Contract Address Details

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

import "../base/Executor.sol";

/// @title Simulate Transaction Accessor - can be used with StorageAccessible to simulate Safe transactions
/// @author Richard Meissner - <richard@gnosis.pm>
contract SimulateTxAccessor is Executor {
    address private immutable accessorSingleton;

    constructor() {
        accessorSingleton = address(this);
    }

    modifier onlyDelegateCall() {
        require(address(this) != accessorSingleton, "SimulateTxAccessor should only be called via delegatecall");
        _;
    }

    function simulate(
        address to,
        uint256 value,
        bytes calldata data,
        Enum.Operation operation
    )
        external
        onlyDelegateCall()
        returns (
            uint256 estimate,
            bool success,
            bytes memory returnData
        )
    {
        uint256 startGas = gasleft();
        success = execute(to, value, data, operation, gasleft());
        estimate = startGas - gasleft();
        // solhint-disable-next-line no-inline-assembly
        assembly {
            // Load free memory location
            let ptr := mload(0x40)
            // We allocate memory for the return data by setting the free memory location to
            // current free memory location + data size + 32 bytes for data size value
            mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
            // Store the size
            mstore(ptr, returndatasize())
            // Store the data
            returndatacopy(add(ptr, 0x20), 0, returndatasize())
            // Point the return data to the correct memory location
            returnData := ptr
        }
    }
}
        

// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;
import "../common/Enum.sol";

/// @title Executor - A contract that can execute transactions
/// @author Richard Meissner - <richard@gnosis.pm>
contract Executor {
    function execute(
        address to,
        uint256 value,
        bytes memory data,
        Enum.Operation operation,
        uint256 txGas
    ) internal returns (bool success) {
        if (operation == Enum.Operation.DelegateCall) {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                success := delegatecall(txGas, to, add(data, 0x20), mload(data), 0, 0)
            }
        } else {
            // solhint-disable-next-line no-inline-assembly
            assembly {
                success := call(txGas, to, value, add(data, 0x20), mload(data), 0, 0)
            }
        }
    }
}
          

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

/// @title Enum - Collection of enums
/// @author Richard Meissner - <richard@gnosis.pm>
contract Enum {
    enum Operation {Call, DelegateCall}
}