// This contract is part of Zellic’s smart contract dataset, which is a collection of publicly available contract code gathered as of March 2023. | |
// SPDX-License-Identifier: MIT | |
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol) | |
pragma solidity ^0.8.1; | |
/** | |
* @dev Collection of functions related to the address type | |
*/ | |
library Address { | |
/** | |
* @dev Returns true if `account` is a contract. | |
* | |
* [IMPORTANT] | |
* ==== | |
* It is unsafe to assume that an address for which this function returns | |
* false is an externally-owned account (EOA) and not a contract. | |
* | |
* Among others, `isContract` will return false for the following | |
* types of addresses: | |
* | |
* - an externally-owned account | |
* - a contract in construction | |
* - an address where a contract will be created | |
* - an address where a contract lived, but was destroyed | |
* ==== | |
* | |
* [IMPORTANT] | |
* ==== | |
* You shouldn't rely on `isContract` to protect against flash loan attacks! | |
* | |
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets | |
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract | |
* constructor. | |
* ==== | |
*/ | |
function isContract(address account) internal view returns (bool) { | |
// This method relies on extcodesize/address.code.length, which returns 0 | |
// for contracts in construction, since the code is only stored at the end | |
// of the constructor execution. | |
return account.code.length > 0; | |
} | |
/** | |
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to | |
* `recipient`, forwarding all available gas and reverting on errors. | |
* | |
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost | |
* of certain opcodes, possibly making contracts go over the 2300 gas limit | |
* imposed by `transfer`, making them unable to receive funds via | |
* `transfer`. {sendValue} removes this limitation. | |
* | |
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more]. | |
* | |
* IMPORTANT: because control is transferred to `recipient`, care must be | |
* taken to not create reentrancy vulnerabilities. Consider using | |
* {ReentrancyGuard} or the | |
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern]. | |
*/ | |
function sendValue(address payable recipient, uint256 amount) internal { | |
require(address(this).balance >= amount, "Address: insufficient balance"); | |
(bool success, ) = recipient.call{value: amount}(""); | |
require(success, "Address: unable to send value, recipient may have reverted"); | |
} | |
/** | |
* @dev Performs a Solidity function call using a low level `call`. A | |
* plain `call` is an unsafe replacement for a function call: use this | |
* function instead. | |
* | |
* If `target` reverts with a revert reason, it is bubbled up by this | |
* function (like regular Solidity function calls). | |
* | |
* Returns the raw returned data. To convert to the expected return value, | |
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`]. | |
* | |
* Requirements: | |
* | |
* - `target` must be a contract. | |
* - calling `target` with `data` must not revert. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCall(address target, bytes memory data) internal returns (bytes memory) { | |
return functionCall(target, data, "Address: low-level call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with | |
* `errorMessage` as a fallback revert reason when `target` reverts. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
return functionCallWithValue(target, data, 0, errorMessage); | |
} | |
/** | |
* @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`. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCallWithValue( | |
address target, | |
bytes memory data, | |
uint256 value | |
) internal returns (bytes memory) { | |
return functionCallWithValue(target, data, value, "Address: low-level call with value failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but | |
* with `errorMessage` as a fallback revert reason when `target` reverts. | |
* | |
* _Available since v3.1._ | |
*/ | |
function functionCallWithValue( | |
address target, | |
bytes memory data, | |
uint256 value, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
require(address(this).balance >= value, "Address: insufficient balance for call"); | |
require(isContract(target), "Address: call to non-contract"); | |
(bool success, bytes memory returndata) = target.call{value: value}(data); | |
return verifyCallResult(success, returndata, errorMessage); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], | |
* but performing a static call. | |
* | |
* _Available since v3.3._ | |
*/ | |
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) { | |
return functionStaticCall(target, data, "Address: low-level static call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], | |
* but performing a static call. | |
* | |
* _Available since v3.3._ | |
*/ | |
function functionStaticCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal view returns (bytes memory) { | |
require(isContract(target), "Address: static call to non-contract"); | |
(bool success, bytes memory returndata) = target.staticcall(data); | |
return verifyCallResult(success, returndata, errorMessage); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], | |
* but performing a delegate call. | |
* | |
* _Available since v3.4._ | |
*/ | |
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) { | |
return functionDelegateCall(target, data, "Address: low-level delegate call failed"); | |
} | |
/** | |
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`], | |
* but performing a delegate call. | |
* | |
* _Available since v3.4._ | |
*/ | |
function functionDelegateCall( | |
address target, | |
bytes memory data, | |
string memory errorMessage | |
) internal returns (bytes memory) { | |
require(isContract(target), "Address: delegate call to non-contract"); | |
(bool success, bytes memory returndata) = target.delegatecall(data); | |
return verifyCallResult(success, returndata, errorMessage); | |
} | |
/** | |
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the | |
* revert reason using the provided one. | |
* | |
* _Available since v4.3._ | |
*/ | |
function verifyCallResult( | |
bool success, | |
bytes memory returndata, | |
string memory errorMessage | |
) internal pure returns (bytes memory) { | |
if (success) { | |
return returndata; | |
} else { | |
// 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 | |
/// @solidity memory-safe-assembly | |
assembly { | |
let returndata_size := mload(returndata) | |
revert(add(32, returndata), returndata_size) | |
} | |
} else { | |
revert(errorMessage); | |
} | |
} | |
} | |
} | |