// 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 9: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.4) (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;
}
function_contextSuffixLength() internalviewvirtualreturns (uint256) {
return0;
}
}
Contract Source Code
File 3 of 9: ERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)pragmasolidity ^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].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* 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}.
*/contractERC20isContext, IERC20, IERC20Metadata{
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowances;
uint256private _totalSupply;
stringprivate _name;
stringprivate _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
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 default value returned by this function, unless
* it's 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}.
*/functiondecimals() publicviewvirtualoverridereturns (uint8) {
return18;
}
/**
* @dev See {IERC20-totalSupply}.
*/functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/functionbalanceOf(address account) publicviewvirtualoverridereturns (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`.
*/functiontransfer(address to, uint256 amount) publicvirtualoverridereturns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
returntrue;
}
/**
* @dev See {IERC20-allowance}.
*/functionallowance(address owner, address spender) publicviewvirtualoverridereturns (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.
*/functionapprove(address spender, uint256 amount) publicvirtualoverridereturns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
returntrue;
}
/**
* @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`.
*/functiontransferFrom(addressfrom, address to, uint256 amount) publicvirtualoverridereturns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
returntrue;
}
/**
* @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.
*/functionincreaseAllowance(address spender, uint256 addedValue) publicvirtualreturns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
returntrue;
}
/**
* @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`.
*/functiondecreaseAllowance(address spender, uint256 subtractedValue) publicvirtualreturns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
returntrue;
}
/**
* @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(addressfrom, address to, uint256 amount) internalvirtual{
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) internalvirtual{
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) internalvirtual{
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) internalvirtual{
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) internalvirtual{
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(addressfrom, address to, uint256 amount) internalvirtual{}
/**
* @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(addressfrom, address to, uint256 amount) internalvirtual{}
}
Contract Source Code
File 4 of 9: 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 9: IERC20Metadata.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)pragmasolidity ^0.8.0;import"../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/interfaceIERC20MetadataisIERC20{
/**
* @dev Returns the name of the token.
*/functionname() externalviewreturns (stringmemory);
/**
* @dev Returns the symbol of the token.
*/functionsymbol() externalviewreturns (stringmemory);
/**
* @dev Returns the decimals places of the token.
*/functiondecimals() externalviewreturns (uint8);
}
Contract Source Code
File 6 of 9: IERC20Permit.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.4) (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.
*
* ==== Security Considerations
*
* There are two important considerations concerning the use of `permit`. The first is that a valid permit signature
* expresses an allowance, and it should not be assumed to convey additional meaning. In particular, it should not be
* considered as an intention to spend the allowance in any specific way. The second is that because permits have
* built-in replay protection and can be submitted by anyone, they can be frontrun. A protocol that uses permits should
* take this into consideration and allow a `permit` call to fail. Combining these two aspects, a pattern that may be
* generally recommended is:
*
* ```solidity
* function doThingWithPermit(..., uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
* try token.permit(msg.sender, address(this), value, deadline, v, r, s) {} catch {}
* doThing(..., value);
* }
*
* function doThing(..., uint256 value) public {
* token.safeTransferFrom(msg.sender, address(this), value);
* ...
* }
* ```
*
* Observe that: 1) `msg.sender` is used as the owner, leaving no ambiguity as to the signer intent, and 2) the use of
* `try/catch` allows the permit to fail and makes the code tolerant to frontrunning. (See also
* {SafeERC20-safeTransferFrom}).
*
* Additionally, note that smart contract wallets (such as Argent or Safe) are not able to produce permit signatures, so
* contracts should have entry points that don't rely on permit.
*/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].
*
* CAUTION: See Security Considerations above.
*/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 7 of 9: 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 8 of 9: PONZIE.sol
// SPDX-License-Identifier: MITpragmasolidity 0.8.19;import"@openzeppelin/contracts/access/Ownable.sol";
import"@openzeppelin/contracts/token/ERC20/ERC20.sol";
import"@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
interfaceIUniswapV2Factory{
eventPairCreated(addressindexed token0, addressindexed token1, address pair, uint256);
functioncreatePair(address tokenA, address tokenB) externalreturns (address pair);
}
interfaceIUniswapV2Router02{
functionfactory() externalpurereturns (address);
functionWETH() externalpurereturns (address);
functionaddLiquidityETH(address token,
uint256 amountTokenDesired,
uint256 amountTokenMin,
uint256 amountETHMin,
address to,
uint256 deadline
) externalpayablereturns (uint256 amountToken, uint256 amountETH, uint256 liquidity);
functionswapExactTokensForETHSupportingFeeOnTransferTokens(uint256 amountIn,
uint256 amountOutMin,
address[] calldata path,
address to,
uint256 deadline
) external;
}
interfaceIWETH{
functiondeposit() externalpayable;
}
/// @title Ponzi.Express/// @notice Ponzi Express TokencontractPonziExpressisERC20, Ownable{
/// STATE VARIABLES ////// @notice Address of UniswapV2Router
IUniswapV2Router02 publicimmutable uniswapV2Router;
/// @notice Address of PONZIE/ETH LPaddresspublicimmutable uniswapV2Pair;
/// @notice WETH addressaddresspublicimmutable WETH;
/// @notice Address of deployeraddresspublicimmutable deployer;
/// @notice PONZIE treasuryaddresspublic treasury;
/// @notice Team wallet addressaddresspublic teamWallet;
/// @notice PONZIE staking contractaddresspublic PONZIEStaking;
/// @notice LP staking contractaddresspublic lpStaking;
boolprivate swapping;
/// @notice Bool if trading is activeboolpublic tradingActive =false;
/// @notice Bool if swap is enabledboolpublic swapEnabled =false;
/// @notice Current percent of supply to swap tokens at (i.e. 50 = 0.05%)uint256public swapPercent;
/// @notice Current buy side total feesuint256public buyTotalFees;
/// @notice Current buy side backing feeuint256public buyBackingFee;
/// @notice Current buy side liquidity feeuint256public buyLiquidityFee;
/// @notice Current buy side team feeuint256public buyTeamFee;
/// @notice Current buy side rev feeuint256public buyRevFee;
/// @notice Current buy side lp staking feeuint256public buyLPStakingFee;
/// @notice Current sell side total feesuint256public sellTotalFees;
/// @notice Current sell side backing feeuint256public sellBackingFee;
/// @notice Current sell side liquidity feeuint256public sellLiquidityFee;
/// @notice Current sell side team feeuint256public sellTeamFee;
/// @notice Current sell side rev feeuint256public sellRevFee;
/// @notice Current sell side lp staking feeuint256public sellLPStakingFee;
/// @notice Current tokens going for backinguint256public tokensForBacking;
/// @notice Current tokens going for liquidityuint256public tokensForLiquidity;
/// @notice Current tokens going for teamuint256public tokensForTeam;
/// @notice Current tokens going towards rev shareuint256public tokensForRev;
/// @notice Current tokens going towards lp stakinguint256public tokensForLPStaking;
/// @notice Timestamp trading went liveuint256public timestampTradingLive;
/// MAPPINGS ////// @dev Bool if address is excluded from feesmapping(address=>bool) private _isExcludedFromFees;
/// @notice Bool if address is excluded from max transaction amountmapping(address=>bool) public _isExcludedMaxTransactionAmount;
/// @notice Bool if address is AMM pairmapping(address=>bool) public automatedMarketMakerPairs;
/// EVENTS ///eventExcludeFromFees(addressindexed account, bool isExcluded);
eventSetAutomatedMarketMakerPair(addressindexed pair, boolindexed value);
eventteamWalletUpdated(addressindexed newWallet, addressindexed oldWallet);
eventSwapAndLiquify(uint256 tokensSwapped, uint256 ethReceived, uint256 tokensIntoLiquidity);
/// CONSTRUCTOR ///constructor() ERC20("Ponzi Express", "PONZIE") {
WETH =0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
uniswapV2Router = _uniswapV2Router;
uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
_setAutomatedMarketMakerPair(address(uniswapV2Pair), true);
// 100% To Starting LPuint256 lpSupply_ =100_000_000ether;
_approve(address(this), address(_uniswapV2Router), type(uint256).max);
swapPercent =100; // 0.10%
buyBackingFee =100;
buyLiquidityFee =100;
buyTeamFee =200;
buyRevFee =100;
buyLPStakingFee =100;
buyTotalFees =600;
sellBackingFee =100;
sellLiquidityFee =100;
sellTeamFee =200;
sellRevFee =100;
sellLPStakingFee =100;
sellTotalFees =600;
deployer =msg.sender;
teamWallet = owner(); // set as team wallet// exclude from paying fees or having max transaction amount
excludeFromFees(owner(), true);
excludeFromFees(address(this), true);
excludeFromFees(address(0xdead), true);
excludeFromMaxTransaction(owner(), true);
excludeFromMaxTransaction(address(this), true);
excludeFromMaxTransaction(address(0xdead), true);
_mint(address(this), lpSupply_);
}
receive() externalpayable{}
/// AMM PAIR ////// @notice Sets if address is AMM pair/// @param pair Address of pair/// @param value Bool if AMM pairfunctionsetAutomatedMarketMakerPair(address pair, bool value) publiconlyOwner{
require(pair != uniswapV2Pair, "The pair cannot be removed from automatedMarketMakerPairs");
_setAutomatedMarketMakerPair(pair, value);
}
/// @dev Internal function to set `value` of `pair`function_setAutomatedMarketMakerPair(address pair, bool value) private{
automatedMarketMakerPairs[pair] = value;
emit SetAutomatedMarketMakerPair(pair, value);
}
/// INTERNAL TRANSFER ////// @dev Internal function to burn `amount` from `account`function_burnFrom(address account, uint256 amount) internal{
uint256 decreasedAllowance_ = allowance(account, msg.sender) - amount;
_approve(account, msg.sender, decreasedAllowance_);
_burn(account, amount);
}
/// @dev Internal function to transfer - handles fee logicfunction_transfer(addressfrom, address to, uint256 amount) internaloverride{
require(from!=address(0), "ERC20: transfer from the zero address");
require(to !=address(0), "ERC20: transfer to the zero address");
if (amount ==0) {
super._transfer(from, to, 0);
return;
}
(bool _limits, uint256 _maxWallet, uint256 _taxMultiplier) = limits();
if (_limits) {
if (from!= owner() && to != owner() && to !=address(0) && to !=address(0xdead) &&!swapping) {
if (!tradingActive) {
require(_isExcludedFromFees[from] || _isExcludedFromFees[to], "Trading is not active.");
}
//when buyif (automatedMarketMakerPairs[from] &&!_isExcludedMaxTransactionAmount[to]) {
require(amount <= _maxWallet, "Buy transfer amount exceeds the max amount.");
require(amount + balanceOf(to) <= _maxWallet, "Max wallet exceeded");
}
//when sellelseif (automatedMarketMakerPairs[to] &&!_isExcludedMaxTransactionAmount[from]) {
require(amount <= _maxWallet, "Sell transfer amount exceeds the max amount.");
}
}
}
uint256 contractTokenBalance = balanceOf(address(this));
bool canSwap = contractTokenBalance >= swapTokensAtAmount();
if (
canSwap && swapEnabled &&!swapping &&!automatedMarketMakerPairs[from] &&!_isExcludedFromFees[from]
&&!_isExcludedFromFees[to]
) {
swapping =true;
swapBack();
swapping =false;
}
bool takeFee =!swapping;
// if any account belongs to _isExcludedFromFee account then remove the feeif (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {
takeFee =false;
}
uint256 fees;
// only take fees on buys/sells, do not take on wallet transfersif (takeFee) {
// on sellif (automatedMarketMakerPairs[to] && sellTotalFees >0) {
fees = (amount * sellTotalFees) /10000;
if (_limits) fees = fees * _taxMultiplier;
tokensForLiquidity += (fees * sellLiquidityFee) / sellTotalFees;
tokensForTeam += (fees * sellTeamFee) / sellTotalFees;
tokensForBacking += (fees * sellBackingFee) / sellTotalFees;
tokensForRev += (fees * sellRevFee) / sellTotalFees;
tokensForLPStaking += (fees * sellLPStakingFee) / sellTotalFees;
}
// on buyelseif (automatedMarketMakerPairs[from] && buyTotalFees >0) {
fees = (amount * buyTotalFees) /10000;
if (_limits) fees = fees * _taxMultiplier;
tokensForLiquidity += (fees * buyLiquidityFee) / buyTotalFees;
tokensForTeam += (fees * buyTeamFee) / buyTotalFees;
tokensForBacking += (fees * buyBackingFee) / buyTotalFees;
tokensForRev += (fees * buyRevFee) / buyTotalFees;
tokensForLPStaking += (fees * buyLPStakingFee) / buyTotalFees;
}
if (fees >0) {
super._transfer(from, address(this), fees);
}
amount -= fees;
}
super._transfer(from, to, amount);
}
/// INTERNAL FUNCTION ////// @dev INTERNAL function to swap `tokenAmount` for ETH/// @dev Invoked in `swapBack()`functionswapTokensForEth(uint256 tokenAmount) internal{
// generate the uniswap pair path of token -> wethaddress[] memory path =newaddress[](2);
path[0] =address(this);
path[1] = uniswapV2Router.WETH();
if (tokenAmount >0) {
// make the swap
uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // accept any amount of ETH
path,
address(this),
block.timestamp
);
}
}
/// @dev INTERNAL function to add `tokenAmount` and `ethAmount` to LP/// @dev Invoked in `swapBack()`functionaddLiquidity(uint256 tokenAmount, uint256 ethAmount) internal{
// add the liquidity
uniswapV2Router.addLiquidityETH{value: ethAmount}(
address(this),
tokenAmount,
0, // slippage is unavoidable0, // slippage is unavoidable
treasury,
block.timestamp
);
}
/// @dev INTERNAL function to transfer fees properly/// @dev Invoked in `_transfer()`functionswapBack() internal{
if (tokensForLPStaking >0) {
super._transfer(address(this), lpStaking, tokensForLPStaking);
tokensForLPStaking =0;
}
uint256 contractBalance = balanceOf(address(this));
uint256 totalTokensToSwap = tokensForLiquidity + tokensForBacking + tokensForTeam + tokensForRev;
bool success;
if (contractBalance ==0|| totalTokensToSwap ==0) {
return;
}
if (contractBalance > swapTokensAtAmount() *20) {
contractBalance = swapTokensAtAmount() *20;
}
// Halve the amount of liquidity tokensuint256 liquidityTokens = (contractBalance * tokensForLiquidity) / totalTokensToSwap /2;
uint256 amountToSwapForETH = contractBalance - liquidityTokens;
swapTokensForEth(amountToSwapForETH);
uint256 ethBalance =address(this).balance;
uint256 ethForBacking = (ethBalance * tokensForBacking) / (totalTokensToSwap - tokensForLiquidity /2);
uint256 ethForTeam = (ethBalance * tokensForTeam) / (totalTokensToSwap - tokensForLiquidity /2);
uint256 ethForRev = (ethBalance * tokensForRev) / (totalTokensToSwap - tokensForLiquidity /2);
uint256 ethForLiquidity = ethBalance - ethForBacking - ethForTeam - ethForRev;
tokensForLiquidity =0;
tokensForBacking =0;
tokensForTeam =0;
tokensForRev =0;
(success,) =address(teamWallet).call{value: ethForTeam}("");
(success,) =address(PONZIEStaking).call{value: ethForRev}("");
if (liquidityTokens >0&& ethForLiquidity >0) {
addLiquidity(liquidityTokens, ethForLiquidity);
emit SwapAndLiquify(amountToSwapForETH, ethForLiquidity, liquidityTokens);
}
(success,) =address(treasury).call{value: address(this).balance}("");
}
/// VIEW FUNCTION ////// @notice Returns if address is excluded from feesfunctionisExcludedFromFees(address account) publicviewreturns (bool) {
return _isExcludedFromFees[account];
}
/// @notice Returns at what percent of supply to swap tokens atfunctionswapTokensAtAmount() publicviewreturns (uint256 amount_) {
amount_ = (totalSupply() * swapPercent) /100000;
}
/// @dev Returns limits if limit in effectfunctionlimits() publicviewreturns (bool limits_, uint256 maxAmount_, uint256 taxMultiplier_) {
if (block.timestamp> timestampTradingLive +90&& timestampTradingLive >0) return (false, 0, 0);
limits_ =true;
maxAmount_ = (totalSupply() *10) /1000; // 1.0% max during for first 90 secondsif (block.timestamp<= timestampTradingLive +30) {
taxMultiplier_ =5;
} // 30% tax first 30 secondselseif (block.timestamp<= timestampTradingLive +60) {
taxMultiplier_ =3;
} // 18% tax second 30 secondselse {
taxMultiplier_ =2;
} // 12% tax third 30 seconds
}
/// USER FUNCTIONS ////// @notice Function for mass approvalfunctionmassApproval() external{
_approve(address(this), address(uniswapV2Router), type(uint256).max);
}
/// @notice Burn PONZIE/// @param account Address to burn PONZIE from/// @param amount Amount of PONZIE to burnfunctionburnFrom(address account, uint256 amount) external{
_burnFrom(account, amount);
}
/// @notice Burn PONZIE/// @param amount Amount to PONZIE to burnfunctionburn(uint256 amount) external{
_burn(msg.sender, amount);
}
/// DEPLOYER ///functionenableTrading() external{
require(msg.sender== deployer, "Not Deployer");
require(timestampTradingLive ==0, "Already live");
tradingActive =true;
swapEnabled =true;
timestampTradingLive =block.timestamp;
addLiquidity(balanceOf(address(this)), address(this).balance);
}
/// OWNER FUNCTIONS ////// @notice Set address of treasuryfunctionsetTreasury(address _treasury) externalpayableonlyOwner{
require(treasury ==address(0), "Treasury already set");
treasury = _treasury;
excludeFromFees(_treasury, true);
excludeFromMaxTransaction(_treasury, true);
}
/// @notice Set staking contract addressesfunctionsetStakingContracts(address _PONZIEStaking, address _lpStaking) externalonlyOwner{
PONZIEStaking = _PONZIEStaking;
lpStaking = _lpStaking;
}
/// @notice Update percent of supply to swap tokens atfunctionupdateSwapTokensAtPercent(uint256 newPercent) externalonlyOwnerreturns (bool) {
require(newPercent >=1, "Swap amount cannot be lower than 0.001% total supply.");
require(newPercent <=500, "Swap amount cannot be higher than 0.50% total supply.");
swapPercent = newPercent;
returntrue;
}
/// @notice Update swap enabled/// @dev Only use to disable contract sales if absolutely necessary (emergency use only)functionupdateSwapEnabled(bool enabled) externalonlyOwner{
swapEnabled = enabled;
}
/// @notice Update buy side feesfunctionupdateBuyFees(uint256 _backingFee,
uint256 _liquidityFee,
uint256 _teamFee,
uint256 _revFee,
uint256 _lpStakingFee
) externalonlyOwner{
buyBackingFee = _backingFee;
buyLiquidityFee = _liquidityFee;
buyTeamFee = _teamFee;
buyRevFee = _revFee;
buyLPStakingFee = _lpStakingFee;
buyTotalFees = buyBackingFee + buyLiquidityFee + buyTeamFee + buyRevFee + buyLPStakingFee;
require(buyTotalFees <=600, "Buy fees must be <= 6%");
}
/// @notice Update sell side feesfunctionupdateSellFees(uint256 _backingFee,
uint256 _liquidityFee,
uint256 _teamFee,
uint256 _revFee,
uint256 _lpStakingFee
) externalonlyOwner{
sellBackingFee = _backingFee;
sellLiquidityFee = _liquidityFee;
sellTeamFee = _teamFee;
sellRevFee = _revFee;
sellLPStakingFee = _lpStakingFee;
sellTotalFees = sellBackingFee + sellLiquidityFee + sellTeamFee + sellRevFee + sellLPStakingFee;
require(sellTotalFees <=600, "Sell fees must be <= 6%");
}
/// @notice Set if an address is excluded from feesfunctionexcludeFromFees(address account, bool excluded) publiconlyOwner{
_isExcludedFromFees[account] = excluded;
emit ExcludeFromFees(account, excluded);
}
/// @notice Set if an address is excluded from max transactionfunctionexcludeFromMaxTransaction(address updAds, bool isEx) publiconlyOwner{
_isExcludedMaxTransactionAmount[updAds] = isEx;
}
/// @notice Update team walletfunctionupdateTeamWallet(address newWallet) externalonlyOwner{
emit teamWalletUpdated(newWallet, teamWallet);
teamWallet = newWallet;
excludeFromFees(newWallet, true);
excludeFromMaxTransaction(newWallet, true);
}
/// @notice Withdraw stuck token from contractfunctionwithdrawStuckToken(address _token, address _to) externalonlyOwner{
require(_token !=address(0), "_token address cannot be 0");
uint256 _contractBalance = IERC20(_token).balanceOf(address(this));
IERC20(_token).transfer(_to, _contractBalance);
}
/// @notice Withdraw stuck ETH from contractfunctionwithdrawStuckEth(address toAddr) externalonlyOwner{
(bool success,) = toAddr.call{value: address(this).balance}("");
require(success);
}
}
Contract Source Code
File 9 of 9: SafeERC20.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.3) (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. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/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));
}
}