Contract 0x71b821aa52a49f32eed535fca6eb5aa130085978 1

 

Contract Overview

0xBitcoin: 0xBTC Token
Balance:
0 MATIC

MATIC Value:
$0.00

Token:
Ad
Ad
Txn Hash Method
Block
From
To
Value [Txn Fee]
0x10c822ffd1c51f6368c39a6e280de7819bbba408ce5c14db6125724d35acf15fApprove204760952021-10-22 4:58:271 hr 29 mins ago0x70d1bb759e18bbff6d04d11d48e6d18a477f7d73 IN  0xBitcoin: 0xBTC Token0 MATIC0.00140136
0xa1004f9d6bb9b6f9d28d75944802e391cc14eb27e3d3fcd44bf1dfcf857bd725Approve204675012021-10-21 23:11:517 hrs 16 mins ago0xe0e009584836428be45b92459efca0209e969674 IN  0xBitcoin: 0xBTC Token0 MATIC0.001541496
0x5336ed796403fc78c1044b7980fee7360bf9e037f5b92a1fe02c352aaf7394bbApprove204663072021-10-21 22:24:278 hrs 3 mins ago0x8178cde1c898758cd345dd4236954db2b1e6eb9a IN  0xBitcoin: 0xBTC Token0 MATIC0.00163492
0x7409c38da61b99400fa73ad742154a142c497d7a251f0a05971541e9f1e286f2Approve204575742021-10-21 16:32:3913 hrs 55 mins ago0x849f5cc001292650d9d2e773a4fb1f77a117c42d IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xfa431cb1f692a9d8a2740d1ce6df56cfc248db3abbd1505ec1585101e725ea80Approve204487672021-10-21 10:56:1119 hrs 32 mins ago0x86a6aa6744d91153944ab267ed6c4e4f21d44cb7 IN  0xBitcoin: 0xBTC Token0 MATIC0.001494784
0x1a82e6a9569af8155d87d4f6cae3dcb6470f674b1317052ebe4b3c98d2f81366Approve204458182021-10-21 8:55:1821 hrs 33 mins ago0x2a6d78e78dcd946f1bc6e150e5b83f174e6e7787 IN  0xBitcoin: 0xBTC Token0 MATIC0.00143654
0x8f52e391ee6cb670fd076d181d7f77b29e99e0c10ffb6694fba0f3cc3ff9b18bApprove204409852021-10-21 5:43:061 day 45 mins ago0xfa35113163bfd33c18a01d1a62d4d14a1ed30a42 IN  0xBitcoin: 0xBTC Token0 MATIC0.0093424
0x8a33851d8bf9d45490e256ece98e51f0fd24a5cc5ad1dd32162e33eb4d6a937cApprove204377732021-10-21 3:39:541 day 2 hrs ago0x0d3dc6528c9dbe07c5b875f780414998a7828d55 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xdbf9b2b06d84dccf04f4bafd8140cea7881e9f97324c4c6bedf8e3af65e751b3Approve204332282021-10-21 0:46:141 day 5 hrs ago0x3379cab328b4eda51201a55b9f5134a02a5dfe4c IN  0xBitcoin: 0xBTC Token0 MATIC0.001494784
0xc15c54d5664d3369a711a1904c6b7dc36090b3b071ea2622aada2f544e7c0286Approve204202012021-10-20 15:47:041 day 14 hrs ago0xd72cdc874a8e5a0f571e9d001ffd6c289665bddc IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x28d40a5ec66c3d66d4cab2719e69e3b8878afd93ce436136763e53851a38d9f5Approve204200862021-10-20 15:40:171 day 14 hrs ago0xe9bf8d45bbaefa6bfe3a8a930c796c7f31f5ef5c IN  0xBitcoin: 0xBTC Token0 MATIC0.00139092
0x7277a3425cdc4c76cde0e3adae557ad0fc02cb299d43e05e83d3247b12a62836Approve204186912021-10-20 14:48:151 day 15 hrs ago0xe493e641e690e8f039858e051e4266e63104ab2f IN  0xBitcoin: 0xBTC Token0 MATIC0.00079428
0x6ddd1a28fb344abf31f2ba7b8a69b754fce504cf482737f048ab54e298dca013Approve204186862021-10-20 14:47:531 day 15 hrs ago0xe493e641e690e8f039858e051e4266e63104ab2f IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x0a7f83e418d735d3bcd8d8fa1c0fbb44afdfc67db8cdcb37f7b0419204e2084eApprove204179562021-10-20 14:22:491 day 16 hrs ago0xe6977a5ff23160f1785530f3332eebb01ef30e97 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x910e4529b680cde7eb4f30bbc16e2f937f494593ea23f8fd881cea2b6c247425Approve204152502021-10-20 12:38:471 day 17 hrs ago0xe3510c639f41447049a6cc56afa4afcf3be75b3a IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xdb188f4ed80d9a636c6b708cd65524561b609845f23b11da2c4cf871e63384e7Approve204148792021-10-20 12:23:531 day 18 hrs ago0x293fa00098fc650c5c99d7f803191d42be36990c IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x29ea229ca42b52451c4c6cb4d7dc6568f298cb13cf31bc40f7010d22b4fea153Approve204146722021-10-20 12:14:391 day 18 hrs ago0x21991f49093d724ba1b489f82e3765c3cded7323 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xec2ea9c19013fe94883e17471cf29d9483fafa6107a1664317b067f7ef65b37dApprove204142582021-10-20 11:54:271 day 18 hrs ago0x92ebb5d970189b56cbc4e425881968f686b606d7 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x141b43d83d73be2a6b2a1f05f274289e6a368fbe4109ee58e5d139b89eb0f2e9Approve204134292021-10-20 11:23:471 day 19 hrs ago0x0e9292b8724c0ec56dbe9a99df4957673a1a00a0 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xdf6c6b4ec34edc48b556d20d7169d2d4305d2a572e2846f40be78bf84bb48fcaApprove204132952021-10-20 11:19:111 day 19 hrs ago0x68157b8633c211564515017459a00514f77b5a0a IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x32e554d5f060848e24631547b4ad4e0157d3efa0780ebcbcb43b5ed856c8edfaApprove204132022021-10-20 11:14:311 day 19 hrs ago0xe413b09654b6ae3d0668ec57d41df9e0ebdbf3be IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x3f048beaaaedb758cde4ade7b029b9e660af2ee0eda69009c821b894f011eb8eApprove204128442021-10-20 10:59:251 day 19 hrs ago0x3e130598205954cfbba55b3faa32b9e6af3d3248 IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0xff1926c3ea8609ba0b3639a182b252b35b5c76b81f03b0de51929b91308b52f1Approve204096202021-10-20 8:45:511 day 21 hrs ago0x783b6470565454f3b3fd4b4ffb47794f6ecb02eb IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x9bb35920be198073176237a4e333db5efae2563fa237ccece05260bb6289e8d4Approve204094642021-10-20 8:37:371 day 21 hrs ago0xbf5a484a9fc4ae22413e4bc9cce565b48ced95bc IN  0xBitcoin: 0xBTC Token0 MATIC0.00139128
0x2504b8e0957a7a8e434a1a3353058507b1e5ef0b535d2a089bc4a03decb3c95bApprove204082722021-10-20 7:50:171 day 22 hrs ago0x6410ab451dba9d6238e3e9d064e0752048f54e4c IN  0xBitcoin: 0xBTC Token0 MATIC0.00140136
[ Download CSV Export 

OVERVIEW

Pure-mined neutral token.

Parent Txn Hash Block From To Value
Loading

Contract Source Code Verified (Exact Match)

Contract Name:
ChildERC20

Compiler Version
v0.6.6+commit.6c089d02

Optimization Enabled:
No with 200 runs

Other Settings:
default evmVersion, None license

Contract Source Code (Solidity)

/**
 *Submitted for verification at polygonscan.com on 2021-06-29
*/

// File: @openzeppelin/contracts/GSN/Context.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/math/SafeMath.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: @openzeppelin/contracts/utils/Address.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.2;

/**
 * @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
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    /**
     * @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");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (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 functionCall(target, data, "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");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
            // 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

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;





/**
 * @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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of 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 {
    using SafeMath for uint256;
    using Address for address;

    mapping (address => uint256) private _balances;

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

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
    }

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

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view 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 {_setupDecimals} is
     * called.
     *
     * 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 returns (uint8) {
        return _decimals;
    }

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

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

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, 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}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), 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};
     *
     * Requirements:
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(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) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is 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:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, 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
     *
     * - `to` 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 = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(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);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
     *
     * This is 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 Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    /**
     * @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 to 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 { }
}

// File: @openzeppelin/contracts/utils/EnumerableSet.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;

/**
 * @dev Library for managing
 * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
 * types.
 *
 * Sets have the following properties:
 *
 * - Elements are added, removed, and checked for existence in constant time
 * (O(1)).
 * - Elements are enumerated in O(n). No guarantees are made on the ordering.
 *
 * ```
 * contract Example {
 *     // Add the library methods
 *     using EnumerableSet for EnumerableSet.AddressSet;
 *
 *     // Declare a set state variable
 *     EnumerableSet.AddressSet private mySet;
 * }
 * ```
 *
 * As of v3.0.0, only sets of type `address` (`AddressSet`) and `uint256`
 * (`UintSet`) are supported.
 */
library EnumerableSet {
    // To implement this library for multiple types with as little code
    // repetition as possible, we write it in terms of a generic Set type with
    // bytes32 values.
    // The Set implementation uses private functions, and user-facing
    // implementations (such as AddressSet) are just wrappers around the
    // underlying Set.
    // This means that we can only create new EnumerableSets for types that fit
    // in bytes32.

    struct Set {
        // Storage of set values
        bytes32[] _values;

        // Position of the value in the `values` array, plus 1 because index 0
        // means a value is not in the set.
        mapping (bytes32 => uint256) _indexes;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function _add(Set storage set, bytes32 value) private returns (bool) {
        if (!_contains(set, value)) {
            set._values.push(value);
            // The value is stored at length-1, but we add 1 to all indexes
            // and use 0 as a sentinel value
            set._indexes[value] = set._values.length;
            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function _remove(Set storage set, bytes32 value) private returns (bool) {
        // We read and store the value's index to prevent multiple reads from the same storage slot
        uint256 valueIndex = set._indexes[value];

        if (valueIndex != 0) { // Equivalent to contains(set, value)
            // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
            // the array, and then remove the last element (sometimes called as 'swap and pop').
            // This modifies the order of the array, as noted in {at}.

            uint256 toDeleteIndex = valueIndex - 1;
            uint256 lastIndex = set._values.length - 1;

            // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
            // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.

            bytes32 lastvalue = set._values[lastIndex];

            // Move the last value to the index where the value to delete is
            set._values[toDeleteIndex] = lastvalue;
            // Update the index for the moved value
            set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based

            // Delete the slot where the moved value was stored
            set._values.pop();

            // Delete the index for the deleted slot
            delete set._indexes[value];

            return true;
        } else {
            return false;
        }
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function _contains(Set storage set, bytes32 value) private view returns (bool) {
        return set._indexes[value] != 0;
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function _length(Set storage set) private view returns (uint256) {
        return set._values.length;
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function _at(Set storage set, uint256 index) private view returns (bytes32) {
        require(set._values.length > index, "EnumerableSet: index out of bounds");
        return set._values[index];
    }

    // AddressSet

    struct AddressSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(AddressSet storage set, address value) internal returns (bool) {
        return _add(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(AddressSet storage set, address value) internal returns (bool) {
        return _remove(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(AddressSet storage set, address value) internal view returns (bool) {
        return _contains(set._inner, bytes32(uint256(value)));
    }

    /**
     * @dev Returns the number of values in the set. O(1).
     */
    function length(AddressSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(AddressSet storage set, uint256 index) internal view returns (address) {
        return address(uint256(_at(set._inner, index)));
    }


    // UintSet

    struct UintSet {
        Set _inner;
    }

    /**
     * @dev Add a value to a set. O(1).
     *
     * Returns true if the value was added to the set, that is if it was not
     * already present.
     */
    function add(UintSet storage set, uint256 value) internal returns (bool) {
        return _add(set._inner, bytes32(value));
    }

    /**
     * @dev Removes a value from a set. O(1).
     *
     * Returns true if the value was removed from the set, that is if it was
     * present.
     */
    function remove(UintSet storage set, uint256 value) internal returns (bool) {
        return _remove(set._inner, bytes32(value));
    }

    /**
     * @dev Returns true if the value is in the set. O(1).
     */
    function contains(UintSet storage set, uint256 value) internal view returns (bool) {
        return _contains(set._inner, bytes32(value));
    }

    /**
     * @dev Returns the number of values on the set. O(1).
     */
    function length(UintSet storage set) internal view returns (uint256) {
        return _length(set._inner);
    }

   /**
    * @dev Returns the value stored at position `index` in the set. O(1).
    *
    * Note that there are no guarantees on the ordering of values inside the
    * array, and it may change when more values are added or removed.
    *
    * Requirements:
    *
    * - `index` must be strictly less than {length}.
    */
    function at(UintSet storage set, uint256 index) internal view returns (uint256) {
        return uint256(_at(set._inner, index));
    }
}

// File: @openzeppelin/contracts/access/AccessControl.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.6.0;




/**
 * @dev Contract module that allows children to implement role-based access
 * control mechanisms.
 *
 * Roles are referred to by their `bytes32` identifier. These should be exposed
 * in the external API and be unique. The best way to achieve this is by
 * using `public constant` hash digests:
 *
 * ```
 * bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
 * ```
 *
 * Roles can be used to represent a set of permissions. To restrict access to a
 * function call, use {hasRole}:
 *
 * ```
 * function foo() public {
 *     require(hasRole(MY_ROLE, msg.sender));
 *     ...
 * }
 * ```
 *
 * Roles can be granted and revoked dynamically via the {grantRole} and
 * {revokeRole} functions. Each role has an associated admin role, and only
 * accounts that have a role's admin role can call {grantRole} and {revokeRole}.
 *
 * By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
 * that only accounts with this role will be able to grant or revoke other
 * roles. More complex role relationships can be created by using
 * {_setRoleAdmin}.
 *
 * WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
 * grant and revoke this role. Extra precautions should be taken to secure
 * accounts that have been granted it.
 */
abstract contract AccessControl is Context {
    using EnumerableSet for EnumerableSet.AddressSet;
    using Address for address;

    struct RoleData {
        EnumerableSet.AddressSet members;
        bytes32 adminRole;
    }

    mapping (bytes32 => RoleData) private _roles;

    bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;

    /**
     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
     *
     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
     * {RoleAdminChanged} not being emitted signaling this.
     *
     * _Available since v3.1._
     */
    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);

    /**
     * @dev Emitted when `account` is granted `role`.
     *
     * `sender` is the account that originated the contract call, an admin role
     * bearer except when using {_setupRole}.
     */
    event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Emitted when `account` is revoked `role`.
     *
     * `sender` is the account that originated the contract call:
     *   - if using `revokeRole`, it is the admin role bearer
     *   - if using `renounceRole`, it is the role bearer (i.e. `account`)
     */
    event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);

    /**
     * @dev Returns `true` if `account` has been granted `role`.
     */
    function hasRole(bytes32 role, address account) public view returns (bool) {
        return _roles[role].members.contains(account);
    }

    /**
     * @dev Returns the number of accounts that have `role`. Can be used
     * together with {getRoleMember} to enumerate all bearers of a role.
     */
    function getRoleMemberCount(bytes32 role) public view returns (uint256) {
        return _roles[role].members.length();
    }

    /**
     * @dev Returns one of the accounts that have `role`. `index` must be a
     * value between 0 and {getRoleMemberCount}, non-inclusive.
     *
     * Role bearers are not sorted in any particular way, and their ordering may
     * change at any point.
     *
     * WARNING: When using {getRoleMember} and {getRoleMemberCount}, make sure
     * you perform all queries on the same block. See the following
     * https://forum.openzeppelin.com/t/iterating-over-elements-on-enumerableset-in-openzeppelin-contracts/2296[forum post]
     * for more information.
     */
    function getRoleMember(bytes32 role, uint256 index) public view returns (address) {
        return _roles[role].members.at(index);
    }

    /**
     * @dev Returns the admin role that controls `role`. See {grantRole} and
     * {revokeRole}.
     *
     * To change a role's admin, use {_setRoleAdmin}.
     */
    function getRoleAdmin(bytes32 role) public view returns (bytes32) {
        return _roles[role].adminRole;
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function grantRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to grant");

        _grantRole(role, account);
    }

    /**
     * @dev Revokes `role` from `account`.
     *
     * If `account` had been granted `role`, emits a {RoleRevoked} event.
     *
     * Requirements:
     *
     * - the caller must have ``role``'s admin role.
     */
    function revokeRole(bytes32 role, address account) public virtual {
        require(hasRole(_roles[role].adminRole, _msgSender()), "AccessControl: sender must be an admin to revoke");

        _revokeRole(role, account);
    }

    /**
     * @dev Revokes `role` from the calling account.
     *
     * Roles are often managed via {grantRole} and {revokeRole}: this function's
     * purpose is to provide a mechanism for accounts to lose their privileges
     * if they are compromised (such as when a trusted device is misplaced).
     *
     * If the calling account had been granted `role`, emits a {RoleRevoked}
     * event.
     *
     * Requirements:
     *
     * - the caller must be `account`.
     */
    function renounceRole(bytes32 role, address account) public virtual {
        require(account == _msgSender(), "AccessControl: can only renounce roles for self");

        _revokeRole(role, account);
    }

    /**
     * @dev Grants `role` to `account`.
     *
     * If `account` had not been already granted `role`, emits a {RoleGranted}
     * event. Note that unlike {grantRole}, this function doesn't perform any
     * checks on the calling account.
     *
     * [WARNING]
     * ====
     * This function should only be called from the constructor when setting
     * up the initial roles for the system.
     *
     * Using this function in any other way is effectively circumventing the admin
     * system imposed by {AccessControl}.
     * ====
     */
    function _setupRole(bytes32 role, address account) internal virtual {
        _grantRole(role, account);
    }

    /**
     * @dev Sets `adminRole` as ``role``'s admin role.
     *
     * Emits a {RoleAdminChanged} event.
     */
    function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
        emit RoleAdminChanged(role, _roles[role].adminRole, adminRole);
        _roles[role].adminRole = adminRole;
    }

    function _grantRole(bytes32 role, address account) private {
        if (_roles[role].members.add(account)) {
            emit RoleGranted(role, account, _msgSender());
        }
    }

    function _revokeRole(bytes32 role, address account) private {
        if (_roles[role].members.remove(account)) {
            emit RoleRevoked(role, account, _msgSender());
        }
    }
}

// File: contracts/common/AccessControlMixin.sol

pragma solidity 0.6.6;


contract AccessControlMixin is AccessControl {
    string private _revertMsg;
    function _setupContractId(string memory contractId) internal {
        _revertMsg = string(abi.encodePacked(contractId, ": INSUFFICIENT_PERMISSIONS"));
    }

    modifier only(bytes32 role) {
        require(
            hasRole(role, _msgSender()),
            _revertMsg
        );
        _;
    }
}

// File: contracts/child/ChildToken/IChildToken.sol

pragma solidity 0.6.6;

interface IChildToken {
    function deposit(address user, bytes calldata depositData) external;
}

// File: contracts/common/Initializable.sol

pragma solidity 0.6.6;

contract Initializable {
    bool inited = false;

    modifier initializer() {
        require(!inited, "already inited");
        _;
        inited = true;
    }
}

// File: contracts/common/EIP712Base.sol

pragma solidity 0.6.6;


contract EIP712Base is Initializable {
    struct EIP712Domain {
        string name;
        string version;
        address verifyingContract;
        bytes32 salt;
    }

    bytes32 internal constant EIP712_DOMAIN_TYPEHASH = keccak256(
        bytes(
            "EIP712Domain(string name,string version,address verifyingContract,bytes32 salt)"
        )
    );
    bytes32 internal domainSeperator;

    // supposed to be called once while initializing.
    // one of the contractsa that inherits this contract follows proxy pattern
    // so it is not possible to do this in a constructor
    function _initializeEIP712(
        string memory name,
        string memory version
    )
        internal
        initializer
    {
        _setDomainSeperator(name, version);
    }

    function _setDomainSeperator(string memory name, string memory version) internal {
        domainSeperator = keccak256(
            abi.encode(
                EIP712_DOMAIN_TYPEHASH,
                keccak256(bytes(name)),
                keccak256(bytes(version)),
                address(this),
                bytes32(getChainId())
            )
        );
    }

    function getDomainSeperator() public view returns (bytes32) {
        return domainSeperator;
    }

    function getChainId() public pure returns (uint256) {
        uint256 id;
        assembly {
            id := chainid()
        }
        return id;
    }

    /**
     * Accept message hash and returns hash message in EIP712 compatible form
     * So that it can be used to recover signer from signature signed using EIP712 formatted data
     * https://eips.ethereum.org/EIPS/eip-712
     * "\\x19" makes the encoding deterministic
     * "\\x01" is the version byte to make it compatible to EIP-191
     */
    function toTypedMessageHash(bytes32 messageHash)
        internal
        view
        returns (bytes32)
    {
        return
            keccak256(
                abi.encodePacked("\x19\x01", getDomainSeperator(), messageHash)
            );
    }
}

// File: contracts/common/NativeMetaTransaction.sol

pragma solidity 0.6.6;



contract NativeMetaTransaction is EIP712Base {
    using SafeMath for uint256;
    bytes32 private constant META_TRANSACTION_TYPEHASH = keccak256(
        bytes(
            "MetaTransaction(uint256 nonce,address from,bytes functionSignature)"
        )
    );
    event MetaTransactionExecuted(
        address userAddress,
        address payable relayerAddress,
        bytes functionSignature
    );
    mapping(address => uint256) nonces;

    /*
     * Meta transaction structure.
     * No point of including value field here as if user is doing value transfer then he has the funds to pay for gas
     * He should call the desired function directly in that case.
     */
    struct MetaTransaction {
        uint256 nonce;
        address from;
        bytes functionSignature;
    }

    function executeMetaTransaction(
        address userAddress,
        bytes memory functionSignature,
        bytes32 sigR,
        bytes32 sigS,
        uint8 sigV
    ) public payable returns (bytes memory) {
        MetaTransaction memory metaTx = MetaTransaction({
            nonce: nonces[userAddress],
            from: userAddress,
            functionSignature: functionSignature
        });

        require(
            verify(userAddress, metaTx, sigR, sigS, sigV),
            "Signer and signature do not match"
        );

        // increase nonce for user (to avoid re-use)
        nonces[userAddress] = nonces[userAddress].add(1);

        emit MetaTransactionExecuted(
            userAddress,
            msg.sender,
            functionSignature
        );

        // Append userAddress and relayer address at the end to extract it from calling context
        (bool success, bytes memory returnData) = address(this).call(
            abi.encodePacked(functionSignature, userAddress)
        );
        require(success, "Function call not successful");

        return returnData;
    }

    function hashMetaTransaction(MetaTransaction memory metaTx)
        internal
        pure
        returns (bytes32)
    {
        return
            keccak256(
                abi.encode(
                    META_TRANSACTION_TYPEHASH,
                    metaTx.nonce,
                    metaTx.from,
                    keccak256(metaTx.functionSignature)
                )
            );
    }

    function getNonce(address user) public view returns (uint256 nonce) {
        nonce = nonces[user];
    }

    function verify(
        address signer,
        MetaTransaction memory metaTx,
        bytes32 sigR,
        bytes32 sigS,
        uint8 sigV
    ) internal view returns (bool) {
        require(signer != address(0), "NativeMetaTransaction: INVALID_SIGNER");
        return
            signer ==
            ecrecover(
                toTypedMessageHash(hashMetaTransaction(metaTx)),
                sigV,
                sigR,
                sigS
            );
    }
}

// File: contracts/ChainConstants.sol

pragma solidity 0.6.6;

contract ChainConstants {
    string constant public ERC712_VERSION = "1";

    uint256 constant public ROOT_CHAIN_ID = 1;
    bytes constant public ROOT_CHAIN_ID_BYTES = hex"01";

    uint256 constant public CHILD_CHAIN_ID = 137;
    bytes constant public CHILD_CHAIN_ID_BYTES = hex"89";
}

// File: contracts/common/ContextMixin.sol

pragma solidity 0.6.6;

abstract contract ContextMixin {
    function msgSender()
        internal
        view
        returns (address payable sender)
    {
        if (msg.sender == address(this)) {
            bytes memory array = msg.data;
            uint256 index = msg.data.length;
            assembly {
                // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
                sender := and(
                    mload(add(array, index)),
                    0xffffffffffffffffffffffffffffffffffffffff
                )
            }
        } else {
            sender = msg.sender;
        }
        return sender;
    }
}

// File: contracts/child/ChildToken/ChildERC20.sol

pragma solidity 0.6.6;








contract ChildERC20 is
    ERC20,
    IChildToken,
    AccessControlMixin,
    NativeMetaTransaction,
    ChainConstants,
    ContextMixin
{
    bytes32 public constant DEPOSITOR_ROLE = keccak256("DEPOSITOR_ROLE");

    constructor(
        string memory name_,
        string memory symbol_,
        uint8 decimals_,
        address childChainManager
    ) public ERC20(name_, symbol_) {
        _setupContractId("ChildERC20");
        _setupDecimals(decimals_);
        _setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
        _setupRole(DEPOSITOR_ROLE, childChainManager);
        _initializeEIP712(name_, ERC712_VERSION);
    }

    function _msgSender()
        internal
        override
        view
        returns (address payable sender)
    {
        return ContextMixin.msgSender();
    }

    /**
     * @notice called when token is deposited on root chain
     * @dev Should be callable only by ChildChainManager
     * Should handle deposit by minting the required amount for user
     * Make sure minting is done only by this function
     * @param user user address for whom deposit is being done
     * @param depositData abi encoded amount
     */
    function deposit(address user, bytes calldata depositData)
        external
        override
        only(DEPOSITOR_ROLE)
    {
        uint256 amount = abi.decode(depositData, (uint256));
        _mint(user, amount);
    }

    /**
     * @notice called when user wants to withdraw tokens back to root chain
     * @dev Should burn user's tokens. This transaction will be verified when exiting on root chain
     * @param amount amount of tokens to withdraw
     */
    function withdraw(uint256 amount) external {
        _burn(_msgSender(), amount);
    }
}

Contract Security Audit

Contract ABI

[{"inputs":[{"internalType":"string","name":"name_","type":"string"},{"internalType":"string","name":"symbol_","type":"string"},{"internalType":"uint8","name":"decimals_","type":"uint8"},{"internalType":"address","name":"childChainManager","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"address","name":"userAddress","type":"address"},{"indexed":false,"internalType":"address payable","name":"relayerAddress","type":"address"},{"indexed":false,"internalType":"bytes","name":"functionSignature","type":"bytes"}],"name":"MetaTransactionExecuted","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bytes32","name":"role","type":"bytes32"},{"indexed":true,"internalType":"bytes32","name":"previousAdminRole","type":"bytes32"},{"indexed":true,"internalType":"bytes32","name":"newAdminRole","type":"bytes32"}],"name":"RoleAdminChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bytes32","name":"role","type":"bytes32"},{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":true,"internalType":"address","name":"sender","type":"address"}],"name":"RoleGranted","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"bytes32","name":"role","type":"bytes32"},{"indexed":true,"internalType":"address","name":"account","type":"address"},{"indexed":true,"internalType":"address","name":"sender","type":"address"}],"name":"RoleRevoked","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"CHILD_CHAIN_ID","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"CHILD_CHAIN_ID_BYTES","outputs":[{"internalType":"bytes","name":"","type":"bytes"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"DEFAULT_ADMIN_ROLE","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"DEPOSITOR_ROLE","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"ERC712_VERSION","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"ROOT_CHAIN_ID","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"ROOT_CHAIN_ID_BYTES","outputs":[{"internalType":"bytes","name":"","type":"bytes"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"user","type":"address"},{"internalType":"bytes","name":"depositData","type":"bytes"}],"name":"deposit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"userAddress","type":"address"},{"internalType":"bytes","name":"functionSignature","type":"bytes"},{"internalType":"bytes32","name":"sigR","type":"bytes32"},{"internalType":"bytes32","name":"sigS","type":"bytes32"},{"internalType":"uint8","name":"sigV","type":"uint8"}],"name":"executeMetaTransaction","outputs":[{"internalType":"bytes","name":"","type":"bytes"}],"stateMutability":"payable","type":"function"},{"inputs":[],"name":"getChainId","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"pure","type":"function"},{"inputs":[],"name":"getDomainSeperator","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"user","type":"address"}],"name":"getNonce","outputs":[{"internalType":"uint256","name":"nonce","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"}],"name":"getRoleAdmin","outputs":[{"internalType":"bytes32","name":"","type":"bytes32"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"},{"internalType":"uint256","name":"index","type":"uint256"}],"name":"getRoleMember","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"}],"name":"getRoleMemberCount","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"},{"internalType":"address","name":"account","type":"address"}],"name":"grantRole","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"},{"internalType":"address","name":"account","type":"address"}],"name":"hasRole","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"},{"internalType":"address","name":"account","type":"address"}],"name":"renounceRole","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"bytes32","name":"role","type":"bytes32"},{"internalType":"address","name":"account","type":"address"}],"name":"revokeRole","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"withdraw","outputs":[],"stateMutability":"nonpayable","type":"function"}]

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

Constructor Arguments (ABI-Encoded and is the last bytes of the Contract Creation Code above)

000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000c00000000000000000000000000000000000000000000000000000000000000008000000000000000000000000a6fa4fb5f76172d178d61b04b0ecd319c5d1c0aa000000000000000000000000000000000000000000000000000000000000000f3078426974636f696e20546f6b656e000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000053078425443000000000000000000000000000000000000000000000000000000

-----Decoded View---------------
Arg [0] : name_ (string): 0xBitcoin Token
Arg [1] : symbol_ (string): 0xBTC
Arg [2] : decimals_ (uint8): 8
Arg [3] : childChainManager (address): 0xa6fa4fb5f76172d178d61b04b0ecd319c5d1c0aa

-----Encoded View---------------
8 Constructor Arguments found :
Arg [0] : 0000000000000000000000000000000000000000000000000000000000000080
Arg [1] : 00000000000000000000000000000000000000000000000000000000000000c0
Arg [2] : 0000000000000000000000000000000000000000000000000000000000000008
Arg [3] : 000000000000000000000000a6fa4fb5f76172d178d61b04b0ecd319c5d1c0aa
Arg [4] : 000000000000000000000000000000000000000000000000000000000000000f
Arg [5] : 3078426974636f696e20546f6b656e0000000000000000000000000000000000
Arg [6] : 0000000000000000000000000000000000000000000000000000000000000005
Arg [7] : 3078425443000000000000000000000000000000000000000000000000000000


Block Transaction Gas Used Reward
Age Block Fee Address BC Fee Address Voting Power Jailed Incoming
Block Uncle Number Difficulty Gas Used Reward
Loading
Loading
Make sure to use the "Vote Down" button for any spammy posts, and the "Vote Up" for interesting conversations.