gecko-dev/xpcom/components/ModuleUtils.h

82 строки
4.2 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_GenericModule_h
#define mozilla_GenericModule_h
#include <type_traits>
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Attributes.h"
#include "mozilla/Module.h"
#define NS_GENERIC_FACTORY_CONSTRUCTOR(_InstanceClass) \
static nsresult _InstanceClass##Constructor(REFNSIID aIID, void** aResult) { \
RefPtr<_InstanceClass> inst; \
\
*aResult = nullptr; \
\
inst = new _InstanceClass(); \
return inst->QueryInterface(aIID, aResult); \
}
#define NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(_InstanceClass, _InitMethod) \
static nsresult _InstanceClass##Constructor(REFNSIID aIID, void** aResult) { \
nsresult rv; \
\
RefPtr<_InstanceClass> inst; \
\
*aResult = nullptr; \
\
inst = new _InstanceClass(); \
rv = inst->_InitMethod(); \
if (NS_SUCCEEDED(rv)) { \
rv = inst->QueryInterface(aIID, aResult); \
} \
\
return rv; \
}
namespace mozilla {
namespace detail {
template <typename T>
struct RemoveAlreadyAddRefed {
using Type = T;
};
template <typename T>
struct RemoveAlreadyAddRefed<already_AddRefed<T>> {
using Type = T;
};
} // namespace detail
} // namespace mozilla
// 'Constructor' that uses an existing getter function that gets a singleton.
#define NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(_InstanceClass, _GetterProc) \
static nsresult _InstanceClass##Constructor(REFNSIID aIID, void** aResult) { \
RefPtr<_InstanceClass> inst; \
\
*aResult = nullptr; \
\
using T = \
mozilla::detail::RemoveAlreadyAddRefed<decltype(_GetterProc())>::Type; \
static_assert( \
std::is_same_v<already_AddRefed<T>, decltype(_GetterProc())>, \
"Singleton constructor must return already_AddRefed"); \
static_assert( \
std::is_base_of<_InstanceClass, T>::value, \
"Singleton constructor must return correct already_AddRefed"); \
inst = _GetterProc(); \
if (nullptr == inst) { \
return NS_ERROR_OUT_OF_MEMORY; \
} \
return inst->QueryInterface(aIID, aResult); \
}
#endif // mozilla_GenericModule_h