// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)pragmasolidity ^0.8.1;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @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
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [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.
* ====
*/functionisContract(address account) internalviewreturns (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://consensys.net/diligence/blog/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/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/functionsendValue(addresspayable 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._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
(bool success, bytesmemory 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._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
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._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionverifyCallResultFromTarget(address target,
bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
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 contractrequire(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._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function_revert(bytesmemory returndata, stringmemory errorMessage) privatepure{
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly/// @solidity memory-safe-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
Contract Source Code
File 2 of 8: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragmasolidity ^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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 3 of 8: DelegateStakingRewardsIDLE.sol
pragmasolidity 0.8.10;import"@openzeppelin/contracts/token/ERC20/IERC20.sol";
import"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import"@openzeppelin/contracts/security/Pausable.sol";
import"@openzeppelin/contracts/access/Ownable.sol";
interfaceIIdle{
functiondelegate(address delegate) external;
}
errorNotWhitelisted();
// https://docs.synthetix.io/contracts/source/contracts/stakingrewardscontractDelegateStakingRewardsIDLEisOwnable, Pausable{
usingSafeERC20forIERC20;
/* ========== STATE VARIABLES ========== */
IERC20 publicimmutable rewardsToken;
IERC20 publicimmutable stakingToken;
uint256public periodFinish;
uint256public rewardRate;
uint256public rewardsDuration;
uint256public lastUpdateTime;
uint256public rewardPerTokenStored;
addresspublic rewardsDistribution;
mapping(address=>uint256) public userRewardPerTokenPaid;
mapping(address=>uint256) public rewards;
mapping(address=>bool) public whitelist;
uint256public _totalSupply;
mapping(address=>uint256) public _balances;
/* ========== INITIALIZE ========== */constructor(address _rewardsDistribution,
address _rewardsToken,
address _stakingToken,
address _owner,
address[] memory _whitelisted
) {
rewardsToken = IERC20(_rewardsToken);
stakingToken = IERC20(_stakingToken);
rewardsDistribution = _rewardsDistribution;
rewardsDuration =7days;
_transferOwnership(_owner);
for (uint256 i =0; i < _whitelisted.length; i++) {
whitelist[_whitelisted[i]] =true;
}
IIdle(address(stakingToken)).delegate(_rewardsDistribution);
}
/* ========== VIEWS ========== */functiontotalSupply() externalviewreturns (uint256) {
return _totalSupply;
}
functionbalanceOf(address account) externalviewreturns (uint256) {
return _balances[account];
}
functionlastTimeRewardApplicable() publicviewreturns (uint256) {
returnblock.timestamp< periodFinish ? block.timestamp : periodFinish;
}
functionrewardPerToken() publicviewreturns (uint256) {
if (_totalSupply ==0) {
return rewardPerTokenStored;
}
return rewardPerTokenStored + ((lastTimeRewardApplicable() - lastUpdateTime) * rewardRate *1e18/ _totalSupply);
}
functionearned(address account) publicviewreturns (uint256) {
return (_balances[account] * (rewardPerToken() - userRewardPerTokenPaid[account]) /1e18) + rewards[account];
}
functiongetRewardForDuration() externalviewreturns (uint256) {
return rewardRate * rewardsDuration;
}
/* ========== MUTATIVE FUNCTIONS ========== */functionstake(uint256 amount) external{
_stake(msg.sender, msg.sender, amount);
}
function_stake(address _user, address _payer, uint256 amount) internalwhenNotPausedupdateReward(_user) {
_checkWhiteList(msg.sender);
require(amount >0, "Cannot stake 0");
_totalSupply += amount;
_balances[_user] += amount;
stakingToken.safeTransferFrom(_payer, address(this), amount);
emit Staked(_user, amount);
}
functionwithdraw(uint256 amount) publicupdateReward(msg.sender) {
_checkWhiteList(msg.sender);
require(amount >0, "Cannot withdraw 0");
_totalSupply -= amount;
_balances[msg.sender] -= amount;
stakingToken.safeTransfer(msg.sender, amount);
emit Withdrawn(msg.sender, amount);
}
functiongetReward() publicupdateReward(msg.sender) {
_checkWhiteList(msg.sender);
uint256 reward = rewards[msg.sender];
if (reward >0) {
rewards[msg.sender] =0;
rewardsToken.safeTransfer(msg.sender, reward);
emit RewardPaid(msg.sender, reward);
}
}
functionexit() external{
_checkWhiteList(msg.sender);
withdraw(_balances[msg.sender]);
getReward();
}
/* ========== UTILITIES ========== */function_checkWhiteList(address _address) internalview{
if (!whitelist[_address]) {
revert NotWhitelisted();
}
}
/* ========== RESTRICTED FUNCTIONS ========== *//// @notice set whitelisted addresse/// @param _address address/// @param _value whitelist valuefunctionsetWhitelist(address _address, bool _value) externalonlyOwner{
whitelist[_address] = _value;
}
/// @notice delegate votes to delegate/// @param _delegate addressfunctionchangeDelegate(address _delegate) externalonlyOwner{
IIdle(address(stakingToken)).delegate(_delegate);
}
// Changed from // function notifyRewardAmount(uint256 reward)// to // function depositReward(address, uint256 reward)// for compatibility reason with IdleCDO. Added also a transferFrom to get the reward amountfunctiondepositReward(address, uint256 reward) externalonlyRewardsDistributionupdateReward(address(0)) {
rewardsToken.safeTransferFrom(msg.sender, address(this), reward);
if (block.timestamp>= periodFinish) {
rewardRate = reward / rewardsDuration;
} else {
uint256 remaining = periodFinish -block.timestamp;
uint256 leftover = remaining * rewardRate;
rewardRate = (reward + leftover) / rewardsDuration;
}
// Ensure the provided reward amount is not more than the balance in the contract.// This keeps the reward rate in the right range, preventing overflows due to// very high values of rewardRate in the earned and rewardsPerToken functions;// Reward + leftover must be less than 2^256 / 10^18 to avoid overflow.uint balance = rewardsToken.balanceOf(address(this));
require(rewardRate <= balance / rewardsDuration, "Provided reward too high");
lastUpdateTime =block.timestamp;
periodFinish =block.timestamp+ rewardsDuration;
emit RewardAdded(reward);
}
// Added to support recovering LP Rewards from other systems such as BAL to be distributed to holdersfunctionrecoverERC20(address tokenAddress, uint256 tokenAmount) externalonlyOwner{
require(tokenAddress !=address(stakingToken), "Cannot withdraw the staking token");
IERC20(tokenAddress).safeTransfer(owner(), tokenAmount);
emit Recovered(tokenAddress, tokenAmount);
}
functionsetRewardsDuration(uint256 _rewardsDuration) externalonlyOwner{
require(
block.timestamp> periodFinish,
"Previous rewards period must be complete before changing the duration for the new period"
);
rewardsDuration = _rewardsDuration;
emit RewardsDurationUpdated(rewardsDuration);
}
functionsetRewardsDistribution(address _rewardsDistribution) externalonlyOwner{
rewardsDistribution = _rewardsDistribution;
}
functionpause() externalonlyOwner{
_pause();
}
functionunpause() externalonlyOwner{
_unpause();
}
/* ========== MODIFIERS ========== */modifierupdateReward(address account) {
rewardPerTokenStored = rewardPerToken();
lastUpdateTime = lastTimeRewardApplicable();
if (account !=address(0)) {
rewards[account] = earned(account);
userRewardPerTokenPaid[account] = rewardPerTokenStored;
}
_;
}
modifieronlyRewardsDistribution() {
require(msg.sender== rewardsDistribution, "Caller is not RewardsDistribution address");
_;
}
/* ========== EVENTS ========== */eventRewardAdded(uint256 reward);
eventStaked(addressindexed user, uint256 amount);
eventWithdrawn(addressindexed user, uint256 amount);
eventRewardPaid(addressindexed user, uint256 reward);
eventRewardsDurationUpdated(uint256 newDuration);
eventRecovered(address token, uint256 amount);
}
Contract Source Code
File 4 of 8: IERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)pragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed 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.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (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.
*/functiontransfer(address to, uint256 amount) externalreturns (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.
*/functionallowance(address owner, address spender) externalviewreturns (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.
*/functionapprove(address spender, uint256 amount) externalreturns (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.
*/functiontransferFrom(addressfrom, address to, uint256 amount) externalreturns (bool);
}
Contract Source Code
File 5 of 8: IERC20Permit.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)pragmasolidity ^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.
*/interfaceIERC20Permit{
/**
* @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].
*/functionpermit(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.
*/functionnonces(address owner) externalviewreturns (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-mixedcasefunctionDOMAIN_SEPARATOR() externalviewreturns (bytes32);
}
Contract Source Code
File 6 of 8: Ownable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)pragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/abstractcontractOwnableisContext{
addressprivate _owner;
eventOwnershipTransferred(addressindexed previousOwner, addressindexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/modifieronlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/functionowner() publicviewvirtualreturns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/function_checkOwner() internalviewvirtual{
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/functionrenounceOwnership() publicvirtualonlyOwner{
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/functiontransferOwnership(address newOwner) publicvirtualonlyOwner{
require(newOwner !=address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/function_transferOwnership(address newOwner) internalvirtual{
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
Contract Source Code
File 7 of 8: Pausable.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)pragmasolidity ^0.8.0;import"../utils/Context.sol";
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/abstractcontractPausableisContext{
/**
* @dev Emitted when the pause is triggered by `account`.
*/eventPaused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/eventUnpaused(address account);
boolprivate _paused;
/**
* @dev Initializes the contract in unpaused state.
*/constructor() {
_paused =false;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/modifierwhenNotPaused() {
_requireNotPaused();
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/modifierwhenPaused() {
_requirePaused();
_;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/functionpaused() publicviewvirtualreturns (bool) {
return _paused;
}
/**
* @dev Throws if the contract is paused.
*/function_requireNotPaused() internalviewvirtual{
require(!paused(), "Pausable: paused");
}
/**
* @dev Throws if the contract is not paused.
*/function_requirePaused() internalviewvirtual{
require(paused(), "Pausable: not paused");
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/function_pause() internalvirtualwhenNotPaused{
_paused =true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/function_unpause() internalvirtualwhenPaused{
_paused =false;
emit Unpaused(_msgSender());
}
}
Contract Source Code
File 8 of 8: SafeERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
import"../extensions/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.
*/librarySafeERC20{
usingAddressforaddress;
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/functionsafeTransfer(IERC20 token, address to, uint256 value) internal{
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/functionsafeTransferFrom(IERC20 token, addressfrom, 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.
*/functionsafeApprove(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));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/functionsafeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal{
uint256 oldAllowance = token.allowance(address(this), spender);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/functionsafeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal{
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
* 0 before setting it to a non-zero value.
*/functionforceApprove(IERC20 token, address spender, uint256 value) internal{
bytesmemory approvalCall =abi.encodeWithSelector(token.approve.selector, spender, value);
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
* Revert on invalid signature.
*/functionsafePermit(
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, bytesmemory 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.bytesmemory returndata =address(token).functionCall(data, "SafeERC20: low-level call failed");
require(returndata.length==0||abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation 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).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/function_callOptionalReturnBool(IERC20 token, bytesmemory data) privatereturns (bool) {
// 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 cannot use {Address-functionCall} here since this should return false// and not revert is the subcall reverts.
(bool success, bytesmemory returndata) =address(token).call(data);
return
success && (returndata.length==0||abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}