Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.11;

import "src/weiroll/CommandBuilder.sol";

abstract contract VM {
    using CommandBuilder for bytes[];

    uint256 constant FLAG_CT_DELEGATECALL = 0x00;
    uint256 constant FLAG_CT_CALL = 0x01;
    uint256 constant FLAG_CT_STATICCALL = 0x02;
    uint256 constant FLAG_CT_VALUECALL = 0x03;
    uint256 constant FLAG_CT_MASK = 0x03;
    uint256 constant FLAG_EXTENDED_COMMAND = 0x40;
    uint256 constant FLAG_TUPLE_RETURN = 0x80;

    uint256 constant SHORT_COMMAND_FILL = 0x000000000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;

    address immutable self;

    error ExecutionFailed(uint256 command_index, address target, string message);

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

    function _execute(bytes32[] calldata commands, bytes[] memory state) internal returns (bytes[] memory) {
        bytes32 command;
        uint256 flags;
        bytes32 indices;

        bool success;
        bytes memory outdata;

        uint256 commandsLength = commands.length;
        for (uint256 i; i < commandsLength;) {
            command = commands[i];
            flags = uint256(command >> 216) & 0xFF; // more efficient
            // flags = uint256(uint8(bytes1(command << 32))); // more readable

            if (flags & FLAG_EXTENDED_COMMAND != 0) {
                indices = commands[++i];
            } else {
                indices = bytes32(uint256(command << 40) | SHORT_COMMAND_FILL);
            }

            if (flags & FLAG_CT_MASK == FLAG_CT_DELEGATECALL) {
                (success, outdata) = address(uint160(uint256(command))).delegatecall( // target
                    // inputs
                    state.buildInputs(
                        //selector
                        bytes4(command),
                        indices
                    )
                );
            } else if (flags & FLAG_CT_MASK == FLAG_CT_CALL) {
                (success, outdata) = address(uint160(uint256(command))).call( // target
                    // inputs
                    state.buildInputs(
                        //selector
                        bytes4(command),
                        indices
                    )
                );
            } else if (flags & FLAG_CT_MASK == FLAG_CT_STATICCALL) {
                (success, outdata) = address(uint160(uint256(command))).staticcall( // target
                    // inputs
                    state.buildInputs(
                        //selector
                        bytes4(command),
                        indices
                    )
                );
            } else if (flags & FLAG_CT_MASK == FLAG_CT_VALUECALL) {
                uint256 callEth;
                bytes memory v = state[uint8(bytes1(indices))];
                require(v.length == 32, "_execute: value call has no value indicated.");
                assembly {
                    callEth := mload(add(v, 0x20))
                }
                (success, outdata) = address(uint160(uint256(command))).call{ // target
                    value: callEth
                }(
                    // inputs
                    state.buildInputs(
                        //selector
                        bytes4(command),
                        bytes32(uint256(indices << 8) | CommandBuilder.IDX_END_OF_ARGS)
                    )
                );
            } else {
                revert("Invalid calltype");
            }

            if (!success) {
                if (outdata.length > 0) {
                    assembly {
                        outdata := add(outdata, 68)
                    }
                }
                revert ExecutionFailed({
                    command_index: 0,
                    target: address(uint160(uint256(command))),
                    message: outdata.length > 0 ? string(outdata) : "Unknown"
                });
            }

            if (flags & FLAG_TUPLE_RETURN != 0) {
                state.writeTuple(bytes1(command << 88), outdata);
            } else {
                state = state.writeOutputs(bytes1(command << 88), outdata);
            }
            unchecked {
                ++i;
            }
        }
        return state;
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.20;

import "src/weiroll/VM.sol";
import "solady/utils/SafeTransferLib.sol";

/// @title  Botmarket
/// @notice Contract recipient from sdToken bounties on Votemarket.
/// @author Stake DAO
/// @custom:contact [email protected]
contract Botmarket {
    using SafeTransferLib for address;

    /// @notice Address of the governance contract.
    address public governance;

    /// @notice Address of the future governance contract.
    address public futureGovernance;

    /// @notice Address authorized to call the execute function.
    mapping(address => bool) public isAllowed;

    ////////////////////////////////////////////////////////////////
    /// --- EVENTS & ERRORS
    ///////////////////////////////////////////////////////////////

    /// @notice Event emitted when a new governance is proposed.
    event GovernanceProposed(address indexed newGovernance);

    /// @notice Event emitted when the governance is changed.
    event GovernanceChanged(address indexed newGovernance);

    /// @notice Throws if caller is not the governance.
    error GOVERNANCE();

    /// @notice Throws if caller is not allowed.
    error NOT_ALLOWED();

    /// @notice Throws if the length of the tokens and amounts arrays are not equal.
    error WRONG_LENGTH();

    ////////////////////////////////////////////////////////////////
    /// --- MODIFIERS
    ///////////////////////////////////////////////////////////////

    modifier onlyGovernance() {
        if (msg.sender != governance) revert GOVERNANCE();
        _;
    }

    modifier onlyAllowed() {
        if (!isAllowed[msg.sender]) revert NOT_ALLOWED();
        _;
    }

    constructor(address _governance) {
        governance = _governance;
    }

    ////////////////////////////////////////////////////////////////
    /// --- ADMIN FUNCTIONS
    ///////////////////////////////////////////////////////////////

    /// @notice Allow an address to call the execute function.
    /// @param _address Address to allow.
    function allowAddress(address _address) external onlyGovernance {
        isAllowed[_address] = true;
    }

    /// @notice Disallow an address to call the execute function.
    /// @param _address Address to disallow.
    function disallowAddress(address _address) external onlyGovernance {
        isAllowed[_address] = false;
    }

    /// @notice Transfer the governance to a new address.
    /// @param _governance Address of the new governance.
    function transferGovernance(address _governance) external onlyGovernance {
        emit GovernanceProposed(futureGovernance = _governance);
    }

    /// @notice Accept the governance transfer.
    function acceptGovernance() external {
        if (msg.sender != futureGovernance) revert GOVERNANCE();
        emit GovernanceChanged(governance = msg.sender);
    }

    /// @notice Withdraw ETH or ERC20 tokens from the contract.
    function withdraw(address[] calldata _tokens, uint256[] calldata _amount, address _recipient)
        external
        onlyAllowed
    {
        if (_tokens.length != _amount.length) revert WRONG_LENGTH();

        for (uint256 i = 0; i < _tokens.length; i++) {
            if (_tokens[i] == address(0)) {
                SafeTransferLib.safeTransferETH(_recipient, _amount[i]);
            } else {
                SafeTransferLib.safeTransfer(_tokens[i], _recipient, _amount[i]);
            }
        }
    }

    receive() external payable {}
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.11;

library CommandBuilder {
    uint256 constant IDX_VARIABLE_LENGTH = 0x80;
    uint256 constant IDX_VALUE_MASK = 0x7f;
    uint256 constant IDX_END_OF_ARGS = 0xff;
    uint256 constant IDX_USE_STATE = 0xfe;

    function buildInputs(bytes[] memory state, bytes4 selector, bytes32 indices)
        internal
        view
        returns (bytes memory ret)
    {
        uint256 free; // Pointer to first free byte in tail part of message
        uint256 idx;

        // Determine the length of the encoded data
        for (uint256 i; i < 32;) {
            idx = uint8(indices[i]);
            if (idx == IDX_END_OF_ARGS) break;
            unchecked {
                free += 32;
            }
            unchecked {
                ++i;
            }
        }

        // Encode it
        uint256 bytesWritten;
        assembly {
            ret := mload(0x40)
            bytesWritten := add(bytesWritten, 4)
            mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
            mstore(add(ret, 32), selector)
        }
        uint256 count = 0;
        bytes memory stateData; // Optionally encode the current state if the call requires it
        for (uint256 i; i < 32;) {
            idx = uint8(indices[i]);
            if (idx == IDX_END_OF_ARGS) break;

            if (idx & IDX_VARIABLE_LENGTH != 0) {
                if (idx == IDX_USE_STATE) {
                    assembly {
                        bytesWritten := add(bytesWritten, 32)
                        mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
                        mstore(add(add(ret, 36), count), free)
                    }
                    if (stateData.length == 0) {
                        stateData = abi.encode(state);
                    }
                    assembly {
                        bytesWritten := add(bytesWritten, mload(stateData))
                        mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
                    }
                    memcpy(stateData, 32, ret, free + 4, stateData.length - 32);
                    free += stateData.length - 32;
                } else {
                    bytes memory stateVar = state[idx & IDX_VALUE_MASK];
                    uint256 arglen = stateVar.length;

                    // Variable length data; put a pointer in the slot and write the data at the end
                    assembly {
                        bytesWritten := add(bytesWritten, 32)
                        mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
                        mstore(add(add(ret, 36), count), free)
                    }
                    assembly {
                        bytesWritten := add(bytesWritten, arglen)
                        mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
                    }
                    memcpy(stateVar, 0, ret, free + 4, arglen);
                    free += arglen;
                }
            } else {
                // Fixed length data; write it directly
                bytes memory stateVar = state[idx & IDX_VALUE_MASK];
                assembly {
                    bytesWritten := add(bytesWritten, mload(stateVar))
                    mstore(0x40, add(ret, and(add(add(bytesWritten, 0x20), 0x1f), not(0x1f))))
                    mstore(add(add(ret, 36), count), mload(add(stateVar, 32)))
                }
            }
            unchecked {
                count += 32;
            }
            unchecked {
                ++i;
            }
        }
        assembly {
            mstore(ret, bytesWritten)
        }
    }

    function writeOutputs(bytes[] memory state, bytes1 index, bytes memory output)
        internal
        pure
        returns (bytes[] memory)
    {
        uint256 idx = uint8(index);
        if (idx == IDX_END_OF_ARGS) return state;

        if (idx & IDX_VARIABLE_LENGTH != 0) {
            if (idx == IDX_USE_STATE) {
                state = abi.decode(output, (bytes[]));
            } else {
                // Check the first field is 0x20 (because we have only a single return value)
                uint256 argptr;
                assembly {
                    argptr := mload(add(output, 32))
                }
                require(argptr == 32, "Only one return value permitted (variable)");

                assembly {
                    // Overwrite the first word of the return data with the length - 32
                    mstore(add(output, 32), sub(mload(output), 32))
                    // Insert a pointer to the return data, starting at the second word, into state
                    mstore(add(add(state, 32), mul(and(idx, IDX_VALUE_MASK), 32)), add(output, 32))
                }
            }
        } else {
            // Single word
            require(output.length == 32, "Only one return value permitted (static)");

            state[idx & IDX_VALUE_MASK] = output;
        }

        return state;
    }

    function writeTuple(bytes[] memory state, bytes1 index, bytes memory output) internal view {
        uint256 idx = uint256(uint8(index));
        if (idx == IDX_END_OF_ARGS) return;

        bytes memory entry = state[idx & IDX_VALUE_MASK] = new bytes(output.length + 32);

        memcpy(output, 0, entry, 32, output.length);
        assembly {
            let l := mload(output)
            mstore(add(entry, 32), l)
        }
    }

    function memcpy(bytes memory src, uint256 srcidx, bytes memory dest, uint256 destidx, uint256 len) internal view {
        assembly {
            pop(staticcall(gas(), 4, add(add(src, 32), srcidx), len, add(add(dest, 32), destidx), len))
        }
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SafeTransferLib.sol)
///
/// @dev Note:
/// - For ETH transfers, please use `forceSafeTransferETH` for gas griefing protection.
/// - For ERC20s, this implementation won't check that a token has code,
///   responsibility is delegated to the caller.
library SafeTransferLib {
    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       CUSTOM ERRORS                        */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev The ETH transfer has failed.
    error ETHTransferFailed();

    /// @dev The ERC20 `transferFrom` has failed.
    error TransferFromFailed();

    /// @dev The ERC20 `transfer` has failed.
    error TransferFailed();

    /// @dev The ERC20 `approve` has failed.
    error ApproveFailed();

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                         CONSTANTS                          */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Suggested gas stipend for contract receiving ETH that disallows any storage writes.
    uint256 internal constant GAS_STIPEND_NO_STORAGE_WRITES = 2300;

    /// @dev Suggested gas stipend for contract receiving ETH to perform a few
    /// storage reads and writes, but low enough to prevent griefing.
    uint256 internal constant GAS_STIPEND_NO_GRIEF = 100000;

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                       ETH OPERATIONS                       */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    // If gas griefing protection is needed, please use the force variants.
    //
    // The regular variants:
    // - Forwards all remaining gas to the target.
    // - Reverts if the target reverts.
    // - Reverts if the current contract has insufficient balance.
    //
    // The force variants:
    // - Forwards with an optional gas stipend
    //   (defaults to `GAS_STIPEND_NO_GRIEF`, which is sufficient for most cases).
    // - If the target reverts, or if the gas stipend is exhausted,
    //   creates a temporary contract to force send the ETH via `SELFDESTRUCT`.
    //   Future compatible with `SENDALL`: https://eips.ethereum.org/EIPS/eip-4758.
    // - Reverts if the current contract has insufficient balance.
    //
    // The try variants:
    // - Forwards with a mandatory gas stipend.
    // - Instead of reverting, returns whether the transfer succeeded.

    /// @dev Sends `amount` (in wei) ETH to `to`.
    function safeTransferETH(address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(call(gas(), to, amount, gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Sends all the ETH in the current contract to `to`.
    function safeTransferAllETH(address to) internal {
        /// @solidity memory-safe-assembly
        assembly {
            // Transfer all the ETH and check if it succeeded or not.
            if iszero(call(gas(), to, selfbalance(), gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
        }
    }

    /// @dev Force sends `amount` (in wei) ETH to `to`, with a `gasStipend`.
    function forceSafeTransferETH(address to, uint256 amount, uint256 gasStipend) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if lt(selfbalance(), amount) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
            if iszero(call(gasStipend, to, amount, gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(amount, 0x0b, 0x16)) {
                    returndatacopy(gas(), returndatasize(), shr(20, gas())) // For gas estimation.
                }
            }
        }
    }

    /// @dev Force sends all the ETH in the current contract to `to`, with a `gasStipend`.
    function forceSafeTransferAllETH(address to, uint256 gasStipend) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(call(gasStipend, to, selfbalance(), gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(selfbalance(), 0x0b, 0x16)) {
                    returndatacopy(gas(), returndatasize(), shr(20, gas())) // For gas estimation.
                }
            }
        }
    }

    /// @dev Force sends `amount` (in wei) ETH to `to`, with `GAS_STIPEND_NO_GRIEF`.
    function forceSafeTransferETH(address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if lt(selfbalance(), amount) {
                mstore(0x00, 0xb12d13eb) // `ETHTransferFailed()`.
                revert(0x1c, 0x04)
            }
            if iszero(call(GAS_STIPEND_NO_GRIEF, to, amount, gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(amount, 0x0b, 0x16)) {
                    returndatacopy(gas(), returndatasize(), shr(20, gas())) // For gas estimation.
                }
            }
        }
    }

    /// @dev Force sends all the ETH in the current contract to `to`, with `GAS_STIPEND_NO_GRIEF`.
    function forceSafeTransferAllETH(address to) internal {
        /// @solidity memory-safe-assembly
        assembly {
            if iszero(call(GAS_STIPEND_NO_GRIEF, to, selfbalance(), gas(), 0x00, gas(), 0x00)) {
                mstore(0x00, to) // Store the address in scratch space.
                mstore8(0x0b, 0x73) // Opcode `PUSH20`.
                mstore8(0x20, 0xff) // Opcode `SELFDESTRUCT`.
                if iszero(create(selfbalance(), 0x0b, 0x16)) {
                    returndatacopy(gas(), returndatasize(), shr(20, gas())) // For gas estimation.
                }
            }
        }
    }

    /// @dev Sends `amount` (in wei) ETH to `to`, with a `gasStipend`.
    function trySafeTransferETH(address to, uint256 amount, uint256 gasStipend)
        internal
        returns (bool success)
    {
        /// @solidity memory-safe-assembly
        assembly {
            success := call(gasStipend, to, amount, gas(), 0x00, gas(), 0x00)
        }
    }

    /// @dev Sends all the ETH in the current contract to `to`, with a `gasStipend`.
    function trySafeTransferAllETH(address to, uint256 gasStipend)
        internal
        returns (bool success)
    {
        /// @solidity memory-safe-assembly
        assembly {
            success := call(gasStipend, to, selfbalance(), gas(), 0x00, gas(), 0x00)
        }
    }

    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
    /*                      ERC20 OPERATIONS                      */
    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

    /// @dev Sends `amount` of ERC20 `token` from `from` to `to`.
    /// Reverts upon failure.
    ///
    /// The `from` account must have at least `amount` approved for
    /// the current contract to manage.
    function safeTransferFrom(address token, address from, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Cache the free memory pointer.
            mstore(0x60, amount) // Store the `amount` argument.
            mstore(0x40, to) // Store the `to` argument.
            mstore(0x2c, shl(96, from)) // Store the `from` argument.
            mstore(0x0c, 0x23b872dd000000000000000000000000) // `transferFrom(address,address,uint256)`.
            // Perform the transfer, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x1c, 0x64, 0x00, 0x20)
                )
            ) {
                mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x60, 0) // Restore the zero slot to zero.
            mstore(0x40, m) // Restore the free memory pointer.
        }
    }

    /// @dev Sends all of ERC20 `token` from `from` to `to`.
    /// Reverts upon failure.
    ///
    /// The `from` account must have their entire balance approved for
    /// the current contract to manage.
    function safeTransferAllFrom(address token, address from, address to)
        internal
        returns (uint256 amount)
    {
        /// @solidity memory-safe-assembly
        assembly {
            let m := mload(0x40) // Cache the free memory pointer.
            mstore(0x40, to) // Store the `to` argument.
            mstore(0x2c, shl(96, from)) // Store the `from` argument.
            mstore(0x0c, 0x70a08231000000000000000000000000) // `balanceOf(address)`.
            // Read the balance, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                    staticcall(gas(), token, 0x1c, 0x24, 0x60, 0x20)
                )
            ) {
                mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x00, 0x23b872dd) // `transferFrom(address,address,uint256)`.
            amount := mload(0x60) // The `amount` is already at 0x60. We'll need to return it.
            // Perform the transfer, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x1c, 0x64, 0x00, 0x20)
                )
            ) {
                mstore(0x00, 0x7939f424) // `TransferFromFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x60, 0) // Restore the zero slot to zero.
            mstore(0x40, m) // Restore the free memory pointer.
        }
    }

    /// @dev Sends `amount` of ERC20 `token` from the current contract to `to`.
    /// Reverts upon failure.
    function safeTransfer(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0xa9059cbb000000000000000000000000) // `transfer(address,uint256)`.
            // Perform the transfer, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                )
            ) {
                mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sends all of ERC20 `token` from the current contract to `to`.
    /// Reverts upon failure.
    function safeTransferAll(address token, address to) internal returns (uint256 amount) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x00, 0x70a08231) // Store the function selector of `balanceOf(address)`.
            mstore(0x20, address()) // Store the address of the current contract.
            // Read the balance, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                    staticcall(gas(), token, 0x1c, 0x24, 0x34, 0x20)
                )
            ) {
                mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x14, to) // Store the `to` argument.
            amount := mload(0x34) // The `amount` is already at 0x34. We'll need to return it.
            mstore(0x00, 0xa9059cbb000000000000000000000000) // `transfer(address,uint256)`.
            // Perform the transfer, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                )
            ) {
                mstore(0x00, 0x90b8ec18) // `TransferFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sets `amount` of ERC20 `token` for `to` to manage on behalf of the current contract.
    /// Reverts upon failure.
    function safeApprove(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
            // Perform the approval, reverting upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                )
            ) {
                mstore(0x00, 0x3e3f8f73) // `ApproveFailed()`.
                revert(0x1c, 0x04)
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Sets `amount` of ERC20 `token` for `to` to manage on behalf of the current contract.
    /// If the initial attempt to approve fails, attempts to reset the approved amount to zero,
    /// then retries the approval again (some tokens, e.g. USDT, requires this).
    /// Reverts upon failure.
    function safeApproveWithRetry(address token, address to, uint256 amount) internal {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, to) // Store the `to` argument.
            mstore(0x34, amount) // Store the `amount` argument.
            mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
            // Perform the approval, retrying upon failure.
            if iszero(
                and( // The arguments of `and` are evaluated from right to left.
                    or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                    call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                )
            ) {
                mstore(0x34, 0) // Store 0 for the `amount`.
                mstore(0x00, 0x095ea7b3000000000000000000000000) // `approve(address,uint256)`.
                pop(call(gas(), token, 0, 0x10, 0x44, 0x00, 0x00)) // Reset the approval.
                mstore(0x34, amount) // Store back the original `amount`.
                // Retry the approval, reverting upon failure.
                if iszero(
                    and(
                        or(eq(mload(0x00), 1), iszero(returndatasize())), // Returned 1 or nothing.
                        call(gas(), token, 0, 0x10, 0x44, 0x00, 0x20)
                    )
                ) {
                    mstore(0x00, 0x3e3f8f73) // `ApproveFailed()`.
                    revert(0x1c, 0x04)
                }
            }
            mstore(0x34, 0) // Restore the part of the free memory pointer that was overwritten.
        }
    }

    /// @dev Returns the amount of ERC20 `token` owned by `account`.
    /// Returns zero if the `token` does not exist.
    function balanceOf(address token, address account) internal view returns (uint256 amount) {
        /// @solidity memory-safe-assembly
        assembly {
            mstore(0x14, account) // Store the `account` argument.
            mstore(0x00, 0x70a08231000000000000000000000000) // `balanceOf(address)`.
            amount :=
                mul(
                    mload(0x20),
                    and( // The arguments of `and` are evaluated from right to left.
                        gt(returndatasize(), 0x1f), // At least 32 bytes returned.
                        staticcall(gas(), token, 0x10, 0x24, 0x20, 0x20)
                    )
                )
        }
    }
}