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

 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2003-2019 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #include "config.h"
 #include "FunctionConstructor.h"

 #include "ExceptionHelpers.h"
 #include "FunctionPrototype.h"
 #include "JSAsyncFunction.h"
 #include "JSAsyncGeneratorFunction.h"
 #include "JSFunction.h"
 #include "JSGeneratorFunction.h"
 #include "JSGlobalObject.h"
 #include "JSCInlines.h"
 #include <wtf/text/StringBuilder.h>

 namespace JSC {

 STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(FunctionConstructor);

 const ClassInfo FunctionConstructor::s_info = { "Function", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(FunctionConstructor) };

 static JSC_DECLARE_HOST_FUNCTION(constructWithFunctionConstructor);
 static JSC_DECLARE_HOST_FUNCTION(callFunctionConstructor);

 JSC_DEFINE_HOST_FUNCTION(constructWithFunctionConstructor, (JSGlobalObject* globalObject, CallFrame* callFrame))
 {
     ArgList args(callFrame);
     return JSValue::encode(constructFunction(globalObject, callFrame, args, FunctionConstructionMode::Function, callFrame->newTarget()));
 }

 // ECMA 15.3.1 The Function Constructor Called as a Function
 JSC_DEFINE_HOST_FUNCTION(callFunctionConstructor, (JSGlobalObject* globalObject, CallFrame* callFrame))
 {
     ArgList args(callFrame);
     return JSValue::encode(constructFunction(globalObject, callFrame, args));
 }

 FunctionConstructor::FunctionConstructor(VM& vm, Structure* structure)
     : InternalFunction(vm, structure, callFunctionConstructor, constructWithFunctionConstructor)
 {
 }

 void FunctionConstructor::finishCreation(VM& vm, FunctionPrototype* functionPrototype)
 {
     Base::finishCreation(vm, 1, vm.propertyNames->Function.string(), PropertyAdditionMode::WithoutStructureTransition);
     putDirectWithoutTransition(vm, vm.propertyNames->prototype, functionPrototype, PropertyAttribute::DontEnum | PropertyAttribute::DontDelete | PropertyAttribute::ReadOnly);
 }

 static String stringifyFunction(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, FunctionConstructionMode functionConstructionMode, ThrowScope& scope, std::optional<int>& functionConstructorParametersEndPosition)
 {
     const char* prefix = nullptr;
     switch (functionConstructionMode) {
     case FunctionConstructionMode::Function:
         prefix = "function ";
         break;
     case FunctionConstructionMode::Generator:
         prefix = "function *";
         break;
     case FunctionConstructionMode::Async:
         prefix = "async function ";
         break;
     case FunctionConstructionMode::AsyncGenerator:
         prefix = "async function*";
         break;
     }

     // How we stringify functions is sometimes important for web compatibility.
     // See https://bugs.webkit.org/show_bug.cgi?id=24350.
     String program;
     functionConstructorParametersEndPosition = std::nullopt;
     if (args.isEmpty())
         program = makeString(prefix, functionName.string(), "() {\n\n}");
     else if (args.size() == 1) {
         auto body = args.at(0).toWTFString(globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         program = tryMakeString(prefix, functionName.string(), "() {\n", body, "\n}");
         if (UNLIKELY(!program)) {
             throwOutOfMemoryError(globalObject, scope);
             return { };
         }
     } else {
         StringBuilder builder(StringBuilder::OverflowHandler::RecordOverflow);
         builder.append(prefix, functionName.string(), '(');

         auto* jsString = args.at(0).toString(globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         auto viewWithString = jsString->viewWithUnderlyingString(globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         builder.append(viewWithString.view);
         for (size_t i = 1; !builder.hasOverflowed() && i < args.size() - 1; i++) {
             auto* jsString = args.at(i).toString(globalObject);
             RETURN_IF_EXCEPTION(scope, { });
             auto viewWithString = jsString->viewWithUnderlyingString(globalObject);
             RETURN_IF_EXCEPTION(scope, { });
             builder.append(", ", viewWithString.view);
         }
         if (UNLIKELY(builder.hasOverflowed())) {
             throwOutOfMemoryError(globalObject, scope);
             return { };
         }

         functionConstructorParametersEndPosition = builder.length() + 1;

         auto* bodyString = args.at(args.size() - 1).toString(globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         auto body = bodyString->viewWithUnderlyingString(globalObject);
         RETURN_IF_EXCEPTION(scope, { });
         builder.append(") {\n", body.view, "\n}");
         if (UNLIKELY(builder.hasOverflowed())) {
             throwOutOfMemoryError(globalObject, scope);
             return { };
         }
         program = builder.toString();
     }

     return program;
 }

 // ECMA 15.3.2 The Function Constructor
 JSObject* constructFunction(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, const SourceOrigin& sourceOrigin, const String& sourceURL, const TextPosition& position, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     if (UNLIKELY(!globalObject->evalEnabled())) {
         auto codeScope = DECLARE_THROW_SCOPE(vm);
         std::optional<int> functionConstructorParametersEndPosition;
         auto code = stringifyFunction(globalObject, args, functionName, functionConstructionMode, codeScope, functionConstructorParametersEndPosition);
         globalObject->globalObjectMethodTable()->reportViolationForUnsafeEval(globalObject, !code.isNull() ? jsNontrivialString(vm, WTFMove(code)) : nullptr);
         throwException(globalObject, scope, createEvalError(globalObject, globalObject->evalDisabledErrorMessage()));
         return nullptr;
     }
     RELEASE_AND_RETURN(scope, constructFunctionSkippingEvalEnabledCheck(globalObject, args, functionName, sourceOrigin, sourceURL, position, -1, functionConstructionMode, newTarget));
 }

 JSObject* constructFunctionSkippingEvalEnabledCheck(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, const SourceOrigin& sourceOrigin, const String& sourceURL, const TextPosition& position, int overrideLineNumber, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
 {
     VM& vm = globalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     std::optional<int> functionConstructorParametersEndPosition;
     auto program = stringifyFunction(globalObject, args, functionName, functionConstructionMode, scope, functionConstructorParametersEndPosition);
     if (program.isNull())
         return nullptr;

     SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
     JSObject* exception = nullptr;
     FunctionExecutable* function = FunctionExecutable::fromGlobalCode(functionName, globalObject, source, exception, overrideLineNumber, functionConstructorParametersEndPosition);
     if (UNLIKELY(!function)) {
         ASSERT(exception);
         throwException(globalObject, scope, exception);
         return nullptr;
     }

     JSGlobalObject* structureGlobalObject = globalObject;
     bool needsSubclassStructure = newTarget && newTarget != globalObject->functionConstructor();
     if (needsSubclassStructure) {
         structureGlobalObject = getFunctionRealm(globalObject, asObject(newTarget));
         RETURN_IF_EXCEPTION(scope, nullptr);
     }
     Structure* structure = nullptr;
     switch (functionConstructionMode) {
     case FunctionConstructionMode::Function:
         structure = JSFunction::selectStructureForNewFuncExp(structureGlobalObject, function);
         break;
     case FunctionConstructionMode::Generator:
         structure = structureGlobalObject->generatorFunctionStructure();
         break;
     case FunctionConstructionMode::Async:
         structure = structureGlobalObject->asyncFunctionStructure();
         break;
     case FunctionConstructionMode::AsyncGenerator:
         structure = structureGlobalObject->asyncGeneratorFunctionStructure();
         break;
     }

     if (needsSubclassStructure) {
         structure = InternalFunction::createSubclassStructure(globalObject, asObject(newTarget), structure);
         RETURN_IF_EXCEPTION(scope, nullptr);
     }

     switch (functionConstructionMode) {
     case FunctionConstructionMode::Function:
         return JSFunction::create(vm, function, globalObject->globalScope(), structure);
     case FunctionConstructionMode::Generator:
         return JSGeneratorFunction::create(vm, function, globalObject->globalScope(), structure);
     case FunctionConstructionMode::Async:
         return JSAsyncFunction::create(vm, function, globalObject->globalScope(), structure);
     case FunctionConstructionMode::AsyncGenerator:
         return JSAsyncGeneratorFunction::create(vm, function, globalObject->globalScope(), structure);
     }

     ASSERT_NOT_REACHED();
     return nullptr;
 }

 // ECMA 15.3.2 The Function Constructor
 JSObject* constructFunction(JSGlobalObject* globalObject, CallFrame* callFrame, const ArgList& args, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
 {
     VM& vm = globalObject->vm();
     return constructFunction(globalObject, args, vm.propertyNames->anonymous, callFrame->callerSourceOrigin(vm), String(), TextPosition(), functionConstructionMode, newTarget);
 }

 } // namespace JSC
	/*
	* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
	* Copyright (C) 2003-2019 Apple Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#include "config.h"
	#include "FunctionConstructor.h"

	#include "ExceptionHelpers.h"
	#include "FunctionPrototype.h"
	#include "JSAsyncFunction.h"
	#include "JSAsyncGeneratorFunction.h"
	#include "JSFunction.h"
	#include "JSGeneratorFunction.h"
	#include "JSGlobalObject.h"
	#include "JSCInlines.h"
	#include <wtf/text/StringBuilder.h>

	namespace JSC {

	STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(FunctionConstructor);

	const ClassInfo FunctionConstructor::s_info = { "Function", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(FunctionConstructor) };

	static JSC_DECLARE_HOST_FUNCTION(constructWithFunctionConstructor);
	static JSC_DECLARE_HOST_FUNCTION(callFunctionConstructor);

	JSC_DEFINE_HOST_FUNCTION(constructWithFunctionConstructor, (JSGlobalObject* globalObject, CallFrame* callFrame))
	{
	ArgList args(callFrame);
	return JSValue::encode(constructFunction(globalObject, callFrame, args, FunctionConstructionMode::Function, callFrame->newTarget()));
	}

	// ECMA 15.3.1 The Function Constructor Called as a Function
	JSC_DEFINE_HOST_FUNCTION(callFunctionConstructor, (JSGlobalObject* globalObject, CallFrame* callFrame))
	{
	ArgList args(callFrame);
	return JSValue::encode(constructFunction(globalObject, callFrame, args));
	}

	FunctionConstructor::FunctionConstructor(VM& vm, Structure* structure)
	: InternalFunction(vm, structure, callFunctionConstructor, constructWithFunctionConstructor)
	{
	}

	void FunctionConstructor::finishCreation(VM& vm, FunctionPrototype* functionPrototype)
	{
	Base::finishCreation(vm, 1, vm.propertyNames->Function.string(), PropertyAdditionMode::WithoutStructureTransition);
	putDirectWithoutTransition(vm, vm.propertyNames->prototype, functionPrototype, PropertyAttribute::DontEnum \| PropertyAttribute::DontDelete \| PropertyAttribute::ReadOnly);
	}

	static String stringifyFunction(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, FunctionConstructionMode functionConstructionMode, ThrowScope& scope, std::optional<int>& functionConstructorParametersEndPosition)
	{
	const char* prefix = nullptr;
	switch (functionConstructionMode) {
	case FunctionConstructionMode::Function:
	prefix = "function ";
	break;
	case FunctionConstructionMode::Generator:
	prefix = "function *";
	break;
	case FunctionConstructionMode::Async:
	prefix = "async function ";
	break;
	case FunctionConstructionMode::AsyncGenerator:
	prefix = "async function*";
	break;
	}

	// How we stringify functions is sometimes important for web compatibility.
	// See https://bugs.webkit.org/show_bug.cgi?id=24350.
	String program;
	functionConstructorParametersEndPosition = std::nullopt;
	if (args.isEmpty())
	program = makeString(prefix, functionName.string(), "() {\n\n}");
	else if (args.size() == 1) {
	auto body = args.at(0).toWTFString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	program = tryMakeString(prefix, functionName.string(), "() {\n", body, "\n}");
	if (UNLIKELY(!program)) {
	throwOutOfMemoryError(globalObject, scope);
	return { };
	}
	} else {
	StringBuilder builder(StringBuilder::OverflowHandler::RecordOverflow);
	builder.append(prefix, functionName.string(), '(');

	auto* jsString = args.at(0).toString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	auto viewWithString = jsString->viewWithUnderlyingString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	builder.append(viewWithString.view);
	for (size_t i = 1; !builder.hasOverflowed() && i < args.size() - 1; i++) {
	auto* jsString = args.at(i).toString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	auto viewWithString = jsString->viewWithUnderlyingString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	builder.append(", ", viewWithString.view);
	}
	if (UNLIKELY(builder.hasOverflowed())) {
	throwOutOfMemoryError(globalObject, scope);
	return { };
	}

	functionConstructorParametersEndPosition = builder.length() + 1;

	auto* bodyString = args.at(args.size() - 1).toString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	auto body = bodyString->viewWithUnderlyingString(globalObject);
	RETURN_IF_EXCEPTION(scope, { });
	builder.append(") {\n", body.view, "\n}");
	if (UNLIKELY(builder.hasOverflowed())) {
	throwOutOfMemoryError(globalObject, scope);
	return { };
	}
	program = builder.toString();
	}

	return program;
	}

	// ECMA 15.3.2 The Function Constructor
	JSObject* constructFunction(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, const SourceOrigin& sourceOrigin, const String& sourceURL, const TextPosition& position, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	if (UNLIKELY(!globalObject->evalEnabled())) {
	auto codeScope = DECLARE_THROW_SCOPE(vm);
	std::optional<int> functionConstructorParametersEndPosition;
	auto code = stringifyFunction(globalObject, args, functionName, functionConstructionMode, codeScope, functionConstructorParametersEndPosition);
	globalObject->globalObjectMethodTable()->reportViolationForUnsafeEval(globalObject, !code.isNull() ? jsNontrivialString(vm, WTFMove(code)) : nullptr);
	throwException(globalObject, scope, createEvalError(globalObject, globalObject->evalDisabledErrorMessage()));
	return nullptr;
	}
	RELEASE_AND_RETURN(scope, constructFunctionSkippingEvalEnabledCheck(globalObject, args, functionName, sourceOrigin, sourceURL, position, -1, functionConstructionMode, newTarget));
	}

	JSObject* constructFunctionSkippingEvalEnabledCheck(JSGlobalObject* globalObject, const ArgList& args, const Identifier& functionName, const SourceOrigin& sourceOrigin, const String& sourceURL, const TextPosition& position, int overrideLineNumber, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
	{
	VM& vm = globalObject->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	std::optional<int> functionConstructorParametersEndPosition;
	auto program = stringifyFunction(globalObject, args, functionName, functionConstructionMode, scope, functionConstructorParametersEndPosition);
	if (program.isNull())
	return nullptr;

	SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
	JSObject* exception = nullptr;
	FunctionExecutable* function = FunctionExecutable::fromGlobalCode(functionName, globalObject, source, exception, overrideLineNumber, functionConstructorParametersEndPosition);
	if (UNLIKELY(!function)) {
	ASSERT(exception);
	throwException(globalObject, scope, exception);
	return nullptr;
	}

	JSGlobalObject* structureGlobalObject = globalObject;
	bool needsSubclassStructure = newTarget && newTarget != globalObject->functionConstructor();
	if (needsSubclassStructure) {
	structureGlobalObject = getFunctionRealm(globalObject, asObject(newTarget));
	RETURN_IF_EXCEPTION(scope, nullptr);
	}
	Structure* structure = nullptr;
	switch (functionConstructionMode) {
	case FunctionConstructionMode::Function:
	structure = JSFunction::selectStructureForNewFuncExp(structureGlobalObject, function);
	break;
	case FunctionConstructionMode::Generator:
	structure = structureGlobalObject->generatorFunctionStructure();
	break;
	case FunctionConstructionMode::Async:
	structure = structureGlobalObject->asyncFunctionStructure();
	break;
	case FunctionConstructionMode::AsyncGenerator:
	structure = structureGlobalObject->asyncGeneratorFunctionStructure();
	break;
	}

	if (needsSubclassStructure) {
	structure = InternalFunction::createSubclassStructure(globalObject, asObject(newTarget), structure);
	RETURN_IF_EXCEPTION(scope, nullptr);
	}

	switch (functionConstructionMode) {
	case FunctionConstructionMode::Function:
	return JSFunction::create(vm, function, globalObject->globalScope(), structure);
	case FunctionConstructionMode::Generator:
	return JSGeneratorFunction::create(vm, function, globalObject->globalScope(), structure);
	case FunctionConstructionMode::Async:
	return JSAsyncFunction::create(vm, function, globalObject->globalScope(), structure);
	case FunctionConstructionMode::AsyncGenerator:
	return JSAsyncGeneratorFunction::create(vm, function, globalObject->globalScope(), structure);
	}

	ASSERT_NOT_REACHED();
	return nullptr;
	}

	// ECMA 15.3.2 The Function Constructor
	JSObject* constructFunction(JSGlobalObject* globalObject, CallFrame* callFrame, const ArgList& args, FunctionConstructionMode functionConstructionMode, JSValue newTarget)
	{
	VM& vm = globalObject->vm();
	return constructFunction(globalObject, args, vm.propertyNames->anonymous, callFrame->callerSourceOrigin(vm), String(), TextPosition(), functionConstructionMode, newTarget);
	}

	} // namespace JSC