Remote GSM

src/contracts/facilitators/gsm/GhoReserve.sol

@@ -1,9 +1,10 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.10;
 
-import {IERC20} from 'aave-v3-origin/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
 import {Ownable} from '@openzeppelin/contracts/access/Ownable.sol';
 import {EnumerableSet} from '@openzeppelin/contracts/utils/structs/EnumerableSet.sol';
+import {SafeCast} from 'src/contracts/dependencies/openzeppelin-contracts/contracts/utils/math/SafeCast.sol';
+import {IERC20} from 'aave-v3-origin/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
 import {VersionedInitializable} from 'aave-v3-origin/contracts/misc/aave-upgradeability/VersionedInitializable.sol';
 import {IGhoReserve} from 'src/contracts/facilitators/gsm/interfaces/IGhoReserve.sol';
 
@@ -15,6 +16,7 @@ import {IGhoReserve} from 'src/contracts/facilitators/gsm/interfaces/IGhoReserve
  */
 contract GhoReserve is Ownable, VersionedInitializable, IGhoReserve {
   using EnumerableSet for EnumerableSet.AddressSet;
+  using SafeCast for uint256;
 
   /// @inheritdoc IGhoReserve
   address public immutable GHO_TOKEN;
@@ -48,14 +50,14 @@ contract GhoReserve is Ownable, VersionedInitializable, IGhoReserve {
     GhoUsage storage entity = _ghoUsage[msg.sender];
     require(entity.limit >= entity.used + amount, 'LIMIT_EXCEEDED');
 
-    entity.used += uint128(amount);
+    entity.used += amount.toUint128();
     IERC20(GHO_TOKEN).transfer(msg.sender, amount);
     emit GhoUsed(msg.sender, amount);
   }
 
   /// @inheritdoc IGhoReserve
   function restore(uint256 amount) external {
-    _ghoUsage[msg.sender].used -= uint128(amount);
+    _ghoUsage[msg.sender].used -= amount.toUint128();
     IERC20(GHO_TOKEN).transferFrom(msg.sender, address(this), amount);
     emit GhoRestored(msg.sender, amount);
   }
@@ -83,7 +85,7 @@ contract GhoReserve is Ownable, VersionedInitializable, IGhoReserve {
   /// @inheritdoc IGhoReserve
   function setLimit(address entity, uint256 limit) external onlyOwner {
     require(_entities.contains(entity), 'ENTITY_DOES_NOT_EXIST');
-    _ghoUsage[entity].limit = uint128(limit);
+    _ghoUsage[entity].limit = limit.toUint128();
 
     emit GhoLimitUpdated(entity, limit);
   }

src/contracts/facilitators/gsm/Gsm.sol

@@ -232,7 +232,7 @@ contract Gsm is AccessControl, VersionedInitializable, EIP712, IGsm {
       IERC20(UNDERLYING_ASSET).safeTransfer(_ghoTreasury, underlyingBalance);
     }
 
-    emit Seized(msg.sender, _ghoTreasury, underlyingBalance, _getUsedGho());
+    emit Seized(msg.sender, _ghoTreasury, underlyingBalance, _getUsed());
     return underlyingBalance;
   }
 
@@ -241,7 +241,7 @@ contract Gsm is AccessControl, VersionedInitializable, EIP712, IGsm {
     require(_isSeized, 'GSM_NOT_SEIZED');
     require(amount > 0, 'INVALID_AMOUNT');
 
-    uint256 usedGho = _getUsedGho();
+    uint256 usedGho = _getUsed();
     if (amount > usedGho) {
       amount = usedGho;
     }
@@ -379,8 +379,8 @@ contract Gsm is AccessControl, VersionedInitializable, EIP712, IGsm {
   }
 
   /// @inheritdoc IGsm
-  function getUsedGho() external view returns (uint256) {
-    return _getUsedGho();
+  function getUsed() external view returns (uint256) {
+    return _getUsed();
   }
 
   /// @inheritdoc IGsm
@@ -553,6 +553,14 @@ contract Gsm is AccessControl, VersionedInitializable, EIP712, IGsm {
     return (finalAssetAmount, finalGrossAmount - finalFee, finalGrossAmount, finalFee);
   }
 
+  /**
+   * @dev Returns the amount of GHO currently used.
+   * @return The amount of GHO used
+   */
+  function _getUsed() internal view returns (uint256) {
+    return IGhoReserve(_ghoReserve).getUsed(address(this));
+  }
+
   /**
    * @dev Returns the maximum amount of GHO that can be used.
    * @return The usage limit of GHO
@@ -570,14 +578,6 @@ contract Gsm is AccessControl, VersionedInitializable, EIP712, IGsm {
     return IGhoReserve(_ghoReserve).getUsage(address(this));
   }
 
-  /**
-   * @dev Returns the amount of GHO currently used.
-   * @return The amount of GHO used
-   */
-  function _getUsedGho() internal view returns (uint256) {
-    return IGhoReserve(_ghoReserve).getUsed(address(this));
-  }
-
   /**
    * @dev Updates Fee Strategy
    * @param feeStrategy The address of the new Fee Strategy

src/contracts/facilitators/gsm/Gsm4626.sol

@@ -44,7 +44,7 @@ contract Gsm4626 is Gsm, IGsm4626 {
   ) external notSeized onlyRole(CONFIGURATOR_ROLE) returns (uint256) {
     require(amount > 0, 'INVALID_AMOUNT');
 
-    uint256 usedGho = _getUsedGho();
+    uint256 usedGho = _getUsed();
     (, uint256 deficit) = _getCurrentBacking(usedGho);
     require(deficit > 0, 'NO_CURRENT_DEFICIT_BACKING');
 
@@ -63,7 +63,7 @@ contract Gsm4626 is Gsm, IGsm4626 {
   ) external notSeized onlyRole(CONFIGURATOR_ROLE) returns (uint256) {
     require(amount > 0, 'INVALID_AMOUNT');
 
-    (, uint256 deficit) = _getCurrentBacking(_getUsedGho());
+    (, uint256 deficit) = _getCurrentBacking(_getUsed());
     require(deficit > 0, 'NO_CURRENT_DEFICIT_BACKING');
 
     uint128 deficitInUnderlying = IGsmPriceStrategy(PRICE_STRATEGY)
@@ -95,7 +95,7 @@ contract Gsm4626 is Gsm, IGsm4626 {
 
   /// @inheritdoc IGsm4626
   function getCurrentBacking() external view returns (uint256, uint256) {
-    return _getCurrentBacking(_getUsedGho());
+    return _getCurrentBacking(_getUsed());
   }
 
   /// @inheritdoc IGhoFacilitator

src/contracts/facilitators/gsm/OwnableFacilitator.sol

@@ -2,8 +2,8 @@
 pragma solidity ^0.8.10;
 
 import {Ownable} from '@openzeppelin/contracts/access/Ownable.sol';
-import {IOwnableFacilitator} from 'src/contracts/facilitators/gsm/interfaces/IOwnableFacilitator.sol';
 import {IGhoToken} from 'src/contracts/gho/interfaces/IGhoToken.sol';
+import {IOwnableFacilitator} from 'src/contracts/facilitators/gsm/interfaces/IOwnableFacilitator.sol';
 
 /**
  * @title OwnableFacilitator

src/contracts/facilitators/gsm/interfaces/IGsm.sol

@@ -321,7 +321,7 @@ interface IGsm is IAccessControl, IGhoFacilitator {
    * @notice Returns the amount of GHO used by the GSM
    * @return The amount of GHO used
    */
-  function getUsedGho() external view returns (uint256);
+  function getUsed() external view returns (uint256);
 
   /**
    * @notice Returns the maximum amount of GHO that can be used

src/contracts/facilitators/gsm/misc/SampleLiquidator.sol

@@ -29,7 +29,7 @@ contract SampleLiquidator is Ownable {
    */
   function triggerBurnAfterSeize(address gsm, uint256 amount) external onlyOwner returns (uint256) {
     IERC20 ghoToken = IERC20(IGsm(gsm).GHO_TOKEN());
-    uint256 usedGho = IGsm(gsm).getUsedGho();
+    uint256 usedGho = IGsm(gsm).getUsed();
     if (amount > usedGho) {
       amount = usedGho;
     }

tests/unit/TestGsm.t.sol

@@ -743,7 +743,7 @@ contract TestGsm is TestGhoBase {
     emit BuyAsset(ALICE, ALICE, 1e6, 1e18, 0);
     GHO_GSM.buyAsset(1e6, ALICE);
 
-    uint256 usedGho = GHO_GSM.getUsedGho();
+    uint256 usedGho = GHO_GSM.getUsed();
     assertEq(usedGho, DEFAULT_CAPACITY - 1e18, 'Unexpected GHO bucket level after buy');
     assertEq(
       GHO_TOKEN.balanceOf(ALICE),
@@ -759,7 +759,7 @@ contract TestGsm is TestGhoBase {
     GHO_GSM.sellAsset(1e6, ALICE);
     vm.stopPrank();
 
-    usedGho = GHO_GSM.getUsedGho();
+    usedGho = GHO_GSM.getUsed();
     assertEq(usedGho, DEFAULT_CAPACITY, 'Unexpected GHO bucket level after second sell');
     assertEq(
       GHO_TOKEN.balanceOf(ALICE),
@@ -1332,7 +1332,7 @@ contract TestGsm is TestGhoBase {
     uint256 seizedAmount = GHO_GSM.seize();
     assertEq(seizedAmount, DEFAULT_GSM_USDX_AMOUNT, 'Unexpected seized amount');
 
-    uint256 usedGho = GHO_GSM.getUsedGho();
+    uint256 usedGho = GHO_GSM.getUsed();
     assertTrue(usedGho > 0, 'Unexpected usedGho amount');
 
     vm.expectRevert('FACILITATOR_BUCKET_LEVEL_NOT_ZERO');
@@ -1346,7 +1346,7 @@ contract TestGsm is TestGhoBase {
     uint256 burnedAmount = GHO_GSM.burnAfterSeize(DEFAULT_GSM_GHO_AMOUNT);
     vm.stopPrank();
     assertEq(burnedAmount, DEFAULT_GSM_GHO_AMOUNT, 'Unexpected burned amount of GHO');
-    assertEq(GHO_GSM.getUsedGho(), 0, 'Unexpected amount of used GHO');
+    assertEq(GHO_GSM.getUsed(), 0, 'Unexpected amount of used GHO');
   }
 
   function testBurnAfterSeizeGreaterAmount() public {

tests/unit/TestGsm4626.t.sol

@@ -392,7 +392,7 @@ contract TestGsm4626 is TestGhoBase {
     emit SellAsset(ALICE, ALICE, DEFAULT_GSM_USDX_EXPOSURE, DEFAULT_CAPACITY, 0);
     GHO_GSM_4626.sellAsset(DEFAULT_GSM_USDX_EXPOSURE, ALICE);
 
-    uint256 usedGho = GHO_GSM_4626.getUsedGho();
+    uint256 usedGho = GHO_GSM_4626.getUsed();
     uint256 ghoLimit = GHO_RESERVE.getLimit(address(GHO_GSM_4626));
     assertEq(usedGho, ghoLimit, 'Unexpected GHO bucket level after initial sell');
     assertEq(
@@ -407,7 +407,7 @@ contract TestGsm4626 is TestGhoBase {
     emit BuyAsset(ALICE, ALICE, 1e6, 1e18, 0);
     GHO_GSM_4626.buyAsset(1e6, ALICE);
 
-    usedGho = GHO_GSM_4626.getUsedGho();
+    usedGho = GHO_GSM_4626.getUsed();
     assertEq(usedGho, DEFAULT_CAPACITY - 1e18, 'Unexpected GHO bucket level after buy');
     assertEq(
       GHO_TOKEN.balanceOf(ALICE),
@@ -423,7 +423,7 @@ contract TestGsm4626 is TestGhoBase {
     GHO_GSM_4626.sellAsset(1e6, ALICE);
     vm.stopPrank();
 
-    usedGho = GHO_GSM_4626.getUsedGho();
+    usedGho = GHO_GSM_4626.getUsed();
     ghoLimit = GHO_RESERVE.getLimit(address(GHO_GSM_4626));
     assertEq(usedGho, ghoLimit, 'Unexpected GHO bucket level after second sell');
     assertEq(
@@ -934,7 +934,7 @@ contract TestGsm4626 is TestGhoBase {
     uint256 burnedAmount = GHO_GSM_4626.burnAfterSeize(DEFAULT_GSM_GHO_AMOUNT);
     vm.stopPrank();
     assertEq(burnedAmount, DEFAULT_GSM_GHO_AMOUNT, 'Unexpected burned amount of GHO');
-    assertEq(GHO_GSM_4626.getUsedGho(), 0, 'Unexpected leftover amount of GHO');
+    assertEq(GHO_GSM_4626.getUsed(), 0, 'Unexpected leftover amount of GHO');
   }
 
   function testBurnAfterSeizeGreaterAmount() public {
@@ -948,7 +948,7 @@ contract TestGsm4626 is TestGhoBase {
     uint256 seizedAmount = GHO_GSM_4626.seize();
     assertEq(seizedAmount, DEFAULT_GSM_USDX_AMOUNT, 'Unexpected seized amount');
 
-    uint256 usedGho = GHO_GSM_4626.getUsedGho();
+    uint256 usedGho = GHO_GSM_4626.getUsed();
     assertTrue(usedGho > 0, 'Unexpected usedGho amount');
 
     vm.expectRevert('FACILITATOR_BUCKET_LEVEL_NOT_ZERO');
@@ -1043,12 +1043,12 @@ contract TestGsm4626 is TestGhoBase {
     GHO_TOKEN.approve(address(GHO_GSM_4626), type(uint256).max);
 
     uint256 balanceBefore = GHO_TOKEN.balanceOf(address(this));
-    uint256 usedGhoBefore = GHO_GSM_4626.getUsedGho();
+    uint256 usedGhoBefore = GHO_GSM_4626.getUsed();
 
     uint256 ghoUsedForBacking = GHO_GSM_4626.backWithGho((DEFAULT_GSM_GHO_AMOUNT / 2) + 1);
 
     uint256 balanceAfter = GHO_TOKEN.balanceOf(address(this));
-    uint256 usedGhoAfter = GHO_GSM_4626.getUsedGho();
+    uint256 usedGhoAfter = GHO_GSM_4626.getUsed();
 
     assertEq(DEFAULT_GSM_GHO_AMOUNT / 2, ghoUsedForBacking);
     assertEq(balanceBefore - balanceAfter, ghoUsedForBacking);