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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2003, 2007, 2008 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "JSValue.h"
#include "BooleanConstructor.h"
#include "BooleanPrototype.h"
#include "Error.h"
#include "ExceptionHelpers.h"
#include "JSGlobalObject.h"
#include "JSFunction.h"
#include "JSNotAnObject.h"
#include "NumberObject.h"
#include <wtf/MathExtras.h>
#include <wtf/StringExtras.h>
namespace JSC {
static const double D32 = 4294967296.0;
// ECMA 9.4
double JSValue::toInteger(ExecState* exec) const
{
if (isInt32())
return asInt32();
double d = toNumber(exec);
return isnan(d) ? 0.0 : trunc(d);
}
double JSValue::toIntegerPreserveNaN(ExecState* exec) const
{
if (isInt32())
return asInt32();
return trunc(toNumber(exec));
}
JSObject* JSValue::toObjectSlowCase(ExecState* exec) const
{
ASSERT(!isCell());
if (isInt32() || isDouble())
return constructNumber(exec, asValue());
if (isTrue() || isFalse())
return constructBooleanFromImmediateBoolean(exec, asValue());
ASSERT(isUndefinedOrNull());
JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
throwError(exec, exception);
return new (exec) JSNotAnObject(exec, exception);
}
JSObject* JSValue::toThisObjectSlowCase(ExecState* exec) const
{
ASSERT(!isCell());
if (isInt32() || isDouble())
return constructNumber(exec, asValue());
if (isTrue() || isFalse())
return constructBooleanFromImmediateBoolean(exec, asValue());
ASSERT(isUndefinedOrNull());
return exec->globalThisValue();
}
JSObject* JSValue::synthesizeObject(ExecState* exec) const
{
ASSERT(!isCell());
if (isNumber())
return constructNumber(exec, asValue());
if (isBoolean())
return constructBooleanFromImmediateBoolean(exec, asValue());
JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
throwError(exec, exception);
return new (exec) JSNotAnObject(exec, exception);
}
JSObject* JSValue::synthesizePrototype(ExecState* exec) const
{
ASSERT(!isCell());
if (isNumber())
return exec->lexicalGlobalObject()->numberPrototype();
if (isBoolean())
return exec->lexicalGlobalObject()->booleanPrototype();
JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
throwError(exec, exception);
return new (exec) JSNotAnObject(exec, exception);
}
#ifndef NDEBUG
char* JSValue::description()
{
static const size_t size = 32;
static char description[size];
if (!*this)
snprintf(description, size, "<JSValue()>");
else if (isInt32())
snprintf(description, size, "Int32: %d", asInt32());
else if (isDouble())
snprintf(description, size, "Double: %lf", asDouble());
else if (isCell())
snprintf(description, size, "Cell: %p", asCell());
else if (isTrue())
snprintf(description, size, "True");
else if (isFalse())
snprintf(description, size, "False");
else if (isNull())
snprintf(description, size, "Null");
else if (isUndefined())
snprintf(description, size, "Undefined");
else
snprintf(description, size, "INVALID");
return description;
}
#endif
// This in the ToInt32 operation is defined in section 9.5 of the ECMA-262 spec.
// Note that this operation is identical to ToUInt32 other than to interpretation
// of the resulting bit-pattern (as such this metod is also called to implement
// ToUInt32).
//
// The operation can be descibed as round towards zero, then select the 32 least
// bits of the resulting value in 2s-complement representation.
int32_t toInt32(double number)
{
int64_t bits = WTF::bitwise_cast<int64_t>(number);
int32_t exp = (static_cast<int32_t>(bits >> 52) & 0x7ff) - 0x3ff;
// If exponent < 0 there will be no bits to the left of the decimal point
// after rounding; if the exponent is > 83 then no bits of precision can be
// left in the low 32-bit range of the result (IEEE-754 doubles have 52 bits
// of fractional precision).
// Note this case handles 0, -0, and all infinte, NaN, & denormal value.
if (exp < 0 || exp > 83)
return 0;
// Select the appropriate 32-bits from the floating point mantissa. If the
// exponent is 52 then the bits we need to select are already aligned to the
// lowest bits of the 64-bit integer representation of tghe number, no need
// to shift. If the exponent is greater than 52 we need to shift the value
// left by (exp - 52), if the value is less than 52 we need to shift right
// accordingly.
int32_t result = (exp > 52)
? static_cast<int32_t>(bits << (exp - 52))
: static_cast<int32_t>(bits >> (52 - exp));
// IEEE-754 double precision values are stored omitting an implicit 1 before
// the decimal point; we need to reinsert this now. We may also the shifted
// invalid bits into the result that are not a part of the mantissa (the sign
// and exponent bits from the floatingpoint representation); mask these out.
if (exp < 32) {
int32_t missingOne = 1 << exp;
result &= missingOne - 1;
result += missingOne;
}
// If the input value was negative (we could test either 'number' or 'bits',
// but testing 'bits' is likely faster) invert the result appropriately.
return bits < 0 ? -result : result;
}
NEVER_INLINE double nonInlineNaN()
{
#if OS(SYMBIAN)
return nanval();
#else
return std::numeric_limits<double>::quiet_NaN();
#endif
}
bool JSValue::isValidCallee()
{
return asObject(asObject(asCell())->getAnonymousValue(0))->isGlobalObject();
}
} // namespace JSC
|
