Add mutating votes getters that give ACL allowance

contracts/governance/utils/VotesConfidential.sol

@@ -63,6 +63,14 @@ abstract contract VotesConfidential is Nonces, EIP712, IERC6372 {
         return _delegateCheckpoints[account].latest();
     }
 
+    function getVotesWithAllowance(address account, bool persistent) public virtual returns (euint64) {
+        _validateVotesAccess(account);
+
+        euint64 votes = getVotes(account);
+        _setACLAllowance(votes, msg.sender, persistent);
+        return votes;
+    }
+
     /**
      * @dev Returns the amount of votes that `account` had at a specific moment in the past. If the {clock} is
      * configured to use block numbers, this will return the value at the end of the corresponding block.
@@ -75,6 +83,18 @@ abstract contract VotesConfidential is Nonces, EIP712, IERC6372 {
         return _delegateCheckpoints[account].upperLookupRecent(_validateTimepoint(timepoint));
     }
 
+    function getPastVotesWithAllowance(
+        address account,
+        uint256 timepoint,
+        bool persistent
+    ) public virtual returns (euint64) {
+        _validateVotesAccess(account);
+
+        euint64 pastVotes = getPastVotes(account, timepoint);
+        _setACLAllowance(pastVotes, msg.sender, persistent);
+        return pastVotes;
+    }
+
     /**
      * @dev Returns the total supply of votes available at a specific moment in the past. If the {clock} is
      * configured to use block numbers, this will return the value at the end of the corresponding block.
@@ -91,6 +111,14 @@ abstract contract VotesConfidential is Nonces, EIP712, IERC6372 {
         return _totalCheckpoints.upperLookupRecent(_validateTimepoint(timepoint));
     }
 
+    function getPastTotalSupplyWithAllowance(uint256 timepoint, bool persistent) public virtual returns (euint64) {
+        _validateVotesAccess(address(0));
+
+        euint64 pastTotalSupply = getPastTotalSupply(timepoint);
+        _setACLAllowance(pastTotalSupply, msg.sender, persistent);
+        return pastTotalSupply;
+    }
+
     /**
      * @dev Returns the current total supply of votes as an encrypted uint64 (euint64). Must be implemented
      * by the derived contract.
@@ -167,15 +195,13 @@ abstract contract VotesConfidential is Nonces, EIP712, IERC6372 {
                 store = _delegateCheckpoints[from];
                 euint64 newValue = store.latest().sub(amount);
                 newValue.allowThis();
-                newValue.allow(from);
                 euint64 oldValue = _push(store, newValue);
                 emit DelegateVotesChanged(from, oldValue, newValue);
             }
             if (to != address(0)) {
                 store = _delegateCheckpoints[to];
                 euint64 newValue = store.latest().add(amount);
                 newValue.allowThis();
-                newValue.allow(to);
                 euint64 oldValue = _push(store, newValue);
                 emit DelegateVotesChanged(to, oldValue, newValue);
             }
@@ -189,11 +215,30 @@ abstract contract VotesConfidential is Nonces, EIP712, IERC6372 {
         return SafeCast.toUint48(timepoint);
     }
 
+    /**
+     * @dev Set the ACL allowance for the given value, account, and persistent flag. If the flag is true,
+     * the allowance will be persistent, otherwise it will be transient.
+     */
+    function _setACLAllowance(euint64 value, address account, bool persistent) internal virtual {
+        if (persistent) {
+            FHE.allow(value, account);
+        } else {
+            FHE.allowTransient(value, account);
+        }
+    }
+
     /**
      * @dev Must return the voting units held by an account.
      */
     function _getVotingUnits(address) internal view virtual returns (euint64);
 
+    /**
+     * @dev Must revert if `msg.sender` is not allowed to get ACL access to the votes of the given account `account`.
+     *
+     * NOTE: A validation to access the votes of the 0 address indicates total supply.
+     */
+    function _validateVotesAccess(address account) internal view virtual;
+
     function _push(CheckpointsConfidential.TraceEuint64 storage store, euint64 value) private returns (euint64) {
         (euint64 oldValue, ) = store.push(clock(), value);
         return oldValue;