AA-173: Remove simulation and view-only methods from the EntryPoint contract

contracts/core/EntryPoint.sol

@@ -26,10 +26,7 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
 
     using UserOperationLib for UserOperation;
 
-    SenderCreator private immutable senderCreator = new SenderCreator();
-
-    // Internal value used during simulation: need to query aggregator.
-    address private constant SIMULATE_FIND_AGGREGATOR = address(1);
+    SenderCreator private senderCreator = new SenderCreator();
 
     // Marker for inner call revert on out of gas
     bytes32 private constant INNER_OUT_OF_GAS = hex"deaddead";
@@ -74,7 +71,10 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
         uint256 opIndex,
         UserOperation calldata userOp,
         UserOpInfo memory opInfo
-    ) private returns (uint256 collected) {
+    )
+    internal
+    returns
+    (uint256 collected) {
         uint256 preGas = gasleft();
         bytes memory context = getMemoryBytesFromOffset(opInfo.contextOffset);
 
@@ -217,41 +217,6 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
         _compensate(beneficiary, collected);
     }
 
-    /// @inheritdoc IEntryPoint
-    function simulateHandleOp(
-        UserOperation calldata op,
-        address target,
-        bytes calldata targetCallData
-    ) external override {
-        UserOpInfo memory opInfo;
-        _simulationOnlyValidations(op);
-        (
-            uint256 validationData,
-            uint256 paymasterValidationData
-        ) = _validatePrepayment(0, op, opInfo);
-        ValidationData memory data = _intersectTimeRange(
-            validationData,
-            paymasterValidationData
-        );
-
-        numberMarker();
-        uint256 paid = _executeUserOp(0, op, opInfo);
-        numberMarker();
-        bool targetSuccess;
-        bytes memory targetResult;
-        if (target != address(0)) {
-            (targetSuccess, targetResult) = target.call(targetCallData);
-        }
-        revert ExecutionResult(
-            opInfo.preOpGas,
-            paid,
-            data.validAfter,
-            data.validUntil,
-            targetSuccess,
-            targetResult
-        );
-    }
-
     /**
      * A memory copy of UserOp static fields only.
      * Excluding: callData, initCode and signature. Replacing paymasterAndData with paymaster.
@@ -364,64 +329,6 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
         }
     }
 
-    /// @inheritdoc IEntryPoint
-    function simulateValidation(UserOperation calldata userOp) external {
-        UserOpInfo memory outOpInfo;
-
-        _simulationOnlyValidations(userOp);
-        (
-            uint256 validationData,
-            uint256 paymasterValidationData
-        ) = _validatePrepayment(0, userOp, outOpInfo);
-        StakeInfo memory paymasterInfo = _getStakeInfo(
-            outOpInfo.mUserOp.paymaster
-        );
-        StakeInfo memory senderInfo = _getStakeInfo(outOpInfo.mUserOp.sender);
-        StakeInfo memory factoryInfo;
-        {
-            bytes calldata initCode = userOp.initCode;
-            address factory = initCode.length >= 20
-                ? address(bytes20(initCode[0:20]))
-                : address(0);
-            factoryInfo = _getStakeInfo(factory);
-        }
-
-        ValidationData memory data = _intersectTimeRange(
-            validationData,
-            paymasterValidationData
-        );
-        address aggregator = data.aggregator;
-        bool sigFailed = aggregator == address(1);
-        ReturnInfo memory returnInfo = ReturnInfo(
-            outOpInfo.preOpGas,
-            outOpInfo.prefund,
-            sigFailed,
-            data.validAfter,
-            data.validUntil,
-            getMemoryBytesFromOffset(outOpInfo.contextOffset)
-        );
-
-        if (aggregator != address(0) && aggregator != address(1)) {
-            AggregatorStakeInfo memory aggregatorInfo = AggregatorStakeInfo(
-                aggregator,
-                _getStakeInfo(aggregator)
-            );
-            revert ValidationResultWithAggregation(
-                returnInfo,
-                senderInfo,
-                factoryInfo,
-                paymasterInfo,
-                aggregatorInfo
-            );
-        }
-        revert ValidationResult(
-            returnInfo,
-            senderInfo,
-            factoryInfo,
-            paymasterInfo
-        );
-    }
-
     /**
      * Get the required prefunded gas fee amount for an operation.
      * @param mUserOp - The user operation in memory.
@@ -482,50 +389,6 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
         revert SenderAddressResult(sender);
     }
 
-    function _simulationOnlyValidations(
-        UserOperation calldata userOp
-    ) internal view {
-        try
-            this._validateSenderAndPaymaster(
-                userOp.initCode,
-                userOp.sender,
-                userOp.paymasterAndData
-            )
-        // solhint-disable-next-line no-empty-blocks
-        {} catch Error(string memory revertReason) {
-            if (bytes(revertReason).length != 0) {
-                revert FailedOp(0, revertReason);
-            }
-        }
-    }
-
-    /**
-     * Called only during simulation.
-     * This function always reverts to prevent warm/cold storage differentiation in simulation vs execution.
-     * @param initCode         - The smart account constructor code.
-     * @param sender           - The sender address.
-     * @param paymasterAndData - The paymaster address followed by the token address to use.
-     */
-    function _validateSenderAndPaymaster(
-        bytes calldata initCode,
-        address sender,
-        bytes calldata paymasterAndData
-    ) external view {
-        if (initCode.length == 0 && sender.code.length == 0) {
-            // it would revert anyway. but give a meaningful message
-            revert("AA20 account not deployed");
-        }
-        if (paymasterAndData.length >= 20) {
-            address paymaster = address(bytes20(paymasterAndData[0:20]));
-            if (paymaster.code.length == 0) {
-                // It would revert anyway. but give a meaningful message.
-                revert("AA30 paymaster not deployed");
-            }
-        }
-        // always revert
-        revert("");
-    }
-
     /**
      * Call account.validateUserOp.
      * Revert (with FailedOp) in case validateUserOp reverts, or account didn't send required prefund.
@@ -707,7 +570,7 @@ contract EntryPoint is IEntryPoint, StakeManager, NonceManager, ReentrancyGuard,
         UserOperation calldata userOp,
         UserOpInfo memory outOpInfo
     )
-        private
+        internal
         returns (uint256 validationData, uint256 paymasterValidationData)
     {
         uint256 preGas = gasleft();

contracts/core/EntryPointSimulations.sol

@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity ^0.8.12;
+
+/* solhint-disable avoid-low-level-calls */
+/* solhint-disable no-inline-assembly */
+
+import "./EntryPoint.sol";
+import "../interfaces/IEntryPointSimulations.sol";
+
+/*
+ * This contract inherits the EntryPoint and extends it with the view-only methods that are executed by
+ * the bundler in order to check UserOperation validity and estimate its gas consumption.
+ * This contract should never be deployed on-chain and is only used as a parameter for the "eth_call" request.
+ */
+contract EntryPointSimulations is EntryPoint, IEntryPointSimulations {
+    // solhint-disable-next-line var-name-mixedcase
+    AggregatorStakeInfo private NOT_AGGREGATED = AggregatorStakeInfo(address(0), StakeInfo(0, 0));
+
+    /**
+     * simulation contract should not be deployed, and specifically, accounts should not trust
+     * it as entrypoint, since the simulation functions don't check the signatures
+     */
+    constructor() {
+        require(block.number < 100, "should not be deployed");
+    }
+
+    /// @inheritdoc IEntryPointSimulations
+    function simulateValidation(
+        UserOperation calldata userOp
+    )
+    external
+    returns (
+        ValidationResult memory
+    ){
+        UserOpInfo memory outOpInfo;
+
+        _simulationOnlyValidations(userOp);
+        (
+            uint256 validationData,
+            uint256 paymasterValidationData
+        ) = _validatePrepayment(0, userOp, outOpInfo);
+        StakeInfo memory paymasterInfo = _getStakeInfo(
+            outOpInfo.mUserOp.paymaster
+        );
+        StakeInfo memory senderInfo = _getStakeInfo(outOpInfo.mUserOp.sender);
+        StakeInfo memory factoryInfo;
+        {
+            bytes calldata initCode = userOp.initCode;
+            address factory = initCode.length >= 20
+                ? address(bytes20(initCode[0 : 20]))
+                : address(0);
+            factoryInfo = _getStakeInfo(factory);
+        }
+
+        ValidationData memory data = _intersectTimeRange(
+            validationData,
+            paymasterValidationData
+        );
+        address aggregator = data.aggregator;
+        bool sigFailed = aggregator == address(1);
+        ReturnInfo memory returnInfo = ReturnInfo(
+            outOpInfo.preOpGas,
+            outOpInfo.prefund,
+            sigFailed,
+            data.validAfter,
+            data.validUntil,
+            getMemoryBytesFromOffset(outOpInfo.contextOffset)
+        );
+
+        AggregatorStakeInfo memory aggregatorInfo = NOT_AGGREGATED;
+        if (aggregator != address(0) && aggregator != address(1)) {
+            aggregatorInfo = AggregatorStakeInfo(
+                aggregator,
+                _getStakeInfo(aggregator)
+            );
+        }
+        return ValidationResult(
+            returnInfo,
+            senderInfo,
+            factoryInfo,
+            paymasterInfo,
+            aggregatorInfo
+        );
+    }
+
+    /// @inheritdoc IEntryPointSimulations
+    function simulateHandleOp(
+        UserOperation calldata op,
+        address target,
+        bytes calldata targetCallData
+    )
+    external nonReentrant
+    returns (
+        ExecutionResult memory
+    ){
+        UserOpInfo memory opInfo;
+        _simulationOnlyValidations(op);
+        (
+            uint256 validationData,
+            uint256 paymasterValidationData
+        ) = _validatePrepayment(0, op, opInfo);
+        ValidationData memory data = _intersectTimeRange(
+            validationData,
+            paymasterValidationData
+        );
+
+        numberMarker();
+        uint256 paid = _executeUserOp(0, op, opInfo);
+        numberMarker();
+        bool targetSuccess;
+        bytes memory targetResult;
+        if (target != address(0)) {
+            (targetSuccess, targetResult) = target.call(targetCallData);
+        }
+        return ExecutionResult(
+            opInfo.preOpGas,
+            paid,
+            data.validAfter,
+            data.validUntil,
+            targetSuccess,
+            targetResult
+        );
+    }
+
+    function _simulationOnlyValidations(
+        UserOperation calldata userOp
+    )
+    internal
+    view
+    {
+        try
+        this._validateSenderAndPaymaster(
+            userOp.initCode,
+            userOp.sender,
+            userOp.paymasterAndData
+        )
+        // solhint-disable-next-line no-empty-blocks
+        {} catch Error(string memory revertReason) {
+            if (bytes(revertReason).length != 0) {
+                revert FailedOp(0, revertReason);
+            }
+        }
+    }
+
+    /**
+     * Called only during simulation.
+     * This function always reverts to prevent warm/cold storage differentiation in simulation vs execution.
+     * @param initCode         - The smart account constructor code.
+     * @param sender           - The sender address.
+     * @param paymasterAndData - The paymaster address followed by the token address to use.
+     */
+    function _validateSenderAndPaymaster(
+        bytes calldata initCode,
+        address sender,
+        bytes calldata paymasterAndData
+    ) external view {
+        if (initCode.length == 0 && sender.code.length == 0) {
+            // it would revert anyway. but give a meaningful message
+            revert("AA20 account not deployed");
+        }
+        if (paymasterAndData.length >= 20) {
+            address paymaster = address(bytes20(paymasterAndData[0 : 20]));
+            if (paymaster.code.length == 0) {
+                // It would revert anyway. but give a meaningful message.
+                revert("AA30 paymaster not deployed");
+            }
+        }
+        // always revert
+        revert("");
+    }
+
+    //make sure depositTo cost is more than normal EntryPoint's cost.
+    // empiric test showed that without this wrapper, simulation depositTo costs less..
+    function depositTo(address account) public override(IStakeManager, StakeManager) payable {
+        uint x;
+        assembly {
+            //some silly code to waste ~200 gas
+            x := exp(mload(0),100)
+        }
+        if (x == 123) {
+            return;
+        }
+        StakeManager.depositTo(account);
+    }
+}

contracts/core/StakeManager.sol

@@ -62,7 +62,7 @@ abstract contract StakeManager is IStakeManager {
      * Add to the deposit of the given account.
      * @param account - The account to add to.
      */
-    function depositTo(address account) public payable {
+    function depositTo(address account) public virtual payable {
         _incrementDeposit(account, msg.value);
         DepositInfo storage info = deposits[account];
         emit Deposited(account, info.deposit);