Remix error 事务已恢复到初始状态

Question

我在 remix 上测试我的智能合约。虽然测试 Start Airdrop 功能运行成功，但当我接近 getAirrop 功能时，我收到错误：

getAirdrop 交易出错：VM 错误：还原。 revert 事务已恢复到初始状态。注意：如果您发送值并且您发送的值应该小于您当前的余额，则调用的函数应该是应付的。调试事务以获取更多信息。

我的智能合约代码是：

/**
 *Submitted for verification at BscScan.com on 2021-05-29
*/

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.5.10;

library SafeMath {
  function add(uint a, uint b) internal pure returns (uint c) {
    c = a + b;
    require(c >= a);
  }
  function sub(uint a, uint b) internal pure returns (uint c) {
    require(b <= a);
    c = a - b;
  }
  function mul(uint a, uint b) internal pure returns (uint c) {
    c = a * b;
    require(a == 0 || c / a == b);
  }
  function div(uint a, uint b) internal pure returns (uint c) {
    require(b > 0);
    c = a / b;
  }
}

contract ERC20Interface {
  function totalSupply() public view returns (uint);
  function balanceOf(address tokenOwner) public view returns (uint balance);
  function allowance(address tokenOwner, address spender) public view returns (uint remaining);
  function transfer(address to, uint tokens) public returns (bool success);
  function approve(address spender, uint tokens) public returns (bool success);
  function transferFrom(address from, address to, uint tokens) public returns (bool success);

  event Transfer(address indexed from, address indexed to, uint tokens);
  event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}

contract ApproveAndCallFallBack {
  function receiveApproval(address from, uint256 tokens, address token, bytes memory data) public;
}

contract Owned {
  address public owner;
  address public newOwner;

  event OwnershipTransferred(address indexed _from, address indexed _to);

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

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

  function transferOwnership(address _newOwner) public onlyOwner {
    newOwner = _newOwner;
  }
  function acceptOwnership() public {
    require(msg.sender == newOwner);
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
    newOwner = address(0);
  }
}

contract TokenERC20 is ERC20Interface, Owned{
  using SafeMath for uint;

  string public symbol;
  string public name;
  uint8 public decimals;
  uint _totalSupply;

  mapping(address => uint) balances;
  mapping(address => mapping(address => uint)) allowed;

  constructor() public {
    symbol = "SHIB";
    name = "Shiba";
    decimals = 0;
    _totalSupply =  1000000000000000;
    balances[owner] = _totalSupply;
    emit Transfer(address(0), owner, _totalSupply);
  }

  function totalSupply() public view returns (uint) {
    return _totalSupply.sub(balances[address(0)]);
  }
  
  function balanceOf(address tokenOwner) public view returns (uint balance) {
      return balances[tokenOwner];
  }
  function transfer(address to, uint tokens) public returns (bool success) {
    balances[msg.sender] = balances[msg.sender].sub(tokens);
    balances[to] = balances[to].add(tokens);
    emit Transfer(msg.sender, to, tokens);
    return true;
  }
  function approve(address spender, uint tokens) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    return true;
  }
  function transferFrom(address from, address to, uint tokens) public returns (bool success) {
    balances[from] = balances[from].sub(tokens);
    allowed[from][msg.sender] = allowed[from][msg.sender].sub(tokens);
    balances[to] = balances[to].add(tokens);
    emit Transfer(from, to, tokens);
    return true;
  }
  function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
    return allowed[tokenOwner][spender];
  }
  function approveAndCall(address spender, uint tokens, bytes memory data) public returns (bool success) {
    allowed[msg.sender][spender] = tokens;
    emit Approval(msg.sender, spender, tokens);
    ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, address(this), data);
    return true;
  }
  function () external payable {
    revert();
  }
}

contract Shiba is TokenERC20 {

  
  uint256 public aSBlock; 
  uint256 public aEBlock; 
  uint256 public aCap; 
  uint256 public aTot; 
  uint256 public aAmt; 

 
  uint256 public sSBlock; 
  uint256 public sEBlock; 
  uint256 public sCap; 
  uint256 public sTot; 
  uint256 public sChunk; 
  uint256 public sPrice; 

  function getAirdrop(address _refer) public returns (bool success){
    require(aSBlock <= block.number && block.number <= aEBlock);
    require(aTot < aCap || aCap == 0);
    aTot ++;
    if(msg.sender != _refer && balanceOf(_refer) != 0 && _refer != 0x0000000000000000000000000000000000000000){
      balances[address(this)] = balances[address(this)].sub(aAmt / 1);
      balances[_refer] = balances[_refer].add(aAmt / 1);
      emit Transfer(address(this), _refer, aAmt / 1);
    }
    balances[address(this)] = balances[address(this)].sub(aAmt);
    balances[msg.sender] = balances[msg.sender].add(aAmt);
    emit Transfer(address(this), msg.sender, aAmt);
    return true;
  }

  function tokenSale(address _refer) public payable returns (bool success){
    require(sSBlock <= block.number && block.number <= sEBlock);
    require(sTot < sCap || sCap == 0);
    uint256 _eth = msg.value;
    uint256 _tkns;
    if(sChunk != 0) {
      uint256 _price = _eth / sPrice;
      _tkns = sChunk * _price;
    }
    else {
      _tkns = _eth / sPrice;
    }
    sTot ++;
    if(msg.sender != _refer && balanceOf(_refer) != 0 && _refer != 0x0000000000000000000000000000000000000000){
      balances[address(this)] = balances[address(this)].sub(_tkns / 2);
      balances[_refer] = balances[_refer].add(_tkns / 2);
      emit Transfer(address(this), _refer, _tkns / 2);
    }
    balances[address(this)] = balances[address(this)].sub(_tkns);
    balances[msg.sender] = balances[msg.sender].add(_tkns);
    emit Transfer(address(this), msg.sender, _tkns);
    return true;
  }

  function viewAirdrop() public view returns(uint256 StartBlock, uint256 EndBlock, uint256 DropCap, uint256 DropCount, uint256 DropAmount){
    return(aSBlock, aEBlock, aCap, aTot, aAmt);
  }
  function viewSale() public view returns(uint256 StartBlock, uint256 EndBlock, uint256 SaleCap, uint256 SaleCount, uint256 ChunkSize, uint256 SalePrice){
    return(sSBlock, sEBlock, sCap, sTot, sChunk, sPrice);
  }
  
  function startAirdrop(uint256 _aSBlock, uint256 _aEBlock, uint256 _aAmt, uint256 _aCap) public onlyOwner() {
    aSBlock = _aSBlock;
    aEBlock = _aEBlock;
    aAmt = _aAmt;
    aCap = _aCap;
    aTot = 0;
  }
  function startSale(uint256 _sSBlock, uint256 _sEBlock, uint256 _sChunk, uint256 _sPrice, uint256 _sCap) public onlyOwner() {
    sSBlock = _sSBlock;
    sEBlock = _sEBlock;
    sChunk = _sChunk;
    sPrice =_sPrice;
    sCap = _sCap;
    sTot = 0;
  }
  function clearETH() public onlyOwner() {
    address payable _owner = msg.sender;
    _owner.transfer(address(this).balance);
  }
  function() external payable {

  }

}

Answer 1

require(aSBlock <= block.number && block.number <= aEBlock);

仅当块号在aSBlock（值6,666,666）和aEBlock（值9,999,999）之间时，此条件才会通过。

BSC 主网上的当前区块数约为 8,000,000，因此会在主网上传递。

但是，Remix EVM 模拟器使用自己的区块编号 - 从您加载 EVM 模拟器时的 #1 开始（通过打开 IDE）并随着每个事务递增（即自动挖掘）。

除非您在当前的 Remix 实例中进行了近 670 万次交易，否则它将不符合条件。

---

然后，您的测试场景（或getContract() 函数 - 我不确定）中也存在逻辑错误，您尝试减去余额但地址没有足够的余额。

balances[address(this)] = balances[address(this)].sub(aAmt);

• balances[address(this)] 为 0
• aAmt 是 50,000,000,000,000

这会在 SafeMath sub() 方法中引发异常 - 否则会导致整数下溢。

注意：address(this) 是合约地址。

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解决方案：

• 在 Remix EVM 模拟器中测试此合约时，使用低得多的 aSBlock 值（例如 1）。
• 在执行getAirdrop() 函数之前，用足够的代币（超过aAmt）为您的合约余额（balances[address(this)]）注资。或者更改getAirdrop() 逻辑，使其不会从合约余额中扣除。取决于你的目标。