// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;

/// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
/// @author Richard Meissner - <[email protected]>
interface IProxy {
    function masterCopy() external view returns (address);
}

/// @title GnosisSafeProxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
/// @author Stefan George - <[email protected]>
/// @author Richard Meissner - <[email protected]>
contract GnosisSafeProxy {
    // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
    // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
    address internal singleton;

    /// @dev Constructor function sets address of singleton contract.
    /// @param _singleton Singleton address.
    constructor(address _singleton) {
        require(_singleton != address(0), "Invalid singleton address provided");
        singleton = _singleton;
    }

    /// @dev Fallback function forwards all transactions and returns all received return data.
    fallback() external payable {
        // solhint-disable-next-line no-inline-assembly
        assembly {
            let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
            // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
            if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                mstore(0, _singleton)
                return(0, 0x20)
            }
            calldatacopy(0, 0, calldatasize())
            let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
            returndatacopy(0, 0, returndatasize())
            if eq(success, 0) {
                revert(0, returndatasize())
            }
            return(0, returndatasize())
        }
    }
}

{
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "outputSelection": {
    "*": {
      "*": [
        "evm.bytecode",
        "evm.deployedBytecode",
        "devdoc",
        "userdoc",
        "metadata",
        "abi"
      ]
    }
  },
  "remappings": []
}

[{"inputs":[{"internalType":"address","name":"_singleton","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"stateMutability":"payable","type":"fallback"}]

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

0x608060405273ffffffffffffffffffffffffffffffffffffffff600054167fa619486e0000000000000000000000000000000000000000000000000000000060003514156050578060005260206000f35b3660008037600080366000845af43d6000803e60008114156070573d6000fd5b3d6000f3fea2646970667358221220d1429297349653a4918076d650332de1a1068c5f3e07c5c82360c277770b955264736f6c63430007060033