Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./libraries/DiamondCloneMinimalLib.sol";
// Contract Author: https://juicelabs.io
//
error FunctionDoesNotExist();
contract UMADBRO {
event OwnershipTransferred(
address indexed previousOwner,
address indexed newOwner
);
constructor(address sawAddress, address[] memory facetAddresses) {
// set the owner
DiamondCloneMinimalLib.accessControlStorage()._owner = msg.sender;
emit OwnershipTransferred(address(0), msg.sender);
// First facet should be the diamondFacet
(, bytes memory err) = facetAddresses[0].delegatecall(
abi.encodeWithSelector(
0xf44a9d52, // initializeDiamondClone Selector
sawAddress,
facetAddresses
)
);
if (err.length > 0) {
revert(string(err));
}
}
// Find facet for function that is called and execute the
// function if a facet is found and return any value.
fallback() external payable {
// retrieve the facet address
address facet = DiamondCloneMinimalLib._getFacetAddressForCall();
// check if the facet address exists on the saw AND is included in our local cut
if (facet == address(0)) revert FunctionDoesNotExist();
// Execute external function from facet using delegatecall and return any value.
assembly {
// copy function selector and any arguments
calldatacopy(0, 0, calldatasize())
// execute function call using the facet
let result := delegatecall(gas(), facet, 0, calldatasize(), 0, 0)
// get any return value
returndatacopy(0, 0, returndatasize())
// return any return value or error back to the caller
switch result
case 0 {
revert(0, returndatasize())
}
default {
return(0, returndatasize())
}
}
}
receive() external payable {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
error FailedToFetchFacet();
// minimal inline subset of the full DiamondCloneLib to reduce deployment gas costs
library DiamondCloneMinimalLib {
bytes32 constant DIAMOND_CLONE_STORAGE_POSITION =
keccak256("diamond.standard.diamond.clone.storage");
bytes32 constant ACCESS_CONTROL_STORAGE_POSITION =
keccak256("Access.Control.library.storage");
struct DiamondCloneStorage {
// address of the diamond saw contract
address diamondSawAddress;
// mapping to all the facets this diamond implements.
mapping(address => bool) facetAddresses;
// gas cache
mapping(bytes4 => address) selectorGasCache;
}
struct AccessControlStorage {
address _owner;
}
function diamondCloneStorage()
internal
pure
returns (DiamondCloneStorage storage s)
{
bytes32 position = DIAMOND_CLONE_STORAGE_POSITION;
assembly {
s.slot := position
}
}
// calls externally to the saw to find the appropriate facet to delegate to
function _getFacetAddressForCall() internal view returns (address addr) {
DiamondCloneStorage storage s = diamondCloneStorage();
addr = s.selectorGasCache[msg.sig];
if (addr != address(0)) {
return addr;
}
(bool success, bytes memory res) = s.diamondSawAddress.staticcall(
abi.encodeWithSelector(0x14bc7560, msg.sig) // facetAddressForSelector
);
if (!success) revert FailedToFetchFacet();
assembly {
addr := mload(add(res, 32))
}
return s.facetAddresses[addr] ? addr : address(0);
}
function accessControlStorage()
internal
pure
returns (AccessControlStorage storage s)
{
bytes32 position = ACCESS_CONTROL_STORAGE_POSITION;
assembly {
s.slot := position
}
}
}