runtime/JSValue.cpp

   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 "JSValue.h"
  25
  26 #include "BooleanConstructor.h"
  27 #include "BooleanPrototype.h"
  28 #include "ExceptionHelpers.h"
  29 #include "JSGlobalObject.h"
  30 #include "JSFunction.h"
  31 #include "JSNotAnObject.h"
  32 #include "NumberObject.h"
  33 #include <wtf/MathExtras.h>
  34 #include <wtf/StringExtras.h>
  35
  36 namespace JSC {
  37
  38 static const double D32 = 4294967296.0;
  39
  40 // ECMA 9.4
  41 double JSValue::toInteger(ExecState* exec) const
  42 {
  43     if (isInt32())
  44         return asInt32();
  45     double d = toNumber(exec);
  46     return isnan(d) ? 0.0 : trunc(d);
  47 }
  48
  49 double JSValue::toIntegerPreserveNaN(ExecState* exec) const
  50 {
  51     if (isInt32())
  52         return asInt32();
  53     return trunc(toNumber(exec));
  54 }
  55
  56 JSObject* JSValue::toObjectSlowCase(ExecState* exec) const
  57 {
  58     ASSERT(!isCell());
  59
  60     if (isInt32() || isDouble())
  61         return constructNumber(exec, asValue());
  62     if (isTrue() || isFalse())
  63         return constructBooleanFromImmediateBoolean(exec, asValue());
  64     ASSERT(isUndefinedOrNull());
  65     JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
  66     exec->setException(exception);
  67     return new (exec) JSNotAnObject(exec, exception);
  68 }
  69
  70 JSObject* JSValue::toThisObjectSlowCase(ExecState* exec) const
  71 {
  72     ASSERT(!isCell());
  73
  74     if (isInt32() || isDouble())
  75         return constructNumber(exec, asValue());
  76     if (isTrue() || isFalse())
  77         return constructBooleanFromImmediateBoolean(exec, asValue());
  78     ASSERT(isUndefinedOrNull());
  79     return exec->globalThisValue();
  80 }
  81
  82 JSObject* JSValue::synthesizeObject(ExecState* exec) const
  83 {
  84     ASSERT(!isCell());
  85     if (isNumber())
  86         return constructNumber(exec, asValue());
  87     if (isBoolean())
  88         return constructBooleanFromImmediateBoolean(exec, asValue());
  89
  90     JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
  91     exec->setException(exception);
  92     return new (exec) JSNotAnObject(exec, exception);
  93 }
  94
  95 JSObject* JSValue::synthesizePrototype(ExecState* exec) const
  96 {
  97     ASSERT(!isCell());
  98     if (isNumber())
  99         return exec->lexicalGlobalObject()->numberPrototype();
 100     if (isBoolean())
 101         return exec->lexicalGlobalObject()->booleanPrototype();
 102
 103     JSNotAnObjectErrorStub* exception = createNotAnObjectErrorStub(exec, isNull());
 104     exec->setException(exception);
 105     return new (exec) JSNotAnObject(exec, exception);
 106 }
 107
 108 #ifndef NDEBUG
 109 char* JSValue::description()
 110 {
 111     static const size_t size = 32;
 112     static char description[size];
 113
 114     if (!*this)
 115         snprintf(description, size, "<JSValue()>");
 116     else if (isInt32())
 117         snprintf(description, size, "Int32: %d", asInt32());
 118     else if (isDouble())
 119         snprintf(description, size, "Double: %lf", asDouble());
 120     else if (isCell())
 121         snprintf(description, size, "Cell: %p", asCell());
 122     else if (isTrue())
 123         snprintf(description, size, "True");
 124     else if (isFalse())
 125         snprintf(description, size, "False");
 126     else if (isNull())
 127         snprintf(description, size, "Null");
 128     else {
 129         ASSERT(isUndefined());
 130         snprintf(description, size, "Undefined");
 131     }
 132
 133     return description;
 134 }
 135 #endif
 136
 137 int32_t toInt32SlowCase(double d, bool& ok)
 138 {
 139     ok = true;
 140
 141     if (d >= -D32 / 2 && d < D32 / 2)
 142         return static_cast<int32_t>(d);
 143
 144     if (isnan(d) || isinf(d)) {
 145         ok = false;
 146         return 0;
 147     }
 148
 149     double d32 = fmod(trunc(d), D32);
 150     if (d32 >= D32 / 2)
 151         d32 -= D32;
 152     else if (d32 < -D32 / 2)
 153         d32 += D32;
 154     return static_cast<int32_t>(d32);
 155 }
 156
 157 uint32_t toUInt32SlowCase(double d, bool& ok)
 158 {
 159     ok = true;
 160
 161     if (d >= 0.0 && d < D32)
 162         return static_cast<uint32_t>(d);
 163
 164     if (isnan(d) || isinf(d)) {
 165         ok = false;
 166         return 0;
 167     }
 168
 169     double d32 = fmod(trunc(d), D32);
 170     if (d32 < 0)
 171         d32 += D32;
 172     return static_cast<uint32_t>(d32);
 173 }
 174
 175 NEVER_INLINE double nonInlineNaN()
 176 {
 177 #if OS(SYMBIAN)
 178     return nanval();
 179 #else
 180     return std::numeric_limits<double>::quiet_NaN();
 181 #endif
 182 }
 183
 184 } // namespace JSC