C++ JSFunction::isHostFunction方法代码示例

JSValue JSFunction::callerGetter(ExecState* exec, JSValue slotBase, PropertyName)
{
    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
    ASSERT(!thisObj->isHostFunction());
    JSValue caller = exec->interpreter()->retrieveCallerFromVMCode(exec, thisObj);

    // See ES5.1 15.3.5.4 - Function.caller may not be used to retrieve a strict caller.
    if (!caller.isObject() || !asObject(caller)->inherits(&JSFunction::s_info))
        return caller;
    JSFunction* function = jsCast<JSFunction*>(caller);
    if (function->isHostFunction() || !function->jsExecutable()->isStrictMode())
        return caller;
    return throwTypeError(exec, ASCIILiteral("Function.caller used to retrieve strict caller"));
}

bool JSFunction::getOwnPropertySlot(JSCell* cell, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostFunction())
        return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);

    if (propertyName == exec->propertyNames().prototype) {
        JSGlobalData& globalData = exec->globalData();
        PropertyOffset offset = thisObject->getDirectOffset(globalData, propertyName);
        if (!isValidOffset(offset)) {
            JSObject* prototype = constructEmptyObject(exec);
            prototype->putDirect(globalData, exec->propertyNames().constructor, thisObject, DontEnum);
            thisObject->putDirect(globalData, exec->propertyNames().prototype, prototype, DontDelete | DontEnum);
            offset = thisObject->getDirectOffset(globalData, exec->propertyNames().prototype);
            ASSERT(isValidOffset(offset));
        }

        slot.setValue(thisObject, thisObject->getDirect(offset), offset);
    }

    if (propertyName == exec->propertyNames().arguments) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, argumentsGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().length) {
        slot.setCacheableCustom(thisObject, lengthGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().name) {
        slot.setCacheableCustom(thisObject, nameGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().caller) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, callerGetter);
        return true;
    }

    return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
}

void VM::releaseExecutableMemory()
{
    prepareToDiscardCode();

    if (entryScope) {
        StackPreservingRecompiler recompiler;
        HeapIterationScope iterationScope(heap);
        HashSet<JSCell*> roots;
        heap.getConservativeRegisterRoots(roots);
        HashSet<JSCell*>::iterator end = roots.end();
        for (HashSet<JSCell*>::iterator ptr = roots.begin(); ptr != end; ++ptr) {
            ScriptExecutable* executable = 0;
            JSCell* cell = *ptr;
            if (cell->inherits(ScriptExecutable::info()))
                executable = static_cast<ScriptExecutable*>(*ptr);
            else if (cell->inherits(JSFunction::info())) {
                JSFunction* function = jsCast<JSFunction*>(*ptr);
                if (function->isHostFunction())
                    continue;
                executable = function->jsExecutable();
            } else
                continue;
            ASSERT(executable->inherits(ScriptExecutable::info()));
            executable->unlinkCalls();
            if (executable->inherits(FunctionExecutable::info()))
                recompiler.currentlyExecutingFunctions.add(static_cast<FunctionExecutable*>(executable));

        }
        heap.objectSpace().forEachLiveCell<StackPreservingRecompiler>(iterationScope, recompiler);
    }
    m_regExpCache->invalidateCode();
    heap.collectAllGarbage();
}

JSValue JSFunction::argumentsGetter(ExecState* exec, JSValue slotBase, PropertyName)
{
    JSFunction* thisObj = jsCast<JSFunction*>(slotBase);
    ASSERT(!thisObj->isHostFunction());

    return retrieveArguments(exec, thisObj);
}

void JSFunction::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostFunction()) {
        Base::put(thisObject, exec, propertyName, value, slot);
        return;
    }
    if (propertyName == exec->propertyNames().prototype) {
        // Make sure prototype has been reified, such that it can only be overwritten
        // following the rules set out in ECMA-262 8.12.9.
        PropertySlot slot;
        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
        thisObject->m_allocationProfile.clear();
        thisObject->m_allocationProfileWatchpoint.notifyWrite();
        // Don't allow this to be cached, since a [[Put]] must clear m_allocationProfile.
        PutPropertySlot dontCache;
        Base::put(thisObject, exec, propertyName, value, dontCache);
        return;
    }
    if (thisObject->jsExecutable()->isStrictMode() && (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().caller)) {
        // This will trigger the property to be reified, if this is not already the case!
        bool okay = thisObject->hasProperty(exec, propertyName);
        ASSERT_UNUSED(okay, okay);
        Base::put(thisObject, exec, propertyName, value, slot);
        return;
    }
    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().name || propertyName == exec->propertyNames().caller) {
        if (slot.isStrictMode())
            throwTypeError(exec, StrictModeReadonlyPropertyWriteError);
        return;
    }
    Base::put(thisObject, exec, propertyName, value, slot);
}

static CodeBlock* codeBlockFromArg(ExecState* exec)
{
    VM& vm = exec->vm();
    if (exec->argumentCount() < 1)
        return nullptr;

    JSValue value = exec->uncheckedArgument(0);
    CodeBlock* candidateCodeBlock = nullptr;
    if (value.isCell()) {
        JSFunction* func = jsDynamicCast<JSFunction*>(vm, value.asCell());
        if (func) {
            if (func->isHostFunction())
                candidateCodeBlock = nullptr;
            else
                candidateCodeBlock = func->jsExecutable()->eitherCodeBlock();
        }
    } else if (value.isDouble()) {
        // If the value is a double, it may be an encoded CodeBlock* that came from
        // $vm.codeBlockForFrame(). We'll treat it as a candidate codeBlock and check if it's
        // valid below before using.
        candidateCodeBlock = reinterpret_cast<CodeBlock*>(bitwise_cast<uint64_t>(value.asDouble()));
    }

    if (candidateCodeBlock && JSDollarVMPrototype::isValidCodeBlock(exec, candidateCodeBlock))
        return candidateCodeBlock;

    if (candidateCodeBlock)
        dataLog("Invalid codeBlock: ", RawPointer(candidateCodeBlock), " ", value, "\n");
    else
        dataLog("Invalid codeBlock: ", value, "\n");
    return nullptr;
}

CallIdentifier createCallIdentifierFromFunctionImp(ExecState* exec, JSObject* function, const String& defaultSourceURL, int defaultLineNumber)
{
    const String& name = getCalculatedDisplayName(exec, function);
    JSFunction* jsFunction = jsDynamicCast<JSFunction*>(function);
    if (jsFunction && !jsFunction->isHostFunction())
        return CallIdentifier(name.isEmpty() ? AnonymousFunction : name, jsFunction->jsExecutable()->sourceURL(), jsFunction->jsExecutable()->lineNo());
    return CallIdentifier(name.isEmpty() ? AnonymousFunction : name, defaultSourceURL, defaultLineNumber);
}

bool JSFunction::deleteProperty(JSCell* cell, ExecState* exec, const Identifier& propertyName)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostFunction())
        return Base::deleteProperty(thisObject, exec, propertyName);
    if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().prototype || propertyName == exec->propertyNames().caller)
        return false;
    return Base::deleteProperty(thisObject, exec, propertyName);
}

BaseSamplerNode* SamplerApollo::willExecute(ExecState* exec, JSValue function, int32_t& lineNo)
{
    ASSERT(lineNo == 0);
    
    if (!seenByProfiler(function))
        return 0;

    JSObject* object = asObject(function);
    
    if (object->inherits(&JSFunction::info)) {
        JSFunction* jsFunction = asFunction(function);
        // we should take lineno only for non host functions
        // otherwise we end up with wrong line numbers for functions like
        // DOM functions, which should have 0 as line number
        // see bug 2587164
        if (!jsFunction->isHostFunction())
			lineNo = jsFunction->jsExecutable()->lineNo();
    }
    
    BaseSamplerNode* samplerNode = getSamplerNodeFor(static_cast<JSCell*>(object));
    if (!samplerNode) {
        // try to inject the object now
        // as it might have been created while sampling was disabled
        // this can happen when the sample buffer runs out of space
        
		ASSERT(exec->dynamicGlobalObject());

        uint64_t globalObjectIdentifier = 0;
        
        JSGlobalObject* globalObject = exec->dynamicGlobalObject();
        
        BaseSamplerNode* globalObjectSample = getSamplerNodeFor(globalObject);
        if (globalObjectSample)
            globalObjectIdentifier = globalObjectSample->identifier();
        
        PassRefPtr<SamplerJSCellNode> samplerNodeRef = adoptRef(new SamplerJSCellNode(globalObjectIdentifier, static_cast<JSCell*>(object), sizeof(JSObject)));
        samplerNode = samplerNodeRef.get();
		
		// the sampler might be stopped by the time we get here
		// and register node will not give an id
		// in this cases we just fail here
        if (!registerNode(samplerNodeRef))
			return 0;
    }
    samplerDidEnterFunction(samplerNode->identifier(), lineNo);

    // do not increment invocationCount if sampling is paused
    // however, we called samplerDidEnterFunction because we need to keep the callstack in sync
    if (UNLIKELY(!samplingNow))
        return samplerNode;

    samplerNode->willExecute();
	
	return samplerNode;
}

bool JSFunction::getOwnPropertySlot(JSCell* cell, ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
    JSFunction* thisObject = static_cast<JSFunction*>(cell);
    if (thisObject->isHostFunction())
        return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);

    if (propertyName == exec->propertyNames().prototype) {
        WriteBarrierBase<Unknown>* location = thisObject->getDirectLocation(exec->globalData(), propertyName);

        if (!location) {
            JSObject* prototype = constructEmptyObject(exec, thisObject->globalObject()->emptyObjectStructure());
            prototype->putDirect(exec->globalData(), exec->propertyNames().constructor, thisObject, DontEnum);
            PutPropertySlot slot;
            thisObject->putDirect(exec->globalData(), exec->propertyNames().prototype, prototype, DontDelete | DontEnum, false, slot);
            location = thisObject->getDirectLocation(exec->globalData(), exec->propertyNames().prototype);
        }

        slot.setValue(thisObject, location->get(), thisObject->offsetForLocation(location));
    }

    if (propertyName == exec->propertyNames().arguments) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->initializeGetterSetterProperty(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Getter | Setter);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, argumentsGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().length) {
        slot.setCacheableCustom(thisObject, lengthGetter);
        return true;
    }

    if (propertyName == exec->propertyNames().caller) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
            if (!result) {
                thisObject->initializeGetterSetterProperty(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Getter | Setter);
                result = Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
                ASSERT(result);
            }
            return result;
        }
        slot.setCacheableCustom(thisObject, callerGetter);
        return true;
    }

    return Base::getOwnPropertySlot(thisObject, exec, propertyName, slot);
}

// ECMA 13.2.2 [[Construct]]
ConstructType JSFunction::getConstructData(JSCell* cell, ConstructData& constructData)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostFunction()) {
        constructData.native.function = thisObject->nativeConstructor();
        return ConstructTypeHost;
    }
    constructData.js.functionExecutable = thisObject->jsExecutable();
    constructData.js.scope = thisObject->scope();
    return ConstructTypeJS;
}

CallType JSFunction::getCallData(JSCell* cell, CallData& callData)
{
    JSFunction* thisObject = jsCast<JSFunction*>(cell);
    if (thisObject->isHostFunction()) {
        callData.native.function = thisObject->nativeFunction();
        return CallTypeHost;
    }
    callData.js.functionExecutable = thisObject->jsExecutable();
    callData.js.scope = thisObject->scope();
    return CallTypeJS;
}

bool JSFunction::defineOwnProperty(JSObject* object, ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor, bool throwException)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (thisObject->isHostFunction())
        return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);

    if (propertyName == exec->propertyNames().prototype) {
        // Make sure prototype has been reified, such that it can only be overwritten
        // following the rules set out in ECMA-262 8.12.9.
        PropertySlot slot;
        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
    } else if (propertyName == exec->propertyNames().arguments || propertyName == exec->propertyNames().length || propertyName == exec->propertyNames().caller) {
        if (!object->isExtensible()) {
            if (throwException)
                throwError(exec, createTypeError(exec, "Attempting to define property on object that is not extensible."));
            return false;
        }
        if (descriptor.configurablePresent() && descriptor.configurable()) {
            if (throwException)
                throwError(exec, createTypeError(exec, "Attempting to configurable attribute of unconfigurable property."));
            return false;
        }
        if (descriptor.enumerablePresent() && descriptor.enumerable()) {
            if (throwException)
                throwError(exec, createTypeError(exec, "Attempting to change enumerable attribute of unconfigurable property."));
            return false;
        }
        if (descriptor.isAccessorDescriptor()) {
            if (throwException)
                throwError(exec, createTypeError(exec, "Attempting to change access mechanism for an unconfigurable property."));
            return false;
        }
        if (descriptor.writablePresent() && descriptor.writable()) {
            if (throwException)
                throwError(exec, createTypeError(exec, "Attempting to change writable attribute of unconfigurable property."));
            return false;
        }
        if (!descriptor.value())
            return true;
        if (propertyName == exec->propertyNames().arguments && sameValue(exec, descriptor.value(), exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject)))
            return true;
        if (propertyName == exec->propertyNames().length && sameValue(exec, descriptor.value(), jsNumber(thisObject->jsExecutable()->parameterCount())))
            return true;
        if (propertyName == exec->propertyNames().caller && sameValue(exec, descriptor.value(), exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject)))
            return true;
        if (throwException)
            throwError(exec, createTypeError(exec, "Attempting to change value of a readonly property."));
        return false;
    }

    return Base::defineOwnProperty(object, exec, propertyName, descriptor, throwException);
}

bool JSFunction::getOwnPropertyDescriptor(JSObject* object, ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (thisObject->isHostFunction())
        return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
    
    if (propertyName == exec->propertyNames().prototype) {
        PropertySlot slot;
        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, propertyName, slot);
        return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
    }
    
    if (propertyName == exec->propertyNames().arguments) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
                ASSERT(result);
            }
            return result;
        }
        descriptor.setDescriptor(exec->interpreter()->retrieveArgumentsFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);
        return true;
    }
    
    if (propertyName == exec->propertyNames().length) {
        descriptor.setDescriptor(jsNumber(thisObject->jsExecutable()->parameterCount()), ReadOnly | DontEnum | DontDelete);
        return true;
    }
    
    if (propertyName == exec->propertyNames().name) {
        descriptor.setDescriptor(thisObject->jsExecutable()->nameValue(), ReadOnly | DontEnum | DontDelete);
        return true;
    }

    if (propertyName == exec->propertyNames().caller) {
        if (thisObject->jsExecutable()->isStrictMode()) {
            bool result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
            if (!result) {
                thisObject->putDirectAccessor(exec, propertyName, thisObject->globalObject()->throwTypeErrorGetterSetter(exec), DontDelete | DontEnum | Accessor);
                result = Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
                ASSERT(result);
            }
            return result;
        }
        descriptor.setDescriptor(exec->interpreter()->retrieveCallerFromVMCode(exec, thisObject), ReadOnly | DontEnum | DontDelete);
        return true;
    }
    
    return Base::getOwnPropertyDescriptor(thisObject, exec, propertyName, descriptor);
}

void JSFunction::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
{
    JSFunction* thisObject = jsCast<JSFunction*>(object);
    if (!thisObject->isHostFunction() && (mode == IncludeDontEnumProperties)) {
        // Make sure prototype has been reified.
        PropertySlot slot;
        thisObject->methodTable()->getOwnPropertySlot(thisObject, exec, exec->propertyNames().prototype, slot);

        propertyNames.add(exec->propertyNames().arguments);
        propertyNames.add(exec->propertyNames().caller);
        propertyNames.add(exec->propertyNames().length);
    }
    Base::getOwnPropertyNames(thisObject, exec, propertyNames, mode);
}