runtime/Arguments.cpp

   1 /*
   2  *  Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
   3  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
   4  *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
   5  *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)
   6  *  Copyright (C) 2007 Maks Orlovich
   7  *
   8  *  This library is free software; you can redistribute it and/or
   9  *  modify it under the terms of the GNU Library General Public
  10  *  License as published by the Free Software Foundation; either
  11  *  version 2 of the License, or (at your option) any later version.
  12  *
  13  *  This library is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  Library General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU Library General Public License
  19  *  along with this library; see the file COPYING.LIB.  If not, write to
  20  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  *  Boston, MA 02110-1301, USA.
  22  *
  23  */
  24
  25 #include "config.h"
  26 #include "Arguments.h"
  27
  28 #include "JSActivation.h"
  29 #include "JSFunction.h"
  30 #include "JSGlobalObject.h"
  31
  32 using namespace std;
  33
  34 namespace JSC {
  35
  36 ASSERT_CLASS_FITS_IN_CELL(Arguments);
  37
  38 const ClassInfo Arguments::s_info = { "Arguments", &JSNonFinalObject::s_info, 0, 0 };
  39
  40 Arguments::~Arguments()
  41 {
  42     if (d->extraArguments != d->extraArgumentsFixedBuffer)
  43         delete [] d->extraArguments;
  44 }
  45
  46 void Arguments::visitChildren(SlotVisitor& visitor)
  47 {
  48     ASSERT_GC_OBJECT_INHERITS(this, &s_info);
  49     COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
  50     ASSERT(structure()->typeInfo().overridesVisitChildren());
  51     JSObject::visitChildren(visitor);
  52
  53     if (d->registerArray)
  54         visitor.appendValues(d->registerArray.get(), d->numParameters);
  55
  56     if (d->extraArguments) {
  57         unsigned numExtraArguments = d->numArguments - d->numParameters;
  58         visitor.appendValues(d->extraArguments, numExtraArguments);
  59     }
  60
  61     visitor.append(&d->callee);
  62
  63     if (d->activation)
  64         visitor.append(&d->activation);
  65 }
  66
  67 void Arguments::copyToRegisters(ExecState* exec, Register* buffer, uint32_t maxSize)
  68 {
  69     if (UNLIKELY(d->overrodeLength)) {
  70         unsigned length = min(get(exec, exec->propertyNames().length).toUInt32(exec), maxSize);
  71         for (unsigned i = 0; i < length; i++)
  72             buffer[i] = get(exec, i);
  73         return;
  74     }
  75
  76     if (LIKELY(!d->deletedArguments)) {
  77         unsigned parametersLength = min(min(d->numParameters, d->numArguments), maxSize);
  78         unsigned i = 0;
  79         for (; i < parametersLength; ++i)
  80             buffer[i] = d->registers[d->firstParameterIndex + i].get();
  81         for (; i < d->numArguments; ++i)
  82             buffer[i] = d->extraArguments[i - d->numParameters].get();
  83         return;
  84     }
  85
  86     unsigned parametersLength = min(min(d->numParameters, d->numArguments), maxSize);
  87     unsigned i = 0;
  88     for (; i < parametersLength; ++i) {
  89         if (!d->deletedArguments[i])
  90             buffer[i] = d->registers[d->firstParameterIndex + i].get();
  91         else
  92             buffer[i] = get(exec, i);
  93     }
  94     for (; i < d->numArguments; ++i) {
  95         if (!d->deletedArguments[i])
  96             buffer[i] = d->extraArguments[i - d->numParameters].get();
  97         else
  98             buffer[i] = get(exec, i);
  99     }
 100 }
 101
 102 void Arguments::fillArgList(ExecState* exec, MarkedArgumentBuffer& args)
 103 {
 104     if (UNLIKELY(d->overrodeLength)) {
 105         unsigned length = get(exec, exec->propertyNames().length).toUInt32(exec);
 106         for (unsigned i = 0; i < length; i++)
 107             args.append(get(exec, i));
 108         return;
 109     }
 110
 111     if (LIKELY(!d->deletedArguments)) {
 112         if (LIKELY(!d->numParameters)) {
 113             args.initialize(d->extraArguments, d->numArguments);
 114             return;
 115         }
 116
 117         if (d->numParameters == d->numArguments) {
 118             args.initialize(&d->registers[d->firstParameterIndex], d->numArguments);
 119             return;
 120         }
 121
 122         unsigned parametersLength = min(d->numParameters, d->numArguments);
 123         unsigned i = 0;
 124         for (; i < parametersLength; ++i)
 125             args.append(d->registers[d->firstParameterIndex + i].get());
 126         for (; i < d->numArguments; ++i)
 127             args.append(d->extraArguments[i - d->numParameters].get());
 128         return;
 129     }
 130
 131     unsigned parametersLength = min(d->numParameters, d->numArguments);
 132     unsigned i = 0;
 133     for (; i < parametersLength; ++i) {
 134         if (!d->deletedArguments[i])
 135             args.append(d->registers[d->firstParameterIndex + i].get());
 136         else
 137             args.append(get(exec, i));
 138     }
 139     for (; i < d->numArguments; ++i) {
 140         if (!d->deletedArguments[i])
 141             args.append(d->extraArguments[i - d->numParameters].get());
 142         else
 143             args.append(get(exec, i));
 144     }
 145 }
 146
 147 bool Arguments::getOwnPropertySlot(ExecState* exec, unsigned i, PropertySlot& slot)
 148 {
 149     if (i < d->numArguments && (!d->deletedArguments || !d->deletedArguments[i])) {
 150         if (i < d->numParameters) {
 151             slot.setValue(d->registers[d->firstParameterIndex + i].get());
 152         } else
 153             slot.setValue(d->extraArguments[i - d->numParameters].get());
 154         return true;
 155     }
 156
 157     return JSObject::getOwnPropertySlot(exec, Identifier(exec, UString::number(i)), slot);
 158 }
 159
 160 void Arguments::createStrictModeCallerIfNecessary(ExecState* exec)
 161 {
 162     if (d->overrodeCaller)
 163         return;
 164
 165     d->overrodeCaller = true;
 166     PropertyDescriptor descriptor;
 167     JSValue thrower = createTypeErrorFunction(exec, "Unable to access caller of strict mode function");
 168     descriptor.setAccessorDescriptor(thrower, thrower, DontEnum | DontDelete | Getter | Setter);
 169     defineOwnProperty(exec, exec->propertyNames().caller, descriptor, false);
 170 }
 171
 172 void Arguments::createStrictModeCalleeIfNecessary(ExecState* exec)
 173 {
 174     if (d->overrodeCallee)
 175         return;
 176
 177     d->overrodeCallee = true;
 178     PropertyDescriptor descriptor;
 179     JSValue thrower = createTypeErrorFunction(exec, "Unable to access callee of strict mode function");
 180     descriptor.setAccessorDescriptor(thrower, thrower, DontEnum | DontDelete | Getter | Setter);
 181     defineOwnProperty(exec, exec->propertyNames().callee, descriptor, false);
 182 }
 183
 184 bool Arguments::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
 185 {
 186     bool isArrayIndex;
 187     unsigned i = propertyName.toArrayIndex(isArrayIndex);
 188     if (isArrayIndex && i < d->numArguments && (!d->deletedArguments || !d->deletedArguments[i])) {
 189         if (i < d->numParameters) {
 190             slot.setValue(d->registers[d->firstParameterIndex + i].get());
 191         } else
 192             slot.setValue(d->extraArguments[i - d->numParameters].get());
 193         return true;
 194     }
 195
 196     if (propertyName == exec->propertyNames().length && LIKELY(!d->overrodeLength)) {
 197         slot.setValue(jsNumber(d->numArguments));
 198         return true;
 199     }
 200
 201     if (propertyName == exec->propertyNames().callee && LIKELY(!d->overrodeCallee)) {
 202         if (!d->isStrictMode) {
 203             slot.setValue(d->callee.get());
 204             return true;
 205         }
 206         createStrictModeCalleeIfNecessary(exec);
 207     }
 208
 209     if (propertyName == exec->propertyNames().caller && d->isStrictMode)
 210         createStrictModeCallerIfNecessary(exec);
 211
 212     return JSObject::getOwnPropertySlot(exec, propertyName, slot);
 213 }
 214
 215 bool Arguments::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
 216 {
 217     bool isArrayIndex;
 218     unsigned i = propertyName.toArrayIndex(isArrayIndex);
 219     if (isArrayIndex && i < d->numArguments && (!d->deletedArguments || !d->deletedArguments[i])) {
 220         if (i < d->numParameters) {
 221             descriptor.setDescriptor(d->registers[d->firstParameterIndex + i].get(), DontEnum);
 222         } else
 223             descriptor.setDescriptor(d->extraArguments[i - d->numParameters].get(), DontEnum);
 224         return true;
 225     }
 226
 227     if (propertyName == exec->propertyNames().length && LIKELY(!d->overrodeLength)) {
 228         descriptor.setDescriptor(jsNumber(d->numArguments), DontEnum);
 229         return true;
 230     }
 231
 232     if (propertyName == exec->propertyNames().callee && LIKELY(!d->overrodeCallee)) {
 233         if (!d->isStrictMode) {
 234             descriptor.setDescriptor(d->callee.get(), DontEnum);
 235             return true;
 236         }
 237         createStrictModeCalleeIfNecessary(exec);
 238     }
 239
 240     if (propertyName == exec->propertyNames().caller && d->isStrictMode)
 241         createStrictModeCallerIfNecessary(exec);
 242
 243     return JSObject::getOwnPropertyDescriptor(exec, propertyName, descriptor);
 244 }
 245
 246 void Arguments::getOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 247 {
 248     if (mode == IncludeDontEnumProperties) {
 249         for (unsigned i = 0; i < d->numArguments; ++i) {
 250             if (!d->deletedArguments || !d->deletedArguments[i])
 251                 propertyNames.add(Identifier(exec, UString::number(i)));
 252         }
 253         propertyNames.add(exec->propertyNames().callee);
 254         propertyNames.add(exec->propertyNames().length);
 255     }
 256     JSObject::getOwnPropertyNames(exec, propertyNames, mode);
 257 }
 258
 259 void Arguments::put(ExecState* exec, unsigned i, JSValue value)
 260 {
 261     if (i < d->numArguments && (!d->deletedArguments || !d->deletedArguments[i])) {
 262         if (i < d->numParameters)
 263             d->registers[d->firstParameterIndex + i].set(exec->globalData(), d->activation ? static_cast<JSCell*>(d->activation.get()) : static_cast<JSCell*>(this), value);
 264         else
 265             d->extraArguments[i - d->numParameters].set(exec->globalData(), this, value);
 266         return;
 267     }
 268
 269     PutPropertySlot slot;
 270     JSObject::put(exec, Identifier(exec, UString::number(i)), value, slot);
 271 }
 272
 273 void Arguments::put(ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
 274 {
 275     bool isArrayIndex;
 276     unsigned i = propertyName.toArrayIndex(isArrayIndex);
 277     if (isArrayIndex && i < d->numArguments && (!d->deletedArguments || !d->deletedArguments[i])) {
 278         if (i < d->numParameters)
 279             d->registers[d->firstParameterIndex + i].set(exec->globalData(), d->activation ? static_cast<JSCell*>(d->activation.get()) : static_cast<JSCell*>(this), value);
 280         else
 281             d->extraArguments[i - d->numParameters].set(exec->globalData(), this, value);
 282         return;
 283     }
 284
 285     if (propertyName == exec->propertyNames().length && !d->overrodeLength) {
 286         d->overrodeLength = true;
 287         putDirect(exec->globalData(), propertyName, value, DontEnum);
 288         return;
 289     }
 290
 291     if (propertyName == exec->propertyNames().callee && !d->overrodeCallee) {
 292         if (!d->isStrictMode) {
 293             d->overrodeCallee = true;
 294             putDirect(exec->globalData(), propertyName, value, DontEnum);
 295             return;
 296         }
 297         createStrictModeCalleeIfNecessary(exec);
 298     }
 299
 300     if (propertyName == exec->propertyNames().caller && d->isStrictMode)
 301         createStrictModeCallerIfNecessary(exec);
 302
 303     JSObject::put(exec, propertyName, value, slot);
 304 }
 305
 306 bool Arguments::deleteProperty(ExecState* exec, unsigned i)
 307 {
 308     if (i < d->numArguments) {
 309         if (!d->deletedArguments) {
 310             d->deletedArguments = adoptArrayPtr(new bool[d->numArguments]);
 311             memset(d->deletedArguments.get(), 0, sizeof(bool) * d->numArguments);
 312         }
 313         if (!d->deletedArguments[i]) {
 314             d->deletedArguments[i] = true;
 315             return true;
 316         }
 317     }
 318
 319     return JSObject::deleteProperty(exec, Identifier(exec, UString::number(i)));
 320 }
 321
 322 bool Arguments::deleteProperty(ExecState* exec, const Identifier& propertyName)
 323 {
 324     bool isArrayIndex;
 325     unsigned i = propertyName.toArrayIndex(isArrayIndex);
 326     if (isArrayIndex && i < d->numArguments) {
 327         if (!d->deletedArguments) {
 328             d->deletedArguments = adoptArrayPtr(new bool[d->numArguments]);
 329             memset(d->deletedArguments.get(), 0, sizeof(bool) * d->numArguments);
 330         }
 331         if (!d->deletedArguments[i]) {
 332             d->deletedArguments[i] = true;
 333             return true;
 334         }
 335     }
 336
 337     if (propertyName == exec->propertyNames().length && !d->overrodeLength) {
 338         d->overrodeLength = true;
 339         return true;
 340     }
 341
 342     if (propertyName == exec->propertyNames().callee && !d->overrodeCallee) {
 343         if (!d->isStrictMode) {
 344             d->overrodeCallee = true;
 345             return true;
 346         }
 347         createStrictModeCalleeIfNecessary(exec);
 348     }
 349
 350     if (propertyName == exec->propertyNames().caller && !d->isStrictMode)
 351         createStrictModeCallerIfNecessary(exec);
 352
 353     return JSObject::deleteProperty(exec, propertyName);
 354 }
 355
 356 } // namespace JSC