/** * Submitted for verification at blockscout.com on 2021-01-29 07:56:55.978691Z */ // File: @openzeppelin/upgrades/contracts/upgradeability/Proxy.sol pragma solidity ^0.5.0; /** * @title Proxy * @dev Implements delegation of calls to other contracts, with proper * forwarding of return values and bubbling of failures. * It defines a fallback function that delegates all calls to the address * returned by the abstract _implementation() internal function. */ contract Proxy { /** * @dev Fallback function. * Implemented entirely in `_fallback`. */ function () payable external { _fallback(); } /** * @return The Address of the implementation. */ function _implementation() internal view returns (address); /** * @dev Delegates execution to an implementation contract. * This is a low level function that doesn't return to its internal call site. * It will return to the external caller whatever the implementation returns. * @param implementation Address to delegate. */ function _delegate(address implementation) internal { 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 Function that is run as the first thing in the fallback function. * Can be redefined in derived contracts to add functionality. * Redefinitions must call super._willFallback(). */ function _willFallback() internal { } /** * @dev fallback implementation. * Extracted to enable manual triggering. */ function _fallback() internal { _willFallback(); _delegate(_implementation()); } } // File: @openzeppelin/upgrades/contracts/utils/Address.sol pragma solidity ^0.5.0; /** * Utility library of inline functions on addresses * * Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol * This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts * when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the * build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version. */ library OpenZeppelinUpgradesAddress { /** * Returns whether the target address is a contract * @dev This function will return false if invoked during the constructor of a contract, * as the code is not actually created until after the constructor finishes. * @param account address of the account to check * @return whether the target address is a contract */ function isContract(address account) internal view returns (bool) { uint256 size; // XXX Currently there is no better way to check if there is a contract in an address // than to check the size of the code at that address. // See https://ethereum.stackexchange.com/a/14016/36603 // for more details about how this works. // TODO Check this again before the Serenity release, because all addresses will be // contracts then. // solhint-disable-next-line no-inline-assembly assembly { size := extcodesize(account) } return size > 0; } } // File: @openzeppelin/upgrades/contracts/upgradeability/BaseUpgradeabilityProxy.sol pragma solidity ^0.5.0; /** * @title BaseUpgradeabilityProxy * @dev This contract implements a proxy that allows to change the * implementation address to which it will delegate. * Such a change is called an implementation upgrade. */ contract BaseUpgradeabilityProxy is Proxy { /** * @dev Emitted when the implementation is upgraded. * @param implementation Address of the new implementation. */ 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 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc; /** * @dev Returns the current implementation. * @return Address of the current implementation */ function _implementation() internal view returns (address impl) { bytes32 slot = IMPLEMENTATION_SLOT; assembly { impl := sload(slot) } } /** * @dev Upgrades the proxy to a new implementation. * @param newImplementation Address of the new implementation. */ function _upgradeTo(address newImplementation) internal { _setImplementation(newImplementation); emit Upgraded(newImplementation); } /** * @dev Sets the implementation address of the proxy. * @param newImplementation Address of the new implementation. */ function _setImplementation(address newImplementation) internal { require(OpenZeppelinUpgradesAddress.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address"); bytes32 slot = IMPLEMENTATION_SLOT; assembly { sstore(slot, newImplementation) } } } // File: @openzeppelin/upgrades/contracts/upgradeability/UpgradeabilityProxy.sol pragma solidity ^0.5.0; /** * @title UpgradeabilityProxy * @dev Extends BaseUpgradeabilityProxy with a constructor for initializing * implementation and init data. */ contract UpgradeabilityProxy is BaseUpgradeabilityProxy { /** * @dev Contract constructor. * @param _logic Address of the initial implementation. * @param _data Data to send as msg.data to the implementation to initialize the proxied contract. * It should include the signature and the parameters of the function to be called, as described in * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding. * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped. */ constructor(address _logic, bytes memory _data) public payable { assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)); _setImplementation(_logic); if(_data.length > 0) { (bool success,) = _logic.delegatecall(_data); require(success); } } } // File: @openzeppelin/upgrades/contracts/upgradeability/BaseAdminUpgradeabilityProxy.sol pragma solidity ^0.5.0; /** * @title BaseAdminUpgradeabilityProxy * @dev This contract combines an upgradeability proxy with an authorization * mechanism for administrative tasks. * All external functions in this contract must be guarded by the * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity * feature proposal that would enable this to be done automatically. */ contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy { /** * @dev Emitted when the administration has been transferred. * @param previousAdmin Address of the previous admin. * @param newAdmin Address of the new admin. */ 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 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103; /** * @dev Modifier to check whether the `msg.sender` is the admin. * If it is, it will run the function. Otherwise, it will delegate the call * to the implementation. */ modifier ifAdmin() { if (msg.sender == _admin()) { _; } else { _fallback(); } } /** * @return The address of the proxy admin. */ function admin() external ifAdmin returns (address) { return _admin(); } /** * @return The address of the implementation. */ function implementation() external ifAdmin returns (address) { return _implementation(); } /** * @dev Changes the admin of the proxy. * Only the current admin can call this function. * @param newAdmin Address to transfer proxy administration to. */ function changeAdmin(address newAdmin) external ifAdmin { require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address"); emit AdminChanged(_admin(), newAdmin); _setAdmin(newAdmin); } /** * @dev Upgrade the backing implementation of the proxy. * Only the admin can call this function. * @param newImplementation Address of the new implementation. */ function upgradeTo(address newImplementation) external ifAdmin { _upgradeTo(newImplementation); } /** * @dev Upgrade the backing implementation of the proxy and call a function * on the new implementation. * This is useful to initialize the proxied contract. * @param newImplementation Address of the new implementation. * @param data Data to send as msg.data in the low level call. * It should include the signature and the parameters of the function to be called, as described in * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding. */ function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin { _upgradeTo(newImplementation); (bool success,) = newImplementation.delegatecall(data); require(success); } /** * @return The admin slot. */ function _admin() internal view returns (address adm) { bytes32 slot = ADMIN_SLOT; assembly { adm := sload(slot) } } /** * @dev Sets the address of the proxy admin. * @param newAdmin Address of the new proxy admin. */ function _setAdmin(address newAdmin) internal { bytes32 slot = ADMIN_SLOT; assembly { sstore(slot, newAdmin) } } /** * @dev Only fall back when the sender is not the admin. */ function _willFallback() internal { require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin"); super._willFallback(); } } // File: @openzeppelin/upgrades/contracts/upgradeability/AdminUpgradeabilityProxy.sol pragma solidity ^0.5.0; /** * @title AdminUpgradeabilityProxy * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for * initializing the implementation, admin, and init data. */ contract AdminUpgradeabilityProxy is BaseAdminUpgradeabilityProxy, UpgradeabilityProxy { /** * Contract constructor. * @param _logic address of the initial implementation. * @param _admin Address of the proxy administrator. * @param _data Data to send as msg.data to the implementation to initialize the proxied contract. * It should include the signature and the parameters of the function to be called, as described in * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding. * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped. */ constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable { assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1)); _setAdmin(_admin); } }