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 "JSGlobalObject.h"
  34 #include "JSNotAnObject.h"
  35 #include "Interpreter.h"
  36 #include "ObjectPrototype.h"
  37 #include "Parser.h"
  38 #include "PropertyNameArray.h"
  39 #include "ScopeChainMark.h"
  40
  41 using namespace WTF;
  42 using namespace Unicode;
  43
  44 namespace JSC {
  45 EncodedJSValue JSC_HOST_CALL callHostFunctionAsConstructor(ExecState* exec)
  46 {
  47     return throwVMError(exec, createNotAConstructorError(exec, exec->callee()));
  48 }
  49
  50 ASSERT_CLASS_FITS_IN_CELL(JSFunction);
  51
  52 const ClassInfo JSFunction::s_info = { "Function", &Base::s_info, 0, 0 };
  53
  54 bool JSFunction::isHostFunctionNonInline() const
  55 {
  56     return isHostFunction();
  57 }
  58
  59 JSFunction::JSFunction(VPtrStealingHackType)
  60     : Base(VPtrStealingHack)
  61 {
  62 }
  63
  64 JSFunction::JSFunction(ExecState* exec, JSGlobalObject* globalObject, Structure* structure, int length, const Identifier& name, NativeExecutable* thunk)
  65     : Base(globalObject, structure)
  66     , m_executable(exec->globalData(), this, thunk)
  67     , m_scopeChain(exec->globalData(), this, globalObject->globalScopeChain())
  68 {
  69     ASSERT(inherits(&s_info));
  70     putDirect(exec->globalData(), exec->globalData().propertyNames->name, jsString(exec, name.isNull() ? "" : name.ustring()), DontDelete | ReadOnly | DontEnum);
  71     putDirect(exec->globalData(), exec->propertyNames().length, jsNumber(length), DontDelete | ReadOnly | DontEnum);
  72 }
  73
  74 JSFunction::JSFunction(ExecState* exec, JSGlobalObject* globalObject, Structure* structure, int length, const Identifier& name, NativeFunction func)
  75     : Base(globalObject, structure)
  76     , m_scopeChain(exec->globalData(), this, globalObject->globalScopeChain())
  77 {
  78     ASSERT(inherits(&s_info));
  79
  80     // Can't do this during initialization because getHostFunction might do a GC allocation.
  81     m_executable.set(exec->globalData(), this, exec->globalData().getHostFunction(func));
  82
  83     putDirect(exec->globalData(), exec->globalData().propertyNames->name, jsString(exec, name.isNull() ? "" : name.ustring()), DontDelete | ReadOnly | DontEnum);
  84     putDirect(exec->globalData(), exec->propertyNames().length, jsNumber(length), DontDelete | ReadOnly | DontEnum);
  85 }
  86
  87 JSFunction::JSFunction(ExecState* exec, FunctionExecutable* executable, ScopeChainNode* scopeChainNode)
  88     : Base(scopeChainNode->globalObject.get(), scopeChainNode->globalObject->functionStructure())
  89     , m_executable(exec->globalData(), this, executable)
  90     , m_scopeChain(exec->globalData(), this, scopeChainNode)
  91 {
  92     ASSERT(inherits(&s_info));
  93     const Identifier& name = static_cast<FunctionExecutable*>(m_executable.get())->name();
  94     putDirect(exec->globalData(), exec->globalData().propertyNames->name, jsString(exec, name.isNull() ? "" : name.ustring()), DontDelete | ReadOnly | DontEnum);
  95 }
  96
  97 JSFunction::~JSFunction()
  98 {
  99     ASSERT(vptr() == JSGlobalData::jsFunctionVPtr);
 100 }
 101
 102 static const char* StrictModeCallerAccessError = "Cannot access caller property of a strict mode function";
 103 static const char* StrictModeArgumentsAccessError = "Cannot access arguments property of a strict mode function";
 104
 105 static void createDescriptorForThrowingProperty(ExecState* exec, PropertyDescriptor& descriptor, const char* message)
 106 {
 107     JSValue thrower = createTypeErrorFunction(exec, message);
 108     descriptor.setAccessorDescriptor(thrower, thrower, DontEnum | DontDelete | Getter | Setter);
 109 }
 110
 111 const UString& JSFunction::name(ExecState* exec)
 112 {
 113     return asString(getDirect(exec->globalData(), exec->globalData().propertyNames->name))->tryGetValue();
 114 }
 115
 116 const UString JSFunction::displayName(ExecState* exec)
 117 {
 118     JSValue displayName = getDirect(exec->globalData(), exec->globalData().propertyNames->displayName);
 119
 120     if (displayName && isJSString(&exec->globalData(), displayName))
 121         return asString(displayName)->tryGetValue();
 122
 123     return UString();
 124 }
 125
 126 const UString JSFunction::calculatedDisplayName(ExecState* exec)
 127 {
 128     const UString explicitName = displayName(exec);
 129
 130     if (!explicitName.isEmpty())
 131         return explicitName;
 132
 133     return name(exec);
 134 }
 135
 136 void JSFunction::visitChildren(SlotVisitor& visitor)
 137 {
 138     ASSERT_GC_OBJECT_INHERITS(this, &s_info);
 139     COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
 140     ASSERT(structure()->typeInfo().overridesVisitChildren());
 141     Base::visitChildren(visitor);
 142
 143     visitor.append(&m_scopeChain);
 144     if (m_executable)
 145         visitor.append(&m_executable);
 146 }
 147
 148 CallType JSFunction::getCallData(CallData& callData)
 149 {
 150     if (isHostFunction()) {
 151         callData.native.function = nativeFunction();
 152         return CallTypeHost;
 153     }
 154     callData.js.functionExecutable = jsExecutable();
 155     callData.js.scopeChain = scope();
 156     return CallTypeJS;
 157 }
 158
 159 JSValue JSFunction::argumentsGetter(ExecState* exec, JSValue slotBase, const Identifier&)
 160 {
 161     JSFunction* thisObj = asFunction(slotBase);
 162     ASSERT(!thisObj->isHostFunction());
 163     return exec->interpreter()->retrieveArguments(exec, thisObj);
 164 }
 165
 166 JSValue JSFunction::callerGetter(ExecState* exec, JSValue slotBase, const Identifier&)
 167 {
 168     JSFunction* thisObj = asFunction(slotBase);
 169     ASSERT(!thisObj->isHostFunction());
 170     return exec->interpreter()->retrieveCaller(exec, thisObj);
 171 }
 172
 173 JSValue JSFunction::lengthGetter(ExecState*, JSValue slotBase, const Identifier&)
 174 {
 175     JSFunction* thisObj = asFunction(slotBase);
 176     ASSERT(!thisObj->isHostFunction());
 177     return jsNumber(thisObj->jsExecutable()->parameterCount());
 178 }
 179
 180 static inline WriteBarrierBase<Unknown>* createPrototypeProperty(JSGlobalData& globalData, JSGlobalObject* globalObject, JSFunction* function)
 181 {
 182     ASSERT(!function->isHostFunction());
 183
 184     ExecState* exec = globalObject->globalExec();
 185     if (WriteBarrierBase<Unknown>* location = function->getDirectLocation(globalData, exec->propertyNames().prototype))
 186         return location;
 187     JSObject* prototype = constructEmptyObject(exec, globalObject->emptyObjectStructure());
 188     prototype->putDirect(globalData, exec->propertyNames().constructor, function, DontEnum);
 189     function->putDirect(globalData, exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
 190     return function->getDirectLocation(exec->globalData(), exec->propertyNames().prototype);
 191 }
 192
 193 void JSFunction::preventExtensions(JSGlobalData& globalData)
 194 {
 195     if (!isHostFunction())
 196         createPrototypeProperty(globalData, scope()->globalObject.get(), this);
 197     JSObject::preventExtensions(globalData);
 198 }
 199
 200 bool JSFunction::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
 201 {
 202     if (isHostFunction())
 203         return Base::getOwnPropertySlot(exec, propertyName, slot);
 204
 205     if (propertyName == exec->propertyNames().prototype) {
 206         WriteBarrierBase<Unknown>* location = getDirectLocation(exec->globalData(), propertyName);
 207
 208         if (!location)
 209             location = createPrototypeProperty(exec->globalData(), scope()->globalObject.get(), this);
 210
 211         slot.setValue(this, location->get(), offsetForLocation(location));
 212     }
 213
 214     if (propertyName == exec->propertyNames().arguments) {
 215         if (jsExecutable()->isStrictMode()) {
 216             throwTypeError(exec, "Can't access arguments object of a strict mode function");
 217             slot.setValue(jsNull());
 218             return true;
 219         }
 220
 221         slot.setCacheableCustom(this, argumentsGetter);
 222         return true;
 223     }
 224
 225     if (propertyName == exec->propertyNames().length) {
 226         slot.setCacheableCustom(this, lengthGetter);
 227         return true;
 228     }
 229
 230     if (propertyName == exec->propertyNames().caller) {
 231         if (jsExecutable()->isStrictMode()) {
 232             throwTypeError(exec, StrictModeCallerAccessError);
 233             slot.setValue(jsNull());
 234             return true;
 235         }
 236         slot.setCacheableCustom(this, callerGetter);
 237         return true;
 238     }
 239
 240     return Base::getOwnPropertySlot(exec, propertyName, slot);
 241 }
 242
 243 bool JSFunction::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
 244 {
 245     if (isHostFunction())
 246         return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
 247
 248     if (propertyName == exec->propertyNames().prototype) {
 249         PropertySlot slot;
 250         getOwnPropertySlot(exec, propertyName, slot);
 251         return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
 252     }
 253
 254     if (propertyName == exec->propertyNames().arguments) {
 255         if (jsExecutable()->isStrictMode())
 256             createDescriptorForThrowingProperty(exec, descriptor, StrictModeArgumentsAccessError);
 257         else
 258             descriptor.setDescriptor(exec->interpreter()->retrieveArguments(exec, this), ReadOnly | DontEnum | DontDelete);
 259         return true;
 260     }
 261
 262     if (propertyName == exec->propertyNames().length) {
 263         descriptor.setDescriptor(jsNumber(jsExecutable()->parameterCount()), ReadOnly | DontEnum | DontDelete);
 264         return true;
 265     }
 266
 267     if (propertyName == exec->propertyNames().caller) {
 268         if (jsExecutable()->isStrictMode())
 269             createDescriptorForThrowingProperty(exec, descriptor, StrictModeCallerAccessError);
 270         else
 271             descriptor.setDescriptor(exec->interpreter()->retrieveCaller(exec, this), ReadOnly | DontEnum | DontDelete);
 272         return true;
 273     }
 274
 275     return Base::getOwnPropertyDescriptor(exec, propertyName, descriptor);
 276 }
 277
 278 void JSFunction::getOwnPropertyNames(ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 279 {
 280     if (!isHostFunction() && (mode == IncludeDontEnumProperties)) {
 281         // Make sure prototype has been reified.
 282         PropertySlot slot;
 283         getOwnPropertySlot(exec, exec->propertyNames().prototype, slot);
 284
 285         propertyNames.add(exec->propertyNames().arguments);
 286         propertyNames.add(exec->propertyNames().callee);
 287         propertyNames.add(exec->propertyNames().caller);
 288         propertyNames.add(exec->propertyNames().length);
 289     }
 290     Base::getOwnPropertyNames(exec, propertyNames, mode);
 291 }
 292
 293 void JSFunction::put(ExecState* exec, const Identifier& propertyName, JSValue value, PutPropertySlot& slot)
 294 {
 295     if (isHostFunction()) {
 296         Base::put(exec, propertyName, value, slot);
 297         return;
 298     }
 299     if (propertyName == exec->propertyNames().prototype) {
 300         // Make sure prototype has been reified, such that it can only be overwritten
 301         // following the rules set out in ECMA-262 8.12.9.
 302         PropertySlot slot;
 303         getOwnPropertySlot(exec, propertyName, slot);
 304     }
 305     if (jsExecutable()->isStrictMode()) {
 306         if (propertyName == exec->propertyNames().arguments) {
 307             throwTypeError(exec, StrictModeArgumentsAccessError);
 308             return;
 309         }
 310         if (propertyName == exec->propertyNames().caller) {
 311             throwTypeError(exec, StrictModeCallerAccessError);
 312             return;
 313         }
 314     }
 315     if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length)
 316         return;
 317     Base::put(exec, propertyName, value, slot);
 318 }
 319
 320 bool JSFunction::deleteProperty(ExecState* exec, const Identifier& propertyName)
 321 {
 322     if (isHostFunction())
 323         return Base::deleteProperty(exec, propertyName);
 324     if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length)
 325         return false;
 326     return Base::deleteProperty(exec, propertyName);
 327 }
 328
 329 // ECMA 13.2.2 [[Construct]]
 330 ConstructType JSFunction::getConstructData(ConstructData& constructData)
 331 {
 332     if (isHostFunction())
 333         return ConstructTypeNone;
 334     constructData.js.functionExecutable = jsExecutable();
 335     constructData.js.scopeChain = scope();
 336     return ConstructTypeJS;
 337 }
 338
 339 } // namespace JSC