Contract Name:
StrategyRouterV2
Contract Source Code:
// SPDX-License-Identifier: AGPL-3.0
pragma solidity ^0.8.15;
import "https://github.com/yearn/yearn-vaults/blob/v0.4.6/contracts/BaseStrategy.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";
interface IVault is IERC20 {
function token() external view returns (address);
function decimals() external view returns (uint256);
function deposit() external;
function pricePerShare() external view returns (uint256);
function totalAssets() external view returns (uint256);
function lockedProfit() external view returns (uint256);
function lockedProfitDegradation() external view returns (uint256);
function lastReport() external view returns (uint256);
function withdraw(
uint256 amount,
address account,
uint256 maxLoss
) external returns (uint256);
}
interface IOracle {
// pull our asset price, in usdc, via yearn's oracle
function getPriceUsdcRecommended(address tokenAddress)
external
view
returns (uint256);
}
interface IHelper {
function sharesToAmount(address vault, uint256 shares)
external
view
returns (uint256);
function amountToShares(address vault, uint256 amount)
external
view
returns (uint256);
}
contract StrategyRouterV2 is BaseStrategy {
using SafeERC20 for IERC20;
/* ========== STATE VARIABLES ========== */
/// @notice The newer yVault we are routing this strategy to.
IVault public yVault;
/// @notice Max percentage loss we will take, in basis points (100% = 10_000). Default setting is zero.
uint256 public maxLoss;
/// @notice Address of our share value helper contract, which we use for conversions between shares and underlying amounts. Big 🧠 math here.
IHelper public constant shareValueHelper =
IHelper(0x444443bae5bB8640677A8cdF94CB8879Fec948Ec);
/// @notice Minimum profit size in USDC that we want to harvest.
/// @dev Only used in harvestTrigger.
uint256 public harvestProfitMinInUsdc;
/// @notice Maximum profit size in USDC that we want to harvest (ignore gas price once we get here).
/// @dev Only used in harvestTrigger.
uint256 public harvestProfitMaxInUsdc;
/// @notice Amount we accept as a loss in liquidatePosition if we don't get 100% back due to rounding errors.
uint256 public dustThreshold;
/// @notice Will only be true on the original deployed contract and not on clones; we don't want to clone a clone.
bool public isOriginal = true;
// Do I really need to explain this one?
string internal strategyName;
/* ========== CONSTRUCTOR ========== */
constructor(
address _vault,
address _yVault,
string memory _strategyName
) BaseStrategy(_vault) {
_initializeThis(_yVault, _strategyName);
}
/* ========== CLONING ========== */
event Cloned(address indexed clone);
/// @notice Use this to clone an exact copy of this strategy on another vault.
/// @param _vault Vault address we want to attach our new strategy to.
/// @param _strategist Address to grant the strategist role.
/// @param _rewards If we have any strategist rewards, send them here.
/// @param _keeper Address to grant the keeper role.
/// @param _yVault The newer vault we will route our funds to.
/// @param _strategyName Name to use for our new strategy.
function cloneRouterStrategy(
address _vault,
address _strategist,
address _rewards,
address _keeper,
address _yVault,
string memory _strategyName
) external virtual returns (address newStrategy) {
require(isOriginal);
// Copied from https://github.com/optionality/clone-factory/blob/master/contracts/CloneFactory.sol
bytes20 addressBytes = bytes20(address(this));
assembly {
// EIP-1167 bytecode
let clone_code := mload(0x40)
mstore(
clone_code,
0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000
)
mstore(add(clone_code, 0x14), addressBytes)
mstore(
add(clone_code, 0x28),
0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000
)
newStrategy := create(0, clone_code, 0x37)
}
StrategyRouterV2(newStrategy).initialize(
_vault,
_strategist,
_rewards,
_keeper,
_yVault,
_strategyName
);
emit Cloned(newStrategy);
}
function initialize(
address _vault,
address _strategist,
address _rewards,
address _keeper,
address _yVault,
string memory _strategyName
) public {
require(address(yVault) == address(0));
_initialize(_vault, _strategist, _rewards, _keeper);
_initializeThis(_yVault, _strategyName);
}
function _initializeThis(address _yVault, string memory _strategyName)
internal
{
yVault = IVault(_yVault);
strategyName = _strategyName;
harvestProfitMinInUsdc = 5_000e6;
harvestProfitMaxInUsdc = 50_000e6;
dustThreshold = 10;
}
/* ========== VIEWS ========== */
/// @notice Strategy name.
function name() external view override returns (string memory) {
return strategyName;
}
/// @notice Total assets the strategy holds, sum of loose and staked want.
function estimatedTotalAssets()
public
view
virtual
override
returns (uint256)
{
return balanceOfWant() + valueOfInvestment();
}
/// @notice Assets delegated to another vault. Helps to avoid double-counting of TVL.
/// @dev While a strategy may have loose want, only donations would be unaccounted for, and thus are not counted here.
/// Note that a strategy could also have loose want from a manual withdrawFromYVault() call.
function delegatedAssets() public view override returns (uint256) {
return vault.strategies(address(this)).totalDebt;
}
/// @notice Balance of want sitting in our strategy.
function balanceOfWant() public view returns (uint256) {
return want.balanceOf(address(this));
}
/// @notice Balance of underlying we are holding as vault tokens of our delegated vault.
function valueOfInvestment() public view virtual returns (uint256) {
return
shareValueHelper.sharesToAmount(
address(yVault),
yVault.balanceOf(address(this))
);
}
/// @notice Balance of underlying we will gain on our next harvest
function claimableProfits() public view returns (uint256 profits) {
uint256 assets = estimatedTotalAssets();
uint256 debt = delegatedAssets();
if (assets > debt) {
unchecked {
profits = assets - debt;
}
} else {
profits = 0;
}
}
/* ========== CORE STRATEGY FUNCTIONS ========== */
function prepareReturn(uint256 _debtOutstanding)
internal
virtual
override
returns (
uint256 _profit,
uint256 _loss,
uint256 _debtPayment
)
{
// serious loss should never happen, but if it does, let's record it accurately
uint256 assets = estimatedTotalAssets();
uint256 debt = delegatedAssets();
// if assets are greater than debt, things are working great!
if (assets >= debt) {
unchecked {
_profit = assets - debt;
}
_debtPayment = _debtOutstanding;
uint256 toFree = _profit + _debtPayment;
// freed is math.min(wantBalance, toFree)
(uint256 freed, ) = liquidatePosition(toFree);
if (toFree > freed) {
if (_debtPayment >= freed) {
_debtPayment = freed;
_profit = 0;
} else {
unchecked {
_profit = freed - _debtPayment;
}
}
}
}
// if assets are less than debt, we are in trouble. don't worry about withdrawing here, just report losses
else {
unchecked {
_loss = debt - assets;
}
}
}
function adjustPosition(uint256 _debtOutstanding)
internal
virtual
override
{
if (emergencyExit) {
return;
}
uint256 balance = balanceOfWant();
if (balance > 0) {
_checkAllowance(address(yVault), address(want), balance);
yVault.deposit();
}
}
function liquidatePosition(uint256 _amountNeeded)
internal
virtual
override
returns (uint256 _liquidatedAmount, uint256 _loss)
{
uint256 balance = balanceOfWant();
if (balance >= _amountNeeded) {
return (_amountNeeded, 0);
}
uint256 toWithdraw;
unchecked {
toWithdraw = _amountNeeded - balance;
}
// withdraw the remainder we need
_withdrawFromYVault(toWithdraw);
uint256 looseWant = balanceOfWant();
// because of slippage, dust-sized losses are acceptable
// however, we don't want to take losses for funds stuck in a strategy in the destination vault
if (_amountNeeded > looseWant) {
uint256 diff = _amountNeeded - looseWant;
_liquidatedAmount = looseWant;
if (diff < dustThreshold) {
_loss = diff;
}
} else {
_liquidatedAmount = _amountNeeded;
}
}
/// @notice Manually withdraw underlying assets from our target vault.
/// @dev Only governance or management may call this.
/// @param _amount Shares of our target vault to withdraw.
function withdrawFromYVault(uint256 _amount) external onlyVaultManagers {
_withdrawFromYVault(_amount);
}
function _withdrawFromYVault(uint256 _amount) internal {
if (_amount == 0) {
return;
}
uint256 _balanceOfYShares = yVault.balanceOf(address(this));
uint256 sharesToWithdraw =
Math.min(
shareValueHelper.amountToShares(address(yVault), _amount),
_balanceOfYShares
);
if (sharesToWithdraw == 0) {
return;
}
yVault.withdraw(sharesToWithdraw, address(this), maxLoss);
}
function liquidateAllPositions()
internal
virtual
override
returns (uint256 _amountFreed)
{
// withdraw as much as we can from vault tokens
uint256 vaultTokenBalance = yVault.balanceOf(address(this));
if (vaultTokenBalance > 0) {
yVault.withdraw(vaultTokenBalance, address(this), maxLoss);
}
// return our want balance
return balanceOfWant();
}
function prepareMigration(address _newStrategy) internal virtual override {
IERC20(yVault).safeTransfer(
_newStrategy,
IERC20(yVault).balanceOf(address(this))
);
}
function protectedTokens()
internal
view
override
returns (address[] memory ret)
{}
function _checkAllowance(
address _contract,
address _token,
uint256 _amount
) internal {
if (IERC20(_token).allowance(address(this), _contract) < _amount) {
IERC20(_token).safeApprove(_contract, 0);
IERC20(_token).safeApprove(_contract, type(uint256).max);
}
}
/// @notice Convert our keeper's eth cost into want
/// @dev We don't use this since we don't factor call cost into our harvestTrigger.
/// @param _amtInWei Amount of ether spent.
/// @return Value of ether in want.
function ethToWant(uint256 _amtInWei)
public
view
virtual
override
returns (uint256)
{}
/* ========== KEEP3RS ========== */
/**
* @notice
* Provide a signal to the keeper that harvest() should be called.
*
* Don't harvest if a strategy is inactive.
* If our profit exceeds our upper limit, then harvest no matter what. For
* our lower profit limit, credit threshold, max delay, and manual force trigger,
* only harvest if our gas price is acceptable.
*
* @param callCostinEth The keeper's estimated gas cost to call harvest() (in wei).
* @return True if harvest() should be called, false otherwise.
*/
function harvestTrigger(uint256 callCostinEth)
public
view
override
returns (bool)
{
// Should not trigger if strategy is not active (no assets and no debtRatio). This means we don't need to adjust keeper job.
if (!isActive()) {
return false;
}
// harvest if we have a profit to claim at our upper limit without considering gas price
uint256 claimableProfit = claimableProfitInUsdc();
if (claimableProfit > harvestProfitMaxInUsdc) {
return true;
}
// check if the base fee gas price is higher than we allow. if it is, block harvests.
if (!isBaseFeeAcceptable()) {
return false;
}
// trigger if we want to manually harvest, but only if our gas price is acceptable
if (forceHarvestTriggerOnce) {
return true;
}
// harvest if we have a sufficient profit to claim, but only if our gas price is acceptable
if (claimableProfit > harvestProfitMinInUsdc) {
return true;
}
StrategyParams memory params = vault.strategies(address(this));
// harvest regardless of profit once we reach our maxDelay
if (block.timestamp - params.lastReport > maxReportDelay) {
return true;
}
// harvest our credit if it's above our threshold
if (vault.creditAvailable() > creditThreshold) {
return true;
}
// otherwise, we don't harvest
return false;
}
/// @notice Calculates the profit if all claimable assets were sold for USDC (6 decimals).
/// @dev Uses yearn's lens oracle, if returned values are strange then troubleshoot there.
/// @return Total return in USDC from taking profits on yToken gains.
function claimableProfitInUsdc() public view returns (uint256) {
IOracle yearnOracle =
IOracle(0x83d95e0D5f402511dB06817Aff3f9eA88224B030); // yearn lens oracle
uint256 underlyingPrice =
yearnOracle.getPriceUsdcRecommended(address(want));
// Oracle returns prices as 6 decimals, so multiply by claimable amount and divide by token decimals
return (claimableProfits() * underlyingPrice) / (10**yVault.decimals());
}
/* ========== SETTERS ========== */
// These functions are useful for setting parameters of the strategy that may need to be adjusted.
/// @notice Set the maximum loss we will accept (due to slippage or locked funds) on a vault withdrawal.
/// @dev Generally, this should be zero, and this function will only be used in special/emergency cases.
/// @param _maxLoss Max percentage loss we will take, in basis points (100% = 10_000).
function setMaxLoss(uint256 _maxLoss) public onlyVaultManagers {
maxLoss = _maxLoss;
}
/// @notice This allows us to set the dust threshold for our strategy.
/// @param _dustThreshold This sets what dust is. If we have less than this remaining after withdrawing, accept it as a loss.
function setDustThreshold(uint256 _dustThreshold)
external
onlyVaultManagers
{
require(_dustThreshold < 10000, "Your size is too much size");
dustThreshold = _dustThreshold;
}
/**
* @notice
* Here we set various parameters to optimize our harvestTrigger.
* @param _harvestProfitMinInUsdc The amount of profit (in USDC, 6 decimals)
* that will trigger a harvest if gas price is acceptable.
* @param _harvestProfitMaxInUsdc The amount of profit in USDC that
* will trigger a harvest regardless of gas price.
*/
function setHarvestTriggerParams(
uint256 _harvestProfitMinInUsdc,
uint256 _harvestProfitMaxInUsdc
) external onlyVaultManagers {
harvestProfitMinInUsdc = _harvestProfitMinInUsdc;
harvestProfitMaxInUsdc = _harvestProfitMaxInUsdc;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator
) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1);
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(
uint256 x,
uint256 y,
uint256 denominator,
Rounding rounding
) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10**64) {
value /= 10**64;
result += 64;
}
if (value >= 10**32) {
value /= 10**32;
result += 32;
}
if (value >= 10**16) {
value /= 10**16;
result += 16;
}
if (value >= 10**8) {
value /= 10**8;
result += 8;
}
if (value >= 10**4) {
value /= 10**4;
result += 4;
}
if (value >= 10**2) {
value /= 10**2;
result += 2;
}
if (value >= 10**1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10**result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result * 8) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.8.15;
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
struct StrategyParams {
uint256 performanceFee;
uint256 activation;
uint256 debtRatio;
uint256 minDebtPerHarvest;
uint256 maxDebtPerHarvest;
uint256 lastReport;
uint256 totalDebt;
uint256 totalGain;
uint256 totalLoss;
}
interface VaultAPI is IERC20 {
function name() external view returns (string calldata);
function symbol() external view returns (string calldata);
function decimals() external view returns (uint256);
function apiVersion() external pure returns (string memory);
function permit(
address owner,
address spender,
uint256 amount,
uint256 expiry,
bytes calldata signature
) external returns (bool);
// NOTE: Vyper produces multiple signatures for a given function with "default" args
function deposit() external returns (uint256);
function deposit(uint256 amount) external returns (uint256);
function deposit(uint256 amount, address recipient) external returns (uint256);
// NOTE: Vyper produces multiple signatures for a given function with "default" args
function withdraw() external returns (uint256);
function withdraw(uint256 maxShares) external returns (uint256);
function withdraw(uint256 maxShares, address recipient) external returns (uint256);
function token() external view returns (address);
function strategies(address _strategy) external view returns (StrategyParams memory);
function pricePerShare() external view returns (uint256);
function totalAssets() external view returns (uint256);
function depositLimit() external view returns (uint256);
function maxAvailableShares() external view returns (uint256);
/**
* View how much the Vault would increase this Strategy's borrow limit,
* based on its present performance (since its last report). Can be used to
* determine expectedReturn in your Strategy.
*/
function creditAvailable() external view returns (uint256);
/**
* View how much the Vault would like to pull back from the Strategy,
* based on its present performance (since its last report). Can be used to
* determine expectedReturn in your Strategy.
*/
function debtOutstanding() external view returns (uint256);
/**
* View how much the Vault expect this Strategy to return at the current
* block, based on its present performance (since its last report). Can be
* used to determine expectedReturn in your Strategy.
*/
function expectedReturn() external view returns (uint256);
/**
* This is the main contact point where the Strategy interacts with the
* Vault. It is critical that this call is handled as intended by the
* Strategy. Therefore, this function will be called by BaseStrategy to
* make sure the integration is correct.
*/
function report(
uint256 _gain,
uint256 _loss,
uint256 _debtPayment
) external returns (uint256);
/**
* This function should only be used in the scenario where the Strategy is
* being retired but no migration of the positions are possible, or in the
* extreme scenario that the Strategy needs to be put into "Emergency Exit"
* mode in order for it to exit as quickly as possible. The latter scenario
* could be for any reason that is considered "critical" that the Strategy
* exits its position as fast as possible, such as a sudden change in
* market conditions leading to losses, or an imminent failure in an
* external dependency.
*/
function revokeStrategy() external;
/**
* View the governance address of the Vault to assert privileged functions
* can only be called by governance. The Strategy serves the Vault, so it
* is subject to governance defined by the Vault.
*/
function governance() external view returns (address);
/**
* View the management address of the Vault to assert privileged functions
* can only be called by management. The Strategy serves the Vault, so it
* is subject to management defined by the Vault.
*/
function management() external view returns (address);
/**
* View the guardian address of the Vault to assert privileged functions
* can only be called by guardian. The Strategy serves the Vault, so it
* is subject to guardian defined by the Vault.
*/
function guardian() external view returns (address);
}
/**
* This interface is here for the keeper bot to use.
*/
interface StrategyAPI {
function name() external view returns (string memory);
function vault() external view returns (address);
function want() external view returns (address);
function apiVersion() external pure returns (string memory);
function keeper() external view returns (address);
function isActive() external view returns (bool);
function delegatedAssets() external view returns (uint256);
function estimatedTotalAssets() external view returns (uint256);
function tendTrigger(uint256 callCost) external view returns (bool);
function tend() external;
function harvestTrigger(uint256 callCost) external view returns (bool);
function harvest() external;
event Harvested(uint256 profit, uint256 loss, uint256 debtPayment, uint256 debtOutstanding);
}
interface HealthCheck {
function check(
uint256 profit,
uint256 loss,
uint256 debtPayment,
uint256 debtOutstanding,
uint256 totalDebt
) external view returns (bool);
}
interface IBaseFee {
function isCurrentBaseFeeAcceptable() external view returns (bool);
}
/**
* @title Yearn Base Strategy
* @author yearn.finance
* @notice
* BaseStrategy implements all of the required functionality to interoperate
* closely with the Vault contract. This contract should be inherited and the
* abstract methods implemented to adapt the Strategy to the particular needs
* it has to create a return.
*
* Of special interest is the relationship between `harvest()` and
* `vault.report()'. `harvest()` may be called simply because enough time has
* elapsed since the last report, and not because any funds need to be moved
* or positions adjusted. This is critical so that the Vault may maintain an
* accurate picture of the Strategy's performance. See `vault.report()`,
* `harvest()`, and `harvestTrigger()` for further details.
*/
abstract contract BaseStrategy {
using SafeERC20 for IERC20;
string public metadataURI;
// health checks
bool public doHealthCheck;
address public healthCheck;
/**
* @notice
* Used to track which version of `StrategyAPI` this Strategy
* implements.
* @dev The Strategy's version must match the Vault's `API_VERSION`.
* @return A string which holds the current API version of this contract.
*/
function apiVersion() public pure returns (string memory) {
return "0.4.6";
}
/**
* @notice This Strategy's name.
* @dev
* You can use this field to manage the "version" of this Strategy, e.g.
* `StrategySomethingOrOtherV1`. However, "API Version" is managed by
* `apiVersion()` function above.
* @return This Strategy's name.
*/
function name() external view virtual returns (string memory);
/**
* @notice
* The amount (priced in want) of the total assets managed by this strategy should not count
* towards Yearn's TVL calculations.
* @dev
* You can override this field to set it to a non-zero value if some of the assets of this
* Strategy is somehow delegated inside another part of of Yearn's ecosystem e.g. another Vault.
* Note that this value must be strictly less than or equal to the amount provided by
* `estimatedTotalAssets()` below, as the TVL calc will be total assets minus delegated assets.
* Also note that this value is used to determine the total assets under management by this
* strategy, for the purposes of computing the management fee in `Vault`
* @return
* The amount of assets this strategy manages that should not be included in Yearn's Total Value
* Locked (TVL) calculation across it's ecosystem.
*/
function delegatedAssets() external view virtual returns (uint256) {
return 0;
}
VaultAPI public vault;
address public strategist;
address public rewards;
address public keeper;
IERC20 public want;
// So indexers can keep track of this
event Harvested(uint256 profit, uint256 loss, uint256 debtPayment, uint256 debtOutstanding);
event UpdatedStrategist(address newStrategist);
event UpdatedKeeper(address newKeeper);
event UpdatedRewards(address rewards);
event UpdatedMinReportDelay(uint256 delay);
event UpdatedMaxReportDelay(uint256 delay);
event UpdatedBaseFeeOracle(address baseFeeOracle);
event UpdatedCreditThreshold(uint256 creditThreshold);
event ForcedHarvestTrigger(bool triggerState);
event EmergencyExitEnabled();
event UpdatedMetadataURI(string metadataURI);
event SetHealthCheck(address);
event SetDoHealthCheck(bool);
// The minimum number of seconds between harvest calls. See
// `setMinReportDelay()` for more details.
uint256 public minReportDelay;
// The maximum number of seconds between harvest calls. See
// `setMaxReportDelay()` for more details.
uint256 public maxReportDelay;
// See note on `setEmergencyExit()`.
bool public emergencyExit;
// See note on `isBaseFeeOracleAcceptable()`.
address public baseFeeOracle;
// See note on `setCreditThreshold()`
uint256 public creditThreshold;
// See note on `setForceHarvestTriggerOnce`
bool public forceHarvestTriggerOnce;
// modifiers
modifier onlyAuthorized() {
_onlyAuthorized();
_;
}
modifier onlyEmergencyAuthorized() {
_onlyEmergencyAuthorized();
_;
}
modifier onlyStrategist() {
_onlyStrategist();
_;
}
modifier onlyGovernance() {
_onlyGovernance();
_;
}
modifier onlyRewarder() {
_onlyRewarder();
_;
}
modifier onlyKeepers() {
_onlyKeepers();
_;
}
modifier onlyVaultManagers() {
_onlyVaultManagers();
_;
}
function _onlyAuthorized() internal {
require(msg.sender == strategist || msg.sender == governance());
}
function _onlyEmergencyAuthorized() internal {
require(msg.sender == strategist || msg.sender == governance() || msg.sender == vault.guardian() || msg.sender == vault.management());
}
function _onlyStrategist() internal {
require(msg.sender == strategist);
}
function _onlyGovernance() internal {
require(msg.sender == governance());
}
function _onlyRewarder() internal {
require(msg.sender == governance() || msg.sender == strategist);
}
function _onlyKeepers() internal {
require(
msg.sender == keeper ||
msg.sender == strategist ||
msg.sender == governance() ||
msg.sender == vault.guardian() ||
msg.sender == vault.management()
);
}
function _onlyVaultManagers() internal {
require(msg.sender == vault.management() || msg.sender == governance());
}
constructor(address _vault) {
_initialize(_vault, msg.sender, msg.sender, msg.sender);
}
/**
* @notice
* Initializes the Strategy, this is called only once, when the
* contract is deployed.
* @dev `_vault` should implement `VaultAPI`.
* @param _vault The address of the Vault responsible for this Strategy.
* @param _strategist The address to assign as `strategist`.
* The strategist is able to change the reward address
* @param _rewards The address to use for pulling rewards.
* @param _keeper The adddress of the _keeper. _keeper
* can harvest and tend a strategy.
*/
function _initialize(
address _vault,
address _strategist,
address _rewards,
address _keeper
) internal {
require(address(want) == address(0), "Strategy already initialized");
vault = VaultAPI(_vault);
want = IERC20(vault.token());
want.safeApprove(_vault, type(uint256).max); // Give Vault unlimited access (might save gas)
strategist = _strategist;
rewards = _rewards;
keeper = _keeper;
// initialize variables
maxReportDelay = 30 days;
creditThreshold = 1_000_000 * 10**vault.decimals(); // set this high by default so we don't get tons of false triggers if not changed
vault.approve(rewards, type(uint256).max); // Allow rewards to be pulled
}
function setHealthCheck(address _healthCheck) external onlyVaultManagers {
emit SetHealthCheck(_healthCheck);
healthCheck = _healthCheck;
}
function setDoHealthCheck(bool _doHealthCheck) external onlyVaultManagers {
emit SetDoHealthCheck(_doHealthCheck);
doHealthCheck = _doHealthCheck;
}
/**
* @notice
* Used to change `strategist`.
*
* This may only be called by governance or the existing strategist.
* @param _strategist The new address to assign as `strategist`.
*/
function setStrategist(address _strategist) external onlyAuthorized {
require(_strategist != address(0));
strategist = _strategist;
emit UpdatedStrategist(_strategist);
}
/**
* @notice
* Used to change `keeper`.
*
* `keeper` is the only address that may call `tend()` or `harvest()`,
* other than `governance()` or `strategist`. However, unlike
* `governance()` or `strategist`, `keeper` may *only* call `tend()`
* and `harvest()`, and no other authorized functions, following the
* principle of least privilege.
*
* This may only be called by governance or the strategist.
* @param _keeper The new address to assign as `keeper`.
*/
function setKeeper(address _keeper) external onlyAuthorized {
require(_keeper != address(0));
keeper = _keeper;
emit UpdatedKeeper(_keeper);
}
/**
* @notice
* Used to change `rewards`. EOA or smart contract which has the permission
* to pull rewards from the vault.
*
* This may only be called by the strategist.
* @param _rewards The address to use for pulling rewards.
*/
function setRewards(address _rewards) external onlyRewarder {
require(_rewards != address(0));
vault.approve(rewards, 0);
rewards = _rewards;
vault.approve(rewards, type(uint256).max);
emit UpdatedRewards(_rewards);
}
/**
* @notice
* Used to change `minReportDelay`. `minReportDelay` is the minimum number
* of blocks that should pass for `harvest()` to be called.
*
* For external keepers (such as the Keep3r network), this is the minimum
* time between jobs to wait. (see `harvestTrigger()`
* for more details.)
*
* This may only be called by governance or the strategist.
* @param _delay The minimum number of seconds to wait between harvests.
*/
function setMinReportDelay(uint256 _delay) external onlyAuthorized {
minReportDelay = _delay;
emit UpdatedMinReportDelay(_delay);
}
/**
* @notice
* Used to change `maxReportDelay`. `maxReportDelay` is the maximum number
* of blocks that should pass for `harvest()` to be called.
*
* For external keepers (such as the Keep3r network), this is the maximum
* time between jobs to wait. (see `harvestTrigger()`
* for more details.)
*
* This may only be called by governance or the strategist.
* @param _delay The maximum number of seconds to wait between harvests.
*/
function setMaxReportDelay(uint256 _delay) external onlyAuthorized {
maxReportDelay = _delay;
emit UpdatedMaxReportDelay(_delay);
}
/**
* @notice
* Used to ensure that any significant credit a strategy has from the
* vault will be automatically harvested.
*
* This may only be called by governance or management.
* @param _creditThreshold The number of want tokens that will
* automatically trigger a harvest.
*/
function setCreditThreshold(uint256 _creditThreshold) external onlyVaultManagers {
creditThreshold = _creditThreshold;
emit UpdatedCreditThreshold(_creditThreshold);
}
/**
* @notice
* Used to automatically trigger a harvest by our keepers. Can be
* useful if gas prices are too high now, and we want to harvest
* later once prices have lowered.
*
* This may only be called by governance or management.
* @param _forceHarvestTriggerOnce Value of true tells keepers to harvest
* our strategy
*/
function setForceHarvestTriggerOnce(bool _forceHarvestTriggerOnce) external onlyVaultManagers {
forceHarvestTriggerOnce = _forceHarvestTriggerOnce;
emit ForcedHarvestTrigger(_forceHarvestTriggerOnce);
}
/**
* @notice
* Used to set our baseFeeOracle, which checks the network's current base
* fee price to determine whether it is an optimal time to harvest or tend.
*
* This may only be called by governance or management.
* @param _baseFeeOracle Address of our baseFeeOracle
*/
function setBaseFeeOracle(address _baseFeeOracle) external onlyVaultManagers {
baseFeeOracle = _baseFeeOracle;
emit UpdatedBaseFeeOracle(_baseFeeOracle);
}
/**
* @notice
* Used to change `metadataURI`. `metadataURI` is used to store the URI
* of the file describing the strategy.
*
* This may only be called by governance or the strategist.
* @param _metadataURI The URI that describe the strategy.
*/
function setMetadataURI(string calldata _metadataURI) external onlyAuthorized {
metadataURI = _metadataURI;
emit UpdatedMetadataURI(_metadataURI);
}
/**
* Resolve governance address from Vault contract, used to make assertions
* on protected functions in the Strategy.
*/
function governance() internal view returns (address) {
return vault.governance();
}
/**
* @notice
* Provide an accurate conversion from `_amtInWei` (denominated in wei)
* to `want` (using the native decimal characteristics of `want`).
* @dev
* Care must be taken when working with decimals to assure that the conversion
* is compatible. As an example:
*
* given 1e17 wei (0.1 ETH) as input, and want is USDC (6 decimals),
* with USDC/ETH = 1800, this should give back 1800000000 (180 USDC)
*
* @param _amtInWei The amount (in wei/1e-18 ETH) to convert to `want`
* @return The amount in `want` of `_amtInEth` converted to `want`
**/
function ethToWant(uint256 _amtInWei) public view virtual returns (uint256);
/**
* @notice
* Provide an accurate estimate for the total amount of assets
* (principle + return) that this Strategy is currently managing,
* denominated in terms of `want` tokens.
*
* This total should be "realizable" e.g. the total value that could
* *actually* be obtained from this Strategy if it were to divest its
* entire position based on current on-chain conditions.
* @dev
* Care must be taken in using this function, since it relies on external
* systems, which could be manipulated by the attacker to give an inflated
* (or reduced) value produced by this function, based on current on-chain
* conditions (e.g. this function is possible to influence through
* flashloan attacks, oracle manipulations, or other DeFi attack
* mechanisms).
*
* It is up to governance to use this function to correctly order this
* Strategy relative to its peers in the withdrawal queue to minimize
* losses for the Vault based on sudden withdrawals. This value should be
* higher than the total debt of the Strategy and higher than its expected
* value to be "safe".
* @return The estimated total assets in this Strategy.
*/
function estimatedTotalAssets() public view virtual returns (uint256);
/*
* @notice
* Provide an indication of whether this strategy is currently "active"
* in that it is managing an active position, or will manage a position in
* the future. This should correlate to `harvest()` activity, so that Harvest
* events can be tracked externally by indexing agents.
* @return True if the strategy is actively managing a position.
*/
function isActive() public view returns (bool) {
return vault.strategies(address(this)).debtRatio > 0 || estimatedTotalAssets() > 0;
}
/**
* Perform any Strategy unwinding or other calls necessary to capture the
* "free return" this Strategy has generated since the last time its core
* position(s) were adjusted. Examples include unwrapping extra rewards.
* This call is only used during "normal operation" of a Strategy, and
* should be optimized to minimize losses as much as possible.
*
* This method returns any realized profits and/or realized losses
* incurred, and should return the total amounts of profits/losses/debt
* payments (in `want` tokens) for the Vault's accounting (e.g.
* `want.balanceOf(this) >= _debtPayment + _profit`).
*
* `_debtOutstanding` will be 0 if the Strategy is not past the configured
* debt limit, otherwise its value will be how far past the debt limit
* the Strategy is. The Strategy's debt limit is configured in the Vault.
*
* NOTE: `_debtPayment` should be less than or equal to `_debtOutstanding`.
* It is okay for it to be less than `_debtOutstanding`, as that
* should only used as a guide for how much is left to pay back.
* Payments should be made to minimize loss from slippage, debt,
* withdrawal fees, etc.
*
* See `vault.debtOutstanding()`.
*/
function prepareReturn(uint256 _debtOutstanding)
internal
virtual
returns (
uint256 _profit,
uint256 _loss,
uint256 _debtPayment
);
/**
* Perform any adjustments to the core position(s) of this Strategy given
* what change the Vault made in the "investable capital" available to the
* Strategy. Note that all "free capital" in the Strategy after the report
* was made is available for reinvestment. Also note that this number
* could be 0, and you should handle that scenario accordingly.
*
* See comments regarding `_debtOutstanding` on `prepareReturn()`.
*/
function adjustPosition(uint256 _debtOutstanding) internal virtual;
/**
* Liquidate up to `_amountNeeded` of `want` of this strategy's positions,
* irregardless of slippage. Any excess will be re-invested with `adjustPosition()`.
* This function should return the amount of `want` tokens made available by the
* liquidation. If there is a difference between them, `_loss` indicates whether the
* difference is due to a realized loss, or if there is some other sitution at play
* (e.g. locked funds) where the amount made available is less than what is needed.
*
* NOTE: The invariant `_liquidatedAmount + _loss <= _amountNeeded` should always be maintained
*/
function liquidatePosition(uint256 _amountNeeded) internal virtual returns (uint256 _liquidatedAmount, uint256 _loss);
/**
* Liquidate everything and returns the amount that got freed.
* This function is used during emergency exit instead of `prepareReturn()` to
* liquidate all of the Strategy's positions back to the Vault.
*/
function liquidateAllPositions() internal virtual returns (uint256 _amountFreed);
/**
* @notice
* Provide a signal to the keeper that `tend()` should be called. The
* keeper will provide the estimated gas cost that they would pay to call
* `tend()`, and this function should use that estimate to make a
* determination if calling it is "worth it" for the keeper. This is not
* the only consideration into issuing this trigger, for example if the
* position would be negatively affected if `tend()` is not called
* shortly, then this can return `true` even if the keeper might be
* "at a loss" (keepers are always reimbursed by Yearn).
* @dev
* `callCostInWei` must be priced in terms of `wei` (1e-18 ETH).
*
* This call and `harvestTrigger()` should never return `true` at the same
* time.
* @param callCostInWei The keeper's estimated gas cost to call `tend()` (in wei).
* @return `true` if `tend()` should be called, `false` otherwise.
*/
function tendTrigger(uint256 callCostInWei) public view virtual returns (bool) {
// We usually don't need tend, but if there are positions that need
// active maintainence, overriding this function is how you would
// signal for that.
// If your implementation uses the cost of the call in want, you can
// use uint256 callCost = ethToWant(callCostInWei);
// It is highly suggested to use the baseFeeOracle here as well.
return false;
}
/**
* @notice
* Adjust the Strategy's position. The purpose of tending isn't to
* realize gains, but to maximize yield by reinvesting any returns.
*
* See comments on `adjustPosition()`.
*
* This may only be called by governance, the strategist, or the keeper.
*/
function tend() external onlyKeepers {
// Don't take profits with this call, but adjust for better gains
adjustPosition(vault.debtOutstanding());
}
/**
* @notice
* Provide a signal to the keeper that `harvest()` should be called. The
* keeper will provide the estimated gas cost that they would pay to call
* `harvest()`, and this function should use that estimate to make a
* determination if calling it is "worth it" for the keeper. This is not
* the only consideration into issuing this trigger, for example if the
* position would be negatively affected if `harvest()` is not called
* shortly, then this can return `true` even if the keeper might be "at a
* loss" (keepers are always reimbursed by Yearn).
* @dev
* `callCostInWei` must be priced in terms of `wei` (1e-18 ETH).
*
* This call and `tendTrigger` should never return `true` at the
* same time.
*
* See `maxReportDelay`, `creditThreshold` to adjust the
* strategist-controlled parameters that will influence whether this call
* returns `true` or not. These parameters will be used in conjunction
* with the parameters reported to the Vault (see `params`) to determine
* if calling `harvest()` is merited.
*
* This trigger also checks the network's base fee to avoid harvesting during
* times of high network congestion.
*
* Consider use of super.harvestTrigger() in any override to build on top
* of this logic instead of replacing it. For example, if using `minReportDelay`.
*
* It is expected that an external system will check `harvestTrigger()`.
* This could be a script run off a desktop or cloud bot (e.g.
* https://github.com/iearn-finance/yearn-vaults/blob/main/scripts/keep.py),
* or via an integration with the Keep3r network (e.g.
* https://github.com/Macarse/GenericKeep3rV2/blob/master/contracts/keep3r/GenericKeep3rV2.sol).
* @param callCostInWei The keeper's estimated gas cost to call `harvest()` (in wei).
* @return `true` if `harvest()` should be called, `false` otherwise.
*/
function harvestTrigger(uint256 callCostInWei) public view virtual returns (bool) {
// Should not trigger if strategy is not active (no assets or no debtRatio)
if (!isActive()) return false;
// check if the base fee gas price is higher than we allow. if it is, block harvests.
if (!isBaseFeeAcceptable()) return false;
// trigger if we want to manually harvest, but only if our gas price is acceptable
if (forceHarvestTriggerOnce) return true;
// Should trigger if hasn't been called in a while
StrategyParams memory params = vault.strategies(address(this));
if ((block.timestamp - params.lastReport) >= maxReportDelay) return true;
// harvest our credit if it's above our threshold or return false
return (vault.creditAvailable() > creditThreshold);
}
/**
* @notice
* Check if the current network base fee is below our external target. If
* not, then harvestTrigger will return false.
* @return `true` if `harvest()` should be allowed, `false` otherwise.
*/
function isBaseFeeAcceptable() public view returns (bool) {
if (baseFeeOracle == address(0)) return true;
else return IBaseFee(baseFeeOracle).isCurrentBaseFeeAcceptable();
}
/**
* @notice
* Harvests the Strategy, recognizing any profits or losses and adjusting
* the Strategy's position.
*
* In the rare case the Strategy is in emergency shutdown, this will exit
* the Strategy's position.
*
* This may only be called by governance, the strategist, or the keeper.
* @dev
* When `harvest()` is called, the Strategy reports to the Vault (via
* `vault.report()`), so in some cases `harvest()` must be called in order
* to take in profits, to borrow newly available funds from the Vault, or
* otherwise adjust its position. In other cases `harvest()` must be
* called to report to the Vault on the Strategy's position, especially if
* any losses have occurred.
*/
function harvest() external onlyKeepers {
uint256 profit = 0;
uint256 loss = 0;
uint256 debtOutstanding = vault.debtOutstanding();
uint256 debtPayment = 0;
if (emergencyExit) {
// Free up as much capital as possible
uint256 amountFreed = liquidateAllPositions();
if (amountFreed < debtOutstanding) {
loss = debtOutstanding - amountFreed;
} else if (amountFreed > debtOutstanding) {
profit = amountFreed - debtOutstanding;
}
debtPayment = debtOutstanding - loss;
} else {
// Free up returns for Vault to pull
(profit, loss, debtPayment) = prepareReturn(debtOutstanding);
}
// we're done harvesting, so reset our trigger if we used it
forceHarvestTriggerOnce = false;
emit ForcedHarvestTrigger(false);
// Allow Vault to take up to the "harvested" balance of this contract,
// which is the amount it has earned since the last time it reported to
// the Vault.
uint256 totalDebt = vault.strategies(address(this)).totalDebt;
debtOutstanding = vault.report(profit, loss, debtPayment);
// Check if free returns are left, and re-invest them
adjustPosition(debtOutstanding);
// call healthCheck contract
if (doHealthCheck && healthCheck != address(0)) {
require(HealthCheck(healthCheck).check(profit, loss, debtPayment, debtOutstanding, totalDebt), "!healthcheck");
} else {
emit SetDoHealthCheck(true);
doHealthCheck = true;
}
emit Harvested(profit, loss, debtPayment, debtOutstanding);
}
/**
* @notice
* Withdraws `_amountNeeded` to `vault`.
*
* This may only be called by the Vault.
* @param _amountNeeded How much `want` to withdraw.
* @return _loss Any realized losses
*/
function withdraw(uint256 _amountNeeded) external returns (uint256 _loss) {
require(msg.sender == address(vault), "!vault");
// Liquidate as much as possible to `want`, up to `_amountNeeded`
uint256 amountFreed;
(amountFreed, _loss) = liquidatePosition(_amountNeeded);
// Send it directly back (NOTE: Using `msg.sender` saves some gas here)
want.safeTransfer(msg.sender, amountFreed);
// NOTE: Reinvest anything leftover on next `tend`/`harvest`
}
/**
* Do anything necessary to prepare this Strategy for migration, such as
* transferring any reserve or LP tokens, CDPs, or other tokens or stores of
* value.
*/
function prepareMigration(address _newStrategy) internal virtual;
/**
* @notice
* Transfers all `want` from this Strategy to `_newStrategy`.
*
* This may only be called by the Vault.
* @dev
* The new Strategy's Vault must be the same as this Strategy's Vault.
* The migration process should be carefully performed to make sure all
* the assets are migrated to the new address, which should have never
* interacted with the vault before.
* @param _newStrategy The Strategy to migrate to.
*/
function migrate(address _newStrategy) external {
require(msg.sender == address(vault));
require(BaseStrategy(_newStrategy).vault() == vault);
prepareMigration(_newStrategy);
want.safeTransfer(_newStrategy, want.balanceOf(address(this)));
}
/**
* @notice
* Activates emergency exit. Once activated, the Strategy will exit its
* position upon the next harvest, depositing all funds into the Vault as
* quickly as is reasonable given on-chain conditions.
*
* This may only be called by governance or the strategist.
* @dev
* See `vault.setEmergencyShutdown()` and `harvest()` for further details.
*/
function setEmergencyExit() external onlyEmergencyAuthorized {
emergencyExit = true;
if (vault.strategies(address(this)).debtRatio != 0) {
vault.revokeStrategy();
}
emit EmergencyExitEnabled();
}
/**
* Override this to add all tokens/tokenized positions this contract
* manages on a *persistent* basis (e.g. not just for swapping back to
* want ephemerally).
*
* NOTE: Do *not* include `want`, already included in `sweep` below.
*
* Example:
* ```
* function protectedTokens() internal override view returns (address[] memory) {
* address[] memory protected = new address[](3);
* protected[0] = tokenA;
* protected[1] = tokenB;
* protected[2] = tokenC;
* return protected;
* }
* ```
*/
function protectedTokens() internal view virtual returns (address[] memory);
/**
* @notice
* Removes tokens from this Strategy that are not the type of tokens
* managed by this Strategy. This may be used in case of accidentally
* sending the wrong kind of token to this Strategy.
*
* Tokens will be sent to `governance()`.
*
* This will fail if an attempt is made to sweep `want`, or any tokens
* that are protected by this Strategy.
*
* This may only be called by governance.
* @dev
* Implement `protectedTokens()` to specify any additional tokens that
* should be protected from sweeping in addition to `want`.
* @param _token The token to transfer out of this vault.
*/
function sweep(address _token) external onlyGovernance {
require(_token != address(want), "!want");
require(_token != address(vault), "!shares");
address[] memory _protectedTokens = protectedTokens();
for (uint256 i; i < _protectedTokens.length; i++) require(_token != _protectedTokens[i], "!protected");
IERC20(_token).safeTransfer(governance(), IERC20(_token).balanceOf(address(this)));
}
}
abstract contract BaseStrategyInitializable is BaseStrategy {
bool public isOriginal = true;
event Cloned(address indexed clone);
constructor(address _vault) BaseStrategy(_vault) {}
function initialize(
address _vault,
address _strategist,
address _rewards,
address _keeper
) external virtual {
_initialize(_vault, _strategist, _rewards, _keeper);
}
function clone(address _vault) external returns (address) {
return clone(_vault, msg.sender, msg.sender, msg.sender);
}
function clone(
address _vault,
address _strategist,
address _rewards,
address _keeper
) public returns (address newStrategy) {
require(isOriginal, "!clone");
// Copied from https://github.com/optionality/clone-factory/blob/master/contracts/CloneFactory.sol
bytes20 addressBytes = bytes20(address(this));
assembly {
// EIP-1167 bytecode
let clone_code := mload(0x40)
mstore(clone_code, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000)
mstore(add(clone_code, 0x14), addressBytes)
mstore(add(clone_code, 0x28), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000)
newStrategy := create(0, clone_code, 0x37)
}
BaseStrategyInitializable(newStrategy).initialize(_vault, _strategist, _rewards, _keeper);
emit Cloned(newStrategy);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/draft-IERC20Permit.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(
address owner,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/draft-IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}