1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DFGLazyJSValue_h
#define DFGLazyJSValue_h
#include <wtf/Platform.h>
#if ENABLE(DFG_JIT)
#include "JSCJSValue.h"
#include <wtf/text/StringImpl.h>
namespace JSC { namespace DFG {
// Represents either a JSValue, or for JSValues that require allocation in the heap,
// it tells you everything you'd need to know in order to allocate it.
enum LazinessKind {
KnownValue,
SingleCharacterString,
KnownStringImpl
};
class LazyJSValue {
public:
LazyJSValue(JSValue value = JSValue())
: m_kind(KnownValue)
{
u.value = JSValue::encode(value);
}
static LazyJSValue singleCharacterString(UChar character)
{
LazyJSValue result;
result.m_kind = SingleCharacterString;
result.u.character = character;
return result;
}
static LazyJSValue knownStringImpl(StringImpl* string)
{
LazyJSValue result;
result.m_kind = KnownStringImpl;
result.u.stringImpl = string;
return result;
}
JSValue tryGetValue() const
{
if (m_kind == KnownValue)
return value();
return JSValue();
}
JSValue getValue(VM&) const;
JSValue value() const
{
ASSERT(m_kind == KnownValue);
return JSValue::decode(u.value);
}
UChar character() const
{
ASSERT(m_kind == SingleCharacterString);
return u.character;
}
StringImpl* stringImpl() const
{
ASSERT(m_kind == KnownStringImpl);
return u.stringImpl;
}
TriState strictEqual(const LazyJSValue& other) const;
unsigned switchLookupValue() const
{
// NB. Not every kind of JSValue will be able to give you a switch lookup
// value, and this method will assert, or do bad things, if you use it
// for a kind of value that can't.
switch (m_kind) {
case KnownValue:
return value().asInt32();
case SingleCharacterString:
return character();
default:
RELEASE_ASSERT_NOT_REACHED();
return 0;
}
}
void dump(PrintStream&) const;
void dumpInContext(PrintStream&, DumpContext*) const;
private:
union {
EncodedJSValue value;
UChar character;
StringImpl* stringImpl;
} u;
LazinessKind m_kind;
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
#endif // DFGLazyJSValue_h
|
