L1OrbitCustomGateway

{{
  "language": "Solidity",
  "sources": {
    "contracts/tokenbridge/ethereum/gateway/L1OrbitCustomGateway.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

pragma solidity ^0.8.0;

import { L1CustomGateway } from "./L1CustomGateway.sol";
import { IERC20Inbox } from "../L1ArbitrumMessenger.sol";
import { IERC20Bridge } from "../../libraries/IERC20Bridge.sol";
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

/**
 * @title Gateway for "custom" bridging functionality in an ERC20-based rollup.
 * @notice Adds new entrypoints that have `_feeAmount` as parameter, while entrypoints without that parameter are reverted.
 */
contract L1OrbitCustomGateway is L1CustomGateway {
    using SafeERC20 for IERC20;

    /**
     * @notice Allows L1 Token contract to trustlessly register its custom L2 counterpart, in an ERC20-based rollup. Retryable costs are paid in native token.
     * @param _l2Address counterpart address of L1 token
     * @param _maxGas max gas for L2 retryable execution
     * @param _gasPriceBid gas price for L2 retryable ticket
     * @param _maxSubmissionCost base submission cost for L2 retryable ticket
     * @param _feeAmount total amount of fees in native token to cover for retryable ticket costs. This amount will be transferred from user to bridge.
     * @return Retryable ticket ID
     */
    function registerTokenToL2(
        address _l2Address,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        uint256 _feeAmount
    ) external returns (uint256) {
        return
            registerTokenToL2(
                _l2Address,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                msg.sender,
                _feeAmount
            );
    }

    /**
     * @notice Allows L1 Token contract to trustlessly register its custom L2 counterpart, in an ERC20-based rollup. Retryable costs are paid in native token.
     * @param _l2Address counterpart address of L1 token
     * @param _maxGas max gas for L2 retryable execution
     * @param _gasPriceBid gas price for L2 retryable ticket
     * @param _maxSubmissionCost base submission cost for L2 retryable ticket
     * @param _creditBackAddress address for crediting back overpayment of _maxSubmissionCost
     * @param _feeAmount total amount of fees in native token to cover for retryable ticket costs. This amount will be transferred from user to bridge.
     * @return Retryable ticket ID
     */
    function registerTokenToL2(
        address _l2Address,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        address _creditBackAddress,
        uint256 _feeAmount
    ) public returns (uint256) {
        return
            _registerTokenToL2(
                _l2Address,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                _creditBackAddress,
                _feeAmount
            );
    }

    /**
     * @notice Allows owner to force register a custom L1/L2 token pair.
     * @dev _l1Addresses[i] counterpart is assumed to be _l2Addresses[i]
     * @param _l1Addresses array of L1 addresses
     * @param _l2Addresses array of L2 addresses
     * @param _maxGas max gas for L2 retryable execution
     * @param _gasPriceBid gas price for L2 retryable ticket
     * @param _maxSubmissionCost base submission cost for L2 retryable ticket
     * @param _feeAmount total amount of fees in native token to cover for retryable ticket costs. This amount will be transferred from user to bridge.
     * @return Retryable ticket ID
     */
    function forceRegisterTokenToL2(
        address[] calldata _l1Addresses,
        address[] calldata _l2Addresses,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        uint256 _feeAmount
    ) external onlyOwner returns (uint256) {
        return
            _forceRegisterTokenToL2(
                _l1Addresses,
                _l2Addresses,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                _feeAmount
            );
    }

    /**
     * @notice Revert 'registerTokenToL2' entrypoint which doesn't have total amount of token fees as an argument.
     */
    function registerTokenToL2(
        address,
        uint256,
        uint256,
        uint256,
        address
    ) public payable override returns (uint256) {
        revert("NOT_SUPPORTED_IN_ORBIT");
    }

    /**
     * @notice Revert 'registerTokenToL2' entrypoint which doesn't have total amount of token fees as an argument.
     */
    function registerTokenToL2(
        address,
        uint256,
        uint256,
        uint256
    ) external payable override returns (uint256) {
        revert("NOT_SUPPORTED_IN_ORBIT");
    }

    /**
     * @notice Revert 'forceRegisterTokenToL2' entrypoint which doesn't have total amount of token fees as an argument.
     */
    function forceRegisterTokenToL2(
        address[] calldata,
        address[] calldata,
        uint256,
        uint256,
        uint256
    ) external payable override onlyOwner returns (uint256) {
        revert("NOT_SUPPORTED_IN_ORBIT");
    }

    function _parseUserEncodedData(bytes memory data)
        internal
        pure
        override
        returns (
            uint256 maxSubmissionCost,
            bytes memory callHookData,
            uint256 tokenTotalFeeAmount
        )
    {
        (maxSubmissionCost, callHookData, tokenTotalFeeAmount) = abi.decode(
            data,
            (uint256, bytes, uint256)
        );
    }

    function _initiateDeposit(
        address _refundTo,
        address _from,
        uint256, // _amount, this info is already contained in _data
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        uint256 tokenTotalFeeAmount,
        bytes memory _data
    ) internal override returns (uint256) {
        return
            sendTxToL2CustomRefund(
                inbox,
                counterpartGateway,
                _refundTo,
                _from,
                tokenTotalFeeAmount,
                0,
                L2GasParams({
                    _maxSubmissionCost: _maxSubmissionCost,
                    _maxGas: _maxGas,
                    _gasPriceBid: _gasPriceBid
                }),
                _data
            );
    }

    function _createRetryable(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _totalFeeAmount,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal override returns (uint256) {
        {
            // Transfer native token amount needed to pay for retryable fees to the inbox.
            // Fee tokens will be transferred from user who initiated the action - that's `_user` account in
            // case call was routed by router, or msg.sender in case gateway's entrypoint was called directly.
            address nativeFeeToken = IERC20Bridge(address(getBridge(_inbox))).nativeToken();
            uint256 inboxNativeTokenBalance = IERC20(nativeFeeToken).balanceOf(_inbox);
            if (inboxNativeTokenBalance < _totalFeeAmount) {
                address transferFrom = isRouter(msg.sender) ? _user : msg.sender;
                IERC20(nativeFeeToken).safeTransferFrom(
                    transferFrom,
                    _inbox,
                    _totalFeeAmount - inboxNativeTokenBalance
                );
            }
        }

        return
            IERC20Inbox(_inbox).createRetryableTicket(
                _to,
                _l2CallValue,
                _maxSubmissionCost,
                _refundTo,
                _user,
                _maxGas,
                _gasPriceBid,
                _totalFeeAmount,
                _data
            );
    }
}
"
    },
    "contracts/tokenbridge/ethereum/gateway/L1CustomGateway.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import { ArbitrumEnabledToken } from "../ICustomToken.sol";
import "./L1ArbitrumExtendedGateway.sol";
import "../../arbitrum/gateway/L2CustomGateway.sol";
import "../../libraries/gateway/ICustomGateway.sol";
import "@openzeppelin/contracts/utils/Address.sol";

import "../../libraries/Whitelist.sol";

/**
 * @title Gatway for "custom" bridging functionality
 * @notice Handles some (but not all!) custom Gateway needs.
 */
contract L1CustomGateway is L1ArbitrumExtendedGateway, ICustomGateway {
    using Address for address;
    // stores addresses of L2 tokens to be used
    mapping(address => address) public override l1ToL2Token;
    // owner is able to force add custom mappings
    address public owner;

    // whitelist not used anymore
    address public whitelist;

    // start of inline reentrancy guard
    // https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.2/contracts/utils/ReentrancyGuard.sol
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;
    uint256 private _status;

    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
        _;
        _status = _NOT_ENTERED;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "ONLY_OWNER");
        _;
    }

    function outboundTransferCustomRefund(
        address _l1Token,
        address _refundTo,
        address _to,
        uint256 _amount,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes calldata _data
    ) public payable override nonReentrant returns (bytes memory res) {
        return
            super.outboundTransferCustomRefund(
                _l1Token,
                _refundTo,
                _to,
                _amount,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }

    function finalizeInboundTransfer(
        address _token,
        address _from,
        address _to,
        uint256 _amount,
        bytes calldata _data
    ) public payable override nonReentrant {
        // the superclass checks onlyCounterpartGateway
        super.finalizeInboundTransfer(_token, _from, _to, _amount, _data);
    }

    function initialize(
        address _l1Counterpart,
        address _l1Router,
        address _inbox,
        address _owner
    ) public {
        L1ArbitrumGateway._initialize(_l1Counterpart, _l1Router, _inbox);
        owner = _owner;
        // disable whitelist by default
        whitelist = address(0);
        // reentrancy guard
        _status = _NOT_ENTERED;
    }

    /**
     * @notice Calculate the address used when bridging an ERC20 token
     * @dev the L1 and L2 address oracles may not always be in sync.
     * For example, a custom token may have been registered but not deploy or the contract self destructed.
     * @param l1ERC20 address of L1 token
     * @return L2 address of a bridged ERC20 token
     */
    function calculateL2TokenAddress(address l1ERC20)
        public
        view
        override(ITokenGateway, TokenGateway)
        returns (address)
    {
        return l1ToL2Token[l1ERC20];
    }

    /**
     * @notice Allows L1 Token contract to trustlessly register its custom L2 counterpart. (other registerTokenToL2 method allows excess eth recovery from _maxSubmissionCost and is recommended)
     * @param _l2Address counterpart address of L1 token
     * @param _maxGas max gas for L2 retryable exrecution
     * @param _gasPriceBid gas price for L2 retryable ticket
     * @param  _maxSubmissionCost base submission cost  L2 retryable tick3et
     * @return Retryable ticket ID
     */
    function registerTokenToL2(
        address _l2Address,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost
    ) external payable virtual returns (uint256) {
        return registerTokenToL2(_l2Address, _maxGas, _gasPriceBid, _maxSubmissionCost, msg.sender);
    }

    /**
     * @notice Allows L1 Token contract to trustlessly register its custom L2 counterpart.
     * param _l2Address counterpart address of L1 token
     * param _maxGas max gas for L2 retryable exrecution
     * param _gasPriceBid gas price for L2 retryable ticket
     * param  _maxSubmissionCost base submission cost  L2 retryable tick3et
     * param _creditBackAddress address for crediting back overpayment of _maxSubmissionCost
     * return Retryable ticket ID
     */
    function registerTokenToL2(
        address _l2Address,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        address _creditBackAddress
    ) public payable virtual returns (uint256) {
        return
            _registerTokenToL2(
                _l2Address,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                _creditBackAddress,
                msg.value
            );
    }

    function _registerTokenToL2(
        address _l2Address,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        address _creditBackAddress,
        uint256 _feeAmount
    ) internal returns (uint256) {
        {
            require(
                ArbitrumEnabledToken(msg.sender).isArbitrumEnabled() == uint8(0xb1),
                "NOT_ARB_ENABLED"
            );

            address currL2Addr = l1ToL2Token[msg.sender];
            if (currL2Addr != address(0)) {
                // if token is already set, don't allow it to set a different L2 address
                require(currL2Addr == _l2Address, "NO_UPDATE_TO_DIFFERENT_ADDR");
            }
        }

        l1ToL2Token[msg.sender] = _l2Address;

        address[] memory l1Addresses = new address[](1);
        address[] memory l2Addresses = new address[](1);
        l1Addresses[0] = msg.sender;
        l2Addresses[0] = _l2Address;

        emit TokenSet(l1Addresses[0], l2Addresses[0]);

        bytes memory _data = abi.encodeWithSelector(
            L2CustomGateway.registerTokenFromL1.selector,
            l1Addresses,
            l2Addresses
        );

        return
            sendTxToL2(
                inbox,
                counterpartGateway,
                _creditBackAddress,
                _feeAmount,
                0,
                _maxSubmissionCost,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }

    function setOwner(address newOwner) external onlyOwner {
        require(newOwner != address(0), "INVALID_OWNER");
        owner = newOwner;
    }

    /**
     * @notice Allows owner to force register a custom L1/L2 token pair.
     * @dev _l1Addresses[i] counterpart is assumed to be _l2Addresses[i]
     * @param _l1Addresses array of L1 addresses
     * @param _l2Addresses array of L2 addresses
     * @param _maxGas max gas for L2 retryable exrecution
     * @param _gasPriceBid gas price for L2 retryable ticket
     * @param  _maxSubmissionCost base submission cost  L2 retryable tick3et
     * @return Retryable ticket ID
     */
    function forceRegisterTokenToL2(
        address[] calldata _l1Addresses,
        address[] calldata _l2Addresses,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost
    ) external payable virtual onlyOwner returns (uint256) {
        return
            _forceRegisterTokenToL2(
                _l1Addresses,
                _l2Addresses,
                _maxGas,
                _gasPriceBid,
                _maxSubmissionCost,
                msg.value
            );
    }

    function _forceRegisterTokenToL2(
        address[] calldata _l1Addresses,
        address[] calldata _l2Addresses,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        uint256 _maxSubmissionCost,
        uint256 _feeAmount
    ) internal returns (uint256) {
        require(_l1Addresses.length == _l2Addresses.length, "INVALID_LENGTHS");

        for (uint256 i = 0; i < _l1Addresses.length; i++) {
            // here we assume the owner checked both addresses offchain before force registering
            // require(address(_l1Addresses[i]).isContract(), "MUST_BE_CONTRACT");
            l1ToL2Token[_l1Addresses[i]] = _l2Addresses[i];
            emit TokenSet(_l1Addresses[i], _l2Addresses[i]);
        }

        bytes memory _data = abi.encodeWithSelector(
            L2CustomGateway.registerTokenFromL1.selector,
            _l1Addresses,
            _l2Addresses
        );

        return
            sendTxToL2(
                inbox,
                counterpartGateway,
                msg.sender,
                _feeAmount,
                0,
                _maxSubmissionCost,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }
}
"
    },
    "contracts/tokenbridge/ethereum/L1ArbitrumMessenger.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "@arbitrum/nitro-contracts/src/bridge/IInbox.sol";
import "@arbitrum/nitro-contracts/src/bridge/IOutbox.sol";

/// @notice L1 utility contract to assist with L1 <=> L2 interactions
/// @dev this is an abstract contract instead of library so the functions can be easily overriden when testing
abstract contract L1ArbitrumMessenger {
    event TxToL2(address indexed _from, address indexed _to, uint256 indexed _seqNum, bytes _data);

    struct L2GasParams {
        uint256 _maxSubmissionCost;
        uint256 _maxGas;
        uint256 _gasPriceBid;
    }

    function sendTxToL2CustomRefund(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        L2GasParams memory _l2GasParams,
        bytes memory _data
    ) internal returns (uint256) {
        // alternative function entry point when struggling with the stack size
        return
            sendTxToL2CustomRefund(
                _inbox,
                _to,
                _refundTo,
                _user,
                _l1CallValue,
                _l2CallValue,
                _l2GasParams._maxSubmissionCost,
                _l2GasParams._maxGas,
                _l2GasParams._gasPriceBid,
                _data
            );
    }

    function sendTxToL2(
        address _inbox,
        address _to,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        L2GasParams memory _l2GasParams,
        bytes memory _data
    ) internal returns (uint256) {
        // alternative function entry point when struggling with the stack size
        return
            sendTxToL2(
                _inbox,
                _to,
                _user,
                _l1CallValue,
                _l2CallValue,
                _l2GasParams._maxSubmissionCost,
                _l2GasParams._maxGas,
                _l2GasParams._gasPriceBid,
                _data
            );
    }

    function sendTxToL2CustomRefund(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal returns (uint256) {
        uint256 seqNum = _createRetryable(
            _inbox,
            _to,
            _refundTo,
            _user,
            _l1CallValue,
            _l2CallValue,
            _maxSubmissionCost,
            _maxGas,
            _gasPriceBid,
            _data
        );
        emit TxToL2(_user, _to, seqNum, _data);
        return seqNum;
    }

    function sendTxToL2(
        address _inbox,
        address _to,
        address _user,
        uint256 _l1CallValue,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal returns (uint256) {
        return
            sendTxToL2CustomRefund(
                _inbox,
                _to,
                _user,
                _user,
                _l1CallValue,
                _l2CallValue,
                _maxSubmissionCost,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }

    function getBridge(address _inbox) internal view returns (IBridge) {
        return IInbox(_inbox).bridge();
    }

    /// @dev the l2ToL1Sender behaves as the tx.origin, the msg.sender should be validated to protect against reentrancies
    function getL2ToL1Sender(address _inbox) internal view returns (address) {
        IOutbox outbox = IOutbox(getBridge(_inbox).activeOutbox());
        address l2ToL1Sender = outbox.l2ToL1Sender();

        require(l2ToL1Sender != address(0), "NO_SENDER");
        return l2ToL1Sender;
    }

    /**
     * @notice Calls inbox to create retryable ticket. Default implementation is for standard Eth-based rollup, but it can be overriden to create retryable in ERC20-based rollup.
     * @param _inbox address of the rollup's inbox
     * @param _to destination L2 contract address
     * @param _refundTo refund address for excess fee
     * @param _user refund address for callvalue
     * @param _totalFeeAmount amount of fees to pay, in Eth or native token, for retryable's execution
     * @param _l2CallValue call value for retryable L2 message
     * @param _maxSubmissionCost Max gas deducted from user's L2 balance to cover base submission fee
     * @param _maxGas Max gas deducted from user's L2 balance to cover L2 execution
     * @param _gasPriceBid price bid for L2 execution
     * @param _data ABI encoded data of L2 message
     * @return unique message number of the retryable transaction
     */
    function _createRetryable(
        address _inbox,
        address _to,
        address _refundTo,
        address _user,
        uint256 _totalFeeAmount,
        uint256 _l2CallValue,
        uint256 _maxSubmissionCost,
        uint256 _maxGas,
        uint256 _gasPriceBid,
        bytes memory _data
    ) internal virtual returns (uint256) {
        return
            IInbox(_inbox).createRetryableTicket{ value: _totalFeeAmount }(
                _to,
                _l2CallValue,
                _maxSubmissionCost,
                _refundTo,
                _user,
                _maxGas,
                _gasPriceBid,
                _data
            );
    }
}

interface IERC20Inbox {
    function createRetryableTicket(
        address to,
        uint256 l2CallValue,
        uint256 maxSubmissionCost,
        address excessFeeRefundAddress,
        address callValueRefundAddress,
        uint256 gasLimit,
        uint256 maxFeePerGas,
        uint256 tokenTotalFeeAmount,
        bytes calldata data
    ) external returns (uint256);
}"
    },
    "contracts/tokenbridge/libraries/IERC20Bridge.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

interface IERC20Bridge {
    /**
     * @dev token that is escrowed in bridge on L1 side and minted on L2 as native currency. Also fees are paid in this token.
     */
    function nativeToken() external view returns (address);
}
"
    },
    "node_modules/@openzeppelin/contracts/token/ERC20/ERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, amount);
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, spender) + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _balances[to] += amount;
        }

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _balances[account] += amount;
        }
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _totalSupply -= amount;
        }

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - amount);
            }
        }
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}
"
    },
    "node_modules/@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    function safePermit(
        IERC20Permit token,
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) internal {
        uint256 nonceBefore = token.nonces(owner);
        token.permit(owner, spender, value, deadline, v, r, s);
        uint256 nonceAfter = token.nonces(owner);
        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
"
    },
    "contracts/tokenbridge/ethereum/ICustomToken.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

interface ArbitrumEnabledToken {
    /// @notice should return `0xb1` if token is enabled for arbitrum gateways
    /// @dev Previous implmentation used to return `uint8(0xa4b1)`, however that causes compile time error in Solidity 0.8. due to type mismatch.
    ///      In current version `uint8(0xb1)` shall be returned, which results in no change as that's the same value as truncated `uint8(0xa4b1)`.
    function isArbitrumEnabled() external view returns (uint8);
}

/**
 * @title Minimum expected interface for L1 custom token (see TestCustomTokenL1.sol for an example implementation)
 */
interface ICustomToken is ArbitrumEnabledToken {
    /**
     * @notice Should make an external call to EthERC20Bridge.registerCustomL2Token
     */
    function registerTokenOnL2(
        address l2CustomTokenAddress,
        uint256 maxSubmissionCostForCustomBridge,
        uint256 maxSubmissionCostForRouter,
        uint256 maxGasForCustomBridge,
        uint256 maxGasForRouter,
        uint256 gasPriceBid,
        uint256 valueForGateway,
        uint256 valueForRouter,
        address creditBackAddress
    ) external payable;

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    function balanceOf(address account) external view returns (uint256);
}

interface L1MintableToken is ICustomToken {
    function bridgeMint(address account, uint256 amount) external;
}

interface L1ReverseToken is L1MintableToken {
    function bridgeBurn(address account, uint256 amount) external;
}
"
    },
    "contracts/tokenbridge/ethereum/gateway/L1ArbitrumExtendedGateway.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "../../libraries/ITransferAndCall.sol";

import "./L1ArbitrumGateway.sol";

interface ITradeableExitReceiver {
    function onExitTransfer(
        address sender,
        uint256 exitNum,
        bytes calldata data
    ) external returns (bool);
}

abstract contract L1ArbitrumExtendedGateway is L1ArbitrumGateway {
    using Address for address;

    struct ExitData {
        bool isExit;
        address _newTo;
        bytes _newData;
    }

    mapping(bytes32 => ExitData) public redirectedExits;

    event WithdrawRedirected(
        address indexed from,
        address indexed to,
        uint256 indexed exitNum,
        bytes newData,
        bytes data,
        bool madeExternalCall
    );

    /**
     * @notice Allows a user to redirect their right to claim a withdrawal to another address.
     * @dev This method also allows you to make an arbitrary call after the transfer.
     * This does not validate if the exit was already triggered. It is assumed the `_exitNum` is
     * validated off-chain to ensure this was not yet triggered.
     * @param _exitNum Sequentially increasing exit counter determined by the L2 bridge
     * @param _initialDestination address the L2 withdrawal call initially set as the destination.
     * @param _newDestination address the L1 will now call instead of the previously set destination
     * @param _newData data to be used in inboundEscrowAndCall
     * @param _data optional data for external call upon transfering the exit
     */
    function transferExitAndCall(
        uint256 _exitNum,
        address _initialDestination,
        address _newDestination,
        bytes calldata _newData,
        bytes calldata _data
    ) external {
        // the initial data doesn't make a difference when transfering you exit
        // since the L2 bridge gives a unique exit ID to each exit
        (address expectedSender, ) = getExternalCall(_exitNum, _initialDestination, "");

        // if you want to transfer your exit, you must be the current destination
        require(msg.sender == expectedSender, "NOT_EXPECTED_SENDER");
        // the inboundEscrowAndCall functionality has been disabled, so no data is allowed
        require(_newData.length == 0, "NO_DATA_ALLOWED");

        setRedirectedExit(_exitNum, _initialDestination, _newDestination, _newData);

        if (_data.length > 0) {
            require(_newDestination.isContract(), "TO_NOT_CONTRACT");
            bool success = ITradeableExitReceiver(_newDestination).onExitTransfer(
                expectedSender,
                _exitNum,
                _data
            );
            require(success, "TRANSFER_HOOK_FAIL");
        }

        emit WithdrawRedirected(
            expectedSender,
            _newDestination,
            _exitNum,
            _newData,
            _data,
            _data.length > 0
        );
    }

    /// @notice this does not verify if the external call was already done
    function getExternalCall(
        uint256 _exitNum,
        address _initialDestination,
        bytes memory _initialData
    ) public view virtual override returns (address target, bytes memory data) {
        // this function is virtual so that subclasses can override it with custom logic where necessary
        bytes32 withdrawData = encodeWithdrawal(_exitNum, _initialDestination);
        ExitData storage exit = redirectedExits[withdrawData];

        // here we don't authenticate `_initialData`. we could hash it into `withdrawData` but would increase gas costs
        // this is safe because if the exit isn't overriden, the _initialData coming from L2 is trusted
        // but if the exit is traded, all we care about is the latest user calldata
        if (exit.isExit) {
            return (exit._newTo, exit._newData);
        } else {
            return (_initialDestination, _initialData);
        }
    }

    function setRedirectedExit(
        uint256 _exitNum,
        address _initialDestination,
        address _newDestination,
        bytes memory _newData
    ) internal virtual {
        bytes32 withdrawData = encodeWithdrawal(_exitNum, _initialDestination);
        redirectedExits[withdrawData] = ExitData(true, _newDestination, _newData);
    }

    function encodeWithdrawal(uint256 _exitNum, address _initialDestination)
        public
        pure
        returns (bytes32)
    {
        // here we assume the L2 bridge gives a unique exitNum to each exit
        return keccak256(abi.encode(_exitNum, _initialDestination));
    }
}
"
    },
    "contracts/tokenbridge/arbitrum/gateway/L2CustomGateway.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pragma solidity ^0.8.0;

import "./L2ArbitrumGateway.sol";
import "../../libraries/gateway/ICustomGateway.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract L2CustomGateway is L2ArbitrumGateway, ICustomGateway {
    // stores addresses of L2 tokens to be used
    mapping(address => address) public override l1ToL2Token;

    function initialize(address _l1Counterpart, address _router) public {
        L2ArbitrumGateway._initialize(_l1Counterpart, _router);
    }

    /**
     * @notice internal utility function used to handle when no contract is deployed at expected address
     */
    function handleNoContract(
        address _l1Token,
        address, /* expectedL2Address */
        address _from,
        address, /* _to */
        uint256 _amount,
        bytes memory /* gatewayData */
    ) internal override returns (bool shouldHalt) {
        // it is assumed that the custom token is deployed in the L2 before deposits are made
        // trigger withdrawal
        // we don't need the return value from triggerWithdrawal since this is forcing a withdrawal back to the L1
        // instead of composing with a L2 dapp
        triggerWithdrawal(_l1Token, address(this), _from, _amount, "");
        return true;
    }

    /**
     * @notice Calculate the address used when bridging an ERC20 token
     * @dev the L1 and L2 address oracles may not always be in sync.
     * For example, a custom token may have been registered but not deploy or the contract self destructed.
     * @param l1ERC20 address of L1 token
     * @return L2 address of a bridged ERC20 token
     */
    function calculateL2TokenAddress(address l1ERC20) public view override returns (address) {
        return l1ToL2Token[l1ERC20];
    }

    function registerTokenFromL1(address[] calldata l1Address, address[] calldata l2Address)
        external
        onlyCounterpartGateway
    {
        // we assume both arrays are the same length, safe since its encoded by the L1
        for (uint256 i = 0; i < l1Address.length; i++) {
            // here we don't check if l2Address is a contract and instead deal with that behaviour
            // in `handleNoContract` this way we keep the l1 and l2 address oracles in sync
            l1ToL2Token[l1Address[i]] = l2Address[i];
            emit TokenSet(l1Address[i], l2Address[i]);
        }
    }
}
"
    },
    "contracts/tokenbridge/libraries/gateway/ICustomGateway.sol": {
      "content": "// SPDX-License-Identifier: Apache-2.0

/*
 * Copyright 2020, Offchain Labs, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;

// import "./ITokenGateway.sol";

interface ICustomGateway {
    function l1ToL2Token(address _l1Token) external view returns (address _l2Token);

    event TokenSet(address indexed l1Address, address indexed l2Address);
}
"
    },
    "node_modules/@openzeppelin/contracts/utils/Address.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
     * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
     *
     * _Available since v4.8._
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        if (success) {
            if (returndata.length == 0) {
                // only check isContract if the call was successful and the return data is empty
                // otherwise we already know that it was a contract
                require(isContract(target), "Address: call to non-contract");
            }
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason or using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            _revert(returndata, errorMessage);
        }
    }

    function _revert(bytes memory returndata, string memory errorMessage) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            /// @solidity memory-safe-assembly
            assembly {
                let returndata_size := mload(returndata)
                revert(add(32, returndata), returndata_size)