0
|
1 |
/*
|
|
2 |
* Copyright (C) 2007, 2008 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 |
*
|
|
8 |
* 1. Redistributions of source code must retain the above copyright
|
|
9 |
* notice, this list of conditions and the following disclaimer.
|
|
10 |
* 2. Redistributions in binary form must reproduce the above copyright
|
|
11 |
* notice, this list of conditions and the following disclaimer in the
|
|
12 |
* documentation and/or other materials provided with the distribution.
|
|
13 |
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
|
|
14 |
* its contributors may be used to endorse or promote products derived
|
|
15 |
* from this software without specific prior written permission.
|
|
16 |
*
|
|
17 |
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
|
|
18 |
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
19 |
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
20 |
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
|
|
21 |
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
22 |
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
23 |
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
24 |
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
25 |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
26 |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
27 |
*/
|
|
28 |
|
|
29 |
#ifndef SymbolTable_h
|
|
30 |
#define SymbolTable_h
|
|
31 |
|
|
32 |
#include "JSObject.h"
|
|
33 |
#include "UString.h"
|
|
34 |
#include <wtf/AlwaysInline.h>
|
|
35 |
|
|
36 |
namespace JSC {
|
|
37 |
|
|
38 |
static ALWAYS_INLINE int missingSymbolMarker() { return std::numeric_limits<int>::max(); }
|
|
39 |
|
|
40 |
// The bit twiddling in this class assumes that every register index is a
|
|
41 |
// reasonably small positive or negative number, and therefore has its high
|
|
42 |
// four bits all set or all unset.
|
|
43 |
|
|
44 |
struct SymbolTableEntry {
|
|
45 |
SymbolTableEntry()
|
|
46 |
: m_bits(0)
|
|
47 |
{
|
|
48 |
}
|
|
49 |
|
|
50 |
SymbolTableEntry(int index)
|
|
51 |
{
|
|
52 |
ASSERT(isValidIndex(index));
|
|
53 |
pack(index, false, false);
|
|
54 |
}
|
|
55 |
|
|
56 |
SymbolTableEntry(int index, unsigned attributes)
|
|
57 |
{
|
|
58 |
ASSERT(isValidIndex(index));
|
|
59 |
pack(index, attributes & ReadOnly, attributes & DontEnum);
|
|
60 |
}
|
|
61 |
|
|
62 |
bool isNull() const
|
|
63 |
{
|
|
64 |
return !m_bits;
|
|
65 |
}
|
|
66 |
|
|
67 |
int getIndex() const
|
|
68 |
{
|
|
69 |
return m_bits >> FlagBits;
|
|
70 |
}
|
|
71 |
|
|
72 |
unsigned getAttributes() const
|
|
73 |
{
|
|
74 |
unsigned attributes = 0;
|
|
75 |
if (m_bits & ReadOnlyFlag)
|
|
76 |
attributes |= ReadOnly;
|
|
77 |
if (m_bits & DontEnumFlag)
|
|
78 |
attributes |= DontEnum;
|
|
79 |
return attributes;
|
|
80 |
}
|
|
81 |
|
|
82 |
void setAttributes(unsigned attributes)
|
|
83 |
{
|
|
84 |
pack(getIndex(), attributes & ReadOnly, attributes & DontEnum);
|
|
85 |
}
|
|
86 |
|
|
87 |
bool isReadOnly() const
|
|
88 |
{
|
|
89 |
return m_bits & ReadOnlyFlag;
|
|
90 |
}
|
|
91 |
|
|
92 |
private:
|
|
93 |
static const unsigned ReadOnlyFlag = 0x1;
|
|
94 |
static const unsigned DontEnumFlag = 0x2;
|
|
95 |
static const unsigned NotNullFlag = 0x4;
|
|
96 |
static const unsigned FlagBits = 3;
|
|
97 |
|
|
98 |
void pack(int index, bool readOnly, bool dontEnum)
|
|
99 |
{
|
|
100 |
m_bits = (index << FlagBits) | NotNullFlag;
|
|
101 |
if (readOnly)
|
|
102 |
m_bits |= ReadOnlyFlag;
|
|
103 |
if (dontEnum)
|
|
104 |
m_bits |= DontEnumFlag;
|
|
105 |
}
|
|
106 |
|
|
107 |
bool isValidIndex(int index)
|
|
108 |
{
|
|
109 |
return ((index << FlagBits) >> FlagBits) == index;
|
|
110 |
}
|
|
111 |
|
|
112 |
int m_bits;
|
|
113 |
};
|
|
114 |
|
|
115 |
struct SymbolTableIndexHashTraits {
|
|
116 |
typedef SymbolTableEntry TraitType;
|
|
117 |
static SymbolTableEntry emptyValue() { return SymbolTableEntry(); }
|
|
118 |
static const bool emptyValueIsZero = true;
|
|
119 |
static const bool needsDestruction = false;
|
|
120 |
};
|
|
121 |
|
|
122 |
typedef HashMap<RefPtr<UString::Rep>, SymbolTableEntry, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, SymbolTableIndexHashTraits> SymbolTable;
|
|
123 |
|
|
124 |
class SharedSymbolTable : public SymbolTable, public RefCounted<SharedSymbolTable>
|
|
125 |
{
|
|
126 |
};
|
|
127 |
|
|
128 |
} // namespace JSC
|
|
129 |
|
|
130 |
#endif // SymbolTable_h
|