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LibWeb: Move initialization of the MainThreadVM to WebContent's main()

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It is a fallible operation, so this lets us abort early if it fails.
This commit is contained in:
Timothy Flynn 2023-03-17 10:56:59 -04:00 • committed by Linus Groh
parent 13dfadba79
commit 6e1b5b541a
4 changed files with 307 additions and 291 deletions
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590
Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp
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@ -32,6 +32,8 @@
namespace Web::Bindings {
static RefPtr<JS::VM> s_main_thread_vm;
// https://html.spec.whatwg.org/multipage/webappapis.html#active-script
HTML::Script* active_script()
{
@ -52,324 +54,330 @@ HTML::Script* active_script()
});
}
JS::VM& main_thread_vm()
ErrorOr<void> initialize_main_thread_vm()
{
static RefPtr<JS::VM> vm;
if (!vm) {
vm = JS::VM::create(make<WebEngineCustomData>()).release_value_but_fixme_should_propagate_errors();
VERIFY(!s_main_thread_vm);
// NOTE: We intentionally leak the main thread JavaScript VM.
// This avoids doing an exhaustive garbage collection on process exit.
vm->ref();
s_main_thread_vm = TRY(JS::VM::create(make<WebEngineCustomData>()));
static_cast<WebEngineCustomData*>(vm->custom_data())->event_loop.set_vm(*vm);
// NOTE: We intentionally leak the main thread JavaScript VM.
// This avoids doing an exhaustive garbage collection on process exit.
s_main_thread_vm->ref();
// 8.1.5.1 HostEnsureCanAddPrivateElement(O), https://html.spec.whatwg.org/multipage/webappapis.html#the-hostensurecanaddprivateelement-implementation
vm->host_ensure_can_add_private_element = [](JS::Object const& object) -> JS::ThrowCompletionOr<void> {
// 1. If O is a WindowProxy object, or implements Location, then return Completion { [[Type]]: throw, [[Value]]: a new TypeError }.
if (is<HTML::WindowProxy>(object) || is<HTML::Location>(object))
return vm->throw_completion<JS::TypeError>("Cannot add private elements to window or location object"sv);
static_cast<WebEngineCustomData*>(s_main_thread_vm->custom_data())->event_loop.set_vm(*s_main_thread_vm);
// 2. Return NormalCompletion(unused).
return {};
};
// 8.1.5.1 HostEnsureCanAddPrivateElement(O), https://html.spec.whatwg.org/multipage/webappapis.html#the-hostensurecanaddprivateelement-implementation
s_main_thread_vm->host_ensure_can_add_private_element = [](JS::Object const& object) -> JS::ThrowCompletionOr<void> {
// 1. If O is a WindowProxy object, or implements Location, then return Completion { [[Type]]: throw, [[Value]]: a new TypeError }.
if (is<HTML::WindowProxy>(object) || is<HTML::Location>(object))
return s_main_thread_vm->throw_completion<JS::TypeError>("Cannot add private elements to window or location object"sv);
// FIXME: Implement 8.1.5.2 HostEnsureCanCompileStrings(callerRealm, calleeRealm), https://html.spec.whatwg.org/multipage/webappapis.html#hostensurecancompilestrings(callerrealm,-calleerealm)
// 2. Return NormalCompletion(unused).
return {};
};
// 8.1.5.3 HostPromiseRejectionTracker(promise, operation), https://html.spec.whatwg.org/multipage/webappapis.html#the-hostpromiserejectiontracker-implementation
vm->host_promise_rejection_tracker = [](JS::Promise& promise, JS::Promise::RejectionOperation operation) {
// 1. Let script be the running script.
// The running script is the script in the [[HostDefined]] field in the ScriptOrModule component of the running JavaScript execution context.
HTML::Script* script { nullptr };
vm->running_execution_context().script_or_module.visit(
[&script](JS::NonnullGCPtr<JS::Script>& js_script) {
script = verify_cast<HTML::ClassicScript>(js_script->host_defined());
},
[&script](JS::NonnullGCPtr<JS::Module>& js_module) {
script = verify_cast<HTML::ModuleScript>(js_module->host_defined());
},
[](Empty) {
});
// FIXME: Implement 8.1.5.2 HostEnsureCanCompileStrings(callerRealm, calleeRealm), https://html.spec.whatwg.org/multipage/webappapis.html#hostensurecancompilestrings(callerrealm,-calleerealm)
// 2. If script is a classic script and script's muted errors is true, then return.
// NOTE: is<T>() returns false if nullptr is passed.
// 8.1.5.3 HostPromiseRejectionTracker(promise, operation), https://html.spec.whatwg.org/multipage/webappapis.html#the-hostpromiserejectiontracker-implementation
s_main_thread_vm->host_promise_rejection_tracker = [](JS::Promise& promise, JS::Promise::RejectionOperation operation) {
// 1. Let script be the running script.
// The running script is the script in the [[HostDefined]] field in the ScriptOrModule component of the running JavaScript execution context.
HTML::Script* script { nullptr };
s_main_thread_vm->running_execution_context().script_or_module.visit(
[&script](JS::NonnullGCPtr<JS::Script>& js_script) {
script = verify_cast<HTML::ClassicScript>(js_script->host_defined());
},
[&script](JS::NonnullGCPtr<JS::Module>& js_module) {
script = verify_cast<HTML::ModuleScript>(js_module->host_defined());
},
[](Empty) {
});
// 2. If script is a classic script and script's muted errors is true, then return.
// NOTE: is<T>() returns false if nullptr is passed.
if (is<HTML::ClassicScript>(script)) {
auto const& classic_script = static_cast<HTML::ClassicScript const&>(*script);
if (classic_script.muted_errors() == HTML::ClassicScript::MutedErrors::Yes)
return;
}
// 3. Let settings object be the current settings object.
// 4. If script is not null, then set settings object to script's settings object.
auto& settings_object = script ? script->settings_object() : HTML::current_settings_object();
switch (operation) {
case JS::Promise::RejectionOperation::Reject:
// 4. If operation is "reject",
// 1. Add promise to settings object's about-to-be-notified rejected promises list.
settings_object.push_onto_about_to_be_notified_rejected_promises_list(promise);
break;
case JS::Promise::RejectionOperation::Handle: {
// 5. If operation is "handle",
// 1. If settings object's about-to-be-notified rejected promises list contains promise, then remove promise from that list and return.
bool removed_about_to_be_notified_rejected_promise = settings_object.remove_from_about_to_be_notified_rejected_promises_list(promise);
if (removed_about_to_be_notified_rejected_promise)
return;
// 3. Remove promise from settings object's outstanding rejected promises weak set.
bool removed_outstanding_rejected_promise = settings_object.remove_from_outstanding_rejected_promises_weak_set(&promise);
// 2. If settings object's outstanding rejected promises weak set does not contain promise, then return.
// NOTE: This is done out of order because removed_outstanding_rejected_promise will be false if the promise wasn't in the set or true if it was and got removed.
if (!removed_outstanding_rejected_promise)
return;
// 4. Let global be settings object's global object.
auto& global = settings_object.global_object();
// 5. Queue a global task on the DOM manipulation task source given global to fire an event named rejectionhandled at global, using PromiseRejectionEvent,
// with the promise attribute initialized to promise, and the reason attribute initialized to the value of promise's [[PromiseResult]] internal slot.
HTML::queue_global_task(HTML::Task::Source::DOMManipulation, global, [&global, &promise] {
// FIXME: This currently assumes that global is a WindowObject.
auto& window = verify_cast<HTML::Window>(global);
HTML::PromiseRejectionEventInit event_init {
{}, // Initialize the inherited DOM::EventInit
/* .promise = */ promise,
/* .reason = */ promise.result(),
};
auto promise_rejection_event = HTML::PromiseRejectionEvent::create(HTML::relevant_realm(global), String::from_deprecated_string(HTML::EventNames::rejectionhandled).release_value_but_fixme_should_propagate_errors(), event_init).release_value_but_fixme_should_propagate_errors();
window.dispatch_event(promise_rejection_event);
});
break;
}
default:
VERIFY_NOT_REACHED();
}
};
// 8.1.5.4.1 HostCallJobCallback(callback, V, argumentsList), https://html.spec.whatwg.org/multipage/webappapis.html#hostcalljobcallback
s_main_thread_vm->host_call_job_callback = [](JS::JobCallback& callback, JS::Value this_value, JS::MarkedVector<JS::Value> arguments_list) {
auto& callback_host_defined = verify_cast<WebEngineCustomJobCallbackData>(*callback.custom_data);
// 1. Let incumbent settings be callback.[[HostDefined]].[[IncumbentSettings]]. (NOTE: Not necessary)
// 2. Let script execution context be callback.[[HostDefined]].[[ActiveScriptContext]]. (NOTE: Not necessary)
// 3. Prepare to run a callback with incumbent settings.
callback_host_defined.incumbent_settings->prepare_to_run_callback();
// 4. If script execution context is not null, then push script execution context onto the JavaScript execution context stack.
if (callback_host_defined.active_script_context)
s_main_thread_vm->push_execution_context(*callback_host_defined.active_script_context);
// 5. Let result be Call(callback.[[Callback]], V, argumentsList).
auto result = JS::call(*s_main_thread_vm, *callback.callback.cell(), this_value, move(arguments_list));
// 6. If script execution context is not null, then pop script execution context from the JavaScript execution context stack.
if (callback_host_defined.active_script_context) {
VERIFY(&s_main_thread_vm->running_execution_context() == callback_host_defined.active_script_context.ptr());
s_main_thread_vm->pop_execution_context();
}
// 7. Clean up after running a callback with incumbent settings.
callback_host_defined.incumbent_settings->clean_up_after_running_callback();
// 8. Return result.
return result;
};
// 8.1.5.4.2 HostEnqueueFinalizationRegistryCleanupJob(finalizationRegistry), https://html.spec.whatwg.org/multipage/webappapis.html#hostenqueuefinalizationregistrycleanupjob
s_main_thread_vm->host_enqueue_finalization_registry_cleanup_job = [](JS::FinalizationRegistry& finalization_registry) {
// 1. Let global be finalizationRegistry.[[Realm]]'s global object.
auto& global = finalization_registry.realm().global_object();
// 2. Queue a global task on the JavaScript engine task source given global to perform the following steps:
HTML::queue_global_task(HTML::Task::Source::JavaScriptEngine, global, [&finalization_registry] {
// 1. Let entry be finalizationRegistry.[[CleanupCallback]].[[Callback]].[[Realm]]'s environment settings object.
auto& entry = host_defined_environment_settings_object(*finalization_registry.cleanup_callback().callback.cell()->realm());
// 2. Check if we can run script with entry. If this returns "do not run", then return.
if (entry.can_run_script() == HTML::RunScriptDecision::DoNotRun)
return;
// 3. Prepare to run script with entry.
entry.prepare_to_run_script();
// 4. Let result be the result of performing CleanupFinalizationRegistry(finalizationRegistry).
auto result = finalization_registry.cleanup();
// 5. Clean up after running script with entry.
entry.clean_up_after_running_script();
// 6. If result is an abrupt completion, then report the exception given by result.[[Value]].
if (result.is_error())
HTML::report_exception(result, finalization_registry.realm());
});
};
// 8.1.5.4.3 HostEnqueuePromiseJob(job, realm), https://html.spec.whatwg.org/multipage/webappapis.html#hostenqueuepromisejob
s_main_thread_vm->host_enqueue_promise_job = [](Function<JS::ThrowCompletionOr<JS::Value>()> job, JS::Realm* realm) {
// 1. If realm is not null, then let job settings be the settings object for realm. Otherwise, let job settings be null.
HTML::EnvironmentSettingsObject* job_settings { nullptr };
if (realm)
job_settings = &host_defined_environment_settings_object(*realm);
// IMPLEMENTATION DEFINED: The JS spec says we must take implementation defined steps to make the currently active script or module at the time of HostEnqueuePromiseJob being invoked
// also be the active script or module of the job at the time of its invocation.
// This means taking it here now and passing it through to the lambda.
auto script_or_module = s_main_thread_vm->get_active_script_or_module();
// 2. Queue a microtask on the surrounding agent's event loop to perform the following steps:
// This instance of "queue a microtask" uses the "implied document". The best fit for "implied document" here is "If the task is being queued by or for a script, then return the script's settings object's responsible document."
// Do note that "implied document" from the spec is handwavy and the spec authors are trying to get rid of it: https://github.com/whatwg/html/issues/4980
auto* script = active_script();
// NOTE: This keeps job_settings alive by keeping realm alive, which is holding onto job_settings.
HTML::queue_a_microtask(script ? script->settings_object().responsible_document().ptr() : nullptr, [job_settings, job = move(job), script_or_module = move(script_or_module)] {
// The dummy execution context has to be kept up here to keep it alive for the duration of the function.
Optional<JS::ExecutionContext> dummy_execution_context;
if (job_settings) {
// 1. If job settings is not null, then check if we can run script with job settings. If this returns "do not run" then return.
if (job_settings->can_run_script() == HTML::RunScriptDecision::DoNotRun)
return;
// 2. If job settings is not null, then prepare to run script with job settings.
job_settings->prepare_to_run_script();
// IMPLEMENTATION DEFINED: Additionally to preparing to run a script, we also prepare to run a callback here. This matches WebIDL's
// invoke_callback() / call_user_object_operation() functions, and prevents a crash in host_make_job_callback()
// when getting the incumbent settings object.
job_settings->prepare_to_run_callback();
// IMPLEMENTATION DEFINED: Per the previous "implementation defined" comment, we must now make the script or module the active script or module.
// Since the only active execution context currently is the realm execution context of job settings, lets attach it here.
job_settings->realm_execution_context().script_or_module = script_or_module;
} else {
// FIXME: We need to setup a dummy execution context in case a JS::NativeFunction is called when processing the job.
// This is because JS::NativeFunction::call excepts something to be on the execution context stack to be able to get the caller context to initialize the environment.
// Do note that the JS spec gives _no_ guarantee that the execution context stack has something on it if HostEnqueuePromiseJob was called with a null realm: https://tc39.es/ecma262/#job-preparedtoevaluatecode
dummy_execution_context = JS::ExecutionContext { s_main_thread_vm->heap() };
dummy_execution_context->script_or_module = script_or_module;
s_main_thread_vm->push_execution_context(dummy_execution_context.value());
}
// 3. Let result be job().
[[maybe_unused]] auto result = job();
// 4. If job settings is not null, then clean up after running script with job settings.
if (job_settings) {
// IMPLEMENTATION DEFINED: Disassociate the realm execution context from the script or module.
job_settings->realm_execution_context().script_or_module = Empty {};
// IMPLEMENTATION DEFINED: See comment above, we need to clean up the non-standard prepare_to_run_callback() call.
job_settings->clean_up_after_running_callback();
job_settings->clean_up_after_running_script();
} else {
// Pop off the dummy execution context. See the above FIXME block about why this is done.
s_main_thread_vm->pop_execution_context();
}
// 5. If result is an abrupt completion, then report the exception given by result.[[Value]].
if (result.is_error())
HTML::report_exception(result, job_settings->realm());
});
};
// 8.1.5.4.4 HostMakeJobCallback(callable), https://html.spec.whatwg.org/multipage/webappapis.html#hostmakejobcallback
s_main_thread_vm->host_make_job_callback = [](JS::FunctionObject& callable) -> JS::JobCallback {
// 1. Let incumbent settings be the incumbent settings object.
auto& incumbent_settings = HTML::incumbent_settings_object();
// 2. Let active script be the active script.
auto* script = active_script();
// 3. Let script execution context be null.
OwnPtr<JS::ExecutionContext> script_execution_context;
// 4. If active script is not null, set script execution context to a new JavaScript execution context, with its Function field set to null,
// its Realm field set to active script's settings object's Realm, and its ScriptOrModule set to active script's record.
if (script) {
script_execution_context = adopt_own(*new JS::ExecutionContext(s_main_thread_vm->heap()));
script_execution_context->function = nullptr;
script_execution_context->realm = &script->settings_object().realm();
if (is<HTML::ClassicScript>(script)) {
auto const& classic_script = static_cast<HTML::ClassicScript const&>(*script);
if (classic_script.muted_errors() == HTML::ClassicScript::MutedErrors::Yes)
return;
}
// 3. Let settings object be the current settings object.
// 4. If script is not null, then set settings object to script's settings object.
auto& settings_object = script ? script->settings_object() : HTML::current_settings_object();
switch (operation) {
case JS::Promise::RejectionOperation::Reject:
// 4. If operation is "reject",
// 1. Add promise to settings object's about-to-be-notified rejected promises list.
settings_object.push_onto_about_to_be_notified_rejected_promises_list(promise);
break;
case JS::Promise::RejectionOperation::Handle: {
// 5. If operation is "handle",
// 1. If settings object's about-to-be-notified rejected promises list contains promise, then remove promise from that list and return.
bool removed_about_to_be_notified_rejected_promise = settings_object.remove_from_about_to_be_notified_rejected_promises_list(promise);
if (removed_about_to_be_notified_rejected_promise)
return;
// 3. Remove promise from settings object's outstanding rejected promises weak set.
bool removed_outstanding_rejected_promise = settings_object.remove_from_outstanding_rejected_promises_weak_set(&promise);
// 2. If settings object's outstanding rejected promises weak set does not contain promise, then return.
// NOTE: This is done out of order because removed_outstanding_rejected_promise will be false if the promise wasn't in the set or true if it was and got removed.
if (!removed_outstanding_rejected_promise)
return;
// 4. Let global be settings object's global object.
auto& global = settings_object.global_object();
// 5. Queue a global task on the DOM manipulation task source given global to fire an event named rejectionhandled at global, using PromiseRejectionEvent,
// with the promise attribute initialized to promise, and the reason attribute initialized to the value of promise's [[PromiseResult]] internal slot.
HTML::queue_global_task(HTML::Task::Source::DOMManipulation, global, [&global, &promise] {
// FIXME: This currently assumes that global is a WindowObject.
auto& window = verify_cast<HTML::Window>(global);
HTML::PromiseRejectionEventInit event_init {
{}, // Initialize the inherited DOM::EventInit
/* .promise = */ promise,
/* .reason = */ promise.result(),
};
auto promise_rejection_event = HTML::PromiseRejectionEvent::create(HTML::relevant_realm(global), String::from_deprecated_string(HTML::EventNames::rejectionhandled).release_value_but_fixme_should_propagate_errors(), event_init).release_value_but_fixme_should_propagate_errors();
window.dispatch_event(promise_rejection_event);
});
break;
}
default:
VERIFY_NOT_REACHED();
}
};
// 8.1.5.4.1 HostCallJobCallback(callback, V, argumentsList), https://html.spec.whatwg.org/multipage/webappapis.html#hostcalljobcallback
vm->host_call_job_callback = [](JS::JobCallback& callback, JS::Value this_value, JS::MarkedVector<JS::Value> arguments_list) {
auto& callback_host_defined = verify_cast<WebEngineCustomJobCallbackData>(*callback.custom_data);
// 1. Let incumbent settings be callback.[[HostDefined]].[[IncumbentSettings]]. (NOTE: Not necessary)
// 2. Let script execution context be callback.[[HostDefined]].[[ActiveScriptContext]]. (NOTE: Not necessary)
// 3. Prepare to run a callback with incumbent settings.
callback_host_defined.incumbent_settings->prepare_to_run_callback();
// 4. If script execution context is not null, then push script execution context onto the JavaScript execution context stack.
if (callback_host_defined.active_script_context)
vm->push_execution_context(*callback_host_defined.active_script_context);
// 5. Let result be Call(callback.[[Callback]], V, argumentsList).
auto result = JS::call(*vm, *callback.callback.cell(), this_value, move(arguments_list));
// 6. If script execution context is not null, then pop script execution context from the JavaScript execution context stack.
if (callback_host_defined.active_script_context) {
VERIFY(&vm->running_execution_context() == callback_host_defined.active_script_context.ptr());
vm->pop_execution_context();
}
// 7. Clean up after running a callback with incumbent settings.
callback_host_defined.incumbent_settings->clean_up_after_running_callback();
// 8. Return result.
return result;
};
// 8.1.5.4.2 HostEnqueueFinalizationRegistryCleanupJob(finalizationRegistry), https://html.spec.whatwg.org/multipage/webappapis.html#hostenqueuefinalizationregistrycleanupjob
vm->host_enqueue_finalization_registry_cleanup_job = [](JS::FinalizationRegistry& finalization_registry) {
// 1. Let global be finalizationRegistry.[[Realm]]'s global object.
auto& global = finalization_registry.realm().global_object();
// 2. Queue a global task on the JavaScript engine task source given global to perform the following steps:
HTML::queue_global_task(HTML::Task::Source::JavaScriptEngine, global, [&finalization_registry] {
// 1. Let entry be finalizationRegistry.[[CleanupCallback]].[[Callback]].[[Realm]]'s environment settings object.
auto& entry = host_defined_environment_settings_object(*finalization_registry.cleanup_callback().callback.cell()->realm());
// 2. Check if we can run script with entry. If this returns "do not run", then return.
if (entry.can_run_script() == HTML::RunScriptDecision::DoNotRun)
return;
// 3. Prepare to run script with entry.
entry.prepare_to_run_script();
// 4. Let result be the result of performing CleanupFinalizationRegistry(finalizationRegistry).
auto result = finalization_registry.cleanup();
// 5. Clean up after running script with entry.
entry.clean_up_after_running_script();
// 6. If result is an abrupt completion, then report the exception given by result.[[Value]].
if (result.is_error())
HTML::report_exception(result, finalization_registry.realm());
});
};
// 8.1.5.4.3 HostEnqueuePromiseJob(job, realm), https://html.spec.whatwg.org/multipage/webappapis.html#hostenqueuepromisejob
vm->host_enqueue_promise_job = [](Function<JS::ThrowCompletionOr<JS::Value>()> job, JS::Realm* realm) {
// 1. If realm is not null, then let job settings be the settings object for realm. Otherwise, let job settings be null.
HTML::EnvironmentSettingsObject* job_settings { nullptr };
if (realm)
job_settings = &host_defined_environment_settings_object(*realm);
// IMPLEMENTATION DEFINED: The JS spec says we must take implementation defined steps to make the currently active script or module at the time of HostEnqueuePromiseJob being invoked
// also be the active script or module of the job at the time of its invocation.
// This means taking it here now and passing it through to the lambda.
auto script_or_module = vm->get_active_script_or_module();
// 2. Queue a microtask on the surrounding agent's event loop to perform the following steps:
// This instance of "queue a microtask" uses the "implied document". The best fit for "implied document" here is "If the task is being queued by or for a script, then return the script's settings object's responsible document."
// Do note that "implied document" from the spec is handwavy and the spec authors are trying to get rid of it: https://github.com/whatwg/html/issues/4980
auto* script = active_script();
// NOTE: This keeps job_settings alive by keeping realm alive, which is holding onto job_settings.
HTML::queue_a_microtask(script ? script->settings_object().responsible_document().ptr() : nullptr, [job_settings, job = move(job), script_or_module = move(script_or_module)] {
// The dummy execution context has to be kept up here to keep it alive for the duration of the function.
Optional<JS::ExecutionContext> dummy_execution_context;
if (job_settings) {
// 1. If job settings is not null, then check if we can run script with job settings. If this returns "do not run" then return.
if (job_settings->can_run_script() == HTML::RunScriptDecision::DoNotRun)
return;
// 2. If job settings is not null, then prepare to run script with job settings.
job_settings->prepare_to_run_script();
// IMPLEMENTATION DEFINED: Additionally to preparing to run a script, we also prepare to run a callback here. This matches WebIDL's
// invoke_callback() / call_user_object_operation() functions, and prevents a crash in host_make_job_callback()
// when getting the incumbent settings object.
job_settings->prepare_to_run_callback();
// IMPLEMENTATION DEFINED: Per the previous "implementation defined" comment, we must now make the script or module the active script or module.
// Since the only active execution context currently is the realm execution context of job settings, lets attach it here.
job_settings->realm_execution_context().script_or_module = script_or_module;
} else {
// FIXME: We need to setup a dummy execution context in case a JS::NativeFunction is called when processing the job.
// This is because JS::NativeFunction::call excepts something to be on the execution context stack to be able to get the caller context to initialize the environment.
// Do note that the JS spec gives _no_ guarantee that the execution context stack has something on it if HostEnqueuePromiseJob was called with a null realm: https://tc39.es/ecma262/#job-preparedtoevaluatecode
dummy_execution_context = JS::ExecutionContext { vm->heap() };
dummy_execution_context->script_or_module = script_or_module;
vm->push_execution_context(dummy_execution_context.value());
}
// 3. Let result be job().
[[maybe_unused]] auto result = job();
// 4. If job settings is not null, then clean up after running script with job settings.
if (job_settings) {
// IMPLEMENTATION DEFINED: Disassociate the realm execution context from the script or module.
job_settings->realm_execution_context().script_or_module = Empty {};
// IMPLEMENTATION DEFINED: See comment above, we need to clean up the non-standard prepare_to_run_callback() call.
job_settings->clean_up_after_running_callback();
job_settings->clean_up_after_running_script();
} else {
// Pop off the dummy execution context. See the above FIXME block about why this is done.
vm->pop_execution_context();
}
// 5. If result is an abrupt completion, then report the exception given by result.[[Value]].
if (result.is_error())
HTML::report_exception(result, job_settings->realm());
});
};
// 8.1.5.4.4 HostMakeJobCallback(callable), https://html.spec.whatwg.org/multipage/webappapis.html#hostmakejobcallback
vm->host_make_job_callback = [](JS::FunctionObject& callable) -> JS::JobCallback {
// 1. Let incumbent settings be the incumbent settings object.
auto& incumbent_settings = HTML::incumbent_settings_object();
// 2. Let active script be the active script.
auto* script = active_script();
// 3. Let script execution context be null.
OwnPtr<JS::ExecutionContext> script_execution_context;
// 4. If active script is not null, set script execution context to a new JavaScript execution context, with its Function field set to null,
// its Realm field set to active script's settings object's Realm, and its ScriptOrModule set to active script's record.
if (script) {
script_execution_context = adopt_own(*new JS::ExecutionContext(vm->heap()));
script_execution_context->function = nullptr;
script_execution_context->realm = &script->settings_object().realm();
if (is<HTML::ClassicScript>(script)) {
script_execution_context->script_or_module = JS::NonnullGCPtr<JS::Script>(*verify_cast<HTML::ClassicScript>(script)->script_record());
} else if (is<HTML::ModuleScript>(script)) {
if (is<HTML::JavaScriptModuleScript>(script)) {
script_execution_context->script_or_module = JS::NonnullGCPtr<JS::Module>(*verify_cast<HTML::JavaScriptModuleScript>(script)->record());
} else {
// NOTE: Handle CSS and JSON module scripts once we have those.
VERIFY_NOT_REACHED();
}
script_execution_context->script_or_module = JS::NonnullGCPtr<JS::Script>(*verify_cast<HTML::ClassicScript>(script)->script_record());
} else if (is<HTML::ModuleScript>(script)) {
if (is<HTML::JavaScriptModuleScript>(script)) {
script_execution_context->script_or_module = JS::NonnullGCPtr<JS::Module>(*verify_cast<HTML::JavaScriptModuleScript>(script)->record());
} else {
// NOTE: Handle CSS and JSON module scripts once we have those.
VERIFY_NOT_REACHED();
}
} else {
VERIFY_NOT_REACHED();
}
}
// 5. Return the JobCallback Record { [[Callback]]: callable, [[HostDefined]]: { [[IncumbentSettings]]: incumbent settings, [[ActiveScriptContext]]: script execution context } }.
auto host_defined = adopt_own(*new WebEngineCustomJobCallbackData(incumbent_settings, move(script_execution_context)));
return { JS::make_handle(&callable), move(host_defined) };
};
// 5. Return the JobCallback Record { [[Callback]]: callable, [[HostDefined]]: { [[IncumbentSettings]]: incumbent settings, [[ActiveScriptContext]]: script execution context } }.
auto host_defined = adopt_own(*new WebEngineCustomJobCallbackData(incumbent_settings, move(script_execution_context)));
return { JS::make_handle(&callable), move(host_defined) };
};
// FIXME: Implement 8.1.5.5.1 HostGetImportMetaProperties(moduleRecord), https://html.spec.whatwg.org/multipage/webappapis.html#hostgetimportmetaproperties
// FIXME: Implement 8.1.5.5.2 HostImportModuleDynamically(referencingScriptOrModule, moduleRequest, promiseCapability), https://html.spec.whatwg.org/multipage/webappapis.html#hostimportmoduledynamically(referencingscriptormodule,-modulerequest,-promisecapability)
// FIXME: Implement 8.1.5.5.3 HostResolveImportedModule(referencingScriptOrModule, moduleRequest), https://html.spec.whatwg.org/multipage/webappapis.html#hostresolveimportedmodule(referencingscriptormodule,-modulerequest)
// FIXME: Implement 8.1.5.5.1 HostGetImportMetaProperties(moduleRecord), https://html.spec.whatwg.org/multipage/webappapis.html#hostgetimportmetaproperties
// FIXME: Implement 8.1.5.5.2 HostImportModuleDynamically(referencingScriptOrModule, moduleRequest, promiseCapability), https://html.spec.whatwg.org/multipage/webappapis.html#hostimportmoduledynamically(referencingscriptormodule,-modulerequest,-promisecapability)
// FIXME: Implement 8.1.5.5.3 HostResolveImportedModule(referencingScriptOrModule, moduleRequest), https://html.spec.whatwg.org/multipage/webappapis.html#hostresolveimportedmodule(referencingscriptormodule,-modulerequest)
// 8.1.5.5.4 HostGetSupportedImportAssertions(), https://html.spec.whatwg.org/multipage/webappapis.html#hostgetsupportedimportassertions
vm->host_get_supported_import_assertions = []() -> Vector<DeprecatedString> {
// 1. Return « "type" ».
return { "type"sv };
};
// 8.1.5.5.4 HostGetSupportedImportAssertions(), https://html.spec.whatwg.org/multipage/webappapis.html#hostgetsupportedimportassertions
s_main_thread_vm->host_get_supported_import_assertions = []() -> Vector<DeprecatedString> {
// 1. Return « "type" ».
return { "type"sv };
};
// 8.1.6.5.3 HostResolveImportedModule(referencingScriptOrModule, moduleRequest), https://html.spec.whatwg.org/multipage/webappapis.html#hostresolveimportedmodule(referencingscriptormodule,-modulerequest)
vm->host_resolve_imported_module = [](JS::ScriptOrModule const& referencing_string_or_module, JS::ModuleRequest const& module_request) -> JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Module>> {
// 1. Let moduleMap and referencingScript be null.
Optional<HTML::ModuleMap&> module_map;
Optional<HTML::Script&> referencing_script;
// 8.1.6.5.3 HostResolveImportedModule(referencingScriptOrModule, moduleRequest), https://html.spec.whatwg.org/multipage/webappapis.html#hostresolveimportedmodule(referencingscriptormodule,-modulerequest)
s_main_thread_vm->host_resolve_imported_module = [](JS::ScriptOrModule const& referencing_string_or_module, JS::ModuleRequest const& module_request) -> JS::ThrowCompletionOr<JS::NonnullGCPtr<JS::Module>> {
// 1. Let moduleMap and referencingScript be null.
Optional<HTML::ModuleMap&> module_map;
Optional<HTML::Script&> referencing_script;
// 2. If referencingScriptOrModule is not null, then:
if (!referencing_string_or_module.has<Empty>()) {
// 1. Set referencingScript to referencingScriptOrModule.[[HostDefined]].
referencing_script = verify_cast<HTML::Script>(referencing_string_or_module.has<JS::NonnullGCPtr<JS::Script>>() ? *referencing_string_or_module.get<JS::NonnullGCPtr<JS::Script>>()->host_defined() : *referencing_string_or_module.get<JS::NonnullGCPtr<JS::Module>>()->host_defined());
// 2. If referencingScriptOrModule is not null, then:
if (!referencing_string_or_module.has<Empty>()) {
// 1. Set referencingScript to referencingScriptOrModule.[[HostDefined]].
referencing_script = verify_cast<HTML::Script>(referencing_string_or_module.has<JS::NonnullGCPtr<JS::Script>>() ? *referencing_string_or_module.get<JS::NonnullGCPtr<JS::Script>>()->host_defined() : *referencing_string_or_module.get<JS::NonnullGCPtr<JS::Module>>()->host_defined());
// 2. Set moduleMap to referencingScript's settings object's module map.
module_map = referencing_script->settings_object().module_map();
}
// 3. Otherwise:
else {
// 1. Assert: there is a current settings object.
// NOTE: This is handled by the HTML::current_settings_object() accessor.
// 2. Set moduleMap to referencingScript's settings object's module map.
module_map = referencing_script->settings_object().module_map();
}
// 3. Otherwise:
else {
// 1. Assert: there is a current settings object.
// NOTE: This is handled by the HTML::current_settings_object() accessor.
// 2. Set moduleMap to the current settings object's module map.
module_map = HTML::current_settings_object().module_map();
}
// 2. Set moduleMap to the current settings object's module map.
module_map = HTML::current_settings_object().module_map();
}
// 4. Let url be the result of resolving a module specifier given referencingScript and moduleRequest.[[Specifier]].
auto url = MUST(HTML::resolve_module_specifier(referencing_script, module_request.module_specifier));
// 4. Let url be the result of resolving a module specifier given referencingScript and moduleRequest.[[Specifier]].
auto url = MUST(HTML::resolve_module_specifier(referencing_script, module_request.module_specifier));
// 5. Assert: the previous step never throws an exception, because resolving a module specifier must have been previously successful
// with these same two arguments (either while creating the corresponding module script, or in fetch an import() module script graph).
// NOTE: Handled by MUST above.
// 5. Assert: the previous step never throws an exception, because resolving a module specifier must have been previously successful
// with these same two arguments (either while creating the corresponding module script, or in fetch an import() module script graph).
// NOTE: Handled by MUST above.
// 6. Let moduleType be the result of running the module type from module request steps given moduleRequest.
auto module_type = HTML::module_type_from_module_request(module_request);
// 6. Let moduleType be the result of running the module type from module request steps given moduleRequest.
auto module_type = HTML::module_type_from_module_request(module_request);
// 7. Let resolvedModuleScript be moduleMap[(url, moduleType)]. (This entry must exist for us to have gotten to this point.)
auto resolved_module_script = module_map->get(url, module_type).value();
// 7. Let resolvedModuleScript be moduleMap[(url, moduleType)]. (This entry must exist for us to have gotten to this point.)
auto resolved_module_script = module_map->get(url, module_type).value();
// 8. Assert: resolvedModuleScript is a module script (i.e., is not null or "fetching").
VERIFY(resolved_module_script.type == HTML::ModuleMap::EntryType::ModuleScript);
// 8. Assert: resolvedModuleScript is a module script (i.e., is not null or "fetching").
VERIFY(resolved_module_script.type == HTML::ModuleMap::EntryType::ModuleScript);
// 9. Assert: resolvedModuleScript's record is not null.
VERIFY(resolved_module_script.module_script->record());
// 9. Assert: resolvedModuleScript's record is not null.
VERIFY(resolved_module_script.module_script->record());
// 10. Return resolvedModuleScript's record.
return JS::NonnullGCPtr(*resolved_module_script.module_script->record());
};
}
return *vm;
// 10. Return resolvedModuleScript's record.
return JS::NonnullGCPtr(*resolved_module_script.module_script->record());
};
return {};
}
JS::VM& main_thread_vm()
{
VERIFY(s_main_thread_vm);
return *s_main_thread_vm;
}
// https://dom.spec.whatwg.org/#queue-a-mutation-observer-compound-microtask