openzeppelin-contracts/contracts/utils/Address.sol

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.2.0) (utils/Address.sol)

pragma solidity ^0.8.20;

import {Errors} from "./Errors.sol";

/**
 * @dev 与地址类型相关的函数集合
 */
library Address {
    /**
     * @dev 在 `target` 处没有代码（它不是一个合约）。
     */
    error AddressEmptyCode(address target);

    /**
     * @dev Solidity 的 `transfer` 的替代品：向 `recipient` 发送 `amount` wei，
     * 转发所有可用的 gas 并在出错时回退。
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] 增加了某些操作码的 gas 成本，
     * 可能使合约超过 `transfer` 施加的 2300 gas 限制，使它们无法通过 `transfer` 接收资金。
     * {sendValue} 移除了这个限制。
     *
     * https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[了解更多]。
     *
     * 重要：因为控制权转移到 `recipient`，必须注意不要创建重入漏洞。
     * 考虑使用 {ReentrancyGuard} 或
     * https://solidity.readthedocs.io/en/v0.8.20/security-considerations.html#use-the-checks-effects-interactions-pattern[检查-效果-交互模式]。
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        if (address(this).balance < amount) {
            revert Errors.InsufficientBalance(address(this).balance, amount);
        }

        (bool success, bytes memory returndata) = recipient.call{value: amount}("");
        if (!success) {
            _revert(returndata);
        }
    }

    /**
     * @dev 使用低级 `call` 执行 Solidity 函数调用。普通的 `call` 是函数调用的不安全替代品：
     * 请使用此函数替代。
     *
     * 如果 `target` 使用回退原因或自定义错误回退，则此函数会将其冒泡（如常规 Solidity 函数调用）。
     * 但是，如果调用没有返回原因就回退，则此函数会使用 {Errors.FailedCall} 错误回退。
     *
     * 返回原始返回数据。要转换为期望的返回值，请使用
     * https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]。
     *
     * 要求：
     *
     * - `target` 必须是一个合约。
     * - 使用 `data` 调用 `target` 不能回退。
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     */
    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        if (address(this).balance < value) {
            revert Errors.InsufficientBalance(address(this).balance, value);
        }
        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResultFromTarget(target, success, returndata);
    }

    /**
     * @dev Tool to verify that a low level call to smart-contract was successful, and reverts if the target
     * was not a contract or bubbling up the revert reason (falling back to {Errors.FailedCall}) in case
     * of an unsuccessful call.
     */
    function verifyCallResultFromTarget(
        address target,
        bool success,
        bytes memory returndata
    ) internal view returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            // only check if target is a contract if the call was successful and the return data is empty
            // otherwise we already know that it was a contract
            if (returndata.length == 0 && target.code.length == 0) {
                revert AddressEmptyCode(target);
            }
            return returndata;
        }
    }

    /**
     * @dev Tool to verify that a low level call was successful, and reverts if it wasn't, either by bubbling the
     * revert reason or with a default {Errors.FailedCall} error.
     */
    function verifyCallResult(bool success, bytes memory returndata) internal pure returns (bytes memory) {
        if (!success) {
            _revert(returndata);
        } else {
            return returndata;
        }
    }

    /**
     * @dev Reverts with returndata if present. Otherwise reverts with {Errors.FailedCall}.
     */
    function _revert(bytes memory returndata) private pure {
        // Look for revert reason and bubble it up if present
        if (returndata.length > 0) {
            // The easiest way to bubble the revert reason is using memory via assembly
            assembly ("memory-safe") {
                revert(add(returndata, 0x20), mload(returndata))
            }
        } else {
            revert Errors.FailedCall();
        }
    }
}