pragma solidity ^0.6.2;

contract Proxy {

    address delegate;
    address owner = msg.sender;

    function upgradeDelegate(address newDelegateAddress) public {
        require(msg.sender == owner);
        delegate = newDelegateAddress;
    }

    fallback() external payable {
        address addr = delegate;
        assembly {
            let freememstart := mload(0x40)
            calldatacopy(freememstart, 0, calldatasize())
            let success := delegatecall(not(0), addr, freememstart, calldatasize(), freememstart, 32)
            switch success
            case 0 { revert(freememstart, 32) }
            default { return(freememstart, 32) }
        }
    }
}

{
  "compilationTarget": {
    "browser/proxy.sol": "Proxy"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}