// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @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
* ====
*/functionisContract(address account) internalviewreturns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in// construction, since the code is only stored at the end of the// constructor execution.uint256 size;
// solhint-disable-next-line no-inline-assemblyassembly { size :=extcodesize(account) }
return size >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].
*/functionsendValue(addresspayable recipient, uint256 amount) internal{
require(address(this).balance>= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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 functionCall(target, data, "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");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.call{ value: value }(data);
return _verifyCallResult(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) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.staticcall(data);
return _verifyCallResult(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) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytesmemory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function_verifyCallResult(bool success, bytesmemory returndata, stringmemory errorMessage) privatepurereturns(bytesmemory) {
if (success) {
return returndata;
} else {
// 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// solhint-disable-next-line no-inline-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
Contract Source Code
File 2 of 10: BuffDoge.sol
pragmasolidity ^0.8.0;import'./Address.sol';
import'./IUniswapV2Factory.sol';
import'./IUniswapV2Pair.sol';
import'./IUniswapV2Router02.sol';
import'./ERC20.sol';
/**
* @notice ERC20 token with cost basis tracking and restricted loss-taking
*/contractBUFFDOGEisERC20{
usingAddressforaddresspayable;
stringpublicoverride name ='BUFFDOGE (buffdoge.online)';
stringpublicoverride symbol ='BUFFDOGE';
addressprivateconstant UNISWAP_ROUTER =0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
addressprivateconstant WETH =0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
uintprivateconstant SUPPLY =1e9ether;
addressprivate _owner;
addressprivate _pair;
uintprivate _openedAt;
uintprivate _closedAt;
mapping (address=>uint) private _basisOf;
mapping (address=>uint) public cooldownOf;
uintprivate _initialBasis;
uintprivate _ath;
uintprivate _athTimestamp;
structMinting {
address recipient;
uint amount;
}
/**
* @notice deploy
*/constructor () payable{
_owner =msg.sender;
// setup uniswap pair and store address
_pair = IUniswapV2Factory(
IUniswapV2Router02(UNISWAP_ROUTER).factory()
).createPair(WETH, address(this));
// prepare to add liquidity
_approve(address(this), UNISWAP_ROUTER, SUPPLY);
// prepare to remove liquidity
IERC20(_pair).approve(UNISWAP_ROUTER, type(uint).max);
}
receive () externalpayable{}
/**
* @notice get cost basis for given address
* @param account address to query
* @return cost basis
*/functionbasisOf (address account
) publicviewreturns (uint) {
uint basis = _basisOf[account];
if (basis ==0&& balanceOf(account) >0) {
basis = _initialBasis;
}
return basis;
}
/**
* @notice mint team tokens prior to opening of trade
* @param mintings structured minting data (recipient, amount)
*/functionmint (
Minting[] calldata mintings
) external{
require(msg.sender== _owner, 'ERR: sender must be owner');
require(_openedAt ==0, 'ERR: already opened');
uint mintedSupply;
for (uint i; i < mintings.length; i++) {
Minting memory m = mintings[i];
uint amount = m.amount;
address recipient = m.recipient;
mintedSupply += amount;
_balances[recipient] += amount;
emit Transfer(address(0), recipient, amount);
}
_totalSupply += mintedSupply;
}
/**
* @notice open trading
* @dev sender must be owner
* @dev trading must not yet have been opened
*/functionopen () external{
require(msg.sender== _owner, 'ERR: sender must be owner');
require(_openedAt ==0, 'ERR: already opened');
_openedAt =block.timestamp;
// add liquidity, set initial cost basis
_mint(address(this), SUPPLY - totalSupply());
_initialBasis = (1ether) *address(this).balance/ balanceOf(address(this));
IUniswapV2Router02(
UNISWAP_ROUTER
).addLiquidityETH{
value: address(this).balance
}(
address(this),
balanceOf(address(this)),
0,
0,
address(this),
block.timestamp
);
}
/**
* @notice close trading
* @dev trading must not yet have been closed
* @dev minimum time since open must have elapsed
*/functionclose () external{
require(_openedAt !=0, 'ERR: not yet opened');
require(_closedAt ==0, 'ERR: already closed');
require(block.timestamp> _openedAt + (1days), 'ERR: too soon');
_closedAt =block.timestamp;
require(
block.timestamp> _athTimestamp + (1weeks),
'ERR: recent ATH'
);
(uint token, ) = IUniswapV2Router02(
UNISWAP_ROUTER
).removeLiquidityETH(
address(this),
IERC20(_pair).balanceOf(address(this)),
0,
0,
address(this),
block.timestamp
);
_burn(address(this), token);
}
/**
* @notice exchange BUFFDOGE for proportion of ETH in contract
* @dev trading must have been closed
*/functionliquidate () external{
require(_closedAt >0, 'ERR: not yet closed');
uint balance = balanceOf(msg.sender);
require(balance !=0, 'ERR: zero balance');
uint payout =address(this).balance* balance / totalSupply();
_burn(msg.sender, balance);
payable(msg.sender).sendValue(payout);
}
/**
* @notice withdraw remaining ETH from contract
* @dev trading must have been closed
* @dev minimum time since close must have elapsed
*/functionliquidateUnclaimed () external{
require(_closedAt >0, 'ERR: not yet closed');
require(block.timestamp> _closedAt + (12weeks), 'ERR: too soon');
payable(_owner).sendValue(address(this).balance);
}
function_beforeTokenTransfer (addressfrom,
address to,
uint amount
) overrideinternal{
super._beforeTokenTransfer(from, to, amount);
// ignore minting and burningif (from==address(0) || to ==address(0)) return;
// ignore add/remove liquidityif (from==address(this) || to ==address(this)) return;
if (from== UNISWAP_ROUTER || to == UNISWAP_ROUTER) return;
require(_openedAt >0);
require(
msg.sender== UNISWAP_ROUTER ||msg.sender== _pair,
'ERR: sender must be uniswap'
);
require(amount <=5e9ether/* revert message not returned by Uniswap */);
address[] memory path =newaddress[](2);
if (from== _pair) {
require(cooldownOf[to] <block.timestamp/* revert message not returned by Uniswap */);
cooldownOf[to] =block.timestamp+ (5minutes);
path[0] = WETH;
path[1] =address(this);
uint[] memory amounts = IUniswapV2Router02(UNISWAP_ROUTER).getAmountsIn(
amount,
path
);
uint balance = balanceOf(to);
uint fromBasis = (1ether) * amounts[0] / amount;
_basisOf[to] = (fromBasis * amount + basisOf(to) * balance) / (amount + balance);
if (fromBasis > _ath) {
_ath = fromBasis;
_athTimestamp =block.timestamp;
}
} elseif (to == _pair) {
// blacklist Vitalik Buterinrequire(from!=0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B/* revert message not returned by Uniswap */);
require(cooldownOf[from] <block.timestamp/* revert message not returned by Uniswap */);
cooldownOf[from] =block.timestamp+ (5minutes);
path[0] =address(this);
path[1] = WETH;
uint[] memory amounts = IUniswapV2Router02(UNISWAP_ROUTER).getAmountsOut(
amount,
path
);
require(basisOf(from) <= (1ether) * amounts[1] / amount /* revert message not returned by Uniswap */);
}
}
}
Contract Source Code
File 3 of 10: Context.sol
// SPDX-License-Identifier: MITpragmasolidity ^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) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691returnmsg.data;
}
}
Contract Source Code
File 4 of 10: ERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"./IERC20.sol";
import"./IERC20Metadata.sol";
import"./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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of 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.
*/abstractcontractERC20isContext, IERC20, IERC20Metadata{
mapping (address=>uint256) internal _balances;
mapping (address=>mapping (address=>uint256)) private _allowances;
uint256internal _totalSupply;
/**
* @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}.
*/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:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/functiontransfer(address recipient, uint256 amount) publicvirtualoverridereturns (bool) {
_transfer(_msgSender(), recipient, amount);
returntrue;
}
/**
* @dev See {IERC20-allowance}.
*/functionallowance(address owner, address spender) publicviewvirtualoverridereturns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/functionapprove(address spender, uint256 amount) publicvirtualoverridereturns (bool) {
_approve(_msgSender(), 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}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/functiontransferFrom(address sender, address recipient, uint256 amount) publicvirtualoverridereturns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
_approve(sender, _msgSender(), currentAllowance - amount);
returntrue;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is 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:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/function_transfer(address sender, address recipient, uint256 amount) internalvirtual{
require(sender !=address(0), "ERC20: transfer from the zero address");
require(recipient !=address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
_balances[sender] = senderBalance - amount;
_balances[recipient] += amount;
emit Transfer(sender, recipient, 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;
_balances[account] += amount;
emit Transfer(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");
_balances[account] = accountBalance - amount;
_totalSupply -= amount;
emit Transfer(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 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 to 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{ }
}
Contract Source Code
File 5 of 10: IERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @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 `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/functiontransfer(address recipient, 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 `sender` to `recipient` 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(address sender, address recipient, uint256 amount) externalreturns (bool);
/**
* @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);
}
Contract Source Code
File 6 of 10: IERC20Metadata.sol
// SPDX-License-Identifier: MITpragmasolidity ^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);
}