Move Error methods to C++

src/builtins/builtins-error.cc

+// Copyright 2016 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/builtins/builtins.h"
+#include "src/builtins/builtins-utils.h"
+
+#include "src/accessors.h"
+#include "src/bootstrapper.h"
+#include "src/property-descriptor.h"
+#include "src/string-builder.h"
+
+namespace v8 {
+namespace internal {
+
+// ES6 section 19.5.1.1 Error ( message )
+BUILTIN(ErrorConstructor) {
+  HandleScope scope(isolate);
+
+  // 1. If NewTarget is undefined, let newTarget be the active function object,
+  // else let newTarget be NewTarget.
+
+  Handle<JSFunction> target = args.target<JSFunction>();
+  Handle<JSReceiver> new_target;
+  if (args.new_target()->IsJSReceiver()) {
+    new_target = Handle<JSReceiver>::cast(args.new_target());
+  } else {
+    new_target = target;
+  }
+
+  // 2. Let O be ? OrdinaryCreateFromConstructor(newTarget, "%ErrorPrototype%",
+  //    « [[ErrorData]] »).
+  Handle<JSObject> err;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, err,
+                                     JSObject::New(target, new_target));
+
+  // 3. If message is not undefined, then
+  //  a. Let msg be ? ToString(message).
+  //  b. Let msgDesc be the PropertyDescriptor{[[Value]]: msg, [[Writable]]:
+  //     true, [[Enumerable]]: false, [[Configurable]]: true}.
+  //  c. Perform ! DefinePropertyOrThrow(O, "message", msgDesc).
+  // 4. Return O.
+
+  Handle<Object> msg = args.atOrUndefined(isolate, 1);
+  if (!msg->IsUndefined(isolate)) {
+    Handle<String> msg_string;
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, msg_string,
+                                       Object::ToString(isolate, msg));
+    RETURN_FAILURE_ON_EXCEPTION(
+        isolate,
+        JSObject::SetOwnPropertyIgnoreAttributes(
+            err, isolate->factory()->message_string(), msg_string, DONT_ENUM));
+  }
+
+  // Capture the stack trace unless we're setting up.
+  if (!isolate->bootstrapper()->IsActive()) {
+    // Optionally capture a more detailed stack trace for the message.
+    RETURN_FAILURE_ON_EXCEPTION(isolate,
+                                isolate->CaptureAndSetDetailedStackTrace(err));
+    // Capture a simple stack trace for the stack property.
+    RETURN_FAILURE_ON_EXCEPTION(isolate,
+                                isolate->CaptureAndSetSimpleStackTrace(err));
+  }
+
+  return *err;
+}
+
+// static
+BUILTIN(ErrorCaptureStackTrace) {
+  HandleScope scope(isolate);
+  Handle<Object> object_obj = args.atOrUndefined(isolate, 1);
+  if (!object_obj->IsJSObject()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kInvalidArgument, object_obj));
+  }
+  Handle<JSObject> object = Handle<JSObject>::cast(object_obj);
+  Handle<Object> caller = args.atOrUndefined(isolate, 2);
+
+  // TODO(jgruber): Eagerly format the stack trace and remove accessors.h
+  // include.
+
+  // Handle writes to the global object.
+
+  if (object->IsJSGlobalProxy()) {
+    Map* map = object->map();
+    if (map->has_hidden_prototype()) {
+      object = handle(JSGlobalObject::cast(map->prototype()), isolate);
+    }
+  }
+
+  // Check if the stack property is read-only.
+
+  bool is_extensible = true;
+  if (!JSObject::IsExtensible(object)) {
+    is_extensible = false;
+  }
+
+  PropertyDescriptor desc;
+  Maybe<bool> owned = JSReceiver::GetOwnPropertyDescriptor(
+      isolate, object, isolate->factory()->stack_string(), &desc);
+  if (owned.FromMaybe(false)) {
+    if (!desc.configurable() || !desc.writable()) {
+      is_extensible = false;
+    }
+  }
+
+  if (!is_extensible) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kDefineDisallowed,
+                              isolate->factory()->stack_string(), object));
+  }
+
+  // Add stack accessors to the given object
+
+  Handle<Map> map(object->map());
+  PropertyAttributes attribs = DONT_ENUM;
+  Handle<AccessorInfo> error_stack =
+      Accessors::ErrorStackInfo(isolate, attribs);
+  {
+    AccessorConstantDescriptor d(Handle<Name>(Name::cast(error_stack->name())),
+                                 error_stack, attribs);
+    Handle<DescriptorArray> old_descriptors(map->instance_descriptors());
+    int index = old_descriptors->SearchWithCache(isolate, *d.GetKey(), *map);
+    if (index == DescriptorArray::kNotFound) {
+      // TODO(jgruber): This ensures we do not crash when CaptureStackTrace is
+      // called on an object with an existing "stack" property. This will be
+      // removed as soon as we move to eager trace formatting.
+      Handle<Map> new_map =
+          Map::CopyInsertDescriptor(map, &d, INSERT_TRANSITION);
+      JSObject::MigrateToMap(object, new_map, 1);
+    }
+  }
+
+  // Collect the stack trace.
+
+  RETURN_FAILURE_ON_EXCEPTION(isolate,
+                              isolate->CaptureAndSetDetailedStackTrace(object));
+  RETURN_FAILURE_ON_EXCEPTION(
+      isolate, isolate->CaptureAndSetSimpleStackTrace(object, caller));
+
+  return *isolate->factory()->undefined_value();
+}
+
+namespace {
+
+MaybeHandle<String> GetStringPropertyOrDefault(Isolate* isolate,
+                                               Handle<JSReceiver> recv,
+                                               Handle<String> key,
+                                               Handle<String> default_str) {
+  Handle<Object> obj;
+  ASSIGN_RETURN_ON_EXCEPTION(isolate, obj, JSObject::GetProperty(recv, key),
+                             String);
+
+  Handle<String> str;
+  if (obj->IsUndefined(isolate)) {
+    str = default_str;
+  } else {
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, str, Object::ToString(isolate, obj),
+                               String);
+  }
+
+  return str;
+}
+
+}  // namespace
+
+// ES6 section 19.5.3.4 Error.prototype.toString ( )
+BUILTIN(ErrorPrototypeToString) {
+  HandleScope scope(isolate);
+
+  // 1. Let O be the this value.
+  // 2. If Type(O) is not Object, throw a TypeError exception.
+  CHECK_RECEIVER(JSReceiver, receiver, "Error.prototype.toString");
+
+  // 3. Let name be ? Get(O, "name").
+  // 4. If name is undefined, let name be "Error"; otherwise let name be
+  // ? ToString(name).
+  Handle<String> name_key = isolate->factory()->name_string();
+  Handle<String> name_default = isolate->factory()->Error_string();
+  Handle<String> name;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, name,
+      GetStringPropertyOrDefault(isolate, receiver, name_key, name_default));
+
+  // 5. Let msg be ? Get(O, "message").
+  // 6. If msg is undefined, let msg be the empty String; otherwise let msg be
+  // ? ToString(msg).
+  Handle<String> msg_key = isolate->factory()->message_string();
+  Handle<String> msg_default = isolate->factory()->empty_string();
+  Handle<String> msg;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, msg,
+      GetStringPropertyOrDefault(isolate, receiver, msg_key, msg_default));
+
+  // 7. If name is the empty String, return msg.
+  // 8. If msg is the empty String, return name.
+  if (name->length() == 0) return *msg;
+  if (msg->length() == 0) return *name;
+
+  // 9. Return the result of concatenating name, the code unit 0x003A (COLON),
+  // the code unit 0x0020 (SPACE), and msg.
+  IncrementalStringBuilder builder(isolate);
+  builder.AppendString(name);
+  builder.AppendCString(": ");
+  builder.AppendString(msg);
+  RETURN_RESULT_OR_FAILURE(isolate, builder.Finish());
+}
+
+}  // namespace internal
+}  // namespace v8