IB20.setRoleAdmin

Sets the admin role for a given role on a B20 token, controlling which role can grant and revoke it.

Signature

IB20.sol

function setRoleAdmin(bytes32 role, bytes32 newAdminRole) external;

Field	Value
Selector	0x1e4e0091
Canonical signature	setRoleAdmin(bytes32,bytes32)

Description

Reassigns the admin of role to newAdminRole. After the call, grantRole and revokeRole for role require the caller to hold newAdminRole, not the previous admin. Only the current admin of role may call this function.

Emits RoleAdminChanged(role, previousAdminRole, newAdminRole).

Parameters

Parameter	Description
role	Role whose admin is being updated.
newAdminRole	New admin role. May be any role, including role itself to lock administration of that role.

Reverts

• AccessControlUnauthorizedAccount(account, neededRole): caller does not hold the current admin role for role, or the token has no admins (transitioned via renounceLastAdmin).

Events

Event	Emitted when
RoleAdminChanged(role, previousAdminRole, newAdminRole)	Admin reassignment succeeds

Access Control

Caller must hold getRoleAdmin(role) at the time of the call. On a fresh token, every role’s admin is DEFAULT_ADMIN_ROLE.

Setting newAdminRole equal to role makes the role self-administrating. Combined with revoking all current holders, this permanently closes the ability to grant that role to new accounts.

Example

Usage Example

// Make BURN_ROLE the admin of MINT_ROLE.
// After this call, only BURN_ROLE holders can grant or revoke MINT_ROLE.
IB20(target).setRoleAdmin(MINT_ROLE, BURN_ROLE);

// Lock MINT_ROLE permanently (self-admin, no holders).
IB20(target).revokeRole(MINT_ROLE, holder);
IB20(target).setRoleAdmin(MINT_ROLE, MINT_ROLE);