1/*
2 * Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
3 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
4 * Copyright (C) 2003, 2007, 2008 Apple Inc. All rights reserved.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public License
17 * along with this library; see the file COPYING.LIB. If not, write to
18 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 *
21 */
22
23#include "config.h"
24#include "JSCell.h"
25
26#include "JSFunction.h"
27#include "JSString.h"
28#include "JSObject.h"
29#include <wtf/MathExtras.h>
30
31namespace JSC {
32
33#if defined NAN && defined INFINITY
34
35extern const double NaN = NAN;
36extern const double Inf = INFINITY;
37
38#else // !(defined NAN && defined INFINITY)
39
40// The trick is to define the NaN and Inf globals with a different type than the declaration.
41// This trick works because the mangled name of the globals does not include the type, although
42// I'm not sure that's guaranteed. There could be alignment issues with this, since arrays of
43// characters don't necessarily need the same alignment doubles do, but for now it seems to work.
44// It would be good to figure out a 100% clean way that still avoids code that runs at init time.
45
46// Note, we have to use union to ensure alignment. Otherwise, NaN_Bytes can start anywhere,
47// while NaN_double has to be 4-byte aligned for 32-bits.
48// With -fstrict-aliasing enabled, unions are the only safe way to do type masquerading.
49
50static const union {
51 struct {
52 unsigned char NaN_Bytes[8];
53 unsigned char Inf_Bytes[8];
54 } bytes;
55
56 struct {
57 double NaN_Double;
58 double Inf_Double;
59 } doubles;
60
61} NaNInf = { {
62#if CPU(BIG_ENDIAN)
63 { 0x7f, 0xf8, 0, 0, 0, 0, 0, 0 },
64 { 0x7f, 0xf0, 0, 0, 0, 0, 0, 0 }
65#elif CPU(MIDDLE_ENDIAN)
66 { 0, 0, 0xf8, 0x7f, 0, 0, 0, 0 },
67 { 0, 0, 0xf0, 0x7f, 0, 0, 0, 0 }
68#else
69 { 0, 0, 0, 0, 0, 0, 0xf8, 0x7f },
70 { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }
71#endif
72} } ;
73
74extern const double NaN = NaNInf.doubles.NaN_Double;
75extern const double Inf = NaNInf.doubles.Inf_Double;
76
77#endif // !(defined NAN && defined INFINITY)
78
79bool JSCell::getUInt32(uint32_t&) const
80{
81 return false;
82}
83
84bool JSCell::getString(ExecState* exec, UString&stringValue) const
85{
86 if (!isString())
87 return false;
88 stringValue = static_cast<const JSString*>(this)->value(exec);
89 return true;
90}
91
92UString JSCell::getString(ExecState* exec) const
93{
94 return isString() ? static_cast<const JSString*>(this)->value(exec) : UString();
95}
96
97JSObject* JSCell::getObject()
98{
99 return isObject() ? asObject(cell: this) : 0;
100}
101
102const JSObject* JSCell::getObject() const
103{
104 return isObject() ? static_cast<const JSObject*>(this) : 0;
105}
106
107CallType JSCell::getCallData(CallData&)
108{
109 return CallTypeNone;
110}
111
112ConstructType JSCell::getConstructData(ConstructData&)
113{
114 return ConstructTypeNone;
115}
116
117bool JSCell::getOwnPropertySlot(ExecState* exec, const Identifier& identifier, PropertySlot& slot)
118{
119 // This is not a general purpose implementation of getOwnPropertySlot.
120 // It should only be called by JSValue::get.
121 // It calls getPropertySlot, not getOwnPropertySlot.
122 JSObject* object = toObject(exec);
123 slot.setBase(object);
124 if (!object->getPropertySlot(exec, propertyName: identifier, slot))
125 slot.setUndefined();
126 return true;
127}
128
129bool JSCell::getOwnPropertySlot(ExecState* exec, unsigned identifier, PropertySlot& slot)
130{
131 // This is not a general purpose implementation of getOwnPropertySlot.
132 // It should only be called by JSValue::get.
133 // It calls getPropertySlot, not getOwnPropertySlot.
134 JSObject* object = toObject(exec);
135 slot.setBase(object);
136 if (!object->getPropertySlot(exec, propertyName: identifier, slot))
137 slot.setUndefined();
138 return true;
139}
140
141void JSCell::put(ExecState* exec, const Identifier& identifier, JSValue value, PutPropertySlot& slot)
142{
143 toObject(exec)->put(exec, propertyName: identifier, value, slot);
144}
145
146void JSCell::put(ExecState* exec, unsigned identifier, JSValue value)
147{
148 toObject(exec)->put(exec, propertyName: identifier, value);
149}
150
151bool JSCell::deleteProperty(ExecState* exec, const Identifier& identifier)
152{
153 return toObject(exec)->deleteProperty(exec, propertyName: identifier);
154}
155
156bool JSCell::deleteProperty(ExecState* exec, unsigned identifier)
157{
158 return toObject(exec)->deleteProperty(exec, propertyName: identifier);
159}
160
161JSObject* JSCell::toThisObject(ExecState* exec) const
162{
163 return toObject(exec);
164}
165
166UString JSCell::toThisString(ExecState* exec) const
167{
168 return toThisObject(exec)->toString(exec);
169}
170
171JSString* JSCell::toThisJSString(ExecState* exec)
172{
173 return jsString(exec, s: toThisString(exec));
174}
175
176const ClassInfo* JSCell::classInfo() const
177{
178 return 0;
179}
180
181JSValue JSCell::getJSNumber()
182{
183 return JSValue();
184}
185
186bool JSCell::isGetterSetter() const
187{
188 return false;
189}
190
191JSValue JSCell::toPrimitive(ExecState*, PreferredPrimitiveType) const
192{
193 ASSERT_NOT_REACHED();
194 return JSValue();
195}
196
197bool JSCell::getPrimitiveNumber(ExecState*, double&, JSValue&)
198{
199 ASSERT_NOT_REACHED();
200 return false;
201}
202
203bool JSCell::toBoolean(ExecState*) const
204{
205 ASSERT_NOT_REACHED();
206 return false;
207}
208
209double JSCell::toNumber(ExecState*) const
210{
211 ASSERT_NOT_REACHED();
212 return 0;
213}
214
215UString JSCell::toString(ExecState*) const
216{
217 ASSERT_NOT_REACHED();
218 return UString();
219}
220
221JSObject* JSCell::toObject(ExecState*) const
222{
223 ASSERT_NOT_REACHED();
224 return 0;
225}
226
227} // namespace JSC
228

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/runtime/JSCell.cpp