Contract Source Code:
File 1 of 1 : AErc20
pragma solidity ^0.5.16;
/**
* @title Artem ERC-20 Contract
* @notice Derived from Compound's cERC20 contract
* https://github.com/compound-finance/compound-protocol/tree/master/contracts
*/
/**
* @title Careful Math
* @notice Derived from OpenZeppelin's SafeMath library
* https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/math/SafeMath.sol
*/
contract CarefulMath {
enum MathError {
NO_ERROR,
DIVISION_BY_ZERO,
INTEGER_OVERFLOW,
INTEGER_UNDERFLOW
}
/**
* @dev Multiplies two numbers, returns an error on overflow.
*/
function mulUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (a == 0) {
return (MathError.NO_ERROR, 0);
}
uint c = a * b;
if (c / a != b) {
return (MathError.INTEGER_OVERFLOW, 0);
} else {
return (MathError.NO_ERROR, c);
}
}
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function divUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (b == 0) {
return (MathError.DIVISION_BY_ZERO, 0);
}
return (MathError.NO_ERROR, a / b);
}
/**
* @dev Subtracts two numbers, returns an error on overflow (i.e. if subtrahend is greater than minuend).
*/
function subUInt(uint a, uint b) internal pure returns (MathError, uint) {
if (b <= a) {
return (MathError.NO_ERROR, a - b);
} else {
return (MathError.INTEGER_UNDERFLOW, 0);
}
}
/**
* @dev Adds two numbers, returns an error on overflow.
*/
function addUInt(uint a, uint b) internal pure returns (MathError, uint) {
uint c = a + b;
if (c >= a) {
return (MathError.NO_ERROR, c);
} else {
return (MathError.INTEGER_OVERFLOW, 0);
}
}
/**
* @dev add a and b and then subtract c
*/
function addThenSubUInt(uint a, uint b, uint c) internal pure returns (MathError, uint) {
(MathError err0, uint sum) = addUInt(a, b);
if (err0 != MathError.NO_ERROR) {
return (err0, 0);
}
return subUInt(sum, c);
}
}
interface ControllerInterface {
function isController() external view returns (bool);
function enterMarkets(address[] calldata aTokens) external returns (uint[] memory);
function exitMarket(address aToken) external returns (uint);
function mintAllowed(address aToken, address minter, uint mintAmount) external returns (uint);
function mintVerify(address aToken, address minter, uint mintAmount, uint mintTokens) external;
function redeemAllowed(address aToken, address redeemer, uint redeemTokens) external returns (uint);
function redeemVerify(address aToken, address redeemer, uint redeemAmount, uint redeemTokens) external;
function borrowAllowed(address aToken, address borrower, uint borrowAmount) external returns (uint);
function borrowVerify(address aToken, address borrower, uint borrowAmount) external;
function repayBorrowAllowed(
address aToken,
address payer,
address borrower,
uint repayAmount) external returns (uint);
function repayBorrowVerify(
address aToken,
address payer,
address borrower,
uint repayAmount,
uint borrowerIndex) external;
function liquidateBorrowAllowed(
address aTokenBorrowed,
address aTokenCollateral,
address liquidator,
address borrower,
uint repayAmount) external returns (uint);
function liquidateBorrowVerify(
address aTokenBorrowed,
address aTokenCollateral,
address liquidator,
address borrower,
uint repayAmount,
uint seizeTokens) external;
function seizeAllowed(
address aTokenCollateral,
address aTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external returns (uint);
function seizeVerify(
address aTokenCollateral,
address aTokenBorrowed,
address liquidator,
address borrower,
uint seizeTokens) external;
function transferAllowed(address aToken, address src, address dst, uint transferTokens) external returns (uint);
function transferVerify(address aToken, address src, address dst, uint transferTokens) external;
/*** Liquidity/Liquidation Calculations ***/
function liquidateCalculateSeizeTokens(
address aTokenBorrowed,
address aTokenCollateral,
uint repayAmount) external view returns (uint, uint);
}
contract ControllerErrorReporter {
event Failure(uint error, uint info, uint detail);
function fail(Error err, FailureInfo info) internal returns (uint) {
emit Failure(uint(err), uint(info), 0);
return uint(err);
}
function failOpaque(Error err, FailureInfo info, uint opaqueError) internal returns (uint) {
emit Failure(uint(err), uint(info), opaqueError);
return uint(err);
}
enum Error {
NO_ERROR,
UNAUTHORIZED,
CONTROLLER_MISMATCH,
INSUFFICIENT_SHORTFALL,
INSUFFICIENT_LIQUIDITY,
INVALID_CLOSE_FACTOR,
INVALID_COLLATERAL_FACTOR,
INVALID_LIQUIDATION_INCENTIVE,
MARKET_NOT_ENTERED,
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,
ZUNUSED
}
}
contract TokenErrorReporter {
event Failure(uint error, uint info, uint detail);
function fail(Error err, FailureInfo info) internal returns (uint) {
emit Failure(uint(err), uint(info), 0);
return uint(err);
}
function failOpaque(Error err, FailureInfo info, uint opaqueError) internal returns (uint) {
emit Failure(uint(err), uint(info), opaqueError);
return uint(err);
}
enum Error {
NO_ERROR,
UNAUTHORIZED,
BAD_INPUT,
CONTROLLER_REJECTION,
CONTROLLER_CALCULATION_ERROR,
INTEREST_RATE_MODEL_ERROR,
INVALID_ACCOUNT_PAIR,
INVALID_CLOSE_AMOUNT_REQUESTED,
INVALID_COLLATERAL_FACTOR,
MATH_ERROR,
MARKET_NOT_FRESH,
MARKET_NOT_LISTED,
TOKEN_INSUFFICIENT_ALLOWANCE,
TOKEN_INSUFFICIENT_BALANCE,
TOKEN_INSUFFICIENT_CASH,
TOKEN_TRANSFER_IN_FAILED,
TOKEN_TRANSFER_OUT_FAILED
}
enum FailureInfo {
ACCEPT_ADMIN_PENDING_ADMIN_CHECK,
ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED,
ACCRUE_INTEREST_BORROW_RATE_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED,
ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED,
ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED,
BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
BORROW_ACCRUE_INTEREST_FAILED,
BORROW_CASH_NOT_AVAILABLE,
BORROW_FRESHNESS_CHECK,
BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
BORROW_MARKET_NOT_LISTED,
BORROW_CONTROLLER_REJECTION,
LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED,
LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED,
LIQUIDATE_COLLATERAL_FRESHNESS_CHECK,
LIQUIDATE_CONTROLLER_REJECTION,
LIQUIDATE_CONTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED,
LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX,
LIQUIDATE_CLOSE_AMOUNT_IS_ZERO,
LIQUIDATE_FRESHNESS_CHECK,
LIQUIDATE_LIQUIDATOR_IS_BORROWER,
LIQUIDATE_REPAY_BORROW_FRESH_FAILED,
LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED,
LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED,
LIQUIDATE_SEIZE_CONTROLLER_REJECTION,
LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER,
LIQUIDATE_SEIZE_TOO_MUCH,
MINT_ACCRUE_INTEREST_FAILED,
MINT_CONTROLLER_REJECTION,
MINT_EXCHANGE_CALCULATION_FAILED,
MINT_EXCHANGE_RATE_READ_FAILED,
MINT_FRESHNESS_CHECK,
MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
MINT_TRANSFER_IN_FAILED,
MINT_TRANSFER_IN_NOT_POSSIBLE,
REDEEM_ACCRUE_INTEREST_FAILED,
REDEEM_CONTROLLER_REJECTION,
REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED,
REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED,
REDEEM_EXCHANGE_RATE_READ_FAILED,
REDEEM_FRESHNESS_CHECK,
REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED,
REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED,
REDEEM_TRANSFER_OUT_NOT_POSSIBLE,
REDUCE_RESERVES_ACCRUE_INTEREST_FAILED,
REDUCE_RESERVES_ADMIN_CHECK,
REDUCE_RESERVES_CASH_NOT_AVAILABLE,
REDUCE_RESERVES_FRESH_CHECK,
REDUCE_RESERVES_VALIDATION,
REPAY_BEHALF_ACCRUE_INTEREST_FAILED,
REPAY_BORROW_ACCRUE_INTEREST_FAILED,
REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_CONTROLLER_REJECTION,
REPAY_BORROW_FRESHNESS_CHECK,
REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED,
REPAY_BORROW_TRANSFER_IN_NOT_POSSIBLE,
SET_COLLATERAL_FACTOR_OWNER_CHECK,
SET_COLLATERAL_FACTOR_VALIDATION,
SET_CONTROLLER_OWNER_CHECK,
SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED,
SET_INTEREST_RATE_MODEL_FRESH_CHECK,
SET_INTEREST_RATE_MODEL_OWNER_CHECK,
SET_MAX_ASSETS_OWNER_CHECK,
SET_ORACLE_MARKET_NOT_LISTED,
SET_PENDING_ADMIN_OWNER_CHECK,
SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED,
SET_RESERVE_FACTOR_ADMIN_CHECK,
SET_RESERVE_FACTOR_FRESH_CHECK,
SET_RESERVE_FACTOR_BOUNDS_CHECK,
TRANSFER_CONTROLLER_REJECTION,
TRANSFER_NOT_ALLOWED,
TRANSFER_NOT_ENOUGH,
TRANSFER_TOO_MUCH
}
}
contract Exponential is CarefulMath {
uint constant expScale = 1e18;
uint constant halfExpScale = expScale/2;
uint constant mantissaOne = expScale;
struct Exp {
uint mantissa;
}
function getExp(uint num, uint denom) pure internal returns (MathError, Exp memory) {
(MathError err0, uint scaledNumerator) = mulUInt(num, expScale);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
(MathError err1, uint rational) = divUInt(scaledNumerator, denom);
if (err1 != MathError.NO_ERROR) {
return (err1, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: rational}));
}
function addExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError error, uint result) = addUInt(a.mantissa, b.mantissa);
return (error, Exp({mantissa: result}));
}
function subExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError error, uint result) = subUInt(a.mantissa, b.mantissa);
return (error, Exp({mantissa: result}));
}
function mulScalar(Exp memory a, uint scalar) pure internal returns (MathError, Exp memory) {
(MathError err0, uint scaledMantissa) = mulUInt(a.mantissa, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: scaledMantissa}));
}
function mulScalarTruncate(Exp memory a, uint scalar) pure internal returns (MathError, uint) {
(MathError err, Exp memory product) = mulScalar(a, scalar);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return (MathError.NO_ERROR, truncate(product));
}
function mulScalarTruncateAddUInt(Exp memory a, uint scalar, uint addend) pure internal returns (MathError, uint) {
(MathError err, Exp memory product) = mulScalar(a, scalar);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return addUInt(truncate(product), addend);
}
function divScalar(Exp memory a, uint scalar) pure internal returns (MathError, Exp memory) {
(MathError err0, uint descaledMantissa) = divUInt(a.mantissa, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return (MathError.NO_ERROR, Exp({mantissa: descaledMantissa}));
}
function divScalarByExp(uint scalar, Exp memory divisor) pure internal returns (MathError, Exp memory) {
/*
We are doing this as:
getExp(mulUInt(expScale, scalar), divisor.mantissa)
How it works:
Exp = a / b;
Scalar = s;
`s / (a / b)` = `b * s / a` and since for an Exp `a = mantissa, b = expScale`
*/
(MathError err0, uint numerator) = mulUInt(expScale, scalar);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
return getExp(numerator, divisor.mantissa);
}
function divScalarByExpTruncate(uint scalar, Exp memory divisor) pure internal returns (MathError, uint) {
(MathError err, Exp memory fraction) = divScalarByExp(scalar, divisor);
if (err != MathError.NO_ERROR) {
return (err, 0);
}
return (MathError.NO_ERROR, truncate(fraction));
}
function mulExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
(MathError err0, uint doubleScaledProduct) = mulUInt(a.mantissa, b.mantissa);
if (err0 != MathError.NO_ERROR) {
return (err0, Exp({mantissa: 0}));
}
// We add half the scale before dividing so that we get rounding instead of truncation.
// See "Listing 6" and text above it at https://accu.org/index.php/journals/1717
// Without this change, a result like 6.6...e-19 will be truncated to 0 instead of being rounded to 1e-18.
(MathError err1, uint doubleScaledProductWithHalfScale) = addUInt(halfExpScale, doubleScaledProduct);
if (err1 != MathError.NO_ERROR) {
return (err1, Exp({mantissa: 0}));
}
(MathError err2, uint product) = divUInt(doubleScaledProductWithHalfScale, expScale);
// The only error `div` can return is MathError.DIVISION_BY_ZERO but we control `expScale` and it is not zero.
assert(err2 == MathError.NO_ERROR);
return (MathError.NO_ERROR, Exp({mantissa: product}));
}
function mulExp(uint a, uint b) pure internal returns (MathError, Exp memory) {
return mulExp(Exp({mantissa: a}), Exp({mantissa: b}));
}
function mulExp3(Exp memory a, Exp memory b, Exp memory c) pure internal returns (MathError, Exp memory) {
(MathError err, Exp memory ab) = mulExp(a, b);
if (err != MathError.NO_ERROR) {
return (err, ab);
}
return mulExp(ab, c);
}
function divExp(Exp memory a, Exp memory b) pure internal returns (MathError, Exp memory) {
return getExp(a.mantissa, b.mantissa);
}
function truncate(Exp memory exp) pure internal returns (uint) {
// Note: We are not using careful math here as we're performing a division that cannot fail
return exp.mantissa / expScale;
}
function lessThanExp(Exp memory left, Exp memory right) pure internal returns (bool) {
return left.mantissa < right.mantissa; //TODO: Add some simple tests and this in another PR yo.
}
function lessThanOrEqualExp(Exp memory left, Exp memory right) pure internal returns (bool) {
return left.mantissa <= right.mantissa;
}
function isZeroExp(Exp memory value) pure internal returns (bool) {
return value.mantissa == 0;
}
}
/**
* @title ERC 20 Token Standard Interface
* https://eips.ethereum.org/EIPS/eip-20
*/
interface EIP20Interface {
/**
* @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 The balance
*/
function balanceOf(address owner) external view returns (uint256 balance);
/**
* @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 returns (bool success);
/**
* @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 returns (bool success);
/**
* @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 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 The number of tokens allowed to be spent (-1 means infinite)
*/
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);
}
/**
* @title EIP20NonStandardInterface
* notice: 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 {
function totalSupply() external view returns (uint256);
function balanceOf(address owner) external view returns (uint256 balance);
function transfer(address dst, uint256 amount) external;
function transferFrom(address src, address dst, uint256 amount) external;
function approve(address spender, uint256 amount) external returns (bool success);
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);
}
/**
* @title Helps contracts guard against reentrancy attacks.
* @author Remco Bloemen <remco@2π.com>, Eenae <[email protected]>
* @dev If you mark a function `nonReentrant`, you should also
* mark it `external`.
*/
contract ReentrancyGuard {
/// @dev counter to allow mutex lock with only one SSTORE operation
uint256 private _guardCounter;
constructor () public {
// The counter starts at one to prevent changing it from zero to a non-zero
// value, which is a more expensive operation.
_guardCounter = 1;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_guardCounter += 1;
uint256 localCounter = _guardCounter;
_;
require(localCounter == _guardCounter, "re-entered");
}
}
interface InterestRateModel {
function getBorrowRate(uint cash, uint borrows, uint reserves) external view returns (uint, uint);
function isInterestRateModel() external view returns (bool);
}
contract AToken is EIP20Interface, Exponential, TokenErrorReporter, ReentrancyGuard {
/**
* @notice Indicator that this is a AToken contract (for inspection)
*/
bool public constant isAToken = true;
/**
* @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
*/
uint public decimals;
/**
* @notice Maximum borrow rate that can ever be applied (.0005% / block)
*/
uint constant borrowRateMaxMantissa = 5e14;
/**
* @notice Maximum fraction of interest that can be set aside for reserves
*/
uint 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-aToken operations
*/
ControllerInterface public controller;
/**
* @notice Model which tells what the current interest rate should be
*/
InterestRateModel public interestRateModel;
/**
* @notice Initial exchange rate used when minting the first ATokens (used when totalSupply = 0)
*/
uint public initialExchangeRateMantissa;
/**
* @notice Fraction of interest currently set aside for reserves
*/
uint public reserveFactorMantissa;
/**
* @notice Block number that interest was last accrued at
*/
uint public accrualBlockNumber;
/**
* @notice Accumulator of total earned interest since the opening of the market
*/
uint public borrowIndex;
/**
* @notice Total amount of outstanding borrows of the underlying in this market
*/
uint public totalBorrows;
/**
* @notice Total amount of reserves of the underlying held in this market
*/
uint public totalReserves;
/**
* @notice Total number of tokens in circulation
*/
uint256 public totalSupply;
/**
* @notice Official record of token balances for each account
*/
mapping (address => uint256) accountTokens;
/**
* @notice Approved token transfer amounts on behalf of others
*/
mapping (address => mapping (address => uint256)) 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 {
uint principal;
uint interestIndex;
}
/**
* @notice Mapping of account addresses to outstanding borrow balances
*/
mapping(address => BorrowSnapshot) accountBorrows;
/*** Market Events ***/
/**
* @notice Event emitted when interest is accrued
*/
event AccrueInterest(uint interestAccumulated, uint borrowIndex, uint totalBorrows);
/**
* @notice Event emitted when tokens are minted
*/
event Mint(address minter, uint mintAmount, uint mintTokens);
/**
* @notice Event emitted when tokens are redeemed
*/
event Redeem(address redeemer, uint redeemAmount, uint redeemTokens);
/**
* @notice Event emitted when underlying is borrowed
*/
event Borrow(address borrower, uint borrowAmount, uint accountBorrows, uint totalBorrows);
/**
* @notice Event emitted when a borrow is repaid
*/
event RepayBorrow(address payer, address borrower, uint repayAmount, uint accountBorrows, uint totalBorrows);
/**
* @notice Event emitted when a borrow is liquidated
*/
event LiquidateBorrow(address liquidator, address borrower, uint repayAmount, address aTokenCollateral, uint 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 controller is changed
*/
event NewController(ControllerInterface oldController, ControllerInterface newController);
/**
* @notice Event emitted when interestRateModel is changed
*/
event NewMarketInterestRateModel(InterestRateModel oldInterestRateModel, InterestRateModel newInterestRateModel);
/**
* @notice Event emitted when the reserve factor is changed
*/
event NewReserveFactor(uint oldReserveFactorMantissa, uint newReserveFactorMantissa);
/**
* @notice Event emitted when the reserves are reduced
*/
event ReservesReduced(address admin, uint reduceAmount, uint newTotalReserves);
constructor( ) public {
admin = msg.sender;
// Set initial exchange rate
initialExchangeRateMantissa = uint(200000000000000);
// Initialize block number and borrow index (block number mocks depend on controller being set)
accrualBlockNumber = getBlockNumber();
borrowIndex = mantissaOne;
name = string("Artem USD Coin");
symbol = string("aUSDC");
decimals = uint(8);
}
function transferTokens(address spender, address src, address dst, uint tokens) internal returns (uint) {
/* Fail if transfer not allowed */
uint allowed = controller.transferAllowed(address(this), src, dst, tokens);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.TRANSFER_CONTROLLER_REJECTION, allowed);
}
/* Do not allow self-transfers */
if (src == dst) {
return fail(Error.BAD_INPUT, FailureInfo.TRANSFER_NOT_ALLOWED);
}
/* Get the allowance, infinite for the account owner */
uint startingAllowance = 0;
if (spender == src) {
startingAllowance = uint(-1);
} else {
startingAllowance = transferAllowances[src][spender];
}
/* Do the calculations, checking for {under,over}flow */
MathError mathErr;
uint allowanceNew;
uint srcTokensNew;
uint dstTokensNew;
(mathErr, allowanceNew) = subUInt(startingAllowance, tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ALLOWED);
}
(mathErr, srcTokensNew) = subUInt(accountTokens[src], tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_NOT_ENOUGH);
}
(mathErr, dstTokensNew) = addUInt(accountTokens[dst], tokens);
if (mathErr != MathError.NO_ERROR) {
return fail(Error.MATH_ERROR, FailureInfo.TRANSFER_TOO_MUCH);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
accountTokens[src] = srcTokensNew;
accountTokens[dst] = dstTokensNew;
/* Eat some of the allowance (if necessary) */
if (startingAllowance != uint(-1)) {
transferAllowances[src][spender] = allowanceNew;
}
/* We emit a Transfer event */
emit Transfer(src, dst, tokens);
/* We call the defense hook (which checks for under-collateralization) */
controller.transferVerify(address(this), src, dst, tokens);
return uint(Error.NO_ERROR);
}
/**
* @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 nonReentrant returns (bool) {
return transferTokens(msg.sender, msg.sender, dst, amount) == uint(Error.NO_ERROR);
}
/**
* @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 nonReentrant returns (bool) {
return transferTokens(msg.sender, src, dst, amount) == uint(Error.NO_ERROR);
}
/**
* @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 returns (bool) {
address src = msg.sender;
transferAllowances[src][spender] = amount;
emit Approval(src, spender, amount);
return true;
}
/**
* @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 returns (uint256) {
return transferAllowances[owner][spender];
}
/**
* @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 returns (uint256) {
return accountTokens[owner];
}
/**
* @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 returns (uint) {
Exp memory exchangeRate = Exp({mantissa: exchangeRateCurrent()});
(MathError mErr, uint balance) = mulScalarTruncate(exchangeRate, accountTokens[owner]);
require(mErr == MathError.NO_ERROR);
return balance;
}
/**
* @notice Get a snapshot of the account's balances, and the cached exchange rate
* @dev This is used by controller 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 returns (uint, uint, uint, uint) {
uint aTokenBalance = accountTokens[account];
uint borrowBalance;
uint exchangeRateMantissa;
MathError mErr;
(mErr, borrowBalance) = borrowBalanceStoredInternal(account);
if (mErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0, 0, 0);
}
(mErr, exchangeRateMantissa) = exchangeRateStoredInternal();
if (mErr != MathError.NO_ERROR) {
return (uint(Error.MATH_ERROR), 0, 0, 0);
}
return (uint(Error.NO_ERROR), aTokenBalance, borrowBalance, exchangeRateMantissa);
}
/**
* @dev Function to simply retrieve block number
* This exists mainly for inheriting test contracts to stub this result.
*/
function getBlockNumber() internal view returns (uint) {
return block.number;
}
/**
* @notice Returns the current per-block borrow interest rate for this aToken
* @return The borrow interest rate per block, scaled by 1e18
*/
function borrowRatePerBlock() external view returns (uint) {
(uint opaqueErr, uint borrowRateMantissa) = interestRateModel.getBorrowRate(getCashPrior(), totalBorrows, totalReserves);
require(opaqueErr == 0, "borrowRatePerBlock: interestRateModel.borrowRate failed"); // semi-opaque
return borrowRateMantissa;
}
/**
* @notice Returns the current per-block supply interest rate for this aToken
* @return The supply interest rate per block, scaled by 1e18
*/
function supplyRatePerBlock() external view returns (uint) {
/* We calculate the supply rate:
* underlying = totalSupply × exchangeRate
* borrowsPer = totalBorrows ÷ underlying
* supplyRate = borrowRate × (1-reserveFactor) × borrowsPer
*/
uint exchangeRateMantissa = exchangeRateStored();
(uint e0, uint borrowRateMantissa) = interestRateModel.getBorrowRate(getCashPrior(), totalBorrows, totalReserves);
require(e0 == 0, "supplyRatePerBlock: calculating borrowRate failed"); // semi-opaque
(MathError e1, Exp memory underlying) = mulScalar(Exp({mantissa: exchangeRateMantissa}), totalSupply);
require(e1 == MathError.NO_ERROR, "supplyRatePerBlock: calculating underlying failed");
(MathError e2, Exp memory borrowsPer) = divScalarByExp(totalBorrows, underlying);
require(e2 == MathError.NO_ERROR, "supplyRatePerBlock: calculating borrowsPer failed");
(MathError e3, Exp memory oneMinusReserveFactor) = subExp(Exp({mantissa: mantissaOne}), Exp({mantissa: reserveFactorMantissa}));
require(e3 == MathError.NO_ERROR, "supplyRatePerBlock: calculating oneMinusReserveFactor failed");
(MathError e4, Exp memory supplyRate) = mulExp3(Exp({mantissa: borrowRateMantissa}), oneMinusReserveFactor, borrowsPer);
require(e4 == MathError.NO_ERROR, "supplyRatePerBlock: calculating supplyRate failed");
return supplyRate.mantissa;
}
/**
* @notice Returns the current total borrows plus accrued interest
* @return The total borrows with interest
*/
function totalBorrowsCurrent() external nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
return totalBorrows;
}
/**
* @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 nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
return borrowBalanceStored(account);
}
/**
* @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 returns (uint) {
(MathError err, uint result) = borrowBalanceStoredInternal(account);
require(err == MathError.NO_ERROR, "borrowBalanceStored: borrowBalanceStoredInternal failed");
return result;
}
/**
* @notice Return the borrow balance of account based on stored data
* @param account The address whose balance should be calculated
* @return (error code, the calculated balance or 0 if error code is non-zero)
*/
function borrowBalanceStoredInternal(address account) internal view returns (MathError, uint) {
/* Note: we do not assert that the market is up to date */
MathError mathErr;
uint principalTimesIndex;
uint result;
/* Get borrowBalance and borrowIndex */
BorrowSnapshot storage borrowSnapshot = accountBorrows[account];
/* If borrowBalance = 0 then borrowIndex is likely also 0.
* Rather than failing the calculation with a division by 0, we immediately return 0 in this case.
*/
if (borrowSnapshot.principal == 0) {
return (MathError.NO_ERROR, 0);
}
/* Calculate new borrow balance using the interest index:
* recentBorrowBalance = borrower.borrowBalance * market.borrowIndex / borrower.borrowIndex
*/
(mathErr, principalTimesIndex) = mulUInt(borrowSnapshot.principal, borrowIndex);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
(mathErr, result) = divUInt(principalTimesIndex, borrowSnapshot.interestIndex);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
return (MathError.NO_ERROR, result);
}
/**
* @notice Accrue interest then return the up-to-date exchange rate
* @return Calculated exchange rate scaled by 1e18
*/
function exchangeRateCurrent() public nonReentrant returns (uint) {
require(accrueInterest() == uint(Error.NO_ERROR), "accrue interest failed");
return exchangeRateStored();
}
/**
* @notice Calculates the exchange rate from the underlying to the AToken
* @dev This function does not accrue interest before calculating the exchange rate
* @return Calculated exchange rate scaled by 1e18
*/
function exchangeRateStored() public view returns (uint) {
(MathError err, uint result) = exchangeRateStoredInternal();
require(err == MathError.NO_ERROR, "exchangeRateStored: exchangeRateStoredInternal failed");
return result;
}
/**
* @notice Calculates the exchange rate from the underlying to the AToken
* @dev This function does not accrue interest before calculating the exchange rate
* @return (error code, calculated exchange rate scaled by 1e18)
*/
function exchangeRateStoredInternal() internal view returns (MathError, uint) {
if (totalSupply == 0) {
/*
* If there are no tokens minted:
* exchangeRate = initialExchangeRate
*/
return (MathError.NO_ERROR, initialExchangeRateMantissa);
} else {
/*
* Otherwise:
* exchangeRate = (totalCash + totalBorrows - totalReserves) / totalSupply
*/
uint totalCash = getCashPrior();
uint cashPlusBorrowsMinusReserves;
Exp memory exchangeRate;
MathError mathErr;
(mathErr, cashPlusBorrowsMinusReserves) = addThenSubUInt(totalCash, totalBorrows, totalReserves);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
(mathErr, exchangeRate) = getExp(cashPlusBorrowsMinusReserves, totalSupply);
if (mathErr != MathError.NO_ERROR) {
return (mathErr, 0);
}
return (MathError.NO_ERROR, exchangeRate.mantissa);
}
}
/**
* @notice Get cash balance of this aToken in the underlying asset
* @return The quantity of underlying asset owned by this contract
*/
function getCash() external view returns (uint) {
return getCashPrior();
}
struct AccrueInterestLocalVars {
MathError mathErr;
uint opaqueErr;
uint borrowRateMantissa;
uint currentBlockNumber;
uint blockDelta;
Exp simpleInterestFactor;
uint interestAccumulated;
uint totalBorrowsNew;
uint totalReservesNew;
uint borrowIndexNew;
}
function getCash_pub() public returns (uint) {
return getCashPrior();
}
/**
* @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 returns (uint) {
AccrueInterestLocalVars memory vars;
/* Calculate the current borrow interest rate */
(vars.opaqueErr, vars.borrowRateMantissa) = interestRateModel.getBorrowRate(getCashPrior(), totalBorrows, totalReserves);
require(vars.borrowRateMantissa <= borrowRateMaxMantissa, "borrow rate is absurdly high");
if (vars.opaqueErr != 0) {
return failOpaque(Error.INTEREST_RATE_MODEL_ERROR, FailureInfo.ACCRUE_INTEREST_BORROW_RATE_CALCULATION_FAILED, vars.opaqueErr);
}
/* Remember the initial block number */
vars.currentBlockNumber = getBlockNumber();
/* Calculate the number of blocks elapsed since the last accrual */
(vars.mathErr, vars.blockDelta) = subUInt(vars.currentBlockNumber, accrualBlockNumber);
assert(vars.mathErr == MathError.NO_ERROR); // Block delta should always succeed and if it doesn't, blow up.
/*
* Calculate the interest accumulated into borrows and reserves and the new index:
* simpleInterestFactor = borrowRate * blockDelta
* interestAccumulated = simpleInterestFactor * totalBorrows
* totalBorrowsNew = interestAccumulated + totalBorrows
* totalReservesNew = interestAccumulated * reserveFactor + totalReserves
* borrowIndexNew = simpleInterestFactor * borrowIndex + borrowIndex
*/
(vars.mathErr, vars.simpleInterestFactor) = mulScalar(Exp({mantissa: vars.borrowRateMantissa}), vars.blockDelta);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_SIMPLE_INTEREST_FACTOR_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.interestAccumulated) = mulScalarTruncate(vars.simpleInterestFactor, totalBorrows);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_ACCUMULATED_INTEREST_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.totalBorrowsNew) = addUInt(vars.interestAccumulated, totalBorrows);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_TOTAL_BORROWS_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.totalReservesNew) = mulScalarTruncateAddUInt(Exp({mantissa: reserveFactorMantissa}), vars.interestAccumulated, totalReserves);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_TOTAL_RESERVES_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.borrowIndexNew) = mulScalarTruncateAddUInt(vars.simpleInterestFactor, borrowIndex, borrowIndex);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.ACCRUE_INTEREST_NEW_BORROW_INDEX_CALCULATION_FAILED, uint(vars.mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/* We write the previously calculated values into storage */
accrualBlockNumber = vars.currentBlockNumber;
borrowIndex = vars.borrowIndexNew;
totalBorrows = vars.totalBorrowsNew;
totalReserves = vars.totalReservesNew;
/* We emit an AccrueInterest event */
emit AccrueInterest(vars.interestAccumulated, vars.borrowIndexNew, totalBorrows);
return uint(Error.NO_ERROR);
}
/**
* @notice Sender supplies assets into the market and receives aTokens 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 mintInternal(uint mintAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return fail(Error(error), FailureInfo.MINT_ACCRUE_INTEREST_FAILED);
}
// mintFresh emits the actual Mint event if successful and logs on errors, so we don't need to
return mintFresh(msg.sender, mintAmount);
}
struct MintLocalVars {
Error err;
MathError mathErr;
uint exchangeRateMantissa;
uint mintTokens;
uint totalSupplyNew;
uint accountTokensNew;
}
/**
* @notice User supplies assets into the market and receives aTokens in exchange
* @dev Assumes interest has already been accrued up to the current block
* @param minter The address of the account which is supplying the assets
* @param mintAmount The amount of the underlying asset to supply
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function mintFresh(address minter, uint mintAmount) internal returns (uint) {
/* Fail if mint not allowed */
uint allowed = controller.mintAllowed(address(this), minter, mintAmount);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.MINT_CONTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.MINT_FRESHNESS_CHECK);
}
MintLocalVars memory vars;
/* Fail if checkTransferIn fails */
vars.err = checkTransferIn(minter, mintAmount);
if (vars.err != Error.NO_ERROR) {
return fail(vars.err, FailureInfo.MINT_TRANSFER_IN_NOT_POSSIBLE);
}
/*
* We get the current exchange rate and calculate the number of aTokens to be minted:
* mintTokens = mintAmount / exchangeRate
*/
(vars.mathErr, vars.exchangeRateMantissa) = exchangeRateStoredInternal();
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.MINT_EXCHANGE_RATE_READ_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.mintTokens) = divScalarByExpTruncate(mintAmount, Exp({mantissa: vars.exchangeRateMantissa}));
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.MINT_EXCHANGE_CALCULATION_FAILED, uint(vars.mathErr));
}
/*
* We calculate the new total supply of aTokens and minter token balance, checking for overflow:
* totalSupplyNew = totalSupply + mintTokens
* accountTokensNew = accountTokens[minter] + mintTokens
*/
(vars.mathErr, vars.totalSupplyNew) = addUInt(totalSupply, vars.mintTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.MINT_NEW_TOTAL_SUPPLY_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.accountTokensNew) = addUInt(accountTokens[minter], vars.mintTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.MINT_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* We call doTransferIn for the minter and the mintAmount
* Note: The aToken must handle variations between ERC-20 and ETH underlying.
* On success, the aToken holds an additional mintAmount of cash.
* If doTransferIn fails despite the fact we checked pre-conditions,
* we revert because we can't be sure if side effects occurred.
*/
vars.err = doTransferIn(minter, mintAmount);
if (vars.err != Error.NO_ERROR) {
return fail(vars.err, FailureInfo.MINT_TRANSFER_IN_FAILED);
}
/* We write previously calculated values into storage */
totalSupply = vars.totalSupplyNew;
accountTokens[minter] = vars.accountTokensNew;
/* We emit a Mint event, and a Transfer event */
emit Mint(minter, mintAmount, vars.mintTokens);
emit Transfer(address(this), minter, vars.mintTokens);
/* We call the defense hook */
controller.mintVerify(address(this), minter, mintAmount, vars.mintTokens);
return uint(Error.NO_ERROR);
}
/**
* @notice Sender redeems aTokens in exchange for the underlying asset
* @dev Accrues interest whether or not the operation succeeds, unless reverted
* @param redeemTokens The number of aTokens to redeem into underlying
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeemInternal(uint redeemTokens) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
return fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
}
// redeemFresh emits redeem-specific logs on errors, so we don't need to
return redeemFresh(msg.sender, redeemTokens, 0);
}
/**
* @notice Sender redeems aTokens 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 redeemUnderlyingInternal(uint redeemAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted redeem failed
return fail(Error(error), FailureInfo.REDEEM_ACCRUE_INTEREST_FAILED);
}
// redeemFresh emits redeem-specific logs on errors, so we don't need to
return redeemFresh(msg.sender, 0, redeemAmount);
}
struct RedeemLocalVars {
Error err;
MathError mathErr;
uint exchangeRateMantissa;
uint redeemTokens;
uint redeemAmount;
uint totalSupplyNew;
uint accountTokensNew;
}
/**
* @notice User redeems aTokens in exchange for the underlying asset
* @dev Assumes interest has already been accrued up to the current block
* @param redeemer The address of the account which is redeeming the tokens
* @param redeemTokensIn The number of aTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be zero)
* @param redeemAmountIn The number of aTokens to redeem into underlying (only one of redeemTokensIn or redeemAmountIn may be zero)
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeemFresh(address payable redeemer, uint redeemTokensIn, uint redeemAmountIn) internal returns (uint) {
require(redeemTokensIn == 0 || redeemAmountIn == 0, "one of redeemTokensIn or redeemAmountIn must be zero");
RedeemLocalVars memory vars;
/* exchangeRate = invoke Exchange Rate Stored() */
(vars.mathErr, vars.exchangeRateMantissa) = exchangeRateStoredInternal();
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_RATE_READ_FAILED, uint(vars.mathErr));
}
/* If redeemTokensIn > 0: */
if (redeemTokensIn > 0) {
/*
* We calculate the exchange rate and the amount of underlying to be redeemed:
* redeemTokens = redeemTokensIn
* redeemAmount = redeemTokensIn x exchangeRateCurrent
*/
vars.redeemTokens = redeemTokensIn;
(vars.mathErr, vars.redeemAmount) = mulScalarTruncate(Exp({mantissa: vars.exchangeRateMantissa}), redeemTokensIn);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_TOKENS_CALCULATION_FAILED, uint(vars.mathErr));
}
} else {
/*
* We get the current exchange rate and calculate the amount to be redeemed:
* redeemTokens = redeemAmountIn / exchangeRate
* redeemAmount = redeemAmountIn
*/
(vars.mathErr, vars.redeemTokens) = divScalarByExpTruncate(redeemAmountIn, Exp({mantissa: vars.exchangeRateMantissa}));
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_EXCHANGE_AMOUNT_CALCULATION_FAILED, uint(vars.mathErr));
}
vars.redeemAmount = redeemAmountIn;
}
/* Fail if redeem not allowed */
uint allowed = controller.redeemAllowed(address(this), redeemer, vars.redeemTokens);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.REDEEM_CONTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.REDEEM_FRESHNESS_CHECK);
}
/*
* We calculate the new total supply and redeemer balance, checking for underflow:
* totalSupplyNew = totalSupply - redeemTokens
* accountTokensNew = accountTokens[redeemer] - redeemTokens
*/
(vars.mathErr, vars.totalSupplyNew) = subUInt(totalSupply, vars.redeemTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_NEW_TOTAL_SUPPLY_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.accountTokensNew) = subUInt(accountTokens[redeemer], vars.redeemTokens);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REDEEM_NEW_ACCOUNT_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/* Fail gracefully if protocol has insufficient cash */
if (getCashPrior() < vars.redeemAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.REDEEM_TRANSFER_OUT_NOT_POSSIBLE);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* We invoke doTransferOut for the redeemer and the redeemAmount.
* Note: The aToken must handle variations between ERC-20 and ETH underlying.
* On success, the aToken has redeemAmount less of cash.
* If doTransferOut fails despite the fact we checked pre-conditions,
* we revert because we can't be sure if side effects occurred.
*/
vars.err = doTransferOut(redeemer, vars.redeemAmount);
require(vars.err == Error.NO_ERROR, "redeem transfer out failed");
/* We write previously calculated values into storage */
totalSupply = vars.totalSupplyNew;
accountTokens[redeemer] = vars.accountTokensNew;
/* We emit a Transfer event, and a Redeem event */
emit Transfer(redeemer, address(this), vars.redeemTokens);
emit Redeem(redeemer, vars.redeemAmount, vars.redeemTokens);
/* We call the defense hook */
controller.redeemVerify(address(this), redeemer, vars.redeemAmount, vars.redeemTokens);
return uint(Error.NO_ERROR);
}
/**
* @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 borrowInternal(uint borrowAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return fail(Error(error), FailureInfo.BORROW_ACCRUE_INTEREST_FAILED);
}
// borrowFresh emits borrow-specific logs on errors, so we don't need to
return borrowFresh(msg.sender, borrowAmount);
}
struct BorrowLocalVars {
Error err;
MathError mathErr;
uint accountBorrows;
uint accountBorrowsNew;
uint totalBorrowsNew;
}
/**
* @notice Users borrow 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 borrowFresh(address payable borrower, uint borrowAmount) internal returns (uint) {
/* Fail if borrow not allowed */
uint allowed = controller.borrowAllowed(address(this), borrower, borrowAmount);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.BORROW_CONTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.BORROW_FRESHNESS_CHECK);
}
/* Fail gracefully if protocol has insufficient underlying cash */
if (getCashPrior() < borrowAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.BORROW_CASH_NOT_AVAILABLE);
}
BorrowLocalVars memory vars;
/*
* We calculate the new borrower and total borrow balances, failing on overflow:
* accountBorrowsNew = accountBorrows + borrowAmount
* totalBorrowsNew = totalBorrows + borrowAmount
*/
(vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(borrower);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.accountBorrowsNew) = addUInt(vars.accountBorrows, borrowAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.totalBorrowsNew) = addUInt(totalBorrows, borrowAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* We invoke doTransferOut for the borrower and the borrowAmount.
* Note: The aToken must handle variations between ERC-20 and ETH underlying.
* On success, the aToken borrowAmount less of cash.
* If doTransferOut fails despite the fact we checked pre-conditions,
* we revert because we can't be sure if side effects occurred.
*/
vars.err = doTransferOut(borrower, borrowAmount);
require(vars.err == Error.NO_ERROR, "borrow transfer out failed");
/* We write the previously calculated values into storage */
accountBorrows[borrower].principal = vars.accountBorrowsNew;
accountBorrows[borrower].interestIndex = borrowIndex;
totalBorrows = vars.totalBorrowsNew;
/* We emit a Borrow event */
emit Borrow(borrower, borrowAmount, vars.accountBorrowsNew, vars.totalBorrowsNew);
/* We call the defense hook */
controller.borrowVerify(address(this), borrower, borrowAmount);
return uint(Error.NO_ERROR);
}
/**
* @notice Sender repays their own borrow
* @param repayAmount The amount to repay
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function repayBorrowInternal(uint repayAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return fail(Error(error), FailureInfo.REPAY_BORROW_ACCRUE_INTEREST_FAILED);
}
// repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
return repayBorrowFresh(msg.sender, msg.sender, repayAmount);
}
/**
* @notice Sender repays a borrow belonging to borrower
* @param borrower the account with the debt being payed off
* @param repayAmount The amount to repay
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function repayBorrowBehalfInternal(address borrower, uint repayAmount) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted borrow failed
return fail(Error(error), FailureInfo.REPAY_BEHALF_ACCRUE_INTEREST_FAILED);
}
// repayBorrowFresh emits repay-borrow-specific logs on errors, so we don't need to
return repayBorrowFresh(msg.sender, borrower, repayAmount);
}
struct RepayBorrowLocalVars {
Error err;
MathError mathErr;
uint repayAmount;
uint borrowerIndex;
uint accountBorrows;
uint accountBorrowsNew;
uint totalBorrowsNew;
}
/**
* @notice Borrows are repaid by another user (possibly the borrower).
* @param payer the account paying off the borrow
* @param borrower the account with the debt being payed off
* @param repayAmount the amount of undelrying tokens being returned
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function repayBorrowFresh(address payer, address borrower, uint repayAmount) internal returns (uint) {
/* Fail if repayBorrow not allowed */
uint allowed = controller.repayBorrowAllowed(address(this), payer, borrower, repayAmount);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.REPAY_BORROW_CONTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.REPAY_BORROW_FRESHNESS_CHECK);
}
RepayBorrowLocalVars memory vars;
/* We remember the original borrowerIndex for verification purposes */
vars.borrowerIndex = accountBorrows[borrower].interestIndex;
/* We fetch the amount the borrower owes, with accumulated interest */
(vars.mathErr, vars.accountBorrows) = borrowBalanceStoredInternal(borrower);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REPAY_BORROW_ACCUMULATED_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/* If repayAmount == -1, repayAmount = accountBorrows */
if (repayAmount == uint(-1)) {
vars.repayAmount = vars.accountBorrows;
} else {
vars.repayAmount = repayAmount;
}
/* Fail if checkTransferIn fails */
vars.err = checkTransferIn(payer, vars.repayAmount);
if (vars.err != Error.NO_ERROR) {
return fail(vars.err, FailureInfo.REPAY_BORROW_TRANSFER_IN_NOT_POSSIBLE);
}
/*
* We calculate the new borrower and total borrow balances, failing on underflow:
* accountBorrowsNew = accountBorrows - repayAmount
* totalBorrowsNew = totalBorrows - repayAmount
*/
(vars.mathErr, vars.accountBorrowsNew) = subUInt(vars.accountBorrows, vars.repayAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REPAY_BORROW_NEW_ACCOUNT_BORROW_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
(vars.mathErr, vars.totalBorrowsNew) = subUInt(totalBorrows, vars.repayAmount);
if (vars.mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.REPAY_BORROW_NEW_TOTAL_BALANCE_CALCULATION_FAILED, uint(vars.mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/*
* We call doTransferIn for the payer and the repayAmount
* Note: The aToken must handle variations between ERC-20 and ETH underlying.
* On success, the aToken holds an additional repayAmount of cash.
* If doTransferIn fails despite the fact we checked pre-conditions,
* we revert because we can't be sure if side effects occurred.
*/
vars.err = doTransferIn(payer, vars.repayAmount);
require(vars.err == Error.NO_ERROR, "repay borrow transfer in failed");
/* We write the previously calculated values into storage */
accountBorrows[borrower].principal = vars.accountBorrowsNew;
accountBorrows[borrower].interestIndex = borrowIndex;
totalBorrows = vars.totalBorrowsNew;
/* We emit a RepayBorrow event */
emit RepayBorrow(payer, borrower, vars.repayAmount, vars.accountBorrowsNew, vars.totalBorrowsNew);
/* We call the defense hook */
controller.repayBorrowVerify(address(this), payer, borrower, vars.repayAmount, vars.borrowerIndex);
return uint(Error.NO_ERROR);
}
/**
* @notice The sender liquidates the borrowers collateral.
* The collateral seized is transferred to the liquidator.
* @param borrower The borrower of this aToken to be liquidated
* @param aTokenCollateral 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 liquidateBorrowInternal(address borrower, uint repayAmount, AToken aTokenCollateral) internal nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
return fail(Error(error), FailureInfo.LIQUIDATE_ACCRUE_BORROW_INTEREST_FAILED);
}
error = aTokenCollateral.accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but we still want to log the fact that an attempted liquidation failed
return fail(Error(error), FailureInfo.LIQUIDATE_ACCRUE_COLLATERAL_INTEREST_FAILED);
}
// liquidateBorrowFresh emits borrow-specific logs on errors, so we don't need to
return liquidateBorrowFresh(msg.sender, borrower, repayAmount, aTokenCollateral);
}
/**
* @notice The liquidator liquidates the borrowers collateral.
* The collateral seized is transferred to the liquidator.
* @param borrower The borrower of this aToken to be liquidated
* @param liquidator The address repaying the borrow and seizing collateral
* @param aTokenCollateral 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 liquidateBorrowFresh(address liquidator, address borrower, uint repayAmount, AToken aTokenCollateral) internal returns (uint) {
/* Fail if liquidate not allowed */
uint allowed = controller.liquidateBorrowAllowed(address(this), address(aTokenCollateral), liquidator, borrower, repayAmount);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.LIQUIDATE_CONTROLLER_REJECTION, allowed);
}
/* Verify market's block number equals current block number */
if (accrualBlockNumber != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.LIQUIDATE_FRESHNESS_CHECK);
}
/* Verify aTokenCollateral market's block number equals current block number */
if (aTokenCollateral.accrualBlockNumber() != getBlockNumber()) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.LIQUIDATE_COLLATERAL_FRESHNESS_CHECK);
}
/* Fail if borrower = liquidator */
if (borrower == liquidator) {
return fail(Error.INVALID_ACCOUNT_PAIR, FailureInfo.LIQUIDATE_LIQUIDATOR_IS_BORROWER);
}
/* Fail if repayAmount = 0 */
if (repayAmount == 0) {
return fail(Error.INVALID_CLOSE_AMOUNT_REQUESTED, FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_ZERO);
}
/* Fail if repayAmount = -1 */
if (repayAmount == uint(-1)) {
return fail(Error.INVALID_CLOSE_AMOUNT_REQUESTED, FailureInfo.LIQUIDATE_CLOSE_AMOUNT_IS_UINT_MAX);
}
/* We calculate the number of collateral tokens that will be seized */
(uint amountSeizeError, uint seizeTokens) = controller.liquidateCalculateSeizeTokens(address(this), address(aTokenCollateral), repayAmount);
if (amountSeizeError != 0) {
return failOpaque(Error.CONTROLLER_CALCULATION_ERROR, FailureInfo.LIQUIDATE_CONTROLLER_CALCULATE_AMOUNT_SEIZE_FAILED, amountSeizeError);
}
/* Fail if seizeTokens > borrower collateral token balance */
if (seizeTokens > aTokenCollateral.balanceOf(borrower)) {
return fail(Error.TOKEN_INSUFFICIENT_BALANCE, FailureInfo.LIQUIDATE_SEIZE_TOO_MUCH);
}
/* Fail if repayBorrow fails */
uint repayBorrowError = repayBorrowFresh(liquidator, borrower, repayAmount);
if (repayBorrowError != uint(Error.NO_ERROR)) {
return fail(Error(repayBorrowError), FailureInfo.LIQUIDATE_REPAY_BORROW_FRESH_FAILED);
}
/* Revert if seize tokens fails (since we cannot be sure of side effects) */
uint seizeError = aTokenCollateral.seize(liquidator, borrower, seizeTokens);
require(seizeError == uint(Error.NO_ERROR), "token seizure failed");
/* We emit a LiquidateBorrow event */
emit LiquidateBorrow(liquidator, borrower, repayAmount, address(aTokenCollateral), seizeTokens);
/* We call the defense hook */
controller.liquidateBorrowVerify(address(this), address(aTokenCollateral), liquidator, borrower, repayAmount, seizeTokens);
return uint(Error.NO_ERROR);
}
/**
* @notice Transfers collateral tokens (this market) to the liquidator.
* @dev Will fail unless called by another aToken during the process of liquidation.
* Its absolutely critical to use msg.sender as the borrowed aToken and not a parameter.
* @param liquidator The account receiving seized collateral
* @param borrower The account having collateral seized
* @param seizeTokens The number of aTokens to seize
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function seize(address liquidator, address borrower, uint seizeTokens) external nonReentrant returns (uint) {
/* Fail if seize not allowed */
uint allowed = controller.seizeAllowed(address(this), msg.sender, liquidator, borrower, seizeTokens);
if (allowed != 0) {
return failOpaque(Error.CONTROLLER_REJECTION, FailureInfo.LIQUIDATE_SEIZE_CONTROLLER_REJECTION, allowed);
}
/* Fail if borrower = liquidator */
if (borrower == liquidator) {
return fail(Error.INVALID_ACCOUNT_PAIR, FailureInfo.LIQUIDATE_SEIZE_LIQUIDATOR_IS_BORROWER);
}
MathError mathErr;
uint borrowerTokensNew;
uint liquidatorTokensNew;
/*
* We calculate the new borrower and liquidator token balances, failing on underflow/overflow:
* borrowerTokensNew = accountTokens[borrower] - seizeTokens
* liquidatorTokensNew = accountTokens[liquidator] + seizeTokens
*/
(mathErr, borrowerTokensNew) = subUInt(accountTokens[borrower], seizeTokens);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.LIQUIDATE_SEIZE_BALANCE_DECREMENT_FAILED, uint(mathErr));
}
(mathErr, liquidatorTokensNew) = addUInt(accountTokens[liquidator], seizeTokens);
if (mathErr != MathError.NO_ERROR) {
return failOpaque(Error.MATH_ERROR, FailureInfo.LIQUIDATE_SEIZE_BALANCE_INCREMENT_FAILED, uint(mathErr));
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
/* We write the previously calculated values into storage */
accountTokens[borrower] = borrowerTokensNew;
accountTokens[liquidator] = liquidatorTokensNew;
/* Emit a Transfer event */
emit Transfer(borrower, liquidator, seizeTokens);
/* We call the defense hook */
controller.seizeVerify(address(this), msg.sender, liquidator, borrower, seizeTokens);
return uint(Error.NO_ERROR);
}
/*** 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)
*
* TODO: Should we add a second arg to verify, like a checksum of `newAdmin` address?
*/
function _setPendingAdmin(address payable newPendingAdmin) external returns (uint) {
// Check caller = admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_PENDING_ADMIN_OWNER_CHECK);
}
// Save current value, if any, for inclusion in log
address oldPendingAdmin = pendingAdmin;
// Store pendingAdmin with value newPendingAdmin
pendingAdmin = newPendingAdmin;
// Emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin)
emit NewPendingAdmin(oldPendingAdmin, newPendingAdmin);
return uint(Error.NO_ERROR);
}
/**
* @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 returns (uint) {
// Check caller is pendingAdmin and pendingAdmin ≠ address(0)
if (msg.sender != pendingAdmin || msg.sender == address(0)) {
return fail(Error.UNAUTHORIZED, FailureInfo.ACCEPT_ADMIN_PENDING_ADMIN_CHECK);
}
// Save current values for inclusion in log
address oldAdmin = admin;
address oldPendingAdmin = pendingAdmin;
// Store admin with value pendingAdmin
admin = pendingAdmin;
// Clear the pending value
pendingAdmin = address(0);
emit NewAdmin(oldAdmin, admin);
emit NewPendingAdmin(oldPendingAdmin, pendingAdmin);
return uint(Error.NO_ERROR);
}
/**
* @notice Sets a new controller for the market
* @dev Admin function to set a new controller
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _setController(ControllerInterface newController) public returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_CONTROLLER_OWNER_CHECK);
}
ControllerInterface oldController = controller;
// Ensure invoke controller.isController() returns true
require(newController.isController(), "marker method returned false");
// Set market's controller to newController
controller = newController;
// Emit NewControllerr(oldController, newController)
emit NewController(oldController, newController);
return uint(Error.NO_ERROR);
}
/**
* @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(uint newReserveFactorMantissa) external nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reserve factor change failed.
return fail(Error(error), FailureInfo.SET_RESERVE_FACTOR_ACCRUE_INTEREST_FAILED);
}
// _setReserveFactorFresh emits reserve-factor-specific logs on errors, so we don't need to.
return _setReserveFactorFresh(newReserveFactorMantissa);
}
/**
* @notice Sets a new reserve factor for the protocol (*requires fresh interest accrual)
* @dev Admin function to set a new reserve factor
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _setReserveFactorFresh(uint newReserveFactorMantissa) internal returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_RESERVE_FACTOR_ADMIN_CHECK);
}
// Verify market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
// TODO: static_assert + no error code?
return fail(Error.MARKET_NOT_FRESH, FailureInfo.SET_RESERVE_FACTOR_FRESH_CHECK);
}
// Check newReserveFactor ≤ maxReserveFactor
if (newReserveFactorMantissa > reserveFactorMaxMantissa) {
return fail(Error.BAD_INPUT, FailureInfo.SET_RESERVE_FACTOR_BOUNDS_CHECK);
}
uint oldReserveFactorMantissa = reserveFactorMantissa;
reserveFactorMantissa = newReserveFactorMantissa;
emit NewReserveFactor(oldReserveFactorMantissa, newReserveFactorMantissa);
return uint(Error.NO_ERROR);
}
/**
* @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(uint reduceAmount) external nonReentrant returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted reduce reserves failed.
return fail(Error(error), FailureInfo.REDUCE_RESERVES_ACCRUE_INTEREST_FAILED);
}
// _reduceReservesFresh emits reserve-reduction-specific logs on errors, so we don't need to.
return _reduceReservesFresh(reduceAmount);
}
/**
* @notice Reduces reserves by transferring to admin
* @dev Requires fresh interest accrual
* @param reduceAmount Amount of reduction to reserves
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function _reduceReservesFresh(uint reduceAmount) internal returns (uint) {
Error err;
// totalReserves - reduceAmount
uint totalReservesNew;
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.REDUCE_RESERVES_ADMIN_CHECK);
}
// We fail gracefully unless market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
// TODO: static_assert + no error code?
return fail(Error.MARKET_NOT_FRESH, FailureInfo.REDUCE_RESERVES_FRESH_CHECK);
}
// Fail gracefully if protocol has insufficient underlying cash
if (getCashPrior() < reduceAmount) {
return fail(Error.TOKEN_INSUFFICIENT_CASH, FailureInfo.REDUCE_RESERVES_CASH_NOT_AVAILABLE);
}
// Check reduceAmount ≤ reserves[n] (totalReserves)
// TODO: I'm following the spec literally here but I think we should we just use SafeMath instead and fail on an error (which would be underflow)
if (reduceAmount > totalReserves) {
return fail(Error.BAD_INPUT, FailureInfo.REDUCE_RESERVES_VALIDATION);
}
/////////////////////////
// EFFECTS & INTERACTIONS
// (No safe failures beyond this point)
totalReservesNew = totalReserves - reduceAmount;
// We checked reduceAmount <= totalReserves above, so this should never revert.
require(totalReservesNew <= totalReserves, "reduce reserves unexpected underflow");
// Store reserves[n+1] = reserves[n] - reduceAmount
totalReserves = totalReservesNew;
// invoke doTransferOut(reduceAmount, admin)
err = doTransferOut(admin, reduceAmount);
// we revert on the failure of this command
require(err == Error.NO_ERROR, "reduce reserves transfer out failed");
emit ReservesReduced(admin, reduceAmount, totalReservesNew);
return uint(Error.NO_ERROR);
}
/**
* @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 returns (uint) {
uint error = accrueInterest();
if (error != uint(Error.NO_ERROR)) {
// accrueInterest emits logs on errors, but on top of that we want to log the fact that an attempted change of interest rate model failed
return fail(Error(error), FailureInfo.SET_INTEREST_RATE_MODEL_ACCRUE_INTEREST_FAILED);
}
// _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to.
return _setInterestRateModelFresh(newInterestRateModel);
}
function _setInterestRateModel_init(InterestRateModel newInterestRateModel) public returns (uint) {
if (msg.sender != admin) {
return fail(Error.MARKET_NOT_FRESH, FailureInfo.SET_INTEREST_RATE_MODEL_FRESH_CHECK);
}
// _setInterestRateModelFresh emits interest-rate-model-update-specific logs on errors, so we don't need to.
interestRateModel = newInterestRateModel;
_setInterestRateModelFresh(interestRateModel);
}
/**
* @notice updates the interest rate model (*requires fresh interest accrual)
* @dev Admin function to 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 _setInterestRateModelFresh(InterestRateModel newInterestRateModel) internal returns (uint) {
// Used to store old model for use in the event that is emitted on success
InterestRateModel oldInterestRateModel;
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_INTEREST_RATE_MODEL_OWNER_CHECK);
}
// We fail gracefully unless market's block number equals current block number
if (accrualBlockNumber != getBlockNumber()) {
// TODO: static_assert + no error code?
return fail(Error.MARKET_NOT_FRESH, FailureInfo.SET_INTEREST_RATE_MODEL_FRESH_CHECK);
}
// Track the market's current interest rate model
oldInterestRateModel = interestRateModel;
// Ensure invoke newInterestRateModel.isInterestRateModel() returns true
require(newInterestRateModel.isInterestRateModel(), "marker method returned false");
// Set the interest rate model to newInterestRateModel
interestRateModel = newInterestRateModel;
// Emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel)
emit NewMarketInterestRateModel(oldInterestRateModel, newInterestRateModel);
return uint(Error.NO_ERROR);
}
/*** Safe Token ***/
/**
* @notice Gets balance of this contract in terms of the underlying
* @dev This excludes the value of the current message, if any
* @return The quantity of underlying owned by this contract
*/
function getCashPrior() internal view returns (uint);
/**
* @dev Checks whether or not there is sufficient allowance for this contract to move amount from `from` and
* whether or not `from` has a balance of at least `amount`. Does NOT do a transfer.
*/
function checkTransferIn(address from, uint amount) internal view returns (Error);
/**
* @dev Performs a transfer in, ideally returning an explanatory error code upon failure rather than reverting.
* If caller has not called `checkTransferIn`, this may revert due to insufficient balance or insufficient allowance.
* If caller has called `checkTransferIn` successfully, this should not revert in normal conditions.
*/
function doTransferIn(address from, uint amount) internal returns (Error);
/**
* @dev Performs a transfer out, ideally returning an explanatory error code upon failure tather than reverting.
* If caller has not called checked protocol's balance, may revert due to insufficient cash held in the contract.
* If caller has checked protocol's balance, and verified it is >= amount, this should not revert in normal conditions.
*/
function doTransferOut(address payable to, uint amount) internal returns (Error);
}
contract AErc20 is AToken {
/**
* @notice Underlying asset for this AToken
*/
address public underlying;
/*** User Interface ***/
/**
* @notice Sender supplies assets into the market and receives aTokens 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(uint mintAmount) external returns (uint) {
return mintInternal(mintAmount);
}
/**
* @notice Sender redeems aTokens in exchange for the underlying asset
* @dev Accrues interest whether or not the operation succeeds, unless reverted
* @param redeemTokens The number of aTokens to redeem into underlying
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function redeem(uint redeemTokens) external returns (uint) {
return redeemInternal(redeemTokens);
}
/**
* @notice Sender redeems aTokens 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(uint redeemAmount) external returns (uint) {
return redeemUnderlyingInternal(redeemAmount);
}
/**
* @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(uint borrowAmount) external returns (uint) {
return borrowInternal(borrowAmount);
}
/**
* @notice Sender repays their own borrow
* @param repayAmount The amount to repay
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function repayBorrow(uint repayAmount) external returns (uint) {
return repayBorrowInternal(repayAmount);
}
/**
* @notice Sender repays a borrow belonging to borrower
* @param borrower the account with the debt being payed off
* @param repayAmount The amount to repay
* @return uint 0=success, otherwise a failure (see ErrorReporter.sol for details)
*/
function repayBorrowBehalf(address borrower, uint repayAmount) external returns (uint) {
return repayBorrowBehalfInternal(borrower, repayAmount);
}
/**
* @notice The sender liquidates the borrowers collateral.
* The collateral seized is transferred to the liquidator.
* @param borrower The borrower of this aToken to be liquidated
* @param aTokenCollateral 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, uint repayAmount, AToken aTokenCollateral) external returns (uint) {
return liquidateBorrowInternal(borrower, repayAmount, aTokenCollateral);
}
/*** Safe Token ***/
/**
* @notice Gets balance of this contract in terms of the underlying
* @dev This excludes the value of the current message, if any
* @return The quantity of underlying tokens owned by this contract
*/
function getCashPrior() internal view returns (uint) {
EIP20Interface token = EIP20Interface(underlying);
return token.balanceOf(address(this));
}
/**
* @dev Checks whether or not there is sufficient allowance for this contract to move amount from `from` and
* whether or not `from` has a balance of at least `amount`. Does NOT do a transfer.
*/
function checkTransferIn(address from, uint amount) internal view returns (Error) {
EIP20Interface token = EIP20Interface(underlying);
if (token.allowance(from, address(this)) < amount) {
return Error.TOKEN_INSUFFICIENT_ALLOWANCE;
}
if (token.balanceOf(from) < amount) {
return Error.TOKEN_INSUFFICIENT_BALANCE;
}
return Error.NO_ERROR;
}
/**
* @dev Similar to EIP20 transfer, except it handles a False result from `transferFrom` and returns an explanatory
* error code rather than reverting. If caller has not called `checkTransferIn`, this may revert due to
* insufficient balance or insufficient allowance. If caller has called `checkTransferIn` prior to this call,
* and it returned Error.NO_ERROR, this should not revert in normal conditions.
*
* Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
* See here: https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
*/
function doTransferIn(address from, uint amount) internal returns (Error) {
EIP20NonStandardInterface token = EIP20NonStandardInterface(underlying);
bool result;
token.transferFrom(from, address(this), amount);
// solium-disable-next-line security/no-inline-assembly
assembly {
switch returndatasize()
case 0 { // This is a non-standard ERC-20
result := not(0) // set result to true
}
case 32 { // This is a complaint ERC-20
returndatacopy(0, 0, 32)
result := mload(0) // Set `result = returndata` of external call
}
default { // This is an excessively non-compliant ERC-20, revert.
revert(0, 0)
}
}
if (!result) {
return Error.TOKEN_TRANSFER_IN_FAILED;
}
return Error.NO_ERROR;
}
/**
* @dev Similar to EIP20 transfer, except it handles a False result from `transfer` and returns an explanatory
* error code rather than reverting. If caller has not called checked protocol's balance, this may revert due to
* insufficient cash held in this contract. If caller has checked protocol's balance prior to this call, and verified
* it is >= amount, this should not revert in normal conditions.
*
* Note: This wrapper safely handles non-standard ERC-20 tokens that do not return a value.
* See here: https://medium.com/coinmonks/missing-return-value-bug-at-least-130-tokens-affected-d67bf08521ca
*/
function doTransferOut(address payable to, uint amount) internal returns (Error) {
EIP20NonStandardInterface token = EIP20NonStandardInterface(underlying);
bool result;
token.transfer(to, amount);
// solium-disable-next-line security/no-inline-assembly
assembly {
switch returndatasize()
case 0 { // This is a non-standard ERC-20
result := not(0) // set result to true
}
case 32 { // This is a complaint ERC-20
returndatacopy(0, 0, 32)
result := mload(0) // Set `result = returndata` of external call
}
default { // This is an excessively non-compliant ERC-20, revert.
revert(0, 0)
}
}
if (!result) {
return Error.TOKEN_TRANSFER_OUT_FAILED;
}
return Error.NO_ERROR;
}
function _setUnderlying(address newunderlying) public returns (uint) {
// Check caller is admin
if (msg.sender != admin) {
return fail(Error.UNAUTHORIZED, FailureInfo.SET_CONTROLLER_OWNER_CHECK);
}
// Set market's controller to newController
underlying = newunderlying;
EIP20Interface(underlying).totalSupply(); // Sanity check the underlying
return uint(Error.NO_ERROR);
}
}