source: webkit/trunk/JavaScriptCore/kjs/SymbolTable.h@ 34424

Last change on this file since 34424 was 33979, checked in by [email protected], 17 years ago

Merge squirrelfish branch into trunk.
  • Property svn:eol-style set to native
File size: 4.0 KB
Line 
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 "object.h"
33#include "ustring.h"
34#include <wtf/AlwaysInline.h>
35
36namespace KJS {
37
38 struct IdentifierRepHash : PtrHash<RefPtr<UString::Rep> > {
39 static unsigned hash(const RefPtr<UString::Rep>& key) { return key->computedHash(); }
40 static unsigned hash(UString::Rep* key) { return key->computedHash(); }
41 };
42
43 static ALWAYS_INLINE int missingSymbolMarker() { return std::numeric_limits<int>::max(); }
44
45 struct SymbolTableEntry {
46 SymbolTableEntry()
47 : rawValue(0)
48 {
49 }
50
51 SymbolTableEntry(int index)
52 {
53 rawValue = index & ~0x80000000 & ~0x40000000;
54 }
55
56 SymbolTableEntry(int index, unsigned attributes)
57 {
58 rawValue = index;
59
60 if (!(attributes & ReadOnly))
61 rawValue &= ~0x80000000;
62
63 if (!(attributes & DontEnum))
64 rawValue &= ~0x40000000;
65 }
66
67 bool isEmpty() const
68 {
69 return rawValue == 0;
70 }
71
72 int getIndex() const
73 {
74 // Every register index we store is negative, so this bit twiddling works correctly
75 return rawValue | 0x80000000 | 0x40000000;
76 }
77
78 unsigned getAttributes() const
79 {
80 unsigned attributes = 0;
81
82 if (rawValue & 0x80000000)
83 attributes |= ReadOnly;
84
85 if (rawValue & 0x40000000)
86 attributes |= DontEnum;
87
88 return attributes;
89 }
90
91 void setAttributes(unsigned attributes)
92 {
93 rawValue = getIndex();
94
95 if (!(attributes & ReadOnly))
96 rawValue &= ~0x80000000;
97
98 if (!(attributes & DontEnum))
99 rawValue &= ~0x40000000;
100 }
101
102 bool isReadOnly() const
103 {
104 return rawValue & 0x80000000;
105 }
106
107 int rawValue;
108 };
109
110 struct SymbolTableIndexHashTraits {
111 typedef SymbolTableEntry TraitType;
112 static SymbolTableEntry emptyValue() { return SymbolTableEntry(); }
113 static const bool emptyValueIsZero = false;
114 static const bool needsDestruction = false;
115 };
116
117 typedef HashMap<RefPtr<UString::Rep>, SymbolTableEntry, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, SymbolTableIndexHashTraits> SymbolTable;
118
119} // namespace KJS
120
121#endif // SymbolTable_h
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