/** *Submitted for verification at BscScan.com on 2020-10-28 */ // File: openzeppelin-solidity/contracts/proxy/Proxy.sol pragma solidity ^0.6.0; /** * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to * be specified by overriding the virtual {_implementation} function. * * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a * different contract through the {_delegate} function. * * The success and return data of the delegated call will be returned back to the caller of the proxy. */ abstract contract Proxy { /** * @dev Delegates the current call to `implementation`. * * This function does not return to its internall call site, it will return directly to the external caller. */ function _delegate(address implementation) internal { // solhint-disable-next-line no-inline-assembly assembly { // Copy msg.data. We take full control of memory in this inline assembly // block because it will not return to Solidity code. We overwrite the // Solidity scratch pad at memory position 0. calldatacopy(0, 0, calldatasize()) // Call the implementation. // out and outsize are 0 because we don't know the size yet. let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0) // Copy the returned data. returndatacopy(0, 0, returndatasize()) switch result // delegatecall returns 0 on error. case 0 { revert(0, returndatasize()) } default { return(0, returndatasize()) } } } /** * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function * and {_fallback} should delegate. */ function _implementation() internal virtual view returns (address); /** * @dev Delegates the current call to the address returned by `_implementation()`. * * This function does not return to its internall call site, it will return directly to the external caller. */ function _fallback() internal { _beforeFallback(); _delegate(_implementation()); } /** * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other * function in the contract matches the call data. */ fallback () payable external { _fallback(); } /** * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data * is empty. */ receive () payable external { _fallback(); } /** * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback` * call, or as part of the Solidity `fallback` or `receive` functions. * * If overriden should call `super._beforeFallback()`. */ function _beforeFallback() internal virtual { } } // File: openzeppelin-solidity/contracts/utils/Address.sol 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) { // This method relies in extcodesize, which returns 0 for contracts in // construction, since the code is only stored at the end of the // constructor execution. uint256 size; // solhint-disable-next-line no-inline-assembly assembly { size := extcodesize(account) } return size > 0; } /** * @dev Replacement for Solidity's `transfer`: sends `amount` wei to * `recipient`, forwarding all available gas and reverting on errors. * * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost * of certain opcodes, possibly making contracts go over the 2300 gas limit * imposed by `transfer`, making them unable to receive funds via * `transfer`. {sendValue} removes this limitation. * * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. * * IMPORTANT: because control is transferred to `recipient`, care must be * taken to not create reentrancy vulnerabilities. Consider using * {ReentrancyGuard} or the * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. */ function sendValue(address payable recipient, uint256 amount) internal { require(address(this).balance >= amount, "Address: insufficient balance"); // 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-solidity/contracts/proxy/UpgradeableProxy.sol pragma solidity ^0.6.0; /** * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an * implementation address that can be changed. This address is stored in storage in the location specified by * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the * implementation behind the proxy. * * Upgradeability is only provided internally through {_upgradeTo}. For an externally upgradeable proxy see * {TransparentUpgradeableProxy}. */ contract UpgradeableProxy is Proxy { /** * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`. * * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded * function call, and allows initializating the storage of the proxy like a Solidity constructor. */ constructor(address _logic, bytes memory _data) public payable { assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1)); _setImplementation(_logic); if(_data.length > 0) { // solhint-disable-next-line avoid-low-level-calls (bool success,) = _logic.delegatecall(_data); require(success); } } /** * @dev Emitted when the implementation is upgraded. */ event Upgraded(address indexed implementation); /** * @dev Storage slot with the address of the current implementation. * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is * validated in the constructor. */ bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc; /** * @dev Returns the current implementation address. */ function _implementation() internal override view returns (address impl) { bytes32 slot = _IMPLEMENTATION_SLOT; // solhint-disable-next-line no-inline-assembly assembly { impl := sload(slot) } } /** * @dev Upgrades the proxy to a new implementation. * * Emits an {Upgraded} event. */ function _upgradeTo(address newImplementation) internal { _setImplementation(newImplementation); emit Upgraded(newImplementation); } /** * @dev Stores a new address in the EIP1967 implementation slot. */ function _setImplementation(address newImplementation) private { require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract"); bytes32 slot = _IMPLEMENTATION_SLOT; // solhint-disable-next-line no-inline-assembly assembly { sstore(slot, newImplementation) } } } // File: openzeppelin-solidity/contracts/proxy/TransparentUpgradeableProxy.sol pragma solidity ^0.6.0; /** * @dev This contract implements a proxy that is upgradeable by an admin. * * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector * clashing], which can potentially be used in an attack, this contract uses the * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two * things that go hand in hand: * * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if * that call matches one of the admin functions exposed by the proxy itself. * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the * implementation. If the admin tries to call a function on the implementation it will fail with an error that says * "admin cannot fallback to proxy target". * * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due * to sudden errors when trying to call a function from the proxy implementation. * * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way, * you should think of the `ProxyAdmin` instance as the real administrative inerface of your proxy. */ contract TransparentUpgradeableProxy is UpgradeableProxy { /** * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and * optionally initialized with `_data` as explained in {UpgradeableProxy-constructor}. */ constructor(address _logic, address _admin, bytes memory _data) public payable UpgradeableProxy(_logic, _data) { assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1)); _setAdmin(_admin); } /** * @dev Emitted when the admin account has changed. */ event AdminChanged(address previousAdmin, address newAdmin); /** * @dev Storage slot with the admin of the contract. * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is * validated in the constructor. */ bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103; /** * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin. */ modifier ifAdmin() { if (msg.sender == _admin()) { _; } else { _fallback(); } } /** * @dev Returns the current admin. * * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}. * * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call. * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103` */ function admin() external ifAdmin returns (address) { return _admin(); } /** * @dev Returns the current implementation. * * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}. * * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call. * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc` */ function implementation() external ifAdmin returns (address) { return _implementation(); } /** * @dev Changes the admin of the proxy. * * Emits an {AdminChanged} event. * * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}. */ function changeAdmin(address newAdmin) external ifAdmin { require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address"); emit AdminChanged(_admin(), newAdmin); _setAdmin(newAdmin); } /** * @dev Upgrade the implementation of the proxy. * * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}. */ function upgradeTo(address newImplementation) external ifAdmin { _upgradeTo(newImplementation); } /** * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the * proxied contract. * * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}. */ function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin { _upgradeTo(newImplementation); // solhint-disable-next-line avoid-low-level-calls (bool success,) = newImplementation.delegatecall(data); require(success); } /** * @dev Returns the current admin. */ function _admin() internal view returns (address adm) { bytes32 slot = _ADMIN_SLOT; // solhint-disable-next-line no-inline-assembly assembly { adm := sload(slot) } } /** * @dev Stores a new address in the EIP1967 admin slot. */ function _setAdmin(address newAdmin) private { bytes32 slot = _ADMIN_SLOT; // solhint-disable-next-line no-inline-assembly assembly { sstore(slot, newAdmin) } } /** * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}. */ function _beforeFallback() internal override virtual { require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target"); super._beforeFallback(); } } // File: contracts/BEP20UpgradeableProxy.sol pragma solidity ^0.6.0; contract BEP20UpgradeableProxy is TransparentUpgradeableProxy { constructor(address logic, address admin, bytes memory data) TransparentUpgradeableProxy(logic, admin, data) public { } }
0.4.18