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()
67 {
68 ++linkingData().refCount;
69 }
70
71 void deref()
72 {
73 unsigned tempRefCount = linkingData().refCount - 1;
74 if (!tempRefCount) {
75 MetadataTable::destroy(this);
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
91private:
92 MetadataTable(UnlinkedMetadataTable&);
93
94 UnlinkedMetadataTable::Offset16* offsetTable16() const { return bitwise_cast<UnlinkedMetadataTable::Offset16*>(this); }
95 UnlinkedMetadataTable::Offset32* offsetTable32() const { return bitwise_cast<UnlinkedMetadataTable::Offset32*>(bitwise_cast<uint8_t*>(this) + UnlinkedMetadataTable::s_offset16TableSize); }
96
97 size_t totalSize() const
98 {
99 return getOffset(UnlinkedMetadataTable::s_offsetTableEntries - 1);
100 }
101
102 UnlinkedMetadataTable::LinkingData& linkingData() const
103 {
104 return *bitwise_cast<UnlinkedMetadataTable::LinkingData*>((bitwise_cast<uint8_t*>(this) - sizeof(UnlinkedMetadataTable::LinkingData)));
105 }
106
107 void* buffer() { return this; }
108
109 bool is32Bit() const { return !offsetTable16()[0]; }
110
111 ALWAYS_INLINE unsigned getOffset(unsigned i) const
112 {
113 unsigned offset = offsetTable16()[i];
114 if (offset)
115 return offset;
116 return offsetTable32()[i];
117 }
118
119 ALWAYS_INLINE uint8_t* getImpl(unsigned i)
120 {
121 return bitwise_cast<uint8_t*>(this) + getOffset(i);
122 }
123
124 static void destroy(MetadataTable*);
125};
126
127} // namespace JSC
128