1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/Vector.h>
29
30namespace JSC {
31
32class JSCell;
33class JSGlobalObject;
34class JSObject;
35class PropertySlot;
36class Structure;
37
38class PolyProtoAccessChain {
39 WTF_MAKE_FAST_ALLOCATED;
40
41public:
42 PolyProtoAccessChain(PolyProtoAccessChain&) = default;
43
44 // Returns nullptr when invalid.
45 static std::unique_ptr<PolyProtoAccessChain> create(JSGlobalObject*, JSCell* base, const PropertySlot&);
46 static std::unique_ptr<PolyProtoAccessChain> create(JSGlobalObject*, JSCell* base, JSObject* target);
47
48 std::unique_ptr<PolyProtoAccessChain> clone()
49 {
50 return makeUnique<PolyProtoAccessChain>(*this);
51 }
52
53 const Vector<Structure*>& chain() const { return m_chain; }
54
55 void dump(Structure* baseStructure, PrintStream& out) const;
56
57 bool operator==(const PolyProtoAccessChain& other) const;
58 bool operator!=(const PolyProtoAccessChain& other) const
59 {
60 return !(*this == other);
61 }
62
63 bool needImpurePropertyWatchpoint() const;
64
65 template <typename Func>
66 void forEach(Structure* baseStructure, const Func& func) const
67 {
68 bool atEnd = !m_chain.size();
69 func(baseStructure, atEnd);
70 for (unsigned i = 0; i < m_chain.size(); ++i) {
71 atEnd = i + 1 == m_chain.size();
72 func(m_chain[i], atEnd);
73 }
74 }
75
76 Structure* slotBaseStructure(Structure* baseStructure) const
77 {
78 if (m_chain.size())
79 return m_chain.last();
80 return baseStructure;
81 }
82
83private:
84 PolyProtoAccessChain() = default;
85
86 // This does not include the base. We rely on AccessCase providing it for us. That said, this data
87 // structure is tied to the base that it was created with.
88 Vector<Structure*> m_chain;
89};
90
91}
92