// 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 <fstream> // NOLINT(readability/streams)
#include <sstream>
#include "src/ast/ast.h"
#include "src/ast/scopeinfo.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/codegen.h"
#include "src/compilation-cache.h"
#include "src/compilation-statistics.h"
#include "src/crankshaft/hydrogen.h"
#include "src/debug/debug.h"
#include "src/deoptimizer.h"
#include "src/frames-inl.h"
#include "src/ic/stub-cache.h"
#include "src/interpreter/interpreter.h"
#include "src/isolate-inl.h"
#include "src/log.h"
#include "src/messages.h"
#include "src/profiler/cpu-profiler.h"
#include "src/profiler/sampler.h"
#include "src/prototype.h"
#include "src/regexp/regexp-stack.h"
#include "src/runtime-profiler.h"
#include "src/simulator.h"
#include "src/snapshot/serialize.h"
#include "src/v8.h"
#include "src/version.h"
#include "src/vm-state-inl.h"
namespace v8 {
namespace internal {
base::Atomic32 ThreadId::highest_thread_id_ = 0;
int ThreadId::AllocateThreadId() {
int new_id = base::NoBarrier_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_ = NULL;
#endif
js_entry_sp_ = NULL;
external_callback_scope_ = NULL;
current_vm_state_ = EXTERNAL;
try_catch_handler_ = NULL;
context_ = NULL;
thread_id_ = ThreadId::Invalid();
external_caught_exception_ = false;
failed_access_check_callback_ = NULL;
save_context_ = NULL;
promise_on_stack_ = NULL;
// These members are re-initialized later after deserialization
// is complete.
pending_exception_ = NULL;
rethrowing_message_ = false;
pending_message_obj_ = NULL;
scheduled_exception_ = NULL;
}
void ThreadLocalTop::Initialize() {
InitializeInternal();
#ifdef USE_SIMULATOR
simulator_ = Simulator::current(isolate_);
#endif
thread_id_ = ThreadId::Current();
}
void ThreadLocalTop::Free() {
// 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::LazyMutex Isolate::thread_data_table_mutex_ = LAZY_MUTEX_INITIALIZER;
Isolate::ThreadDataTable* Isolate::thread_data_table_ = NULL;
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 = NULL;
{
base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
per_thread = thread_data_table_->Lookup(this, thread_id);
if (per_thread == NULL) {
per_thread = new PerIsolateThreadData(this, thread_id);
thread_data_table_->Insert(per_thread);
}
DCHECK(thread_data_table_->Lookup(this, 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_.Pointer());
PerIsolateThreadData* per_thread =
thread_data_table_->Lookup(this, 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 = NULL;
{
base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
per_thread = thread_data_table_->Lookup(this, thread_id);
}
return per_thread;
}
void Isolate::InitializeOncePerProcess() {
base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
CHECK(thread_data_table_ == NULL);
isolate_key_ = base::Thread::CreateThreadLocalKey();
#if DEBUG
base::NoBarrier_Store(&isolate_key_created_, 1);
#endif
thread_id_key_ = base::Thread::CreateThreadLocalKey();
per_isolate_thread_data_key_ = base::Thread::CreateThreadLocalKey();
thread_data_table_ = new Isolate::ThreadDataTable();
}
Address Isolate::get_address_from_id(Isolate::AddressId id) {
return isolate_addresses_[id];
}
char* Isolate::Iterate(ObjectVisitor* 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(ObjectVisitor* v, ThreadLocalTop* thread) {
// Visit the roots from the top for a given thread.
v->VisitPointer(&thread->pending_exception_);
v->VisitPointer(&(thread->pending_message_obj_));
v->VisitPointer(bit_cast<Object**>(&(thread->context_)));
v->VisitPointer(&thread->scheduled_exception_);
for (v8::TryCatch* block = thread->try_catch_handler();
block != NULL;
block = block->next_) {
v->VisitPointer(bit_cast<Object**>(&(block->exception_)));
v->VisitPointer(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(ObjectVisitor* v) {
ThreadLocalTop* current_t = thread_local_top();
Iterate(v, current_t);
}
void Isolate::IterateDeferredHandles(ObjectVisitor* visitor) {
for (DeferredHandles* deferred = deferred_handles_head_;
deferred != NULL;
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 != NULL;
deferred = deferred->next_) {
List<Object**>* blocks = &deferred->blocks_;
for (int i = 0; i < blocks->length(); 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_ = NULL;
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(unsigned int magic, void* ptr1, void* ptr2,
unsigned int magic2) {
const int kMaxStackTraceSize = 32 * KB;
Handle<String> trace = StackTraceString();
uint8_t buffer[kMaxStackTraceSize];
int length = Min(kMaxStackTraceSize - 1, trace->length());
String::WriteToFlat(*trace, buffer, 0, length);
buffer[length] = '\0';
// TODO(dcarney): convert buffer to utf8?
base::OS::PrintError("Stacktrace (%x-%x) %p %p: %s\n", magic, magic2, ptr1,
ptr2, reinterpret_cast<char*>(buffer));
base::OS::Abort();
}
// Determines whether the given stack frame should be displayed in
// a stack trace. The caller is the error constructor that asked
// for the stack trace to be collected. The first time a construct
// call to this function is encountered it is skipped. The seen_caller
// in/out parameter is used to remember if the caller has been seen
// yet.
static bool IsVisibleInStackTrace(JSFunction* fun,
Object* caller,
Object* receiver,
bool* seen_caller) {
if ((fun == caller) && !(*seen_caller)) {
*seen_caller = true;
return false;
}
// Skip all frames until we've seen the caller.
if (!(*seen_caller)) return false;
// Functions defined in native 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 && fun->shared()->IsBuiltin()) {
return fun->shared()->native();
}
return true;
}
Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSObject> error_object,
Handle<Object> caller) {
// Get stack trace limit.
Handle<JSObject> error = error_function();
Handle<String> stackTraceLimit =
factory()->InternalizeUtf8String("stackTraceLimit");
DCHECK(!stackTraceLimit.is_null());
Handle<Object> stack_trace_limit =
JSReceiver::GetDataProperty(error, stackTraceLimit);
if (!stack_trace_limit->IsNumber()) return factory()->undefined_value();
int limit = FastD2IChecked(stack_trace_limit->Number());
limit = Max(limit, 0); // Ensure that limit is not negative.
int initial_size = Min(limit, 10);
Handle<FixedArray> elements =
factory()->NewFixedArrayWithHoles(initial_size * 4 + 1);
// If the caller parameter is a function we skip frames until we're
// under it before starting to collect.
bool seen_caller = !caller->IsJSFunction();
// First element is reserved to store the number of sloppy frames.
int cursor = 1;
int frames_seen = 0;
int sloppy_frames = 0;
bool encountered_strict_function = false;
for (JavaScriptFrameIterator iter(this);
!iter.done() && frames_seen < limit;
iter.Advance()) {
JavaScriptFrame* frame = iter.frame();
// Set initial size to the maximum inlining level + 1 for the outermost
// function.
List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
frame->Summarize(&frames);
for (int i = frames.length() - 1; i >= 0; i--) {
Handle<JSFunction> fun = frames[i].function();
Handle<Object> recv = frames[i].receiver();
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(*fun, *caller, *recv, &seen_caller)) continue;
// Filter out frames from other security contexts.
if (!this->context()->HasSameSecurityTokenAs(fun->context())) continue;
if (cursor + 4 > elements->length()) {
int new_capacity = JSObject::NewElementsCapacity(elements->length());
Handle<FixedArray> new_elements =
factory()->NewFixedArrayWithHoles(new_capacity);
for (int i = 0; i < cursor; i++) {
new_elements->set(i, elements->get(i));
}
elements = new_elements;
}
DCHECK(cursor + 4 <= elements->length());
Handle<Code> code = frames[i].code();
Handle<Smi> offset(Smi::FromInt(frames[i].offset()), this);
// The stack trace API should not expose receivers and function
// objects on frames deeper than the top-most one with a strict
// mode function. The number of sloppy frames is stored as
// first element in the result array.
if (!encountered_strict_function) {
if (is_strict(fun->shared()->language_mode())) {
encountered_strict_function = true;
} else {
sloppy_frames++;
}
}
elements->set(cursor++, *recv);
elements->set(cursor++, *fun);
elements->set(cursor++, *code);
elements->set(cursor++, *offset);
frames_seen++;
}
}
elements->set(0, Smi::FromInt(sloppy_frames));
elements->Shrink(cursor);
Handle<JSArray> result = factory()->NewJSArrayWithElements(elements);
result->set_length(Smi::FromInt(cursor));
// TODO(yangguo): Queue this structured stack trace for preprocessing on GC.
return result;
}
MaybeHandle<JSObject> Isolate::CaptureAndSetDetailedStackTrace(
Handle<JSObject> 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<JSArray> stack_trace = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
RETURN_ON_EXCEPTION(
this, JSObject::SetProperty(error_object, key, stack_trace, STRICT),
JSObject);
}
return error_object;
}
MaybeHandle<JSObject> Isolate::CaptureAndSetSimpleStackTrace(
Handle<JSObject> error_object, 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, caller);
RETURN_ON_EXCEPTION(
this, JSObject::SetProperty(error_object, key, stack_trace, STRICT),
JSObject);
return error_object;
}
Handle<JSArray> 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->IsJSArray()) return Handle<JSArray>::cast(stack_trace);
if (!capture_stack_trace_for_uncaught_exceptions_) return Handle<JSArray>();
// Try to get details from simple stack trace.
Handle<JSArray> detailed_stack_trace =
GetDetailedFromSimpleStackTrace(error_object);
if (!detailed_stack_trace.is_null()) {
// Save the detailed stack since the simple one might be withdrawn later.
JSObject::SetProperty(error_object, key_detailed, detailed_stack_trace,
STRICT).Assert();
}
return detailed_stack_trace;
}
class CaptureStackTraceHelper {
public:
CaptureStackTraceHelper(Isolate* isolate,
StackTrace::StackTraceOptions options)
: isolate_(isolate) {
if (options & StackTrace::kColumnOffset) {
column_key_ =
factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("column"));
}
if (options & StackTrace::kLineNumber) {
line_key_ =
factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("lineNumber"));
}
if (options & StackTrace::kScriptId) {
script_id_key_ =
factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("scriptId"));
}
if (options & StackTrace::kScriptName) {
script_name_key_ =
factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("scriptName"));
}
if (options & StackTrace::kScriptNameOrSourceURL) {
script_name_or_source_url_key_ = factory()->InternalizeOneByteString(
STATIC_CHAR_VECTOR("scriptNameOrSourceURL"));
}
if (options & StackTrace::kFunctionName) {
function_key_ = factory()->InternalizeOneByteString(
STATIC_CHAR_VECTOR("functionName"));
}
if (options & StackTrace::kIsEval) {
eval_key_ =
factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("isEval"));
}
if (options & StackTrace::kIsConstructor) {
constructor_key_ = factory()->InternalizeOneByteString(
STATIC_CHAR_VECTOR("isConstructor"));
}
}
Handle<JSObject> NewStackFrameObject(Handle<JSFunction> fun, int position,
bool is_constructor) {
Handle<JSObject> stack_frame =
factory()->NewJSObject(isolate_->object_function());
Handle<Script> script(Script::cast(fun->shared()->script()));
if (!line_key_.is_null()) {
int script_line_offset = script->line_offset();
int line_number = Script::GetLineNumber(script, position);
// line_number is already shifted by the script_line_offset.
int relative_line_number = line_number - script_line_offset;
if (!column_key_.is_null() && relative_line_number >= 0) {
Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()));
int start = (relative_line_number == 0) ? 0 :
Smi::cast(line_ends->get(relative_line_number - 1))->value() + 1;
int column_offset = position - start;
if (relative_line_number == 0) {
// For the case where the code is on the same line as the script
// tag.
column_offset += script->column_offset();
}
JSObject::AddProperty(stack_frame, column_key_,
handle(Smi::FromInt(column_offset + 1), isolate_),
NONE);
}
JSObject::AddProperty(stack_frame, line_key_,
handle(Smi::FromInt(line_number + 1), isolate_),
NONE);
}
if (!script_id_key_.is_null()) {
JSObject::AddProperty(stack_frame, script_id_key_,
handle(Smi::FromInt(script->id()), isolate_), NONE);
}
if (!script_name_key_.is_null()) {
JSObject::AddProperty(stack_frame, script_name_key_,
handle(script->name(), isolate_), NONE);
}
if (!script_name_or_source_url_key_.is_null()) {
Handle<Object> result = Script::GetNameOrSourceURL(script);
JSObject::AddProperty(stack_frame, script_name_or_source_url_key_, result,
NONE);
}
if (!function_key_.is_null()) {
Handle<Object> fun_name = JSFunction::GetDebugName(fun);
JSObject::AddProperty(stack_frame, function_key_, fun_name, NONE);
}
if (!eval_key_.is_null()) {
Handle<Object> is_eval = factory()->ToBoolean(
script->compilation_type() == Script::COMPILATION_TYPE_EVAL);
JSObject::AddProperty(stack_frame, eval_key_, is_eval, NONE);
}
if (!constructor_key_.is_null()) {
Handle<Object> is_constructor_obj = factory()->ToBoolean(is_constructor);
JSObject::AddProperty(stack_frame, constructor_key_, is_constructor_obj,
NONE);
}
return stack_frame;
}
private:
inline Factory* factory() { return isolate_->factory(); }
Isolate* isolate_;
Handle<String> column_key_;
Handle<String> line_key_;
Handle<String> script_id_key_;
Handle<String> script_name_key_;
Handle<String> script_name_or_source_url_key_;
Handle<String> function_key_;
Handle<String> eval_key_;
Handle<String> constructor_key_;
};
int PositionFromStackTrace(Handle<FixedArray> elements, int index) {
DisallowHeapAllocation no_gc;
Object* maybe_code = elements->get(index + 2);
if (maybe_code->IsSmi()) {
return Smi::cast(maybe_code)->value();
} else {
Code* code = Code::cast(maybe_code);
Address pc = code->address() + Smi::cast(elements->get(index + 3))->value();
return code->SourcePosition(pc);
}
}
Handle<JSArray> Isolate::GetDetailedFromSimpleStackTrace(
Handle<JSObject> error_object) {
Handle<Name> key = factory()->stack_trace_symbol();
Handle<Object> property = JSReceiver::GetDataProperty(error_object, key);
if (!property->IsJSArray()) return Handle<JSArray>();
Handle<JSArray> simple_stack_trace = Handle<JSArray>::cast(property);
CaptureStackTraceHelper helper(this,
stack_trace_for_uncaught_exceptions_options_);
int frames_seen = 0;
Handle<FixedArray> elements(FixedArray::cast(simple_stack_trace->elements()));
int elements_limit = Smi::cast(simple_stack_trace->length())->value();
int frame_limit = stack_trace_for_uncaught_exceptions_frame_limit_;
if (frame_limit < 0) frame_limit = (elements_limit - 1) / 4;
Handle<JSArray> stack_trace = factory()->NewJSArray(frame_limit);
for (int i = 1; i < elements_limit && frames_seen < frame_limit; i += 4) {
Handle<Object> recv = handle(elements->get(i), this);
Handle<JSFunction> fun =
handle(JSFunction::cast(elements->get(i + 1)), this);
bool is_constructor =
recv->IsJSObject() &&
Handle<JSObject>::cast(recv)->map()->GetConstructor() == *fun;
int position = PositionFromStackTrace(elements, i);
Handle<JSObject> stack_frame =
helper.NewStackFrameObject(fun, position, is_constructor);
FixedArray::cast(stack_trace->elements())->set(frames_seen, *stack_frame);
frames_seen++;
}
stack_trace->set_length(Smi::FromInt(frames_seen));
return stack_trace;
}
Handle<JSArray> Isolate::CaptureCurrentStackTrace(
int frame_limit, StackTrace::StackTraceOptions options) {
CaptureStackTraceHelper helper(this, options);
// Ensure no negative values.
int limit = Max(frame_limit, 0);
Handle<JSArray> stack_trace = factory()->NewJSArray(frame_limit);
StackTraceFrameIterator it(this);
int frames_seen = 0;
while (!it.done() && (frames_seen < limit)) {
JavaScriptFrame* frame = it.frame();
// Set initial size to the maximum inlining level + 1 for the outermost
// function.
List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
frame->Summarize(&frames);
for (int i = frames.length() - 1; i >= 0 && frames_seen < limit; i--) {
Handle<JSFunction> fun = frames[i].function();
// Filter frames from other security contexts.
if (!(options & StackTrace::kExposeFramesAcrossSecurityOrigins) &&
!this->context()->HasSameSecurityTokenAs(fun->context())) continue;
int position = frames[i].code()->SourcePosition(frames[i].pc());
Handle<JSObject> stack_frame =
helper.NewStackFrameObject(fun, position, frames[i].is_constructor());
FixedArray::cast(stack_trace->elements())->set(frames_seen, *stack_frame);
frames_seen++;
}
it.Advance();
}
stack_trace->set_length(Smi::FromInt(frames_seen));
return stack_trace;
}
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_ = NULL;
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;
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;
}
static inline AccessCheckInfo* GetAccessCheckInfo(Isolate* isolate,
Handle<JSObject> receiver) {
Object* maybe_constructor = receiver->map()->GetConstructor();
if (!maybe_constructor->IsJSFunction()) return NULL;
JSFunction* constructor = JSFunction::cast(maybe_constructor);
if (!constructor->shared()->IsApiFunction()) return NULL;
Object* data_obj =
constructor->shared()->get_api_func_data()->access_check_info();
if (data_obj == isolate->heap()->undefined_value()) return NULL;
return AccessCheckInfo::cast(data_obj);
}
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 = GetAccessCheckInfo(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::IsInternallyUsedPropertyName(Handle<Object> name) {
if (name->IsSymbol()) {
return Handle<Symbol>::cast(name)->is_private();
}
return name.is_identical_to(factory()->hidden_string());
}
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;
v8::NamedSecurityCallback named_callback = nullptr;
{ DisallowHeapAllocation no_gc;
AccessCheckInfo* access_check_info = GetAccessCheckInfo(this, receiver);
if (!access_check_info) return false;
Object* fun_obj = access_check_info->callback();
callback = v8::ToCData<v8::AccessCheckCallback>(fun_obj);
if (!callback) {
fun_obj = access_check_info->named_callback();
named_callback = v8::ToCData<v8::NamedSecurityCallback>(fun_obj);
if (!named_callback) return false;
data = handle(access_check_info->data(), this);
}
}
LOG(this, ApiSecurityCheck());
{
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
if (callback) {
return callback(v8::Utils::ToLocal(accessing_context),
v8::Utils::ToLocal(receiver));
}
Handle<Object> key = factory()->undefined_value();
return named_callback(v8::Utils::ToLocal(receiver), v8::Utils::ToLocal(key),
v8::ACCESS_HAS, v8::Utils::ToLocal(data));
}
}
const char* const Isolate::kStackOverflowMessage =
"Uncaught RangeError: Maximum call stack size exceeded";
Object* Isolate::StackOverflow() {
HandleScope scope(this);
// At this point we cannot create an Error object using its javascript
// constructor. Instead, we copy the pre-constructed boilerplate and
// attach the stack trace as a hidden property.
Handle<Object> exception;
if (bootstrapper()->IsActive()) {
// There is no boilerplate to use during bootstrapping.
exception = factory()->NewStringFromAsciiChecked(
MessageTemplate::TemplateString(MessageTemplate::kStackOverflow));
} else {
Handle<JSObject> boilerplate = stack_overflow_boilerplate();
Handle<JSObject> copy = factory()->CopyJSObject(boilerplate);
CaptureAndSetSimpleStackTrace(copy, factory()->undefined_value());
exception = copy;
}
Throw(*exception, nullptr);
#ifdef VERIFY_HEAP
if (FLAG_verify_heap && FLAG_stress_compaction) {
heap()->CollectAllAvailableGarbage("trigger compaction");
}
#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() {
// 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 == NULL || 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 occured
// 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
}
Object* Isolate::Throw(Object* exception, MessageLocation* location) {
DCHECK(!has_pending_exception());
HandleScope scope(this);
Handle<Object> exception_handle(exception, this);
// 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 == NULL && 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 &&
PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT &&
(!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();
Code* code = nullptr;
Context* context = nullptr;
intptr_t offset = 0;
Address handler_sp = nullptr;
Address handler_fp = nullptr;
// Special handling of termination exceptions, uncatchable by JavaScript 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.done(); iter.Advance()) {
StackFrame* frame = iter.frame();
// For JSEntryStub frames we always have a handler.
if (frame->is_entry() || frame->is_entry_construct()) {
StackHandler* handler = frame->top_handler();
// Restore the next handler.
thread_local_top()->handler_ = handler->next()->address();
// Gather information from the handler.
code = frame->LookupCode();
handler_sp = handler->address() + StackHandlerConstants::kSize;
offset = Smi::cast(code->handler_table()->get(0))->value();
break;
}
// For optimized frames we perform a lookup in the handler table.
if (frame->is_optimized() && catchable_by_js) {
OptimizedFrame* js_frame = static_cast<OptimizedFrame*>(frame);
int stack_slots = 0; // Will contain stack slot count of frame.
offset = js_frame->LookupExceptionHandlerInTable(&stack_slots, NULL);
if (offset >= 0) {
// 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::kFixedFrameSizeFromFp -
stack_slots * kPointerSize;
// Gather information from the frame.
code = frame->LookupCode();
handler_sp = return_sp;
handler_fp = frame->fp();
break;
}
}
// For JavaScript frames we perform a range lookup in the handler table.
if (frame->is_java_script() && catchable_by_js) {
JavaScriptFrame* js_frame = static_cast<JavaScriptFrame*>(frame);
int stack_slots = 0; // Will contain operand stack depth of handler.
offset = js_frame->LookupExceptionHandlerInTable(&stack_slots, NULL);
if (offset >= 0) {
// Compute the stack pointer from the frame pointer. This ensures that
// operand stack slots are dropped for nested statements. Also restore
// correct context for the handler which is pushed within the try-block.
Address return_sp = frame->fp() -
StandardFrameConstants::kFixedFrameSizeFromFp -
stack_slots * kPointerSize;
STATIC_ASSERT(TryBlockConstant::kElementCount == 1);
context = Context::cast(Memory::Object_at(return_sp - kPointerSize));
// Gather information from the frame.
code = frame->LookupCode();
handler_sp = return_sp;
handler_fp = frame->fp();
break;
}
}
RemoveMaterializedObjectsOnUnwind(frame);
}
// Handler must exist.
CHECK(code != nullptr);
// Store information to be consumed by the CEntryStub.
thread_local_top()->pending_handler_context_ = context;
thread_local_top()->pending_handler_code_ = code;
thread_local_top()->pending_handler_offset_ = offset;
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;
}
Isolate::CatchType Isolate::PredictExceptionCatcher() {
Address external_handler = thread_local_top()->try_catch_handler_address();
Address entry_handler = Isolate::handler(thread_local_top());
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();
// For JSEntryStub frames we update the JS_ENTRY handler.
if (frame->is_entry() || frame->is_entry_construct()) {
entry_handler = frame->top_handler()->next()->address();
}
// For JavaScript frames we perform a lookup in the handler table.
if (frame->is_java_script()) {
JavaScriptFrame* js_frame = static_cast<JavaScriptFrame*>(frame);
int stack_slots = 0; // The computed stack slot count is not used.
HandlerTable::CatchPrediction prediction;
if (js_frame->LookupExceptionHandlerInTable(&stack_slots, &prediction) >
0) {
// We are conservative with our prediction: try-finally is considered
// to always rethrow, to meet the expectation of the debugger.
if (prediction == HandlerTable::CAUGHT) return CAUGHT_BY_JAVASCRIPT;
}
}
// 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 != nullptr && !try_catch_handler()->is_verbose_) {
if (entry_handler == nullptr || entry_handler > external_handler) {
return CAUGHT_BY_EXTERNAL;
}
}
}
// Handler not found.
return NOT_CAUGHT;
}
void Isolate::RemoveMaterializedObjectsOnUnwind(StackFrame* frame) {
if (frame->is_optimized()) {
bool removed = materialized_object_store_->Remove(frame->fp());
USE(removed);
// If there were any materialized objects, the code should be
// marked for deopt.
DCHECK(!removed || frame->LookupCode()->marked_for_deoptimization());
}
}
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());
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();
}
}
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) {
StackTraceFrameIterator it(this);
while (!it.done()) {
HandleScope scope(this);
// Find code position if recorded in relocation info.
JavaScriptFrame* frame = it.frame();
int pos = frame->LookupCode()->SourcePosition(frame->pc());
Handle<Object> pos_obj(Smi::FromInt(pos), this);
// Fetch function and receiver.
Handle<JSFunction> fun(frame->function());
Handle<Object> recv(frame->receiver(), this);
// Advance to the next JavaScript frame and determine if the
// current frame is the top-level frame.
it.Advance();
Handle<Object> is_top_level = factory()->ToBoolean(it.done());
// Generate and print stack trace line.
Handle<String> line =
Execution::GetStackTraceLine(recv, fun, pos_obj, is_top_level);
if (line->length() > 0) {
line->PrintOn(out);
PrintF(out, "\n");
}
}
}
bool Isolate::ComputeLocation(MessageLocation* target) {
StackTraceFrameIterator it(this);
if (!it.done()) {
JavaScriptFrame* frame = it.frame();
JSFunction* fun = frame->function();
Object* script = fun->shared()->script();
if (script->IsScript() &&
!(Script::cast(script)->source()->IsUndefined())) {
Handle<Script> casted_script(Script::cast(script));
// 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.
List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
it.frame()->Summarize(&frames);
FrameSummary& summary = frames.last();
int pos = summary.code()->SourcePosition(summary.pc());
*target = MessageLocation(casted_script, pos, pos + 1, handle(fun));
return true;
}
}
return false;
}
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<FixedArray> elements(FixedArray::cast(simple_stack_trace->elements()));
int elements_limit = Smi::cast(simple_stack_trace->length())->value();
for (int i = 1; i < elements_limit; i += 4) {
Handle<JSFunction> fun =
handle(JSFunction::cast(elements->get(i + 1)), this);
if (!fun->shared()->IsSubjectToDebugging()) continue;
Object* script = fun->shared()->script();
if (script->IsScript() &&
!(Script::cast(script)->source()->IsUndefined())) {
int pos = PositionFromStackTrace(elements, i);
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<JSArray> stack_trace_object;
if (capture_stack_trace_for_uncaught_exceptions_) {
if (Object::IsErrorObject(this, exception)) {
// 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 == NULL &&
(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 == nullptr) 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 == nullptr) 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 == nullptr) 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 == nullptr) 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::ReportPendingMessages() {
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;
// 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 (IsExternalHandlerOnTop(exception)) {
// 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() && should_report_exception) {
HandleScope scope(this);
Handle<JSMessageObject> message(JSMessageObject::cast(message_obj));
Handle<JSValue> script_wrapper(JSValue::cast(message->script()));
Handle<Script> script(Script::cast(script_wrapper->value()));
int start_pos = message->start_position();
int end_pos = message->end_position();
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message);
}
}
MessageLocation Isolate::GetMessageLocation() {
DCHECK(has_pending_exception());
if (thread_local_top_.pending_exception_ != heap()->termination_exception() &&
!thread_local_top_.pending_message_obj_->IsTheHole()) {
Handle<JSMessageObject> message_obj(
JSMessageObject::cast(thread_local_top_.pending_message_obj_));
Handle<JSValue> script_wrapper(JSValue::cast(message_obj->script()));
Handle<Script> script(Script::cast(script_wrapper->value()));
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(thread_local_top()->try_catch_handler_address() != NULL);
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,
Handle<JSFunction> function) {
ThreadLocalTop* tltop = thread_local_top();
PromiseOnStack* prev = tltop->promise_on_stack_;
Handle<JSObject> global_promise =
Handle<JSObject>::cast(global_handles()->Create(*promise));
Handle<JSFunction> global_function =
Handle<JSFunction>::cast(global_handles()->Create(*function));
tltop->promise_on_stack_ =
new PromiseOnStack(global_function, global_promise, prev);
}
void Isolate::PopPromise() {
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == NULL) return;
PromiseOnStack* prev = tltop->promise_on_stack_->prev();
Handle<Object> global_function = tltop->promise_on_stack_->function();
Handle<Object> global_promise = tltop->promise_on_stack_->promise();
delete tltop->promise_on_stack_;
tltop->promise_on_stack_ = prev;
global_handles()->Destroy(global_function.location());
global_handles()->Destroy(global_promise.location());
}
Handle<Object> Isolate::GetPromiseOnStackOnThrow() {
Handle<Object> undefined = factory()->undefined_value();
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == NULL) return undefined;
Handle<JSFunction> promise_function = tltop->promise_on_stack_->function();
// Find the top-most try-catch or try-finally handler.
if (PredictExceptionCatcher() != CAUGHT_BY_JAVASCRIPT) return undefined;
for (JavaScriptFrameIterator it(this); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
int stack_slots = 0; // The computed stack slot count is not used.
if (frame->LookupExceptionHandlerInTable(&stack_slots, NULL) > 0) {
// Throwing inside a Promise only leads to a reject if not caught by an
// inner try-catch or try-finally.
if (frame->function() == *promise_function) {
return tltop->promise_on_stack_->promise();
}
return undefined;
}
}
return undefined;
}
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;
}
Handle<Context> Isolate::native_context() {
return handle(context()->native_context());
}
Handle<Context> Isolate::GetCallingNativeContext() {
JavaScriptFrameIterator it(this);
if (debug_->in_debug_scope()) {
while (!it.done()) {
JavaScriptFrame* frame = it.frame();
Context* context = Context::cast(frame->context());
if (context->native_context() == *debug_->debug_context()) {
it.Advance();
} else {
break;
}
}
}
if (it.done()) return Handle<Context>::null();
JavaScriptFrame* frame = it.frame();
Context* context = Context::cast(frame->context());
return Handle<Context>(context->native_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() == NULL || context()->IsContext());
return from + sizeof(ThreadLocalTop);
}
Isolate::ThreadDataTable::ThreadDataTable()
: list_(NULL) {
}
Isolate::ThreadDataTable::~ThreadDataTable() {
// TODO(svenpanne) The assertion below would fire if an embedder does not
// cleanly dispose all Isolates before disposing v8, so we are conservative
// and leave it out for now.
// DCHECK_NULL(list_);
}
Isolate::PerIsolateThreadData::~PerIsolateThreadData() {
#if defined(USE_SIMULATOR)
delete simulator_;
#endif
}
Isolate::PerIsolateThreadData*
Isolate::ThreadDataTable::Lookup(Isolate* isolate,
ThreadId thread_id) {
for (PerIsolateThreadData* data = list_; data != NULL; data = data->next_) {
if (data->Matches(isolate, thread_id)) return data;
}
return NULL;
}
void Isolate::ThreadDataTable::Insert(Isolate::PerIsolateThreadData* data) {
if (list_ != NULL) list_->prev_ = data;
data->next_ = list_;
list_ = data;
}
void Isolate::ThreadDataTable::Remove(PerIsolateThreadData* data) {
if (list_ == data) list_ = data->next_;
if (data->next_ != NULL) data->next_->prev_ = data->prev_;
if (data->prev_ != NULL) data->prev_->next_ = data->next_;
delete data;
}
void Isolate::ThreadDataTable::RemoveAllThreads(Isolate* isolate) {
PerIsolateThreadData* data = list_;
while (data != NULL) {
PerIsolateThreadData* next = data->next_;
if (data->isolate() == isolate) Remove(data);
data = next;
}
}
#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
Isolate::Isolate(bool enable_serializer)
: embedder_data_(),
entry_stack_(NULL),
stack_trace_nesting_level_(0),
incomplete_message_(NULL),
bootstrapper_(NULL),
runtime_profiler_(NULL),
compilation_cache_(NULL),
counters_(NULL),
code_range_(NULL),
logger_(NULL),
stats_table_(NULL),
stub_cache_(NULL),
code_aging_helper_(NULL),
deoptimizer_data_(NULL),
materialized_object_store_(NULL),
capture_stack_trace_for_uncaught_exceptions_(false),
stack_trace_for_uncaught_exceptions_frame_limit_(0),
stack_trace_for_uncaught_exceptions_options_(StackTrace::kOverview),
memory_allocator_(NULL),
keyed_lookup_cache_(NULL),
context_slot_cache_(NULL),
descriptor_lookup_cache_(NULL),
handle_scope_implementer_(NULL),
unicode_cache_(NULL),
inner_pointer_to_code_cache_(NULL),
global_handles_(NULL),
eternal_handles_(NULL),
thread_manager_(NULL),
has_installed_extensions_(false),
regexp_stack_(NULL),
date_cache_(NULL),
call_descriptor_data_(NULL),
// TODO(bmeurer) Initialized lazily because it depends on flags; can
// be fixed once the default isolate cleanup is done.
random_number_generator_(NULL),
serializer_enabled_(enable_serializer),
has_fatal_error_(false),
initialized_from_snapshot_(false),
cpu_profiler_(NULL),
heap_profiler_(NULL),
function_entry_hook_(NULL),
deferred_handles_head_(NULL),
optimizing_compile_dispatcher_(NULL),
stress_deopt_count_(0),
virtual_handler_register_(NULL),
virtual_slot_register_(NULL),
next_optimization_id_(0),
js_calls_from_api_counter_(0),
#if TRACE_MAPS
next_unique_sfi_id_(0),
#endif
use_counter_callback_(NULL),
basic_block_profiler_(NULL),
cancelable_task_manager_(new CancelableTaskManager()),
abort_on_uncaught_exception_callback_(NULL) {
{
base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
CHECK(thread_data_table_);
}
id_ = base::NoBarrier_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
// heap_histograms_ initializes itself.
memset(&js_spill_information_, 0, sizeof(js_spill_information_));
#endif
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);
init_memcopy_functions(this);
}
void Isolate::TearDown() {
TRACE_ISOLATE(tear_down);
// 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(base::NoBarrier_Load(&isolate_key_created_) == 1);
Isolate* saved_isolate =
reinterpret_cast<Isolate*>(base::Thread::GetThreadLocal(isolate_key_));
SetIsolateThreadLocals(this, NULL);
Deinit();
{
base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
thread_data_table_->RemoveAllThreads(this);
}
delete this;
// Restore the previous current isolate.
SetIsolateThreadLocals(saved_isolate, saved_data);
}
void Isolate::GlobalTearDown() {
delete thread_data_table_;
thread_data_table_ = NULL;
}
void Isolate::ClearSerializerData() {
delete external_reference_table_;
external_reference_table_ = NULL;
delete external_reference_map_;
external_reference_map_ = NULL;
}
void Isolate::Deinit() {
TRACE_ISOLATE(deinit);
debug()->Unload();
FreeThreadResources();
if (concurrent_recompilation_enabled()) {
optimizing_compile_dispatcher_->Stop();
delete optimizing_compile_dispatcher_;
optimizing_compile_dispatcher_ = NULL;
}
if (heap_.mark_compact_collector()->sweeping_in_progress()) {
heap_.mark_compact_collector()->EnsureSweepingCompleted();
}
DumpAndResetCompilationStats();
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 = logger_->sampler();
if (sampler && sampler->IsActive()) sampler->Stop();
delete interpreter_;
interpreter_ = NULL;
delete deoptimizer_data_;
deoptimizer_data_ = NULL;
builtins_.TearDown();
bootstrapper_->TearDown();
if (runtime_profiler_ != NULL) {
delete runtime_profiler_;
runtime_profiler_ = NULL;
}
delete basic_block_profiler_;
basic_block_profiler_ = NULL;
heap_.TearDown();
logger_->TearDown();
cancelable_task_manager()->CancelAndWait();
delete heap_profiler_;
heap_profiler_ = NULL;
delete cpu_profiler_;
cpu_profiler_ = NULL;
delete root_index_map_;
root_index_map_ = NULL;
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);
// Has to be called while counters_ are still alive
runtime_zone_.DeleteKeptSegment();
// The entry stack must be empty when we get here.
DCHECK(entry_stack_ == NULL || entry_stack_->previous_item == NULL);
delete entry_stack_;
entry_stack_ = NULL;
delete unicode_cache_;
unicode_cache_ = NULL;
delete date_cache_;
date_cache_ = NULL;
delete[] call_descriptor_data_;
call_descriptor_data_ = NULL;
delete regexp_stack_;
regexp_stack_ = NULL;
delete descriptor_lookup_cache_;
descriptor_lookup_cache_ = NULL;
delete context_slot_cache_;
context_slot_cache_ = NULL;
delete keyed_lookup_cache_;
keyed_lookup_cache_ = NULL;
delete stub_cache_;
stub_cache_ = NULL;
delete code_aging_helper_;
code_aging_helper_ = NULL;
delete stats_table_;
stats_table_ = NULL;
delete materialized_object_store_;
materialized_object_store_ = NULL;
delete logger_;
logger_ = NULL;
delete counters_;
counters_ = NULL;
delete handle_scope_implementer_;
handle_scope_implementer_ = NULL;
delete code_tracer();
set_code_tracer(NULL);
delete compilation_cache_;
compilation_cache_ = NULL;
delete bootstrapper_;
bootstrapper_ = NULL;
delete inner_pointer_to_code_cache_;
inner_pointer_to_code_cache_ = NULL;
delete thread_manager_;
thread_manager_ = NULL;
delete memory_allocator_;
memory_allocator_ = NULL;
delete code_range_;
code_range_ = NULL;
delete global_handles_;
global_handles_ = NULL;
delete eternal_handles_;
eternal_handles_ = NULL;
delete string_stream_debug_object_cache_;
string_stream_debug_object_cache_ = NULL;
delete random_number_generator_;
random_number_generator_ = NULL;
delete debug_;
debug_ = NULL;
delete cancelable_task_manager_;
cancelable_task_manager_ = nullptr;
#if USE_SIMULATOR
Simulator::TearDown(simulator_i_cache_, simulator_redirection_);
simulator_i_cache_ = nullptr;
simulator_redirection_ = nullptr;
#endif
}
void Isolate::InitializeThreadLocal() {
thread_local_top_.isolate_ = this;
thread_local_top_.Initialize();
}
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)) {
try_catch_handler()->can_continue_ = false;
try_catch_handler()->has_terminated_ = true;
try_catch_handler()->exception_ = heap()->null_value();
} else {
v8::TryCatch* handler = try_catch_handler();
DCHECK(thread_local_top_.pending_message_obj_->IsJSMessageObject() ||
thread_local_top_.pending_message_obj_->IsTheHole());
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()) return true;
handler->message_obj_ = thread_local_top_.pending_message_obj_;
}
return true;
}
void Isolate::InitializeLoggingAndCounters() {
if (logger_ == NULL) {
logger_ = new Logger(this);
}
if (counters_ == NULL) {
counters_ = new Counters(this);
}
}
bool Isolate::Init(Deserializer* des) {
TRACE_ISOLATE(init);
stress_deopt_count_ = FLAG_deopt_every_n_times;
has_fatal_error_ = false;
if (function_entry_hook() != NULL) {
// 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(des == NULL);
}
// The initialization process does not handle memory exhaustion.
AlwaysAllocateScope always_allocate(this);
memory_allocator_ = new MemoryAllocator(this);
code_range_ = new CodeRange(this);
// Safe after setting Heap::isolate_, and initializing StackGuard
heap_.SetStackLimits();
#define ASSIGN_ELEMENT(CamelName, hacker_name) \
isolate_addresses_[Isolate::k##CamelName##Address] = \
reinterpret_cast<Address>(hacker_name##_address());
FOR_EACH_ISOLATE_ADDRESS_NAME(ASSIGN_ELEMENT)
#undef ASSIGN_ELEMENT
compilation_cache_ = new CompilationCache(this);
keyed_lookup_cache_ = new KeyedLookupCache();
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);
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);
// Enable logging before setting up the heap
logger_->SetUp(this);
// Initialize other runtime facilities
#if defined(USE_SIMULATOR)
#if V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_ARM64 || V8_TARGET_ARCH_MIPS || \
V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC
Simulator::Initialize(this);
#endif
#endif
code_aging_helper_ = new CodeAgingHelper(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("heap setup");
return false;
}
deoptimizer_data_ = new DeoptimizerData(memory_allocator_);
const bool create_heap_objects = (des == NULL);
if (create_heap_objects && !heap_.CreateHeapObjects()) {
V8::FatalProcessOutOfMemory("heap object creation");
return false;
}
if (create_heap_objects) {
// Terminate the cache array with the sentinel so we can iterate.
partial_snapshot_cache_.Add(heap_.undefined_value());
}
InitializeThreadLocal();
bootstrapper_->Initialize(create_heap_objects);
builtins_.SetUp(this, create_heap_objects);
if (FLAG_log_internal_timer_events) {
set_event_logger(Logger::DefaultEventLoggerSentinel);
}
if (FLAG_trace_hydrogen || FLAG_trace_hydrogen_stubs) {
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.
if (!create_heap_objects) {
des->Deserialize(this);
}
stub_cache_->Initialize();
if (FLAG_ignition) {
interpreter_->Initialize();
}
// 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_.amount_of_external_allocated_memory_)),
Internals::kAmountOfExternalAllocatedMemoryOffset);
CHECK_EQ(static_cast<int>(OFFSET_OF(
Isolate,
heap_.amount_of_external_allocated_memory_at_last_global_gc_)),
Internals::kAmountOfExternalAllocatedMemoryAtLastGlobalGCOffset);
time_millis_at_init_ = heap_.MonotonicallyIncreasingTimeInMs();
heap_.NotifyDeserializationComplete();
if (!create_heap_objects) {
// Now that the heap is consistent, it's OK to generate the code for the
// deopt entry table that might have been referred to by optimized code in
// the snapshot.
HandleScope scope(this);
Deoptimizer::EnsureCodeForDeoptimizationEntry(
this,
Deoptimizer::LAZY,
kDeoptTableSerializeEntryCount - 1);
}
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);
StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime(this);
StubFailureTrampolineStub::GenerateAheadOfTime(this);
}
initialized_from_snapshot_ = (des != NULL);
if (!FLAG_inline_new) heap_.DisableInlineAllocation();
return true;
}
// Initialized lazily to allow early
// v8::V8::SetAddHistogramSampleFunction calls.
StatsTable* Isolate::stats_table() {
if (stats_table_ == NULL) {
stats_table_ = new StatsTable;
}
return stats_table_;
}
void Isolate::Enter() {
Isolate* current_isolate = NULL;
PerIsolateThreadData* current_data = CurrentPerIsolateThreadData();
if (current_data != NULL) {
current_isolate = current_data->isolate_;
DCHECK(current_isolate != NULL);
if (current_isolate == this) {
DCHECK(Current() == this);
DCHECK(entry_stack_ != NULL);
DCHECK(entry_stack_->previous_thread_data == NULL ||
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(data != NULL);
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(entry_stack_ != NULL);
DCHECK(entry_stack_->previous_thread_data == NULL ||
entry_stack_->previous_thread_data->thread_id().Equals(
ThreadId::Current()));
if (--entry_stack_->entry_count > 0) return;
DCHECK(CurrentPerIsolateThreadData() != NULL);
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_ != NULL) {
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_ != NULL) {
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_ != NULL) {
deferred->next_->previous_ = deferred->previous_;
}
if (deferred->previous_ != NULL) {
deferred->previous_->next_ = deferred->next_;
}
}
void Isolate::DumpAndResetCompilationStats() {
if (turbo_statistics() != nullptr) {
OFStream os(stdout);
os << *turbo_statistics() << std::endl;
}
if (hstatistics() != nullptr) hstatistics()->Print();
delete turbo_statistics_;
turbo_statistics_ = nullptr;
delete hstatistics_;
hstatistics_ = nullptr;
}
HStatistics* Isolate::GetHStatistics() {
if (hstatistics() == NULL) set_hstatistics(new HStatistics());
return hstatistics();
}
CompilationStatistics* Isolate::GetTurboStatistics() {
if (turbo_statistics() == NULL)
set_turbo_statistics(new CompilationStatistics());
return turbo_statistics();
}
HTracer* Isolate::GetHTracer() {
if (htracer() == NULL) set_htracer(new HTracer(id()));
return htracer();
}
CodeTracer* Isolate::GetCodeTracer() {
if (code_tracer() == NULL) set_code_tracer(new CodeTracer(id()));
return code_tracer();
}
Map* Isolate::get_initial_js_array_map(ElementsKind kind, Strength strength) {
if (IsFastElementsKind(kind)) {
DisallowHeapAllocation no_gc;
Object* const initial_js_array_map = context()->native_context()->get(
Context::ArrayMapIndex(kind, strength));
if (!initial_js_array_map->IsUndefined()) {
return Map::cast(initial_js_array_map);
}
}
return nullptr;
}
bool Isolate::use_crankshaft() const {
return FLAG_crankshaft &&
!serializer_enabled_ &&
CpuFeatures::SupportsCrankshaft();
}
bool Isolate::IsFastArrayConstructorPrototypeChainIntact() {
PropertyCell* no_elements_cell = heap()->array_protector();
bool cell_reports_intact =
no_elements_cell->value()->IsSmi() &&
Smi::cast(no_elements_cell->value())->value() == kArrayProtectorValid;
#ifdef DEBUG
Map* root_array_map =
get_initial_js_array_map(GetInitialFastElementsKind());
Context* native_context = context()->native_context();
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));
if (root_array_map == NULL || 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.
PrototypeIterator iter(this, initial_array_proto);
if (iter.IsAtEnd() || iter.GetCurrent() != initial_object_proto) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
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;
}
iter.Advance();
if (!iter.IsAtEnd()) {
DCHECK_EQ(false, cell_reports_intact);
return cell_reports_intact;
}
#endif
return cell_reports_intact;
}
void Isolate::UpdateArrayProtectorOnSetElement(Handle<JSObject> object) {
if (IsFastArrayConstructorPrototypeChainIntact() &&
object->map()->is_prototype_map()) {
Object* context = heap()->native_contexts_list();
while (!context->IsUndefined()) {
Context* current_context = Context::cast(context);
if (current_context->get(Context::INITIAL_OBJECT_PROTOTYPE_INDEX) ==
*object ||
current_context->get(Context::INITIAL_ARRAY_PROTOTYPE_INDEX) ==
*object) {
PropertyCell::SetValueWithInvalidation(
factory()->array_protector(),
handle(Smi::FromInt(kArrayProtectorInvalid), this));
break;
}
context = current_context->get(Context::NEXT_CONTEXT_LINK);
}
}
}
bool Isolate::IsAnyInitialArrayPrototype(Handle<JSArray> array) {
if (array->map()->is_prototype_map()) {
Object* context = heap()->native_contexts_list();
while (!context->IsUndefined()) {
Context* current_context = Context::cast(context);
if (current_context->get(Context::INITIAL_ARRAY_PROTOTYPE_INDEX) ==
*array) {
return true;
}
context = current_context->get(Context::NEXT_CONTEXT_LINK);
}
}
return false;
}
CallInterfaceDescriptorData* Isolate::call_descriptor_data(int index) {
DCHECK(0 <= index && index < CallDescriptors::NUMBER_OF_DESCRIPTORS);
return &call_descriptor_data_[index];
}
base::RandomNumberGenerator* Isolate::random_number_generator() {
if (random_number_generator_ == NULL) {
if (FLAG_random_seed != 0) {
random_number_generator_ =
new base::RandomNumberGenerator(FLAG_random_seed);
} else {
random_number_generator_ = new base::RandomNumberGenerator();
}
}
return random_number_generator_;
}
Object* Isolate::FindCodeObject(Address a) {
return inner_pointer_to_code_cache()->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<JSObject> Isolate::SetUpSubregistry(Handle<JSObject> registry,
Handle<Map> map, const char* cname) {
Handle<String> name = factory()->InternalizeUtf8String(cname);
Handle<JSObject> obj = factory()->NewJSObjectFromMap(map);
JSObject::NormalizeProperties(obj, CLEAR_INOBJECT_PROPERTIES, 0,
"SetupSymbolRegistry");
JSObject::AddProperty(registry, name, obj, NONE);
return obj;
}
Handle<JSObject> Isolate::GetSymbolRegistry() {
if (heap()->symbol_registry()->IsSmi()) {
Handle<Map> map = factory()->NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
Handle<JSObject> registry = factory()->NewJSObjectFromMap(map);
heap()->set_symbol_registry(*registry);
SetUpSubregistry(registry, map, "for");
SetUpSubregistry(registry, map, "for_api");
SetUpSubregistry(registry, map, "keyFor");
SetUpSubregistry(registry, map, "private_api");
}
return Handle<JSObject>::cast(factory()->symbol_registry());
}
void Isolate::AddCallCompletedCallback(CallCompletedCallback callback) {
for (int i = 0; i < call_completed_callbacks_.length(); i++) {
if (callback == call_completed_callbacks_.at(i)) return;
}
call_completed_callbacks_.Add(callback);
}
void Isolate::RemoveCallCompletedCallback(CallCompletedCallback callback) {
for (int i = 0; i < call_completed_callbacks_.length(); i++) {
if (callback == call_completed_callbacks_.at(i)) {
call_completed_callbacks_.Remove(i);
}
}
}
void Isolate::FireCallCompletedCallback() {
bool has_call_completed_callbacks = !call_completed_callbacks_.is_empty();
bool run_microtasks = autorun_microtasks() && pending_microtask_count();
if (!has_call_completed_callbacks && !run_microtasks) return;
if (!handle_scope_implementer()->CallDepthIsZero()) return;
if (run_microtasks) RunMicrotasks();
// Fire callbacks. Increase call depth to prevent recursive callbacks.
v8::Isolate::SuppressMicrotaskExecutionScope suppress(
reinterpret_cast<v8::Isolate*>(this));
for (int i = 0; i < call_completed_callbacks_.length(); i++) {
call_completed_callbacks_.at(i)();
}
}
void Isolate::SetPromiseRejectCallback(PromiseRejectCallback callback) {
promise_reject_callback_ = callback;
}
void Isolate::ReportPromiseReject(Handle<JSObject> promise,
Handle<Object> value,
v8::PromiseRejectEvent event) {
if (promise_reject_callback_ == NULL) return;
Handle<JSArray> 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<Object> microtask) {
DCHECK(microtask->IsJSFunction() || microtask->IsCallHandlerInfo());
Handle<FixedArray> queue(heap()->microtask_queue(), this);
int num_tasks = pending_microtask_count();
DCHECK(num_tasks <= queue->length());
if (num_tasks == 0) {
queue = factory()->NewFixedArray(8);
heap()->set_microtask_queue(*queue);
} else if (num_tasks == queue->length()) {
queue = factory()->CopyFixedArrayAndGrow(queue, num_tasks);
heap()->set_microtask_queue(*queue);
}
DCHECK(queue->get(num_tasks)->IsUndefined());
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));
while (pending_microtask_count() > 0) {
HandleScope scope(this);
int num_tasks = pending_microtask_count();
Handle<FixedArray> queue(heap()->microtask_queue(), this);
DCHECK(num_tasks <= queue->length());
set_pending_microtask_count(0);
heap()->set_microtask_queue(heap()->empty_fixed_array());
for (int i = 0; i < num_tasks; i++) {
HandleScope scope(this);
Handle<Object> microtask(queue->get(i), this);
if (microtask->IsJSFunction()) {
Handle<JSFunction> microtask_function =
Handle<JSFunction>::cast(microtask);
SaveContext save(this);
set_context(microtask_function->context()->native_context());
MaybeHandle<Object> maybe_exception;
MaybeHandle<Object> result = Execution::TryCall(
this, microtask_function, factory()->undefined_value(), 0, NULL,
&maybe_exception);
// If execution is terminating, just bail out.
Handle<Object> exception;
if (result.is_null() && maybe_exception.is_null()) {
// Clear out any remaining callbacks in the queue.
heap()->set_microtask_queue(heap()->empty_fixed_array());
set_pending_microtask_count(0);
return;
}
} else {
Handle<CallHandlerInfo> callback_info =
Handle<CallHandlerInfo>::cast(microtask);
v8::MicrotaskCallback callback =
v8::ToCData<v8::MicrotaskCallback>(callback_info->callback());
void* data = v8::ToCData<void*>(callback_info->data());
callback(data);
}
}
}
}
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_ == NULL) {
basic_block_profiler_ = new BasicBlockProfiler();
}
return basic_block_profiler_;
}
std::string Isolate::GetTurboCfgFileName() {
if (FLAG_trace_turbo_cfg_file == NULL) {
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(heap()->detached_contexts());
int length = detached_contexts->length();
detached_contexts = factory()->CopyFixedArrayAndGrow(detached_contexts, 2);
detached_contexts->set(length, Smi::FromInt(0));
detached_contexts->set(length + 1, *cell);
heap()->set_detached_contexts(*detached_contexts);
}
void Isolate::CheckDetachedContextsAfterGC() {
HandleScope scope(this);
Handle<FixedArray> detached_contexts(heap()->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::cast(detached_contexts->get(i))->value();
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::cast(detached_contexts->get(i))->value();
DCHECK(detached_contexts->get(i + 1)->IsWeakCell());
WeakCell* cell = WeakCell::cast(detached_contexts->get(i + 1));
if (mark_sweeps > 3) {
PrintF("detached context 0x%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<Heap::CONCURRENT_TO_SWEEPER>(
*detached_contexts, length - new_length);
}
}
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 = reinterpret_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() != NULL) {
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() ? NULL : *context_);
isolate_->set_save_context(prev_);
}
#ifdef DEBUG
AssertNoContextChange::AssertNoContextChange(Isolate* isolate)
: isolate_(isolate), context_(isolate->context(), isolate) {}
#endif // DEBUG
bool PostponeInterruptsScope::Intercept(StackGuard::InterruptFlag flag) {
// First check whether the previous scope intercepts.
if (prev_ && prev_->Intercept(flag)) return true;
// Then check whether this scope intercepts.
if ((flag & intercept_mask_)) {
intercepted_flags_ |= flag;
return true;
}
return false;
}
} // namespace internal
} // namespace v8