// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023. | |
// SPDX-License-Identifier: GPL-3.0-or-later | |
// File: @openzeppelin/contracts/utils/Context.sol | |
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Provides information about the current execution context, including the | |
* sender of the transaction and its data. While these are generally available | |
* via msg.sender and msg.data, they should not be accessed in such a direct | |
* manner, since when dealing with meta-transactions the account sending and | |
* paying for execution may not be the actual sender (as far as an application | |
* is concerned). | |
* | |
* This contract is only required for intermediate, library-like contracts. | |
*/ | |
abstract contract Context { | |
function _msgSender() internal view virtual returns (address) { | |
return msg.sender; | |
} | |
function _msgData() internal view virtual returns (bytes calldata) { | |
return msg.data; | |
} | |
} | |
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol | |
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Interface of the ERC20 standard as defined in the EIP. | |
*/ | |
interface IERC20 { | |
/** | |
* @dev Emitted when `value` tokens are moved from one account (`from`) to | |
* another (`to`). | |
* | |
* Note that `value` may be zero. | |
*/ | |
event Transfer(address indexed from, address indexed to, uint256 value); | |
/** | |
* @dev Emitted when the allowance of a `spender` for an `owner` is set by | |
* a call to {approve}. `value` is the new allowance. | |
*/ | |
event Approval(address indexed owner, address indexed spender, uint256 value); | |
/** | |
* @dev Returns the amount of tokens in existence. | |
*/ | |
function totalSupply() external view returns (uint256); | |
/** | |
* @dev Returns the amount of tokens owned by `account`. | |
*/ | |
function balanceOf(address account) external view returns (uint256); | |
/** | |
* @dev Moves `amount` tokens from the caller's account to `to`. | |
* | |
* Returns a boolean value indicating whether the operation succeeded. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function transfer(address to, uint256 amount) external returns (bool); | |
/** | |
* @dev Returns the remaining number of tokens that `spender` will be | |
* allowed to spend on behalf of `owner` through {transferFrom}. This is | |
* zero by default. | |
* | |
* This value changes when {approve} or {transferFrom} are called. | |
*/ | |
function allowance(address owner, address spender) external view returns (uint256); | |
/** | |
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens. | |
* | |
* Returns a boolean value indicating whether the operation succeeded. | |
* | |
* IMPORTANT: Beware that changing an allowance with this method brings the risk | |
* that someone may use both the old and the new allowance by unfortunate | |
* transaction ordering. One possible solution to mitigate this race | |
* condition is to first reduce the spender's allowance to 0 and set the | |
* desired value afterwards: | |
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729 | |
* | |
* Emits an {Approval} event. | |
*/ | |
function approve(address spender, uint256 amount) external returns (bool); | |
/** | |
* @dev Moves `amount` tokens from `from` to `to` using the | |
* allowance mechanism. `amount` is then deducted from the caller's | |
* allowance. | |
* | |
* Returns a boolean value indicating whether the operation succeeded. | |
* | |
* Emits a {Transfer} event. | |
*/ | |
function transferFrom( | |
address from, | |
address to, | |
uint256 amount | |
) external returns (bool); | |
} | |
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol | |
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Interface for the optional metadata functions from the ERC20 standard. | |
* | |
* _Available since v4.1._ | |
*/ | |
interface IERC20Metadata is IERC20 { | |
/** | |
* @dev Returns the name of the token. | |
*/ | |
function name() external view returns (string memory); | |
/** | |
* @dev Returns the symbol of the token. | |
*/ | |
function symbol() external view returns (string memory); | |
/** | |
* @dev Returns the decimals places of the token. | |
*/ | |
function decimals() external view returns (uint8); | |
} | |
// File: @openzeppelin/contracts/token/ERC20/ERC20.sol | |
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Implementation of the {IERC20} interface. | |
* | |
* This implementation is agnostic to the way tokens are created. This means | |
* that a supply mechanism has to be added in a derived contract using {_mint}. | |
* For a generic mechanism see {ERC20PresetMinterPauser}. | |
* | |
* TIP: For a detailed writeup see our guide | |
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How | |
* to implement supply mechanisms]. | |
* | |
* We have followed general OpenZeppelin Contracts guidelines: functions revert | |
* instead returning `false` on failure. This behavior is nonetheless | |
* conventional and does not conflict with the expectations of ERC20 | |
* applications. | |
* | |
* Additionally, an {Approval} event is emitted on calls to {transferFrom}. | |
* This allows applications to reconstruct the allowance for all accounts just | |
* by listening to said events. Other implementations of the EIP may not emit | |
* these events, as it isn't required by the specification. | |
* | |
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance} | |
* functions have been added to mitigate the well-known issues around setting | |
* allowances. See {IERC20-approve}. | |
*/ | |
contract ERC20 is Context, IERC20, IERC20Metadata { | |
mapping(address => uint256) private _balances; | |
mapping(address => mapping(address => uint256)) private _allowances; | |
uint256 private _totalSupply; | |
string private _name; | |
string private _symbol; | |
/** | |
* @dev Sets the values for {name} and {symbol}. | |
* | |
* The default value of {decimals} is 18. To select a different value for | |
* {decimals} you should overload it. | |
* | |
* All two of these values are immutable: they can only be set once during | |
* construction. | |
*/ | |
constructor(string memory name_, string memory symbol_) { | |
_name = name_; | |
_symbol = symbol_; | |
} | |
/** | |
* @dev Returns the name of the token. | |
*/ | |
function name() public view virtual override returns (string memory) { | |
return _name; | |
} | |
/** | |
* @dev Returns the symbol of the token, usually a shorter version of the | |
* name. | |
*/ | |
function symbol() public view virtual override returns (string memory) { | |
return _symbol; | |
} | |
/** | |
* @dev Returns the number of decimals used to get its user representation. | |
* For example, if `decimals` equals `2`, a balance of `505` tokens should | |
* be displayed to a user as `5.05` (`505 / 10 ** 2`). | |
* | |
* Tokens usually opt for a value of 18, imitating the relationship between | |
* Ether and Wei. This is the value {ERC20} uses, unless this function is | |
* overridden; | |
* | |
* NOTE: This information is only used for _display_ purposes: it in | |
* no way affects any of the arithmetic of the contract, including | |
* {IERC20-balanceOf} and {IERC20-transfer}. | |
*/ | |
function decimals() public view virtual override returns (uint8) { | |
return 18; | |
} | |
/** | |
* @dev See {IERC20-totalSupply}. | |
*/ | |
function totalSupply() public view virtual override returns (uint256) { | |
return _totalSupply; | |
} | |
/** | |
* @dev See {IERC20-balanceOf}. | |
*/ | |
function balanceOf(address account) public view virtual override returns (uint256) { | |
return _balances[account]; | |
} | |
/** | |
* @dev See {IERC20-transfer}. | |
* | |
* Requirements: | |
* | |
* - `to` cannot be the zero address. | |
* - the caller must have a balance of at least `amount`. | |
*/ | |
function transfer(address to, uint256 amount) public virtual override returns (bool) { | |
address owner = _msgSender(); | |
_transfer(owner, to, amount); | |
return true; | |
} | |
/** | |
* @dev See {IERC20-allowance}. | |
*/ | |
function allowance(address owner, address spender) public view virtual override returns (uint256) { | |
return _allowances[owner][spender]; | |
} | |
/** | |
* @dev See {IERC20-approve}. | |
* | |
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on | |
* `transferFrom`. This is semantically equivalent to an infinite approval. | |
* | |
* Requirements: | |
* | |
* - `spender` cannot be the zero address. | |
*/ | |
function approve(address spender, uint256 amount) public virtual override returns (bool) { | |
address owner = _msgSender(); | |
_approve(owner, spender, amount); | |
return true; | |
} | |
/** | |
* @dev See {IERC20-transferFrom}. | |
* | |
* Emits an {Approval} event indicating the updated allowance. This is not | |
* required by the EIP. See the note at the beginning of {ERC20}. | |
* | |
* NOTE: Does not update the allowance if the current allowance | |
* is the maximum `uint256`. | |
* | |
* Requirements: | |
* | |
* - `from` and `to` cannot be the zero address. | |
* - `from` must have a balance of at least `amount`. | |
* - the caller must have allowance for ``from``'s tokens of at least | |
* `amount`. | |
*/ | |
function transferFrom( | |
address from, | |
address to, | |
uint256 amount | |
) public virtual override returns (bool) { | |
address spender = _msgSender(); | |
_spendAllowance(from, spender, amount); | |
_transfer(from, to, amount); | |
return true; | |
} | |
/** | |
* @dev Atomically increases the allowance granted to `spender` by the caller. | |
* | |
* This is an alternative to {approve} that can be used as a mitigation for | |
* problems described in {IERC20-approve}. | |
* | |
* Emits an {Approval} event indicating the updated allowance. | |
* | |
* Requirements: | |
* | |
* - `spender` cannot be the zero address. | |
*/ | |
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) { | |
address owner = _msgSender(); | |
_approve(owner, spender, allowance(owner, spender) + addedValue); | |
return true; | |
} | |
/** | |
* @dev Atomically decreases the allowance granted to `spender` by the caller. | |
* | |
* This is an alternative to {approve} that can be used as a mitigation for | |
* problems described in {IERC20-approve}. | |
* | |
* Emits an {Approval} event indicating the updated allowance. | |
* | |
* Requirements: | |
* | |
* - `spender` cannot be the zero address. | |
* - `spender` must have allowance for the caller of at least | |
* `subtractedValue`. | |
*/ | |
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) { | |
address owner = _msgSender(); | |
uint256 currentAllowance = allowance(owner, spender); | |
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero"); | |
unchecked { | |
_approve(owner, spender, currentAllowance - subtractedValue); | |
} | |
return true; | |
} | |
/** | |
* @dev Moves `amount` of tokens from `from` to `to`. | |
* | |
* This internal function is equivalent to {transfer}, and can be used to | |
* e.g. implement automatic token fees, slashing mechanisms, etc. | |
* | |
* Emits a {Transfer} event. | |
* | |
* Requirements: | |
* | |
* - `from` cannot be the zero address. | |
* - `to` cannot be the zero address. | |
* - `from` must have a balance of at least `amount`. | |
*/ | |
function _transfer( | |
address from, | |
address to, | |
uint256 amount | |
) internal virtual { | |
require(from != address(0), "ERC20: transfer from the zero address"); | |
require(to != address(0), "ERC20: transfer to the zero address"); | |
_beforeTokenTransfer(from, to, amount); | |
uint256 fromBalance = _balances[from]; | |
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance"); | |
unchecked { | |
_balances[from] = fromBalance - amount; | |
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by | |
// decrementing then incrementing. | |
_balances[to] += amount; | |
} | |
emit Transfer(from, to, amount); | |
_afterTokenTransfer(from, to, amount); | |
} | |
/** @dev Creates `amount` tokens and assigns them to `account`, increasing | |
* the total supply. | |
* | |
* Emits a {Transfer} event with `from` set to the zero address. | |
* | |
* Requirements: | |
* | |
* - `account` cannot be the zero address. | |
*/ | |
function _mint(address account, uint256 amount) internal virtual { | |
require(account != address(0), "ERC20: mint to the zero address"); | |
_beforeTokenTransfer(address(0), account, amount); | |
_totalSupply += amount; | |
unchecked { | |
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above. | |
_balances[account] += amount; | |
} | |
emit Transfer(address(0), account, amount); | |
_afterTokenTransfer(address(0), account, amount); | |
} | |
/** | |
* @dev Destroys `amount` tokens from `account`, reducing the | |
* total supply. | |
* | |
* Emits a {Transfer} event with `to` set to the zero address. | |
* | |
* Requirements: | |
* | |
* - `account` cannot be the zero address. | |
* - `account` must have at least `amount` tokens. | |
*/ | |
function _burn(address account, uint256 amount) internal virtual { | |
require(account != address(0), "ERC20: burn from the zero address"); | |
_beforeTokenTransfer(account, address(0), amount); | |
uint256 accountBalance = _balances[account]; | |
require(accountBalance >= amount, "ERC20: burn amount exceeds balance"); | |
unchecked { | |
_balances[account] = accountBalance - amount; | |
// Overflow not possible: amount <= accountBalance <= totalSupply. | |
_totalSupply -= amount; | |
} | |
emit Transfer(account, address(0), amount); | |
_afterTokenTransfer(account, address(0), amount); | |
} | |
/** | |
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens. | |
* | |
* This internal function is equivalent to `approve`, and can be used to | |
* e.g. set automatic allowances for certain subsystems, etc. | |
* | |
* Emits an {Approval} event. | |
* | |
* Requirements: | |
* | |
* - `owner` cannot be the zero address. | |
* - `spender` cannot be the zero address. | |
*/ | |
function _approve( | |
address owner, | |
address spender, | |
uint256 amount | |
) internal virtual { | |
require(owner != address(0), "ERC20: approve from the zero address"); | |
require(spender != address(0), "ERC20: approve to the zero address"); | |
_allowances[owner][spender] = amount; | |
emit Approval(owner, spender, amount); | |
} | |
/** | |
* @dev Updates `owner` s allowance for `spender` based on spent `amount`. | |
* | |
* Does not update the allowance amount in case of infinite allowance. | |
* Revert if not enough allowance is available. | |
* | |
* Might emit an {Approval} event. | |
*/ | |
function _spendAllowance( | |
address owner, | |
address spender, | |
uint256 amount | |
) internal virtual { | |
uint256 currentAllowance = allowance(owner, spender); | |
if (currentAllowance != type(uint256).max) { | |
require(currentAllowance >= amount, "ERC20: insufficient allowance"); | |
unchecked { | |
_approve(owner, spender, currentAllowance - amount); | |
} | |
} | |
} | |
/** | |
* @dev Hook that is called before any transfer of tokens. This includes | |
* minting and burning. | |
* | |
* Calling conditions: | |
* | |
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens | |
* will be transferred to `to`. | |
* - when `from` is zero, `amount` tokens will be minted for `to`. | |
* - when `to` is zero, `amount` of ``from``'s tokens will be burned. | |
* - `from` and `to` are never both zero. | |
* | |
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. | |
*/ | |
function _beforeTokenTransfer( | |
address from, | |
address to, | |
uint256 amount | |
) internal virtual {} | |
/** | |
* @dev Hook that is called after any transfer of tokens. This includes | |
* minting and burning. | |
* | |
* Calling conditions: | |
* | |
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens | |
* has been transferred to `to`. | |
* - when `from` is zero, `amount` tokens have been minted for `to`. | |
* - when `to` is zero, `amount` of ``from``'s tokens have been burned. | |
* - `from` and `to` are never both zero. | |
* | |
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. | |
*/ | |
function _afterTokenTransfer( | |
address from, | |
address to, | |
uint256 amount | |
) internal virtual {} | |
} | |
// File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol | |
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/extensions/ERC20Burnable.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Extension of {ERC20} that allows token holders to destroy both their own | |
* tokens and those that they have an allowance for, in a way that can be | |
* recognized off-chain (via event analysis). | |
*/ | |
abstract contract ERC20Burnable is Context, ERC20 { | |
/** | |
* @dev Destroys `amount` tokens from the caller. | |
* | |
* See {ERC20-_burn}. | |
*/ | |
function burn(uint256 amount) public virtual { | |
_burn(_msgSender(), amount); | |
} | |
/** | |
* @dev Destroys `amount` tokens from `account`, deducting from the caller's | |
* allowance. | |
* | |
* See {ERC20-_burn} and {ERC20-allowance}. | |
* | |
* Requirements: | |
* | |
* - the caller must have allowance for ``accounts``'s tokens of at least | |
* `amount`. | |
*/ | |
function burnFrom(address account, uint256 amount) public virtual { | |
_spendAllowance(account, _msgSender(), amount); | |
_burn(account, amount); | |
} | |
} | |
// File: @openzeppelin/contracts/token/ERC20/extensions/ERC20Capped.sol | |
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/ERC20Capped.sol) | |
pragma solidity ^0.8.17; | |
/** | |
* @dev Extension of {ERC20} that adds a cap to the supply of tokens. | |
*/ | |
abstract contract ERC20Capped is ERC20 { | |
uint256 private immutable _cap; | |
/** | |
* @dev Sets the value of the `cap`. This value is immutable, it can only be | |
* set once during construction. | |
*/ | |
constructor(uint256 cap_) { | |
require(cap_ > 0, "ERC20Capped: cap is 0"); | |
_cap = cap_; | |
} | |
/** | |
* @dev Returns the cap on the token's total supply. | |
*/ | |
function cap() public view virtual returns (uint256) { | |
return _cap; | |
} | |
/** | |
* @dev See {ERC20-_mint}. | |
*/ | |
function _mint(address account, uint256 amount) internal virtual override { | |
require(ERC20.totalSupply() + amount <= cap(), "ERC20Capped: cap exceeded"); | |
super._mint(account, amount); | |
} | |
} | |
// File: contracts/USDTOKEN.sol | |
// contracts/USDTOKEN.sol | |
pragma solidity ^0.8.17; | |
/** | |
* @title ContractName | |
* @dev ContractDescription | |
* @custom:dev-run-script contracts/USDTOKEN.sol | |
*/ | |
contract ContractName {} | |
contract USDTOKEN is ERC20Capped, ERC20Burnable { | |
address payable public owner; | |
uint256 public blockReward; | |
constructor(uint256 cap, uint256 reward) ERC20 ("USDTOKEN", "USDT") ERC20Capped(cap * (10 ** decimals())) { | |
owner = payable(msg.sender); | |
_mint(owner, 70000000 * (10 ** decimals())); | |
blockReward = reward * (10 ** decimals()); | |
} | |
function _mint(address account, uint256 amount) internal virtual override(ERC20Capped, ERC20) { | |
require(ERC20.totalSupply() + amount <= cap(), "ERC20Capped: cap exceeded"); | |
super._mint(account, amount); | |
} | |
function _mintMinerReward() internal { | |
_mint(block.coinbase, blockReward); | |
} | |
function _beforeTokenTransfer(address from, address to, uint256 value) internal virtual override { | |
if(from != address(0) && to != block.coinbase && block.coinbase != address(0)) { | |
_mintMinerReward(); | |
} | |
super._beforeTokenTransfer(from, to, value); | |
} | |
function setBlockReward(uint256 reward) public onlyOwner { | |
blockReward = reward * (10 ** decimals()); | |
} | |
modifier onlyOwner { | |
require(msg.sender == owner, "Only the owner can call this function"); | |
_; | |
} | |
} |