Contract Name:
SyntheticToken
Contract Source Code:
File 1 of 1 : SyntheticToken
// File: @openzeppelin/contracts/GSN/Context.sol
pragma solidity ^0.6.0;
/*
* @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 GSN 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.
*/
contract Context {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor () internal { }
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
pragma solidity ^0.6.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, 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.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// File: @openzeppelin/contracts/math/SafeMath.sol
pragma solidity ^0.6.0;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
// File: @openzeppelin/contracts/utils/Address.sol
pragma solidity ^0.6.2;
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly { codehash := extcodehash(account) }
return (codehash != accountHash && codehash != 0x0);
}
/**
* @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");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
}
// File: @openzeppelin/contracts/token/ERC20/ERC20.sol
pragma solidity ^0.6.0;
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20MinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20 {
using SafeMath for uint256;
using Address for address;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name, string memory symbol) public {
_name = name;
_symbol = symbol;
_decimals = 18;
}
/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @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 value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* 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}.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @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};
*
* Requirements:
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
/**
* @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.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
/**
* @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`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
*
* This is internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal {
_decimals = decimals_;
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}
// File: contracts/common/implementation/MultiRole.sol
pragma solidity ^0.6.0;
library Exclusive {
struct RoleMembership {
address member;
}
function isMember(RoleMembership storage roleMembership, address memberToCheck) internal view returns (bool) {
return roleMembership.member == memberToCheck;
}
function resetMember(RoleMembership storage roleMembership, address newMember) internal {
require(newMember != address(0x0), "Cannot set an exclusive role to 0x0");
roleMembership.member = newMember;
}
function getMember(RoleMembership storage roleMembership) internal view returns (address) {
return roleMembership.member;
}
function init(RoleMembership storage roleMembership, address initialMember) internal {
resetMember(roleMembership, initialMember);
}
}
library Shared {
struct RoleMembership {
mapping(address => bool) members;
}
function isMember(RoleMembership storage roleMembership, address memberToCheck) internal view returns (bool) {
return roleMembership.members[memberToCheck];
}
function addMember(RoleMembership storage roleMembership, address memberToAdd) internal {
require(memberToAdd != address(0x0), "Cannot add 0x0 to a shared role");
roleMembership.members[memberToAdd] = true;
}
function removeMember(RoleMembership storage roleMembership, address memberToRemove) internal {
roleMembership.members[memberToRemove] = false;
}
function init(RoleMembership storage roleMembership, address[] memory initialMembers) internal {
for (uint256 i = 0; i < initialMembers.length; i++) {
addMember(roleMembership, initialMembers[i]);
}
}
}
/**
* @title Base class to manage permissions for the derived class.
*/
abstract contract MultiRole {
using Exclusive for Exclusive.RoleMembership;
using Shared for Shared.RoleMembership;
enum RoleType { Invalid, Exclusive, Shared }
struct Role {
uint256 managingRole;
RoleType roleType;
Exclusive.RoleMembership exclusiveRoleMembership;
Shared.RoleMembership sharedRoleMembership;
}
mapping(uint256 => Role) private roles;
event ResetExclusiveMember(uint256 indexed roleId, address indexed newMember, address indexed manager);
event AddedSharedMember(uint256 indexed roleId, address indexed newMember, address indexed manager);
event RemovedSharedMember(uint256 indexed roleId, address indexed oldMember, address indexed manager);
/**
* @notice Reverts unless the caller is a member of the specified roleId.
*/
modifier onlyRoleHolder(uint256 roleId) {
require(holdsRole(roleId, msg.sender), "Sender does not hold required role");
_;
}
/**
* @notice Reverts unless the caller is a member of the manager role for the specified roleId.
*/
modifier onlyRoleManager(uint256 roleId) {
require(holdsRole(roles[roleId].managingRole, msg.sender), "Can only be called by a role manager");
_;
}
/**
* @notice Reverts unless the roleId represents an initialized, exclusive roleId.
*/
modifier onlyExclusive(uint256 roleId) {
require(roles[roleId].roleType == RoleType.Exclusive, "Must be called on an initialized Exclusive role");
_;
}
/**
* @notice Reverts unless the roleId represents an initialized, shared roleId.
*/
modifier onlyShared(uint256 roleId) {
require(roles[roleId].roleType == RoleType.Shared, "Must be called on an initialized Shared role");
_;
}
/**
* @notice Whether `memberToCheck` is a member of roleId.
* @dev Reverts if roleId does not correspond to an initialized role.
* @param roleId the Role to check.
* @param memberToCheck the address to check.
* @return True if `memberToCheck` is a member of `roleId`.
*/
function holdsRole(uint256 roleId, address memberToCheck) public view returns (bool) {
Role storage role = roles[roleId];
if (role.roleType == RoleType.Exclusive) {
return role.exclusiveRoleMembership.isMember(memberToCheck);
} else if (role.roleType == RoleType.Shared) {
return role.sharedRoleMembership.isMember(memberToCheck);
}
revert("Invalid roleId");
}
/**
* @notice Changes the exclusive role holder of `roleId` to `newMember`.
* @dev Reverts if the caller is not a member of the managing role for `roleId` or if `roleId` is not an
* initialized, ExclusiveRole.
* @param roleId the ExclusiveRole membership to modify.
* @param newMember the new ExclusiveRole member.
*/
function resetMember(uint256 roleId, address newMember) public onlyExclusive(roleId) onlyRoleManager(roleId) {
roles[roleId].exclusiveRoleMembership.resetMember(newMember);
emit ResetExclusiveMember(roleId, newMember, msg.sender);
}
/**
* @notice Gets the current holder of the exclusive role, `roleId`.
* @dev Reverts if `roleId` does not represent an initialized, exclusive role.
* @param roleId the ExclusiveRole membership to check.
* @return the address of the current ExclusiveRole member.
*/
function getMember(uint256 roleId) public view onlyExclusive(roleId) returns (address) {
return roles[roleId].exclusiveRoleMembership.getMember();
}
/**
* @notice Adds `newMember` to the shared role, `roleId`.
* @dev Reverts if `roleId` does not represent an initialized, SharedRole or if the caller is not a member of the
* managing role for `roleId`.
* @param roleId the SharedRole membership to modify.
* @param newMember the new SharedRole member.
*/
function addMember(uint256 roleId, address newMember) public onlyShared(roleId) onlyRoleManager(roleId) {
roles[roleId].sharedRoleMembership.addMember(newMember);
emit AddedSharedMember(roleId, newMember, msg.sender);
}
/**
* @notice Removes `memberToRemove` from the shared role, `roleId`.
* @dev Reverts if `roleId` does not represent an initialized, SharedRole or if the caller is not a member of the
* managing role for `roleId`.
* @param roleId the SharedRole membership to modify.
* @param memberToRemove the current SharedRole member to remove.
*/
function removeMember(uint256 roleId, address memberToRemove) public onlyShared(roleId) onlyRoleManager(roleId) {
roles[roleId].sharedRoleMembership.removeMember(memberToRemove);
emit RemovedSharedMember(roleId, memberToRemove, msg.sender);
}
/**
* @notice Removes caller from the role, `roleId`.
* @dev Reverts if the caller is not a member of the role for `roleId` or if `roleId` is not an
* initialized, SharedRole.
* @param roleId the SharedRole membership to modify.
*/
function renounceMembership(uint256 roleId) public onlyShared(roleId) onlyRoleHolder(roleId) {
roles[roleId].sharedRoleMembership.removeMember(msg.sender);
emit RemovedSharedMember(roleId, msg.sender, msg.sender);
}
/**
* @notice Reverts if `roleId` is not initialized.
*/
modifier onlyValidRole(uint256 roleId) {
require(roles[roleId].roleType != RoleType.Invalid, "Attempted to use an invalid roleId");
_;
}
/**
* @notice Reverts if `roleId` is initialized.
*/
modifier onlyInvalidRole(uint256 roleId) {
require(roles[roleId].roleType == RoleType.Invalid, "Cannot use a pre-existing role");
_;
}
/**
* @notice Internal method to initialize a shared role, `roleId`, which will be managed by `managingRoleId`.
* `initialMembers` will be immediately added to the role.
* @dev Should be called by derived contracts, usually at construction time. Will revert if the role is already
* initialized.
*/
function _createSharedRole(
uint256 roleId,
uint256 managingRoleId,
address[] memory initialMembers
) internal onlyInvalidRole(roleId) {
Role storage role = roles[roleId];
role.roleType = RoleType.Shared;
role.managingRole = managingRoleId;
role.sharedRoleMembership.init(initialMembers);
require(
roles[managingRoleId].roleType != RoleType.Invalid,
"Attempted to use an invalid role to manage a shared role"
);
}
/**
* @notice Internal method to initialize an exclusive role, `roleId`, which will be managed by `managingRoleId`.
* `initialMember` will be immediately added to the role.
* @dev Should be called by derived contracts, usually at construction time. Will revert if the role is already
* initialized.
*/
function _createExclusiveRole(
uint256 roleId,
uint256 managingRoleId,
address initialMember
) internal onlyInvalidRole(roleId) {
Role storage role = roles[roleId];
role.roleType = RoleType.Exclusive;
role.managingRole = managingRoleId;
role.exclusiveRoleMembership.init(initialMember);
require(
roles[managingRoleId].roleType != RoleType.Invalid,
"Attempted to use an invalid role to manage an exclusive role"
);
}
}
// File: contracts/common/interfaces/ExpandedIERC20.sol
pragma solidity ^0.6.0;
/**
* @title ERC20 interface that includes burn and mint methods.
*/
abstract contract ExpandedIERC20 is IERC20 {
/**
* @notice Burns a specific amount of the caller's tokens.
* @dev Only burns the caller's tokens, so it is safe to leave this method permissionless.
*/
function burn(uint256 value) external virtual;
/**
* @notice Mints tokens and adds them to the balance of the `to` address.
* @dev This method should be permissioned to only allow designated parties to mint tokens.
*/
function mint(address to, uint256 value) external virtual returns (bool);
}
// File: contracts/common/implementation/ExpandedERC20.sol
pragma solidity ^0.6.0;
/**
* @title An ERC20 with permissioned burning and minting. The contract deployer will initially
* be the owner who is capable of adding new roles.
*/
contract ExpandedERC20 is ExpandedIERC20, ERC20, MultiRole {
enum Roles {
// Can set the minter and burner.
Owner,
// Addresses that can mint new tokens.
Minter,
// Addresses that can burn tokens that address owns.
Burner
}
/**
* @notice Constructs the ExpandedERC20.
* @param _tokenName The name which describes the new token.
* @param _tokenSymbol The ticker abbreviation of the name. Ideally < 5 chars.
* @param _tokenDecimals The number of decimals to define token precision.
*/
constructor(
string memory _tokenName,
string memory _tokenSymbol,
uint8 _tokenDecimals
) public ERC20(_tokenName, _tokenSymbol) {
_setupDecimals(_tokenDecimals);
_createExclusiveRole(uint256(Roles.Owner), uint256(Roles.Owner), msg.sender);
_createSharedRole(uint256(Roles.Minter), uint256(Roles.Owner), new address[](0));
_createSharedRole(uint256(Roles.Burner), uint256(Roles.Owner), new address[](0));
}
/**
* @dev Mints `value` tokens to `recipient`, returning true on success.
* @param recipient address to mint to.
* @param value amount of tokens to mint.
* @return True if the mint succeeded, or False.
*/
function mint(address recipient, uint256 value)
external
override
onlyRoleHolder(uint256(Roles.Minter))
returns (bool)
{
_mint(recipient, value);
return true;
}
/**
* @dev Burns `value` tokens owned by `msg.sender`.
* @param value amount of tokens to burn.
*/
function burn(uint256 value) external override onlyRoleHolder(uint256(Roles.Burner)) {
_burn(msg.sender, value);
}
}
// File: contracts/common/implementation/Lockable.sol
pragma solidity ^0.6.0;
/**
* @title A contract that provides modifiers to prevent reentrancy to state-changing and view-only methods. This contract
* is inspired by https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/ReentrancyGuard.sol
* and https://github.com/balancer-labs/balancer-core/blob/master/contracts/BPool.sol.
*/
contract Lockable {
bool private _notEntered;
constructor() internal {
// Storing an initial non-zero value makes deployment a bit more
// expensive, but in exchange the refund on every call to nonReentrant
// will be lower in amount. Since refunds are capped to a percetange of
// the total transaction's gas, it is best to keep them low in cases
// like this one, to increase the likelihood of the full refund coming
// into effect.
_notEntered = true;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_preEntranceCheck();
_preEntranceSet();
_;
_postEntranceReset();
}
/**
* @dev Designed to prevent a view-only method from being re-entered during a call to a `nonReentrant()` state-changing method.
*/
modifier nonReentrantView() {
_preEntranceCheck();
_;
}
// Internal methods are used to avoid copying the require statement's bytecode to every `nonReentrant()` method.
// On entry into a function, `_preEntranceCheck()` should always be called to check if the function is being re-entered.
// Then, if the function modifies state, it should call `_postEntranceSet()`, perform its logic, and then call `_postEntranceReset()`.
// View-only methods can simply call `_preEntranceCheck()` to make sure that it is not being re-entered.
function _preEntranceCheck() internal view {
// On the first call to nonReentrant, _notEntered will be true
require(_notEntered, "ReentrancyGuard: reentrant call");
}
function _preEntranceSet() internal {
// Any calls to nonReentrant after this point will fail
_notEntered = false;
}
function _postEntranceReset() internal {
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_notEntered = true;
}
}
// File: contracts/financial-templates/common/SyntheticToken.sol
pragma solidity ^0.6.0;
/**
* @title Burnable and mintable ERC20.
* @dev The contract deployer will initially be the only minter, burner and owner capable of adding new roles.
*/
contract SyntheticToken is ExpandedERC20, Lockable {
/**
* @notice Constructs the SyntheticToken.
* @param tokenName The name which describes the new token.
* @param tokenSymbol The ticker abbreviation of the name. Ideally < 5 chars.
* @param tokenDecimals The number of decimals to define token precision.
*/
constructor(
string memory tokenName,
string memory tokenSymbol,
uint8 tokenDecimals
) public ExpandedERC20(tokenName, tokenSymbol, tokenDecimals) nonReentrant() {}
/**
* @notice Add Minter role to account.
* @dev The caller must have the Owner role.
* @param account The address to which the Minter role is added.
*/
function addMinter(address account) external nonReentrant() {
addMember(uint256(Roles.Minter), account);
}
/**
* @notice Remove Minter role from account.
* @dev The caller must have the Owner role.
* @param account The address from which the Minter role is removed.
*/
function removeMinter(address account) external nonReentrant() {
removeMember(uint256(Roles.Minter), account);
}
/**
* @notice Add Burner role to account.
* @dev The caller must have the Owner role.
* @param account The address to which the Burner role is added.
*/
function addBurner(address account) external nonReentrant() {
addMember(uint256(Roles.Burner), account);
}
/**
* @notice Removes Burner role from account.
* @dev The caller must have the Owner role.
* @param account The address from which the Burner role is removed.
*/
function removeBurner(address account) external nonReentrant() {
removeMember(uint256(Roles.Burner), account);
}
/**
* @notice Reset Owner role to account.
* @dev The caller must have the Owner role.
* @param account The new holder of the Owner role.
*/
function resetOwner(address account) external nonReentrant() {
resetMember(uint256(Roles.Owner), account);
}
/**
* @notice Checks if a given account holds the Minter role.
* @param account The address which is checked for the Minter role.
* @return bool True if the provided account is a Minter.
*/
function isMinter(address account) public view nonReentrantView() returns (bool) {
return holdsRole(uint256(Roles.Minter), account);
}
/**
* @notice Checks if a given account holds the Burner role.
* @param account The address which is checked for the Burner role.
* @return bool True if the provided account is a Burner.
*/
function isBurner(address account) public view nonReentrantView() returns (bool) {
return holdsRole(uint256(Roles.Burner), account);
}
}