GenericEIP1967Migrator

Git Source

Minimal migrator that upgrades an EIP-1967 proxy to a new implementation.

*HOW IT WORKS

• This contract is deployed as a standalone “migrator”.
• Your proxied contract implements the XMTP Migratable pattern. When governance sets this migrator’s address in the ParameterRegistry and calls proxy.migrate(), the proxy will delegatecall("") into this contract (empty calldata).
• Because it’s a delegatecall, this fallback executes in the proxy’s storage context, so it can write the EIP-1967 implementation slot on the proxy. WHAT IT DOES
• Writes NEW_IMPL into the EIP-1967 implementation slot.
• Emits the standard IERC1967.Upgraded(newImpl) event. WHAT IT DOES NOT DO
• Does not run any initialization or data migration on the new implementation. If you need state transforms or an initialize(...) call, use a purpose-built migrator that (after setting the slot) delegatecalls the new impl with the desired calldata. SAFETY NOTES
• This migrator is intentionally tiny: fewer moving parts, easier to audit.
• Make sure newImpl preserves storage layout and initializer semantics.
• Only allow migrate() to be reachable via your governed parameter (migrator key).*

State Variables

_IMPLEMENTATION_SLOT

bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1)

bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

newImpl

The implementation that the proxy will be upgraded to.

address public immutable newImpl;

Functions

constructor

constructor(address newImpl_);

Parameters

fallback

Entry point when the proxy delegatecalls this contract with empty calldata.

Runs in the proxy’s context (storage is the proxy’s), so we can sstore the slot. Emits the standard ERC-1967 Upgraded event via the imported interface.

fallback() external;

Errors

InvalidImplementation

error InvalidImplementation();