Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/ProxyAdmin.sol)
pragma solidity ^0.8.0;
import "./TransparentUpgradeableProxy.sol";
import "../../access/Ownable.sol";
/**
* @dev This is an auxiliary contract meant to be assigned as the admin of a {TransparentUpgradeableProxy}. For an
* explanation of why you would want to use this see the documentation for {TransparentUpgradeableProxy}.
*/
contract ProxyAdmin is Ownable {
/**
* @dev Returns the current implementation of `proxy`.
*
* Requirements:
*
* - This contract must be the admin of `proxy`.
*/
function getProxyImplementation(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
// We need to manually run the static call since the getter cannot be flagged as view
// bytes4(keccak256("implementation()")) == 0x5c60da1b
(bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
require(success);
return abi.decode(returndata, (address));
}
/**
* @dev Returns the current admin of `proxy`.
*
* Requirements:
*
* - This contract must be the admin of `proxy`.
*/
function getProxyAdmin(ITransparentUpgradeableProxy proxy) public view virtual returns (address) {
// We need to manually run the static call since the getter cannot be flagged as view
// bytes4(keccak256("admin()")) == 0xf851a440
(bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
require(success);
return abi.decode(returndata, (address));
}
/**
* @dev Changes the admin of `proxy` to `newAdmin`.
*
* Requirements:
*
* - This contract must be the current admin of `proxy`.
*/
function changeProxyAdmin(ITransparentUpgradeableProxy proxy, address newAdmin) public virtual onlyOwner {
proxy.changeAdmin(newAdmin);
}
/**
* @dev Upgrades `proxy` to `implementation`. See {TransparentUpgradeableProxy-upgradeTo}.
*
* Requirements:
*
* - This contract must be the admin of `proxy`.
*/
function upgrade(ITransparentUpgradeableProxy proxy, address implementation) public virtual onlyOwner {
proxy.upgradeTo(implementation);
}
/**
* @dev Upgrades `proxy` to `implementation` and calls a function on the new implementation. See
* {TransparentUpgradeableProxy-upgradeToAndCall}.
*
* Requirements:
*
* - This contract must be the admin of `proxy`.
*/
function upgradeAndCall(
ITransparentUpgradeableProxy proxy,
address implementation,
bytes memory data
) public payable virtual onlyOwner {
proxy.upgradeToAndCall{value: msg.value}(implementation, data);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.3) (proxy/transparent/TransparentUpgradeableProxy.sol)
pragma solidity ^0.8.0;
import "../ERC1967/ERC1967Proxy.sol";
/**
* @dev Interface for {TransparentUpgradeableProxy}. In order to implement transparency, {TransparentUpgradeableProxy}
* does not implement this interface directly, and some of its functions are implemented by an internal dispatch
* mechanism. The compiler is unaware that these functions are implemented by {TransparentUpgradeableProxy} and will not
* include them in the ABI so this interface must be used to interact with it.
*/
interface ITransparentUpgradeableProxy is IERC1967 {
function admin() external view returns (address);
function implementation() external view returns (address);
function changeAdmin(address) external;
function upgradeTo(address) external;
function upgradeToAndCall(address, bytes memory) external payable;
}
/**
* @dev This contract implements a proxy that is upgradeable by an admin.
*
* To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
* clashing], which can potentially be used in an attack, this contract uses the
* https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
* things that go hand in hand:
*
* 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
* that call matches one of the admin functions exposed by the proxy itself.
* 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
* implementation. If the admin tries to call a function on the implementation it will fail with an error that says
* "admin cannot fallback to proxy target".
*
* These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
* the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
* to sudden errors when trying to call a function from the proxy implementation.
*
* Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
* you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
*
* NOTE: The real interface of this proxy is that defined in `ITransparentUpgradeableProxy`. This contract does not
* inherit from that interface, and instead the admin functions are implicitly implemented using a custom dispatch
* mechanism in `_fallback`. Consequently, the compiler will not produce an ABI for this contract. This is necessary to
* fully implement transparency without decoding reverts caused by selector clashes between the proxy and the
* implementation.
*
* WARNING: It is not recommended to extend this contract to add additional external functions. If you do so, the compiler
* will not check that there are no selector conflicts, due to the note above. A selector clash between any new function
* and the functions declared in {ITransparentUpgradeableProxy} will be resolved in favor of the new one. This could
* render the admin operations inaccessible, which could prevent upgradeability. Transparency may also be compromised.
*/
contract TransparentUpgradeableProxy is ERC1967Proxy {
/**
* @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
* optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
*/
constructor(
address _logic,
address admin_,
bytes memory _data
) payable ERC1967Proxy(_logic, _data) {
_changeAdmin(admin_);
}
/**
* @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
*
* CAUTION: This modifier is deprecated, as it could cause issues if the modified function has arguments, and the
* implementation provides a function with the same selector.
*/
modifier ifAdmin() {
if (msg.sender == _getAdmin()) {
_;
} else {
_fallback();
}
}
/**
* @dev If caller is the admin process the call internally, otherwise transparently fallback to the proxy behavior
*/
function _fallback() internal virtual override {
if (msg.sender == _getAdmin()) {
bytes memory ret;
bytes4 selector = msg.sig;
if (selector == ITransparentUpgradeableProxy.upgradeTo.selector) {
ret = _dispatchUpgradeTo();
} else if (selector == ITransparentUpgradeableProxy.upgradeToAndCall.selector) {
ret = _dispatchUpgradeToAndCall();
} else if (selector == ITransparentUpgradeableProxy.changeAdmin.selector) {
ret = _dispatchChangeAdmin();
} else if (selector == ITransparentUpgradeableProxy.admin.selector) {
ret = _dispatchAdmin();
} else if (selector == ITransparentUpgradeableProxy.implementation.selector) {
ret = _dispatchImplementation();
} else {
revert("TransparentUpgradeableProxy: admin cannot fallback to proxy target");
}
assembly {
return(add(ret, 0x20), mload(ret))
}
} else {
super._fallback();
}
}
/**
* @dev Returns the current admin.
*
* TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
* https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
* `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
*/
function _dispatchAdmin() private returns (bytes memory) {
_requireZeroValue();
address admin = _getAdmin();
return abi.encode(admin);
}
/**
* @dev Returns the current implementation.
*
* TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
* https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
* `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
*/
function _dispatchImplementation() private returns (bytes memory) {
_requireZeroValue();
address implementation = _implementation();
return abi.encode(implementation);
}
/**
* @dev Changes the admin of the proxy.
*
* Emits an {AdminChanged} event.
*/
function _dispatchChangeAdmin() private returns (bytes memory) {
_requireZeroValue();
address newAdmin = abi.decode(msg.data[4:], (address));
_changeAdmin(newAdmin);
return "";
}
/**
* @dev Upgrade the implementation of the proxy.
*/
function _dispatchUpgradeTo() private returns (bytes memory) {
_requireZeroValue();
address newImplementation = abi.decode(msg.data[4:], (address));
_upgradeToAndCall(newImplementation, bytes(""), false);
return "";
}
/**
* @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
* by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
* proxied contract.
*/
function _dispatchUpgradeToAndCall() private returns (bytes memory) {
(address newImplementation, bytes memory data) = abi.decode(msg.data[4:], (address, bytes));
_upgradeToAndCall(newImplementation, data, true);
return "";
}
/**
* @dev Returns the current admin.
*/
function _admin() internal view virtual returns (address) {
return _getAdmin();
}
/**
* @dev To keep this contract fully transparent, all `ifAdmin` functions must be payable. This helper is here to
* emulate some proxy functions being non-payable while still allowing value to pass through.
*/
function _requireZeroValue() private {
require(msg.value == 0);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
pragma solidity ^0.8.0;
import "../Proxy.sol";
import "./ERC1967Upgrade.sol";
/**
* @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
* implementation address that can be changed. This address is stored in storage in the location specified by
* https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
* implementation behind the proxy.
*/
contract ERC1967Proxy is Proxy, ERC1967Upgrade {
/**
* @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
*
* If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
* function call, and allows initializing the storage of the proxy like a Solidity constructor.
*/
constructor(address _logic, bytes memory _data) payable {
_upgradeToAndCall(_logic, _data, false);
}
/**
* @dev Returns the current implementation address.
*/
function _implementation() internal view virtual override returns (address impl) {
return ERC1967Upgrade._getImplementation();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
pragma solidity ^0.8.0;
/**
* @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
* instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
* be specified by overriding the virtual {_implementation} function.
*
* Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
* different contract through the {_delegate} function.
*
* The success and return data of the delegated call will be returned back to the caller of the proxy.
*/
abstract contract Proxy {
/**
* @dev Delegates the current call to `implementation`.
*
* This function does not return to its internal call site, it will return directly to the external caller.
*/
function _delegate(address implementation) internal virtual {
assembly {
// Copy msg.data. We take full control of memory in this inline assembly
// block because it will not return to Solidity code. We overwrite the
// Solidity scratch pad at memory position 0.
calldatacopy(0, 0, calldatasize())
// Call the implementation.
// out and outsize are 0 because we don't know the size yet.
let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
// Copy the returned data.
returndatacopy(0, 0, returndatasize())
switch result
// delegatecall returns 0 on error.
case 0 {
revert(0, returndatasize())
}
default {
return(0, returndatasize())
}
}
}
/**
* @dev This is a virtual function that should be overridden so it returns the address to which the fallback function
* and {_fallback} should delegate.
*/
function _implementation() internal view virtual returns (address);
/**
* @dev Delegates the current call to the address returned by `_implementation()`.
*
* This function does not return to its internal call site, it will return directly to the external caller.
*/
function _fallback() internal virtual {
_beforeFallback();
_delegate(_implementation());
}
/**
* @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
* function in the contract matches the call data.
*/
fallback() external payable virtual {
_fallback();
}
/**
* @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
* is empty.
*/
receive() external payable virtual {
_fallback();
}
/**
* @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
* call, or as part of the Solidity `fallback` or `receive` functions.
*
* If overridden should call `super._beforeFallback()`.
*/
function _beforeFallback() internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.3) (proxy/ERC1967/ERC1967Upgrade.sol)
pragma solidity ^0.8.2;
import "../beacon/IBeacon.sol";
import "../../interfaces/IERC1967.sol";
import "../../interfaces/draft-IERC1822.sol";
import "../../utils/Address.sol";
import "../../utils/StorageSlot.sol";
/**
* @dev This abstract contract provides getters and event emitting update functions for
* https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
*
* _Available since v4.1._
*
* @custom:oz-upgrades-unsafe-allow delegatecall
*/
abstract contract ERC1967Upgrade is IERC1967 {
// This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
/**
* @dev Storage slot with the address of the current implementation.
* This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
/**
* @dev Returns the current implementation address.
*/
function _getImplementation() internal view returns (address) {
return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
}
/**
* @dev Stores a new address in the EIP1967 implementation slot.
*/
function _setImplementation(address newImplementation) private {
require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
}
/**
* @dev Perform implementation upgrade
*
* Emits an {Upgraded} event.
*/
function _upgradeTo(address newImplementation) internal {
_setImplementation(newImplementation);
emit Upgraded(newImplementation);
}
/**
* @dev Perform implementation upgrade with additional setup call.
*
* Emits an {Upgraded} event.
*/
function _upgradeToAndCall(
address newImplementation,
bytes memory data,
bool forceCall
) internal {
_upgradeTo(newImplementation);
if (data.length > 0 || forceCall) {
Address.functionDelegateCall(newImplementation, data);
}
}
/**
* @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
*
* Emits an {Upgraded} event.
*/
function _upgradeToAndCallUUPS(
address newImplementation,
bytes memory data,
bool forceCall
) internal {
// Upgrades from old implementations will perform a rollback test. This test requires the new
// implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
// this special case will break upgrade paths from old UUPS implementation to new ones.
if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
_setImplementation(newImplementation);
} else {
try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
} catch {
revert("ERC1967Upgrade: new implementation is not UUPS");
}
_upgradeToAndCall(newImplementation, data, forceCall);
}
}
/**
* @dev Storage slot with the admin of the contract.
* This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
/**
* @dev Returns the current admin.
*/
function _getAdmin() internal view returns (address) {
return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
}
/**
* @dev Stores a new address in the EIP1967 admin slot.
*/
function _setAdmin(address newAdmin) private {
require(newAdmin != address(0), "ERC1967: new admin is the zero address");
StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
}
/**
* @dev Changes the admin of the proxy.
*
* Emits an {AdminChanged} event.
*/
function _changeAdmin(address newAdmin) internal {
emit AdminChanged(_getAdmin(), newAdmin);
_setAdmin(newAdmin);
}
/**
* @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
* This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
*/
bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
/**
* @dev Returns the current beacon.
*/
function _getBeacon() internal view returns (address) {
return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
}
/**
* @dev Stores a new beacon in the EIP1967 beacon slot.
*/
function _setBeacon(address newBeacon) private {
require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
require(
Address.isContract(IBeacon(newBeacon).implementation()),
"ERC1967: beacon implementation is not a contract"
);
StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
}
/**
* @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
* not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
*
* Emits a {BeaconUpgraded} event.
*/
function _upgradeBeaconToAndCall(
address newBeacon,
bytes memory data,
bool forceCall
) internal {
_setBeacon(newBeacon);
emit BeaconUpgraded(newBeacon);
if (data.length > 0 || forceCall) {
Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
pragma solidity ^0.8.0;
/**
* @dev This is the interface that {BeaconProxy} expects of its beacon.
*/
interface IBeacon {
/**
* @dev Must return an address that can be used as a delegate call target.
*
* {BeaconProxy} will check that this address is a contract.
*/
function implementation() external view returns (address);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.3) (interfaces/IERC1967.sol)
pragma solidity ^0.8.0;
/**
* @dev ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC.
*
* _Available since v4.9._
*/
interface IERC1967 {
/**
* @dev Emitted when the implementation is upgraded.
*/
event Upgraded(address indexed implementation);
/**
* @dev Emitted when the admin account has changed.
*/
event AdminChanged(address previousAdmin, address newAdmin);
/**
* @dev Emitted when the beacon is changed.
*/
event BeaconUpgraded(address indexed beacon);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
pragma solidity ^0.8.0;
/**
* @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
* proxy whose upgrades are fully controlled by the current implementation.
*/
interface IERC1822Proxiable {
/**
* @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
* address.
*
* IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
* bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
* function revert if invoked through a proxy.
*/
function proxiableUUID() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (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 functionCallWithValue(target, data, 0, "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");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or 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 {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) 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
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)
pragma solidity ^0.8.0;
/**
* @dev Library for reading and writing primitive types to specific storage slots.
*
* Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
* This library helps with reading and writing to such slots without the need for inline assembly.
*
* The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
*
* Example usage to set ERC1967 implementation slot:
* ```
* contract ERC1967 {
* bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
*
* function _getImplementation() internal view returns (address) {
* return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
* }
*
* function _setImplementation(address newImplementation) internal {
* require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
* StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
* }
* }
* ```
*
* _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
*/
library StorageSlot {
struct AddressSlot {
address value;
}
struct BooleanSlot {
bool value;
}
struct Bytes32Slot {
bytes32 value;
}
struct Uint256Slot {
uint256 value;
}
/**
* @dev Returns an `AddressSlot` with member `value` located at `slot`.
*/
function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `BooleanSlot` with member `value` located at `slot`.
*/
function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
*/
function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
/**
* @dev Returns an `Uint256Slot` with member `value` located at `slot`.
*/
function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
/// @solidity memory-safe-assembly
assembly {
r.slot := slot
}
}
}