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 21 namespace 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. 25 namespace internal { 26 27 template <typename T> 28 struct 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 45 template <typename Params> 46 struct ParamsUseScopedRefptrCorrectly { 47 enum { value = 0 }; 48 }; 49 50 template <> 51 struct ParamsUseScopedRefptrCorrectly<Tuple0> { 52 enum { value = 1 }; 53 }; 54 55 template <typename A> 56 struct ParamsUseScopedRefptrCorrectly<Tuple1<A> > { 57 enum { value = !NeedsScopedRefptrButGetsRawPtr<A>::value }; 58 }; 59 60 template <typename A, typename B> 61 struct ParamsUseScopedRefptrCorrectly<Tuple2<A, B> > { 62 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 63 NeedsScopedRefptrButGetsRawPtr<B>::value) }; 64 }; 65 66 template <typename A, typename B, typename C> 67 struct ParamsUseScopedRefptrCorrectly<Tuple3<A, B, C> > { 68 enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value || 69 NeedsScopedRefptrButGetsRawPtr<B>::value || 70 NeedsScopedRefptrButGetsRawPtr<C>::value) }; 71 }; 72 73 template <typename A, typename B, typename C, typename D> 74 struct 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 81 template <typename A, typename B, typename C, typename D, typename E> 82 struct 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 90 template <typename A, typename B, typename C, typename D, typename E, 91 typename F> 92 struct 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 }; 100 101 template <typename A, typename B, typename C, typename D, typename E, 102 typename F, typename G> 103 struct 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 }; 112 113 template <typename A, typename B, typename C, typename D, typename E, 114 typename F, typename G, typename H> 115 struct 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