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
|
/*
* Copyright (C) 2013, 2014 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
#if ENABLE(DFG_JIT)
#include "DFGCommon.h"
#include "DFGFrozenValue.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(FrozenValue* value = FrozenValue::emptySingleton())
: m_kind(KnownValue)
{
u.value = 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;
}
FrozenValue* tryGetValue(Graph&) const
{
if (m_kind == KnownValue)
return value();
return nullptr;
}
JSValue getValue(VM&) const;
FrozenValue* value() const
{
ASSERT(m_kind == KnownValue);
return 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;
uintptr_t switchLookupValue(SwitchKind) const;
void dump(PrintStream&) const;
void dumpInContext(PrintStream&, DumpContext*) const;
private:
union {
FrozenValue* value;
UChar character;
StringImpl* stringImpl;
} u;
LazinessKind m_kind;
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
#endif // DFGLazyJSValue_h
|
