Source/JavaScriptCore/runtime/IteratorOperations.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
  * Copyright (C) 2016-2017 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "IteratorOperations.h"

 #include "JSCInlines.h"
 #include "ObjectConstructor.h"

 namespace JSC {

 JSValue iteratorNext(JSGlobalObject* globalObject, IterationRecord iterationRecord, JSValue argument)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue iterator = iterationRecord.iterator;
     JSValue nextFunction = iterationRecord.nextMethod;

     auto nextFunctionCallData = getCallData(vm, nextFunction);
     if (nextFunctionCallData.type == CallData::Type::None)
         return throwTypeError(globalObject, scope);

     MarkedArgumentBuffer nextFunctionArguments;
     if (!argument.isEmpty())
         nextFunctionArguments.append(argument);
     ASSERT(!nextFunctionArguments.hasOverflowed());
     JSValue result = call(globalObject, nextFunction, nextFunctionCallData, iterator, nextFunctionArguments);
     RETURN_IF_EXCEPTION(scope, JSValue());

     if (!result.isObject())
         return throwTypeError(globalObject, scope, "Iterator result interface is not an object."_s);

     return result;
 }

 JSValue iteratorValue(JSGlobalObject* globalObject, JSValue iterResult)
 {
     return iterResult.get(globalObject, globalObject->vm().propertyNames->value);
 }

 bool iteratorComplete(JSGlobalObject* globalObject, JSValue iterResult)
 {
     JSValue done = iterResult.get(globalObject, globalObject->vm().propertyNames->done);
     return done.toBoolean(globalObject);
 }

 JSValue iteratorStep(JSGlobalObject* globalObject, IterationRecord iterationRecord)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue result = iteratorNext(globalObject, iterationRecord);
     RETURN_IF_EXCEPTION(scope, JSValue());
     bool done = iteratorComplete(globalObject, result);
     RETURN_IF_EXCEPTION(scope, JSValue());
     if (done)
         return jsBoolean(false);
     return result;
 }

 void iteratorClose(JSGlobalObject* globalObject, JSValue iterator)
 {
     VM& vm = globalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
     auto catchScope = DECLARE_CATCH_SCOPE(vm);

     Exception* exception = nullptr;
     if (UNLIKELY(catchScope.exception())) {
         exception = catchScope.exception();
         catchScope.clearException();
     }

     JSValue returnFunction = iterator.get(globalObject, vm.propertyNames->returnKeyword);
     if (UNLIKELY(throwScope.exception()) || returnFunction.isUndefinedOrNull()) {
         if (exception)
             throwException(globalObject, throwScope, exception);
         return;
     }

     auto returnFunctionCallData = getCallData(vm, returnFunction);
     if (returnFunctionCallData.type == CallData::Type::None) {
         if (exception)
             throwException(globalObject, throwScope, exception);
         else
             throwTypeError(globalObject, throwScope);
         return;
     }

     MarkedArgumentBuffer returnFunctionArguments;
     ASSERT(!returnFunctionArguments.hasOverflowed());
     JSValue innerResult = call(globalObject, returnFunction, returnFunctionCallData, iterator, returnFunctionArguments);

     if (exception) {
         throwException(globalObject, throwScope, exception);
         return;
     }

     RETURN_IF_EXCEPTION(throwScope, void());

     if (!innerResult.isObject()) {
         throwTypeError(globalObject, throwScope, "Iterator result interface is not an object."_s);
         return;
     }
 }

 static constexpr PropertyOffset valuePropertyOffset = 0;
 static constexpr PropertyOffset donePropertyOffset = 1;

 Structure* createIteratorResultObjectStructure(VM& vm, JSGlobalObject& globalObject)
 {
     Structure* iteratorResultStructure = vm.structureCache.emptyObjectStructureForPrototype(&globalObject, globalObject.objectPrototype(), JSFinalObject::defaultInlineCapacity());
     PropertyOffset offset;
     iteratorResultStructure = Structure::addPropertyTransition(vm, iteratorResultStructure, vm.propertyNames->value, 0, offset);
     RELEASE_ASSERT(offset == valuePropertyOffset);
     iteratorResultStructure = Structure::addPropertyTransition(vm, iteratorResultStructure, vm.propertyNames->done, 0, offset);
     RELEASE_ASSERT(offset == donePropertyOffset);
     return iteratorResultStructure;
 }

 JSObject* createIteratorResultObject(JSGlobalObject* globalObject, JSValue value, bool done)
 {
     VM& vm = globalObject->vm();
     JSObject* resultObject = constructEmptyObject(vm, globalObject->iteratorResultObjectStructure());
     resultObject->putDirect(vm, valuePropertyOffset, value);
     resultObject->putDirect(vm, donePropertyOffset, jsBoolean(done));
     return resultObject;
 }

 bool hasIteratorMethod(JSGlobalObject* globalObject, JSValue value)
 {
     auto& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     if (!value.isObject())
         return false;

     JSObject* object = asObject(value);
     CallData callData;
     JSValue applyMethod = object->getMethod(globalObject, callData, vm.propertyNames->iteratorSymbol, "Symbol.iterator property should be callable"_s);
     RETURN_IF_EXCEPTION(scope, false);

     return !applyMethod.isUndefined();
 }

 JSValue iteratorMethod(JSGlobalObject* globalObject, JSObject* object)
 {
     auto& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     CallData callData;
     JSValue method = object->getMethod(globalObject, callData, vm.propertyNames->iteratorSymbol, "Symbol.iterator property should be callable"_s);
     RETURN_IF_EXCEPTION(scope, jsUndefined());

     return method;
 }

 IterationRecord iteratorForIterable(JSGlobalObject* globalObject, JSObject* object, JSValue iteratorMethod)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     auto iteratorMethodCallData = getCallData(vm, iteratorMethod);
     if (iteratorMethodCallData.type == CallData::Type::None) {
         throwTypeError(globalObject, scope);
         return { };
     }

     ArgList iteratorMethodArguments;
     JSValue iterator = call(globalObject, iteratorMethod, iteratorMethodCallData, object, iteratorMethodArguments);
     RETURN_IF_EXCEPTION(scope, { });

     if (!iterator.isObject()) {
         throwTypeError(globalObject, scope);
         return { };
     }

     JSValue nextMethod = iterator.getObject()->get(globalObject, vm.propertyNames->next);
     RETURN_IF_EXCEPTION(scope, { });

     return { iterator, nextMethod };
 }

 IterationRecord iteratorForIterable(JSGlobalObject* globalObject, JSValue iterable)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     JSValue iteratorFunction = iterable.get(globalObject, vm.propertyNames->iteratorSymbol);
     RETURN_IF_EXCEPTION(scope, { });

     auto iteratorFunctionCallData = getCallData(vm, iteratorFunction);
     if (iteratorFunctionCallData.type == CallData::Type::None) {
         throwTypeError(globalObject, scope);
         return { };
     }

     ArgList iteratorFunctionArguments;
     JSValue iterator = call(globalObject, iteratorFunction, iteratorFunctionCallData, iterable, iteratorFunctionArguments);
     RETURN_IF_EXCEPTION(scope, { });

     if (!iterator.isObject()) {
         throwTypeError(globalObject, scope);
         return { };
     }

     JSValue nextMethod = iterator.getObject()->get(globalObject, vm.propertyNames->next);
     RETURN_IF_EXCEPTION(scope, { });

     return { iterator, nextMethod };
 }

 IterationMode getIterationMode(VM& vm, JSGlobalObject* globalObject, JSValue iterable, JSValue symbolIterator)
 {
     if (!iterable.inherits<JSArray>(vm))
         return IterationMode::Generic;

     if (!globalObject->arrayIteratorProtocolWatchpointSet().isStillValid())
         return IterationMode::Generic;

     // This is correct because we just checked the watchpoint is still valid.
     JSFunction* symbolIteratorFunction = jsDynamicCast<JSFunction*>(vm, symbolIterator);
     if (!symbolIteratorFunction)
         return IterationMode::Generic;

     // We don't want to allocate the values function just to check if it's the same as our function so we use the concurrent accessor.
     // FIXME: This only works for arrays from the same global object as ourselves but we should be able to support any pairing.
     if (globalObject->arrayProtoValuesFunctionConcurrently() != symbolIteratorFunction)
         return IterationMode::Generic;

     return IterationMode::FastArray;
 }

 IterationMode getIterationMode(VM& vm, JSGlobalObject* globalObject, JSValue iterable)
 {
     if (!iterable.inherits<JSArray>(vm))
         return IterationMode::Generic;

     JSArray* array = jsCast<JSArray*>(iterable);
     Structure* structure = array->structure(vm);
     // FIXME: We want to support broader JSArrays as long as array[@@iterator] is not defined.
     if (!globalObject->isOriginalArrayStructure(structure))
         return IterationMode::Generic;

     if (!globalObject->arrayIteratorProtocolWatchpointSet().isStillValid())
         return IterationMode::Generic;

     // Now, Array has original Array Structures and arrayIteratorProtocolWatchpointSet is not fired.
     // This means,
     // 1. Array.prototype is [[Prototype]].
     // 2. array[@@iterator] is not overridden.
     // 3. Array.prototype[@@iterator] is an expected one.
     // So, we can say this will create an expected ArrayIterator.
     return IterationMode::FastArray;
 }

 } // namespace JSC
	/*
	* Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
	* Copyright (C) 2016-2017 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "IteratorOperations.h"

	#include "JSCInlines.h"
	#include "ObjectConstructor.h"

	namespace JSC {

	JSValue iteratorNext(JSGlobalObject* globalObject, IterationRecord iterationRecord, JSValue argument)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue iterator = iterationRecord.iterator;
	JSValue nextFunction = iterationRecord.nextMethod;

	auto nextFunctionCallData = getCallData(vm, nextFunction);
	if (nextFunctionCallData.type == CallData::Type::None)
	return throwTypeError(globalObject, scope);

	MarkedArgumentBuffer nextFunctionArguments;
	if (!argument.isEmpty())
	nextFunctionArguments.append(argument);
	ASSERT(!nextFunctionArguments.hasOverflowed());
	JSValue result = call(globalObject, nextFunction, nextFunctionCallData, iterator, nextFunctionArguments);
	RETURN_IF_EXCEPTION(scope, JSValue());

	if (!result.isObject())
	return throwTypeError(globalObject, scope, "Iterator result interface is not an object."_s);

	return result;
	}

	JSValue iteratorValue(JSGlobalObject* globalObject, JSValue iterResult)
	{
	return iterResult.get(globalObject, globalObject->vm().propertyNames->value);
	}

	bool iteratorComplete(JSGlobalObject* globalObject, JSValue iterResult)
	{
	JSValue done = iterResult.get(globalObject, globalObject->vm().propertyNames->done);
	return done.toBoolean(globalObject);
	}

	JSValue iteratorStep(JSGlobalObject* globalObject, IterationRecord iterationRecord)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue result = iteratorNext(globalObject, iterationRecord);
	RETURN_IF_EXCEPTION(scope, JSValue());
	bool done = iteratorComplete(globalObject, result);
	RETURN_IF_EXCEPTION(scope, JSValue());
	if (done)
	return jsBoolean(false);
	return result;
	}

	void iteratorClose(JSGlobalObject* globalObject, JSValue iterator)
	{
	VM& vm = globalObject->vm();
	auto throwScope = DECLARE_THROW_SCOPE(vm);
	auto catchScope = DECLARE_CATCH_SCOPE(vm);

	Exception* exception = nullptr;
	if (UNLIKELY(catchScope.exception())) {
	exception = catchScope.exception();
	catchScope.clearException();
	}

	JSValue returnFunction = iterator.get(globalObject, vm.propertyNames->returnKeyword);
	if (UNLIKELY(throwScope.exception()) \|\| returnFunction.isUndefinedOrNull()) {
	if (exception)
	throwException(globalObject, throwScope, exception);
	return;
	}

	auto returnFunctionCallData = getCallData(vm, returnFunction);
	if (returnFunctionCallData.type == CallData::Type::None) {
	if (exception)
	throwException(globalObject, throwScope, exception);
	else
	throwTypeError(globalObject, throwScope);
	return;
	}

	MarkedArgumentBuffer returnFunctionArguments;
	ASSERT(!returnFunctionArguments.hasOverflowed());
	JSValue innerResult = call(globalObject, returnFunction, returnFunctionCallData, iterator, returnFunctionArguments);

	if (exception) {
	throwException(globalObject, throwScope, exception);
	return;
	}

	RETURN_IF_EXCEPTION(throwScope, void());

	if (!innerResult.isObject()) {
	throwTypeError(globalObject, throwScope, "Iterator result interface is not an object."_s);
	return;
	}
	}

	static constexpr PropertyOffset valuePropertyOffset = 0;
	static constexpr PropertyOffset donePropertyOffset = 1;

	Structure* createIteratorResultObjectStructure(VM& vm, JSGlobalObject& globalObject)
	{
	Structure* iteratorResultStructure = vm.structureCache.emptyObjectStructureForPrototype(&globalObject, globalObject.objectPrototype(), JSFinalObject::defaultInlineCapacity());
	PropertyOffset offset;
	iteratorResultStructure = Structure::addPropertyTransition(vm, iteratorResultStructure, vm.propertyNames->value, 0, offset);
	RELEASE_ASSERT(offset == valuePropertyOffset);
	iteratorResultStructure = Structure::addPropertyTransition(vm, iteratorResultStructure, vm.propertyNames->done, 0, offset);
	RELEASE_ASSERT(offset == donePropertyOffset);
	return iteratorResultStructure;
	}

	JSObject* createIteratorResultObject(JSGlobalObject* globalObject, JSValue value, bool done)
	{
	VM& vm = globalObject->vm();
	JSObject* resultObject = constructEmptyObject(vm, globalObject->iteratorResultObjectStructure());
	resultObject->putDirect(vm, valuePropertyOffset, value);
	resultObject->putDirect(vm, donePropertyOffset, jsBoolean(done));
	return resultObject;
	}

	bool hasIteratorMethod(JSGlobalObject* globalObject, JSValue value)
	{
	auto& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	if (!value.isObject())
	return false;

	JSObject* object = asObject(value);
	CallData callData;
	JSValue applyMethod = object->getMethod(globalObject, callData, vm.propertyNames->iteratorSymbol, "Symbol.iterator property should be callable"_s);
	RETURN_IF_EXCEPTION(scope, false);

	return !applyMethod.isUndefined();
	}

	JSValue iteratorMethod(JSGlobalObject* globalObject, JSObject* object)
	{
	auto& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	CallData callData;
	JSValue method = object->getMethod(globalObject, callData, vm.propertyNames->iteratorSymbol, "Symbol.iterator property should be callable"_s);
	RETURN_IF_EXCEPTION(scope, jsUndefined());

	return method;
	}

	IterationRecord iteratorForIterable(JSGlobalObject* globalObject, JSObject* object, JSValue iteratorMethod)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	auto iteratorMethodCallData = getCallData(vm, iteratorMethod);
	if (iteratorMethodCallData.type == CallData::Type::None) {
	throwTypeError(globalObject, scope);
	return { };
	}

	ArgList iteratorMethodArguments;
	JSValue iterator = call(globalObject, iteratorMethod, iteratorMethodCallData, object, iteratorMethodArguments);
	RETURN_IF_EXCEPTION(scope, { });

	if (!iterator.isObject()) {
	throwTypeError(globalObject, scope);
	return { };
	}

	JSValue nextMethod = iterator.getObject()->get(globalObject, vm.propertyNames->next);
	RETURN_IF_EXCEPTION(scope, { });

	return { iterator, nextMethod };
	}

	IterationRecord iteratorForIterable(JSGlobalObject* globalObject, JSValue iterable)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	JSValue iteratorFunction = iterable.get(globalObject, vm.propertyNames->iteratorSymbol);
	RETURN_IF_EXCEPTION(scope, { });

	auto iteratorFunctionCallData = getCallData(vm, iteratorFunction);
	if (iteratorFunctionCallData.type == CallData::Type::None) {
	throwTypeError(globalObject, scope);
	return { };
	}

	ArgList iteratorFunctionArguments;
	JSValue iterator = call(globalObject, iteratorFunction, iteratorFunctionCallData, iterable, iteratorFunctionArguments);
	RETURN_IF_EXCEPTION(scope, { });

	if (!iterator.isObject()) {
	throwTypeError(globalObject, scope);
	return { };
	}

	JSValue nextMethod = iterator.getObject()->get(globalObject, vm.propertyNames->next);
	RETURN_IF_EXCEPTION(scope, { });

	return { iterator, nextMethod };
	}

	IterationMode getIterationMode(VM& vm, JSGlobalObject* globalObject, JSValue iterable, JSValue symbolIterator)
	{
	if (!iterable.inherits<JSArray>(vm))
	return IterationMode::Generic;

	if (!globalObject->arrayIteratorProtocolWatchpointSet().isStillValid())
	return IterationMode::Generic;

	// This is correct because we just checked the watchpoint is still valid.
	JSFunction* symbolIteratorFunction = jsDynamicCast<JSFunction*>(vm, symbolIterator);
	if (!symbolIteratorFunction)
	return IterationMode::Generic;

	// We don't want to allocate the values function just to check if it's the same as our function so we use the concurrent accessor.
	// FIXME: This only works for arrays from the same global object as ourselves but we should be able to support any pairing.
	if (globalObject->arrayProtoValuesFunctionConcurrently() != symbolIteratorFunction)
	return IterationMode::Generic;

	return IterationMode::FastArray;
	}

	IterationMode getIterationMode(VM& vm, JSGlobalObject* globalObject, JSValue iterable)
	{
	if (!iterable.inherits<JSArray>(vm))
	return IterationMode::Generic;

	JSArray* array = jsCast<JSArray*>(iterable);
	Structure* structure = array->structure(vm);
	// FIXME: We want to support broader JSArrays as long as array[@@iterator] is not defined.
	if (!globalObject->isOriginalArrayStructure(structure))
	return IterationMode::Generic;

	if (!globalObject->arrayIteratorProtocolWatchpointSet().isStillValid())
	return IterationMode::Generic;

	// Now, Array has original Array Structures and arrayIteratorProtocolWatchpointSet is not fired.
	// This means,
	// 1. Array.prototype is [[Prototype]].
	// 2. array[@@iterator] is not overridden.
	// 3. Array.prototype[@@iterator] is an expected one.
	// So, we can say this will create an expected ArrayIterator.
	return IterationMode::FastArray;
	}

	} // namespace JSC