LibJS: Add infallible variant of VM::push_execution_context()

It makes no sense to require passing a global object and doing a stack
space check in some cases where running out of stack is highly unlikely,
we can't recover from errors, and currently ignore the result anyway.

This is most commonly in constructors and when setting things up, rather
than regular function calls.

Tests/Spreadsheet/test-spreadsheet.cpp

@@ -27,7 +27,7 @@ TESTJS_RUN_FILE_FUNCTION(String const&, JS::Interpreter& interpreter, JS::Execut
         }
         auto script = result.release_value();
 
-        interpreter.vm().push_execution_context(global_execution_context, interpreter.realm().global_object());
+        interpreter.vm().push_execution_context(global_execution_context);
         MUST(interpreter.run(*script));
         interpreter.vm().pop_execution_context();
     };

Userland/Applications/Spreadsheet/Workbook.cpp

@@ -39,8 +39,7 @@ Workbook::Workbook(NonnullRefPtrVector<Sheet>&& sheets, GUI::Window& parent_wind
     m_main_execution_context.variable_environment = &m_interpreter->realm().global_environment();
     m_main_execution_context.realm = &m_interpreter->realm();
     m_main_execution_context.is_strict_mode = true;
-    MUST(m_vm->push_execution_context(m_main_execution_context, m_interpreter->global_object()));
-
+    m_vm->push_execution_context(m_main_execution_context);
     m_vm->enable_default_host_import_module_dynamically_hook();
 }
 

Userland/Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -59,7 +59,7 @@ Interpreter::ValueAndFrame Interpreter::run_and_return_frame(Executable const& e
         execution_context.realm = &m_realm;
         // FIXME: How do we know if we're in strict mode? Maybe the Bytecode::Block should know this?
         // execution_context.is_strict_mode = ???;
-        MUST(vm().push_execution_context(execution_context, global_object()));
+        vm().push_execution_context(execution_context);
         pushed_execution_context = true;
     }
 

Userland/Libraries/LibJS/Interpreter.h

@@ -56,14 +56,13 @@ public:
 
         // 5. Set the ScriptOrModule of newContext to null. (This was done during execution context construction)
 
+        // 6. Push newContext onto the execution context stack; newContext is now the running execution context.
+        vm.push_execution_context(interpreter->m_global_execution_context);
+
         // 7. If the host requires use of an exotic object to serve as realm's global object, let global be such an object created in a host-defined manner.
         //    Otherwise, let global be undefined, indicating that an ordinary object should be created as the global object.
         auto* global_object = static_cast<GlobalObject*>(interpreter->heap().allocate_without_global_object<GlobalObjectType>(forward<Args>(args)...));
 
-        // 6. Push newContext onto the execution context stack; newContext is now the running execution context.
-        //    NOTE: This is out of order from the spec, but it shouldn't matter here.
-        vm.push_execution_context(interpreter->m_global_execution_context, *global_object);
-
         // 8. If the host requires that the this binding in realm's global scope return an object other than the global object, let thisValue be such an object created
         //    in a host-defined manner. Otherwise, let thisValue be undefined, indicating that realm's global this binding should be the global object.
         if constexpr (IsSame<GlobalObjectType, GlobalThisObjectType>) {

Userland/Libraries/LibJS/Runtime/VM.h

@@ -90,6 +90,11 @@ public:
         return m_stack_info.size_free() < 32 * KiB;
     }
 
+    void push_execution_context(ExecutionContext& context)
+    {
+        m_execution_context_stack.append(&context);
+    }
+
     ThrowCompletionOr<void> push_execution_context(ExecutionContext& context, GlobalObject& global_object)
     {
         // Ensure we got some stack space left, so the next function call doesn't kill us.

Userland/Libraries/LibTest/JavaScriptTestRunner.h

@@ -363,7 +363,7 @@ inline JSFileResult TestRunner::run_file_test(const String& test_path)
         JS::Bytecode::Interpreter bytecode_interpreter(interpreter->global_object(), interpreter->realm());
         MUST(bytecode_interpreter.run(*executable));
     } else {
-        g_vm->push_execution_context(global_execution_context, interpreter->global_object());
+        g_vm->push_execution_context(global_execution_context);
         MUST(interpreter->run(*test_script));
         g_vm->pop_execution_context();
     }
@@ -382,7 +382,7 @@ inline JSFileResult TestRunner::run_file_test(const String& test_path)
             (void)bytecode_interpreter.run(*executable);
         }
     } else {
-        g_vm->push_execution_context(global_execution_context, interpreter->global_object());
+        g_vm->push_execution_context(global_execution_context);
         (void)interpreter->run(file_script.value());
         g_vm->pop_execution_context();
     }

Userland/Libraries/LibWeb/Bindings/MainThreadVM.cpp

@@ -138,7 +138,7 @@ JS::VM& main_thread_vm()
 
             // 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)
-                MUST(vm->push_execution_context(*callback_host_defined.active_script_context, callback.callback.cell()->global_object()));
+                vm->push_execution_context(*callback_host_defined.active_script_context);
 
             // 5. Let result be Call(callback.[[Callback]], V, argumentsList).
             auto result = JS::call(global_object, *callback.callback.cell(), this_value, move(arguments_list));
@@ -228,7 +228,7 @@ JS::VM& main_thread_vm()
                     auto script_record = script_or_module.get<WeakPtr<JS::Script>>();
                     dummy_execution_context = JS::ExecutionContext { vm->heap() };
                     dummy_execution_context->script_or_module = script_or_module;
-                    vm->push_execution_context(dummy_execution_context.value(), script_record->realm().global_object());
+                    vm->push_execution_context(dummy_execution_context.value());
                 }
 
                 // 3. Let result be job().

Userland/Libraries/LibWeb/DOM/EventTarget.cpp

@@ -372,9 +372,10 @@ Bindings::CallbackType* EventTarget::get_current_value_of_event_handler(FlyStrin
             return nullptr;
         }
 
-        // 8. Push settings object's realm execution context onto the JavaScript execution context stack; it is now the running JavaScript execution context.
         auto& global_object = settings_object.global_object();
-        global_object.vm().push_execution_context(settings_object.realm_execution_context(), global_object);
+
+        // 8. Push settings object's realm execution context onto the JavaScript execution context stack; it is now the running JavaScript execution context.
+        global_object.vm().push_execution_context(settings_object.realm_execution_context());
 
         // 9. Let function be the result of calling OrdinaryFunctionCreate, with arguments:
         // functionPrototype

Userland/Libraries/LibWeb/HTML/Scripting/Environments.cpp

@@ -78,7 +78,7 @@ RunScriptDecision EnvironmentSettingsObject::can_run_script()
 void EnvironmentSettingsObject::prepare_to_run_script()
 {
     // 1. Push settings's realm execution context onto the JavaScript execution context stack; it is now the running JavaScript execution context.
-    global_object().vm().push_execution_context(realm_execution_context(), global_object());
+    global_object().vm().push_execution_context(realm_execution_context());
 
     // FIXME: 2. Add settings to the currently running task's script evaluation environment settings object set.
 }

Userland/Libraries/LibWeb/HTML/Worker.cpp

@@ -160,7 +160,7 @@ void Worker::run_a_worker(AK::URL& url, EnvironmentSettingsObject& outside_setti
     m_execution_context.variable_environment = &m_worker_realm->global_environment();
     m_execution_context.realm = m_worker_realm;
 
-    m_worker_vm->push_execution_context(m_execution_context, *m_worker_scope);
+    m_worker_vm->push_execution_context(m_execution_context);
     m_worker_realm->set_global_object(*m_worker_scope, m_worker_scope);
 
     // 8. Let worker global scope be the global object of realm execution context's Realm component.

Userland/Services/WebContent/WebContentConsoleClient.cpp

@@ -31,7 +31,7 @@ WebContentConsoleClient::WebContentConsoleClient(JS::Console& console, WeakPtr<J
     // NOTE: We need to push an execution context here for NativeFunction::create() to succeed during global object initialization.
     // It gets removed immediately after creating the interpreter in Document::interpreter().
     auto& eso = verify_cast<Web::HTML::EnvironmentSettingsObject>(*m_interpreter->realm().host_defined());
-    vm.push_execution_context(eso.realm_execution_context(), global_object);
+    vm.push_execution_context(eso.realm_execution_context());
     console_global_object->initialize_global_object();
     vm.pop_execution_context();