1/*
2 * Copyright (C) 2018 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 "ConcurrentJSLock.h"
29#include "ICStatusMap.h"
30#include "InstanceOfVariant.h"
31#include "StubInfoSummary.h"
32
33namespace JSC {
34
35class AccessCase;
36class CodeBlock;
37class StructureStubInfo;
38
39class InstanceOfStatus {
40public:
41 enum State {
42 // It's uncached so we have no information.
43 NoInformation,
44
45 // It's cached in a simple way.
46 Simple,
47
48 // It's known to often take slow path.
49 TakesSlowPath
50 };
51
52 InstanceOfStatus()
53 : m_state(NoInformation)
54 {
55 }
56
57 InstanceOfStatus(State state)
58 : m_state(state)
59 {
60 ASSERT(state == NoInformation || state == TakesSlowPath);
61 }
62
63 explicit InstanceOfStatus(StubInfoSummary summary)
64 {
65 switch (summary) {
66 case StubInfoSummary::NoInformation:
67 m_state = NoInformation;
68 return;
69 case StubInfoSummary::Simple:
70 case StubInfoSummary::MakesCalls:
71 RELEASE_ASSERT_NOT_REACHED();
72 return;
73 case StubInfoSummary::TakesSlowPath:
74 case StubInfoSummary::TakesSlowPathAndMakesCalls:
75 m_state = TakesSlowPath;
76 return;
77 }
78 RELEASE_ASSERT_NOT_REACHED();
79 }
80
81 static InstanceOfStatus computeFor(CodeBlock*, ICStatusMap&, unsigned bytecodeIndex);
82
83#if ENABLE(DFG_JIT)
84 static InstanceOfStatus computeForStubInfo(const ConcurrentJSLocker&, StructureStubInfo*);
85#endif
86
87 State state() const { return m_state; }
88
89 bool isSet() const { return m_state != NoInformation; }
90 explicit operator bool() const { return isSet(); }
91
92 bool isSimple() const { return m_state == Simple; }
93 bool takesSlowPath() const { return m_state == TakesSlowPath; }
94
95 JSObject* commonPrototype() const;
96
97 size_t numVariants() const { return m_variants.size(); }
98 const Vector<InstanceOfVariant, 2>& variants() const { return m_variants; }
99 const InstanceOfVariant& at(size_t index) const { return m_variants[index]; }
100 const InstanceOfVariant& operator[](size_t index) const { return at(index); }
101
102 void filter(const StructureSet&);
103
104 void dump(PrintStream&) const;
105
106private:
107 void appendVariant(const InstanceOfVariant&);
108
109 State m_state;
110 Vector<InstanceOfVariant, 2> m_variants;
111};
112
113} // namespace JSC
114
115