diff options
Diffstat (limited to 'packages/contracts/src/2.0.0/forwarder/MixinERC20.sol')
-rw-r--r-- | packages/contracts/src/2.0.0/forwarder/MixinERC20.sol | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol b/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol new file mode 100644 index 000000000..53d4116d7 --- /dev/null +++ b/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol @@ -0,0 +1,68 @@ +/* + + Copyright 2018 ZeroEx Intl. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + +*/ + +pragma solidity ^0.4.24; +pragma experimental ABIEncoderV2; + +contract MixinERC20 { + + string constant ERROR_TRANSFER_FAILED = "TRANSFER_FAILED"; + bytes4 constant ERC20_TRANSFER_SELECTOR = bytes4(keccak256("transfer(address,uint256)")); + + function transferToken( + address token, + address to, + uint256 amount + ) + internal + { + // Transfer tokens. + // We do a raw call so we can check the success separate + // from the return data. + bool success = token.call(abi.encodeWithSelector( + ERC20_TRANSFER_SELECTOR, + to, + amount + )); + require( + success, + "TRANSFER_FAILED" + ); + + // Check return data. + // If there is no return data, we assume the token incorrectly + // does not return a bool. In this case we expect it to revert + // on failure, which was handled above. + // If the token does return data, we require that it is a single + // value that evaluates to true. + assembly { + if returndatasize { + success := 0 + if eq(returndatasize, 32) { + // First 64 bytes of memory are reserved scratch space + returndatacopy(0, 0, 32) + success := mload(0) + } + } + } + require( + success, + "TRANSFER_FAILED" + ); + } +} |