// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023. // File: @openzeppelin/contracts/utils/introspection/IERC165.sol // OpenZeppelin Contracts v4.4.0 (utils/introspection/IERC165.sol) // SPDX-License-Identifier: MIT pragma solidity 0.8.7; /** * @dev Interface of the ERC165 standard, as defined in the * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * Implementers can declare support of contract interfaces, which can then be * queried by others ({ERC165Checker}). * * For an implementation, see {ERC165}. */ interface IERC165 { /** * @dev Returns true if this contract implements the interface defined by * `interfaceId`. See the corresponding * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * to learn more about how these ids are created. * * This function call must use less than 30 000 gas. */ function supportsInterface(bytes4 interfaceId) external view returns (bool); } // File: @openzeppelin/contracts/utils/introspection/ERC165.sol // OpenZeppelin Contracts v4.4.0 (utils/introspection/ERC165.sol) pragma solidity 0.8.7; /** * @dev Implementation of the {IERC165} interface. * * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check * for the additional interface id that will be supported. For example: * * ```solidity * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { * return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId); * } * ``` * * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation. */ abstract contract ERC165 is IERC165 { /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IERC165).interfaceId; } } // File: @openzeppelin/contracts/utils/Strings.sol // OpenZeppelin Contracts v4.4.0 (utils/Strings.sol) pragma solidity 0.8.7; /** * @dev String operations. */ library Strings { bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef"; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { // Inspired by OraclizeAPI's implementation - MIT licence // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol if (value == 0) { return "0"; } uint256 temp = value; uint256 digits; while (temp != 0) { digits++; temp /= 10; } bytes memory buffer = new bytes(digits); while (value != 0) { digits -= 1; buffer[digits] = bytes1(uint8(48 + uint256(value % 10))); value /= 10; } return string(buffer); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { if (value == 0) { return "0x00"; } uint256 temp = value; uint256 length = 0; while (temp != 0) { length++; temp >>= 8; } return toHexString(value, length); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = _HEX_SYMBOLS[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } } // File: @openzeppelin/contracts/access/IAccessControl.sol // OpenZeppelin Contracts v4.4.0 (access/IAccessControl.sol) pragma solidity 0.8.7; /** * @dev External interface of AccessControl declared to support ERC165 detection. */ interface IAccessControl { /** * @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 {AccessControl-_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) external view returns (bool); /** * @dev Returns the admin role that controls `role`. See {grantRole} and * {revokeRole}. * * To change a role's admin, use {AccessControl-_setRoleAdmin}. */ function getRoleAdmin(bytes32 role) external view returns (bytes32); /** * @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) external; /** * @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) external; /** * @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) external; } // File: @openzeppelin/contracts/utils/Context.sol pragma solidity 0.8.7; /** * @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 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) { return msg.sender; } function _msgData() internal view virtual returns (bytes calldata) { return msg.data; } } // File: @openzeppelin/contracts/access/AccessControl.sol // OpenZeppelin Contracts v4.4.0 (access/AccessControl.sol) pragma solidity 0.8.7; /** * @dev Contract module that allows children to implement role-based access * control mechanisms. This is a lightweight version that doesn't allow enumerating role * members except through off-chain means by accessing the contract event logs. Some * applications may benefit from on-chain enumerability, for those cases see * {AccessControlEnumerable}. * * 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, IAccessControl, ERC165 { struct RoleData { mapping(address => bool) members; bytes32 adminRole; } mapping(bytes32 => RoleData) private _roles; bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00; /** * @dev Modifier that checks that an account has a specific role. Reverts * with a standardized message including the required role. * * The format of the revert reason is given by the following regular expression: * * /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/ * * _Available since v4.1._ */ modifier onlyRole(bytes32 role) { _checkRole(role, _msgSender()); _; } /** * @dev See {IERC165-supportsInterface}. */ function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) { return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId); } /** * @dev Returns `true` if `account` has been granted `role`. */ function hasRole(bytes32 role, address account) public view override returns (bool) { return _roles[role].members[account]; } /** * @dev Revert with a standard message if `account` is missing `role`. * * The format of the revert reason is given by the following regular expression: * * /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/ */ function _checkRole(bytes32 role, address account) internal view { if (!hasRole(role, account)) { revert( string( abi.encodePacked( "AccessControl: account ", Strings.toHexString(uint160(account), 20), " is missing role ", Strings.toHexString(uint256(role), 32) ) ) ); } } /** * @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 override 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 override onlyRole(getRoleAdmin(role)) { _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 override onlyRole(getRoleAdmin(role)) { _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 revoked `role`, emits a {RoleRevoked} * event. * * Requirements: * * - the caller must be `account`. */ function renounceRole(bytes32 role, address account) public virtual override { 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}. * ==== * * NOTE: This function is deprecated in favor of {_grantRole}. */ 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 { bytes32 previousAdminRole = getRoleAdmin(role); _roles[role].adminRole = adminRole; emit RoleAdminChanged(role, previousAdminRole, adminRole); } /** * @dev Grants `role` to `account`. * * Internal function without access restriction. */ function _grantRole(bytes32 role, address account) internal virtual { if (!hasRole(role, account)) { _roles[role].members[account] = true; emit RoleGranted(role, account, _msgSender()); } } /** * @dev Revokes `role` from `account`. * * Internal function without access restriction. */ function _revokeRole(bytes32 role, address account) internal virtual { if (hasRole(role, account)) { _roles[role].members[account] = false; emit RoleRevoked(role, account, _msgSender()); } } } // File: @openzeppelin/contracts/security/Pausable.sol // OpenZeppelin Contracts v4.4.0 (security/Pausable.sol) pragma solidity 0.8.7; /** * @dev Contract module which allows children to implement an emergency stop * mechanism that can be triggered by an authorized account. * * This module is used through inheritance. It will make available the * modifiers `whenNotPaused` and `whenPaused`, which can be applied to * the functions of your contract. Note that they will not be pausable by * simply including this module, only once the modifiers are put in place. */ abstract contract Pausable is Context { /** * @dev Emitted when the pause is triggered by `account`. */ event Paused(address account); /** * @dev Emitted when the pause is lifted by `account`. */ event Unpaused(address account); bool private _paused; /** * @dev Initializes the contract in unpaused state. */ constructor() { _paused = false; } /** * @dev Returns true if the contract is paused, and false otherwise. */ function paused() public view virtual returns (bool) { return _paused; } /** * @dev Modifier to make a function callable only when the contract is not paused. * * Requirements: * * - The contract must not be paused. */ modifier whenNotPaused() { require(!paused(), "Pausable: paused"); _; } /** * @dev Modifier to make a function callable only when the contract is paused. * * Requirements: * * - The contract must be paused. */ modifier whenPaused() { require(paused(), "Pausable: not paused"); _; } /** * @dev Triggers stopped state. * * Requirements: * * - The contract must not be paused. */ function _pause() internal virtual whenNotPaused { _paused = true; emit Paused(_msgSender()); } /** * @dev Returns to normal state. * * Requirements: * * - The contract must be paused. */ function _unpause() internal virtual whenPaused { _paused = false; emit Unpaused(_msgSender()); } } // File: @openzeppelin/contracts/token/ERC20/IERC20.sol pragma solidity 0.8.7; /** * @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/token/ERC20/extensions/IERC20Metadata.sol pragma solidity 0.8.7; /** * @dev Interface for the optional metadata functions from the ERC20 standard. * * _Available since v4.1._ */ interface IERC20Metadata is IERC20 { /** * @dev Returns the name of the token. */ function name() external view returns (string memory); /** * @dev Returns the symbol of the token. */ function symbol() external view returns (string memory); /** * @dev Returns the decimals places of the token. */ function decimals() external view returns (uint8); } // File: @openzeppelin/contracts/token/ERC20/ERC20.sol pragma solidity 0.8.7; /** * @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 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: * * - `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); uint256 currentAllowance = _allowances[sender][_msgSender()]; require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance"); unchecked { _approve(sender, _msgSender(), currentAllowance - 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) { _approve(_msgSender(), spender, _allowances[_msgSender()][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) { uint256 currentAllowance = _allowances[_msgSender()][spender]; require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); unchecked { _approve(_msgSender(), spender, currentAllowance - subtractedValue); } return true; } /** * @dev Moves `amount` of tokens from `sender` to `recipient`. * * 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: * * - `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); uint256 senderBalance = _balances[sender]; require(senderBalance >= amount, "ERC20: transfer amount exceeds balance"); unchecked { _balances[sender] = senderBalance - amount; } _balances[recipient] += amount; emit Transfer(sender, recipient, amount); _afterTokenTransfer(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: * * - `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; _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; } _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 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 {} } // File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol pragma solidity 0.8.7; /** * @dev Extension of {ERC20} that allows token holders to destroy both their own * tokens and those that they have an allowance for, in a way that can be * recognized off-chain (via event analysis). */ abstract contract ERC20Burnable is Context, ERC20 { /** * @dev Destroys `amount` tokens from the caller. * * See {ERC20-_burn}. */ function burn(uint256 amount) public virtual { _burn(_msgSender(), amount); } /** * @dev Destroys `amount` tokens from `account`, deducting from the caller's * allowance. * * See {ERC20-_burn} and {ERC20-allowance}. * * Requirements: * * - the caller must have allowance for ``accounts``'s tokens of at least * `amount`. */ function burnFrom(address account, uint256 amount) public virtual { uint256 currentAllowance = allowance(account, _msgSender()); require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance"); unchecked { _approve(account, _msgSender(), currentAllowance - amount); } _burn(account, amount); } } // File: contracts/BMC.sol pragma solidity 0.8.7; contract BlackMagicCoin is ERC20, ERC20Burnable, Pausable, AccessControl { bytes32 public constant PAUSER_ROLE = keccak256("PAUSER_ROLE"); bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE"); address internal constant _safe = 0xd8806d66E24b702e0A56fb972b75D24CAd656821; uint256 public MAX_SUPPLY; mapping(address => bool) public Blacklist; event BlackListed(address wallet, bool status); constructor(uint256 max_supply) ERC20("Black Magic Coin", "BMC") { _grantRole(DEFAULT_ADMIN_ROLE, _safe); _grantRole(PAUSER_ROLE, _safe); _grantRole(MINTER_ROLE, _safe); MAX_SUPPLY = max_supply; } function pause() public onlyRole(PAUSER_ROLE) { _pause(); } function unpause() public onlyRole(PAUSER_ROLE) { _unpause(); } function mint(address to, uint256 amount) public onlyRole(MINTER_ROLE) { require( totalSupply() + amount <= MAX_SUPPLY, "Error: Max supply reached, 1 Billion tokens minted." ); _mint(to, amount); } function _beforeTokenTransfer(address from, address to, uint256 amount) internal whenNotPaused override { require(!Blacklist[from], "BMC: You are banned from Transfer"); super._beforeTokenTransfer(from, to, amount); } function BlacklistAddress(address actor) public onlyRole(PAUSER_ROLE) { Blacklist[actor] = true; emit BlackListed(actor, true); } function UnBlacklistAddress(address actor) public onlyRole(PAUSER_ROLE) { Blacklist[actor] = false; emit BlackListed(actor, false); } }