p2pix-smart-contracts/contracts/lib/utils/SafeTransferLib.sol

118 lines
4.3 KiB
Solidity

// SPDX-License-Identifier: MIT
pragma solidity >=0.8.4;
import { ERC20 } from "../tokens/ERC20.sol";
/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @dev Caution! This library won't check that a token has code, responsibility is delegated to the caller.
library SafeTransferLib {
/*//////////////////////////////////////////////////////////////
ETH OPERATIONS
//////////////////////////////////////////////////////////////*/
function safeTransferETH(
address to,
uint256 amount
) internal {
bool success;
assembly {
// Transfer the ETH and store if it succeeded or not.
success := call(gas(), to, amount, 0, 0, 0, 0)
}
require(success, "ETH_TRANSFER_FAILED");
}
/*//////////////////////////////////////////////////////////////
ERC20 OPERATIONS
//////////////////////////////////////////////////////////////*/
function safeTransferFrom(
ERC20 token,
address from,
address to,
uint256 amount
) internal {
bool success;
assembly {
// We'll write our calldata to this slot below, but restore it later.
let memPointer := mload(0x40)
// Write the abi-encoded calldata into memory, beginning with the function selector.
mstore(
0,
0x23b872dd00000000000000000000000000000000000000000000000000000000
)
mstore(4, from) // Append the "from" argument.
mstore(36, to) // Append the "to" argument.
mstore(68, amount) // Append the "amount" argument.
success := and(
// Set success to whether the call reverted, if not we check it either
// returned exactly 1 (can't just be non-zero data), or had no return data.
or(
and(
eq(mload(0), 1),
gt(returndatasize(), 31)
),
iszero(returndatasize())
),
// We use 100 because that's the total length of our calldata (4 + 32 * 3)
// Counterintuitively, this call() must be positioned after the or() in the
// surrounding and() because and() evaluates its arguments from right to left.
call(gas(), token, 0, 0, 100, 0, 32)
)
mstore(0x60, 0) // Restore the zero slot to zero.
mstore(0x40, memPointer) // Restore the memPointer.
}
require(success, "TRANSFER_FROM_FAILED");
}
function safeTransfer(
ERC20 token,
address to,
uint256 amount
) internal {
bool success;
assembly {
// We'll write our calldata to this slot below, but restore it later.
let memPointer := mload(0x40)
// Write the abi-encoded calldata into memory, beginning with the function selector.
mstore(
0,
0xa9059cbb00000000000000000000000000000000000000000000000000000000
)
mstore(4, to) // Append the "to" argument.
mstore(36, amount) // Append the "amount" argument.
success := and(
// Set success to whether the call reverted, if not we check it either
// returned exactly 1 (can't just be non-zero data), or had no return data.
or(
and(
eq(mload(0), 1),
gt(returndatasize(), 31)
),
iszero(returndatasize())
),
// We use 68 because that's the total length of our calldata (4 + 32 * 2)
// Counterintuitively, this call() must be positioned after the or() in the
// surrounding and() because and() evaluates its arguments from right to left.
call(gas(), token, 0, 0, 68, 0, 32)
)
mstore(0x60, 0) // Restore the zero slot to zero.
mstore(0x40, memPointer) // Restore the memPointer.
}
require(success, "TRANSFER_FAILED");
}
}