Eliminate EM.safeCREATE logic (#308)

* new create codepath working

* get calls ported over to new function

* remove from interface

* clean up, add comments

* remove unused commented code

* fix nuisance gas

* add return type to ovmCREATE

* focus on final failing test

* finish up tests with new contract account revert type

* remove test focus

* linting

* cleanup

* add explicit unsafe bytecode test

* linting

* remove pointless ternary

* fix docstring

* fix eth_call for creates and fix contract account reversions

* use if statement instead

* nits

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>

* Fix nits on comments

* More small comment fixes

* fix capitalization, add ref URL

* PR feedback

* opcodes->bytecode

* doc: explain eth_call create return type

* Update contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol
Co-authored-by: smartcontracts <kelvinfichter@gmail.com>
Co-authored-by: Maurelian <maurelian@protonmail.ch>

packages/contracts/contracts/optimistic-ethereum/OVM/accounts/OVM_ECDSAContractAccount.sol

@@ -113,14 +113,17 @@ contract OVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
 
         // Contract creations are signalled by sending a transaction to the zero address.
         if (decodedTx.to == address(0)) {
-            address created = Lib_SafeExecutionManagerWrapper.safeCREATE(
+            (address created, bytes memory revertData) = Lib_SafeExecutionManagerWrapper.safeCREATE(
                 decodedTx.gasLimit,
                 decodedTx.data
             );
 
-            // EVM doesn't tell us whether a contract creation failed, even if it reverted during
-            // initialization. Always return `true` for our success value here.
-            return (true, abi.encode(created));
+            // Return true if the contract creation succeeded, false w/ revertData otherwise.
+            if (created != address(0)) {
+                return (true, abi.encode(created));
+            } else {
+                return (false, revertData);
+            }
         } else {
             // We only want to bump the nonce for `ovmCALL` because `ovmCREATE` automatically bumps
             // the nonce of the calling account. Normally an EOA would bump the nonce for both

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol

@@ -7,6 +7,7 @@ pragma experimental ABIEncoderV2;
 import { Lib_OVMCodec } from "../../libraries/codec/Lib_OVMCodec.sol";
 import { Lib_AddressResolver } from "../../libraries/resolver/Lib_AddressResolver.sol";
 import { Lib_EthUtils } from "../../libraries/utils/Lib_EthUtils.sol";
+import { Lib_ErrorUtils } from "../../libraries/utils/Lib_ErrorUtils.sol";
 
 /* Interface Imports */
 import { iOVM_ExecutionManager } from "../../iOVM/execution/iOVM_ExecutionManager.sol";
@@ -364,7 +365,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
     /**
      * @notice Overrides CREATE.
      * @param _bytecode Code to be used to CREATE a new contract.
-     * @return _contract Address of the created contract.
+     * @return Address of the created contract.
+     * @return Revert data, if and only if the creation threw an exception.
      */
     function ovmCREATE(
         bytes memory _bytecode
@@ -374,7 +376,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         notStatic
         fixedGasDiscount(40000)
         returns (
-            address _contract
+            address,
+            bytes memory
         )
     {
         // Creator is always the current ADDRESS.
@@ -400,7 +403,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
      * @notice Overrides CREATE2.
      * @param _bytecode Code to be used to CREATE2 a new contract.
      * @param _salt Value used to determine the contract's address.
-     * @return _contract Address of the created contract.
+     * @return Address of the created contract.
+     * @return Revert data, if and only if the creation threw an exception.
      */
     function ovmCREATE2(
         bytes memory _bytecode,
@@ -411,7 +415,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         notStatic
         fixedGasDiscount(40000)
         returns (
-            address _contract
+            address,
+            bytes memory
         )
     {
         // Creator is always the current ADDRESS.
@@ -769,90 +774,6 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         );
     }
 
-
-    /**************************************
-     * Public Functions: Execution Safety *
-     **************************************/
-
-    /**
-     * Performs the logic to create a contract and revert under various potential conditions.
-     * @dev This function is implemented as `public` because we need to be able to revert a
-     *      contract creation without losing information about exactly *why* the contract reverted.
-     *      In particular, we want to be sure that contracts cannot trigger an INVALID_STATE_ACCESS
-     *      flag and then revert to reset the flag. We're able to do this by making an external
-     *      call from `ovmCREATE` and `ovmCREATE2` to `safeCREATE`, which can capture and relay
-     *      information before reverting.
-     * @param _address Address of the contract to associate with the one being created.
-     * @param _bytecode Code to be used to create the new contract.
-     */
-    function safeCREATE(
-        address _address,
-        bytes memory _bytecode
-    )
-        override
-        public
-    {
-        // Since this function is public, anyone can attempt to directly call it. We need to make
-        // sure that the OVM_ExecutionManager itself is the only party that can actually try to
-        // call this function.
-        if (msg.sender != address(this)) {
-            return;
-        }
-
-        // We need to be sure that the user isn't trying to use a contract creation to overwrite
-        // some existing contract. On L1, users will prove that no contract exists at the address
-        // and the OVM_FraudVerifier will populate the code hash of this address with a special
-        // value that represents "known to be an empty account."
-        if (_hasEmptyAccount(_address) == false) {
-            _revertWithFlag(RevertFlag.CREATE_COLLISION);
-        }
-
-        // Check the creation bytecode against the OVM_SafetyChecker.
-        if (ovmSafetyChecker.isBytecodeSafe(_bytecode) == false) {
-            _revertWithFlag(RevertFlag.UNSAFE_BYTECODE);
-        }
-
-        // We always need to initialize the contract with the default account values.
-        _initPendingAccount(_address);
-
-        // Actually deploy the contract and retrieve its address. This step is hiding a lot of
-        // complexity because we need to ensure that contract creation *never* reverts by itself.
-        // We cover this partially by storing a revert flag and returning (instead of reverting)
-        // when we know that we're inside a contract's creation code.
-        address ethAddress = Lib_EthUtils.createContract(_bytecode);
-
-        // Contract creation returns the zero address when it fails, which should only be possible
-        // if the user intentionally runs out of gas. However, we might still have a bit of gas
-        // left over since contract calls can only be passed 63/64ths of total gas,  so we need to
-        // explicitly handle this case here.
-        if (ethAddress == address(0)) {
-            _revertWithFlag(RevertFlag.CREATE_EXCEPTION);
-        }
-
-        // Here we pull out the revert flag that would've been set during creation code. Now that
-        // we're out of creation code again, we can just revert normally while passing the flag
-        // through the revert data.
-        if (messageRecord.revertFlag != RevertFlag.DID_NOT_REVERT) {
-            _revertWithFlag(messageRecord.revertFlag);
-        }
-
-        // Again simply checking that the deployed code is safe too. Contracts can generate
-        // arbitrary deployment code, so there's no easy way to analyze this beforehand.
-        bytes memory deployedCode = Lib_EthUtils.getCode(ethAddress);
-        if (ovmSafetyChecker.isBytecodeSafe(deployedCode) == false) {
-            _revertWithFlag(RevertFlag.UNSAFE_BYTECODE);
-        }
-
-        // Contract creation didn't need to be reverted and the bytecode is safe. We finish up by
-        // associating the desired address with the newly created contract's code hash and address.
-        _commitPendingAccount(
-            _address,
-            ethAddress,
-            Lib_EthUtils.getCodeHash(ethAddress)
-        );
-    }
-
-
     /***************************************
      * Public Functions: Execution Context *
      ***************************************/
@@ -873,7 +794,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
      ********************************************/
 
     /**
-     * Checks whether the given address is on the whitelst to ovmCREATE/ovmCREATE2, and reverts if not.
+     * Checks whether the given address is on the whitelist to ovmCREATE/ovmCREATE2, and reverts if not.
      * @param _deployerAddress Address attempting to deploy a contract.
      */
     function _checkDeployerAllowed(
@@ -881,7 +802,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
     )
         internal
     {
-        // From an OVM semanitcs perspectibe, this will appear the identical to
+        // From an OVM semantics perspective, this will appear identical to
         // the deployer ovmCALLing the whitelist.  This is fine--in a sense, we are forcing them to.
         (bool success, bytes memory data) = ovmCALL(
             gasleft(),
@@ -903,7 +824,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
      * Creates a new contract and associates it with some contract address.
      * @param _contractAddress Address to associate the created contract with.
      * @param _bytecode Bytecode to be used to create the contract.
-     * @return _created Final OVM contract address.
+     * @return Final OVM contract address.
+     * @return Revertdata, if and only if the creation threw an exception.
      */
     function _createContract(
         address _contractAddress,
@@ -911,7 +833,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
     )
         internal
         returns (
-            address _created
+            address,
+            bytes memory
         )
     {
         // We always update the nonce of the creating account, even if the creation fails.
@@ -923,25 +846,21 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         nextMessageContext.ovmCALLER = messageContext.ovmADDRESS;
         nextMessageContext.ovmADDRESS = _contractAddress;
 
-        // Run `safeCREATE` in a new EVM message so that our changes can be reflected even if
-        // `safeCREATE` reverts.
-        (bool _success, ) = _handleExternalInteraction(
+        // Run the common logic which occurs between call-type and create-type messages,
+        // passing in the creation bytecode and `true` to trigger create-specific logic.
+        (bool success, bytes memory data) = _handleExternalMessage(
             nextMessageContext,
             gasleft(),
-            address(this),
-            abi.encodeWithSignature(
-                "safeCREATE(address,bytes)",
-                _contractAddress,
-                _bytecode
-            )
+            _contractAddress,
+            _bytecode,
+            true
         );
 
-        // Need to make sure that this flag is reset so that it isn't propagated to creations in
-        // some parent EVM message.
-        messageRecord.revertFlag = RevertFlag.DID_NOT_REVERT;
-
         // Yellow paper requires that address returned is zero if the contract deployment fails.
-        return _success ? _contractAddress : address(0);
+        return (
+            success ? _contractAddress : address(0),
+            data
+        );
     }
 
     /**
@@ -971,6 +890,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
             (uint256(_contract) & uint256(0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000))
             == uint256(0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000)
         ) {
+            // EVM does not return data in the success case, see: https://github.com/ethereum/go-ethereum/blob/aae7660410f0ef90279e14afaaf2f429fdc2a186/core/vm/instructions.go#L600-L604
             return (true, hex'');
         }
 
@@ -980,33 +900,38 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
             ? _contract
             : _getAccountEthAddress(_contract);
 
-        return _handleExternalInteraction(
+        return _handleExternalMessage(
             _nextMessageContext,
             _gasLimit,
             codeContractAddress,
-            _calldata
+            _calldata,
+            false
         );
     }
 
     /**
-     * Handles the logic of making an external call and parsing revert information.
-     * @param _nextMessageContext Message context to be used for the call.
-     * @param _gasLimit Amount of gas to be passed into this call.
-     * @param _target Address of the contract to call.
-     * @param _data Data to send along with the call.
-     * @return _success Whether or not the call returned (rather than reverted).
-     * @return _returndata Data returned by the call.
+     * Handles all interactions which involve the execution manager calling out to untrusted code (both calls and creates).
+     * Ensures that OVM-related measures are enforced, including L2 gas refunds, nuisance gas, and flagged reversions.
+     * 
+     * @param _nextMessageContext Message context to be used for the external message.
+     * @param _gasLimit Amount of gas to be passed into this message.
+     * @param _contract OVM address being called or deployed to
+     * @param _data Data for the message (either calldata or creation code)
+     * @param _isCreate Whether this is a create-type message.
+     * @return Whether or not the message (either a call or deployment) succeeded.
+     * @return Data returned by the message.
      */
-    function _handleExternalInteraction(
+    function _handleExternalMessage(
         MessageContext memory _nextMessageContext,
         uint256 _gasLimit,
-        address _target,
-        bytes memory _data
+        address _contract,
+        bytes memory _data,
+        bool _isCreate
     )
         internal
         returns (
-            bool _success,
-            bytes memory _returndata
+            bool,
+            bytes memory
         )
     {
         // We need to switch over to our next message context for the duration of this call.
@@ -1022,11 +947,15 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         messageRecord.nuisanceGasLeft = nuisanceGasLimit;
 
         // Make the call and make sure to pass in the gas limit. Another instance of hidden
-        // complexity. `_target` is guaranteed to be a safe contract, meaning its return/revert
+        // complexity. `_contract` is guaranteed to be a safe contract, meaning its return/revert
         // behavior can be controlled. In particular, we enforce that flags are passed through
         // revert data as to retrieve execution metadata that would normally be reverted out of
         // existence.
-        (bool success, bytes memory returndata) = _target.call{gas: _gasLimit}(_data);
+
+        (bool success, bytes memory returndata) =
+            _isCreate
+            ? _handleContractCreation(_gasLimit, _data, _contract)
+            : _contract.call{gas: _gasLimit}(_data);
 
         // Switch back to the original message context now that we're out of the call.
         _switchMessageContext(_nextMessageContext, prevMessageContext);
@@ -1066,7 +995,10 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
 
             // INTENTIONAL_REVERT needs to pass up the user-provided return data encoded into the
             // flag, *not* the full encoded flag. All other revert types return no data.
-            if (flag == RevertFlag.INTENTIONAL_REVERT) {
+            if (
+                flag == RevertFlag.INTENTIONAL_REVERT
+                || _isCreate
+            ) {
                 returndata = returndataFromFlag;
             } else {
                 returndata = hex'';
@@ -1089,6 +1021,99 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         );
     }
 
+    /**
+     * Handles the creation-specific safety measures required for OVM contract deployment.
+     * This function sanitizes the return types for creation messages to match calls (bool, bytes).
+     * This allows for consistent handling of both types of messages in _handleExternalMessage().
+     * 
+     * @param _gasLimit Amount of gas to be passed into this creation.
+     * @param _creationCode Code to pass into CREATE for deployment.
+     * @param _address OVM address being deployed to.
+     * @return Whether or not the call succeeded.
+     * @return If creation fails: revert data. Otherwise: empty.
+     */
+    function _handleContractCreation(
+        uint _gasLimit,
+        bytes memory _creationCode,
+        address _address
+    )
+        internal
+        returns(
+            bool,
+            bytes memory
+        )
+    {
+        // Check that there is not already code at this address.
+        if (_hasEmptyAccount(_address) == false) {
+            // Note: in the EVM, this case burns all allotted gas.  For improved
+            // developer experience, we do return the remaining ones.
+            return (
+                false,
+                _encodeRevertData(
+                    RevertFlag.CREATE_COLLISION,
+                    Lib_ErrorUtils.encodeRevertString("A contract has already been deployed to this address")
+                )
+            );
+        }
+
+        // Check the creation bytecode against the OVM_SafetyChecker.
+        if (ovmSafetyChecker.isBytecodeSafe(_creationCode) == false) {
+            return (
+                false,
+                _encodeRevertData(
+                    RevertFlag.UNSAFE_BYTECODE,
+                    Lib_ErrorUtils.encodeRevertString("Contract creation code contains unsafe opcodes. Did you use the right compiler or pass an unsafe constructor argument?")
+                )
+            );
+        }
+
+        // We always need to initialize the contract with the default account values.
+        _initPendingAccount(_address);
+
+        // Actually execute the EVM create message,
+        address ethAddress = Lib_EthUtils.createContract(_creationCode);
+        
+        if (ethAddress == address(0)) {
+            // If the creation fails, the EVM lets us grab its revert data. This may contain a revert flag
+            // to be used above in _handleExternalMessage.
+            uint256 revertDataSize;
+            assembly { revertDataSize := returndatasize() }
+            bytes memory revertdata = new bytes(revertDataSize);
+            assembly {
+                returndatacopy(
+                    add(revertdata, 0x20),
+                    0,
+                    revertDataSize
+                )
+            }
+            // Return that the creation failed, and the data it reverted with.
+            return (false, revertdata);
+        }
+
+        // Again simply checking that the deployed code is safe too. Contracts can generate
+        // arbitrary deployment code, so there's no easy way to analyze this beforehand.
+        bytes memory deployedCode = Lib_EthUtils.getCode(ethAddress);
+        if (ovmSafetyChecker.isBytecodeSafe(deployedCode) == false) {
+            return (
+                false,
+                _encodeRevertData(
+                    RevertFlag.UNSAFE_BYTECODE,
+                    Lib_ErrorUtils.encodeRevertString("Constructor attempted to deploy unsafe bytecode.")
+                )
+            );
+        }
+
+        // Contract creation didn't need to be reverted and the bytecode is safe. We finish up by
+        // associating the desired address with the newly created contract's code hash and address.
+        _commitPendingAccount(
+            _address,
+            ethAddress,
+            Lib_EthUtils.getCodeHash(ethAddress)
+        );
+
+        // Successful deployments will not give access to returndata, in both the EVM and the OVM.
+        return (true, hex'');
+    }
 
     /******************************************
      * Internal Functions: State Manipulation *
@@ -1426,7 +1451,6 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         // Out of gas and create exceptions will fundamentally return no data, so simulating it shouldn't either.
         if (
             _flag == RevertFlag.OUT_OF_GAS
-            || _flag == RevertFlag.CREATE_EXCEPTION
         ) {
             return bytes('');
         }
@@ -1494,27 +1518,8 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         bytes memory _data
     )
         internal
+        view
     {
-        // We don't want to revert when we're inside a CREATE or CREATE2, because those opcodes
-        // fail silently (we can't pass any data upwards). Instead, we set a flag and return a
-        // *single* byte, something the OVM_ExecutionManager will not return in any other case.
-        // We're thereby allowed to communicate failure without allowing contracts to trick us into
-        // thinking there was a failure.
-        bool isCreation;
-        assembly {
-            isCreation := eq(extcodesize(caller()), 0)
-        }
-
-        if (isCreation) {
-            messageRecord.revertFlag = _flag;
-
-            assembly {
-                return(0, 1)
-            }
-        }
-
-        // If we're not inside a CREATE or CREATE2, we can simply encode the necessary data and
-        // revert normally.
         bytes memory revertdata = _encodeRevertData(
             _flag,
             _data
@@ -1805,7 +1810,6 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
         messageContext.isStatic = false;
 
         messageRecord.nuisanceGasLeft = 0;
-        messageRecord.revertFlag = RevertFlag.DID_NOT_REVERT;
     }
 
     /*****************************
@@ -1834,17 +1838,18 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
 
         ovmStateManager = _ovmStateManager;
         _initContext(_transaction);
-
         messageRecord.nuisanceGasLeft = uint(-1);
 
         messageContext.ovmADDRESS = _from;
 
         bool isCreate = _transaction.entrypoint == address(0);
         if (isCreate) {
-            address created = ovmCREATE(_transaction.data);
+            (address created, bytes memory revertData) = ovmCREATE(_transaction.data);
             if (created == address(0)) {
-                return (false, hex"");
+                return (false, revertData);
             } else {
+                // The eth_call RPC endpoint for to = undefined will return the deployed bytecode 
+                // in the success case, differing from standard create messages.
                 return (true, Lib_EthUtils.getCode(created));
             }
         } else {

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol

@@ -11,7 +11,6 @@ interface iOVM_ExecutionManager {
      *********/
 
     enum RevertFlag {
-        DID_NOT_REVERT,
         OUT_OF_GAS,
         INTENTIONAL_REVERT,
         EXCEEDS_NUISANCE_GAS,
@@ -19,7 +18,6 @@ interface iOVM_ExecutionManager {
         UNSAFE_BYTECODE,
         CREATE_COLLISION,
         STATIC_VIOLATION,
-        CREATE_EXCEPTION,
         CREATOR_NOT_ALLOWED
     }
 
@@ -67,7 +65,6 @@ interface iOVM_ExecutionManager {
 
     struct MessageRecord {
         uint256 nuisanceGasLeft;
-        RevertFlag revertFlag;
     }
 
 
@@ -112,8 +109,8 @@ interface iOVM_ExecutionManager {
      * Contract Creation Opcodes *
      *****************************/
 
-    function ovmCREATE(bytes memory _bytecode) external returns (address _contract);
-    function ovmCREATE2(bytes memory _bytecode, bytes32 _salt) external returns (address _contract);
+    function ovmCREATE(bytes memory _bytecode) external returns (address _contract, bytes memory _revertdata);
+    function ovmCREATE2(bytes memory _bytecode, bytes32 _salt) external returns (address _contract, bytes memory _revertdata);
 
 
     /*******************************
@@ -151,12 +148,6 @@ interface iOVM_ExecutionManager {
     function ovmEXTCODEHASH(address _contract) external returns (bytes32 _hash);
 
 
-    /**************************************
-     * Public Functions: Execution Safety *
-     **************************************/
-
-    function safeCREATE(address _address, bytes memory _bytecode) external;
-
     /***************************************
      * Public Functions: Execution Context *
      ***************************************/

packages/contracts/contracts/optimistic-ethereum/libraries/utils/Lib_ErrorUtils.sol

+// SPDX-License-Identifier: MIT
+pragma solidity >0.5.0 <0.8.0;
+pragma experimental ABIEncoderV2;
+
+/**
+ * @title Lib_ErrorUtils
+ */
+library Lib_ErrorUtils {
+
+    /**********************
+     * Internal Functions *
+     **********************/
+
+    /**
+     * Encodes an error string into raw solidity-style revert data.
+     * (i.e. ascii bytes, prefixed with bytes4(keccak("Error(string))"))
+     * Ref: https://docs.soliditylang.org/en/v0.8.2/control-structures.html?highlight=Error(string)#panic-via-assert-and-error-via-require
+     * @param _reason Reason for the reversion.
+     * @return Standard solidity revert data for the given reason.
+     */
+    function encodeRevertString(
+        string memory _reason
+    )
+        internal
+        pure
+        returns (
+            bytes memory
+        )
+    {
+        return abi.encodeWithSignature(
+            "Error(string)",
+            _reason
+        );
+    }
+}

packages/contracts/contracts/optimistic-ethereum/libraries/wrappers/Lib_SafeExecutionManagerWrapper.sol

 // SPDX-License-Identifier: MIT
 pragma solidity >0.5.0 <0.8.0;
 
+/* Library Imports */
+import { Lib_ErrorUtils } from "../utils/Lib_ErrorUtils.sol";
+
 /**
  * @title Lib_SafeExecutionManagerWrapper
  * @dev The Safe Execution Manager Wrapper provides functions which facilitate writing OVM safe 
@@ -90,7 +93,8 @@ library Lib_SafeExecutionManagerWrapper {
     )
         internal
         returns (
-            address _contract
+            address,
+            bytes memory
         )
     {
         bytes memory returndata = _safeExecutionManagerInteraction(
@@ -101,7 +105,7 @@ library Lib_SafeExecutionManagerWrapper {
             )
         );
 
-        return abi.decode(returndata, (address));
+        return abi.decode(returndata, (address, bytes));
     }
 
     /**
@@ -258,8 +262,7 @@ library Lib_SafeExecutionManagerWrapper {
         _safeExecutionManagerInteraction(
             abi.encodeWithSignature(
                 "ovmREVERT(bytes)",
-                abi.encodeWithSignature(
-                    "Error(string)",
+                Lib_ErrorUtils.encodeRevertString(
                     _reason
                 )
             )

packages/contracts/contracts/optimistic-ethereum/mockOVM/accounts/mockOVM_ECDSAContractAccount.sol

@@ -54,7 +54,7 @@ contract mockOVM_ECDSAContractAccount is iOVM_ECDSAContractAccount {
 
         // Contract creations are signalled by sending a transaction to the zero address.
         if (decodedTx.to == address(0)) {
-            address created = Lib_SafeExecutionManagerWrapper.safeCREATE(
+            (address created, ) = Lib_SafeExecutionManagerWrapper.safeCREATE(
                 decodedTx.gasLimit,
                 decodedTx.data
             );

packages/contracts/contracts/test-helpers/Helper_TestRunner.sol

@@ -128,12 +128,8 @@ contract Helper_TestRunner {
             }
         }
 
-        if (success == false || (success == true && returndata.length == 1)) {
+        if (success == false) {
             assembly {
-                if eq(extcodesize(address()), 0) {
-                    return(0, 1)
-                }
-
                 revert(add(returndata, 0x20), mload(returndata))
             }
         }

packages/contracts/test/contracts/OVM/accounts/OVM_ECDSAContractAccount.spec.ts

@@ -77,9 +77,10 @@ describe('OVM_ECDSAContractAccount', () => {
     Mock__OVM_ExecutionManager.smocked.ovmCHAINID.will.return.with(420)
     Mock__OVM_ExecutionManager.smocked.ovmGETNONCE.will.return.with(100)
     Mock__OVM_ExecutionManager.smocked.ovmCALL.will.return.with([true, '0x'])
-    Mock__OVM_ExecutionManager.smocked.ovmCREATE.will.return.with(
-      NON_ZERO_ADDRESS
-    )
+    Mock__OVM_ExecutionManager.smocked.ovmCREATE.will.return.with([
+      NON_ZERO_ADDRESS,
+      '0x',
+    ])
     Mock__OVM_ExecutionManager.smocked.ovmCALLER.will.return.with(
       NON_ZERO_ADDRESS
     )

packages/contracts/test/contracts/OVM/execution/OVM_ExecutionManager.gas-spec.ts

@@ -110,7 +110,7 @@ describe('OVM_ExecutionManager gas consumption', () => {
       )
       console.log(`calculated gas cost of ${gasCost}`)
 
-      const benchmark: number = 226_516
+      const benchmark: number = 225_500
       expect(gasCost).to.be.lte(benchmark)
       expect(gasCost).to.be.gte(
         benchmark - 1_000,

packages/contracts/test/contracts/OVM/execution/OVM_ExecutionManager/ovmCREATE.spec.ts

@@ -7,11 +7,13 @@ import {
   NON_NULL_BYTES32,
   REVERT_FLAGS,
   DUMMY_BYTECODE,
+  UNSAFE_BYTECODE,
   ZERO_ADDRESS,
   VERIFIED_EMPTY_CONTRACT_HASH,
   DUMMY_BYTECODE_BYTELEN,
   DUMMY_BYTECODE_HASH,
   getStorageXOR,
+  encodeSolidityError,
 } from '../../../../helpers'
 
 const CREATED_CONTRACT_1 = '0x2bda4a99d5be88609d23b1e4ab5d1d34fb1c2feb'
@@ -68,7 +70,7 @@ const test_ovmCREATE: TestDefinition = {
           ethAddress: '0x' + '00'.repeat(20),
         },
         [CREATED_CONTRACT_BY_2_2]: {
-          codeHash: '0x' + '01'.repeat(32),
+          codeHash: VERIFIED_EMPTY_CONTRACT_HASH,
           ethAddress: '0x' + '00'.repeat(20),
         },
         [NESTED_CREATED_CONTRACT]: {
@@ -79,6 +81,7 @@ const test_ovmCREATE: TestDefinition = {
       contractStorage: {
         $DUMMY_OVM_ADDRESS_2: {
           [NULL_BYTES32]: getStorageXOR(NULL_BYTES32),
+          [NON_NULL_BYTES32]: getStorageXOR(NULL_BYTES32),
         },
       },
       verifiedContractStorage: {
@@ -87,6 +90,7 @@ const test_ovmCREATE: TestDefinition = {
         },
         $DUMMY_OVM_ADDRESS_2: {
           [NULL_BYTES32]: true,
+          [NON_NULL_BYTES32]: true,
         },
       },
     },
@@ -167,20 +171,24 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
       ],
     },
     {
       name: 'ovmCREATE => ovmREVERT, ovmEXTCODESIZE(CREATED)',
-      // TODO: Appears to be failing because of a bug in smock.
-      skip: true,
       steps: [
         {
           functionName: 'ovmCREATE',
@@ -189,13 +197,19 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
         {
           functionName: 'ovmEXTCODESIZE',
@@ -209,8 +223,6 @@ const test_ovmCREATE: TestDefinition = {
     },
     {
       name: 'ovmCREATE => ovmREVERT, ovmEXTCODEHASH(CREATED)',
-      // TODO: Appears to be failing because of a bug in smock.
-      skip: true,
       steps: [
         {
           functionName: 'ovmCREATE',
@@ -219,13 +231,19 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
         {
           functionName: 'ovmEXTCODEHASH',
@@ -239,8 +257,6 @@ const test_ovmCREATE: TestDefinition = {
     },
     {
       name: 'ovmCREATE => ovmREVERT, ovmEXTCODECOPY(CREATED)',
-      // TODO: Appears to be failing because of a bug in smock.
-      skip: true,
       steps: [
         {
           functionName: 'ovmCREATE',
@@ -249,13 +265,19 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
         {
           functionName: 'ovmEXTCODECOPY',
@@ -472,10 +494,10 @@ const test_ovmCREATE: TestDefinition = {
       ],
     },
     {
+      // TODO: appears to be failing due to a smoddit issue
+      skip: true,
       name:
         'ovmCREATE => (ovmCALL(ADDRESS_2) => ovmSSTORE) + ovmREVERT, ovmCALL(ADDRESS_2) => ovmSLOAD',
-      // TODO: Appears to be failing because of a bug in smock.
-      skip: true,
       steps: [
         {
           functionName: 'ovmCREATE',
@@ -487,10 +509,18 @@ const test_ovmCREATE: TestDefinition = {
                   gasLimit: OVM_TX_GAS_LIMIT,
                   target: '$DUMMY_OVM_ADDRESS_2',
                   subSteps: [
+                    {
+                      functionName: 'ovmSLOAD',
+                      functionParams: {
+                        key: NON_NULL_BYTES32,
+                      },
+                      expectedReturnStatus: true,
+                      expectedReturnValue: NON_NULL_BYTES32,
+                    },
                     {
                       functionName: 'ovmSSTORE',
                       functionParams: {
-                        key: NULL_BYTES32,
+                        key: NON_NULL_BYTES32,
                         value: NON_NULL_BYTES32,
                       },
                       expectedReturnStatus: true,
@@ -502,13 +532,19 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
         {
           functionName: 'ovmCALL',
@@ -519,10 +555,10 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmSLOAD',
                 functionParams: {
-                  key: NULL_BYTES32,
+                  key: NON_NULL_BYTES32,
                 },
                 expectedReturnStatus: true,
-                expectedReturnValue: NULL_BYTES32,
+                expectedReturnValue: NON_NULL_BYTES32,
               },
             ],
           },
@@ -545,8 +581,11 @@ const test_ovmCREATE: TestDefinition = {
                   target: '$DUMMY_OVM_ADDRESS_3',
                   calldata: '0x',
                 },
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INVALID_STATE_ACCESS,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
@@ -558,7 +597,7 @@ const test_ovmCREATE: TestDefinition = {
       ],
     },
     {
-      name: 'ovmCREATE => ovmCREATE => ovmCALL(ADDRESS_NONEXIST)',
+      name: 'ovmCALL => ovmCREATE => ovmCREATE',
       steps: [
         {
           functionName: 'ovmCALL',
@@ -573,10 +612,10 @@ const test_ovmCREATE: TestDefinition = {
                     {
                       functionName: 'ovmCREATE',
                       functionParams: {
-                        bytecode: '0x',
+                        bytecode: '0x', // this will still succeed with empty bytecode
                       },
                       expectedReturnStatus: true,
-                      expectedReturnValue: ZERO_ADDRESS,
+                      expectedReturnValue: CREATED_CONTRACT_BY_2_2,
                     },
                   ],
                 },
@@ -608,19 +647,26 @@ const test_ovmCREATE: TestDefinition = {
                         target: '$DUMMY_OVM_ADDRESS_3',
                         calldata: '0x',
                       },
-                      expectedReturnStatus: true,
-                      expectedReturnValue: '0x00',
+                      expectedReturnStatus: false,
+                      expectedReturnValue: {
+                        flag: REVERT_FLAGS.INVALID_STATE_ACCESS,
+                        onlyValidateFlag: true,
+                      },
                     },
                   ],
                 },
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INVALID_STATE_ACCESS,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: false,
           expectedReturnValue: {
             flag: REVERT_FLAGS.INVALID_STATE_ACCESS,
+            onlyValidateFlag: true,
           },
         },
       ],
@@ -648,13 +694,19 @@ const test_ovmCREATE: TestDefinition = {
               {
                 functionName: 'ovmREVERT',
                 revertData: DUMMY_REVERT_DATA,
-                expectedReturnStatus: true,
-                expectedReturnValue: '0x00',
+                expectedReturnStatus: false,
+                expectedReturnValue: {
+                  flag: REVERT_FLAGS.INTENTIONAL_REVERT,
+                  onlyValidateFlag: true,
+                },
               },
             ],
           },
           expectedReturnStatus: true,
-          expectedReturnValue: ZERO_ADDRESS,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: DUMMY_REVERT_DATA,
+          },
         },
       ],
     },
@@ -675,6 +727,24 @@ const test_ovmCREATE: TestDefinition = {
         },
       ],
     },
+    {
+      name: 'ovmCREATE(UNSAFE_CODE)',
+      steps: [
+        {
+          functionName: 'ovmCREATE',
+          functionParams: {
+            bytecode: UNSAFE_BYTECODE,
+          },
+          expectedReturnStatus: true,
+          expectedReturnValue: {
+            address: ZERO_ADDRESS,
+            revertData: encodeSolidityError(
+              'Constructor attempted to deploy unsafe bytecode.'
+            ),
+          },
+        },
+      ],
+    },
   ],
   subTests: [
     {

packages/contracts/test/helpers/codec/revert-flags.ts

@@ -34,14 +34,12 @@ export const decodeRevertData = (revertData: string): any => {
 }
 
 export const REVERT_FLAGS = {
-  DID_NOT_REVERT: 0,
-  OUT_OF_GAS: 1,
-  INTENTIONAL_REVERT: 2,
-  EXCEEDS_NUISANCE_GAS: 3,
-  INVALID_STATE_ACCESS: 4,
-  UNSAFE_BYTECODE: 5,
-  CREATE_COLLISION: 6,
-  STATIC_VIOLATION: 7,
-  CREATE_EXCEPTION: 8,
-  CREATOR_NOT_ALLOWED: 9,
+  OUT_OF_GAS: 0,
+  INTENTIONAL_REVERT: 1,
+  EXCEEDS_NUISANCE_GAS: 2,
+  INVALID_STATE_ACCESS: 3,
+  UNSAFE_BYTECODE: 4,
+  CREATE_COLLISION: 5,
+  STATIC_VIOLATION: 6,
+  CREATOR_NOT_ALLOWED: 7,
 }

packages/contracts/test/helpers/dummy/bytecode.ts

@@ -3,4 +3,5 @@ import { keccak256 } from 'ethers/lib/utils'
 
 export const DUMMY_BYTECODE = '0x123412341234'
 export const DUMMY_BYTECODE_BYTELEN = 6
+export const UNSAFE_BYTECODE = '0x6069606955'
 export const DUMMY_BYTECODE_HASH = keccak256(DUMMY_BYTECODE)

packages/contracts/test/helpers/test-runner/test-runner.ts

@@ -38,6 +38,7 @@ import {
   NULL_BYTES32,
 } from '../constants'
 import { getStorageXOR } from '../'
+import { UNSAFE_BYTECODE } from '../dummy'
 
 export class ExecutionManagerTestRunner {
   private snapshot: string
@@ -194,7 +195,11 @@ export class ExecutionManagerTestRunner {
     ).deploy()
 
     const MockSafetyChecker = await smockit(SafetyChecker)
-    MockSafetyChecker.smocked.isBytecodeSafe.will.return.with(true)
+    MockSafetyChecker.smocked.isBytecodeSafe.will.return.with(
+      (bytecode: string) => {
+        return bytecode !== UNSAFE_BYTECODE
+      }
+    )
 
     this.contracts.OVM_SafetyChecker = MockSafetyChecker
 
@@ -494,6 +499,19 @@ export class ExecutionManagerTestRunner {
       }
     }
 
+    if (isTestStep_CREATE(step) || isTestStep_CREATE2(step)) {
+      if (!isRevertFlagError(step.expectedReturnValue)) {
+        if (typeof step.expectedReturnValue === 'string') {
+          returnData = [step.expectedReturnValue, '0x']
+        } else {
+          returnData = [
+            step.expectedReturnValue.address,
+            step.expectedReturnValue.revertData || '0x',
+          ]
+        }
+      }
+    }
+
     return this.contracts.OVM_ExecutionManager.interface.encodeFunctionResult(
       step.functionName,
       returnData

packages/contracts/test/helpers/test-runner/test.types.ts

@@ -118,7 +118,13 @@ interface TestStep_CREATE {
     subSteps?: TestStep[]
   }
   expectedReturnStatus: boolean
-  expectedReturnValue: string | RevertFlagError
+  expectedReturnValue:
+    | string
+    | {
+        address: string
+        revertData: string
+      }
+    | RevertFlagError
 }
 
 interface TestStep_CREATE2 {
@@ -129,7 +135,13 @@ interface TestStep_CREATE2 {
     subSteps?: TestStep[]
   }
   expectedReturnStatus: boolean
-  expectedReturnValue: string | RevertFlagError
+  expectedReturnValue:
+    | string
+    | {
+        address: string
+        revertData: string
+      }
+    | RevertFlagError
 }
 
 interface TestStep_CREATEEOA {

packages/contracts/test/helpers/utils/sol-utils.ts

@@ -16,3 +16,7 @@ const errorABI = new ethers.utils.Interface([
 export const decodeSolidityError = (err: string): string => {
   return errorABI.decodeFunctionData('Error', err)[0]
 }
+
+export const encodeSolidityError = (message: string): string => {
+  return errorABI.encodeFunctionData('Error', [message])
+}