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 "Instruction.h"
29#include "Opcode.h"
30#include "UnlinkedMetadataTable.h"
31#include <wtf/RefCounted.h>
32
33namespace JSC {
34
35class CodeBlock;
36
37// MetadataTable has a bit strange memory layout for LLInt optimization.
38// [UnlinkedMetadataTable::LinkingData][MetadataTable]
39// ^
40// The pointer of MetadataTable points at this address.
41class MetadataTable {
42 WTF_MAKE_FAST_ALLOCATED;
43 WTF_MAKE_NONCOPYABLE(MetadataTable);
44 friend class LLIntOffsetsExtractor;
45 friend class UnlinkedMetadataTable;
46public:
47 ~MetadataTable();
48
49 ALWAYS_INLINE Instruction::Metadata* get(OpcodeID opcodeID)
50 {
51 ASSERT(opcodeID < NUMBER_OF_BYTECODE_WITH_METADATA);
52 return reinterpret_cast<Instruction::Metadata*>(getImpl(opcodeID));
53 }
54
55 template<typename Op, typename Functor>
56 ALWAYS_INLINE void forEach(const Functor& func)
57 {
58 auto* metadata = bitwise_cast<typename Op::Metadata*>(get(Op::opcodeID));
59 auto* end = bitwise_cast<typename Op::Metadata*>(getImpl(Op::opcodeID + 1));
60 for (; metadata + 1 <= end; ++metadata)
61 func(*metadata);
62 }
63
64 size_t sizeInBytes();
65
66 void ref() const
67 {
68 ++linkingData().refCount;
69 }
70
71 void deref() const
72 {
73 unsigned tempRefCount = linkingData().refCount - 1;
74 if (!tempRefCount) {
75 this->~MetadataTable();
76 return;
77 }
78 linkingData().refCount = tempRefCount;
79 }
80
81 unsigned refCount() const
82 {
83 return linkingData().refCount;
84 }
85
86 unsigned hasOneRef() const
87 {
88 return refCount() == 1;
89 }
90
91 UnlinkedMetadataTable::Offset* buffer()
92 {
93 return bitwise_cast<UnlinkedMetadataTable::Offset*>(this);
94 }
95
96private:
97 MetadataTable(UnlinkedMetadataTable&);
98
99 UnlinkedMetadataTable::LinkingData& linkingData() const
100 {
101 return *bitwise_cast<UnlinkedMetadataTable::LinkingData*>((bitwise_cast<uint8_t*>(this) - sizeof(UnlinkedMetadataTable::LinkingData)));
102 }
103
104 ALWAYS_INLINE uint8_t* getImpl(unsigned i)
105 {
106 return bitwise_cast<uint8_t*>(this) + buffer()[i];
107 }
108};
109
110} // namespace JSC
111