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chromium / v8 / v8 / b49206ded97c4eaac7c273ce004d840a0185d40e / . / src / isolate.cc
blob: e7429c3cea8e64bad31338343c952ba0f9de4fe4 [file] [log] [blame]
// 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/isolate.h"
#include <stdlib.h>
#include <atomic>
#include <fstream> // NOLINT(readability/streams)
#include <sstream>
#include <unordered_map>
#include "src/api.h"
#include "src/assembler-inl.h"
#include "src/ast/ast-value-factory.h"
#include "src/ast/context-slot-cache.h"
#include "src/base/adapters.h"
#include "src/base/hashmap.h"
#include "src/base/platform/platform.h"
#include "src/base/sys-info.h"
#include "src/base/utils/random-number-generator.h"
#include "src/basic-block-profiler.h"
#include "src/bootstrapper.h"
#include "src/builtins/constants-table-builder.h"
#include "src/cancelable-task.h"
#include "src/code-stubs.h"
#include "src/compilation-cache.h"
#include "src/compilation-statistics.h"
#include "src/compiler-dispatcher/compiler-dispatcher.h"
#include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
#include "src/debug/debug.h"
#include "src/deoptimizer.h"
#include "src/elements.h"
#include "src/frames-inl.h"
#include "src/ic/stub-cache.h"
#include "src/instruction-stream.h"
#include "src/interpreter/interpreter.h"
#include "src/isolate-inl.h"
#include "src/libsampler/sampler.h"
#include "src/log.h"
#include "src/messages.h"
#include "src/objects/frame-array-inl.h"
#include "src/objects/promise-inl.h"
#include "src/profiler/cpu-profiler.h"
#include "src/profiler/tracing-cpu-profiler.h"
#include "src/prototype.h"
#include "src/regexp/regexp-stack.h"
#include "src/runtime-profiler.h"
#include "src/setup-isolate.h"
#include "src/simulator.h"
#include "src/snapshot/startup-deserializer.h"
#include "src/tracing/tracing-category-observer.h"
#include "src/trap-handler/trap-handler.h"
#include "src/unicode-cache.h"
#include "src/v8.h"
#include "src/version.h"
#include "src/visitors.h"
#include "src/vm-state-inl.h"
#include "src/wasm/compilation-manager.h"
#include "src/wasm/wasm-code-manager.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-objects.h"
#include "src/zone/accounting-allocator.h"
namespace v8 {
namespace internal {
base::Atomic32 ThreadId::highest_thread_id_ = 0;
#ifdef V8_EMBEDDED_BUILTINS
extern const uint8_t* DefaultEmbeddedBlob();
extern uint32_t DefaultEmbeddedBlobSize();
#ifdef V8_MULTI_SNAPSHOTS
extern const uint8_t* TrustedEmbeddedBlob();
extern uint32_t TrustedEmbeddedBlobSize();
#endif
namespace {
// These variables provide access to the current embedded blob without requiring
// an isolate instance. This is needed e.g. by Code::InstructionStart, which may
// not have access to an isolate but still needs to access the embedded blob.
// The variables are initialized by each isolate in Init(). Writes and reads are
// relaxed since we can guarantee that the current thread has initialized these
// variables before accessing them. Different threads may race, but this is fine
// since they all attempt to set the same values of the blob pointer and size.
std::atomic<const uint8_t*> current_embedded_blob_(nullptr);
std::atomic<uint32_t> current_embedded_blob_size_(0);
} // namespace
void Isolate::SetEmbeddedBlob(const uint8_t* blob, uint32_t blob_size) {
embedded_blob_ = blob;
embedded_blob_size_ = blob_size;
current_embedded_blob_.store(blob, std::memory_order_relaxed);
current_embedded_blob_size_.store(blob_size, std::memory_order_relaxed);
#ifdef DEBUG
if (blob != nullptr) {
// 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();
CHECK_EQ(d.Hash(), d.CreateHash());
}
#endif // DEBUG
}
const uint8_t* Isolate::embedded_blob() const { return embedded_blob_; }
uint32_t Isolate::embedded_blob_size() const { return embedded_blob_size_; }
// static
const uint8_t* Isolate::CurrentEmbeddedBlob() {
return current_embedded_blob_.load(std::memory_order::memory_order_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobSize() {
return current_embedded_blob_size_.load(
std::memory_order::memory_order_relaxed);
}
#endif // V8_EMBEDDED_BUILTINS
int ThreadId::AllocateThreadId() {
int new_id = base::Relaxed_AtomicIncrement(&highest_thread_id_, 1);
return new_id;
}
int ThreadId::GetCurrentThreadId() {
int thread_id = base::Thread::GetThreadLocalInt(Isolate::thread_id_key_);
if (thread_id == 0) {
thread_id = AllocateThreadId();
base::Thread::SetThreadLocalInt(Isolate::thread_id_key_, thread_id);
}
return thread_id;
}
ThreadLocalTop::ThreadLocalTop() {
InitializeInternal();
}
void ThreadLocalTop::InitializeInternal() {
c_entry_fp_ = 0;
c_function_ = 0;
handler_ = 0;
#ifdef USE_SIMULATOR
simulator_ = nullptr;
#endif
js_entry_sp_ = kNullAddress;
external_callback_scope_ = nullptr;
current_vm_state_ = EXTERNAL;
try_catch_handler_ = nullptr;
context_ = nullptr;
thread_id_ = ThreadId::Invalid();
external_caught_exception_ = false;
failed_access_check_callback_ = nullptr;
save_context_ = nullptr;
promise_on_stack_ = nullptr;
// These members are re-initialized later after deserialization
// is complete.
pending_exception_ = nullptr;
wasm_caught_exception_ = nullptr;
rethrowing_message_ = false;
pending_message_obj_ = nullptr;
scheduled_exception_ = nullptr;
}
void ThreadLocalTop::Initialize() {
InitializeInternal();
#ifdef USE_SIMULATOR
simulator_ = Simulator::current(isolate_);
#endif
thread_id_ = ThreadId::Current();
}
void ThreadLocalTop::Free() {
wasm_caught_exception_ = nullptr;
// Match unmatched PopPromise calls.
while (promise_on_stack_) isolate_->PopPromise();
}
base::Thread::LocalStorageKey Isolate::isolate_key_;
base::Thread::LocalStorageKey Isolate::thread_id_key_;
base::Thread::LocalStorageKey Isolate::per_isolate_thread_data_key_;
base::Atomic32 Isolate::isolate_counter_ = 0;
#if DEBUG
base::Atomic32 Isolate::isolate_key_created_ = 0;
#endif
Isolate::PerIsolateThreadData*
Isolate::FindOrAllocatePerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::Current();
PerIsolateThreadData* per_thread = nullptr;
{
base::LockGuard<base::Mutex> lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
if (per_thread == nullptr) {
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() {
int thread_id_int = base::Thread::GetThreadLocalInt(Isolate::thread_id_key_);
if (thread_id_int) {
ThreadId thread_id = ThreadId(thread_id_int);
DCHECK(!thread_manager_->mutex_owner_.Equals(thread_id));
base::LockGuard<base::Mutex> 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::LockGuard<base::Mutex> lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
}
return per_thread;
}
void Isolate::InitializeOncePerProcess() {
isolate_key_ = base::Thread::CreateThreadLocalKey();
#if DEBUG
base::Relaxed_Store(&isolate_key_created_, 1);
#endif
thread_id_key_ = base::Thread::CreateThreadLocalKey();
per_isolate_thread_data_key_ = base::Thread::CreateThreadLocalKey();
}
Address Isolate::get_address_from_id(IsolateAddressId id) {
return isolate_addresses_[id];
}
char* Isolate::Iterate(RootVisitor* v, char* thread_storage) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(thread_storage);
Iterate(v, thread);
return thread_storage + sizeof(ThreadLocalTop);
}
void Isolate::IterateThread(ThreadVisitor* v, char* t) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(t);
v->VisitThread(this, thread);
}
void Isolate::Iterate(RootVisitor* v, ThreadLocalTop* thread) {
// Visit the roots from the top for a given thread.
v->VisitRootPointer(Root::kTop, nullptr, &thread->pending_exception_);
v->VisitRootPointer(Root::kTop, nullptr, &thread->wasm_caught_exception_);
v->VisitRootPointer(Root::kTop, nullptr, &thread->pending_message_obj_);
v->VisitRootPointer(Root::kTop, nullptr,
bit_cast<Object**>(&(thread->context_)));
v->VisitRootPointer(Root::kTop, nullptr, &thread->scheduled_exception_);
for (v8::TryCatch* block = thread->try_catch_handler(); block != nullptr;
block = block->next_) {
v->VisitRootPointer(Root::kTop, nullptr,
bit_cast<Object**>(&(block->exception_)));
v->VisitRootPointer(Root::kTop, nullptr,
bit_cast<Object**>(&(block->message_obj_)));
}
// Iterate over pointers on native execution stack.
for (StackFrameIterator it(this, thread); !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
}
void Isolate::Iterate(RootVisitor* v) {
ThreadLocalTop* current_t = thread_local_top();
Iterate(v, current_t);
}
void Isolate::IterateDeferredHandles(RootVisitor* visitor) {
for (DeferredHandles* deferred = deferred_handles_head_; deferred != nullptr;
deferred = deferred->next_) {
deferred->Iterate(visitor);
}
}
#ifdef DEBUG
bool Isolate::IsDeferredHandle(Object** handle) {
// Each DeferredHandles instance keeps the handles to one job in the
// concurrent recompilation queue, containing a list of blocks. Each block
// contains kHandleBlockSize handles except for the first block, which may
// not be fully filled.
// We iterate through all the blocks to see whether the argument handle
// belongs to one of the blocks. If so, it is deferred.
for (DeferredHandles* deferred = deferred_handles_head_; deferred != nullptr;
deferred = deferred->next_) {
std::vector<Object**>* blocks = &deferred->blocks_;
for (size_t i = 0; i < blocks->size(); i++) {
Object** block_limit = (i == 0) ? deferred->first_block_limit_
: blocks->at(i) + kHandleBlockSize;
if (blocks->at(i) <= handle && handle < block_limit) return true;
}
}
return false;
}
#endif // DEBUG
void Isolate::RegisterTryCatchHandler(v8::TryCatch* that) {
thread_local_top()->set_try_catch_handler(that);
}
void Isolate::UnregisterTryCatchHandler(v8::TryCatch* that) {
DCHECK(thread_local_top()->try_catch_handler() == that);
thread_local_top()->set_try_catch_handler(that->next_);
}
Handle<String> Isolate::StackTraceString() {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
HeapStringAllocator allocator;
StringStream::ClearMentionedObjectCache(this);
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator);
Handle<String> stack_trace = accumulator.ToString(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
return stack_trace;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToStdOut();
return factory()->empty_string();
} else {
base::OS::Abort();
// Unreachable
return factory()->empty_string();
}
}
void Isolate::PushStackTraceAndDie(void* ptr1, void* ptr2, void* ptr3,
void* ptr4) {
StackTraceFailureMessage message(this, ptr1, ptr2, ptr3, ptr4);
message.Print();
base::OS::Abort();
}
void StackTraceFailureMessage::Print() volatile {
// Print the details of this failure message object, including its own address
// to force stack allocation.
base::OS::PrintError(
"Stacktrace:\n ptr1=%p\n ptr2=%p\n ptr3=%p\n ptr4=%p\n "
"failure_message_object=%p\n%s",
ptr1_, ptr2_, ptr3_, ptr4_, this, &js_stack_trace_[0]);
}
StackTraceFailureMessage::StackTraceFailureMessage(Isolate* isolate, void* ptr1,
void* ptr2, void* ptr3,
void* ptr4) {
isolate_ = isolate;
ptr1_ = ptr1;
ptr2_ = ptr2;
ptr3_ = ptr3;
ptr4_ = ptr4;
// Write a stracktrace into the {js_stack_trace_} buffer.
const size_t buffer_length = arraysize(js_stack_trace_);
memset(&js_stack_trace_, 0, buffer_length);
FixedStringAllocator fixed(&js_stack_trace_[0], buffer_length - 1);
StringStream accumulator(&fixed, StringStream::kPrintObjectConcise);
isolate->PrintStack(&accumulator, Isolate::kPrintStackVerbose);
// Keeping a reference to the last code objects to increase likelyhood that
// they get included in the minidump.
const size_t code_objects_length = arraysize(code_objects_);
size_t i = 0;
StackFrameIterator it(isolate);
for (; !it.done() && i < code_objects_length; it.Advance()) {
code_objects_[i++] = it.frame()->unchecked_code();
}
}
namespace {
class FrameArrayBuilder {
public:
FrameArrayBuilder(Isolate* isolate, FrameSkipMode mode, int limit,
Handle<Object> caller)
: isolate_(isolate), mode_(mode), limit_(limit), caller_(caller) {
switch (mode_) {
case SKIP_FIRST:
skip_next_frame_ = true;
break;
case SKIP_UNTIL_SEEN:
DCHECK(caller_->IsJSFunction());
skip_next_frame_ = true;
break;
case SKIP_NONE:
skip_next_frame_ = false;
break;
}
elements_ = isolate->factory()->NewFrameArray(Min(limit, 10));
}
void AppendStandardFrame(StandardFrame* frame) {
std::vector<FrameSummary> frames;
frame->Summarize(&frames);
// A standard frame may include many summarized frames (due to inlining).
for (size_t i = frames.size(); i != 0 && !full(); i--) {
const auto& summ = frames[i - 1];
if (summ.IsJavaScript()) {
//====================================================================
// Handle a JavaScript frame.
//====================================================================
const auto& summary = summ.AsJavaScript();
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(summary.function())) continue;
Handle<AbstractCode> abstract_code = summary.abstract_code();
const int offset = summary.code_offset();
bool is_constructor = summary.is_constructor();
// Help CallSite::IsConstructor correctly detect hand-written
// construct stubs.
if (abstract_code->IsCode() &&
Code::cast(*abstract_code)->is_construct_stub()) {
is_constructor = true;
}
int flags = 0;
Handle<JSFunction> function = summary.function();
if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
if (is_constructor) flags |= FrameArray::kIsConstructor;
elements_ = FrameArray::AppendJSFrame(
elements_, TheHoleToUndefined(isolate_, summary.receiver()),
function, abstract_code, offset, flags);
} else if (summ.IsWasmCompiled()) {
//====================================================================
// Handle a WASM compiled frame.
//====================================================================
const auto& summary = summ.AsWasmCompiled();
if (summary.code()->kind() != wasm::WasmCode::kFunction) {
continue;
}
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = 0;
if (instance->compiled_module()->shared()->is_asm_js()) {
flags |= FrameArray::kIsAsmJsWasmFrame;
if (WasmCompiledFrame::cast(frame)->at_to_number_conversion()) {
flags |= FrameArray::kAsmJsAtNumberConversion;
}
} else {
flags |= FrameArray::kIsWasmFrame;
}
elements_ = FrameArray::AppendWasmFrame(
elements_, instance, summary.function_index(), summary.code(),
summary.code_offset(), flags);
} else if (summ.IsWasmInterpreted()) {
//====================================================================
// Handle a WASM interpreted frame.
//====================================================================
const auto& summary = summ.AsWasmInterpreted();
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = FrameArray::kIsWasmInterpretedFrame;
DCHECK(!instance->compiled_module()->shared()->is_asm_js());
elements_ = FrameArray::AppendWasmFrame(elements_, instance,
summary.function_index(), {},
summary.byte_offset(), flags);
}
}
}
void AppendBuiltinExitFrame(BuiltinExitFrame* exit_frame) {
Handle<JSFunction> function = handle(exit_frame->function(), isolate_);
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(function)) return;
Handle<Object> receiver(exit_frame->receiver(), isolate_);
Handle<Code> code(exit_frame->LookupCode(), isolate_);
const int offset =
static_cast<int>(exit_frame->pc() - code->InstructionStart());
int flags = 0;
if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
if (exit_frame->IsConstructor()) flags |= FrameArray::kIsConstructor;
elements_ = FrameArray::AppendJSFrame(elements_, receiver, function,
Handle<AbstractCode>::cast(code),
offset, flags);
}
bool full() { return elements_->FrameCount() >= limit_; }
Handle<FrameArray> GetElements() {
elements_->ShrinkToFit();
return elements_;
}
private:
// Poison stack frames below the first strict mode frame.
// The stack trace API should not expose receivers and function
// objects on frames deeper than the top-most one with a strict mode
// function.
bool IsStrictFrame(Handle<JSFunction> function) {
if (!encountered_strict_function_) {
encountered_strict_function_ =
is_strict(function->shared()->language_mode());
}
return encountered_strict_function_;
}
// Determines whether the given stack frame should be displayed in a stack
// trace.
bool IsVisibleInStackTrace(Handle<JSFunction> function) {
return ShouldIncludeFrame(function) && IsNotHidden(function) &&
IsInSameSecurityContext(function);
}
// This mechanism excludes a number of uninteresting frames from the stack
// trace. This can be be the first frame (which will be a builtin-exit frame
// for the error constructor builtin) or every frame until encountering a
// user-specified function.
bool ShouldIncludeFrame(Handle<JSFunction> function) {
switch (mode_) {
case SKIP_NONE:
return true;
case SKIP_FIRST:
if (!skip_next_frame_) return true;
skip_next_frame_ = false;
return false;
case SKIP_UNTIL_SEEN:
if (skip_next_frame_ && (*function == *caller_)) {
skip_next_frame_ = false;
return false;
}
return !skip_next_frame_;
}
UNREACHABLE();
}
bool IsNotHidden(Handle<JSFunction> function) {
// Functions defined not in user scripts are not visible unless directly
// exposed, in which case the native flag is set.
// The --builtins-in-stack-traces command line flag allows including
// internal call sites in the stack trace for debugging purposes.
if (!FLAG_builtins_in_stack_traces &&
!function->shared()->IsUserJavaScript()) {
return function->shared()->native();
}
return true;
}
bool IsInSameSecurityContext(Handle<JSFunction> function) {
return isolate_->context()->HasSameSecurityTokenAs(function->context());
}
// TODO(jgruber): Fix all cases in which frames give us a hole value (e.g. the
// receiver in RegExp constructor frames.
Handle<Object> TheHoleToUndefined(Isolate* isolate, Handle<Object> in) {
return (in->IsTheHole(isolate))
? Handle<Object>::cast(isolate->factory()->undefined_value())
: in;
}
Isolate* isolate_;
const FrameSkipMode mode_;
int limit_;
const Handle<Object> caller_;
bool skip_next_frame_ = true;
bool encountered_strict_function_ = false;
Handle<FrameArray> elements_;
};
bool GetStackTraceLimit(Isolate* isolate, int* result) {
Handle<JSObject> error = isolate->error_function();
Handle<String> key = isolate->factory()->stackTraceLimit_string();
Handle<Object> stack_trace_limit = JSReceiver::GetDataProperty(error, key);
if (!stack_trace_limit->IsNumber()) return false;
// Ensure that limit is not negative.
*result = Max(FastD2IChecked(stack_trace_limit->Number()), 0);
if (*result != FLAG_stack_trace_limit) {
isolate->CountUsage(v8::Isolate::kErrorStackTraceLimit);
}
return true;
}
bool NoExtension(const v8::FunctionCallbackInfo<v8::Value>&) { return false; }
} // namespace
Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSReceiver> error_object,
FrameSkipMode mode,
Handle<Object> caller) {
DisallowJavascriptExecution no_js(this);
int limit;
if (!GetStackTraceLimit(this, &limit)) return factory()->undefined_value();
FrameArrayBuilder builder(this, mode, limit, caller);
for (StackFrameIterator iter(this); !iter.done() && !builder.full();
iter.Advance()) {
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION:
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN:
builder.AppendStandardFrame(JavaScriptFrame::cast(frame));
break;
case StackFrame::BUILTIN_EXIT:
// BuiltinExitFrames are not standard frames, so they do not have
// Summarize(). However, they may have one JS frame worth showing.
builder.AppendBuiltinExitFrame(BuiltinExitFrame::cast(frame));
break;
case StackFrame::WASM_COMPILED:
builder.AppendStandardFrame(WasmCompiledFrame::cast(frame));
break;
case StackFrame::WASM_INTERPRETER_ENTRY:
builder.AppendStandardFrame(WasmInterpreterEntryFrame::cast(frame));
break;
default:
break;
}
}
// TODO(yangguo): Queue this structured stack trace for preprocessing on GC.
return factory()->NewJSArrayWithElements(builder.GetElements());
}
MaybeHandle<JSReceiver> Isolate::CaptureAndSetDetailedStackTrace(
Handle<JSReceiver> error_object) {
if (capture_stack_trace_for_uncaught_exceptions_) {
// Capture stack trace for a detailed exception message.
Handle<Name> key = factory()->detailed_stack_trace_symbol();
Handle<FixedArray> stack_trace = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
RETURN_ON_EXCEPTION(this,
JSReceiver::SetProperty(error_object, key, stack_trace,
LanguageMode::kStrict),
JSReceiver);
}
return error_object;
}
MaybeHandle<JSReceiver> Isolate::CaptureAndSetSimpleStackTrace(
Handle<JSReceiver> error_object, FrameSkipMode mode,
Handle<Object> caller) {
// Capture stack trace for simple stack trace string formatting.
Handle<Name> key = factory()->stack_trace_symbol();
Handle<Object> stack_trace =
CaptureSimpleStackTrace(error_object, mode, caller);
RETURN_ON_EXCEPTION(this,
JSReceiver::SetProperty(error_object, key, stack_trace,
LanguageMode::kStrict),
JSReceiver);
return error_object;
}
Handle<FixedArray> Isolate::GetDetailedStackTrace(
Handle<JSObject> error_object) {
Handle<Name> key_detailed = factory()->detailed_stack_trace_symbol();
Handle<Object> stack_trace =
JSReceiver::GetDataProperty(error_object, key_detailed);
if (stack_trace->IsFixedArray()) return Handle<FixedArray>::cast(stack_trace);
return Handle<FixedArray>();
}
Address Isolate::GetAbstractPC(int* line, int* column) {
JavaScriptFrameIterator it(this);
if (it.done()) {
*line = -1;
*column = -1;
return kNullAddress;
}
JavaScriptFrame* frame = it.frame();
DCHECK(!frame->is_builtin());
int position = frame->position();
Object* maybe_script = frame->function()->shared()->script();
if (maybe_script->IsScript()) {
Handle<Script> script(Script::cast(maybe_script), this);
Script::PositionInfo info;
Script::GetPositionInfo(script, position, &info, Script::WITH_OFFSET);
*line = info.line + 1;
*column = info.column + 1;
} else {
*line = position;
*column = -1;
}
if (frame->is_interpreted()) {
InterpretedFrame* iframe = static_cast<InterpretedFrame*>(frame);
Address bytecode_start =
reinterpret_cast<Address>(iframe->GetBytecodeArray()) - kHeapObjectTag +
BytecodeArray::kHeaderSize;
return bytecode_start + iframe->GetBytecodeOffset();
}
return frame->pc();
}
class CaptureStackTraceHelper {
public:
explicit CaptureStackTraceHelper(Isolate* isolate) : isolate_(isolate) {}
Handle<StackFrameInfo> NewStackFrameObject(FrameSummary& summ) {
if (summ.IsJavaScript()) return NewStackFrameObject(summ.AsJavaScript());
if (summ.IsWasm()) return NewStackFrameObject(summ.AsWasm());
UNREACHABLE();
}
Handle<StackFrameInfo> NewStackFrameObject(
const FrameSummary::JavaScriptFrameSummary& summ) {
int code_offset;
Handle<ByteArray> source_position_table;
Handle<Object> maybe_cache;
Handle<SimpleNumberDictionary> cache;
if (!FLAG_optimize_for_size) {
code_offset = summ.code_offset();
source_position_table =
handle(summ.abstract_code()->source_position_table(), isolate_);
maybe_cache = handle(summ.abstract_code()->stack_frame_cache(), isolate_);
if (maybe_cache->IsSimpleNumberDictionary()) {
cache = Handle<SimpleNumberDictionary>::cast(maybe_cache);
} else {
cache = SimpleNumberDictionary::New(isolate_, 1);
}
int entry = cache->FindEntry(code_offset);
if (entry != NumberDictionary::kNotFound) {
Handle<StackFrameInfo> frame(
StackFrameInfo::cast(cache->ValueAt(entry)));
DCHECK(frame->function_name()->IsString());
Handle<String> function_name = summ.FunctionName();
if (function_name->Equals(String::cast(frame->function_name()))) {
return frame;
}
}
}
Handle<StackFrameInfo> frame = factory()->NewStackFrameInfo();
Handle<Script> script = Handle<Script>::cast(summ.script());
Script::PositionInfo info;
bool valid_pos = Script::GetPositionInfo(script, summ.SourcePosition(),
&info, Script::WITH_OFFSET);
if (valid_pos) {
frame->set_line_number(info.line + 1);
frame->set_column_number(info.column + 1);
}
frame->set_script_id(script->id());
frame->set_script_name(script->name());
frame->set_script_name_or_source_url(script->GetNameOrSourceURL());
frame->set_is_eval(script->compilation_type() ==
Script::COMPILATION_TYPE_EVAL);
Handle<String> function_name = summ.FunctionName();
frame->set_function_name(*function_name);
frame->set_is_constructor(summ.is_constructor());
frame->set_is_wasm(false);
if (!FLAG_optimize_for_size) {
auto new_cache = SimpleNumberDictionary::Set(cache, code_offset, frame);
if (*new_cache != *cache || !maybe_cache->IsNumberDictionary()) {
AbstractCode::SetStackFrameCache(summ.abstract_code(), new_cache);
}
}
frame->set_id(next_id());
return frame;
}
Handle<StackFrameInfo> NewStackFrameObject(
const FrameSummary::WasmFrameSummary& summ) {
Handle<StackFrameInfo> info = factory()->NewStackFrameInfo();
Handle<WasmSharedModuleData> shared(
summ.wasm_instance()->compiled_module()->shared(), isolate_);
Handle<String> name = WasmSharedModuleData::GetFunctionName(
isolate_, shared, summ.function_index());
info->set_function_name(*name);
// Encode the function index as line number (1-based).
info->set_line_number(summ.function_index() + 1);
// Encode the byte offset as column (1-based).
int position = summ.byte_offset();
// Make position 1-based.
if (position >= 0) ++position;
info->set_column_number(position);
info->set_script_id(summ.script()->id());
info->set_is_wasm(true);
info->set_id(next_id());
return info;
}
private:
inline Factory* factory() { return isolate_->factory(); }
int next_id() const {
int id = isolate_->last_stack_frame_info_id() + 1;
isolate_->set_last_stack_frame_info_id(id);
return id;
}
Isolate* isolate_;
};
Handle<FixedArray> Isolate::CaptureCurrentStackTrace(
int frame_limit, StackTrace::StackTraceOptions options) {
DisallowJavascriptExecution no_js(this);
CaptureStackTraceHelper helper(this);
// Ensure no negative values.
int limit = Max(frame_limit, 0);
Handle<FixedArray> stack_trace_elems = factory()->NewFixedArray(limit);
int frames_seen = 0;
for (StackTraceFrameIterator it(this); !it.done() && (frames_seen < limit);
it.Advance()) {
StandardFrame* frame = it.frame();
// Set initial size to the maximum inlining level + 1 for the outermost
// function.
std::vector<FrameSummary> frames;
frame->Summarize(&frames);
for (size_t i = frames.size(); i != 0 && frames_seen < limit; i--) {
FrameSummary& frame = frames[i - 1];
if (!frame.is_subject_to_debugging()) continue;
// Filter frames from other security contexts.
if (!(options & StackTrace::kExposeFramesAcrossSecurityOrigins) &&
!this->context()->HasSameSecurityTokenAs(*frame.native_context()))
continue;
Handle<StackFrameInfo> new_frame_obj = helper.NewStackFrameObject(frame);
stack_trace_elems->set(frames_seen, *new_frame_obj);
frames_seen++;
}
}
stack_trace_elems->Shrink(frames_seen);
return stack_trace_elems;
}
void Isolate::PrintStack(FILE* out, PrintStackMode mode) {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
StringStream::ClearMentionedObjectCache(this);
HeapStringAllocator allocator;
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator, mode);
accumulator.OutputToFile(out);
InitializeLoggingAndCounters();
accumulator.Log(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToFile(out);
}
}
static void PrintFrames(Isolate* isolate,
StringStream* accumulator,
StackFrame::PrintMode mode) {
StackFrameIterator it(isolate);
for (int i = 0; !it.done(); it.Advance()) {
it.frame()->Print(accumulator, mode, i++);
}
}
void Isolate::PrintStack(StringStream* accumulator, PrintStackMode mode) {
// The MentionedObjectCache is not GC-proof at the moment.
DisallowHeapAllocation no_gc;
HandleScope scope(this);
DCHECK(accumulator->IsMentionedObjectCacheClear(this));
// Avoid printing anything if there are no frames.
if (c_entry_fp(thread_local_top()) == 0) return;
accumulator->Add(
"\n==== JS stack trace =========================================\n\n");
PrintFrames(this, accumulator, StackFrame::OVERVIEW);
if (mode == kPrintStackVerbose) {
accumulator->Add(
"\n==== Details ================================================\n\n");
PrintFrames(this, accumulator, StackFrame::DETAILS);
accumulator->PrintMentionedObjectCache(this);
}
accumulator->Add("=====================\n\n");
}
void Isolate::SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback) {
thread_local_top()->failed_access_check_callback_ = callback;
}
void Isolate::ReportFailedAccessCheck(Handle<JSObject> receiver) {
if (!thread_local_top()->failed_access_check_callback_) {
return ScheduleThrow(*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
DCHECK(receiver->IsAccessCheckNeeded());
DCHECK(context());
// Get the data object from access check info.
HandleScope scope(this);
Handle<Object> data;
{ DisallowHeapAllocation no_gc;
AccessCheckInfo* access_check_info = AccessCheckInfo::Get(this, receiver);
if (!access_check_info) {
AllowHeapAllocation doesnt_matter_anymore;
return ScheduleThrow(
*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
data = handle(access_check_info->data(), this);
}
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
thread_local_top()->failed_access_check_callback_(
v8::Utils::ToLocal(receiver), v8::ACCESS_HAS, v8::Utils::ToLocal(data));
}
bool Isolate::MayAccess(Handle<Context> accessing_context,
Handle<JSObject> receiver) {
DCHECK(receiver->IsJSGlobalProxy() || receiver->IsAccessCheckNeeded());
// Check for compatibility between the security tokens in the
// current lexical context and the accessed object.
// During bootstrapping, callback functions are not enabled yet.
if (bootstrapper()->IsActive()) return true;
{
DisallowHeapAllocation no_gc;
if (receiver->IsJSGlobalProxy()) {
Object* receiver_context =
JSGlobalProxy::cast(*receiver)->native_context();
if (!receiver_context->IsContext()) return false;
// Get the native context of current top context.
// avoid using Isolate::native_context() because it uses Handle.
Context* native_context =
accessing_context->global_object()->native_context();
if (receiver_context == native_context) return true;
if (Context::cast(receiver_context)->security_token() ==
native_context->security_token())
return true;
}
}
HandleScope scope(this);
Handle<Object> data;
v8::AccessCheckCallback callback = nullptr;
{ DisallowHeapAllocation no_gc;
AccessCheckInfo* access_check_info = AccessCheckInfo::Get(this, receiver);
if (!access_check_info) return false;
Object* fun_obj = access_check_info->callback();
callback = v8::ToCData<v8::AccessCheckCallback>(fun_obj);
data = handle(access_check_info->data(), this);
}
LOG(this, ApiSecurityCheck());
{
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
return callback(v8::Utils::ToLocal(accessing_context),
v8::Utils::ToLocal(receiver), v8::Utils::ToLocal(data));
}
}
Object* Isolate::StackOverflow() {
if (FLAG_abort_on_stack_or_string_length_overflow) {
FATAL("Aborting on stack overflow");
}
DisallowJavascriptExecution no_js(this);
HandleScope scope(this);
Handle<JSFunction> fun = range_error_function();
Handle<Object> msg = factory()->NewStringFromAsciiChecked(
MessageTemplate::TemplateString(MessageTemplate::kStackOverflow));
Handle<Object> no_caller;
Handle<Object> exception;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
this, exception,
ErrorUtils::Construct(this, fun, fun, msg, SKIP_NONE, no_caller, true));
Throw(*exception, nullptr);
#ifdef VERIFY_HEAP
if (FLAG_verify_heap && FLAG_stress_compaction) {
heap()->CollectAllGarbage(Heap::kNoGCFlags,
GarbageCollectionReason::kTesting);
}
#endif // VERIFY_HEAP
return heap()->exception();
}
Object* Isolate::TerminateExecution() {
return Throw(heap_.termination_exception(), nullptr);
}
void Isolate::CancelTerminateExecution() {
if (try_catch_handler()) {
try_catch_handler()->has_terminated_ = false;
}
if (has_pending_exception() &&
pending_exception() == heap_.termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
if (has_scheduled_exception() &&
scheduled_exception() == heap_.termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_scheduled_exception();
}
}
void Isolate::RequestInterrupt(InterruptCallback callback, void* data) {
ExecutionAccess access(this);
api_interrupts_queue_.push(InterruptEntry(callback, data));
stack_guard()->RequestApiInterrupt();
}
void Isolate::InvokeApiInterruptCallbacks() {
RuntimeCallTimerScope runtimeTimer(
this, RuntimeCallCounterId::kInvokeApiInterruptCallbacks);
// Note: callback below should be called outside of execution access lock.
while (true) {
InterruptEntry entry;
{
ExecutionAccess access(this);
if (api_interrupts_queue_.empty()) return;
entry = api_interrupts_queue_.front();
api_interrupts_queue_.pop();
}
VMState<EXTERNAL> state(this);
HandleScope handle_scope(this);
entry.first(reinterpret_cast<v8::Isolate*>(this), entry.second);
}
}
void ReportBootstrappingException(Handle<Object> exception,
MessageLocation* location) {
base::OS::PrintError("Exception thrown during bootstrapping\n");
if (location == nullptr || location->script().is_null()) return;
// We are bootstrapping and caught an error where the location is set
// and we have a script for the location.
// In this case we could have an extension (or an internal error
// somewhere) and we print out the line number at which the error occurred
// to the console for easier debugging.
int line_number =
location->script()->GetLineNumber(location->start_pos()) + 1;
if (exception->IsString() && location->script()->name()->IsString()) {
base::OS::PrintError(
"Extension or internal compilation error: %s in %s at line %d.\n",
String::cast(*exception)->ToCString().get(),
String::cast(location->script()->name())->ToCString().get(),
line_number);
} else if (location->script()->name()->IsString()) {
base::OS::PrintError(
"Extension or internal compilation error in %s at line %d.\n",
String::cast(location->script()->name())->ToCString().get(),
line_number);
} else if (exception->IsString()) {
base::OS::PrintError("Extension or internal compilation error: %s.\n",
String::cast(*exception)->ToCString().get());
} else {
base::OS::PrintError("Extension or internal compilation error.\n");
}
#ifdef OBJECT_PRINT
// Since comments and empty lines have been stripped from the source of
// builtins, print the actual source here so that line numbers match.
if (location->script()->source()->IsString()) {
Handle<String> src(String::cast(location->script()->source()));
PrintF("Failing script:");
int len = src->length();
if (len == 0) {
PrintF(" <not available>\n");
} else {
PrintF("\n");
int 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
}
bool Isolate::is_catchable_by_wasm(Object* exception) {
if (!is_catchable_by_javascript(exception) || !exception->IsJSError())
return false;
HandleScope scope(this);
Handle<Object> exception_handle(exception, this);
return JSReceiver::HasProperty(Handle<JSReceiver>::cast(exception_handle),
factory()->InternalizeUtf8String(
wasm::WasmException::kRuntimeIdStr))
.IsJust();
}
Object* Isolate::Throw(Object* exception, MessageLocation* location) {
DCHECK(!has_pending_exception());
HandleScope scope(this);
Handle<Object> exception_handle(exception, this);
if (FLAG_print_all_exceptions) {
printf("=========================================================\n");
printf("Exception thrown:\n");
if (location) {
Handle<Script> script = location->script();
Handle<Object> name(script->GetNameOrSourceURL(), this);
printf("at ");
if (name->IsString() && String::cast(*name)->length() > 0)
String::cast(*name)->PrintOn(stdout);
else
printf("<anonymous>");
// Script::GetLineNumber and Script::GetColumnNumber can allocate on the heap to
// initialize the line_ends array, so be careful when calling them.
#ifdef DEBUG
if (AllowHeapAllocation::IsAllowed()) {
#else
if ((false)) {
#endif
printf(", %d:%d - %d:%d\n",
Script::GetLineNumber(script, location->start_pos()) + 1,
Script::GetColumnNumber(script, location->start_pos()),
Script::GetLineNumber(script, location->end_pos()) + 1,
Script::GetColumnNumber(script, location->end_pos()));
} else {
printf(", line %d\n", script->GetLineNumber(location->start_pos()) + 1);
}
}
exception->Print();
printf("Stack Trace:\n");
PrintStack(stdout);
printf("=========================================================\n");
}
// Determine whether a message needs to be created for the given exception
// depending on the following criteria:
// 1) External v8::TryCatch missing: Always create a message because any
// JavaScript handler for a finally-block might re-throw to top-level.
// 2) External v8::TryCatch exists: Only create a message if the handler
// captures messages or is verbose (which reports despite the catch).
// 3) ReThrow from v8::TryCatch: The message from a previous throw still
// exists and we preserve it instead of creating a new message.
bool requires_message = try_catch_handler() == nullptr ||
try_catch_handler()->is_verbose_ ||
try_catch_handler()->capture_message_;
bool rethrowing_message = thread_local_top()->rethrowing_message_;
thread_local_top()->rethrowing_message_ = false;
// Notify debugger of exception.
if (is_catchable_by_javascript(exception)) {
debug()->OnThrow(exception_handle);
}
// 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_handle, location);
} else {
Handle<Object> message_obj = CreateMessage(exception_handle, location);
thread_local_top()->pending_message_obj_ = *message_obj;
// For any exception not caught by JavaScript, even when an external
// handler is present:
// If the abort-on-uncaught-exception flag is specified, and if the
// embedder didn't specify a custom uncaught exception callback,
// or if the custom callback determined that V8 should abort, then
// abort.
if (FLAG_abort_on_uncaught_exception) {
CatchType prediction = PredictExceptionCatcher();
if ((prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) &&
(!abort_on_uncaught_exception_callback_ ||
abort_on_uncaught_exception_callback_(
reinterpret_cast<v8::Isolate*>(this)))) {
// Prevent endless recursion.
FLAG_abort_on_uncaught_exception = false;
// This flag is intended for use by JavaScript developers, so
// print a user-friendly stack trace (not an internal one).
PrintF(stderr, "%s\n\nFROM\n",
MessageHandler::GetLocalizedMessage(this, message_obj).get());
PrintCurrentStackTrace(stderr);
base::OS::Abort();
}
}
}
}
// Set the exception being thrown.
set_pending_exception(*exception_handle);
return heap()->exception();
}
Object* Isolate::ReThrow(Object* exception) {
DCHECK(!has_pending_exception());
// Set the exception being re-thrown.
set_pending_exception(exception);
return heap()->exception();
}
Object* Isolate::UnwindAndFindHandler() {
Object* exception = pending_exception();
auto FoundHandler = [&](Context* context, Address instruction_start,
intptr_t handler_offset,
Address constant_pool_address, Address handler_sp,
Address handler_fp) {
// Store information to be consumed by the CEntryStub.
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;
// Return and clear pending exception.
clear_pending_exception();
return exception;
};
// Special handling of termination exceptions, uncatchable by JavaScript and
// Wasm code, we unwind the handlers until the top ENTRY handler is found.
bool catchable_by_js = is_catchable_by_javascript(exception);
// Compute handler and stack unwinding information by performing a full walk
// over the stack and dispatching according to the frame type.
for (StackFrameIterator iter(this);; iter.Advance()) {
// Handler must exist.
DCHECK(!iter.done());
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
// For JSEntryStub frames we always have a handler.
StackHandler* handler = frame->top_handler();
// Restore the next handler.
thread_local_top()->handler_ = handler->next()->address();
// Gather information from the handler.
Code* code = frame->LookupCode();
HandlerTable table(code);
return FoundHandler(nullptr, code->InstructionStart(),
table.LookupReturn(0), code->constant_pool(),
handler->address() + StackHandlerConstants::kSize,
0);
}
case StackFrame::WASM_COMPILED: {
if (trap_handler::IsThreadInWasm()) {
trap_handler::ClearThreadInWasm();
}
if (!FLAG_experimental_wasm_eh || !is_catchable_by_wasm(exception)) {
break;
}
int stack_slots = 0; // Will contain stack slot count of frame.
WasmCompiledFrame* wasm_frame = static_cast<WasmCompiledFrame*>(frame);
int offset = wasm_frame->LookupExceptionHandlerInTable(&stack_slots);
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 -
stack_slots * kPointerSize;
// This is going to be handled by Wasm, so we need to set the TLS flag
// again.
trap_handler::SetThreadInWasm();
set_wasm_caught_exception(exception);
wasm::WasmCode* wasm_code =
wasm_engine()->code_manager()->LookupCode(frame->pc());
return FoundHandler(nullptr, wasm_code->instruction_start(), offset,
wasm_code->constant_pool(), return_sp, frame->fp());
}
case StackFrame::OPTIMIZED: {
// For optimized frames we perform a lookup in the handler table.
if (!catchable_by_js) break;
OptimizedFrame* js_frame = static_cast<OptimizedFrame*>(frame);
int stack_slots = 0; // Will contain stack slot count of frame.
int offset =
js_frame->LookupExceptionHandlerInTable(&stack_slots, nullptr);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures
// that argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
stack_slots * kPointerSize;
// Gather information from the frame.
Code* code = frame->LookupCode();
// TODO(bmeurer): Turbofanned BUILTIN frames appear as OPTIMIZED,
// but do not have a code kind of OPTIMIZED_FUNCTION.
if (code->kind() == Code::OPTIMIZED_FUNCTION &&
code->marked_for_deoptimization()) {
// If the target code is lazy deoptimized, we jump to the original
// return address, but we make a note that we are throwing, so
// that the deoptimizer can do the right thing.
offset = static_cast<int>(frame->pc() - code->entry());
set_deoptimizer_lazy_throw(true);
}
return FoundHandler(nullptr, code->InstructionStart(), offset,
code->constant_pool(), return_sp, frame->fp());
}
case StackFrame::STUB: {
// Some stubs are able to handle exceptions.
if (!catchable_by_js) break;
StubFrame* stub_frame = static_cast<StubFrame*>(frame);
Code* code = stub_frame->LookupCode();
if (!code->IsCode() || code->kind() != Code::BUILTIN ||
!code->handler_table_offset() || !code->is_turbofanned()) {
break;
}
int stack_slots = 0; // Will contain stack slot count of frame.
int offset = stub_frame->LookupExceptionHandlerInTable(&stack_slots);
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 -
stack_slots * kPointerSize;
return FoundHandler(nullptr, code->InstructionStart(), offset,
code->constant_pool(), return_sp, frame->fp());
}
case StackFrame::INTERPRETED: {
// For interpreted frame we perform a range lookup in the handler table.
if (!catchable_by_js) break;
InterpretedFrame* js_frame = static_cast<InterpretedFrame*>(frame);
int register_slots = InterpreterFrameConstants::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 * kPointerSize;
// Patch the bytecode offset in the interpreted frame to reflect the
// position of the exception handler. The special builtin below will
// take care of continuing to dispatch at that position. Also restore
// the correct context for the handler from the interpreter register.
Context* context =
Context::cast(js_frame->ReadInterpreterRegister(context_reg));
js_frame->PatchBytecodeOffset(static_cast<int>(offset));
Code* code =
builtins()->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
return FoundHandler(context, code->InstructionStart(), 0,
code->constant_pool(), return_sp, frame->fp());
}
case StackFrame::BUILTIN:
// For builtin frames we are guaranteed not to find a handler.
if (catchable_by_js) {
CHECK_EQ(-1,
JavaScriptFrame::cast(frame)->LookupExceptionHandlerInTable(
nullptr, nullptr));
}
break;
case StackFrame::WASM_INTERPRETER_ENTRY: {
if (trap_handler::IsThreadInWasm()) {
trap_handler::ClearThreadInWasm();
}
WasmInterpreterEntryFrame* interpreter_frame =
WasmInterpreterEntryFrame::cast(frame);
// TODO(wasm): Implement try-catch in the interpreter.
interpreter_frame->debug_info()->Unwind(frame->fp());
} break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
// Builtin continuation frames with catch can handle exceptions.
if (!catchable_by_js) break;
JavaScriptBuiltinContinuationWithCatchFrame* js_frame =
JavaScriptBuiltinContinuationWithCatchFrame::cast(frame);
js_frame->SetException(exception);
// Reconstruct the stack pointer from the frame pointer.
Address return_sp = js_frame->fp() - js_frame->GetSPToFPDelta();
Code* code = js_frame->LookupCode();
return FoundHandler(nullptr, code->InstructionStart(), 0,
code->constant_pool(), return_sp, frame->fp());
} break;
default:
// All other types can not handle exception.
break;
}
if (frame->is_optimized()) {
// Remove per-frame stored materialized objects.
bool removed = materialized_object_store_->Remove(frame->fp());
USE(removed);
// If there were any materialized objects, the code should be
// marked for deopt.
DCHECK_IMPLIES(removed, frame->LookupCode()->marked_for_deoptimization());
}
}
UNREACHABLE();
}
namespace {
HandlerTable::CatchPrediction PredictException(JavaScriptFrame* frame) {
HandlerTable::CatchPrediction prediction;
if (frame->is_optimized()) {
if (frame->LookupExceptionHandlerInTable(nullptr, nullptr) > 0) {
// This optimized frame will catch. It's handler table does not include
// exception prediction, and we need to use the corresponding handler
// tables on the unoptimized code objects.
std::vector<FrameSummary> summaries;
frame->Summarize(&summaries);
for (size_t i = summaries.size(); i != 0; i--) {
const FrameSummary& summary = summaries[i - 1];
Handle<AbstractCode> code = summary.AsJavaScript().abstract_code();
if (code->IsCode() && code->kind() == AbstractCode::BUILTIN) {
prediction = code->GetCode()->GetBuiltinCatchPrediction();
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
// Must have been constructed from a bytecode array.
CHECK_EQ(AbstractCode::INTERPRETED_FUNCTION, code->kind());
int code_offset = summary.code_offset();
HandlerTable table(code->GetBytecodeArray());
int index = table.LookupRange(code_offset, nullptr, &prediction);
if (index <= 0) continue;
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
}
} else if (frame->LookupExceptionHandlerInTable(nullptr, &prediction) > 0) {
return prediction;
}
return HandlerTable::UNCAUGHT;
}
Isolate::CatchType ToCatchType(HandlerTable::CatchPrediction prediction) {
switch (prediction) {
case HandlerTable::UNCAUGHT:
return Isolate::NOT_CAUGHT;
case HandlerTable::CAUGHT:
return Isolate::CAUGHT_BY_JAVASCRIPT;
case HandlerTable::PROMISE:
return Isolate::CAUGHT_BY_PROMISE;
case HandlerTable::DESUGARING:
return Isolate::CAUGHT_BY_DESUGARING;
case HandlerTable::ASYNC_AWAIT:
return Isolate::CAUGHT_BY_ASYNC_AWAIT;
default:
UNREACHABLE();
}
}
} // anonymous namespace
Isolate::CatchType Isolate::PredictExceptionCatcher() {
Address external_handler = thread_local_top()->try_catch_handler_address();
if (IsExternalHandlerOnTop(nullptr)) return CAUGHT_BY_EXTERNAL;
// Search for an exception handler by performing a full walk over the stack.
for (StackFrameIterator iter(this); !iter.done(); iter.Advance()) {
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
Address entry_handler = frame->top_handler()->next()->address();
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
if (external_handler != kNullAddress &&
!try_catch_handler()->is_verbose_) {
if (entry_handler == kNullAddress ||
entry_handler > external_handler) {
return CAUGHT_BY_EXTERNAL;
}
}
} break;
// For JavaScript frames we perform a lookup in the handler table.
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN: {
JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
Isolate::CatchType prediction = ToCatchType(PredictException(js_frame));
if (prediction == NOT_CAUGHT) break;
return prediction;
} break;
case StackFrame::STUB: {
Handle<Code> code(frame->LookupCode());
if (!code->IsCode() || code->kind() != Code::BUILTIN ||
!code->handler_table_offset() || !code->is_turbofanned()) {
break;
}
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
Handle<Code> code(frame->LookupCode());
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
default:
// All other types can not handle exception.
break;
}
}
// Handler not found.
return NOT_CAUGHT;
}
Object* Isolate::ThrowIllegalOperation() {
if (FLAG_stack_trace_on_illegal) PrintStack(stdout);
return Throw(heap()->illegal_access_string());
}
void Isolate::ScheduleThrow(Object* exception) {
// When scheduling a throw we first throw the exception to get the
// error reporting if it is uncaught before rescheduling it.
Throw(exception);
PropagatePendingExceptionToExternalTryCatch();
if (has_pending_exception()) {
thread_local_top()->scheduled_exception_ = pending_exception();
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
}
void Isolate::RestorePendingMessageFromTryCatch(v8::TryCatch* handler) {
DCHECK(handler == try_catch_handler());
DCHECK(handler->HasCaught());
DCHECK(handler->rethrow_);
DCHECK(handler->capture_message_);
Object* message = reinterpret_cast<Object*>(handler->message_obj_);
DCHECK(message->IsJSMessageObject() || message->IsTheHole(this));
thread_local_top()->pending_message_obj_ = message;
}
void Isolate::CancelScheduledExceptionFromTryCatch(v8::TryCatch* handler) {
DCHECK(has_scheduled_exception());
if (scheduled_exception() == handler->exception_) {
DCHECK(scheduled_exception() != heap()->termination_exception());
clear_scheduled_exception();
}
if (thread_local_top_.pending_message_obj_ == handler->message_obj_) {
clear_pending_message();
}
}
Object* Isolate::PromoteScheduledException() {
Object* thrown = scheduled_exception();
clear_scheduled_exception();
// Re-throw the exception to avoid getting repeated error reporting.
return ReThrow(thrown);
}
void Isolate::PrintCurrentStackTrace(FILE* out) {
for (StackTraceFrameIterator it(this); !it.done(); it.Advance()) {
if (!it.is_javascript()) continue;
HandleScope scope(this);
JavaScriptFrame* frame = it.javascript_frame();
Handle<Object> receiver(frame->receiver(), this);
Handle<JSFunction> function(frame->function(), this);
Handle<AbstractCode> code(AbstractCode::cast(frame->LookupCode()), this);
const int offset = static_cast<int>(frame->pc() - code->InstructionStart());
JSStackFrame site(this, receiver, function, code, offset);
Handle<String> line = site.ToString().ToHandleChecked();
if (line->length() > 0) {
line->PrintOn(out);
PrintF(out, "\n");
}
}
}
bool Isolate::ComputeLocation(MessageLocation* target) {
StackTraceFrameIterator it(this);
if (it.done()) return false;
StandardFrame* frame = it.frame();
// 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.
std::vector<FrameSummary> frames;
frame->Summarize(&frames);
FrameSummary& summary = frames.back();
int pos = summary.SourcePosition();
Handle<SharedFunctionInfo> shared;
Handle<Object> script = summary.script();
if (!script->IsScript() ||
(Script::cast(*script)->source()->IsUndefined(this))) {
return false;
}
if (summary.IsJavaScript()) {
shared = handle(summary.AsJavaScript().function()->shared());
}
*target = MessageLocation(Handle<Script>::cast(script), pos, pos + 1, shared);
return true;
}
bool Isolate::ComputeLocationFromException(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSObject()) return false;
Handle<Name> start_pos_symbol = factory()->error_start_pos_symbol();
Handle<Object> start_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), start_pos_symbol);
if (!start_pos->IsSmi()) return false;
int start_pos_value = Handle<Smi>::cast(start_pos)->value();
Handle<Name> end_pos_symbol = factory()->error_end_pos_symbol();
Handle<Object> end_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), end_pos_symbol);
if (!end_pos->IsSmi()) return false;
int end_pos_value = Handle<Smi>::cast(end_pos)->value();
Handle<Name> script_symbol = factory()->error_script_symbol();
Handle<Object> script = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), script_symbol);
if (!script->IsScript()) return false;
Handle<Script> cast_script(Script::cast(*script));
*target = MessageLocation(cast_script, start_pos_value, end_pos_value);
return true;
}
bool Isolate::ComputeLocationFromStackTrace(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSObject()) return false;
Handle<Name> key = factory()->stack_trace_symbol();
Handle<Object> property =
JSReceiver::GetDataProperty(Handle<JSObject>::cast(exception), key);
if (!property->IsJSArray()) return false;
Handle<JSArray> simple_stack_trace = Handle<JSArray>::cast(property);
Handle<FrameArray> elements(FrameArray::cast(simple_stack_trace->elements()));
const int frame_count = elements->FrameCount();
for (int i = 0; i < frame_count; i++) {
if (elements->IsWasmFrame(i) || elements->IsAsmJsWasmFrame(i)) {
Handle<WasmCompiledModule> compiled_module(
elements->WasmInstance(i)->compiled_module());
uint32_t func_index =
static_cast<uint32_t>(elements->WasmFunctionIndex(i)->value());
int code_offset = elements->Offset(i)->value();
// TODO(titzer): store a reference to the code object in FrameArray;
// a second lookup here could lead to inconsistency.
int byte_offset =
FrameSummary::WasmCompiledFrameSummary::GetWasmSourcePosition(
compiled_module->GetNativeModule()->GetCode(func_index),
code_offset);
bool is_at_number_conversion =
elements->IsAsmJsWasmFrame(i) &&
elements->Flags(i)->value() & FrameArray::kAsmJsAtNumberConversion;
int pos = WasmSharedModuleData::GetSourcePosition(
handle(compiled_module->shared(), this), func_index, byte_offset,
is_at_number_conversion);
Handle<Script> script(compiled_module->shared()->script());
*target = MessageLocation(script, pos, pos + 1);
return true;
}
Handle<JSFunction> fun = handle(elements->Function(i), this);
if (!fun->shared()->IsSubjectToDebugging()) continue;
Object* script = fun->shared()->script();
if (script->IsScript() &&
!(Script::cast(script)->source()->IsUndefined(this))) {
AbstractCode* abstract_code = elements->Code(i);
const int code_offset = elements->Offset(i)->value();
const int pos = abstract_code->SourcePosition(code_offset);
Handle<Script> casted_script(Script::cast(script));
*target = MessageLocation(casted_script, pos, pos + 1);
return true;
}
}
return false;
}
Handle<JSMessageObject> Isolate::CreateMessage(Handle<Object> exception,
MessageLocation* location) {
Handle<FixedArray> stack_trace_object;
if (capture_stack_trace_for_uncaught_exceptions_) {
if (exception->IsJSError()) {
// We fetch the stack trace that corresponds to this error object.
// If the lookup fails, the exception is probably not a valid Error
// object. In that case, we fall through and capture the stack trace
// at this throw site.
stack_trace_object =
GetDetailedStackTrace(Handle<JSObject>::cast(exception));
}
if (stack_trace_object.is_null()) {
// Not an error object, we capture stack and location at throw site.
stack_trace_object = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
}
}
MessageLocation computed_location;
if (location == nullptr &&
(ComputeLocationFromException(&computed_location, exception) ||
ComputeLocationFromStackTrace(&computed_location, exception) ||
ComputeLocation(&computed_location))) {
location = &computed_location;
}
return MessageHandler::MakeMessageObject(
this, MessageTemplate::kUncaughtException, location, exception,
stack_trace_object);
}
bool Isolate::IsJavaScriptHandlerOnTop(Object* exception) {
DCHECK_NE(heap()->the_hole_value(), exception);
// For uncatchable exceptions, the JavaScript handler cannot be on top.
if (!is_catchable_by_javascript(exception)) return false;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
if (entry_handler == kNullAddress) return false;
// Get the address of the external handler so we can compare the address to
// determine which one is closer to the top of the stack.
Address external_handler = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return true;
// 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.
return (entry_handler < external_handler);
}
bool Isolate::IsExternalHandlerOnTop(Object* exception) {
DCHECK_NE(heap()->the_hole_value(), exception);
// Get the address of the external handler so we can compare the address to
// determine which one is closer to the top of the stack.
Address external_handler = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return false;
// For uncatchable exceptions, the external handler is always on top.
if (!is_catchable_by_javascript(exception)) return true;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
if (entry_handler == kNullAddress) return true;
// 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.
return (entry_handler > external_handler);
}
void Isolate::ReportPendingMessagesImpl(bool report_externally) {
Object* exception = pending_exception();
// Clear the pending message object early to avoid endless recursion.
Object* message_obj = thread_local_top_.pending_message_obj_;
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)) return;
// Determine whether the message needs to be reported to all message handlers
// depending on whether and external v8::TryCatch or an internal JavaScript
// handler is on top.
bool should_report_exception;
if (report_externally) {
// Only report the exception if the external handler is verbose.
should_report_exception = try_catch_handler()->is_verbose_;
} else {
// Report the exception if it isn't caught by JavaScript code.
should_report_exception = !IsJavaScriptHandlerOnTop(exception);
}
// Actually report the pending message to all message handlers.
if (!message_obj->IsTheHole(this) && should_report_exception) {
HandleScope scope(this);
Handle<JSMessageObject> message(JSMessageObject::cast(message_obj), this);
Handle<JSValue> script_wrapper(JSValue::cast(message->script()), this);
Handle<Script> script(Script::cast(script_wrapper->value()), this);
int start_pos = message->start_position();
int end_pos = message->end_position();
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message);
}
}
void Isolate::ReportPendingMessages() {
DCHECK(AllowExceptions::IsAllowed(this));
// The embedder might run script in response to an exception.
AllowJavascriptExecutionDebugOnly allow_script(this);
Object* exception = pending_exception();
// Try to propagate the exception to an external v8::TryCatch handler. If
// propagation was unsuccessful, then we will get another chance at reporting
// the pending message if the exception is re-thrown.
bool has_been_propagated = PropagatePendingExceptionToExternalTryCatch();
if (!has_been_propagated) return;
ReportPendingMessagesImpl(IsExternalHandlerOnTop(exception));
}
void Isolate::ReportPendingMessagesFromJavaScript() {
DCHECK(AllowExceptions::IsAllowed(this));
auto IsHandledByJavaScript = [=]() {
// In this situation, the exception is always a non-terminating exception.
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
DCHECK_NE(entry_handler, kNullAddress);
entry_handler =
reinterpret_cast<StackHandler*>(entry_handler)->next()->address();
// Get the address of the external handler so we can compare the address to
// determine which one is closer to the top of the stack.
Address external_handler = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return true;
return (entry_handler < external_handler);
};
auto IsHandledExternally = [=]() {
Address external_handler = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return false;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
DCHECK_NE(entry_handler, kNullAddress);
entry_handler =
reinterpret_cast<StackHandler*>(entry_handler)->next()->address();
return (entry_handler > external_handler);
};
auto PropagateToExternalHandler = [=]() {
if (IsHandledByJavaScript()) {
thread_local_top_.external_caught_exception_ = false;
return false;
}
if (!IsHandledExternally()) {
thread_local_top_.external_caught_exception_ = false;
return true;
}
thread_local_top_.external_caught_exception_ = true;
v8::TryCatch* handler = try_catch_handler();
DCHECK(thread_local_top_.pending_message_obj_->IsJSMessageObject() ||
thread_local_top_.pending_message_obj_->IsTheHole(this));
handler->can_continue_ = true;
handler->has_terminated_ = false;
handler->exception_ = pending_exception();
// Propagate to the external try-catch only if we got an actual message.
if (thread_local_top_.pending_message_obj_->IsTheHole(this)) return true;
handler->message_obj_ = thread_local_top_.pending_message_obj_;
return true;
};
// Try to propagate to an external v8::TryCatch handler.
if (!PropagateToExternalHandler()) return;
ReportPendingMessagesImpl(true);
}
MessageLocation Isolate::GetMessageLocation() {
DCHECK(has_pending_exception());
if (thread_local_top_.pending_exception_ != heap()->termination_exception() &&
!thread_local_top_.pending_message_obj_->IsTheHole(this)) {
Handle<JSMessageObject> message_obj(
JSMessageObject::cast(thread_local_top_.pending_message_obj_), this);
Handle<JSValue> script_wrapper(JSValue::cast(message_obj->script()), this);
Handle<Script> script(Script::cast(script_wrapper->value()), this);
int start_pos = message_obj->start_position();
int end_pos = message_obj->end_position();
return MessageLocation(script, start_pos, end_pos);
}
return MessageLocation();
}
bool Isolate::OptionalRescheduleException(bool is_bottom_call) {
DCHECK(has_pending_exception());
PropagatePendingExceptionToExternalTryCatch();
bool is_termination_exception =
pending_exception() == heap_.termination_exception();
// Do not reschedule the exception if this is the bottom call.
bool clear_exception = is_bottom_call;
if (is_termination_exception) {
if (is_bottom_call) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
} else if (thread_local_top()->external_caught_exception_) {
// If the exception is externally caught, clear it if there are no
// JavaScript frames on the way to the C++ frame that has the
// external handler.
DCHECK_NE(thread_local_top()->try_catch_handler_address(), kNullAddress);
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
JavaScriptFrameIterator it(this);
if (it.done() || (it.frame()->sp() > external_handler_address)) {
clear_exception = true;
}
}
// Clear the exception if needed.
if (clear_exception) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
// Reschedule the exception.
thread_local_top()->scheduled_exception_ = pending_exception();
clear_pending_exception();
return true;
}
void Isolate::PushPromise(Handle<JSObject> promise) {
ThreadLocalTop* tltop = thread_local_top();
PromiseOnStack* prev = tltop->promise_on_stack_;
Handle<JSObject> global_promise = global_handles()->Create(*promise);
tltop->promise_on_stack_ = new PromiseOnStack(global_promise, prev);
}
void Isolate::PopPromise() {
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return;
PromiseOnStack* prev = tltop->promise_on_stack_->prev();
Handle<Object> global_promise = tltop->promise_on_stack_->promise();
delete tltop->promise_on_stack_;
tltop->promise_on_stack_ = prev;
global_handles()->Destroy(global_promise.location());
}
namespace {
bool InternalPromiseHasUserDefinedRejectHandler(Isolate* isolate,
Handle<JSPromise> promise);
bool PromiseHandlerCheck(Isolate* isolate, Handle<JSReceiver> handler,
Handle<JSReceiver> deferred_promise) {
// Recurse to the forwarding Promise, if any. This may be due to
// - await reaction forwarding to the throwaway Promise, which has
// a dependency edge to the outer Promise.
// - PromiseIdResolveHandler forwarding to the output of .then
// - Promise.all/Promise.race forwarding to a throwaway Promise, which
// has a dependency edge to the generated outer Promise.
// Otherwise, this is a real reject handler for the Promise.
Handle<Symbol> key = isolate->factory()->promise_forwarding_handler_symbol();
Handle<Object> forwarding_handler = JSReceiver::GetDataProperty(handler, key);
if (forwarding_handler->IsUndefined(isolate)) {
return true;
}
if (!deferred_promise->IsJSPromise()) {
return true;
}
return InternalPromiseHasUserDefinedRejectHandler(
isolate, Handle<JSPromise>::cast(deferred_promise));
}
bool InternalPromiseHasUserDefinedRejectHandler(Isolate* isolate,
Handle<JSPromise> promise) {
// If this promise was marked as being handled by a catch block
// in an async function, then it has a user-defined reject handler.
if (promise->handled_hint()) return true;
// If this Promise is subsumed by another Promise (a Promise resolved
// with another Promise, or an intermediate, hidden, throwaway Promise
// within async/await), then recurse on the outer Promise.
// In this case, the dependency is one possible way that the Promise
// could be resolved, so it does not subsume the other following cases.
Handle<Symbol> key = isolate->factory()->promise_handled_by_symbol();
Handle<Object> outer_promise_obj = JSObject::GetDataProperty(promise, key);
if (outer_promise_obj->IsJSPromise() &&
InternalPromiseHasUserDefinedRejectHandler(
isolate, Handle<JSPromise>::cast(outer_promise_obj))) {
return true;
}
if (promise->status() == Promise::kPending) {
Handle<Object> current(promise->reactions(), isolate);
while (!current->IsSmi()) {
Handle<PromiseReaction> current_reaction =
Handle<PromiseReaction>::cast(current);
Handle<HeapObject> payload(current_reaction->payload(), isolate);
Handle<JSPromise> current_promise;
if (JSPromise::From(payload).ToHandle(&current_promise)) {
if (current_reaction->reject_handler()->IsCallable()) {
Handle<JSReceiver> current_handler(
JSReceiver::cast(current_reaction->reject_handler()), isolate);
if (PromiseHandlerCheck(isolate, current_handler, current_promise)) {
return true;
}
} else {
if (InternalPromiseHasUserDefinedRejectHandler(isolate,
current_promise)) {
return true;
}
}
}
current = handle(current_reaction->next(), isolate);
}
}
return false;
}
} // namespace
bool Isolate::PromiseHasUserDefinedRejectHandler(Handle<Object> promise) {
if (!promise->IsJSPromise()) return false;
return InternalPromiseHasUserDefinedRejectHandler(
this, Handle<JSPromise>::cast(promise));
}
Handle<Object> Isolate::GetPromiseOnStackOnThrow() {
Handle<Object> undefined = factory()->undefined_value();
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return undefined;
// Find the top-most try-catch or try-finally handler.
CatchType prediction = PredictExceptionCatcher();
if (prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) {
return undefined;
}
Handle<Object> retval = undefined;
PromiseOnStack* promise_on_stack = tltop->promise_on_stack_;
for (StackFrameIterator it(this); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
HandlerTable::CatchPrediction catch_prediction;
if (frame->is_java_script()) {
catch_prediction = PredictException(JavaScriptFrame::cast(frame));
} else if (frame->type() == StackFrame::STUB) {
Code* code = frame->LookupCode();
if (!code->IsCode() || code->kind() != Code::BUILTIN ||
!code->handler_table_offset() || !code->is_turbofanned()) {
continue;
}
catch_prediction = code->GetBuiltinCatchPrediction();
} else {
continue;
}
switch (catch_prediction) {
case HandlerTable::UNCAUGHT:
continue;
case HandlerTable::CAUGHT:
case HandlerTable::DESUGARING:
if (retval->IsJSPromise()) {
// Caught the result of an inner async/await invocation.
// Mark the inner promise as caught in the "synchronous case" so
// that Debug::OnException will see. In the synchronous case,
// namely in the code in an async function before the first
// await, the function which has this exception event has not yet
// returned, so the generated Promise has not yet been marked
// by AsyncFunctionAwaitCaught with promiseHandledHintSymbol.
Handle<JSPromise>::cast(retval)->set_handled_hint(true);
}
return retval;
case HandlerTable::PROMISE:
return promise_on_stack
? Handle<Object>::cast(promise_on_stack->promise())
: undefined;
case HandlerTable::ASYNC_AWAIT: {
// If in the initial portion of async/await, continue the loop to pop up
// successive async/await stack frames until an asynchronous one with
// dependents is found, or a non-async stack frame is encountered, in
// order to handle the synchronous async/await catch prediction case:
// assume that async function calls are awaited.
if (!promise_on_stack) return retval;
retval = promise_on_stack->promise();
if (PromiseHasUserDefinedRejectHandler(retval)) {
return retval;
}
promise_on_stack = promise_on_stack->prev();
continue;
}
}
}
return retval;
}
void Isolate::SetCaptureStackTraceForUncaughtExceptions(
bool capture,
int frame_limit,
StackTrace::StackTraceOptions options) {
capture_stack_trace_for_uncaught_exceptions_ = capture;
stack_trace_for_uncaught_exceptions_frame_limit_ = frame_limit;
stack_trace_for_uncaught_exceptions_options_ = options;
}
void Isolate::SetAbortOnUncaughtExceptionCallback(
v8::Isolate::AbortOnUncaughtExceptionCallback callback) {
abort_on_uncaught_exception_callback_ = callback;
}
namespace {
void AdvanceWhileDebugContext(JavaScriptFrameIterator& it, Debug* debug) {
if (!debug->in_debug_scope()) return;
while (!it.done()) {
Context* context = Context::cast(it.frame()->context());
if (context->native_context() == *debug->debug_context()) {
it.Advance();
} else {
break;
}
}
}
} // namespace
Handle<Context> Isolate::GetCallingNativeContext() {
JavaScriptFrameIterator it(this);
AdvanceWhileDebugContext(it, debug_);
if (it.done()) return Handle<Context>::null();
JavaScriptFrame* frame = it.frame();
Context* context = Context::cast(frame->context());
return Handle<Context>(context->native_context(), this);
}
Handle<Context> Isolate::GetIncumbentContext() {
JavaScriptFrameIterator it(this);
AdvanceWhileDebugContext(it, debug_);
// 1st candidate: most-recently-entered author function's context
// if it's newer than the last Context::BackupIncumbentScope entry.
if (!it.done() &&
static_cast<const void*>(it.frame()) >
static_cast<const void*>(top_backup_incumbent_scope())) {
Context* context = Context::cast(it.frame()->context());
return Handle<Context>(context->native_context(), this);
}
// 2nd candidate: the last Context::Scope's incumbent context if any.
if (top_backup_incumbent_scope()) {
return Utils::OpenHandle(
*top_backup_incumbent_scope()->backup_incumbent_context_);
}
// Last candidate: the entered context.
// 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)->GetEnteredContext();
return Utils::OpenHandle(*entered_context);
}
char* Isolate::ArchiveThread(char* to) {
MemCopy(to, reinterpret_cast<char*>(thread_local_top()),
sizeof(ThreadLocalTop));
InitializeThreadLocal();
clear_pending_exception();
clear_pending_message();
clear_scheduled_exception();
return to + sizeof(ThreadLocalTop);
}
char* Isolate::RestoreThread(char* from) {
MemCopy(reinterpret_cast<char*>(thread_local_top()), from,
sizeof(ThreadLocalTop));
// This might be just paranoia, but it seems to be needed in case a
// thread_local_top_ is restored on a separate OS thread.
#ifdef USE_SIMULATOR
thread_local_top()->simulator_ = Simulator::current(this);
#endif
DCHECK(context() == nullptr || context()->IsContext());
return from + sizeof(ThreadLocalTop);
}
Isolate::ThreadDataTable::ThreadDataTable() : table_() {}
Isolate::ThreadDataTable::~ThreadDataTable() {}
void Isolate::ReleaseManagedObjects() {
Isolate::ManagedObjectFinalizer* current =
managed_object_finalizers_list_.next_;
managed_object_finalizers_list_.next_ = nullptr;
while (current != nullptr) {
Isolate::ManagedObjectFinalizer* next = current->next_;
current->Dispose();
current = next;
}
// No new managed objects should pop up during finalization.
DCHECK_NULL(managed_object_finalizers_list_.next_);
}
void Isolate::RegisterForReleaseAtTeardown(
Isolate::ManagedObjectFinalizer* finalizer) {
DCHECK_NOT_NULL(finalizer->value_);
DCHECK_NOT_NULL(finalizer->deleter_);
DCHECK_NULL(finalizer->prev_);
DCHECK_NULL(finalizer->next_);
// Insert at head. We keep the head alive for the lifetime of the Isolate
// because otherwise we can't reset the head, should we delete it before
// the isolate expires
Isolate::ManagedObjectFinalizer* next = managed_object_finalizers_list_.next_;
managed_object_finalizers_list_.next_ = finalizer;
finalizer->prev_ = &managed_object_finalizers_list_;
finalizer->next_ = next;
if (next != nullptr) next->prev_ = finalizer;
}
void Isolate::UnregisterFromReleaseAtTeardown(
Isolate::ManagedObjectFinalizer* finalizer) {
DCHECK_NOT_NULL(finalizer);
DCHECK_NOT_NULL(finalizer->prev_);
finalizer->prev_->next_ = finalizer->next_;
if (finalizer->next_ != nullptr) finalizer->next_->prev_ = finalizer->prev_;
}
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
#define TRACE_ISOLATE(tag) \
do { \
if (FLAG_trace_isolates) { \
PrintF("Isolate %p (id %d)" #tag "\n", \
reinterpret_cast<void*>(this), id()); \
} \
} while (false)
#else
#define TRACE_ISOLATE(tag)
#endif
class VerboseAccountingAllocator : public AccountingAllocator {
public:
VerboseAccountingAllocator(Heap* heap, size_t allocation_sample_bytes,
size_t pool_sample_bytes)
: heap_(heap),
last_memory_usage_(0),
last_pool_size_(0),
nesting_deepth_(0),
allocation_sample_bytes_(allocation_sample_bytes),
pool_sample_bytes_(pool_sample_bytes) {}
v8::internal::Segment* GetSegment(size_t size) override {
v8::internal::Segment* memory = AccountingAllocator::GetSegment(size);
if (memory) {
size_t malloced_current = GetCurrentMemoryUsage();
size_t pooled_current = GetCurrentPoolSize();
if (last_memory_usage_.Value() + allocation_sample_bytes_ <
malloced_current ||
last_pool_size_.Value() + pool_sample_bytes_ < pooled_current) {
PrintMemoryJSON(malloced_current, pooled_current);
last_memory_usage_.SetValue(malloced_current);
last_pool_size_.SetValue(pooled_current);
}
}
return memory;
}
void ReturnSegment(v8::internal::Segment* memory) override {
AccountingAllocator::ReturnSegment(memory);
size_t malloced_current = GetCurrentMemoryUsage();
size_t pooled_current = GetCurrentPoolSize();
if (malloced_current + allocation_sample_bytes_ <
last_memory_usage_.Value() ||
pooled_current + pool_sample_bytes_ < last_pool_size_.Value()) {
PrintMemoryJSON(malloced_current, pooled_current);
last_memory_usage_.SetValue(malloced_current);
last_pool_size_.SetValue(pooled_current);
}
}
void ZoneCreation(const Zone* zone) override {
PrintZoneModificationSample(zone, "zonecreation");
nesting_deepth_.Increment(1);
}
void ZoneDestruction(const Zone* zone) override {
nesting_deepth_.Decrement(1);
PrintZoneModificationSample(zone, "zonedestruction");
}
private:
void PrintZoneModificationSample(const Zone* zone, const char* type) {
PrintF(
"{"
"\"type\": \"%s\", "
"\"isolate\": \"%p\", "
"\"time\": %f, "
"\"ptr\": \"%p\", "
"\"name\": \"%s\", "
"\"size\": %" PRIuS
","
"\"nesting\": %" PRIuS "}\n",
type, reinterpret_cast<void*>(heap_->isolate()),
heap_->isolate()->time_millis_since_init(),
reinterpret_cast<const void*>(zone), zone->name(),
zone->allocation_size(), nesting_deepth_.Value());
}
void PrintMemoryJSON(size_t malloced, size_t pooled) {
// Note: Neither isolate, nor heap is locked, so be careful with accesses
// as the allocator is potentially used on a concurrent thread.
double time = heap_->isolate()->time_millis_since_init();
PrintF(
"{"
"\"type\": \"zone\", "
"\"isolate\": \"%p\", "
"\"time\": %f, "
"\"allocated\": %" PRIuS
","
"\"pooled\": %" PRIuS "}\n",
reinterpret_cast<void*>(heap_->isolate()), time, malloced, pooled);
}
Heap* heap_;
base::AtomicNumber<size_t> last_memory_usage_;
base::AtomicNumber<size_t> last_pool_size_;
base::AtomicNumber<size_t> nesting_deepth_;
size_t allocation_sample_bytes_, pool_sample_bytes_;
};
#ifdef DEBUG
base::AtomicNumber<size_t> Isolate::non_disposed_isolates_;
#endif // DEBUG
Isolate::Isolate()
: embedder_data_(),
entry_stack_(nullptr),
stack_trace_nesting_level_(0),
incomplete_message_(nullptr),
bootstrapper_(nullptr),
runtime_profiler_(nullptr),
compilation_cache_(nullptr),
logger_(nullptr),
load_stub_cache_(nullptr),
store_stub_cache_(nullptr),
deoptimizer_data_(nullptr),
deoptimizer_lazy_throw_(false),
materialized_object_store_(nullptr),
capture_stack_trace_for_uncaught_exceptions_(false),
stack_trace_for_uncaught_exceptions_frame_limit_(0),
stack_trace_for_uncaught_exceptions_options_(StackTrace::kOverview),
context_slot_cache_(nullptr),
descriptor_lookup_cache_(nullptr),
handle_scope_implementer_(nullptr),
unicode_cache_(nullptr),
allocator_(FLAG_trace_zone_stats ? new VerboseAccountingAllocator(
&heap_, 256 * KB, 128 * KB)
: new AccountingAllocator()),
inner_pointer_to_code_cache_(nullptr),
global_handles_(nullptr),
eternal_handles_(nullptr),
thread_manager_(nullptr),
setup_delegate_(nullptr),
regexp_stack_(nullptr),
date_cache_(nullptr),
call_descriptor_data_(nullptr),
// TODO(bmeurer) Initialized lazily because it depends on flags; can
// be fixed once the default isolate cleanup is done.
random_number_generator_(nullptr),
fuzzer_rng_(nullptr),
rail_mode_(PERFORMANCE_ANIMATION),
promise_hook_or_debug_is_active_(false),
promise_hook_(nullptr),
load_start_time_ms_(0),
serializer_enabled_(false),
has_fatal_error_(false),
initialized_from_snapshot_(false),
is_tail_call_elimination_enabled_(true),
is_isolate_in_background_(false),
cpu_profiler_(nullptr),
heap_profiler_(nullptr),
code_event_dispatcher_(new CodeEventDispatcher()),
function_entry_hook_(nullptr),
deferred_handles_head_(nullptr),
optimizing_compile_dispatcher_(nullptr),
stress_deopt_count_(0),
force_slow_path_(false),
next_optimization_id_(0),
#if V8_SFI_HAS_UNIQUE_ID
next_unique_sfi_id_(0),
#endif
is_running_microtasks_(false),
use_counter_callback_(nullptr),
basic_block_profiler_(nullptr),
cancelable_task_manager_(new CancelableTaskManager()),
abort_on_uncaught_exception_callback_(nullptr),
total_regexp_code_generated_(0) {
id_ = base::Relaxed_AtomicIncrement(&isolate_counter_, 1);
TRACE_ISOLATE(constructor);
memset(isolate_addresses_, 0,
sizeof(isolate_addresses_[0]) * (kIsolateAddressCount + 1));
heap_.isolate_ = this;
stack_guard_.isolate_ = this;
// ThreadManager is initialized early to support locking an isolate
// before it is entered.
thread_manager_ = new ThreadManager();
thread_manager_->isolate_ = this;
#ifdef DEBUG
non_disposed_isolates_.Increment(1);
#endif // DEBUG
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);
tracing_cpu_profiler_.reset(new TracingCpuProfilerImpl(this));
init_memcopy_functions(this);
}
void Isolate::TearDown() {
TRACE_ISOLATE(tear_down);
tracing_cpu_profiler_.reset();
if (FLAG_stress_sampling_allocation_profiler > 0) {
heap_profiler()->StopSamplingHeapProfiler();
}
// 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 = CurrentPerIsolateThreadData();
DCHECK_EQ(base::Relaxed_Load(&isolate_key_created_), 1);
Isolate* saved_isolate =
reinterpret_cast<Isolate*>(base::Thread::GetThreadLocal(isolate_key_));
SetIsolateThreadLocals(this, nullptr);
Deinit();
{
base::LockGuard<base::Mutex> lock_guard(&thread_data_table_mutex_);
thread_data_table_.RemoveAllThreads();
}
#ifdef DEBUG
non_disposed_isolates_.Decrement(1);
#endif // DEBUG
delete this;
// Restore the previous current isolate.
SetIsolateThreadLocals(saved_isolate, saved_data);
}
void Isolate::ClearSerializerData() {
delete external_reference_map_;
external_reference_map_ = nullptr;
}
void Isolate::Deinit() {
TRACE_ISOLATE(deinit);
debug()->Unload();
if (concurrent_recompilation_enabled()) {
optimizing_compile_dispatcher_->Stop();
delete optimizing_compile_dispatcher_;
optimizing_compile_dispatcher_ = nullptr;
}
wasm_engine()->TearDown();
heap_.mark_compact_collector()->EnsureSweepingCompleted();
heap_.memory_allocator()->unmapper()->EnsureUnmappingCompleted();
DumpAndResetStats();
if (FLAG_print_deopt_stress) {
PrintF(stdout, "=== Stress deopt counter: %u\n", stress_deopt_count_);
}
if (cpu_profiler_) {
cpu_profiler_->DeleteAllProfiles();
}
// We must stop the logger before we tear down other components.
sampler::Sampler* sampler = logger_->sampler();
if (sampler && sampler->IsActive()) sampler->Stop();
FreeThreadResources();
// We start with the heap tear down so that releasing managed objects does
// not cause a GC.
heap_.StartTearDown();
// Release managed objects before shutting down the heap. The finalizer might
// need to access heap objects.
ReleaseManagedObjects();
delete deoptimizer_data_;
deoptimizer_data_ = nullptr;
builtins_.TearDown();
bootstrapper_->TearDown();
if (runtime_profiler_ != nullptr) {
delete runtime_profiler_;
runtime_profiler_ = nullptr;
}
delete basic_block_profiler_;
basic_block_profiler_ = nullptr;
delete heap_profiler_;
heap_profiler_ = nullptr;
compiler_dispatcher_->AbortAll(BlockingBehavior::kBlock);
delete compiler_dispatcher_;
compiler_dispatcher_ = nullptr;
cancelable_task_manager()->CancelAndWait();
heap_.TearDown();
logger_->TearDown();
#ifdef V8_EMBEDDED_BUILTINS
if (DefaultEmbeddedBlob() == nullptr && embedded_blob() != nullptr) {
// We own the embedded blob. Free it.
uint8_t* data = const_cast<uint8_t*>(embedded_blob_);
InstructionStream::FreeOffHeapInstructionStream(data, embedded_blob_size_);
}
#endif
delete interpreter_;
interpreter_ = nullptr;
delete ast_string_constants_;
ast_string_constants_ = nullptr;
delete cpu_profiler_;
cpu_profiler_ = nullptr;
code_event_dispatcher_.reset();
delete root_index_map_;
root_index_map_ = nullptr;
ClearSerializerData();
}
void Isolate::SetIsolateThreadLocals(Isolate* isolate,
PerIsolateThreadData* data) {
base::Thread::SetThreadLocal(isolate_key_, isolate);
base::Thread::SetThreadLocal(per_isolate_thread_data_key_, data);
}
Isolate::~Isolate() {
TRACE_ISOLATE(destructor);
// The entry stack must be empty when we get here.
DCHECK(entry_stack_ == nullptr || entry_stack_->previous_item == nullptr);
delete entry_stack_;
entry_stack_ = nullptr;
delete unicode_cache_;
unicode_cache_ = nullptr;
delete date_cache_;
date_cache_ = nullptr;
delete[] call_descriptor_data_;
call_descriptor_data_ = nullptr;
delete regexp_stack_;
regexp_stack_ = nullptr;
delete descriptor_lookup_cache_;
descriptor_lookup_cache_ = nullptr;
delete context_slot_cache_;
context_slot_cache_ = nullptr;
delete load_stub_cache_;
load_stub_cache_ = nullptr;
delete store_stub_cache_;
store_stub_cache_ = nullptr;
delete materialized_object_store_;
materialized_object_store_ = nullptr;
delete logger_;
logger_ = nullptr;
delete handle_scope_implementer_;
handle_scope_implementer_ = nullptr;
delete code_tracer();
set_code_tracer(nullptr);
delete compilation_cache_;
compilation_cache_ = nullptr;
delete bootstrapper_;
bootstrapper_ = nullptr;
delete inner_pointer_to_code_cache_;
inner_pointer_to_code_cache_ = nullptr;
delete thread_manager_;
thread_manager_ = nullptr;
delete global_handles_;
global_handles_ = nullptr;
delete eternal_handles_;
eternal_handles_ = nullptr;
delete string_stream_debug_object_cache_;
string_stream_debug_object_cache_ = nullptr;
delete random_number_generator_;
random_number_generator_ = nullptr;
delete fuzzer_rng_;
fuzzer_rng_ = nullptr;
delete debug_;
debug_ = nullptr;
delete cancelable_task_manager_;
cancelable_task_manager_ = nullptr;
delete allocator_;
allocator_ = nullptr;
}
void Isolate::InitializeThreadLocal() {
thread_local_top_.isolate_ = this;
thread_local_top_.Initialize();
}
void Isolate::SetTerminationOnExternalTryCatch() {
if (try_catch_handler() == nullptr) return;
try_catch_handler()->can_continue_ = false;
try_catch_handler()->has_terminated_ = true;
try_catch_handler()->exception_ = heap()->null_value();
}
bool Isolate::PropagatePendingExceptionToExternalTryCatch() {
Object* exception = pending_exception();
if (IsJavaScriptHandlerOnTop(exception)) {
thread_local_top_.external_caught_exception_ = false;
return false;
}
if (!IsExternalHandlerOnTop(exception)) {
thread_local_top_.external_caught_exception_ = false;
return true;
}
thread_local_top_.external_caught_exception_ = true;
if (!is_catchable_by_javascript(exception)) {
SetTerminationOnExternalTryCatch();
} else {
v8::TryCatch* handler = try_catch_handler();
DCHECK(thread_local_top_.pending_message_obj_->IsJSMessageObject() ||
thread_local_top_.pending_message_obj_->IsTheHole(this));
handler->can_continue_ = true;
handler->has_terminated_ = false;
handler->exception_ = pending_exception();
// Propagate to the external try-catch only if we got an actual message.
if (thread_local_top_.pending_message_obj_->IsTheHole(this)) return true;
handler->message_obj_ = thread_local_top_.pending_message_obj_;
}
return true;
}
bool Isolate::InitializeCounters() {
if (async_counters_) return false;
async_counters_ = std::make_shared<Counters>(this);
return true;
}
void Isolate::InitializeLoggingAndCounters() {
if (logger_ == nullptr) {
logger_ = new Logger(this);
}
InitializeCounters();
}
namespace {
void PrintBuiltinSizes(Isolate* isolate) {
Builtins* builtins = isolate->builtins();
for (int i = 0; i < Builtins::builtin_count; i++) {
const char* name = builtins->name(i);
const char* kind = Builtins::KindNameOf(i);
Code* code = builtins->builtin(i);
PrintF(stdout, "%s Builtin, %s, %d\n", kind, name, code->InstructionSize());
}
}
#ifdef V8_EMBEDDED_BUILTINS
void CreateOffHeapTrampolines(Isolate* isolate) {
DCHECK(isolate->serializer_enabled());
DCHECK_NOT_NULL(isolate->embedded_blob());
DCHECK_NE(0, isolate->embedded_blob_size());
HandleScope scope(isolate);
Builtins* builtins = isolate->builtins();
EmbeddedData d = EmbeddedData::FromBlob();
CodeSpaceMemoryModificationScope code_allocation(isolate->heap());
for (int i = 0; i < Builtins::builtin_count; i++) {
if (!Builtins::IsIsolateIndependent(i)) continue;
Address instruction_start = d.InstructionStartOfBuiltin(i);
Handle<Code> trampoline = isolate->factory()->NewOffHeapTrampolineFor(
builtins->builtin_handle(i), instruction_start);
// Note that references to the old, on-heap code objects may still exist on
// the heap. This is fine for the sake of serialization, as serialization
// will replace all of them with a builtin reference which is later
// deserialized to point to the object within the builtins table.
//
// From this point onwards, some builtin code objects may be unreachable and
// thus collected by the GC.
builtins->set_builtin(i, *trampoline);
if (isolate->logger()->is_logging_code_events() ||
isolate->is_profiling()) {
isolate->logger()->LogCodeObject(*trampoline);
}
}
}
#endif // V8_EMBEDDED_BUILTINS
} // namespace
#ifdef V8_EMBEDDED_BUILTINS
void Isolate::PrepareEmbeddedBlobForSerialization() {
// When preparing the embedded blob, ensure it doesn't exist yet.
DCHECK_NULL(embedded_blob());
DCHECK_NULL(DefaultEmbeddedBlob());
DCHECK(serializer_enabled());
// The isolate takes ownership of this pointer into an executable mmap'd
// area. We muck around with const-casts because the standard use-case in
// shipping builds is for embedded_blob_ to point into a read-only
// .text-embedded section.
uint8_t* data;
uint32_t size;
InstructionStream::CreateOffHeapInstructionStream(this, &data, &size);
SetEmbeddedBlob(const_cast<const uint8_t*>(data), size);
CreateOffHeapTrampolines(this);
}
#endif // V8_EMBEDDED_BUILTINS
bool Isolate::Init(StartupDeserializer* des) {
TRACE_ISOLATE(init);
base::ElapsedTimer timer;
if (des == nullptr && FLAG_profile_deserialization) timer.Start();
time_millis_at_init_ = heap_.MonotonicallyIncreasingTimeInMs();
stress_deopt_count_ = FLAG_deopt_every_n_times;
force_slow_path_ = FLAG_force_slow_path;
has_fatal_error_ = false;
if (function_entry_hook() != nullptr) {
// When function entry hooking is in effect, we have to create the code
// stubs from scratch to get entry hooks, rather than loading the previously
// generated stubs from disk.
// If this assert fires, the initialization path has regressed.
DCHECK_NULL(des);
}
// The initialization process does not handle memory exhaustion.
AlwaysAllocateScope always_allocate(this);
// Safe after setting Heap::isolate_, and initializing StackGuard
heap_.SetStackLimits();
#define ASSIGN_ELEMENT(CamelName, hacker_name) \
isolate_addresses_[IsolateAddressId::k##CamelName##Address] = \
reinterpret_cast<Address>(hacker_name##_address());
FOR_EACH_ISOLATE_ADDRESS_NAME(ASSIGN_ELEMENT)
#undef ASSIGN_ELEMENT
compilation_cache_ = new CompilationCache(this);
context_slot_cache_ = new ContextSlotCache();
descriptor_lookup_cache_ = new DescriptorLookupCache();
unicode_cache_ = new UnicodeCache();
inner_pointer_to_code_cache_ = new InnerPointerToCodeCache(this);
global_handles_ = new GlobalHandles(this);
eternal_handles_ = new EternalHandles();
bootstrapper_ = new Bootstrapper(this);
handle_scope_implementer_ = new HandleScopeImplementer(this);
load_stub_cache_ = new StubCache(this);
store_stub_cache_ = new StubCache(this);
materialized_object_store_ = new MaterializedObjectStore(this);
regexp_stack_ = new RegExpStack();
regexp_stack_->isolate_ = this;
date_cache_ = new DateCache();
call_descriptor_data_ =
new CallInterfaceDescriptorData[CallDescriptors::NUMBER_OF_DESCRIPTORS];
cpu_profiler_ = new CpuProfiler(this);
heap_profiler_ = new HeapProfiler(heap());
interpreter_ = new interpreter::Interpreter(this);
compiler_dispatcher_ =
new CompilerDispatcher(this, V8::GetCurrentPlatform(), FLAG_stack_size);
#ifdef V8_EMBEDDED_BUILTINS
#ifdef V8_MULTI_SNAPSHOTS
if (FLAG_untrusted_code_mitigations) {
SetEmbeddedBlob(DefaultEmbeddedBlob(), DefaultEmbeddedBlobSize());
} else {
SetEmbeddedBlob(TrustedEmbeddedBlob(), TrustedEmbeddedBlobSize());
}
#else
SetEmbeddedBlob(DefaultEmbeddedBlob(), DefaultEmbeddedBlobSize());
#endif
#endif
// Enable logging before setting up the heap
logger_->SetUp(this);
{ // NOLINT
// 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);
}
// SetUp the object heap.
DCHECK(!heap_.HasBeenSetUp());
if (!heap_.SetUp()) {
V8::FatalProcessOutOfMemory(this, "heap setup");
return false;
}
// Setup the wasm engine. Currently, there's one per Isolate.
const size_t max_code_size =
kRequiresCodeRange
? std::min(kMaxWasmCodeMemory,
heap_.memory_allocator()->code_range()->size())
: kMaxWasmCodeMemory;
wasm_engine_.reset(new wasm::WasmEngine(
std::unique_ptr<wasm::WasmCodeManager>(new wasm::WasmCodeManager(
reinterpret_cast<v8::Isolate*>(this), max_code_size))));
// Initialize the interface descriptors ahead of time.
#define INTERFACE_DESCRIPTOR(Name, ...) \
{ Name##Descriptor(this); }
INTERFACE_DESCRIPTOR_LIST(INTERFACE_DESCRIPTOR)
#undef INTERFACE_DESCRIPTOR
deoptimizer_data_ = new DeoptimizerData(heap());
const bool create_heap_objects = (des == nullptr);
if (setup_delegate_ == nullptr) {
setup_delegate_ = new SetupIsolateDelegate(create_heap_objects);
}
if (!setup_delegate_->SetupHeap(&heap_)) {
V8::FatalProcessOutOfMemory(this, "heap object creation");
return false;
}
if (create_heap_objects) {
// Terminate the partial snapshot cache so we can iterate.
partial_snapshot_cache_.push_back(heap_.undefined_value());
#ifdef V8_EMBEDDED_BUILTINS
if (serializer_enabled()) {
builtins_constants_table_builder_ =
new BuiltinsConstantsTableBuilder(this);
}
#endif
}
InitializeThreadLocal();
bootstrapper_->Initialize(create_heap_objects);
setup_delegate_->SetupBuiltins(this);
if (create_heap_objects) heap_.CreateFixedStubs();
if (FLAG_log_internal_timer_events) {
set_event_logger(Logger::DefaultEventLoggerSentinel);
}
if (FLAG_trace_turbo || FLAG_trace_turbo_graph) {
PrintF("Concurrent recompilation has been disabled for tracing.\n");
} else if (OptimizingCompileDispatcher::Enabled()) {
optimizing_compile_dispatcher_ = new OptimizingCompileDispatcher(this);
}
// Initialize runtime profiler before deserialization, because collections may
// occur, clearing/updating ICs.
runtime_profiler_ = new RuntimeProfiler(this);
// If we are deserializing, read the state into the now-empty heap.
{
AlwaysAllocateScope always_allocate(this);
CodeSpaceMemoryModificationScope modification_scope(&heap_);
if (!create_heap_objects) des->DeserializeInto(this);
load_stub_cache_->Initialize();
store_stub_cache_->Initialize();
setup_delegate_->SetupInterpreter(interpreter_);
#ifdef V8_EMBEDDED_BUILTINS
if (create_heap_objects && serializer_enabled()) {
builtins_constants_table_builder_->Finalize();
delete builtins_constants_table_builder_;
builtins_constants_table_builder_ = nullptr;
}
#endif // V8_EMBEDDED_BUILTINS
heap_.NotifyDeserializationComplete();
}
delete setup_delegate_;
setup_delegate_ = nullptr;
if (FLAG_print_builtin_size) PrintBuiltinSizes(this);
// Finish initialization of ThreadLocal after deserialization is done.
clear_pending_exception();
clear_pending_message();
clear_scheduled_exception();
// Deserializing may put strange things in the root array's copy of the
// stack guard.
heap_.SetStackLimits();
// Quiet the heap NaN if needed on target platform.
if (!create_heap_objects) Assembler::QuietNaN(heap_.nan_value());
if (FLAG_trace_turbo) {
// Create an empty file.
std::ofstream(GetTurboCfgFileName().c_str(), std::ios_base::trunc);
}
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, embedder_data_)),
Internals::kIsolateEmbedderDataOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, heap_.roots_)),
Internals::kIsolateRootsOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, heap_.external_memory_)),
Internals::kExternalMemoryOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(Isolate, heap_.external_memory_limit_)),
Internals::kExternalMemoryLimitOffset);
CHECK_EQ(static_cast<int>(
OFFSET_OF(Isolate, heap_.external_memory_at_last_mark_compact_)),
Internals::kExternalMemoryAtLastMarkCompactOffset);
CHECK_EQ(
static_cast<int>(OFFSET_OF(Isolate, heap_.external_reference_table_)),
Internals::kIsolateRootsOffset +
Heap::kRootsExternalReferenceTableOffset);
{
HandleScope scope(this);
ast_string_constants_ = new AstStringConstants(this, heap()->HashSeed());
}
if (!serializer_enabled()) {
// Ensure that all stubs which need to be generated ahead of time, but
// cannot be serialized into the snapshot have been generated.
HandleScope scope(this);
CodeStub::GenerateFPStubs(this);
}
initialized_from_snapshot_ = (des != nullptr);
if (!FLAG_inline_new) heap_.DisableInlineAllocation();
if (FLAG_stress_sampling_allocation_profiler > 0) {
uint64_t sample_interval = FLAG_stress_sampling_allocation_profiler;
int stack_depth = 128;
v8::HeapProfiler::SamplingFlags sampling_flags =
v8::HeapProfiler::SamplingFlags::kSamplingForceGC;
heap_profiler()->StartSamplingHeapProfiler(sample_interval, stack_depth,
sampling_flags);
}
if (des == nullptr && FLAG_profile_deserialization) {
double ms = timer.Elapsed().InMillisecondsF();
PrintF("[Initializing isolate from scratch took %0.3f ms]\n", ms);
}
return true;
}
void Isolate::Enter() {
Isolate* current_isolate = nullptr;
PerIsolateThreadData* current_data = CurrentPerIsolateThreadData();
if (current_data != nullptr) {
current_isolate = current_data->isolate_;
DCHECK_NOT_NULL(current_isolate);
if (current_isolate == this) {
DCHECK(Current() == this);
DCHECK_NOT_NULL(entry_stack_);
DCHECK(entry_stack_->previous_thread_data == nullptr ||
entry_stack_->previous_thread_data->thread_id().Equals(
ThreadId::Current()));
// Same thread re-enters the isolate, no need to re-init anything.
entry_stack_->entry_count++;
return;
}
}
PerIsolateThreadData* data = FindOrAllocatePerThreadDataForThisThread();
DCHECK_NOT_NULL(data);
DCHECK(data->isolate_ == this);
EntryStackItem* item = new EntryStackItem(current_data,
current_isolate,
entry_stack_);
entry_stack_ = item;
SetIsolateThreadLocals(this, data);
// In case it's the first time some thread enters the isolate.
set_thread_id(data->thread_id());
}
void Isolate::Exit() {
DCHECK_NOT_NULL(entry_stack_);
DCHECK(entry_stack_->previous_thread_data == nullptr ||
entry_stack_->previous_thread_data->thread_id().Equals(
ThreadId::Current()));
if (--entry_stack_->entry_count > 0) return;
DCHECK_NOT_NULL(CurrentPerIsolateThreadData());
DCHECK(CurrentPerIsolateThreadData()->isolate_ == this);
// Pop the stack.
EntryStackItem* item = entry_stack_;
entry_stack_ = item->previous_item;
PerIsolateThreadData* previous_thread_data = item->previous_thread_data;
Isolate* previous_isolate = item->previous_isolate;
delete item;
// Reinit the current thread for the isolate it was running before this one.
SetIsolateThreadLocals(previous_isolate, previous_thread_data);
}
void Isolate::LinkDeferredHandles(DeferredHandles* deferred) {
deferred->next_ = deferred_handles_head_;
if (deferred_handles_head_ != nullptr) {
deferred_handles_head_->previous_ = deferred;
}
deferred_handles_head_ = deferred;
}
void Isolate::UnlinkDeferredHandles(DeferredHandles* deferred) {
#ifdef DEBUG
// In debug mode assert that the linked list is well-formed.
DeferredHandles* deferred_iterator = deferred;
while (deferred_iterator->previous_ != nullptr) {
deferred_iterator = deferred_iterator->previous_;
}
DCHECK(deferred_handles_head_ == deferred_iterator);
#endif
if (deferred_handles_head_ == deferred) {
deferred_handles_head_ = deferred_handles_head_->next_;
}
if (deferred->next_ != nullptr) {
deferred->next_->previous_ = deferred->previous_;
}
if (deferred->previous_ != nullptr) {
deferred->previous_->next_ = deferred->next_;
}
}
void Isolate::DumpAndResetStats() {
if (turbo_statistics() != nullptr) {
DCHECK(FLAG_turbo_stats || FLAG_turbo_stats_nvp);
OFStream os(stdout);
if (FLAG_turbo_stats) {
AsPrintableStatistics ps = {*turbo_statistics(), false};
os << ps << std::endl;
}
if (FLAG_turbo_stats_nvp) {
AsPrintableStatistics ps = {*turbo_statistics(), true};
os << ps << std::endl;
}
}
delete turbo_statistics_;
turbo_statistics_ = nullptr;
if (V8_UNLIKELY(FLAG_runtime_stats ==
v8::tracing::TracingCategoryObserver::ENABLED_BY_NATIVE)) {
counters()->runtime_call_stats()->Print();
counters()->runtime_call_stats()->Reset();
}
}
void Isolate::AbortConcurrentOptimization(BlockingBehavior behavior) {
if (concurrent_recompilation_enabled()) {
DisallowHeapAllocation no_recursive_gc;
optimizing_compile_dispatcher()->Flush(behavior);
}
}
CompilationStatistics* Isolate::GetTurboStatistics() {
if (turbo_statistics() == nullptr)
set_turbo_statistics(new CompilationStatistics());
return turbo_statistics();
}
CodeTracer* Isolate::GetCodeTracer() {
if (code_tracer() == nullptr) set_code_tracer(new CodeTracer(id()));
return code_tracer();
}
bool Isolate::use_optimizer() {
return FLAG_opt && !serializer_enabled_ && CpuFeatures::SupportsOptimizer() &&
!is_precise_count_code_coverage() && !is_block_count_code_coverage();
}
bool Isolate::NeedsSourcePositionsForProfiling() const {
return FLAG_trace_deopt || FLAG_trace_turbo || FLAG_trace_turbo_graph ||
FLAG_turbo_profiling || FLAG_perf_prof || is_profiling() ||
debug_->is_active() || logger_->is_logging() || FLAG_trace_maps;
}
void Isolate::SetFeedbackVectorsForProfilingTools(Object* value) {
DCHECK(value->IsUndefined(this) || value->IsArrayList());
heap()->set_feedback_vectors_for_profiling_tools(value);
}
void Isolate::MaybeInitializeVectorListFromHeap() {
if (!heap()->feedback_vectors_for_profiling_tools()->IsUndefined(this)) {
// Already initialized, return early.
DCHECK(heap()->feedback_vectors_for_profiling_tools()->IsArrayList());
return;
}
// Collect existing feedback vectors.
std::vector<Handle<FeedbackVector>> vectors;
{
HeapIterator heap_iterator(heap());
while (HeapObject* current_obj = heap_iterator.next()) {
if (!current_obj->IsFeedbackVector()) continue;
FeedbackVector* vector = FeedbackVector::cast(current_obj);
SharedFunctionInfo* shared = vector->shared_function_info();
// No need to preserve the feedback vector for non-user-visible functions.
if (!shared->IsSubjectToDebugging()) continue;
vectors.emplace_back(vector, this);
}
}
// Add collected feedback vectors to the root list lest we lose them to GC.
Handle<ArrayList> list =
ArrayList::New(this, static_cast<int>(vectors.size()));
for (const auto& vector : vectors) list = ArrayList::Add(list, vector);
SetFeedbackVectorsForProfilingTools(*list);
}
bool Isolate::IsArrayOrObjectOrStringPrototype(Object* object) {
Object* context = heap()->native_contexts_list();
while (!context->IsUndefined(this)) {
Context* current_context = Context::cast(context);
if (current_context->initial_object_prototype() == object ||
current_context->initial_array_prototype() == object ||
current_context->initial_string_prototype() == object) {
return true;
}
context = current_context->next_context_link();
}
return false;
}
bool Isolate::IsInAnyContext(Object* object, uint32_t index) {
DisallowHeapAllocation no_gc;
Object* context = heap()->native_contexts_list();
while (!context->IsUndefined(this)) {
Context* current_context = Context::cast(context);
if (current_context->get(index) == object) {
return true;
}
context = current_context->next_context_link();
}
return false;
}
bool Isolate::IsNoElementsProtectorIntact(Context* context) {
PropertyCell* no_elements_cell = heap()->no_elements_protector();
bool cell_reports_intact =
no_elements_cell->value()->IsSmi() &&
Smi::ToInt(no_elements_cell->value()) == kProtectorValid;
#ifdef DEBUG
Context* native_context = context->native_context();
Map* root_array_map =
native_context->GetInitialJSArrayMap(GetInitialFastElementsKind());
JSObject* initial_array_proto = JSObject::cast(
native_context->get(Context::INITIAL_ARRAY_PROTOTYPE_INDEX));
JSObject* initial_object_proto = JSObject::cast(
native_context->get(Context::INITIAL_OBJECT_PROTOTYPE_INDEX));
JSObject* initial_string_proto = JSObject::cast(
native_context->get(Context::INITIAL_STRING_PROTOTYPE_INDEX));
if (root_array_map == nullptr ||
initial_array_proto == initial_object_proto) {
// We are in the bootstrapping process, and the entire check sequence
// shouldn't be performed.
return cell_reports_intact;
}
// Check that the array prototype hasn't been altered WRT empty elements.
if (root_array_map->prototype() != initial_array_proto) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
FixedArrayBase* elements = initial_array_proto->elements();
if (elements != heap()->empty_fixed_array() &&
elements != heap()->empty_slow_element_dictionary()) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
// Check that the Object.prototype hasn't been altered WRT empty elements.
elements = initial_object_proto->elements();
if (elements != heap()->empty_fixed_array() &&
elements != heap()->empty_slow_element_dictionary()) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
// Check that the Array.prototype has the Object.prototype as its
// [[Prototype]] and that the Object.prototype has a null [[Prototype]].
PrototypeIterator iter(this, initial_array_proto);
if (iter.IsAtEnd() || iter.GetCurrent() != initial_object_proto) {
DCHECK_EQ(false, cell_reports_intact);
DCHECK(!has_pending_exception());
return cell_reports_intact;
}
iter.Advance();
if (!iter.IsAtEnd()) {
DCHECK_EQ(false, cell_reports_intact);
DCHECK(!has_pending_exception());
return cell_reports_intact;
}
DCHECK(!has_pending_exception());
// Check that the String.prototype hasn't been altered WRT empty elements.
elements = initial_string_proto->elements();
if (elements != heap()->empty_fixed_array() &&
elements != heap()->empty_slow_element_dictionary()) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
// Check that the String.prototype has the Object.prototype
// as its [[Prototype]] still.
if (initial_string_proto->map()->prototype() != initial_object_proto) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
#endif
return cell_reports_intact;
}
bool Isolate::IsNoElementsProtectorIntact() {
return Isolate::IsNoElementsProtectorIntact(context());
}
bool Isolate::IsIsConcatSpreadableLookupChainIntact() {
Cell* is_concat_spreadable_cell = heap()->is_concat_spreadable_protector();
bool is_is_concat_spreadable_set =
Smi::ToInt(is_concat_spreadable_cell->value()) == kProtectorInvalid;
#ifdef DEBUG
Map* root_array_map =
raw_native_context()->GetInitialJSArrayMap(GetInitialFastElementsKind());
if (root_array_map == nullptr) {
// Ignore the value of is_concat_spreadable during bootstrap.
return !is_is_concat_spreadable_set;
}
Handle<Object> array_prototype(array_function()->prototype(), this);
Handle<Symbol> key = factory()->is_concat_spreadable_symbol();
Handle<Object> value;
LookupIterator it(array_prototype, key);
if (it.IsFound() && !JSReceiver::GetDataProperty(&it)->IsUndefined(this)) {
// TODO(cbruni): Currently we do not revert if we unset the
// @@isConcatSpreadable property on Array.prototype or Object.prototype
// hence the reverse implication doesn't hold.
DCHECK(is_is_concat_spreadable_set);
return false;
}
#endif // DEBUG
return !is_is_concat_spreadable_set;
}
bool Isolate::IsIsConcatSpreadableLookupChainIntact(JSReceiver* receiver) {
if (!IsIsConcatSpreadableLookupChainIntact()) return false;
return !receiver->HasProxyInPrototype(this);
}
bool Isolate::IsPromiseHookProtectorIntact() {
PropertyCell* promise_hook_cell = heap()->promise_hook_protector();
bool is_promise_hook_protector_intact =
Smi::ToInt(promise_hook_cell->value()) == kProtectorValid;
DCHECK_IMPLIES(is_promise_hook_protector_intact,
!promise_hook_or_debug_is_active_);
return is_promise_hook_protector_intact;
}
bool Isolate::IsPromiseResolveLookupChainIntact() {
Cell* promise_resolve_cell = heap()->promise_resolve_protector();
bool is_promise_resolve_protector_intact =
Smi::ToInt(promise_resolve_cell->value()) == kProtectorValid;
return is_promise_resolve_protector_intact;
}
bool Isolate::IsPromiseThenLookupChainIntact() {
PropertyCell* promise_then_cell = heap()->promise_then_protector();
bool is_promise_then_protector_intact =
Smi::ToInt(promise_then_cell->value()) == kProtectorValid;
return is_promise_then_protector_intact;
}
bool Isolate::IsPromiseThenLookupChainIntact(Handle<JSReceiver> receiver) {
DisallowHeapAllocation no_gc;
if (!receiver->IsJSPromise()) return false;
if (!IsInAnyContext(receiver->map()->prototype(),
Context::PROMISE_PROTOTYPE_INDEX)) {
return false;
}
return IsPromiseThenLookupChainIntact();
}
void Isolate::UpdateNoElementsProtectorOnSetElement(Handle<JSObject> object) {
DisallowHeapAllocation no_gc;
if (!object->map()->is_prototype_map()) return;
if (!IsNoElementsProtectorIntact()) return;
if (!IsArrayOrObjectOrStringPrototype(*object)) return;
PropertyCell::SetValueWithInvalidation(
factory()->no_elements_protector(),
handle(Smi::FromInt(kProtectorInvalid), this));
}
void Isolate::InvalidateIsConcatSpreadableProtector() {
DCHECK(factory()->is_concat_spreadable_protector()->value()->IsSmi());
DCHECK(IsIsConcatSpreadableLookupChainIntact());
factory()->is_concat_spreadable_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsIsConcatSpreadableLookupChainIntact());
}
void Isolate::InvalidateArrayConstructorProtector() {
DCHECK(factory()->array_constructor_protector()->value()->IsSmi());
DCHECK(IsArrayConstructorIntact());
factory()->array_constructor_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsArrayConstructorIntact());
}
void Isolate::InvalidateArraySpeciesProtector() {
DCHECK(factory()->array_species_protector()->value()->IsSmi());
DCHECK(IsArraySpeciesLookupChainIntact());
factory()->array_species_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsArraySpeciesLookupChainIntact());
}
void Isolate::InvalidateTypedArraySpeciesProtector() {
DCHECK(factory()->typed_array_species_protector()->value()->IsSmi());
DCHECK(IsTypedArraySpeciesLookupChainIntact());
factory()->typed_array_species_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsTypedArraySpeciesLookupChainIntact());
}
void Isolate::InvalidatePromiseSpeciesProtector() {
DCHECK(factory()->promise_species_protector()->value()->IsSmi());
DCHECK(IsPromiseSpeciesLookupChainIntact());
factory()->promise_species_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsPromiseSpeciesLookupChainIntact());
}
void Isolate::InvalidateStringLengthOverflowProtector() {
DCHECK(factory()->string_length_protector()->value()->IsSmi());
DCHECK(IsStringLengthOverflowIntact());
factory()->string_length_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsStringLengthOverflowIntact());
}
void Isolate::InvalidateArrayIteratorProtector() {
DCHECK(factory()->array_iterator_protector()->value()->IsSmi());
DCHECK(IsArrayIteratorLookupChainIntact());
PropertyCell::SetValueWithInvalidation(
factory()->array_iterator_protector(),
handle(Smi::FromInt(kProtectorInvalid), this));
DCHECK(!IsArrayIteratorLookupChainIntact());
}
void Isolate::InvalidateArrayBufferNeuteringProtector() {
DCHECK(factory()->array_buffer_neutering_protector()->value()->IsSmi());
DCHECK(IsArrayBufferNeuteringIntact());
PropertyCell::SetValueWithInvalidation(
factory()->array_buffer_neutering_protector(),
handle(Smi::FromInt(kProtectorInvalid), this));
DCHECK(!IsArrayBufferNeuteringIntact());
}
void Isolate::InvalidatePromiseHookProtector() {
DCHECK(factory()->promise_hook_protector()->value()->IsSmi());
DCHECK(IsPromiseHookProtectorIntact());
PropertyCell::SetValueWithInvalidation(
factory()->promise_hook_protector(),
handle(Smi::FromInt(kProtectorInvalid), this));
DCHECK(!IsPromiseHookProtectorIntact());
}
void Isolate::InvalidatePromiseResolveProtector() {
DCHECK(factory()->promise_resolve_protector()->value()->IsSmi());
DCHECK(IsPromiseResolveLookupChainIntact());
factory()->promise_resolve_protector()->set_value(
Smi::FromInt(kProtectorInvalid));
DCHECK(!IsPromiseResolveLookupChainIntact());
}
void Isolate::InvalidatePromiseThenProtector() {
DCHECK(factory()->promise_then_protector()->value()->IsSmi());
DCHECK(IsPromiseThenLookupChainIntact());
PropertyCell::SetValueWithInvalidation(
factory()->promise_then_protector(),
handle(Smi::FromInt(kProtectorInvalid), this));
DCHECK(!IsPromiseThenLookupChainIntact());
}
bool Isolate::IsAnyInitialArrayPrototype(Handle<JSArray> array) {
DisallowHeapAllocation no_gc;
return IsInAnyContext(*array, Context::INITIAL_ARRAY_PROTOTYPE_INDEX);
}
CallInterfaceDescriptorData* Isolate::call_descriptor_data(int index) {
DCHECK(0 <= index && index < CallDescriptors::NUMBER_OF_DESCRIPTORS);
return &call_descriptor_data_[index];
}
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() {
return ensure_rng_exists(&random_number_generator_, FLAG_random_seed);
}
base::RandomNumberGenerator* Isolate::fuzzer_rng() {
if (fuzzer_rng_ == nullptr) {
int64_t seed = FLAG_fuzzer_random_seed;
if (seed == 0) {
seed = random_number_generator()->initial_seed();
}
fuzzer_rng_ = new base::RandomNumberGenerator(seed);
}
return fuzzer_rng_;
}
int Isolate::GenerateIdentityHash(uint32_t mask) {
int hash;
int attempts = 0;
do {
hash = random_number_generator()->NextInt() & mask;
} while (hash == 0 && attempts++ < 30);
return hash != 0 ? hash : 1;
}
Code* Isolate::FindCodeObject(Address a) {
return heap()->GcSafeFindCodeForInnerPointer(a);
}
#ifdef DEBUG
#define ISOLATE_FIELD_OFFSET(type, name, ignored) \
const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
#undef ISOLATE_FIELD_OFFSET
#endif
Handle<Symbol> Isolate::SymbolFor(Heap::RootListIndex dictionary_index,
Handle<String> name, bool private_symbol) {
Handle<String> key = factory()->InternalizeString(name);
Handle<NameDictionary> dictionary =
Handle<NameDictionary>::cast(heap()->root_handle(dictionary_index));
int entry = dictionary->FindEntry(key);
Handle<Symbol> symbol;
if (entry == NameDictionary::kNotFound) {
symbol =
private_symbol ? factory()->NewPrivateSymbol() : factory()->NewSymbol();
symbol->set_name(*key);
dictionary = NameDictionary::Add(dictionary, key, symbol,
PropertyDetails::Empty(), &entry);
switch (dictionary_index) {
case Heap::kPublicSymbolTableRootIndex:
symbol->set_is_public(true);
heap()->set_public_symbol_table(*dictionary);
break;
case Heap::kApiSymbolTableRootIndex:
heap()->set_api_symbol_table(*dictionary);
break;
case Heap::kApiPrivateSymbolTableRootIndex:
heap()->set_api_private_symbol_table(*dictionary);
break;
default:
UNREACHABLE();
}
} else {
symbol = Handle<Symbol>(Symbol::cast(dictionary->ValueAt(entry)));
}
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::AddMicrotasksCompletedCallback(
MicrotasksCompletedCallback callback) {
auto pos = std::find(microtasks_completed_callbacks_.begin(),
microtasks_completed_callbacks_.end(), callback);
if (pos != microtasks_completed_callbacks_.end()) return;
microtasks_completed_callbacks_.push_back(callback);
}
void Isolate::RemoveMicrotasksCompletedCallback(
MicrotasksCompletedCallback callback) {
auto pos = std::find(microtasks_completed_callbacks_.begin(),
microtasks_completed_callbacks_.end(), callback);
if (pos == microtasks_completed_callbacks_.end()) return;
microtasks_completed_callbacks_.erase(pos);
}
void Isolate::FireCallCompletedCallback() {
if (!handle_scope_implementer()->CallDepthIsZero()) return;
bool run_microtasks =
pending_microtask_count() &&
!handle_scope_implementer()->HasMicrotasksSuppressions() &&
handle_scope_implementer()->microtasks_policy() ==
v8::MicrotasksPolicy::kAuto;
if (run_microtasks) RunMicrotasks();
if (call_completed_callbacks_.empty()) return;
// Fire callbacks. Increase call depth to prevent recursive callbacks.
v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(this);
v8::Isolate::SuppressMicrotaskExecutionScope suppress(isolate);
std::vector<CallCompletedCallback> callbacks(call_completed_callbacks_);
for (auto& callback : callbacks) {
callback(reinterpret_cast<v8::Isolate*>(this));
}
}
void Isolate::DebugStateUpdated() {
bool promise_hook_or_debug_is_active = promise_hook_ || debug()->is_active();
if (promise_hook_or_debug_is_active && IsPromiseHookProtectorIntact()) {
InvalidatePromiseHookProtector();
}
promise_hook_or_debug_is_active_ = promise_hook_or_debug_is_active;
}
namespace {
MaybeHandle<JSPromise> NewRejectedPromise(Isolate* isolate,
v8::Local<v8::Context> api_context,
Handle<Object> exception) {
v8::Local<v8::Promise::Resolver> resolver;
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
isolate, resolver, v8::Promise::Resolver::New(api_context),
MaybeHandle<JSPromise>());
RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
isolate, resolver->Reject(api_context, v8::Utils::ToLocal(exception)),
MaybeHandle<JSPromise>());
v8::Local<v8::Promise> promise = resolver->GetPromise();
return v8::Utils::OpenHandle(*promise);
}
} // namespace
MaybeHandle<JSPromise> Isolate::RunHostImportModuleDynamicallyCallback(
Handle<Script> referrer, Handle<Object> specifier) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(native_context());
if (host_import_module_dynamically_callback_ == nullptr) {
Handle<Object> exception =
factory()->NewError(error_function(), MessageTemplate::kUnsupported);
return NewRejectedPromise(this, api_context, exception);
}
Handle<String> specifier_str;
MaybeHandle<String> maybe_specifier = Object::ToString(this, specifier);
if (!maybe_specifier.ToHandle(&specifier_str)) {
Handle<Object> exception(pending_exception(), this);
clear_pending_exception();
return NewRejectedPromise(this, api_context, exception);
}
DCHECK(!has_pending_exception());
v8::Local<v8::Promise> promise;
ASSIGN_RETURN_ON_SCHEDULED_EXCEPTION_VALUE(
this, promise,
host_import_module_dynamically_callback_(
api_context, v8::Utils::ScriptOrModuleToLocal(referrer),
v8::Utils::ToLocal(specifier_str)),
MaybeHandle<JSPromise>());
return v8::Utils::OpenHandle(*promise);
}
void Isolate::SetHostImportModuleDynamicallyCallback(
HostImportModuleDynamicallyCallback callback) {
host_import_module_dynamically_callback_ = callback;
}
Handle<JSObject> Isolate::RunHostInitializeImportMetaObjectCallback(
Handle<Module> module) {
Handle<Object> host_meta(module->import_meta(), this);
if (host_meta->IsTheHole(this)) {
host_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(module),
v8::Local<v8::Object>::Cast(v8::Utils::ToLocal(host_meta)));
}
module->set_import_meta(*host_meta);
}
return Handle<JSObject>::cast(host_meta);
}
void Isolate::SetHostInitializeImportMetaObjectCallback(
HostInitializeImportMetaObjectCallback callback) {
host_initialize_import_meta_object_callback_ = callback;
}
void Isolate::SetPromiseHook(PromiseHook hook) {
promise_hook_ = hook;
DebugStateUpdated();
}
void Isolate::RunPromiseHook(PromiseHookType type, Handle<JSPromise> promise,
Handle<Object> parent) {
if (debug()->is_active()) debug()->RunPromiseHook(type, promise, parent);
if (promise_hook_ == nullptr) return;
promise_hook_(type, v8::Utils::PromiseToLocal(promise),
v8::Utils::ToLocal(parent));
}
void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
promise_reject_callback_ = callback;
}
void Isolate::ReportPromiseReject(Handle<JSPromise> promise,
Handle<Object> value,
v8::PromiseRejectEvent event) {
DCHECK_EQ(v8::Promise::kRejected, promise->status());
if (promise_reject_callback_ == nullptr) return;
Handle<FixedArray> stack_trace;
if (event == v8::kPromiseRejectWithNoHandler && value->IsJSObject()) {
stack_trace = GetDetailedStackTrace(Handle<JSObject>::cast(value));
}
promise_reject_callback_(v8::PromiseRejectMessage(
v8::Utils::PromiseToLocal(promise), event, v8::Utils::ToLocal(value),
v8::Utils::StackTraceToLocal(stack_trace)));
}
void Isolate::EnqueueMicrotask(Handle<Microtask> microtask) {
Handle<FixedArray> queue(heap()->microtask_queue(), this);
int num_tasks = pending_microtask_count();
DCHECK_LE(num_tasks, queue->length());
if (num_tasks == queue->length()) {
queue = factory()->CopyFixedArrayAndGrow(queue, std::max(num_tasks, 8));
heap()->set_microtask_queue(*queue);
}
DCHECK_LE(8, queue->length());
DCHECK_LT(num_tasks, queue->length());
DCHECK(queue->get(num_tasks)->IsUndefined(this));
queue->set(num_tasks, *microtask);
set_pending_microtask_count(num_tasks + 1);
}
void Isolate::RunMicrotasks() {
// Increase call depth to prevent recursive callbacks.
v8::Isolate::SuppressMicrotaskExecutionScope suppress(
reinterpret_cast<v8::Isolate*>(this));
if (pending_microtask_count()) {
is_running_microtasks_ = true;
TRACE_EVENT0("v8.execute", "RunMicrotasks");
TRACE_EVENT_CALL_STATS_SCOPED(this, "v8", "V8.RunMicrotasks");
HandleScope scope(this);
MaybeHandle<Object> maybe_exception;
MaybeHandle<Object> maybe_result = Execution::RunMicrotasks(
this, Execution::MessageHandling::kReport, &maybe_exception);
// If execution is terminating, bail out, clean up, and propagate to
// TryCatch scope.
if (maybe_result.is_null() && maybe_exception.is_null()) {
heap()->set_microtask_queue(heap()->empty_fixed_array());
set_pending_microtask_count(0);
handle_scope_implementer()->LeaveMicrotaskContext();
SetTerminationOnExternalTryCatch();
}
CHECK_EQ(0, pending_microtask_count());
CHECK_EQ(0, heap()->microtask_queue()->length());
is_running_microtasks_ = false;
}
FireMicrotasksCompletedCallback();
}
void Isolate::SetUseCounterCallback(v8::Isolate::UseCounterCallback callback) {
DCHECK(!use_counter_callback_);
use_counter_callback_ = callback;
}
void Isolate::CountUsage(v8::Isolate::UseCounterFeature feature) {
// The counter callback may cause the embedder to call into V8, which is not
// generally possible during GC.
if (heap_.gc_state() == Heap::NOT_IN_GC) {
if (use_counter_callback_) {
HandleScope handle_scope(this);
use_counter_callback_(reinterpret_cast<v8::Isolate*>(this), feature);
}
} else {
heap_.IncrementDeferredCount(feature);
}
}
BasicBlockProfiler* Isolate::GetOrCreateBasicBlockProfiler() {
if (basic_block_profiler_ == nullptr) {
basic_block_profiler_ = new BasicBlockProfiler();
}
return basic_block_profiler_;
}
std::string Isolate::GetTurboCfgFileName() {
if (FLAG_trace_turbo_cfg_file == nullptr) {
std::ostringstream os;
os << "turbo-" << base::OS::GetCurrentProcessId() << "-" << id() << ".cfg";
return os.str();
} else {
return FLAG_trace_turbo_cfg_file;
}
}
// Heap::detached_contexts tracks detached contexts as pairs
// (number of GC since the context was detached, the context).
void Isolate::AddDetachedContext(Handle<Context> context) {
HandleScope scope(this);
Handle<WeakCell> cell = factory()->NewWeakCell(context);
Handle<FixedArray> detached_contexts =
factory()->CopyFixedArrayAndGrow(factory()->detached_contexts(), 2);
int new_length = detached_contexts->length();
detached_contexts->set(new_length - 2, Smi::kZero);
detached_contexts->set(new_length - 1, *cell);
heap()->set_detached_contexts(*detached_contexts);
}
void Isolate::CheckDetachedContextsAfterGC() {
HandleScope scope(this);
Handle<FixedArray> detached_contexts = factory()->detached_contexts();
int length = detached_contexts->length();
if (length == 0) return;
int new_length = 0;
for (int i = 0; i < length; i += 2) {
int mark_sweeps = Smi::ToInt(detached_contexts->get(i));
DCHECK(detached_contexts->get(i + 1)->IsWeakCell());
WeakCell* cell = WeakCell::cast(detached_contexts->get(i + 1));
if (!cell->cleared()) {
detached_contexts->set(new_length, Smi::FromInt(mark_sweeps + 1));
detached_contexts->set(new_length + 1, cell);
new_length += 2;
}
counters()->detached_context_age_in_gc()->AddSample(mark_sweeps + 1);
}
if (FLAG_trace_detached_contexts) {
PrintF("%d detached contexts are collected out of %d\n",
length - new_length, length);
for (int i = 0; i < new_length; i += 2) {
int mark_sweeps = Smi::ToInt(detached_contexts->get(i));
DCHECK(detached_contexts->get(i + 1)->IsWeakCell());
WeakCell* cell = WeakCell::cast(detached_contexts->get(i + 1));
if (mark_sweeps > 3) {
PrintF("detached context %p\n survived %d GCs (leak?)\n",
static_cast<void*>(cell->value()), mark_sweeps);
}
}
}
if (new_length == 0) {
heap()->set_detached_contexts(heap()->empty_fixed_array());
} else if (new_length < length) {
heap()->RightTrimFixedArray(*detached_contexts, length - new_length);
}
}
double Isolate::LoadStartTimeMs() {
base::LockGuard<base::Mutex> guard(&rail_mutex_);
return load_start_time_ms_;
}
void Isolate::SetRAILMode(RAILMode rail_mode) {
RAILMode old_rail_mode = rail_mode_.Value();
if (old_rail_mode != PERFORMANCE_LOAD && rail_mode == PERFORMANCE_LOAD) {
base::LockGuard<base::Mutex> guard(&rail_mutex_);
load_start_time_ms_ = heap()->MonotonicallyIncreasingTimeInMs();
}
rail_mode_.SetValue(rail_mode);
if (old_rail_mode == PERFORMANCE_LOAD && rail_mode != PERFORMANCE_LOAD) {
heap()->incremental_marking()->incremental_marking_job()->ScheduleTask(
heap());
}
if (FLAG_trace_rail) {
PrintIsolate(this, "RAIL mode: %s\n", RAILModeName(rail_mode));
}
}
void Isolate::IsolateInBackgroundNotification() {
is_isolate_in_background_ = true;
heap()->ActivateMemoryReducerIfNeeded();
}
void Isolate::IsolateInForegroundNotification() {
is_isolate_in_background_ = false;
}
void Isolate::PrintWithTimestamp(const char* format, ...) {
base::OS::Print("[%d:%p] %8.0f ms: ", base::OS::GetCurrentProcessId(),
static_cast<void*>(this), time_millis_since_init());
va_list arguments;
va_start(arguments, format);
base::OS::VPrint(format, arguments);
va_end(arguments);
}
void Isolate::SetIdle(bool is_idle) {
if (!is_profiling()) return;
StateTag state = current_vm_state();
DCHECK(state == EXTERNAL || state == IDLE);
if (js_entry_sp() != kNullAddress) return;
if (is_idle) {
set_current_vm_state(IDLE);
} else if (state == IDLE) {
set_current_vm_state(EXTERNAL);
}
}
bool StackLimitCheck::JsHasOverflowed(uintptr_t gap) const {
StackGuard* stack_guard = isolate_->stack_guard();
#ifdef USE_SIMULATOR
// The simulator uses a separate JS stack.
Address jssp_address = Simulator::current(isolate_)->get_sp();
uintptr_t jssp = static_cast<uintptr_t>(jssp_address);
if (jssp - gap < stack_guard->real_jslimit()) return true;
#endif // USE_SIMULATOR
return GetCurrentStackPosition() - gap < stack_guard->real_climit();
}
SaveContext::SaveContext(Isolate* isolate)
: isolate_(isolate), prev_(isolate->save_context()) {
if (isolate->context() != nullptr) {
context_ = Handle<Context>(isolate->context());
}
isolate->set_save_context(this);
c_entry_fp_ = isolate->c_entry_fp(isolate->thread_local_top());
}
SaveContext::~SaveContext() {
isolate_->set_context(context_.is_null() ? nullptr : *context_);
isolate_->set_save_context(prev_);
}
bool SaveContext::IsBelowFrame(StandardFrame* frame) {
return (c_entry_fp_ == 0) || (c_entry_fp_ > frame->sp());
}
#ifdef DEBUG
AssertNoContextChange::AssertNoContextChange(Isolate* isolate)
: isolate_(isolate), context_(isolate->context(), isolate) {}
#endif // DEBUG
bool InterruptsScope::Intercept(StackGuard::InterruptFlag flag) {
InterruptsScope* last_postpone_scope = nullptr;
for (InterruptsScope* current = this; current; current = current->prev_) {
// We only consider scopes related to passed flag.
if (!(current->intercept_mask_ & flag)) continue;
if (current->mode_ == kRunInterrupts) {
// If innermost scope is kRunInterrupts scope, prevent interrupt from
// beeing prevented.
if (!last_postpone_scope) return false;
} else {
DCHECK_EQ(current->mode_, kPostponeInterrupts);
last_postpone_scope = current;
}
}
// If there is no postpone scope for passed flag then we should not inrecept.
if (!last_postpone_scope) return false;
last_postpone_scope->intercepted_flags_ |= flag;
return true;
}
} // namespace internal
} // namespace v8