flashloan-rs 0.2.3

Minimal Multicall3 Flashloan Module
Documentation 
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/// @title SafeTransferLib
/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solady (https://github.com/vectorized/solady/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @author clabby <https://github.com/clabby>
/// @dev Caution! This library won't check that a token has code, responsibility is delegated to the caller.

#define macro SAFE_TRANSFER_ETH() = takes (2) {
    // Input stack:        [to, amount]
    0x00 dup1 dup1 dup1 // [0x00, 0x00, 0x00, 0x00, to, amount]
    swap5 swap1 swap4   // [to, amount, 0x00, 0x00, 0x00, 0x00]
    gas call            // [call_success]
    success jumpi       // []

    // Revert with `ETHTransferFailed()` error
    0xb12d13eb 0x00 mstore
    0x04 0x1c revert

    success:
    // Return stack:       []
}

#define macro SAFE_TRANSFER_FROM(mem_ptr) = takes (4) {
    // Input stack:        [from, to, amount, token]
    __RIGHTPAD(0x23b872dd) // [transferFrom_selector, from, to, amount, token]
    <mem_ptr> mstore    // [from, to, amount, token]

    // TODO: If we designate a 128 byte scratch space for this macro,
    //       no need to do these additions at runtime.
    <mem_ptr> 0x04 add  // [mem_ptr + 0x04, from, to, amount, token]
    mstore              // [to, amount, token]
    <mem_ptr> 0x24 add  // [mem_ptr + 0x24, to, amount, token]
    mstore              // [amount, token]
    <mem_ptr> 0x44 add  // [mem_ptr + 0x44, amount, token]
    mstore              // [token]

    <mem_ptr>           // [mem_ptr, token]
    0x64 dup2 0x00      // [0x00, mem_ptr, 0x64, mem_ptr, token]
    0x20 swap5          // [token, 0x00, mem_ptr, 0x64, mem_ptr, 0x20]
    gas call            // [success]

    returndatasize      // [returndatasize, success]
    iszero              // [returndatasize == 0, success]
    <mem_ptr> mload     // [data, returndatasize == 0, success]
    0x01 eq             // [data == 0x01, returndatasize == 0, success]
    or                  // [data == 0x01 | returndatasize == 0, success]

    and                 // [success & (data == 0x01 | returndatasize == 0)]
    success jumpi       // []

    0x7939f424 0x00 mstore
    0x04 0x1c revert

    success:
    // Return stack:       []
}

#define macro SAFE_TRANSFER(mem_ptr) = takes (3) {
    // Input stack:        [to, amount, token]

    __RIGHTPAD(0xa9059cbb) // [transfer_selector, to, amount, token]
    <mem_ptr> mstore    // [to, amount, token]

    // TODO: If we designate a 96 byte scratch space for this macro,
    //       no need to do these additions at runtime.
    <mem_ptr> 0x04 add  // [mem_ptr + 0x04, to, amount, token]
    mstore              // [amount, token]
    <mem_ptr> 0x24 add  // [mem_ptr + 0x24, amount, token]
    mstore

    <mem_ptr>           // [mem_ptr, token]
    0x44 dup2 0x00      // [0x00, mem_ptr, 0x44, mem_ptr, token]
    0x20 swap5          // [token, 0x00, mem_ptr, 0x44, mem_ptr, 0x20]
    gas call            // [success]

    returndatasize      // [returndatasize, success]
    iszero              // [returndatasize == 0, success]
    <mem_ptr> mload     // [data, returndatasize == 0, success]
    0x01 eq             // [data == 0x01, returndatasize == 0, success]
    or                  // [data == 0x01 | returndatasize == 0, success]

    and                 // [success & (data == 0x01 | returndatasize == 0)]
    success jumpi       // []

    0x90b8ec18 0x00 mstore
    0x04 0x1c revert

    success:
    // Return stack:       []
}

#define macro SAFE_APPROVE(mem_ptr) = takes (3) {
    // Input stack:        [to, amount, token]

    __RIGHTPAD(0x095ea7b3) // [transfer_selector, to, amount, token]
    <mem_ptr> mstore    // [to, amount, token]

    // TODO: If we designate a 96 byte scratch space for this macro,
    //       no need to do these additions at runtime.
    <mem_ptr> 0x04 add  // [mem_ptr + 0x04, to, amount, token]
    mstore              // [amount, token]
    <mem_ptr> 0x24 add  // [mem_ptr + 0x24, amount, token]
    mstore

    <mem_ptr>           // [mem_ptr, token]
    0x44 dup2 0x00      // [0x00, mem_ptr, 0x44, mem_ptr, token]
    0x20 swap5          // [token, 0x00, mem_ptr, 0x44, mem_ptr, 0x20]
    gas call            // [success]

    returndatasize      // [returndatasize, success]
    iszero              // [returndatasize == 0, success]
    <mem_ptr> mload     // [data, returndatasize == 0, success]
    0x01 eq             // [data == 0x01, returndatasize == 0, success]
    or                  // [data == 0x01 | returndatasize == 0, success]

    and                 // [success & (data == 0x01 | returndatasize == 0)]
    success jumpi       // []

    0x3e3f8f73 0x00 mstore
    0x04 0x1c revert

    success:
    // Return stack:       []
}