32 lines
1.1 KiB
Solidity
32 lines
1.1 KiB
Solidity
pragma solidity 0.4.24;
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import "./IsContract.sol";
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import "./ERCProxy.sol";
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contract DelegateProxy is ERCProxy, IsContract {
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uint256 internal constant FWD_GAS_LIMIT = 10000;
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/**
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* @dev Performs a delegatecall and returns whatever the delegatecall returned (entire context execution will return!)
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* @param _dst Destination address to perform the delegatecall
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* @param _calldata Calldata for the delegatecall
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*/
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function delegatedFwd(address _dst, bytes _calldata) internal {
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require(isContract(_dst));
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uint256 fwdGasLimit = FWD_GAS_LIMIT;
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assembly {
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let result := delegatecall(sub(gas, fwdGasLimit), _dst, add(_calldata, 0x20), mload(_calldata), 0, 0)
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let size := returndatasize
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let ptr := mload(0x40)
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returndatacopy(ptr, 0, size)
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// revert instead of invalid() bc if the underlying call failed with invalid() it already wasted gas.
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// if the call returned error data, forward it
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switch result case 0 { revert(ptr, size) }
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default { return(ptr, size) }
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}
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}
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}
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