Contract Source Code:

/// SPDX-License-Identifier: GPL-3.0

/// Copyright (C) 2023 Portals.fi

/// @author Portals.fi
/// @notice This contract bundles multiple methods into a single transaction.
/// @dev Do not grant approvals to this contract unless they are completely
/// consumed or are revoked at the end of the transaction.

pragma solidity 0.8.19;

import { IPortalsMulticall } from
    "../multicall/interface/IPortalsMulticall.sol";
import { ReentrancyGuard } from "solmate/utils/ReentrancyGuard.sol";
import { ERC20 } from "solmate/tokens/ERC20.sol";

contract PortalsMulticall is IPortalsMulticall, ReentrancyGuard {
    /// @dev Executes a series of calls in a single transaction
    /// @param calls The calls to execute
    function aggregate(Call[] calldata calls)
        external
        payable
        override
        nonReentrant
    {
        for (uint256 i = 0; i < calls.length;) {
            IPortalsMulticall.Call memory call = calls[i];
            uint256 value;
            if (call.inputToken == address(0)) {
                value = address(this).balance;
                _setAmount(call.data, call.amountIndex, value);
            } else {
                _setAmount(
                    call.data,
                    call.amountIndex,
                    ERC20(call.inputToken).balanceOf(address(this))
                );
            }

            (bool success, bytes memory returnData) =
                call.target.call{ value: value }(call.data);
            if (!success) {
                // Next 5 lines from https://ethereum.stackexchange.com/a/83577
                if (returnData.length < 68) {
                    revert("PortalsMulticall: failed");
                }
                assembly {
                    returnData := add(returnData, 0x04)
                }
                revert(abi.decode(returnData, (string)));
            }
            unchecked {
                ++i;
            }
        }
    }

    /// @notice Transfers ETH from this contract to the specified address
    /// @param to The address to transfer ETH to
    /// @param amount The quantity of ETH to transfer
    function transferEth(address to, uint256 amount)
        external
        payable
    {
        (bool success,) = to.call{ value: amount }("");
        require(success, "PortalsMulticall: failed to transfer ETH");
    }

    /// @dev Sets the quantity of a token a specified index in the data
    /// @param data The data to set the quantity in
    /// @param amountIndex The index of the quantity of inputToken in the data
    function _setAmount(
        bytes memory data,
        uint256 amountIndex,
        uint256 amount
    ) private pure {
        if (amountIndex == type(uint256).max) return;
        assembly {
            mstore(add(data, add(36, mul(amountIndex, 32))), amount)
        }
    }

    receive() external payable { }
}

/// SPDX-License-Identifier: GPL-3.0

/// Copyright (C) 2023 Portals.fi

/// @author Portals.fi
/// @notice Interface for the Portals Multicall contract

pragma solidity 0.8.19;

interface IPortalsMulticall {
    /// @dev Describes a call to be executed in the aggregate function of PortalsMulticall.sol
    /// @param inputToken The token to sell
    /// @param target The target contract to call
    /// @param data The data to call the target contract with
    /// @param amountIndex The index of the quantity of inputToken in the data
    struct Call {
        address inputToken;
        address target;
        bytes data;
        uint256 amountIndex;
    }

    /// @dev Executes a series of calls in a single transaction
    /// @param calls An array of Call to execute
    function aggregate(Call[] calldata calls) external payable;
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Gas optimized reentrancy protection for smart contracts.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/utils/ReentrancyGuard.sol)
/// @author Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/security/ReentrancyGuard.sol)
abstract contract ReentrancyGuard {
    uint256 private locked = 1;

    modifier nonReentrant() virtual {
        require(locked == 1, "REENTRANCY");

        locked = 2;

        _;

        locked = 1;
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/transmissions11/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
    /*//////////////////////////////////////////////////////////////
                                 EVENTS
    //////////////////////////////////////////////////////////////*/

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /*//////////////////////////////////////////////////////////////
                            METADATA STORAGE
    //////////////////////////////////////////////////////////////*/

    string public name;

    string public symbol;

    uint8 public immutable decimals;

    /*//////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;

    mapping(address => mapping(address => uint256)) public allowance;

    /*//////////////////////////////////////////////////////////////
                            EIP-2612 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 internal immutable INITIAL_CHAIN_ID;

    bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;

    mapping(address => uint256) public nonces;

    /*//////////////////////////////////////////////////////////////
                               CONSTRUCTOR
    //////////////////////////////////////////////////////////////*/

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        INITIAL_CHAIN_ID = block.chainid;
        INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
    }

    /*//////////////////////////////////////////////////////////////
                               ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/

    function approve(address spender, uint256 amount) public virtual returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transfer(address to, uint256 amount) public virtual returns (bool) {
        balanceOf[msg.sender] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(msg.sender, to, amount);

        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.

        if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

        return true;
    }

    /*//////////////////////////////////////////////////////////////
                             EIP-2612 LOGIC
    //////////////////////////////////////////////////////////////*/

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");

        // Unchecked because the only math done is incrementing
        // the owner's nonce which cannot realistically overflow.
        unchecked {
            address recoveredAddress = ecrecover(
                keccak256(
                    abi.encodePacked(
                        "\x19\x01",
                        DOMAIN_SEPARATOR(),
                        keccak256(
                            abi.encode(
                                keccak256(
                                    "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
                                ),
                                owner,
                                spender,
                                value,
                                nonces[owner]++,
                                deadline
                            )
                        )
                    )
                ),
                v,
                r,
                s
            );

            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");

            allowance[recoveredAddress][spender] = value;
        }

        emit Approval(owner, spender, value);
    }

    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
        return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
    }

    function computeDomainSeparator() internal view virtual returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                    keccak256(bytes(name)),
                    keccak256("1"),
                    block.chainid,
                    address(this)
                )
            );
    }

    /*//////////////////////////////////////////////////////////////
                        INTERNAL MINT/BURN LOGIC
    //////////////////////////////////////////////////////////////*/

    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(address(0), to, amount);
    }

    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;

        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }

        emit Transfer(from, address(0), amount);
    }
}