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

 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2003-2017 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 "Completion.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 EncodedJSValue JSC_HOST_CALL constructWithFunctionConstructor(ExecState* exec)
 {
     ArgList args(exec);
     return JSValue::encode(constructFunction(exec, jsCast<InternalFunction*>(exec->jsCallee())->globalObject(exec->vm()), args, FunctionConstructionMode::Function, exec->newTarget()));
 }

 // ECMA 15.3.1 The Function Constructor Called as a Function
 static EncodedJSValue JSC_HOST_CALL callFunctionConstructor(ExecState* exec)
 {
     ArgList args(exec);
     return JSValue::encode(constructFunction(exec, jsCast<InternalFunction*>(exec->jsCallee())->globalObject(exec->vm()), args));
 }

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

 void FunctionConstructor::finishCreation(VM& vm, FunctionPrototype* functionPrototype)
 {
     Base::finishCreation(vm, functionPrototype->classInfo()->className);
     putDirectWithoutTransition(vm, vm.propertyNames->prototype, functionPrototype, PropertyAttribute::DontEnum | PropertyAttribute::DontDelete | PropertyAttribute::ReadOnly);
     putDirectWithoutTransition(vm, vm.propertyNames->length, jsNumber(1), PropertyAttribute::ReadOnly | PropertyAttribute::DontEnum);
 }

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

     if (!globalObject->evalEnabled())
         return throwException(exec, scope, createEvalError(exec, globalObject->evalDisabledErrorMessage()));
     RELEASE_AND_RETURN(scope, constructFunctionSkippingEvalEnabledCheck(exec, globalObject, args, functionName, sourceOrigin, sourceURL, position, -1, functionConstructionMode, newTarget));
 }

 JSObject* constructFunctionSkippingEvalEnabledCheck(
     ExecState* exec, 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 = exec->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);

     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;
     }

     auto checkBody = [&] (const String& body) {
         // The spec mandates that the body parses a valid function body independent
         // of the parameters.
         String program = makeString("(", prefix, "(){\n", body, "\n})");
         SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
         JSValue exception;
         checkSyntax(exec, source, &exception);
         if (exception) {
             scope.throwException(exec, exception);
             return;
         }
     };

     // How we stringify functions is sometimes important for web compatibility.
     // See https://bugs.webkit.org/show_bug.cgi?id=24350.
     String program;
     if (args.isEmpty())
         program = makeString("{", prefix, functionName.string(), "() {\n\n}}");
     else if (args.size() == 1) {
         auto body = args.at(0).toWTFString(exec);
         RETURN_IF_EXCEPTION(scope, nullptr);
         checkBody(body);
         RETURN_IF_EXCEPTION(scope, nullptr);
         program = makeString("{", prefix, functionName.string(), "() {\n", body, "\n}}");
     } else {
         StringBuilder builder;
         builder.append('{');
         builder.append(prefix);
         builder.append(functionName.string());
         builder.append('(');
         StringBuilder parameterBuilder;
         auto viewWithString = args.at(0).toString(exec)->viewWithUnderlyingString(exec);
         RETURN_IF_EXCEPTION(scope, nullptr);
         parameterBuilder.append(viewWithString.view);
         for (size_t i = 1; i < args.size() - 1; i++) {
             parameterBuilder.appendLiteral(", ");
             auto viewWithString = args.at(i).toString(exec)->viewWithUnderlyingString(exec);
             RETURN_IF_EXCEPTION(scope, nullptr);
             parameterBuilder.append(viewWithString.view);
         }
         auto body = args.at(args.size() - 1).toWTFString(exec);
         RETURN_IF_EXCEPTION(scope, nullptr);

         {
             // The spec mandates that the parameters parse as a valid parameter list
             // independent of the function body.
             String program = tryMakeString("(", prefix, "(", parameterBuilder.toString(), "){\n\n})");
             if (UNLIKELY(!program)) {
                 throwOutOfMemoryError(exec, scope);
                 return nullptr;
             }
             SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
             JSValue exception;
             checkSyntax(exec, source, &exception);
             if (exception) {
                 scope.throwException(exec, exception);
                 return nullptr;
             }
         }

         builder.append(parameterBuilder);
         builder.appendLiteral(") {\n");
         checkBody(body);
         RETURN_IF_EXCEPTION(scope, nullptr);
         builder.append(body);
         builder.appendLiteral("\n}}");
         program = builder.toString();
     }

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

     Structure* structure = nullptr;
     switch (functionConstructionMode) {
     case FunctionConstructionMode::Function:
         structure = JSFunction::selectStructureForNewFuncExp(globalObject, function);
         break;
     case FunctionConstructionMode::Generator:
         structure = globalObject->generatorFunctionStructure();
         break;
     case FunctionConstructionMode::Async:
         structure = globalObject->asyncFunctionStructure();
         break;
     case FunctionConstructionMode::AsyncGenerator:
         structure = globalObject->asyncGeneratorFunctionStructure();
         break;
     }

     Structure* subclassStructure = InternalFunction::createSubclassStructure(exec, newTarget, structure);
     RETURN_IF_EXCEPTION(scope, nullptr);

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

     ASSERT_NOT_REACHED();
     return nullptr;
 }

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

 } // namespace JSC
	/*
	* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
	* Copyright (C) 2003-2017 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 "Completion.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 EncodedJSValue JSC_HOST_CALL constructWithFunctionConstructor(ExecState* exec)
	{
	ArgList args(exec);
	return JSValue::encode(constructFunction(exec, jsCast<InternalFunction*>(exec->jsCallee())->globalObject(exec->vm()), args, FunctionConstructionMode::Function, exec->newTarget()));
	}

	// ECMA 15.3.1 The Function Constructor Called as a Function
	static EncodedJSValue JSC_HOST_CALL callFunctionConstructor(ExecState* exec)
	{
	ArgList args(exec);
	return JSValue::encode(constructFunction(exec, jsCast<InternalFunction*>(exec->jsCallee())->globalObject(exec->vm()), args));
	}

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

	void FunctionConstructor::finishCreation(VM& vm, FunctionPrototype* functionPrototype)
	{
	Base::finishCreation(vm, functionPrototype->classInfo()->className);
	putDirectWithoutTransition(vm, vm.propertyNames->prototype, functionPrototype, PropertyAttribute::DontEnum \| PropertyAttribute::DontDelete \| PropertyAttribute::ReadOnly);
	putDirectWithoutTransition(vm, vm.propertyNames->length, jsNumber(1), PropertyAttribute::ReadOnly \| PropertyAttribute::DontEnum);
	}

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

	if (!globalObject->evalEnabled())
	return throwException(exec, scope, createEvalError(exec, globalObject->evalDisabledErrorMessage()));
	RELEASE_AND_RETURN(scope, constructFunctionSkippingEvalEnabledCheck(exec, globalObject, args, functionName, sourceOrigin, sourceURL, position, -1, functionConstructionMode, newTarget));
	}

	JSObject* constructFunctionSkippingEvalEnabledCheck(
	ExecState* exec, 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 = exec->vm();
	auto scope = DECLARE_THROW_SCOPE(vm);

	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;
	}

	auto checkBody = [&] (const String& body) {
	// The spec mandates that the body parses a valid function body independent
	// of the parameters.
	String program = makeString("(", prefix, "(){\n", body, "\n})");
	SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
	JSValue exception;
	checkSyntax(exec, source, &exception);
	if (exception) {
	scope.throwException(exec, exception);
	return;
	}
	};

	// How we stringify functions is sometimes important for web compatibility.
	// See https://bugs.webkit.org/show_bug.cgi?id=24350.
	String program;
	if (args.isEmpty())
	program = makeString("{", prefix, functionName.string(), "() {\n\n}}");
	else if (args.size() == 1) {
	auto body = args.at(0).toWTFString(exec);
	RETURN_IF_EXCEPTION(scope, nullptr);
	checkBody(body);
	RETURN_IF_EXCEPTION(scope, nullptr);
	program = makeString("{", prefix, functionName.string(), "() {\n", body, "\n}}");
	} else {
	StringBuilder builder;
	builder.append('{');
	builder.append(prefix);
	builder.append(functionName.string());
	builder.append('(');
	StringBuilder parameterBuilder;
	auto viewWithString = args.at(0).toString(exec)->viewWithUnderlyingString(exec);
	RETURN_IF_EXCEPTION(scope, nullptr);
	parameterBuilder.append(viewWithString.view);
	for (size_t i = 1; i < args.size() - 1; i++) {
	parameterBuilder.appendLiteral(", ");
	auto viewWithString = args.at(i).toString(exec)->viewWithUnderlyingString(exec);
	RETURN_IF_EXCEPTION(scope, nullptr);
	parameterBuilder.append(viewWithString.view);
	}
	auto body = args.at(args.size() - 1).toWTFString(exec);
	RETURN_IF_EXCEPTION(scope, nullptr);

	{
	// The spec mandates that the parameters parse as a valid parameter list
	// independent of the function body.
	String program = tryMakeString("(", prefix, "(", parameterBuilder.toString(), "){\n\n})");
	if (UNLIKELY(!program)) {
	throwOutOfMemoryError(exec, scope);
	return nullptr;
	}
	SourceCode source = makeSource(program, sourceOrigin, sourceURL, position);
	JSValue exception;
	checkSyntax(exec, source, &exception);
	if (exception) {
	scope.throwException(exec, exception);
	return nullptr;
	}
	}

	builder.append(parameterBuilder);
	builder.appendLiteral(") {\n");
	checkBody(body);
	RETURN_IF_EXCEPTION(scope, nullptr);
	builder.append(body);
	builder.appendLiteral("\n}}");
	program = builder.toString();
	}

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

	Structure* structure = nullptr;
	switch (functionConstructionMode) {
	case FunctionConstructionMode::Function:
	structure = JSFunction::selectStructureForNewFuncExp(globalObject, function);
	break;
	case FunctionConstructionMode::Generator:
	structure = globalObject->generatorFunctionStructure();
	break;
	case FunctionConstructionMode::Async:
	structure = globalObject->asyncFunctionStructure();
	break;
	case FunctionConstructionMode::AsyncGenerator:
	structure = globalObject->asyncGeneratorFunctionStructure();
	break;
	}

	Structure* subclassStructure = InternalFunction::createSubclassStructure(exec, newTarget, structure);
	RETURN_IF_EXCEPTION(scope, nullptr);

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

	ASSERT_NOT_REACHED();
	return nullptr;
	}

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

	} // namespace JSC