Hello,
So I was working on this reflection contract but have hit a bit of a conundrum.
My uniswapv2router02 parent contains an instance of `using SafeMath for uint256;`, while my main contract also contains an instance of using SafeMath for uint256;
This results in a failed compile returning the following:
DeclarationError: Identifier already declared.
--> /C/Users/xxxxx/sc20210716_01/contracts/NJP.sol:11:1:
|
11 | import "@uniswap/uniswap-v2-periphery-master/contracts/UniswapV2Router02.sol";
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Note: The previous declaration is here:
--> @openzeppelin/contracts/token/ERC20/IERC20.sol:8:1:
|
8 | interface IERC20 {
| ^ (Relevant source part starts here and spans across multiple lines).
,DeclarationError: Identifier already declared.
--> /C/Users/xxxxx/sc20210716_01/contracts/NJP.sol:11:1:
|
11 | import "@uniswap/uniswap-v2-periphery-master/contracts/UniswapV2Router02.sol";
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Note: The previous declaration is here:
--> @openzeppelin/contracts/utils/math/SafeMath.sol:15:1:
|
15 | library SafeMath {
| ^ (Relevant source part starts here and spans across multiple lines).
Compilation failed. See above.
Truffle v5.3.14 (core: 5.3.14)
Node v14.17.1
Is there a known work around for this?
SOURCE:
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol";
import "@uniswap/uniswap-v2-periphery-master/contracts/UniswapV2Router02.sol";
//----------------------------------------------------------------------------------------------------
//NJP CONTRACT
contract NJP is Context, IERC20, Ownable {
using SafeMath for uint256;
using Address for address;
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//GLOBAL MAPPINGS AND VARIABLES
mapping (address => uint256) private _rOwned;
mapping (address => uint256) private _tOwned;
mapping (address => mapping (address => uint256)) private _allowances;
mapping (address => bool) private _isExcludedFromFee;
mapping (address => bool) private _isExcluded;
address[] private _excluded;
uint256 private constant MAX = ~uint256(0);
uint256 private _tTotal = 1000000000 * 10**6 * 10**9;
uint256 private _rTotal = (MAX - (MAX % _tTotal));
uint256 private _tFeeTotal;
string private _name = "NJP";
string private _symbol = "NJP";
uint8 private _decimals = 9;
uint256 public _taxFee = 5;
uint256 private _previousTaxFee = _taxFee;
uint256 public _liquidityFee = 5;
uint256 private _previousLiquidityFee = _liquidityFee;
IUniswapV2Router02 public immutable uniswapV2Router;
address public immutable uniswapV2Pair;
bool inSwapAndLiquify;
bool public swapAndLiquifyEnabled = true;
uint256 public _maxTxAmount = 5000000 * 10**6 * 10**9;
uint256 public numTokensSellToAddToLiquidity = 500000 * 10**6 * 10**9;
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//CONTRACT EVENTS
event TaxFeeUpdated(uint256 taxFee);
event LiquidityFeeUpdated(uint256 liquidityFee);
event ExcludeFromRewardUpdated(address account);
event IncludeInRewardUpdated(address account);
event ExcludeFromFeeUpdated(address account);
event IncludeInFeeUpdated(address account);
event MaxTxAmountUpdated(uint _maxTxAmount);
event SwapAndLiquifyEnabledUpdated(bool enabled);
event NumTokensSellToAddToLiquidityUpdated(uint256 _numTokensSellToAddToLiquidity);
event SwapAndLiquify(
uint256 tokensSwapped,
uint256 ethReceived,
uint256 tokensIntoLiqudity
);
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//TIME LOCK
modifier lockTheSwap {
inSwapAndLiquify = true;
_;
inSwapAndLiquify = false;
}
enum Lock {
TAX_FEE,
LIQUIDITY_FEE,
EXCLUDE_FROM_REWARD,
INCLUDE_IN_REWARD,
EXCLUDE_FROM_FEE,
INCLUDE_IN_FEE,
MAX_TX,
SWAP_AND_LIQUIFY_ENABLED,
NUM_TOKENS_SELL_TO_ADD_TO_LIQUIDITY
}
uint256 private constant _TIMELOCK = 1 days;
mapping(Lock => uint256) public timelocks;
modifier unlocked(Lock _lock) {
require(timelocks[_lock] != 0 && timelocks[_lock] <= block.timestamp, "Function is timelocked");
_;
timelocks[_lock] = 0;
}
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//CONSTRUCTOR
constructor () public {
_rOwned[_msgSender()] = _rTotal;
IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x10ED43C718714eb63d5aA57B78B54704E256024E);
// Create a uniswap pair for this new token
uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
.createPair(address(this), _uniswapV2Router.WETH());
// set the rest of the contract variables
uniswapV2Router = _uniswapV2Router;
//exclude owner and this contract from fee
_isExcludedFromFee[owner()] = true;
_isExcludedFromFee[address(this)] = true;
emit Transfer(address(0), _msgSender(), _tTotal);
}
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//ERC20 STANDARDS
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public view returns (uint8) {
return _decimals;
}
function totalSupply() public view override returns (uint256) {
return _tTotal;
}
function balanceOf(address account) public view override returns (uint256) {
if (_isExcluded[account]) return _tOwned[account];
return tokenFromReflection(_rOwned[account]);
}
function transfer(address recipient, uint256 amount) public override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function allowance(address owner, address spender) public view override returns (uint256) {
return _allowances[owner][spender];
}
function approve(address spender, uint256 amount) public override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//REWARD -- REFLECTIONS -- FEES -- TAXES
function isExcludedFromReward(address account) public view returns (bool) {
return _isExcluded[account];
}
function totalFees() public view returns (uint256) {
return _tFeeTotal;
}
function deliver(uint256 tAmount) public {
address sender = _msgSender();
require(!_isExcluded[sender], "Excluded addresses cannot call this function");
(uint256 rAmount,,,,,) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rTotal = _rTotal.sub(rAmount);
_tFeeTotal = _tFeeTotal.add(tAmount);
}
function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) {
require(tAmount <= _tTotal, "Amount must be less than supply");
if (!deductTransferFee) {
(uint256 rAmount,,,,,) = _getValues(tAmount);
return rAmount;
} else {
(,uint256 rTransferAmount,,,,) = _getValues(tAmount);
return rTransferAmount;
}
}
function tokenFromReflection(uint256 rAmount) public view returns(uint256) {
require(rAmount <= _rTotal, "Amount must be less than total reflections");
uint256 currentRate = _getRate();
return rAmount.div(currentRate);
}
function excludeFromReward(address account) public onlyOwner unlocked(Lock.EXCLUDE_FROM_REWARD) {
require(!_isExcluded[account], "Account is already excluded");
if(_rOwned[account] > 0) {
_tOwned[account] = tokenFromReflection(_rOwned[account]);
}
_isExcluded[account] = true;
_excluded.push(account);
emit ExcludeFromRewardUpdated(account);
}
function includeInReward(address account) external onlyOwner unlocked(Lock.INCLUDE_IN_REWARD) {
require(_isExcluded[account], "Account is already excluded");
for (uint256 i = 0; i < _excluded.length; i++) {
if (_excluded[i] == account) {
_excluded[i] = _excluded[_excluded.length - 1];
_tOwned[account] = 0;
_isExcluded[account] = false;
_excluded.pop();
break;
}
}
emit IncludeInRewardUpdated(account);
}
function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function excludeFromFee(address account) public onlyOwner unlocked(Lock.EXCLUDE_FROM_FEE) {
_isExcludedFromFee[account] = true;
emit ExcludeFromFeeUpdated(account);
}
function includeInFee(address account) public onlyOwner unlocked(Lock.INCLUDE_IN_FEE) {
_isExcludedFromFee[account] = false;
emit IncludeInFeeUpdated(account);
}
function setTaxFeePercent(uint256 taxFee) external onlyOwner unlocked(Lock.TAX_FEE) {
require(taxFee <= 15, "Amount must be less than or equal to 15");
_taxFee = taxFee;
emit TaxFeeUpdated(taxFee);
}
function setLiquidityFeePercent(uint256 liquidityFee) external onlyOwner unlocked(Lock.LIQUIDITY_FEE) {
require(liquidityFee <= 15, "Amount must be less than or equal to 15");
_liquidityFee = liquidityFee;
emit LiquidityFeeUpdated(liquidityFee);
}
function setMaxTxPercent(uint256 maxTxPercent) external onlyOwner unlocked(Lock.MAX_TX) {
require(maxTxPercent > 0, "Amount must be greater than 0");
_maxTxAmount = _tTotal.mul(maxTxPercent).div(
10**2
);
emit MaxTxAmountUpdated(_maxTxAmount);
}
function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner unlocked(Lock.SWAP_AND_LIQUIFY_ENABLED) {
swapAndLiquifyEnabled = _enabled;
emit SwapAndLiquifyEnabledUpdated(_enabled);
}
function setNumTokensSellToAddToLiquidity(uint256 _numTokensSellToAddToLiquidity) external onlyOwner unlocked(Lock.NUM_TOKENS_SELL_TO_ADD_TO_LIQUIDITY) {
numTokensSellToAddToLiquidity = _numTokensSellToAddToLiquidity;
emit NumTokensSellToAddToLiquidityUpdated(_numTokensSellToAddToLiquidity);
}
//to recieve ETH from uniswapV2Router when swapping
receive() external payable {}
function _reflectFee(uint256 rFee, uint256 tFee) private {
_rTotal = _rTotal.sub(rFee);
_tFeeTotal = _tFeeTotal.add(tFee);
}
function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256) {
(uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getTValues(tAmount);
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, tLiquidity, _getRate());
return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee, tLiquidity);
}
function _getTValues(uint256 tAmount) private view returns (uint256, uint256, uint256) {
uint256 tFee = calculateTaxFee(tAmount);
uint256 tLiquidity = calculateLiquidityFee(tAmount);
uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity);
return (tTransferAmount, tFee, tLiquidity);
}
function _getRValues(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 currentRate) private pure returns (uint256, uint256, uint256) {
uint256 rAmount = tAmount.mul(currentRate);
uint256 rFee = tFee.mul(currentRate);
uint256 rLiquidity = tLiquidity.mul(currentRate);
uint256 rTransferAmount = rAmount.sub(rFee).sub(rLiquidity);
return (rAmount, rTransferAmount, rFee);
}
function _getRate() private view returns(uint256) {
(uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
return rSupply.div(tSupply);
}
function _getCurrentSupply() private view returns(uint256, uint256) {
uint256 rSupply = _rTotal;
uint256 tSupply = _tTotal;
for (uint256 i = 0; i < _excluded.length; i++) {
if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal);
rSupply = rSupply.sub(_rOwned[_excluded[i]]);
tSupply = tSupply.sub(_tOwned[_excluded[i]]);
}
if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal);
return (rSupply, tSupply);
}
function _takeLiquidity(uint256 tLiquidity) private {
uint256 currentRate = _getRate();
uint256 rLiquidity = tLiquidity.mul(currentRate);
_rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity);
if(_isExcluded[address(this)])
_tOwned[address(this)] = _tOwned[address(this)].add(tLiquidity);
}
function calculateTaxFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_taxFee).div(
10**2
);
}
function calculateLiquidityFee(uint256 _amount) private view returns (uint256) {
return _amount.mul(_liquidityFee).div(
10**2
);
}
function removeAllFee() private {
if(_taxFee == 0 && _liquidityFee == 0) return;
_previousTaxFee = _taxFee;
_previousLiquidityFee = _liquidityFee;
_taxFee = 0;
_liquidityFee = 0;
}
function restoreAllFee() private {
_taxFee = _previousTaxFee;
_liquidityFee = _previousLiquidityFee;
}
function isExcludedFromFee(address account) public view returns(bool) {
return _isExcludedFromFee[account];
}
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//INTERNAL (PRIVATE)
function _approve(address owner, address spender, uint256 amount) private {
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);
}
function _transfer(
address from,
address to,
uint256 amount
) private {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
if(from != owner() && to != owner())
require(amount <= _maxTxAmount, "Transfer amount exceeds the maxTxAmount.");
// is the token balance of this contract address over the min number of
// tokens that we need to initiate a swap + liquidity lock?
// also, don't get caught in a circular liquidity event.
// also, don't swap & liquify if sender is uniswap pair.
uint256 contractTokenBalance = balanceOf(address(this));
if(contractTokenBalance >= _maxTxAmount)
{
contractTokenBalance = _maxTxAmount;
}
bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity;
if (
overMinTokenBalance &&
!inSwapAndLiquify &&
from != uniswapV2Pair &&
swapAndLiquifyEnabled
) {
contractTokenBalance = numTokensSellToAddToLiquidity;
//add liquidity
swapAndLiquify(contractTokenBalance);
}
//indicates if fee should be deducted from transfer
bool takeFee = true;
//if any account belongs to _isExcludedFromFee account then remove the fee
if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){
takeFee = false;
}
//transfer amount, it will take tax, burn, liquidity fee
_tokenTransfer(from,to,amount,takeFee);
}
//----------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------
//UNISWAP FUNCTIONS
function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap {
// split the contract balance into halves
uint256 half = contractTokenBalance.div(2);
uint256 otherHalf = contractTokenBalance.sub(half);
// capture the contract's current ETH balance.
// this is so that we can capture exactly the amount of ETH that the
// swap creates, and not make the liquidity event include any ETH that
// has been manually sent to the contract
uint256 initialBalance = address(this).balance;
// swap tokens for ETH
swapTokensForEth(half); // <- this breaks the ETH -> HATE swap when swap+liquify is triggered
// how much ETH did we just swap into?
uint256 newBalance = address(this).balance.sub(initialBalance);
// add liquidity to uniswap
addLiquidity(otherHalf, newBalance);
emit SwapAndLiquify(half, newBalance, otherHalf);
}
function swapTokensForEth(uint256 tokenAmount) private {
// generate the uniswap pair path of token -> weth
address[] memory path = new address[](2);
path[0] = address(this);
path[1] = uniswapV2Router.WETH();
_approve(address(this), address(uniswapV2Router), tokenAmount);
// make the swap
uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0, // accept any amount of ETH
path,
address(this),
block.timestamp
);
}
function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
// approve token transfer to cover all possible scenarios
_approve(address(this), address(uniswapV2Router), tokenAmount);
// add the liquidity
uniswapV2Router.addLiquidityETH{value: ethAmount}(
address(this),
tokenAmount,
0, // slippage is unavoidable
0, // slippage is unavoidable
address(0),
block.timestamp
);
}
//this method is responsible for taking all fee, if takeFee is true
function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private {
if(!takeFee)
removeAllFee();
if (_isExcluded[sender] && !_isExcluded[recipient]) {
_transferFromExcluded(sender, recipient, amount);
} else if (!_isExcluded[sender] && _isExcluded[recipient]) {
_transferToExcluded(sender, recipient, amount);
} else if (!_isExcluded[sender] && !_isExcluded[recipient]) {
_transferStandard(sender, recipient, amount);
} else if (_isExcluded[sender] && _isExcluded[recipient]) {
_transferBothExcluded(sender, recipient, amount);
} else {
_transferStandard(sender, recipient, amount);
}
if(!takeFee)
restoreAllFee();
}
function _transferStandard(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferToExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_takeLiquidity(tLiquidity);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function unlock(Lock _lock) public onlyOwner {
timelocks[_lock] = block.timestamp + _TIMELOCK;
}
function lock(Lock _lock) public onlyOwner {
timelocks[_lock] = 0;
}}
//----------------------------------------------------------------------------------------------------