| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ |
| #define BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ |
| |
| #include <tuple> |
| #include <type_traits> |
| |
| #include "base/memory/ref_counted.h" |
| |
| // It is dangerous to post a task with a T* argument where T is a subtype of |
| // RefCounted(Base|ThreadSafeBase), since by the time the parameter is used, the |
| // object may already have been deleted since it was not held with a |
| // scoped_refptr. Example: http://crbug.com/27191 |
| // The following set of traits are designed to generate a compile error |
| // whenever this antipattern is attempted. |
| |
| namespace base { |
| |
| // This is a base internal implementation file used by task.h and callback.h. |
| // Not for public consumption, so we wrap it in namespace internal. |
| namespace internal { |
| |
| template <typename T> |
| struct NeedsScopedRefptrButGetsRawPtr { |
| enum { |
| // Human readable translation: you needed to be a scoped_refptr if you are a |
| // raw pointer type and are convertible to a RefCounted(Base|ThreadSafeBase) |
| // type. |
| value = (std::is_pointer<T>::value && |
| (std::is_convertible<T, subtle::RefCountedBase*>::value || |
| std::is_convertible<T, subtle::RefCountedThreadSafeBase*>::value)) |
| }; |
| }; |
| |
| template <typename Params> |
| struct ParamsUseScopedRefptrCorrectly { |
| enum { value = 0 }; |
| }; |
| |
| template <> |
| struct ParamsUseScopedRefptrCorrectly<std::tuple<>> { |
| enum { value = 1 }; |
| }; |
| |
| template <typename Head, typename... Tail> |
| struct ParamsUseScopedRefptrCorrectly<std::tuple<Head, Tail...>> { |
| enum { value = !NeedsScopedRefptrButGetsRawPtr<Head>::value && |
| ParamsUseScopedRefptrCorrectly<std::tuple<Tail...>>::value }; |
| }; |
| |
| } // namespace internal |
| |
| } // namespace base |
| |
| #endif // BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ |
