Contract Name:
ERC1967Proxy
Contract Source Code:
File 1 of 1 : ERC1967Proxy
// SPDX-License-Identifier: MIT
pragma solidity 0.8.16;
// OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
/**
* @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 {}
}
/// @title IERC1967Upgrade
/// @author Rohan Kulkarni
/// @notice The external ERC1967Upgrade events and errors
interface IERC1967Upgrade {
/// ///
/// EVENTS ///
/// ///
/// @notice Emitted when the implementation is upgraded
/// @param impl The address of the implementation
event Upgraded(address impl);
/// ///
/// ERRORS ///
/// ///
/// @dev Reverts if an implementation is an invalid upgrade
/// @param impl The address of the invalid implementation
error INVALID_UPGRADE(address impl);
/// @dev Reverts if an implementation upgrade is not stored at the storage slot of the original
error UNSUPPORTED_UUID();
/// @dev Reverts if an implementation does not support ERC1822 proxiableUUID()
error ONLY_UUPS();
}
// OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
/**
* @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);
}
// OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)
/**
* @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
}
}
}
/// @title EIP712
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (utils/Address.sol)
/// - Uses custom errors `INVALID_TARGET()` & `DELEGATE_CALL_FAILED()`
/// - Adds util converting address to bytes32
library Address {
/// ///
/// ERRORS ///
/// ///
/// @dev Reverts if the target of a delegatecall is not a contract
error INVALID_TARGET();
/// @dev Reverts if a delegatecall has failed
error DELEGATE_CALL_FAILED();
/// ///
/// FUNCTIONS ///
/// ///
/// @dev Utility to convert an address to bytes32
function toBytes32(address _account) internal pure returns (bytes32) {
return bytes32(uint256(uint160(_account)) << 96);
}
/// @dev If an address is a contract
function isContract(address _account) internal view returns (bool rv) {
assembly {
rv := gt(extcodesize(_account), 0)
}
}
/// @dev Performs a delegatecall on an address
function functionDelegateCall(address _target, bytes memory _data) internal returns (bytes memory) {
if (!isContract(_target)) revert INVALID_TARGET();
(bool success, bytes memory returndata) = _target.delegatecall(_data);
return verifyCallResult(success, returndata);
}
/// @dev Verifies a delegatecall was successful
function verifyCallResult(bool _success, bytes memory _returndata) internal pure returns (bytes memory) {
if (_success) {
return _returndata;
} else {
if (_returndata.length > 0) {
assembly {
let returndata_size := mload(_returndata)
revert(add(32, _returndata), returndata_size)
}
} else {
revert DELEGATE_CALL_FAILED();
}
}
}
}
/// @title ERC1967Upgrade
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (proxy/ERC1967/ERC1967Upgrade.sol)
/// - Uses custom errors declared in IERC1967Upgrade
/// - Removes ERC1967 admin and beacon support
abstract contract ERC1967Upgrade is IERC1967Upgrade {
/// ///
/// CONSTANTS ///
/// ///
/// @dev bytes32(uint256(keccak256('eip1967.proxy.rollback')) - 1)
bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
/// @dev bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1)
bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
/// ///
/// FUNCTIONS ///
/// ///
/// @dev Upgrades to an implementation with security checks for UUPS proxies and an additional function call
/// @param _newImpl The new implementation address
/// @param _data The encoded function call
function _upgradeToAndCallUUPS(
address _newImpl,
bytes memory _data,
bool _forceCall
) internal {
if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
_setImplementation(_newImpl);
} else {
try IERC1822Proxiable(_newImpl).proxiableUUID() returns (bytes32 slot) {
if (slot != _IMPLEMENTATION_SLOT) revert UNSUPPORTED_UUID();
} catch {
revert ONLY_UUPS();
}
_upgradeToAndCall(_newImpl, _data, _forceCall);
}
}
/// @dev Upgrades to an implementation with an additional function call
/// @param _newImpl The new implementation address
/// @param _data The encoded function call
function _upgradeToAndCall(
address _newImpl,
bytes memory _data,
bool _forceCall
) internal {
_upgradeTo(_newImpl);
if (_data.length > 0 || _forceCall) {
Address.functionDelegateCall(_newImpl, _data);
}
}
/// @dev Performs an implementation upgrade
/// @param _newImpl The new implementation address
function _upgradeTo(address _newImpl) internal {
_setImplementation(_newImpl);
emit Upgraded(_newImpl);
}
/// @dev Stores the address of an implementation
/// @param _impl The implementation address
function _setImplementation(address _impl) private {
if (!Address.isContract(_impl)) revert INVALID_UPGRADE(_impl);
StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = _impl;
}
/// @dev The address of the current implementation
function _getImplementation() internal view returns (address) {
return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
}
}
/// @title ERC1967Proxy
/// @author Rohan Kulkarni
/// @notice Modified from OpenZeppelin Contracts v4.7.3 (proxy/ERC1967/ERC1967Proxy.sol)
/// - Inherits a modern, minimal ERC1967Upgrade
contract ERC1967Proxy is IERC1967Upgrade, Proxy, ERC1967Upgrade {
/// ///
/// CONSTRUCTOR ///
/// ///
/// @dev Initializes the proxy with an implementation contract and encoded function call
/// @param _logic The implementation address
/// @param _data The encoded function call
constructor(address _logic, bytes memory _data) payable {
_upgradeToAndCall(_logic, _data, false);
}
/// ///
/// FUNCTIONS ///
/// ///
/// @dev The address of the current implementation
function _implementation() internal view virtual override returns (address) {
return ERC1967Upgrade._getImplementation();
}
}
