GovernanceERC20

Contract · src/erc20/GovernanceERC20.sol

Explained in: Governance tokens

Author: Aragon X

Inherits: IERC20MintableUpgradeable, Initializable, ERC165Upgradeable, ERC20VotesUpgradeable, DaoAuthorizableUpgradeable

An OpenZeppelin Votes compatible ERC-20 token, used for voting and managed by a DAO.

security-contact: sirt@aragon.org

Constructor

constructor

constructor(IDAO _dao, string _name, string _symbol, GovernanceERC20.MintSettings _mintSettings)

Calls the initialize function.

Parameter	Type	Description
_dao	IDAO	The managing DAO.
_name	string	The name of the ERC-20 governance token.
_symbol	string	The symbol of the ERC-20 governance token.
_mintSettings	GovernanceERC20.MintSettings	The token mint settings struct containing the receivers, the amounts and ensureDelegationOnMint.

Functions

allowance

function allowance(address owner, address spender) external view returns (uint256)

Selector: 0xdd62ed3e

Dev: See {IERC20-allowance}.

approve

function approve(address spender, uint256 amount) external returns (bool)

Selector: 0x095ea7b3

Dev: See {IERC20-approve}.

NOTE: If amount is the maximum uint256, the allowance is not updated on transferFrom. This is semantically equivalent to an infinite approval.

Requirements:

• spender cannot be the zero address.

balanceOf

function balanceOf(address account) external view returns (uint256)

Selector: 0x70a08231

Dev: See {IERC20-balanceOf}.

checkpoints

function checkpoints(
    address account,
    uint32 pos
) external view returns (ERC20VotesUpgradeable.Checkpoint)

Selector: 0xf1127ed8

Dev: Get the pos-th checkpoint for account.

Returns	Type	Description
[0]	ERC20VotesUpgradeable.Checkpoint

clock

function clock() external view returns (uint48)

Selector: 0x91ddadf4

Dev: Clock used for flagging checkpoints. Can be overridden to implement timestamp based checkpoints (and voting).

CLOCK_MODE

function CLOCK_MODE() external view returns (string)

Selector: 0x4bf5d7e9

Dev: Description of the clock

dao

function dao() external view returns (IDAO)

Selector: 0x4162169f

Returns the DAO contract.

decimals

function decimals() external view returns (uint8)

Selector: 0x313ce567

Dev: Returns the number of decimals used to get its user representation. For example, if decimals equals 2, a balance of 505 tokens should be displayed to a user as 5.05 (505 / 10 ** 2).

Tokens usually opt for a value of 18, imitating the relationship between Ether and Wei. This is the default value returned by this function, unless it's overridden.

NOTE: This information is only used for display purposes: it in no way affects any of the arithmetic of the contract, including {IERC20-balanceOf} and {IERC20-transfer}.

decreaseAllowance

function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool)

Selector: 0xa457c2d7

Dev: Atomically decreases the allowance granted to spender by the caller.

This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}.

Emits an {Approval} event indicating the updated allowance.

Requirements:

• spender cannot be the zero address.
• spender must have allowance for the caller of at least subtractedValue.

delegate

function delegate(address delegatee) external

Selector: 0x5c19a95c

Dev: Delegate votes from the sender to delegatee.

delegateBySig

function delegateBySig(
    address delegatee,
    uint256 nonce,
    uint256 expiry,
    uint8 v,
    bytes32 r,
    bytes32 s
) external

Selector: 0xc3cda520

Dev: Delegates votes from signer to delegatee

delegates

function delegates(address account) external view returns (address)

Selector: 0x587cde1e

Dev: Get the address account is currently delegating to.

DOMAIN_SEPARATOR

function DOMAIN_SEPARATOR() external view returns (bytes32)

Selector: 0x3644e515

Dev: Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.

eip712Domain

function eip712Domain() external view returns (bytes1 fields, string name, string version, uint256 chainId, address verifyingContract, bytes32 salt, uint256[] extensions)

Selector: 0x84b0196e

Dev: See {EIP-5267}.

Available since v4.9.

freezeMinting

function freezeMinting() external

Selector: 0xc013f30f

Disables the mint() function permanently

getEnsureDelegationOnMint

function getEnsureDelegationOnMint() external view returns (bool)

Selector: 0xd9957169

Whether mint() enables self delegation if the receiver has no delegate.

getMintingFrozen

function getMintingFrozen() external view returns (bool)

Selector: 0x081f4b8c

Returns true if the ability to mint tokens has been frozen

getPastTotalSupply

function getPastTotalSupply(uint256 timepoint) external view returns (uint256)

Selector: 0x8e539e8c

Dev: Retrieve the totalSupply at the end of timepoint. Note, this value is the sum of all balances. It is NOT the sum of all the delegated votes!

Requirements:

• timepoint must be in the past

getPastVotes

function getPastVotes(address account, uint256 timepoint) external view returns (uint256)

Selector: 0x3a46b1a8

Dev: Retrieve the number of votes for account at the end of timepoint.

Requirements:

• timepoint must be in the past

getVotes

function getVotes(address account) external view returns (uint256)

Selector: 0x9ab24eb0

Dev: Gets the current votes balance for account

increaseAllowance

function increaseAllowance(address spender, uint256 addedValue) external returns (bool)

Selector: 0x39509351

Dev: Atomically increases the allowance granted to spender by the caller.

This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}.

Emits an {Approval} event indicating the updated allowance.

Requirements:

• spender cannot be the zero address.

initialize

function initialize(
    IDAO _dao,
    string _name,
    string _symbol,
    GovernanceERC20.MintSettings _mintSettings
) external

Selector: 0x6273f4dc

Initializes the contract and mints tokens to a list of receivers.

Parameter	Type	Description
_dao	IDAO	The managing DAO.
_name	string	The name of the ERC-20 governance token.
_symbol	string	The symbol of the ERC-20 governance token.
_mintSettings	GovernanceERC20.MintSettings	The token mint settings struct containing the receivers, the amounts and ensureDelegationOnMint.

mint

function mint(address to, uint256 amount) external

Selector: 0x40c10f19

Mints tokens to an address.

Parameter	Type	Description
to	address	The address receiving the tokens.
amount	uint256	The amount of tokens to be minted.

name

function name() external view returns (string)

Selector: 0x06fdde03

Dev: Returns the name of the token.

nonces

function nonces(address owner) external view returns (uint256)

Selector: 0x7ecebe00

Dev: Returns the current nonce for owner. This value must be included whenever a signature is generated for {permit}. Every successful call to {permit} increases owner's nonce by one. This prevents a signature from being used multiple times.

numCheckpoints

function numCheckpoints(address account) external view returns (uint32)

Selector: 0x6fcfff45

Dev: Get number of checkpoints for account.

permit

function permit(
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
) external

Selector: 0xd505accf

Dev: Sets value as the allowance of spender over owner's tokens, given owner's signed approval. IMPORTANT: The same issues {IERC20-approve} has related to transaction ordering also apply here. Emits an {Approval} event. Requirements: - spender cannot be the zero address. - deadline must be a timestamp in the future. - v, r and s must be a valid secp256k1 signature from owner over the EIP712-formatted function arguments. - the signature must use owner's current nonce (see {nonces}). For more information on the signature format, see the https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP section]. CAUTION: See Security Considerations above.

supportsInterface

function supportsInterface(bytes4 _interfaceId) external view returns (bool)

Selector: 0x01ffc9a7

Checks if this or the parent contract supports an interface by its ID.

Parameter	Type	Description
_interfaceId	bytes4	The ID of the interface.

symbol

function symbol() external view returns (string)

Selector: 0x95d89b41

Dev: Returns the symbol of the token, usually a shorter version of the name.

totalSupply

function totalSupply() external view returns (uint256)

Selector: 0x18160ddd

Dev: See {IERC20-totalSupply}.

transfer

function transfer(address to, uint256 amount) external returns (bool)

Selector: 0xa9059cbb

Dev: See {IERC20-transfer}.

Requirements:

• to cannot be the zero address.
• the caller must have a balance of at least amount.

transferFrom

function transferFrom(address from, address to, uint256 amount) external returns (bool)

Selector: 0x23b872dd

Dev: See {IERC20-transferFrom}.

Emits an {Approval} event indicating the updated allowance. This is not required by the EIP. See the note at the beginning of {ERC20}.

NOTE: Does not update the allowance if the current allowance is the maximum uint256.

Requirements:

• from and to cannot be the zero address.
• from must have a balance of at least amount.
• the caller must have allowance for from's tokens of at least amount.

Events

Approval

event Approval(address indexed owner, address indexed spender, uint256 value)

Dev: Emitted when the allowance of a spender for an owner is set by a call to {approve}. value is the new allowance.

DelegateChanged

event DelegateChanged(
    address indexed delegator,
    address indexed fromDelegate,
    address indexed toDelegate
)

Dev: Emitted when an account changes their delegate.

DelegateVotesChanged

event DelegateVotesChanged(
    address indexed delegate,
    uint256 previousBalance,
    uint256 newBalance
)

Dev: Emitted when a token transfer or delegate change results in changes to a delegate's number of votes.

EIP712DomainChanged

event EIP712DomainChanged()

Dev: MAY be emitted to signal that the domain could have changed.

Initialized

event Initialized(uint8 version)

Dev: Triggered when the contract has been initialized or reinitialized.

MintingFrozen

event MintingFrozen()

Emitted when minting is frozen permanently

Transfer

event Transfer(address indexed from, address indexed to, uint256 value)

Dev: Emitted when value tokens are moved from one account (from) to another (to).

Note that value may be zero.

Errors

DaoUnauthorized

error DaoUnauthorized(address dao, address where, address who, bytes32 permissionId)

Thrown if a call is unauthorized in the associated DAO.

Parameter	Type	Description
dao	address	The associated DAO.
where	address	The context in which the authorization reverted.
who	address	The address (EOA or contract) missing the permission.
permissionId	bytes32	The permission identifier.

MintingIsFrozen

error MintingIsFrozen()

Thrown when attempting to mint when minting is permanently disabled

MintSettingsArrayLengthMismatch

error MintSettingsArrayLengthMismatch(uint256 receiversArrayLength, uint256 amountsArrayLength)

Thrown if the number of receivers and amounts specified in the mint settings do not match.

Parameter	Type	Description
receiversArrayLength	uint256	The length of the receivers array.
amountsArrayLength	uint256	The length of the amounts array.

Constants

Public, so each is also readable through a generated getter.

MINT_PERMISSION_ID

bytes32 public constant MINT_PERMISSION_ID = keccak256("MINT_PERMISSION");

Value: 0xb737b436e6cc542520cb79ec04245c720c38eebfa56d9e2d99b043979db20e4c

The permission identifier to mint new tokens

Structs

Checkpoint

Inherited from ERC20VotesUpgradeable.

struct Checkpoint {
    uint32 fromBlock;
    uint224 votes;
}

MintSettings

struct MintSettings {
    address[] receivers;
    uint256[] amounts;
    bool ensureDelegationOnMint;
}

The settings for the initial mint of the token.

Dev: The lengths of receivers and amounts must match.

Field	Type	Description
receivers	address[]	The receivers of the tokens. On initialization only.
amounts	uint256[]	The amounts of tokens to be minted for each receiver. On initialization only.
ensureDelegationOnMint	bool	Whether mint() calls should self delegate if the receiver doesn't have one.