runtime/JSFunction.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 "JSFunction.h"
  27
  28 #include "CodeBlock.h"
  29 #include "CommonIdentifiers.h"
  30 #include "CallFrame.h"
  31 #include "ExceptionHelpers.h"
  32 #include "FunctionPrototype.h"
  33 #include "GetterSetter.h"
  34 #include "JSArray.h"
  35 #include "JSGlobalObject.h"
  36 #include "JSNotAnObject.h"
  37 #include "Interpreter.h"
  38 #include "ObjectPrototype.h"
  39 #include "Parser.h"
  40 #include "PropertyNameArray.h"
  41 #include "ScopeChainMark.h"
  42
  43 using namespace WTF;
  44 using namespace Unicode;
  45
  46 namespace JSC {
  47 EncodedJSValue JSC_HOST_CALL callHostFunctionAsConstructor(ExecState* exec)
  48 {
  49     return throwVMError(exec, createNotAConstructorError(exec, exec->callee()));
  50 }
  51
  52 ASSERT_CLASS_FITS_IN_CELL(JSFunction);
  53 ASSERT_HAS_TRIVIAL_DESTRUCTOR(JSFunction);
  54
  55 const ClassInfo JSFunction::s_info = { "Function", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(JSFunction) };
  56
  57 bool JSFunction::isHostFunctionNonInline() const
  58 {
  59     return isHostFunction();
  60 }
  61
  62 JSFunction* JSFunction::create(ExecState* exec, JSGlobalObject* globalObject, int length, const Identifier& name, NativeFunction nativeFunction, Intrinsic intrinsic, NativeFunction nativeConstructor)
  63 {
  64     NativeExecutable* executable;
  65 #if !ENABLE(JIT)
  66     UNUSED_PARAM(intrinsic);
  67 #else
  68     if (intrinsic != NoIntrinsic && exec->globalData().canUseJIT()) {
  69         ASSERT(nativeConstructor == callHostFunctionAsConstructor);
  70         executable = exec->globalData().getHostFunction(nativeFunction, intrinsic);
  71     } else
  72 #endif
  73         executable = exec->globalData().getHostFunction(nativeFunction, nativeConstructor);
  74
  75     JSFunction* function = new (NotNull, allocateCell<JSFunction>(*exec->heap())) JSFunction(exec, globalObject, globalObject->functionStructure());
  76     // Can't do this during initialization because getHostFunction might do a GC allocation.
  77     function->finishCreation(exec, executable, length, name);
  78     return function;
  79 }
  80
  81 JSFunction::JSFunction(ExecState* exec, JSGlobalObject* globalObject, Structure* structure)
  82     : Base(exec->globalData(), structure)
  83     , m_executable()
  84     , m_scopeChain(exec->globalData(), this, globalObject->globalScopeChain())
  85 {
  86 }
  87
  88 JSFunction::JSFunction(ExecState* exec, FunctionExecutable* executable, ScopeChainNode* scopeChainNode)
  89     : Base(exec->globalData(), scopeChainNode->globalObject->functionStructure())
  90     , m_executable(exec->globalData(), this, executable)
  91     , m_scopeChain(exec->globalData(), this, scopeChainNode)
  92 {
  93 }
  94
  95 void JSFunction::finishCreation(ExecState* exec, NativeExecutable* executable, int length, const Identifier& name)
  96 {
  97     Base::finishCreation(exec->globalData());
  98     ASSERT(inherits(&s_info));
  99     m_executable.set(exec->globalData(), this, executable);
 100     putDirect(exec->globalData(), exec->globalData().propertyNames->name, jsString(exec, name.isNull() ? "" : name.ustring()), DontDelete | ReadOnly | DontEnum);
 101     putDirect(exec->globalData(), exec->propertyNames().length, jsNumber(length), DontDelete | ReadOnly | DontEnum);
 102 }
 103
 104 void JSFunction::finishCreation(ExecState* exec, FunctionExecutable* executable, ScopeChainNode* scopeChainNode)
 105 {
 106     Base::finishCreation(exec->globalData());
 107     ASSERT(inherits(&s_info));
 108
 109     // Switching the structure here is only safe if we currently have the function structure!
 110     ASSERT(structure() == scopeChainNode->globalObject->functionStructure());
 111     setStructure(exec->globalData(), scopeChainNode->globalObject->namedFunctionStructure());
 112     putDirectOffset(exec->globalData(), scopeChainNode->globalObject->functionNameOffset(), executable->nameValue());
 113 }
 114
 115 const UString& JSFunction::name(ExecState* exec)
 116 {
 117     return asString(getDirect(exec->globalData(), exec->globalData().propertyNames->name))->tryGetValue();
 118 }
 119
 120 const UString JSFunction::displayName(ExecState* exec)
 121 {
 122     JSValue displayName = getDirect(exec->globalData(), exec->globalData().propertyNames->displayName);
 123
 124     if (displayName && isJSString(displayName))
 125         return asString(displayName)->tryGetValue();
 126
 127     return UString();
 128 }
 129
 130 const UString JSFunction::calculatedDisplayName(ExecState* exec)
 131 {
 132     const UString explicitName = displayName(exec);
 133
 134     if (!explicitName.isEmpty())
 135         return explicitName;
 136
 137     const UString actualName = name(exec);
 138     if (!actualName.isEmpty() || isHostFunction())
 139         return actualName;
 140
 141     return jsExecutable()->inferredName().ustring();
 142 }
 143
 144 const SourceCode* JSFunction::sourceCode() const
 145 {
 146     if (isHostFunction())
 147         return 0;
 148     return &jsExecutable()->source();
 149 }
 150
 151 void JSFunction::visitChildren(JSCell* cell, SlotVisitor& visitor)
 152 {
 153     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 154     ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
 155     COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
 156     ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
 157     Base::visitChildren(thisObject, visitor);
 158
 159     visitor.append(&thisObject->m_scopeChain);
 160     if (thisObject->m_executable)
 161         visitor.append(&thisObject->m_executable);
 162 }
 163
 164 CallType JSFunction::getCallData(JSCell* cell, CallData& callData)
 165 {
 166     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 167     if (thisObject->isHostFunction()) {
 168         callData.native.function = thisObject->nativeFunction();
 169         return CallTypeHost;
 170     }
 171     callData.js.functionExecutable = thisObject->jsExecutable();
 172     callData.js.scopeChain = thisObject->scope();
 173     return CallTypeJS;
 174 }
 175
 176 JSValue JSFunction::argumentsGetter(ExecState* exec, JSValue slotBase, const Identifier&)
 177 {
 178     JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
 179     ASSERT(!thisObj->isHostFunction());
 180     return exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObj);
 181 }
 182
 183 JSValue JSFunction::callerGetter(ExecState* exec, JSValue slotBase, const Identifier&)
 184 {
 185     JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
 186     ASSERT(!thisObj->isHostFunction());
 187     JSValue caller = exec->interpreter()->retrieveCallerFromVMCode(exec, thisObj);
 188
 189     // See ES5.1 15.3.5.4 - Function.caller may not be used to retrieve a strict caller.
 190     if (!caller.isObject() || !asObject(caller)->inherits(&JSFunction::s_info))
 191         return caller;
 192     JSFunction* function = jsCast<JSFunction*>(caller);
 193     if (function->isHostFunction() || !function->jsExecutable()->isStrictMode())
 194         return caller;
 195     return throwTypeError(exec, "Function.caller used to retrieve strict caller");
 196 }
 197
 198 JSValue JSFunction::lengthGetter(ExecState*, JSValue slotBase, const Identifier&)
 199 {
 200     JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
 201     ASSERT(!thisObj->isHostFunction());
 202     return jsNumber(thisObj->jsExecutable()->parameterCount());
 203 }
 204
 205 bool JSFunction::getOwnPropertySlot(JSCell* cell, ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
 206 {
 207     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 208     if (thisObject->isHostFunction())
 209         return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 210
 211     if (propertyName == exec->propertyNames().prototype) {
 212         WriteBarrierBase<Unknown>* location = thisObject->getDirectLocation(exec->globalData(), propertyName);
 213
 214         if (!location) {
 215             JSObject* prototype = constructEmptyObject(exec, thisObject->globalObject()->emptyObjectStructure());
 216             prototype->putDirect(exec->globalData(), exec->propertyNames().constructor, thisObject, DontEnum);
 217             thisObject->putDirect(exec->globalData(), exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
 218             location = thisObject->getDirectLocation(exec->globalData(), exec->propertyNames().prototype);
 219         }
 220
 221         slot.setValue(thisObject, location->get(), thisObject->offsetForLocation(location));
 222     }
 223
 224     if (propertyName == exec->propertyNames().arguments) {
 225         if (thisObject->jsExecutable()->isStrictMode()) {
 226             bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 227             if (!result) {
 228                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 229                 result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 230                 ASSERT(result);
 231             }
 232             return result;
 233         }
 234         slot.setCacheableCustom(thisObject, argumentsGetter);
 235         return true;
 236     }
 237
 238     if (propertyName == exec->propertyNames().length) {
 239         slot.setCacheableCustom(thisObject, lengthGetter);
 240         return true;
 241     }
 242
 243     if (propertyName == exec->propertyNames().caller) {
 244         if (thisObject->jsExecutable()->isStrictMode()) {
 245             bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 246             if (!result) {
 247                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 248                 result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 249                 ASSERT(result);
 250             }
 251             return result;
 252         }
 253         slot.setCacheableCustom(thisObject, callerGetter);
 254         return true;
 255     }
 256
 257     return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
 258 }
 259
 260 bool JSFunction::getOwnPropertyDescriptor(JSObject* object, ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
 261 {
 262     JSFunction* thisObject = jsCast<JSFunction*>(object);
 263     if (thisObject->isHostFunction())
 264         return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 265
 266     if (propertyName == exec->propertyNames().prototype) {
 267         PropertySlot slot;
 268         thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
 269         return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 270     }
 271
 272     if (propertyName == exec->propertyNames().arguments) {
 273         if (thisObject->jsExecutable()->isStrictMode()) {
 274             bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 275             if (!result) {
 276                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 277                 result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 278                 ASSERT(result);
 279             }
 280             return result;
 281         }
 282         descriptor.setDescriptor(exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);
 283         return true;
 284     }
 285
 286     if (propertyName == exec->propertyNames().length) {
 287         descriptor.setDescriptor(jsNumber(thisObject->jsExecutable()->parameterCount()), ReadOnly | DontEnum | DontDelete);
 288         return true;
 289     }
 290
 291     if (propertyName == exec->propertyNames().caller) {
 292         if (thisObject->jsExecutable()->isStrictMode()) {
 293             bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 294             if (!result) {
 295                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 296                 result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 297                 ASSERT(result);
 298             }
 299             return result;
 300         }
 301         descriptor.setDescriptor(exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);
 302         return true;
 303     }
 304
 305     return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
 306 }
 307
 308 void JSFunction::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 309 {
 310     JSFunction* thisObject = jsCast<JSFunction*>(object);
 311     if (!thisObject->isHostFunction() && (mode == IncludeDontEnumProperties)) {
 312         // Make sure prototype has been reified.
 313         PropertySlot slot;
 314         thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, exec->propertyNames().prototype, slot);
 315
 316         propertyNames.add(exec->propertyNames().arguments);
 317         propertyNames.add(exec->propertyNames().caller);
 318         propertyNames.add(exec->propertyNames().length);
 319     }
 320     Base::getOwnPropertyNames(thisObject, exec, propertyNames, mode);
 321 }
 322
 323 void JSFunction::put(JSCell* cell, ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
 324 {
 325     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 326     if (thisObject->isHostFunction()) {
 327         Base::put(thisObject, exec, propertyName, value, slot);
 328         return;
 329     }
 330     if (propertyName == exec->propertyNames().prototype) {
 331         // Make sure prototype has been reified, such that it can only be overwritten
 332         // following the rules set out in ECMA-262 8.12.9.
 333         PropertySlot slot;
 334         thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
 335     }
 336     if (thisObject->jsExecutable()->isStrictMode() && (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().caller)) {
 337         // This will trigger the property to be reified, if this is not already the case!
 338         bool okay = thisObject->hasProperty(exec, propertyName);
 339         ASSERT_UNUSED(okay, okay);
 340         Base::put(thisObject, exec, propertyName, value, slot);
 341         return;
 342     }
 343     if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().caller) {
 344         if (slot.isStrictMode())
 345             throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
 346         return;
 347     }
 348     Base::put(thisObject, exec, propertyName, value, slot);
 349 }
 350
 351 bool JSFunction::deleteProperty(JSCell* cell, ExecState* exec, const Identifier& propertyName)
 352 {
 353     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 354     // For non-host functions, don't let these properties by deleted - except by DefineOwnProperty.
 355     if (!thisObject->isHostFunction() && !exec->globalData().isInDefineOwnProperty()
 356         && (propertyName == exec->propertyNames().arguments
 357             || propertyName == exec->propertyNames().length
 358             || propertyName == exec->propertyNames().prototype
 359             || propertyName == exec->propertyNames().caller))
 360         return false;
 361     return Base::deleteProperty(thisObject, exec, propertyName);
 362 }
 363
 364 bool JSFunction::defineOwnProperty(JSObject* object, ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor, bool throwException)
 365 {
 366     JSFunction* thisObject = jsCast<JSFunction*>(object);
 367     if (thisObject->isHostFunction())
 368         return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
 369
 370     if (propertyName == exec->propertyNames().prototype) {
 371         // Make sure prototype has been reified, such that it can only be overwritten
 372         // following the rules set out in ECMA-262 8.12.9.
 373         PropertySlot slot;
 374         thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
 375         return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
 376     }
 377
 378     bool valueCheck;
 379     if (propertyName == exec->propertyNames().arguments) {
 380         if (thisObject->jsExecutable()->isStrictMode()) {
 381             if (!Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor))
 382                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 383             return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
 384         }
 385         valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject));
 386     } else if (propertyName == exec->propertyNames().caller) {
 387         if (thisObject->jsExecutable()->isStrictMode()) {
 388             if (!Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor))
 389                 thisObject->putDirectAccessor(exec->globalData(), propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
 390             return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
 391         }
 392         valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject));
 393     } else if (propertyName == exec->propertyNames().length)
 394         valueCheck = !descriptor.value() || sameValue(exec, descriptor.value(), jsNumber(thisObject->jsExecutable()->parameterCount()));
 395     else
 396         return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
 397
 398     if (descriptor.configurablePresent() && descriptor.configurable()) {
 399         if (throwException)
 400             throwError(exec, createTypeError(exec, "Attempting to configurable attribute of unconfigurable property."));
 401         return false;
 402     }
 403     if (descriptor.enumerablePresent() && descriptor.enumerable()) {
 404         if (throwException)
 405             throwError(exec, createTypeError(exec, "Attempting to change enumerable attribute of unconfigurable property."));
 406         return false;
 407     }
 408     if (descriptor.isAccessorDescriptor()) {
 409         if (throwException)
 410             throwError(exec, createTypeError(exec, "Attempting to change access mechanism for an unconfigurable property."));
 411         return false;
 412     }
 413     if (descriptor.writablePresent() && descriptor.writable()) {
 414         if (throwException)
 415             throwError(exec, createTypeError(exec, "Attempting to change writable attribute of unconfigurable property."));
 416         return false;
 417     }
 418     if (!valueCheck) {
 419         if (throwException)
 420             throwError(exec, createTypeError(exec, "Attempting to change value of a readonly property."));
 421         return false;
 422     }
 423     return true;
 424 }
 425
 426 // ECMA 13.2.2 [[Construct]]
 427 ConstructType JSFunction::getConstructData(JSCell* cell, ConstructData& constructData)
 428 {
 429     JSFunction* thisObject = jsCast<JSFunction*>(cell);
 430     if (thisObject->isHostFunction()) {
 431         constructData.native.function = thisObject->nativeConstructor();
 432         return ConstructTypeHost;
 433     }
 434     constructData.js.functionExecutable = thisObject->jsExecutable();
 435     constructData.js.scopeChain = thisObject->scope();
 436     return ConstructTypeJS;
 437 }
 438
 439
 440 UString getCalculatedDisplayName(CallFrame* callFrame, JSObject* object)
 441 {
 442     if (JSFunction* function = jsDynamicCast<JSFunction*>(object))
 443         return function->calculatedDisplayName(callFrame);
 444     if (InternalFunction* function = jsDynamicCast<InternalFunction*>(object))
 445         return function->calculatedDisplayName(callFrame);
 446     return callFrame->globalData().propertyNames->emptyIdentifier.ustring();
 447 }
 448
 449 } // namespace JSC