[ESnext] Implement Promise.prototype.finally

src/bootstrapper.cc

 // Copyright 2014 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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/ieee754.h"
 #include "src/code-stubs.h"
@@ skipping 3601 matching lines @@
                         NONE);
 }
 
 void Genesis::InitializeGlobal_harmony_async_iteration() {
   if (!FLAG_harmony_async_iteration) return;
   Handle<JSFunction> symbol_fun(native_context()->symbol_function());
   InstallConstant(isolate(), symbol_fun, "asyncIterator",
                   factory()->async_iterator_symbol());
 }
 
+void Genesis::InitializeGlobal_harmony_promise_finally() {
+  if (!FLAG_harmony_promise_finally) return;
+
+  Handle<JSFunction> constructor(native_context()->promise_function());
+  Handle<JSObject> prototype(JSObject::cast(constructor->instance_prototype()));
+  SimpleInstallFunction(prototype, "finally", Builtins::kPromiseFinally, 1,
+                        true, DONT_ENUM);
+
+  // The promise prototype map has changed because we added a property
+  // to prototype, so we update the saved map.
+  Handle<Map> prototype_map(prototype->map());
+  Map::SetShouldBeFastPrototypeMap(prototype_map, true, isolate());
+  native_context()->set_promise_prototype_map(*prototype_map);
+
+  {
+    Handle<Code> code =
+        handle(isolate()->builtins()->builtin(Builtins::kPromiseThenFinally),
+               isolate());
+    Handle<SharedFunctionInfo> info = factory()->NewSharedFunctionInfo(
+        factory()->empty_string(), code, false);
+    info->set_internal_formal_parameter_count(1);
+    info->set_length(1);
+    info->set_native(true);
+    native_context()->set_promise_then_finally_shared_fun(*info);
+  }
+
+  {
+    Handle<Code> code =
+        handle(isolate()->builtins()->builtin(Builtins::kPromiseCatchFinally),
+               isolate());
+    Handle<SharedFunctionInfo> info = factory()->NewSharedFunctionInfo(
+        factory()->empty_string(), code, false);
+    info->set_internal_formal_parameter_count(1);
+    info->set_length(1);
+    info->set_native(true);
+    native_context()->set_promise_catch_finally_shared_fun(*info);
+  }
+
+  {
+    Handle<Code> code = handle(
+        isolate()->builtins()->builtin(Builtins::kPromiseValueThunkFinally),
+        isolate());
+    Handle<SharedFunctionInfo> info = factory()->NewSharedFunctionInfo(
+        factory()->empty_string(), code, false);
+    info->set_internal_formal_parameter_count(0);
+    info->set_length(0);
+    native_context()->set_promise_value_thunk_finally_shared_fun(*info);
+  }
+
+  {
+    Handle<Code> code =
+        handle(isolate()->builtins()->builtin(Builtins::kPromiseThrowerFinally),
+               isolate());
+    Handle<SharedFunctionInfo> info = factory()->NewSharedFunctionInfo(
+        factory()->empty_string(), code, false);
+    info->set_internal_formal_parameter_count(0);
+    info->set_length(0);
+    native_context()->set_promise_thrower_finally_shared_fun(*info);
+  }
+}
+
 #ifdef V8_I18N_SUPPORT
 void Genesis::InitializeGlobal_datetime_format_to_parts() {
   if (!FLAG_datetime_format_to_parts) return;
   Handle<JSReceiver> exports_container(
       JSReceiver::cast(native_context()->exports_container()));
   Handle<JSObject> date_time_format_prototype(JSObject::cast(
       native_context()->intl_date_time_format_function()->prototype()));
   Handle<JSFunction> format_date_to_parts = Handle<JSFunction>::cast(
       JSReceiver::GetProperty(
           exports_container,
@@ skipping 514 matching lines @@
   static const char* icu_case_mapping_natives[] = {nullptr};
   static const char* datetime_format_to_parts_natives[] = {nullptr};
 #endif
   static const char* harmony_restrictive_generators_natives[] = {nullptr};
   static const char* harmony_trailing_commas_natives[] = {nullptr};
   static const char* harmony_function_tostring_natives[] = {nullptr};
   static const char* harmony_class_fields_natives[] = {nullptr};
   static const char* harmony_object_rest_spread_natives[] = {nullptr};
   static const char* harmony_async_iteration_natives[] = {nullptr};
   static const char* harmony_dynamic_import_natives[] = {nullptr};
+  static const char* harmony_promise_finally_natives[] = {nullptr};
 
   for (int i = ExperimentalNatives::GetDebuggerCount();
        i < ExperimentalNatives::GetBuiltinsCount(); i++) {
 #define INSTALL_EXPERIMENTAL_NATIVES(id, desc)                                \
   if (FLAG_##id) {                                                            \
     for (size_t j = 0; id##_natives[j] != NULL; j++) {                        \
       Vector<const char> script_name = ExperimentalNatives::GetScriptName(i); \
       if (strncmp(script_name.start(), id##_natives[j],                       \
                   script_name.length()) == 0) {                               \
         if (!Bootstrapper::CompileExperimentalBuiltin(isolate(), i)) {        \
@@ skipping 735 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8