
uint32_t frame_count =
frames->ulength().value() / CallSiteInfo::Fields::kCount;
for (uint32_t i = 0; i < frame_count; ++i) {
DirectHandle<CallSiteInfo> frame =
CallSiteInfo::ConstructFromRawData(this, frames, i);
if (should_include_frame_callback) {
Tagged<Object> raw_script_name = frame->GetScriptNameOrSourceURL();
v8::Local<v8::String> script_name_local;
v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(this);
if (IsString(raw_script_name)) {
DirectHandle<String> script_name =
Handle<String>(Cast<String>(raw_script_name), this);
script_name_local = v8::Utils::ToLocal(script_name);
} else {
script_name_local = v8::String::Empty(v8_isolate);
}
if (should_include_frame_callback(v8_isolate, script_name_local)) {
SerializeCallSiteInfo(this, frame, &builder);
} else {
builder.AppendString("<redacted>");
}
} else {
SerializeCallSiteInfo(this, frame, &builder);
}
if (i != frame_count - 1) builder.AppendCharacter('\n');
}
DirectHandle<String> stack_trace = builder.Finish().ToHandleChecked();
stack_trace->PrintOn(out);
}
bool Isolate::ComputeLocation(MessageLocation* target) {
DebuggableStackFrameIterator 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 (!IsScript(*script) || IsUndefined(Cast<Script>(*script)->source())) {
return false;
}
if (summary.IsJavaScript()) {
shared = handle(summary.AsJavaScript().function()->shared(), this);
}
if (summary.AreSourcePositionsAvailable()) {
int pos = summary.SourcePosition();
*target = MessageLocation(Cast<Script>(script), pos, pos + 1, shared);
} else {
*target =
MessageLocation(Cast<Script>(script), shared, summary.code_offset());
}
return true;
}
bool Isolate::ComputeLocationFromException(MessageLocation* target,
DirectHandle<Object> exception) {
if (!IsJSObject(*exception)) return false;
DirectHandle<Name> start_pos_symbol = factory()->error_start_pos_symbol();
DirectHandle<Object> start_pos = JSReceiver::GetDataProperty(
this, Cast<JSObject>(exception), start_pos_symbol);
if (!IsSmi(*start_pos)) return false;
int start_pos_value = Cast<Smi>(*start_pos).value();
DirectHandle<Name> end_pos_symbol = factory()->error_end_pos_symbol();
DirectHandle<Object> end_pos = JSReceiver::GetDataProperty(
this, Cast<JSObject>(exception), end_pos_symbol);
if (!IsSmi(*end_pos)) return false;
int end_pos_value = Cast<Smi>(*end_pos).value();
DirectHandle<Name> script_symbol = factory()->error_script_symbol();
DirectHandle<Object> script = JSReceiver::GetDataProperty(
this, Cast<JSObject>(exception), script_symbol);
if (!IsScript(*script)) return false;
Handle<Script> cast_script(Cast<Script>(*script), this);
*target = MessageLocation(cast_script, start_pos_value, end_pos_value);
return true;
}
bool Isolate::ComputeLocationFromSimpleStackTrace(
MessageLocation* target, DirectHandle<Object> exception) {
if (!IsJSReceiver(*exception)) {
return false;
}
DirectHandle<FixedArray> call_site_infos =
GetSimpleStackTrace(Cast<JSReceiver>(exception));
uint32_t call_site_infos_count = call_site_infos->ulength().value();
for (uint32_t i = 0; i < call_site_infos_count; ++i) {
DirectHandle<CallSiteInfo> call_site_info(
Cast<CallSiteInfo>(call_site_infos->get(i)), this);
if (CallSiteInfo::ComputeLocation(call_site_info, target)) {
return true;
}
}
return false;
}
bool Isolate::ComputeLocationFromDetailedStackTrace(
MessageLocation* target, DirectHandle<Object> exception) {
if (!IsJSReceiver(*exception)) return false;
DirectHandle<StackTraceInfo> stack_trace =
GetDetailedStackTrace(Cast<JSReceiver>(exception));
if (stack_trace.is_null() || stack_trace->length() == 0) {
return false;
}
DirectHandle<StackFrameInfo> info(stack_trace->get(0), this);
const int pos = StackFrameInfo::GetSourcePosition(info);
*target = MessageLocation(handle(info->script(), this), pos, pos + 1);
return true;
}
Handle<JSMessageObject> Isolate::CreateMessage(DirectHandle<Object> exception,
MessageLocation* location) {
DirectHandle<StackTraceInfo> stack_trace;
if (capture_stack_trace_for_uncaught_exceptions_) {
if (IsJSObject(*exception)) {
// First, check whether a stack trace is already present on this object.
// It maybe an Error, or the embedder may have stored a stack trace using
// Exception::CaptureStackTrace().
// If the lookup fails, we fall through and capture the stack trace
// at this throw site.
stack_trace = GetDetailedStackTrace(Cast<JSObject>(exception));
}
if (stack_trace.is_null()) {
// Not an error object, we capture stack and location at throw site.
stack_trace = 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);
}
Handle<JSMessageObject> Isolate::CreateMessageFromException(
DirectHandle<Object> exception) {
DirectHandle<StackTraceInfo> stack_trace;
if (IsJSError(*exception)) {
stack_trace = GetDetailedStackTrace(Cast<JSObject>(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);
}
Isolate::ExceptionHandlerType Isolate::TopExceptionHandlerType(
Tagged<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(bool report) {
Tagged<Object> exception_obj = 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 = PropagateExceptionToExternalTryCatch(top_handler);
if (!has_been_propagated) return;
if (!report) return;
DCHECK(AllowExceptions::IsAllowed(this));
// The embedder might run script in response to an exception.
AllowJavascriptExecutionDebugOnly allow_script(this);
// Clear the pending message object early to avoid endless recursion.
Tagged<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()->IsVerbose();
} else {
should_report_exception = true;
}
// Actually report the pending message to all message handlers.
if (!IsTheHole(message_obj) && should_report_exception) {
HandleScope scope(this);
DirectHandle<JSMessageObject> message(Cast<JSMessageObject>(message_obj),
this);
Handle<Script> script(message->script(), this);
// Clear the exception and restore it afterwards, otherwise
// CollectSourcePositions will abort.
{
ExceptionScope exception_scope(this);
JSMessageObject::EnsureSourcePositionsAvailable(this, message);
}
int start_pos = message->GetStartPosition();
int end_pos = message->GetEndPosition();
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message);
}
}
namespace {
bool ReceiverIsForwardingHandler(Isolate* isolate,
DirectHandle<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.
DirectHandle<Symbol> key =
isolate->factory()->promise_forwarding_handler_symbol();
DirectHandle<Object> forwarding_handler =
JSReceiver::GetDataProperty(isolate, handler, key);
return !IsUndefined(*forwarding_handler);
}
bool WalkPromiseTreeInternal(
Isolate* isolate, DirectHandle<JSPromise> promise,
const std::function<void(Isolate::PromiseHandler)>& callback) {
if (promise->status() != Promise::kPending) {
// If a rejection reaches an exception that isn't pending, it will be
// treated as caught.
return true;
}
bool any_caught = false;
bool any_uncaught = false;
DirectHandle<Object> current(promise->reactions(), isolate);
while (!IsSmi(*current)) {
auto reaction = Cast<PromiseReaction>(current);
DirectHandle<HeapObject> promise_or_capability(
reaction->promise_or_capability(), isolate);
if (!IsUndefined(*promise_or_capability)) {
if (!IsJSPromise(*promise_or_capability)) {
promise_or_capability = direct_handle(
Cast<PromiseCapability>(promise_or_capability)->promise(), isolate);
}
if (IsJSPromise(*promise_or_capability)) {
DirectHandle<JSPromise> next_promise =
Cast<JSPromise>(promise_or_capability);
bool caught = false;
DirectHandle<JSReceiver> reject_handler;
if (!IsUndefined(reaction->reject_handler())) {
reject_handler = direct_handle(
Cast<JSReceiver>(reaction->reject_handler()), isolate);
if (!ReceiverIsForwardingHandler(isolate, reject_handler) &&
!IsBuiltinForwardingRejectHandler(isolate, *reject_handler)) {
caught = true;
}
}
// Pass each handler to the callback
DirectHandle<JSGeneratorObject> async_function;
if (TryGetAsyncGenerator(isolate, reaction).ToHandle(&async_function)) {
caught = caught ||
PredictExceptionFromGenerator(async_function, isolate) ==
HandlerTable::CAUGHT;
// Look at the async function, not the individual handlers
callback({async_function->function()->shared(), true});
} else {
// Not an async function, look at individual handlers
if (!IsUndefined(reaction->fulfill_handler())) {
DirectHandle<JSReceiver> fulfill_handler(
Cast<JSReceiver>(reaction->fulfill_handler()), isolate);
if (!ReceiverIsForwardingHandler(isolate, fulfill_handler)) {
if (IsBuiltinFunction(isolate, *fulfill_handler,
Builtin::kPromiseThenFinally)) {
// If this is the finally handler, get the wrapped callback
// from the context to use instead
DirectHandle<Context> context(
Cast<JSFunction>(reaction->fulfill_handler())->context(),
isolate);
int const index =
PromiseBuiltins::PromiseFinallyContextSlot::kOnFinallySlot;
fulfill_handler = direct_handle(
Cast<JSReceiver>(context->GetNoCell(index)), isolate);
}
if (IsJSFunction(*fulfill_handler)) {
callback({Cast<JSFunction>(fulfill_handler)->shared(), true});
}
}
}
if (caught) {
// We've already checked that this isn't undefined or
// a forwarding handler
if (IsJSFunction(*reject_handler)) {
callback({Cast<JSFunction>(reject_handler)->shared(), true});
}
}
}
caught =
caught || WalkPromiseTreeInternal(isolate, next_promise, callback);
any_caught = any_caught || caught;
any_uncaught = any_uncaught || !caught;
}
} else {
#if V8_ENABLE_WEBASSEMBLY
DirectHandle<WasmSuspenderObject> suspender;
if (TryGetWasmSuspender(isolate, reaction->fulfill_handler())
.ToHandle(&suspender)) {
// If in the future we support Wasm exceptions or ignore listing in
// Wasm, we will need to iterate through these frames. For now, we
// only care about the resulting promise.
DirectHandle<JSPromise> next_promise(
Cast<JSPromise>(suspender->promise()), isolate);
bool caught = WalkPromiseTreeInternal(isolate, next_promise, callback);
any_caught = any_caught || caught;
any_uncaught = any_uncaught || !caught;
}
#endif // V8_ENABLE_WEBASSEMBLY
}
current = direct_handle(reaction->next(), isolate);
}
bool caught = any_caught && !any_uncaught;
if (!caught) {
// If there is an outer promise, follow that to see if it is caught.
DirectHandle<Symbol> key = isolate->factory()->promise_handled_by_symbol();
DirectHandle<Object> outer_promise_obj =
JSReceiver::GetDataProperty(isolate, promise, key);
if (IsJSPromise(*outer_promise_obj)) {
return WalkPromiseTreeInternal(
isolate, Cast<JSPromise>(outer_promise_obj), callback);
}
}
return caught;
}
// Helper functions to scan for calls to .catch.
using interpreter::Bytecode;
using interpreter::Bytecodes;
enum PromiseMethod { kThen, kCatch, kFinally, kInvalid };
// Requires the iterator to be on a GetNamedProperty instruction
PromiseMethod GetPromiseMethod(
Isolate* isolate, const interpreter::BytecodeArrayIterator& iterator) {
DirectHandle<Object> object = iterator.GetConstantForOperand(1, isolate);
if (!IsString(*object)) {
return kInvalid;
}
auto str = Cast<String>(object);
if (str->Equals(ReadOnlyRoots(isolate).then_string())) {
return kThen;
} else if (str->IsEqualTo(base::StaticCharVector("catch"))) {
return kCatch;
} else if (str->IsEqualTo(base::StaticCharVector("finally"))) {
return kFinally;
} else {
return kInvalid;
}
}
bool TouchesRegister(const interpreter::BytecodeArrayIterator& iterator,
int index) {
Bytecode bytecode = iterator.current_bytecode();
int num_operands = Bytecodes::NumberOfOperands(bytecode);
const interpreter::OperandType* operand_types =
Bytecodes::GetOperandTypes(bytecode);
for (int i = 0; i < num_operands; ++i) {
if (Bytecodes::IsRegisterOperandType(operand_types[i])) {
int base_index = iterator.GetRegisterOperand(i).index();
uint32_t num_registers;
if (Bytecodes::IsRegisterListOperandType(operand_types[i])) {
num_registers = iterator.GetRegisterCountOperand(++i);
} else {
num_registers =
Bytecodes::GetNumberOfRegistersRepresentedBy(operand_types[i]);
}
if (base_index <= index &&
index < base_index + base::checked_cast<int>(num_registers)) {
return true;
}
}
}
if (Bytecodes::WritesImplicitRegister(bytecode)) {
return iterator.GetStarTargetRegister().index() == index;
}
return false;
}
bool CallsCatchMethod(Isolate* isolate, Handle<BytecodeArray> bytecode_array,
int offset) {
interpreter::BytecodeArrayIterator iterator(bytecode_array, offset);
while (!iterator.done()) {
// We should be on a call instruction of some kind. While we could check
// this, it may be difficult to create an exhaustive list of instructions
// that could call, such as property getters, but at a minimum this
// instruction should write to the accumulator.
if (!Bytecodes::WritesAccumulator(iterator.current_bytecode())) {
return false;
}
iterator.Advance();
// While usually the next instruction is a Star, sometimes we store and
// reload from context first.
if (iterator.done()) {
return false;
}
if (iterator.current_bytecode() == Bytecode::kStaCurrentContextSlot ||
iterator.current_bytecode() == Bytecode::kStaCurrentContextSlotNoCell) {
// Step over patterns like:
// StaCurrentContextSlot[NoCell] [x]
// LdaImmutableCurrentContextSlot/LdaCurrentContext[NoCell] [x]
unsigned int slot = iterator.GetContextSlotOperand(0);
iterator.Advance();
if (!iterator.done() &&
(iterator.current_bytecode() ==
Bytecode::kLdaImmutableCurrentContextSlot ||
iterator.current_bytecode() == Bytecode::kLdaCurrentContextSlot ||
iterator.current_bytecode() ==
Bytecode::kLdaCurrentContextSlotNoCell)) {
if (iterator.GetContextSlotOperand(0) != slot) {
return false;
}
iterator.Advance();
}
} else if (iterator.current_bytecode() == Bytecode::kStaContextSlot ||
iterator.current_bytecode() == Bytecode::kStaContextSlotNoCell) {
// Step over patterns like:
// StaContextSlot[NoCell] r_x [y] [z]
// LdaContextSlot[NoCell] r_x [y] [z]
int context = iterator.GetRegisterOperand(0).index();
unsigned int slot = iterator.GetContextSlotOperand(1);
unsigned int depth = iterator.GetUnsignedImmediateOperand(2);
iterator.Advance();
if (!iterator.done() &&
(iterator.current_bytecode() == Bytecode::kLdaImmutableContextSlot ||
iterator.current_bytecode() == Bytecode::kLdaContextSlot ||
iterator.current_bytecode() == Bytecode::kLdaContextSlotNoCell)) {
if (iterator.GetRegisterOperand(0).index() != context ||
iterator.GetContextSlotOperand(1) != slot ||
iterator.GetUnsignedImmediateOperand(2) != depth) {
return false;
}
iterator.Advance();
}
} else if (iterator.current_bytecode() == Bytecode::kStaLookupSlot) {
// Step over patterns like:
// StaLookupSlot [x] [_]
// LdaLookupSlot [x]
unsigned int slot = iterator.GetConstantPoolIndexOperand(0);
iterator.Advance();
if (!iterator.done() &&
(iterator.current_bytecode() == Bytecode::kLdaLookupSlot ||
iterator.current_bytecode() ==
Bytecode::kLdaLookupSlotInsideTypeof)) {
if (iterator.GetConstantPoolIndexOperand(0) != slot) {
return false;
}
iterator.Advance();
}
}
// Next instruction should be a Star (store accumulator to register)
if (iterator.done() || !Bytecodes::IsAnyStar(iterator.current_bytecode())) {
return false;
}
// The register it stores to will be assumed to be our promise
int promise_register = iterator.GetStarTargetRegister().index();
// TODO(crbug/40283993): Should we loop over non-matching instructions here
// to allow code like
// `const promise = foo(); console.log(...); promise.catch(...);`?
iterator.Advance();
// We should be on a GetNamedProperty instruction.
if (iterator.done() ||
iterator.current_bytecode() != Bytecode::kGetNamedProperty ||
iterator.GetRegisterOperand(0).index() != promise_register) {
return false;
}
PromiseMethod method = GetPromiseMethod(isolate, iterator);
if (method == kInvalid) {
return false;
}
iterator.Advance();
// Next instruction should be a Star (save immediate to register)
if (iterator.done() || !Bytecodes::IsAnyStar(iterator.current_bytecode())) {
return false;
}
// This register contains the method we will eventually invoke
int method_register = iterator.GetStarTargetRegister().index();
if (method_register == promise_register) {
return false;
}
// Now we step over multiple instructions creating the arguments for the
// method.
while (true) {
iterator.Advance();
if (iterator.done()) {
return false;
}
Bytecode bytecode = iterator.current_bytecode();
if (bytecode == Bytecode::kCallProperty1 ||
bytecode == Bytecode::kCallProperty2) {
// This is a call property call of the right size, but is it a call of
// the method and on the promise?
if (iterator.GetRegisterOperand(0).index() == method_register &&
iterator.GetRegisterOperand(1).index() == promise_register) {
// This is our method call, but does it catch?
if (method == kCatch ||
(method == kThen && bytecode == Bytecode::kCallProperty2)) {
return true;
}
// Break out of the inner loop, continuing the outer loop. We
// will use the same procedure to check for chained method calls.
break;
}
}
// Check for some instructions that should make us give up scanning.
if (Bytecodes::IsJump(bytecode) || Bytecodes::IsSwitch(bytecode) ||
Bytecodes::Returns(bytecode) ||
Bytecodes::UnconditionallyThrows(bytecode)) {
// Stop scanning at control flow instructions that aren't calls
return false;
}
if (TouchesRegister(iterator, promise_register) ||
TouchesRegister(iterator, method_register)) {
// Stop scanning at instruction that unexpectedly interacts with one of
// the registers we care about.
return false;
}
}
}
return false;
}
bool CallsCatchMethod(const StackFrameSummaryIterator& iterator) {
if (!iterator.frame()->is_javascript()) {
return false;
}
if (iterator.frame_summary().IsJavaScript()) {
auto& js_summary = iterator.frame_summary().AsJavaScript();
if (Tagged<BytecodeArray> bytecode_array;
TryCast(js_summary.abstract_code()->ToUnionType(), &bytecode_array)) {
if (CallsCatchMethod(iterator.isolate(),
handle(bytecode_array, iterator.isolate()),
js_summary.code_offset())) {
return true;
}
}
}
return false;
}
} // namespace
bool Isolate::WalkCallStackAndPromiseTree(
MaybeDirectHandle<JSPromise> rejected_promise,
const std::function<void(PromiseHandler)>& callback) {
bool is_promise_rejection = false;
DirectHandle<JSPromise> promise;
if (rejected_promise.ToHandle(&promise)) {
is_promise_rejection = true;
// If the promise has reactions, follow them and assume we are done. If
// it has no reactions, assume promise is returned up the call stack and
// trace accordingly. If the promise is not pending, it has no reactions
// and is probably the result of a call to Promise.reject().
if (promise->status() != Promise::kPending) {
// Ignore this promise; set to null
rejected_promise = MaybeDirectHandle<JSPromise>();
} else if (IsSmi(promise->reactions())) {
// Also check that there is no outer promise
DirectHandle<Symbol> key = factory()->promise_handled_by_symbol();
if (!IsJSPromise(*JSReceiver::GetDataProperty(this, promise, key))) {
// Ignore this promise; set to null
rejected_promise = MaybeDirectHandle<JSPromise>();
}
}
}
if (!is_promise_rejection && TopExceptionHandlerType(Tagged<Object>()) ==
ExceptionHandlerType::kExternalTryCatch) {
return true; // caught by external
}
// Search for an exception handler by performing a full walk over the stack.
for (StackFrameSummaryIterator iter(this); !iter.done(); iter.Advance()) {
Isolate::CatchType prediction = PredictExceptionCatchAtFrame(iter);
bool caught;
if (rejected_promise.is_null()) {
switch (prediction) {
case NOT_CAUGHT:
// Uncaught unless this is a promise rejection and the code will call
// .catch()
caught = is_promise_rejection && CallsCatchMethod(iter);
break;
case CAUGHT_BY_ASYNC_AWAIT:
// Uncaught unless this is a promise rejection and the code will call
// .catch()
caught = is_promise_rejection && CallsCatchMethod(iter);
// Exceptions turn into promise rejections here
is_promise_rejection = true;
break;
case CAUGHT_BY_PROMISE:
// Exceptions turn into promise rejections here
// TODO(leese): Perhaps we can handle the case where the reject method
// is called in the promise constructor and it is still on the stack
// by ignoring all try/catches on the stack until we get to the right
// CAUGHT_BY_PROMISE?
is_promise_rejection = true;
caught = false;
break;
case CAUGHT_BY_EXTERNAL:
caught = !is_promise_rejection;
break;
case CAUGHT_BY_JAVASCRIPT:
caught = true;
// Unless this is a promise rejection and the function is not async...
DCHECK(iter.has_frame_summary());
const FrameSummary& summary = iter.frame_summary();
if (is_promise_rejection && summary.IsJavaScript()) {
// If the catch happens in an async function, assume it will
// await this promise. Alternately, if the code will call .catch,
// assume it is on this promise.
caught = IsAsyncFunction(iter.frame_summary()
.AsJavaScript()
.function()
->shared()
->kind()) ||
CallsCatchMethod(iter);
}
break;
}
} else {
// The frame that calls the reject handler will not catch that promise
// regardless of what else it does. We will trace where this rejection
// goes according to its reaction callbacks, but we first need to handle
// the topmost debuggable frame just to ensure there is a debuggable
// frame and to permit ignore listing there.
caught = false;
}
if (iter.frame()->is_javascript()) {
bool debuggable = false;
DCHECK(iter.has_frame_summary());
const FrameSummary& summary = iter.frame_summary();
if (summary.IsJavaScript()) {
const auto& info = summary.AsJavaScript().function()->shared();
if (info->IsSubjectToDebugging()) {
callback({info, false});
debuggable = true;
}
}
// Ignore the rest of the call stack if this is a rejection and the
// promise has handlers; we will trace where the rejection goes instead
// of where it came from.
if (debuggable && !rejected_promise.is_null()) {
break;
}
}
if (caught) {
return true;
}
}
if (rejected_promise.is_null()) {
// Now follow promises if this is a promise reaction job.
rejected_promise = TryGetCurrentTaskPromise(this);
}
if (rejected_promise.ToHandle(&promise)) {
return WalkPromiseTreeInternal(this, promise, callback);
}
// Nothing caught.
return false;
}
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(DirectHandle<NativeContext> context) {
DirectHandle<JSGlobalObject> global =
direct_handle(context->global_object(), this);
// If some fuzzer decided to make the global object non-extensible, then
// we can't install any features (and would CHECK-fail if we tried).
if (!global->map()->is_extensible()) return;
DirectHandle<String> sab_name = factory()->SharedArrayBuffer_string();
if (IsSharedArrayBufferConstructorEnabled(context)) {
if (!JSObject::HasRealNamedProperty(this, global, sab_name)
.FromMaybe(true)) {
JSObject::AddProperty(this, global, factory()->SharedArrayBuffer_string(),
shared_array_buffer_fun(), DONT_ENUM);
}
}
}
bool Isolate::IsSharedArrayBufferConstructorEnabled(
DirectHandle<NativeContext> context) {
if (!v8_flags.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::IsWasmCustomDescriptorsEnabled(
DirectHandle<NativeContext> context) {
#ifdef V8_ENABLE_WEBASSEMBLY
if (!v8_flags.wasm_custom_descriptors_permitted) return false;
v8::WasmCustomDescriptorsEnabledCallback callback =
wasm_custom_descriptors_enabled_callback();
if (callback) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
if (callback(api_context)) return true;
}
return v8_flags.wasm_custom_descriptors;
#else
return false;
#endif
}
DirectHandle<NativeContext> Isolate::GetIncumbentContextSlow() {
JavaScriptStackFrameIterator 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)) {
Tagged<Context> context = Cast<Context>(it.frame()->context());
// If the topmost_script_having_context is set then it must be correct.
if (DEBUG_BOOL && !topmost_script_having_context().is_null()) {
DCHECK_EQ(topmost_script_having_context()->native_context(),
context->native_context());
}
return DirectHandle<NativeContext>(context->native_context(), this);
}
DCHECK(topmost_script_having_context().is_null());
// 2nd candidate: the last Context::Scope's incumbent context if any.
if (top_backup_incumbent_scope()) {
v8::Local<v8::Context> incumbent_context =
top_backup_incumbent_scope()->backup_incumbent_context_;
return Utils::OpenDirectHandle(*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::OpenDirectHandle(*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() || IsContext(context()));
return from + sizeof(ThreadLocalTop);
}
void Isolate::ReleaseSharedPtrs() {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
auto delete_pointers = [this](ManagedPtrDestructor** list) {
while (*list) {
ManagedPtrDestructor* l = *list;
ManagedPtrDestructor* n = nullptr;
*list = nullptr;
for (; l != nullptr; l = n) {
l->external_memory_accounter_.Decrease(
reinterpret_cast<v8::Isolate*>(this), l->estimated_size_);
l->destructor_(l->shared_ptr_ptr_);
n = l->next_;
delete l;
}
}
};
delete_pointers(&managed_ptr_destructors_head_);
if (is_shared_space_isolate()) {
delete_pointers(&shared_managed_ptr_destructors_head_);
}
}
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) {
if (destructor->shared_ && !is_shared_space_isolate()) {
shared_space_isolate()->RegisterManagedPtrDestructor(destructor);
return;
}
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
DCHECK_NULL(destructor->prev_);
DCHECK_NULL(destructor->next_);
ManagedPtrDestructor** list = destructor->shared_
? &shared_managed_ptr_destructors_head_
: &managed_ptr_destructors_head_;
if (*list) {
(*list)->prev_ = destructor;
}
destructor->next_ = *list;
*list = destructor;
}
void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
if (destructor->shared_ && !is_shared_space_isolate()) {
shared_space_isolate()->UnregisterManagedPtrDestructor(destructor);
return;
}
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
if (destructor->prev_) {
destructor->prev_->next_ = destructor->next_;
} else {
ManagedPtrDestructor** list = destructor->shared_
? &shared_managed_ptr_destructors_head_
: &managed_ptr_destructors_head_;
DCHECK_EQ(destructor, *list);
*list = destructor->next_;
}
if (destructor->next_) destructor->next_->prev_ = destructor->prev_;
destructor->prev_ = nullptr;
destructor->next_ = nullptr;
}
// static
void Isolate::IterateRegistersAndStackOfSimulator(
::heap::base::StackVisitor* visitor) {
Isolate* isolate = Isolate::TryGetCurrent();
if (!isolate) return;
SimulatorStack::IterateRegistersAndStack(isolate, visitor);
}
#if V8_ENABLE_WEBASSEMBLY
bool Isolate::IsOnCentralStack(Address addr) {
auto stack = SimulatorStack::GetCentralStackView(this);
Address stack_top = reinterpret_cast<Address>(stack.begin());
#if !USE_SIMULATOR
// Try to use the stack limit reported by the system instead of V8's own
// conservative limit to avoid false positives.
Address real_stack_top = base::Stack::GetReservedStackLimit();
if (real_stack_top) {
stack_top = real_stack_top;
}
#endif
Address stack_base = reinterpret_cast<Address>(stack.end());
return stack_top < addr && addr <= stack_base;
}
bool Isolate::IsOnCentralStack() {
#if USE_SIMULATOR
return IsOnCentralStack(Simulator::current(this)->get_sp());
#else
return IsOnCentralStack(GetCurrentStackPosition());
#endif
}
void Isolate::AddSharedWasmMemory(
DirectHandle<WasmMemoryObject> memory_object) {
DirectHandle<WeakArrayList> shared_wasm_memories =
factory()->shared_wasm_memories();
// Avoid adding the same memory object multiple times.
if (shared_wasm_memories->Contains(MakeWeak(*memory_object))) return;
shared_wasm_memories = WeakArrayList::Append(
this, shared_wasm_memories, MaybeObjectDirectHandle::Weak(memory_object));
heap()->set_shared_wasm_memories(*shared_wasm_memories);
}
template <wasm::JumpBuffer::StackState new_state_of_old_stack,
wasm::JumpBuffer::StackState expected_target_state>
void Isolate::SwitchStacks(wasm::StackMemory* from, wasm::StackMemory* to,
Address sp, Address fp, Address pc) {
SBXCHECK_EQ(from->jmpbuf()->state, wasm::JumpBuffer::Active);
DCHECK_EQ(from, isolate_data()->active_stack());
constexpr bool is_resume =
expected_target_state == wasm::JumpBuffer::Suspended;
#if DEBUG
constexpr bool is_return =
new_state_of_old_stack == wasm::JumpBuffer::Retired;
constexpr bool is_suspend =
new_state_of_old_stack == wasm::JumpBuffer::Suspended;
#endif
from->jmpbuf()->state = new_state_of_old_stack;
if constexpr (new_state_of_old_stack != wasm::JumpBuffer::Retired) {
from->jmpbuf()->sp = sp;
from->jmpbuf()->fp = fp;
from->jmpbuf()->pc = pc;
from->jmpbuf()->stack_limit =
reinterpret_cast<void*>(stack_guard()->real_jslimit());
from->jmpbuf()->is_on_central_stack =
thread_local_top()->is_on_central_stack_flag_;
from->set_contains_only_old_pointers(false);
}
SBXCHECK_EQ(to->jmpbuf()->state, expected_target_state);
to->jmpbuf()->state = wasm::JumpBuffer::Active;
isolate_data()->set_active_stack(to);
DisallowGarbageCollection no_gc;
if constexpr (is_resume) {
// To resume multiple stacks at once, we have to update the parent of the
// tail of the list:
wasm::StackMemory* tail = to;
while (tail->jmpbuf()->parent != nullptr) {
tail = tail->jmpbuf()->parent;
}
tail->jmpbuf()->parent = from;
} else {
// Return or suspend.
static_assert(expected_target_state == wasm::JumpBuffer::Inactive);
wasm::StackMemory* prev = from;
wasm::StackMemory* skipped = from->jmpbuf()->parent;
while (skipped != to) {
// Should have been checked already.
DCHECK(!skipped->jmpbuf()->is_on_central_stack);
prev = skipped;
skipped = skipped->jmpbuf()->parent;
}
// Clear the parent to mark the end of the suspended stack chain.
prev->jmpbuf()->parent = nullptr;
}
uintptr_t limit = reinterpret_cast<uintptr_t>(to->jmpbuf()->stack_limit);
// Synchronize the stack limit with the active continuation for
// stack-switching. This can be done before or after changing the stack
// pointer itself, as long as we update both before the next stack check.
// {StackGuard::SetStackLimitForStackSwitching} doesn't update the value of
// the jslimit if it contains a sentinel value, and it is also thread-safe. So
// if an interrupt is requested before, during or after this call, it will be
// preserved and handled at the next stack check.
stack_guard()->SetStackLimitForStackSwitching(limit);
// Update the central stack info.
if (!thread_local_top()->is_on_central_stack_flag_ &&
to->jmpbuf()->is_on_central_stack) {
DCHECK(is_suspend || is_return);
DCHECK_EQ(expected_target_state, wasm::JumpBuffer::Inactive);
thread_local_top()->is_on_central_stack_flag_ = true;
thread_local_top()->central_stack_sp_ = to->central_stack_sp();
#if DEBUG
from->set_central_stack_sp(kNullAddress);
#endif
thread_local_top()->central_stack_limit_ =
reinterpret_cast<Address>(to->jmpbuf()->stack_limit);
} else if (thread_local_top()->is_on_central_stack_flag_ &&
!to->jmpbuf()->is_on_central_stack) {
thread_local_top()->is_on_central_stack_flag_ = false;
if (is_resume) {
// Record the current central stack SP, we will switch back to it for
// non-wasm calls. Save the previous value to restore it when we return to
// this stack.
from->set_central_stack_sp(thread_local_top()->central_stack_sp_);
thread_local_top()->central_stack_sp_ = from->jmpbuf()->sp;
thread_local_top()->central_stack_limit_ =
reinterpret_cast<Address>(from->jmpbuf()->stack_limit);
}
}
}
template void
Isolate::SwitchStacks<wasm::JumpBuffer::Suspended, wasm::JumpBuffer::Inactive>(
wasm::StackMemory* from, wasm::StackMemory* to, Address sp, Address fp,
Address pc);
template void
Isolate::SwitchStacks<wasm::JumpBuffer::Inactive, wasm::JumpBuffer::Suspended>(
wasm::StackMemory* from, wasm::StackMemory* to, Address sp, Address fp,
Address pc);
template void
Isolate::SwitchStacks<wasm::JumpBuffer::Retired, wasm::JumpBuffer::Inactive>(
wasm::StackMemory* from, wasm::StackMemory* to, Address sp, Address fp,
Address pc);
void Isolate::RetireWasmStack(wasm::StackMemory* stack) {
if (!stack->stack_obj().is_null()) {
// Clear the owning {WasmStackObject}'s external pointer to prevent a UAF.
stack->stack_obj()->set_stack(this, nullptr);
stack->set_stack_obj({});
}
size_t index = stack->index();
// We can only return from a stack that was still in the global list.
DCHECK_LT(index, wasm_stacks().size());
std::unique_ptr<wasm::StackMemory> stack_ptr =
std::move(wasm_stacks()[index]);
DCHECK_EQ(stack_ptr.get(), stack);
if (index != wasm_stacks().size() - 1) {
wasm_stacks()[index] = std::move(wasm_stacks().back());
wasm_stacks()[index]->set_index(index);
}
wasm_stacks().pop_back();
for (size_t i = 0; i < wasm_stacks().size(); ++i) {
SLOW_DCHECK(wasm_stacks()[i]->index() == i);
}
stack_pool().Add(std::move(stack_ptr));
}
wasm::WasmOrphanedGlobalHandle* Isolate::NewWasmOrphanedGlobalHandle() {
return wasm::WasmEngine::NewOrphanedGlobalHandle(&wasm_orphaned_handle_);
}
#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();
}
#ifdef DEBUG
std::atomic<size_t> Isolate::non_disposed_isolates_;
#endif // DEBUG
// static
Isolate* Isolate::New() { return New(IsolateGroup::AcquireDefault()); }
// static
Isolate* Isolate::New(IsolateGroup* group) { return Allocate(group); }
// static
Isolate* Isolate::Allocate(IsolateGroup* group) {
// v8::V8::Initialize() must be called before creating any isolates.
DCHECK_NOT_NULL(V8::GetCurrentPlatform());
// Allocate Isolate itself on C++ heap, ensuring page alignment.
void* isolate_ptr = base::AlignedAlloc(sizeof(Isolate), kMinimumOSPageSize);
// IsolateAllocator manages the virtual memory resources for the Isolate.
Isolate* isolate = new (isolate_ptr) Isolate(group);
#ifdef V8_ENABLE_SANDBOX_HARDWARE_SUPPORT
// TODO(427392572): sandboxed code currently still requires write access to
// the Isolate object. This is unsafe and we'll need to fix that eventually.
SandboxHardwareSupport::RegisterUnsafeSandboxExtensionMemory(
reinterpret_cast<Address>(isolate_ptr), sizeof(Isolate));
#endif
#ifdef DEBUG
non_disposed_isolates_++;
#endif // DEBUG
return isolate;
}
// static
void Isolate::Delete(Isolate* isolate) {
Deinitialize(isolate);
Free(isolate);
}
// static
void Isolate::Deinitialize(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();
Isolate* saved_isolate = isolate->TryGetCurrent();
SetIsolateThreadLocals(isolate, nullptr);
isolate->set_thread_id(ThreadId::Current());
isolate->heap()->SetStackStart();
isolate->Deinit();
#ifdef DEBUG
non_disposed_isolates_--;
#endif // DEBUG
IsolateGroup* group = isolate->isolate_group();
isolate->~Isolate();
// Only release the group once all other Isolate members have been destroyed.
group->Release();
// Restore the previous current isolate.
SetIsolateThreadLocals(saved_isolate, saved_data);
}
// static
void Isolate::Free(Isolate* isolate) {
DCHECK_NOT_NULL(isolate);
// Free the memory allocated for the Isolate.
base::AlignedFree(isolate);
}
void Isolate::SetUpFromReadOnlyArtifacts(ReadOnlyArtifacts* artifacts) {
DCHECK_NOT_NULL(artifacts);
int id = artifacts->initial_next_unique_sfi_id();
InitializeNextUniqueSfiId(id);
DCHECK_NOT_NULL(artifacts->read_only_heap());
DCHECK_IMPLIES(read_only_heap_ != nullptr,
read_only_heap_ == artifacts->read_only_heap());
read_only_heap_ = artifacts->read_only_heap();
heap_.SetUpFromReadOnlyHeap(read_only_heap_);
}
v8::PageAllocator* Isolate::page_allocator() const {
return isolate_group()->page_allocator();
}
Isolate::Isolate(IsolateGroup* isolate_group)
: isolate_data_(this, isolate_group),
isolate_group_(isolate_group),
id_(isolate_counter.fetch_add(1, std::memory_order_relaxed)),
allocator_(new TracingAccountingAllocator(this)),
traced_handles_(this),
builtins_(this),
#if defined(DEBUG) || defined(VERIFY_HEAP)
num_active_deserializers_(0),
#endif
logger_(new Logger()),
detailed_source_positions_for_profiling_(v8_flags.detailed_line_info),
persistent_handles_list_(new PersistentHandlesList()),
jitless_(v8_flags.jitless),
next_unique_sfi_id_(0),
next_module_async_evaluation_ordinal_(
SourceTextModule::kFirstAsyncEvaluationOrdinal),
cancelable_task_manager_(new CancelableTaskManager()),
#if defined(V8_ENABLE_ETW_STACK_WALKING)
etw_tracing_enabled_(false),
etw_trace_interpreted_frames_(v8_flags.interpreted_frames_native_stack),
etw_in_rundown_(false),
#endif // V8_ENABLE_ETW_STACK_WALKING
stack_size_(v8_flags.stack_size * KB) {
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();
#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();
#if V8_ENABLE_WEBASSEMBLY
// If we are in production V8 and not in mksnapshot we have to pass the
// landing pad builtin to the WebAssembly TrapHandler.
// TODO(ahaas): Isolate creation is the earliest point in time when builtins
// are available, so we cannot set the landing pad earlier at the moment.
// However, if builtins ever get loaded during process initialization time,
// then the initialization of the trap handler landing pad should also go
// there.
// TODO(ahaas): The code of the landing pad does not have to be a builtin,
// we could also just move it to the trap handler, and implement it e.g. with
// inline assembly. It's not clear if that's worth it.
if (Isolate::CurrentEmbeddedBlobCodeSize() && !v8_flags.wasm_jitless) {
Address landing_pad =
Builtins::EmbeddedEntryOf(Builtin::kWasmTrapHandlerLandingPad);
i::trap_handler::SetLandingPad(landing_pad);
}
#endif // V8_ENABLE_WEBASSEMBLY
}
void Isolate::CheckIsolateLayout() {
#ifdef V8_ENABLE_SANDBOX
static_assert(static_cast<int>(ExternalPointerTable::BaseOffset()) ==
Internals::kExternalEntityTableBasePointerOffset);
static_assert(static_cast<int>(TrustedPointerTable::BaseOffset()) ==
Internals::kExternalEntityTableBasePointerOffset);
static_assert(static_cast<int>(JSDispatchTable::BaseOffset()) ==
Internals::kExternalEntityTableBasePointerOffset);
static_assert(static_cast<int>(sizeof(ExternalPointerTable)) ==
Internals::kExternalEntityTableSize);
static_assert(static_cast<int>(sizeof(TrustedPointerTable)) ==
Internals::kExternalEntityTableSize);
static_assert(static_cast<int>(sizeof(JSDispatchTable)) ==
Internals::kExternalEntityTableSize);
#endif
static_assert(OFFSET_OF(Isolate, isolate_data_) == 0);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.stack_guard_)) ==
Internals::kIsolateStackGuardOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.is_marking_flag_)) ==
Internals::kVariousBooleanFlagsOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.error_message_param_)) ==
Internals::kErrorMessageParamOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.builtin_tier0_entry_table_)) ==
Internals::kBuiltinTier0EntryTableOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.builtin_tier0_table_)) ==
Internals::kBuiltinTier0TableOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.new_allocation_info_)) ==
Internals::kNewAllocationInfoOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.old_allocation_info_)) ==
Internals::kOldAllocationInfoOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.fast_c_call_caller_fp_)) ==
Internals::kIsolateFastCCallCallerFpOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.fast_c_call_caller_pc_)) ==
Internals::kIsolateFastCCallCallerPcOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.cage_base_)) ==
Internals::kIsolateCageBaseOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.long_task_stats_counter_)) ==
Internals::kIsolateLongTaskStatsCounterOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.stack_guard_)) ==
Internals::kIsolateStackGuardOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.thread_local_top_)) ==
Internals::kIsolateThreadLocalTopOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.handle_scope_data_)) ==
Internals::kIsolateHandleScopeDataOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.handle_scope_implementer_)) ==
Internals::kIsolateHandleScopeImplementerOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.embedder_data_)) ==
Internals::kIsolateEmbedderDataOffset);
#ifdef V8_COMPRESS_POINTERS
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.external_pointer_table_)) ==
Internals::kIsolateExternalPointerTableOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.shared_external_pointer_table_)) ==
Internals::kIsolateSharedExternalPointerTableAddressOffset);
#endif
#ifdef V8_ENABLE_SANDBOX
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.trusted_cage_base_)) ==
Internals::kIsolateTrustedCageBaseOffset);
static_assert(static_cast<int>(
OFFSET_OF(Isolate, isolate_data_.trusted_pointer_table_)) ==
Internals::kIsolateTrustedPointerTableOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.shared_trusted_pointer_table_)) ==
Internals::kIsolateSharedTrustedPointerTableAddressOffset);
#endif
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.js_dispatch_table_)) ==
Internals::kIsolateJSDispatchTableOffset);
static_assert(static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.api_callback_thunk_argument_)) ==
Internals::kIsolateApiCallbackThunkArgumentOffset);
static_assert(
static_cast<int>(OFFSET_OF(
Isolate, isolate_data_.continuation_preserved_embedder_data_)) ==
Internals::kContinuationPreservedEmbedderDataOffset);
static_assert(
static_cast<int>(OFFSET_OF(Isolate, isolate_data_.roots_table_)) ==
Internals::kIsolateRootsOffset);
CHECK(IsAligned(reinterpret_cast<Address>(&isolate_data_),
kIsolateDataAlignment));
static_assert(Internals::kStackGuardSize == sizeof(StackGuard));
static_assert(Internals::kBuiltinTier0TableSize ==
Builtins::kBuiltinTier0Count * kSystemPointerSize);
static_assert(Internals::kBuiltinTier0EntryTableSize ==
Builtins::kBuiltinTier0Count * kSystemPointerSize);
// Ensure that certain hot IsolateData fields fall into the same CPU cache
// line.
constexpr size_t kCacheLineSize = 64;
static_assert(OFFSET_OF(Isolate, isolate_data_) == 0);
// Fields written on every CEntry/CallApiCallback/CallApiGetter call.
// See MacroAssembler::EnterExitFrame/LeaveExitFrame.
constexpr size_t kCEntryFPCacheLine = RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, thread_local_top_.c_entry_fp_));
static_assert(kCEntryFPCacheLine ==
RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, thread_local_top_.c_function_)));
static_assert(kCEntryFPCacheLine ==
RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, thread_local_top_.context_)));
static_assert(
kCEntryFPCacheLine ==
RoundDown<kCacheLineSize>(OFFSET_OF(
IsolateData, thread_local_top_.topmost_script_having_context_)));
static_assert(kCEntryFPCacheLine ==
RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, thread_local_top_.last_api_entry_)));
// Fields written on every MacroAssembler::CallCFunction call.
static_assert(RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, fast_c_call_caller_fp_)) ==
RoundDown<kCacheLineSize>(
OFFSET_OF(IsolateData, fast_c_call_caller_pc_)));
// LinearAllocationArea objects must not cross cache line boundary.
static_assert(
RoundDown<kCacheLineSize>(OFFSET_OF(IsolateData, new_allocation_info_)) ==
RoundDown<kCacheLineSize>(OFFSET_OF(IsolateData, new_allocation_info_) +
sizeof(LinearAllocationArea) - 1));
static_assert(
RoundDown<kCacheLineSize>(OFFSET_OF(IsolateData, old_allocation_info_)) ==
RoundDown<kCacheLineSize>(OFFSET_OF(IsolateData, old_allocation_info_) +
sizeof(LinearAllocationArea) - 1));
}
void Isolate::ClearSerializerData() {
delete external_reference_map_;
external_reference_map_ = nullptr;
}
// When profiling status changes, call this function to update the single bool
// cache.
void Isolate::UpdateLogObjectRelocation() {
log_object_relocation_ =
v8_flags.verify_predictable || IsLoggingCodeCreation() ||
v8_file_logger()->is_logging() ||
(heap()->heap_profiler() != nullptr &&
heap()->heap_profiler()->is_tracking_object_moves()) ||
heap()->has_heap_object_allocation_tracker();
}
#ifdef V8_ENABLE_REGEXP_DIAGNOSTICS
void Isolate::PrintAndClearRegExpSubjectStrings() {
if (trace_regexp_exec_subject_indices_.empty()) return;
DCHECK(v8_flags.trace_regexp_exec_ool_subjects);
PrintF("--- RegExp Trace Subject Strings ---\n");
for (size_t i = 0; i < trace_regexp_exec_subject_indices_.size(); ++i) {
Handle<String> subject = Cast<String>(
eternal_handles()->Get(trace_regexp_exec_subject_indices_[i]));
std::unique_ptr<char[]> c_str = subject->ToCString();
PrintF("Subject #%zu: %s\n", i, c_str.get());
}
trace_regexp_exec_subject_indices_.clear();
trace_regexp_exec_subject_hash_to_index_.clear();
}
#endif // V8_ENABLE_REGEXP_DIAGNOSTICS
void Isolate::CompactMicrotaskQueues() {
microtask_queues_.erase(
std::remove_if(microtask_queues_.begin(), microtask_queues_.end(),
[](const auto& weak_ptr) { return !weak_ptr; }),
microtask_queues_.end());
}
void Isolate::RegisterMicrotaskQueue(MicrotaskQueue* queue) {
CompactMicrotaskQueues();
microtask_queues_.push_back(queue);
}
void Isolate::Deinit() {
TRACE_ISOLATE(deinit);
#ifdef V8_ENABLE_REGEXP_DIAGNOSTICS
PrintAndClearRegExpSubjectStrings();
#endif // V8_ENABLE_REGEXP_DIAGNOSTICS
#if defined(V8_USE_PERFETTO)
PerfettoLogger::UnregisterIsolate(this);
#endif // defined(V8_USE_PERFETTO)
// All client isolates should already be detached when the shared heap isolate
// tears down.
if (is_shared_space_isolate()) {
global_safepoint()->AssertNoClientsOnTearDown();
}
if (GlobalSafepoint* safepoint = global_safepoint();
safepoint && this != safepoint->shared_space_isolate()) {
IgnoreLocalGCRequests ignore_gc_requests(heap());
main_thread_local_heap()->ExecuteMainThreadWhileParked(
[safepoint]() { safepoint->clients_mutex_.Lock(); });
}
#ifdef DEBUG
// Don't run Builtins::VerifyGetJSBuiltinState() during snapshot creation.
if (v8_flags.verify_get_js_builtin_state && !serializer_enabled()) {
const bool kAllowNonInitialState = true;
builtins()->VerifyGetJSBuiltinState(kAllowNonInitialState);
}
#endif
// We start with the heap tear down so that releasing managed objects does
// not cause a GC.
heap_.StartTearDown();
DisallowGarbageCollection no_gc;
IgnoreLocalGCRequests ignore_gc_requests(heap());
#if V8_ENABLE_WEBASSEMBLY && V8_ENABLE_DRUMBRAKE
if (v8_flags.wasm_jitless) {
wasm::WasmInterpreter::NotifyIsolateDisposal(this);
} else if (v8_flags.wasm_enable_exec_time_histograms &&
v8_flags.slow_histograms) {
wasm_execution_timer_->Terminate();
}
#endif // V8_ENABLE_WEBASSEMBLY && V8_ENABLE_DRUMBRAKE
tracing_cpu_profiler_.reset();
if (v8_flags.stress_sampling_allocation_profiler > 0) {
heap()->heap_profiler()->StopSamplingHeapProfiler();
}
metrics_recorder_->NotifyIsolateDisposal();
recorder_context_id_map_.clear();
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_->StartTearDown();
}
if (v8_flags.print_deopt_stress) {
PrintF(stdout, "=== Stress deopt counter: %" PRIu64 "\n",
isolate_data_.stress_deopt_count_);
}
// We must stop the logger before we tear down other components.
sampler::Sampler* sampler = v8_file_logger_->sampler();
if (sampler && sampler->IsActive()) sampler->Stop();
v8_file_logger_->StopProfilerThread();
FreeThreadResources();
// Stop concurrent tasks before destroying resources since they might still
// use those.
cancelable_task_manager()->CancelAndWait();
// Delete any remaining regexp::ResultVector instances.
for (int32_t* v : active_dynamic_regexp_result_vectors_) {
#ifdef V8_ENABLE_SANDBOX_HARDWARE_SUPPORT
SandboxFree(v);
#else
delete[] v;
#endif
}
active_dynamic_regexp_result_vectors_.clear();
// Cancel all compiler tasks.
#ifdef V8_ENABLE_SPARKPLUG
delete baseline_batch_compiler_;
baseline_batch_compiler_ = nullptr;
#endif // V8_ENABLE_SPARKPLUG
#ifdef V8_ENABLE_MAGLEV
delete maglev_concurrent_dispatcher_;
maglev_concurrent_dispatcher_ = nullptr;
#endif // V8_ENABLE_MAGLEV
if (lazy_compile_dispatcher_) {
lazy_compile_dispatcher_->AbortAll();
lazy_compile_dispatcher_.reset();
}
if (concurrent_recompilation_enabled()) {
optimizing_compile_dispatcher_->FinishTearDown();
delete optimizing_compile_dispatcher_;
optimizing_compile_dispatcher_ = nullptr;
}
// At this point there are no more background threads left in this isolate.
heap_.safepoint()->AssertMainThreadIsOnlyThread();
// Tear down data that requires the shared heap before detaching.
heap_.TearDownWithSharedHeap();
DumpAndResetBuiltinsProfileData();
// Detach from the isolate group and then unlock the mutex.
if (GlobalSafepoint* safepoint = global_safepoint();
safepoint && this != safepoint->shared_space_isolate()) {
safepoint->RemoveClient(this);
safepoint->clients_mutex_.Unlock();
}
shared_space_isolate_.reset();
// Since there are no other threads left, we can lock this mutex without any
// ceremony. This signals to the tear down code that we are in a safepoint.
base::RecursiveMutexGuard safepoint(&heap_.safepoint()->local_heaps_mutex_);
ReleaseSharedPtrs();
builtins_.TearDown();
bootstrapper_->TearDown();
if (tiering_manager_ != nullptr) {
delete tiering_manager_;
tiering_manager_ = nullptr;
}
#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();
// Contains zones that should be released to the page pool before the heap is
// torn down.
delete ast_string_constants_;
ast_string_constants_ = nullptr;
heap_.TearDown();
isolate_group()->RemoveIsolate(this);
delete inner_pointer_to_code_cache_;
inner_pointer_to_code_cache_ = nullptr;
main_thread_local_isolate_.reset();
FILE* logfile = v8_file_logger_->TearDownAndGetLogFile();
if (logfile != nullptr) base::Fclose(logfile);
#if defined(V8_ENABLE_ETW_STACK_WALKING)
if (v8_flags.enable_etw_stack_walking ||
v8_flags.enable_etw_by_custom_filter_only) {
ETWJITInterface::RemoveIsolate(this);
}
#endif // defined(V8_ENABLE_ETW_STACK_WALKING)
#if V8_ENABLE_WEBASSEMBLY
wasm::GetWasmEngine()->RemoveIsolate(this);
delete wasm_code_look_up_cache_;
wasm_code_look_up_cache_ = nullptr;
#endif // V8_ENABLE_WEBASSEMBLY
TearDownEmbeddedBlob();
delete interpreter_;
interpreter_ = nullptr;
delete logger_;
logger_ = nullptr;
delete root_index_map_;
root_index_map_ = nullptr;
delete compiler_zone_;
compiler_zone_ = nullptr;
compiler_cache_ = nullptr;
SetCodePages(nullptr);
ClearSerializerData();
if (OwnsStringTables()) {
string_forwarding_table()->TearDown();
} else {
DCHECK_NULL(string_table_.get());
DCHECK_NULL(string_forwarding_table_.get());
}
if (!is_shared_space_isolate()) {
DCHECK_NULL(shared_struct_type_registry_.get());
}
#ifdef V8_COMPRESS_POINTERS
external_pointer_table().TearDownSpace(
heap()->young_external_pointer_space());
external_pointer_table().TearDownSpace(heap()->old_external_pointer_space());
external_pointer_table().DetachSpaceFromReadOnlySegments(
heap()->read_only_external_pointer_space());
external_pointer_table().TearDownSpace(
heap()->read_only_external_pointer_space());
external_pointer_table().TearDown();
if (owns_shareable_data()) {
shared_external_pointer_table().TearDownSpace(
shared_external_pointer_space());
shared_external_pointer_table().TearDown();
delete isolate_data_.shared_external_pointer_table_;
isolate_data_.shared_external_pointer_table_ = nullptr;
delete shared_external_pointer_space_;
shared_external_pointer_space_ = nullptr;
}
cpp_heap_pointer_table().TearDownSpace(heap()->cpp_heap_pointer_space());
cpp_heap_pointer_table().TearDown();
#endif // V8_COMPRESS_POINTERS
#ifdef V8_ENABLE_SANDBOX
trusted_pointer_table().TearDownSpace(heap()->trusted_pointer_space());
trusted_pointer_table().DetachSpaceFromReadOnlySegments(
heap()->read_only_trusted_pointer_space());
trusted_pointer_table().TearDownSpace(
heap()->read_only_trusted_pointer_space());
trusted_pointer_table().TearDown();
if (owns_shareable_data()) {
shared_trusted_pointer_table().TearDownSpace(
shared_trusted_pointer_space());
shared_trusted_pointer_table().TearDown();
delete isolate_data_.shared_trusted_pointer_table_;
isolate_data_.shared_trusted_pointer_table_ = nullptr;
delete shared_trusted_pointer_space_;
shared_trusted_pointer_space_ = nullptr;
}
#endif // V8_ENABLE_SANDBOX
js_dispatch_table().TearDownSpace(heap()->js_dispatch_table_space());
#if V8_STATIC_DISPATCH_HANDLES_BOOL
js_dispatch_table().DetachSpaceFromReadOnlySegments(
heap()->read_only_js_dispatch_table_space());
#endif // V8_STATIC_DISPATCH_HANDLES_BOOL
js_dispatch_table().TearDownSpace(
heap()->read_only_js_dispatch_table_space());
js_dispatch_table().TearDown();
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
thread_data_table_.RemoveAllThreads();
}
}
void Isolate::SetIsolateThreadLocals(Isolate* isolate,
PerIsolateThreadData* data) {
Isolate::SetCurrent(isolate);
LocalHeap::SetCurrent(isolate && isolate->main_thread_local_isolate()
? isolate->main_thread_local_heap()
: nullptr);
g_current_per_isolate_thread_data_ = data;
#ifdef V8_COMPRESS_POINTERS_IN_MULTIPLE_CAGES
V8HeapCompressionScheme::InitBase(isolate ? isolate->cage_base()
: kNullAddress);
TrustedSpaceCompressionScheme::InitBase(
isolate ? isolate->isolate_group()->GetTrustedPtrComprCageBase()
: kNullAddress);
IsolateGroup::set_current(isolate ? isolate->isolate_group() : nullptr);
#ifdef V8_EXTERNAL_CODE_SPACE
ExternalCodeCompressionScheme::InitBase(isolate ? isolate->code_cage_base()
: kNullAddress);
#endif
#ifdef V8_ENABLE_SANDBOX
Sandbox::set_current(isolate ? isolate->isolate_group()->sandbox() : nullptr);
#endif
#endif // V8_COMPRESS_POINTERS_IN_MULTIPLE_CAGES
if (isolate && isolate->main_thread_local_isolate()) {
WriteBarrier::SetForThread(
isolate->main_thread_local_heap()->marking_barrier());
} else {
WriteBarrier::SetForThread(nullptr);
}
}
Isolate::~Isolate() {
TRACE_ISOLATE(destructor);
DCHECK_NULL(current_deoptimizer_);
// The entry stack must be empty when we get here.
DCHECK(entry_stack_ == nullptr ||
entry_stack_.load()->previous_item == nullptr);
delete entry_stack_;
entry_stack_ = nullptr;
delete date_cache_;
date_cache_ = nullptr;
regexp::Stack::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 define_own_stub_cache_;
define_own_stub_cache_ = nullptr;
delete materialized_object_store_;
materialized_object_store_ = nullptr;
delete v8_file_logger_;
v8_file_logger_ = nullptr;
delete code_tracer();
set_code_tracer(nullptr);
delete compilation_cache_;
compilation_cache_ = nullptr;
delete bootstrapper_;
bootstrapper_ = nullptr;
delete thread_manager_;
thread_manager_ = nullptr;
bigint_processor_->Destroy();
delete global_handles_;
global_handles_ = nullptr;
delete eternal_handles_;
eternal_handles_ = nullptr;
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmEngine::FreeAllOrphanedGlobalHandles(wasm_orphaned_handle_);
#endif
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;
DCHECK_NULL(builtins_effects_analyzer_);
// Assert that |default_microtask_queue_| is the last MicrotaskQueue instance.
CompactMicrotaskQueues();
if (DEBUG_BOOL && default_microtask_queue_) {
DCHECK_EQ(microtask_queues_.size(), 1);
}
default_microtask_queue_ = nullptr;
// isolate_group_ released in caller, to ensure that all member destructors
// run before potentially unmapping the isolate's VirtualMemoryArea.
}
void Isolate::InitializeThreadLocal() {
thread_local_top()->Initialize(this);
// This method might be called on a thread that's not bound to any Isolate
// and thus pointer compression schemes might have cage base value unset.
// So, allow heap access here to let the checks work.
i::PtrComprCageAccessScope ptr_compr_cage_access_scope(this);
clear_exception();
clear_pending_message();
}
void Isolate::SetTerminationOnExternalTryCatch() {
DCHECK_IMPLIES(v8_flags.strict_termination_checks,
is_execution_terminating());
if (try_catch_handler() == nullptr) return;
try_catch_handler()->set_can_continue(false);
try_catch_handler()->exception_ = reinterpret_cast<void*>(
ReadOnlyRoots(heap()).termination_exception().ptr());
}
bool Isolate::PropagateExceptionToExternalTryCatch(
ExceptionHandlerType top_handler) {
Tagged<Object> exception = this->exception();
if (top_handler == ExceptionHandlerType::kJavaScriptHandler) return false;
if (top_handler == ExceptionHandlerType::kNone) return true;
DCHECK_EQ(ExceptionHandlerType::kExternalTryCatch, top_handler);
if (!is_catchable_by_javascript(exception)) {
SetTerminationOnExternalTryCatch();
} else {
v8::TryCatch* handler = try_catch_handler();
DCHECK(IsJSMessageObject(pending_message()) ||
IsTheHole(pending_message()));
handler->set_can_continue(true);
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;
}
namespace {
inline Tagged<FunctionTemplateInfo> GetTargetFunctionTemplateInfo(
const v8::FunctionCallbackInfo<v8::Value>& info) {
Tagged<Object> target = FunctionCallbackArguments::GetTarget(info);
if (IsFunctionTemplateInfo(target)) {
return Cast<FunctionTemplateInfo>(target);
}
CHECK(Is<JSFunction>(target));
Tagged<SharedFunctionInfo> shared_info = Cast<JSFunction>(target)->shared();
return shared_info->api_func_data();
}
} // namespace
void Isolate::NotifyExceptionPropagationCallback() {
DCHECK_NOT_NULL(exception_propagation_callback_);
// Try to figure out whether the exception was thrown directly from an
// Api callback and if it's the case then call the
// |exception_propagation_callback_| with relevant data.
ExternalCallbackScope* ext_callback_scope = external_callback_scope();
StackFrameIterator it(this);
if (it.done() && !ext_callback_scope) {
// The exception was thrown directly by embedder code without crossing
// "C++ -> JS" or "C++ -> Api callback" boundary.
return;
}
if (it.done() ||
(ext_callback_scope &&
ext_callback_scope->JSStackComparableAddress() < it.frame()->fp())) {
// There were no crossings of "C++ -> JS" boundary at all or they happened
// earlier than the last crossing of the "C++ -> Api callback" boundary.
// In this case all the data about Api callback is available in the
// |ext_callback_scope| object.
DCHECK_NOT_NULL(ext_callback_scope);
v8::ExceptionContext kind = ext_callback_scope->exception_context();
switch (kind) {
case v8::ExceptionContext::kConstructor:
case v8::ExceptionContext::kOperation: {
DCHECK_NOT_NULL(ext_callback_scope->callback_info());
auto callback_info =
reinterpret_cast<const v8::FunctionCallbackInfo<v8::Value>*>(
ext_callback_scope->callback_info());
DirectHandle<JSReceiver> receiver =
Utils::OpenDirectHandle(*callback_info->This());
DirectHandle<FunctionTemplateInfo> function_template_info(
GetTargetFunctionTemplateInfo(*callback_info), this);
ReportExceptionFunctionCallback(receiver, function_template_info, kind);
return;
}
case v8::ExceptionContext::kAttributeGet:
case v8::ExceptionContext::kAttributeSet:
case v8::ExceptionContext::kIndexedQuery:
case v8::ExceptionContext::kIndexedGetter:
case v8::ExceptionContext::kIndexedDescriptor:
case v8::ExceptionContext::kIndexedSetter:
case v8::ExceptionContext::kIndexedDefiner:
case v8::ExceptionContext::kIndexedDeleter:
case v8::ExceptionContext::kNamedQuery:
case v8::ExceptionContext::kNamedGetter:
case v8::ExceptionContext::kNamedDescriptor:
case v8::ExceptionContext::kNamedSetter:
case v8::ExceptionContext::kNamedDefiner:
case v8::ExceptionContext::kNamedDeleter:
case v8::ExceptionContext::kNamedEnumerator: {
DCHECK_NOT_NULL(ext_callback_scope->callback_info());
auto callback_info =
reinterpret_cast<const v8::PropertyCallbackInfo<v8::Value>*>(
ext_callback_scope->callback_info());
DirectHandle<Object> holder =
Utils::OpenDirectHandle(*callback_info->Holder());
DCHECK(IsJSReceiver(*holder));
using PCA = PropertyCallbackArguments;
DirectHandle<Name> name;
if (PCA::IsNamed(*callback_info)) {
name = PCA::GetPropertyName(*callback_info);
} else {
uint32_t index = PCA::GetPropertyIndex(*callback_info);
// TODO(ishell): consider just querying the cache without updating it.
name = factory()->SizeToString(index);
}
// Currently we call only ApiGetters from JS code.
ReportExceptionPropertyCallback(Cast<JSReceiver>(holder), name, kind);
return;
}
case v8::ExceptionContext::kUnknown:
DCHECK_WITH_MSG(kind != v8::ExceptionContext::kUnknown,
"ExternalCallbackScope should not use "
"v8::ExceptionContext::kUnknown exception context");
return;
}
UNREACHABLE();
}
// There were no crossings of "C++ -> Api callback" boundary or they
// happened before crossing the "C++ -> JS" boundary.
// In this case all the data about Api callback is available in the
// topmost "JS -> Api callback" frame (ApiCallbackExitFrame or
// ApiAccessorExitFrame).
DCHECK(!it.done());
StackFrame::Type frame_type = it.frame()->type();
switch (frame_type) {
case StackFrame::API_CALLBACK_EXIT:
case StackFrame::API_CONSTRUCT_EXIT: {
ApiCallbackExitFrame* frame = ApiCallbackExitFrame::cast(it.frame());
DirectHandle<JSReceiver> receiver(Cast<JSReceiver>(frame->receiver()),
this);
DirectHandle<FunctionTemplateInfo> function_template_info =
frame->GetFunctionTemplateInfo();
v8::ExceptionContext callback_kind =
frame_type == StackFrame::API_CONSTRUCT_EXIT
? v8::ExceptionContext::kConstructor
: v8::ExceptionContext::kOperation;
ReportExceptionFunctionCallback(receiver, function_template_info,
callback_kind);
return;
}
case StackFrame::API_NAMED_ACCESSOR_EXIT: {
ApiNamedAccessorExitFrame* frame =
ApiNamedAccessorExitFrame::cast(it.frame());
DirectHandle<Object> holder(frame->holder(), this);
DirectHandle<Name> name(frame->property_name(), this);
DCHECK(IsJSReceiver(*holder));
// Currently we call only ApiGetters from JS code.
ReportExceptionPropertyCallback(Cast<JSReceiver>(holder), name,
v8::ExceptionContext::kAttributeGet);
return;
}
case StackFrame::API_INDEXED_ACCESSOR_EXIT:
// These frames are not created yet.
UNREACHABLE();
case StackFrame::TURBOFAN_JS:
// This must be a fast Api call.
CHECK(it.frame()->InFastCCall());
// TODO(ishell): support fast Api calls.
return;
case StackFrame::EXIT:
case StackFrame::BUILTIN_EXIT:
// This is a regular runtime function or C++ builtin.
return;
#if V8_ENABLE_WEBASSEMBLY
case StackFrame::WASM:
case StackFrame::WASM_SEGMENT_START:
// No more info.
return;
#endif // V8_ENABLE_WEBASSEMBLY
default:
// Other types are not expected, so just hard-crash.
CHECK_NE(frame_type, frame_type);
}
}
void Isolate::ReportExceptionFunctionCallback(
DirectHandle<JSReceiver> receiver,
DirectHandle<FunctionTemplateInfo> function,
v8::ExceptionContext exception_context) {
DCHECK(exception_context == v8::ExceptionContext::kConstructor ||
exception_context == v8::ExceptionContext::kOperation);
DCHECK_NOT_NULL(exception_propagation_callback_);
// Ignore exceptions that we can't extend.
if (!IsJSReceiver(this->exception())) return;
DirectHandle<JSReceiver> exception(Cast<JSReceiver>(this->exception()), this);
DirectHandle<Object> maybe_message(pending_message(), this);
DirectHandle<String> property_name =
IsUndefined(function->class_name())
? factory()->empty_string()
: Handle<String>(Cast<String>(function->class_name()), this);
DirectHandle<String> interface_name =
IsUndefined(function->interface_name())
? factory()->empty_string()
: Handle<String>(Cast<String>(function->interface_name()), this);
if (exception_context != ExceptionContext::kConstructor) {
exception_context =
static_cast<ExceptionContext>(function->exception_context());
}
{
v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(this);
// Ignore any exceptions thrown inside the callback and rethrow the
// original exception/message.
TryCatch try_catch(v8_isolate);
exception_propagation_callback_(v8::ExceptionPropagationMessage(
v8_isolate, v8::Utils::ToLocal(exception),
v8::Utils::ToLocal(interface_name), v8::Utils::ToLocal(property_name),
exception_context));
try_catch.Reset();
}
ReThrow(*exception, *maybe_message);
}
void Isolate::ReportExceptionPropertyCallback(
DirectHandle<JSReceiver> holder, DirectHandle<Name> name,
v8::ExceptionContext exception_context) {
DCHECK_NOT_NULL(exception_propagation_callback_);
if (!IsJSReceiver(this->exception())) return;
DirectHandle<JSReceiver> exception(Cast<JSReceiver>(this->exception()), this);
DirectHandle<Object> maybe_message(pending_message(), this);
DirectHandle<String> property_name;
std::ignore = Name::ToFunctionName(this, name).ToHandle(&property_name);
DirectHandle<String> interface_name =
JSReceiver::GetConstructorName(this, holder);
{
v8::Isolate* v8_isolate = reinterpret_cast<v8::Isolate*>(this);
// Ignore any exceptions thrown inside the callback and rethrow the
// original exception/message.
TryCatch try_catch(v8_isolate);
exception_propagation_callback_(v8::ExceptionPropagationMessage(
v8_isolate, v8::Utils::ToLocal(exception),
v8::Utils::ToLocal(interface_name), v8::Utils::ToLocal(property_name),
exception_context));
try_catch.Reset();
}
ReThrow(*exception, *maybe_message);
}
void Isolate::SetExceptionPropagationCallback(
ExceptionPropagationCallback callback) {
exception_propagation_callback_ = callback;
}
bool Isolate::InitializeCounters() {
if (async_counters_) return false;
async_counters_ = std::make_shared<Counters>(this);
return true;
}
void Isolate::InitializeLoggingAndCounters() {
if (v8_file_logger_ == nullptr) {
v8_file_logger_ = new V8FileLogger(this);
}
InitializeCounters();
}
namespace {
void FinalizeBuiltinCodeObjects(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());
EmbeddedData d = EmbeddedData::FromBlob(isolate);
HandleScope scope(isolate);
static_assert(Builtins::kAllBuiltinsAreIsolateIndependent);
for (Builtin builtin = Builtins::kFirst; builtin <= Builtins::kLast;
++builtin) {
DirectHandle<Code> old_code = isolate->builtins()->code_handle(builtin);
// Note that `old_code.instruction_start` might point to `old_code`'s
// InstructionStream which might be GCed once we replace the old code
// with the new code.
Address instruction_start = d.InstructionStartOf(builtin);
DirectHandle<Code> new_code =
isolate->factory()->NewCodeObjectForEmbeddedBuiltin(old_code,
instruction_start);
// From this point onwards, the old builtin code object is unreachable and
// will be collected by the next GC.
isolate->builtins()->set_code(builtin, *new_code);
}
}
#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_size == 0) {
CHECK_EQ(0, data_size);
} else {
SetEmbeddedBlob(code, code_size, data, data_size);
}
}
void Isolate::CreateAndSetEmbeddedBlob() {
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
PrepareBuiltinSourcePositionMap();
// 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();
FinalizeBuiltinCodeObjects(this);
}
void Isolate::InitializeIsShortBuiltinCallsEnabled() {
if (V8_SHORT_BUILTIN_CALLS_BOOL && v8_flags.short_builtin_calls) {
#if defined(V8_OS_ANDROID)
// On Android, the check is not operative to detect memory, and re-embedded
// builtins don't have a memory cost.
is_short_builtin_calls_enabled_ = true;
#else
// Check if the system has more than 4GB of physical memory by comparing the
// old space size with respective threshold value.
is_short_builtin_calls_enabled_ = (heap_.MaxOldGenerationSize() >=
kShortBuiltinCallsOldSpaceSizeThreshold);
#endif // defined(V8_OS_ANDROID)
// Additionally, enable if there is already a process-wide CodeRange that
// has re-embedded builtins.
if (COMPRESS_POINTERS_BOOL) {
CodeRange* code_range = isolate_group()->GetCodeRange();
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());
}
}
}
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);
}
namespace {
static std::string ToHexString(uintptr_t address) {
std::stringstream stream_address;
stream_address << "0x" << std::hex << address;
return stream_address.str();
}
} // namespace
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,
ToHexString(isolate_address));
const uintptr_t ro_space_firstpage_address =
heap()->read_only_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kReadonlySpaceFirstPageAddress,
ToHexString(ro_space_firstpage_address));
const uintptr_t old_space_firstpage_address =
heap()->old_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kOldSpaceFirstPageAddress,
ToHexString(old_space_firstpage_address));
if (heap()->code_range_base()) {
const uintptr_t code_range_base_address = heap()->code_range_base();
add_crash_key_callback_(v8::CrashKeyId::kCodeRangeBaseAddress,
ToHexString(code_range_base_address));
}
if (heap()->code_space()->first_page()) {
const uintptr_t code_space_firstpage_address =
heap()->code_space()->FirstPageAddress();
add_crash_key_callback_(v8::CrashKeyId::kCodeSpaceFirstPageAddress,
ToHexString(code_space_firstpage_address));
}
const v8::StartupData* data = Snapshot::DefaultSnapshotBlob();
// TODO(cbruni): Implement strategy to infrequently collect this.
const uint32_t v8_snapshot_checksum_calculated = 0;
add_crash_key_callback_(v8::CrashKeyId::kSnapshotChecksumCalculated,
ToHexString(v8_snapshot_checksum_calculated));
const uint32_t v8_snapshot_checksum_expected =
Snapshot::GetExpectedChecksum(data);
add_crash_key_callback_(v8::CrashKeyId::kSnapshotChecksumExpected,
ToHexString(v8_snapshot_checksum_expected));
}
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 final : public bigint::Platform {
public:
using digit_t = bigint::digit_t;
~BigIntPlatform() final = default;
#if V8_ENABLE_SANDBOX
explicit BigIntPlatform(Isolate* isolate)
: isolate_(isolate),
allocator_(IsolateGroup::current()->GetInSandboxAllocator()) {}
digit_t* Allocate(size_t count) final {
DCHECK_LT(count, std::numeric_limits<size_t>::max() / sizeof(digit_t));
return static_cast<digit_t*>(
allocator_->AllocateUninitializedOrCrash(count * sizeof(digit_t)));
}
void Free(digit_t* ptr) final { allocator_->Free(ptr); }
#else
explicit BigIntPlatform(Isolate* isolate) : isolate_(isolate) {}
digit_t* Allocate(size_t count) final { return new digit_t[count]; }
void Free(digit_t* ptr) final { delete[] ptr; }
#endif // V8_ENABLE_SANDBOX
bool InterruptRequested() final {
StackLimitCheck interrupt_check(isolate_);
return (interrupt_check.InterruptRequested() &&
isolate_->stack_guard()->HasTerminationRequest());
}
private:
Isolate* isolate_;
#if V8_ENABLE_SANDBOX
v8::Allocator* allocator_;
#endif // V8_ENABLE_SANDBOX
};
} // namespace
#ifdef V8_COMPRESS_POINTERS
VirtualMemoryCage* Isolate::GetPtrComprCodeCageForTesting() {
return V8_EXTERNAL_CODE_SPACE_BOOL ? heap_.code_range()
: isolate_group_->GetPtrComprCage();
}
#endif // V8_COMPRESS_POINTERS
void Isolate::VerifyStaticRoots() {
#if V8_STATIC_ROOTS_BOOL
#define STATIC_ROOTS_FAILED_MSG \
"Read-only heap layout changed. Run `tools/dev/gen-static-roots.py` to " \
"update static-roots.h."
static_assert(static_cast<int>(RootIndex::kReadOnlyRootsCount) ==
StaticReadOnlyRootsPointerTable.size(),
STATIC_ROOTS_FAILED_MSG);
auto& roots = roots_table();
RootIndex idx = RootIndex::kFirstReadOnlyRoot;
for (Tagged_t cmp_ptr : StaticReadOnlyRootsPointerTable) {
Address the_root = roots[idx];
Address ptr = V8HeapCompressionScheme::DecompressTagged(cmp_ptr);
CHECK_WITH_MSG(the_root == ptr, STATIC_ROOTS_FAILED_MSG);
++idx;
}
idx = RootIndex::kFirstReadOnlyRoot;
#define CHECK_NAME(_1, _2, CamelName) \
CHECK_WITH_MSG(StaticReadOnlyRoot::k##CamelName == \
V8HeapCompressionScheme::CompressObject(roots[idx]), \
STATIC_ROOTS_FAILED_MSG); \
++idx;
STRONG_READ_ONLY_ROOT_LIST(CHECK_NAME)
#undef CHECK_NAME
// Check if instance types to map range mappings are still valid.
//
// Is##type(map) may be computed by checking if the map pointer lies in a
// statically known range of addresses, whereas Is##type(instance_type) is the
// definitive source of truth. If they disagree it means that a particular
// entry in InstanceTypeChecker::kUniqueMapRangeOfInstanceTypeRangeList is out
// of date. This can also happen if an instance type is starting to be used by
// more maps.
//
// If this check fails either re-arrange allocations in the read-only heap
// such that the static map range is restored (consult static-roots.h for a
// sorted list of addresses) or remove the offending entry from the list.
for (idx = RootIndex::kFirstRoot; idx <= RootIndex::kLastRoot; ++idx) {
#if V8_ENABLE_WEBASSEMBLY
// WasmNull is entirely inaccessible, we cannot loads its instance type.
if (idx == RootIndex::kWasmNull) continue;
#endif // V8_ENABLE_WEBASSEMBLY
Tagged<Object> obj = roots_table().slot(idx).load(this);
if (obj.ptr() == kNullAddress || !IsMap(obj)) continue;
Tagged<Map> map = Cast<Map>(obj);
#define INSTANCE_TYPE_CHECKER_SINGLE(type, _) \
CHECK_EQ(InstanceTypeChecker::Is##type(map), \
InstanceTypeChecker::Is##type(map->instance_type()));
INSTANCE_TYPE_CHECKERS_SINGLE(INSTANCE_TYPE_CHECKER_SINGLE)
#undef INSTANCE_TYPE_CHECKER_SINGLE
#define INSTANCE_TYPE_CHECKER_RANGE(type, _1, _2) \
CHECK_EQ(InstanceTypeChecker::Is##type(map), \
InstanceTypeChecker::Is##type(map->instance_type()));
INSTANCE_TYPE_CHECKERS_RANGE(INSTANCE_TYPE_CHECKER_RANGE)
#undef INSTANCE_TYPE_CHECKER_RANGE
// This limit is used in various places as a fast IsJSReceiver check.
CHECK_IMPLIES(
InstanceTypeChecker::IsPrimitiveHeapObject(map->instance_type()),
V8HeapCompressionScheme::CompressObject(map.ptr()) <
InstanceTypeChecker::kNonJsReceiverMapLimit);
CHECK_IMPLIES(InstanceTypeChecker::IsJSReceiver(map->instance_type()),
V8HeapCompressionScheme::CompressObject(map.ptr()) >=
InstanceTypeChecker::kNonJsReceiverMapLimit);
CHECK(InstanceTypeChecker::kNonJsReceiverMapLimit <
read_only_heap()->read_only_space()->Capacity());
if (InstanceTypeChecker::IsString(map->instance_type())) {
CHECK_EQ(InstanceTypeChecker::IsString(map),
InstanceTypeChecker::IsString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsSeqString(map),
InstanceTypeChecker::IsSeqString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsExternalString(map),
InstanceTypeChecker::IsExternalString(map->instance_type()));
CHECK_EQ(
InstanceTypeChecker::IsUncachedExternalString(map),
InstanceTypeChecker::IsUncachedExternalString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsInternalizedString(map),
InstanceTypeChecker::IsInternalizedString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsConsString(map),
InstanceTypeChecker::IsConsString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsSlicedString(map),
InstanceTypeChecker::IsSlicedString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsThinString(map),
InstanceTypeChecker::IsThinString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsOneByteString(map),
InstanceTypeChecker::IsOneByteString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsTwoByteString(map),
InstanceTypeChecker::IsTwoByteString(map->instance_type()));
CHECK_EQ(InstanceTypeChecker::IsSharedString(map),
InstanceTypeChecker::IsSharedString(map->instance_type()));
}
}
// Sanity check the API
CHECK_EQ(
v8::internal::Internals::GetRoot(reinterpret_cast<v8::Isolate*>(this),
static_cast<int>(RootIndex::kNullValue)),
ReadOnlyRoots(this).null_value().ptr());
#undef STATIC_ROOTS_FAILED_MSG
#endif // V8_STATIC_ROOTS_BOOL
}
bool Isolate::Init(SnapshotData* startup_snapshot_data,
SnapshotData* read_only_snapshot_data,
SnapshotData* shared_heap_snapshot_data, bool can_rehash) {
TRACE_ISOLATE(init);
#ifdef V8_COMPRESS_POINTERS_IN_SHARED_CAGE
CHECK_EQ(V8HeapCompressionScheme::base(), cage_base());
#endif // V8_COMPRESS_POINTERS_IN_SHARED_CAGE
const bool create_heap_objects = (shared_heap_snapshot_data == nullptr);
// We either have both or none.
DCHECK_EQ(create_heap_objects, startup_snapshot_data == nullptr);
DCHECK_EQ(create_heap_objects, read_only_snapshot_data == nullptr);
EnableRoAllocationForSnapshotScope enable_ro_allocation(this);
base::ElapsedTimer timer;
if (create_heap_objects && v8_flags.profile_deserialization) timer.Start();
time_millis_at_init_ = heap_.MonotonicallyIncreasingTimeInMs();
task_runner_ = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
reinterpret_cast<v8::Isolate*>(this));
isolate_group()->AddIsolate(this);
Isolate* const use_shared_space_isolate =
isolate_group()->shared_space_isolate();
#if DEBUG
is_shared_space_isolate_initialized_ = true;
#endif // DEBUG
CHECK_IMPLIES(is_shared_space_isolate(), V8_CAN_CREATE_SHARED_HEAP_BOOL);
force_slow_path_ = v8_flags.force_slow_path;
flush_denormals_ = base::FPU::GetFlushDenormals();
has_fatal_error_ = false;
// The initialization process does not handle memory exhaustion.
AlwaysAllocateScope always_allocate(heap());
// 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();
global_handles_ = new GlobalHandles(this);
eternal_handles_ = new EternalHandles();
bootstrapper_ = new Bootstrapper(this);
load_stub_cache_ = new StubCache(this);
store_stub_cache_ = new StubCache(this);
define_own_stub_cache_ = new StubCache(this);
materialized_object_store_ = new MaterializedObjectStore(this);
regexp_stack_ = regexp::Stack::New();
isolate_data_.set_regexp_static_result_offsets_vector(
jsregexp_static_offsets_vector());
date_cache_ = new DateCache();
interpreter_ = new interpreter::Interpreter(this);
bigint_processor_ = bigint::Processor::New(new BigIntPlatform(this));
if (v8_flags.lazy_compile_dispatcher) {
lazy_compile_dispatcher_ = std::make_unique<LazyCompileDispatcher>(
this, V8::GetCurrentPlatform(), v8_flags.stack_size);
}
#ifdef V8_ENABLE_SPARKPLUG
baseline_batch_compiler_ = new baseline::BaselineBatchCompiler(this);
#endif // V8_ENABLE_SPARKPLUG
#ifdef V8_ENABLE_MAGLEV
maglev_concurrent_dispatcher_ = new maglev::MaglevConcurrentDispatcher(this);
#endif // V8_ENABLE_MAGLEV
#if USE_SIMULATOR
simulator_data_ = new SimulatorData;
#endif
// Enable logging before setting up the heap
v8_file_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();
}
// Requires a LocalHeap to be set up to register a GC epilogue callback.
inner_pointer_to_code_cache_ = new InnerPointerToCodeCache(this);
#if V8_ENABLE_WEBASSEMBLY
wasm_code_look_up_cache_ = new wasm::WasmCodeLookupCache;
#endif // V8_ENABLE_WEBASSEMBLY
// Lock clients_mutex_ in order to prevent shared GCs from other clients
// during deserialization.
std::optional<base::RecursiveMutexGuard> clients_guard;
if (GlobalSafepoint* safepoint = global_safepoint();
safepoint && this != safepoint->shared_space_isolate()) {
clients_guard.emplace(&safepoint->clients_mutex_);
safepoint->AppendClient(this);
}
shared_space_isolate_ = use_shared_space_isolate;
isolate_data_.is_shared_space_isolate_flag_ = is_shared_space_isolate();
isolate_data_.uses_shared_heap_flag_ = has_shared_space();
isolate_data_.stress_deopt_count_ = v8_flags.deopt_every_n_times;
isolate_data_.has_lazy_closures_ = v8_flags.proto_assign_seq_lazy_func_opt;
if (use_shared_space_isolate && !is_shared_space_isolate() &&
use_shared_space_isolate->heap()
->incremental_marking()
->IsMajorMarking()) {
heap_.SetIsMarkingFlag(true);
}
// Set up the object heap.
DCHECK(!heap_.HasBeenSetUp());
heap_.SetUp(main_thread_local_heap());
MicrotaskQueue::SetUpDefaultMicrotaskQueue(this);
InitializeIsShortBuiltinCallsEnabled();
if (!create_heap_objects) {
// Must be done before deserializing RO space, since RO space may contain
// builtin Code objects which point into the (potentially remapped)
// embedded blob.
MaybeRemapEmbeddedBuiltinsIntoCodeRange();
}
{
// Must be done before deserializing RO space since the deserialization
// process refers to these data structures.
isolate_data_.external_reference_table()->InitIsolateIndependent(
isolate_group()->external_ref_table());
#ifdef V8_COMPRESS_POINTERS
external_pointer_table().Initialize();
external_pointer_table().InitializeSpace(
heap()->read_only_external_pointer_space());
external_pointer_table().AttachSpaceToReadOnlySegments(
heap()->read_only_external_pointer_space());
external_pointer_table().InitializeSpace(
heap()->young_external_pointer_space());
external_pointer_table().InitializeSpace(
heap()->old_external_pointer_space());
cpp_heap_pointer_table().Initialize();
cpp_heap_pointer_table().InitializeSpace(heap()->cpp_heap_pointer_space());
#endif // V8_COMPRESS_POINTERS
#ifdef V8_ENABLE_SANDBOX
trusted_pointer_table().Initialize();
trusted_pointer_table().InitializeSpace(
heap()->read_only_trusted_pointer_space());
trusted_pointer_table().AttachSpaceToReadOnlySegments(
heap()->read_only_trusted_pointer_space());
trusted_pointer_table().InitializeSpace(heap()->trusted_pointer_space());
#endif // V8_ENABLE_SANDBOX
}
{
// LocalHeap initialization requires the TLS variable to be set already.
// However, we can't move SetIsolateThreadLocals here because the marking
// barrier isn't setup yet.
SetCurrentLocalHeapScope local_heap_scope(this);
isolate_group()->SetupReadOnlyHeap(this, read_only_snapshot_data,
can_rehash);
heap_.SetUpSpaces();
}
DCHECK_EQ(this, Isolate::Current());
PerIsolateThreadData* const current_data = CurrentPerIsolateThreadData();
DCHECK_EQ(current_data->isolate(), this);
SetIsolateThreadLocals(this, current_data);
if (OwnsStringTables()) {
string_table_ = std::make_unique<StringTable>(this);
string_forwarding_table_ = std::make_unique<StringForwardingTable>(this);
} else {
// Only refer to shared string table after attaching to the shared isolate.
DCHECK(has_shared_space());
DCHECK(!is_shared_space_isolate());
DCHECK_NOT_NULL(string_table());
DCHECK_NOT_NULL(string_forwarding_table());
}
#ifdef V8_EXTERNAL_CODE_SPACE
{
VirtualMemoryCage* code_cage;
if (heap_.code_range()) {
code_cage = heap_.code_range();
} else {
CHECK(jitless_);
// In jitless mode the code space pages will be allocated in the main
// pointer compression cage.
code_cage = isolate_group_->GetPtrComprCage();
}
code_cage_base_ = ExternalCodeCompressionScheme::PrepareCageBaseAddress(
code_cage->base());
if (COMPRESS_POINTERS_IN_MULTIPLE_CAGES_BOOL) {
// .. now that it's available, initialize the thread-local base.
ExternalCodeCompressionScheme::InitBase(code_cage_base_);
}
CHECK_EQ(ExternalCodeCompressionScheme::base(), code_cage_base_);
// Ensure that ExternalCodeCompressionScheme is applicable to all objects
// stored in the code cage.
using ComprScheme = ExternalCodeCompressionScheme;
Address base = code_cage->base() + kHeapObjectTag;
Address last = base + code_cage->size() - kTaggedSize;
Address upper_bound = base + kPtrComprCageReservationSize - kTaggedSize;
PtrComprCageBase code_cage_base{code_cage_base_};
CHECK_EQ(base,
ComprScheme::DecompressTagged(ComprScheme::CompressAny(base)));
CHECK_EQ(last,
ComprScheme::DecompressTagged(ComprScheme::CompressAny(last)));
CHECK_EQ(upper_bound, ComprScheme::DecompressTagged(
ComprScheme::CompressAny(upper_bound)));
}
#endif // V8_EXTERNAL_CODE_SPACE
js_dispatch_table().Initialize();
isolate_data_.external_reference_table()->Init(this);
#ifdef V8_COMPRESS_POINTERS
if (owns_shareable_data()) {
isolate_data_.shared_external_pointer_table_ = new ExternalPointerTable();
shared_external_pointer_space_ = new ExternalPointerTable::Space();
shared_external_pointer_table().Initialize();
shared_external_pointer_table().InitializeSpace(
shared_external_pointer_space());
} else {
DCHECK(has_shared_space());
isolate_data_.shared_external_pointer_table_ =
shared_space_isolate()->isolate_data_.shared_external_pointer_table_;
shared_external_pointer_space_ =
shared_space_isolate()->shared_external_pointer_space_;
}
#endif // V8_COMPRESS_POINTERS
#ifdef V8_ENABLE_SANDBOX
if (owns_shareable_data()) {
isolate_data_.shared_trusted_pointer_table_ = new TrustedPointerTable();
shared_trusted_pointer_space_ = new TrustedPointerTable::Space();
shared_trusted_pointer_table().Initialize();
shared_trusted_pointer_table().InitializeSpace(
shared_trusted_pointer_space());
} else {
DCHECK(has_shared_space());
isolate_data_.shared_trusted_pointer_table_ =
shared_space_isolate()->isolate_data_.shared_trusted_pointer_table_;
shared_trusted_pointer_space_ =
shared_space_isolate()->shared_trusted_pointer_space_;
}
#endif // V8_ENABLE_SANDBOX
JSDispatchTable::Space* read_only_js_dispatch_table_space =
heap()->read_only_js_dispatch_table_space();
js_dispatch_table().InitializeSpace(read_only_js_dispatch_table_space);
// To avoid marking trying to write to these read-only cells they are
// allocated black. Target code objects in the read-only dispatch table are
// read-only code objects.
#if V8_STATIC_DISPATCH_HANDLES_BOOL
js_dispatch_table().AttachSpaceToReadOnlySegments(
read_only_js_dispatch_table_space);
#endif // V8_STATIC_DISPATCH_HANDLES_BOOL
js_dispatch_table().InitializeSpace(heap()->js_dispatch_table_space());
#if V8_ENABLE_WEBASSEMBLY
wasm::GetWasmEngine()->AddIsolate(this);
// Initialize the central stack for JSPI/WasmFX:
wasm::StackMemory* stack(wasm::StackMemory::GetCentralStackView(this));
stack->jmpbuf()->state = wasm::JumpBuffer::Active;
this->wasm_stacks().emplace_back(stack);
stack->set_index(0);
isolate_data_.set_active_stack(wasm_stacks()[0].get());
if (v8_flags.trace_wasm_stack_switching) {
PrintF("Set up central stack object (limit: %p, base: %p)\n",
stack->jslimit(), reinterpret_cast<void*>(stack->base()));
}
#if V8_TARGET_OS_WIN
// Stack::GetStackStart() is meant to return the native stack start, but we
// update the TEB's StackBase during wasm stack switching. So call it during
// initialization to ensure that it caches the correct value.
base::Stack::GetStackStart();
#endif
#endif // V8_ENABLE_WEBASSEMBLY
#if defined(V8_ENABLE_ETW_STACK_WALKING)
if (v8_flags.enable_etw_stack_walking ||
v8_flags.enable_etw_by_custom_filter_only) {
ETWJITInterface::AddIsolate(this);
}
#endif // defined(V8_ENABLE_ETW_STACK_WALKING)
isolate_data_.cpu_features_ = CpuFeatures::SupportedFeatures();
if (setup_delegate_ == nullptr) {
setup_delegate_ = new SetupIsolateDelegate;
}
if (!v8_flags.inline_new) heap_.DisableInlineAllocation();
if (!setup_delegate_->SetupHeap(this, create_heap_objects)) {
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);
if (v8_flags.concurrent_builtin_generation) {
optimizing_compile_dispatcher_ = new OptimizingCompileDispatcher(
this, isolate_group_->optimizing_compile_task_executor());
optimizing_compile_dispatcher_->set_finalize(false);
}
setup_delegate_->SetupBuiltins(this, true);
if (v8_flags.concurrent_builtin_generation) {
delete optimizing_compile_dispatcher_;
optimizing_compile_dispatcher_ = nullptr;
}
builtins_constants_table_builder_->Finalize();
delete builtins_constants_table_builder_;
builtins_constants_table_builder_ = nullptr;
CreateAndSetEmbeddedBlob();
} else {
setup_delegate_->SetupBuiltins(this, false);
}
if ((v8_flags.trace_turbo || v8_flags.trace_turbo_graph ||
v8_flags.turbo_profiling || v8_flags.print_turbolev_frontend ||
v8_flags.print_turbolev_inline_functions) &&
!v8_flags.concurrent_turbo_tracing) {
PrintF("Concurrent recompilation has been disabled for tracing.\n");
} else if (OptimizingCompileDispatcher::Enabled()) {
optimizing_compile_dispatcher_ = new OptimizingCompileDispatcher(
this, isolate_group_->optimizing_compile_task_executor());
}
// Initialize before deserialization since collections may occur,
// clearing/updating ICs (and thus affecting tiering decisions).
tiering_manager_ = new TieringManager(this);
if (!create_heap_objects) {
// If we are deserializing, read the state into the now-empty heap.
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();
}
InitializeBuiltinJSDispatchTable();
if (DEBUG_BOOL) VerifyStaticRoots();
load_stub_cache_->Initialize();
store_stub_cache_->Initialize();
define_own_stub_cache_->Initialize();
interpreter_->Initialize();
heap_.NotifyDeserializationComplete();
delete setup_delegate_;
setup_delegate_ = nullptr;
Builtins::InitializeIsolateDataTables(this);
// Extra steps in the logger after the heap has been set up.
v8_file_logger_->LateSetup(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
if (v8_flags.print_builtin_code) builtins()->PrintBuiltinCode();
if (v8_flags.print_builtin_size) builtins()->PrintBuiltinSize();
// Finish initialization of ThreadLocal after deserialization is done.
clear_exception();
clear_pending_message();
// Quiet the heap NaN if needed on target platform.
if (!create_heap_objects) {
Assembler::QuietNaN(ReadOnlyRoots(this).nan_value());
}
if (v8_flags.trace_turbo) {
// Create an empty file.
std::ofstream(GetTurboCfgFileName(this).c_str(), std::ios_base::trunc);
}
isolate_data_.continuation_preserved_embedder_data_ =
*factory()->undefined_value();
{
HandleScope scope(this);
ast_string_constants_ = new AstStringConstants(this, HashSeed(this));
}
initialized_from_snapshot_ = !create_heap_objects;
if (v8_flags.stress_sampling_allocation_profiler > 0) {
uint64_t sample_interval = v8_flags.stress_sampling_allocation_profiler;
int stack_depth = 128;
v8::HeapProfiler::SamplingFlags sampling_flags =
v8::HeapProfiler::SamplingFlags::kSamplingForceGC;
heap()->heap_profiler()->StartSamplingHeapProfiler(
sample_interval, stack_depth, sampling_flags);
}
if (create_heap_objects && v8_flags.profile_deserialization) {
double ms = timer.Elapsed().InMillisecondsF();
PrintF("[Initializing isolate from scratch took %0.3f ms]\n", ms);
}
if (initialized_from_snapshot_) {
SLOW_DCHECK(SharedFunctionInfo::UniqueIdsAreUnique(this));
}
if (v8_flags.harmony_struct) {
// Initialize or get the struct type registry shared by all isolates.
if (is_shared_space_isolate()) {
shared_struct_type_registry_ =
std::make_unique<SharedStructTypeRegistry>();
} else {
DCHECK_NOT_NULL(shared_struct_type_registry());
}
}
#ifdef V8_ENABLE_WEBASSEMBLY
#if V8_STATIC_ROOTS_BOOL
// Protect the payload of wasm null.
if (!page_allocator()->DecommitPages(
reinterpret_cast<void*>(factory()->wasm_null()->address()),
WasmNull::kSize)) {
V8::FatalProcessOutOfMemory(this, "decommitting WasmNull payload");
}
#endif // V8_STATIC_ROOTS_BOOL
#endif // V8_ENABLE_WEBASSEMBLY
if (v8_flags.unmap_holes) {
// Protect the payload of each hole.
#define UNMAP_HOLE(CamelName, snake_name, _) \
if (!page_allocator()->DecommitPages( \
reinterpret_cast<void*>(&factory()->snake_name()->payload_), \
Hole::kPayloadSize)) { \
V8::FatalProcessOutOfMemory(this, "decommitting " #CamelName " payload"); \
}
HOLE_LIST(UNMAP_HOLE)
#undef UNMAP_HOLE
}
// Isolate initialization allocates long living objects that should be
// pretenured to old space.
DCHECK_IMPLIES(heap()->new_space(), heap()->new_space()->Size() == 0);
DCHECK_IMPLIES(heap()->new_lo_space(), heap()->new_lo_space()->Size() == 0);
DCHECK_EQ(heap()->gc_count(), kInitialGCEpoch);
#if defined(V8_ENABLE_ETW_STACK_WALKING)
if (v8_flags.enable_etw_stack_walking ||
v8_flags.enable_etw_by_custom_filter_only) {
ETWJITInterface::MaybeSetHandlerNow(this);
}
#endif // defined(V8_ENABLE_ETW_STACK_WALKING)
#if defined(V8_USE_PERFETTO)
PerfettoLogger::RegisterIsolate(this);
#endif // defined(V8_USE_PERFETTO)
initialized_ = true;
return true;
}
void Isolate::Enter() {
Isolate* current_isolate = nullptr;
PerIsolateThreadData* current_data = CurrentPerIsolateThreadData();
#ifdef V8_ENABLE_CHECKS
// No different thread must have entered the isolate. Allow re-entering.
ThreadId thread_id = ThreadId::Current();
if (current_thread_id_.IsValid()) {
CHECK_EQ(current_thread_id_, thread_id);
} else {
CHECK_EQ(0, current_thread_counter_);
current_thread_id_ = thread_id;
}
current_thread_counter_++;
#endif
// Set the stack start for the main thread that enters the isolate.
heap()->SetStackStart();
if (current_data != nullptr) {
current_isolate = current_data->isolate_;
DCHECK_NOT_NULL(current_isolate);
if (current_isolate == this) {
DCHECK(Current() == this);
auto entry_stack = entry_stack_.load();
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() {
auto current_entry_stack = entry_stack_.load();
DCHECK_NOT_NULL(current_entry_stack);
DCHECK(current_entry_stack->previous_thread_data == nullptr ||
current_entry_stack->previous_thread_data->thread_id() ==
ThreadId::Current());
#ifdef V8_ENABLE_CHECKS
// The current thread must have entered the isolate.
CHECK_EQ(current_thread_id_, ThreadId::Current());
if (--current_thread_counter_ == 0) current_thread_id_ = ThreadId::Invalid();
#endif
if (--current_entry_stack->entry_count > 0) return;
DCHECK_NOT_NULL(CurrentPerIsolateThreadData());
DCHECK(CurrentPerIsolateThreadData()->isolate_ == this);
// Pop the stack.
entry_stack_ = current_entry_stack->previous_item;
PerIsolateThreadData* previous_thread_data =
current_entry_stack->previous_thread_data;
Isolate* previous_isolate = current_entry_stack->previous_isolate;
delete current_entry_stack;
// Reinit the current thread for the isolate it was running before this one.
SetIsolateThreadLocals(previous_isolate, previous_thread_data);
}
OptimizingCompileDispatcher* Isolate::SetOptimizingCompileDispatcherForTesting(
OptimizingCompileDispatcher* dispatcher) {
return std::exchange(optimizing_compile_dispatcher_, dispatcher);
}
std::unique_ptr<PersistentHandles> Isolate::NewPersistentHandles() {
return std::make_unique<PersistentHandles>(this);
}
void Isolate::DumpAndResetStats() {
if (v8_flags.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(v8_flags.turbo_stats || v8_flags.turbo_stats_nvp);
StdoutStream os;
if (v8_flags.turbo_stats) {
AsPrintableStatistics ps = {"Turbofan", *turbo_statistics_, false};
os << ps << std::endl;
}
if (v8_flags.turbo_stats_nvp) {
AsPrintableStatistics ps = {"Turbofan", *turbo_statistics_, true};
os << ps << std::endl;
}
turbo_statistics_.reset();
}
#ifdef V8_ENABLE_MAGLEV
if (maglev_statistics_ != nullptr) {
DCHECK(v8_flags.maglev_stats || v8_flags.maglev_stats_nvp);
StdoutStream os;
if (v8_flags.maglev_stats) {
AsPrintableStatistics ps = {"Maglev", *maglev_statistics_, false};
os << ps << std::endl;
}
if (v8_flags.maglev_stats_nvp) {
AsPrintableStatistics ps = {"Maglev", *maglev_statistics_, true};
os << ps << std::endl;
}
maglev_statistics_.reset();
}
#endif // V8_ENABLE_MAGLEV
#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 (v8_flags.turbo_stats_wasm) {
wasm::GetWasmEngine()->DumpAndResetTurboStatistics();
}
#endif // V8_ENABLE_WEBASSEMBLY
if (v8_flags.trace_number_string_cache) {
PrintNumberStringCacheStats("DumpAndResetStats", true);
}
#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
}
void Isolate::DumpAndResetBuiltinsProfileData() {
if (BasicBlockProfiler::Get()->HasData(this)) {
#ifndef V8_FUZZILLI
if (v8_flags.turbo_profiling_output) {
FILE* f = std::fopen(v8_flags.turbo_profiling_output, "w");
if (f == nullptr) {
FATAL("Unable to open file \"%s\" for writing.\n",
v8_flags.turbo_profiling_output.value());
}
OFStream pgo_stream(f);
BasicBlockProfiler::Get()->Log(this, pgo_stream);
} else {
StdoutStream out;
BasicBlockProfiler::Get()->Print(this, out);
}
#endif // !V8_FUZZILLI
BasicBlockProfiler::Get()->ResetCounts(this);
}
}
void Isolate::IncreaseConcurrentOptimizationPriority(
CodeKind kind, Tagged<SharedFunctionInfo> function) {
DCHECK_EQ(kind, CodeKind::TURBOFAN_JS);
optimizing_compile_dispatcher()->Prioritize(function);
}
void Isolate::AbortConcurrentOptimization(BlockingBehavior behavior) {
if (concurrent_recompilation_enabled()) {
DisallowGarbageCollection no_recursive_gc;
optimizing_compile_dispatcher()->Flush(behavior);
}
#ifdef V8_ENABLE_MAGLEV
if (maglev_concurrent_dispatcher()->is_enabled()) {
DisallowGarbageCollection no_recursive_gc;
maglev_concurrent_dispatcher()->Flush(behavior);
}
#endif
}
void Isolate::WaitForConcurrentOptimizationJobs() {
if (concurrent_recompilation_enabled()) {
optimizing_compile_dispatcher()->WaitUntilCompilationJobsDone();
}
#ifdef V8_ENABLE_MAGLEV
if (maglev_concurrent_dispatcher()->is_enabled()) {
maglev_concurrent_dispatcher()->AwaitCompileJobs();
}
#endif // V8_ENABLE_MAGLEV
}
std::shared_ptr<CompilationStatistics> Isolate::GetTurboStatistics() {
if (turbo_statistics_ == nullptr) {
turbo_statistics_.reset(new CompilationStatistics());
}
return turbo_statistics_;
}
#ifdef V8_ENABLE_MAGLEV
std::shared_ptr<CompilationStatistics> Isolate::GetMaglevStatistics() {
if (maglev_statistics_ == nullptr) {
maglev_statistics_.reset(new CompilationStatistics());
}
return maglev_statistics_;
}
#endif // V8_ENABLE_MAGLEV
CodeTracer* Isolate::GetCodeTracer() {
if (code_tracer() == nullptr) set_code_tracer(new CodeTracer(id()));
return code_tracer();
}
bool Isolate::use_optimizer() {
// TODO(v8:7700): Update this predicate for a world with multiple tiers.
return (v8_flags.turbofan || v8_flags.maglev) && !serializer_enabled_ &&
CpuFeatures::SupportsOptimizer() && !is_precise_count_code_coverage();
}
bool Isolate::NeedsDetailedOptimizedCodeLineInfo() const {
return NeedsSourcePositions() || detailed_source_positions_for_profiling();
}
bool Isolate::IsLoggingCodeCreation() const {
return v8_file_logger()->is_listening_to_code_events() || is_profiling() ||
v8_flags.log_function_events ||
logger()->is_listening_to_code_events();
}
bool Isolate::AllowsCodeCompaction() const {
return v8_flags.compact_code_space && logger()->allows_code_compaction();
}
bool Isolate::NeedsSourcePositions() const {
return
// Static conditions.
v8_flags.trace_deopt || v8_flags.trace_turbo ||
v8_flags.trace_turbo_graph || v8_flags.turbo_profiling ||
v8_flags.print_maglev_code || v8_flags.perf_prof || v8_flags.log_maps ||
v8_flags.log_ic || v8_flags.log_function_events ||
v8_flags.heap_snapshot_on_oom ||
// Dynamic conditions; changing any of these conditions triggers source
// position collection for the entire heap
// (CollectSourcePositionsForAllBytecodeArrays).
is_profiling() || debug_->is_active() || v8_file_logger_->is_logging();
}
void Isolate::SetFeedbackVectorsForProfilingTools(Tagged<Object> value) {
DCHECK(IsUndefined(value) || IsArrayList(value));
heap()->set_feedback_vectors_for_profiling_tools(value);
}
void Isolate::MaybeInitializeVectorListFromHeap() {
if (!IsUndefined(heap()->feedback_vectors_for_profiling_tools())) {
// Already initialized, return early.
DCHECK(IsArrayList(heap()->feedback_vectors_for_profiling_tools()));
return;
}
// Collect existing feedback vectors.
DirectHandleVector<FeedbackVector> vectors(this);
{
HeapObjectIterator heap_iterator(heap());
for (Tagged<HeapObject> current_obj = heap_iterator.Next();
!current_obj.is_null(); current_obj = heap_iterator.Next()) {
if (!IsFeedbackVector(current_obj)) continue;
Tagged<FeedbackVector> vector = Cast<FeedbackVector>(current_obj);
Tagged<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.
DirectHandle<ArrayList> list =
ArrayList::New(this, static_cast<uint32_t>(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;
}
void Isolate::IncreaseDateCacheStampAndInvalidateProtector() {
// There's no need to update stamp and invalidate the protector since there
// were no JSDate instances created yet and thus such a configuration change
// is not observable anyway.
if (!isolate_data()->is_date_cache_used_) return;
if (isolate_data()->date_cache_stamp_ < Smi::kMaxValue) {
++isolate_data()->date_cache_stamp_;
} else {
isolate_data()->date_cache_stamp_ = 1;
}
if (Protectors::IsNoDateTimeConfigurationChangeIntact(this)) {
Protectors::InvalidateNoDateTimeConfigurationChange(this);
}
}
Isolate::KnownPrototype Isolate::IsArrayOrObjectOrStringPrototype(
Tagged<JSObject> object) {
Tagged<Map> metamap = object->map()->map();
Tagged<NativeContext> native_context = metamap->native_context();
if (native_context->initial_object_prototype() == object) {
return KnownPrototype::kObject;
} else if (native_context->initial_array_prototype() == object) {
return KnownPrototype::kArray;
} else if (native_context->initial_string_prototype() == object) {
return KnownPrototype::kString;
}
return KnownPrototype::kNone;
}
bool Isolate::IsInCreationContext(Tagged<JSObject> object, uint32_t index) {
DisallowGarbageCollection no_gc;
Tagged<Map> metamap = object->map()->map();
// Filter out native-context independent objects.
if (metamap == ReadOnlyRoots(this).meta_map()) return false;
Tagged<NativeContext> native_context = metamap->native_context();
return native_context->GetNoCell(index) == object;
}
void Isolate::UpdateNoElementsProtectorOnSetElement(
DirectHandle<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);
}
void Isolate::UpdateProtectorsOnSetPrototype(
DirectHandle<JSObject> object, DirectHandle<Object> new_prototype) {
UpdateNoElementsProtectorOnSetPrototype(object);
UpdateTypedArraySpeciesLookupChainProtectorOnSetPrototype(object);
UpdateNumberStringNotRegexpLikeProtectorOnSetPrototype(object);
UpdateStringWrapperToPrimitiveProtectorOnSetPrototype(object, new_prototype);
}
void Isolate::UpdateTypedArraySpeciesLookupChainProtectorOnSetPrototype(
DirectHandle<JSObject> object) {
// Setting the __proto__ of TypedArray constructor could change TypedArray's
// @@species. So we need to invalidate the @@species protector.
if (IsTypedArrayConstructor(*object) &&
Protectors::IsTypedArraySpeciesLookupChainIntact(this)) {
Protectors::InvalidateTypedArraySpeciesLookupChain(this);
}
}
void Isolate::UpdateNumberStringNotRegexpLikeProtectorOnSetPrototype(
DirectHandle<JSObject> object) {
if (!Protectors::IsNumberStringNotRegexpLikeIntact(this)) {
return;
}
// We need to protect the prototype chain of `Number.prototype` and
// `String.prototype`.
// Since `Object.prototype.__proto__` is not writable, we can assume it
// doesn't occur here. We detect `Number.prototype` and `String.prototype` by
// checking for a prototype that is a JSPrimitiveWrapper. This is a safe
// approximation. Using JSPrimitiveWrapper as prototype should be
// sufficiently rare.
DCHECK(!IsJSObjectPrototype(*object));
if (object->map()->is_prototype_map() && (IsJSPrimitiveWrapper(*object))) {
Protectors::InvalidateNumberStringNotRegexpLike(this);
}
}
void Isolate::UpdateStringWrapperToPrimitiveProtectorOnSetPrototype(
DirectHandle<JSObject> object, DirectHandle<Object> new_prototype) {
if (!Protectors::IsStringWrapperToPrimitiveIntact(this)) {
return;
}
// We can have a custom @@toPrimitive on a string wrapper also if we subclass
// String and the subclass (or one of its subclasses) defines its own
// @@toPrimitive. Thus we invalidate the protector whenever we detect
// subclassing String - it should be reasonably rare.
if (IsStringWrapper(*object) || IsStringWrapper(*new_prototype)) {
Protectors::InvalidateStringWrapperToPrimitive(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_, v8_flags.random_seed);
}
base::RandomNumberGenerator* Isolate::fuzzer_rng() {
if (fuzzer_rng_ == nullptr) {
int64_t seed = v8_flags.fuzzer_random_seed;
if (seed == 0) {
seed = random_number_generator()->initial_seed();
}
fuzzer_rng_ = new base::RandomNumberGenerator(seed);
}
return fuzzer_rng_;
}
void Isolate::SetStackSize(size_t v) {
stack_size_ = v;
#if V8_ENABLE_WEBASSEMBLY
// During early isolate initialization (inside v8::Isolate::Initialize),
// SetStackSize is called before Isolate::Init allocates the first central
// Wasm stack. When that happens, wasm_stacks() is empty. Skip the bounds
// update since the central stack will query stack_size() upon creation.
if (!wasm_stacks().empty()) {
wasm_stacks()[0]->UpdateCentralStackLimit(this);
}
#endif
}
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;
}
#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
DirectHandle<Symbol> Isolate::SymbolFor(RootIndex dictionary_index,
Handle<String> name,
bool private_symbol) {
DirectHandle<String> key = factory()->InternalizeString(name);
Handle<RegisteredSymbolTable> dictionary =
Cast<RegisteredSymbolTable>(root_handle(dictionary_index));
InternalIndex entry = dictionary->FindEntry(this, key);
DirectHandle<Symbol> symbol;
if (entry.is_not_found()) {
symbol =
private_symbol ? factory()->NewPrivateSymbol() : factory()->NewSymbol();
symbol->set_description(*key);
dictionary = RegisteredSymbolTable::Add(this, dictionary, key, symbol);
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 =
DirectHandle<Symbol>(Cast<Symbol>(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 &&
!is_execution_terminating();
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));
}
}
#ifdef V8_ENABLE_WEBASSEMBLY
void Isolate::WasmInitJSPIFeature() {
if (v8_flags.wasm_jitless) return;
if (isolate_data_.active_suspender().is_null()) {
DCHECK_EQ(wasm_stacks().size(), 1);
// Add a sentinel active suspender object to represent the
// initial stack. This ensures that other suspenders created via
// JSPI always have a parent to suspend to.
HandleScope scope(this);
DirectHandle<WasmSuspenderObject> suspender =
factory()->NewWasmSuspenderObject();
suspender->set_stack(this, wasm_stacks()[0].get());
isolate_data_.set_active_suspender(*suspender);
}
}
#endif
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 {
MaybeDirectHandle<JSPromise> NewRejectedPromise(
Isolate* isolate, v8::Local<v8::Context> api_context,
DirectHandle<Object> exception) {
v8::Local<v8::Promise::Resolver> resolver;
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(isolate, resolver,
v8::Promise::Resolver::New(api_context),
MaybeDirectHandle<JSPromise>());
RETURN_ON_EXCEPTION_VALUE(
isolate, resolver->Reject(api_context, v8::Utils::ToLocal(exception)),
MaybeDirectHandle<JSPromise>());
v8::Local<v8::Promise> promise = resolver->GetPromise();
return v8::Utils::OpenDirectHandle(*promise);
}
} // namespace
MaybeDirectHandle<JSPromise> Isolate::RunHostImportModuleDynamicallyCallback(
MaybeDirectHandle<Script> maybe_referrer, Handle<Object> specifier,
ModuleImportPhase phase,
MaybeDirectHandle<Object> maybe_import_options_argument) {
DCHECK(!is_execution_terminating());
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(native_context());
switch (phase) {
case ModuleImportPhase::kDefer:
case ModuleImportPhase::kEvaluation:
if (host_import_module_dynamically_callback_ == nullptr &&
host_import_module_with_phase_dynamically_callback_ == nullptr) {
DirectHandle<Object> exception = factory()->NewError(
error_function(), MessageTemplate::kUnsupported);
return NewRejectedPromise(this, api_context, exception);
}
break;
case ModuleImportPhase::kSource:
if (host_import_module_with_phase_dynamically_callback_ == nullptr) {
DirectHandle<Object> exception = factory()->NewError(
error_function(), MessageTemplate::kUnsupported);
return NewRejectedPromise(this, api_context, exception);
}
break;
}
DirectHandle<String> specifier_str;
MaybeDirectHandle<String> maybe_specifier = Object::ToString(this, specifier);
if (!maybe_specifier.ToHandle(&specifier_str)) {
if (is_execution_terminating()) {
return MaybeDirectHandle<JSPromise>();
}
DirectHandle<Object> exception(this->exception(), this);
clear_exception();
return NewRejectedPromise(this, api_context, exception);
}
DCHECK(!has_exception());
v8::Local<v8::Promise> promise;
DirectHandle<FixedArray> import_attributes_array;
if (!GetImportAttributesFromArgument(maybe_import_options_argument)
.ToHandle(&import_attributes_array)) {
if (is_execution_terminating()) {
return MaybeDirectHandle<JSPromise>();
}
DirectHandle<Object> exception(this->exception(), this);
clear_exception();
return NewRejectedPromise(this, api_context, exception);
}
DirectHandle<FixedArray> host_defined_options;
DirectHandle<Object> resource_name;
if (maybe_referrer.is_null()) {
host_defined_options = factory()->empty_fixed_array();
resource_name = factory()->null_value();
} else {
DirectHandle<Script> referrer = maybe_referrer.ToHandleChecked();
host_defined_options =
direct_handle(referrer->host_defined_options(), this);
resource_name = direct_handle(referrer->name(), this);
}
switch (phase) {
case ModuleImportPhase::kEvaluation:
// TODO(42204365): Deprecate HostImportModuleDynamicallyCallback once
// HostImportModuleWithPhaseDynamicallyCallback is stable.
if (host_import_module_with_phase_dynamically_callback_ != nullptr) {
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(
this, promise,
host_import_module_with_phase_dynamically_callback_(
api_context, v8::Utils::ToLocal(host_defined_options),
v8::Utils::ToLocal(resource_name),
v8::Utils::ToLocal(specifier_str), phase,
ToApiHandle<v8::FixedArray>(import_attributes_array)),
MaybeDirectHandle<JSPromise>());
} else {
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(
this, promise,
host_import_module_dynamically_callback_(
api_context, v8::Utils::ToLocal(host_defined_options),
v8::Utils::ToLocal(resource_name),
v8::Utils::ToLocal(specifier_str),
ToApiHandle<v8::FixedArray>(import_attributes_array)),
MaybeDirectHandle<JSPromise>());
}
break;
case ModuleImportPhase::kDefer:
case ModuleImportPhase::kSource:
CHECK(v8_flags.js_source_phase_imports || v8_flags.js_defer_import_eval);
CHECK_NOT_NULL(host_import_module_with_phase_dynamically_callback_);
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(
this, promise,
host_import_module_with_phase_dynamically_callback_(
api_context, v8::Utils::ToLocal(host_defined_options),
v8::Utils::ToLocal(resource_name),
v8::Utils::ToLocal(specifier_str), phase,
ToApiHandle<v8::FixedArray>(import_attributes_array)),
MaybeDirectHandle<JSPromise>());
break;
default:
UNREACHABLE();
}
return v8::Utils::OpenDirectHandle(*promise);
}
MaybeDirectHandle<FixedArray> Isolate::GetImportAttributesFromArgument(
MaybeDirectHandle<Object> maybe_import_options_argument) {
DirectHandle<FixedArray> import_attributes_array =
factory()->empty_fixed_array();
DirectHandle<Object> import_options_argument;
if (!maybe_import_options_argument.ToHandle(&import_options_argument) ||
IsUndefined(*import_options_argument)) {
return import_attributes_array;
}
// The parser shouldn't have allowed the second argument to import() if
// the flag wasn't enabled.
DCHECK(v8_flags.harmony_import_attributes);
if (!IsJSReceiver(*import_options_argument)) {
this->Throw(
*factory()->NewTypeError(MessageTemplate::kNonObjectImportArgument));
return MaybeDirectHandle<FixedArray>();
}
DirectHandle<JSReceiver> import_options_argument_receiver =
Cast<JSReceiver>(import_options_argument);
DirectHandle<Object> import_attributes_object;
if (v8_flags.harmony_import_attributes) {
DirectHandle<Name> with_key = factory()->with_string();
if (!JSReceiver::GetProperty(this, import_options_argument_receiver,
with_key)
.ToHandle(&import_attributes_object)) {
// This can happen if the property has a getter function that throws
// an error.
return MaybeDirectHandle<FixedArray>();
}
}
// If there is no 'with' option in the options bag, it's not an error. Just do
// the import() as if no attributes were provided.
if (IsUndefined(*import_attributes_object)) return import_attributes_array;
if (!IsJSReceiver(*import_attributes_object)) {
this->Throw(
*factory()->NewTypeError(MessageTemplate::kNonObjectAttributesOption));
return MaybeDirectHandle<FixedArray>();
}
DirectHandle<JSReceiver> import_attributes_object_receiver =
Cast<JSReceiver>(import_attributes_object);
DirectHandle<FixedArray> attribute_keys;
if (!KeyAccumulator::GetKeys(this, import_attributes_object_receiver,
KeyCollectionMode::kOwnOnly, ENUMERABLE_STRINGS,
GetKeysConversion::kConvertToString)
.ToHandle(&attribute_keys)) {
// This happens if the attributes object is a Proxy whose ownKeys() or
// getOwnPropertyDescriptor() trap throws.
return MaybeDirectHandle<FixedArray>();
}
bool has_non_string_attribute = false;
// The attributes will be passed to the host in the form: [key1,
// value1, key2, value2, ...].
constexpr uint32_t kAttributeEntrySizeForDynamicImport = 2;
uint32_t attributes_keys_len = attribute_keys->ulength().value();
import_attributes_array = factory()->NewFixedArray(
attributes_keys_len * kAttributeEntrySizeForDynamicImport);
for (uint32_t i = 0; i < attributes_keys_len; i++) {
DirectHandle<String> attribute_key(Cast<String>(attribute_keys->get(i)),
this);
DirectHandle<Object> attribute_value;
if (!Object::GetPropertyOrElement(this, import_attributes_object_receiver,
attribute_key)
.ToHandle(&attribute_value)) {
// This can happen if the property has a getter function that throws
// an error.
return MaybeDirectHandle<FixedArray>();
}
if (!IsString(*attribute_value)) {
has_non_string_attribute = true;
}
import_attributes_array->set((i * kAttributeEntrySizeForDynamicImport),
*attribute_key);
import_attributes_array->set((i * kAttributeEntrySizeForDynamicImport) + 1,
*attribute_value);
}
if (has_non_string_attribute) {
this->Throw(*factory()->NewTypeError(
MessageTemplate::kNonStringImportAttributeValue));
return MaybeDirectHandle<FixedArray>();
}
return import_attributes_array;
}
void Isolate::ClearKeptObjects() { heap()->ClearKeptObjects(); }
void Isolate::SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyCallback callback) {
host_import_module_dynamically_callback_ = callback;
}
void Isolate::SetHostImportModuleWithPhaseDynamicallyCallback(
HostImportModuleWithPhaseDynamicallyCallback callback) {
host_import_module_with_phase_dynamically_callback_ = callback;
}
MaybeHandle<JSObject> Isolate::RunHostInitializeImportMetaObjectCallback(
DirectHandle<SourceTextModule> module) {
CHECK(IsTheHole(module->import_meta(kAcquireLoad)));
Handle<JSObject> import_meta = factory()->NewJSObjectWithNullProto();
if (host_initialize_import_meta_object_callback_ != nullptr) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(native_context());
host_initialize_import_meta_object_callback_(
api_context, Utils::ToLocal(Cast<Module>(module)),
v8::Local<v8::Object>::Cast(v8::Utils::ToLocal(import_meta)));
if (has_exception()) return {};
}
return import_meta;
}
void Isolate::SetHostInitializeImportMetaObjectCallback(
HostInitializeImportMetaObjectCallback callback) {
host_initialize_import_meta_object_callback_ = callback;
}
void Isolate::SetHostCreateShadowRealmContextCallback(
HostCreateShadowRealmContextCallback callback) {
host_create_shadow_realm_context_callback_ = callback;
}
MaybeDirectHandle<NativeContext>
Isolate::RunHostCreateShadowRealmContextCallback() {
if (host_create_shadow_realm_context_callback_ == nullptr) {
DirectHandle<Object> exception =
factory()->NewError(error_function(), MessageTemplate::kUnsupported);
Throw(*exception);
return kNullMaybeHandle;
}
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(native_context());
v8::Local<v8::Context> shadow_realm_context;
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(
this, shadow_realm_context,
host_create_shadow_realm_context_callback_(api_context),
MaybeDirectHandle<NativeContext>());
DirectHandle<Context> shadow_realm_context_handle =
v8::Utils::OpenDirectHandle(*shadow_realm_context);
DCHECK(IsNativeContext(*shadow_realm_context_handle));
shadow_realm_context_handle->set_scope_info(
ReadOnlyRoots(this).shadow_realm_scope_info());
return Cast<NativeContext>(shadow_realm_context_handle);
}
MaybeDirectHandle<Object> Isolate::RunPrepareStackTraceCallback(
DirectHandle<NativeContext> context, DirectHandle<JSObject> error,
DirectHandle<JSArray> sites) {
v8::Local<v8::Context> api_context = Utils::ToLocal(context);
v8::Local<v8::Value> stack;
API_ASSIGN_RETURN_ON_EXCEPTION_VALUE(
this, stack,
prepare_stack_trace_callback_(api_context, Utils::ToLocal(error),
Utils::ToLocal(sites)),
MaybeDirectHandle<Object>());
return Utils::OpenDirectHandle(*stack);
}
bool Isolate::IsJSApiWrapperNativeError(DirectHandle<JSReceiver> obj) {
return is_js_api_wrapper_native_error_callback_ != nullptr &&
is_js_api_wrapper_native_error_callback_(
reinterpret_cast<v8::Isolate*>(this), Utils::ToLocal(obj));
}
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());
}
}
#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;
}
#if defined(V8_ENABLE_ETW_STACK_WALKING)
void Isolate::SetFilterETWSessionByURLCallback(
FilterETWSessionByURLCallback callback) {
filter_etw_session_by_url_callback_ = callback;
}
void Isolate::SetFilterETWSessionByURL2Callback(
FilterETWSessionByURL2Callback callback) {
filter_etw_session_by_url2_callback_ = callback;
}
FilterETWSessionByURLResult Isolate::RunFilterETWSessionByURLCallback(
const std::string& etw_filter_payload) {
if (context().is_null()) {
// No context to retrieve the current URL.
return {false, false};
}
v8::Local<v8::Context> context = Utils::ToLocal(native_context());
if (filter_etw_session_by_url2_callback_) {
return filter_etw_session_by_url2_callback_(context, etw_filter_payload);
} else if (filter_etw_session_by_url_callback_) {
bool enable_etw_tracing =
filter_etw_session_by_url_callback_(context, etw_filter_payload);
return {enable_etw_tracing, v8_flags.interpreted_frames_native_stack};
}
// If no callback is installed, by default enable etw tracing but disable
// tracing of interpreter stack frames.
return {true, v8_flags.interpreted_frames_native_stack};
}
#endif // V8_ENABLE_ETW_STACK_WALKING
void Isolate::SetAddCrashKeyCallback(AddCrashKeyCallback callback) {
add_crash_key_callback_ = callback;
// Log the initial set of data.
AddCrashKeysForIsolateAndHeapPointers();
}
void Isolate::SetCrashKeyStringCallbacks(
AllocateCrashKeyStringCallback allocate_callback,
SetCrashKeyStringCallback set_callback) {
allocate_crash_key_string_callback_ = allocate_callback;
set_crash_key_string_callback_ = set_callback;
}
bool Isolate::HasCrashKeyStringCallbacks() {
DCHECK_EQ(static_cast<bool>(allocate_crash_key_string_callback_),
static_cast<bool>(set_crash_key_string_callback_));
return static_cast<bool>(allocate_crash_key_string_callback_);
}
CrashKey Isolate::AllocateCrashKeyString(const char key[], CrashKeySize size) {
CHECK(HasCrashKeyStringCallbacks());
#if DEBUG
// Keys are limited in their length, see
// crash_reporter::internal::kCrashKeyStorageKeySize in
// components/crash/core/common/crash_key.h.
static constexpr size_t kCrashKeyStorageKeySize = 40;
DCHECK_LT(strlen(key), kCrashKeyStorageKeySize);
#endif // DEBUG
return allocate_crash_key_string_callback_(key, size);
}
CrashKey Isolate::AddCrashKeyString(const char key[], CrashKeySize size,
std::string_view value) {
CrashKey crash_key = AllocateCrashKeyString(key, size);
SetCrashKeyString(crash_key, value);
return crash_key;
}
void Isolate::SetCrashKeyString(CrashKey key, std::string_view value) {
if (!set_crash_key_string_callback_) return;
set_crash_key_string_callback_(key, value);
}
void Isolate::SetReleaseCppHeapCallback(
v8::Isolate::ReleaseCppHeapCallback callback) {
release_cpp_heap_callback_ = callback;
}
void Isolate::RunReleaseCppHeapCallback(std::unique_ptr<v8::CppHeap> cpp_heap) {
if (release_cpp_heap_callback_) {
// Invalidate the isolate alive token, as the CppHeap will continue to exist
// after the isolate is destroyed.
CppHeap::From(cpp_heap.get())->invalidate_isolate_alive_token();
release_cpp_heap_callback_(std::move(cpp_heap));
}
}
std::shared_ptr<bool> Isolate::cpp_heap_isolate_alive_token() const {
return CppHeap::From(heap_.cpp_heap())->isolate_alive_token();
}
void Isolate::SetPromiseHook(PromiseHook hook) {
promise_hook_ = hook;
PromiseHookStateUpdated();
}
void Isolate::RunAllPromiseHooks(PromiseHookType type,
DirectHandle<JSPromise> promise,
DirectHandle<Object> parent) {
#ifdef V8_ENABLE_JAVASCRIPT_PROMISE_HOOKS
if (HasContextPromiseHooks()) {
native_context()->RunPromiseHook(type, promise, parent);
}
#endif
if (HasIsolatePromiseHooks() || HasAsyncEventDelegate()) {
RunPromiseHook(type, promise, parent);
}
}
void Isolate::RunPromiseHook(PromiseHookType type,
DirectHandle<JSPromise> promise,
DirectHandle<Object> parent) {
if (!HasIsolatePromiseHooks()) return;
DCHECK(promise_hook_ != nullptr);
promise_hook_(type, v8::Utils::ToLocal(promise), v8::Utils::ToLocal(parent));
}
void Isolate::OnAsyncFunctionSuspended(DirectHandle<JSPromise> promise,
DirectHandle<JSPromise> parent,
int skip_frame_count) {
DCHECK(!promise->has_async_task_id());
RunAllPromiseHooks(PromiseHookType::kInit, promise, parent);
if (HasAsyncEventDelegate()) {
DCHECK_NE(nullptr, async_event_delegate_);
current_async_task_id_ =
JSPromise::GetNextAsyncTaskId(current_async_task_id_);
promise->set_async_task_id(current_async_task_id_);
async_event_delegate_->AsyncEventOccurred(
debug::kDebugAwait, promise->async_task_id(), false, skip_frame_count);
}
}
void Isolate::OnPromiseThen(DirectHandle<JSPromise> promise) {
if (!HasAsyncEventDelegate()) return;
Maybe<debug::DebugAsyncActionType> action_type =
Nothing<debug::DebugAsyncActionType>();
for (JavaScriptStackFrameIterator frame_it(this); !frame_it.done();
frame_it.Advance()) {
std::vector<Handle<SharedFunctionInfo>> infos;
frame_it.frame()->GetFunctions(&infos);
for (DirectHandle<SharedFunctionInfo> info : base::Reversed(infos)) {
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(!promise->has_async_task_id());
current_async_task_id_ =
JSPromise::GetNextAsyncTaskId(current_async_task_id_);
promise->set_async_task_id(current_async_task_id_);
const int kDontSkipFrames = 0;
async_event_delegate_->AsyncEventOccurred(
action_type.FromJust(), promise->async_task_id(),
debug()->IsBlackboxed(info), kDontSkipFrames);
}
return;
}
}
}
void Isolate::OnPromiseBefore(DirectHandle<JSPromise> promise) {
RunPromiseHook(PromiseHookType::kBefore, promise,
factory()->undefined_value());
if (HasAsyncEventDelegate()) {
if (promise->has_async_task_id()) {
const int kDontSkipFrames = 0;
async_event_delegate_->AsyncEventOccurred(debug::kDebugWillHandle,
promise->async_task_id(), false,
kDontSkipFrames);
}
}
}
void Isolate::OnPromiseAfter(DirectHandle<JSPromise> promise) {
RunPromiseHook(PromiseHookType::kAfter, promise,
factory()->undefined_value());
if (HasAsyncEventDelegate()) {
if (promise->has_async_task_id()) {
const int kDontSkipFrames = 0;
async_event_delegate_->AsyncEventOccurred(debug::kDebugDidHandle,
promise->async_task_id(), false,
kDontSkipFrames);
}
}
}
void Isolate::OnStackTraceCaptured(DirectHandle<StackTraceInfo> stack_trace) {
if (HasAsyncEventDelegate()) {
const int kDontSkipFrames = 0;
async_event_delegate_->AsyncEventOccurred(debug::kDebugStackTraceCaptured,
stack_trace->id(), false,
kDontSkipFrames);
}
}
void Isolate::OnTerminationDuringRunMicrotasks() {
DCHECK(is_execution_terminating());
// This performs cleanup for when RunMicrotasks (in
// builtins-microtask-queue-gen.cc) is aborted via a termination exception.
// This has to be kept in sync with the code in said file. Currently this
// includes:
//
// (1) Resetting the |current_microtask| slot on the Isolate to avoid leaking
// memory (and also to keep |current_microtask| not being undefined as an
// indicator that we're currently pumping the microtask queue).
// (2) Empty the promise stack to avoid leaking memory.
// (3) If the |current_microtask| is a promise reaction or resolve thenable
// job task, then signal the async event delegate and debugger that the
// microtask finished running.
//
// Reset the |current_microtask| global slot.
DirectHandle<Microtask> current_microtask(
Cast<Microtask>(heap()->current_microtask()), this);
heap()->set_current_microtask(ReadOnlyRoots(this).undefined_value());
if (IsPromiseReactionJobTask(*current_microtask)) {
auto promise_reaction_job_task =
Cast<PromiseReactionJobTask>(current_microtask);
DirectHandle<HeapObject> promise_or_capability(
promise_reaction_job_task->promise_or_capability(), this);
if (IsPromiseCapability(*promise_or_capability)) {
promise_or_capability = direct_handle(
Cast<PromiseCapability>(promise_or_capability)->promise(), this);
}
if (IsJSPromise(*promise_or_capability)) {
OnPromiseAfter(Cast<JSPromise>(promise_or_capability));
}
} else if (IsPromiseResolveThenableJobTask(*current_microtask)) {
auto promise_resolve_thenable_job_task =
Cast<PromiseResolveThenableJobTask>(current_microtask);
DirectHandle<JSPromise> promise_to_resolve(
promise_resolve_thenable_job_task->promise_to_resolve(), this);
OnPromiseAfter(promise_to_resolve);
}
SetTerminationOnExternalTryCatch();
}
void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
promise_reject_callback_ = callback;
}
void Isolate::ReportPromiseReject(DirectHandle<JSPromise> promise,
DirectHandle<Object> value,
v8::PromiseRejectEvent event) {
if (promise_reject_callback_ == nullptr) return;
promise_reject_callback_(v8::PromiseRejectMessage(
v8::Utils::ToLocal(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) {
CountUsage(base::VectorOf({feature}));
}
void Isolate::CountUsage(
base::Vector<const v8::Isolate::UseCounterFeature> features) {
// 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(IsContext(context()));
DCHECK(IsNativeContext(context()->native_context()));
if (use_counter_callback_) {
HandleScope handle_scope(this);
for (auto feature : features) {
use_counter_callback_(reinterpret_cast<v8::Isolate*>(this), feature);
}
}
} else {
heap_.IncrementDeferredCounts(features);
}
}
int Isolate::GetNextScriptId() { return heap()->NextScriptId(); }
// static
std::string Isolate::GetTurboCfgFileName(Isolate* isolate) {
if (const char* filename = v8_flags.trace_turbo_cfg_file) return filename;
std::ostringstream os;
os << "turbo-" << base::OS::GetCurrentProcessId() << "-";
if (isolate != nullptr) {
os << isolate->id();
} else {
os << "any";
}
os << ".cfg";
return os.str();
}
// Heap::detached_contexts tracks detached contexts as pairs
// (the context, number of GC since the context was detached).
void Isolate::AddDetachedContext(DirectHandle<Context> context) {
HandleScope scope(this);
Handle<WeakArrayList> detached_contexts = factory()->detached_contexts();
detached_contexts = WeakArrayList::AddToEnd(
this, detached_contexts, MaybeObjectDirectHandle::Weak(context),
Smi::zero());
heap()->set_detached_contexts(*detached_contexts);
}
void Isolate::CheckDetachedContextsAfterGC() {
HandleScope scope(this);
DirectHandle<WeakArrayList> detached_contexts =
factory()->detached_contexts();
const uint32_t length = detached_contexts->length().value();
if (length == 0) return;
uint32_t new_length = 0;
for (uint32_t i = 0; i < length; i += 2) {
Tagged<MaybeObject> context = detached_contexts->Get(i);
DCHECK(context.IsWeakOrCleared());
if (!context.IsCleared()) {
int mark_sweeps = detached_contexts->Get(i + 1).ToSmi().value();
detached_contexts->Set(new_length, context);
detached_contexts->Set(new_length + 1, Smi::FromInt(mark_sweeps + 1));
new_length += 2;
}
}
detached_contexts->set_length(new_length);
uint32_t last_context_index = new_length;
while (last_context_index < length) {
detached_contexts->Set(last_context_index, Smi::zero());
++last_context_index;
}
if (v8_flags.trace_detached_contexts) {
PrintF("%d detached contexts are collected out of %d\n",
length - new_length, length);
for (uint32_t i = 0; i < new_length; i += 2) {
Tagged<MaybeObject> context = detached_contexts->Get(i);
int mark_sweeps = detached_contexts->Get(i + 1).ToSmi().value();
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(DirectHandle<NativeContext> env) {
if (env->IsDetached()) {
// Respective global_proxy_for_api object must be "attached" to the
// global object.
DCHECK(!env->global_object()->global_proxy_for_api()->IsDetachedFrom(
env->global_object()));
return;
}
{
// Create a copy of JSGlobalProxy that will be used as holder for contextual
// accesses to global properties in detached context that involve Api
// callbacks (both accessor and interceptor).
// This JSGlobalProxy keeps 1:1 relationship to JSGlobalObject but looses
// the global object identity and looses connection to respective embedder
// fields and Api wrappers.
CHECK_EQ(env->global_object()->global_proxy_for_api(),
env->global_object()->global_proxy());
DirectHandle<Map> map(env->global_object()->global_proxy_for_api()->map(),
this);
DirectHandle<JSGlobalProxy> global_proxy_for_api =
Cast<JSGlobalProxy>(factory()->NewJSObjectFromMap(
map, AllocationType::kOld, {},
NewJSObjectType::kMaybeEmbedderFieldsAndApiWrapper));
env->global_object()->set_global_proxy_for_api(*global_proxy_for_api);
DCHECK(!global_proxy_for_api->IsDetachedFrom(env->global_object()));
}
ReadOnlyRoots roots(this);
DirectHandle<JSGlobalProxy> global_proxy(env->global_proxy(), this);
// NOTE: Turbofan's JSNativeContextSpecialization and Maglev depend on
// DetachGlobal causing a map change.
JSObject::ForceSetPrototype(this, global_proxy, factory()->null_value());
// Detach the global object from the native context by making its map
// contextless (use the global metamap instead of the contextful one).
global_proxy->map()->set_map(this, roots.meta_map());
global_proxy->map()->set_constructor_or_back_pointer(roots.null_value(),
kRelaxedStore);
if (v8_flags.track_detached_contexts) AddDetachedContext(env);
DCHECK(global_proxy->IsDetached());
env->set_microtask_queue(this, nullptr);
// Invalidate the EnqueueMicrotask cache if it references this context.
if (current_microtask_native_context() == *env) {
set_current_microtask_native_context(Smi::zero());
}
// Set security token back to default (unique) state making sure that only
// accesses from the same native context are allowed.
env->set_security_token(env->global_object());
}
void Isolate::SetIsLoading(bool is_loading) {
if (is_loading) {
heap()->NotifyLoadingStarted();
} else {
heap()->NotifyLoadingEnded();
}
if (v8_flags.trace_rail) {
// TODO(crbug.com/373688984): Switch to a trace flag for loading state.
PrintIsolate(this, "RAIL mode: %s\n", is_loading ? "LOAD" : "ANIMATION");
}
}
void Isolate::SetIsInputHandling(bool is_input_handling) {
if (is_input_handling) {
heap()->NotifyInputHandlingStarted();
} else {
heap()->NotifyInputHandlingEnded();
}
}
void Isolate::SetPriority(v8::Isolate::Priority priority) {
priority_ = priority;
heap()->tracer()->UpdateCurrentEventPriority(priority_);
if (priority_ == v8::Isolate::Priority::kBestEffort) {
heap()->ActivateMemoryReducerIfNeeded();
}
}
namespace {
base::LazyMutex print_with_timestamp_mutex_ = LAZY_MUTEX_INITIALIZER;
} // namespace
void Isolate::PrintWithTimestamp(const char* format, ...) {
base::MutexGuard guard(print_with_timestamp_mutex_.Pointer());
static constexpr size_t kBufferSize = 16 * KB;
static char output_buffer[kBufferSize];
va_list arguments;
va_start(arguments, format);
vsnprintf(output_buffer, kBufferSize, format, arguments);
va_end(arguments);
base::OS::Print("[%d:%p:%d] %8.0f ms: %s", base::OS::GetCurrentProcessId(),
static_cast<void*>(this), id(), time_millis_since_init(),
output_buffer);
#if defined(V8_USE_PERFETTO)
TRACE_EVENT_INSTANT("v8", "V8.PrintWithTimestamp", "value", output_buffer);
#endif
}
void Isolate::SetIdle(bool is_idle) {
StateTag state = current_vm_state();
if (js_entry_sp() != kNullAddress) return;
DCHECK(IsIdle(state));
if (is_idle) {
set_current_vm_state(IDLE);
} else if (state == IDLE) {
set_current_vm_state(IDLE_EXTERNAL);
}
}
void Isolate::CollectSourcePositionsForAllBytecodeArrays() {
if (!initialized_) return;
HandleScope scope(this);
std::vector<Handle<SharedFunctionInfo>> sfis;
{
HeapObjectIterator iterator(heap());
for (Tagged<HeapObject> obj = iterator.Next(); !obj.is_null();
obj = iterator.Next()) {
if (!IsSharedFunctionInfo(obj)) continue;
Tagged<SharedFunctionInfo> sfi = Cast<SharedFunctionInfo>(obj);
// If the script is a Smi, then the SharedFunctionInfo is in
// the process of being deserialized.
Tagged<Object> script = sfi->raw_script(kAcquireLoad);
if (IsSmi(script)) {
DCHECK_EQ(script, Smi::uninitialized_deserialization_value());
continue;
}
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,
DirectHandle<Object> locales) {
if (IsUndefined(*locales)) return "";
return std::string(Cast<String>(*locales)->ToCString().get());
}
bool StringEqualsLocales(Isolate* isolate, const std::string& str,
DirectHandle<Object> locales) {
if (IsUndefined(*locales)) return str.empty();
return Cast<String>(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,
DirectHandle<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,
DirectHandle<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::HandleStackOverflowAndTerminationRequest() {
DCHECK(InterruptRequested());
if (V8_UNLIKELY(HasOverflowed())) {
isolate_->StackOverflow();
return true;
}
if (V8_UNLIKELY(isolate_->stack_guard()->HasTerminationRequest())) {
isolate_->TerminateExecution();
return true;
}
return false;
}
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();
}
#if V8_ENABLE_WEBASSEMBLY
bool StackLimitCheck::WasmHasOverflowed(uintptr_t gap) const {
StackGuard* stack_guard = isolate_->stack_guard();
wasm::StackMemory* active_stack = isolate_->isolate_data()->active_stack();
uintptr_t sp = 0;
uintptr_t limit = 0;
auto fp = isolate_->thread_local_top()->c_entry_fp_;
// This must be called from a runtime function, so we must be on the central
// stack and the CEntry FP must be set.
DCHECK(isolate_->IsOnCentralStack());
DCHECK_NE(fp, 0);
if (active_stack->Contains(fp)) {
// If wasm was running on a secondary stack, we had to switch to the central
// stack to perform this check, and the current SP is not relevant in this
// case. Check whether the wasm SP overflowed the wasm stack limit instead.
sp = fp + ExitFrameConstants::kCallerSPDisplacement;
limit = reinterpret_cast<uintptr_t>(active_stack->jslimit());
} else {
#ifdef USE_SIMULATOR
// The simulator uses a separate JS stack.
// Use it if code is executed on the central 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
sp = GetCurrentStackPosition();
limit = stack_guard->real_climit();
}
return sp - gap < limit;
}
bool StackLimitCheck::WasmGrowableStackHasOverflowed(uintptr_t gap) const {
// Initial stack overflow check for growable stacks.
// Called from a fast C call, check the current SP directly.
wasm::StackMemory* active_stack = isolate_->isolate_data()->active_stack();
#ifdef USE_SIMULATOR
uintptr_t sp = Simulator::current(isolate_)->get_sp();
#else
uintptr_t sp = GetCurrentStackPosition();
#endif
DCHECK(active_stack->Contains(sp));
uintptr_t limit = reinterpret_cast<uintptr_t>(active_stack->jslimit());
return sp - gap < limit;
}
#endif
SaveContext::SaveContext(Isolate* isolate) : isolate_(isolate) {
if (!isolate->context().is_null()) {
context_ = Handle<Context>(isolate->context(), isolate);
}
if (!isolate->topmost_script_having_context().is_null()) {
topmost_script_having_context_ =
Handle<Context>(isolate->topmost_script_having_context(), isolate);
}
}
SaveContext::~SaveContext() {
isolate_->set_context(context_.is_null() ? Tagged<Context>{} : *context_);
isolate_->set_topmost_script_having_context(
topmost_script_having_context_.is_null()
? Tagged<Context>{}
: *topmost_script_having_context_);
}
SaveAndSwitchContext::SaveAndSwitchContext(Isolate* isolate,
Tagged<Context> new_context)
: SaveContext(isolate) {
isolate->set_context(new_context);
}
#ifdef DEBUG
AssertNoContextChange::AssertNoContextChange(Isolate* isolate)
: isolate_(isolate),
context_(isolate->context(), isolate),
topmost_script_having_context_(isolate->topmost_script_having_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(MutablePage* 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)
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(
DirectHandle<NativeContext> context) {
if (serializer_enabled_) return v8::metrics::Recorder::ContextId::Empty();
i::Tagged<i::Object> id = context->recorder_context_id();
if (IsNullOrUndefined(id)) {
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(IsSmi(id));
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();
}
// |chunk| is either a Page or an executable LargePage.
void Isolate::RemoveCodeMemoryChunk(MutablePage* 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)
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)
}
#if V8_ENABLE_DRUMBRAKE
void Isolate::initialize_wasm_execution_timer() {
DCHECK(v8_flags.wasm_enable_exec_time_histograms &&
v8_flags.slow_histograms && !v8_flags.wasm_jitless);
wasm_execution_timer_ =
std::make_unique<wasm::WasmExecutionTimer>(this, false);
}
#endif // V8_ENABLE_DRUMBRAKE
#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::LocalsBlockListCacheRehash() {
if (IsEphemeronHashTable(heap()->locals_block_list_cache())) {
Tagged<EphemeronHashTable> cache =
Cast<EphemeronHashTable>(heap()->locals_block_list_cache());
cache->Rehash();
}
}
void Isolate::LocalsBlockListCacheSet(
DirectHandle<ScopeInfo> scope_info,
DirectHandle<ScopeInfo> outer_scope_info,
DirectHandle<StringSet> locals_blocklist) {
Handle<EphemeronHashTable> cache;
if (IsEphemeronHashTable(heap()->locals_block_list_cache())) {
cache = handle(Cast<EphemeronHashTable>(heap()->locals_block_list_cache()),
this);
} else {
CHECK(IsUndefined(heap()->locals_block_list_cache()));
constexpr int kInitialCapacity = 8;
cache = EphemeronHashTable::New(this, kInitialCapacity);
}
DCHECK(IsEphemeronHashTable(*cache));
DirectHandle<Object> value;
if (!outer_scope_info.is_null()) {
value = factory()->NewTuple2(outer_scope_info, locals_blocklist,
AllocationType::kYoung);
} else {
value = locals_blocklist;
}
CHECK(!value.is_null());
cache = EphemeronHashTable::Put(this, cache, scope_info, value);
heap()->set_locals_block_list_cache(*cache);
}
Tagged<UnionOf<TheHole, StringSet>> Isolate::LocalsBlockListCacheGet(
DirectHandle<ScopeInfo> scope_info) {
DisallowGarbageCollection no_gc;
if (!IsEphemeronHashTable(heap()->locals_block_list_cache())) {
return ReadOnlyRoots(this).the_hole_value();
}
Tagged<Object> maybe_value =
Cast<EphemeronHashTable>(heap()->locals_block_list_cache())
->Lookup(scope_info);
if (IsTheHole(maybe_value)) return Cast<TheHole>(maybe_value);
if (Tagged<Tuple2> tuple; TryCast<Tuple2>(maybe_value, &tuple)) {
return Cast<StringSet>(tuple->value2());
}
CHECK(IsStringSet(maybe_value));
return Cast<StringSet>(maybe_value);
}
void DefaultWasmAsyncResolvePromiseCallback(
v8::Isolate* isolate, v8::Local<v8::Context> context,
v8::Local<v8::Promise::Resolver> resolver, v8::Local<v8::Value> result,
WasmAsyncSuccess success) {
MicrotasksScope microtasks_scope(context,
MicrotasksScope::kDoNotRunMicrotasks);
Maybe<bool> ret = success == WasmAsyncSuccess::kSuccess
? resolver->Resolve(context, result)
: resolver->Reject(context, result);
// It's guaranteed that no exceptions will be thrown by these
// operations, but execution might be terminating.
CHECK(ret.IsJust() ? ret.FromJust() : isolate->IsExecutionTerminating());
}
void Isolate::InitializeBuiltinJSDispatchTable() {
static_assert(Builtins::kAllBuiltinsAreIsolateIndependent);
JSDispatchTable& jdt = js_dispatch_table();
#if V8_STATIC_DISPATCH_HANDLES_BOOL
// For static dispatch handles we need:
// 1. Builtins be shared across isolates.
// 2. Predictable handles in the dispatch table's r/o segment.
static_assert(Builtins::kCodeObjectsAreInROSpace);
static_assert(JSDispatchTable::kUseContiguousMemory);
JSDispatchHandle last_handle = kNullJSDispatchHandle;
JSDispatchTable::UnsealReadOnlySegmentScope unseal_scope(&jdt);
for (JSBuiltinDispatchHandleRoot::Idx idx =
JSBuiltinDispatchHandleRoot::kFirst;
idx < JSBuiltinDispatchHandleRoot::kCount;
idx = static_cast<JSBuiltinDispatchHandleRoot::Idx>(
static_cast<int>(idx) + 1)) {
Builtin builtin = JSBuiltinDispatchHandleRoot::to_builtin(idx);
DCHECK(Builtins::IsIsolateIndependent(builtin));
Tagged<Code> code = builtins_.code(builtin);
if (code->is_disabled_builtin()) {
// Initialize preallocated entry for disabled builtin with kIllegal
// builtin's Code to ensure that the actual builtin's code can't be
// called by reusing the dispatch table handle.
code = builtins_.code(Builtin::kIllegal);
}
DCHECK_EQ(code->entrypoint_tag(), CodeEntrypointTag::kJSEntrypointTag);
// Since we are sharing the dispatch handles we need all isolates to
// share the builtin code objects.
DCHECK_IMPLIES(!serializer_enabled_, HeapLayout::InReadOnlySpace(code));
// TODO(olivf, 40931165): It might be more robust to get the static
// parameter count of this builtin.
int parameter_count = code->parameter_count();
JSDispatchHandle handle = jdt.AllocateAndInitializeEntry(
heap()->read_only_js_dispatch_table_space(), parameter_count, code);
DCHECK_EQ(builtin_dispatch_handle(idx), handle);
// Read only entries should be consecutive.
DCHECK_EQ(handle, JSDispatchTable::IndexToHandle(
JSDispatchTable::HandleToIndex(last_handle) + 1));
last_handle = handle;
CHECK_EQ(handle,
JSDispatchTable::GetStaticHandleForReadOnlySegmentEntry(idx));
}
#else
for (JSBuiltinDispatchHandleRoot::Idx idx =
JSBuiltinDispatchHandleRoot::kFirst;
idx < JSBuiltinDispatchHandleRoot::kCount;
idx = static_cast<JSBuiltinDispatchHandleRoot::Idx>(
static_cast<int>(idx) + 1)) {
Builtin builtin = JSBuiltinDispatchHandleRoot::to_builtin(idx);
Tagged<Code> code = builtins_.code(builtin);
DCHECK_LT(idx, JSBuiltinDispatchHandleRoot::kTableSize);
JSDispatchHandle handle = kNullJSDispatchHandle;
// Don't allocate dispatch table entry for disabled builtin to ensure
// it's impossible to call it.
if (!code->is_disabled_builtin()) {
int parameter_count = code->parameter_count();
handle = jdt.AllocateAndInitializeEntry(heap()->js_dispatch_table_space(),
parameter_count, code);
}
isolate_data_.builtin_dispatch_table()[idx] = handle;
}
#endif // !V8_STATIC_DISPATCH_HANDLES_BOOL
}
void Isolate::PrintNumberStringCacheStats(const char* comment,
bool final_summary) {
#define FETCH_COUNTER(name) \
uint32_t name = static_cast<uint32_t>(counters()->name()->Get());
FETCH_COUNTER(write_barriers)
FETCH_COUNTER(number_string_cache_smi_probes)
FETCH_COUNTER(number_string_cache_smi_misses)
FETCH_COUNTER(number_string_cache_double_probes)
FETCH_COUNTER(number_string_cache_double_misses)
#undef FETCH_COUNTER
PrintF("=== NumberToString cache usage stats (%s):\n", comment);
if (final_summary && write_barriers == 0) {
// If write barriers count is zero, then it's most likely because
// builtins are compiled without --native-code-counters.
PrintF(
"=== WARNING: empty stats! Ensure gn args contain: "
"`v8_enable_snapshot_native_code_counters = true`\n");
}
double smi_miss_rate =
number_string_cache_smi_probes
? static_cast<double>(number_string_cache_smi_misses) /
number_string_cache_smi_probes
: 0;
double double_miss_rate =
number_string_cache_double_probes
? static_cast<double>(number_string_cache_double_misses) /
number_string_cache_double_probes
: 0;
PrintF("=== SmiStringCache miss rate: %.6f (%d / %d)\n", //
smi_miss_rate, number_string_cache_smi_misses,
number_string_cache_smi_probes);
PrintF("=== DoubleStringCache miss rate: %.6f (%d / %d)\n", //
double_miss_rate, number_string_cache_double_misses,
number_string_cache_double_probes);
uint32_t smi_string_cache_capacity =
factory()->smi_string_cache()->capacity();
uint32_t smi_string_used_entries =
factory()->smi_string_cache()->GetUsedEntriesCount();
uint32_t double_string_cache_capacity =
factory()->double_string_cache()->capacity();
uint32_t double_string_used_entries =
factory()->double_string_cache()->GetUsedEntriesCount();
double smi_cache_utilization_rate =
static_cast<double>(smi_string_used_entries) / smi_string_cache_capacity;
double double_cache_utilization_rate =
static_cast<double>(double_string_used_entries) /
double_string_cache_capacity;
PrintF("=== SmiStringCache utilization: %.6f (%d / %d)\n", //
smi_cache_utilization_rate, smi_string_used_entries,
smi_string_cache_capacity);
PrintF("=== DoubleStringCache utilization: %.6f (%d / %d)\n", //
double_cache_utilization_rate, double_string_used_entries,
double_string_cache_capacity);
if (final_summary) {
PrintF("=== --smi-string-cache-size=%d\n",
v8_flags.smi_string_cache_size.value());
PrintF("=== --double-string-cache-size=%d\n",
v8_flags.double_string_cache_size.value());
}
PrintF("\n");
}
} // namespace internal
} // namespace v8