#include "module_wrap.h"

#include "env.h"

#include "memory_tracker-inl.h"

#include "node_contextify.h"

#include "node_errors.h"

#include "node_external_reference.h"

#include "node_internals.h"

#include "node_process-inl.h"

#include "node_watchdog.h"

#include "util-inl.h"

#include <sys/stat.h> // S_IFDIR

#include <algorithm>

namespace node {

namespace loader {

using errors::TryCatchScope;

using node::contextify::ContextifyContext;

using v8::Array;

using v8::ArrayBufferView;

using v8::Context;

using v8::Data;

using v8::EscapableHandleScope;

using v8::Exception;

using v8::FixedArray;

using v8::Function;

using v8::FunctionCallbackInfo;

using v8::FunctionTemplate;

using v8::Global;

using v8::HandleScope;

using v8::Int32;

using v8::Integer;

using v8::Isolate;

using v8::Just;

using v8::JustVoid;

using v8::Local;

using v8::LocalVector;

using v8::Maybe;

using v8::MaybeLocal;

using v8::MemorySpan;

using v8::Message;

using v8::MicrotaskQueue;

using v8::Module;

using v8::ModuleRequest;

using v8::Name;

using v8::Nothing;

using v8::Null;

using v8::Object;

using v8::ObjectTemplate;

using v8::PrimitiveArray;

using v8::Promise;

using v8::PromiseRejectEvent;

using v8::ScriptCompiler;

using v8::ScriptOrigin;

using v8::String;

using v8::Symbol;

using v8::UnboundModuleScript;

using v8::Undefined;

using v8::Value;

void ModuleCacheKey::MemoryInfo(MemoryTracker* tracker) const {

tracker->TrackField("specifier", specifier);

tracker->TrackField("import_attributes", import_attributes);

}

std::string ModuleCacheKey::ToString() const {

std::string result = "ModuleCacheKey(\"" + specifier + "\"";

if (!import_attributes.empty()) {

result += ", {";

bool first = true;

for (const auto& attr : import_attributes) {

if (first) {

first = false;

} else {

result += ", ";

}

result += attr.first + ": " + attr.second;

}

result += "}";

}

result += ")";

return result;

}

template <int elements_per_attribute>

ModuleCacheKey ModuleCacheKey::From(Local<Context> context,

Local<String> specifier,

Local<FixedArray> import_attributes) {

CHECK_EQ(import_attributes->Length() % elements_per_attribute, 0);

Isolate* isolate = context->GetIsolate();

std::size_t h1 = specifier->GetIdentityHash();

size_t num_attributes = import_attributes->Length() / elements_per_attribute;

ImportAttributeVector attributes;

attributes.reserve(num_attributes);

std::size_t h2 = 0;

for (int i = 0; i < import_attributes->Length();

i += elements_per_attribute) {

Local<String> v8_key = import_attributes->Get(context, i).As<String>();

Local<String> v8_value =

import_attributes->Get(context, i + 1).As<String>();

Utf8Value key_utf8(isolate, v8_key);

Utf8Value value_utf8(isolate, v8_value);

attributes.emplace_back(key_utf8.ToString(), value_utf8.ToString());

h2 ^= v8_key->GetIdentityHash();

h2 ^= v8_value->GetIdentityHash();

}

// Combine the hashes using a simple XOR and bit shift to reduce

// collisions. Note that the hash does not guarantee uniqueness.

std::size_t hash = h1 ^ (h2 << 1);

Utf8Value utf8_specifier(isolate, specifier);

return ModuleCacheKey{utf8_specifier.ToString(), attributes, hash};

}

ModuleCacheKey ModuleCacheKey::From(Local<Context> context,

Local<ModuleRequest> v8_request) {

return From(

context, v8_request->GetSpecifier(), v8_request->GetImportAttributes());

}

ModuleWrap::ModuleWrap(Realm* realm,

Local<Object> object,

Local<Module> module,

Local<String> url,

Local<Object> context_object,

Local<Value> synthetic_evaluation_step)

: BaseObject(realm, object),

module_(realm->isolate(), module),

module_hash_(module->GetIdentityHash()) {

realm->env()->hash_to_module_map.emplace(module_hash_, this);

object->SetInternalField(kModuleSlot, module);

object->SetInternalField(kURLSlot, url);

object->SetInternalField(kSyntheticEvaluationStepsSlot,

synthetic_evaluation_step);

object->SetInternalField(kContextObjectSlot, context_object);

object->SetInternalField(kLinkedRequestsSlot,

v8::Undefined(realm->isolate()));

if (!synthetic_evaluation_step->IsUndefined()) {

synthetic_ = true;

}

MakeWeak();

module_.SetWeak();

HandleScope scope(realm->isolate());

Local<Context> context = realm->context();

Local<FixedArray> requests = module->GetModuleRequests();

for (int i = 0; i < requests->Length(); i++) {

ModuleCacheKey module_cache_key = ModuleCacheKey::From(

context, requests->Get(context, i).As<ModuleRequest>());

resolve_cache_[module_cache_key] = i;

}

}

ModuleWrap::~ModuleWrap() {

auto range = env()->hash_to_module_map.equal_range(module_hash_);

for (auto it = range.first; it != range.second; ++it) {

if (it->second == this) {

env()->hash_to_module_map.erase(it);

break;

}

}

}

Local<Context> ModuleWrap::context() const {

Local<Value> obj = object()->GetInternalField(kContextObjectSlot).As<Value>();

// If this fails, there is likely a bug e.g. ModuleWrap::context() is accessed

// before the ModuleWrap constructor completes.

CHECK(obj->IsObject());

return obj.As<Object>()->GetCreationContextChecked();

}

ModuleWrap* ModuleWrap::GetLinkedRequest(uint32_t index) {

DCHECK(IsLinked());

Isolate* isolate = env()->isolate();

EscapableHandleScope scope(isolate);

Local<Data> linked_requests_data =

object()->GetInternalField(kLinkedRequestsSlot);

DCHECK(linked_requests_data->IsValue() &&

linked_requests_data.As<Value>()->IsArray());

Local<Array> requests = linked_requests_data.As<Array>();

CHECK_LT(index, requests->Length());

Local<Value> module_value;

if (!requests->Get(context(), index).ToLocal(&module_value)) {

return nullptr;

}

CHECK(module_value->IsObject());

Local<Object> module_object = module_value.As<Object>();

ModuleWrap* module_wrap;

ASSIGN_OR_RETURN_UNWRAP(&module_wrap, module_object, nullptr);

return module_wrap;

}

ModuleWrap* ModuleWrap::GetFromModule(Environment* env,

Local<Module> module) {

auto range = env->hash_to_module_map.equal_range(module->GetIdentityHash());

for (auto it = range.first; it != range.second; ++it) {

if (it->second->module_ == module) {

return it->second;

}

}

return nullptr;

}

Maybe<bool> ModuleWrap::CheckUnsettledTopLevelAwait() {

Isolate* isolate = env()->isolate();

Local<Context> context = env()->context();

// This must be invoked when the environment is shutting down, and the module

// is kept alive by the module wrap via an internal field.

CHECK(env()->exiting());

CHECK(!module_.IsEmpty());

Local<Module> module = module_.Get(isolate);

// It's a synthetic module, likely a facade wrapping CJS.

if (!module->IsSourceTextModule()) {

return Just(true);

}

if (!module->IsGraphAsync()) { // There is no TLA, no need to check.

return Just(true);

}

auto stalled_messages =

std::get<1>(module->GetStalledTopLevelAwaitMessages(isolate));

if (stalled_messages.empty()) {

return Just(true);

}

if (env()->options()->warnings) {

for (auto& message : stalled_messages) {

std::string reason = "Warning: Detected unsettled top-level await at ";

std::string info =

FormatErrorMessage(isolate, context, "", message, true);

reason += info;

FPrintF(stderr, "%s\n", reason);

}

}

return Just(false);

}

Local<PrimitiveArray> ModuleWrap::GetHostDefinedOptions(

Isolate* isolate, Local<Symbol> id_symbol) {

Local<PrimitiveArray> host_defined_options =

PrimitiveArray::New(isolate, HostDefinedOptions::kLength);

host_defined_options->Set(isolate, HostDefinedOptions::kID, id_symbol);

return host_defined_options;

}

// new ModuleWrap(url, context, source, lineOffset, columnOffset[, cachedData]);

// new ModuleWrap(url, context, source, lineOffset, columnOffset,

// idSymbol);

// new ModuleWrap(url, context, exportNames, evaluationCallback[, cjsModule])

void ModuleWrap::New(const FunctionCallbackInfo<Value>& args) {

CHECK(args.IsConstructCall());

CHECK_GE(args.Length(), 3);

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = realm->isolate();

Local<Object> that = args.This();

CHECK(args[0]->IsString());

Local<String> url = args[0].As<String>();

Local<Context> context;

ContextifyContext* contextify_context = nullptr;

if (args[1]->IsUndefined()) {

context = that->GetCreationContextChecked();

} else {

CHECK(args[1]->IsObject());

contextify_context = ContextifyContext::ContextFromContextifiedSandbox(

realm->env(), args[1].As<Object>());

CHECK_NOT_NULL(contextify_context);

context = contextify_context->context();

}

int line_offset = 0;

int column_offset = 0;

bool synthetic = args[2]->IsArray();

bool can_use_builtin_cache = false;

Local<PrimitiveArray> host_defined_options =

PrimitiveArray::New(isolate, HostDefinedOptions::kLength);

Local<Symbol> id_symbol;

if (synthetic) {

// new ModuleWrap(url, context, exportNames, evaluationCallback[,

// cjsModule])

CHECK(args[3]->IsFunction());

} else {

// new ModuleWrap(url, context, source, lineOffset, columnOffset[,

// cachedData]);

// new ModuleWrap(url, context, source, lineOffset, columnOffset,

// idSymbol);

CHECK(args[2]->IsString());

CHECK(args[3]->IsNumber());

line_offset = args[3].As<Int32>()->Value();

CHECK(args[4]->IsNumber());

column_offset = args[4].As<Int32>()->Value();

if (args[5]->IsSymbol()) {

id_symbol = args[5].As<Symbol>();

can_use_builtin_cache =

(id_symbol ==

realm->isolate_data()->source_text_module_default_hdo());

} else {

id_symbol = Symbol::New(isolate, url);

}

host_defined_options = GetHostDefinedOptions(isolate, id_symbol);

if (that->SetPrivate(context,

realm->isolate_data()->host_defined_option_symbol(),

id_symbol)

.IsNothing()) {

return;

}

}

ShouldNotAbortOnUncaughtScope no_abort_scope(realm->env());

TryCatchScope try_catch(realm->env());

Local<Module> module;

{

Context::Scope context_scope(context);

if (synthetic) {

CHECK(args[2]->IsArray());

Local<Array> export_names_arr = args[2].As<Array>();

uint32_t len = export_names_arr->Length();

LocalVector<String> export_names(realm->isolate(), len);

for (uint32_t i = 0; i < len; i++) {

Local<Value> export_name_val;

if (!export_names_arr->Get(context, i).ToLocal(&export_name_val)) {

return;

}

CHECK(export_name_val->IsString());

export_names[i] = export_name_val.As<String>();

}

const MemorySpan<const Local<String>> span(export_names.begin(),

export_names.size());

module = Module::CreateSyntheticModule(

isolate, url, span, SyntheticModuleEvaluationStepsCallback);

} else {

// When we are compiling for the default loader, this will be

// std::nullopt, and CompileSourceTextModule() should use

// on-disk cache.

std::optional<ScriptCompiler::CachedData*> user_cached_data;

if (id_symbol !=

realm->isolate_data()->source_text_module_default_hdo()) {

user_cached_data = nullptr;

}

if (args[5]->IsArrayBufferView()) {

CHECK(!can_use_builtin_cache); // We don't use this option internally.

Local<ArrayBufferView> cached_data_buf = args[5].As<ArrayBufferView>();

uint8_t* data =

static_cast<uint8_t*>(cached_data_buf->Buffer()->Data());

user_cached_data =

new ScriptCompiler::CachedData(data + cached_data_buf->ByteOffset(),

cached_data_buf->ByteLength());

}

Local<String> source_text = args[2].As<String>();

bool cache_rejected = false;

if (!CompileSourceTextModule(realm,

source_text,

url,

line_offset,

column_offset,

host_defined_options,

user_cached_data,

&cache_rejected)

.ToLocal(&module)) {

if (try_catch.HasCaught() && !try_catch.HasTerminated()) {

CHECK(!try_catch.Message().IsEmpty());

CHECK(!try_catch.Exception().IsEmpty());

AppendExceptionLine(realm->env(),

try_catch.Exception(),

try_catch.Message(),

ErrorHandlingMode::MODULE_ERROR);

try_catch.ReThrow();

}

return;

}

if (user_cached_data.has_value() && user_cached_data.value() != nullptr &&

cache_rejected) {

THROW_ERR_VM_MODULE_CACHED_DATA_REJECTED(

realm, "cachedData buffer was rejected");

try_catch.ReThrow();

return;

}

if (that->Set(context,

realm->env()->source_url_string(),

module->GetUnboundModuleScript()->GetSourceURL())

.IsNothing()) {

return;

}

if (that->Set(context,

realm->env()->source_map_url_string(),

module->GetUnboundModuleScript()->GetSourceMappingURL())

.IsNothing()) {

return;

}

}

}

if (that->Set(context,

realm->isolate_data()->synthetic_string(),

v8::Boolean::New(isolate, synthetic))

.IsNothing()) {

return;

}

if (!that->Set(context, realm->isolate_data()->url_string(), url)

.FromMaybe(false)) {

return;

}

if (synthetic && args[4]->IsObject() &&

that->Set(context, realm->isolate_data()->imported_cjs_symbol(), args[4])

.IsNothing()) {

return;

}

// Initialize an empty slot for source map cache before the object is frozen.

if (that->SetPrivate(context,

realm->isolate_data()->source_map_data_private_symbol(),

Undefined(isolate))

.IsNothing()) {

return;

}

// Use the extras object as an object whose GetCreationContext() will be the

// original `context`, since the `Context` itself strictly speaking cannot

// be stored in an internal field.

Local<Object> context_object = context->GetExtrasBindingObject();

Local<Value> synthetic_evaluation_step =

synthetic ? args[3] : Undefined(realm->isolate()).As<Value>();

ModuleWrap* obj = new ModuleWrap(

realm, that, module, url, context_object, synthetic_evaluation_step);

obj->contextify_context_ = contextify_context;

args.GetReturnValue().Set(that);

}

MaybeLocal<Module> ModuleWrap::CompileSourceTextModule(

Realm* realm,

Local<String> source_text,

Local<String> url,

int line_offset,

int column_offset,

Local<PrimitiveArray> host_defined_options,

std::optional<ScriptCompiler::CachedData*> user_cached_data,

bool* cache_rejected) {

Isolate* isolate = realm->isolate();

EscapableHandleScope scope(isolate);

ScriptOrigin origin(url,

line_offset,

column_offset,

true, // is cross origin

-1, // script id

Local<Value>(), // source map URL

false, // is opaque (?)

false, // is WASM

true, // is ES Module

host_defined_options);

ScriptCompiler::CachedData* cached_data = nullptr;

CompileCacheEntry* cache_entry = nullptr;

// When compiling for the default loader, user_cached_data is std::nullptr.

// When compiling for vm.Module, it's either nullptr or a pointer to the

// cached data.

if (user_cached_data.has_value()) {

cached_data = user_cached_data.value();

} else if (realm->env()->use_compile_cache()) {

cache_entry = realm->env()->compile_cache_handler()->GetOrInsert(

source_text, url, CachedCodeType::kESM);

}

if (cache_entry != nullptr && cache_entry->cache != nullptr) {

// source will take ownership of cached_data.

cached_data = cache_entry->CopyCache();

}

ScriptCompiler::Source source(source_text, origin, cached_data);

ScriptCompiler::CompileOptions options;

if (cached_data == nullptr) {

options = ScriptCompiler::kNoCompileOptions;

} else {

options = ScriptCompiler::kConsumeCodeCache;

}

Local<Module> module;

if (!ScriptCompiler::CompileModule(isolate, &source, options)

.ToLocal(&module)) {

return scope.EscapeMaybe(MaybeLocal<Module>());

}

if (options == ScriptCompiler::kConsumeCodeCache) {

*cache_rejected = source.GetCachedData()->rejected;

}

if (cache_entry != nullptr) {

realm->env()->compile_cache_handler()->MaybeSave(

cache_entry, module, *cache_rejected);

}

return scope.Escape(module);

}

static Local<Object> createImportAttributesContainer(

Realm* realm,

Isolate* isolate,

Local<FixedArray> raw_attributes,

const int elements_per_attribute) {

CHECK_EQ(raw_attributes->Length() % elements_per_attribute, 0);

size_t num_attributes = raw_attributes->Length() / elements_per_attribute;

LocalVector<Name> names(isolate, num_attributes);

LocalVector<Value> values(isolate, num_attributes);

for (int i = 0; i < raw_attributes->Length(); i += elements_per_attribute) {

int idx = i / elements_per_attribute;

names[idx] = raw_attributes->Get(realm->context(), i).As<Name>();

values[idx] = raw_attributes->Get(realm->context(), i + 1).As<Value>();

}

Local<Object> attributes = Object::New(

isolate, Null(isolate), names.data(), values.data(), num_attributes);

attributes->SetIntegrityLevel(realm->context(), v8::IntegrityLevel::kFrozen)

.Check();

return attributes;

}

static Local<Array> createModuleRequestsContainer(

Realm* realm, Isolate* isolate, Local<FixedArray> raw_requests) {

EscapableHandleScope scope(isolate);

Local<Context> context = realm->context();

LocalVector<Value> requests(isolate, raw_requests->Length());

for (int i = 0; i < raw_requests->Length(); i++) {

Local<ModuleRequest> module_request =

raw_requests->Get(realm->context(), i).As<ModuleRequest>();

Local<String> specifier = module_request->GetSpecifier();

// Contains the import attributes for this request in the form:

// [key1, value1, source_offset1, key2, value2, source_offset2, ...].

Local<FixedArray> raw_attributes = module_request->GetImportAttributes();

Local<Object> attributes =

createImportAttributesContainer(realm, isolate, raw_attributes, 3);

Local<Name> names[] = {

realm->isolate_data()->specifier_string(),

realm->isolate_data()->attributes_string(),

};

Local<Value> values[] = {

specifier,

attributes,

};

DCHECK_EQ(arraysize(names), arraysize(values));

Local<Object> request =

Object::New(isolate, Null(isolate), names, values, arraysize(names));

request->SetIntegrityLevel(context, v8::IntegrityLevel::kFrozen).Check();

requests[i] = request;

}

return scope.Escape(Array::New(isolate, requests.data(), requests.size()));

}

void ModuleWrap::GetModuleRequests(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

Local<Object> that = args.This();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, that);

Local<Module> module = obj->module_.Get(isolate);

args.GetReturnValue().Set(createModuleRequestsContainer(

realm, isolate, module->GetModuleRequests()));

}

// moduleWrap.link(moduleWraps)

void ModuleWrap::Link(const FunctionCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

Realm* realm = Realm::GetCurrent(args);

Local<Context> context = realm->context();

ModuleWrap* dependent;

ASSIGN_OR_RETURN_UNWRAP(&dependent, args.This());

CHECK_EQ(args.Length(), 1);

Local<FixedArray> requests =

dependent->module_.Get(isolate)->GetModuleRequests();

Local<Array> modules = args[0].As<Array>();

CHECK_EQ(modules->Length(), static_cast<uint32_t>(requests->Length()));

for (int i = 0; i < requests->Length(); i++) {

ModuleCacheKey module_cache_key = ModuleCacheKey::From(

context, requests->Get(context, i).As<ModuleRequest>());

DCHECK(dependent->resolve_cache_.contains(module_cache_key));

Local<Value> module_i;

Local<Value> module_cache_i;

uint32_t coalesced_index = dependent->resolve_cache_[module_cache_key];

if (!modules->Get(context, i).ToLocal(&module_i) ||

!modules->Get(context, coalesced_index).ToLocal(&module_cache_i) ||

!module_i->StrictEquals(module_cache_i)) {

// If the module is different from the one of the same request, throw an

// error.

THROW_ERR_MODULE_LINK_MISMATCH(

realm->env(),

"Module request '%s' at index %d must be linked "

"to the same module requested at index %d",

module_cache_key.ToString(),

i,

coalesced_index);

return;

}

}

args.This()->SetInternalField(kLinkedRequestsSlot, modules);

dependent->linked_ = true;

}

void ModuleWrap::Instantiate(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Context> context = obj->context();

Local<Module> module = obj->module_.Get(isolate);

if (!obj->IsLinked()) {

THROW_ERR_VM_MODULE_LINK_FAILURE(realm->env(), "module is not linked");

return;

}

TryCatchScope try_catch(realm->env());

USE(module->InstantiateModule(context, ResolveModuleCallback));

if (try_catch.HasCaught() && !try_catch.HasTerminated()) {

CHECK(!try_catch.Message().IsEmpty());

CHECK(!try_catch.Exception().IsEmpty());

AppendExceptionLine(realm->env(),

try_catch.Exception(),

try_catch.Message(),

ErrorHandlingMode::MODULE_ERROR);

try_catch.ReThrow();

return;

}

}

void ModuleWrap::Evaluate(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = realm->isolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Context> context = obj->context();

Local<Module> module = obj->module_.Get(isolate);

ContextifyContext* contextify_context = obj->contextify_context_;

MicrotaskQueue* microtask_queue = nullptr;

if (contextify_context != nullptr)

microtask_queue = contextify_context->microtask_queue();

// module.evaluate(timeout, breakOnSigint)

CHECK_EQ(args.Length(), 2);

CHECK(args[0]->IsNumber());

int64_t timeout;

if (!args[0]->IntegerValue(realm->context()).To(&timeout)) {

return;

}

CHECK(args[1]->IsBoolean());

bool break_on_sigint = args[1]->IsTrue();

ShouldNotAbortOnUncaughtScope no_abort_scope(realm->env());

TryCatchScope try_catch(realm->env());

bool timed_out = false;

bool received_signal = false;

MaybeLocal<Value> result;

auto run = [&]() {

MaybeLocal<Value> result = module->Evaluate(context);

Local<Value> res;

if (result.ToLocal(&res) && microtask_queue) {

DCHECK(res->IsPromise());

// To address https://github.com/nodejs/node/issues/59541 when the

// module has its own separate microtask queue in microtaskMode

// "afterEvaluate", we avoid returning a promise built inside the

// module's own context.

//

// Instead, we build a promise in the outer context, which we resolve

// with {result}, then we checkpoint the module's own queue, and finally

// we return the outer-context promise.

//

// If we simply returned the inner promise {result} directly, per

// https://tc39.es/ecma262/#sec-newpromiseresolvethenablejob, the outer

// context, when resolving a promise coming from a different context,

// would need to enqueue a task (known as a thenable job task) onto the

// queue of that different context (the module's context). But this queue

// will normally not be checkpointed after evaluate() returns.

//

// This means that the execution flow in the outer context would

// silently fall through at the statement (in lib/internal/vm/module.js):

// await this[kWrap].evaluate(timeout, breakOnSigint)

//

// This is true for any promises created inside the module's context

// and made available to the outer context, as the node:vm doc explains.

//

// We must handle this particular return value differently to make it

// possible to await on the result of evaluate().

Local<Context> outer_context = isolate->GetCurrentContext();

Local<Promise::Resolver> resolver;

if (!Promise::Resolver::New(outer_context).ToLocal(&resolver)) {

return MaybeLocal<Value>();

}

if (resolver->Resolve(outer_context, res).IsNothing()) {

return MaybeLocal<Value>();

}

result = resolver->GetPromise();

microtask_queue->PerformCheckpoint(isolate);

}

return result;

};

if (break_on_sigint && timeout != -1) {

Watchdog wd(isolate, timeout, &timed_out);

SigintWatchdog swd(isolate, &received_signal);

result = run();

} else if (break_on_sigint) {

SigintWatchdog swd(isolate, &received_signal);

result = run();

} else if (timeout != -1) {

Watchdog wd(isolate, timeout, &timed_out);

result = run();

} else {

result = run();

}

if (result.IsEmpty()) {

CHECK(try_catch.HasCaught());

}

// Convert the termination exception into a regular exception.

if (timed_out || received_signal) {

if (!realm->env()->is_main_thread() && realm->env()->is_stopping()) return;

isolate->CancelTerminateExecution();

// It is possible that execution was terminated by another timeout in

// which this timeout is nested, so check whether one of the watchdogs

// from this invocation is responsible for termination.

if (timed_out) {

THROW_ERR_SCRIPT_EXECUTION_TIMEOUT(realm->env(), timeout);

} else if (received_signal) {

THROW_ERR_SCRIPT_EXECUTION_INTERRUPTED(realm->env());

}

}

if (try_catch.HasCaught()) {

if (!try_catch.HasTerminated())

try_catch.ReThrow();

return;

}

Local<Value> res;

if (result.ToLocal(&res)) {

args.GetReturnValue().Set(res);

}

}

void ModuleWrap::InstantiateSync(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Context> context = obj->context();

Local<Module> module = obj->module_.Get(isolate);

Environment* env = realm->env();

{

TryCatchScope try_catch(env);

USE(module->InstantiateModule(context, ResolveModuleCallback));

if (try_catch.HasCaught() && !try_catch.HasTerminated()) {

CHECK(!try_catch.Message().IsEmpty());

CHECK(!try_catch.Exception().IsEmpty());

AppendExceptionLine(env,

try_catch.Exception(),

try_catch.Message(),

ErrorHandlingMode::MODULE_ERROR);

try_catch.ReThrow();

return;

}

}

// TODO(joyeecheung): record Module::HasTopLevelAwait() in every ModuleWrap

// and infer the asynchronicity from a module's children during linking.

args.GetReturnValue().Set(module->IsGraphAsync());

}

Maybe<void> ThrowIfPromiseRejected(Realm* realm, Local<Promise> promise) {

Isolate* isolate = realm->isolate();

Local<Context> context = realm->context();

if (promise->State() != Promise::PromiseState::kRejected) {

return JustVoid();

}

// The rejected promise is created by V8, so we don't get a chance to mark

// it as resolved before the rejection happens from evaluation. But we can

// tell the promise rejection callback to treat it as a promise rejected

// before handler was added which would remove it from the unhandled

// rejection handling, since we are converting it into an error and throw

// from here directly.

Local<Value> type =

Integer::New(isolate,

static_cast<int32_t>(

PromiseRejectEvent::kPromiseHandlerAddedAfterReject));

Local<Value> args[] = {type, promise, Undefined(isolate)};

if (realm->promise_reject_callback()

->Call(context, Undefined(isolate), arraysize(args), args)

.IsEmpty()) {

return Nothing<void>();

}

Local<Value> exception = promise->Result();

Local<Message> message = Exception::CreateMessage(isolate, exception);

AppendExceptionLine(

realm->env(), exception, message, ErrorHandlingMode::MODULE_ERROR);

isolate->ThrowException(exception);

return Nothing<void>();

}

void ThrowIfPromiseRejected(const FunctionCallbackInfo<Value>& args) {

if (!args[0]->IsPromise()) {

return;

}

ThrowIfPromiseRejected(Realm::GetCurrent(args), args[0].As<Promise>());

}

void ModuleWrap::EvaluateSync(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Context> context = obj->context();

Local<Module> module = obj->module_.Get(isolate);

Environment* env = realm->env();

Local<Value> result;

{

TryCatchScope try_catch(env);

if (!module->Evaluate(context).ToLocal(&result)) {

if (try_catch.HasCaught()) {

if (!try_catch.HasTerminated()) {

try_catch.ReThrow();

}

return;

}

}

}

CHECK(result->IsPromise());

Local<Promise> promise = result.As<Promise>();

if (ThrowIfPromiseRejected(realm, promise).IsNothing()) {

return;

}

if (module->IsGraphAsync()) {

CHECK(env->options()->print_required_tla);

auto stalled_messages =

std::get<1>(module->GetStalledTopLevelAwaitMessages(isolate));

if (stalled_messages.size() != 0) {

for (auto& message : stalled_messages) {

std::string reason = "Error: unexpected top-level await at ";

std::string info =

FormatErrorMessage(isolate, context, "", message, true);

reason += info;

FPrintF(stderr, "%s\n", reason);

}

}

THROW_ERR_REQUIRE_ASYNC_MODULE(env, args[0], args[1]);

return;

}

CHECK_EQ(promise->State(), Promise::PromiseState::kFulfilled);

args.GetReturnValue().Set(module->GetModuleNamespace());

}

void ModuleWrap::GetNamespaceSync(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Module> module = obj->module_.Get(isolate);

switch (module->GetStatus()) {

case Module::Status::kUninstantiated:

case Module::Status::kInstantiating:

return realm->env()->ThrowError(

"Cannot get namespace, module has not been instantiated");

case Module::Status::kInstantiated:

case Module::Status::kEvaluating:

case Module::Status::kEvaluated:

case Module::Status::kErrored:

break;

}

if (module->IsGraphAsync()) {

return THROW_ERR_REQUIRE_ASYNC_MODULE(realm->env(), args[0], args[1]);

}

Local<Value> result = module->GetModuleNamespace();

args.GetReturnValue().Set(result);

}

void ModuleWrap::GetNamespace(const FunctionCallbackInfo<Value>& args) {

Realm* realm = Realm::GetCurrent(args);

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Module> module = obj->module_.Get(isolate);

switch (module->GetStatus()) {

case Module::Status::kUninstantiated:

case Module::Status::kInstantiating:

return realm->env()->ThrowError(

"cannot get namespace, module has not been instantiated");

case Module::Status::kInstantiated:

case Module::Status::kEvaluating:

case Module::Status::kEvaluated:

case Module::Status::kErrored:

break;

default:

UNREACHABLE();

}

Local<Value> result = module->GetModuleNamespace();

args.GetReturnValue().Set(result);

}

void ModuleWrap::GetStatus(const FunctionCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Module> module = obj->module_.Get(isolate);

args.GetReturnValue().Set(module->GetStatus());

}

void ModuleWrap::IsGraphAsync(const FunctionCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Module> module = obj->module_.Get(isolate);

args.GetReturnValue().Set(module->IsGraphAsync());

}

void ModuleWrap::HasTopLevelAwait(const FunctionCallbackInfo<Value>& args) {

Isolate* isolate = args.GetIsolate();

ModuleWrap* obj;

ASSIGN_OR_RETURN_UNWRAP(&obj, args.This());

Local<Module> module = obj->module_.Get(isolate);

// Check if module is valid

if (module.IsEmpty()) {

args.GetReturnValue().Set(false);

return;

}

// For source text modules, check if the graph is async

// For synthetic modules, it's always false

bool has_top_level_await =

module->IsSourceTextModule() && module->IsGraphAsync();