Contract Source Code:

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./CTokenInterfaces.sol";

/**
 * @title Compound's CErc20Delegator Contract
 * @notice CTokens which wrap an EIP-20 underlying and delegate to an implementation
 * @author Compound
 */
contract CErc20Delegator is CTokenInterface, CErc20Interface, CDelegatorInterface {
  /**
   * @notice Construct a new money market
   * @param underlying_ The address of the underlying asset
   * @param comptroller_ The address of the Comptroller
   * @param interestRateModel_ The address of the interest rate model
   * @param initialExchangeRateMantissa_ The initial exchange rate, scaled by 1e18
   * @param name_ ERC-20 name of this token
   * @param symbol_ ERC-20 symbol of this token
   * @param decimals_ ERC-20 decimal precision of this token
   * @param admin_ Address of the administrator of this token
   * @param implementation_ The address of the implementation the contract delegates to
   * @param becomeImplementationData The encoded args for becomeImplementation
   */
  constructor(
    address underlying_,
    ComptrollerInterface comptroller_,
    InterestRateModel interestRateModel_,
    uint256 initialExchangeRateMantissa_,
    string memory name_,
    string memory symbol_,
    uint8 decimals_,
    address payable admin_,
    address implementation_,
    bytes memory becomeImplementationData
  ) {
    // Creator of the contract is admin during initialization
    admin = payable(msg.sender);

    // First delegate gets to initialize the delegator (i.e. storage contract)
    delegateTo(
      implementation_,
      abi.encodeWithSignature(
        "initialize(address,address,address,uint256,string,string,uint8)",
        underlying_,
        comptroller_,
        interestRateModel_,
        initialExchangeRateMantissa_,
        name_,
        symbol_,
        decimals_
      )
    );

    // New implementations always get set via the settor (post-initialize)
    _setImplementation(implementation_, false, becomeImplementationData);

    // Set the proper admin now that initialization is done
    admin = admin_;
  }

  /**
   * @notice Called by the admin to update the implementation of the delegator
   * @param implementation_ The address of the new implementation for delegation
   * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation
   * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation
   */
  function _setImplementation(
    address implementation_,
    bool allowResign,
    bytes memory becomeImplementationData
  ) public override {
    require(msg.sender == admin, "CErc20Delegator::_setImplementation: Caller must be admin");

    if (allowResign) {
      delegateToImplementation(abi.encodeWithSignature("_resignImplementation()"));
    }

    address oldImplementation = implementation;
    implementation = implementation_;

    delegateToImplementation(abi.encodeWithSignature("_becomeImplementation(bytes)", becomeImplementationData));

    emit NewImplementation(oldImplementation, implementation);
  }

  /**
   * @notice Sender supplies assets into the market and receives cTokens in exchange
   * @dev Accrues interest whether or not the operation succeeds, unless reverted
   * @param mintAmount The amount of the underlying asset to supply
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function mint(uint256 mintAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("mint(uint256)", mintAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sender redeems cTokens in exchange for the underlying asset
   * @dev Accrues interest whether or not the operation succeeds, unless reverted
   * @param redeemTokens The number of cTokens to redeem into underlying
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function redeem(uint256 redeemTokens) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("redeem(uint256)", redeemTokens));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sender redeems cTokens in exchange for a specified amount of underlying asset
   * @dev Accrues interest whether or not the operation succeeds, unless reverted
   * @param redeemAmount The amount of underlying to redeem
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function redeemUnderlying(uint256 redeemAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("redeemUnderlying(uint256)", redeemAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sender borrows assets from the protocol to their own address
   * @param borrowAmount The amount of the underlying asset to borrow
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function borrow(uint256 borrowAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("borrow(uint256)", borrowAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sender repays their own borrow
   * @param repayAmount The amount to repay, or -1 for the full outstanding amount
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function repayBorrow(uint256 repayAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("repayBorrow(uint256)", repayAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sender repays a borrow belonging to borrower
   * @param borrower the account with the debt being payed off
   * @param repayAmount The amount to repay, or -1 for the full outstanding amount
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function repayBorrowBehalf(address borrower, uint256 repayAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("repayBorrowBehalf(address,uint256)", borrower, repayAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice The sender liquidates the borrowers collateral.
   *  The collateral seized is transferred to the liquidator.
   * @param borrower The borrower of this cToken to be liquidated
   * @param cTokenCollateral The market in which to seize collateral from the borrower
   * @param repayAmount The amount of the underlying borrowed asset to repay
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function liquidateBorrow(
    address borrower,
    uint256 repayAmount,
    CTokenInterface cTokenCollateral
  ) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("liquidateBorrow(address,uint256,address)", borrower, repayAmount, cTokenCollateral));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Transfer `amount` tokens from `msg.sender` to `dst`
   * @param dst The address of the destination account
   * @param amount The number of tokens to transfer
   * @return Whether or not the transfer succeeded
   */
  function transfer(address dst, uint256 amount) external override returns (bool) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("transfer(address,uint256)", dst, amount));
    return abi.decode(data, (bool));
  }

  /**
   * @notice Transfer `amount` tokens from `src` to `dst`
   * @param src The address of the source account
   * @param dst The address of the destination account
   * @param amount The number of tokens to transfer
   * @return Whether or not the transfer succeeded
   */
  function transferFrom(
    address src,
    address dst,
    uint256 amount
  ) external override returns (bool) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("transferFrom(address,address,uint256)", src, dst, amount));
    return abi.decode(data, (bool));
  }

  /**
   * @notice Approve `spender` to transfer up to `amount` from `src`
   * @dev This will overwrite the approval amount for `spender`
   *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
   * @param spender The address of the account which may transfer tokens
   * @param amount The number of tokens that are approved (-1 means infinite)
   * @return Whether or not the approval succeeded
   */
  function approve(address spender, uint256 amount) external override returns (bool) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("approve(address,uint256)", spender, amount));
    return abi.decode(data, (bool));
  }

  /**
   * @notice Get the current allowance from `owner` for `spender`
   * @param owner The address of the account which owns the tokens to be spent
   * @param spender The address of the account which may transfer tokens
   * @return The number of tokens allowed to be spent (-1 means infinite)
   */
  function allowance(address owner, address spender) external view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("allowance(address,address)", owner, spender));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Get the token balance of the `owner`
   * @param owner The address of the account to query
   * @return The number of tokens owned by `owner`
   */
  function balanceOf(address owner) external view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("balanceOf(address)", owner));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Get the underlying balance of the `owner`
   * @dev This also accrues interest in a transaction
   * @param owner The address of the account to query
   * @return The amount of underlying owned by `owner`
   */
  function balanceOfUnderlying(address owner) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("balanceOfUnderlying(address)", owner));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Get a snapshot of the account's balances, and the cached exchange rate
   * @dev This is used by comptroller to more efficiently perform liquidity checks.
   * @param account Address of the account to snapshot
   * @return (possible error, token balance, borrow balance, exchange rate mantissa)
   */
  function getAccountSnapshot(address account)
    external
    view
    override
    returns (
      uint256,
      uint256,
      uint256,
      uint256
    )
  {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("getAccountSnapshot(address)", account));
    return abi.decode(data, (uint256, uint256, uint256, uint256));
  }

  /**
   * @notice Returns the current per-block borrow interest rate for this cToken
   * @return The borrow interest rate per block, scaled by 1e18
   */
  function borrowRatePerBlock() external view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("borrowRatePerBlock()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Returns the current per-block supply interest rate for this cToken
   * @return The supply interest rate per block, scaled by 1e18
   */
  function supplyRatePerBlock() external view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("supplyRatePerBlock()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Returns the current total borrows plus accrued interest
   * @return The total borrows with interest
   */
  function totalBorrowsCurrent() external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("totalBorrowsCurrent()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accrue interest to updated borrowIndex and then calculate account's borrow balance using the updated borrowIndex
   * @param account The address whose balance should be calculated after updating borrowIndex
   * @return The calculated balance
   */
  function borrowBalanceCurrent(address account) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("borrowBalanceCurrent(address)", account));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Return the borrow balance of account based on stored data
   * @param account The address whose balance should be calculated
   * @return The calculated balance
   */
  function borrowBalanceStored(address account) public view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("borrowBalanceStored(address)", account));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accrue interest then return the up-to-date exchange rate
   * @return Calculated exchange rate scaled by 1e18
   */
  function exchangeRateCurrent() public override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("exchangeRateCurrent()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Calculates the exchange rate from the underlying to the CToken
   * @dev This function does not accrue interest before calculating the exchange rate
   * @return Calculated exchange rate scaled by 1e18
   */
  function exchangeRateStored() public view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("exchangeRateStored()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Get cash balance of this cToken in the underlying asset
   * @return The quantity of underlying asset owned by this contract
   */
  function getCash() external view override returns (uint256) {
    bytes memory data = delegateToViewImplementation(abi.encodeWithSignature("getCash()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Applies accrued interest to total borrows and reserves.
   * @dev This calculates interest accrued from the last checkpointed block
   *      up to the current block and writes new checkpoint to storage.
   */
  function accrueInterest() public override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("accrueInterest()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Transfers collateral tokens (this market) to the liquidator.
   * @dev Will fail unless called by another cToken during the process of liquidation.
   *  Its absolutely critical to use msg.sender as the borrowed cToken and not a parameter.
   * @param liquidator The account receiving seized collateral
   * @param borrower The account having collateral seized
   * @param seizeTokens The number of cTokens to seize
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function seize(
    address liquidator,
    address borrower,
    uint256 seizeTokens
  ) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("seize(address,address,uint256)", liquidator, borrower, seizeTokens));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice A public function to sweep accidental ERC-20 transfers to this contract. Tokens are sent to admin (timelock)
   * @param token The address of the ERC-20 token to sweep
   */
  function sweepToken(EIP20NonStandardInterface token) external override {
    delegateToImplementation(abi.encodeWithSignature("sweepToken(address)", token));
  }

  /*** Admin Functions ***/

  /**
   * @notice Begins transfer of admin rights. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
   * @dev Admin function to begin change of admin. The newPendingAdmin must call `_acceptAdmin` to finalize the transfer.
   * @param newPendingAdmin New pending admin.
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _setPendingAdmin(address payable newPendingAdmin) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_setPendingAdmin(address)", newPendingAdmin));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Sets a new comptroller for the market
   * @dev Admin function to set a new comptroller
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _setComptroller(ComptrollerInterface newComptroller) public override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_setComptroller(address)", newComptroller));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice accrues interest and sets a new reserve factor for the protocol using _setReserveFactorFresh
   * @dev Admin function to accrue interest and set a new reserve factor
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _setReserveFactor(uint256 newReserveFactorMantissa) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_setReserveFactor(uint256)", newReserveFactorMantissa));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accepts transfer of admin rights. msg.sender must be pendingAdmin
   * @dev Admin function for pending admin to accept role and update admin
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _acceptAdmin() external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_acceptAdmin()"));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accrues interest and adds reserves by transferring from admin
   * @param addAmount Amount of reserves to add
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _addReserves(uint256 addAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_addReserves(uint256)", addAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accrues interest and reduces reserves by transferring to admin
   * @param reduceAmount Amount of reduction to reserves
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _reduceReserves(uint256 reduceAmount) external override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_reduceReserves(uint256)", reduceAmount));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Accrues interest and updates the interest rate model using _setInterestRateModelFresh
   * @dev Admin function to accrue interest and update the interest rate model
   * @param newInterestRateModel the new interest rate model to use
   * @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
   */
  function _setInterestRateModel(InterestRateModel newInterestRateModel) public override returns (uint256) {
    bytes memory data = delegateToImplementation(abi.encodeWithSignature("_setInterestRateModel(address)", newInterestRateModel));
    return abi.decode(data, (uint256));
  }

  /**
   * @notice Internal method to delegate execution to another contract
   * @dev It returns to the external caller whatever the implementation returns or forwards reverts
   * @param callee The contract to delegatecall
   * @param data The raw data to delegatecall
   * @return The returned bytes from the delegatecall
   */
  function delegateTo(address callee, bytes memory data) internal returns (bytes memory) {
    (bool success, bytes memory returnData) = callee.delegatecall(data);
    assembly {
      if eq(success, 0) {
        revert(add(returnData, 0x20), returndatasize())
      }
    }
    return returnData;
  }

  /**
   * @notice Delegates execution to the implementation contract
   * @dev It returns to the external caller whatever the implementation returns or forwards reverts
   * @param data The raw data to delegatecall
   * @return The returned bytes from the delegatecall
   */
  function delegateToImplementation(bytes memory data) public returns (bytes memory) {
    return delegateTo(implementation, data);
  }

  /**
   * @notice Delegates execution to an implementation contract
   * @dev It returns to the external caller whatever the implementation returns or forwards reverts
   *  There are an additional 2 prefix uints from the wrapper returndata, which we ignore since we make an extra hop.
   * @param data The raw data to delegatecall
   * @return The returned bytes from the delegatecall
   */
  function delegateToViewImplementation(bytes memory data) public view returns (bytes memory) {
    (bool success, bytes memory returnData) = address(this).staticcall(abi.encodeWithSignature("delegateToImplementation(bytes)", data));
    assembly {
      if eq(success, 0) {
        revert(add(returnData, 0x20), returndatasize())
      }
    }
    return abi.decode(returnData, (bytes));
  }

  /**
   * @notice Delegates execution to an implementation contract
   * @dev It returns to the external caller whatever the implementation returns or forwards reverts
   */
  fallback() external payable {
    require(msg.value == 0, "CErc20Delegator:fallback: cannot send value to fallback");

    // delegate all other functions to current implementation
    (bool success, ) = implementation.delegatecall(msg.data);

    assembly {
      let free_mem_ptr := mload(0x40)
      returndatacopy(free_mem_ptr, 0, returndatasize())

      switch success
      case 0 {
        revert(free_mem_ptr, returndatasize())
      }
      default {
        return(free_mem_ptr, returndatasize())
      }
    }
  }
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

import "./ComptrollerInterface.sol";
import "./InterestRateModel.sol";
import "./EIP20NonStandardInterface.sol";
import "./ErrorReporter.sol";

contract CTokenStorage {
  /**
   * @dev Guard variable for re-entrancy checks
   */
  bool internal _notEntered;

  /**
   * @notice EIP-20 token name for this token
   */
  string public name;

  /**
   * @notice EIP-20 token symbol for this token
   */
  string public symbol;

  /**
   * @notice EIP-20 token decimals for this token
   */
  uint8 public decimals;

  // Maximum borrow rate that can ever be applied (.0005% / block)
  uint256 internal constant borrowRateMaxMantissa = 0.0005e16;

  // Maximum fraction of interest that can be set aside for reserves
  uint256 internal constant reserveFactorMaxMantissa = 1e18;

  /**
   * @notice Administrator for this contract
   */
  address payable public admin;

  /**
   * @notice Pending administrator for this contract
   */
  address payable public pendingAdmin;

  /**
   * @notice Contract which oversees inter-cToken operations
   */
  ComptrollerInterface public comptroller;

  /**
   * @notice Model which tells what the current interest rate should be
   */
  InterestRateModel public interestRateModel;

  // Initial exchange rate used when minting the first CTokens (used when totalSupply = 0)
  uint256 internal initialExchangeRateMantissa;

  /**
   * @notice Fraction of interest currently set aside for reserves
   */
  uint256 public reserveFactorMantissa;

  /**
   * @notice Block number that interest was last accrued at
   */
  uint256 public accrualBlockNumber;

  /**
   * @notice Accumulator of the total earned interest rate since the opening of the market
   */
  uint256 public borrowIndex;

  /**
   * @notice Total amount of outstanding borrows of the underlying in this market
   */
  uint256 public totalBorrows;

  /**
   * @notice Total amount of reserves of the underlying held in this market
   */
  uint256 public totalReserves;

  /**
   * @notice Total number of tokens in circulation
   */
  uint256 public totalSupply;

  // Official record of token balances for each account
  mapping(address => uint256) internal accountTokens;

  // Approved token transfer amounts on behalf of others
  mapping(address => mapping(address => uint256)) internal transferAllowances;

  /**
   * @notice Container for borrow balance information
   * @member principal Total balance (with accrued interest), after applying the most recent balance-changing action
   * @member interestIndex Global borrowIndex as of the most recent balance-changing action
   */
  struct BorrowSnapshot {
    uint256 principal;
    uint256 interestIndex;
  }

  // Mapping of account addresses to outstanding borrow balances
  mapping(address => BorrowSnapshot) internal accountBorrows;

  /**
   * @notice Share of seized collateral that is added to reserves
   */
  uint256 public constant protocolSeizeShareMantissa = 2.8e16; //2.8%
}

abstract contract CTokenInterface is CTokenStorage {
  /**
   * @notice Indicator that this is a CToken contract (for inspection)
   */
  bool public constant isCToken = true;

  /*** Market Events ***/

  /**
   * @notice Event emitted when interest is accrued
   */
  event AccrueInterest(uint256 cashPrior, uint256 interestAccumulated, uint256 borrowIndex, uint256 totalBorrows);

  /**
   * @notice Event emitted when tokens are minted
   */
  event Mint(address minter, uint256 mintAmount, uint256 mintTokens);

  /**
   * @notice Event emitted when tokens are redeemed
   */
  event Redeem(address redeemer, uint256 redeemAmount, uint256 redeemTokens);

  /**
   * @notice Event emitted when underlying is borrowed
   */
  event Borrow(address borrower, uint256 borrowAmount, uint256 accountBorrows, uint256 totalBorrows);

  /**
   * @notice Event emitted when a borrow is repaid
   */
  event RepayBorrow(address payer, address borrower, uint256 repayAmount, uint256 accountBorrows, uint256 totalBorrows);

  /**
   * @notice Event emitted when a borrow is liquidated
   */
  event LiquidateBorrow(address liquidator, address borrower, uint256 repayAmount, address cTokenCollateral, uint256 seizeTokens);

  /*** Admin Events ***/

  /**
   * @notice Event emitted when pendingAdmin is changed
   */
  event NewPendingAdmin(address oldPendingAdmin, address newPendingAdmin);

  /**
   * @notice Event emitted when pendingAdmin is accepted, which means admin is updated
   */
  event NewAdmin(address oldAdmin, address newAdmin);

  /**
   * @notice Event emitted when comptroller is changed
   */
  event NewComptroller(ComptrollerInterface oldComptroller, ComptrollerInterface newComptroller);

  /**
   * @notice Event emitted when interestRateModel is changed
   */
  event NewMarketInterestRateModel(InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel);

  /**
   * @notice Event emitted when the reserve factor is changed
   */
  event NewReserveFactor(uint256 oldReserveFactorMantissa, uint256 newReserveFactorMantissa);

  /**
   * @notice Event emitted when the reserves are added
   */
  event ReservesAdded(address benefactor, uint256 addAmount, uint256 newTotalReserves);

  /**
   * @notice Event emitted when the reserves are reduced
   */
  event ReservesReduced(address admin, uint256 reduceAmount, uint256 newTotalReserves);

  /**
   * @notice EIP20 Transfer event
   */
  event Transfer(address indexed from, address indexed to, uint256 amount);

  /**
   * @notice EIP20 Approval event
   */
  event Approval(address indexed owner, address indexed spender, uint256 amount);

  /*** User Interface ***/

  function transfer(address dst, uint256 amount) external virtual returns (bool);

  function transferFrom(
    address src,
    address dst,
    uint256 amount
  ) external virtual returns (bool);

  function approve(address spender, uint256 amount) external virtual returns (bool);

  function allowance(address owner, address spender) external view virtual returns (uint256);

  function balanceOf(address owner) external view virtual returns (uint256);

  function balanceOfUnderlying(address owner) external virtual returns (uint256);

  function getAccountSnapshot(address account)
    external
    view
    virtual
    returns (
      uint256,
      uint256,
      uint256,
      uint256
    );

  function borrowRatePerBlock() external view virtual returns (uint256);

  function supplyRatePerBlock() external view virtual returns (uint256);

  function totalBorrowsCurrent() external virtual returns (uint256);

  function borrowBalanceCurrent(address account) external virtual returns (uint256);

  function borrowBalanceStored(address account) external view virtual returns (uint256);

  function exchangeRateCurrent() external virtual returns (uint256);

  function exchangeRateStored() external view virtual returns (uint256);

  function getCash() external view virtual returns (uint256);

  function accrueInterest() external virtual returns (uint256);

  function seize(
    address liquidator,
    address borrower,
    uint256 seizeTokens
  ) external virtual returns (uint256);

  /*** Admin Functions ***/

  function _setPendingAdmin(address payable newPendingAdmin) external virtual returns (uint256);

  function _acceptAdmin() external virtual returns (uint256);

  function _setComptroller(ComptrollerInterface newComptroller) external virtual returns (uint256);

  function _setReserveFactor(uint256 newReserveFactorMantissa) external virtual returns (uint256);

  function _reduceReserves(uint256 reduceAmount) external virtual returns (uint256);

  function _setInterestRateModel(InterestRateModel newInterestRateModel) external virtual returns (uint256);
}

contract CErc20Storage {
  /**
   * @notice Underlying asset for this CToken
   */
  address public underlying;
}

abstract contract CErc20Interface is CErc20Storage {
  /*** User Interface ***/

  function mint(uint256 mintAmount) external virtual returns (uint256);

  function redeem(uint256 redeemTokens) external virtual returns (uint256);

  function redeemUnderlying(uint256 redeemAmount) external virtual returns (uint256);

  function borrow(uint256 borrowAmount) external virtual returns (uint256);

  function repayBorrow(uint256 repayAmount) external virtual returns (uint256);

  function repayBorrowBehalf(address borrower, uint256 repayAmount) external virtual returns (uint256);

  function liquidateBorrow(
    address borrower,
    uint256 repayAmount,
    CTokenInterface cTokenCollateral
  ) external virtual returns (uint256);

  function sweepToken(EIP20NonStandardInterface token) external virtual;

  /*** Admin Functions ***/

  function _addReserves(uint256 addAmount) external virtual returns (uint256);
}

contract CDelegationStorage {
  /**
   * @notice Implementation address for this contract
   */
  address public implementation;
}

abstract contract CDelegatorInterface is CDelegationStorage {
  /**
   * @notice Emitted when implementation is changed
   */
  event NewImplementation(address oldImplementation, address newImplementation);

  /**
   * @notice Called by the admin to update the implementation of the delegator
   * @param implementation_ The address of the new implementation for delegation
   * @param allowResign Flag to indicate whether to call _resignImplementation on the old implementation
   * @param becomeImplementationData The encoded bytes data to be passed to _becomeImplementation
   */
  function _setImplementation(
    address implementation_,
    bool allowResign,
    bytes memory becomeImplementationData
  ) external virtual;
}

abstract contract CDelegateInterface is CDelegationStorage {
  /**
   * @notice Called by the delegator on a delegate to initialize it for duty
   * @dev Should revert if any issues arise which make it unfit for delegation
   * @param data The encoded bytes data for any initialization
   */
  function _becomeImplementation(bytes memory data) external virtual;

  /**
   * @notice Called by the delegator on a delegate to forfeit its responsibility
   */
  function _resignImplementation() external virtual;
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

abstract contract ComptrollerInterface {
    /// @notice Indicator that this is a Comptroller contract (for inspection)
    bool public constant isComptroller = true;

    /*** Assets You Are In ***/

    function enterMarkets(address[] calldata cTokens) virtual external returns (uint[] memory);
    function exitMarket(address cToken) virtual external returns (uint);

    /*** Policy Hooks ***/

    function mintAllowed(address cToken, address minter, uint mintAmount) virtual external returns (uint);
    function mintVerify(address cToken, address minter, uint mintAmount, uint mintTokens) virtual external;

    function redeemAllowed(address cToken, address redeemer, uint redeemTokens) virtual external returns (uint);
    function redeemVerify(address cToken, address redeemer, uint redeemAmount, uint redeemTokens) virtual external;

    function whitelistBorrowerAdd(address borrower) virtual external returns (uint);
    function setBorrowerLimits(address borrower, uint256 _borrowLimit) virtual external returns (uint);
    function getBorrowerLimits(address borrower) virtual external returns (uint);


    function borrowAllowed(address cToken, address borrower, uint borrowAmount) virtual external returns (uint);
    function borrowVerify(address cToken, address borrower, uint borrowAmount) virtual external;

    function repayBorrowAllowed(
        address cToken,
        address payer,
        address borrower,
        uint repayAmount) virtual external returns (uint);
    function repayBorrowVerify(
        address cToken,
        address payer,
        address borrower,
        uint repayAmount,
        uint borrowerIndex) virtual external;

    function liquidateBorrowAllowed(
        address cTokenBorrowed,
        address cTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount) virtual external returns (uint);
    function liquidateBorrowVerify(
        address cTokenBorrowed,
        address cTokenCollateral,
        address liquidator,
        address borrower,
        uint repayAmount,
        uint seizeTokens) virtual external;

    function seizeAllowed(
        address cTokenCollateral,
        address cTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens) virtual external returns (uint);
    function seizeVerify(
        address cTokenCollateral,
        address cTokenBorrowed,
        address liquidator,
        address borrower,
        uint seizeTokens) virtual external;

    function transferAllowed(address cToken, address src, address dst, uint transferTokens) virtual external returns (uint);
    function transferVerify(address cToken, address src, address dst, uint transferTokens) virtual external;

    /*** Liquidity/Liquidation Calculations ***/

    function liquidateCalculateSeizeTokens(
        address cTokenBorrowed,
        address cTokenCollateral,
        uint repayAmount) virtual external view returns (uint, uint);
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @title Compound's InterestRateModel Interface
 * @author Compound
 */
abstract contract InterestRateModel {
  /// @notice Indicator that this is an InterestRateModel contract (for inspection)
  bool public constant isInterestRateModel = true;

  /**
   * @notice Calculates the current borrow interest rate per block
   * @param cash The total amount of cash the market has
   * @param borrows The total amount of borrows the market has outstanding
   * @param reserves The total amount of reserves the market has
   * @return The borrow rate per block (as a percentage, and scaled by 1e18)
   */
  function getBorrowRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves
  ) external view virtual returns (uint256);

  /**
   * @notice Calculates the current supply interest rate per block
   * @param cash The total amount of cash the market has
   * @param borrows The total amount of borrows the market has outstanding
   * @param reserves The total amount of reserves the market has
   * @param reserveFactorMantissa The current reserve factor the market has
   * @return The supply rate per block (as a percentage, and scaled by 1e18)
   */
  function getSupplyRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves,
    uint256 reserveFactorMantissa
  ) external view virtual returns (uint256);
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

/**
 * @title EIP20NonStandardInterface
 * @dev Version of ERC20 with no return values for `transfer` and `transferFrom`
 *  See https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
 */
interface EIP20NonStandardInterface {
  /**
   * @notice Get the total number of tokens in circulation
   * @return The supply of tokens
   */
  function totalSupply() external view returns (uint256);

  /**
   * @notice Gets the balance of the specified address
   * @param owner The address from which the balance will be retrieved
   * @return balance The balance
   */
  function balanceOf(address owner) external view returns (uint256 balance);

  ///
  /// !!!!!!!!!!!!!!
  /// !!! NOTICE !!! `transfer` does not return a value, in violation of the ERC-20 specification
  /// !!!!!!!!!!!!!!
  ///

  /**
   * @notice Transfer `amount` tokens from `msg.sender` to `dst`
   * @param dst The address of the destination account
   * @param amount The number of tokens to transfer
   */
  function transfer(address dst, uint256 amount) external;

  ///
  /// !!!!!!!!!!!!!!
  /// !!! NOTICE !!! `transferFrom` does not return a value, in violation of the ERC-20 specification
  /// !!!!!!!!!!!!!!
  ///

  /**
   * @notice Transfer `amount` tokens from `src` to `dst`
   * @param src The address of the source account
   * @param dst The address of the destination account
   * @param amount The number of tokens to transfer
   */
  function transferFrom(
    address src,
    address dst,
    uint256 amount
  ) external;

  /**
   * @notice Approve `spender` to transfer up to `amount` from `src`
   * @dev This will overwrite the approval amount for `spender`
   *  and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve)
   * @param spender The address of the account which may transfer tokens
   * @param amount The number of tokens that are approved
   * @return success Whether or not the approval succeeded
   */
  function approve(address spender, uint256 amount) external returns (bool success);

  /**
   * @notice Get the current allowance from `owner` for `spender`
   * @param owner The address of the account which owns the tokens to be spent
   * @param spender The address of the account which may transfer tokens
   * @return remaining The number of tokens allowed to be spent
   */
  function allowance(address owner, address spender) external view returns (uint256 remaining);

  event Transfer(address indexed from, address indexed to, uint256 amount);
  event Approval(address indexed owner, address indexed spender, uint256 amount);
}

// SPDX-License-Identifier: BSD-3-Clause
pragma solidity ^0.8.10;

contract ComptrollerErrorReporter {
  enum Error {
    NO_ERROR,
    UNAUTHORIZED,
    COMPTROLLER_MISMATCH,
    INSUFFICIENT_SHORTFALL,
    INSUFFICIENT_LIQUIDITY,
    INVALID_CLOSE_FACTOR,
    INVALID_COLLATERAL_FACTOR,
    INVALID_LIQUIDATION_INCENTIVE,
    MARKET_NOT_ENTERED, // no longer possible
    MARKET_NOT_LISTED,
    MARKET_ALREADY_LISTED,
    MATH_ERROR,
    NONZERO_BORROW_BALANCE,
    PRICE_ERROR,
    REJECTION,
    SNAPSHOT_ERROR,
    TOO_MANY_ASSETS,
    TOO_MUCH_REPAY
  }

  enum FailureInfo {
    ACCEPT_ADMIN_PENDING_ADMIN_CHECK,
    ACCEPT_PENDING_IMPLEMENTATION_ADDRESS_CHECK,
    EXIT_MARKET_BALANCE_OWED,
    EXIT_MARKET_REJECTION,
    SET_CLOSE_FACTOR_OWNER_CHECK,
    SET_CLOSE_FACTOR_VALIDATION,
    SET_COLLATERAL_FACTOR_OWNER_CHECK,
    SET_COLLATERAL_FACTOR_NO_EXISTS,
    SET_COLLATERAL_FACTOR_VALIDATION,
    SET_COLLATERAL_FACTOR_WITHOUT_PRICE,
    SET_IMPLEMENTATION_OWNER_CHECK,
    SET_LIQUIDATION_INCENTIVE_OWNER_CHECK,
    SET_LIQUIDATION_INCENTIVE_VALIDATION,
    SET_MAX_ASSETS_OWNER_CHECK,
    SET_PENDING_ADMIN_OWNER_CHECK,
    SET_PENDING_IMPLEMENTATION_OWNER_CHECK,
    SET_PRICE_ORACLE_OWNER_CHECK,
    SUPPORT_MARKET_EXISTS,
    SUPPORT_MARKET_OWNER_CHECK,
    SET_PAUSE_GUARDIAN_OWNER_CHECK,
    SET_BORROWER_LIMIT_CHECK
  }

  /**
   * @dev `error` corresponds to enum Error; `info` corresponds to enum FailureInfo, and `detail` is an arbitrary
   * contract-specific code that enables us to report opaque error codes from upgradeable contracts.
   **/
  event Failure(uint256 error, uint256 info, uint256 detail);

  /**
   * @dev use this when reporting a known error from the money market or a non-upgradeable collaborator
   */
  function fail(Error err, FailureInfo info) internal returns (uint256) {
    emit Failure(uint256(err), uint256(info), 0);

    return uint256(err);
  }

  /**
   * @dev use this when reporting an opaque error from an upgradeable collaborator contract
   */
  function failOpaque(
    Error err,
    FailureInfo info,
    uint256 opaqueError
  ) internal returns (uint256) {
    emit Failure(uint256(err), uint256(info), opaqueError);

    return uint256(err);
  }
}

contract TokenErrorReporter {
  uint256 public constant NO_ERROR = 0; // support legacy return codes

  error TransferComptrollerRejection(uint256 errorCode);
  error TransferNotAllowed();
  error TransferNotEnough();
  error TransferTooMuch();

  error MintComptrollerRejection(uint256 errorCode);
  error MintFreshnessCheck();

  error RedeemComptrollerRejection(uint256 errorCode);
  error RedeemFreshnessCheck();
  error RedeemTransferOutNotPossible();

  error BorrowComptrollerRejection(uint256 errorCode);
  error BorrowFreshnessCheck();
  error BorrowCashNotAvailable();

  error RepayBorrowComptrollerRejection(uint256 errorCode);
  error RepayBorrowFreshnessCheck();

  error LiquidateComptrollerRejection(uint256 errorCode);
  error LiquidateFreshnessCheck();
  error LiquidateCollateralFreshnessCheck();
  error LiquidateAccrueBorrowInterestFailed(uint256 errorCode);
  error LiquidateAccrueCollateralInterestFailed(uint256 errorCode);
  error LiquidateLiquidatorIsBorrower();
  error LiquidateCloseAmountIsZero();
  error LiquidateCloseAmountIsUintMax();
  error LiquidateRepayBorrowFreshFailed(uint256 errorCode);

  error LiquidateSeizeComptrollerRejection(uint256 errorCode);
  error LiquidateSeizeLiquidatorIsBorrower();

  error AcceptAdminPendingAdminCheck();

  error SetComptrollerOwnerCheck();
  error SetPendingAdminOwnerCheck();

  error SetReserveFactorAdminCheck();
  error SetReserveFactorFreshCheck();
  error SetReserveFactorBoundsCheck();

  error AddReservesFactorFreshCheck(uint256 actualAddAmount);

  error ReduceReservesAdminCheck();
  error ReduceReservesFreshCheck();
  error ReduceReservesCashNotAvailable();
  error ReduceReservesCashValidation();

  error SetInterestRateModelOwnerCheck();
  error SetInterestRateModelFreshCheck();
}