1// Copyright (c) 2011 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ 6#define BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ 7#pragma once 8 9#include "base/memory/ref_counted.h" 10#include "base/template_util.h" 11#include "base/tuple.h" 12#include "build/build_config.h" 13 14// It is dangerous to post a task with a T* argument where T is a subtype of 15// RefCounted(Base|ThreadSafeBase), since by the time the parameter is used, the 16// object may already have been deleted since it was not held with a 17// scoped_refptr. Example: http://crbug.com/27191 18// The following set of traits are designed to generate a compile error 19// whenever this antipattern is attempted. 20 21namespace base { 22 23// This is a base internal implementation file used by task.h and callback.h. 24// Not for public consumption, so we wrap it in namespace internal. 25namespace internal { 26 27template <typename T> 28struct NeedsScopedRefptrButGetsRawPtr { 29#if defined(OS_WIN) 30 enum { 31 value = base::false_type::value 32 }; 33#else 34 enum { 35 // Human readable translation: you needed to be a scoped_refptr if you are a 36 // raw pointer type and are convertible to a RefCounted(Base|ThreadSafeBase) 37 // type. 38 value = (is_pointer<T>::value && 39 (is_convertible<T, subtle::RefCountedBase*>::value || 40 is_convertible<T, subtle::RefCountedThreadSafeBase*>::value)) 41 }; 42#endif 43}; 44 45template <typename Params> 46struct ParamsUseScopedRefptrCorrectly { 47 enum { value = 0 }; 48}; 49 50template <> 51struct ParamsUseScopedRefptrCorrectly<Tuple0> { 52 enum { value = 1 }; 53}; 54 55template <typename A> 56struct ParamsUseScopedRefptrCorrectly<Tuple1<A> > { 57 enum { value = !NeedsScopedRefptrButGetsRawPtr<A>::value }; 58}; 59 60template <typename A, typename B> 61struct ParamsUseScopedRefptrCorrectly<Tuple2<A, B> > { 62 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 63 NeedsScopedRefptrButGetsRawPtr<B>::value) }; 64}; 65 66template <typename A, typename B, typename C> 67struct ParamsUseScopedRefptrCorrectly<Tuple3<A, B, C> > { 68 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 69 NeedsScopedRefptrButGetsRawPtr<B>::value || 70 NeedsScopedRefptrButGetsRawPtr<C>::value) }; 71}; 72 73template <typename A, typename B, typename C, typename D> 74struct ParamsUseScopedRefptrCorrectly<Tuple4<A, B, C, D> > { 75 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 76 NeedsScopedRefptrButGetsRawPtr<B>::value || 77 NeedsScopedRefptrButGetsRawPtr<C>::value || 78 NeedsScopedRefptrButGetsRawPtr<D>::value) }; 79}; 80 81template <typename A, typename B, typename C, typename D, typename E> 82struct ParamsUseScopedRefptrCorrectly<Tuple5<A, B, C, D, E> > { 83 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 84 NeedsScopedRefptrButGetsRawPtr<B>::value || 85 NeedsScopedRefptrButGetsRawPtr<C>::value || 86 NeedsScopedRefptrButGetsRawPtr<D>::value || 87 NeedsScopedRefptrButGetsRawPtr<E>::value) }; 88}; 89 90template <typename A, typename B, typename C, typename D, typename E, 91 typename F> 92struct ParamsUseScopedRefptrCorrectly<Tuple6<A, B, C, D, E, F> > { 93 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 94 NeedsScopedRefptrButGetsRawPtr<B>::value || 95 NeedsScopedRefptrButGetsRawPtr<C>::value || 96 NeedsScopedRefptrButGetsRawPtr<D>::value || 97 NeedsScopedRefptrButGetsRawPtr<E>::value || 98 NeedsScopedRefptrButGetsRawPtr<F>::value) }; 99}; 100 101template <typename A, typename B, typename C, typename D, typename E, 102 typename F, typename G> 103struct ParamsUseScopedRefptrCorrectly<Tuple7<A, B, C, D, E, F, G> > { 104 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 105 NeedsScopedRefptrButGetsRawPtr<B>::value || 106 NeedsScopedRefptrButGetsRawPtr<C>::value || 107 NeedsScopedRefptrButGetsRawPtr<D>::value || 108 NeedsScopedRefptrButGetsRawPtr<E>::value || 109 NeedsScopedRefptrButGetsRawPtr<F>::value || 110 NeedsScopedRefptrButGetsRawPtr<G>::value) }; 111}; 112 113template <typename A, typename B, typename C, typename D, typename E, 114 typename F, typename G, typename H> 115struct ParamsUseScopedRefptrCorrectly<Tuple8<A, B, C, D, E, F, G, H> > { 116 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 117 NeedsScopedRefptrButGetsRawPtr<B>::value || 118 NeedsScopedRefptrButGetsRawPtr<C>::value || 119 NeedsScopedRefptrButGetsRawPtr<D>::value || 120 NeedsScopedRefptrButGetsRawPtr<E>::value || 121 NeedsScopedRefptrButGetsRawPtr<F>::value || 122 NeedsScopedRefptrButGetsRawPtr<G>::value || 123 NeedsScopedRefptrButGetsRawPtr<H>::value) }; 124}; 125 126} // namespace internal 127 128} // namespace base 129 130#endif // BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_ 131