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GovernorUpgradeable.sol
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GovernorUpgradeable.sol
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// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.1) (governance/Governor.sol)
pragma solidity ^0.8.0;
import "../token/ERC721/IERC721ReceiverUpgradeable.sol";
import "../token/ERC1155/IERC1155ReceiverUpgradeable.sol";
import "../utils/cryptography/ECDSAUpgradeable.sol";
import "../utils/cryptography/EIP712Upgradeable.sol";
import "../utils/introspection/ERC165Upgradeable.sol";
import "../utils/math/SafeCastUpgradeable.sol";
import "../utils/structs/DoubleEndedQueueUpgradeable.sol";
import "../utils/AddressUpgradeable.sol";
import "../utils/ContextUpgradeable.sol";
import "./IGovernorUpgradeable.sol";
import "../proxy/utils/Initializable.sol";
/**
* @dev Core of the governance system, designed to be extended though various modules.
*
* This contract is abstract and requires several functions to be implemented in various modules:
*
* - A counting module must implement {quorum}, {_quorumReached}, {_voteSucceeded} and {_countVote}
* - A voting module must implement {_getVotes}
* - Additionally, {votingPeriod} must also be implemented
*
* _Available since v4.3._
*/
abstract contract GovernorUpgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, EIP712Upgradeable, IGovernorUpgradeable, IERC721ReceiverUpgradeable, IERC1155ReceiverUpgradeable {
using DoubleEndedQueueUpgradeable for DoubleEndedQueueUpgradeable.Bytes32Deque;
bytes32 public constant BALLOT_TYPEHASH = keccak256("Ballot(uint256 proposalId,uint8 support)");
bytes32 public constant EXTENDED_BALLOT_TYPEHASH =
keccak256("ExtendedBallot(uint256 proposalId,uint8 support,string reason,bytes params)");
// solhint-disable var-name-mixedcase
struct ProposalCore {
// --- start retyped from Timers.BlockNumber at offset 0x00 ---
uint64 voteStart;
address proposer;
bytes4 __gap_unused0;
// --- start retyped from Timers.BlockNumber at offset 0x20 ---
uint64 voteEnd;
bytes24 __gap_unused1;
// --- Remaining fields starting at offset 0x40 ---------------
bool executed;
bool canceled;
}
// solhint-enable var-name-mixedcase
string private _name;
/// @custom:oz-retyped-from mapping(uint256 => Governor.ProposalCore)
mapping(uint256 => ProposalCore) private _proposals;
// This queue keeps track of the governor operating on itself. Calls to functions protected by the
// {onlyGovernance} modifier needs to be whitelisted in this queue. Whitelisting is set in {_beforeExecute},
// consumed by the {onlyGovernance} modifier and eventually reset in {_afterExecute}. This ensures that the
// execution of {onlyGovernance} protected calls can only be achieved through successful proposals.
DoubleEndedQueueUpgradeable.Bytes32Deque private _governanceCall;
/**
* @dev Restricts a function so it can only be executed through governance proposals. For example, governance
* parameter setters in {GovernorSettings} are protected using this modifier.
*
* The governance executing address may be different from the Governor's own address, for example it could be a
* timelock. This can be customized by modules by overriding {_executor}. The executor is only able to invoke these
* functions during the execution of the governor's {execute} function, and not under any other circumstances. Thus,
* for example, additional timelock proposers are not able to change governance parameters without going through the
* governance protocol (since v4.6).
*/
modifier onlyGovernance() {
require(_msgSender() == _executor(), "Governor: onlyGovernance");
if (_executor() != address(this)) {
bytes32 msgDataHash = keccak256(_msgData());
// loop until popping the expected operation - throw if deque is empty (operation not authorized)
while (_governanceCall.popFront() != msgDataHash) {}
}
_;
}
/**
* @dev Sets the value for {name} and {version}
*/
function __Governor_init(string memory name_) internal onlyInitializing {
__EIP712_init_unchained(name_, version());
__Governor_init_unchained(name_);
}
function __Governor_init_unchained(string memory name_) internal onlyInitializing {
_name = name_;
}
/**
* @dev Function to receive ETH that will be handled by the governor (disabled if executor is a third party contract)
*/
receive() external payable virtual {
require(_executor() == address(this), "Governor: must send to executor");
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165Upgradeable, ERC165Upgradeable) returns (bool) {
bytes4 governorCancelId = this.cancel.selector ^ this.proposalProposer.selector;
bytes4 governorParamsId = this.castVoteWithReasonAndParams.selector ^
this.castVoteWithReasonAndParamsBySig.selector ^
this.getVotesWithParams.selector;
// The original interface id in v4.3.
bytes4 governor43Id = type(IGovernorUpgradeable).interfaceId ^
type(IERC6372Upgradeable).interfaceId ^
governorCancelId ^
governorParamsId;
// An updated interface id in v4.6, with params added.
bytes4 governor46Id = type(IGovernorUpgradeable).interfaceId ^ type(IERC6372Upgradeable).interfaceId ^ governorCancelId;
// For the updated interface id in v4.9, we use governorCancelId directly.
return
interfaceId == governor43Id ||
interfaceId == governor46Id ||
interfaceId == governorCancelId ||
interfaceId == type(IERC1155ReceiverUpgradeable).interfaceId ||
super.supportsInterface(interfaceId);
}
/**
* @dev See {IGovernor-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IGovernor-version}.
*/
function version() public view virtual override returns (string memory) {
return "1";
}
/**
* @dev See {IGovernor-hashProposal}.
*
* The proposal id is produced by hashing the ABI encoded `targets` array, the `values` array, the `calldatas` array
* and the descriptionHash (bytes32 which itself is the keccak256 hash of the description string). This proposal id
* can be produced from the proposal data which is part of the {ProposalCreated} event. It can even be computed in
* advance, before the proposal is submitted.
*
* Note that the chainId and the governor address are not part of the proposal id computation. Consequently, the
* same proposal (with same operation and same description) will have the same id if submitted on multiple governors
* across multiple networks. This also means that in order to execute the same operation twice (on the same
* governor) the proposer will have to change the description in order to avoid proposal id conflicts.
*/
function hashProposal(
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
bytes32 descriptionHash
) public pure virtual override returns (uint256) {
return uint256(keccak256(abi.encode(targets, values, calldatas, descriptionHash)));
}
/**
* @dev See {IGovernor-state}.
*/
function state(uint256 proposalId) public view virtual override returns (ProposalState) {
ProposalCore storage proposal = _proposals[proposalId];
if (proposal.executed) {
return ProposalState.Executed;
}
if (proposal.canceled) {
return ProposalState.Canceled;
}
uint256 snapshot = proposalSnapshot(proposalId);
if (snapshot == 0) {
revert("Governor: unknown proposal id");
}
uint256 currentTimepoint = clock();
if (snapshot >= currentTimepoint) {
return ProposalState.Pending;
}
uint256 deadline = proposalDeadline(proposalId);
if (deadline >= currentTimepoint) {
return ProposalState.Active;
}
if (_quorumReached(proposalId) && _voteSucceeded(proposalId)) {
return ProposalState.Succeeded;
} else {
return ProposalState.Defeated;
}
}
/**
* @dev Part of the Governor Bravo's interface: _"The number of votes required in order for a voter to become a proposer"_.
*/
function proposalThreshold() public view virtual returns (uint256) {
return 0;
}
/**
* @dev See {IGovernor-proposalSnapshot}.
*/
function proposalSnapshot(uint256 proposalId) public view virtual override returns (uint256) {
return _proposals[proposalId].voteStart;
}
/**
* @dev See {IGovernor-proposalDeadline}.
*/
function proposalDeadline(uint256 proposalId) public view virtual override returns (uint256) {
return _proposals[proposalId].voteEnd;
}
/**
* @dev Returns the account that created a given proposal.
*/
function proposalProposer(uint256 proposalId) public view virtual override returns (address) {
return _proposals[proposalId].proposer;
}
/**
* @dev Amount of votes already cast passes the threshold limit.
*/
function _quorumReached(uint256 proposalId) internal view virtual returns (bool);
/**
* @dev Is the proposal successful or not.
*/
function _voteSucceeded(uint256 proposalId) internal view virtual returns (bool);
/**
* @dev Get the voting weight of `account` at a specific `timepoint`, for a vote as described by `params`.
*/
function _getVotes(address account, uint256 timepoint, bytes memory params) internal view virtual returns (uint256);
/**
* @dev Register a vote for `proposalId` by `account` with a given `support`, voting `weight` and voting `params`.
*
* Note: Support is generic and can represent various things depending on the voting system used.
*/
function _countVote(
uint256 proposalId,
address account,
uint8 support,
uint256 weight,
bytes memory params
) internal virtual;
/**
* @dev Default additional encoded parameters used by castVote methods that don't include them
*
* Note: Should be overridden by specific implementations to use an appropriate value, the
* meaning of the additional params, in the context of that implementation
*/
function _defaultParams() internal view virtual returns (bytes memory) {
return "";
}
/**
* @dev See {IGovernor-propose}. This function has opt-in frontrunning protection, described in {_isValidDescriptionForProposer}.
*/
function propose(
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
string memory description
) public virtual override returns (uint256) {
address proposer = _msgSender();
require(_isValidDescriptionForProposer(proposer, description), "Governor: proposer restricted");
uint256 currentTimepoint = clock();
require(
getVotes(proposer, currentTimepoint - 1) >= proposalThreshold(),
"Governor: proposer votes below proposal threshold"
);
uint256 proposalId = hashProposal(targets, values, calldatas, keccak256(bytes(description)));
require(targets.length == values.length, "Governor: invalid proposal length");
require(targets.length == calldatas.length, "Governor: invalid proposal length");
require(targets.length > 0, "Governor: empty proposal");
require(_proposals[proposalId].voteStart == 0, "Governor: proposal already exists");
uint256 snapshot = currentTimepoint + votingDelay();
uint256 deadline = snapshot + votingPeriod();
_proposals[proposalId] = ProposalCore({
proposer: proposer,
voteStart: SafeCastUpgradeable.toUint64(snapshot),
voteEnd: SafeCastUpgradeable.toUint64(deadline),
executed: false,
canceled: false,
__gap_unused0: 0,
__gap_unused1: 0
});
emit ProposalCreated(
proposalId,
proposer,
targets,
values,
new string[](targets.length),
calldatas,
snapshot,
deadline,
description
);
return proposalId;
}
/**
* @dev See {IGovernor-execute}.
*/
function execute(
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
bytes32 descriptionHash
) public payable virtual override returns (uint256) {
uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);
ProposalState currentState = state(proposalId);
require(
currentState == ProposalState.Succeeded || currentState == ProposalState.Queued,
"Governor: proposal not successful"
);
_proposals[proposalId].executed = true;
emit ProposalExecuted(proposalId);
_beforeExecute(proposalId, targets, values, calldatas, descriptionHash);
_execute(proposalId, targets, values, calldatas, descriptionHash);
_afterExecute(proposalId, targets, values, calldatas, descriptionHash);
return proposalId;
}
/**
* @dev See {IGovernor-cancel}.
*/
function cancel(
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
bytes32 descriptionHash
) public virtual override returns (uint256) {
uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);
require(state(proposalId) == ProposalState.Pending, "Governor: too late to cancel");
require(_msgSender() == _proposals[proposalId].proposer, "Governor: only proposer can cancel");
return _cancel(targets, values, calldatas, descriptionHash);
}
/**
* @dev Internal execution mechanism. Can be overridden to implement different execution mechanism
*/
function _execute(
uint256 /* proposalId */,
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
bytes32 /*descriptionHash*/
) internal virtual {
string memory errorMessage = "Governor: call reverted without message";
for (uint256 i = 0; i < targets.length; ++i) {
(bool success, bytes memory returndata) = targets[i].call{value: values[i]}(calldatas[i]);
AddressUpgradeable.verifyCallResult(success, returndata, errorMessage);
}
}
/**
* @dev Hook before execution is triggered.
*/
function _beforeExecute(
uint256 /* proposalId */,
address[] memory targets,
uint256[] memory /* values */,
bytes[] memory calldatas,
bytes32 /*descriptionHash*/
) internal virtual {
if (_executor() != address(this)) {
for (uint256 i = 0; i < targets.length; ++i) {
if (targets[i] == address(this)) {
_governanceCall.pushBack(keccak256(calldatas[i]));
}
}
}
}
/**
* @dev Hook after execution is triggered.
*/
function _afterExecute(
uint256 /* proposalId */,
address[] memory /* targets */,
uint256[] memory /* values */,
bytes[] memory /* calldatas */,
bytes32 /*descriptionHash*/
) internal virtual {
if (_executor() != address(this)) {
if (!_governanceCall.empty()) {
_governanceCall.clear();
}
}
}
/**
* @dev Internal cancel mechanism: locks up the proposal timer, preventing it from being re-submitted. Marks it as
* canceled to allow distinguishing it from executed proposals.
*
* Emits a {IGovernor-ProposalCanceled} event.
*/
function _cancel(
address[] memory targets,
uint256[] memory values,
bytes[] memory calldatas,
bytes32 descriptionHash
) internal virtual returns (uint256) {
uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);
ProposalState currentState = state(proposalId);
require(
currentState != ProposalState.Canceled &&
currentState != ProposalState.Expired &&
currentState != ProposalState.Executed,
"Governor: proposal not active"
);
_proposals[proposalId].canceled = true;
emit ProposalCanceled(proposalId);
return proposalId;
}
/**
* @dev See {IGovernor-getVotes}.
*/
function getVotes(address account, uint256 timepoint) public view virtual override returns (uint256) {
return _getVotes(account, timepoint, _defaultParams());
}
/**
* @dev See {IGovernor-getVotesWithParams}.
*/
function getVotesWithParams(
address account,
uint256 timepoint,
bytes memory params
) public view virtual override returns (uint256) {
return _getVotes(account, timepoint, params);
}
/**
* @dev See {IGovernor-castVote}.
*/
function castVote(uint256 proposalId, uint8 support) public virtual override returns (uint256) {
address voter = _msgSender();
return _castVote(proposalId, voter, support, "");
}
/**
* @dev See {IGovernor-castVoteWithReason}.
*/
function castVoteWithReason(
uint256 proposalId,
uint8 support,
string calldata reason
) public virtual override returns (uint256) {
address voter = _msgSender();
return _castVote(proposalId, voter, support, reason);
}
/**
* @dev See {IGovernor-castVoteWithReasonAndParams}.
*/
function castVoteWithReasonAndParams(
uint256 proposalId,
uint8 support,
string calldata reason,
bytes memory params
) public virtual override returns (uint256) {
address voter = _msgSender();
return _castVote(proposalId, voter, support, reason, params);
}
/**
* @dev See {IGovernor-castVoteBySig}.
*/
function castVoteBySig(
uint256 proposalId,
uint8 support,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override returns (uint256) {
address voter = ECDSAUpgradeable.recover(
_hashTypedDataV4(keccak256(abi.encode(BALLOT_TYPEHASH, proposalId, support))),
v,
r,
s
);
return _castVote(proposalId, voter, support, "");
}
/**
* @dev See {IGovernor-castVoteWithReasonAndParamsBySig}.
*/
function castVoteWithReasonAndParamsBySig(
uint256 proposalId,
uint8 support,
string calldata reason,
bytes memory params,
uint8 v,
bytes32 r,
bytes32 s
) public virtual override returns (uint256) {
address voter = ECDSAUpgradeable.recover(
_hashTypedDataV4(
keccak256(
abi.encode(
EXTENDED_BALLOT_TYPEHASH,
proposalId,
support,
keccak256(bytes(reason)),
keccak256(params)
)
)
),
v,
r,
s
);
return _castVote(proposalId, voter, support, reason, params);
}
/**
* @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
* voting weight using {IGovernor-getVotes} and call the {_countVote} internal function. Uses the _defaultParams().
*
* Emits a {IGovernor-VoteCast} event.
*/
function _castVote(
uint256 proposalId,
address account,
uint8 support,
string memory reason
) internal virtual returns (uint256) {
return _castVote(proposalId, account, support, reason, _defaultParams());
}
/**
* @dev Internal vote casting mechanism: Check that the vote is pending, that it has not been cast yet, retrieve
* voting weight using {IGovernor-getVotes} and call the {_countVote} internal function.
*
* Emits a {IGovernor-VoteCast} event.
*/
function _castVote(
uint256 proposalId,
address account,
uint8 support,
string memory reason,
bytes memory params
) internal virtual returns (uint256) {
ProposalCore storage proposal = _proposals[proposalId];
require(state(proposalId) == ProposalState.Active, "Governor: vote not currently active");
uint256 weight = _getVotes(account, proposal.voteStart, params);
_countVote(proposalId, account, support, weight, params);
if (params.length == 0) {
emit VoteCast(account, proposalId, support, weight, reason);
} else {
emit VoteCastWithParams(account, proposalId, support, weight, reason, params);
}
return weight;
}
/**
* @dev Relays a transaction or function call to an arbitrary target. In cases where the governance executor
* is some contract other than the governor itself, like when using a timelock, this function can be invoked
* in a governance proposal to recover tokens or Ether that was sent to the governor contract by mistake.
* Note that if the executor is simply the governor itself, use of `relay` is redundant.
*/
function relay(address target, uint256 value, bytes calldata data) external payable virtual onlyGovernance {
(bool success, bytes memory returndata) = target.call{value: value}(data);
AddressUpgradeable.verifyCallResult(success, returndata, "Governor: relay reverted without message");
}
/**
* @dev Address through which the governor executes action. Will be overloaded by module that execute actions
* through another contract such as a timelock.
*/
function _executor() internal view virtual returns (address) {
return address(this);
}
/**
* @dev See {IERC721Receiver-onERC721Received}.
*/
function onERC721Received(address, address, uint256, bytes memory) public virtual override returns (bytes4) {
return this.onERC721Received.selector;
}
/**
* @dev See {IERC1155Receiver-onERC1155Received}.
*/
function onERC1155Received(
address,
address,
uint256,
uint256,
bytes memory
) public virtual override returns (bytes4) {
return this.onERC1155Received.selector;
}
/**
* @dev See {IERC1155Receiver-onERC1155BatchReceived}.
*/
function onERC1155BatchReceived(
address,
address,
uint256[] memory,
uint256[] memory,
bytes memory
) public virtual override returns (bytes4) {
return this.onERC1155BatchReceived.selector;
}
/**
* @dev Check if the proposer is authorized to submit a proposal with the given description.
*
* If the proposal description ends with `#proposer=0x???`, where `0x???` is an address written as a hex string
* (case insensitive), then the submission of this proposal will only be authorized to said address.
*
* This is used for frontrunning protection. By adding this pattern at the end of their proposal, one can ensure
* that no other address can submit the same proposal. An attacker would have to either remove or change that part,
* which would result in a different proposal id.
*
* If the description does not match this pattern, it is unrestricted and anyone can submit it. This includes:
* - If the `0x???` part is not a valid hex string.
* - If the `0x???` part is a valid hex string, but does not contain exactly 40 hex digits.
* - If it ends with the expected suffix followed by newlines or other whitespace.
* - If it ends with some other similar suffix, e.g. `#other=abc`.
* - If it does not end with any such suffix.
*/
function _isValidDescriptionForProposer(
address proposer,
string memory description
) internal view virtual returns (bool) {
uint256 len = bytes(description).length;
// Length is too short to contain a valid proposer suffix
if (len < 52) {
return true;
}
// Extract what would be the `#proposer=0x` marker beginning the suffix
bytes12 marker;
assembly {
// - Start of the string contents in memory = description + 32
// - First character of the marker = len - 52
// - Length of "#proposer=0x0000000000000000000000000000000000000000" = 52
// - We read the memory word starting at the first character of the marker:
// - (description + 32) + (len - 52) = description + (len - 20)
// - Note: Solidity will ignore anything past the first 12 bytes
marker := mload(add(description, sub(len, 20)))
}
// If the marker is not found, there is no proposer suffix to check
if (marker != bytes12("#proposer=0x")) {
return true;
}
// Parse the 40 characters following the marker as uint160
uint160 recovered = 0;
for (uint256 i = len - 40; i < len; ++i) {
(bool isHex, uint8 value) = _tryHexToUint(bytes(description)[i]);
// If any of the characters is not a hex digit, ignore the suffix entirely
if (!isHex) {
return true;
}
recovered = (recovered << 4) | value;
}
return recovered == uint160(proposer);
}
/**
* @dev Try to parse a character from a string as a hex value. Returns `(true, value)` if the char is in
* `[0-9a-fA-F]` and `(false, 0)` otherwise. Value is guaranteed to be in the range `0 <= value < 16`
*/
function _tryHexToUint(bytes1 char) private pure returns (bool, uint8) {
uint8 c = uint8(char);
unchecked {
// Case 0-9
if (47 < c && c < 58) {
return (true, c - 48);
}
// Case A-F
else if (64 < c && c < 71) {
return (true, c - 55);
}
// Case a-f
else if (96 < c && c < 103) {
return (true, c - 87);
}
// Else: not a hex char
else {
return (false, 0);
}
}
}
/**
* @dev This empty reserved space is put in place to allow future versions to add new
* variables without shifting down storage in the inheritance chain.
* See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
*/
uint256[46] private __gap;
}