0

我想部署我的合同，但我有很多警告，我不知道所有的意思。

函数 SpastToken.increaseApproval(address,uint256) 的 Gas 要求很高。（其他函数 11 次） BasicToken.balanceOf(address) ：变量的名称 balance 和 balances 非常相似。注意：此静态分析当前不考虑修饰符。

如果您永远不希望 x 为假，请使用 assert(x)，而不是在任何情况下（除了代码中的错误）。如果 x 可能为假，则使用 require(x)，例如无效输入或外部组件故障。

contract Ownable {
address public owner;
event OwnershipTransferred(address indexed previousOwner, address indexed 
newOwner);

constructor() public {
owner = msg.sender;
}

modifier onlyOwner() {
require(msg.sender == owner);
_;
}

function transferOwnership(address newOwner) public onlyOwner {
require(newOwner != address(0));
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
}

}

contract ERC20Basic {
function totalSupply() public view returns (uint256);
function balanceOf(address who) public view returns (uint256);
function transfer(address to, uint256 value) public returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}

/**
* @title ERC20 interface
*/
contract ERC20 is ERC20Basic {
function allowance(address owner, address spender) public view returns 
(uint256);
function transferFrom(address from, address to, uint256 value) public 
returns (bool);
function approve(address spender, uint256 value) public returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 
value);
}
/**
* @title Basic token
*/
contract BasicToken is ERC20Basic {
using SafeMath for uint256;

mapping(address => uint256) balances;

uint256 totalSupply_;

function totalSupply() public view returns (uint256) {
return totalSupply_;
}

function transfer(address _to, uint256 _value) public returns (bool) {
require(_to != address(0));
require(_value <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}

function balanceOf(address _owner) public view returns (uint256 balance) {
return balances[_owner];
}
}

/**
* @title Standard ERC20 token
*/
contract StandardToken is ERC20, BasicToken {
mapping (address => mapping (address => uint256)) internal allowed;
function transferFrom(address _from, address _to, uint256 _value) public 
returns (bool) {
require(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);

balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}

function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}

function allowance(address _owner, address _spender) public view returns 
(uint256) {
return allowed[_owner][_spender];
}
function increaseApproval(address _spender, uint _addedValue) public returns 
(bool) {
allowed[msg.sender][_spender] = allowed[msg.sender] 
[_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval(address _spender, uint _subtractedValue) public 
returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}

}

contract SpastToken is StandardToken, Ownable {

string public name;
string public symbol;
uint8 public decimals;
uint256 public initialSupply;

constructor() public {
name = 'SPAST-Coin';
symbol = 'SPAS';
decimals = 18;
initialSupply = 100000000 * 10 ** uint256(decimals);
totalSupply_ = initialSupply;
balances[owner] = initialSupply;
emit Transfer(0x0, owner, initialSupply);
}
}
4

1 回答 1

1

我认为这些警告是不言自明的。除了关于断言的最后一个。那个基本上说你应该用它assert()来检查代码中的逻辑错误（那将是你做错的事情），而你应该用它require()来检查输入是否合法（那将是调用者的错误）。我认为其余的警告无法进一步解释，请考虑使用谷歌搜索。然而，带有变量名的那个只是为了帮助您避免类似变量名的拼写错误，并且不会以任何方式影响执行。此处未出现的修饰符警告试图告诉您可以为您的函数使用更严格的修饰符，这又会使阅读代码更简单。

于 2018-11-08T11:56:55.900 回答