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