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Diffstat (limited to 'xpcom/components/ModuleUtils.h')
| -rw-r--r-- | xpcom/components/ModuleUtils.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/xpcom/components/ModuleUtils.h b/xpcom/components/ModuleUtils.h new file mode 100644 index 0000000000..92ec8aa173 --- /dev/null +++ b/xpcom/components/ModuleUtils.h @@ -0,0 +1,81 @@ +/* -*- 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 |