comment near sendERC20 function (Utils.sol)

matter-labs · Jun 3, 2020 · 1af9917 · 1af9917
1 parent 7944bad
commit 1af9917
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Showing 2 changed files with 9 additions and 7 deletions.
diff --git a/contracts/contracts/Utils.sol b/contracts/contracts/Utils.sol
@@ -1,5 +1,6 @@
 pragma solidity ^0.5.0;
 
+import "./IERC20.sol";
 import "./Bytes.sol";
 
 library Utils {
@@ -14,12 +15,14 @@ library Utils {
     }
 
     /// @notice Sends tokens
+    /// @dev NOTE: this function handles tokens that have transfer function not strictly compatible with ERC20 standard
+    /// @dev NOTE: call `transfer` to this token may return (bool) or nothing
     /// @param _token Token address
     /// @param _to Address of recipient
     /// @param _amount Amount of tokens to transfer
     /// @return bool flag indicating that transfer is successful
-    function sendERC20(address _token, address _to, uint256 _amount) internal returns (bool) {
-        (bool callSuccess, bytes memory callReturnValueEncoded) = _token.call(
+    function sendERC20(IERC20 _token, address _to, uint256 _amount) internal returns (bool) {
+        (bool callSuccess, bytes memory callReturnValueEncoded) = address(_token).call(
             abi.encodeWithSignature("transfer(address,uint256)", _to, _amount)
         );
         // `transfer` method may return (bool) or nothing.
@@ -35,7 +38,7 @@ library Utils {
         // TODO: Use constant from Config
         uint256 ETH_WITHDRAWAL_GAS_LIMIT = 10000;
 
-        (bool callSuccess,) = _to.call.gas(ETH_WITHDRAWAL_GAS_LIMIT).value(_amount)("");
+        (bool callSuccess, ) = _to.call.gas(ETH_WITHDRAWAL_GAS_LIMIT).value(_amount)("");
         return callSuccess;
     }
 

diff --git a/contracts/contracts/ZkSync.sol b/contracts/contracts/ZkSync.sol
@@ -1,6 +1,5 @@
 pragma solidity ^0.5.0;
 
-import "./IERC20.sol";
 import "./ReentrancyGuard.sol";
 import "./SafeMath.sol";
 import "./SafeMathUInt128.sol";
@@ -97,7 +96,7 @@ contract ZkSync is UpgradeableMaster, Storage, Config, Events, ReentrancyGuard {
         require(msg.sender == address(this), "wtg10"); // wtg10 - can be called only from this contract as one "external" call (to revert all this function state changes if it is needed)
 
         uint256 balance_before = _token.balanceOf(address(this));
-        require(Utils.sendERC20(address(_token), _to, _amount), "wtg11"); // wtg11 - ERC20 transfer fails
+        require(Utils.sendERC20(_token, _to, _amount), "wtg11"); // wtg11 - ERC20 transfer fails
         uint256 balance_after = _token.balanceOf(address(this));
         require(balance_before.sub(balance_after) <= _maxAmount, "wtg12"); // wtg12 - rollup balance difference (before and after transfer) is bigger than _maxAmount
 
@@ -135,7 +134,7 @@ contract ZkSync is UpgradeableMaster, Storage, Config, Events, ReentrancyGuard {
                 } else {
                     address tokenAddr = governance.tokenAddresses(tokenId);
                     // we can just check that call not reverts because it wants to withdraw all amount
-                    (sent,) = address(this).call.gas(ERC20_WITHDRAWAL_GAS_LIMIT)(
+                    (sent, ) = address(this).call.gas(ERC20_WITHDRAWAL_GAS_LIMIT)(
                         abi.encodeWithSignature("withdrawERC20Guarded(address,address,uint128,uint128)", tokenAddr, to, amount, amount)
                     );
                 }
@@ -177,7 +176,7 @@ contract ZkSync is UpgradeableMaster, Storage, Config, Events, ReentrancyGuard {
     /// @param _amount Ether amount to withdraw
     function withdrawETH(uint128 _amount) external nonReentrant {
         registerWithdrawal(0, _amount, msg.sender);
-        (bool success,) = msg.sender.call.value(_amount)("");
+        (bool success, ) = msg.sender.call.value(_amount)("");
         require(success, "fwe11"); // ETH withdraw failed
     }