gin/object_template_builder.cc

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gin/object_template_builder.h"

#include <stdint.h>

#include <string_view>

#include "gin/interceptor.h"
#include "gin/per_isolate_data.h"
#include "gin/public/wrapper_info.h"
#include "v8/include/v8-exception.h"
#include "v8/include/v8-template.h"

namespace gin {

namespace {

WrappableBase* WrappableFromV8(v8::Isolate* isolate,
                               v8::Local<v8::Value> val) {
  if (!val->IsObject()) {
    return nullptr;
  }
  v8::Local<v8::Object> obj = v8::Local<v8::Object>::Cast(val);
  WrapperInfo* info = WrapperInfo::From(obj);

  // If this fails, the object is not managed by Gin.
  if (!info) {
    return nullptr;
  }

  // We don't further validate the type of the object, but assume it's derived
  // from WrappableBase. We look up the pointer in a global registry, to make
  // sure it's actually pointed to a valid life object.
  return static_cast<WrappableBase*>(
      obj->GetAlignedPointerFromInternalField(kEncodedValueIndex));
}

NamedPropertyInterceptor* NamedInterceptorFromV8(v8::Isolate* isolate,
                                                 v8::Local<v8::Value> val) {
  WrappableBase* base = WrappableFromV8(isolate, val);
  if (!base) {
    return nullptr;
  }
  return PerIsolateData::From(isolate)->GetNamedPropertyInterceptor(base);
}

IndexedPropertyInterceptor* IndexedInterceptorFromV8(
    v8::Isolate* isolate,
    v8::Local<v8::Value> val) {
  WrappableBase* base = WrappableFromV8(isolate, val);
  if (!base) {
    return nullptr;
  }
  return PerIsolateData::From(isolate)->GetIndexedPropertyInterceptor(base);
}

v8::Intercepted NamedPropertyGetter(
    v8::Local<v8::Name> property,
    const v8::PropertyCallbackInfo<v8::Value>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  NamedPropertyInterceptor* interceptor =
      NamedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return v8::Intercepted::kNo;
  }

  std::string name;
  ConvertFromV8(isolate, property, &name);
  v8::Local<v8::Value> result = interceptor->GetNamedProperty(isolate, name);
  if (!result.IsEmpty()) {
    info.GetReturnValue().SetNonEmpty(result);
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

v8::Intercepted NamedPropertySetter(
    v8::Local<v8::Name> property,
    v8::Local<v8::Value> value,
    const v8::PropertyCallbackInfo<void>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  NamedPropertyInterceptor* interceptor =
      NamedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return v8::Intercepted::kNo;
  }
  std::string name;
  ConvertFromV8(isolate, property, &name);
  if (interceptor->SetNamedProperty(isolate, name, value)) {
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

v8::Intercepted NamedPropertyQuery(
    v8::Local<v8::Name> property,
    const v8::PropertyCallbackInfo<v8::Integer>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  NamedPropertyInterceptor* interceptor =
      NamedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return v8::Intercepted::kNo;
  }
  std::string name;
  ConvertFromV8(isolate, property, &name);
  if (!interceptor->GetNamedProperty(isolate, name).IsEmpty()) {
    info.GetReturnValue().Set(v8::None);
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

void NamedPropertyEnumerator(const v8::PropertyCallbackInfo<v8::Array>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  NamedPropertyInterceptor* interceptor =
      NamedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return;
  }
  v8::Local<v8::Value> properties;
  if (!TryConvertToV8(isolate, interceptor->EnumerateNamedProperties(isolate),
                      &properties)) {
    return;
  }
  info.GetReturnValue().Set(v8::Local<v8::Array>::Cast(properties));
}

v8::Intercepted IndexedPropertyQuery(
    uint32_t index,
    const v8::PropertyCallbackInfo<v8::Integer>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  IndexedPropertyInterceptor* interceptor =
      IndexedInterceptorFromV8(isolate, info.Holder());
  if (interceptor &&
      !interceptor->GetIndexedProperty(isolate, index).IsEmpty()) {
    info.GetReturnValue().Set(v8::None);
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

v8::Intercepted IndexedPropertyGetter(
    uint32_t index,
    const v8::PropertyCallbackInfo<v8::Value>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  IndexedPropertyInterceptor* interceptor =
      IndexedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return v8::Intercepted::kNo;
  }
  v8::Local<v8::Value> result = interceptor->GetIndexedProperty(isolate, index);
  if (!result.IsEmpty()) {
    info.GetReturnValue().SetNonEmpty(result);
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

v8::Intercepted IndexedPropertySetter(
    uint32_t index,
    v8::Local<v8::Value> value,
    const v8::PropertyCallbackInfo<void>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  IndexedPropertyInterceptor* interceptor =
      IndexedInterceptorFromV8(isolate, info.Holder());
  if (interceptor && interceptor->SetIndexedProperty(isolate, index, value)) {
    return v8::Intercepted::kYes;
  }
  return v8::Intercepted::kNo;
}

void IndexedPropertyEnumerator(
    const v8::PropertyCallbackInfo<v8::Array>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  IndexedPropertyInterceptor* interceptor =
      IndexedInterceptorFromV8(isolate, info.Holder());
  if (!interceptor) {
    return;
  }
  v8::Local<v8::Value> properties;
  if (!TryConvertToV8(isolate, interceptor->EnumerateIndexedProperties(isolate),
                      &properties)) {
    return;
  }
  info.GetReturnValue().Set(v8::Local<v8::Array>::Cast(properties));
}

void Constructor(const v8::FunctionCallbackInfo<v8::Value>& info) {
  v8::Isolate* isolate = info.GetIsolate();
  isolate->ThrowException(v8::Exception::Error(info.Data().As<v8::String>()));
}

}  // namespace

ObjectTemplateBuilder::ObjectTemplateBuilder(v8::Isolate* isolate)
    : ObjectTemplateBuilder(isolate, nullptr) {}

ObjectTemplateBuilder::ObjectTemplateBuilder(v8::Isolate* isolate,
                                             const char* type_name)
    : isolate_(isolate),
      type_name_(type_name),
      constructor_template_(v8::FunctionTemplate::New(
          isolate,
          &Constructor,
          StringToV8(
              isolate,
              type_name
                  ? base::StrCat({"Objects of type ", type_name,
                                  " cannot be created using the constructor."})
                  : "Objects of this type cannot be created using the "
                    "constructor"))),
      template_(constructor_template_->InstanceTemplate()) {
  template_->SetInternalFieldCount(kNumberOfInternalFields);
}

ObjectTemplateBuilder::ObjectTemplateBuilder(
    const ObjectTemplateBuilder& other) = default;

ObjectTemplateBuilder::~ObjectTemplateBuilder() = default;

ObjectTemplateBuilder& ObjectTemplateBuilder::AddNamedPropertyInterceptor() {
  template_->SetHandler(v8::NamedPropertyHandlerConfiguration(
      &NamedPropertyGetter, &NamedPropertySetter, &NamedPropertyQuery, nullptr,
      &NamedPropertyEnumerator, v8::Local<v8::Value>(),
      v8::PropertyHandlerFlags::kOnlyInterceptStrings));
  return *this;
}

ObjectTemplateBuilder& ObjectTemplateBuilder::AddIndexedPropertyInterceptor() {
  template_->SetHandler(v8::IndexedPropertyHandlerConfiguration(
      &IndexedPropertyGetter, &IndexedPropertySetter, &IndexedPropertyQuery,
      nullptr, &IndexedPropertyEnumerator, v8::Local<v8::Value>()));
  return *this;
}

ObjectTemplateBuilder& ObjectTemplateBuilder::SetImpl(
    const std::string_view& name,
    v8::Local<v8::Data> val) {
  template_->Set(StringToSymbol(isolate_, name), val);
  return *this;
}

ObjectTemplateBuilder& ObjectTemplateBuilder::SetImpl(v8::Local<v8::Name> name,
                                                      v8::Local<v8::Data> val) {
  template_->Set(name, val);
  return *this;
}

ObjectTemplateBuilder& ObjectTemplateBuilder::SetPropertyImpl(
    const std::string_view& name,
    v8::Local<v8::FunctionTemplate> getter,
    v8::Local<v8::FunctionTemplate> setter) {
  template_->SetAccessorProperty(StringToSymbol(isolate_, name), getter,
                                 setter);
  return *this;
}

ObjectTemplateBuilder& ObjectTemplateBuilder::SetLazyDataPropertyImpl(
    const std::string_view& name,
    v8::AccessorNameGetterCallback callback,
    v8::Local<v8::Value> data) {
  template_->SetLazyDataProperty(StringToSymbol(isolate_, name), callback,
                                 data);
  return *this;
}

v8::Local<v8::ObjectTemplate> ObjectTemplateBuilder::Build() {
  v8::Local<v8::ObjectTemplate> result = template_;
  template_.Clear();
  constructor_template_.Clear();
  return result;
}

}  // namespace gin